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Sample records for frp web-bonded rc

  1. FRP strengthening of RC walls with openings

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Sas, Gabriel; Täljsten, Björn

    2009-01-01

    Strengthening reinforced concrete (RC) walls with openings using fibre reinforced polymers (FRP) has been experimentally proven to be a viable rehabilitation method. However, very few theoretical investigations are reported. In this paper two methods of analysis are presented. Since openings vary...... in size, the analysis of a strengthened wall can be divided into frame idealization method for large openings, and combined disk and frame analysis for smaller openings. The first method provides an easy to use tool in practical engineering, where the latter describes the principles of a ductile...

  2. Anchoring FRP laminates for the seismic strengthening of RC columns

    OpenAIRE

    Sadone, Raphaëlle; Quiertant, Marc; FERRIER, Emmanuel; Chataigner, Sylvain; Mercier, Julien

    2012-01-01

    This paper aims to examine the effectiveness of seismic strengthening of reinforced concrete (RC) columns by externally bonded Fibre Reinforced Polymer (FRP). Particularly, a novel strengthening system, designed for the flexural strengthening of columns is studied. This flexural strengthening is achieved by FRP plates bonded longitudinally and anchored at the column-stub junction. The proposed system is validated through an experimental campaign carried out on full-scale RC columns. Different...

  3. TESTS ON STRUCTURALLY DEFICIENT RC SLABS STRENGTHENED WITH FIBRE REINFORCED POLYMER (FRP) COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    S.T. Smith; S.J. Kim

    2004-01-01

    This paper reports the results of a series of tests on fibre reinforced polymer (FRP) strengthened reinforced concrete (RC) slabs, which were recently undertaken at the University of Technology,Sydney. The slabs were reinforced with high-strength low-ductile steel reinforcement and strengthened with either carbon FRP (CFRP) or glass FRP (GFRP) composites. The unstrengthened control slabs failed by fracture of the steel tension reinforcement while the FRP strengthened slabs failed by debonding of the FRP followed by rupture of the tension steel. The FRP-strengthened slabs were stronger than their unstrengthened counterparts and displayed considerable ductility.

  4. Modeling of FRP-jacketed RC columns subject to combined axial and lateral loads

    OpenAIRE

    Lee, Chung-Sheng

    2006-01-01

    To successfully use the fiber-reinforced-polymer (FRP) overlay technique for the seismic retrofit and the blast- hardening of RC columns, the mechanical behavior of the FRP-confined concrete needs to be understood and its response needs to be accurately predicted. Although a number of studies have been conducted to-date, it is still not clear how the main parameters affect the axial stress- strain response of a FRP-confined concrete cylinder. In particular, while it is understood that FRP jac...

  5. Experimental study on seismic behavior of circular RC columns strengthened with pre-stressed FRP strips

    Science.gov (United States)

    Zhou, Changdong; Lu, Xilin; Li, Hui; Tian, Teng

    2013-12-01

    Bonding fiber reinforced polymer (FRP) has been commonly used to improve the seismic behavior of circular reinforced concrete (RC) columns in engineering practice. However, FRP jackets have a significant stress hysteresis effect in this strengthening method, and pre-tensioning the FRP can overcome this problem. This paper presents test results of 25 circular RC columns strengthened with pre-stressed FRP strips under low cyclic loading. The pre-stressing of the FRP strips, types of FRP strips and longitudinal reinforcement, axial load ratio, pre-damage degree and surface treatments of the specimens are considered as the primary factors in the tests. According to the failure modes and hysteresis curves of the specimens, these factors are analyzed to investigate their effect on bearing capacity, ductility, hysteretic behavior, energy dissipation capacity and other important seismic behaviors. The results show that the initial lateral confined stress provided by pre-stressed FRP strips can effectively inhibit the emergence and development of diagonal shear cracks, and change the failure modes of specimens from brittle shear failure to bending or bending-shear failure with better ductility. As a result, the bearing capacity, ductility, energy dissipation capacity and deformation capacity of the strengthened specimens are all significantly improved.

  6. FRP-RC Beam in Shear: Mechanical Model and Assessment Procedure for Pseudo-Ductile Behavior

    Directory of Open Access Journals (Sweden)

    Floriana Petrone

    2014-07-01

    Full Text Available This work deals with the development of a mechanics-based shear model for reinforced concrete (RC elements strengthened in shear with fiber-reinforced polymer (FRP and a design/assessment procedure capable of predicting the failure sequence of resisting elements: the yielding of existing transverse steel ties and the debonding of FRP sheets/strips, while checking the corresponding compressive stress in concrete. The research aims at the definition of an accurate capacity equation, consistent with the requirement of the pseudo-ductile shear behavior of structural elements, that is, transverse steel ties yield before FRP debonding and concrete crushing. For the purpose of validating the proposed model, an extended parametric study and a comparison against experimental results have been conducted: it is proven that the common accepted rule of assuming the shear capacity of RC members strengthened in shear with FRP as the sum of the maximum contribution of both FRP and stirrups can lead to an unsafe overestimation of the shear capacity. This issue has been pointed out by some authors, when comparing experimental shear capacity values with the theoretical ones, but without giving a convincing explanation of that. In this sense, the proposed model represents also a valid instrument to better understand the mechanical behavior of FRP-RC beams in shear and to calculate their actual shear capacity.

  7. Disbond detection with piezoelectric wafer active sensors in RC structures strengthened with FRP composite overlays

    Institute of Scientific and Technical Information of China (English)

    Victor Giurgiutiu; Kent Harries; Michael Petrou; Joel Bost; Josh B. Quattlebaum

    2003-01-01

    The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ nondestructive evaluation (NDE) for structural health monitoring (SHM) of reinforced concrete (RC) structures strengthened with fiber reinforced polymer (FRP) composite overlays is explored. First, the disbond detection method were developed on coupon specimens consisting of concrete blocks covered with an FRP composite layer. It was found that the prescnce of a disbond crack drastically changes the electromecbanical (E/M) impedance spectrum measured at the PWAS terminals. The spectral changes depend on the distance between the PWAS and the crack tip. Second, large scale experiments were conducted on a RC beam strengthened with carbon fiber reinforced polymer (CFRP) composite overlay. The beam was subject to an acccleratcd fatigue load regime in a three-point bending configuration up to a total of807,415 cycles. During these fatigue tests, the CFRP overlay experienced disbonding beginning at about 500,000 cycles. The PWAS were able to detect the disbonding before it could be reliably seen by visual inspection. Good correlation between the PWAS readings and the position and extent of disbond damage was observed. These preliminary results demonstrate the potential of PWAS technology for SHM of RC structures strengthened with FRP composite ovcrlays.

  8. Effect of Shear Resistance on Flexural Debonding Load-Carrying Capacity of RC Beams Strengthened with Externally Bonded FRP Composites

    Directory of Open Access Journals (Sweden)

    Guibing Li

    2014-05-01

    Full Text Available Debonding failure is the main failure mode in flexurally strengthened reinforced concrete beams by externally bonded or near surface mounted fibre reinforced polymer (FRP composites. It is believed that FRP debonding will be initiated if the shear stress on the concrete-FRP interface reaches the tensile strength of concrete. However, it was found through experimental and analytical studies that the debonding mechanism of FRP composites has the potential of shear failure in combination with debonding failure. Moreover, the shear failure probably influences the debonding failure. Presently, there are very little experimental and analytical studies to investigate the influence of shear resistance of reinforced concrete (RC beam on FRP debonding failure. The current study investigates and analyzes the effect of shear resistance on FRP debonding failure based on test results. The analytical results show that the shear resistance of RC beam has a great effect on flexural debonding load-carrying capacity of FRP-strengthened RC beam. The influence of shear resistance on flexural debonding load-carrying capacity must be fully considered in flexural strengthening design of RC beams.

  9. Rapid Repair of Earthquake Damaged RC Interior Beam-wide Column Joints and Beam-wall Joints Using FRP Composites

    Institute of Scientific and Technical Information of China (English)

    LI Bing; LIM Chee Leong

    2009-01-01

    This paper studies the seismic performance of FRP-strengthened RC interior non-seismically detailed beam-wide columns and beam-wall joints after limited seismic damage. Four eccentric and concentric beam-wide column joints and two beam-wall joints, initially damaged in a previous study, were repaired and tested under constant axial loads (0. \\fc'Ag and 0. 35 fc'Ag ) and lateral cyclic loading. The rapid repair technique developed, aimed to restore the original strength and to provide minimum drift capacity. The repair schemes were characterized by the use of; (a) epoxy injections and polymer modified cementitious mortar to seal the cracks and replace spalled concrete; and (b) glass (GFRP) and carbon (CFRP) sheets to enhance the joint performance. The FRP sheets were effectively prevented against possible debonding through the use of fiber anchors. Comparison between responses of specimens before and after repair clearly indicated reasonable restoration in strength, drift capacity, stiffness and cumulative energy dissipation capacity. All specimens failed with delamination of FRP sheets at beam-column joint interfaces. The rapid repair technique developed in this study is recommended for mass upgrading or repair of earthquake damaged beam-column joints.

  10. Evaluation of FRP Confinement Models for Substandard Rectangular RC Columns Based on Full-Scale Reversed Cyclic Lateral Loading Tests in Strong and Weak Directions

    Directory of Open Access Journals (Sweden)

    Hamid Farrokh Ghatte

    2016-09-01

    Full Text Available Although many theoretical and experimental studies are available on external confinement of columns using fiber-reinforced polymer (FRP jackets, as well as numerous models proposed for the axial stress-axial strain relation of concrete confined with FRP jackets, they have not been validated with a sufficient amount and variety of experimental data obtained through full-scale tests of reinforced concrete (RC columns with different geometrical and mechanical characteristics. Particularly, no systematical experimental data have been presented on full-scale rectangular substandard RC columns subjected to reversed cyclic lateral loads along either their strong or weak axes. In this study, firstly, test results of five full-scale rectangular substandard RC columns with a cross-sectional aspect ratio of two (300 mm × 600 mm are briefly summarized. The columns were tested under constant axial load and reversed cyclic lateral loads along their strong or weak axes before and after retrofitting with external FRP jackets. In the second stage, inelastic lateral force-displacement relationships of the columns are obtained analytically, making use of the plastic hinge assumption and different FRP confinement models available in the literature. Finally, the analytical findings are compared with the test results for both strong and weak directions of the columns. Comparisons showed that use of different models for the stress-strain relationship of FRP-confined concrete can yield significantly non-conservative or too conservative retrofit designs, particularly in terms of deformation capacity.

  11. FRP 加固 RC 连续梁桥抗震性能试验研究%Tests for aseismic performances of a RC continuous girder bridge retrofitted by FRP jacket

    Institute of Scientific and Technical Information of China (English)

    林元铮; 田石柱

    2016-01-01

    Taking a reinforced concrete continuous girder bridge as the study object,retrofitting the plastic region of piers with FRP jacket,the aseismic performances of the bridge structure were studied with hybrid tests.The fixed pier bearing most seismic action was taken as a test element and physically tested in a lab while the other parts of the bridge structure were taken as calculation elements and simulated numerically with OpenSees.After integrating and combining different parts with the hybrid test platform--OpenFresco,the dynamic responses of the overall bridge structure under seismic action were obtained.At last,the test results and Open Sees finite element analysis ones were compared.The results showed that the aseismic performances of the RC continuous girder bridge can be improved effectively after retrofitted with FRP jacket,and the test results agree well with those of finite element analysis.%以某钢筋混凝土连续梁桥作为研究对象,对其桥墩进行了塑性铰区的 FRP 抗震加固,采用混合试验技术研究了该桥梁结构的抗震性能。将连续梁桥结构承担主要地震作用的固定墩作为试验单元,进行真实的物理试验;将桥梁结构其余部分作为计算单元通过有限元软件 OpenSees 进行模拟,通过 OpenFresco 混合试验平台集成协调,完成了该连续梁桥的抗震混合试验。最后将试验结果与 OpenSees 有限元分析结果进行了对比。研究结果表明,FRP 抗震加固能够有效改善桥梁的抗震性能;试验结果与有限元分析结果吻合较好。

  12. Flexural Strengthening of RC Slabs Using a Hybrid FRP-UHPC System Including Shear Connector

    Directory of Open Access Journals (Sweden)

    Jiho Moon

    2017-01-01

    Full Text Available A polymeric hybrid composite system made of UHPC and CFRP was proposed as a retrofit system to enhance flexural strength and ductility of RC slabs. While the effectiveness of the proposed system was confirmed previously through testing three full-scale one-way slabs having two continuous spans, the slabs retrofitted with the hybrid system failed in shear. This sudden shear failure would stem from the excessive enhancement of the flexural strength over the shear strength. In this study, shear connectors were installed between the hybrid system and a RC slab. Using simple beam, only positive moment section was examined. Two full-scale RC slabs were cast and tested to failure: the first as a control and the second using this new strengthening technique. The proposed strengthening system increased the ultimate load carrying capacity of the slab by 70%, the stiffness by 60%, and toughness by 128%. The efficiency of shear connectors on ductile behavior of the retrofitted slab was also confirmed. After the UHPC top is separated from the slab, the shear connector transfer shear load and the slab system were in force equilibrium by compression in UHPC and tension in CFRP.

  13. FRP加固RC梁界面疲劳损伤红外检测分析%Analysis of Interfacial Fatigue Behavior of RC Beams Strengthened with FRP Based on Infrared Thermography

    Institute of Scientific and Technical Information of China (English)

    邓江东; 黄培彦; 宗周红

    2010-01-01

    FRP-混凝土界面剥离损伤的探测是界面力学分析的一个难点.基于三个标准试件探讨了红外检测方法对FRP-混凝土界面剥离探测的精度、可行性以及剥离判断的标准,并对常幅疲劳荷载下FRP加固钢筋混凝土(RC)梁界面的疲劳行为进行了跟踪记录,分析了界面的疲劳破坏过程.试验结果表明,FRP加固RC梁界面存在初始的未粘结区,在疲劳加载的初期界面剥离快速增加,随后在大部分疲劳寿命期内保持稳定,在最后数千次加载循环内界面损伤失稳发展导致整个加固构件的破坏.文中基于红外数据给出了每个阶段的疲劳加载次数和界面剥离损伤的面积.

  14. Analysis and behaviour of FRP-confined short concrete columns subjected to eccentric loading

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fibre-reinforced polymer (FRP) composites were widely utilized in civil engineering structures as the retrofit of reinforced concrete (RC) columns. To design FRP jackets safely and economically, the behaviour of such columns should be predicted first. This paper is concerned with the analysis and behaviour of FRP-confined RC circular and rectangular short columns subjected to eccentric loading. A simple design-oriented stress-strain model for FRP-confined concrete in a section analysis was first proposed. The accuracy was then proved by two test data. Following that, a parametric study including amount of FRP confinement, FRP strain capacity, unconfined concrete strength and shape of column section is provided. Some conclusions were obtained at the end of the paper. The work here will provide a comprehensive understanding of the behaviour of FRP-confined concrete columns. The simplicity of the model also enables a simple equivalent stress block to be developed for direct use in practical design.

  15. RECENT DEVELOPMENTS IN FRP STRENGTHENING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    Zhishen WU(吴智深); Hedong Niu

    2004-01-01

    This paper mainly gives a State-of-the-Art report of recent development in FRP strengthening techniques for structural rehabilitation by starting with a brief review on some achievements in clarifying bonding/debonding mechanisms and developing evaluation/design methodology for predicting debonding failure caused by intermedioate flexural cracks of con crete.Due to some drawbacks of current FRP bonding technique,two effective FRP strengthening methods,i.e.FRP prestressing and hybrid strengthening techniques,are investigated in detail to make full advantage of FRP composite materials.Combining with the newly develiped PBO fiber sheets,a more effective prestressing method is established as compared with carbon fiber sheets,a more effective prestressing method is established as compared with carbon fiber sheets,where several anchorage treatments are also established to prevent anchorage bond failure due to high shear stress concentration after release of prestressed FRP ends.In addition,the fatigue performance of RC beams externally strenghened with prestressed PBO fiber sheets is experimentally studied.For the developments of hybrid composites and their strengthening methods,both experimental and analytical studies are performed to clarify the hybrid strengthening behavior in structures.

  16. Facility Response Plan (FRP)

    Data.gov (United States)

    U.S. Environmental Protection Agency — A Facility Response Plan (FRP) demonstrates a facility's preparedness to respond to a worst case oil discharge. Under the Clean Water Act, as amended by the Oil...

  17. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

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

  18. New Strengthening Techniques with FRP Laminates and Interfacial Fracture Theories

    Institute of Scientific and Technical Information of China (English)

    Hong YUAN; Zhishen WU

    2000-01-01

    The use of FRP composites in the form of sheet or plate bonded to the large-scale RC structures is becoming an increasing attractive solution to the strengthening of existing structures. Compared with traditional steel plate strengthening, FRP possesses excellent behavior such as lightness in weight, high strength-to-weight and stiffness-to-weight ratio, high corrosion and fatigue resistance, electronic neutrality, and great efficiency in construction. A important failure mode for FRP-strengthened structures is debondings.Therefore, the LEFM and NLFM are utilized to treat this problem. Closed form expressions for energy release rate, load-carrying capacity, load-displacement relation and interfacial crack propagation are obtained, in which a local shear stress-slip law with softening is adopted.

  19. An experimentally based analytical model for the shear capacity of FRP-strengthened reinforced concrete beams

    Science.gov (United States)

    Pellegrino, C.; Modena, C.

    2008-05-01

    This paper deals with the shear strengthening of Reinforced Concrete (RC) flexural members with externally bonded Fiber-Reinforced Polymers (FRPs). The interaction between an external FRP and an internal transverse steel reinforcement is not considered in actual code recommendations, but it strongly influences the efficiency of the shear strengthening rehabilitation technique and, as a consequence, the computation of interacting contributions to the nominal shear strength of beams. This circumstance is also discussed on the basis of the results of an experimental investigation of rectangular RC beams strengthened in shear with "U-jacketed" carbon FRP sheets. Based on experimental results of the present and other investigations, a new analytical model for describing the shear capacity of RC beams strengthened according to the most common schemes (side-bonded and "U-jacketed"), taking into account the interaction between steel and FRP shear strength contributions, is proposed.

  20. Crack-induced debonding failure in fiber reinforced plastics (FRP) strengthened concrete beams: Experimental and theoretical analysis

    Science.gov (United States)

    Pan, Jinlong

    External bonding of FRP plates to the tension substrate of RC beams has been accepted as an efficient and effective technique for flexural strengthening. In this thesis, different problems related to crack-induced debonding of the FRP plate in the flexural strengthened concrete beams have been investigated. FRP strengthened RC beam may fail by FRP debonding from the bottom of a major flexural crack in the span. This kind of failure is studied with the direct shear test in the present research work. Our experimental investigation focuses on the effect of concrete composition on the bond behavior between FRP and concrete. Based on the test results, the bond capacity of the specimen is found to be governed by the concrete surface tensile strength, aggregate size and aggregate content. Then, the neural network is employed to derive an empirical expression for the interfacial fracture energy in terms of concrete surface tensile strength and aggregate content. Using the empirical equation, simulated bond capacity is in good agreement with experimental results. In the FRP strengthened RC beams, debonding of the FRP plate often occurs under the presence of multiple cracks along the span. In the present thesis, experimental and theoretical investigations are performed to study the effect of multiple secondary cracks on the debonding behavior and ultimate load capacity. A new analytical model for FRP debonding under multiple cracks has been developed. The effect of the multiple secondary cracks on the shear softening in the debonded zone is explicitly considered in the model. Using the new model, the simulated values of ultimate load when debonding occurs are in good agreement with measured values. In the FRP strengthened RC beams, concrete cover separation or plate end debonding can be avoided by applying tapers at the FRP plate end. In this situation, it is easier for FRP debonding to be induced by a major flexural crack close to the support. To study the effect of the

  1. Strengthening of RC bridge slabs using CFRP sheets

    Directory of Open Access Journals (Sweden)

    Fahmy A. Fathelbab

    2014-12-01

    Full Text Available Many old structures became structurally insufficient to carry the new loading conditions requirements. Moreover, they suffer from structural degradation, reinforcement steel bars corrosion, bad weather conditions…etc. Many official authorities in several countries had recognized many old bridges and buildings as structurally deficient by today’s standards. Due to these reasons, structural strengthening became an essential requirement and different strengthening techniques appeared in market. Fiber Reinforced Polymer (FRP strengthening techniques established a good position among all other techniques, giving excellent structural results, low time required and moderate cost compared with the other techniques. The main purpose of this research is to study analytically the strengthening of a reinforced concrete bridge slabs due to excessive loads, using externally bonded FRP sheets technique. A commercial finite element program ANSYS was used to perform a structural linear and non-linear analysis for strengthened slab models using several schemes of FRP sheets. A parametric study was performed to evaluate analytically the effect of changing both FRP stiffness and FRP schemes in strengthening RC slabs. Comparing the results with control slab (reinforced concrete slab without strengthening it is obvious that attaching FRP sheets to the RC slab increases its capacity and enhances the ductility/toughness.

  2. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

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

  3. EXTERNAL PRESTRESSING OF RC T-BEAMS WITH CFRP TENDONS

    DEFF Research Database (Denmark)

    Bennitz, Anders; Schmidt, Jacob Wittrup; Täljsten, Björn

    2009-01-01

    as prestressing materials does however require a new design philosophy. FRPs are in contradiction to high strength prestressing steel linearly elastic until failure and they are, in their nature, also generally orthotropic. The behaviour of a RC-structure prestressed with FRP might therefore differ from...... a structure prestressed with high strength steel although both the ultimate tensile capacity and the modulus of elasticity in some cases are the same. A number of guidelines for the usage of FRP have been published within the last years with [6] as a good example. To verify design principles stated in [6...... study contained in this paper should serve as a contribution to a similar database for RC-structures prestressed with FRP materials. As such it should be possible to combine with tests performed in a wide range of publications, [8-10]. It should also give researchers involved in the project...

  4. RC Beams Strengthened with Mechanically Fastened Composites: Experimental Results and Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Enzo Martinelli

    2014-03-01

    Full Text Available The use of mechanically-fastened fiber-reinforced polymer (MF-FRP systems has recently emerged as a competitive solution for the flexural strengthening of reinforced concrete (RC beams and slabs. An overview of the experimental research has proven the effectiveness and the potentiality of the MF-FRP technique which is particularly suitable for emergency repairs or when the speed of installation and immediacy of use are imperative. A finite-element (FE model has been recently developed by the authors with the aim to simulate the behavior of RC beams strengthened in bending by MF-FRP laminates; such a model has also been validated by using a wide experimental database collected from the literature. By following the previous study, the FE model and the assembled database are considered herein with the aim of better exploring the influence of some specific aspects on the structural response of MF-FRP strengthened members, such as the bearing stress-slip relationship assumed for the FRP-concrete interface, the stress-strain law considered for reinforcing steel rebars and the cracking process in RC members resulting in the well-known tension stiffening effect. The considerations drawn from this study will be useful to researchers for the calibration of criteria and design rules for strengthening RC beams through MF-FRP laminates.

  5. FRP reinforcement of timber structures

    OpenAIRE

    Schober, Kay-Uwe; Harte, Annette M.; Kliger, Robert; Jockwer, Robert; Xu, Qingfeng; Chen, Jian-fei

    2015-01-01

    Timber engineering has advanced over recent decades to offer an alternative to traditional materials and methods. The bonding of fibre reinforced plastics (FRP) with adhesives to timber structures for repair and strengthening has many advantages. However, the lack of established design rules has strongly restrained the use of FRP strengthening in many situations, where these could be a preferable option to most traditional techniques. A significant body of research has been carried out in rec...

  6. Quasi-plane-hypothesis of strain coordination for RC beams seismically strengthened with externally-bonded or near-surface mounted fiber reinforced plastic

    Science.gov (United States)

    Ren, Zhenhua; Zeng, Xiantao; Liu, Hanlong; Zhou, Fengjun

    2013-03-01

    The application of fiber reinforced plastic (FRP), including carbon FRP and glass FRP, for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement (EBR) and near-surface mounted (NSM) strengthening techniques. This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods, including externally-bonded and near-surface mounted FRP, to study the strain coordination of the FRP and steel rebar of the RC beam. Since there is relative slipping between the RC beam and the FRP, the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis; that is, the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height ( h 0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis. The strain of the FRP and steel rebar satisfies the equation: ɛ FRP= βɛ steel, and the value of β is equal to 1.1-1.3 according to the test results.

  7. Strengthening of reinforced concrete beams with basalt-based FRP sheets: An analytical assessment

    Science.gov (United States)

    Nerilli, Francesca; Vairo, Giuseppe

    2016-06-01

    In this paper the effectiveness of the flexural strengthening of RC beams through basalt fiber-reinforced sheets is investigated. The non-linear flexural response of RC beams strengthened with FRP composites applied at the traction side is described via an analytical formulation. Validation results and some comparative analyses confirm soundness and consistency of the proposed approach, and highlight the good mechanical performances (in terms of strength and ductility enhancement of the beam) produced by basalt-based reinforcements in comparison with traditional glass or carbon FRPs.

  8. The use of FRP in FGD applications

    Energy Technology Data Exchange (ETDEWEB)

    Don Kelley

    2007-01-15

    Record amounts of wet flue gas desulphurisation (FGD) equipment made from fibre reinforced plastic (FRP) are currently being installed in coal-fired power plants in North America. While regulations are driving the current demand for wet FGD equipment, a significant increase in the price of high nickel alloy is driving the use of less costly FRP in wet FGD systems. Don Kelley of Ashland Performance Materials compares the cost and reliability of FRP with other materials in wet FGD applications.

  9. Modular FRP Composite Bridge Deck

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The bridge infrastructure of the United States is in constant need of repair and rehabilitation. It is reported that 43% of the bridges in the USA have been identified as being structurally deficient or functionally obsolete due to corrosion. SuperdeckTM, a non-corrosive fiber reinforced polymer (FRP) composite bridge deck. The Deck is designed and engineered into a lightweight, strong and rigid structure that will not corrode. The deck sections, composed of hexagon and double-trapezoid profi...

  10. Intelligent FRP retrofits for critical civil infrastructures

    Science.gov (United States)

    Jiang, Guoliang; Peters, Kara

    2007-04-01

    In this paper, the concept, modeling and preliminary testing of an intelligent FRP retrofit with self-monitoring capabilities for critical civil infrastructures are presented. This intelligent system is based on an easy-to-apply configuration of FRP pre-preg tapes with multiple stacked unidirectional layers of piezoelectric or SMA actuators and integrated optical fiber sensors. This intelligent retrofit will be able to not only monitor conditions including bonding of the FRP to the structure and opening of concrete cracks, but also minimize the crack opening and retard the progression of further FRP debonding. Towards this end, a computationally efficient two-dimensional shear stress-transfer model based on a simplified shear lag analysis is developed, with consideration of the fact that the stress transfer between the FRP, actuator and sensor layers in the intelligent system is complex. The effectiveness of this model is demonstrated through one numerical benchmark problem and one typical FRP configuration, with comparison of each to full threedimensional finite element models. The agreement between the two formulations is shown to be further improved by adjustment of the assumed shape functions. A preliminary experiment is also presented in which pre-fabricated optical fiber ribbons are embedded into the FRP strengthening of a full-scale concrete beam. Results from static loading test of the FRP strengthened beam show the feasibility of this technique for the self-monitoring FRP retrofits.

  11. Retrofitting of RC Slabs Against Explosive Loads

    Institute of Scientific and Technical Information of China (English)

    WU Chengqing; OEHLERS Deric John; XIA Shaohua

    2006-01-01

    With the increase of terrorist bomb attacks on buildings,there is a need to develop advanced retrofitting techniques to strengthen structures against blast loads.Currently,several guidelines including an Australian version for retrofitting reinforced concrete (RC) structures are available for the design of retrofitting systems against seismic and monotonic loads using steel or fibre reinforced polymer (FRP) plates that can be either adhesively bonded to the surface or near surface mounted to the concrete cover.However,none of these guidelines provide advice suitable for retrofitting structures subjected to blast loads.In this paper,numerical models are used to simulate the performance of retrofitted RC slabs subjected to blast loads.Airblast pressure distributions on the surface of the slabs estimated in a previous study are used as input in the analysis.A material damage model developedpreviously for concrete and an elastoplastic model for steel bars are employed in this research for modelling reinforced concrete behaviour due to explosive loads.The material models and blast loading are coded into a finite element computer program LS-DYNA3D to do the analysis.With the numerical model,parametric studies are conducted to investigate RC slabs retrofitted by either externally bonded or near-surface mounted plates or GFRP sheets subjected to blast loads.Discussion is made on the effectiveness of the retrofitting system for RC slabs against blast loads.

  12. A state of the art review on reinforced concrete beams with openings retrofitted with FRP

    Science.gov (United States)

    Osman, Bashir H.; Wu, Erjun; Ji, Bohai; S Abdelgader, Abdeldime M.

    2016-09-01

    The use of externally bonded fiber reinforced polymer (FRP) sheets, strips or steel plates is a modern and convenient way for strengthening of reinforced concrete (RC) beams. Several researches have been carried out on reinforced concrete beams with web openings that strengthened using fiber reinforced polymer composite. Majority of researches focused on shear strengthening compared with flexural strengthening, while others studied the effect of openings on shear and flexural separately with various loading. This paper investigates the impact of more than sixty articles on opening reinforced concrete beams with and without strengthening by fiber reinforcement polymers FRP. Moreover, important practical issues, which are contributed in shear strengthening of beams with different strengthening techniques, such as steel plate and FRP laminate, and detailed with various design approaches are discussed. Furthermore, a simple technique of applying fiber reinforced polymer contributed with steel plate for strengthening the RC beams with openings under different load application is concluded. Directions for future research based on the existing gaps of the present works are presented.

  13. Lagged strain of laminates in RC beams strengthened with fiber-reinforced polymer

    Institute of Scientific and Technical Information of China (English)

    HE Xue-jun; ZHOU Chao-yang; LI Yi-hui; XU Ling

    2007-01-01

    Based on the theory of concrete structure, a new expression was derived for lagged strain of fiber-reinforced polymer(FRP) laminates in reinforced concrete (RC) beams strengthened with FRP. The influence of different preloaded states and nonlinear stress-strain relationship of compressed concrete were both taken into account in this approach. Then a simplified expression was given by ignoring tensile resistance of concrete. Comparison of analytical predictions with experimental results indicates satisfactory accuracy of the procedures. The errors are less than 8% and 10% respectively when the tensile resistance of concrete is or not considered. While the maximum error of existing procedures is up to 60%.

  14. Region 9 Facility Response Plan (FRP) - 2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — A Facility Response Plan (FRP) demonstrates a facility's preparedness to respond to a worst case oil discharge. Under the Clean Water Act, as amended by the Oil...

  15. Seismic performance and global ductility of RC frames rehabilitated with retrofitted joints by CFRP laminates

    Science.gov (United States)

    Fakharifar, M.; Sharbatdar, M. K.; Lin, Z.; Dalvand, A.; Sivandi-Pour, A.; Chen, G.

    2014-03-01

    This paper presents a new FRP retrofitting scheme to strengthen local beam-column joints in reinforced concrete (RC) frames. The new retrofitting scheme was proposed following a preliminary study of four different existing retrofitting schemes. A numerical simulation was conducted to evaluate the effectiveness of FRP-strengthened reinforced concrete frames by bridging behavior of local joints to the whole structure. Local confinement effects due to varying retrofitting schemes in the joints were simulated in the frame model. The seismic behavior factor was used to evaluate the seismic performance of the strengthened RC frames. The results demonstrated that the new proposed retrofitting scheme was robust and promising, and finite element analysis appropriately captured the strength and global ductility of the frame due to upgrading of the local joints.

  16. Parameters That Effect the Interfacial Stresses in Fibre Reinforced Plastic Laminates Strengthened Rc Beams

    Directory of Open Access Journals (Sweden)

    Barış Sayın

    2010-01-01

    Full Text Available The use of externally bonded fiber-reinforced plastic (FRP laminates for strengthening of reinforced concrete beams has become an effective method. This method has been used because of the advantages of FRP materials such as their high strength-to-weight ratio, good corrosion resistance, and versatility in coping with different sectional shapes and corners. Many studies on this theme have been carried out since the early 1900s. In this study, interfacial stresses of reinforced concrete beams strengthened with FRP effect the parameters will be studied as experimental and numerical. Adhesives used in the beams applied to FRP's thickness, adhesive type and the state of the concrete surface, produced experimental samples are exposed to the bending effect will be studied as a comparative. Afterwards, by using the ANSYS® WB finite element program to model and analyze RC beams by externally bonding FRP will be carried out. Adhesive thickness, adhesive type, the concrete surface will be performed by entering the parameters for analysis of stress can be obtained as a result. Thus, the analytical expressions of stress and normal stress equations will establish should be modified. Finite element analysis and experimental results will be compared, compatibility investigated, the results and recommendations presented by the study be completed.

  17. A Viscoelastic Constitutive Law For FRP Materials

    Science.gov (United States)

    Ascione, Luigi; Berardi, Valentino Paolo; D'Aponte, Anna

    2011-09-01

    The present study deals with the long-term behavior of fiber-reinforced polymer (FRP) materials in civil engineering. More specifically, the authors propose a mechanical model capable of predicting the viscoelastic behavior of FRP laminates in the field of linear viscoelasticity, starting from that of the matrix material and fiber. The model is closely connected with the low FRP stress levels in civil engineering applications. The model is based on a micromechanical approach which assumes that there is a perfect adhesion between the matrix and fiber. The long-term behavior of the phases is described through a four-parameter rheological law. A validation of the model has also been developed by matching the predicted behavior with an experimental one available in the literature.

  18. Simulation of the FRP Product

    Science.gov (United States)

    Paugam, Ronan; Wooster, Martin; Johnston, Joshua; Gastellu-Etchegorry, Jean-Philippe

    2014-05-01

    Among the different alternative of remote sensing technologies for estimating global fire carbon emission, the thermally-based measures of fire radiative power (FRP; and its temporal integration, fire radiative energy or FRE) has the potential to capture the spatial and temporal variability of fire occurrence. It was shown that a strong linear relationship exists between the total amount of thermal radiant energy emitted by a fire over its lifetime (the FRE) and the amount of fuel burned. Since all vegetation is 50(±5)% carbon, it is therefore in theory a potentially simple matter to measure the FRE and estimate the carbon release. In a fire inventory like the Global Fire Assimilation System (GFAS), the total carbon emission is derived from a gridded FRE product forced by the MODIS observation, using Ct = β x FRE x Ef, where β is a conversion factor initially estimated from small scale experiment as β=0.368 and later derived for different bio dome by comparison with the Global Fire Emission Database (GFED). The sensitivities of the above equation to (i) different types of fire activity (ie, flaming, smoldering, torching), (ii) sensor view angles or (iii) soot/smoke absorption have not yet been well studied. The investigation of these types of sensitivity, and of the information content of thermal IR observations of actively burning fires in general, is one of the primary subjects of this study. Our approach is based on a combination of observational work and simulations conducted via the linkage of different fire models and the 3D radiative transfer (RT) model DART operating in the thermal domain. The radiation properties of a fire as seen from above its plume (e.g. space/air borne sensor) depend on the temperature distribution, the gas concentration (mainly CO2, H2O), and the amount, shape, distribution and optical properties of the soot particles in the flame (where they are emitting) and in the cooling plume (where they are mainly absorbing). While gas and

  19. Global Loads on FRP Ship Hulls

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1997-01-01

    Fibre reinforced plastic (FRP) composites used for high-speed vessels have lower modulus of elasticity than the conventionally used steels.Therefore, for large fast ships the lowest natural frequencies of the global hull modes can be relatively low compared to the frequency of waveencounter....... As part of the NoKoS project it was decided to investigate the effect of hull flexibility on the wave-induced as well as accidental structural loads on high-speed ships.Especially it was decided to determine whether there is an upper size of FRP and aluminium mono-hulls caused by continuous wave action...

  20. Survey on the FRP waste recycling system; FRP haikibutsu recycle system ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Using the area around the Ariake Sea in Kyushu as a model case, the FRP (fiber reinforced plastics) waste recycling system which can be established in Japan has been investigated in cooperation with local government bodies and fishery organizations. As a result, some proposals are provided. The recovery of waste boats utilizing existing sales outlets for fishing boats will facilitate efficient transport, efficient removal of vessel fixtures, and information management and user guidance via existing sales routes. This should make it possible to systematically secure and dispose a certain volume of scrapped FRP boats, and thus generate savings in the disposal costs. In the Phase 1, the main focus will be on establishing the recovery system for scrapped FRP boats to promote reuse and prevent improper disposal. In the Phase 2, the economics will be improved by expanding the recovery system to include other FRP waste products. In the Phase 3, the number of recyclable items will be increased, and thus the recycling system will be completed. 3 refs., 11 figs., 7 tabs.

  1. Problem of Delamination in RC Beams Strengthened by FRP with Rheological Model of Adhesive Leyer

    Science.gov (United States)

    Kula, Krzysztof; Socha, Tomasz

    2016-12-01

    This paper deals with one of the most dangerous failure modes in layered structures, namely delamination. The strengthening layer is modelled by a solid-shell finite element. The mechanical modelling of delamination onset and propagation is based upon a cohesive zone model implemented into a cohesive element located between adhesive layer and a concrete structure. The long time behavior of epoxy adhesive layer is modelled with the five-parameter rheological model. The numerical simulations are accomplished within the commercial software package Abaqus by the implementation of a user-written finite element and user-written material.

  2. Are Available Models Reliable for Predicting the FRP Contribution to the Shear Resistance of RC Beams?

    DEFF Research Database (Denmark)

    Sas, G.; Täljsten, Björn; Barros, J.;

    2009-01-01

    In this paper the trustworthiness of the existing theory for predicting the fiber-reinforced plastic contribution to the shear resistance of reinforced concrete beams is discussed. The most well-known shear models for external bonded reinforcement are presented, commented on, and compared...

  3. Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2016-01-01

    Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

  4. Fabrication and experimentation of FRP helical spring

    Science.gov (United States)

    Ekanthappa, J.; Shiva Shankar, G. S.; Amith, B. M.; Gagan, M.

    2016-09-01

    In present scenario, the automobile industry sector is showing increased interest in reducing the unsprung weight of the automobile & hence increasing the fuel Efficiency. One of the feasible sub systems of a vehicle where weight reduction may be attempted is vehicle- suspension system. Usage of composite material is a proven way to lower the component weight without any compromise in strength. The composite materials are having high specific strength, more elastic strain energy storage capacity in comparison with those of steel. Therefore, helical coil spring made of steel is replaceable by composite cylindrical helical coil spring. This research aims at preparing a re-usable mandrel (mould) of Mild steel, developing a setup for fabrication, fabrication of FRP helical spring using continuous glass fibers and Epoxy Resin (Polymer). Experimentation has been conducted on fabricated FRP helical spring to determine its strength parameters & for failure analysis. It is found that spring stiffness (K) of Glass/Epoxy helical-spring is greater than steel-coil spring with reduced weight.

  5. An Expert System in FRP Composite Material Design

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An expert system prototype for fibre-reinforced plastic matrix (FRP) composite material design,ESFRP, has been developed. The system consists of seven main functional parts: a general inference engine, a set of knowledge bases, a material properties algorithm base, an explanation engine, various data bases, several function models and the user interface. The ESFRP can simulate human experts to make design scheme for fibre-reinforced plastics design, FRP layered plates design and FRP typical engineering components design. It can also predict the material properties and make strength analysis according to the micro and macro mechanics of composite materials. A satisfied result can be gained through the reiterative design.

  6. Durability of concrete structures strengthened with FRP laminates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the fast freeze-thaw cycling test, the alkaline immersion test, the water immersion test and the wet-thermal exposure test, the influence of aggressive environments on mechanical behavior of FRP was studied. CFRP specimens subjected to aggressive environments showed good durability with no significant degradation in tensile strength and modulus; however, GFRP specimens exhibited a little decrease in mechanical property after aggressive environments exposure. Based on the fast freeze-thaw cycling test and the wet-thermal exposure test, the influence of aggressive environments on the bond behavior between FRP and concrete, mechanical behavior of concrete beams and columns strengthened with FRP laminates was studied. The results showed that the bond strength had a significant decrease compared with those specimens kept at room temperature, and the specimens strengthened with FRP exhibited good durability.

  7. FRP Composites Strengthening of Concrete Columns under Various Loading Conditions

    Directory of Open Access Journals (Sweden)

    Azadeh Parvin

    2014-04-01

    Full Text Available This paper provides a review of some of the progress in the area of fiber reinforced polymers (FRP-strengthening of columns for several loading scenarios including impact load. The addition of FRP materials to upgrade deficiencies or to strengthen structural components can save lives by preventing collapse, reduce the damage to infrastructure, and the need for their costly replacement. The retrofit with FRP materials with desirable properties provides an excellent replacement for traditional materials, such as steel jacket, to strengthen the reinforced concrete structural members. Existing studies have shown that the use of FRP materials restore or improve the column original design strength for possible axial, shear, or flexure and in some cases allow the structure to carry more load than it was designed for. The paper further concludes that there is a need for additional research for the columns under impact loading senarios. The compiled information prepares the ground work for further evaluation of FRP-strengthening of columns that are deficient in design or are in serious need for repair due to additional load or deterioration.

  8. FRP/steel composite damage acoustic emission monitoring and analysis

    Science.gov (United States)

    Li, Dongsheng; Chen, Zhi

    2015-04-01

    FRP is a new material with good mechanical properties, such as high strength of extension, low density, good corrosion resistance and anti-fatigue. FRP and steel composite has gotten a wide range of applications in civil engineering because of its good performance. As the FRP/steel composite get more and more widely used, the monitor of its damage is also getting more important. To monitor this composite, acoustic emission (AE) is a good choice. In this study, we prepare four identical specimens to conduct our test. During the testing process, the AE character parameters and mechanics properties were obtained. Damaged properties of FRP/steel composite were analyzed through acoustic emission (AE) signals. By the growing trend of AE accumulated energy, the severity of the damage made on FRP/steel composite was estimated. The AE sentry function has been successfully used to study damage progression and fracture emerge release rate of composite laminates. This technique combines the cumulative AE energy with strain energy of the material rather than analyzes the AE information and mechanical separately.

  9. Experimental evaluation and field implementation of FRP bridge deck modules

    Directory of Open Access Journals (Sweden)

    Woraphot Prachasaree

    2008-07-01

    Full Text Available Construction of highway bridge decks using fiber reinforced polymer (FRP composite deck and superstructuremodules in lieu of concrete decks has proven to be feasible. However, FRP’s are not widely accepted yet despite theirbenefits such as non-corrosiveness, higher strength to weight ratio, and better fatigue resistance than conventional materials.Lack of wider usage of FRP material is mainly attributed to the absence of: 1 standardized test procedures, 2 designspecifications, and 3 construction procedures. The higher initial cost is also inhibiting bridge engineers in selecting FRPmodules as highway bridge super structural systems.Implementation of FRP composites technology for highway bridge decks leads to higher safety and lower life cyclecosts. Significant ongoing research and development of FRP deck modules as illustrated herein, has proven to enhancedeck module properties in developing FRP modules with enhanced structural performance.Prodeck 4 is one such multicellular deck that was recently developed, and extensively evaluated for static and fatigueloads, and its response results are presented herein. From rigorous testing, it was concluded that Prodeck 4 could resistAASHTO HS 25 loading with maximum stringer spacing of 48 inches. This led to construction of two bridges (one in Ohioand other in West Virginia using Prodeck 4 as decking.

  10. Concrete-Filled-Large Deformable FRP Tubular Columns under Axial Compressive Loading

    OpenAIRE

    Omar I. Abdelkarim; Mohamed A. ElGawady

    2015-01-01

    The behavior of concrete-filled fiber tubes (CFFT) polymers under axial compressive loading was investigated. Unlike the traditional fiber reinforced polymers (FRP) such as carbon, glass, aramid, etc., the FRP tubes in this study were designed using large rupture strains FRP which are made of recycled materials such as plastic bottles; hence, large rupture strain (LRS) FRP composites are environmentally friendly and can be used in the context of green construction. This study performed finite...

  11. The Tension-Stiffening Contribution of NSM CFRP to the Behavior of Strengthened RC Beams

    Directory of Open Access Journals (Sweden)

    Ahmad Azim Shukri

    2015-07-01

    Full Text Available Tension stiffening is a characteristic behavior of reinforced concrete (RC beams which is directly affected by the bond-slip property of steel bar and concrete interfaces. A beam strengthened with a near-surface mounted (NSM technique would be even more affected by tension stiffening, as the NSM reinforcement also possess a bond-slip property. Yet assessing how much the tension stiffening of NSM contributes to the behavior of RC beams is difficult due to the fact that bond-slip effects cannot be directly incorporated into a strain-based moment-curvature analysis. As such, the tension stiffening is typically incorporated through various empirical formulations, which can require a great deal of testing and calibrations to be done. In this paper a relatively new method, which can be called the mechanics-based segmental approach, is used to directly simulate the tension stiffening effect of NSM reinforcements on RC beams, without the need for empirical formulations to indirectly simulate the tension stiffening. Analysis shows that the tension stiffening of NSM fiber reinforced polymer (FRP contributes a significant portion to the stiffness and strength of the strengthened RC beam not only during serviceability, but at all load levels.

  12. Shear Strengthening of RC Beams Using Sprayed Glass Fiber Reinforced Polymer

    Directory of Open Access Journals (Sweden)

    Sayed Mohamad Soleimani

    2012-01-01

    Full Text Available The effectiveness of externally bonded sprayed glass fiber reinforced polymer (Sprayed GFRP in shear strengthening of RC beams under quasi-static loading is investigated. Different techniques were utilized to enhance the bond between concrete and Sprayed GFRP, involving the use of through bolts and nuts paired with concrete surface preparation through sandblasting and through the use of a pneumatic chisel prior to Sprayed GFRP application. It was found that roughening the concrete surface using a pneumatic chisel and using through bolts and nuts were the most effective techniques. Also, Sprayed GFRP applied on 3 sides (U-shaped was found to be more effective than 2-sided Sprayed GFRP in shear strengthening. Sprayed GFRP increased the shear load-carrying capacity and energy absorption capacities of RC beams. It was found that the load-carrying capacity of strengthened RC beams was related to an effective strain of applied Sprayed GFRP. This strain was related to Sprayed GFRP configuration and the technique used to enhance the concrete-FRP bond. Finally, an equation was proposed to calculate the contribution of Sprayed GFRP in the shear strength of an RC beam.

  13. Concrete-Filled-Large Deformable FRP Tubular Columns under Axial Compressive Loading

    Directory of Open Access Journals (Sweden)

    Omar I. Abdelkarim

    2015-10-01

    Full Text Available The behavior of concrete-filled fiber tubes (CFFT polymers under axial compressive loading was investigated. Unlike the traditional fiber reinforced polymers (FRP such as carbon, glass, aramid, etc., the FRP tubes in this study were designed using large rupture strains FRP which are made of recycled materials such as plastic bottles; hence, large rupture strain (LRS FRP composites are environmentally friendly and can be used in the context of green construction. This study performed finite element (FE analysis using LS-DYNA software to conduct an extensive parametric study on CFFT. The effects of the FRP confinement ratio, the unconfined concrete compressive strength ( , column size, and column aspect ratio on the behavior of the CFFT under axial compressive loading were investigated during this study. A comparison between the behavior of the CFFTs with LRS-FRP and those with traditional FRP (carbon and glass with a high range of confinement ratios was conducted as well. A new hybrid FRP system combined with traditional and LRS-FRP is proposed. Generally, the CFFTs with LRS-FRP showed remarkable behavior under axial loading in strength and ultimate strain. Equations to estimate the concrete dilation parameter and dilation angle of the CFFTs with LRS-FRP tubes and hybrid FRP tubes are suggested.

  14. Effect of the Fiber Type and Axial Stiffness of FRCM on the Flexural Strengthening of RC Beams

    Directory of Open Access Journals (Sweden)

    Abdulla Jabr

    2017-01-01

    Full Text Available The use of externally-bonded fiber-reinforced polymer (FRP sheets has been successfully used in the repair and strengthening of both the shear and flexural capacities of reinforced concrete (RC beams, slabs and columns since the 1990s. However, the externally-bonded FRP reinforcements still present many disadvantages, such as poor performance in elevated temperature and fire, lack of permeability and strength degradation when exposed to ultraviolet radiation. To remedy such drawbacks, the fiber-/fabric-reinforced cementitious matrix (FRCM has been recently introduced. The FRCM system consists of a fiber mesh or grid embedded in a cementitious bonding material. The present research investigates the flexural strengthening of reinforced concrete (RC beams with FRCM. The experimental testing included eight large-scale concrete beams, 150 mm × 250 mm × 2400 mm, internally reinforced with steel bars and strengthened in flexure with FRCM. The investigated parameters were the internal steel reinforcement ratio and the FRCM systems. Two steel reinforcement ratios of 0.18 and 0.36 of the balanced reinforcement ratio, as well as three FRCM systems using glass, carbon and PBO fibers were investigated. Test results are presented in terms of load-deflection, load-strain and load-crack width relationships. The test results indicated that the PBO FRCM significantly increased the ultimate capacity of the strengthened RC beams with both low and moderate internal reinforcement ratios compared to the glass and carbon FRCM.

  15. FRP tendon anchorage in post-tensioned concrete structures

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Täljsten, Björn; Bennitz, Anders

    2008-01-01

    Strengthening of building structures by the use of various external post-tensioning steel tendon systems, is known to be a very efficient method. However, FRP as material in external post-tensioning projects has been investigated during the last decade. The advantages for this material are the high...... effective Young´s modulus and the high stress capacity in the linear elastic range of the material. The use of external tendons increases the requirements on the anchorage systems. This is in particular important when using un-bonded tendon systems, where the anchorage and deviators are the only force...... transfer points. The demand for high capacity anchorage tendons is fulfilled for steel tendons, but no competitive mechanical anchor has yet been developed for FRP tendon. A new small, reliable and more user friendly anchor has to be developed, before FRP tendons can be utilized with all of its capacity...

  16. Wear properties of nanosilica filled epoxy polymers and FRP composites

    Directory of Open Access Journals (Sweden)

    A. Jumahat

    2015-09-01

    Full Text Available This paper is aimed to determine the wear properties of nanosilica filled epoxy polymers and FRP composites. Woven fiberglass has been deployed as the reinforcement material. The fibers were mixed with three different percentages of nanosilica-modified epoxy resin, i.e: 5wt%; 13wt%; 25wt%, in order to fabricate the desired samples of FRP composites. The effect of nanosilica on wear properties was evaluated using dry sliding wear and slurry tests. The results show that increasing the amount of nanosilica content has reduced the amount of accumulated mass loss. It was found that the FRP laminates with 25wt% of nanosilica have the highest wear resistance. The nanosilica filled fiber reinforced polymer composites have a high potential in tribological application such as ball bearing housing and snow sleds.

  17. A mechanical model for FRP-strengthened beams in bending

    Directory of Open Access Journals (Sweden)

    P. S. Valvo

    2012-10-01

    Full Text Available We analyse the problem of a simply supported beam, strengthened with a fibre-reinforced polymer (FRP strip bonded to its intrados and subjected to bending couples applied to its end sections. A mechanical model is proposed, whereby the beam and FRP strip are modelled according to classical beam theory, while the adhesive and its neighbouring layers are modelled as an interface having a piecewise linear constitutive law defined over three intervals (elastic response – softening response – debonding. The model is described by a set of differential equations with appropriate boundary conditions. An analytical solution to the problem is determined, including explicit expressions for the internal forces, displacements and interfacial stresses. The model predicts an overall non-linear mechanical response for the strengthened beam, ranging over several stages: from linearly elastic behaviour to damage, until the complete detachment of the FRP reinforcement.

  18. Dynamic Characterization of an All-FRP Bridge

    Science.gov (United States)

    Casalegno, C.; Russo, S.

    2017-03-01

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

  19. FRP-Confined Recycled Coarse Aggregate Concrete: Experimental Investigation and Model Comparison

    Directory of Open Access Journals (Sweden)

    Yingwu Zhou

    2016-10-01

    Full Text Available The in situ application of recycled aggregate concrete (RAC is of great significance in environmental protection and construction resources sustainability. However, it has been limited to nonstructural purposes due to its poor mechanical performance. External confinement using steel tubes and fiber-reinforced polymer (FRP can significantly improve the mechanical performance of RAC and thus the first-ever study on the axial compressive behavior of glass FRP (GFRP-confined RAC was recently reported. To have a full understanding of FRP-confined RAC, this paper has extended the type of FRP and presents a systematic experimental study on the axial compressive performance of carbon FRP (CFRP-confined RAC. The mechanical properties of CFRP-confined RAC from the perspective of the failure mode, ultimate strength and strain, and stress–strain relationship responses were analyzed. Integrated with existing experimental data of FRP-confined RAC, the paper compiles a database for the mechanical properties of FRP-confined RAC. Based on the database, the effects of FRP type (i.e., GFRP and CFRP and the replacement ratio of recycled coarse aggregate were investigated. The results indicated that the stress–stain behavior of FRP-confined RAC depended heavily on the unconfined concrete strength and the FRP confining pressure instead of the replacement ratio. Therefore, this study adopted eleven high-performance ultimate strength and strain models developed for FRP-confined normal aggregate concrete (NAC to predict the mechanical properties of FRP-confined RAC. All the predictions had good agreement with the test results, which further confirmed similar roles played by FRP confinement in improving the mechanical properties of RAC and improving those of NAC. On this basis, this paper finally recommended a stress–strain relationship model for FRP-confined RAC.

  20. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup;

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...

  1. Mechanical anchorage of FRP tendons – A literature review

    DEFF Research Database (Denmark)

    Schmidt, Jacob W.; Bennitz, Anders; Täljsten, Björn

    2012-01-01

    anchorage systems for use with Aramid, Glass and Carbon FRP tendons have been proposed over the last two decades. Each system is usually tailored to a particular type of tendon. This paper presents a brief overview of bonded anchorage applications while the primary literature review discusses three methods...

  2. Performance Analysis of CFRP Composite Strips Confined RC Columns under Axial Compression

    Directory of Open Access Journals (Sweden)

    J. Raja Murugadoss

    2015-01-01

    Full Text Available In an attempt to mitigate the high cost of FRP composite strengthening, an experimental investigation was carried out that sought to achieve efficient and most favorable FRP strengthening using CFRP composite strips. 50 mm wide CFRP composite strips were used in two different spacings (20 mm and 40 mm to confine columns. The test results of the column confined with smaller spacing (20 mm showed significant restraint of axial deformation of the column and enhanced the strength capacity to a maximum of 99.20% compared to that of reference column. In contrast, the column confined by strips with larger spacing (40 mm failed by crushing of concrete alone, which occurred even before the CFRP strips reached their ultimate strain. In addition, the embodied energy that exists in the CFRP strips could not be utilized effectively. The stress and strength enhancement ratio of this present study was compared with the previous research that has been conducted on columns confined with full wrapping. From the obtained results, it is recommended that CFRP strips with a spacing of 20 mm be used to improve the strength capacity of the RC column; in addition, this wrapping technique provides economic benefits compared to a column confined with full wrapping.

  3. Numerical Study of FRP Reinforced Concrete Slabs at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Masoud Adelzadeh

    2014-02-01

    Full Text Available One-way glass fibre reinforced polymer (GFRP reinforced concrete slabs at elevated temperatures are investigated through numerical modeling. Serviceability and strength requirements of ACI-440.1R are considered for the design of the slabs. Diagrams to determine fire endurance of slabs by employing “strength domain” failure criterion are presented. Comparisons between the existing “temperature domain” method with the more representative “strength domain” method show that the “temperature domain” method is conservative. Additionally, a method to increase the fire endurance of slabs by placing FRP reinforcement in two layers is investigated numerically. The amount of fire endurance gained by placing FRP in two layers increases as the thickness of slab increases.

  4. Structural performance of complex core systems for FRP-balsa composite sandwich bridge decks

    OpenAIRE

    Osei-Antwi, Michael

    2014-01-01

    Based on current fiber-reinforced polymer (FRP) composite construction principles, FRP decks fall into two categories: pultruded decks and sandwich decks. Sandwich decks comprise face sheets and either honeycombs or foams reinforced with internal FRP webs for shear resistance. The honeycomb structure and the webs cause debonding between the upper face sheets and the core due to the uneven support of the former. An alternative material that has high shear capacity and can provide uniform ...

  5. Compressive Strength of a Longitudinally Stiffened FRP Panel

    DEFF Research Database (Denmark)

    Riber, Hans Jørgen; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    1997-01-01

    A structural analysis of a cross stiffened orthotropic FRP panel subjected to uni-axial compressive load is crarried out. Analytical Calculations of the strength of the panel are presented and compared to finite element analysis performed by different authors. Both analytica and finite element ap...... approaches confirm an identical failrue scenario. In the present case, the load carrying capacity of the stiffened panel is limited by the plate stiffener debonding stress....

  6. A Review on Strengthening Steel Beams Using FRP under Fatigue

    Directory of Open Access Journals (Sweden)

    Mohamed Kamruzzaman

    2014-01-01

    Full Text Available In recent decades, the application of fibre-reinforced polymer (FRP composites for strengthening structural elements has become an efficient option to meet the increased cyclic loads or repair due to corrosion or fatigue cracking. Hence, the objective of this study is to explore the existing FRP reinforcing techniques to care for fatigue damaged structural steel elements. This study covers the surface treatment techniques, adhesive curing, and support conditions under cyclic loading including fatigue performance, crack propagation, and failure modes with finite element (FE simulation of the steel bridge girders and structural elements. FRP strengthening composites delay initial cracking, reduce the crack growth rate, extend the fatigue life, and decrease the stiffness decay with residual deflection. Prestressed carbon fibre-reinforced polymer (CFRP is the best strengthening option. End anchorage prevents debonding of the CRRP strips at the beam ends by reducing the local interfacial shear and peel stresses. Hybrid-joint, nanoadhesive, and carbon-flex can also be attractive for strengthening systems.

  7. Experimental investigation on FRP to steel adhesively-bonded joint under tensile loading

    NARCIS (Netherlands)

    Jiang, X.; Kolstein, M.H.; Bijlaard, F.S.K.

    2012-01-01

    Due to various advantages of Fibre-Reinforced Polymer (FRP) decks, the FRP to steel composite girder system is being increasingly used in the construction of new bridges as well as the rehabilitation projects of old bridges. This paper focus on the mechanical behaviors and failure modes of the adhes

  8. Practical applications of asset management and comakership business models for FRP bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2012-01-01

    Fibre Reinforced Polymer (FRP) material and the associated technologies for bridge construction and refurbishment have been proven to be durable and sustainable. Much research and a number of recent projects have demonstrated that FRP bridges can also be cost-effective, provided that the cost and be

  9. Analisis Teknis dan Ekonomis Pembangunan Kapal Ikan 30GT Konstruksi FRP Menggunakan Metode Laminasi Vacuum Infusion

    Directory of Open Access Journals (Sweden)

    Rengga Eka Putra Atmanegara

    2016-04-01

    Full Text Available Produksi kapal ikan 30GT konstruksi FRP di Indonesia masih menggunakan metode laminasi hand lay up. Metode hand lay up memiliki kekurangan pada kebutuhan jam orang dan kualitas produksi. Metode vacuum infusion merupakan salah satu metode laminasi fibreglass yang memiliki keunggulan. Tujuan tugas akhir ini adalah untuk menganalisis secara teknis dan ekonomis produksi kapal ikan 30GT konstruksi FRP menggunakan metode laminasi vacuum infusion. Pertama, produksi kapal ikan 30GT konstruksi FRP diobservasi. Kedua, data produksi kapal ikan 30GT konstruksi FRP dikumpulkan. Ketiga, menganalisis teknis dan ekonomis pembangunan kapal ikan 30GT konstruksi FRP metode laminasi hand lay up dan vacuum infusion yang telah dilakukan. Hasil dari penerapan metode vacuum infusion pada produksi kapal ikan 30GT konstruksi FRP mengalami pengurangan sebesar 7,26%. Kualitas produksi vacuum infusion lebih baik 22,83% dibandingkan hand lay up. Dari hasil analisis ekonomis, biaya produksi kapal ikan 30GT konstruksi FRP metode laminasi vacuum infusion lebih mahal 12,9% dari pada metode laminasi hand lay up. Produktivitas tenaga kerja metode laminasi vacuum infusion lebih tinggi 24,94% dari pada metode laminasi hand lay up. Pembangunan galangan kapal konstruksi FRP metode vacuum infusion membutuhkan biaya investasi sebesar Rp 14.383.141.000 dan Payback Period (PP pada tahun ke-10.

  10. How Not to Combine RC4 States

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Jha, Sonu

    2015-01-01

    Over the past few years, an attractive design paradigm has emerged, that aims to produce new stream cipher designs, by combining one or more independently produced RC4 states. The ciphers so produced turn out to be faster than RC4 on any software platform, mainly because the average number...

  11. Repair of corrosion-damaged columns using FRP wraps

    Science.gov (United States)

    Baiyasi, Mohamad Imad

    Many bridge columns in Michigan are damaged by chloride contamination resulting in the corrosion of the steel reinforcement, and swelling and spalling of the concrete and use of the bridges is typically continued. This in itself may not be a serious problem since most columns in Michigan are over-designed and the loss of strength is not a significant issue. However, the lack of any method to minimize or prevent corrosion of the steel results in continued deterioration and unsightly columns. Polymer composite (also known as fiber-reinforced polymer or FRP) jackets offer a possible remedy to this problem. They offer a rapid repair technique with the potential to enhance the longterm durability and compression strength of damaged columns due to the confinement that is provided when fibers are oriented in the hoop direction. Fibers oriented in the vertical direction can enhance the bending strength. Experiments were conducted to assess the effects of using FRP wraps with fibers oriented in the hoop direction for rehabilitating corrosion-damaged columns. Issues that were explored are: (1) effect of freeze-thaw and wet-dry cycles on the properties of FRP panels; (2) freeze-thaw durability of concrete square and cylindrical specimens wrapped with glass and carbon FRP and subjected to an internal expansive force; and (3) effect of wrapping on the rate of corrosion in an accelerated corrosion test. The results of the freeze-thaw experiment indicate that freeze-thaw cycles have no statistically significant effect on the compressive strength of glass and carbon wrapped specimens. For round specimens, glass and carbon wraps increased the strength by a factor of about 2.3 and 2.6, respectively. For square specimens, glass and carbon wraps increased the strength by a factor of 1.4--1.5. Freeze-thaw conditioning generally reduced the longitudinal failure strain of wrapped specimens. The square wrapped specimens had lower compressive strength compared to the round specimens, even

  12. Behavior of FRP-Confined Concrete-Filled Steel Tube Columns

    Directory of Open Access Journals (Sweden)

    Yiyan Lu

    2014-05-01

    Full Text Available This paper presents the results of an experimental study into the behavior of concrete-filled steel tube columns confined by fiber-reinforced polymer (FRP. Eleven columns were tested to investigate the effects of the FRP layer number, the thickness of the steel tube and concrete strength on their load capacity and axial deformation capacity. The experimental results indicated that the FRP wrap can effectively confine the concrete expansion and delay the local buckling of the steel tube. Both the load capacity and the axial deformation capacity of concrete-filled steel tube columns can be substantially enhanced with FRP confinement. A model is proposed to predict the load capacity of the FRP-confined concrete-filled steel tube columns. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature.

  13. Analytical and Numerical Modelling of FRP Debonding from Concrete Substrate under Pure Shearing

    Institute of Scientific and Technical Information of China (English)

    PAN Jinlong; XU Zhun; C K Y Leung; LI Zongjin

    2012-01-01

    External bonding of fiber reinforced polymer (FRP) composites on the concrete structures has been proved to be an effective and efficient way to strengthen concrete structures.For a FRP strengthened concrete beam,it is usually observed that the failure occurs in the concrete and a thin layer of concrete is attached on the surface of the debonded FRP plate.To study the debond behavior between concrete and FRP composites,an analytical model based on the three-parameter model is developed to study the debonding behavior for the FRP-to-concrete joint under pure shearing.Then,nonlinear FEM analysis is conducted to verify the proposed analytical model.The FEM results shows good agreement with the results from the model.Finally,with the analytical model,sensitivity analyses are performed to study the effect of the interfacial parameters or the geometric parameters on the debonding behavior.

  14. Behaviour of FRP confined concrete in square columns

    Directory of Open Access Journals (Sweden)

    de Diego, A.

    2015-12-01

    Full Text Available A significant amount of research has been conducted on FRP-confined circular columns, but much less is known about rectangular/square columns in which the effectiveness of confinement is much reduced. This paper presents the results of experimental investigations on low strength square concrete columns confined with FRP. Axial compression tests were performed on ten intermediate size columns. The tests results indicate that FRP composites can significantly improve the bearing capacity and ductility of square section reinforced concrete columns with rounded corners. The strength enhancement ratio is greater the lower the concrete strength and also increases with the stiffness of the jacket. The confined concrete behaviour was predicted according to the more accepted theoretical models and compared with experimental results. There are two key parameters which critically influence the fitting of the models: the strain efficiency factor and the effect of confinement in non-circular sections.La mayoría de las investigaciones sobre hormigón confinado con FRP se han realizado sobre pilares de sección circular, pero el comportamiento en secciones cuadradas/rectangulares, donde el confinamiento es menos eficaz, es mucho menos conocido. Este trabajo presenta los resultados de un estudio experimental sobre probetas de hormigón de baja resistencia y sección cuadrada. Se han ensayado a compresión centrada diez probetas de tamaño intermedio. Los resultados indican que el confinamiento mejora significativamente la resistencia y ductilidad del hormigón en columnas de sección cuadrada con las esquinas redondeadas. El incremento de resistencia es mayor cuanto menor es la resistencia del hormigón sin confinar y también aumenta con la rigidez del encamisado. Los resultados se compararon con los obtenidos según los modelos teóricos más aceptados. Hay dos parámetros críticos en el ajuste de los modelos: el factor de eficiencia de la deformación y el

  15. FIRE PROTECTION OF TIMBER STRUCTURES STRENGTHENED WITH FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Radek Zigler

    2015-12-01

    Full Text Available Modern, progressive methods of structures’ strengthening based on the use of composite materials composed of high strength fibers (carbon, glass, aramid or basalt and matrices based on epoxy resins brings, among many indisputable advantages (low weight, high effectiveness, easy application etc. also some disadvantages. One of the major disadvantages is a low fire resistance of these materials due to the low glass transition temperature Tg of the resin used. Based on an extensive research of strengthening of historic structures with FRP materials [1], the article outlines possible approaches to this problem, especially while strengthening timber load- bearing structures of historic buildings.

  16. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

    Full Text Available The paper investigated the use of fiberglass-reinforced plastic (FRP grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

  17. A comparison of FRP-sandwich penetrating impact test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, M. [VTT Manufacturing Technology, Espoo (Finland). Maritime and Mechanical Engineering

    1996-12-31

    The main objective of this project is to identify the test methods which provide useful results for the different types of penetrating impacts occurring in sandwich structures. A series of penetrating impact tests on FRP-sandwich panels is performed using three different test methods and the results of the test methods are compared. The test methods used are the standardised method ISO 6603 and two non-standardised methods. The first non-standardised method uses a pyramid-shaped impactor instead of the cylindrical impactor used in the ISO 6603 method. In the second non-standardised method, the impact test is performed quasistatically using a cylindrical impactor. Possible stages of failure occurring in FRP-sandwich during a penetrating impact are illustrated. A comprehensive test method should be able to provoke various failure modes, as observed in impact failures of actual sandwich structures. The results obtained with the three test methods lead to a different ranking in impact strength of the panels. Hence, impact test results obtained with different test methods are not even qualitatively comparable. The pyramid-shaped impactor is able to generate clearly more failure modes than the cylindrical impactor in the ISO 6603 method. Therefore, it is considered to be of more practical value for determining the impact strength of PRP-sandwich structures. (orig.) (15 refs.)

  18. Research advance of near-surface mounted fiber-reinforced polymer to concrete%表层嵌贴FRP-混凝土黏结加固研究进展

    Institute of Scientific and Technical Information of China (English)

    童谷生; 蔡少杰

    2014-01-01

    Near-surface mounted(NSM)fiber-reinforced polymer(FRP)reinforcement is one of the latest and most promising strength-ening techniques for reinforced concrete(RC)structures.Research on this topic mainly focused on the bonding mechanism and the flexural strengthening.The paper presents bond mechanics of NSM FRP bars/strips to concrete including the bond test methods ,effect of test vari-ables,bond failure modes,analytical modeling,local bond shear stress-slip relationship.It provides a critical review of existing research in this area,identifies gaps of knowledge,and outlines directions for further research.%表层嵌贴FRP修复加固混凝土结构是一种富有前景的新型技术,目前该技术领域的研究主要集中在黏结机理和抗弯加固两方面。论述表层嵌贴FRP-混凝土的试验方法、主要控制参数、破坏模式、黏结机理、界面黏结滑移本构关系等。最后,对目前国内外表层嵌贴FRP-混凝土黏结性能的研究现状进行探讨,希望为表层嵌贴FRP加固技术的进一步研究发展提供方向。

  19. Study on fabrication of smart FRP-OFBG composite laminates and their sensing properties

    Science.gov (United States)

    Wang, Yanlei; Zhou, Zhi; Ou, Jinping

    2007-01-01

    Fiber reinforced polymer (FRP) has gained much attention in civil engineering due to its high strength-to-weight and stiffness-to-weight ratios, corrosion resistance and good fatigue resistance. Optical Fiber Bragg Grating (OFBG) is now widely accepted as smart sensor due to its advantages of electric-magnetic resistance, small size, distributed sensing, durability, and so on. Combined the FRP with OFBG, new kind of smart FRP-OFBG composite laminates was developed. Fabrication method of the smart composite laminates was introduced in this paper. The study presented the basic principle of OFBG sensors. Then the strain and temperature sensing properties of the proposed smart FRP-OFBG composite laminates were experimentally studied on material test system and under hot water, respectively. The experimental results indicate the strain sensing properties of the smart FRP-OFBG composite laminates are nearly the same as that of bare OFBG, however, the temperature sensing abilities of the smart FRP-OFBG composite laminates are improved and the sensitivity coefficient is nearly 3.2 times as much as that of bare OFBG. The strain and temperature sensing precisions of the smart FRP-OFBG composite laminates are 1 μ\\Vegr and 0.03 °C, respectively. The smart FRYOFBG composite laminates are very proper for application in civil engineering.

  20. Electrochemical characteristics on corrosion of steel reinforced concrete columns wrapped with fiber reinforced polymer%FRP 加固混凝土柱钢筋锈蚀电化学特性

    Institute of Scientific and Technical Information of China (English)

    卢亦焱; 齐波; 李杉; 李娜

    2015-01-01

    通过外加电流加速试验获得锈蚀钢筋混凝土柱,采用纤维增强聚合物(FRP)全裹方法对其进行加固,然后通过盐溶液干湿交替方法对FRP加固柱进行钢筋锈蚀试验,利用电化学工作站量测FRP加固柱的钢筋半电池电位和线性极化曲线,分析FRP加固柱的钢筋锈蚀电化学特性。试验结果表明:随着干湿交替次数的增加,外粘CFRP和GFRP加固柱的钢筋半电池电位呈先升高后稳定趋势,线性极化电阻呈增大趋势,腐蚀电流密度呈降低趋势;外粘CFRP和GFRP加固法均能在一定程度减缓钢筋混凝土柱的钢筋锈蚀,CFRP延缓钢筋锈蚀效果优于GFRP 。%Reinforced concrete (RC) columns were corroded through impressed current accelerated test and then treated with surface bonded fiber reinforced polymer (FRP). Following cure of the res‐in ,all of specimens were put into wet‐dry environment. During the test ,the half‐cell potential and linear polarization curve measures were recorded once 2 numbers of wet‐dry cycles through electro‐chemical w orkstation. Electrochemical characteristics of reinforcing bars embedded in FRP w rapped RC columns were analyzed. The tested results show that ,with the increasing of numbers of wet‐dry cycles ,the carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) w rapped RC columns have increasing trend in the linear‐polarization resistance and reducing trend in corrosion current density. While half‐cell potential of reinforcing bars of CFRP and GFRP w rapped RC columns display increasing in first 2 numbers of wet‐dry cycles and then remaining constant. RC columns that treated with surface bonded CFRP or GFRP strengthening method retard corrosion of steel bars in a certain degree. The efficiency of retarded corrosion of steel bar for RC columns wrapped with CFRP is better than that of RC column wrapped with GFRP.

  1. Accelerated Testing for Long-Term Durability of Various FRP Laminates for Marine Use

    Science.gov (United States)

    Miyano, Yasushi; Nakada, Masayuki

    The prediction of long-term fatigue life of various FRP laminates combined with resins, fibers and fabrics for marine use under temperature and water environments were performed by our developed accelerated testing methodology based on the time-temperature superposition principle (TTSP). The base material of five kinds of FRP laminates employed in this study was plain fabric CFRP laminates T300 carbon fibers/vinylester (T300/VE). The first selection of FRP laminate to T300/VE was the combinations of different fabrics, that is flat yarn plain fabric T700 carbon fibers/vinylester (T700/VE-F) and multi-axial knitted T700 carbon fibers/vinylester (T700/VE-K) for marine use and the second selection of FRP laminates to T300/VE was the combinations with different fibers and matrix resin, that is plain fabric T300 carbon fibers/epoxy (T300/EP) and plain fabric E-glass fibers/vinylester (E-glass/VE). These five kinds of FRP laminates were prepared under three water absorption conditions of Dry, Wet and Wet C Dry after molding. The three-point bending constant strain rate (CSR) tests for these FRP laminates at three conditions of water absorption were carried out at various temperatures and strain rates. Furthermore, the three-point bending fatigue tests for these specimens were carried out at various temperatures and frequencies. The flexural CSR and fatigue strengths of these five kinds of FRP laminates strongly depend on water absorption as well as time and temperature. The mater curves of fatigue strength as well as CSR strength for these FRP laminates at three water absorption conditions are constructed by using the test data based on TTSP. It is possible to predict the long term fatigue life for these FRP laminates under an arbitrary temperature and water absorption conditions by using the master curves.

  2. Static inelastic analysis of RC shear walls

    Science.gov (United States)

    Chen, Qin; Qian, Jiaru

    2002-06-01

    A macro-model of a reinforced concrete (RC) shear wall is developed for static inelastic analysis. The model is composed of RC column elements and RC membrane elements. The column elements are used to model the boundary zone and the membrane elements are used to model the wall panel. Various types of constitutive relationships of concrete could be adopted for the two kinds of elements. To perform analysis, the wall is divided into layers along its height. Two adjacent layers are connected with a rigid beam. There are only three unknown displacement components for each layer. A method called single degree of freedom compensation is adopted to solve the peak value of the capacity curve. The post-peak stage analysis is performed using a forced iteration approach. The macro-model developed in the study and the complete process analysis methodology are verified by the experimental and static inelastic analytical results of four RC shear wall specimens.

  3. Static inelastic analysis of RC shear walls

    Institute of Scientific and Technical Information of China (English)

    陈勤; 钱稼茹

    2002-01-01

    A macro-model of a reinforced concrete (RC) shear wall is developed for static inelastic analysis. The model iscomposed of RC column elements and RC membrane elements. The column elements are used to model the boundary zone andthe membrane elements are used to model the wall panel. Various types of constitutive relationships of concrete could beadopted for the two kinds of elements. To perform analysis, the wall is divided into layers along its height. Two adjacent layersare connected with a rigid beam. There are only three unknown displacement components for each layer. A method called singledegree of freedom compensation is adopted to solve the peak value of the capacity curve. The post-peak stage analysis isperformed using a forced iteration approach. The macro-model developed in the study and the complete process analysismethodology are verified by the experimental and static inelastic analytical results of four RC shear wall specimens.

  4. Development of Embedded Vascular Networks in FRP for Active/Passive Thermal Management

    Science.gov (United States)

    2015-04-01

    AFRL-AFOSR-UK-TR-2015-0019 Development of Embedded Vascular Networks in FRP for Active/Passive Thermal Management Katarzyna...To) 30 September 2012 – 31 December 2014 4. TITLE AND SUBTITLE Development of Embedded Vascular Networks in FRP for Active/Passive Thermal...Z39-18     Page 1 of 16     Project  Title:      Development  of   Embedded  Vascular  Networks  in  FRP  for

  5. Biaxial Flexural Strength and Estimation of Size on the Strength Properties of FRP Composites

    Directory of Open Access Journals (Sweden)

    M. N. Saraf

    1990-04-01

    Full Text Available Fibre reinforced plastics (FRP are widely used as structural materials. For designing structural components, a designer is provided with data based on unidirectional testing. But in real structural applications the component is subjected to multiaxial stress throughout the material. Hence a multiaxial test is a better gauge of the behaviour of FRP components in service. In the present paper a ring-on-ring method was adopted which produces biaxial flexural stress on the FRP specimen. Wubull's statistical weakest link theory was applied to standardize the complexity and to assess the reliability of the results.

  6. 3D Numerical Realization of FRP Mircrostructure from High-Res X-Ray CT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Currently, characterization of constituent-level failure in state-of-the-art FRP composites is limited to two-dimensional observations (e.g. using optical or...

  7. REPAIR AND STRENGTHENING OF REINFORCED CONCRETE BEAMS USING FIBRE REINFORCED POLIMER (FRP MATERIALS

    Directory of Open Access Journals (Sweden)

    Nihat ÇETİNKAYA

    2004-03-01

    Full Text Available The use of Fibre Reinforced Polimer (FRP materials for the repair and strengthening of Reinforced Concrete structures has become widespread recently. FRP materials are being prefered because they have very high tensile strength, resistance to corrosion and they do not affect the use of the building during the repair and strengthening process. Four reinfoced concrete beams repaired and strengthened with FRP materials have been used in this study which were performed at Pamukkale University-Faculty of Engineering- Civil Engineering Department- Structural Engineering Laboratuary. The behaviour of the beams before and after repair and strengthening was compared by obtaining the load- displacement curves under static loading. In this study, it was observed that the repair and strengthening of reinforced concrete beams by using FRP materials had increased the load carrying capacity significantly.

  8. Structural Performance of Light Weight Multicellular FRP Composite Bridge Deck Using Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    Woraphot Prachasaree; Pongsak Sookmanee

    2012-01-01

    Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials,non-corrosiveness and modularization,which should help engineers to obtain more efficient and cost effective structural materials and systems.Currently,FRP composites are becoming more popular in civil engineering applications.The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling,and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations.The relative deflection,equivalent flexural rigidity,failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail.The finite element results showing good correlations with experimental data are presented in this work.

  9. Some security results of the RC4+ stream cipher

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Jha, Sonu

    2015-01-01

    The RC4+ stream cipher was proposed as an alternative to the well known RC4 stream cipher. It was claimed by the authors that this new stream cipher was designed to overcome all the weaknesses reported against the alleged RC4 stream cipher. In the design specifications of RC4+, the authors make u...

  10. Effect of Chloride Content on Bond Behavior Between FRP and Concrete

    Institute of Scientific and Technical Information of China (English)

    潘金龙; 黄毅方; 邢锋

    2010-01-01

    For reinforced concrete structures located along the seaside, the penetration of chloride ions into concrete may be a threat to the durability of the structures. Experimental investigations were carried out to study the effect of chloride content on the bond behavior between concrete and fiber reinforced polymer (FRP) plates. Direct shear tests were conducted on the FRP strengthened concrete members. Before testing, the specimens were immersed in NaCl solutions with concentrations ranging from 3%—15% for di...

  11. Confining concrete with sisal and jute FRP as alternatives for CFRP and GFRP

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2015-12-01

    Full Text Available This research paper presents an experimental investigation on the confinement strength and confinement modulus of concrete cylinders confined using different types of natural fibre composites and a comparative performance analysis with different artificial fibre based composite materials. The paper also highlights the need to switch over from the utilization of artificial fibres, which are non-renewable and fossil fuel products, to environmental beneficial materials like green fibres. The utilization of plant products like sisal and jute fibres and their composites in various structural engineering applications addresses the issues of sustainability and renewability with constructional materials. The paper describes a suitable mechanical treatment method like high temperature conditioning, which aids us in further improving the properties of these woven natural materials like sisal and jute for composite fabrication and utilization. Heat treated natural fibres of woven sisal and jute were utilized for confining concrete cylinders similar to CFRP and GFRP confinement and their confinement characteristics were obtained and compared. All the cylinders were subjected to monotonic axial compressive loads, so as to evaluate the effect of confinement on the axial load carrying capacity and all their failure modes were discussed thoroughly. The results indicated superior performance by sisal FRP as well as jute FRP confined cylinders as compared to controlled or unconfined cylinders, also sisal FRP wrapped cylinders displayed ultimate axial load of comparable magnitude to CFRP confinement. Natural FRP confinement displayed superior confinement modulus and confinement strength, also the ultimate axial load of concrete cylinders confined with natural FRPs underwent 66% enhancement by sisal FRP and 48% enhancement by jute FRP, in comparison with controlled or unconfined cylinders. Enhancement in axial load carrying capacity was 83% with CFRP confinement

  12. Blast Design of Reinforced Concrete and Masonry Components Retrofitted with FRP

    Science.gov (United States)

    2010-07-01

    ultimate flexural and shear resistance of the upgraded walls. The methodology for estimating the flexural resistance of concrete and masonry components...recommended value not including any environmental effects or debonding The FRP reinforcement is typically applied to a concrete or masonry wall...have enough tensile and shear strength to transfer the force and develop the strength of the bonded FRP reinforcement . The durability of the

  13. Fractional-order RC and RL circuits

    KAUST Repository

    Radwan, Ahmed Gomaa

    2012-05-30

    This paper is a step forward to generalize the fundamentals of the conventional RC and RL circuits in fractional-order sense. The effect of fractional orders is the key factor for extra freedom, more flexibility, and novelty. The conditions for RC and RL circuits to act as pure imaginary impedances are derived, which are unrealizable in the conventional case. In addition, the sensitivity analyses of the magnitude and phase response with respect to all parameters showing the locations of these critical values are discussed. A qualitative revision for the fractional RC and RL circuits in the frequency domain is provided. Numerical and PSpice simulations are included to validate this study. © Springer Science+Business Media, LLC 2012.

  14. Behaviour of concrete beams reinforced withFRP prestressed concrete prisms

    Science.gov (United States)

    Svecova, Dagmar

    The use of fibre reinforced plastics (FRP) to reinforce concrete is gaining acceptance. However, due to the relatively low modulus of FRP, in comparison to steel, such structures may, if sufficient amount of reinforcement is not used, suffer from large deformations and wide cracks. FRP is generally more suited for prestressing. Since it is not feasible to prestress all concrete structures to eliminate the large deflections of FRP reinforced concrete flexural members, researchers are focusing on other strategies. A simple method for avoiding excessive deflections is to provide sufficiently high amount of FRP reinforcement to limit its stress (strain) to acceptable levels under service loads. This approach will not be able to take advantage of the high strength of FRP and will be generally uneconomical. The current investigation focuses on the feasibility of an alternative strategy. This thesis deals with the flexural and shear behaviour of concrete beams reinforced with FRP prestressed concrete prisms. FRP prestressed concrete prisms (PCP) are new reinforcing bars, made by pretensioning FRP and embedding it in high strength grout/concrete. The purpose of the research is to investigate the feasibility of using such pretensioned rebars, and their effect on the flexural and shear behaviour of reinforced concrete beams over the entire loading range. Due to the prestress in the prisms, deflection of concrete beams reinforced with this product is substantially reduced, and is comparable to similarly steel reinforced beams. The thesis comprises both theoretical and experimental investigations. In the experimental part, nine beams reinforced with FRP prestressed concrete prisms, and two companion beams, one steel and one FRP reinforced were tested. All the beams were designed to carry the same ultimate moment. Excellent flexural and shear behaviour of beams reinforced with higher prestressed prisms is reported. When comparing deflections of three beams designed to have the

  15. Constitutive Modeling and Numerical Simulation of Frp Confined Concrete Specimens

    Science.gov (United States)

    Smitha, Gopinath; Ramachandramurthy, Avadhanam; Nagesh, Ranganatha Iyer; Shahulhameed, Eduvammal Kunhimoideen

    2014-09-01

    Fiber-reinforced polymer (FRP) composites are generally used for the seismic retrofit of concrete members to enhance their strength and ductility. In the present work, the confining effect of Carbon Fiber-Reinforced Polymer (CFRP) composite layers has been investigated by numerical simulation. The numerical simulation has been carried out using nonlinear finite element analysis (FEA) to predict the response behaviour of CFRP-wrapped concrete cylinders. The nonlinear behaviour of concrete in compression and the linear elastic behaviour of CFRP has been modeled using an appropriate constitutive relationship. A cohesive model has been developed for modeling the interface between the concrete and CFRP. The interaction and damage failure criteria between the concrete to the cohesive element and the cohesive element to the CFRP has also been accounted for in the modeling. The response behaviour of the wrapped concrete specimen has been compared with the proposed interface model and with a perfectly bonded condition. The results obtained from the present study showed good agreement with the experimental load-displacement response and the failure pattern in the literature. Further, a sensitivity analysis has been carried out to study the effect of the number of layers of CFRP on the concrete specimens. It has been observed that wrapping with two layers was found to be the optimum, beyond which the response becomes flexible but with a higher load-carrying capacity

  16. Bond strength investigations and structural applicability of composite fiber-reinforced polymer (FRP) rebars

    Science.gov (United States)

    Kachlakev, Damian Ivanov

    The composite FRP rebars research at Oregon State University was initiated in 1993 principally to develop a non-metallic hollow reinforcement. It was recognized that the tensile properties of such reinforcement are unquestionably superior to steel, but its performance in concrete could be problematic. The bond between FRP rebars and concrete was identified as a critical area of concern. The purpose of this study is (i) to analyze a variety of FRP and steel reinforcing units; (ii) to advance the knowledge of bond mechanism, failure modes, and parameters influencing the bond strength; (iii) to compare composite rebars to conventional steel and to assess their applicability as reinforcing members. Commercially available FRP rebars were investigated. Particular emphasis was given to a hollow glass FRP rod designed at Oregon State University. Several parameters were investigated, including: failure mode, concrete compressive strength, rebar diameter and circumference/cross section ratio, embedment length, concrete cover, and microstructure of the composite rebars. It was recognized that the ASTM C234-90 pull-out standard is test of concrete strength. Therefore, a modified pull-out test was developed for evaluating the bond strength behavior. A newly developed European bond test procedure was compared with locally modified version of the pull-out method. The new procedure was used for the first time in the United States. The study demonstrated a phenomenon, not reported in the published research at this time, defined as a size effect. The size effects result in lower bond strength with increasing area of the interface between FRP bars and concrete. The next phase of the research was dedicated to the hollow glass FRP rebar. The goal was to compare its bond properties to conventional steel and solid FRP bars. The study led to two new phenomena not described in the literature previously. Results showed that the concrete compressive strength does not significantly affect the

  17. Moment-Curvature Behaviors of Concrete Beams Singly Reinforced by Steel-FRP Composite Bars

    Directory of Open Access Journals (Sweden)

    Zeyang Sun

    2017-01-01

    Full Text Available A steel-fiber-reinforced polymer (FRP composite bar (SFCB is a kind of rebar with inner steel bar wrapped by FRP, which can achieve a better anticorrosion performance than that of ordinary steel bar. The high ultimate strength of FRP can also provide a significant increase in load bearing capacity. Based on the adequate simulation of the load-displacement behaviors of concrete beams reinforced by SFCBs, a parametric analysis of the moment-curvature behaviors of concrete beams that are singly reinforced by SFCB was conducted. The critical reinforcement ratio for differentiating the beam’s failure mode was presented, and the concept of the maximum possible peak curvature (MPPC was proposed. After the ultimate curvature reached MPPC, it decreased with an increase in the postyield stiffness ratio (rsf, and the theoretical calculation method about the curvatures before and after the MPPC was derived. The influence of the reinforcement ratio, effective depth, and FRP ultimate strain on the ultimate point was studied by the dimensionless moment and curvature. By calculating the envelope area under the moment-curvature curve, the energy ductility index can obtain a balance between the bearing capacity and the deformation ability. This paper can provide a reference for the design of concrete beams that are reinforced by SFCB or hybrid steel bar/FRP bar.

  18. Behavior of FRP Bars-Reinforced Concrete Slabs under Temperature and Sustained Load Effects

    Directory of Open Access Journals (Sweden)

    Hizia Bellakehal

    2014-03-01

    Full Text Available The large temperature variation has a harmful effect on concrete structures reinforced with fiber reinforced polymer (FRP bars. This is due to the significant difference between transverse coefficient of thermal expansion of these bars and that of the hardened concrete. This difference generates a radial pressure at the FRP bar/concrete interface, and may cause splitting cracks within concrete. This paper presents results of an experimental and analytical study carried out on FRP-reinforced concrete slabs subjected, simultaneously, to thermal and mechanical loads. The analytical model based on the theory of linear elasticity consists to evaluate combined effects of thermal and mechanical loads on the transverse expansion of FRP bars. Parameters studied in this investigation are the concrete cover thickness, FRP bar diameter, and the temperature variation. The thermal cycles were varied from −30 to +60 °C. Comparisons between analytical and experimental results show that transverse strains predicted from the proposed model are in good correlation with experimental results.

  19. An investigation into the impact of cryogenic environment on mechanical stresses in FRP composites

    Science.gov (United States)

    Fifo, O.; Basu, B.

    2015-07-01

    Fibre reinforced polymer (FRP) composites are fast becoming a highly utilised engineering material for high performance applications due to their light weight and high strength. Carbon fibre and other high strength fibres are commonly used in design of aerospace structures, wind turbine blades, etc. and potentially for propellant tanks of launch vehicles. For the aforementioned fields of application, stability of the material is essential over a wide range of temperature particularly for structures in hostile environments. Many studies have been conducted, experimentally, over the last decade to investigate the mechanical behaviour of FRP materials at varying subzero temperature. Likewise, tests on aging and cycling effect (room to low temperature) on the mechanical response of FRP have been reported. However, a relatively lesser focused area has been the mechanical behaviour of FRP composites under cryogenic environment. This article reports a finite element method of investigating the changes in the mechanical characteristics of an FRP material when temperature based analysis falls below zero. The simulated tests are carried out using a finite element package with close material properties used in the cited literatures. Tensile test was conducted and the results indicate that the mechanical responses agree with those reported in the literature sited.

  20. Effect of the braiding angle on the energy absorption properties of a hybrid braided FRP tube

    Energy Technology Data Exchange (ETDEWEB)

    Okano, M.; Sugimoto, K. [Kyoto Institute of Technology, Kyoto (Japan). Div. of Advanced Fibro Science; Saito, H. [Kanazawa Institute of Technology, Kanazawa (Japan); Nakai, A.; Hamada, H. [Kyoto Institute of Technology, Kyoto (Japan)

    2005-07-01

    Energy absorption is achieved by the combination of various fracture mechanisms such as fibre fracture, delamination, and central crack. However, serious problems would arise if this energy absorption ability were compromised by brittle crack propagation of the cross-sectional central part. In a previous study, the use of flexible resin with lower stiffness and higher toughness than the resin generally used was suggested as a method to restrain brittle crack propagation. In this study, hybrid braided fibre reinforced plastic (FRP) tubes were fabricated according to the previous study involving FRP rods. In this case, the flexible resin was applied to middle-end-fibre. The energy absorption characteristics and crushing mechanisms based on precise cross-sectional observation of the crush zone of the braided FRP tubes with or without the presence of flexible resin in middle-end-fibre were investigated. It was found that braided FRP tubes with or without the presence of flexible resin in middle-end-fibre were investigated. It was found that braided FRP tube with a 30{sup o} braiding angle, together with the presence of flexible resins, shows significant improvement in terms of energy absorption ability. The added flexibility of the tubes owing to the addition of flexible resin in turn causes short cracks, more fibre breakage, and consequently enhanced energy absorption properties. (author)

  1. Distributed Long-Gauge Optical Fiber Sensors Based Self-Sensing FRP Bar for Concrete Structure.

    Science.gov (United States)

    Tang, Yongsheng; Wu, Zhishen

    2016-02-25

    Brillouin scattering-based distributed optical fiber (OF) sensing technique presents advantages for concrete structure monitoring. However, the existence of spatial resolution greatly decreases strain measurement accuracy especially around cracks. Meanwhile, the brittle feature of OF also hinders its further application. In this paper, the distributed OF sensor was firstly proposed as long-gauge sensor to improve strain measurement accuracy. Then, a new type of self-sensing fiber reinforced polymer (FRP) bar was developed by embedding the packaged long-gauge OF sensors into FRP bar, followed by experimental studies on strain sensing, temperature sensing and basic mechanical properties. The results confirmed the superior strain sensing properties, namely satisfied accuracy, repeatability and linearity, as well as excellent mechanical performance. At the same time, the temperature sensing property was not influenced by the long-gauge package, making temperature compensation easy. Furthermore, the bonding performance between self-sensing FRP bar and concrete was investigated to study its influence on the sensing. Lastly, the sensing performance was further verified with static experiments of concrete beam reinforced with the proposed self-sensing FRP bar. Therefore, the self-sensing FRP bar has potential applications for long-term structural health monitoring (SHM) as embedded sensors as well as reinforcing materials for concrete structures.

  2. Seismic retroftting of RC columns with RC jackets and wing walls with different structural details

    Science.gov (United States)

    Chang, Shuenn-Yih; Chen, Ting-Wei; Tran, Ngoc-Cuong; Liao, Wen-I.

    2014-06-01

    An original reinforced concrete (RC) column and four strengthened specimens, two with RC jackets and two with wing walls, were tested in this study. The original column specimen was designed to comply with older (pre-1999) design standards so that the usual detailing deficiencies in existing school buildings in Taiwan could be simulated. Two different structural details were chosen to fabricate the full-scale specimens for each retrofitting technique. The study confirmed that either RC jacketing or the installation of wing walls with two different structural details can effectively improve the stiffness and strength of an existing column. RC jacketing shows a better improvement in energy dissipation and ductility when compared to the columns with wing walls installed. This is because the two RC jacketed columns experienced a flexural failure, while a shear failure was found in the two columns with the wing walls installed, and thus led to a drastic decrease of the maximum lateral strengths and ductility. Since many factors may affect the installation of a post-installed anchor, it is better to use standard hooks to replace post-installed anchors in some specific points when using RC jacketing or installing wing walls.

  3. Pretreatment of Woven Jute FRP Composite and Its Use in Strengthening of Reinforced Concrete Beams in Flexure

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available Environmental awareness motivates researchers worldwide to perform studies of natural fibre reinforced polymer composites, as they come with many advantages and are primarily sustainable. The present study aims at evaluating the mechanical characteristics of natural woven jute fibre reinforced polymer (FRP composite subjected to three different pretreatments, alkali, benzyl chloride, and lastly heat treatment. It was concluded that heat treatment is one of the most suitable treatment methods for enhancing mechanical properties of jute FRP. Durability studies on Jute FRP pertaining to some common environmental conditions were also carried out such as effect of normal water and thermal aging on the tensile strength of jute FRP followed by fire flow test. The heat treated woven jute FRP composites were subsequently used for flexural strengthening of reinforced concrete beams in full and strip wrapping configurations. The study includes the effect of flexural strengthening provided by woven jute FRP, study of different failure modes, load deflection behavior, effect on the first crack load, and ultimate flexural strength of concrete beams strengthened using woven jute FRP subjected to bending loads. The study concludes that woven jute FRP is a suitable material which can be used for flexural upgradation of reinforced concrete beams.

  4. The cyanobacterial Fluorescence Recovery Protein has two distinct activities: Orange Carotenoid Protein amino acids involved in FRP interaction.

    Science.gov (United States)

    Thurotte, Adrien; Bourcier de Carbon, Céline; Wilson, Adjélé; Talbot, Léa; Cot, Sandrine; López-Igual, Rocio; Kirilovsky, Diana

    2017-04-01

    To deal with fluctuating light condition, cyanobacteria have developed a photoprotective mechanism which, under high light conditions, decreases the energy arriving at the photochemical centers. It relies on a photoswitch, the Orange Carotenoid Protein (OCP). Once photoactivated, OCP binds to the light harvesting antenna, the phycobilisome (PBS), and triggers the thermal dissipation of the excess energy absorbed. Deactivation of the photoprotective mechanism requires the intervention of a third partner, the Fluorescence Recovery Protein (FRP). FRP by interacting with the photoactivated OCP accelerates its conversion to the non-active form and its detachment from the phycobilisome. We have studied the interaction of FRP with free and phycobilisome-bound OCP. Several OCP variants were constructed and characterized. In this article we show that OCP amino acid F299 is essential and D220 important for OCP deactivation mediated by FRP. Mutations of these amino acids did not affect FRP activity as helper to detach OCP from phycobilisomes. In addition, while mutated R60L FRP is inactive on OCP deactivation, its activity on the detachment of the OCP from the phycobilisomes is not affected. Thus, our results demonstrate that FRP has two distinct activities: it accelerates OCP detachment from phycobilisomes and then it helps deactivation of the OCP. They also suggest that different OCP and FRP amino acids could be involved in these two activities.

  5. A generalized method of active RC network synthesis.

    Science.gov (United States)

    Leach, D. P.; Chan, S.-P.

    1971-01-01

    A completely general active RC network synthesis technique using a grounded gyrator and a summing amplifier is described. The technique overcomes serious limitations of previous RC-gyrator realizations and offers advantages o ver other general active RC synthesis methods. The technique is well suited for construction using thin-film RC networks and integrated circuit operational amplifiers, and provides a configuration which is quite insensitive to element variations.

  6. Novel hybrid FRP tubular columns for sustainable mining infrastructure:Recent research at University of Wollongong

    Institute of Scientific and Technical Information of China (English)

    Yu Tao; Remennikov Alex M.

    2014-01-01

    This paper introduces, for applications in the mining industry, an innovative hybrid column form which consists of an inner steel tube, an outer fibre-reinforced polymer (FRP) tube and an annular concrete infill between them. The two tubes may be concentrically placed to produce a section form more suitable for columns, or eccentrically placed to produce a section form more suitable for beams. The FRP is combined with steel and concrete in these hybrid structural members in such a way that the advantages of FRP are appropriately exploited while its disadvantages are minimized. As a result, these hybrid members pos-sess excellent corrosion resistance as well as excellent ductility and seismic resistance. This paper sum-marizes existing research on this new form of structural members, and discusses their potential applications in mining infrastructure before presenting a summary of the recent and current studies at University of Wollongong (UOW) on their structural behaviour and design.

  7. An Experimental Simulation to Validate FEM to Predict Transverse Young’s Modulus of FRP Composites

    Directory of Open Access Journals (Sweden)

    V. S. Sai

    2013-01-01

    Full Text Available Finite element method finds application in the analysis of FRP composites due to its versatility in getting the solution for complex cases which are not possible by exact classical analytical approaches. The finite element result is questionable unless it is obtained from converged mesh and properly validated. In the present work specimens are prepared with metallic materials so that the arrangement of fibers is close to hexagonal packing in a matrix as similar arrangement in case of FRP is complex due to the size of fibers. Transverse Young’s moduli of these specimens are determined experimentally. Equivalent FE models are designed and corresponding transverse Young’s moduli are compared with the experimental results. It is observed that the FE values are in good agreement with the experimental results, thus validating FEM for predicting transverse modulus of FRP composites.

  8. Constitutive Behavior and Finite Element Analysis of FRP Composite and Concrete Members

    Directory of Open Access Journals (Sweden)

    Ki Yong Ann

    2013-09-01

    Full Text Available The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement effect of concrete from a three-dimensional failure surface in triaxial stress states. The constitutive behavior of the FRP composite was formulated from the two-dimensional classical lamination theory. To predict the flexural behavior of circular cross-section with FRP sheet and concrete composite, a layered discretization of cross-sections was incorporated into nonlinear isoparametric beam finite elements. The predicted constitutive behavior was validated by a comparison to available experimental results in the compressive and flexural beam loading test.

  9. Synthetic aperture radar image processing techniques for damage detection of FRP-concrete systems

    Science.gov (United States)

    Yu, Tzuyang

    2017-04-01

    Electromagnetic imaging enables researchers and engineers to assess the surface and subsurface condition of concrete structures using radar and microwave sensors. Among existing radar imaging methods, synthetic aperture radar (SAR) imaging offers flexible resolution for various purposes in condition assessment. In this paper, two novel SAR image processing techniques are reported for the subsurface condition assessment of FRP(fiber reinforced polymer)-strengthened concrete systems; mathematical morphology (MM) and the K-R-I transform. Glass FRP (GFRP) and carbon CFRP (CFRP) strengthened concrete cylinders are used as examples. From our experimental results, it is found that both techniques are capable of quantifying SAR images for condition assessment. It is also found that Euler's number and the coefficient of correlation of K-R-I curves of SAR images can be used for monitoring subsurface changes in FRP-concrete systems.

  10. Fatigue behavior of RC T-beams

    Directory of Open Access Journals (Sweden)

    Omar A. Farghal

    2014-09-01

    Full Text Available The objective of this research is to study the fatigue performance of reinforced concrete (RC T-beams strengthened in shear with Carbon Fiber Reinforced Polymer (CFRP composite. Experiments were conducted on RC beams with and without CFRP sheets bonded on their web surfaces and subjected to static and cycling loading. The obtained results showed that the strengthened beams could survive one million cycles of cyclic loading (=50% of maximum static load with no apparent signs of damage (premature failure demonstrating the effectiveness of CFRP strengthening system on extending the fatigue life of structures. Also, for beams having the same geometry, the applied strengthening technique can significantly enhance the cycling load particularly, in case of beams provided with U-jacket sheets. Moreover, although the failure mode for the different beams was a brittle one, the strengthened beams provided with U-jacket sheets approved an acceptable enhancement in the structural ductility.

  11. Measuring the RC time constant with Arduino

    Science.gov (United States)

    Pereira, N. S. A.

    2016-11-01

    In this work we use the Arduino UNO R3 open source hardware platform to assemble an experimental apparatus for the measurement of the time constant of an RC circuit. With adequate programming, the Arduino is used as a signal generator, a data acquisition system and a basic signal visualisation tool. Theoretical calculations are compared with direct observations from an analogue oscilloscope. Data processing and curve fitting is performed on a spreadsheet. The results obtained for the six RC test circuits are within the expected interval of values defined by the tolerance of the components. The hardware and software prove to be adequate to the proposed measurements and therefore adaptable to a laboratorial teaching and learning context.

  12. Fractional RC and LC Electrical Circuits

    Directory of Open Access Journals (Sweden)

    Gómez-Aguilar José Francisco

    2014-04-01

    Full Text Available In this paper we propose a fractional differential equation for the electrical RC and LC circuit in terms of the fractional time derivatives of the Caputo type. The order of the derivative being considered is 0 < ɣ ≤1. To keep the dimensionality of the physical parameters R, L, C the new parameter σ is introduced. This parameter characterizes the existence of fractional structures in the system. A relation between the fractional order time derivative ɣ and the new parameter σ is found. The numeric Laplace transform method was used for the simulation of the equations results. The results show that the fractional differential equations generalize the behavior of the charge, voltage and current depending of the values of ɣ. The classical cases are recovered by taking the limit when ɣ = 1. An analysis in the frequency domain of an RC circuit shows the application and use of fractional order differential equations.

  13. Concrete laterally confined with fibre-reinforced polymers (FRP: experimental study and theoretical model

    Directory of Open Access Journals (Sweden)

    Casas, J. R.

    2010-02-01

    Full Text Available This paper presents the findings of an experimental and analytical study of concrete cylinder behaviour when wrapped in fibreglass or carbon fibre-reinforced polymers (FRP. Compression testing was conducted on normal (30 MPa and high (70 MPa strength confined and unconfined concrete cylinders measuring 150 x 300 mm. The stress-strain relationship was evaluated in both cases. The findings showed that strength and ductility rose with FRP confinement. The experimental findings were used to develop an analytical model for predicting the stress-strain behaviour of FRP-confined concrete. A comparison of the experimental and analytical results revealed that the model can satisfactorily predict the stress-strain behaviour and ultimate compressive strength of the concretes studied.

    Este trabajo presenta los resultados de un estudio experimental y analítico del comportamiento de elementos de hormigón confinados con polímeros reforzados con fibras (FRP de vidrio y carbono. El programa experimental consistió en ensayar cilindros de hormigón de 150 x 300 mm (confinados y sin confinar bajo compresión axial en dos niveles de resistencia: normal (30 MPa y alta resistencia (70 MPa. En ambos casos, se evaluó el comportamiento tensión-deformación. Los resultados muestran que la resistencia y ductilidad se incrementan con el confinamiento con FRP. A partir de los resultados experimentales, se desarrolló un modelo analítico para predecir el comportamiento tensión-deformación del hormigón confinado con FRP. La comparación de los resultados experimentales y analíticos muestra que el modelo es aplicable a los hormigones estudiados, proporcionando predicciones satisfactorias del comportamiento tensión-deformación y de la resistencia a compresión última.

  14. 47 CFR 95.201 - (R/C Rule 1) What is the Radio Control (R/C) Radio Service?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 1) What is the Radio Control (R/C) Radio Service? 95.201 Section 95.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service...

  15. 喷射FRP加固震损钢筋混凝土柱抗震性能试验%Test of seismic performance of earthquake damaged reinforced concrete columns strengthened with sprayed FRP

    Institute of Scientific and Technical Information of China (English)

    谷倩; 董格; GETAHUNE Bitewlgn Mekonnen; 王翔

    2016-01-01

    Based on the tensile strength tests of 12 groups of 72 pieces of sprayed fiber reinforced polymer (FRP) specimens,the effects of factors such as fiber type,resin matrix material,fibers volume fraction,hybrid ratio of fi-bers and fiber length etc.on the properties such as tensile strength,elastic modulus and elongation at break etc.of sprayed FRP were investigated.The seismic performance of earthquake damaged reinforced concrete (RC)columns specimens strengthened with sprayed basalt fiber reinforced polymer (BFRP)and hybrid basalt-carbon fiber rein-forced polymer (BF-CFRP)was investigated by the quasi-static test of 8 RC columns,and the influences of the thickness of sprayed FRP layer,hybrid ratio of fibers,pre-damage degree of columns and the axial compression ratio of column etc.on the ultimate load capacity,lateral deformation resistance,degradation characteristics of stiffness and hysteresis properties of the strengthened specimens were analyzed.The test results show that the cooperative working performance of glass fiber and vinylester matrix is the best,and basalt fiber can be used as a favorable suc-cedaneum of glass fiber because of its excellent performance of high durability,good ductility and good cooperative working performance with vinylester matrix;hybrid basalt fibers with small amount of carbon fibers used as rein-forcement for resin matrix can effectively increase the tensile strength and deformation performance of sprayed FRP;earthquake damaged RC column can almost be rehabilitated to its designed ultimate load capacity before the earth-quake damage by strengthening with sprayed FRP,and both the ductility and the ability of energy dissipation can be effectively enhanced.This strengthening technique can fast strengthen the earthquake damaged RC column in seis-mic area and effectively hinder the collapse of whole structures exposed to the aftershock and other heavy damages.%通过12组72件喷射纤维/树脂复合材料(FRP)试样的拉伸强度

  16. ELASTO-PLASTIC BEHAVIOR OF RC FRAMES COMPOSED OF STEEL JACKETTED RC SHORT COLUMNS AND SPANDREL WALLS

    OpenAIRE

    Nasruddin

    2012-01-01

    This experimental study is a part of the investigation on the seismic design method for Double Tubes Hybrid System (DTHS) for buildings. This structural system consists of RC core walls as the interior tube, and the exterior frames composed of RC short columns and RC spandrel walls as the exterior tube. The RC core walls are designed as the Energy Dissipation Structural Walls (EDSW), which are composed of RC coupled shear walls linked by short steel H-shaped beams as the energy dissipation de...

  17. Nucleotide variation of sFRP5 gene is not associated with obesity in children and adolescents.

    Science.gov (United States)

    Van Camp, Jasmijn K; Beckers, Sigri; Zegers, Doreen; Verhulst, Stijn L; Van Hoorenbeeck, Kim; Massa, Guy; Verrijken, An; Desager, Kristine N; Van Gaal, Luc F; Van Hul, Wim

    2016-10-01

    Because sFRP5 was shown to be an important extracellular modulator of the Wnt pathway, regulating adipogenesis, we wanted to investigate the role of sFRP5 variants in human, monogenic obesity by performing mutation analysis. We screened the complete sFRP5 coding region in 622 obese children and adolescents and 503 lean control individuals by high-resolution melting curve analysis and direct sequencing. We found a total of 15 sequence variants in sFRP5, 10 of which resulted in a non-synonymous amino acid change. Five of these variants were, to our knowledge, not previously reported. For one of the variants (c.-3G>A), we identified a trend towards association between the variant frequency and the obese phenotype. We argue that, when looking at conservation and location inside known protein domains, several of the identified variants (D103N, A113V, K212N and H317L), may affect sFRP5 protein function. In addition, we found c.-3G>A, residing in the Kozak sequence, with a lower frequency in cases compared to controls. However, functional studies investigating the effect of sFRP5 variants on protein function are necessary to determine the true role of sFRP5 genetic variation in human, monogenic obesity.

  18. Mechanical properties and aesthetics of FRP orthodontic wire fabricated by hot drawing.

    Science.gov (United States)

    Imai, T; Watari, F; Yamagata, S; Kobayashi, M; Nagayama, K; Toyoizumi, Y; Nakamura, S

    1998-12-01

    The FRP wires 0.5 mm in diameter with a multiple fiber structure were fabricated by drawing the fiber polymer complex at 250 degrees C for an esthetic, transparent orthodontic wire. Biocompatible CaO-P2O5-SiO2-Al2O3 (CPSA) glass fibers of 8-20 microm in diameter were oriented unidirectionally in the longitudinal direction in PMMA matrix. The mechanical properties were investigated by 3-point flexural test. The FRP wire showed sufficient strength and a very good elastic recovery after deformation. Young's modulus and the flexural load at deflection 1 mm were nearly independent of the fiber diameter and linearly increased with the fiber fraction. The dependence on fiber fraction obeys well the rule of mixture. This FRP wire could cover the range of strength corresponding to the conventional metal orthodontic wires from Ni-Ti used in the initial stage of orthodontic treatments to Co-Cr used in the final stage by changing the volume ratio of glass fibers with the same external diameter. The estheticity in external appearance was excellent. Thus the new FRP wire can satisfy both mechanical properties necessary for an orthodontic wire and enough estheticity, which was not possible for the conventional metal wire.

  19. Mineral-Based Bonding of Carbon FRP to Strengthen Concrete Structures

    DEFF Research Database (Denmark)

    Täljsten, Björn; Blanksvärd, T.

    2007-01-01

    The advantages of fiber-reinforced polymer (FRP) -strengthening have been shown time and again during the last decade. Several thousand structures retrofitted with FRPs exist worldwide. There are various reasons why the retrofit is needed, but it is not uncommon for the demands on the structure t...

  20. Experimental and Numerical Investigation of the FRP Shear Mechanism for Concrete Sandwich Panels

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Sopal, G.; Rizkalla, S.

    2015-01-01

    This paper investigates the composite action of 46 segments representing precast concrete sandwich panels (PCSPs) using a fiber-reinforced polymer [FRP; specifically, a carbon fiber-reinforced polymer (CFRP)] grid/rigid foam as a shear mechanism. The experimental aspect of the research reported i...

  1. Mechanical Behaviour and Durability of FRP-to-steel Adhesively-bonded Joints

    NARCIS (Netherlands)

    Jiang, X.

    2013-01-01

    During the last two decades, fiber-reinforced polymer (FRP) bridge decks have been increasingly used as a competitive alternative for wood, concrete and orthotropic steel decks, due to their various advantages: light-weight, good corrosion resistance, low maintenance cost and rapid installation for

  2. In-situ monitoring of curing and ageing effects in FRP plates using embedded FBG sensors

    Science.gov (United States)

    Xian, Guijun; Wang, Chuan; Li, Hui

    2010-04-01

    In recent years, fiber reinforced polymer (FRP) composites have been widely applied in civil engineering for retrofitting or renewal of existing structures. Since FRP composite may degrade when exposed to severe outdoor environments, a serious concern has been raised on its long term durability. In the present study, fiber Bragg grating (FBG) sensors were embedded in glass-, carbon- and basalt-fiber reinforced epoxy based FRP plates with wet lay-up technology, to in-situ monitor the stain changes in FRPs during the curing, and water immersion and freeze-thaw ageing processes. The study demonstrates that the curing of epoxy resin brings in a slight tension strain (e.g., 10 ~ 30 μɛ) along the fiber direction and a high contraction (e.g., ~ 1100μɛ) in the direction perpendicular to the fibers, mainly due to the resin shrinkage. The cured FRP strips were then subjected to distilled water immersion at 80oC and freeze-thaw cycles from -30°C to 30°C. Remarkable strain changes of FRPs due to the variation of the temperatures during freeze-thaw cycles indicate the potential property degradation from fatigue. The maximum strain change is dependent on the fiber types and directions to the fiber. Based on the monitored strain values with temperature change and water uptake content, CTE (coefficient of thermal expansion) and CME (coefficient of moisture expansion) are exactly determined for the FRPs.

  3. Reliability model for ductile hybrid FRP rebar using randomly dispersed chopped fibers

    Science.gov (United States)

    Behnam, Bashar Ramzi

    Fiber reinforced polymer composites or simply FRP composites have become more attractive to civil engineers in the last two decades due to their unique mechanical properties. However, there are many obstacles such as low elasticity modulus, non-ductile behavior, high cost of the fibers, high manufacturing costs, and absence of rigorous characterization of the uncertainties of the mechanical properties that restrict the use of these composites. However, when FRP composites are used to develop reinforcing rebars in concrete structural members to replace the conventional steel, a huge benefit can be achieved since FRP materials don't corrode. Two FRP rebar models are proposed that make use of multiple types of fibers to achieve ductility, and chopped fibers are used to reduce the manufacturing costs. In order to reach the most optimum fractional volume of each type of fiber, to minimize the cost of the proposed rebars, and to achieve a safe design by considering uncertainties in the materials and geometry of sections, appropriate material resistance factors have been developed, and a Reliability Based Design Optimization (RBDO), has been conducted for the proposed schemes.

  4. Mechanical Behaviour and Durability of FRP-to-steel Adhesively-bonded Joints

    NARCIS (Netherlands)

    Jiang, X.

    2013-01-01

    During the last two decades, fiber-reinforced polymer (FRP) bridge decks have been increasingly used as a competitive alternative for wood, concrete and orthotropic steel decks, due to their various advantages: light-weight, good corrosion resistance, low maintenance cost and rapid installation for

  5. Comparison between TRM and FRP strengthening systems at preventing buckling failure of brick masonry walls

    Directory of Open Access Journals (Sweden)

    Bernat-Maso, E.

    2016-09-01

    Full Text Available Fibre Reinforced Polymer (FRP and Textile Reinforced Mortar (TRM have been studied, compared and applied to strengthen brick masonry walls. The comparison of their performance against second order bending effects is addressed in this paper for the first time. Experimental and analytical data from previous researches and new analytical data for TRM cases are summarised, ordered and systematically compared to analyse the structural response of strengthened brick masonry walls. The results show a similar performance for both systems in terms of load bearing capacity and in-plane response. However, TRM strengthened cases showed greater lateral deformation than FRP ones.Materiales tipo Fibre Reinforced Polymer (FRP y Textile Reinforced Mortar (TRM han sido estudiados, comparados y aplicados para reforzar muros de fábrica de ladrillo. La comparación de su comportamiento frente a efectos de flexión de segundo orden se abordada en este artículo por primera vez. Datos experimentales y analíticos de investigaciones previas y nuevos datos analíticos para los casos de TRM son resumidos, ordenados y sistemáticamente comparados para analizar la respuesta estructural de los muros de fábrica de ladrillo reforzados. Los resultados muestran un comportamiento similar de los dos sistemas respecto su capacidad de carga y su respuesta en el plano. Los casos reforzados con TRM mostraron desplazamientos laterales superiores a los reforzados con FRP.

  6. Statistical Elmore delay of RC interconnect tree

    Institute of Scientific and Technical Information of China (English)

    Dong Gang; Yang Yang; Chai Chang-Chun; Yang Yin-Tang

    2010-01-01

    As feature size keeps scaling down, process variations can dramatically reduce the accuracy in the estimation of interconnect performance. This paper proposes a statistical Elmore delay model for RC interconnect tree in the presence of process variations. The suggested method translates the process variations into parasitic parameter extraction and statistical Elmore delay evaluation. Analytical expressions of mean and standard deviation of interconnect delay can be obtained in a given fluctuation range of interconnect geometric parameters. Experimental results demonstrate that the approach matches well with Monte Carlo simulations. The errors of proposed mean and standard deviation are less than 1% and 7%, respectively. Simulations prove that our model is efficient and accurate.

  7. An Arduino Investigation of the RC Circuit

    Science.gov (United States)

    Galeriu, Calin; Letson, Cheryl; Esper, Geoffrey

    2015-05-01

    The experimental investigation of the charging or discharging of a capacitor through a resistor is of fundamental importance to the study of electricity. Students taking the Physics SAT or the AP Physics C: Electricity and Magnetism test have to prove their knowledge of time-varying behavior in RC circuits. While the classical experiment is done using a voltmeter and a stopwatch, this procedure is tedious and prone to human errors. We have developed an alternative procedure in which the voltage, the current, and the time are all measured electronically with the help of an Arduino Uno microcontroller board.

  8. Detection of Fatigue Crack in Basalt FRP Laminate Composite Pipe using Electrical Potential Change Method

    Science.gov (United States)

    Altabey, Wael A.; Noori, Mohammed

    2017-05-01

    Novel modulation electrical potential change (EPC) method for fatigue crack detection in a basalt fibre reinforced polymer (FRP) laminate composite pipe is carried out in this paper. The technique is applied to a laminate pipe with an embedded crack in three layers [0º/90º/0º]s. EPC is applied for evaluating the dielectric properties of basalt FRP pipe by using an electrical capacitance sensor (ECS) to discern damages in the pipe. Twelve electrodes are mounted on the outer surface of the pipe and the changes in the modulation dielectric properties of the piping system are analyzed to detect damages in the pipe. An embedded crack is created by a fatigue internal pressure test. The capacitance values, capacitance change and node potential distribution of ECS electrodes are calculated before and after crack initiates using a finite element method (FEM) by ANSYS and MATLAB, which are combined to simulate sensor characteristics and fatigue behaviour. The crack lengths of the basalt FRP are investigated for various number of cycles to failure for determining crack growth rate. Response surfaces are adopted as a tool for solving inverse problems to estimate crack lengths from the measured electric potential differences of all segments between electrodes to validate the FEM results. The results show that, the good convergence between the FEM and estimated results. Also the results of this study show that the electrical potential difference of the basalt FRP laminate increases during cyclic loading, caused by matrix cracking. The results indicate that the proposed method successfully provides fatigue crack detection for basalt FRP laminate composite pipes.

  9. LSA SAF Meteosat FRP Products: Part 2 – Evaluation and demonstration of use in the Copernicus Atmosphere Monitoring Service (CAMS

    Directory of Open Access Journals (Sweden)

    G. Roberts

    2015-06-01

    Full Text Available Characterising the dynamics of landscape scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI on-board the Meteosat Second Generation (MSG series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and northern and southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP dataset, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS, and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9–13 and 65–77% respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously

  10. LSA SAF Meteosat FRP Products: Part 2 - Evaluation and demonstration of use in the Copernicus Atmosphere Monitoring Service (CAMS)

    Science.gov (United States)

    Roberts, G.; Wooster, M. J.; Xu, W.; Freeborn, P. H.; Morcrette, J.-J.; Jones, L.; Benedetti, A.; Kaiser, J.

    2015-06-01

    Characterising the dynamics of landscape scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO) sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP) products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF) from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on-board the Meteosat Second Generation (MSG) series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and northern and southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP dataset, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS), and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9-13 and 65-77% respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously collected MODIS

  11. LSA SAF Meteosat FRP products - Part 2: Evaluation and demonstration for use in the Copernicus Atmosphere Monitoring Service (CAMS)

    Science.gov (United States)

    Roberts, G.; Wooster, M. J.; Xu, W.; Freeborn, P. H.; Morcrette, J.-J.; Jones, L.; Benedetti, A.; Jiangping, H.; Fisher, D.; Kaiser, J. W.

    2015-11-01

    Characterising the dynamics of landscape-scale wildfires at very high temporal resolutions is best achieved using observations from Earth Observation (EO) sensors mounted onboard geostationary satellites. As a result, a number of operational active fire products have been developed from the data of such sensors. An example of which are the Fire Radiative Power (FRP) products, the FRP-PIXEL and FRP-GRID products, generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF) from imagery collected by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) series of geostationary EO satellites. The processing chain developed to deliver these FRP products detects SEVIRI pixels containing actively burning fires and characterises their FRP output across four geographic regions covering Europe, part of South America and Northern and Southern Africa. The FRP-PIXEL product contains the highest spatial and temporal resolution FRP data set, whilst the FRP-GRID product contains a spatio-temporal summary that includes bias adjustments for cloud cover and the non-detection of low FRP fire pixels. Here we evaluate these two products against active fire data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) and compare the results to those for three alternative active fire products derived from SEVIRI imagery. The FRP-PIXEL product is shown to detect a substantially greater number of active fire pixels than do alternative SEVIRI-based products, and comparison to MODIS on a per-fire basis indicates a strong agreement and low bias in terms of FRP values. However, low FRP fire pixels remain undetected by SEVIRI, with errors of active fire pixel detection commission and omission compared to MODIS ranging between 9-13 % and 65-77 % respectively in Africa. Higher errors of omission result in greater underestimation of regional FRP totals relative to those derived from simultaneously collected MODIS

  12. BALANCED TRUNCATED MODELS OF RC INTERCONNECT CIRCUITS AND THEIR SIMULATION

    Institute of Scientific and Technical Information of China (English)

    Yuan Baoguo; Wang Ben; Wang Shengguo

    2005-01-01

    The Balanced Truncation Method (BTM) is applied to an even distributed RC interconnect case by using Wang's closed-forms of even distributed RC interconnect models. The results show that extremely high order RC interconnect can be high-accurately approximated by only third order balanced model. Related simulations are executed in both time domain and frequency domain. The results may be applied to VLSI interconnect model reduction and design.

  13. 装配式FRP筋混凝土节点研究%Prefabricated FRP Tendons Concrete Node Research

    Institute of Scientific and Technical Information of China (English)

    刘志威

    2016-01-01

    为了解决钢筋锈蚀的问题,研究人员提出采用 FRP 筋来替代钢筋使用到腐蚀环境中。由于 FRP 筋成型之后无法进行焊接和机械加工,文中提出在使用 FRP 筋混凝土时采用装配式的结构形式进行施工,之后对装配式FRP筋混凝土节点进行设计,再通过有限元模拟分析节点的力学性能。%In the island of engineering structure,reinforcement corrosion is a major problem affecting the safety of structure.In order to solve this problem,researchers put forward using FRP reinforcement to replace the steel used in corrosion environment.The FRP material is a thermosetting material,the anisotropy is serious,so it can not be welded and mechanical processing,so the assembly structure will be more convenient.This paper mainly puts forward the structure form of FRP reinforced concrete node,through the finite element simulation analysis of mechanical properties of the node.

  14. EXTERNAL PRESTRESSING OF RC T-BEAMS WITH CFRP TENDONS

    DEFF Research Database (Denmark)

    Bennitz, Anders; Schmidt, Jacob Wittrup; Täljsten, Björn

    2009-01-01

    As the acceptance for non-stressed FRP (Fibre Reinforced Polymers) increase steadily in the construction industry, the industries susceptibility for new ideas in the material’s usage increase. Improving the performance of a bridge, a parking garage or a multistory building by the use of appropriate...... FRPs is about to become common practice. Several guidelines on the subject have been presented during the last decade, e.g. [1-5]. Next step is to further utilize the excellent behaviour of the advanced material, in particular CFRP (Carbon Fiber Reinforced Polymers). CFRPs have mechanical properties...... an introduction to problems involved with the use of prestressing with FRP and highlight differences in the behaviour of the structure compared to one prestressed with steel strands....

  15. FRP-钢管-混凝土构件抗震性能试验研究%Experimental study on seismic property of concrete filled FRP- steel tube

    Institute of Scientific and Technical Information of China (English)

    朱春阳; 赵颖华; 李晓飞

    2013-01-01

    The same size specimens strengthened by FRP (CFRP/GFRP) sheets with different wrapping modes were studied experimentally by quasi-static test system for the purpose of investigating the mechanical property of concrete filled GFRP - steel tube structure under combined seismic loading and comparing it with concrete filled CFRP steel tube. Combined loads including axial pressure and bending were applied to simulate the complex seismic loadings. The test results indicate that the strengthening of FRP (CFRP/GFRP) is potential and effective for significant improvements in dynamic bending resistance of the structures. Concrete filled GFRP - steel tube equips higher ductility, comparing with concrete filled steel tube, energy dissipation coefficient of the components with circumferential, longitudinal and bi - directional GFRP improve 2.0%, 7.0% and 12. 7% respectively, while components with circumferential, longitudinal and bi-directional CFRP get improvement of 2. 0% , 5. 8% and 6. 7% respectively.%为了研究低周循环往复荷载作用下GFRP(glass fiber reinforced polymer)-钢管-混凝构件的力学性能以及对比CFRP(carbon fiber reinforced polymer)-钢管-混凝土构件的性能差异,对尺寸相同而加固方式不同的圆形截面FRP(GFRP、CFRP)-钢管-混凝土试件进行了拟静力试验,荷载采用轴压、双向弯曲的组合来模拟地震动力.结果表明:FRP(GFRP、CFRP)的加固可以有效地提高构件抗动态弯曲的能力;GFRP-钢管-混凝土构件延性高于相同情况下CFRP -钢管-混凝土构件;与普通钢管-混凝土相比,环向、纵向和双向包裹的GFRP-钢管-混凝土构件的耗能系数分别提高2.0%、7.0%和12.7%,而CFRP-钢管-混凝土分别提高2.0%、5.8%和6.7%.

  16. Barras de FRP: avaliando o módulo de elasticidade não destrutivamente FRP bars: assesing elastic modulus nondestructively

    Directory of Open Access Journals (Sweden)

    Protasio F Castro

    1997-06-01

    Full Text Available Um estudo experimental foi realizado com o objetivo de contribuir com o desenvolvimento de métodos de ensaios de avaliação das características mecânicas das barras de plástico reforçado com fibra (FRP a serem utilizadas como armadura nas obras de engenharia civil. Comparou-se o módulo de elasticidade estático, obtido por ensaio de tração em uma máquina universal, com o módulo de elasticidade dinâmico, obtido por ensaios não destrutivos. O módulo de elasticidade dinâmico foi determinado utilizando-se dois métodos de propagação de ondas: o pulso ultra-sônico e a freqüência de ressonância. Os valores do módulo de elasticidade dinâmico e os valores do módulo de elasticidade estático obtidos a partir da curva tensão-deformação dos ensaios de tração são significativamente semelhantes. Os resultados mostram que os ensaios de módulo de elasticidade dinâmico possuem potencial para serem utilizados na linha de fabricação das barras de FRP como controle da produção.An experimental study was carried out to support the development of standards test methods for fiber reinforced plastic (FRP bars used as concrete reinforcement. In addition, this study compares the elastic modulus values from tensile stress-strain curves with the dynamic values obtained nondestructively. Dynamic modulus of elasticity was determined using two stress wave propagation methods: ultrasonic pulse velocity and resonant frequency. The dynamic values compared favorably with values obtained from tensile stress-strain curves. The results showed the feasibility of using nondestructive methods, as control test, to estimate FRP bars elastic modulus in a manufacture process.

  17. Novel Predictive Model of the Debonding Strength for Masonry Members Retrofitted with FRP

    Directory of Open Access Journals (Sweden)

    Iman Mansouri

    2016-11-01

    Full Text Available Strengthening of masonry members using externally bonded (EB fiber-reinforced polymer (FRP composites has become a famous structural strengthening method over the past decade due to the popular advantages of FRP composites, including their high strength-to-weight ratio and excellent corrosion resistance. In this study, gene expression programming (GEP, as a novel tool, has been used to predict the debonding strength of retrofitted masonry members. The predictions of the new debonding resistance model, as well as several other models, are evaluated by comparing their estimates with experimental results of a large test database. The results indicate that the new model has the best efficiency among the models examined and represents an improvement to other models. The root mean square errors (RMSE of the best empirical Kashyap model in training and test data were, respectively, reduced by 51.7% and 41.3% using the GEP model in estimating debonding strength.

  18. Effect of adhesive thickness and concrete strength on FRP-Concrete Bonds

    OpenAIRE

    López González, Julio César; Fernandez Gomez, Jaime Antonio; González Valle, Enrique

    2012-01-01

    The use of fiber-reinforced polymer (FRP) composites for strengthening, repairing, or rehabilitating concrete structures has become more and more popular in the last 10 years. Irrespective of the type of strengthening used, design is conditioned, among others, by concrete-composite bond failure, normally attributed to stress at the interface between these two materials. Single shear, double shear, and notched beam tests are the bond tests most commonly used by the scientific community to esti...

  19. Utilisation of fibre reinforced polymer (FRP) composites in the confinement of concrete

    OpenAIRE

    Ciupala, Mihaela Anca; Pilakoutas, K.; Mortazavi, A.A.

    2007-01-01

    This paper presents an experimental investigation carried out on concrete cylinders\\ud confined with fibre reinforced polymers (FRP), subjected to monotonic and cyclic loading.\\ud Carbon fibres (CFRP) were used as confining material for the concrete specimens. The failure\\ud mode, reinforcement ratio based on jacket thickness and type of loading are examined. The study\\ud shows that external confinement of concrete can enhance its strength and ductility as well as result\\ud in large energy ab...

  20. Strength Modeling of Reinforced Concrete Beam with Externally Bonded FRP Reinforcement

    Directory of Open Access Journals (Sweden)

    N. Pannirselvam

    2008-01-01

    Full Text Available This research study presents the evaluation of the structural behaviour of reinforced concrete beams with externally bonded Fibre Reinforced Polymer (FRP reinforcements. Three different steel ratios with two different Glass Fibre Reinforced Polymer (GFRP types and two different thicknesses in each type of GFRP were used. Totally fifteen rectangular beams of 3 m length were cast. Three rectangular beams were used as reference beam (Control Beams and the remaining were fixed with GFRP laminates on the soffit of the rectangular beam. The variables considered for the study includes longitudinal steel ratio, type of GFRP laminates, thickness of GFRP laminates and composite ratios. Flexural test, using simple beam with third-point loading was adopted to study the performance of FRP plated beams interms flexural strength, deflection, ductility and was compared with the unplated beams. The test results show that the beams strengthened with GFRP laminates exhibit better performance. The flexural strength and ductility increase with increase in thickness of GFRP plate. The increase in first crack loads was up to 88.89% for 3 mm thick WRGFRP plates and 100.00% for 5 mm WRGFRP plated beams and increase in ductility interms of energy and deflection was found to be 56.01 and 64.69% respectively with 5 mm thick GFRP plated beam. Strength models were developed for predicting the flexural strength (ultimate load, service load and ductility of FRP beams. The strength model developed give prediction matching the measurements.

  1. Combined Transverse Steel-External FRP Confinement Model for Rectangular Reinforced Concrete Columns

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Rahmani

    2016-02-01

    Full Text Available Recently, the need to increase the strength of reinforced concrete members has become a subject that civil engineers are interested in tackling. Of the many proposed solutions, fiber-reinforced polymer (FRP materials have attracted attention due to their superior properties, such as high strength-to-weight ratio, high energy absorption and excellent corrosion resistance. FRP wrapping of concrete columns is done to enhance the ultimate strength due to the confinement effect, which is normally induced by steel ties. The existence of the two confinement systems changes the nature of the problem, thus necessitating specialized nonlinear analysis to obtain the column’s ultimate capacity. Existing research focused on a single confinement system. Furthermore, very limited research on rectangular sections was found in the literature. In this work, a model to estimate the combined behavior of the two systems in rectangular columns is proposed. The calculation of the effective lateral pressure is based on the Lam and Teng model and the Mander model for FRP wraps and steel ties, respectively. The model then generates stress-strain diagrams for both the concrete core and the cover. The model was developed for the analysis in extreme load events, where all possible contributions to the column’s ultimate capacity should be accounted for without any margin of safety. The model was validated against experiments, and the results obtained showed good agreement with almost all of the available experimental data.

  2. THEORETICAL MODEL ON INTERFACE FAILURE MECHANISM OF REINFORCED CONCRETE CONTINUOUS BEAM STRENGTHENED BY FRP

    Institute of Scientific and Technical Information of China (English)

    Hong Yuan; Zifeng Lin

    2009-01-01

    Fiber reinforced polymer (FRP) composites are increasingly being used for the re-pair and strengthening of deteriorated concrete structural components through adhesive bonding of prefabricated strips/plates and the wet lay-up of fabric. Interracial bond failure modes have at-tracted the attention of researchers because of the importance. The objective of the present study is to analyse the interface failure mechanism of reinforced concrete continuous beam strength-ened by FRP. An analytical solution has been firstly presented to predict the entire debonding process of the model. The realistic bi-linear bond-slip interfacial law was adopted to study this problem. The crack propagation process of the loaded model was divided into four stages (elastic, elastic-softening, elastic-softening-debonded and softening-debonded stage). Among them, elastic-softening-debonded stage has four sub-stages. The equations are solved by adding suitable stress and displacement boundary conditions. Finally, critical value of bond length is determined to make the failure mechanism in the paper effective by solving the simultaneously linear algebraic equations. The interaction between the upper and lower FRP plates can be neglected if axial stiffness ratio of the concrete-to-plate prism is large enough.

  3. Experimental Study on Bond Behavior of FRP-Concrete Interface in Hygrothermal Environment

    Directory of Open Access Journals (Sweden)

    X. H. Zheng

    2016-01-01

    Full Text Available As the technique of fiber-reinforced polymer (FRP composite material strengthened reinforced concrete structures is widely used in the field of civil engineering, durability of the strengthened structures has attracted more attention in recent years. Hygrothermal environment has an adverse effect on the bond behavior of the interface between FRP and concrete. This paper focuses on the bond durability of carbon fiber laminate- (CFL- concrete interface in hygrothermal condition which simulates the climate characteristic in South China. Twenty 100 mm × 100 mm × 720 mm specimens were divided into 6 groups based on different temperature and humidity. After pretreatment in hygrothermal environment, the specimens were tested using double shear method. Strain gauges bonded along the CFL surface and linear variation displacement transducers (LVDTs were used to measure longitudinal strains and slip of the interface. Failure mode, ultimate capacity, load-deflection relationship, and relative slip were analyzed. The bond behavior of FRP-concrete interface under hygrothermal environment was studied. Results show that the ultimate bearing capacity of the interface reduced after exposure to hygrothermal environments. The decreasing ranges were up to 27.9% after exposure at high temperature and humidity (60°C, 95% RH. The maximum strains (εmax of the specimens pretreated decreased obviously which indicated decay of the bond behavior after exposure to the hygrothermal environment.

  4. Shear Behaviour of RC T-Beams with Externally Bonded Discrete CFF Strips – A Experimental and Finite Element Study

    Directory of Open Access Journals (Sweden)

    Jayaprakash Jaganathan

    2014-10-01

    Full Text Available The application of fibre reinforced polymer (FRP composites for retrofitting and strengthening of existing reinforced concrete (RC structures has fascinated the attention of researchers and engineers in the recent decades.  This paper presents the results of experimental and finite element (FE investigation of shear behaviour of reinforced concrete T-beams repaired with externally bonded bi-directional discrete carbon fibre fabric (CFF strips.  The reinforced concrete T-beams were tested under four point bending system to investigate the performance of CFF shear strengthening scheme in terms of ultimate load carrying capacity.  These beams were modelled using LUSAS software.  To evaluate the behaviour of the simulated models, the predicted results were compared with the experimental results.  The experimental results show that the gain in shear capacity of the CFF repaired beams ranged between 20% and 40% over the control beam.  Thus, it can be concluded that the externally bonded CFF strips significantly increased the shear capacity of CFF repaired beams.  It was generally observed that the developed FE model shows better agreement with the experimental results.  The results of load-deflection profile, cracking pattern, modes of failure, and strain distribution in discrete CFF strips are presented.

  5. Numerical Evaluations of Functionally Graded RC Slabs

    Directory of Open Access Journals (Sweden)

    M. Mastali

    2014-01-01

    Full Text Available Nowadays, using fibrous materials is used widely in strengthening applications such as cross-section enlargement and using functionally graded reinforced concrete. Functionally graded reinforced concrete is used as multireinforced concrete layers that can be reinforced by different fiber types. The objective of this research was to address the structural benefits of functionally graded concrete materials by performing analytical simulations. In order to achieve this purpose, in the first stage of this study, three functionally graded reinforced concretes by steel and polypropylene (PP were experimentally tested under flexural loading. Inverse analysis was applied to obtain the used material properties of reinforced concrete by FEMIX software. After obtaining the material properties, to assess the performance of proposed slabs, some other cases were proposed and numerically evaluated under flexural and shear loading. The results showed that increasing steel fiber in reinforced entire cross section led to achieve better shear and flexural performance while the best performance of reinforced functionally graded slabs was achieved for slab at 1% fiber content. In the second stage, nineteen reinforced functionally graded RC slabs with steel bars were simulated and assessed and some other cases were considered which were not experimentally tested.

  6. Diabetic osteopenia by decreased β-catenin signaling is partly induced by epigenetic derepression of sFRP-4 gene.

    Directory of Open Access Journals (Sweden)

    Kiyoshi Mori

    Full Text Available In diabetics, methylglyoxal (MG, a glucose-derived metabolite, plays a noxious role by inducing oxidative stress, which causes and exacerbates a series of complications including low-turnover osteoporosis. In the present study, while MG treatment of mouse bone marrow stroma-derived ST2 cells rapidly suppressed the expression of osteotrophic Wnt-targeted genes, including that of osteoprotegerin (OPG, a decoy receptor of the receptor activator of NF-kappaB ligand (RANKL, it significantly enhanced that of secreted Frizzled-related protein 4 (sFRP-4, a soluble inhibitor of Wnts. On the assumption that upregulated sFRP-4 is a trigger that downregulates Wnt-related genes, we sought out the molecular mechanism whereby oxidative stress enhanced the sFRP-4 gene. Sodium bisulfite sequencing revealed that the sFRP-4 gene was highly methylated around the sFRP-4 gene basic promoter region, but was not altered by MG treatment. Electrophoretic gel motility shift assay showed that two continuous CpG loci located five bases upstream of the TATA-box were, when methylated, a target of methyl CpG binding protein 2 (MeCP2 that was sequestered upon induction of 8-hydroxy-2-deoxyguanosine, a biomarker of oxidative damage to DNA. These in vitro data suggest that MG-derived oxidative stress (not CpG demethylation epigenetically and rapidly derepress sFRP-4 gene expression. We speculate that under persistent oxidative stress, as in diabetes and during aging, osteopenia and ultimately low-turnover osteoporosis become evident partly due to osteoblastic inactivation by suppressed Wnt signaling of mainly canonical pathways through the derepression of sFRP-4 gene expression.

  7. Experimental Investigation of Tension Stiffening in RC Ties

    Directory of Open Access Journals (Sweden)

    Aleksandr Sokolov

    2016-01-01

    Full Text Available The increasing application of high-performance materials in civil engineering led to the development of reinforced concrete (RC structures with reduced cross sections and increased spans. In such structures serviceability limit state often becomes the governing condition of the design. Present study investigates the deformation behaviour of high-strength RC ties reinforced with high-grade bars. Experimental investigation was carried out measuring the postcracking stiffness of the specimens at high strain levels. It was found that, despite the reduction in stiffness, a considerable part of the average tensile stresses were carried by the concrete at the advanced loading stages, thus effectively stiffening the RC member.

  8. Trapezoidal Numerical Integration of Fire Radiative Power (FRP) Provides More Reliable Estimation of Fire Radiative Energy (FRE) and so Biomass Consumption Than Conventional Estimation Methods

    Science.gov (United States)

    Sathyachandran, S. K.; Roy, D. P.; Boschetti, L.

    2014-12-01

    The Fire Radiative Power (FRP) [MW] is a measure of the rate of biomass combustion and can be retrieved from ground based and satellite observations using middle infra-red measurements. The temporal integral of FRP is the Fire Radiative Energy (FRE) [MJ] and is related linearly to the total biomass consumption and so pyrogenic emissions. Satellite derived biomass consumption and emissions estimates have been derived conventionally by computing the summed total FRP, or the average FRP (arithmetic average of FRP retrievals), over spatial geographic grids for fixed time periods. These two methods are prone to estimation bias, especially under irregular sampling conditions such as provided by polar-orbiting satellites, because the FRP can vary rapidly in space and time as a function of the fire behavior. Linear temporal integration of FRP taking into account when the FRP values were observed and using the trapezoidal rule for numerical integration has been suggested as an alternate FRE estimation method. In this study FRP data measured rapidly with a dual-band radiometer over eight prescribed fires are used to compute eight FRE values using the sum, mean and trapezoidal estimation approaches under a variety of simulated irregular sampling conditions. The estimated values are compared to biomass consumed measurements for each of the eight fires to provide insights into which method provides more accurate and precise biomass consumption estimates. The three methods are also applied to continental MODIS FRP data to study their differences using polar orbiting satellite data. The research findings indicate that trapezoidal FRP numerical integration provides the most reliable estimator.

  9. Nonlinear modeling of the cyclic response of RC columns

    OpenAIRE

    De Melo, J; Varum,H.; T. Rossetto; C. Fernandes; A. Costa

    2012-01-01

    Cyclic load reversals (like those induced by earthquakes) result in accelerated bond degradation, leading to significant bar slippage. The bond-slip mechanism is reported to be one of the most common causes of damage and even collapse of existing RC structures subjected to earthquake loading. RC structures with plain reinforcing bars, designed and built prior to the enforcement of the modern seismic-oriented design philosophies, are particularly sensitive to bond degradation. However, perfect...

  10. Modeling the Flexural Carrying Capacity of Corroded RC Beam

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-hui; LIU Xi-la

    2008-01-01

    Considering the change of bond strength between corroded steel and concrete, flexural carrying ca-pacity of corroded reinforced concrete (RC) beam was calculated. On the basis of the condition of equilibriumof forces and compatibility of deformations for the whole beam, a model for the prediction of flexural carryingcapacity of the corroded RC beam was proposed. Comparison of the model's predictions with the experimentalresults published in the literature shows the practicality of the proposed method.

  11. Seismic Response of RC Framed Buildings with Open Ground Storey

    Directory of Open Access Journals (Sweden)

    Somani Kishangopal J

    2015-02-01

    Full Text Available RC framed buildings are generally designed without considering the structural action of masonry infill walls. These masonry infill walls are widely used as partitions and considered as non-structural elements. But they affect both the structural and non-structural performance of RC buildings during earthquake. RC framed building with open ground storey is known as soft storey, which performs poorly during earthquake. In order to study this total 144 RC framed buildings having bare frame, full infill frame and open ground storey frame were analyzed by seismic coefficient method and response spectrum method for various seismic hazards. The present study deals with the comparison of base shear for medium rise RC framed buildings having P+5, P+7, P+9 and P+11 storeys for various seismic zones (III, IV & V and for various soil conditions (Hard & Medium as per IS 1893(part 1: 2002. This work helps in understanding the effect of earthquake with increase in height of RC framed buildings on base shear for various seismic zones and soil conditions. The result shows that the effect of infill stiffness on structural response is significant under lateral loads. It is found that the presence infill walls increases the base shear by 60-65% more than bare frame by both seismic coefficient method and response spectrum method.

  12. Analysis and optimization of RC delay in vertical nanoplate FET

    Science.gov (United States)

    Woo, Changbeom; Ko, Kyul; Kim, Jongsu; Kim, Minsoo; Kang, Myounggon; Shin, Hyungcheol

    2017-10-01

    In this paper, we have analyzed short channel effects (SCEs) and RC delay with Vertical nanoplate FET (VNFET) using 3-D Technology computer-aided design (TCAD) simulation. The device is based on International Technology Road-map for Semiconductor (ITRS) 2013 recommendations, and it has initially gate length (LG) of 12.2 nm, channel thickness (Tch) of 4 nm, and spacer length (LSD) of 6 nm. To obtain improved performance by reducing RC delay, each dimension is adjusted (LG = 12.2 nm, Tch = 6 nm, LSD = 11.9 nm). It has each characteristic in this dimension (Ion/Ioff = 1.64 × 105, Subthreshold swing (S.S.) = 73 mV/dec, Drain-induced barrier lowering (DIBL) = 60 mV/V, and RC delay = 0.214 ps). Furthermore, with long shallow trench isolation (STI) length and thick insulator thickness (Ti), we can reduce RC delay from 0.214 ps to 0.163 ps. It is about a 23.8% reduction. Without decreasing drain current, there is a reduction of RC delay as reducing outer fringing capacitance (Cof). Finally, when source/drain spacer length is set to be different, we have verified RC delay to be optimum.

  13. A coupled interface-body nonlocal damage model for the analysis of FRP strengthening detachment from cohesive material

    Directory of Open Access Journals (Sweden)

    J. Toti

    2011-10-01

    Full Text Available In the present work, a new model of the FRP-concrete or masonry interface, which accounts for the coupling occurring between the degradation of the cohesive material and the FRP detachment, is presented; in particular, a coupled interface-body nonlocal damage model is proposed. A nonlocal damage and plasticity model is developed for the quasi-brittle material. For the interface, a model which accounts for the mode I, mode II and mixed mode of damage and for the unilateral contact and friction effects is developed. Two different ways of performing the coupling between the body damage and the interface damage are proposed and compared. Some numerical applications are carried out in order to assess the performances of the proposed model in reproducing the mechanical behavior of the masonry elements strengthened with external FRP reinforcements.

  14. Use of a molecular decoy to segregate transport from antigenicity in the FrpB iron transporter from Neisseria meningitidis.

    Directory of Open Access Journals (Sweden)

    Muhammad Saleem

    Full Text Available FrpB is an outer membrane transporter from Neisseria meningitidis, the causative agent of meningococcal meningitis. It is a member of the TonB-dependent transporter (TBDT family and is responsible for iron uptake into the periplasm. FrpB is subject to a high degree of antigenic variation, principally through a region of hypervariable sequence exposed at the cell surface. From the crystal structures of two FrpB antigenic variants, we identify a bound ferric ion within the structure which induces structural changes on binding which are consistent with it being the transported substrate. Binding experiments, followed by elemental analysis, verified that FrpB binds Fe(3+ with high affinity. EPR spectra of the bound Fe(3+ ion confirmed that its chemical environment was consistent with that observed in the crystal structure. Fe(3+ binding was reduced or abolished on mutation of the Fe(3+-chelating residues. FrpB orthologs were identified in other Gram-negative bacteria which showed absolute conservation of the coordinating residues, suggesting the existence of a specific TBDT sub-family dedicated to the transport of Fe(3+. The region of antigenic hypervariability lies in a separate, external sub-domain, whose structure is conserved in both the F3-3 and F5-1 variants, despite their sequence divergence. We conclude that the antigenic sub-domain has arisen separately as a result of immune selection pressure to distract the immune response from the primary transport function. This would enable FrpB to function as a transporter independently of antibody binding, by using the antigenic sub-domain as a 'molecular decoy' to distract immune surveillance.

  15. Behavior of Concrete Cylinders Strengthened with a Basalt-FRP and Subjected to Mechanical Loads and Elevated Temperatures

    Science.gov (United States)

    Tulendinov, T.; Zesers, A.; Tamužs, V.

    2017-09-01

    Concrete samples were manufactured and strengthened with a basalt FRP (BFRP) using two kinds of winding patterns (spiral and tight). The efficiency of common and temperature-resistant epoxy binders were studied. Some of the samples were encased in an external concrete shell for an additional protection of the FRP reinforcement during heating. Both plain and polypropylene-microfiber-reinforced concretes were used for the external casing. Stress-strain relations of the samples before and after heating were obtained. The effects of high temperatures on the integrity of concrete samples with a BFRP reinforcement was investigated.

  16. Nonlinear micromechanics-based finite element analysis of the interfacial behaviour of FRP-strengthened reinforced concrete beams

    Science.gov (United States)

    Abd El Baky, Hussien

    This research work is devoted to theoretical and numerical studies on the flexural behaviour of FRP-strengthened concrete beams. The objectives of this research are to extend and generalize the results of simple experiments, to recommend new design guidelines based on accurate numerical tools, and to enhance our comprehension of the bond performance of such beams. These numerical tools can be exploited to bridge the existing gaps in the development of analysis and modelling approaches that can predict the behaviour of FRP-strengthened concrete beams. The research effort here begins with the formulation of a concrete model and development of FRP/concrete interface constitutive laws, followed by finite element simulations for beams strengthened in flexure. Finally, a statistical analysis is carried out taking the advantage of the aforesaid numerical tools to propose design guidelines. In this dissertation, an alternative incremental formulation of the M4 microplane model is proposed to overcome the computational complexities associated with the original formulation. Through a number of numerical applications, this incremental formulation is shown to be equivalent to the original M4 model. To assess the computational efficiency of the incremental formulation, the "arc-length" numerical technique is also considered and implemented in the original Bazant et al. [2000] M4 formulation. Finally, the M4 microplane concrete model is coded in FORTRAN and implemented as a user-defined subroutine into the commercial software package ADINA, Version 8.4. Then this subroutine is used with the finite element package to analyze various applications involving FRP strengthening. In the first application a nonlinear micromechanics-based finite element analysis is performed to investigate the interfacial behaviour of FRP/concrete joints subjected to direct shear loadings. The intention of this part is to develop a reliable bond--slip model for the FRP/concrete interface. The bond

  17. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-02-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as materialalternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforcedplastics single skin. The weakness of this FRP was heavy construction and requires many production time.Therefore, will be checked comparison between single skin with sandwich constructions for shell.In this research, the way for making composite is hand lay up method with three various thickness of skinthere are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin,must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesiarules for the fiberglass ship.Based on the result, indicates that optimization skin thickness of sandwich construction applies Corematwhich tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT.Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  18. Efficacy of Thermally Conditioned Sisal FRP Composite on the Shear Characteristics of Reinforced Concrete Beams

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available The development of commercially viable composites based on natural resources for a wide range of applications is on the rise. Efforts include new methods of production and the utilization of natural reinforcements to make biodegradable composites with lignocellulosic fibers, for various engineering applications. In this work, thermal conditioning of woven sisal fibre was carried out, followed by the development of woven sisal fibre reinforced polymer composite system, and its tensile and flexural behaviour was characterized. It was observed that thermal conditioning improved the tensile strength and the flexural strength of the woven sisal fibre composites, which were observed to bear superior values than those in the untreated ones. Then, the efficacy of woven sisal fibre reinforced polymer composite for shear strengthening of reinforced concrete beams was evaluated using two types of techniques: full and strip wrapping techniques. Detailed analysis of the load deflection behaviour and fracture study of reinforced concrete beams strengthened with woven sisal under shearing load were carried out, and it was concluded that woven sisal FRP strengthened beams, underwent very ductile nature of failure, without any delamination or debonding of sisal FRP, and also increased the shear strength and the first crack load of the reinforced concrete beams.

  19. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-04-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as material alternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforced plastics single skin. The weakness of this FRP was heavy construction and requires many production time. Therefore, will be checked comparison between single skin with sandwich constructions for shell. In this research, the way for making composite is hand lay up method with three various thickness of skin there are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin, must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesia rules for the fiberglass ship. Based on the result, indicates that optimization skin thickness of sandwich construction applies Coremat which tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes 23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT. Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  20. sFRP2 in the aged microenvironment drives melanoma metastasis and therapy resistance

    Science.gov (United States)

    Kaur, Amanpreet; Webster, Marie R.; Marchbank, Katie; Behera, Reeti; Ndoye, Abibatou; Kugel, Curtis H.; Dang, Vanessa M.; Appleton, Jessica; O’Connell, Michael P.; Cheng, Phil; Valiga, Alexander A.; Morissette, Rachel; McDonnell, Nazli B.; Ferrucci, Luigi; Kossenkov, Andrew V.; Meeth, Katrina; Tang, Hsin-Yao; Yin, Xiangfan; Wood, William H.; Lehrmann, Elin; Becker, Kevin G.; Flaherty, Keith T.; Frederick, Dennie T.; Wargo, Jennifer A.; Cooper, Zachary A.; Tetzlaff, Michael T.; Hudgens, Courtney; Aird, Katherine M.; Zhang, Rugang; Xu, Xiaowei; Liu, Qin; Bartlett, Edmund; Karakousis, Giorgos; Eroglu, Zeynep; Lo, Roger S.; Chan, Matthew; Menzies, Alexander M.; Long, Georgina V.; Johnson, Douglas B.; Sosman, Jeffrey; Schilling, Bastian; Schadendorf, Dirk; Speicher, David W.; Bosenberg, Marcus; Ribas, Antoni; Weeraratna, Ashani T.

    2016-01-01

    Cancer is a disease of aging, and aged cancer patients have a poorer prognosis. This may be due to accumulated cellular damage, decreases in adaptive immunity, and chronic inflammation. However, the effects of the aged microenvironment on tumor progression have been largely unexplored. Since dermal fibroblasts can have profound impacts on melanoma progression1–4 we examined whether age-related changes in dermal fibroblasts could drive melanoma metastasis and response to targeted therapy. We find that aged fibroblasts secrete a Wnt antagonist, sFRP2, which activates a multi-step signaling cascade in melanoma cells that results in a decrease in β-catenin and MITF, and ultimately the loss of a key redox effector, APE1. Loss of APE1 attenuates the response of melanoma cells to ROS-induced DNA damage, rendering them more resistant to targeted therapy (vemurafenib). Age-related increases in sFRP2 also augment both angiogenesis and metastasis of melanoma cells. These data provide an integrated view of how fibroblasts in the aged microenvironment contribute to tumor progression, offering new paradigms for the design of therapy for the elderly. PMID:27042933

  1. Deformation behavior of FRP-metal composites locally reinforced with carbon fibers

    Science.gov (United States)

    Scholze, M.; Kolonko, A.; Lindner, T.; Lampke, T.; Helbig, F.

    2016-03-01

    This study investigates variations of hybrid laminates, consisting of one aluminum sheet and a unidirectional glass fiber (GF) reinforced polyamide 6 (PA6) basic structure with partial carbon fiber (CF) reinforcement. To create these heterogeneous FRP laminates, it is necessary to design and produce semi-finished textile-based products. Moreover, a warp knitting machine in conjunction with a warp thread offset unit was used to generate bionic inspired compounds. By the variation of stacking prior to the consolidation process of the hybrid laminate, an oriented CF reinforcement at the top and middle layer of the FRP is realized. In both cases the GFRP layer prevents contact between the aluminum and carbon fibers. In so doing, the high strength of carbon fibers can be transferred to the hybrid laminate in load directions with an active prevention of contact corrosion. The interface strength between thermoplastic and metal component was improved by a thermal spray coating on the aluminum sheet. Because of the high surface roughness and porosity, mechanical interlock was used to provide high interface strength without bonding agents between both components. The resulting mechanical properties of the hybrid laminates are evaluated by three point bending tests in different load directions. The effect of local fiber orientation and layer positioning on failure and deformation mechanism is additionally investigated by digital image correlation (DIC).

  2. Influence of terahertz waves on the penetration in thick FRP composite materials

    Science.gov (United States)

    Im, Kwang-Hee; Hsu, David K.; Chiou, Chien-Ping; Barnard, Daniel J.; Yang, In-Young; Park, Je-Woong

    2014-02-01

    Fiber reinforced plastics (FRP) are increasingly utilized in engineering structures because of their performance and fabrication advantages. With this increased utilization, a technique to gage quality and further characterize the materials would be beneficial. The nondestructive applications for Terahertz (T-ray) methods have also experienced increased utilization for evaluating engineering materials and will be reported on here in applications for the inspection and characterization of FRP materials used in wind energy components. First, refraction and transmission T-ray modes are used to determine the refractive index (n) of a glass fiber reinforced plastic (GFRP) reference sample, and extended for calculating the refractive indices for a sample of GFRP, balsa and epoxy. Additionally, carbon fiber reinforced plastic (CFRP) samples were evaluated with respect to fiber directions versus T-ray electric field polarization direction to evaluate the level of penetration of T-ray energy due to the fiber orientation dependent conductivity of this composite material. Finally, an evaluation of T-ray data was made to evaluate resonance effects, where the resonance frequency was found to agree with that expected from reflections from individual plies in thick GFRP laminates.

  3. CNG transport by ship with FRP pressure vessels access to east coast gas

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, S. [Trans Ocean Gas Inc., St. John' s, NL (Canada)

    2005-07-01

    This paper discussed the Trans Ocean Gas (TOG) method for transporting compressed natural gas (CNG). CNG transportation offers an alternative method for transporting stranded natural gas to existing markets and for creating new natural gas markets that are not feasible for liquefied natural gas (LNG) or pipelines. Trans Ocean Gas Inc. (TOG) modified an existing fibre reinforced plastic (FRP) pressure vessel technology to safely store CNG on a ship. The newly developed containment system has proven to overcome all the deficiencies of steel-based systems. TOG patented the containment system and will license its use to owners of stranded gas and shipping service providers around the world. The CNG systems will be built and assembled throughout facilities in Atlantic Canada. FRP pressure vessels have been proven safe and reliable through critical applications in the national defense, aerospace, and natural gas vehicle industries. They are light-weight, highly reliable, have very safe failure modes, are corrosion resistant, and have excellent low temperature characteristics. Under TOG's scheme, natural gas can be stored at two thirds the density of LNG without costly processing. TOG's proposed design and testing of a CNG system was reviewed in detail. figs.

  4. 国外FRP预浸料发展概况%Foreign Developments of FRP Prepregs

    Institute of Scientific and Technical Information of China (English)

    叶鼎铨

    2013-01-01

    Prepregs are semi-finished fiber reinforced plastics ( FRP ) products that are pre-impregnated with resin and can be stored, ready to be used for molding composite end-products. Prepregs are divided into thermoset and thermoplastic preppregs. Due to their ease of use, consistent properties, low void content, clean molding operation and other advantages, prepregs are becoming increasingly common in the composite industry, exhibiting a very good prospect.%预浸料是用树脂预先浸渍,可以储存的纤维增强塑料( FRP)半成品,随时可以用来制造复合材料制品。预浸料有热固性和热塑性预浸料之分。因它们容易使用、性能稳定、空隙率低、模塑过程清洁等诸多优点,预浸料在复合材料工业中日趋普遍,前景甚好。

  5. 47 CFR 95.220 - (R/C Rules 20) What must I do if the FCC tells me that my R/C station is causing interference?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rules 20) What must I do if the FCC tells.../C) Radio Service Other Things You Need to Know § 95.220 (R/C Rules 20) What must I do if the FCC tells me that my R/C station is causing interference? (a) If the FCC tells you that your R/C station...

  6. 47 CFR 95.217 - (R/C Rule 17) May I operate my R/C station transmitter by remote control?

    Science.gov (United States)

    2010-10-01

    ... transmitter by remote control? 95.217 Section 95.217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... control? (a) You may not operate an R/C transmitter by radio remote control. (See R/C Rule 12, § 95.212.) (b) You may operate an R/C transmitter by wireline remote control if you obtain specific approval in...

  7. 47 CFR 95.223 - (R/C Rule 23) Do I have to make my R/C station available for inspection?

    Science.gov (United States)

    2010-10-01

    ... available for inspection? 95.223 Section 95.223 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service Other Things You Need to Know § 95.223 (R/C Rule 23) Do I have to make my R/C station available for...

  8. Innovation on RC Waffle and Ribbed Slab Analysis Models

    Directory of Open Access Journals (Sweden)

    P. Hájek

    2000-01-01

    Full Text Available Waffle and ribbed reinforced concrete slabs are widely used in building constructions in view of the flexibility design and structural efficiency. The wide range of reinforced concrete and composite waffle and ribbed slabs has been theoretically analysed and tested from the point of view of structural behaviour within the research performed in the last years. The results of the experimental investigation, supported by theoretical conclusions, have confirmed significantly better structural properties of the composite waffle slabs (composed from RC and ceramic fillers than the assumptions usually considered in common analysis models. New analysis equivalent models for structural analysis RC and composite waffle and ribbed structures have been developed and compared with the test results. In the paper are presented some generalized conclusions as a basis for the formulation of principles of an optimized design of RC waffle and ribbed slab structures.

  9. Seismic Behavior of Corroded RC Bridges: Review and Research Gaps

    Directory of Open Access Journals (Sweden)

    Kaveh Andisheh

    2016-01-01

    Full Text Available Chloride-induced corrosion and its effect on structural and seismic performance of reinforced concrete (RC structures have been the topic of several research projects in past decades. This literature review summarizes the state of the art by presenting a brief description of chloride-induced corrosion, its main characteristics and influencing factors, a summary of experimental published data, and existing corrosion-induced deterioration models together with numerical and experimental methods used to evaluate corroded RC bridge pier. This literature review highlights the need for reliable deterioration models for RC structures and appropriate analysis methods are needed for design of new structures or assessment of existing civil engineering structures especially in seismic areas.

  10. The FRP1 F-box gene has different functions in sexuality, pathogenicity and metabolism in three fungal pathogens

    NARCIS (Netherlands)

    Jonkers, W.; van Kan, J.A.L.; Tijm, P.; Lee, Y.-W.; Tudzynski, P.; Rep, M.; Michielse, C.B.

    2011-01-01

    Plant-pathogenic fungi employ a variety of infection strategies; as a result, fungi probably rely on different sets of proteins for successful infection. The F-box protein Frp1, only present in filamentous fungi belonging to the Sordariomycetes, Leotiomycetes and Dothideomycetes, is required for

  11. The use of fibre-reinforced polymers (FRP in bridges as a favourable solution for the environment

    Directory of Open Access Journals (Sweden)

    Żyjewski Artur

    2017-01-01

    Full Text Available The purpose of this article is to show the modern engineering, in which sustainability and taking care of ecology play a significant role. The authors are focused on FRP composite materials and their applications in civil engineering. Case studies showing renovation and design of new bridges with the use of FRP are presented and discussed to clarify benefits, which this solution provides. Main advantages of FRP materials in comparison with traditional ones, like concrete or steel are showed. The environmental impact of composites is described with respect to all life cycle of a product. Furthermore, some forms of waste management are covered. Last part of the paper refers to scientific description of the pedestrian bridge made of FRP, which was realized under the Fobridge research grant. The group of researchers headed by professor Chróścielewski from Gdansk University of Technology has developed a design solution of the pedestrian bridge manufactured in one production cycle. Moreover, the footbridge construction contains a significant share of a recyclable material commonly called PET. The article contains main characteristics of the structure and production process based on the resin infusion.

  12. DOLOČANJE REGULACIJSKIH PARAMETROV REAKCIJSKEGA SISTEMA RC1

    OpenAIRE

    Tompa, Saša

    2014-01-01

    V diplomskem delu opisujemo določanje vrednosti regulacijskih parametrov reakcijskega kalorimetra RC1e Mettler Toledo in reaktorskega sistema EasyMax 102 Mettler Toledo. Parametre smo določali z metodo po Ziegler-ju in Nichols-u. Ta metoda temelji na regulacijskem sistemu brez povratne zanke. Vrednosti za povratno zanko smo izračunali z Excelovim diagramom, s katerim smo izračunali P in I regulacijska parametra. Reaktor RC1e smo uporabili za poskuse z večjimi volumni, medtem ko EasyMax za tis...

  13. Impact three-point bending tests on FRP by split-Hopkinson bar technique. Hopkinson boho ni yoru FRP no shogeki santenmage shiken

    Energy Technology Data Exchange (ETDEWEB)

    Higashida, F.; Ogawa, K. (Kyoto University, Kyoto (Japan). Faculty of Engineering)

    1990-10-15

    Fiber reinforced plastics (FRP) are widely used as high ratio strength structural material and strong interest is taken in their impact strength. In their impact bending test, observation is made of stress waveform, with which largely interferes high frequency fluctuation. Various measurement methods being studied to eliminate that interference, the present report used a split-Hopkinson bar technique, not influenced by the reflection of stress wave in the tester, and made impact three-point bending tests, up to about 15cm/s in impact speed, on CFRP and GFRP by having loosely ramped incident stress act. The result gave a smooth relation, almost free from high frequency fluctuation, between the load and time, which relation could accurately derive bending rigidity, breaking strength, etc. Of the CFRP and GFRP, elucidation was further made of independency of bending strength upon the strain speed, relation between the maximum stress and strain speed, effect of deformation speed on the three-point bending strength, etc. 35 refs., 8 figs., 1 tab.

  14. LaRC local area networks to support distributed computing

    Science.gov (United States)

    Riddle, E. P.

    1984-01-01

    The Langley Research Center's (LaRC) Local Area Network (LAN) effort is discussed. LaRC initiated the development of a LAN to support a growing distributed computing environment at the Center. The purpose of the network is to provide an improved capability (over inteactive and RJE terminal access) for sharing multivendor computer resources. Specifically, the network will provide a data highway for the transfer of files between mainframe computers, minicomputers, work stations, and personal computers. An important influence on the overall network design was the vital need of LaRC researchers to efficiently utilize the large CDC mainframe computers in the central scientific computing facility. Although there was a steady migration from a centralized to a distributed computing environment at LaRC in recent years, the work load on the central resources increased. Major emphasis in the network design was on communication with the central resources within the distributed environment. The network to be implemented will allow researchers to utilize the central resources, distributed minicomputers, work stations, and personal computers to obtain the proper level of computing power to efficiently perform their jobs.

  15. Damage Localization and Quantification of Earthquake Excited RC-Frames

    DEFF Research Database (Denmark)

    Skjærbæk, P.S.; Nielsen, Søren R.K.; Kirkegaard, Poul Henning;

    In the paper a recently proposed method for damage localization and quantification of RC-structures from response measurements is tested on experimental data. The method investigated requires at least one response measurement along the structure and the ground surface acceleration. Further, the t...

  16. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

    Presently, there is no clear method for determining the optimal railway bridge design for a particular ground type and expected seismic intensity. Four main types of RC bridge dominate the current multi-span railway bridge design trends – the Simply Supported Beam, Continuous Box-Girder (CBG), CBG...

  17. Cathodic protection of RC structures - Far more than bridge decks

    NARCIS (Netherlands)

    Nerland, O.C.; Polder, R.B.

    2002-01-01

    When the first trials with Cathodic Protection (CP) on reinforced concrete (RC) structures were carried out nearly 30 years ago the main aim was treating steel in bridge decks, suffering from chloride induced corrosion. Various types of anode systems (conductive asphalt, conductive mortars, carbon f

  18. Monitoring the production of FRP composites: A review of in-line sensing methods

    Directory of Open Access Journals (Sweden)

    S. Konstantopoulos

    2014-11-01

    Full Text Available Composites manufacturing is characterized by many degrees of freedom. Different materials, geometries and thermo-dynamical conditions contribute to a behavior that is difficult to predict. Monitoring the running process (in-line monitoring eliminates the need for prediction; real time data provided by appropriate sensing systems can be used in the direction of process optimization, quality upgrade or material characterization. The aim of the review at hand is to record and discuss the latest progress in the field of in-line composites monitoring with a focus on Fiber Reinforced Polymericbased (FRP composite structures. Summaries of each sensor’s principles of operation, appropriate association with polymer/composite properties detection, brief descriptions of representative studies, a critical overview of implementation aspects and discussion on the upcoming trends, contribute in constructing a complete picture.

  19. Life cycle cost analysis of new FRP based solar parabolic trough collector hot water generation system

    Institute of Scientific and Technical Information of China (English)

    A. VALAN ARASU; T. SORNAKUMAR

    2008-01-01

    Parabolic trough collectors (PTCs) are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic (FRP) based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 (1986). The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91 ℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 (US$ 573) only. In the present work, life cycle savings (LCS) method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems.

  20. 75 FR 1356 - RC2 Corporation, Provisional Acceptance of a Settlement Agreement and Order

    Science.gov (United States)

    2010-01-11

    ... manufactured by OW rather than by RC2's other Chinese contract manufacturer. RC2 cross-referenced each of the...) any claims under the Equal Access to Justice Act. 25. The Commission may publicize the terms of...

  1. FRP Composites for Retrofit and Construction of Structures:Recent Research at The Hong Kong Polytechnic University

    Institute of Scientific and Technical Information of China (English)

    腾锦光

    2004-01-01

    @@ At The Hong Kong Polytechnic University, on-going research addresses many aspects of the theory of FRP-strengthened structures and the innovative use of FRP composites in new construction. A very brief summary of some of the recent research progresses made at The Hong Kong Polytechnic University (PolyU) is given here. Further details of these recent developments can be found in the references listed at the end. Some of the research summarized here has been carried out in collaboration with researchers at other institutions, including the University of Edinburgh, Tsinghua University, Zhejiang University, the University of Adelaide, Fuzhou University, Jinan University and the National Engineering Research Centre for Diagnosis and Rehabilitation of Industrial Buildings.

  2. The RC Circuit: An Approach with Fourier Transforms

    Indian Academy of Sciences (India)

    2016-11-01

    In this article we shall mathematically analyse the Resistor-Capacitor (RC) circuit with the help of Fourier transforms(FT). This very general technique gives us a lot of insight intosolving first order differential equations with source terms dependingon time. In itself, the RC circuit is by far the mostcommonplace entity in modern electronics. But the method ofFT is not the accepted custom for an electronic engineer, whois probably more comfortable working with complex impedancesand phasors while solving problems in network analysis.In fact, what is used much more extensively is the Laplacetransform. But a lot of things, (including the complex impedanceitself, and some insight into complex analysis) can be understoodbetter if we use the FT approach to solve the differentialequations that come up in network analysis. The use of FTcomes smoothly from first principles – precisely what we setout to demonstrate here.

  3. Design Aspect of including Infill Wall in RC Frame Design*

    Directory of Open Access Journals (Sweden)

    Sukrawa, M.

    2014-01-01

    Full Text Available This study compares analysis and design of a four story reinforced concrete (RC frame structure with infill wall at upper levels and open at basement level. For the analysis, the RC frame are modeled as open frame (MOF and infilled-frames using six compression only cross diagonal strut (MIF-Strut, and infilled frame using shell elements (MIF-Shell. Another model, MIF-Full, is created by adding walls at basement level of the MIF-Strut to study the effect of wall discontinuity. All three dimensional models are loaded with gravity load and quake load appropriate for South Bali region. Results show that the infilled-frame models are 4.8 times stiffer than MOF in the wall direction. Perpendicular to the wall, however, the stiffness increase is 29%. Soft storey mechanism exists in the absence of wall at basement level, regardless of reasonable column dimensions.

  4. 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...

  5. Shearography and pulsed stimulated infrared thermography applied to a nondestructive evaluation of FRP strengthening systems bonded on concrete structures

    OpenAIRE

    Taillade, Frédéric; Quiertant, Marc; Benzarti, Karim; Aubagnac, Christophe

    2011-01-01

    This paper presents two complementary techniques, shearography and pulsed stimulated infrared thermography, used to detect and characterize depth and width of the adhesion defects (delaminations or adhesive disbonds) of externally bonded fiber-reinforced polymers (FRP) on concrete surface structures. Shearography associated to a depressure load on the one hand, and step heating infrared thermography on the other hand are presented. In a first step, the feasibility study of the two methods is ...

  6. Distributed sensing of RC beams with HCFRP sensors

    Science.gov (United States)

    Yang, Caiqian; Wu, Zhishen; Ye, Lieping

    2005-05-01

    This paper addresses a novel type of hybrid carbon fiber-reinforced polymer (HCFRP) sensors suitable for the structural health monitoring (SHM) of civil engineering structures. The HCFRP sensors are composed of different types of carbon tows, which are active materials due to their electrical conductivity, piezoresistivity, excellent mechanical properties and resistance to corrosion. The HCFRP sensors are designed to comprise three types of carbon tows-high strength (HS), high modulus (HM) and middle modulus (MM), in order to realize a distributed and broad-based sensing function. Two types of HCFRP sensors, with and without pretreatment, are fabricated and investigated. The HCFRP sensors are bonded with epoxy resins on the bottom concrete surface of RC beam specimens to monitor the average strain, the initiation and propagation of cracks. The experimental results indicate that such kinds of sensors are characterized with broad-based and distributed sensing feasibilities. As a result, the structural health of the RC beams can be monitored and evaluated through characterizing the relationships between the change in electrical resistance of the HCFRP sensors, the average strain and the crack width of the RC beams. In addition, it is also revealed that the damages can also be located by properly adding the number of electrodes.

  7. Investigation on Strengthening Approaches Adopted for Poorly Detailed RC Corbels

    Directory of Open Access Journals (Sweden)

    Ram Chandra Neupane

    2017-05-01

    Full Text Available Poor detailing of the position of bearing pad over reinforced concrete (RC corbel may lead to premature failure, which is undesired and structurally vulnerable. An appropriate retrofitting solution is necessary to ensure the functionality of such RC corbels. Considering the growing popularity of external carbon fiber-reinforced polymer (CFRP in retrofitting, this research examines the effectiveness of an externally wrapped unidirectional CFRP sheet and compares its performance against traditional retrofitting methods. Moreover, it is intended to fulfill the lack of extensive research on external CFRP application for corbel strengthening. A total of eight medium-scale corbel specimens were tested on vertical load. Observed premature failure due to placing the bearing pad near the edge of corbel was verified and the effectiveness of the proposed structural strengthening solutions was studied. Experimental results show that although the loading capacity of the damaged corbel due to the poor detailing of bearing pad position could not be fully recovered, the external CFRP wrapping method demonstrated superior performance over RC jacketing and was able to prevent localized failure. Further study based on non-linear 3D finite element analysis (FEA was carried out to identify the governing parameters of each retrofitting solution. Numerical studies suggested important parameters of various retrofitting alternatives for higher capacity assurance.

  8. How Reliable is the Durability of RC Structures?

    Directory of Open Access Journals (Sweden)

    B. Teplý

    2004-01-01

    Full Text Available The goal of this paper is to show some trends and time profiles of the reliability index relevant to the Serviceability Limit State considering the design service life of RC structures. The interactive web page “RC_LifeTime” – originated by the authors – is used (see http://www.stm.fce.vutbr.cz/. The depassivation of reinforcing steel due to carbonation is considered conservatively as a limiting condition. It is based on model concrete carbonation with 12 random input variables; the Latin Hypercube Sampling simulation method is used. RC_LifeTime offers the following options: Service Life Assessment – a statistical evaluation of service life, where optionally the target value of reliability index ß may be an additional input value and then the corresponding service life is the output value; Concrete Cover Assessment – a statistical evaluation of concrete cover value for the target service life, where optionally the required concrete cover value may be input in this case and the relevant reliability index ß describes the reliability of reinforcement depassivation. 

  9. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    Science.gov (United States)

    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 the nonlinear and inelastic response of both the soil-footing interface and the structure. To this end, a novel scale model RC (1:50 scale) that simulates reasonably well the elastic response and the failure of prototype RC elements is utilized, along with realistic representation of the soil behavior in a geotechnical centrifuge. A variety of seismic ground motions are considered as excitations. They result in consistent demonstrably beneficial performance of the rocking-isolated pier in comparison with the one designed conventionally. Seismic demand is reduced in terms of both inertial load and deck drift. Furthermore, foundation uplifting has a self-centering potential, whereas soil yielding is shown to provide a particularly effective energy dissipation mechanism, exhibiting significant resistance to cumulative damage. Thanks to such mechanisms, the rocking pier survived, with no signs of structural distress, a deleterious sequence of seismic motions that caused collapse of the conventionally designed pier. © 2014 The Authors Earthquake Engineering & Structural Dynamics Published by John Wiley & Sons Ltd. PMID:26300573

  10. Binding of sFRP-3 to EGF in the extra-cellular space affects proliferation, differentiation and morphogenetic events regulated by the two molecules.

    Directory of Open Access Journals (Sweden)

    Raffaella Scardigli

    Full Text Available BACKGROUND: sFRP-3 is a soluble antagonist of Wnts, widely expressed in developing embryos. The Wnt gene family comprises cysteine-rich secreted ligands that regulate cell proliferation, differentiation, organogenesis and oncogenesis of different organisms ranging from worms to mammals. In the canonical signal transduction pathway Wnt proteins bind to the extracellular domain of Frizzled receptors and consequently recruit Dishevelled (Dsh to the cell membrane. In addition to Wnt membrane receptors belonging to the Frizzled family, several other molecules have been described which share homology in the CRD domain and lack the putative trans-membrane domain, such as sFRP molecules (soluble Frizzled Related Protein. Among them, sFRP-3 was originally isolated from bovine articular cartilage and also as a component of the Spemann organizer. sFRP-3 blocks Wnt-8 induced axis duplication in Xenopus embryos and binds to the surface of cells expressing a membrane-anchored form of Wnt-1. Injection of sFRP-3 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that sFRP-3 specifically blocks EGF-induced fibroblast proliferation and foci formation. Over-expression of sFRP-3 reverts EGF-mediated inhibition of hair follicle development in the mouse ectoderm while its ablation in Xenopus maintains EGF-mediated inhibition of ectoderm differentiation. Conversely, over-expression of EGF reverts the inhibition of somitic myogenesis and axis truncation in Xenopus and mouse embryos caused by sFRP-3. In vitro experiments demonstrated a direct binding of EGF to sFRP-3 both on heparin and on the surface of CHO cells where the molecule had been membrane anchored. CONCLUSIONS/SIGNIFICANCE: sFRP-3 and EGF reciprocally inhibit their effects on cell proliferation, differentiation and morphogenesis and indeed are expressed in contiguous domains of the embryo, suggesting that in

  11. Technique for reduction of mechanical losses in AC superconducting coils due to thermal expansion properties of various FRP bobbins

    Science.gov (United States)

    Sekine, N.; Tada, S.; Higuchi, T.; Furumura, Y.; Takao, T.; Yamanaka, A.

    2005-10-01

    We reported about reduction of mechanical losses in AC superconducting coils. The method is the use of FRP bobbins fabricated with special fibers. Since their FRPs have negative thermal expansion coefficient to the fiber direction, the FRP bobbins expand to the circumferential direction during cooling down. In case of the superconducting coils with such FRP bobbins, the winding tensions do not decrease during cooling down. Therefore, the mechanical losses are reduced by the suppression of wire's vibration. Their special FRPs are a Dyneema® fiber reinforced plastic (DFRP), a Dyneema and glass fiber reinforced plastic (DGFRP), and a Zylon® fiber reinforced plastic (ZFRP). These materials have negative thermal expansion coefficient to the fiber direction, however, the amplitudes of thermal expansion are various by the quantity or quality of the fiber. In this paper, the values of thermal expansion were actually measured, and it was discussed about the influence on the mechanical losses. At the experimental results, the mechanical loss was small, so that the thermal strain to the circumferential direction on the coil was large. Moreover, in case of the coils with sufficiently strong winding tensions at coil-operating temperature, the mechanical losses vanished.

  12. Technique for reduction of mechanical losses in AC superconducting coils due to thermal expansion properties of various FRP bobbins

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, N. [Tsukamoto Laboratory, Faculty of Engineering, Yokohama National University, 79-5, Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)]. E-mail: n-sekine@tsukalab.dnj.ynu.ac.jp; Tada, S. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Higuchi, T. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Furumura, Y. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Takao, T. [Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Yamanaka, A. [Research Center, Toyobo, Co., Ltd, 2-1-1, Katata, Otsu, Shiga 520-0292 (Japan)

    2005-10-01

    We reported about reduction of mechanical losses in AC superconducting coils. The method is the use of FRP bobbins fabricated with special fibers. Since their FRPs have negative thermal expansion coefficient to the fiber direction, the FRP bobbins expand to the circumferential direction during cooling down. In case of the superconducting coils with such FRP bobbins, the winding tensions do not decrease during cooling down. Therefore, the mechanical losses are reduced by the suppression of wire's vibration. Their special FRPs are a Dyneema[reg] fiber reinforced plastic (DFRP), a Dyneema and glass fiber reinforced plastic (DGFRP), and a Zylon[reg] fiber reinforced plastic (ZFRP). These materials have negative thermal expansion coefficient to the fiber direction, however, the amplitudes of thermal expansion are various by the quantity or quality of the fiber. In this paper, the values of thermal expansion were actually measured, and it was discussed about the influence on the mechanical losses. At the experimental results, the mechanical loss was small, so that the thermal strain to the circumferential direction on the coil was large. Moreover, in case of the coils with sufficiently strong winding tensions at coil-operating temperature, the mechanical losses vanished.

  13. Concrete Infill Monitoring in Concrete-Filled FRP Tubes Using a PZT-Based Ultrasonic Time-of-Flight Method.

    Science.gov (United States)

    Luo, Mingzhang; Li, Weijie; Hei, Chuang; Song, Gangbing

    2016-12-07

    Concrete-filled fiber-reinforced polymer tubes (CFFTs) have attracted interest for their structural applications in corrosive environments. However, a weak interfacial strength between the fiber-reinforced polymer (FRP) tube and the concrete infill may develop due to concrete shrinkage and inadequate concrete compaction during concrete casting, which will destroy the confinement effect and thereby reduce the load bearing capacity of a CFFT. In this paper, the lead zirconate titanate (PZT)-based ultrasonic time-of-flight (TOF) method was adopted to assess the concrete infill condition of CFFTs. The basic idea of this method is that the velocity of the ultrasonic wave propagation in the FRP material is about half of that in concrete material. Any voids or debonding created along the interface between the FRP tube and the concrete will delay the arrival time between the pairs of PZT transducers. A comparison of the arrival times of the PZT pairs between the intact and the defected CFFT was made to assess the severity of the voids or the debonding. The feasibility of the methodology was analyzed using a finite-difference time-domain-based numerical simulation. Experiments were setup to validate the numerical results, which showed good agreement with the numerical findings. The results showed that the ultrasonic time-of-flight method is able to detect the concrete infill condition of CFFTs.

  14. Wnt, Frizzled, and sFRP gene expression patterns during gastrulation in the starfish Patiria (Asterina) pectinifera.

    Science.gov (United States)

    Kawai, Narudo; Kuraishi, Ritsu; Kaneko, Hiroyuki

    2016-05-01

    By the initial phase of gastrulation, Wnt pathway regulation mediates endomesoderm specification and establishes the animal-vegetal axis, thereby leading to proper gastrulation in starfish. To provide insight into the ancestral mechanism regulating deuterostome gastrulation, we identified the gene expression patterns of Wnt, Frizzled (Fz), and secreted frizzled-related protein (sFRP) family genes, which play a role in the initial stage of the Wnt pathway, in starfish Patiria (Asterina) pectinifera embryos using whole mount in situ hybridization. We identified ten Wnt, four Fz, and two sFRP paralogues. From the hatching blastula to the late gastrula stage, the majority of the Wnt genes and both Fz5/8 and sFRP1/5 were expressed in the posterior and anterior half of the embryo, respectively. Wnt8, Fz1, and Fz4 showed restricted expression in the lateral ectoderm. On the other hand, several genes were expressed de novo in the restricted domain of the archenteron at the late gastrula stage. These results suggest that the canonical and/or non-canonical Wnt pathway might implicate endomesoderm specification, anterior-posterior axis establishment, anterior-posterior patterning, and archenteron morphogenesis in the developmental context of starfish embryos. From comparison with the expression patterns observed in Patria miniata, we consider that the Wnt pathway is conserved among starfishes.

  15. Effects of Elevated Temperatures on the Compressive Strength Capacity of Concrete Cylinders Confined with FRP Sheets: An Experimental Investigation

    Directory of Open Access Journals (Sweden)

    Sherif El-Gamal

    2015-01-01

    Full Text Available Due to their high strength, corrosion resistance, and durability, fiber reinforced polymers (FRP are very attractive for civil engineering applications. One of these applications is the strengthening of concrete columns with FRP sheets. The performance of this strengthening technique at elevated temperature is still questionable and needs more investigations. This research investigates the effects of exposure to high temperatures on the compressive strength of concrete cylinders wrapped with glass and carbon FRP sheets. Test specimens consisted of 30 unwrapped and 60 wrapped concrete cylinders. All specimens were exposed to temperatures of 100, 200, and 300°C for periods of 1, 2, and 3 hours. The compressive strengths of the unwrapped concrete cylinders were compared with their counterparts of the wrapped cylinders. For the unwrapped cylinders, test results showed that the elevated temperatures considered in this study had almost no effect on their compressive strength; however, the wrapped specimens were significantly affected, especially those wrapped with GFRP sheets. The compressive strength of the wrapped specimens decreased as the exposure period and the temperature level increased. After three hours of exposure to 300°C, a maximum compressive strength loss of about 25.3% and 37.9%, respectively, was recorded in the wrapped CFRP and GFRP specimens.

  16. Estimating Landscape Fire Particulate Matter (PM) Emissions over Southern Africa using MSG-SEVIRI Fire Radiative Power (FRP) and MODIS Aerosol Optical Thickness Observations

    Science.gov (United States)

    Mota, Bernardo; Wooster, Martin J.

    2016-04-01

    The approach to estimating landscape fire fuel consumption based on the remotely sensed fire radiative power (FRP) thermal energy release rate, as opposed to burned area, is now relatively widely used in studies of fire emissions, including operationally within the Copernicus Atmosphere Monitoring Service (CAMS). Nevertheless, there are still limitations to the approach, including uncertainties associated with using only the few daily overpasses typically provided by polar orbiting satellite systems, the conversion between FRP and smoke emissions, and the increased likelihood that the more frequent data from geostationary systems fails to detect the (probably highly numerous) smaller (i.e. low FRP) component of a regions fire regime. In this study, we address these limitations to directly estimate fire emissions of Particular Matter (PM; or smoke aerosols) by presenting an approach combining the "bottom-up" FRP observations available every 15 minutes across Africa from the Meteosat Spinning Enhanced Visible and Infrared Imager (SEVIRI) Fire Radiative Product (FRP) processed at the EUMETSAT LSA SAF, and the "top-down" aerosol optical thickness (AOT) measures of the fire plumes themselves as measured by the Moderate-resolution Imaging Spectro-radiometer (MODIS) sensors aboard the Terra (MOD04_L2) and Aqua (MYD04_L2) satellites. We determine PM emission coefficients that relate directly to FRP measures by combining these two datasets, and the use of the almost continuous geostationary FRP observations allows us to do this without recourse to (uncertain) data on wind speed at the (unknown) height of the matching plume. We also develop compensation factors to address the detection limitations of small/low intensity (low FRP) fires, and remove the need to estimate fuel consumption by going directly from FRP to PM emissions. We derive the smoke PM emissions coefficients per land cover class by comparing the total fire radiative energy (FRE) released from individual fires

  17. Mode-Ⅰ fracture and durability of FRP-concrete bonded interfaces

    Institute of Scientific and Technical Information of China (English)

    Qiao Pizhong; Xu Yingwu

    2008-01-01

    In this study, a work-of-fracture method using a three-point bend beam (3PBB) specimen, which is commonly used to determine the fracture energy of concrete, was adapted to evaluate the mode-Ⅰ fracture and durability of fiber-reinforced polymer (FRP) composite-concrete bonded interfaces. Interface fracture properties were evaluated with established data reduction procedures. The proposed test method is primarily for use in evaluating the effects of freeze-thaw (F-T) and wet-dry (W-D) cycles that are the accelerated aging protocols on the mode-Ⅰ fracture of carbon FRP-concrete bonded interfaces. The results of the mode-Ⅰ fracture tests of F-T and W-D cycle-conditioned specimens show that both the critical load and fracture energy decrease as the number of cycles increases, and their degradation pattern has a nearly linear relationship with the number of cycles. However, compared with the effect of the F-T cycles, the critical load and fracture energy degrade at a slower rate with W-D cycles, which suggests that F-T cyclic conditioning causes more deterioration of carbon fiber-reinforced polymer (CFRP)-concrete bonded interface. After 50 and 100 conditioning cycles, scaling of concrete was observed in all the specimens subjected to F-T cycles, but not in those subjected to W-D cycles. The examination of interface fracture surfaces along the bonded interfaces with varying numbers of F-T and W-D conditioning cycles shows that (1) cohesive failure of CFRP composites is not observed in all fractured surfaces; (2) for the control specimens that have not been exposed to any conditioning cycles, the majority of interface failure is a result of cohesive fracture of concrete (peeling of concrete from the concrete substrate), which means that the cracks mostly propagate within the concrete; and (3) as the number of F-T or W-D conditioning cycles increases, adhesive failure along the interface begins to emerge and gradually increases. It is thus concluded that the fracture

  18. Mode-I fracture and durability of FRP-concrete bonded interfaces

    Directory of Open Access Journals (Sweden)

    Qiao Pizhong

    2008-12-01

    Full Text Available In this study, a work-of-fracture method using a three-point bend beam (3PBB specimen, which is commonly used to determine the fracture energy of concrete, was adapted to evaluate the mode-I fracture and durability of fiber-reinforced polymer (FRP composite-concrete bonded interfaces. Interface fracture properties were evaluated with established data reduction procedures. The proposed test method is primarily for use in evaluating the effects of freeze-thaw (F-T and wet-dry (W-D cycles that are the accelerated aging protocols on the mode-I fracture of carbon FRP-concrete bonded interfaces. The results of the mode-I fracture tests of F-T and W-D cycle-conditioned specimens show that both the critical load and fracture energy decrease as the number of cycles increases, and their degradation pattern has a nearly linear relationship with the number of cycles. However, compared with the effect of the F-T cycles, the critical load and fracture energy degrade at a slower rate with W-D cycles, which suggests that F-T cyclic conditioning causes more deterioration of carbon fiber-reinforced polymer (CFRP-concrete bonded interface. After 50 and 100 conditioning cycles, scaling of concrete was observed in all the specimens subjected to F-T cycles, but not in those subjected to W-D cycles. The examination of interface fracture surfaces along the bonded interfaces with varying numbers of F-T and W-D conditioning cycles shows that (1 cohesive failure of CFRP composites is not observed in all fractured surfaces; (2 for the control specimens that have not been exposed to any conditioning cycles, the majority of interface failure is a result of cohesive fracture of concrete (peeling of concrete from the concrete substrate, which means that the cracks mostly propagate within the concrete; and (3 as the number of F-T or W-D conditioning cycles increases, adhesive failure along the interface begins to emerge and gradually increases. It is thus concluded that the

  19. Microtomographic Analysis of Impact Damage in FRP Composite Laminates: A Comparative Study

    Directory of Open Access Journals (Sweden)

    M. Alemi-Ardakani

    2013-01-01

    Full Text Available With the advancement of testing tools, the ability to characterize mechanical properties of fiber reinforced polymer (FRP composites under extreme loading scenarios has allowed designers to use these materials in high-level applications more confidently. Conventionally, impact characterization of composite materials is studied via nondestructive techniques such as ultrasonic C-scanning, infrared thermography, X-ray, and acoustography. None of these techniques, however, enable 3D microscale visualization of the damage at different layers of composite laminates. In this paper, a 3D microtomographic technique has been employed to visualize and compare impact damage modes in a set of thermoplastic laminates. The test samples were made of commingled polypropylene (PP and glass fibers with two different architectures, including the plain woven and unidirectional. Impact testing using a drop-weight tower, followed by postimpact four-point flexural testing and nondestructive tomographic analysis demonstrated a close relationship between the type of fibre architecture and the induced impact damage mechanisms and their extensions.

  20. Mechanical Properties of Steel-FRP Composite Bars under Tensile and Compressive Loading

    Directory of Open Access Journals (Sweden)

    Zeyang Sun

    2017-01-01

    Full Text Available The factory-produced steel-fiber reinforced polymer composite bar (SFCB is a new kind of reinforcement for concrete structures. The manufacturing technology of SFCB is presented based on a large number of handmade specimens. The calculated stress-strain curves of ordinary steel bar and SFCB under repeated tensile loading agree well with the corresponding experimental results. The energy-dissipation capacity and residual strain of both steel bar and SFCB were analyzed. Based on the good simulation results of ordinary steel bar and FRP bar under compressive loading, the compressive behavior of SFCB under monotonic loading was studied using the principle of equivalent flexural rigidity. There are three failure modes of SFCB under compressive loading: elastic buckling, postyield buckling, and no buckling (ultimate compressive strength is reached. The increase in the postyield stiffness of SFCB rsf can delay the postyield buckling of SFCB with a large length-to-diameter ratio, and an empirical equation for the relationship between the postbuckling stress and rsf is suggested, which can be used for the design of concrete structures reinforced by SFCB to consider the effect of reinforcement buckling.

  1. Research and Development on Control System of Novel Winding Machine for High-pressure FRP Pipeline

    Institute of Scientific and Technical Information of China (English)

    YOU Bo; XU Jiazhong; HU Haiyan; CHENG Ningbo; ZHANG Qingli

    2006-01-01

    The novel winding machine adopted steam inside solidification technics, can wind, solidify and extract high-pressure fiber reinforced plastic (FRP) pipelines in one single machine. Its control system consisted of the winding and extraction subsystem and the steam inside solidification subsystem. In order to improve the control precision and stability, a real-time control method was adopted in the winding and extraction subsystem. In this method, high-precision TRIO motion controller combined with industrial personal computer (IPC) forms an open-type CNC system which supports multitask. The Modbus protocol was adopted for the communication between the IPC and TRIO motion controller. The human-machine interface (HMI) was developed with VC++ 6.0 and the control software of the motion controller was developed with TRIO BASIC language. In the steam inside solidification subsystem, embedded IPC and PLC were used to realize the closed-loop control of the steam temperature and the HMI was developed with MCGS 5.1 under WinCE. Practices show that this system has the good performances of high precision, good stability and high efficiency.

  2. The Influence of Fiber Type and Conformation on the Damping Property of FRP Composite

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; CHEN Wei; WANG Jun; LIU Hanxing

    2012-01-01

    In order to get a fiber reinforced plastic(FRP) composite with good damping property as well as good mechanical properties,different types of reinforcing materials were used to reinforcing a damping resin.The influence of fiber types and conformation on the damping property of the composite are tested.Compared to the glass fiber(GF),carbon fiber(CF) can improve the damping factor of the composites; the highest tanδ value is 0.827 while the Tg is 22.5 ℃.The style of the fibers also influences the damping factors of the composite.The composite reinforced with mat has higher loss factors than that composite reinforced with clothe for the reason that the former has the ability to deform and the composite has higher resin content.The loss factor of GF mat reinforced composite is 0.704 while the T is 27 ℃.Both composite has good damping properties and can be used as the damping layer of the structural damping composite.

  3. Glulam beams reinforced with FRP strips and their application in architecture

    Directory of Open Access Journals (Sweden)

    Solarov Radivoj

    2014-01-01

    Full Text Available This paper emphasizes the advantage of using carbon polymers while producing and strengthening glulam beams. Due to advanced research carried out in this field, the first application of carbon polymers based products was implemented in Western countries. Structural elements containing carbon polymers, or being reinforced by them, show higher resistance and durability properties, as well as the ability to be produced in various shapes. These features can find best application in architecture so the architects’ imagination in design could be realized. Many attractive buildings were constructed over the last decade, each of them showing exceptional safety, resistance to atmospheric influences, durability and cost-efficiency. Beside application of carbon polymers in the construction of new buildings, they are even more important in the field of historic heritage restoration. The original research carried out on ten samples in the laboratory is presented in the second part of the paper. Position of the reinforcement on the samples was chosen as it would be done in practical retrofit cases. Deformations of the samples exposed to pure bending were measured, so their behaviour in the elastic range could be analysed based on the results. Measured results were compared to those calculated by using FEM model, developed with software package AxisVM. Based on performed analysis, the conclusion was made that by strengthening timber glulam beams with FRP strips, the simple and efficient static load bearing capacity upgrade is gained.

  4. Meteosat SEVIRI Fire Radiative Power (FRP products from the Land Surface Analysis Satellite Applications Facility (LSA SAF – Part 1: Algorithms, product contents and analysis

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2015-06-01

    Full Text Available Characterising changes in landscape scale fire activity at very high temporal resolution is best achieved using thermal observations of actively burning fires made from geostationary Earth observation (EO satellites. Over the last decade or more, a series of research and/or operational "active fire" products have been developed from these types of geostationary observations, often with the aim of supporting the generation of data related to biomass burning fuel consumption and trace gas and aerosol emission fields. The Fire Radiative Power (FRP products generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF from data collected by the Meteosat Second Generation (MSG Spinning Enhanced Visible and Infrared Imager (SEVIRI are one such set of products, and are freely available in both near real-time and archived form. Every 15 min, the algorithms used to generate these products identify and map the location of new SEVIRI observations containing actively burning fires, and characterise their individual rates of radiative energy release (fire radiative power; FRP that is believed proportional to rates of biomass consumption and smoke emission. The FRP-PIXEL product contains the highest spatial resolution FRP dataset, delivered for all of Europe, northern and southern Africa, and part of South America at a spatial resolution of 3 km (decreasing away from the west African sub-satellite point at the full 15 min temporal resolution. The FRP-GRID product is an hourly summary of the FRP-PIXEL data, produced at a 5° grid cell size and including simple bias adjustments for meteorological cloud cover and for the regional underestimation of FRP caused, primarily, by the non-detection of low FRP fire pixels at SEVIRI's relatively coarse pixel size. Here we describe the enhanced geostationary Fire Thermal Anomaly (FTA algorithm used to detect the SEVIRI active fire pixels, and detail methods used to deliver atmospherically corrected FRP

  5. 燃煤电厂玻璃钢烟道设计与研究%Design Research of FRP Flue for Coal-ifred Power Plant

    Institute of Scientific and Technical Information of China (English)

    罗树青; 董胜宪; 丁安心; 王继辉

    2015-01-01

    The temperature of flue gas disposed by wet flue gas desulfurization is lower without gas heater (GGH) and large number of condensate which have strong corrosion toward the FRP flue, are produced by reason of condensation of the flue gas in the inner wall, FRP flue has the dual nature of both structural and functional materials and can meet the requirements of power plants. Firstly, this paper mainly introduced the application situation of FRP flue at home and abroad. The quantities of FRP flue installed are increasing abroad and FRP flue became one of important corrosion resistance materials in the developed country like American and Europe. The application of FRP flue start in recent years and a few of FRP flue was in the service, but the development of FRP flue is quick and the design standard and product standard of FRP flue have been published at home. In generally, the understanding in the design and construction is still lacking. Finally, the author discuss and research the resin material selection and joint design of FRP flue according to the FRP liner and FRP flue engineering which the author participate and design experience of FRP product.%经过湿法脱硫且不加装烟气加热装置的烟气的温度比较低,烟气在烟道内壁冷凝产生大量的冷凝液,对烟道的腐蚀很大,玻璃钢烟道集功能性和结构一体,能满足电厂的运行要求。本文首先阐述了玻璃钢烟道在国内外的应用研究现状,在国外玻璃钢烟道的安装数量不断增加,已经成为主要烟道防腐材料之一;国内玻璃钢烟道应用已有几年时间,发展较快,已经出版了相应的设计标准或产品标准。但总的来说,国内对玻璃钢烟道设计及施工认识还不够。最后作者利用自己参与的玻璃钢烟道、烟道工程及相关的玻璃钢制品的设计经验,对玻璃钢烟道树脂原材料的选材、玻璃钢烟道接口设计进行了简单的探讨和研究。

  6. The gammaTuRC Nanomachine Mechanism and Future Applications

    Science.gov (United States)

    Riehlman, Timothy D.

    The complexity and precision of the eukaryotic cell's cytoskeletal network is unrivaled by any man-made systems, perfected by billions of years of evolution, mastering elegant processes of self-assembly, error correction, and self-repair. Understanding the capabilities of these networks will have important and far reaching applications in human medicine by aiding our understanding of developmental processes, cellular division, and disease mechanisms, and through biomimicry will provide insights for biosynthetic manufacturing at the nanoscale and across scales. My research utilizes cross species techniques from Human to the model organism of Fission Yeast to investigate the structure and mechanisms of the g-tubulin ring complex (gTuRC). The gTuRC is a highly conserved eukaryotic multiprotein complex serving as a microtubule organizing center (MTOC) responsible for microtubule nucleation through templating, regulation of dynamics, and establishment of microtubule polarity. Microtubules are 25 nm diameter dynamic flexible polymers of a/b-tubulin heterodimers that function as scaffolds, force generators, distributors, and intracellular highways. The microtubule cytoskeleton is essential for numerous fundamental cellular processes such as mitotic division of chromosomes and cell division, organelle distribution within the cell, cell signaling, and cell shape. This incredible diversity in functions is made possible in part due to molecular motor Kinesin-like proteins (Klps), which allow expansion into more specialized neural, immune, and ciliated cell functions. Combined, the MTOC, microtubules, and Klps represent ideal microtubule cytoskeleton protein (MCP) modular components for in vitro biomimicry towards generation of adaptable patterned networks for human designed applications. My research investigates the hypothesis that a mechanistic understanding of conserved MTOC gTuRC mechanisms will help us understand dynamic cellular nanomachines and their ability to self

  7. Antagonizing canonical Wnt signaling pathway by recombinant human sFRP4 purified from E. coli and its implications in cancer therapy.

    Science.gov (United States)

    Ghoshal, Archita; Ghosh, Siddhartha Sankar

    2016-07-01

    The Wnt signaling pathway plays a predominant role in aberrant proliferation in myriad of cancers. In non-cancerous cells, Wnts are blocked by the secreted frizzled-related proteins (sFRPs) that are generally downregulated in cancer cells. We have purified and characterized bacterially expressed glutathione S-transferase-tagged SFRP4 from a novel clone generated from human cell origin. Cervical cancer (HeLa) and lung cancer (A549) cells, in which Wnt and associated genes were found to be expressed, were treated with the purified recombinant sFRP4, which revealed a significant dose-dependent cell growth inhibition up to 40 %. The current investigation on functionality of this bacterially produced recombinant sFRP4 in arresting cancer cell proliferation is the first of its kind, where G2/M phase arrest and early apoptosis were evident. Increase in phosphorylated β-catenin in sFRP4 treatment indicated inhibition of Wnt pathway, which was further confirmed by downregulation of pro-proliferative genes, namely cyclin D1, c-myc, and survivin. Functional activity of recombinant sFRP4 was further exploited in co-therapy module with chemotherapeutic drugs to decipher molecular events. Collectively, our study on purified recombinant sFRP4 from bacterial host holds great promise in targeting Wnt signaling for exploring new strategies to combat cancer.

  8. Interface Capacity of Repaired Concrete Columns Strengthened with RC Jackets

    Directory of Open Access Journals (Sweden)

    Achillopoulou Dimitra

    2014-12-01

    Full Text Available The study describes the retrofit of repaired elements by reinforced concrete (RC jacketing conducted to quantify the influence of initial construction deficiencies and of different type of anchors to the ability of the interface to transfer loads. Sixteen specimens (section scale 1:2 were designed with variables the initial deficiencies and the confinement ratio. The results indicate that: a the maximum resistance load and dissipated energy of initially damaged specimens are decreased; b surpassing a specific amount of damage, columns even suitably repaired present lower strain capacity, c welded bars lead to buckling of longitudinal bars.

  9. Quasi-Static Analysis of LaRC THUNDER Actuators

    Science.gov (United States)

    Campbell, Joel F.

    2007-01-01

    An analytic approach is developed to predict the shape and displacement with voltage in the quasi-static limit of LaRC Thunder Actuators. The problem is treated with classical lamination theory and Von Karman non-linear analysis. In the case of classical lamination theory exact analytic solutions are found. It is shown that classical lamination theory is insufficient to describe the physical situation for large actuators but is sufficient for very small actuators. Numerical results are presented for the non-linear analysis and compared with experimental measurements. Snap-through behavior, bifurcation, and stability are presented and discussed.

  10. Connecting Time and Frequency in the RC Circuit

    Science.gov (United States)

    Moya, A. A.

    2017-04-01

    Charging and discharging processes of a capacitor through a resistor, as well as the concept of impedance in alternating current circuits, are topics covered in introductory physics courses. The experimental study of the charge and discharge of a capacitor through a resistor is a well-established lab exercise that is used to introduce concepts such as exponential increase or decrease and time constant. Determining the time constant of the RC circuit has important practical applications because, for example, it can be used to measure unknown values of resistance or capacitance. The transient experiment can be done by using a voltmeter and stopwatch, signal generator and oscilloscope, or even low-cost data acquisition systems such as Arduino. An equivalent topic when studying alternating current circuits arises from the characterization of the impedance of the series or parallel combination of the capacitor and the resistor as a function of frequency. Determining the time constant of the RC circuit by means of impedance measurements for different frequencies is a known experimental technique that can be done using not only LCR meters but also basic instrumentation in the physics lab such as a signal generator, frequency counter, and multimeter. However, lab exercises dealing with RC circuits in alternating current usually focus on their use as filters, and the potential applications in the field of the electrical characterization of material systems are ignored. In this work, we describe a simple exercise showing how the time constant of the RC circuit can easily be determined in the introductory physics lab by means of impedance measurements as a function of frequency. This exercise allows students to learn experimental techniques that find application to characterize the time constants of the charge transport processes in material systems. Moreover, comparison of the time constants obtained from transient and frequency analysis allows us to relate the time and

  11. Response reduction factor of irregular RC buildings in Kathmandu valley

    Science.gov (United States)

    Chaulagain, Hemchandra; Rodrigues, Hugo; Spacone, Enrico; Guragain, Ramesh; Mallik, Radhakrishna; Varum, Humberto

    2014-09-01

    Most current seismic design includes the nonlinear response of a structure through a response reduction factor ( R). This allows the designer to use a linear elastic force-based approach while accounting for nonlinear behavior and deformation limits. In fact, the response reduction factor is used in modern seismic codes to scale down the elastic response of a structure. This study focuses on estimating the actual ` R' value for engineered design/construction of reinforced concrete (RC) buildings in Kathmandu valley. The ductility and overstrength of representative RC buildings in Kathmandu are investigated. Nonlinear pushover analysis was performed on structural models in order to evaluate the seismic performance of buildings. Twelve representative engineered irregular buildings with a variety of characteristics located in the Kathmandu valley were selected and studied. Furthermore, the effects of overstrength on the ductility factor, beam column capacity ratio on the building ductility, and load path on the response reduction factor, are examined. Finally, the results are further analyzed and compared with different structural parameters of the buildings.

  12. Seismic strengthening of RC structures with exterior shear walls

    Indian Academy of Sciences (India)

    Hasan Kaplan; Salih Yilmaz; Nihat Cetinkaya; Ergin Atimtay

    2011-02-01

    Vulnerable buildings and their rehabilitation are important problems for earthquake regions. In recent decades the goal of building rehabilitation and strengthening has gained research attention and numerous techniques have been developed to achieve this. However, most of these strengthening techniques disturb the occupants, who must vacate the building during renovation. In this study, a new strengthening alternative for RC structures, namely exterior shear walls, has been experimentally investigated under reversed cyclic loading. Using the proposed technique, it is possible to strengthen structures without disturbing their users or vacating the building during renovation. In this technique, shear walls are installed in parallel to the building’s exterior sides. It has been observed that the usage of exterior shear walls considerably improve the capacity and sway stiffness of RC structures. The experimental results have also been compared and found to be in agreement with the numerical solutions. Post attached exterior shear walls behaved as a monolithic member of the structure. Design considerations for the exterior shear wall-strengthened buildings have also been discussed in the paper.

  13. Assessment and Strengthening of Existing Rc Framed Structures

    Directory of Open Access Journals (Sweden)

    Cătălin Badea

    2006-01-01

    Full Text Available Existing structures built before the 1970s are gravity load designed with inadequate lateral load resistance because earlier codes specified lower levels of seismic loads and many of these structures are still in service beyond their design life. On the other hand, some deterioration of component parts of buildings is encountered in old structures due to the actions of different hazard factors. Theoretical aspects on the risk assessment of the reinforced concrete structures are pre¬sented. The earthquake capacity ratio is analyzed for reinforced concrete framed structure. More attention is paid to the seismic shear force capacity and some new procedures are introduced to estimate the earthquake capacity of existing structures. The assessment, rehabilitation and redesign were performed on an industrial RC framed structure. The main problems comprised local damage due to industrial exploitation of some structural elements (concrete cover dislocated over a large surface, complete corro¬sion of many stirrups, deep corrosion of main reinforcement, some broken reinforcement and weak reinforcement of columns and beams under seismic action. The redesign and reha¬bilitation of the RC structure was performed for both types of damages by using reinforced concrete jacketing solutions.

  14. Seismic performance of masonry-infilled RC frames

    Directory of Open Access Journals (Sweden)

    Mircea Bârnaure

    2016-09-01

    Full Text Available The masonry infill of RC frames structures is generally considered as non-structural. The design of the concrete frames is often made by ignoring the influence of the masonry infill, which is only accounted for its mass. The experience on buildings submitted to earthquakes shows that masonry infill walls completely change the behaviour of bare frames due to increased initial stiffness and low deformability. The way in which masonry infills affect the RC frames members is difficult to predict, as different failure modes can occur either in the masonry or in the surrounding frame. In addition to local effects, the position of the masonry infills at different levels can lead to structural irregularity, with a strong influence on the global seismic response of the building. Less infilled stories, also called soft stories, have a particularly unfavourable behaviour under seismic loads, as frame members at these levels are more susceptible to failure. This paper analyses the differences in the behaviour of bare and infilled frames through numerical modelling. Nonlinear push-over analyses of infilled frames are carried out under in-plane vertical and lateral loading. The infill panels are modelled as equivalent single diagonal struts. Several force-displacements laws are considered for these diagonals.

  15. A liquid drop RC filter apparatus for detection.

    Science.gov (United States)

    Nanayakkara, Yasith S; Armstrong, Daniel W

    2011-11-01

    A new analytical detector based on a liquid drop resistor-capacitor (RC) filter is described, in which transformed gain vs. frequency curves are used to analyze compounds. This detector can be used to detect either charged or neutral species (that are dielectrically different) which are dissolved in a liquid (e.g., water, alcohol, solvent mixtures, etc.). This device was fabricated by modifying an electrowetting on dielectric (EWOD)-based experimental setup. When a liquid drop is placed on a dielectric surface, the system acts as a RC filter. At a given frequency, gain is a function of conductivity, surface tension, dielectric constant, double-layer thickness of the solid-liquid drop interface, as well as the applied voltage. Since different liquids and solutions have different physical properties, each liquid/solution has a unique curve (peak) in gain vs. frequency plot. This is the basic principle behind the detector. Different amounts of zinc chloride dissolved in water, benzalkonium chloride in water, 1-methylimidazole in water, cetyltrimethyl-ammonium chloride (CTAC) in water, and CTAC dissolved in ethylene glycol solutions were tested with the detector as proof of principle. The device can be used as a stand-alone detector or can easily be coupled with droplet based microfluidic lab-on-a-chip systems such as EWOD-based microfluidic chips.

  16. Numerical Analysis of Dynamic Behavior of RC Slabs Under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    DU Hao; LI Zhongxian

    2009-01-01

    In Order to reduce economic and life losses due to terrorism or accidental explosion threats,reinforced concrete(RC)slabs of buildings need to be designed or retrofitted to resist blast loading.In this paper the dynamic behavior Of RC slabs under blast loading and its influencing factors are studied.The numerical model of an RC slab subjected to blast loading is established using the explicit dynamic analysis software.Both the strain rate effect and the damage accumulation are taken into account in the material model.The dynamic responses of the RC slab subiected to blast loading are analyzed,and the influence of concrete strength,thickness and reinforcement ratio on the behavior of the RC slab under blast loading iS numerically investigated.Based on the numerical results.some principles for blast-resistant design and retrofitting are proposed to improve the behavior of the RC slab subjected to blast loading.

  17. The analysis of the number of fixed points in the key extending algorithm of RC4

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The probabilities of the state transitions of the initial value So in the S table of RC4 are described by a kind of bistochastic matrices, and then a computational formula for such bistochastic matrices is given, by which the mathematical expectation of the number of fixed points in the key extending algorithm of RC4 is obtained. As a result, a statistical weakness of the key extending algorithm of RC4 is presented.

  18. 47 CFR 95.225 - (R/C Rule 25) How do I contact the FCC?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 25) How do I contact the FCC? 95.225... (R/C Rule 25) How do I contact the FCC? (a) FCC National Call Center at 1-888-225-5322. (b) FCC World Wide Web homepage: http://www.fcc.gov. (c) In writing, to FCC, Attention: R/C, 1270 Fairfield...

  19. Potentials of Optical Damage Assessment Techniques in Automotive Crash-Concepts composed of FRP-Steel Hybrid Material Systems

    Science.gov (United States)

    Dlugosch, M.; Spiegelhalter, B.; Soot, T.; Lukaszewicz, D.; Fritsch, J.; Hiermaier, S.

    2017-05-01

    With car manufacturers simultaneously facing increasing passive safety and efficiency requirements, FRP-metal hybrid material systems are one way to design lightweight and crashworthy vehicle structures. Generic automotive hybrid structural concepts have been tested under crash loading conditions. In order to assess the state of overall damage and structural integrity, and primarily to validate simulation data, several NDT techniques have been assessed regarding their potential to detect common damage mechanisms in such hybrid systems. Significant potentials were found particularly in combining 3D-topography laser scanning and X-Ray imaging results. Ultrasonic testing proved to be limited by the signal coupling quality on damaged or curved surfaces.

  20. Experimental Investigation on Three Dimensional RC Infilled Frame - RC Plane Frame Interactions With Slab for Seismic Resistance

    Directory of Open Access Journals (Sweden)

    Suyamburaja Arulselvan

    2008-01-01

    Full Text Available Experimental investigation was planned and conducted to study the influence of brick masonry infill and slab in a three-dimensional reinforced cement concrete frame. In this study, one-fifth scale 3D R.C frame representing single story, three bays with central bay brick infill at the sides and a long single bay without infill in the middle of the frame along loading direction and two numbers of two bays at the edges without infill and two numbers of single bay without infill in the transverse direction with slab, has been taken for experimental investigation and the available methods of theoretical analysis for the frames have been carried out. Totally ten columns, eight columns in both ends of the frame along loading direction and two columns in middle along loading direction, were constructed in the frame. Until the cracks developed in infills, the contribution of the infill to both lateral stiffness and strength is very significant. The infill and slab also changes the dynamic characteristics of the frame. The change in lateral stiffness, strength, ductility and natural period of the framed structure due to the presence of infills and slab change the behavior of the building under seismic action. The object of this study was to investigate the behavior of such three dimensional RC infilled frames with slab under seismic loads. Analytical works was done to understand the strength and behavior of these types of frames.

  1. Behavior of R/C Cylindrical Panel Subjected to Combined Axial and Shear Loadings

    OpenAIRE

    Hara, Takashi

    2009-01-01

    p. 1722-1730 Reinforced concrete (R/C) cylindrical panels have been applied to the roof or the underground structures. Also, in constructing a high rise building, an R/C wall is often used to improve the lateral rigidity of the building comparing with beam column systems under wind or seismic loading. In this paper, the behavior of R/C cylindrical shell under combined axial and lateral shear loadings is analyzed numerically. R/C cylindrical shells are often adopted for the core wa...

  2. Data of evolutionary structure change: 1E1RC-2HLDT [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1E1RC-2HLDT 1E1R 2HLD C T ADTSVDLEETGRVLSIGDGIARVHGLRNVQAEEMVEFSS...VQTGLKAVDALVPIGRGQRELIIGDRQTGKTAVALDTILNQKRWNNGSDESKKLYCVYVAVGQKRSTVAQLVQTLEQHDAMKYSIIVAATASEAAPLQYLAPFTAASI... 2HLD T 2HLDT AAFAQ--

  3. 玻璃钢活节式灯桩的设计计算%DESIGN CALCULATION OF FRP LIGHTSTAKE WITH FLEXIBLE JOINTS

    Institute of Scientific and Technical Information of China (English)

    赵会娟; 林维学; 付秀君; 王喜斌

    2001-01-01

    本文探讨了玻璃钢活节灯桩的设计计算思想,给出了玻璃钢活节式灯桩静水力性能、环境荷载、水动力性能和灯桩沉块的计算方法。%The article explores the idea in designing and res earching FRP lightstake with flexible joints. It provides the calculating methods of performance of FRP lightstake in static water force, environmental lo ad the motive power of water as well as sinking block .

  4. 浅谈手糊产品用玻璃钢模具的制作%DlSCUSSION ON PRODUCTION OF FRP-MOULD FOR CONTACT LAMINATING PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    陈德华

    2001-01-01

    本文阐述了从母模设计到玻璃钢模具翻制的全过程后,又对玻璃钢模具的保养、维护作了简要分析;对提高玻璃钢模具制作水平、延长模具使用寿命具有指导意义。%The whole course from design of master mould to production of FRPmou1d is discussed in this paper and describes how to maintain FRP mould. It has guiding significance to improve FRP mould and to extend its service life.

  5. Study on behavior of car and driver in the very small commuter car made of FRP during collision using scale model. Under the consideration of thorax deformation of driver using airbag; FRP sei mokei ni yoru FRP sei chokeiryo jissha shototsuji no kuruma to join no anzensei ni kansuru kenkyu. Kyobu henkei tokusei wo yusuru join ni taisuru air gab no koka

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, H.; Morisawa, M.; Yoshino, T. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Keio University, Tokyo (Japan); Ishizuki, H. [Satake Co., Tokyo (Japan)

    1997-10-01

    In this study, after having performed simulation which took up scale models substituting for full scale model of commuter car made of FRP, we carried out collision tests to barrier. Here, we made enquiries about the occupant safety by changing the collision speed and the deformation characteristics of the seat belt, during head-on barrier collision using one-fifth scale models. We sought for the occupant`s safe combinations among the deformation characteristics of airbag and the thorax deformation. In this case, the degree of the occupants injury were estimated using HIC values, 3msecG and maximum deformation of the thorax. 7 refs., 5 figs.

  6. RC Columns Strengthened with Novel CFRP Systems: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Annalisa Napoli

    2015-10-01

    Full Text Available This paper presents an experimental study undertaken to investigate the seismic behavior of full scale square (300 mm × 300 mm reinforced concrete (RC columns strengthened with novel systems employing carbon fiber-reinforced polymers (CFRP wraps. Experimental tests were carried out by subjecting specimens to a constant axial load and a cyclically reversed horizontal force applied in displacement control. Results have allowed for investigating the influence of the used strengthening systems on the specimens’ performance in terms of flexural strength and ductility as well as on the exhibited failure modes. The effectiveness of the studied techniques is also evaluated by comparing the performance of tested specimens with that of companion columns strengthened with alternative CFRP systems investigated in a previous experimental campaign.

  7. Distributed TLDs in RC floors and their vibration reduction efficiency

    Institute of Scientific and Technical Information of China (English)

    Ye Lieping; Lu Xinzheng; Qu Zhe; Hou Jianqun

    2008-01-01

    A novel distributed tuned liquid damper (DTLD) for reducing vibration in structures is proposed in this paper. The basic working principle of the DTLDs is to fill the empty space inside the pipes or boxes of cast-in-situ hollow reinforced concrete (RC) floor slabs with water or other liquid. The pipes or boxes then work as a series of small TLDs inside the structure, to increase the damping ratio of the entire structural system. Numerical simulation that accounts for the fluid-structure coupling effect is carried out to evaluate the vibration-reduction efficiency of the DTLDs. The results show that the DTLDs are able to considerably increase the damping of the structure and thus reduce its vibration. An additional benefit is that the DTLDs do not require architectural space to be added to the structure.

  8. Structural Performance of a Hybrid FRP-Aluminum Modular Triangular Truss System Subjected to Various Loading Conditions

    Directory of Open Access Journals (Sweden)

    Dongdong Zhang

    2014-01-01

    Full Text Available A novel hybrid FRP-aluminum truss system has been employed in a two-rut modular bridge superstructure composed of twin inverted triangular trusses. The actual flexural behavior of a one-rut truss has been previously investigated under the on-axis loading test; however, the structural performance of the one-rut truss subjected to an off-axis load is still not fully understood. In this paper, a geometrical linear finite element model is introduced and validated by the on-axis loading test; the structural performance of the one-rut truss subjected to off-axis load was numerically obtained; the dissimilarities of the structural performance between the two different loading cases are investigated in detail. The results indicated that (1 the structural behavior of the off-axis load differs from that of the on-axis load, and the off-axis load is the critical loading condition controlling the structural performance of the triangular truss; (2 under the off-axis load, the FRP trussed members and connectors bear certain out-of-plane bending moments and are subjected to a complicated stress state; and (3 the stress state of these members does not match that of the initial design, and optimization for the redesign of these members is needed, especially for the pretightened teeth connectors.

  9. Comparison of lock-in and pulse-phase thermography for defect characterization in FRP composites applied to concrete

    Science.gov (United States)

    Brown, Jeff; Chittineni, Sai Harsha

    2015-05-01

    Thermal imaging is a well-established technique for the non-destructive evaluation of FRP composites applied to reinforced concrete. Defect characterization using IR thermography, however, remains a topic of on-going research, and there are currently no universally accepted standards for data collection or interpretation. This research involved large scale thermography inspection of two FRP strengthened bridge girders that were removed from service after approximately 10 years of service in a potentially corrosive marine environment. Trial inspections were performed on test areas where defects could be identified using sounding methods. Two procedures showed the most promise for identifying and characterizing defects: sinusoidal (lock-in style) heating with periods ranging from 5 s to 40 s and constant step heating for 30 s followed by 60 s of cooling. Both methods resulted in a series of phase images that provided insight into the depth and general nature of detected defects. This paper presents the findings of a comparison study between these two thermal imaging techniques.

  10. Identification of a Maximum Softening Damage Indicator of RC-Structures Using Time-Frequency Techniques

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R.K.; Micaletti, R. C.;

    This paper considers estimation of the Maximum Damage Indicator (MSDI) by using time-frequency system identification techniques for an RC-structure subjected to earthquake excitation. The MSDI relates the global damage state of the RC-structure to the relative decrease of the fundamental eigenfre...

  11. 47 CFR 95.647 - FRS unit and R/C transmitter antennas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false FRS unit and R/C transmitter antennas. 95.647... transmitter antennas. The antenna of each FRS unit, and the antenna of each R/C station transmitting in the 72-76 MHz band, must be an integral part of the transmitter. The antenna must have no gain (as...

  12. 47 CFR 95.207 - (R/C Rule 7) On what channels may I operate?

    Science.gov (United States)

    2010-10-01

    ... caused to the remote control of industrial equipment operating on the same or adjacent frequencies or to... RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service How to Operate An R/c Station... of an aircraft) or a model surface craft device (any small imitation of a boat, car or vehicle...

  13. Fire Radiative Power (FRP)-based Emission Factors of PM2.5, CO and NOX for Remote Sensing of Biomass Burning Emissions

    Science.gov (United States)

    Karandana Gamalathge, T. D.; Chen, L. W. A.

    2015-12-01

    Large-scale biomass burning such as forest fires represents an important and yet uncertain source of air pollutants and greenhouse gases on a global scale. Due to the highly accidental nature of forest fires, satellite remote sensing could be a promising method to develop regional and global fire emission inventories on a real-time basis. Reliable fire radiative power (FRP)-based fuel consumption and emission factors are critical in this approach. In an attempt to obtain the information, laboratory combustion experiments were conducted to simultaneously monitor FRP, fuel consumption, and emissions of fine particulate matter (PM2.5), carbon monoxide (CO), and reactive nitrogen oxides (NO and NO2). FRP were quantified using temperature-resolved values from a thermal imager instead of conventionally used average temperature, as the former provides more realistic estimates. For dry Ponderosa pine branches, a common fuel in the Sierra Nevada, a strong correlation (r2 ~ 0.8) between FRP and the mass reduction rate (MRR) was found. This led to a radiative energy yield (REY) of 8.5 ± 1.2 MJ/kg, assuming blackbody radiation and a flame emissivity of 0.5. Mass-based emission factors were determined with the carbon balance approach. Considering the ratio of mass-based emission factors and the REY, FRP-based emission factors: PM2.5: 11 g/MJ, CO: 8.0 g/MJ, NO: 0.33 g/MJ, and NO2: 0.07 g/MJ were quantified. The application of this approach to other fuel types and uncertainties in the measurements will be discussed.

  14. Alignment method of off-axis RC reflective optical system

    Science.gov (United States)

    Xue-min, Zhang; Xing, Song; Zhi-jun, Zhang; Hou, Xiao-hua

    2016-10-01

    Off-axis optical system has a wide application in space optics and remote detective area. The high surface shape accuracy can be ensured with the development of advanced manufacture technique. So the only condition which limits the wide application of off-axis optical system is how to realize the precise alignment of it. Based on a RC reflective optical system whose diameter is 400mm, the alignment method which combines the high resolution initial placement and computer-aided alignment is introduced. By designing a system which can measure the off-axis fabrication and off-axis angle precisely, the high resolution initial placement of off-axis mirror can be ensured with a measurement accuracy of +/-0.05mm and +/-10". The good initial placement can give a good initial state, so the computer-aided model can be converged well. The experiment shows that a system which has a good initial placement could have a good wave aberration of 0.04λ after three times iteration adjustment.

  15. Expected damages of retrofitted bridges with RC jacketing

    Science.gov (United States)

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

    2015-07-01

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

  16. Earthquake Response Mitigation of RC Building Using Friction Pendulum System

    Directory of Open Access Journals (Sweden)

    Sudarshan B. Sanap

    2014-11-01

    Full Text Available Earthquake hazard mitigation is very sensitive issue now a day’s therefore researchers are struggling for optimum solution since last few decades. Base isolation technique is one of the effective techniques which give better results seismic hazard mitigation under earthquake excitation particularly in building structures, bridges and water tanks etc. Base isolation reduces not only the effects of earthquake acceleration to be transmitted to the structures, but also protects the content of building while simultaneous supporting the mass of structure. This study proposed a realistic ten storey RC building which is model as shear type lumped mass having single degrees-of-freedom at each floor level. This building is isolated by Friction Pendulum System of sliding base isolated type and excited under unidirectional ground motion due to four realistic earthquakes namely, Imperial Valley, 1940, Loma Prieta, 1989, Kobe, 1995 and Northridge, 1994. The governing equation of motion for the building solved using Newmarks method whereas isolation system is modelled by Wen’s model. The effectiveness of proposed isolation system and building response has been evaluated by coding in MATLAB 8.2 computing software. Further, effectiveness of isolation system is also studied in terms of peak responses of building. The results obtained from the study underscored that Friction Pendulum System works effectively in limiting the building responses during excitation due to earthquakes.

  17. Torsional Strengthening of RC Beams Using GFRP Composites

    Science.gov (United States)

    Patel, Paresh V.; Jariwala, Vishnu H.; Purohit, Sharadkumar P.

    2016-09-01

    Fiber reinforced polymer as an external reinforcement is used extensively for axial, flexural and shear strengthening in structural systems. The strengthening of members subjected to torsion is recently being explored. The loading mechanism of beams located at the perimeter of buildings which carry loads from slabs, joists and beams from one side of the member generates torsion that are transferred from the beams to the columns. In this work an experimental investigation on the improvement of the torsional resistance of reinforced concrete beams using Glass Fiber Reinforced Polymer (GFRP) is presented. Total 24 RC beams have been cast in this work. Ten beams of dimension 150 mm × 150 mm × 1300 mm are subjected to pure torsion while fourteen beams of 150 mm × 150 mm × 1700 mm are subjected to combined torsion and bending. Two beams in each category are designated as control specimen and remaining beams are strengthened by GFRP wrapping of different configurations. Pure torsion on specimens is applied using specially fabricated support mechanism and universal testing machine. For applying combined torsion and bending a loading frame and test set up are fabricated. Measurements of angle of twist at regular interval of torque, torsion at first crack, and ultimate torque, are obtained for all specimens. Results of different wrapping configurations are compared for control and strengthened beams to suggest effective GFRP wrapping configuration.

  18. Experiment study on RC frame retrofitted by the external structure

    Science.gov (United States)

    Liu, Chunyang; Shi, Junji; Hiroshi, Kuramoto; Taguchi, Takashi; Kamiya, Takashi

    2016-09-01

    A new retrofitting method is proposed herein for reinforced concrete (RC) structures through attachment of an external structure. The external structure consists of a fiber concrete encased steel frame, connection slab and transverse beams. The external structure is connected to the existing structure through a connection slab and transverse beams. Pseudostatic experiments were carried out on one unretrofitted specimen and three retrofitted frame specimens. The characteristics, including failure mode, crack pattern, hysteresis loops behavior, relationship of strain and displacement of the concrete slab, are demonstrated. The results show that the load carrying capacity is obviously increased, and the extension length of the slab and the number of columns within the external frame are important influence factors on the working performance of the existing structure. In addition, the displacement difference between the existing structure and the outer structure was caused mainly by three factors: shear deformation of the slab, extraction of transverse beams, and drift of the conjunction part between the slab and the existing frame. Furthermore, the total deformation determined by the first two factors accounted for approximately 80% of the damage, therefore these factors should be carefully considered in engineering practice to enhance the effects of this new retrofitting method.

  19. The role of relational capital (RC in green supply chain management (GSCM

    Directory of Open Access Journals (Sweden)

    Claudia Viviane Viegas

    2015-09-01

    Full Text Available Green Supply Chain Management (GSCM is an emergent issue in operations management. It is addressed to intra and inter-organizational practices adoption in order to promote sustainability in supply chains. Relational Capital (RC, also an emergent issue, plays a relevant role to resize views based solely in transactions costs and resources to a relationship view leaned on governance for information, trust and longevity in relationships, looking for positive results for all the chain’s participants. This article reviews and criticizes seminal literature on intangible assets in order to rescue RC features and link them to GSCM development. Through exploratory and descriptive methods, recent studies on RC and GSCM are identified with respect their descriptors – ways in which RC is understood and employed in GSCM; focus – goals and main use of RC; and directionality – if developments of RC in GSCM are addressed from producers to their suppliers and respective clients, or if suppliers and clients also address results of RC. It is concluded that, usually, there is unidirectionality in the application of such efforts: improvement initiatives go from the producer to the supplier or client development, but processes through which environmental practices of suppliers and clients influence the performance of GSCM are poor explored.

  20. Research of Effective Width of FRP U-shaped Hoop Reinforcement Properties of Concrete Beams by Shear

    Directory of Open Access Journals (Sweden)

    Li Baokun

    2015-01-01

    Full Text Available The paste fiber reinforced composite material (hereinafter referred to as FRP U-shaped hoop of reinforced concrete beams interfacial debonding is an important reinforcement technology research. For the effective width of the CFRP U-shaped hoop reinforcement, it is still a lack of in-depth research, only relying on the test research huge workload, this article (ANSYS and the numerical simulation in the whole process of the shear load release properties of finite element calculation software. According to the results of finite element analysis, the author studied the CFRP U-shaped hoop to increase the width of the shear capacity of reinforced concrete beams by the impact.

  1. Exact Output Response Computation of RC Interconnects Under General Polynomial Input Waveforms

    Directory of Open Access Journals (Sweden)

    L. M. Patnaik

    2000-01-01

    Full Text Available Accurate output response computation of RC interconnects under various input excitations is a key issue in deep submicron delay analysis. In this paper, we present an exact analysis of output response computation of a distributed RC interconnect under input signals that are polynomial in time (tn. A simple, recursive equation that helps us to calculate the interconnect response under higher order polynomial inputs in terms of the lower order polynomial responses is derived. To the best of our knowledge, this is the first exact output response analysis of RC interconnects under generalized polynomial inputs.

  2. Cracking and Deformation Modelling of Tensile RC Members Using Stress Transfer Approach

    Directory of Open Access Journals (Sweden)

    Ronaldas Jakubovskis

    2016-12-01

    Full Text Available The paper presents a modeling technique for bond, cracking and deformation analysis of RC members. The proposed mod-eling technique is not restricted by the geometrical dimensions of the analyzed member and may be applied for various load-ing conditions. Tensile as well as bending RC members may be analyzed using the proposed technique. Adequacy of the modeling strategy was evaluated by the developed numerical discrete crack algorithm, which allows modeling deformation and cracking behavior of tensile RC members. Comparison of experimental and numerical results proved the applicability of the proposed modeling strategy.

  3. Computational Modelling Strategies for Nonlinear Response Prediction of Corroded Circular RC Bridge Piers

    Directory of Open Access Journals (Sweden)

    Mohammad M. Kashani

    2016-01-01

    Full Text Available A numerical model is presented that enables simulation of the nonlinear flexural response of corroded reinforced concrete (RC components. The model employs a force-based nonlinear fibre beam-column element. A new phenomenological uniaxial material model for corroded reinforcing steel is used. This model accounts for the impact of corrosion on buckling strength, postbuckling behaviour, and low-cycle fatigue degradation of vertical reinforcement under cyclic loading. The basic material model is validated through comparison of simulated and observed responses for uncorroded RC columns. The model is used to explore the impact of corrosion on the inelastic response of corroded RC columns.

  4. High Temperature VARTM with LaRC Polyimides

    Science.gov (United States)

    Cano, Roberto J.; Grimsley, Brian W.; Jensen, Brian J.; Kellen, Charles B.

    2004-01-01

    Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems for advanced aerospace applications that can be processed without the use of an autoclave. Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Vacuum assisted resin transfer molding (VARTM) has shown potential to reduce the manufacturing cost of composite structures. In VARTM, the fibrous preform is infiltrated on a rigid tool surface contained beneath a flexible vacuum bag. Both resin injection and fiber compaction are achieved under pressures of 101.3 KPa or less. Recent studies have demonstrated the feasibility of the VARTM process for fabrication of void free structures utilizing epoxy resin systems with fiber volume fractions approaching 60%. In this work, the VARTM process has been extended to the fabrication of composite panels from polyimide systems developed at the Langley Research Center. This work has focused on processing LARC(trademark) PETI-8 (Langley Research Center Phenylethynyl Terminated Imide- 8), an aromatic polyimide based on 3,3',4,4' -biphenyltetracarboxylic dianhydride, a 50:50 molar ratio of 3,4'-oxydianiline and 1,3-bis(3-aminophenoxy)benzene, with 4-phenylethynylphthalic anhydride as the endcapping agent. Various molecular weight versions were investigated to determine their feasibility of being processed by VARTM at elevated temperatures. An injection temperature of approximately 280 C was required to achieve the necessary viscosity (VARTM pressures. Laminate quality and initial mechanical properties are presented for LARC(trademark) PETI-8 and 6k IM7 uniweave fabric.

  5. Pro-inflammatory wnt5a and anti-inflammatory sFRP5 are differentially regulated by nutritional factors in obese human subjects.

    Directory of Open Access Journals (Sweden)

    Dominik M Schulte

    Full Text Available BACKGROUND: Obesity is associated with macrophage infiltration of adipose tissue. These inflammatory cells affect adipocytes not only by classical cytokines but also by the secreted glycopeptide wnt5a. Healthy adipocytes are able to release the wnt5a inhibitor sFRP5. This protective effect, however, was found to be diminished in obesity. The aim of the present study was to examine (1 whether obese human subjects exhibit increased serum concentrations of wnt5a and (2 whether wnt5a and/or sFRP5 serum concentrations in obese subjects can be influenced by caloric restriction. METHODOLOGY: 23 obese human subjects (BMI 44.1 ± 1.1 kg/m(2 and 12 age- and sex-matched lean controls (BMI 22.3 ± 0.4 kg/m(2 were included in the study. Obese subjects were treated with a very low-calorie diet (approximately 800 kcal/d for 12 weeks. Body composition was assessed by impedance analysis, insulin sensitivity was estimated by HOMA-IR and the leptin-to-adiponectin ratio and wnt5a and sFRP5 serum concentrations were measured by ELISA. sFRP5 expression in human adipose tissue biopsies was further determined on protein level by immunohistology. PRINCIPAL FINDINGS: Pro-inflammatory wnt5a was not measurable in any serum sample of lean control subjects. In patients with obesity, however, wnt5a became significantly detectable consistent with low grade inflammation in such subjects. Caloric restriction resulted in a weight loss from 131.9 ± 4.0 to 112.3 ± 3.2 kg in the obese patients group. This was accompanied by a significant decrease of HOMA-IR and leptin-to-adiponectin ratio, indicating improved insulin sensitivity. Interestingly, these metabolic improvements were associated with a significant increase in serum concentrations of the anti-inflammatory factor and wnt5a-inhibitor sFRP5. CONCLUSIONS/SIGNIFICANCE: Obesity is associated with elevated serum levels of pro-inflammatory wnt5a in humans. Furthermore, caloric restriction beneficially affects serum concentrations

  6. artificial neural network model for low strength rc beam shear capacity

    African Journals Online (AJOL)

    User

    predicting the shear strength of 26 low strength RC beams. Even though ... research activity over the last 20 years. The ... 2012 Kwame Nkrumah University of Science and Technology (KNUST) ... art approach to computation procedures is the.

  7. Advanced field-solver techniques for RC extraction of integrated circuits

    CERN Document Server

    Yu, Wenjian

    2014-01-01

    Resistance and capacitance (RC) extraction is an essential step in modeling the interconnection wires and substrate coupling effect in nanometer-technology integrated circuits (IC). The field-solver techniques for RC extraction guarantee the accuracy of modeling, and are becoming increasingly important in meeting the demand for accurate modeling and simulation of VLSI designs. Advanced Field-Solver Techniques for RC Extraction of Integrated Circuits presents a systematic introduction to, and treatment of, the key field-solver methods for RC extraction of VLSI interconnects and substrate coupling in mixed-signal ICs. Various field-solver techniques are explained in detail, with real-world examples to illustrate the advantages and disadvantages of each algorithm. This book will benefit graduate students and researchers in the field of electrical and computer engineering, as well as engineers working in the IC design and design automation industries. Dr. Wenjian Yu is an Associate Professor at the Department of ...

  8. Experimental Study of RC Beams Strengthened with CFRP Sheets Under Sustaining Loads

    Institute of Scientific and Technical Information of China (English)

    WANG Wenwei; LI Guo

    2006-01-01

    Seven reinforced concrete (RC) beams strengthened in flexure using carbon fiber reinforced polymer (CFRP) sheets subjected to different sustaining loads were tested. The effects of initial load and load history on the ultimate strength of strengthened RC beams were examined by externally bonded CFRP sheets. The main experimental parameters included different levels of sustaining load at the time of strengthening, and load history. Experimental results show that sustaining load levels at the time of strengthening have important influences on the ultimate strength of strengthened RC beams. If the initial load is the same, the ultimate strength of RC beams strengthened with CFRP sheets is almost the same regardless of load history at the time of strengthening.

  9. Data of evolutionary structure change: 1E1RC-2HLDA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1E1RC-2HLDA 1E1R 2HLD C A ADTSVDLEETGRVLSIGDGIARVHGLRNVQAEEMVEFSS...ELFYKGIRPAINVGLSVSRVGSAAQTRAMKQVAGTMKLELAQYREVAAFAQFGSDLDAATQQLLSRGVRLTELLKQGQYSPMAIEEQVAVIYAGVRGYLDKLEPSKIT...RPAINVGLSVSRVGSAAQVKALKQVAGSLKLFLAQYREVAAFAQS--DLDASTKQTLVRGERLTQLLKQNQYSPLATEEQV...fEVID> 0 2HLD A 2HLDA AFAQS--DLDAS GGG -- HH

  10. Out of the Autoclave Fabrication of LaRC[TradeMark] PETI-9 Polyimide Laminates

    Science.gov (United States)

    Cano, Robert J.; Jensen, Brian J.

    2013-01-01

    The NASA Langley Research Center developed polyimide system, LaRC PETI-9, has successfully been processed into composites by high temperature vacuum assisted resin transfer molding (HT-VARTM). To extend the application of this high use temperature material to other out-of-autoclave (OOA) processing techniques, the fabrication of PETI- 9 laminates was evaluated using only a vacuum bag and oven cure. A LaRC PETI-9 polyimide solution in NMP was prepared and successfully utilized to fabricate unidirectional IM7 carbon fiber prepreg that was subsequently processed into composites with a vacuum bag and oven cure OOA process. Composite panels of good quality were successfully fabricated and mechanically tested. Processing characteristics, composite panel quality and mechanical properties are presented in this work. The resultant properties are compared to previously developed LaRC material systems processed by both autoclave and OOA techniques including the well characterized, autoclave processed LaRC PETI-5.

  11. The evaluation of the individual impact factor of researchers and research centers using the RC algorithm.

    Science.gov (United States)

    Cordero-Villafáfila, Amelia; Ramos-Brieva, Jesus A

    2015-01-01

    The RC algorithm quantitatively evaluates the personal impact factor of the scientific production of isolated researchers. The authors propose an adaptation of RC to evaluate the personal impact factor of research centers, hospitals and other research groups. Thus, these could be classified according to the accredited impact of the results of their scientific work between researchers of the same scientific area. This could be useful for channelling budgets and grants for research.

  12. FRP人行天桥的结构性能与设计指标研究%Research on Structural Performance and Design Indices of FRP Footbridges

    Institute of Scientific and Technical Information of China (English)

    冯鹏; 金飞飞; 叶列平

    2011-01-01

    A tentative FRP cable-stayed footbridge was investigated, in which the design method and design indices of FRP footbridges were studied. Firstly, the analysis of mechanical properties of the FRP footbridge made of large section industrialization pultruded profiles was carried out. It was found that FRP footbridge had the high loading capacity, while the deformation and the vibration comfort were the main controlling parameters for structural design. Furthermore, based on summarizing the deformation limits of the footbridge in domestic and international codes and considering the finite element analysis and the field measurement results, the deflection limit of 1/500 span length for FRP footbridge was proposed. The indices for the pedestrian vibration comfort requirements were also summarized, and the frequency limit, acceleration limit and excitation load were analyzed. Considering the finite element analysis and the field measurement results, it was concluded that the acceleration should be the controlling indicator, and simplifiedexcitation load model and calculation method for acceleration were proposed. After reviewing the variety of damping ratio of real bridge in literature, the damping ratio of FRP footbridge was suggested to take as 0. 008 for single component and 0. 02 for multi-component structures. Based on the proposed design indices above, the limit span of continuous beam FRP footbridge and cable-stayed FRP footbridge were analyzed. For the cable-stayed FRP footbridge, the results of finite element analysis and field measurement showed that it could not meet the designing requirements. Hence, the improvement of overlaying a concrete layer was proposed. After it, the behaviors of the FRP footbridge met the requirements. All these works made out the design approach and the design indices for FRP footbridges, which were proved to be practical and reasonable through the actual FRP footbridge. Results show that overlaying a concrete layer is an effective

  13. Application Analysis on FRP Composite Material Cable Bracket%玻璃钢复合材料电缆支架的应用分析

    Institute of Scientific and Technical Information of China (English)

    马昀涛; 李凌睿; 朱萍

    2013-01-01

    针对金属电缆支架易锈蚀等问题,介绍一种新型玻璃钢复合材料电缆支架,分析其存在优势和应用情况,认为玻璃钢复合材料电缆支架替代金属电缆支架切实可行。%Because metal cable support is easy to rust,propo-ses a new composite cable support,analyzes the advantages of FRP composite material cable support and application, considers that it is feasible to replace metal cable support with FRP composite material cable support.

  14. 玻璃钢蜂窝夹层结构支撑点的设计%DESIGN OF SUPPORTING SPOT INSIDE FRP HONEYCOMB SADWICH PANELS

    Institute of Scientific and Technical Information of China (English)

    何玉梅; 林有才; 等

    2001-01-01

    In this paper, strength of supporting spot inside FRP honeycomb sandwich panels are stuided on the basis of comparision of thr ee kind supporting spot models,and effect of model of supporting spot on strengt h of radome made of FRP honeycomb sandwich panels are discussed.%本文研究了某地面雷达天线罩采用的含有预埋件的玻璃钢蜂窝夹层结构支撑点的强度,把含有三种不同形式支撑点的蜂窝夹层结构试件的强度进行了对比,讨论了支撑点的形式对结构强度的影响。

  15. Numerical Analysis of Interface Bonding between Fiber Reinforced Polymer and Clay Brick%FRP 与砖界面粘结性能的数值分析

    Institute of Scientific and Technical Information of China (English)

    黄奕辉; 罗才松; 黄田良

    2015-01-01

    A numerical model is proposed to this paper to simulate the bonding stress distribution on the interface be-tween fiber reinforced polymer (FRP)and brick based on finite element software ABAQUS.Using the numerical model, the load-displacement curve and the bonding stress distributions of FRP-brick interface are obtained,which shows the model is feasible.Bond bearing capacity increases with the increase of FRP′s bond length.When the bond length reaches a certain value,bond bearing capacity does not increased,but it can improve the ductility of the specimens,and raise the limit displacement.%利用有限元软件 ABAQUS 建立纤维复合材料(FRP)-砖界面分析模型,模拟其粘结应力分布,加载端荷载-位移曲线及界面应力的传递过程,并与试验结果进行对比分析。结果表明:数值模拟结果与试验结果吻合较好,采用的 FRP-砖界面计算模型具有可行性;粘结承载力随着 FRP 与砖粘结长度的增加而增加,当粘结长度达到某一定值后,粘结承载力基本不增长,此时增加粘结长度可改善试件的延性,增加试件的极限位移。

  16. Constructing Novel Fiber Reinforced Plastic (FRP) Composites through a Biomimetic Approach: Connecting Glass Fiber with Nanosized Boron Nitride by Polydopamine Coating

    OpenAIRE

    XueMei Wen; ZaoZao Xiao; Tao Jiang; Jian Li; Wei Zhang; Lei Zhang; Huaiqi Shao

    2013-01-01

    A biomimetic method was developed to construct novel fiber reinforced plastic (FRP) composites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was coated on glass fiber (GF) surface. The polydopamine-treated GF (D-GF) adsorbed boron nitride (BN) nanoparticles, while obtaining micronano multiscale hybrid fillers BN-D-GF. Scanning electron microscopy (SEM) results showed that the strong interfacial interaction brought by the polydopamine benefits the loading amount as well ...

  17. Analysis on Adhesively-Bonded Joints of FRP-steel Composite Bridge under Combined Loading: Arcan Test Study and Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2016-01-01

    Full Text Available The research presented in this paper is an experimental study and numerical analysis on mechanical behavior of the adhesively-bonded joint between FRP sandwich bridge deck and steel girder. Generally, there are three typical stress states in the adhesively-bonded joint: shear stress, tensile stress, and combination of both. To realize these stress states in the adhesively-bonded joint during tests, a specific loading device is developed with the capacity of providing six different loading angles, which are 0°(pure tension, 18°, 36°, 54°, 72° and 90°(pure shear. Failure modes of adhesively-bonded joints are investigated. It indicates that, for the pure shear loading, the failure mode is the cohesive failure (near the interface between the adhesive layer and the steel support in the adhesive layer. For the pure tensile and combined loading conditions, the failure mode is the combination of fiber breaking, FRP delamination and interfacial adhesion failure between the FRP sandwich deck and the adhesive layer. The load-bearing capacities of adhesive joints under combined loading are much lower than those of the pure tensile and pure shear loading conditions. According to the test results of six angle loading conditions, a tensile/shear failure criterion of the adhesively-bonded joint is obtained. By using Finite Element (FE modeling method, linear elastic simulations are performed to characterize the stress distribution throughout the adhesively-bonded joint.

  18. Constructing Novel Fiber Reinforced Plastic (FRP Composites through a Biomimetic Approach: Connecting Glass Fiber with Nanosized Boron Nitride by Polydopamine Coating

    Directory of Open Access Journals (Sweden)

    XueMei Wen

    2013-01-01

    Full Text Available A biomimetic method was developed to construct novel fiber reinforced plastic (FRP composites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was coated on glass fiber (GF surface. The polydopamine-treated GF (D-GF adsorbed boron nitride (BN nanoparticles, while obtaining micronano multiscale hybrid fillers BN-D-GF. Scanning electron microscopy (SEM results showed that the strong interfacial interaction brought by the polydopamine benefits the loading amount as well as dispersion of the nano-BN on GF’s surface. The BN-D-GF was incorporated into epoxy resin to construct “FRP nanocomposites.” The morphology, dynamic mechanical and thermal characteristics of the FRP nanocomposites were analyzed. SEM morphology revealed that BN-D-GF heterogeneous dispersed in epoxy matrix. There was good adhesion between the polymer matrix and the BN-D-GF filler. The dynamic modulus and mechanical loss were studied using dynamic mechanical analysis (DMA. Compared with neat epoxy and untreated GF reinforced composites, BN-D-GF/epoxy and D-GF/epoxy systems showed improved mechanical properties. The thermal conductivity, Shore D hardness, and insulation properties were also enhanced.

  19. PartialRC: A Partial Recomputing Method for Efficient Fault Recovery on GPGPUs

    Institute of Scientific and Technical Information of China (English)

    Xin-Hai Xu; Xue-Jun Yang; Jing-Ling Xue; Yu-Fei Lin; Yi-Song Lin

    2012-01-01

    GPGPUs are increasingly being used to as performance accelerators for HPC (High Performance Computing) applications in CPU/GPU heterogeneous computing systems,including TianHe-lA,the world's fastest supercomputer in the TOP500 list,built at NUDT (National University of Defense Technology) last year.However,despite their performance advantages,GPGPUs do not provide built-in fault-tolerant mechanisms to offer reliability guarantees required by many HPC applications.By analyzing the SIMT (single-instruction,multiple-thread) characteristics of programs running on GPGPUs,we have developed PartialRC,a new checkpoint-based compiler-directed partial recomputing method,for achieving efficient fault recovery by leveraging the phenomenal computing power of GPGPUs.In this paper,we introduce our PartialRC method that recovers from errors detected in a code region by partially re-computing the region,describe a checkpoint-based faulttolerance framework developed on PartialRC,and discuss an implementation on the CUDA platform.Validation using a range of representative CUDA programs on NVIDIA GPGPUs against FullRC (a traditional full-recomputing CheckpointRollback-Restart fault recovery method for CPUs) shows that PartialRC reduces significantly the fault recovery overheads incurred by FulIRC,by 73.5% when errors occur earlier during execution and 74.6% when errors occur later on average.In addition,PartialRC also reduces error detection overheads incurred by FullRC during fault recovery while incurring negligible performance overheads when no fault happens.

  20. Fiber Reinfoced Polymer Used for Flooding Protection of Engineering Structures Made of RC and Brick Masonry

    Directory of Open Access Journals (Sweden)

    Gabriel Oprişan

    2008-01-01

    Full Text Available Urban and rural floods are becoming nowadays a frequent problem to be dealt with, by both the population and the authorities. Floods and flood related natural disasters act against the civil, industrial and agricultural structures by the hydrostatic and hydrodynamic pressures of water. A set of protective solutions based on Fiber Reinforced Polymer (FRP composite materials, for structural elements of buildings subjected to flood loadings, is proposed and analysed. These solutions are achieved by using the hand lay-up forming technique utilizing glass, carbon or aramid fibers fabrics pre-impregnated with thermosetting epoxy, polyester or vynilester resins. The application of these FRP composites is carried out on reinforced concrete columns and beams as well as on brick masonry works aiming to increase in the overall load bearing capacity, especially against horizontal loads. An improved protection against excessive humidity is also envisaged. The Finite Elements Method based LUSAS software was used to simulate a partially flooded structure. The numerical modeling was carried out in both the un-strengthened and strengthened conditions of the structure in order to assess the increasing in load and deformation capacities of the structural elements. Volumetric finite elements were used for modeling the concrete and masonry members.

  1. Experimental study on seismic performance of concrete columns reinforced by steel-FRP composite bars%钢-连续纤维复合筋增强混凝土柱抗震性能试验研究

    Institute of Scientific and Technical Information of China (English)

    孙泽阳; 吴刚; 吴智深; 张敏

    2011-01-01

    The seismic performance of concrete columns reinforced by Steel-FRP(Fiber Reinforced Polymer) Composite Bar(SFCB) is quite different from that of ordinary RC(Reinforced Concrete) columns.Horizontal cyclic loading tests were conducted on concrete columns reinforced by SFCB and ordinary steel bars,separately,with an axial compression ratio of 0.12.Fiber types(basalt and carbon fibers) and steel/fiber ratio of SFCB were the main variable parameters.Test results showed that: ①compared with ordinary RC column,concrete columns reinforced by SFCB had stable post-yield stiffness,and the load could increase significantly after the yielding of SFCB inner steel bar;②due to the post-yield stiffness of SFCB,SFCB reinforced concrete column had less column base curvature demand than ordinary RC column at the same column cap lateral deformation level,and therefore smaller unloading residual deformation could be achieved;③the outer FRP type of SFCB significantly influenced the performance of SFCB reinforced concrete columns,and steel-BFRP(basalt FRP) composite bar reinforced concrete columns had better ductility(longer effective length of post-yield stiffness) and smaller unloading residual deformation than steel-CFRP(carbon FRP) composite bar columns under the same unloading displacement.%具有稳定二次刚度和良好震后可修复性的钢-连续纤维复合筋(SFCB)增强混凝土柱的抗震性能与普通RC柱有较大差别,本文对在水平往复荷载作用下,轴压比为0.12的4个SFCB增强混凝土柱及1个RC对比柱的抗震性能进行试验研究。SFCB增强混凝土柱主要变化参数为SFCB中的纤维种类(玄武岩纤维和碳纤维)和钢/纤维比例。研究结果表明:①SFCB增强混凝土柱相对普通RC柱具有稳定的二次刚度,在复合筋内芯钢筋屈服后,SFCB增强混凝土柱承载力仍可稳定提高;②SFCB增强混凝土柱由于复合筋的二次刚度,实现了在与普通RC柱

  2. sFRP5抑制Wnt3a对黑素细胞黑素形成作用的初步研究%SFRP5 suppresses melanin formation of melanocytes through Wnt3a inhibition

    Institute of Scientific and Technical Information of China (English)

    汤寅虹; 杨珂; 杨恬; 叶吉星; 刘鹏; 连小华; 郭海英; 彭惠民

    2014-01-01

    目的 研究sFRP5抑制Wnt3a对黑素细胞黑素形成的作用.方法 以永生化的黑素细胞为模型,利用腺病毒表达载体,设置Control组、Wnt3a处理组、Wnt3a+ sFRP5处理组进行以下实验:L-DOPA测定酪氨酸酶(tyrosinase,TYR)活性;Masson-Fontanas银染色法观察黑素形成情况;RT-PCR检测酪氨酸酶相关蛋白1(tyrosinase-related protein 1, TRP-1)、TYR基因的表达;Western blot检测TRP-1、TYR蛋白的表达水平.结果 L-DOPA测定酪氨酸酶活性结果显示Wnt3a+ sFRP5处理组TYR活性低于Wnt3a处理组,差异有统计学意义(P<0.05);Masson-Fontanas银染色法显示Wnt3a+sFRP5处理组形成的黑素明显低于Wnt3a处理组;RT-PCR检测结果显示Wnt3a+ sFRP5处理组能下调TRP-1、TYR基因的表达(P< 0.05);Western blot检测结果显示Wnt3a+ sFRP5处理组能下调TRP-1、TYR蛋白的表达水平(P<0.05).结论 sFRP5能抑制Wnt3a对黑素细胞黑素生成的作用.

  3. 预应力纤维布混合锚固分析与试验研究%Analysis and Testing Study of Hybrid Anchorage of Prestressed FRP

    Institute of Scientific and Technical Information of China (English)

    李青松; 孟少平; 单岗; 王侠伟

    2011-01-01

    In order to improve the deficiency in the technology of embedded prestressed FRP reinforcement, with the principle of anchoring bond and additional mechanical anchoring working together, the tensioning end of prestressed FRP is anchored twice after the tension and bonding of the FRP, then removing the existing fixture and anchor. To ensure the reliability of anchoring, the paper makes a theoretical analysis of the performance of the bonding layer in the anchoring end and an experimental research on hybrid anchoring end. The research results show that the change of the performance in the bonding layer improves its anchoring ability significantly, and the steel plate can be squeezed to provide pressure to improve and enhance the performance of the bonding layer,which guarantee the quality of anchoring end. The method of combining bonding layer with hybrid anchorage of the steel plate can provide the adequate anchoring capacity, improve the construction techniques, lessen the cost and the boost the application of prestress FRP reinforcement in the practical constructions.%为了改善嵌人式预应力纤维布(FRP)加固技术的不足之处,利用粘结与机械锚固共同工作的原理,在预应力FRP张拉粘贴完毕后,对张拉端进行二次锚固,粘结层硬化后拆除原有锚夹具.为保证锚固端的可靠性,本文对锚固端粘结层的性能进行了理论分析,并对混合锚固端进行了试验研究.研究结果表明:通过改变粘结层的性能,可大幅度提高粘结层的锚固能力;钢板压条可提供挤压力,改善和提高了粘结层的受力性能,便于保证锚同端施工质量,可靠性好.采用粘结层与钢板压条混合锚固的方式可为预应力FRP提供足够的锚固力,改善了施工工艺,明显降低加固成本,促进了预应力FRP加固技术在实际工程中的应用.

  4. Upgrading the seismic capacity of existing RC buildings using buckling restrained braces

    Directory of Open Access Journals (Sweden)

    Hamdy Abou-Elfath

    2017-06-01

    Full Text Available Many existing RC buildings do not meet the lateral strength requirements of current seismic codes and are vulnerable to significant damage or collapse in the event of future earthquakes. In the past few decades, buckling-restrained braces have become increasingly popular as a lateral force resisting system because of their capability of improving the strength, the stiffness and the energy absorbing capacity of structures. This study evaluates the seismic upgrading of a 6-story RC-building using single diagonal buckling restrained braces. Seismic evaluation in this study has been carried out by static pushover analysis and time history earthquake analysis. Ten ground motions with different PGA levels are used in the analysis. The mean plus one standard deviation values of the roof-drift ratio, the maximum story drift ratio, the brace ductility factors and the member strain responses are used as the basis for the seismic performance evaluations. The results obtained in this study indicate that strengthening of RC buildings with buckling restrained braces is an efficient technique as it significantly increases the PGA capacity of the RC buildings. The results also indicate the increase in the PGA capacity of the RC building with the increase in the amount of the braces.

  5. RC-QOL score for rotator cuff pathology: adaptation to Italian.

    Science.gov (United States)

    Papalia, Rocco; Osti, Leonardo; Leonardi, Francesco; Denaro, Vincenzo; Maffulli, Nicola

    2010-10-01

    We translated and adapted the English RC-QOL (rotator cuff quality of life) questionnaire into Italian and performed reliability and validity evaluations of the Italian RC-QOL version in patients with rotator cuff tears. The RC-QOL English version was translated into Italian by a bilingual orthopaedic surgeon. The back translation of the Italian version into English was performed by another bilingual orthopaedic surgeon. The original version was compared with the back translation. The RC-QOL questionnaire was then administered to 22 subjects (range 45-74 years) with a diagnosis of rotator cuff tears. For test-retest evaluation, the 22 patients were asked to complete the questionnaire at first examination, and 30 min following the end of this examination. The intraclass correlation coefficient for the 22 patients was 0.94 (95% CI = 0.85-0.98), indicating a high reliability. There were no significant differences between the scores immediately after the consultation and 30 min later. The Italian and the English versions of the RC-QOL questionnaire evaluate the same aspects of clinical severity in patients with rotator cuff tears.

  6. Effect of CFRP strengthening on the response of RC slabs to hard projectile impact

    Energy Technology Data Exchange (ETDEWEB)

    Almusallam, Tarek; Al-Salloum, Yousef; Alsayed, Saleh; Iqbal, Rizwan; Abbas, Husain, E-mail: abbas_husain@hotmail.com

    2015-05-15

    Highlights: • Studied response of CFRP-strengthened RC slabs under the impact load. • Slabs were tested under the strike of hemispherical steel projectiles at varying impact. • The slabs were analyzed numerically using LS-DYNA. • Strengthening increased the ballistic limit velocity by 18% and perforation energy by 56.7%. • CFRP sheet reduced the crater damage and contained the flying concrete fragments. - Abstract: In this paper impact response of CFRP-strengthened RC panels under the impact of non-deformable projectiles has been presented. The control and CFRP-strengthened RC slab panels were tested under the strike of hemispherical nosed steel projectiles at varying impact velocities. The response of these panels was investigated experimentally as well as numerically. The damage of the slab panels was measured in terms of the penetration depth, formation of cracks, spalling and scabbing areas and fracture of CFRP sheet. This study presents a practical and efficient numerical method for analyzing the impact response of CFRP-strengthened RC structures using LS-DYNA. The CFRP strengthening was found to increase the ballistic limit velocity by 18%, perforation energy of RC slabs by 56.7%, reduce the front crater damage and contains the flying of concrete fragments from the rear face. The maximum impact force occurs at almost same penetration depth for the control and CFRP-strengthened slabs but the restraint provided by CFRP increased the penetration depth by about 1/19.3 of the thickness of slab.

  7. Single-molecule spectroscopy on RC-LH1 complexes of Rhodopseudomonas acidophila strain 10050.

    Science.gov (United States)

    Böhm, Paul S; Southall, June; Cogdell, Richard J; Köhler, Jürgen

    2013-03-21

    We have revisited the RC-LH1 complex from Rhodopseudomonas (Rps.) acidophila for single-molecule spectroscopy. For the current study the pigment-protein complexes were stabilized in the detergent buffer solution using a relatively mild detergent (dodecyl-β-D-maltoside (DDM) instead of lauryldimethylamine N-oxide (LDAO)). This leads to a significant reduction of the fraction of broken/dissociated RC-LH1 complexes with respect to previous studies and has allowed us to investigate a sufficiently large sample of individual RC-LH1 complexes. For most of the complexes the fluorescence-excitation spectra exhibit a narrow spectral feature at the red end of the spectrum. Analysis of the statistics of the spectral properties yields a close resemblance with the results obtained on RC-LH1 complexes from Rps. palustris for which a low-resolution X-ray structure is available. Based on this comparison we come to the conclusion that for both species the RC-LH1 complex can be described by the same structural model, that is, an overall elliptical assembly of pigments that features a gap.

  8. Modèle de confinement pour les colonnes de section circulaire en béton armé confiné avec des enveloppes en polymère renforcé de fibres de carbone Confinement model for circular RC columns wrapped with CFRP composite

    Directory of Open Access Journals (Sweden)

    Benzaid R.

    2012-09-01

    Full Text Available Un programme experimental comprenant des essais sur 30 cylindres 160×320 mm a ete mene en vue de determiner le gain de resistance et de ductilite du beton confine par collage externe de tissu de polymere renforce de fibres de carbone (PRFC. Les variables etudiees sont la resistance a la compression du beton non confine f’co, le niveau de confinement, exprime par le nombre de plis de PRFC applique aux eprouvettes. La deformation circonferentielle a la rupture du composite PRF et l’feffet de la pression de confinement laterale effective de l’fenveloppe composite ont ete egalement etudies. Pour l’fensemble des specimens testes, l’faugmentation de la rigidite du confinement entraine a la fois une augmentation significative de la resistance a la compression axiale et de la ductilite des specimens en beton confine avec des PRFC par rapport aux specimens en beton non confine. Base sur les resultats experimentaux, un modele de confinement pratique est propose pour predire la resistance a la compression maximale du beton confine avec des materiaux composites (f’cc et la deformation axiale correspondante (εcc. The present paper deals with the analysis of experimental results, in terms of load carrying capacity and strains, obtained from tests on plain- and reinforced- concrete (RC cylinder, strengthened with external carbon-fiber-reinforced polymer (CFRP. The parameters considered are the number of composite layers, the compressive strength of unconfined concrete. The effective circumferential FRP failure strain and the effect of the effective lateral confining pressure were investigated. Totally thirty cylinders (160×320 mm were subjected to axial compression which includes control specimens. All the test specimens were loaded to failure in axial compression and the behaviour of the specimens in the axial and transverse directions was investigated. Test results shown that the CFRP wrap increases the strength and ductility of reinforced

  9. Development of easy-to-use reverse-phase liquid chromatographic methods for determining PRE-084, RC-33 and RC-34 in biological matrices. The first step for in vivo analysis of sigma1 receptor agonists.

    Science.gov (United States)

    Marra, Annamaria; Rossi, Daniela; Maggi, Lauretta; Corana, Federica; Mannucci, Barbara; Peviani, Marco; Curti, Daniela; Collina, Simona

    2016-04-01

    Over the years there has been a growing interest in the therapeutic potential for central nervous system pathologies of sigma receptor modulators. The widely studied PRE-084 and our compounds RC-33 and RC-34 are very potent and selective sigma 1 receptor agonists that could represent promising drug candidates for Amyotrophic Lateral Sclerosis (ALS). Herein, we develop and validate robust and easy-to-use reverse-phase chromatographic methods suitable for detecting and quantifying PRE-084, RC-33 and RC-34 in mouse blood, brain and spinal cord. An HPLC/UV/ESI-MS system was employed for analyzing PRE-084 and an HPLC/UV-PDA system for determining RC-33 and RC-34. Chromatographic separations were achieved on Waters Symmetry RP18 column (150 × 3.9 mm, 5 µm), eluting with water and acetonitrile (both containing 0.1% formic acid) in gradient conditions. The recovery of PRE-084, RC-33 and RC-34 was >95% in all the considered matrices. Their limits of quantitation and detection were also determined. Validation proved the methods be suitable for separating tested compounds from endogenous interferences, being characterized by good sensitivity, linearity, precision and accuracy. A preliminary central nervous system distribution study showed a high distribution of RC-33 in brain and spinal cord, with concentration values well above the determined limit of quantitation. The proposed methods will be used in future preclinical investigations.

  10. Automatically produced FRP beams with embedded FOS in complex geometry: process, material compatibility, micromechanical analysis, and performance tests

    Science.gov (United States)

    Gabler, Markus; Tkachenko, Viktoriya; Küppers, Simon; Kuka, Georg G.; Habel, Wolfgang R.; Milwich, Markus; Knippers, Jan

    2012-04-01

    The main goal of the presented work was to evolve a multifunctional beam composed out of fiber reinforced plastics (FRP) and an embedded optical fiber with various fiber Bragg grating sensors (FBG). These beams are developed for the use as structural member for bridges or industrial applications. It is now possible to realize large scale cross sections, the embedding is part of a fully automated process and jumpers can be omitted in order to not negatively influence the laminate. The development includes the smart placement and layout of the optical fibers in the cross section, reliable strain transfer, and finally the coupling of the embedded fibers after production. Micromechanical tests and analysis were carried out to evaluate the performance of the sensor. The work was funded by the German ministry of economics and technology (funding scheme ZIM). Next to the authors of this contribution, Melanie Book with Röchling Engineering Plastics KG (Haren/Germany; Katharina Frey with SAERTEX GmbH & Co. KG (Saerbeck/Germany) were part of the research group.

  11. A simple analytical solution for predicting deflection of a hybrid FRP-aluminum modular space truss bridge

    Institute of Scientific and Technical Information of China (English)

    李飞; 张冬冬; 赵启林; 邓安仲

    2015-01-01

    A novel hybrid FRP-aluminum space truss was employed in a two-rut modular bridge superstructure, which is composed of standard structural units. The main objective of this work was to obtain a simple analytical solution that can conveniently predict the deflection of the proposed hybrid space truss bridge. The analytical formulae are expected to possess a straightforward format and simple calculation process. A simple description of the proposed bridge was introduced. The design formulae of the deflection were derived based on a simplified analytical plane truss model, which possessed hinge nodes and was subsequently simplified as two solid web beams during the theoretical derivation process. To validate the analytical model and formulae, numerical and experimental works were conducted and compared with the theoretical solutions. The results indicate that the analytical formulae provide higher deflection magnitudes with a difference of <1.5% compared with the experiments performed and <4.5% compared with the FE model used; the simplified plane truss is thus shown to be an effective analytical model for the derivation of deflection design formulae, which can conveniently calculate the deflection of the hybrid space truss bridge with satisfactory accuracy.

  12. Standard practice for determining damage-Based design Stress for fiberglass reinforced plastic (FRP) materials using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice details procedures for establishing the direct stress and shear stress damage-based design values for use in the damage-based design criterion for materials to be used in FRP vessels and other composite structures. The practice uses data derived from acoustic emission examination of four-point beam bending tests and in-plane shear tests (see ASME Section X, Article RT-8). 1.2 The onset of lamina damage is indicated by the presence of significant acoustic emission during the reload portion of load/reload cycles. "Significant emission" is defined with historic index. 1.3 Units - The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical conversions to SI units which are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health pr...

  13. Single-step affinity purification of recombinant proteins using a self-excising module from Neisseria meningitidis FrpC

    Science.gov (United States)

    Sadilkova, Lenka; Osicka, Radim; Sulc, Miroslav; Linhartova, Irena; Novak, Petr; Sebo, Peter

    2008-01-01

    Purification of recombinant proteins is often a challenging process involving several chromatographic steps that must be optimized for each target protein. Here, we developed a self-excising module allowing single-step affinity chromatography purification of untagged recombinant proteins. It consists of a 250-residue-long self-processing module of the Neisseria meningitidis FrpC protein with a C-terminal affinity tag. The N terminus of the module is fused to the C terminus of a target protein of interest. Upon binding of the fusion protein to an affinity matrix from cell lysate and washing out contaminating proteins, site-specific cleavage of the Asp–Pro bond linking the target protein to the self-excising module is induced by calcium ions. This results in the release of the target protein with only a single aspartic acid residue added at the C terminus, while the self-excising affinity module remains trapped on the affinity matrix. The system was successfully tested with several target proteins, including glutathione-S-transferase, maltose-binding protein, β-galactosidase, chloramphenicol acetyltransferase, and adenylate cyclase, and two different affinity tags, chitin-binding domain or poly-His. Moreover, it was demonstrated that it can be applied as an alternative to two currently existing systems, based on the self-splicing intein of Saccharomyces cerevisiae and sortase A of Staphylococcus aureus. PMID:18662906

  14. Predictive validity of the MMPI-2 clinical, PSY-5, and RC scales for therapy disruptive behavior.

    Science.gov (United States)

    Scholte, Wubbo; Tiemens, Bea G; Verheul, Roel; Meerman, Anke; Egger, Jos; Hutschemaekers, Giel

    2012-11-01

    Impulsive acts, parasuicidal behavior, and other therapy disruptive incidents occur frequently in the treatment of patients with personality disorders and increase the risk that patients will drop out of treatment. This study examined the predictive validity of the Minnesota Multiphasic Personality Inventory (MMPI)-2 Restructured Clinical (RC) and Psychopathology Five (PSY-5) Scales for therapy disruptive behavior and compared them with the original clinical scales. Using an inventory, the treatment staff recorded the therapy disruptive behavior of 104 patients with personality disorders who were receiving inpatient psychotherapy. Both the RC and the PSY-5 scales predicted several categories of therapy disruptive behavior, and both scales predicted more categories of therapy disruptive behavior than the original clinical scales. Anger outbursts were predicted especially well by a combination of two of the RC scales. The information about the MMPI-2 obtained in this study may be helpful in case formulation when initiating inpatient treatment for patients with personality disorders.

  15. An experimental investigation on the ultimate strength of epoxy repaired braced partial infilled RC frames

    Science.gov (United States)

    Dubey, Shailendra Kumar Damodar; Kute, Sunil

    2014-09-01

    Due to earthquake, buildings are damaged partially or completely. Particularly structures with soft storey are mostly affected. In general, such damaged structures are repaired and reused. In this regard, an experimental investigation was planned and conducted on models of single-bay, single-storey of partial concrete infilled reinforced concrete (RC) frames up to collapse with corner, central and diagonal steel bracings. Such collapsed frames were repaired with epoxy resin and retested. The initiative was to identify the behaviour, extent of restored ultimate strength and deflection of epoxy-retrofitted frames in comparison to the braced RC frames. The performance of such frames has been considered only for lateral loads. In comparison to bare RC frames, epoxy repaired partial infilled frames have significant increase in the lateral load capacity. Central bracing is more effective than corner and diagonal bracing. For the same load, epoxy repaired frames have comparable deflection than similar braced frames.

  16. Modeling of R/C Servo Motor and Application to Underactuated Mechanical Systems

    Science.gov (United States)

    Ishikawa, Masato; Kitayoshi, Ryohei; Wada, Takashi; Maruta, Ichiro; Sugie, Toshiharu

    An R/C servo motor is a compact package of a DC geard-motor associated with a position servo controller. They are widely used in small-sized robotics and mechatronics by virtue of their compactness, easiness-to-use and high/weight ratio. However, it is crucial to clarify their internal model (including the embedded position servo) in order to improve control performance of mechatronic systems using R/C servo motors, such as biped robots or underactuted sysyems. In this paper, we propose a simple and realistic internal model of the R/C servo motors including the embedded servo controller, and estimate their physical parameters using continuous-time system identification method. We also provide a model of reference-to-torque transfer function so that we can estimate the internal torque acting on the load.

  17. Flexural strengthening of Reinforced Concrete (RC) Beams Retrofitted with Corrugated Glass Fiber Reinforced Polymer (GFRP) Laminates

    Science.gov (United States)

    Aravind, N.; Samanta, Amiya K.; Roy, Dilip Kr. Singha; Thanikal, Joseph V.

    2015-01-01

    Strengthening the structural members of old buildings using advanced materials is a contemporary research in the field of repairs and rehabilitation. Many researchers used plain Glass Fiber Reinforced Polymer (GFRP) sheets for strengthening Reinforced Concrete (RC) beams. In this research work, rectangular corrugated GFRP laminates were used for strengthening RC beams to achieve higher flexural strength and load carrying capacity. Type and dimensions of corrugated profile were selected based on preliminary study using ANSYS software. A total of twenty one beams were tested to study the load carrying capacity of control specimens and beams strengthened with plain sheets and corrugated laminates using epoxy resin. This paper presents the experimental and theoretical study on flexural strengthening of Reinforced Concrete (RC) beams using corrugated GFRP laminates and the results are compared. Mathematical models were developed based on the experimental data and then the models were validated.

  18. Limit of axial force ratio and requirement for stirrups of RC columns with special shape

    Institute of Scientific and Technical Information of China (English)

    WANG Yiqun; XU Yidong; ZHAO Yanjing; CHEN Yunxia

    2007-01-01

    Thousands of columns with special shape are analyzed by nonlinear numerical methods. The ductility is calculated to investigate the limit of the axial force ratio and circumstantial requirement for stirrups of an reinforced concrete (RC) column with special shape, in the point of view of the characteristic value for providing stirrup. The limit of the axial force ratio of columns with special shape in relation to the characteristic value of the stirrup is obtained. Then, the effect of stirrup arrangement on the ductility of the RC column is discussed in case of buckling of the longitudinal reinforcement and constraint concrete columns. The complete requirement for stirrups of RC column with special shape is given.

  19. Nonlinear analysis of RC cylindrical tank and subsoil accounting for a low concrete strength

    Directory of Open Access Journals (Sweden)

    Lewiński Paweł M.

    2017-01-01

    Full Text Available The paper discusses deformational and incremental approaches to a nonlinear FE analysis of soil-structure interaction including the description of behaviour of the RC structure and the subsoil under short-term loading. Two kinds of constitutive models for ground and structure were adopted for a nonlinear interaction analysis of the RC cylindrical tank with subsoil. The constitutive laws for concrete and subsoil were developed in compliance with the deformational and flow theories of plasticity. Moreover, a non-linear elastic-brittle-plastic analysis of RC axi-symmetric structures using finite element iterative techniques is presented. The results of the two types of FE analysis of soil-structure interaction are compared taking into account a low concrete strength of tank structure.

  20. Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide

    Directory of Open Access Journals (Sweden)

    Conrads Thomas P

    2011-07-01

    Full Text Available Abstract Background RC-101, a cationic peptide retrocyclin analog, has in vitro activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF, enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS. Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV. RC-101 was monitored by LC-MS/MS for up to 72 h. Results RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects. Conclusions Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.

  1. Derivation of the clinical grade human embryonic stem cell line RCe013-A (RC-9

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe013-A (RC-9 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a failed to fertilise oocyte voluntarily donated as unsuitable and surplus to fertility requirements following informed consent. RCe013-A (RC-9 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro and in vivo. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  2. Derivation of the clinical grade human embryonic stem cell line RCe016-A (RC-12

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe016-A (RC-12 was derived under quality assured compliance with UK regulations, EU Directives and International guidance for tissue procurement, processing and storage according to good manufacturing practice (GMP standards. The cell line was derived from a cryopreserved blastocyst stage embryo voluntarily donated as surplus to fertility requirements following informed consent. RCe016-A (RC-12 shows normal pluripotency marker expression and differentiation to three germ layers in vitro. Karyology revealed a mixed male karyotype at early passage (P15, which resolved as normal 46XY by passage 33. Microsatellite PCR identity, HLA and blood group typing data is available.

  3. Derivation of the clinical grade human embryonic stem cell line RCe019-A (RC-15

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe019-A (RC-15 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a cleavage stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe019-A (RC-15 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 46XX/47XX, +8 female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  4. Derivation of the clinical grade human embryonic stem cell line RCe015-A (RC-11

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe015-A (RC-11 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a fragmented cleavage stage embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe015-A (RC-11 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro and in vivo. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  5. Derivation of the clinical grade human embryonic stem cell line RCe021-A (RC-17

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-07-01

    Full Text Available The human embryonic stem cell line RCe021-A (RC-17 was derived under quality assured compliance with UK regulation, European Union Directives and International guidance for tissue procurement, processing and storage according to Good Manufacturing Practice (GMP standards. The cell line was derived from a day 3 embryo voluntarily donated as unsuitable or surplus to fertility requirements following informed consent. RCe021-A (RC-17 shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  6. Assessment of Damage in Seismically Excited RC-Structures from a Single Measured Response

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Cakmak, A. S.

    1996-01-01

    A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated. The dist......A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated...

  7. Earthquake Analysis for the System of RC Building with a Steel Tower

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A steel tower topping an RC building comprises a non-proportional damping structural system with different damping ratios. To compare the results from the non-proportional damping model and the equivalent damping model ,the structural system was calculated with the two damping models during earthquake respectively, using earthquake time history analysis computer program developed by the authors. Differences in the calculated results of inner forces and displacements using the two damping models were observed. It is found that if the equivalent damping model is used in design, the consequence will be unsafe for the steel tower and too safe for the RC building at the same time.

  8. Debilidad SAC en el algoritmo de cifrado en flujo RC4

    Directory of Open Access Journals (Sweden)

    Evaristo J. Madarro Capó

    2017-05-01

    Full Text Available En este trabajo se describe una interesante vía para la detección de la existencia de entradas de colisión en el algoritmo de cifrado en flujo RC4 basado en el criterio estricto de avalancha y se discuten los resultados obtenidos en comparación con las debilidades y ataques reportados sobre el RC4 que plantean la existencia de una fuerte correlación entre los parámetros de entrada y salida del algoritmo.

  9. Psychometric Properties of the MMPI-2-RF Somatic Complaints (RC1) Scale

    Science.gov (United States)

    Thomas, Michael L.; Locke, Dona E. C.

    2010-01-01

    The MMPI-2 Restructured Form (MMPI-2-RF; Tellegen & Ben-Porath, 2008) was designed to be psychometrically superior to its MMPI-2 counterpart. However, the test has yet to be extensively evaluated in diverse clinical settings. The purpose of this study was to examine the psychometric properties of the MMPI-2-RF Somatic Complaints (RC1) scale in…

  10. Susceptibility of the MMPI-2 Clinical, Restructured Clinical (RC), and Content Scales to Overreporting and Underreporting

    Science.gov (United States)

    Sellbom, Martin; Ben-Porath, Yossef S.; Graham, John R.; Arbisi, Paul A.; Bagby, R. Michael

    2005-01-01

    The authors examined and compared the susceptibility of three Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scale sets (Clinical, Restructured Clinical [RC], and Content) to over- and underreporting using five analog samples. Two samples of 85 and 191 undergraduate students, respectively, took the MMPI-2 under underreporting versus…

  11. Elevation Differences between MMPI-2 Clinical and Restructured Clinical (RC) Scales: Frequency, Origins, and Interpretative Implications

    Science.gov (United States)

    Sellbom, Martin; Ben-Porath, Yossef S.; McNulty, John L.; Arbisi, Paul A.; Graham, John R.

    2006-01-01

    The frequency, origin, and interpretative implications of elevation differences on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) clinical and restructured clinical (RC) scales were examined. Two large clinical samples consisting of 1,770 outpatients and 2,438 inpatients were used for this study. Three potential factors…

  12. Identification Report: Earthquake Test on 2-Bay, 6-Story Scale 1:5 RC-Frames

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Skjærbæk, P. S.; Nielsen, Søren R. K.

    The aim of the present report is to supply the identification results from the tests performed with a laboratory model of a plane 6-storey, 2-bay scale 1:5 RC-frame at Aalborg University, Denmark during the autumn 1996. The tests were performed as a part of a Ph.D study considering evaluation of ...

  13. GENERACIÓN DE POLINOMIOS DE SCHUBERT CON COCOA II: GRAFOS RC.

    Directory of Open Access Journals (Sweden)

    Fernando Novoa

    2004-06-01

    Full Text Available El polinomio de Schubert asociado a una permutación w es codificado por medio de la información contenida en ciertos grafos rc. Presentamos un programa para el cómputo de los polinomios de Schubert por medio de movimientos definidos sobre estos grafos.

  14. Creating updated, scientifically-calibrated mosaic images for the RC3 catalogue

    CERN Document Server

    Lee, Jung Lin

    2015-01-01

    The Third Reference Catalogue of Bright Galaxies (RC3) is a reasonably complete listing of 23,011 nearby, large, bright galaxies. By using the final imaging data release from the Sloan Digital Sky Survey, we generate scientifically-calibrated FITS mosaics by using the montage program for all SDSS imaging bands for all RC3 galaxies that lie within the survey footprint. We further combine the SDSS g, r, and i band FITS mosaics for these galaxies to create color-composite images by using the STIFF program. We generalized this software framework to make FITS mosaics and color-composite images for an arbitrary catalog and imaging data set. Due to positional inaccuracies inherent in the RC3 catalog, we employ a recursive algorithm in our mosaicking pipeline that first determines the correct location for each galaxy, and subsequently applies the mosaicking procedure. As an additional test of this new software pipeline and to obtain mosaic images of a larger sample of RC3 galaxies, we also applied this pipeline to ph...

  15. Application of ANN to evaluate effective parameters affecting failure load and displacement of RC buildings

    Directory of Open Access Journals (Sweden)

    M. Hakan Arslan

    2009-06-01

    Full Text Available This study investigated the efficiency of an artificial neural network (ANN in predicting and determining failure load and failure displacement of multi story reinforced concrete (RC buildings. The study modeled a RC building with four stories and three bays, with a load bearing system composed of columns and beams. Non-linear static pushover analysis of the key parameters in change defined in Turkish Earthquake Code (TEC-2007 for columns and beams was carried out and the capacity curves, failure loads and displacements were obtained. Totally 720 RC buildings were analyzed according to the change intervals of the parameters chosen. The input parameters were selected as longitudinal bar ratio (ρl of columns, transverse reinforcement ratio (Asw/sc, axial load level (N/No, column and beam cross section, strength of concrete (fc and the compression bar ratio (ρ'/ρ on the beam supports. Data from the nonlinear analysis were assessed with ANN in terms of failure load and failure displacement. For all outputs, ANN was trained and tested using of 11 back-propagation methods. All of the ANN models were found to perform well for both failure loads and displacements. The analyses also indicated that a considerable portion of existing RC building stock in Turkey may not meet the safety standards of the Turkish Earthquake Code (TEC-2007.

  16. Power Efficient Gigabit Communication Over Capacitively Driven RC-Limited On-Chip Interconnects

    NARCIS (Netherlands)

    Mensink, E.; Schinkel, Daniel; Klumperink, Eric A.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

    2010-01-01

    Abstract—This paper presents a set of circuit techniques to achieve high data rate point-to-point communication over long on-chip RC-limited wire-pairs. The ideal line termination impedances for a flat transfer function with linear phase (pure delay) are derived, using an s-parameter wire-pair

  17. Study on shear strengthening of RC continuous T-beams using different layers of CFRP strips

    Energy Technology Data Exchange (ETDEWEB)

    Alferjani, M. B. S.; Samad, A. A. Abdul; Mohamad, Noridah [Faculty of Civil and Environmental Engineering, Universiti Tun Hussein Onn Malaysia, Batu Pahat (Malaysia); Elrawaff, Blkasem S.; Elzaroug, Omer [Faculty of Civil Engineering Omar Al Mukhtar University, Bayda, Libya, Africa (Libya)

    2015-05-15

    Carbon fiber reinforced polymer (CFRP) laminates are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. However, this paper presents the results of an experimental investigation for enhancing the shear capacity of reinforced concrete (RC) continuous T- beams using different layers of CFRP wrapping schemes. A total of three concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on ultimate shear strength and shear capacity of the beams. One beam was kept as control beams, while other beams were strengthened with externally bonded CFRP strips with three side bonding and one or two layers of CFRP strips. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers provided the most effective strengthening for RC continuous T- beam. Beam strengthened using this scheme showed 23.21% increase in shear capacity as compared to the control beam. Two prediction models available in literature were used for computing the contribution of CFRP strips and compared with the experimental results.

  18. Problems and their solutions in practical application of Eurocodes in seismic design of RC structures

    Directory of Open Access Journals (Sweden)

    Milev Jordan

    2016-01-01

    Full Text Available The main purpose of the paper is to present practical application of Eurocodes in the field of RC structures design. The selected examples represent the main problems in practical application of Eurocodes for seismic analysis and design of RC Structures in Bulgarian construction practice. The analysis is focused on some structural and economic problems as well as on some contradictions in Eurocode 8 itself. Special attention is paid to the practical solution of the following problems: recognition of torsionally flexible systems, stiffness reduction of RC elements for linear analysis dimensions and detailing of confined boundary areas of shear walls, detailing of wall structures, etc. Those problems appear during the practical design of some buildings in Bulgaria. Several proposals for solving some problems defined in the paper are presented through some practical examples. Some conclusions are made for further application of Eurocode 8 in the design and construction practice. The importance of some rules and procedures in Eurocode 8 is supported by the examples of damaged RC members during the past earthquakes. The problems of Eurocode 8 and their solutions are illustrated through the experience of Bulgarian construction practice.

  19. Virtual RC Damping of LCL-Filtered Voltage Source Converters with Extended Selective Harmonic Compensation

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    Active damping and harmonic compensation are two common challenges faced by LCL-filtered voltage source converters. To manage them holistically, this paper begins by proposing a virtual RC damper in parallel with the passive filter capacitor. The virtual damper is actively inserted by feeding back...... in the laboratory with results obtained for demonstrating stability and harmonic compensation....

  20. Study on shear strengthening of RC continuous T-beams using different layers of CFRP strips

    Science.gov (United States)

    Alferjani, M. B. S.; Samad, A. A. Abdul; Elrawaff, Blkasem S.; Elzaroug, Omer; Mohamad, Noridah

    2015-05-01

    Carbon fiber reinforced polymer (CFRP) laminates are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. However, this paper presents the results of an experimental investigation for enhancing the shear capacity of reinforced concrete (RC) continuous T- beams using different layers of CFRP wrapping schemes. A total of three concrete beams were tested and various sheet configurations and layouts were studied to determine their effects on ultimate shear strength and shear capacity of the beams. One beam was kept as control beams, while other beams were strengthened with externally bonded CFRP strips with three side bonding and one or two layers of CFRP strips. From the test results, it was found that all schemes were found to be effective in enhancing the shear strength of RC beams. It was observed that the strength increases with the number of sheet layers provided the most effective strengthening for RC continuous T- beam. Beam strengthened using this scheme showed 23.21% increase in shear capacity as compared to the control beam. Two prediction models available in literature were used for computing the contribution of CFRP strips and compared with the experimental results.

  1. Power Efficient Gigabit Communication Over Capacitively Driven RC-Limited On-Chip Interconnects

    NARCIS (Netherlands)

    Mensink, Eisse; Schinkel, Daniël; Klumperink, Eric A.M.; Tuijl, van Ed; Nauta, Bram

    2010-01-01

    This paper presents a set of circuit techniques to achieve high data rate point-to-point communication over long on-chip RC-limited wire-pairs. The ideal line termination impedances for a flat transfer function with linear phase (pure delay) are derived, using an s-parameter wire-pair model. It is s

  2. Nannoplankton from RC9-156 in the southeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.

    A deep sea core RC9-156 collected in the Arabian Sea at a water depth of 4583 m was analysed for calcareous nannoplankton and dissolution studies. Twelve species of nannoplankton were identified and based on the assemblage, it is suggested...

  3. 47 CFR 95.208 - (R/C Rule 8) How high may I put my antenna?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 8) How high may I put my antenna? 95.208 Section 95.208 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... § 95.208 (R/C Rule 8) How high may I put my antenna? (a) Antenna means the radiating system...

  4. Generation of equivalent forms of operational trans-conductance amplifier-RC sinusoidal oscillators: the nullor approach

    Directory of Open Access Journals (Sweden)

    Raj Senani

    2014-06-01

    Full Text Available It has been shown in two earlier papers published from this study that corresponding to a given single-operational trans-conductance amplifier (single-OTA-RC and dual-OTA-RC sinusoidal oscillators, there are three other structurally distinct equivalent forms having the same characteristic equation, one of which employs both grounded capacitors (GC. In this study, an earlier nullor-based theory of generating equivalent op-amp oscillator circuits, proposed by the first author, is extended to derive equivalent OTA-RC circuits which discloses the existence of an additional number of equivalent forms for the same given OTA-RC oscillators than those predicted by the quoted earlier works, and thereby considerably enlarging the set of equivalents of a given OTA-RC oscillator. Furthermore, the presented nullor-based theory of generating equivalent OTA-RC oscillators results in three additional interesting outcomes: (i the revelation that corresponding to any given OTA-RC oscillator there are two ‘both-GC’ oscillators (and not merely one, as derived in the quoted earlier works; (ii the availability of explicit current outputs in several of the derived equivalents and (iii the realisability explicit-current-output ‘quadrature oscillators’ in some of the generated equivalent oscillators. The workability of the generated equivalent OTA-RC oscillators has been verified by SPICE simulations, based on CMOS OTAs using 0.18 µm CMOS technology process parameters, and some sample results are given.

  5. Fiber Optic Assessment of Damage in Frp Strengthened Structures%光纤传感器测量FRP加固结构的损伤

    Institute of Scientific and Technical Information of China (English)

    赵鸣; 赵鸿; 赵阳; F.Ansari

    2002-01-01

    A distributed fiber optic sensor is developed for condition monitoring of civil infrastructure sys-tems. The fiber optic sensor is especially useful in applications involving structures strengthened by fiberreinforced polymer (FRP) composites. The sensor principles are simple and therefore, practical for detec-tion of cracks, debonding and deformation measurements. Structural monitoring capability of the sensorwas evaluated through experiments with cracked reinforced concrete beams strengthened by way of CFRP(Carbon Fiber Reinforced Polymer) fabrics. Sensor principle and experimental results are presented anddiscussed.

  6. Cálculo en agotamiento de secciones de fábrica reforzadas a flexión con láminas de FRP

    Directory of Open Access Journals (Sweden)

    Martínez, S.

    2015-12-01

    Full Text Available Masonry structures can hardly resist tensile loads. For this reason these structures are vulnerable to accidental actions, such as earthquakes, or when they suffer damage that change their geometry conditions, for instead, due to differential soil settlements. This paper presents an ultimate limit state method for checking FRP-strengthened unreinforced masonry sections. The method is similar to the one used for reinforced concrete members, but it is adapted to masonry and FRP laminates particularities. In this proposal a bilinear strength-strain relationship is used and the FRP design strain is limited to take into account different aspects which cause the plate can’t reach its ultimate strength. In particular, it is proposed a “bond reduction factor”, derived from a large bending test database.Las estructuras de fábrica apenas tienen capacidad para resistir tracciones lo que las hace vulnerables ante acciones desestabilizantes de tipo accidental, como terremotos, o cuando sufren daños que alteran su geometría, por ejemplo, por asientos diferenciales. En este trabajo se presenta un método para la comprobación en agotamiento de secciones de fábrica reforzadas a flexión con láminas de FRP. Está basado en el procedimiento de cálculo de la capacidad resistente de secciones de hormigón pero adaptado a las particularidades y condicionantes de las fábricas reforzadas. En esta propuesta se utiliza un diagrama de cálculo tensión deformación de la fábrica de tipo bilineal y se limita la deformación de cálculo del refuerzo teniendo en consideración ciertos aspectos que provocan que no pueda desarrollar toda su resistencia. En concreto, se propone un «coeficiente reductor por adherencia» que se determina a partir de una amplia base de datos con ensayos de flexión.

  7. FRP衬里树脂重防腐之缺陷及解决办法%Defects&Solutions of FRP Lining Resin Heavy-duty

    Institute of Scientific and Technical Information of China (English)

    欧阳自强

    2012-01-01

      This paper systematically summarizes problems and fabrication quality defects of the thermosetting resin, particularly unsaturated polyester resins and vinyl ester resin in anti-corrosion FRP Lining engineer, then analyzes their reasons and put forward solutions.%  本文系统总结了热固性树脂,尤其是不饱和聚酯树脂和乙烯基酯树脂在制作重防腐玻璃钢衬里时遇到的问题及施工质量缺陷,分析其原因,提出解决对策。

  8. FRP人行桥的人致振动特性研究%VIBRATION STUDY ON FRP FOOTBRIDGE UNDER HUMAN-INDUCED LOAD

    Institute of Scientific and Technical Information of China (English)

    金飞飞; 冯鹏; 叶列平

    2011-01-01

    As the new structural materials and long span footbridge being used these years, the vibration prob lem due to human-induced load has become a significant issue. Especially in regards to the light-weight FRP foot bridge , the weight of crowd can' t be overlooked, thus when analyzing the dynamic response of FRP footbridge, it' s necessary to consider the influence of crowd. In this paper, the human body internal driven force is introduced and derived, then the vertical coupling vibration equations are established. With the numerical analysis method, the dy namic response of an actual FRP cable-stayed footbridge is analyzed under different pedestrian flows, and the effect of reducing the dynamic response by paving a layer of concrete is also analyzed. All theoretical analysis shows that the FRP cable-stayed footbridge can meet the requirement of dynamic performance under human-induced load.%近年来随着新材料以及大跨度人行天桥的不断出现,由行人行走引起的振动问题日渐显著.尤其在轻质FRP人行天桥中,行人质量相对桥梁本身质量不可忽略,在计算FRP人行天桥动力响应时,需要考虑行人带来的影响.本文通过引入并推导了行人人体驱动力,建立起行人与人行天桥之间的耦合竖向振动方程.利用数值分析方法分析了一座实际FRP斜拉人行桥在不同行人通行量下的动力响应,并分析了上铺混凝土面层对改善动力响应的效果.理论分析表明,该FRP斜拉桥可满足对人行天桥动力性能的要求.

  9. Perbandingan Algoritma Enkripsi GGHN(8,8 dan RC4 Untuk Video Conference

    Directory of Open Access Journals (Sweden)

    Satriyo Satriyo

    2012-01-01

    Full Text Available Encryption is a solutions to secure the information transmitted through the medium of communication that can not be intercepted by unauthorized parties. This study implemented two algorithms i.e. RC4 and GGHN (8.8 in video conference. This study compared the speed  of  both  encryption  and  decryption  of  the  encryption  algorithm,  and  perform  measurements  of  bandwidth .  From  the  results  of measurements of the speed can be concluded that the RC4 algorithm is 1.53 times and 1.34 times faster than GGHN(8,8 for encryption and  decryption  audio  data.  The  encryption  and  decryption  video  data  RC4  are  1.44  times  and  1.09  times  faster  than  GHN(8,8. Bandwidth  usage  for  video  conferencing  without  encryption  and  bandwidth  usage  on  a  video  conference  with  RC4  encryption  and GGHN (8.8 is the same.Keywords: Video Conference; RC4; GGHN(8,8; Real Time Protocol.

  10. Tomographic reconstruction of storm time RC ion distribution from ENA images on board multiple spacecraft

    Science.gov (United States)

    Ma, Shu-Ying; Yan, Wei-Nan; Xu, Liang

    2015-11-01

    A quantitative retrieval of 3-D distribution of energetic ions as energetic neutral atoms (ENA) sources is a challenging task. In this paper the voxel computerized tomography (CT) method is initially applied to reconstruct the 3-D distribution of energetic ions in the magnetospheric ring current (RC) region from ENA emission images on board multiple spacecraft. To weaken the influence of low-altitude emission (LAE) on the reconstruction, the LAE-associated ENA intensities are corrected by invoking the thick-target approximation. To overcome the divergence in iteration due to discordant instrument biases, a differential ENA voxel CT method is developed. The method is proved reliable and advantageous by numerical simulation for the case of constant bias independent of viewing angle. Then this method is implemented with ENA data measured by the Two Wide-angle Imaging Neutral-atom Spectrometers mission which performs stereoscopic ENA imaging. The 3-D spatial distributions and energy spectra of RC ion flux intensity are reconstructed for energies of 4-50 keV during the main phase of a major magnetic storm. The retrieved ion flux distributions seem to correspond to an asymmetric partial RC, located mainly around midnight favoring the postmidnight with L = 3.5-7.0 in the equatorial plane. The RC ion distributions with magnetic local time depend on energy, with major equatorial flux peak for lower energy located east of that for higher energy. In comparison with the ion energy spectra measured by Time History of Events and Macroscale Interactions during Substorms-D satellite flying in the RC region, the retrieved spectrum from remotely sensed ENA images are well matched with the in situ measurements.

  11. 防腐混凝土梁长期力学性能试验研究%THE STUDY ON CREEP BEHAVIOR OF FRP REBAR REINFORCED ANTISEPTIC CONCRETE BEAM

    Institute of Scientific and Technical Information of China (English)

    余启明; 吴卫国; 李军向; 晏石林

    2009-01-01

    FRP rural resin concrete which has extensive application prospect is a kind of anti-corrosive new en-gineering material. Although it's stronger in compression than cementitious concrete, its tension behavior is weak, the reinforcement of polymer concrete beams in the tension zone with puhruded profiles made of resin and glass fibers are a good compromise between strength and stiffness. In this paper, firstly the experience has performed about the bending and creep characteristic of non-FRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam, the creep curves are gained of the beams under different loads by four-point bending tests method, analysis is carried on the viscoelasticity nature, the result shows that FRP not only enhances the furan resin concrete beam's ini-tial stiffness and strength, but also obviously reduces the creep strain of the beam. Secondly the creep model varia-bles are determined through the least square method, the bending creep power law model are separately built of non-FRP reinforced furan resin concrete beam and FRP reinforced furan concrete beam,which is the basis of estimation of material's long term mechanics performance, and also has important project practical value to the FRP furan resin concrete structure design.%玻璃钢(FRP)筋防腐混凝土是一种强度高、全方位耐腐蚀的新型工程材料,具有十分广泛的应用前景.本文先对防腐混凝土梁采用四点弯曲试验方法,对FRP筋加强混凝土梁的弯曲长期力学特性进行了试验研究与分析,得到了梁在不同荷载水平作用下的蠕变曲线.结果表明,FRP筋不仅提高了防腐混凝土梁的初始刚度和强度,且明显降低了梁的蠕变变形.最后,运用最小二乘法确定蠕变模型参数,分别建立了防腐混凝土粱和FRP筋加强防腐混凝土梁的弯曲蠕变幂律模型,为估计材料的长期力学性能提供依据,对FRP筋防腐混凝土结构设计具有重要的价值.

  12. P-RC APMP废水的性质--密度和黏度%Properties of P-RC APMP waste water-Density and viscosity

    Institute of Scientific and Technical Information of China (English)

    刘秋娟; 霍晓东; 毛远

    2013-01-01

      研究了P-RC APMP废水的性质,包括波美度、相对密度、黏度、固形物的元素分析、燃烧热等。结果表明,相对密度、波美度与固形物含量均呈正比线性关系,与温度呈反比线性关系。黏度随着固形物含量的增大而升高,随温度的上升而减小。当固形物含量超过约40%时,黏度急剧增大。固形物中C元素所占的比例为31.18%,H元素为3.93%,N为0.46%, S为0.008%。固形物的有机物含量为69.74%,无机物含量为30.26%,燃烧热为12457kJ/kg。%The properties of P-RC APMP effluent, including relative density, Baume degree, viscosity, higher heating value (HHV) and element percentage of the effluent solid were studied in this paper. The results show that relative density, viscosity, Baumé degree and concentration have a direct proportional-linear correlation to solid content, but there is a linear proportion by inversion between Baumé degree and temperature. Viscosity rises sharply when concentration is more than 40%. The percentage of carbon, hydrogen, nitrogen and sulphur in the solid content of P-RC APMP effluent are 31.18%, 3.93%, 0.46%and 0.008%respectively.

  13. Experimental and Numerical Research on Seismic Performance of Earthquake-Damaged RC Frame Strengthened with CFRP Sheets

    Directory of Open Access Journals (Sweden)

    Lai Wang

    2016-01-01

    Full Text Available In order to assess the seismic performance of damaged reinforced concrete (RC frame strengthened with carbon fiber reinforced polymers (CFRP sheets, two experimental specimens with identical reinforcement ratio and geometric dimensions were designed following Chinese code for seismic design of buildings. Experimental specimens consist of a reference (undamaged RC frame, namely, KJ-1, and an earthquake-damaged RC frame strengthened with CFRP sheets, namely, KJ-2. A pseudostatic test was conducted on the two specimens to simulate moderate earthquake damage. The strengthening effects of CFRP sheets on damaged RC frame were discussed in terms of hysteretic curve, skeleton curve, stiffness degradation, and ductility. In addition, numerical method based on fiber model method was utilized to analyze the seismic performance of KJ-1 and KJ-2 and it is compared with the experimental result. Both the results confirm that the method of exterior bonding CFRP sheets on the damaged RC frame has restored the seismic performance such as bearing capacity, stiffness, and ductility to its original undamaged level, and some of the seismic performance of the damaged RC frame strengthened with CFRP sheets is even better than the undamaged one, which proves that the method has significant effect in strengthening postearthquake-damaged RC frames.

  14. RC-160的碘標方法比較及其生物分布特征%Comparison radioiodination methods of RC-160 and its biodistribution in normal mice

    Institute of Scientific and Technical Information of China (English)

    汪静; 王喜青; 王連剛; 李富軍

    2002-01-01

    目的擬建立一種高效碘標多肽RC-160的方法.方法以溴代琥珀酰亞胺(NBS) 為氧化劑,常規氯胺T法作為對照,對125I-RC-160的標記率、比活度進行評價,并觀察125I-RC-160在正常小鼠體内的生物分布特征.結果在丙酮:生理鹽水=1:1體系中,測得125I-RC-160的標記率NBS法為92%,比放射性為1.75×1012Bq/mmoL,標記率隨NBS用量增加而增高,最佳用量比為RC-160(μg):125I(MBq):NBS(μg)=3:7.4:1,且產物無需純化;Ch-T法標記率為56%.,比放射性為0.65×1012Bq/mmoL,經SepPaK-C18反向色譜柱純化,125I-RC-160的放射化學純度>98%.標記物在血中清除較快,注射后不到1小時血中的放射性就下降了87.2%;125I-RC-160在腎内濃集度很低,主要經過消化系統排出體外.結論NBS法可高效碘標多肽,標記后無需純化,减少了對操作者的輻射,是一種碘標的理想方法.%Objective We aims to establish a method of labeling of RC-160 with 125I. Methods NBS was used as oxi dant. Ch-T method was also performed as control. Labeling yield and specific activity of 125I-RC-160 were determined.Biodistribution of 125 I-RC-160 in normal mice was observed. Results When using acetone and saline (1: 1) as developer,labeling yield and specific radioactivity of 125 I-RC-160 was 92% and 1.75 × 10 12 Bq/mmol respectively with NBS method.The labeling yield was raised with the increase of NBS dose. The optimal dose of RC-160 (g): 125I (MBq): NBS (g)was 3: 7.4: 1. The 125 I-RC-160 prepared with NBS method needed no purification. Labeling yield and specific radioac tivity of 125I-RC-160 was 56% and 0. 65 1012 Bq/mmol respectively with Ch-T method. Reverse-phase (RP) chromatog raphy was used to purify the products. Radiochemical purity of 125I-RC-160 was over 98% with Ch-T method. Radioactiv-ity of 125 I-RC-160 in blood was decreased by 87.2% within less than 1 hr, which indicated that a substantial amount of the injected dose had been cleared from blood. Very little

  15. Comparison of Response between RC and SC Containment Structures Subjected to Aircraft Impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup; Choi, In Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Tae Hyo [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    Since the aircraft terror to the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly interested. The possibilities of aircraft impacts against nuclear power plants are one of important category. To date, the impact load of the analysis on aircraft impacts has been applied to target structures in local areas by using the impact force-time history function of Riera. However, Riera forcing function is not recommended at the expectation of unreasonable damage or perforation to target structures. The numerical analysis of rc and sc containment structures subjected to aircraft impact is performed by using the AUTODYN-3D. It is carried out the four different types for RC and SC structures. Thus, in this study, the different behaviors of containment structures and the safety of SC structure are expected

  16. Dynamic Characteristics of a Model and Prototype for 3D-RC Structure

    Directory of Open Access Journals (Sweden)

    Moniuddin Md. Khaja

    2016-06-01

    Full Text Available Infill walls provide durable and economical partitions that have relatively excellent thermal and sound insulation with high fire resistance. Monolithic infilled walls are provided within RC structures without being analyzed as a combination of concrete and brick elements, although in reality they act as a single unit during earthquakes. The performance of such structures during earthquakes has proved to be superior in comparison to bare frames in terms of stiffness, strength and energy dissipation. To know the dynamic characteristics of monolithic infill wall panels and masonry infill, modal, response spectrum and time history analyses have been carried out on a model and prototype of a 3D RC structure for a comparative study.

  17. Evaluation of the main parameters affecting seismic performance of the RC buildings

    Indian Academy of Sciences (India)

    Hayri Baytan Ozmen; Mehmet Inel; Emrah Meral

    2014-04-01

    Low and mid-rise reinforced concrete (RC) buildings consist of an important portion of the building stock in many earthquake prone countries. Therefore understanding their seismic behaviour is important for mitigation studies. This study aims to evaluate how much and when; seismic code, number of stories, concrete strength, amount of transverse reinforcement and infill-wall contribution parameters are important for seismic performances of RC buildings. Seismic performances of the models reflecting different cases are determined for different performance levels and seismic loading conditions. Based on the considered values of the parameters, it is concluded that: modern code specifications and higher transverse reinforcement 50%, the concrete strength up to 66%, infill-walls 15% and number of story 55% increase the seismic performance for life safety level. Evaluations on the effect of the considered parameters for different performance levels and seismic loadings in relation with other parameters are also given in this paper.

  18. Solving for the RC4 stream cipher state register using a genetic algorithm

    Directory of Open Access Journals (Sweden)

    Benjamin Ferriman

    2014-06-01

    Full Text Available The RC4 stream cipher has shown to be quite resilient to cryptanalysis for the 26 years it has been around. The algorithm is still one of the most widely used methods of encryption over the Internet today being implemented through the Secure Socket Layer and Transport Layer Security protocols. Genetic algorithms are a sub-class of evolutionary algorithms that have been used to help solve many different problems of optimization in a variety of disciplines. In this paper we will examine the abilities of the genetic algorithm as a tool to help solve the permutation that is stored as the state register of the RC4 stream cipher. Finally, we will show that on average the genetic algorithm can solve 100% of the keystream in 2121:5 generations.

  19. Prediction of Global and Localized Damage and Future Reliability for RC Structures subject to Earthquakes

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.;

    1997-01-01

    The paper deals with the prediction of global and localized damage and the future reliability estimation of partly damaged reinforced concrete (RC) structures under seismic excitation. Initially, a global maximum softening damage indicator is considered based on the variation of the eigenfrequency...... of the first mode due to the stiffness and strength deterioration of the structure. The hysteresis of the first mode is modelled by a Clough and Johnston hysteretic oscillator with a degrading elastic fraction of the restoring force. The linear parameters of the model are assumed to be known, measured before....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

  20. Prediction of Global and Localized Damage and Future Reliability for RC Structures subject to Earthquakes

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.;

    1994-01-01

    The paper deals with the prediction of global and localized damage and the future reliability estimation of partly damaged reinforced concrete (RC) structures under seismic excitation. Initially, a global maximum softening damage indicator is considered based on the variation of the eigenfrequency...... of the first mode due to the stiffness and strength deterioration of the structure. The hysteresis of the first mode is modelled by a Clough and Johnston hysteretic oscillator with a degrading elastic fraction of the restoring force. The linear parameters of the model are assumed to be known, measured before....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

  1. EFFECT OF NaOH CHARGE ON FIBER CHARACTERISTICS OF P-RC APMP PULP

    Institute of Scientific and Technical Information of China (English)

    FangongKong; JiachuanChen; GuihlmYang; EhaochengLi; HuaiyuZha~

    2004-01-01

    Fiber screen analysis, fiber quality analysis and SEMobservation were used to investigate the effects ofNaOH charge on fiber characteristics in TriploidPopulus Tomentosa P-RC APMP pulping in thispaper. The results showed that increasing NaOHcharge in P-RC APMP process could reduce energyconsumption and fines percent, increase the meanfiber length and long fiber percent and make the curlindex and kink index of fiber ascend. The resultsfrom SEM observation illustrated that the fiber withhigh NaOH charge had higher softness degree, bettercutting resistant ability and better inter-fiber bondingability. With increasing of NaOH charge, the surfaceof handsheets became more and more smooth, andthere were less and less gaps and holes on the papersurface.

  2. EFFECT OF NaOH CHARGE ON FIBER CHARACTERISTICS OF P-RC APMP PULP

    Institute of Scientific and Technical Information of China (English)

    Fangong Kong; Jiachuan Chen; Guihua Yang; Zhaocheng Li; Huaiyu Zhan

    2004-01-01

    Fiber screen analysis, fiber quality analysis and SEM observation were used to investigate the effects of NaOH charge on fiber characteristics in Triploid Populus Tomentosa P-RC APMP pulping in this paper. The results showed that increasing NaOH charge in P-RC APMP process could reduce energy consumption and fines percent, increase the mean fiber length and long fiber percent and make the curl index and kink index of fiber ascend. The results from SEM observation illustrated that the fiber with high NaOH charge had higher softness degree, better cutting resistant ability and better inter-fiber bonding ability. With increasing of NaOH charge, the surface of handsheets became more and more smooth, and there were less and less gaps and holes on the paper surface.

  3. Crystal structure of the RC-LH1 core complex from Rhodopseudomonas palustris.

    Science.gov (United States)

    Roszak, Aleksander W; Howard, Tina D; Southall, June; Gardiner, Alastair T; Law, Christopher J; Isaacs, Neil W; Cogdell, Richard J

    2003-12-12

    The crystal structure at 4.8 angstrom resolution of the reaction center-light harvesting 1 (RC-LH1) core complex from Rhodopseudomonas palustris shows the reaction center surrounded by an oval LH1 complex that consists of 15 pairs of transmembrane helical alpha- and beta-apoproteins and their coordinated bacteriochlorophylls. Complete closure of the RC by the LH1 is prevented by a single transmembrane helix, out of register with the array of inner LH1 alpha-apoproteins. This break, located next to the binding site in the reaction center for the secondary electron acceptor ubiquinone (UQB), may provide a portal through which UQB can transfer electrons to cytochrome b/c1.

  4. Low-cost detection of RC-IED activation signals in VHF band

    Science.gov (United States)

    Camargo Suarez, Victor Hugo; Marulanda B., Jose Ignacio

    2014-05-01

    The proliferation of Radio Controlled Improvised Explosive Devices (RC-IED) is a growing threat around the world. The ease of construction and low cost of these devices are transforming common things in lethal tramps. The fight against this threats normally involves the use of sophisticated and expensive equipment of Electronic Warfare based on high speed DSP systems, just to detect the presence of detonation signals. In this work is showed how to find activation signals based on the characteristic of the power in a specific band and the previous knowledge about the detonation signals. As proof of concept we have taken the information about the RC-IEDs used in the Colombian conflict and develop an algorithm to find detonation signals based on the measured power in frequencies between 136 MHz and 174 MHz (2 meter civil band)

  5. Understanding of self-terminating pulse generation using silicon controlled rectifier and RC load

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chris, E-mail: chrischang81@gmail.com; Karunasiri, Gamani, E-mail: karunasiri@nps.edu [Department of Physics, Naval Postgraduate School, Monterey, CA 93943 (United States); Alves, Fabio, E-mail: falves@alionscience.com [Alion Science and Technology at NPS, Monterey, CA 93943 (United States)

    2016-01-15

    Recently a silicon controlled rectifier (SCR)-based circuit that generates self-terminating voltage pulses was employed for the detection of light and ionizing radiation in pulse mode. The circuit consisted of a SCR connected in series with a RC load and DC bias. In this paper, we report the investigation of the physics underlying the pulsing mechanism of the SCR-based. It was found that during the switching of SCR, the voltage across the capacitor increased beyond that of the DC bias, thus generating a reverse current in the circuit, which helped to turn the SCR off. The pulsing was found to be sustainable only for a specific range of RC values depending on the SCR’s intrinsic turn-on/off times. The findings of this work will help to design optimum SCR based circuits for pulse mode detection of light and ionizing radiation without external amplification circuitry.

  6. Understanding of self-terminating pulse generation using silicon controlled rectifier and RC load

    Science.gov (United States)

    Chang, Chris; Alves, Fabio; Karunasiri, Gamani

    2016-01-01

    Recently a silicon controlled rectifier (SCR)-based circuit that generates self-terminating voltage pulses was employed for the detection of light and ionizing radiation in pulse mode. The circuit consisted of a SCR connected in series with a RC load and DC bias. In this paper, we report the investigation of the physics underlying the pulsing mechanism of the SCR-based. It was found that during the switching of SCR, the voltage across the capacitor increased beyond that of the DC bias, thus generating a reverse current in the circuit, which helped to turn the SCR off. The pulsing was found to be sustainable only for a specific range of RC values depending on the SCR's intrinsic turn-on/off times. The findings of this work will help to design optimum SCR based circuits for pulse mode detection of light and ionizing radiation without external amplification circuitry.

  7. Architecture, Design and Implementation of RC64, a Many-Core High-Performance DSP for Space Applications

    Science.gov (United States)

    Ginosar, Ran; Aviely, Peleg; Liran, Tuvia; Alon, Dov; Dobkin, Reuven; Goldberg, Michael

    2013-08-01

    RC64, a novel 64-core many-core signal processing chip targets DSP performance of 12.8 GIPS, 100 GOPS and 12.8 single precision GFLOS while dissipating only 3 Watts. RC64 employs advanced DSP cores, a multi-bank shared memory and a hardware scheduler, supports DDR2 memory and communicates over five proprietary 6.4 Gbps channels. The programming model employs sequential fine-grain tasks and a separate task map to define task dependencies. RC64 is implemented as a 200 MHz ASIC on Tower 130nm CMOS technology, assembled in hermetically sealed ceramic QFP package and qualified to the highest space standards.

  8. Derivation of the human embryonic stem cell line RCe008-A (RC-4

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe008-A (RC-4 was derived from a blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to ectoderm and mesoderm in vitro. It has a mixed 46XX/45X female karyotype and microsatellite PCR identity and blood group typing data is available.

  9. Discussion of "Simplified Model of Low Cycle Fatigue for RC Frames"

    OpenAIRE

    1999-01-01

    To model strength degradation due to low cycle fatigue, at least three different approaches can be considered. One possibility is based on the formulation of a new free energy function and damage energy release rate, as was proposed by Ju(1989). The second approach uses the notion of bounding surface introduced in cyclic plasticity by Dafalias and Popov (1975). From this concept, some models have been proposed to quantify damage in concrete or RC (Suaris et al. 1990). The model proposed by...

  10. Hysteretic MDOF Model to Quantify Damage for RC Shear Frames Subject to Earthquakes

    DEFF Research Database (Denmark)

    Köylüoglu, H. Ugur; Nielsen, Søren R.K.; Cakmak, Ahmet S.

    A hysteretic mechanical formulation is derived to quantify local, modal and overall damage in reinforced concrete (RC) shear frames subject to seismic excitation. Each interstorey is represented by a Clough and Johnston (1966) hysteretic constitutive relation with degrading elastic fraction of th...... shear frame is subject to simulated earthquake excitations, which are modelled as a stationary Gaussian stochastic process with Kanai-Tajimi spectrum, multiplied by an envelope function. The relationship between local, modal and overall damage indices is investigated statistically....

  11. Parallel-path biquad active-RC oscillator with enhanced harmonic rejection

    Science.gov (United States)

    Vosper, J. V.; Heima, M.; Cryan, R. A.

    1995-04-01

    A biquad active-RC oscillator is described and a linear analysis given which shows that harmonics injected within the feedback loop are multiplied by a factor which is inversely proportional to the effective open-loop Q-factor Q(sub 0). Experimental results show that distortion is low at high Q(sub 0) values even when saturated operation of the main gain-producing opamp is allowed.

  12. Derivation of the human embryonic stem cell line RCe012-A (RC-8)

    OpenAIRE

    P.A. De Sousa; B.J. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Collins, D. M.; Greenshields, A.; H. Bradburn; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe012-A (RC-8) was derived from a frozen and thawed day 5 embryo cultivated to the blastocyst stage. The embryo was voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyoty...

  13. Derivation of the human embryonic stem cell line RCe006-A (RC-2)

    OpenAIRE

    P.A. De Sousa; B. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Gardner, J.; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe006-A (RC-2) was derived from a frozen and thawed blastocyst voluntarily donated as surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line exhibits expression of expected pluripotency markers and in vitro differentiation potential to three germinal lineage representative cell populations. It has a male trisomy 12 karyotype (47XY, +12). Mic...

  14. Derivation of the human embryonic stem cell line RCe011-A (RC-7)

    OpenAIRE

    P.A. De Sousa; B.J. Tye; Collins, D. M.; Bruce, K.; P. Dand; RUSSELL, G.; H. Bradburn; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe011-A (RC-7) was derived from a failed to fertilise oocyte voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group t...

  15. Derivation of the human embryonic stem cell line RCe007-A (RC-3

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

    Full Text Available The human embryonic stem cell line RCe007-A (RC-3 was derived from a blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and HLA and blood group typing data is available.

  16. Derivation of the human embryonic stem cell line RCe007-A (RC-3)

    OpenAIRE

    P.A. De Sousa; B. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Gardner, J.; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe007-A (RC-3) was derived from a blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and HLA and blood group typing data is available.

  17. Derivation of the human embryonic stem cell line RCe010-A (RC-6)

    OpenAIRE

    P.A. De Sousa; B.J. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Collins, D. M.; H. Bradburn; Gardner, J.; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe010-A (RC-6) was derived from a frozen and thawed blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group...

  18. Derivation of the human embryonic stem cell line RCe014-A (RC-10)

    OpenAIRE

    P.A. De Sousa; B.J. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Collins, D. M.; Greenshields, A.; H. Bradburn; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe014-A (RC-10) was derived from a fresh oocyte voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 46XY and 47XY +12 male karyotype and microsatellite PCR identity, HLA and blood group ty...

  19. Derivation of the human embryonic stem cell line RCe008-A (RC-4)

    OpenAIRE

    P.A. De Sousa; B. Tye; Bruce, K.; P. Dand; Gardner, J.; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe008-A (RC-4) was derived from a blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to ectoderm and mesoderm in vitro. It has a mixed 46XX/45X female karyotype and microsatellite PCR identity and blood group typing data is av...

  20. Nonlinear Control for Trajectory Tracking of a Nonholonomic RC-Hovercraft with Discrete Inputs

    OpenAIRE

    Dictino Chaos; David Moreno-Salinas; Rocío Muñoz-Mansilla; Joaquín Aranda

    2013-01-01

    This work studies the problem of trajectory tracking for an underactuated RC-hovercraft, the control of which must be done by means of discrete inputs. Thus, the aim is to control a vehicle with very simple propellers that produce only a discrete set of control commands, and with minimal information about the dynamics of the actuators. The control problem is approached as a cascade control problem, where the outer loop stabilizes the position error, and the inner loop stabilizes the orientat...

  1. Risk Quantification for Sustaining Coastal Military Installation Asset and Mission Capabilities (RC-1701)

    Science.gov (United States)

    2014-06-06

    Infrastructure Protection PBL Planetary Boundary Layer POL Petroleum, Oils, & Lubricants QDR Quadrennial Defense Review vii RC Resource...Analysis SWAN Simulating WAves Nearshore model SWL Still Water Level (aka surge) TC96 TC96 Planetary Boundary Layer (PBL) wind model TDC Technical...study area, armored or artificial shorelines were commonly found in most urban /suburban areas and in rural areas where private property was vulnerable

  2. Contribution to SER Prediction: A New Metric Based on RC Transient Simulations

    Science.gov (United States)

    Micolau, G.; Castellani-Coulie, K.; Aziza, H.; Portal, J.-M.

    2012-08-01

    This work focuses on speeding up simulation time of SEU systematic detection in a 90 nm SRAM cell. Simulations were run in order to validate a simplified approach based on the injection of a noise source current at the sensitive node of an analytical RC circuit. Moreover, a new SEU reliability metric, mandatory for reliability studies, is introduced. It is based on based on transient I-V simulations.

  3. RC2S: A Cognitive Remediation Program to Improve Social Cognition in Schizophrenia and Related Disorders.

    Science.gov (United States)

    Peyroux, Elodie; Franck, Nicolas

    2014-01-01

    In people with psychiatric disorders, particularly those suffering from schizophrenia and related illnesses, pronounced difficulties in social interactions are a key manifestation. These difficulties can be partly explained by impairments in social cognition, defined as the ability to understand oneself and others in the social world, which includes abilities such as emotion recognition, theory of mind (ToM), attributional style, and social perception and knowledge. The impact of several kinds of interventions on social cognition has been studied recently. The best outcomes in the area of social cognition in schizophrenia are those obtained by way of cognitive remediation programs. New strategies and programs in this line are currently being developed, such as RC2S (cognitive remediation of social cognition) in Lyon, France. Considering that the social cognitive deficits experienced by patients with schizophrenia are very diverse, and that the main objective of social cognitive remediation programs is to improve patients' functioning in their daily social life, RC2S was developed as an individualized and flexible program that allows patients to practice social interaction in a realistic environment through the use of virtual reality techniques. In the RC2S program, the patient's goal is to assist a character named Tom in various social situations. The underlying idea for the patient is to acquire cognitive strategies for analyzing social context and emotional information in order to understand other characters' mental states and to help Tom manage his social interactions. In this paper, we begin by presenting some data regarding the social cognitive impairments found in schizophrenia and related disorders, and we describe how these deficits are targeted by social cognitive remediation. Then we present the RC2S program and discuss the advantages of computer-based simulation to improve social cognition and social functioning in people with psychiatric disorders.

  4. 谈谈LIU98rc VHF遥控设备的改进

    Institute of Scientific and Technical Information of China (English)

    郭丽

    2002-01-01

    本文介绍了VHF地-空通信的发展趋势和现状,并结合这些情况,提出对现有liu98rc VHF地-空遥控通信设备的一些改进设想及实现这些功能需考虑的技术问题。

  5. RC2S: a cognitive remediation program to improve social cognition in schizophrenia and related disorders

    Directory of Open Access Journals (Sweden)

    Elodie ePEYROUX

    2014-06-01

    Full Text Available In people with psychiatric disorders, particularly those suffering from schizophrenia and related illnesses, pronounced difficulties in social interactions are a key manifestation. These difficulties can be partly explained by impairments in social cognition, defined as the ability to understand oneself and others in the social world, which includes abilities such as emotion recognition, theory of mind, attributional style, and social perception and knowledge. The impact of several kinds of interventions on social cognition has been studied recently. The best outcomes in the area of social cognition in schizophrenia are those obtained by way of cognitive remediation programs. New strategies and programs in this line are currently being developed, such as RC2S (Cognitive Remediation of Social Cognition in Lyon, France. Considering that the social cognitive deficits experienced by patients with schizophrenia are very diverse, and that the main objective of social cognitive remediation programs is to improve patients’ functioning in their daily social life, RC2S was developed as an individualized and flexible program that allows patients to practice social interaction in a realistic environment through the use of virtual-reality techniques. In the RC2S program, the patient’s goal is to assist a character named Tom in various social situations. The underlying idea for the patient is to acquire cognitive strategies for analyzing social context and emotional information in order to understand other characters’ mental states and to help Tom manage his social interactions. In this paper, we begin by presenting some data regarding the social cognitive impairments found in schizophrenia and related disorders, and we describe how these deficits are targeted by social cognitive remediation. Then we present the RC2S program and discuss the advantages of computer-based simulation to improve social cognition and social functioning in people with

  6. Extracting Concrete Thermal Characteristics from Temperature Time History of RC Column Exposed to Standard Fire

    OpenAIRE

    Jung J. Kim; Kwang-Soo Youm; Reda Taha, Mahmoud M.

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The ther...

  7. Pros and cons of multistory RC tunnel-form (box-type) buildings

    Science.gov (United States)

    Kalkan, E.; Yuksel, S.B.

    2008-01-01

    Tunnel-form structural systems (i.e., box systems), having a load-carrying mechanism composed of reinforced concrete (RC) shear walls and slabs only, have been prevailingly utilized in the construction of multistory residential units. The superiority of tunnel-form buildings over their conventional counterparts stems from the enhanced earthquake resistance they provide, and the considerable speed and economy of their construction. During recent earthquakes in Turkey, they exhibited better seismic performance in contrast to the damaged condition of a number of RC frames and dual systems (i.e., RC frames with shear wall configurations). Thus the tunnel-form system has become a primary construction technique in many seismically active regions. In this paper, the strengths and weaknesses of tunnel-form buildings are addressed in terms of design considerations and construction applications. The impacts of shear wall reinforcement ratio and its detailing on system ductility, loadcarrying capacity and failure mechanism under seismic forces are evaluated at section and global system levels. Influences of tension/compression coupling and wall openings on the response are also discussed. Three-dimensional nonlinear finite element models, verified through comparisons with experimental results, were used for numerical assessments. Findings from this projection provide useful information on adequate vertical reinforcement ratio and boundary reinforcement to achieve enhanced performance of tunnel-form buildings under seismic actions. Copyright ?? 2007 John Wiley & Sons, Ltd.

  8. Pushover Analyses of a R/C Frame by Distinct Software

    Science.gov (United States)

    Pereira, V. G.; Barros, R. C.; Cesar, M. B.

    2010-05-01

    A series of pushover analyses on two-dimensional RC frames, part of an office building, are performed. They constitute a detailed parametric study, varying the number of stories and its height, and also the bay width. Regarding the stated objective, several commercial packages universally used in the design of civil engineering structures were used, namely SAP 2000, SeismoStruct and MIDAS. To represent the influence of the masonry infill panels, the equivalent tie method is used considering several values for the tie width. The influence of other parameters, on the structural behavior of the RC frame through a pushover analysis, is also analyzed: the confinement of the structural elements (columns and beams) and the length and location of the plastic hinges forming near the end of the structural elements. Finally, it is also parameterized the behavior of the structure when submitted to different load patterns, such as: uniform and modal, as suggested in the Eurocode 8, and triangular. Major conclusions of the study elaborated are presented and future developments are pointed-out in order to deepen the pushover analysis of two dimensional RC frames.

  9. Optimization of the place of the plastic hinges by steel braces at RC buildings

    Science.gov (United States)

    Hatami, Farzad; Ragheb, Mohammad; Namazi, Meysam

    2012-12-01

    Usage of steel braces has become a solution not only for retrofitting of RC structures but as a method in designing of concrete frames in recent years. Although X-braced RC frames have been number of successful studies, but eccentric braced RC frames have not been studied seriously. Maybe it's because of the non ductile behaviour of concrete beams. In this article, a numerical study was conducted to evaluate performance of concrete frames, braced with eccentric steel brace with a vertical steel shear link. Vertical steel shear link eliminated shortcomings of non ductile concrete beam. Therefore 4, 8 and 12 storey concrete frames were designed and subjected to a push over analysis. Life safety level was chose to evaluate the frames and hinges performance. Results were compared with the same frames designed with X braces and moment resisting frame. Results indicated that steel braces shift the place of plastic hinges to be formed on the bracing members instead of columns and beams. Furthermore steel braces delayed the process of formation of first plastic hinge and column failure mechanism.

  10. Evaluation of Structural Robustness against Column Loss: Methodology and Application to RC Frame Buildings.

    Science.gov (United States)

    Bao, Yihai; Main, Joseph A; Noh, Sam-Young

    2017-08-01

    A computational methodology is presented for evaluating structural robustness against column loss. The methodology is illustrated through application to reinforced concrete (RC) frame buildings, using a reduced-order modeling approach for three-dimensional RC framing systems that includes the floor slabs. Comparisons with high-fidelity finite-element model results are presented to verify the approach. Pushdown analyses of prototype buildings under column loss scenarios are performed using the reduced-order modeling approach, and an energy-based procedure is employed to account for the dynamic effects associated with sudden column loss. Results obtained using the energy-based approach are found to be in good agreement with results from direct dynamic analysis of sudden column loss. A metric for structural robustness is proposed, calculated by normalizing the ultimate capacities of the structural system under sudden column loss by the applicable service-level gravity loading and by evaluating the minimum value of this normalized ultimate capacity over all column removal scenarios. The procedure is applied to two prototype 10-story RC buildings, one employing intermediate moment frames (IMFs) and the other employing special moment frames (SMFs). The SMF building, with its more stringent seismic design and detailing, is found to have greater robustness.

  11. Multifunctional Cement Composites Strain and Damage Sensors Applied on Reinforced Concrete (RC Structural Elements

    Directory of Open Access Journals (Sweden)

    Pedro Garcés

    2013-03-01

    Full Text Available In this research, strain-sensing and damage-sensing functional properties of cement composites have been studied on a conventional reinforced concrete (RC beam. Carbon nanofiber (CNFCC and fiber (CFCC cement composites were used as sensors on a 4 m long RC beam. Different casting conditions (in situ or attached, service location (under tension or compression and electrical contacts (embedded or superficial were compared. Both CNFCC and CFCC were suitable as strain sensors in reversible (elastic sensing condition testing. CNFCC showed higher sensitivities (gage factor up to 191.8, while CFCC only reached gage factors values of 178.9 (tension or 49.5 (compression. Furthermore, damage-sensing tests were run, increasing the applied load progressively up to the RC beam failure. In these conditions, CNFCC sensors were also strain sensitive, but no damage sensing mechanism was detected for the strain levels achieved during the tests. Hence, these cement composites could act as strain sensors, even for severe damaged structures near to their collapse.

  12. Switching control of an R/C hovercraft: stabilization and smooth switching.

    Science.gov (United States)

    Tanaka, K; Iwasaki, M; Wang, H O

    2001-01-01

    This paper presents stable switching control of an radio-controlled (R/C) hovercraft that is a nonholonomic (nonlinear) system. To exactly represent its nonlinear dynamics, more importantly, to maintain controllability of the system, we newly propose a switching fuzzy model that has locally Takagi-Sugeno (T-S) fuzzy models and switches them according to states, external variables, and/or time. A switching fuzzy controller is constructed by mirroring the rule structure of the switching fuzzy model of an R/C hovercraft. We derive linear matrix inequality (LMI) conditions for ensuring the stability of the closed-loop system consisting of a switching fuzzy model and controller. Furthermore, to guarantee smooth switching of control input at switching boundaries, we also derive a smooth switching condition represented in terms of LMIs. A stable switching fuzzy controller satisfying the smooth switching condition is designed by simultaneously solving both of the LMIs. The simulation and experimental results for the trajectory control of an R/C hovercraft show the validity of the switching fuzzy model and controller design, particularly, the smooth switching condition.

  13. Non-Linear Static Analysis of G+6 Storeyed RC Buildings with Openings in Infill Walls

    Directory of Open Access Journals (Sweden)

    Praveen Rathod

    2014-09-01

    Full Text Available Masonry infill walls are commonly used in the RC frame structure buildings. Openings are inevitable part of the infill walls. Openings in infill walls significantly decrease the lateral strength and stiffness of RC frames. In the present study two-dimensional seven storeyed reinforced concrete (RC building models are considered with of (5%, 25%, and 35% openings Bare frame and soft storey buildings are modeled considering special moment resisting frame (SMRF for medium soil profile and zone III. Concrete block infill walls are modeled as pin-jointed single equivalent diagonal strut. Pushover analysis is carried out for both default and user defined hinge properties as per FEMA 440 guidelines using SAP2000 software. Results of default and user defined hinge properties are studied by pushover analysis. The results of ductility ratio, safety ratio, global stiffness, and hinge status at performance point are compared with the models. Authors conclude that as the percentage of openings increases, vulnerability increases in the infill walls. The user-defined hinge model is better than the default-hinge model in reflecting nonlinear behavior. The misuse of default-hinge properties may lead to unreasonable displacement capacities for existing structures. However, if the default-hinge model is preferred due to simplicity, the user should be aware of what is provided in the program and should avoid the misuse of default-hinge properties.

  14. Damage Assessment of Two-Way Bending RC Slabs Subjected to Blast Loadings

    Directory of Open Access Journals (Sweden)

    Haokai Jia

    2014-01-01

    Full Text Available Terrorist attacks on vulnerable structures and their individual structural members may cause considerable damage and loss of life. However, the research work on response and damage analysis of single structural components, for example, a slab to blast loadings, is limited in the literature and this is necessary for assessing its vulnerability. This study investigates the blast response and damage assessment of a two-way bending reinforced concrete (RC slab subjected to blast loadings. Numerical modeling and analysis are carried out using the commercial finite element code LS-DYNA 971. A damage assessment criterion for the two-way bending RC slab is defined based on the original and residual uniformly distributed load-carrying capacity. Parametric studies are carried out to investigate the effects of explosive weight and explosive position on the damage mode of the two-way RC slab. Some design parameters, such as the boundary conditions and the negative reinforcement steel bar length, are also discussed. The illustrated results show that the proposed criterion can apply to all failure modes. The damage assessment results are more accurate than the ones due to the conventional deformation criterion.

  15. nRC: non-coding RNA Classifier based on structural features.

    Science.gov (United States)

    Fiannaca, Antonino; La Rosa, Massimo; La Paglia, Laura; Rizzo, Riccardo; Urso, Alfonso

    2017-01-01

    Non-coding RNA (ncRNA) are small non-coding sequences involved in gene expression regulation of many biological processes and diseases. The recent discovery of a large set of different ncRNAs with biologically relevant roles has opened the way to develop methods able to discriminate between the different ncRNA classes. Moreover, the lack of knowledge about the complete mechanisms in regulative processes, together with the development of high-throughput technologies, has required the help of bioinformatics tools in addressing biologists and clinicians with a deeper comprehension of the functional roles of ncRNAs. In this work, we introduce a new ncRNA classification tool, nRC (non-coding RNA Classifier). Our approach is based on features extraction from the ncRNA secondary structure together with a supervised classification algorithm implementing a deep learning architecture based on convolutional neural networks. We tested our approach for the classification of 13 different ncRNA classes. We obtained classification scores, using the most common statistical measures. In particular, we reach an accuracy and sensitivity score of about 74%. The proposed method outperforms other similar classification methods based on secondary structure features and machine learning algorithms, including the RNAcon tool that, to date, is the reference classifier. nRC tool is freely available as a docker image at https://hub.docker.com/r/tblab/nrc/. The source code of nRC tool is also available at https://github.com/IcarPA-TBlab/nrc.

  16. Stiffness degradation-based damage model for RC members and structures using fiber-beam elements

    Science.gov (United States)

    Guo, Zongming; Zhang, Yaoting; Lu, Jiezhi; Fan, Jian

    2016-12-01

    To meet the demand for an accurate and highly efficient damage model with a distinct physical meaning for performance-based earthquake engineering applications, a stiffness degradation-based damage model for reinforced concrete (RC) members and structures was developed using fiber beam-column elements. In this model, damage indices for concrete and steel fibers were defined by the degradation of the initial reloading modulus and the low-cycle fatigue law. Then, section, member, story and structure damage was evaluated by the degradation of the sectional bending stiffness, rod-end bending stiffness, story lateral stiffness and structure lateral stiffness, respectively. The damage model was realized in Matlab by reading in the outputs of OpenSees. The application of the damage model to RC columns and a RC frame indicates that the damage model is capable of accurately predicting the magnitude, position, and evolutionary process of damage, and estimating story damage more precisely than inter-story drift. Additionally, the damage model establishes a close connection between damage indices at various levels without introducing weighting coefficients or force-displacement relationships. The development of the model has perfected the damage assessment function of OpenSees, laying a solid foundation for damage estimation at various levels of a large-scale structure subjected to seismic loading.

  17. Effect of Large Negative Phase of Blast Loading on Structural Response of RC Elements

    Directory of Open Access Journals (Sweden)

    Syed Zubair Iman

    2016-01-01

    Full Text Available Structural response of reinforced concrete (RC elements for analysis and design are often obtained using the positive phase of the blast pressure curve disregarding the negative phase assuming insignificant contribution from the negative phase of the loading. Although, some insight on the effect of negative phase of blast pressure based on elastic single-degree-of-freedom (SDOF analysis was presented before, the influence of negative phase on different types of resistance functions of SDOF models and on realistic finite element analysis has not been explored. In this study, the effects of inclusion of pulse negative phase on structural response of RC elements from SDOF analysis and from more detailed finite element analysis have been investigated. Investigation of SDOF part has been conducted using MATLAB code that utilizes non-linear resistance functions of SDOF model. Detailed numerical investigation using finite element code DIANA was conducted on the significance of the negative phase on structural response. In the FE model, different support stiffness was used to explore the effect of support stiffness on the structural response due to blast negative phase. Results from SDOF and FE analyses present specific situations where the effect of large negative phase was found to be significant on the structural response of RC elements.

  18. Evaluation of Structural Robustness against Column Loss: Methodology and Application to RC Frame Buildings

    Science.gov (United States)

    Bao, Yihai; Main, Joseph A.; Noh, Sam-Young

    2017-01-01

    A computational methodology is presented for evaluating structural robustness against column loss. The methodology is illustrated through application to reinforced concrete (RC) frame buildings, using a reduced-order modeling approach for three-dimensional RC framing systems that includes the floor slabs. Comparisons with high-fidelity finite-element model results are presented to verify the approach. Pushdown analyses of prototype buildings under column loss scenarios are performed using the reduced-order modeling approach, and an energy-based procedure is employed to account for the dynamic effects associated with sudden column loss. Results obtained using the energy-based approach are found to be in good agreement with results from direct dynamic analysis of sudden column loss. A metric for structural robustness is proposed, calculated by normalizing the ultimate capacities of the structural system under sudden column loss by the applicable service-level gravity loading and by evaluating the minimum value of this normalized ultimate capacity over all column removal scenarios. The procedure is applied to two prototype 10-story RC buildings, one employing intermediate moment frames (IMFs) and the other employing special moment frames (SMFs). The SMF building, with its more stringent seismic design and detailing, is found to have greater robustness. PMID:28890599

  19. Strengthening of RC Slabs with Symmetric Openings Using GFRP Composite Beams

    Directory of Open Access Journals (Sweden)

    Yeol Choi

    2013-12-01

    Full Text Available This paper describes the results of experimental testing of glass fiber reinforced plastic (GFRP composite beam strengthened reinforced concrete (RC slabs with two symmetrical openings. Specimens, one-half scale, have been designed and fabricated to reflect the most common RC bathroom slab used in school buildings. The specimen had dimensions of 2000 mm (width × 150 mm (thickness × 3000 mm (length were used with the two openings of 300 mm × 400 mm. The aim of this study is to investigate the most effective strengthening method using GFRP composite beams in slabs with openings for enhancing the load-carrying capacity and stiffness. Test results showed that the strengthened slabs seems to increase the load-carrying capacity by 29%, 21% and 12% over that of the control specimen for diagonal, parallel and surround strengthening respectively. Furthermore, test results showed that the diagonal-strengthened system is one of the most effective methods for strengthening an RC slab with openings in terms of load-carrying capacity, stiffness and crack patterns.

  20. RC-1 organic Rankine bottoming cycle for an adiabatic diesel engine. Final report

    Energy Technology Data Exchange (ETDEWEB)

    DiNanno, L.R.; DiBella, F.A.; Koplow, M.D.

    1983-12-01

    A system analysis and preliminary design were conducted for an organic Rankine-cycle system to bottom the high-temperature waste heat of an adiabatic diesel engine. The bottoming cycle is a compact package that includes a cylindrical air-cooled condenser-regenerator module and other unique features. The bottoming cycle output is 56 horsepower at design point conditions when compounding the reference 317 horsepower turbocharged (TC) diesel engine with a resulting brake specific fuel consumption of 0.268 lb/hp-hr for the compound engine. The bottoming cycle when applied to a turbocompound (TCPD) diesel delivers a compound engine brake specific fuel consumption of 0.258 lb/hp-hr. This system for heavy-duty trnsport applications uses the organic working fluid RC-1, which is a mixture of 60 mole percent pentafluorobenzene (PFB) and 40 mole percent hexafluorobenzene (HFB). Included in these 1983 work efforts was the thermal stability testing of the RC-1 organic fluid in a dynamic fluid test loop that simulates the operation of Rankine-cycle. More than 1600 hours of operation were completed with results showing that the RC-1 is thermally stable up to 900/sup 0/F. This report describes the work performed for one of the multiple contracts awarded under the Department of Energy's Heavy-Duty Transport Technology Program.

  1. SPARC's Stratospheric Sulfur and its Role in Climate Activity (SSiRC)

    Science.gov (United States)

    Thomason, Larry

    2015-01-01

    The stratospheric aerosol layer is a key component in the climate system. It affects the radiative balance of the atmosphere directly through interactions with solar and terrestrial radiation, and indirectly through its effect on stratospheric ozone. Because the stratospheric aerosol layer is prescribed in many climate models and Chemistry-Climate Models (CCMs), model simulations of future atmospheric conditions and climate generally do not account for the interaction between the aerosol-sulfur cycle and changes in the climate system. The present understanding of how the stratospheric aerosol layer may be affected by future climate change and how the stratospheric aerosol layer may drive climate change is, therefore, very limited. The purposes of SSiRC (Stratospheric Sulfur and its Role in Climate) include: (i) providing a coordinating structure for the various individual activities already underway in different research centers; (ii) encouraging and supporting new instrumentation and measurements of sulfur containing compounds, such as COS, DMS, and non-volcanic SO2 in the UT/LS globally; and (iii) initiating new model/data inter-comparisons. SSiRC is developing collaborations with a number of other SPARC activities including CCMI and ACAM. This presentation will highlight the scientific goals of this project and on-going activities and propose potential interactions between SSiRC and ACAM.

  2. Damage Assessment of Two-Way Bending RC Slabs Subjected to Blast Loadings

    Science.gov (United States)

    Jia, Haokai; Wu, Guiying

    2014-01-01

    Terrorist attacks on vulnerable structures and their individual structural members may cause considerable damage and loss of life. However, the research work on response and damage analysis of single structural components, for example, a slab to blast loadings, is limited in the literature and this is necessary for assessing its vulnerability. This study investigates the blast response and damage assessment of a two-way bending reinforced concrete (RC) slab subjected to blast loadings. Numerical modeling and analysis are carried out using the commercial finite element code LS-DYNA 971. A damage assessment criterion for the two-way bending RC slab is defined based on the original and residual uniformly distributed load-carrying capacity. Parametric studies are carried out to investigate the effects of explosive weight and explosive position on the damage mode of the two-way RC slab. Some design parameters, such as the boundary conditions and the negative reinforcement steel bar length, are also discussed. The illustrated results show that the proposed criterion can apply to all failure modes. The damage assessment results are more accurate than the ones due to the conventional deformation criterion. PMID:25121134

  3. Economic & technological equations and characteristic analyses for inshore FRP trawl boats%近海玻璃钢拖网渔船的技术经济方程和特征分析

    Institute of Scientific and Technical Information of China (English)

    陶冶; 奚海波; 王建彬; 于红; 吴俊峰; 贾复

    2015-01-01

    根据近海玻璃钢( FRP)拖网渔船缺乏技术经济论证数学模型的问题,建立了针对玻璃钢拖网渔船的技术经济方程,对方程中的油耗、经济寿命、造价、维修费用、折旧费等经济影响因素进行了分析比较。结果表明:多数指标变量对玻璃钢渔船的经济性是有利的,仅造价指标具有负面影响,本研究中建立的技术经济方程有效地满足了玻璃钢最优船型论证的需要,可为船舶建造、捕捞管理提供计算及指导依据。%In view of the problem of lack of the math model for the evaluation of optimum fiber reinforced plastics ( FRP) trawl boats, series of economic & technological equations were in this paper proposed, and comparatively analyzed the factors influencing economy of FRP trawls boat, such as fuel consumption, economic life-span, cost, maintain expense, and depreciation cost were analysed comparatively. The results showed that most of the target variable is good for the economy of the FRP fishing trawler, only the cost showing a negative influence. These equa-tions can effectively meet the needs of the FRP optimal ship type evaluation, and provide the basis of the calculation for the construction, management and fishing department.

  4. Evolution trends in vulnerability of R/C buildings exposed to earthquake induced landslide hazard

    Science.gov (United States)

    Fotopoulou, S.; Pitilakis, K.

    2012-04-01

    The assessment of landslide risk depends on the evaluation of landslide hazard and the vulnerability of exposed structures which both change with time. The real, dynamic vulnerability modeling of structures due to landslides may be significantly affected by aging considerations, anthropogenic actions, cumulative damage from past landslide events and retrofitting measures. The present work aims at the development of an efficient analytical methodology to assess the evolution of building vulnerability with time exposed to earthquake -induced landslide hazard. In particular, the aging of typical RC buildings is considered by including probabilistic models of corrosion deterioration of the RC elements within the vulnerability modeling framework. Two potential adverse corrosion scenarios are examined: chloride and carbonation induced corrosion of the steel reinforcement. An application of the proposed methodology to reference low-rise RC buildings exposed to the combined effect of seismically induced landslide differential displacements and reinforcement corrosion is provided. Both buildings with stiff and flexible foundation system standing near the crest of a potentially precarious soil slope are examined. Non linear static time history analyses of the buildings are performed using a fibre-based finite element code. In this analysis type, the applied loads (displacements) at the foundation level vary in the pseudo-time domain, according to a load pattern prescribed as the differential permanent landslide displacement (versus time) curves triggered by the earthquake. The distribution for the corrosion initiation time is assessed through Monte Carlo simulation using appropriate probabilistic models for the carbonation and the chloride induced corrosion. Then, the loss of area of steel over time due to corrosion of the RC elements is modeled as a reduction in longitudinal reinforcing bar cross-sectional area in the fibre section model. Time dependent structural limit

  5. Generation of equivalent forms of operational trans-conductance amplifier-RC sinusoidal oscillators: the nullor approach

    OpenAIRE

    Raj Senani; Manish Gupta; Data Ram Bhaskar; Abdhesh Kumar Singh

    2014-01-01

    It has been shown in two earlier papers published from this study that corresponding to a given single-operational trans-conductance amplifier (single-OTA)-RC and dual-OTA-RC sinusoidal oscillators, there are three other structurally distinct equivalent forms having the same characteristic equation, one of which employs both grounded capacitors (GC). In this study, an earlier nullor-based theory of generating equivalent op-amp oscillator circuits, proposed by the first author, is extended to ...

  6. Investigation of Ultimate Shear Capacity of RC Deep Beams with Opening using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Ebrahim KhalilzadeVahidi

    2016-07-01

    Full Text Available Deep beams are structural elements loaded as beams in which a significant amount of the load is transferred to the supports by a compression strut joining the load and the reaction. According to ACI 318-08 ration of free span to height in deep beams are less than 4. The ratio of shear span (the distance between the concentrated load to support in deep beam is less than 2. Loading transmission mechanism in these beams is loads to reaction. The model takes into account the effects of the effective depth, shear span-to-depth ratio, modulus of elasticity, ratio of the FRP, flexural reinforcement and compressive concrete strength on shear strength. It is also goal to extend an effectual and applied neural network model. So, mechanical attribute and dimensional properties of strengthening beams are chosen as input data. A developed harmony search (HS algorithm in ANN models is trained, validated and tested by 30 deep beams with opening. Afterward ANN results are estimated with ABAQUS results and theoretical prediction computed from ACI 318-08. Comparisons between the predicted values and 30 test data showed that the developed ANN model resulted in improved statistical parameters with better accuracy than other existing equations. Performed analysis showed that the neural network model is more accurate than the guideline equations with respect to the experimental results and can be applied satisfactorily within the range of parameters covered in this study.   

  7. Modelling of Hybrid Materials and Interface Defects through Homogenization Approach for the Prediction of Effective Thermal Conductivity of FRP Composites Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    C. Mahesh

    2013-01-01

    Full Text Available Finite element method is effectively used to homogenize the thermal conductivity of FRP composites consisting of hybrid materials and fibre-matrix debonds at some of the fibres. The homogenized result at microlevel is used to determine the property of the layer using macromechanics principles; thereby, it is possible to minimize the computational efforts required to solve the problem as in state through only micromechanics approach. The working of the proposed procedure is verified for three different problems: (i hybrid composite having two different fibres in alternate layers, (ii fibre-matrix interface debond in alternate layers, and (iii fibre-matrix interface debond at one fibre in a group of four fibres in one unit cell. It is observed that the results are in good agreement with those obtained through pure micro-mechanics approach.

  8. Open fibre reinforced plastic (FRP) flat plate collector (FPC) and spray network systems for augmenting the evaporation rate of tannery effluent (soak liquor)

    Energy Technology Data Exchange (ETDEWEB)

    Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai 625 015 (India); Mani, A. [Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600 036 (India)

    2007-12-15

    Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. (author)

  9. Eigenvalue Buckling Analysis of FRP Transmission Tower%玻璃钢输电塔中稳定构件布置形式的研究

    Institute of Scientific and Technical Information of China (English)

    屈成忠; 朱瑞玲; 王孙宝

    2013-01-01

    以通用设计中的110 kV输电塔为计算模型,研究了将玻璃钢材料应用于输电塔上能满足结构稳定性的构件布置形式,采用特征值屈曲分析对风荷载作用下不同塔腿和塔身形式的输电塔进行了有限元计算.结果表明,主材用角钢、其他构件用玻璃钢的输电塔结构和改变塔腿形式或再进一步将塔身下半部改为具有水平材的双腹杆形式均能满足结构稳定性要求.%According to the 110 kV power transmission towers in general design, the stable form of transmission tower used FRP components was researched. Considering the influences of the different arrangement of tower legs and tower body on the stability of structure, the finite element calculation of transmission tower under wind load was carried out through the eigenvalue buckling analysis. It is concluded that the transmission tower whose principal material are angle steel and others are FRP can meet the requirements of the structure stability through modifying the form of legs or the first body to become the double ventral pole form with a level pole.

  10. Seismic performance evaluation of existing RC buildings designed as per past codes of practice

    Indian Academy of Sciences (India)

    K Rama Raju; A Cinitha; Nagesh R Iyer

    2012-04-01

    Assessing the capacity of existing building as per the present codes of practice is an important task in performance-based evaluation. In order to enhance the performance of existing buildings to the present level of ductile design prescribed by present codes and find the retrofit or design a rehabilitation system, there is an urgent need to assess accurately the actual lateral load resistance and the potential failure modes. In this paper, a typical 6-storey reinforced concrete (RC) building frame is designed for four design cases as per the provisions in three revisions of IS: 1893 and IS: 456 and it is analysed using user-defined (UD) nonlinear hinge properties or default-hinge (DF) properties, given in SAP 2000 based on the FEMA-356 and ATC-40 guidelines. An analytical procedure is developed to evaluate the yield, plastic and ultimate rotation capacities of RC elements of the framed buildings and these details are used to define user-defined inelastic effect of hinge for columns as P-M-M and for beams as M3 curves. A simplified three parameter model is used to find the stress–strain curves of RC elements beyond the post yield region of confined concrete. Building performance of structural components in terms of target building performance levels are studied with the nonlinear static analysis. The possible differences in the results of pushover analysis due to default- and user-defined nonlinear component properties at different performance levels of the building are studied.

  11. ALGORITMA RC4 DALAM PROTEKSI TRANSMISI DAN HASIL QUERY UNTUK ORDBMS POSTGRESQL

    Directory of Open Access Journals (Sweden)

    Yuri Ariyanto

    2009-01-01

    Full Text Available In this research will be worked through about how cryptography RC4's algorithm implementation in protection to query result and of query, security by encryption and descryption up to both is in network. Implementation of this research which is build software in client that function access databases that is placed by the side of server. Software that building to have facility for encryption and descryption query result and of query that is sent from client goes to server and. transmission query result and of query can secure its security. Well guaranted transmission security him of query result and of query can be told to succeed if success software can encryption query result and of query which transmission so that in the event of scanning to both, scanning will not understand data content. Conclusion of this research that is woke up software succeed encryption query and result of query which transmission between application of client and of server databases. Abstract in Bahasa Indonesia: Pada penelitian ini dibahas mengenai bagaimana mengimplementasikan algoritma kriptografi RC4 dalam proteksi terhadap query dan hasil query, pengamanan dilakukan dengan cara melakukan enkripsi dan dekripsi selama keduanya berada di dalam jaringan. Pengimplementasian dari penelitian ini yaitu membangun sebuah software yang akan diletakkan di sisi client yang berfungsi mengakses database yang diletakkan di sisi server. Software yang dibangun memiliki fasilitas untuk mengenkripsi dan mendektipsi query dan hasil query yang dikirimkan dari client ke server dan juga sebaliknya. Dengan demikian tramsmisi query dan hasil query dapat terjamin keamanannya.Terjaminnya keamanan transmisi query dan hasil query dapat dikatakan berhasil jika software berhasil mengenkripsi query dan hasil query yang ditransmisikan sehingga apabila terjadi penyadapan terhadap keduanya, penyadap tidak akan mengerti isi data tersebut. Kesimpulan dari penelitian ini yaitu software yang dibangun

  12. Best Position of R.C. Shear Wall due to seismic loads

    Directory of Open Access Journals (Sweden)

    Amita Baghel

    2017-02-01

    Full Text Available A shear wall is a wall that is designed to resist shear, the lateral force that causes the bulk of damage in earthquakes. Many building codes mandate the use of such walls to make homes safer and more stable. In this work, a G+2 storey R.C. building frame has been considered and analyzed for seismic zone-lll(Jabalpur using staad.prov8i (series4 package, special moment resisting frame (SMRF and hard rock types used in work. Parameters are taken to compare and analyze for the results are Node displacement and Reactions for different arrangements

  13. Derivation of the human embryonic stem cell line RCe006-A (RC-2

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe006-A (RC-2 was derived from a frozen and thawed blastocyst voluntarily donated as surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line exhibits expression of expected pluripotency markers and in vitro differentiation potential to three germinal lineage representative cell populations. It has a male trisomy 12 karyotype (47XY, +12. Microsatellite DNA marker identity and HLA and blood group typing data are available.

  14. Derivation of the human embryonic stem cell line RCe014-A (RC-10

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe014-A (RC-10 was derived from a fresh oocyte voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a mixed 46XY and 47XY +12 male karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  15. Derivation of the human embryonic stem cell line RCe012-A (RC-8

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe012-A (RC-8 was derived from a frozen and thawed day 5 embryo cultivated to the blastocyst stage. The embryo was voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  16. Quasi-Static Analysis of Round LaRC THUNDER Actuators

    Science.gov (United States)

    Campbell, Joel F.

    2007-01-01

    An analytic approach is developed to predict the shape and displacement with voltage in the quasi-static limit of round LaRC Thunder Actuators. The problem is treated with classical lamination theory and Von Karman non-linear analysis. In the case of classical lamination theory exact analytic solutions are found. It is shown that classical lamination theory is insufficient to describe the physical situation for large actuators but is sufficient for very small actuators. Numerical results are presented for the non-linear analysis and compared with experimental measurements. Snap-through behavior, bifurcation, and stability are presented and discussed.

  17. Derivation of the human embryonic stem cell line RCe011-A (RC-7

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe011-A (RC-7 was derived from a failed to fertilise oocyte voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  18. Derivation of the human embryonic stem cell line RCe010-A (RC-6

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe010-A (RC-6 was derived from a frozen and thawed blastocyst voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XY male karyotype and microsatellite PCR identity, HLA and blood group typing data are available.

  19. 美空军RC-135侦察机年前服役

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    美国空军官员称,空军最新式和最先进的RC-135“铆钉连接”(Rivet Joint)电子侦听飞机将在11月前后达到使用准备状态。该机将安装能更准备搜集信号情报(SIGNIT)的装置,并将使数据能更自动化和更快速的传递到处理站和指挥中心。

  20. Finite Element Calculation of the Flexural Stiffness of Corroded RC Eccentric Compressive Members

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua; WEI Jun; PAN Qiao; HUANG Ying

    2010-01-01

    A finite element calculation model of corroded RC eccentric compressive members was build using finite element software ANSYS. The model considers the decline of mechanical properties and the effective section of a corroded steel bar, as well as the deterioration of bond character between corroded reinforcement and concrete. The reliability of the finite element model was evaluated by comparing the results of the finite element calculation with the data from experiments. Based on the finite element analysis results, the influence of corrosion degree, the diameter change of the longitudinal reinforcing bars and the spacing change of stirrups on the flexural stiffness were calculated and analyzed.

  1. Human geminin promotes pre-RC formation and DNA replication by stabilizing CDT1 in mitosis

    DEFF Research Database (Denmark)

    Ballabeni, Andrea; Melixetian, Marina; Zamponi, Raffaella

    2004-01-01

    -mediated degradation by inhibiting its ubiquitination. In particular, Geminin ensures basal levels of CDT1 during S phase and its accumulation during mitosis. Consistently, inhibition of Geminin synthesis during M phase leads to impairment of pre-RC formation and DNA replication during the following cell cycle....... Moreover, we show that inhibition of CDK1 during mitosis, and not Geminin depletion, is sufficient for premature formation of pre-RCs, indicating that CDK activity is the major mitotic inhibitor of licensing in human cells. Taken together with recent data from our laboratory, our results demonstrate...

  2. Trade-off between TMA and RC configurations for JANUS camera

    Science.gov (United States)

    Greggio, D.; Magrin, D.; Munari, M.; Paolinetti, R.; Turella, A.; Zusi, M.; Cremonese, G.; Debei, S.; Della Corte, V.; Friso, E.; Hoffmann, H.; Jaumann, R.; Michaelis, H.; Mugnuolo, R.; Olivieri, A.; Palumbo, P.; Ragazzoni, R.; Schmitz, N.

    2016-07-01

    JANUS (Jovis Amorum Ac Natorum Undique Scrutator) is a high-resolution visible camera designed for the ESA space mission JUICE (Jupiter Icy moons Explorer). The main scientific goal of JANUS is to observe the surface of the Jupiter satellites Ganymede and Europa in order to characterize their physical and geological properties. During the design phases, we have proposed two possible optical configurations: a Three Mirror Anastigmat (TMA) and a Ritchey-Chrétien (RC) both matching the performance requirements. Here we describe the two optical solutions and compare their performance both in terms of achieved optical quality, sensitivity to misalignment and stray light performances.

  3. RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Vera L. Oliveira-Freitas

    2015-01-01

    Full Text Available RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR, RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P<0.001. The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P=0.005. Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P<0.013. No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β (P=0.159 and TNF-α (P=0.260, as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis.

  4. Biochemical and molecular characterization of RcSUS1, a cytosolic sucrose synthase phosphorylated in vivo at serine 11 in developing castor oil seeds.

    Science.gov (United States)

    Fedosejevs, Eric T; Ying, Sheng; Park, Joonho; Anderson, Erin M; Mullen, Robert T; She, Yi-Min; Plaxton, William C

    2014-11-28

    Sucrose synthase (SUS) catalyzes the UDP-dependent cleavage of sucrose into UDP-glucose and fructose and has become an important target for improving seed crops via metabolic engineering. A UDP-specific SUS homotetramer composed of 93-kDa subunits was purified to homogeneity from the triacylglyceride-rich endosperm of developing castor oil seeds (COS) and identified as RcSUS1 by mass spectrometry. RcSUS1 transcripts peaked during early development, whereas levels of SUS activity and immunoreactive 93-kDa SUS polypeptides maximized during mid-development, becoming undetectable in fully mature COS. The cytosolic location of the enzyme was established following transient expression of RcSUS1-enhanced YFP in tobacco suspension cells and fluorescence microscopy. Immunological studies using anti-phosphosite-specific antibodies revealed dynamic and high stoichiometric in vivo phosphorylation of RcSUS1 at its conserved Ser-11 residue during COS development. Incorporation of (32)P(i) from [γ-(32)P]ATP into a RcSUS1 peptide substrate, alongside a phosphosite-specific ELISA assay, established the presence of calcium-dependent RcSUS1 (Ser-11) kinase activity. Approximately 10% of RcSUS1 was associated with COS microsomal membranes and was hypophosphorylated relative to the remainder of RcSUS1 that partitioned into the soluble, cytosolic fraction. Elimination of sucrose supply caused by excision of intact pods of developing COS abolished RcSUS1 transcription while triggering the progressive dephosphorylation of RcSUS1 in planta. This did not influence the proportion of RcSUS1 associated with microsomal membranes but instead correlated with a subsequent marked decline in SUS activity and immunoreactive RcSUS1 polypeptides. Phosphorylation at Ser-11 appears to protect RcSUS1 from proteolysis, rather than influence its kinetic properties or partitioning between the soluble cytosol and microsomal membranes.

  5. Extracting Concrete Thermal Characteristics from Temperature Time History of RC Column Exposed to Standard Fire

    Directory of Open Access Journals (Sweden)

    Jung J. Kim

    2014-01-01

    Full Text Available A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment.

  6. Design of Visco-Elastic Dampers for RC Frame for Site-Specific Earthquake

    Science.gov (United States)

    Kamatchi, P.; Rama Raju, K.; Ravisankar, K.; Iyer, Nagesh R.

    2016-11-01

    Number of Reinforced Concrete (RC) framed buildings have got damaged at Ahmedabad city, India located at about 240 km away from epicenter during January 2001, 7.6 moment magnitude (Mw) Bhuj earthquake. In the present study, two dimensional nonlinear time history dynamic analyses of a typical 13 storey frame assumed to be located at Ahmedabad is carried out with the rock level and surface level site-specific ground motion for scenario earthquake of Mw 7.6 from Bhuj. Artificial ground motions are generated using extended finite source stochastic model with seismological parameters reported in literature for 2001 Bhuj earthquake. Surface level ground motions are obtained for a typical soil profile of 100 m depth reported in literature through one dimensional equivalent linear wave propagation analyses. From the analyses, failure of frame is observed for surface level ground motions which indicates that, in addition to the in-adequacy of the cross sections and reinforcement of the RC members of the frame chosen, the rich energy content of the surface level ground motion near the fundamental time period of the frame has also contributed for the failure of frame. As a part of retrofitting measure, five Visco-elastic Dampers (VED) in chevron bracing are added to frame. For the frame considered in the present study, provision of VED is found to be effective to mitigate damage for the soil site considered.

  7. RC beams shear-strengthened with fabric-reinforced-cementitious-matrix (FRCM) composite

    Science.gov (United States)

    Loreto, Giovanni; Babaeidarabad, Saman; Leardini, Lorenzo; Nanni, Antonio

    2015-12-01

    The interest in retrofit/rehabilitation of existing concrete structures has increased due to degradation and/or introduction of more stringent design requirements. Among the externally-bonded strengthening systems fiber-reinforced polymers is the most widely known technology. Despite its effectiveness as a material system, the presence of an organic binder has some drawbacks that could be addressed by using in its place a cementitious binder as in fabric-reinforced cementitious matrix (FRCM) systems. The purpose of this paper is to evaluate the behavior of reinforced concrete (RC) beams strengthened in shear with U-wraps made of FRCM. An extensive experimental program was undertaken in order to understand and characterize this composite when used as a strengthening system. The laboratory results demonstrate the technical viability of FRCM for shear strengthening of RC beams. Based on the experimental and analytical results, FRCM increases shear strength but not proportionally to the number of fabric plies installed. On the other hand, FRCM failure modes are related with a high consistency to the amount of external reinforcement applied. Design considerations based on the algorithms proposed by ACI guidelines are also provided.

  8. 3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

    Directory of Open Access Journals (Sweden)

    Francesco Bencardino

    2016-05-01

    Full Text Available The purpose of this study is to evaluate, through a nonlinear Finite Element (FE analysis, the structural behavior of Reinforced Concrete (RC beams externally strengthened by using Steel Reinforced Grout (SRG and Steel Reinforced Polymer (SRP systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

  9. Predicting the seismic performance of typical R/C healthcare facilities: emphasis on hospitals

    Science.gov (United States)

    Bilgin, Huseyin; Frangu, Idlir

    2017-07-01

    Reinforced concrete (RC) type of buildings constitutes an important part of the current building stock in earthquake prone countries such as Albania. Seismic response of structures during a severe earthquake plays a vital role in the extent of structural damage and resulting injuries and losses. In this context, this study evaluates the expected performance of a five-story RC healthcare facility, representative of common practice in Albania, designed according to older codes. The design was based on the code requirements used in this region during the mid-1980s. Non-linear static and dynamic time history analyses were conducted on the structural model using the Zeus NL computer program. The dynamic time history analysis was conducted with a set of ground motions from real earthquakes. The building responses were estimated in global levels. FEMA 356 criteria were used to predict the seismic performance of the building. The structural response measures such as capacity curve and inter-story drift under the set of ground motions and pushover analyses results were compared and detailed seismic performance assessment was done. The main aim of this study is considering the application and methodology for the earthquake performance assessment of existing buildings. The seismic performance of the structural model varied significantly under different ground motions. Results indicate that case study building exhibit inadequate seismic performance under different seismic excitations. In addition, reasons for the poor performance of the building is discussed.

  10. Quasistatic Seismic Damage Indicators for RC Structures from Dissipating Energies in Tangential Subspaces

    Directory of Open Access Journals (Sweden)

    Wilfried B. Krätzig

    2014-01-01

    Full Text Available This paper applies recent research on structural damage description to earthquake-resistant design concepts. Based on the primary design aim of life safety, this work adopts the necessity of additional protection aims for property, installation, and equipment. This requires the definition of damage indicators, which are able to quantify the arising structural damage. As in present design, it applies nonlinear quasistatic (pushover concepts due to code provisions as simplified dynamic design tools. Substituting so nonlinear time-history analyses, seismic low-cycle fatigue of RC structures is approximated in similar manner. The treatment will be embedded into a finite element environment, and the tangential stiffness matrix KT in tangential subspaces then is identified as the most general entry for structural damage information. Its spectra of eigenvalues λi or natural frequencies ωi of the structure serve to derive damage indicators Di, applicable to quasistatic evaluation of seismic damage. Because det KT=0 denotes structural failure, such damage indicators range from virgin situation Di=0 to failure Di=1 and thus correspond with Fema proposals on performance-based seismic design. Finally, the developed concept is checked by reanalyses of two experimentally investigated RC frames.

  11. Predicting the seismic performance of typical R/C healthcare facilities: emphasis on hospitals

    Science.gov (United States)

    Bilgin, Huseyin; Frangu, Idlir

    2017-09-01

    Reinforced concrete (RC) type of buildings constitutes an important part of the current building stock in earthquake prone countries such as Albania. Seismic response of structures during a severe earthquake plays a vital role in the extent of structural damage and resulting injuries and losses. In this context, this study evaluates the expected performance of a five-story RC healthcare facility, representative of common practice in Albania, designed according to older codes. The design was based on the code requirements used in this region during the mid-1980s. Non-linear static and dynamic time history analyses were conducted on the structural model using the Zeus NL computer program. The dynamic time history analysis was conducted with a set of ground motions from real earthquakes. The building responses were estimated in global levels. FEMA 356 criteria were used to predict the seismic performance of the building. The structural response measures such as capacity curve and inter-story drift under the set of ground motions and pushover analyses results were compared and detailed seismic performance assessment was done. The main aim of this study is considering the application and methodology for the earthquake performance assessment of existing buildings. The seismic performance of the structural model varied significantly under different ground motions. Results indicate that case study building exhibit inadequate seismic performance under different seismic excitations. In addition, reasons for the poor performance of the building is discussed.

  12. Probabilistic seismic performance assessment of lap-spliced RC columns retrofitted by steel wrapping jackets

    Science.gov (United States)

    Choi, Eunsoo; Youn, Heejung; Cho, Baik-Soon

    2016-06-01

    In this study, the seismic fragility curves of two reinforced concrete (RC) columns that were lap-spliced at the bottom and retrofitted with steel wrapping jackets were generated. Their seismic performance was probabilistically assessed in comparison to that of lap-spliced or continuous reinforcement RC columns. This study used two types of steel wrapping jackets, a full jacket and a split jacket. Analytical models of the four types of columns were developed based on the experimental results of the columns using OpenSEES, which is effective in conducting nonlinear time history analyses. A suite of ten artificial ground motions, modified from recorded ground motions, was used to perform nonlinear time history analyses of the analytical models with scaling of the peak ground acceleration from 0.1 g to 1.0 g in increments of 0.1 g. The steel wrapping jackets did not increase the medians for yield (slight damage state) of the lap-spiced column and did not exceed the corresponding median of the continuous reinforcement column. However, the two steel jackets increased the medians for failure by 1.872 and 2.017 times, respectively, and exceeded the corresponding median of the continuous reinforcement column by 11.8% and 20.5%, respectively.

  13. Dependence of Spiral Galaxy Distribution on Viewing Angle in RC3

    Institute of Scientific and Technical Information of China (English)

    MA Jun; SONG Guo-Xuan; SHU Cheng-Gang

    2000-01-01

    The normalized inclination distributions are presented for the spiral galaxies in RC3. The results show that,except for the bin of 81°-90°, in which the apparent minor isophotal diameters that are used to obtain the inclinations are affected by the central bulges, the distributions for Sa, Sab, Scd and Sd are well consistent with the Monte-Carlo simulation of random inclinations within 3-σ, and Sb and Sbc almost, but Sc is different. One reason for the difference between the real distribution and the Monte-Carlo simulation of Sc may be that some quite inclined spirals, the arms of which are inherently loosely wound on the galactic plane and should be classified to Sc galaxies, have been incorrectly classified to the earlier ones, because the tightness of spiral arms which is one of the criteria of the Hubble classification in RC3 is different between on the galactic plane and on the tangent plane of the celestial sphere. Our result also implies that there might exist biases in the luminosity functions of individual Hubble types if spiral galaxies are only classified visually.

  14. Damage assessment of a two-span RC slab using wavelet analysis

    Science.gov (United States)

    Zhu, X. Q.; Hao, H.

    2007-04-01

    A two-span RC slab that measures 6400mm×800mm×100mm with 3000mm spans and 200mm overhang on each end was tested to failure in the laboratory. UB sections were used as supports. The slab was designed according to the moment redistribution method with 11 N6 bars at 75mm centres for both positive and negative reinforcement. The slab was incrementally loaded at the middle of each span to different load levels to create crack damage using four-point loading. Twelve loading stages were performed with increasing maximum load level. Two load cells are used to record the static loads on left and right spans. The crack locations and lengths were monitored in addition to the displacement measurements. Four displacement transducers are located at two sides of the middle of each span to measure the deflection under the static load. Three sets of accelerometers with nine of them in each set are evenly distributed along the slab to measure the dynamic responses. The measured responses from the RC slab in different cracked damage states are analyzed using the wavelet transform (WT). The damping ratios and instantaneous frequency are extracted. The results show that the damping ratio and instantaneous frequency changes could be two good indicators of damage in the reinforced concrete structure.

  15. Concrete Mix Design for Service Life of RC Structures under Carbonation Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Seung-Jun Kwon

    2014-01-01

    Full Text Available Steel corrosion in reinforced concrete (RC structure is such a critical problem to structural safety that many researches have been performed for maintaining required performance during intended service life. This paper is for a numerical technique for obtaining optimum concrete mix proportions through genetic algorithm (GA for RC structures under carbonation which is considered as a serious deterioration in underground sites and big cities. For this study, mix proportions and CO2 diffusion coefficients are analyzed through the previous studies, and then the fitness function of CO2 diffusion coefficient is derived through regression analysis. The fitness function from 69 test results includes 5 variables of mix proportions such as w/c (water to cement ratio, cement content, sand content percentage, coarse aggregate content, and R.H. (relative humidity. Through GA technique, simulated mix proportions are obtained for 12 cases of verification and they show reasonable results with average relative error of 4.6%. Assuming intended service life and design parameters, intended CO2 diffusion coefficients and cement contents are determined and then related mix proportions are simulated. The proposed technique can provide initial concrete mix proportions which satisfy service life under carbonation.

  16. Improving social cognition in people with schizophrenia with RC2S: two single-case studies

    Directory of Open Access Journals (Sweden)

    Elodie ePEYROUX

    2016-04-01

    Full Text Available Difficulties in social interactions are a central characteristic of people with schizophrenia, and can be partly explained by impairments of social cognitive processes. New strategies of cognitive remediation have been recently developed to target these deficits. The RC2S therapy is an individualized and partly computerized program through which patients practice social interactions and develop social cognitive abilities with simulation techniques in a realistic environment. Here we present the results of two case studies involving two patients with schizophrenia presenting with specific profiles of impaired social cognition. Each patient completed three baseline sessions, 14 treatment sessions, and three follow up sessions at the end of the therapy – and for one patient, another three sessions nine months later. We used a multiple baseline design to assess specific components of social cognition according to the patients’ profiles. Functioning and symptomatology were also assessed at the end of the treatment and six months later. Results highlight significant improvements in the targeted social cognitive processes and positive changes in functioning in the long term. The RC2S program seems thus to be a new useful program for social cognitive remediation in schizophrenia.

  17. Design strength evaluation of RC beams under radiation environments for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Won-Hee [Institute for Infrastructure Engineering, University of Western Sydney, Penrith, NSW 2751 (Australia); Kwon, Tae-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Hyeong-Tae [Department of Civil and Environmental Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Kyoungsoo, E-mail: k-park@yonsei.ac.kr [Department of Civil and Environmental Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2016-05-15

    Neutron irradiation changes the behavior of construction materials such as strength and ductility, and thus structural design equations or their safety margins should accordingly be updated for the design of nuclear power plants (NPP) under irradiation. However, current design codes do not account for such changes in material strength. In this study, a framework is proposed to evaluate the change of the safety margins in design equations of reinforced concrete (RC) flexural members under radiation environments. Material strength changes are approximated on the basis of a collected test database, and the design strengths of RC beams are evaluated considering these material strength changes. The evaluation results demonstrate that the design strength of an under-reinforced flexural member can increase while the design strength of an over-reinforced member generally decreases. These results are associated with the material strength changes such that the yield strength of steel increases and the compressive strength of concrete decreases with the fluence of neutron radiation. Current NPP design codes need to further consider this un-conservative design possibility due to the design strength reduction of flexural members under irradiation.

  18. A More Sustainable Way for Producing RC Sandwich Panels On-Site and in Developing Countries

    Directory of Open Access Journals (Sweden)

    Lorenzo Graziani

    2017-03-01

    Full Text Available The purpose of this work is to assess if traditionally used welded connectors for joining the two skins of reinforced concrete (RC sandwich panels, used as structural walls and horizontal structural elements, can be substituted with bent ones. In this way, the scope of the effort is to reduce drastically the energy required during manufacturing, thus having a much more sustainable building product. Wire mesh on site production, in fact, requires a large amount of energy for the welding process, as stated by several Environmental Product Declaration (EPD. In addition, the production of sandwich panels with bent connectors requires a low level of automation and no qualified labor allowing the diffusion in developing countries. The procedures used to execute the work were both experimental and numerical. Structural performances were examined by testing full-scale sandwich panels under (axial and eccentric compression and flexural loads. Additionally, a Finite Element (FE study was developed to investigate and to optimize the dimension of welded mesh and the number of connectors. The major findings show that it is possible to substitute welded connectors with bent ones without compromising the structural performance of the tested RC sandwich panels, thus having a more sustainable way for producing these last ones.

  19. Improving Social Cognition in People with Schizophrenia with RC2S: Two Single-Case Studies.

    Science.gov (United States)

    Peyroux, Elodie; Franck, Nicolas

    2016-01-01

    Difficulties in social interactions are a central characteristic of people with schizophrenia, and can be partly explained by impairments of social cognitive processes. New strategies of cognitive remediation have been recently developed to target these deficits. The RC2S therapy is an individualized and partly computerized program through which patients practice social interactions and develop social cognitive abilities with simulation techniques in a realistic environment. Here, we present the results of two case-studies involving two patients with schizophrenia presenting with specific profiles of impaired social cognition. Each patient completed three baseline sessions, 14 treatment sessions, and 3 follow-up sessions at the end of the therapy - and for 1 patient, another 3 sessions 9 months later. We used a multiple baseline design to assess specific components of social cognition according to the patients' profiles. Functioning and symptomatology were also assessed at the end of the treatment and 6 months later. Results highlight significant improvements in the targeted social cognitive processes and positive changes in functioning in the long term. The RC2S program seems, thus, to be a new useful program for social cognitive remediation in schizophrenia.

  20. Comments on recent measurements of R(c) and R(b)

    Energy Technology Data Exchange (ETDEWEB)

    Dunietz, Isard; Incandela, Joseph; Snider, Frederick D.; Tesima, Kyuzo; Watanabe, Isamu

    1996-06-01

    Discrepancies between Standard Model predictions and experimental measurements of the fractions R_c and R_b of hadronic Z decays to charm and bottom are investigated. We show that there exists a discrepancy in two complementary determinations of B(Bbar --> D X). Reducing the branching ratio B(D0 --> K- Pi+) by about 15% from currently accepted values to 3.50+/-0.21 removes the discrepancy. Since B(D0 --> K- Pi+) calibrates most charmed hadron yields, the reduced value also eliminates the discrepancy between the predicted and measured values of R_c and mitigates a problem in semileptonic B decays. A reduction in B(D0 --> K- Pi+) would also mean that roughly 15% of all D0 and D+ decays have not been properly taken into account. It is shown that if the missing decay modes involve multiple charged particles, they would be more likely to pass the requirements for lifetime B tagging at LEP and SLC. This would mean that the charm tagging efficiency in (Z --> c cbar) has been underestimated. As a consequence R_b would need to be revised downward, potentially bringing it in line with the Standard Model prediction.

  1. Comments on recent measurements of R$_{c}$ and R$_{b}$

    CERN Document Server

    Dunietz, Isard; Snider, F D; Tesima, K; Watanabe, I; Dunietz, Isard; Incandela, Joseph; Snider, Frederick D; Tesima, Kyuzo; Watanabe, Isamu

    1996-01-01

    Discrepancies between Standard Model predictions and experimental measurements of the fractions R_c and R_b of hadronic Z decays to charm and bottom are investigated. We show that there exists a discrepancy in two complementary determinations of B(Bbar --> D X). Reducing the branching ratio B(D0 --> K- Pi+) by about 15% from currently accepted values to 3.50+/-0.21 removes the discrepancy. Since B(D0 --> K- Pi+) calibrates most charmed hadron yields, the reduced value also eliminates the discrepancy between the predicted and measured values of R_c and mitigates a problem in semileptonic B decays. A reduction in B(D0 --> K- Pi+) would also mean that roughly 15% of all D0 and D+ decays have not been properly taken into account. It is shown that if the missing decay modes involve multiple charged particles, they would be more likely to pass the requirements for lifetime B tagging at LEP and SLC. This would mean that the charm tagging efficiency in (Z --> c cbar) has been underestimated. As a consequence R_b woul...

  2. Physical aging and solvent effects on the fracture of LaRC-TPI adhesives

    Science.gov (United States)

    Dillard, David A.; St.clair, Terry L.; Johnson, W. Steven

    1992-01-01

    When amorphous materials are quenched below their glass transition temperature, excess enthalpy is trapped in the glassy material because the viscosity is too great to allow the material to remain in volumetric equilibrium. Over time, this excess free volume is reduced as the material slowly approaches its equilibrium configuration. This process, known as physical aging, leads to substantial changes in the constitutive behavior of polymers, as has been widely discussed in the literature. Less is known about the effects of this physical aging process on fracture and fatigue properties of aged materials. The original goal of the summer was to investigate the effects of physical aging on the fracture and fatigue behavior of LaRC-TPI, a thermoplastic polyimide developed at NASA-Langley. Preliminary results are reported, although a lack of equipment availability prevented completion of this task. In the process of making specimens, the current LaRC-TPI was observed to be extremely susceptible to environmental stress cracking. A study of the unique failure patterns resulting from this degradation process in bonded joints was conducted and is also reported herein.

  3. Preparation of graphite conductive paint and its application to the construction of RC circuits on paper

    Science.gov (United States)

    Grisales, C.; Herrera, N.; Fajardo, F.

    2016-09-01

    We describe a simple procedure for the preparation of graphite-based conductive paint and determine its basic transport properties when applied, comparing them to those of pencil strokes. Ohm’s law was fulfilled on the applied paint, which makes it an ideal strategy to teach the relations between a resistor’s length, width and resistance. The conductive paint was used in the construction of RC circuits on paper in a simple and didactic format. Using only the paint and a piece of cardboard, a completely functional parallel plate capacitor can be constructed with different plate geometries; in particular, we painted circular and rectangular plates. The charge and discharge cycles of the two RC circuits painted were observed in the oscilloscope. We obtained characteristic times and estimated the value of the dielectric constant of paper, which serves as a dielectric between the plates of the capacitors. We found conductive paint to be a useful and easy method to teach basic electricity and circuit concepts in fundamental courses and lab practices because it allows one to visualise properties such as the dependence of resistance and capacitance with geometric factors using a specific material.

  4. Design of Visco-Elastic Dampers for RC Frame for Site-Specific Earthquake

    Science.gov (United States)

    Kamatchi, P.; Rama Raju, K.; Ravisankar, K.; Iyer, Nagesh R.

    2016-12-01

    Number of Reinforced Concrete (RC) framed buildings have got damaged at Ahmedabad city, India located at about 240 km away from epicenter during January 2001, 7.6 moment magnitude (Mw) Bhuj earthquake. In the present study, two dimensional nonlinear time history dynamic analyses of a typical 13 storey frame assumed to be located at Ahmedabad is carried out with the rock level and surface level site-specific ground motion for scenario earthquake of Mw 7.6 from Bhuj. Artificial ground motions are generated using extended finite source stochastic model with seismological parameters reported in literature for 2001 Bhuj earthquake. Surface level ground motions are obtained for a typical soil profile of 100 m depth reported in literature through one dimensional equivalent linear wave propagation analyses. From the analyses, failure of frame is observed for surface level ground motions which indicates that, in addition to the in-adequacy of the cross sections and reinforcement of the RC members of the frame chosen, the rich energy content of the surface level ground motion near the fundamental time period of the frame has also contributed for the failure of frame. As a part of retrofitting measure, five Visco-elastic Dampers (VED) in chevron bracing are added to frame. For the frame considered in the present study, provision of VED is found to be effective to mitigate damage for the soil site considered.

  5. Extracting concrete thermal characteristics from temperature time history of RC column exposed to standard fire.

    Science.gov (United States)

    Kim, Jung J; Youm, Kwang-Soo; Reda Taha, Mahmoud M

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment.

  6. Lactobacillus rhamnosus RC007 intended for feed additive: immune-stimulatory properties and ameliorating effects on TNBS-induced colitis.

    Science.gov (United States)

    Dogi, C; García, G; De Moreno de LeBlanc, A; Greco, C; Cavaglieri, L

    2016-09-01

    Lactobacillus rhamnosus RC007 is a potential probiotic bacterium that can exert beneficial effects as supplement for animal feed, by improving the immune status in healthy host, and by providing therapeutic benefits to infected/inflamed animals. The aim of the present work was to evaluate in vivo the beneficial properties of L. rhamnosus RC007, intended for animal feed, when administered to healthy and trinitro-benzene-sulfonic-acid (TNBS) colitis induced BALB/c mice. The administration of L. rhamnosus RC007 to healthy mice during 10 days increased the phagocytic activity of peritoneal macrophages and the number of immunoglobulin A+ cells in the lamina proper of the small intestine. Significant increases of monocyte chemotactic protein 1, interleukin (IL)-10 and tumour necrosis factor alpha (TNF-α) concentrations, and in the ratio between anti- and pro-inflammatory cytokines (IL-10/TNF-α) were observed in intestinal fluids after administration of bacteria. In the inflammation model, less body weight loss, macroscopic and histological damages in the large intestine were accompanied by increased IL-10/TNF-α ratio in the intestinal fluids of mice from the L. rhamnosus-TNBS group when compared to the TNBS group. In a healthy host, the oral administration of L. rhamnosus RC007 kept the gut immune system stimulated allowing a faster response to noxious stimulus. Mice that received L. rhamnosus RC007 also decreased the severity of the intestinal inflammation.

  7. Caught red-handed: Rc encodes a basic helix-loop-helix protein conditioning red pericarp in rice.

    Science.gov (United States)

    Sweeney, Megan T; Thomson, Michael J; Pfeil, Bernard E; McCouch, Susan

    2006-02-01

    Rc is a domestication-related gene required for red pericarp in rice (Oryza sativa). The red grain color is ubiquitous among the wild ancestors of O. sativa, in which it is closely associated with seed shattering and dormancy. Rc encodes a basic helix-loop-helix (bHLH) protein that was fine-mapped to an 18.5-kb region on rice chromosome 7 using a cross between Oryza rufipogon (red pericarp) and O. sativa cv Jefferson (white pericarp). Sequencing of the alleles from both mapping parents as well as from two independent genetic stocks of Rc revealed that the dominant red allele differed from the recessive white allele by a 14-bp deletion within exon 6 that knocked out the bHLH domain of the protein. A premature stop codon was identified in the second mutant stock that had a light red pericarp. RT-PCR experiments confirmed that the Rc gene was expressed in both red- and white-grained rice but that a shortened transcript was present in white varieties. Phylogenetic analysis, supported by comparative mapping in rice and maize (Zea mays), showed that Rc, a positive regulator of proanthocyanidin, is orthologous with INTENSIFIER1, a negative regulator of anthocyanin production in maize, and is not in the same clade as rice bHLH anthocyanin regulators.

  8. Ca(2+)-binding reduces conformational flexibility of RC-LH1 core complex from thermophile Thermochromatium tepidum.

    Science.gov (United States)

    Jakob-Grun, Selma; Radeck, Jara; Braun, Paula

    2012-03-01

    The light-harvesting complex, LH1, of thermophile purple bacteria Thermochromatium tepidum consists of an array of α- and β-polypeptides which assemble the photoactive bacteriochlorophyll and closely interact with the membrane-lipids. In this study, we investigated the effect of calcium and manganese ions on the protein structure and thermostability of the reaction centre (RC)-LH1/lipid complex. The binding of Ca(2+), but not Mn(2+) is shown to shift the LH1 Q ( y ) absorption maximum from ~889 to 915 nm and to significantly raise the thermostability of the RC-LH1 complex. The ATR-FTIR spectra indicate that interaction of Ca(2+) as monitored by the carboxylates' vibration of aspartate residues, but not Mn(2+) induces changes in the α-helix packing arrangement. The reduced rate of (1)H/(2)H exchange of proteins' amide protons shows that the accessibility to (2)H(2)O is significantly lowered in Ca(2+)-substituted RC-LH1/lipid complexes. In particular, exchange with the associated lipid molecules, is significantly retarded. These results suggest that the thermostability of the RC-LH1 complex is raised by the distinct interaction with calcium cations which reduces the RC-LH1/lipid dynamics, particularly, at the membrane-water interface.

  9. Inference in Graphical Gaussian Models with Edge and Vertex Symmetries with the gRc Package for R

    DEFF Research Database (Denmark)

    Højsgaard, Søren; Lauritzen, Steffen L

    2007-01-01

    In this paper we present the R package gRc for statistical inference in graphical Gaussian models in which symmetry restrictions have been imposed on the concentration or partial correlation matrix. The models are represented by coloured graphs where parameters associated with edges or vertices o...... of same colour are restricted to being identical. We describe algorithms for maximum likelihood estimation and discuss model selection issues. The paper illustrates the practical use of the gRc package......In this paper we present the R package gRc for statistical inference in graphical Gaussian models in which symmetry restrictions have been imposed on the concentration or partial correlation matrix. The models are represented by coloured graphs where parameters associated with edges or vertices...

  10. Specific in vivo binding in the rat brain of [{sup 18}F]RP 62203: A selective 5-HT{sub 2A} receptor radioligand for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Besret, Laurent; Dauphin, Francois; Huard, Cecile; Lasne, Marie-Claire; Vivet, Richard; Mickala, Patrick; Barbelivien, Alexandra; Baron, Jean-Claude

    1996-02-01

    In vivo pharmacokinetic and brain binding characteristics of [{sup 18}F]RP 62203, a selective high-affinity serotonergic 5-HT{sub 2A} receptor antagonist, were assessed in the rat following intravenous injection of trace amount of the radioligand. The radioactive distribution profile observed in the brain 60 min after injection was characterized by greater than fourfold higher uptake in neocortex as compared to cerebellum (0.38 {+-} 0.07% injected dose/g, % ID/g and 0.08 {+-} 0.01 ID/g, respectively), consistent with in vivo specific binding to the 5-HT{sub 2A} receptor. Furthermore, specific [{sup 18}F]RP 62203 binding significantly correlated with the reported in vitro distribution of 5-HT{sub 2A} receptors, but not with known concentration profiles of dopaminergic D{sub 2} or adrenergic {alpha}{sub 1} receptors. Finally, detectable specific binding was abolished by pretreatment with large doses of ritanserin, a selective 5-HT{sub 2A} antagonist, which resulted in uniform uptakes across cortical, striatal and cerebellar tissues. Thus, [{sup 18}F]RP 62203 appears to be a promising selective tool to visualize and quantify 5-HT{sub 2A} brain receptors in vivo with positron emission tomography.

  11. Protective effect of RC-3095, an antagonist of the gastrin-releasing peptide receptor, in experimental arthritis.

    Science.gov (United States)

    Oliveira, P G; Grespan, R; Pinto, L G; Meurer, L; Brenol, J C T; Roesler, R; Schwartsmann, G; Cunha, F Q; Xavier, R M

    2011-10-01

    To evaluate the antiinflammatory effects of RC-3095 in 2 experimental models of arthritis, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA), and to determine the mechanisms of action involved. RC-3095 was administered daily to mice with CIA and mice with AIA, after induction of disease with methylated bovine serum albumin. Disease incidence and severity were assessed using a clinical index and evaluation of histologic features, respectively. In mice with CIA, gastrin-releasing peptide receptor (GRPR) was detected by immunohistochemical analysis, while in mice with AIA, migration of neutrophils, presence of glycosaminoglycans, and lymphocyte proliferation, determined using the MTT assay, were assessed. Expression of cytokines interleukin-17 (IL-17), IL-1β, and tumor necrosis factor α (TNFα) was evaluated in all mouse knees using enzyme-linked immunosorbent assay. Treg cell production was assessed by flow cytometry in the joints of mice with AIA. In mice with AIA, administration of RC-3095 reduced neutrophil migration, mechanical hypernociception, and proteoglycan loss. These findings were associated with inhibition of the levels of all 3 proinflammatory cytokines, decreased lymphocyte proliferation, and increased Treg cell numbers. In the CIA model, treatment with RC-3095 led to a significant reduction in arthritis clinical scores and the severity of disease determined histologically. Synovial inflammation, synovial hyperplasia, pannus formation, and extensive erosive changes were all dramatically reduced in the arthritic mice treated with RC-3095. Furthermore, arthritic mice treated with RC-3095 showed a significant reduction in the concentrations of IL-17, IL-1β, and TNFα, and showed a diminished expression of GRPR. These findings suggest that the GRP pathway has a significant role in chronic arthritis, and its inhibition can be explored as a possible therapeutic strategy in rheumatoid arthritis. Copyright © 2011 by the American College

  12. Combinatorial interactions are required for the efficient recruitment of pho repressive complex (PhoRC to polycomb response elements.

    Directory of Open Access Journals (Sweden)

    Tatyana G Kahn

    2014-07-01

    Full Text Available Polycomb Group (PcG proteins are epigenetic repressors that control metazoan development and cell differentiation. In Drosophila, PcG proteins form five distinct complexes targeted to genes by Polycomb Response Elements (PREs. Of all PcG complexes PhoRC is the only one that contains a sequence-specific DNA binding subunit (PHO or PHOL, which led to a model that places PhoRC at the base of the recruitment hierarchy. Here we demonstrate that in vivo PHO is preferred to PHOL as a subunit of PhoRC and that PHO and PHOL associate with PREs and a subset of transcriptionally active promoters. Although the binding to the promoter sites depends on the quality of recognition sequences, the binding to PREs does not. Instead, the efficient recruitment of PhoRC to PREs requires the SFMBT subunit and crosstalk with Polycomb Repressive Complex 1. We find that human YY1 protein, the ortholog of PHO, binds sites at active promoters in the human genome but does not bind most PcG target genes, presumably because the interactions involved in the targeting to Drosophila PREs are lost in the mammalian lineage. We conclude that the recruitment of PhoRC to PREs is based on combinatorial interactions and propose that such a recruitment strategy is important to attenuate the binding of PcG proteins when the target genes are transcriptionally active. Our findings allow the appropriate placement of PhoRC in the PcG recruitment hierarchy and provide a rationale to explain why YY1 is unlikely to serve as a general recruiter of mammalian Polycomb complexes despite its reported ability to participate in PcG repression in flies.

  13. Serial Peripheral Interface Communication Between MCU EM78P447A and RF Reader IC MF RC530

    Institute of Scientific and Technical Information of China (English)

    YOU Zhi; CHEN Shu-zhen; HUANG Ji-wu

    2005-01-01

    A significant method in the way the MCU EM78P447A manipulates the RF reader IC MF RC530's functions used in RF IC card application is presented. In this paper, RF reader IC MF RC530's SPI compatible interface is introduced. The kernel technologies including SPI connection, software design,register initiation, request-response between the reader IC and the MCU, authentication and the proper format of the key are explained. Adopting the serial peripheral interface is the innovation in the paper. The SPI communication mode proves feasible and precise. Furthermore, in the way we avoid the abuse of parallel interface.

  14. A new 4π(LS)-γ coincidence counter at NCBJ RC POLATOM with TDCR detector in the beta channel.

    Science.gov (United States)

    Ziemek, T; Jęczmieniowski, A; Cacko, D; Broda, R; Lech, E

    2016-03-01

    A new 4π(LS)-γ coincidence system (TDCRG) was built at the NCBJ RC POLATOM. The counter consists of a TDCR detector in the beta channel and scintillation detector with NaI(Tl) crystal in the gamma channel. The system is equipped with a digital board with FPGA, which records and analyses coincidences in the TDCR detector and coincidences between the beta and gamma channels. The characteristics of the system and a scheme of the FPGA implementation with behavioral simulation are given. The TDCRG counter was validated by activity measurements on (14)C and (60)Co solutions standardized in RC POLATOM using previously validated methods.

  15. A high-resolution time interpolator based on a delay locked loop and an RC delay line

    CERN Document Server

    Mota, M

    1999-01-01

    An architecture for a time interpolation circuit with an rms error of ~25 ps has been developed in a 0.7- mu m CMOS technology. It is based on a delay locked loop (DLL) driven by a 160-MHz reference clock and a passive RC delay line controlled by an autocalibration circuit. Start-up calibration of the RC delay line is performed using code density tests (CDT). The very small temperature/voltage dependence of R and C parameters and the self calibrating DLL results in a low- power, high-resolution time interpolation circuit in a standard digital CMOS technology. (11 refs).

  16. 要漂亮,更要冷酷!—酷冷至尊COSMOS RC1000机箱

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    酷冷至尊新推出的COSMOS RC1000机箱是专门针对发烧友设计的产品。它的侧板采用铝合金,内部支架则采用镀锌钢架结构、非常牢固、净重达到了16.9公斤,和普通机箱相比,用坚如磐石来形容COSMOS RC1000并不为过。

  17. Dimensionamiento del refuerzo a flexión con laminados de polímeros reforzados con fibras (FRP evitando su desprendimiento prematuro

    Directory of Open Access Journals (Sweden)

    Oller, E.

    2013-12-01

    Full Text Available According to the available experimental research related to structures flexurally strengthened by bonding fiber reinforced polymer (FRP laminates, the laminate debonds in a brittle manner in most tests. This debonding failure usually initiates in the most loaded regions due the effect of intermediate cracks (intermediate crack debonding. From the beginning of this technique, several models have been developed to avoid this premature failure. However, some of them present a significant scatter in relation to the experimental data. This paper presents a comparative analysis of the existing formulations through a database of tests compiled by the authors. Afterwards, a design procedure based on a shear-bending moment interaction diagram related to intermediate crack debonding is presented. This interaction diagram depends on the maximum shear force between crack discontinuities. Finally, the proposed method is compared to the rest of the models obtaining satisfactory results when predicting the failure load.La investigación experimental de elementos de hormigón reforzados a flexión mediante la adhesión de laminados de polímeros reforzados con fibras (FRP muestra que en la mayor parte de ensayos, el laminado se desprende de forma prematura iniciándose normalmente el fallo en las regiones más solicitadas debido al efecto de las fisuras intermedias. Desde los inicios de esta técnica de refuerzo, se han desarrollado modelos para evitar este tipo de rotura, la mayoría de los cuales presentan una dispersión considerable comparando sus resultados con los experimentales. En este artículo se presenta un análisis comparativo de diferentes formulaciones existentes a partir de una base de datos de ensayos recopilada por los autores. Posteriormente, se propone un método de dimensionamiento basado en un diagrama de interacción cortante-flexión asociado al desprendimiento del refuerzo, que depende de la máxima fuerza rasante transmitida entre

  18. Preliminary study of impact fragility to RC wall subjected to aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup; Hahm, Dae Gi; Choi, In Kil [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    International experience has shown that internal and external hazards such as fires, earthquakes, and aircraft impacts can be significant safety contributors to the risk to infrastructures such as nuclear power plants. Since the aircraft accident at the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly of the interest and is one of important categories of an unexpected external hazard field. To date, aircraft impact analyses has most focused on the response analysis to the target structures. However, this preliminary study carried out an impact fragility analysis to reinforced concrete (RC) wall subjected to an aircraft impact. The aircraft velocity is used as the important variable of this study. The impact analysis of the applied Ri era's forcing function is used by Abaqus/Explicit.

  19. Calibrating and validating a FE model for long-term behavior of RC beams

    Directory of Open Access Journals (Sweden)

    Tošić Nikola D.

    2014-01-01

    Full Text Available This study presents the research carried out in finding an optimal finite element (FE model for calculating the long-term behavior of reinforced concrete (RC beams. A multi-purpose finite element software DIANA was used. A benchmark test in the form of a simply supported beam loaded in four point bending was selected for model calibration. The result was the choice of 3-node beam elements, a multi-directional fixed crack model with constant stress cut-off, nonlinear tension softening and constant shear retention and a creep and shrinkage model according to CEB-FIP Model Code 1990. The model was then validated on 14 simply supported beams and 6 continuous beams. Good agreement was found with experimental results (within ±15%.

  20. A review on: The influence of soil conditions on the seismic forces in RC buildings

    Directory of Open Access Journals (Sweden)

    Mr. Rahul Sawant

    2015-06-01

    Full Text Available This study focuses on a review of the influence of soil conditions on the seismic forces in RC buildings. The aim of this study is to gain understanding the effect of the local site conditions on the seismic forces in building. The study helps in creating awareness about the importance of the local site conditions, such as proximity to the source of earthquakes (faults and the local geological and topographical features in the earthquake resistant design of buildings. The current Indian code of practice for seismic analysis IS 1893:2002, specifies seismic zones to consider different levels of intensity of ground shaking, There are also maps of the principal tectonic features and lithological formations. This paper shows the soil condition effects studied by the various researchers.

  1. Nonlinear Control for Trajectory Tracking of a Nonholonomic RC-Hovercraft with Discrete Inputs

    Directory of Open Access Journals (Sweden)

    Dictino Chaos

    2013-01-01

    Full Text Available This work studies the problem of trajectory tracking for an underactuated RC-hovercraft, the control of which must be done by means of discrete inputs. Thus, the aim is to control a vehicle with very simple propellers that produce only a discrete set of control commands, and with minimal information about the dynamics of the actuators. The control problem is approached as a cascade control problem, where the outer loop stabilizes the position error, and the inner loop stabilizes the orientation of the vehicle. Stability of the controller is theoretically demonstrated and the robustness of the control law against disturbances and noise is established. Simulation examples and experiments on a real setup validate the control law showing the real system to be robust against disturbances, noise, and outdated dynamics.

  2. Design and Development of RC Railed Robot for Coffee Nursery Logistics

    Directory of Open Access Journals (Sweden)

    Marivic Gatan Dizon

    2014-12-01

    Full Text Available The Remote Controlled (RC Railed Robot was designed and developed to transfer polybags from manual operation to an automated logistic system. Gizduino microcontroller was used to read and interpret commands sent and received by the transceivers to the robot and a remote to command instructions to the robot.The project was tested and evaluated at the Coffee Nursery of Cavite State University by determining the speed of the robot, the effectiveness of the remote control and the accuracy of the robot to lift a pallet and place it into an empty space.Results showed that the robot was able to receive and interpret commands provided by the remote control as well as perform the tasks successfully.The most significant recommendation was to use a counterweight at the rear side of the robot to avoid unnecessary derailments of the robot if lifting heavier or greater number of pallets is desired.

  3. Influences of load pattern selection and higher modes on pushover analysis for R.C. structures

    Institute of Scientific and Technical Information of China (English)

    HOU Shuang; OU Jin-ping

    2008-01-01

    Load pattern selection is one of the critical issues in pushover analysis (POA) when the influence of higher modes is evident. In terms of interstory drift, comparisons between the nonlinear time history analysis (NL-THA) and the pushover analysis (POA) were conducted for three typical RC frame buildings under a va-riety of ground motion levels. Eight typical earthquake inputs, including four earthquake records and four artifi-cial earthquake waves, were employed as the input of NL-THA; five typical lateral load patterns were consid-ered in POA. By means of modal participation factor, the higher mode effect in POA was quantified considering floor numbers and the ground motion intensity. Suggestions about load pattern selection in POA were provided when higher mode influence was found evident.

  4. Mechanical compression release device in steel bracing system for retrofitting RC frames

    Institute of Scientific and Technical Information of China (English)

    H. Ghaffarzadeh; M.R. Maheri

    2006-01-01

    The development of an innovative structural system with satisfactory seismic performance of braced systems is an important and challenging area of interest in structural engineering. In this paper, a device that can release the compressive force in the bracing members is developed, and its performance is evaluated. For comparison, four steel braced RC frames were constructed and tested under reverse cyclic loads. Two of them had different amounts of bracing and the other two had the same amount of bracing but incorporated different type of device, called compression release device, which is developed and described in this paper. It can be concluded from the test results that the newly developed device can effectively be used in steel braced systems to prevent buckling failure of the bracing members. Therefore, the device enhances the ductility of brace-framed systems by allowing an adequate capacity for energy dissipation.

  5. Experimental study and analysis on fatigue stiffness of RC beams strengthened with CFRP and steel plate

    Institute of Scientific and Technical Information of China (English)

    LU Yi-yan; HU Ling; LI Shan; WANG Kang-hao

    2016-01-01

    The objective of this work is to investigate the fatigue behavior of reinforced concrete (RC) beams strengthened with externally bonded carbon fiber reinforced polymer (CFRP) and steel plate. An experimental investigation and theoretical analysis were made on the law of deflection development and stiffness degradation, as well as the influence of fatigue load ranges. Test results indicate that the law of three-stage change under fatigue loading is followed by both midspan deflection and permanent deflection, which also have positive correlation with fatigue load amplitude. Fatigue stiffness of composite strengthened beams degrades gradually with the increasing of number of cycles. Based on the experimental results, a theoretical model by effective moment of inertia method is developed for calculating the sectional stiffness of such composite strengthened beams under fatigue loading, and the calculated results are in good agreement with the experimental results.

  6. LQG optimal compensator transfer function for the NASA LaRC CSI Evolutionary Model

    Science.gov (United States)

    Balakrishnan, A. V.

    1994-01-01

    Following the general form for LQG optimal compensators for flexible structures with collocated rate sensors we develop an explicit compensator transfer function for the NASA LaRC CSI Evolutionary model in the form: psi(i omega) = g i omega B(sub u)(sup *)(-M(sub b)omega(exp 2) + T(i omega) + i gamma omega B(sub u)Bu(sub u)(sup *))(exp -1)B(sub u) where T(i omega) is a 48 x 48 positive definite matrix whose derivation is the main result of this report. The undamped mode frequencies can be expressed in terms of T(i omega) as the zeros of Det (-omega(exp 2)M(sub b) + T(i omega)) while 'clamped-clamped' modes of the structure (with all nodes clamped) are the poles.

  7. Nonlinear dynamic analysis based on experimental data of RC telecommunication towers subjected to wind loading

    Directory of Open Access Journals (Sweden)

    Marcelo A. Silva

    2006-01-01

    Full Text Available The goal of this paper is to propose a nonlinear dynamic model based on experimental data and NBR-6123-87 to accomplish a nonlinear dynamic analysis of slender structures subjected to wind loading. At first we compute the static answer given by the mean wind speed. In this part of the problem we consider the concept of effective stiffness to represent the physical nonlinearity of material and a P-Delta method to represent the geometrical nonlinearity. Considering the final stiffness obtained in that P-Delta method, we compute the dynamic answer given by the floating wind speed, according to the discrete dynamic model given by NBR-6123-87. A 40 m RC telecommunication tower was analyzed, and the results obtained were compared with those given by linear static and dynamic models.

  8. Research on SOC estimation based on second-order RC model

    Directory of Open Access Journals (Sweden)

    Xieyang Wang

    2012-11-01

    Full Text Available The estimation accuracy of batteries’ State of Charge (SOC plays an important role in the development of hybrid electric vehicle (HEV. Accurate estimation of SOC can prevent battery from overly charging and discharging, so the lifetime of batteries will be increased. Although Kalman filter algorithm has better estimation accuracy for HEV application in which the current changes fast, Kalman filter algorithm deeply relies on the battery model. In other words, the accuracy of batteries’ SOC estimation needs precise batteries models. Besides, when the HEV is running, the statistical characteristics of noise produced in the course of the battery management system collecting data are unknown. This can cause estimated performance of Kalman filter algorithm to decrease even diffuse. To solve the problem, adaptive Kalman filter algorithm is adopted to estimate battery SOC based on the second order RC battery model in this paper. Through MATLAB simulation analysis, the estimation accuracy of battery SOC is improved to some extent.

  9. A numerical design approach for single amplifier, Active-RC Butterworth filter of order 5

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2007-01-01

    A design method is presented for the design of all pole lowpass active-RC filters applying operational amplifiers. The operational amplifier model used is the integrator model: omegat/s where omegat is the unity gain frequency. The design method is used for the design of a fifth order Butterworth...... filter applying just one operational amplifier coupled as a unity gain amplifier. It is shown that the influence from the real operational amplifier may be reduced by trimming just one resistor in the circuit. The unity gain amplifiers have the advantage of providing low power consumption, yielding...... a large dynamic range, sometimes simplifying the amplifier design and being usable over a larger frequency range than conventional constant gain amplifiers. The Schoeffler sensitivity index is used as a basis for a sensitivity comparison with other similar filters reported in the literature. © 2007 IEEE....

  10. Elasto-Plasticity Critical Corrosive Ratio Model for RC Structure Corrosive Expanding Crack

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; LU Yiyan; LIU Li

    2007-01-01

    The parameter of filling expanding ratio n, plasticity factor k1 and deformation parameter k2 is raised, and then the elasto-plasticity critical corrosive ratio model for RC structure corrosive expanding crack based on elasto-plasticity theory is constructed in this paper. The influences of parameters such as filling expansion ratio n, plasticity factor k1, deformation parameter k2, Poisson ratio of concrete v, diameter of reinforced bar d and protective layer thickness c on the critical corrosive ratio are researched by theory analysis and experiments. The experimental results validate the accuracy of the model. According to the experimental study, the least squares solution is calculated as n=1.8,k1 =0.61,k2 =0.5.

  11. Theoretical and experimental investigation of optimal capacitor charging process in RC circuit

    Science.gov (United States)

    Xia, Shaojun; Chen, Lingen

    2017-05-01

    The problem of optimal capacitor charging in a RC circuit is investigated using finite-time thermodynamics (FTT). Both the resistor and the capacitor are assumed to be nonlinear, and the optimal time paths of source voltage for the minimum charging time and the minimum Joule heat dissipation are obtained by using optimal control theory, respectively. The optimal time path of source voltage is also compared with the classical strategies of constant source voltage and linear source voltage operations. The results show that the optimal time path of source voltage for the minimum charging time consists of the initial and final instantaneous voltage change and the middle maximum admissable constant-voltage branches, which is independent of the nonlinear characteristics of both the resistor and the capacitor; when the ratio of the time constant of the circuit to the charging time is relatively smaller, the charging strategy of linear electric-source voltage is much closer to the optimal time path of the source voltage of the minimum Joule heat dissipation, while, when the ratio of the time constant of the circuit to the charging time is relatively larger, the charging strategy of constant source voltage is much closer to the optimal time path of source voltage of the minimum Joule heat dissipation; when the resistance is constant, the voltage difference between the source and the capacitor for the minimum Joule heat dissipation of the process is always a constant whether the capacitor is linear or nonlinear, and this conclusion is also valid for the case with the current law of "function of difference". An experiment of capacitor charging processes in the RC circuit is performed finally, and the results show that real voltage profiles of the resistor for different charging strategies are consistent with the corresponding results of theoretical analysis.

  12. Evaluation of seismic performance of reinforced concrete (RC) buildings under near-field earthquakes

    Science.gov (United States)

    Moniri, Hassan

    2017-03-01

    Near-field ground motions are significantly severely affected on seismic response of structure compared with far-field ground motions, and the reason is that the near-source forward directivity ground motions contain pulse-long periods. Therefore, the cumulative effects of far-fault records are minor. The damage and collapse of engineering structures observed in the last decades' earthquakes show the potential of damage in existing structures under near-field ground motions. One important subject studied by earthquake engineers as part of a performance-based approach is the determination of demand and collapse capacity under near-field earthquake. Different methods for evaluating seismic structural performance have been suggested along with and as part of the development of performance-based earthquake engineering. This study investigated the results of illustrious characteristics of near-fault ground motions on the seismic response of reinforced concrete (RC) structures, by the use of Incremental Nonlinear Dynamic Analysis (IDA) method. Due to the fact that various ground motions result in different intensity-versus-response plots, this analysis is done again under various ground motions in order to achieve significant statistical averages. The OpenSees software was used to conduct nonlinear structural evaluations. Numerical modelling showed that near-source outcomes cause most of the seismic energy from the rupture to arrive in a single coherent long-period pulse of motion and permanent ground displacements. Finally, a vulnerability of RC building can be evaluated against pulse-like near-fault ground motions effects.

  13. Evaluation of seismic performance of reinforced concrete (RC) buildings under near-field earthquakes

    Science.gov (United States)

    Moniri, Hassan

    2017-01-01

    Near-field ground motions are significantly severely affected on seismic response of structure compared with far-field ground motions, and the reason is that the near-source forward directivity ground motions contain pulse-long periods. Therefore, the cumulative effects of far-fault records are minor. The damage and collapse of engineering structures observed in the last decades' earthquakes show the potential of damage in existing structures under near-field ground motions. One important subject studied by earthquake engineers as part of a performance-based approach is the determination of demand and collapse capacity under near-field earthquake. Different methods for evaluating seismic structural performance have been suggested along with and as part of the development of performance-based earthquake engineering. This study investigated the results of illustrious characteristics of near-fault ground motions on the seismic response of reinforced concrete (RC) structures, by the use of Incremental Nonlinear Dynamic Analysis (IDA) method. Due to the fact that various ground motions result in different intensity-versus-response plots, this analysis is done again under various ground motions in order to achieve significant statistical averages. The OpenSees software was used to conduct nonlinear structural evaluations. Numerical modelling showed that near-source outcomes cause most of the seismic energy from the rupture to arrive in a single coherent long-period pulse of motion and permanent ground displacements. Finally, a vulnerability of RC building can be evaluated against pulse-like near-fault ground motions effects.

  14. 基于MF-RC500射频卡读写系统设计%Design of RF Card Read-write System Based on MF-RC500

    Institute of Scientific and Technical Information of China (English)

    郭国法; 淡丹; 张开生

    2015-01-01

    针对射频卡的读写系统,采用STC89S52为主控芯片,研究了MF-RC500的射频卡读写系统设计方法,通过RS232为数据传输接口连接上位机以及键盘来构建一种适用于各个应用场合的非接触式IC卡读写系统,程序中利用单片机的低功耗模式达到系统节能降耗的目的。实验表明,基于MF-RC500射频卡读写系统设计运行稳定,切实可行。%TO radio frequency (RF) card read-write system,the main control chip of STC89S52 is adopted and the design method of RF card read-write system based on MF-RC500 is researched. Through RS232 interface for data transmission to connect PC and keyboard ,a kind of non-contact IC card read-write system adapting to the various applications is built ,using low power mode of microcontroller to achieve the purpose of system energy saving. Experiments show that the RF card reader based on MF-RC500 system running well, is feasible.

  15. FGF23、MEPE和sFRP4在肿瘤性骨软化症发病机制中的作用%Roles of FGF23,MEPE and sFRP4 in the pathogenesis of tumor induced osteomalacia

    Institute of Scientific and Technical Information of China (English)

    姜艳; 夏维波; 孟迅吾

    2009-01-01

    肿瘤性骨软化症(TIO)是由于肿瘤引起肾脏排磷增加,所造成的获得性低血磷骨软化-症.近来研究显示,肿瘤分泌的体液因子(如调磷因子)可以影响体内磷的平衡,而成纤维细胞牛长因子-23(FGF-23)、细胞外基质磷酸糖蛋白(MEPE)和分泌型卷曲相关蛋白(sFRP)4可能就是调磷因子.它们通过抑制肾小管上皮细胞磷的回吸收,抑制肾脏1,α羟化酶的活性,从而调节血磷,使患者血磷降低,尿磷增多,血1,25(OH)2D3水平降低或正常,从而参与TIO的发生.%Tumor induced osteomalacia(TIO) is an acquired hypophosphatemie syndrome caused y tumors.Experimental evidence suggests that the biochemical and skeletal defects are caused by humeral factors(phosphatonins)from the tumor.The potential candidates for phosphatonins,such as fibroblast growth factor-23(FGF-23),matrix extracellular phosphoglyeoprotein(MEPE)and secreted frizzled related protein 4(sFRP4)are characterized by impaired renal tubular reabsorption of phosphate,and inhibited l,α hydroxylase.They induce low levels of serum phosphate and 1,25-dihydroxyvitamin D3,therefore,play important roles in the pathogenesis of TIO.

  16. Bacillus velezensis RC 218 as a biocontrol agent to reduce Fusarium head blight and deoxynivalenol accumulation in wheat

    Science.gov (United States)

    Bacillus velezensis RC 218 was originally isolated for the anthers of wheat as a potential antagonist of Fusarium graminearium, the causal agent of Fusarium head blight. It was demonstrated to have antagonist activity against the plant pathogen with in vitro and greenhouse assays. The current study ...

  17. Strengthening of RC Beams with Large Openings in Shear by CFRP Laminates: Experiment and 2D Nonlinear Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    S.C. Chin

    2012-05-01

    Full Text Available This study presents the experimental study and numerical analysis of Reinforced Concrete (RC beams with large square openings placed in the shear region, at a distance 0.5d and d away from the support, strengthened by Carbon Fiber Reinforced Polymer (CFRP laminates. This research aims to investigate the strength losses in RC beam due to the presence of large square openings placed at two different locations in shear region. Also, in order to re-gain the beam structural capacity loss due to the openings, strengthening by CFRP laminates around the openings were studied. A total of six RC beams were tested to failure under four point loading including control beams, un-strengthened and strengthened RC beams with large square openings in shear region at a distance 0.5d and d away from the support. The CFRP strengthening configuration considered in this study was a full wrapping system around the square openings. A nonlinear finite element program, ATENA was used to validate the results of the tested beams. Comparisons between the finite element predictions and experimental results in terms of crack patterns and load deflection relationships are presented. The crack pattern results of the finite element model show good agreement with the experimental data. The load midspan deflection curves of the finite element models exhibited a stiffer result compared to the experimental beams. The possible reason may be due to the perfect bond assumption between the concrete and steel reinforcement.

  18. Magnetic phase transitions in (RC) m(NiB) 2 intermetallic compounds observed by a local probe

    Science.gov (United States)

    Sánchez, D. R.; Tróchez, J. C.; Micklitz, H.; Fontes, M. B.; Giordanengo, B.; Baggio-Saitovitch, E.

    1997-08-01

    Samples of (RC) m(NiB) 2 with 1 % of Ni substituted by Fe were studied by Mössbauer spectroscopy, these experiments provided evidence of pair-breaking field at the Ni metal site in the RENi 2B 2C series and we expect to be able to determine the spin orientation for RENiBC series.

  19. An Experimental Study on Hybrid Noncompression CF Bracing and GF Sheet Wrapping Reinforcement Method to Restore Damaged RC Structures

    Directory of Open Access Journals (Sweden)

    Kang Seok Lee

    2015-01-01

    Full Text Available We describe a novel technique for restoration of reinforced concrete (RC structures that have sustained damage during an earthquake. The reinforcement scheme described here is a hybrid seismic retrofitting technique that combines noncompression X-bracing using CF with externally bonded GF sheets to strengthen RC structures that have sustained damage following an earthquake. The GF sheet is used to improve the ductility of columns, and the noncompression CF X-bracing system, which consists of CF bracing and anchors to replace the conventional steel bracing and bolt connections, is used to increase the lateral strength of the framing system. We report seismic restoration capacity, which enables reuse of the damaged RC frames via the hybrid CF X-bracing and GF sheet wrapping system. Cyclic loading tests were carried out to investigate hysteresis of the lateral load-drift relations, as well as the ductility. The GF sheet significantly improved the ductility of columns, resulting in a change in failure mode. The strengthening effect of conventional CF sheets used in columns is not sufficient with respect to lateral strength and stiffness. However, this study results in a significant increase in the strength of the structure due to the use of CF X-bracing and inhibited buckling failure of the bracing. This result can be exploited to develop guidelines for the application of the reinforcement system to restore damaged RC structures.

  20. 47 CFR 95.219 - (R/C Rule 19) How do I answer correspondence from the FCC?

    Science.gov (United States)

    2010-10-01

    ... from the FCC? 95.219 Section 95.219 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... You Need to Know § 95.219 (R/C Rule 19) How do I answer correspondence from the FCC? (a) If it appears to the FCC that you have violated the Communications Act or FCC rules, the FCC may send you...

  1. RC-class and LC-class on fixed point theorems for α-Caristi type contraction mappings

    Directory of Open Access Journals (Sweden)

    Arslan Hojat Ansari

    2017-06-01

    Full Text Available In this paper, we introduce the notion of (α,ℋLC,fRC-Caristi type contraction mappings and prove fixed point theorem by using this notion on complete metric space. To illustrate our result, we construct an example.

  2. Mechanical Performance and Chloride Diffusivity of Cracked RC Specimens Exposed to Freeze-Thaw Cycles and Intermittent Immersion in Seawater

    Directory of Open Access Journals (Sweden)

    Bei Shen

    2016-01-01

    Full Text Available The effects of crack width on chloride ingress and mechanical behavior of reinforced concrete (RC specimens were experimentally studied after exposure to 300 cycles of freeze-thaw and seawater immersion (75 times. Cracks were induced prior to exposure by an eccentric compression load which was sustained until the end of the exposure period. The maximum cracks widths induced in the four column specimens were 0, 0.06, 0.11, and 0.15 mm, respectively. Results show that when the crack width was less than 0.06 mm, the effect of cracks on chloride ingress could be neglected. However, when the crack width was more than 0.11 mm, chloride ingress was accelerated. Results of static loading tests show that both yield load and ultimate load of RC columns decreased as crack width increased. When the crack width was 0.15 mm, yield load and ultimate load of RC column specimen decreased by 17.0% and 18.9%, respectively, compared to a specimen without cracks. It was concluded that crack width significantly promoted local chloride ingress and mechanical performance degradation of RC structures in cold coastal regions or exposed to deicing salts.

  3. A case of hyperkalemia after transfusion of irradiated red cell concentrate in mannitol-adenine-phosphate (RC-MAP)

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Akira; Yokota, Kimio; Aoki, Masanori; Sari, Atsuo [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    1998-11-01

    A 72-year-old male, 45 kg in weight, underwent anterior and posterior fixations of the lumbar vertebra. Preanesthetic blood chemistry was within normal range. Following transfusion of 400 ml of RC-MAP in two hours (11 days after blood collection and 2 days after irradiation at a dose of 20 Gy), and then another 100 ml of 400 ml RC-MAP (12 days after blood collection and 2 days after irradiation at a dose of 20 Gy), the patient`s serum kalium value increased from 4.8 to 5.5 mEq/l. Even though the transfusion was immediately discontinued, the level continued to rise to 6.0 mEq/l. It subsequently fell to the normal level with glucose-insulin therapy. The hyperkalemia in this case could have been attributable to the period of storage after irradiation, the transfusion of salvaged autologous blood, and the storage state of RC-MAP. However, since the kalium values of RC-MAP and the salvaged autologous blood were not measured in this case, the exact cause was unknown. In conclusion, hyperkalemia can occur in patients during transfusion of irradiated blood. Therefore, kalium levels should be monitored carefully. (author)

  4. Thermodynamically leveraged Tandem catalysis for ester RC(O)O-R' bond hydrogenolysis. scope and mechanism.

    Energy Technology Data Exchange (ETDEWEB)

    Lohr, Tracy L.; Li, Zhi; Assary, Rajeev S.; Curtiss, Larry A.; Marks, Tobin J.

    2015-06-01

    Rapid and selective formal hydrogenolysis of aliphatic ester RC(O)O-R' linkages is achieved by a tandem homogeneous metal triflate + supported palladium catalytic system. The triflate catalyzes the mildly exothermic, turnover-limiting O-R' cleavage process, whereas the exothermic hydrogenation of the intermediate alkene further drives the overall reaction to completion.

  5. 工程结构用FRP筋的力学性能%Mechanics Performance of FRP Tendons Used in Engineering Structure

    Institute of Scientific and Technical Information of China (English)

    朱虹; 钱洋

    2006-01-01

    通过分析工程结构用纤维增强塑料(FRP)筋的组成和物理力学性能特点,对比FRP筋性能和钢筋性能的不同之处,指出了FRP筋在工程结构中的适用性和应用前景.通过试验研究,分析了局部弯折对芳纶纤维增强塑料(AFRP)筋极限抗拉强度、加载速率和加载历史对编织型芳纶纤维筋(FiBRA)型AFRP筋弹性模量,以及应力水平对FiBRA型AFRP筋松弛率的影响,建立了规格为FA11的FiBRA型AFRP筋的松弛率计算公式.结果表明,局部弯折可能导致FRP筋的极限抗拉强度下降,FiBRA型AFRP筋编织状的成型特征造成其弹性模量在张拉过程中是渐趋稳定的,并且造成其总松弛量较大,工程应用时需充分考虑这些因素.

  6. Flexural Behavior of Steel-Fiber-Added-RC (SFARC Beams with C30 and C50 Classes of Concrete

    Directory of Open Access Journals (Sweden)

    Hamid Pesaran Behbahani

    2012-04-01

    Full Text Available Although conventional reinforced concrete (RC is the most globally used building material; however, its detrimental structural characteristics such as brittle failure mechanism in tension need to be improved. Discrete and short steel fibers (SFs can be added into the concrete mix to improve its brittleness. The effects of the addition of optimum percentage of SFs on flexural behavior of RC beams have been investigated in this paper. In this study, the optimum percentage of hooked-end SFs with the dimensions of 0.75 mm in diameter and 50 mm in length are added in RC beams with two different classes of concrete (i.e. two different compressive strengths of 30MPa (C30 and 50MPa (C50. In order to determine the optimum percentage of SFs added to the concrete mix, 15 prisms and 30 cubes with 5 different percentages of SFs (i.e. 0%v/v, 0.5%v/v, 1%v/v, 1.5%v/v, and 2%v/v from both C30 and C50 classes of concrete have been tested. Based on the results of the flexural strength and compressive strength tests, it is found that the optimum value is 1% by volume (i.e. 78.5 kg/m3 for the specific type of fiber used in this study. Subsequently, to investigate the flexural behavior of steel fiber added RC (SFARC beams compared to conventional RC beams with no SFs, two RC beams with the dimensions of 170 mm in height, 120 mm in width, and 2400 mm in length, with the SF percentages of 0 and 1%v/v and both having exactly the same steel reinforcement were tested under flexure using a four-point loading test setup for both C30 and C50 classes of concrete. The experimental results show that the SFARC beams with 1% by volume of the SFs have higher first cracking strength, ultimate flexural strength, stiffness, and ductility compared to that of the conventional RC beams with no SFs. Furthermore, the addition of the SFs has more effects on the RC beams with higher compressive strength (50 MPa compared to lower concrete grade (30 MPa.

  7. Time-dependent reliability of corrosion-affected RC beams-Part 1: Estimation of time-dependent strengths and associated variability

    Energy Technology Data Exchange (ETDEWEB)

    Bhargava, Kapilesh, E-mail: kapilesh_66@yahoo.co.u [Architecture and Civil Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Mori, Yasuhiro [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8603 (Japan); Ghosh, A.K. [Reactor Safety Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2011-05-15

    Research highlights: Predictive models for corrosion-induced damages in RC structures. Formulations for time-dependent flexural and shear strengths of corroded RC beams. Methodology for mean and c.o.v. for time-dependent strengths of corroded RC beams. Simple estimation of mean and c.o.v. for flexural strength with loss of bond. - Abstract: The structural deterioration of reinforced concrete (RC) structures due to reinforcement corrosion is a major worldwide problem. Damages to RC structures due to reinforcement corrosion manifest in the form of expansion, cracking and eventual spalling of the cover concrete; thereby resulting in serviceability and durability degradation of such structures. In addition to loss of cover, RC structure may suffer structural damages due to loss of reinforcement cross-sectional area, and loss of bond between corroded reinforcement and surrounding cracked concrete, sometimes to the extent that the structural failure becomes inevitable. This paper forms the first part of a study which addresses time-dependent reliability analyses of RC beams affected by reinforcement corrosion. In this paper initially the predictive models are presented for the quantitative assessment of time-dependent damages in RC beams, recognized as loss of mass and cross-sectional area of reinforcing bar, loss of concrete section owing to the peeling of cover concrete, and loss of bond between corroded reinforcement and surrounding cracked concrete. Then these models have been used to present analytical formulations for evaluating time-dependent flexural and shear strengths of corroded RC beams, based on the standard composite mechanics expressions for RC sections. Further by considering variability in the identified basic variables that could affect the time-dependent strengths of corrosion-affected RC beams, the estimation of statistical descriptions for the time-dependent strengths is presented for a typical simply supported RC beam. The statistical descriptions

  8. Ginsenoside Rc Promotes Anti-Adipogenic Activity on 3T3-L1 Adipocytes by Down-Regulating C/EBPα and PPARγ

    Directory of Open Access Journals (Sweden)

    Ji-Won Yang

    2015-01-01

    Full Text Available Panax ginseng and its major components, the ginsenosides, are widely used in oriental medicine for the prevention of various disorders. In the present study, the inhibitory activity of ginsenoside Rc on adipogenesis was investigated using the 3T3-L1 cell line. The results obtained showed that Rc reduced the proliferation and viability of 3T3-L1 preadipocytes in a dose-dependent manner. Treatment with Rc decreased the number of adipocytes and reduced lipid accumulation in maturing 3T3-L1 preadipocytes, demonstrating an inhibitory effect on lipogenesis. Moreover, it was found that Rc directly induced lipolysis in adipocytes and down-regulated the expression of major transcription factors of the adipogenesis pathway, such as PPARγ and C/EBPα. These findings indicate that Rc is capable of suppressing adipogenesis and therefore they seem to be natural bioactive factors effective in adipose tissue mass modulation.

  9. Physical-chemical and microbiological stability of biotherapy Candida albicans RC in different potencies

    Directory of Open Access Journals (Sweden)

    Sheila Garcia

    2011-09-01

    Full Text Available Introduction: Oral Candidiasis is an opportunist fungal infection, with high incidence in HIV and immunosuppressed patients and Candida albicans is the most common causing agent. In some cases, it can evolve to resistant injuries to antifungal conventional therapy. According to Brazilian Homeopathic Pharmacopeia (BHP [1], biotherapic medicines are prepared from chemically undefined biological products. Biotherapics created by Brazilian doctor Roberto Costa (RC have a different homeopathic compounding technique, as its dynamization starts from the ethiologic agent of the illness in its alive form, which present higher capability to stimulate the host immunological system [2,3]. Aim: The goal of this study was evaluate the physical-chemical and microbiological stability of Candida albicans RC potencies under different conditions of storage. Methodology: To prepare the biotherapics, one part of Candida albicans yeast suspension (109 cell/ml was diluted in 9 parts of sterile distillated water. After preparing this 1:10 dilution, the sample was undergone 100 succussions, resulting in the first decimal dilution (1x. Then, one part of this solution was diluted in 9 parts of sterile distillated water and submitted to 100 succussions, generating the 2x. This process was successively repeated following BHP, until 30x. Water 30x was prepared by the same technique, as control. All the solutions were prepared in aseptic and sterile conditions. Biotherapics 6x, 12x, 18x, 24x, 30x and water 30x were storage under refrigeration (2 to 8°C and at room temperate (25°C during 8 weeks. Every 15 days, the following parameters were analyzed: pH, electrical conductivity, UV absorbance (260 and 280 nm. Microbiological analyses were performed after 3 weeks by colony forming unit (CFU method [4]. Results: The preliminary analyses performed at times zero, 15, 30 and 45 days suggest that electrical conductivity of these solutions tend to increase

  10. Pseudo-Static Experiment and Analysis on Seismic Behavior of the RC Columns Strengthened by GHPFRCC

    Directory of Open Access Journals (Sweden)

    Li Xiuling

    2015-09-01

    Full Text Available Green high performance fiber reinforced cementitious composites (GHPFRCC are a new class of sustainable cementitious composites, employing a high volume of fly ash to replace cement. In addition to increasing the sustainability of the construction environment, GHPFRCC exhibits a high tensile ductility and multiple cracking behaviors in the strainhardening state. These materials can effectively improve the structural energy dissipation capacity and structural durability. In this study, the optimum mixture ratio of GHPFRCC is presented established using an orthogonal experiment for a specific engineering application. The described GHPFRCC sustains the mechanical performance of concrete and is employed as the outer cladding to strengthen concrete columns. The finite element analysis of the material was based on the software ABAQUS and pseudo static experiments were conducted to exhibit retrofitting of GHPFRCC applied in the rehabilitation of seismic-damaged concrete columns. The computed and experimental results showed that GHPFRCC, while incorporating high volume fly ash, can retain significant multiple cracking behaviors. The energy dissipation capacity of the GHPFRCC reinforced concrete (RC column is better than the comparable unreinforced column.

  11. A multi-standard active-RC filter with accurate tuning system

    Energy Technology Data Exchange (ETDEWEB)

    Ma Heping; Yuan Fang; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Dai, F F, E-mail: hpma@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-09-15

    A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 {mu}m 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm{sup 2} and 0.11 mm{sup 2} (calibration circuit excluded), respectively.

  12. Pencil-on-Paper Capacitors for Hand-Drawn RC Circuits and Capacitive Sensing

    Directory of Open Access Journals (Sweden)

    Jonathan E. Thompson

    2017-01-01

    Full Text Available Electronic capacitors were constructed via hand-printing on paper using pencil graphite. Graphite traces were used to draw conductive connections and capacitor plates on opposing sides of a sheet of standard notebook paper. The paper served as the dielectric separating the plates. Capacitance of the devices was generally < 1000 pF and scaled with surface area of the plate electrodes. By combining a pencil-drawn capacitor with an additional resistive pencil trace, an RC low-pass filter was demonstrated. Further utility of the pencil-on-paper devices was demonstrated through description of a capacitive force transducer and reversible chemical sensing. The latter was achieved for water vapor when the hygroscopic cellulose matrix of the paper capacitor’s dielectric adsorbed water. The construction and demonstration of pencil-on-paper capacitive elements broadens the scope of paper-based electronic circuits while allowing new opportunities in the rapidly expanding field of paper-based sensors.

  13. Vibration based structural assessment of the rehabilitation intervention in r.c. segmental bridge

    Directory of Open Access Journals (Sweden)

    Franchetti Paolo

    2015-01-01

    Full Text Available A vibration based structural assessment campaign was carried out on a r.c. segmental bridge in North East Italy. The bridge has a cantilever static scheme, fixed at the top of the piers and with a hinge at the centre of the span. The particular configuration of the hinge consists in a couple of steel elements, each one composed by a tongue and groove joint. Since the year 1960, the hinge was subjected to consumption and degradation, that caused a malfunctioning of the device. An intervention of rehabilitation of the bridge led to a reinforcement of the existing hinges with the coupling of new metallic devices: new tongue and groove hinges were applied, that by one side allow the horizontal displacements and rotation, by the other side strongly reduce the relative vertical displacements of the two parts of the bridge. A dynamic test campaign was set up in order to assess the effectiveness of the intervention. The principal dynamic parameters were calculated and analysed with respect to the intervention that was realized. The tests clearly showed the effectiveness of the intervention, and helped the designer to have a better understanding of the structural behaviour of the bridge.

  14. The risk for progressive collapse of RC frame structures located in seismic areas in Romania

    Directory of Open Access Journals (Sweden)

    Adrian G. MARCHIŞ

    2014-12-01

    Full Text Available In this study the risk for progressive collapse of RC framed buildings located in seismic areas in Romania is investigated. Structures with three, six and ten stories, each in turn are designed for three distinct seismic zones: low (ag=0.08g, moderate (ag=0.16g and high (ag=0.24g. Using the provisions provided by the GSA (2003 Guidelines, a nonlinear dynamic analysis is carried out first in order to establish the risk for progressive collapse of the models under investigation. It is shown that all the structures are not expected to fail when subjected to abnormal loading (sudden column removal. A nonlinear incremental dynamic analysis is conducted next in order to estimate with the maximum accuracy the ultimate load bearing capacity to progressive collapse of the damaged models. Based on the capacity curves provided by this procedure, it is shown that all the structures are capable of sustaining a higher load than the standard GSA loading before failure. Using these capacity curves, the influence of the seismic design on the progressive collapse resistance is quantified as well.

  15. Seismic design factors for RC special moment resisting frames in Dubai, UAE

    Science.gov (United States)

    Alhamaydeh, Mohammad; Abdullah, Sulayman; Hamid, Ahmed; Mustapha, Abdilwahhab

    2011-12-01

    This study investigates the seismic design factors for three reinforced concrete (RC) framed buildings with 4, 16 and 32-stories in Dubai, UAE utilizing nonlinear analysis. The buildings are designed according to the response spectrum procedure defined in the 2009 International Building Code (IBC'09). Two ensembles of ground motion records with 10% and 2% probability of exceedance in 50 years (10/50 and 2/50, respectively) are used. The nonlinear dynamic responses to the earthquake records are computed using IDARC-2D. Key seismic design parameters are evaluated; namely, response modification factor ( R), deflection amplification factor ( C d), system overstrength factor ( Ω o), and response modification factor for ductility ( R d ) in addition to inelastic interstory drift. The evaluated seismic design factors are found to significantly depend on the considered ground motion (10/50 versus 2/50). Consequently, resolution to the controversy of Dubai seismicity is urged. The seismic design factors for the 2/50 records show an increase over their counterparts for the 10/50 records in the range of 200%-400%, except for the Ω o factor, which shows a mere 30% increase. Based on the observed trends, perioddependent R and C d factors are recommended if consistent collapse probability (or collapse prevention performance) in moment frames with varying heights is to be expected.

  16. A Fully On-Chip Gm-Opamp-RC Based Preamplifier for Electret Condenser Microphones

    Science.gov (United States)

    Le, Huy-Binh; Ryu, Seung-Tak; Lee, Sang-Gug

    An on-chip CMOS preamplifier for direct signal readout from an electret capacitor microphone has been designed with high immunity to common-mode and supply noise. The Gm-Opamp-RC based high impedance preamplifier helps to remove all disadvantages of the conventional JFET based amplifier and can drive a following switched-capacitor sigma-delta modulator in order to realize a compact digital electret microphone. The proposed chip is designed based on 0.18µm CMOS technology, and the simulation results show 86dB of dynamic range with 4.5µVrms of input-referred noise for an audio bandwidth of 20kHz and a total harmonic distortion (THD) of 1% at 90mVrms input. Power supply rejection ratio (PSRR) and common-mode rejection ration (CMRR) are more than 95dB at 1kHz. The proposed design dissipates 125µA and can operate over a wide supply voltage range of 1.6V to 3.3V.

  17. Detection and tracking of RC model aircraft in LWIR microgrid polarimeter data

    Science.gov (United States)

    Ratliff, Bradley M.; LeMaster, Daniel A.; Mack, Robert T.; Villeneuve, Pierre V.; Weinheimer, Jeffrey J.; Middendorf, John R.

    2011-10-01

    The LWIR microgrid Polarized InfraRed Advanced Tactical Experiment (PIRATE) sensor was used to image several types of RC model aircraft at varying ranges and speeds under different background conditions. The data were calibrated and preprocessed using recently developed microgrid processing algorithms prior to estimation of the thermal (s0) and polarimetric (s1 and s2) Stokes vector images. The data were then analyzed to assess the utility of polarimetric information when the thermal s0 data is augmented with s1 and s2 information for several model aircraft detection and tracking scenarios. Multi-variate analysis tools were applied in conjunction with multi-hypothesis detection schemes to assess detection performance of the aircraft under different background clutter conditions. We find that polarization is able to improve detection performance when compared with the corresponding thermal data in nearly all cases. A tracking algorithm was applied to a sequence of s0 and corresponding degree of linear polarization (DoLP) images. An initial assessment was performed to determine whether polarization information can provide additional utility in these tracking scenarios.

  18. Allele Types ofRcGene of Weedy Rice from Jiangsu Province, China

    Institute of Scientific and Technical Information of China (English)

    LIXiao-yan; QIANGSheng; SONGXiao-ling; CAIKun; SUNYi-na; SHIZhi-hua; DAIWei-min

    2014-01-01

    Weedy rice(Oryza sativaf.spontanea), the predominant type of which has a red pericarp, seriously inhibits growth and yield of direct-seeded rice in Jiangsu Province, China. In this study, we randomly selected 10 weedy rice accessions from 10 plots in Jiangsu, and then sequenced the full lengths of theirRcgenes (approximately 6.4 kb). In addition, we collected 166 different full-lengthRc genes in theOryzagenus from the literature and from GenBank. A collinearity sequence analysis showed that the 10 weedy riceaccessions from Jiangsu all had the same wild-type allele of theRcgene. Single nucleotide polymorphisms indicated thatthe nucleotide polymorphisms (π= 0.19) and theproportion of segregation sites(θw= 0.28) of theRcgenes in the 10 weedy rice accessions from Jiangsu were higher than those in 56 weedy rice accessions from USA (π= 0.09 andθw= 0.07). Haplotype and phylogenetic analyses showed thattheRcgenes of weedy rice accessions from Jiangsu were not revertants of therc gene found in Asian cultivated rice(O. sativa) varietieswith white pericarp. In addition,Rcgene sequences of the rice varieties Lvdao from Lianyungang, Jiangsu and Tangdao from Anhui were more similar to those of cultivated rice than to the weedy rice from Jiangsu. These findings support the continued quarantine of weedy rice and clarify the evolutionary mechanism of the red pericarp found in the weedy rice of Jiangsu.

  19. Development of a rocking R/C shear wall system implementing repairable structural fuses

    Science.gov (United States)

    Parsafar, Saeed; Moghadam, Abdolreza S.

    2017-09-01

    In the last decades, the concept of earthquake resilient structural systems is becoming popular in which the rocking structure is considered as a viable option for buildings in regions of high seismicity. To this end, a novel wall-base connection based on the " repairable structure" approach is proposed and evaluated. The proposed system is made of several steel plates and high strength bolts act as a friction connection. To achieve the desired rocking motion in the proposed system, short-slotted holes are used in vertical directions for connecting the steel plates to the shear wall (SW). The experimental and numerical studies were performed using a series of displacement control quasi-static cyclic tests on a reference model and four different configurations of the proposed connection installed at the wall corners. The seismic response of the proposed system is compared to the conventional SW in terms of energy dissipation and damage accumulation. In terms of energy dissipation, the proposed system depicted better performance with 95% more energy dissipation capability compared to conventional SW. In terms of damage accumulation, the proposed SW system is nearly undamaged compared to the conventional wall system, which was severely damaged at the wall-base region. Overall, the introduced concept presents a feasible solution for R/C structures when a low-damage design is targeted, which can improve the seismic performance of the structural system significantly.

  20. Hausdorff-Based RC and IESIL Combined Positioning Algorithm for Underwater Geomagnetic Navigation

    Directory of Open Access Journals (Sweden)

    Lin Yi

    2010-01-01

    Full Text Available This paper presents a primitive solution with novel scheme and algorithm for Underwater geoMagnetic Navigation (UMN, which now occurs as the hot-point in the research field of navigation. UMN as an independent or supplementary technique can theoretically supply accurate locations for marine vehicles, but in practice there are plenty of restrictions for UMN's application (e.g., geomagnetic daily variation. After analysis of the theoretical model of geomagnetic positioning in the correlation-matching mode from the viewpoint of pattern recognition, this paper proposed an appropriate matching scenario and a combined positioning algorithm for UMN. The subalgorithm of Hausdorff-based Relative Correlation (RC corresponding to the pattern classification module implements the coarse positioning, and the subalgorithm of Isograms Equidistance-Segmenting theIntersection Lines (IESILs associated with the module of feature extraction continues the fine positioning. The experiments based on the simulation platform and the real-surveyed data both validate the new algorithm, and its efficiency and accuracy are also discussed. It can be concluded that the work introduced in this paper gives an initial and real validation of UMN's potentiality.

  1. Flexural Strengthening of RC Slabs with Prestressed CFRP Strips Using Different Anchorage Systems

    Directory of Open Access Journals (Sweden)

    José Sena-Cruz

    2015-10-01

    Full Text Available Externally Bonded Reinforcement (EBR technique has been widely used for flexural strengthening of concrete structures by using carbon fiber-reinforced polymers (CFRP. EBR technique offers several structural advantages when the CFRP material is prestressed. This paper presents an experimental and numerical study on reinforced (RC slabs strengthened in flexure with prestressed CFRP strips as a structural strengthening system. The strips are applied as an externally bonded reinforcement (EBR and anchored with either a mechanical or a gradient anchorage. The former foresees metallic anchorage plates fixed to the concrete substrate, while the latter is based on an accelerated epoxy resin curing followed by a segment-wise prestress force decrease at the strip ends. Both anchorage systems, in combination with different CFRP strip geometries, were subjected to static loading tests. It could be demonstrated that the composite strip’s performance is better exploited when prestressing is used, with slightly higher overall load carrying capacities for mechanical anchorages than for the gradient anchorage. The performed investigations by means of a cross-section analysis supported the experimental observation that in case a mechanical anchorage is used, progressive strip debonding changes the fully bonded configuration to an unbonded end-anchored system. The inclusion of defined debonding criteria for both the anchorage zones and free length between the anchorage regions allowed to precisely capture the ultimate loading forces.

  2. SEISMIC FRAGILITY ANALYSIS OF IMPROVED RC FRAMES USING DIFFERENT TYPES OF BRACING

    Directory of Open Access Journals (Sweden)

    HAMED HAMIDI JAMNANI

    2017-04-01

    Full Text Available Application of bracings to increase the lateral stiffness of building structures is a technique of seismic improvement that engineers frequently have recourse to. Accordingly, investigating the role of bracings in concrete structures along with the development of seismic fragility curves are of overriding concern to civil engineers. In this research, an ordinary RC building, designed according to the 1st edition of Iranian seismic code, was selected for examination. According to FEMA 356 code, this building is considered to be vulnerable. To improve the seismic performance of this building, 3 different types of bracings, which are Concentrically Braced Frames, Eccentrically Braced Frames and Buckling Restrained Frames were employed, and each bracing element was distributed in 3 different locations in the building. The researchers developed fragility curves and utilized 30 earthquake records on the Peak Ground Acceleration seismic intensity scale to carry out a time history analysis. Tow damage scale, including Inter-Story Drifts and Plastic Axial Deformation were also used. The numerical results obtained from this investigation confirm that Plastic Axial Deformation is more reliable than conventional approaches in developing fragility curves for retrofitted frames. In lieu of what is proposed, the researchers selected the suitable damage scale and developed and compared log-normal distribution of fragility curves first for the original and then for the retrofitted building.

  3. Implementasi Aplikasi Kriptografi Pada Layanan Pesan Singkat (SMS Menggunakan Algoritma RC6 Berbasis Android

    Directory of Open Access Journals (Sweden)

    Widi Puji Atmojo

    2016-08-01

    Full Text Available Security is a very important aspect in data communication. In the last decade, there was a rapid development in mobile phone technology. Smartphone have been equipped with various features and one of them is the short message service (SMS. However, messages sent via mobile phone networks pose threat to be accessed by people who do not have any authorization. Therefore, it is necessary to do research on the development of software to enhance the security of messages through message encryption and decryption features. This application uses Java programming language with SDK (Software Development Kit Android and Android Studio 1.3.1 as an editor. The initial step of this research is to encrypt the original message to produce the ciphertext message. The second step is to decrypt ciphertext incoming messages to become genuine message. Results from this research are an Android-based application that can perform encryption and decryption of the SMS messages using the RC6 algorithm. With the application of cryptography for SMS messages, the expected level of information security of the message can be improved so that the message will be more secure from unauthorized access.

  4. Comparative Study on Flexural Strengthening of RC Beams using CFRP Laminate by Different Techniques

    Science.gov (United States)

    Jeevan, N.; Jagannatha Reddy, H. N.

    2017-08-01

    This paper presents a detailed study on flexural behaviour of RC beams strengthened using Carbon Fiber Reinforced Polymer (CFRP) laminate. A detailed study was made on strengthened beam using Externally Bonded Laminate (EBL) and Internally Bonded Laminate (IBL) techniques. In IBL technique the laminate is sandwiched between the layers of epoxy mounted on the cover portion by the groove. The beams were designed as under-reinforced section. Totally six beams were casted, out of this two beams were control beams. Strengthened beams were divided into two sets (IBL and EBL) of two beams each. The main aim of this work is to delay the debonding failure in order to enhance the ultimate load carrying capacity for strengthened beams. Four-point bending flexural tests were conducted on specimens up to failure. The experimental results illustrate that, the strengthened beams significantly increases the cracking, working and ultimate load when compared with control beams. IBL technique shows the significant increase in the debonding strain by delaying the beam from debonding failure which in turn enhances the ultimate load by almost 73% compared with control beam and 39% with EBL technique. All the deflection values from the experiments are within the limit of codal provisions. The IBL technique was emerged as the better strengthening technique, which increases almost 41% of working load (Pw) compared with strengthening codes.

  5. Seismic Behavor of RC Beam-Column Joint with Additional Bars under Cyclic Loading

    Institute of Scientific and Technical Information of China (English)

    LU Xilin; Tonny H.URUKAP; LI Sen

    2011-01-01

    The behavior of Beam-Column Joints in moment resisting frame structures are susceptible to damage caused by seismic effects due to poor performance of the joint. A good number of researches were carried out to understand the complex mechanism of RC joints which are considered in seismic design code practices presently adopted. The traditional construction detailing of transverse reinforcement have shown serious joint failure.This paper introduces a new design philosophy involving the use of additional diagonal bars within the joint particularly suitable for low to medium seismic effects in earthquake zones throughout the world. In lieu to this study, ten (10) full-scale interior beam-column specimens were constructed with various additional reinforcement details and configurations as will be discussed in the later. The experiment provided adequate results to proof the idea of additional bars as suitable approach in reinforced concrete structures where earthquake is eminent. While compared with overall cracking observation during the test, the specimen with additional bars (diagonal and straight) had shown few cracks on the column than the ones without. Furthermore, concrete confinement is certainly an important design method as recommended by certain international codes.

  6. Effect of Response Reduction Factor on Peak Floor Acceleration Demand in Mid-Rise RC Buildings

    Science.gov (United States)

    Surana, Mitesh; Singh, Yogendra; Lang, Dominik H.

    2017-06-01

    Estimation of Peak Floor Acceleration (PFA) demand along the height of a building is crucial for the seismic safety of nonstructural components. The effect of the level of inelasticity, controlled by the response reduction factor (strength ratio), is studied using incremental dynamic analysis. A total of 1120 nonlinear dynamic analyses, using a suite of 30 recorded ground motion time histories, are performed on mid-rise reinforced-concrete (RC) moment-resisting frame buildings covering a wide range in terms of their periods of vibration. The obtained PFA demands are compared with some of the major national seismic design and retrofit codes (IS 1893 draft version, ASCE 41, EN 1998, and NZS 1170.4). It is observed that the PFA demand at the building's roof level decreases with increasing period of vibration as well as with strength ratio. However, current seismic building codes do not account for these effects thereby producing very conservative estimates of PFA demands. Based on the identified parameters affecting the PFA demand, a model to obtain the PFA distribution along the height of a building is proposed. The proposed model is validated with spectrum-compatible time history analyses of the considered buildings with different strength ratios.

  7. Study on preparation of 125I-RC-160 with NBS and its biodistribution in animals%125I-RC-160的NBS标记法研究及体内生物学分布特征

    Institute of Scientific and Technical Information of China (English)

    王喆; 汪静; 程时武; 李国权

    2004-01-01

    目的: 研究一种125I直接标记RC-160的简便高效的方法,并观察125I-RC-160在正常小鼠体内的生物学分布特征.方法: 采用N-溴代琥珀酸亚胺(NBS)作为氧化剂,在RC-160定量的反应体系中加入不同量的125I 与NBS,探索标记的最佳反应比例;纯化后产物进行正常小鼠体内生物学分布检测.结果: 反应体系最佳比例为RC-160 ∶125I ∶NBS=10 μg ∶7.4 MBq ∶30 μg,标记率可达到76.9﹪,经Sep-Pak C18反相色谱柱纯化,放化纯达到95.7﹪;标记产物在血液、心肌、肾脏中清除快,肺脏浓集度最高,肝、脾、胃肠浓集度较高.结论: 本方法步骤简便,标记率高,是一种比较理想的碘标方法,标记肽主要经消化系统代谢.

  8. 基于CL RC632的射频读写器的RFID系统设计%Design of RFID system for RF reader-writer based on CL RC632

    Institute of Scientific and Technical Information of China (English)

    马欢; 张涛

    2012-01-01

    设计一种基于STC11F32XE单片机和CL RC632芯片的非接触式射频读写器.首先介绍RFID系统的组成和CL RC632的特性,再根据其原理完成硬件电路设计和软件功能实现.该系统使用Mifare卡作为系统的应答器,通过执行防冲突命令序列使得PICC完全置于PCD控制下.读卡器输出方式为标准输出或连续输出,独立授权方式.经过测试,读/写距离6~10 cm,射频功率小于1 mW,集成化程度高,适合于工业运用环境.%A non-contact RF reader writer based on STC11F32XE microcontroller and CL RC632 chip was designed, introduces The composition of RFID system and features of CL RC632 chip are introduced. The circuit design of hardwares is completed and the software functions are implement according to its principle. Mifare card is taken as the transpender of the system. The PICC is completely control by the PCD through the implementation of anticollision command sequence. The output mode of the card reader is standard or continuous. Its accreditation mode is independent. The testing result shows that the effective distance is 6~10 cm and RF power is less than 1 mW. This system has high degree of integration and is suitable for the industrial environment.

  9. Identification and characterization of RcMADS1, an AGL24 ortholog from the holoparasitic plant Rafflesia cantleyi Solms-Laubach (Rafflesiaceae.

    Directory of Open Access Journals (Sweden)

    Rengasamy Ramamoorthy

    Full Text Available Rafflesia, a holoparasitic genus that produces the largest flower in the world is characterized by the absence of leaves, stem and other macroscopic organs. To better understand the molecular regulation of flower development in this genus we isolated and characterized a floral MADS-box gene, namely, RcMADS1 from Rafflesia cantleyi. Heterologous expression analysis in Arabidopsis was chosen because Rafflesia is not amenable to genetic manipulations. RcMADS1 shares sequence similarity with AGAMOUS-LIKE 24 (AGL24 and SHORT VEGETATIVE PHASE (SVP of Arabidopsis. Ectopic expression of RcMADS1 in Arabidopsis caused early flowering and conversion of sepals and petals into leaf-like structures, and carpels into inflorescences. In 35S::RcMADS1 plants SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1, a downstream target gene of AGL24, was upregulated. 35S::RcMADS1 plants exhibit early flowering and conversion of the floral meristem into inflorescence meristem, as in 35S::AGL24 plants. Similar to AGL24, RcMADS1 could rescue the late flowering phenotypes of agl24-1 and FRIGIDA, but not the early flowering of svp-41. Based on these results, we propose that RcMADS1 is a functional ortholog of Arabidopsis AGL24.

  10. CURRENT STATUS AND PROSPECTS OF STUDY ON LOW VELOCITY IMPACT DAMAGED CHARACTERIZATION OF FIBER-REINFORCED COMPOSITE LAMINATES%FRP 层合板低速冲击损伤特性研究现状与展望

    Institute of Scientific and Technical Information of China (English)

    张颖军; 梅志远; 朱锡

    2011-01-01

    纤维增强复合材料层合板(FRP)由于具有比强度高、比模量高、可设计性强等特性,在工程领域得到越来越广泛的应用.但是低速冲击造成的损伤对层合板力学性能的影响非常显著,导致其强度和刚度下降.本文针对近年来纤维增强复合材料层合板低速冲击作用下的损伤研究进行了综述和回顾,重点介绍了试验研究方法、模拟计算研究方法、FRP 层合板损伤性能表征方法,并对有待于进一步研究的问题进行了展望.%Fiber-reinforced composite laminates have been widely used in engineering area because of its special properties, such as high specific strength, high specific stiffness and excellent designability. But the effect of damage caused by low velocity impact on the FRP is remarkable, which can reduce the strength and stiffness. The study on damage of fiber-reinforced composite laminates under low velocity impact in recent years is summarized and reviewed in this article. The main contents of the article are as follows: experimental methods, simulating and calculating methods, characterization of composites damage, and some problems to be studied in the future are proposed.

  11. Single-step purification of recombinant proteins using elastin-like peptide-mediated inverse transition cycling and self-processing module from Neisseria meningitides FrpC.

    Science.gov (United States)

    Liu, Wen-Jun; Wu, Qian; Xu, Bi; Zhang, Xin-Yu; Xia, Xiao-Li; Sun, Huai-Chang

    2014-06-01

    Purification of recombinant proteins is a major task and challenge in biotechnology and medicine. In this paper we report a novel single-step recombinant protein purification system which was based on elastin-like peptide (ELP)-mediated reversible phase transition and FrpC self-processing module (SPM)-mediated cleavage. After construction of a SPM-ELP fusion expression vector, we cloned the coding sequence for green fluorescent protein (GFP), the Fc portion of porcine IgG (pFc) or human β defensin 3 (HBD3) into the vector, transformed the construct into Escherichia coli, and induced the fusion protein expression with IPTG. The target-SPM-ELP fusion proteins GFP-SPM-ELP, Fc-SPM-ELP and HBD3-SPM-ELP were expressed in a soluble form and efficiently purified from the clarified cell extracts by two rounds of inverse transition cycling (ITC). Under the optimized conditions, the SPM-mediated cleavage efficiencies for the three fusion proteins ranged from 92% to 93%. After an additional round of ITC, the target proteins GFP, pFc and HBD3 were recovered with purities ranging from 90% to 100% and yields ranging from 1.1 to 36mg/L in shake flasks. The endotoxin levels in all of the three target proteins were proteins were functionally active with the expected molecular weights. These experimental results confirmed the high specificity and efficiency of SPM-mediated cleavage, and suggested the applicability of SPM-ELP fusion system for purification of recombinant proteins.

  12. Development of a Novel Elastic Acrylic Polyurethane FRP Primers%新型弹性丙烯酸聚氨酯玻璃钢底漆的研制

    Institute of Scientific and Technical Information of China (English)

    李儒剑; 孟兆荣; 周升; 曾凡辉; 陈立斌

    2011-01-01

    Fiberglass reinfored plastic ( FRP) primers was prepared from elastic acrylic resin & HDI polymer as film - forming materials, whose various properties met the designed requirements. It was found that different HDI polymer curing agents with various functionality affected primers' mechanical property and workability, and slighthly affected primers' chemical resistance and durability. High molecular weight block copolymer dispersant with pigment - compatible groups was better than amino polyester dispersant for primers' grinding and storage. Organic modified bentonite and fumed silica both had more contributions to improvement of film thickness than polyethylene wax slurry did.%以弹性丙烯酸树脂和HDI聚合物为成膜物制得双组分玻璃钢专用底漆,经测试其各项性能达到设计要求.研究发现:不同官能度的HDI聚合物固化剂对涂料的力学性能和施工性能有影响,但对耐化学品和耐久性影响不大;带亲颜料基团的高分子嵌段共聚物分散剂对漆料的研磨效率和贮存稳定性贡献要大于氨基聚酯型分散剂;有机改性膨润土和气相二氧化硅比聚乙烯蜡浆对涂料喷涂施工厚度提高效果要明显.

  13. RcRR1, a Rosa canina type-A response regulator gene, is involved in cytokinin-modulated rhizoid organogenesis.

    Directory of Open Access Journals (Sweden)

    Bin Gao

    Full Text Available In vitro, a new protocol of plant regeneration in rose was achieved via protocorm-like bodies (PLBs induced from the root-like organs named rhizoids that developed from leaf explants. The development of rhizoids is a critical stage for efficient regeneration, which is triggered by exogenous auxin. However, the role of cytokinin in the control of organogenesis in rose is as yet uncharacterized. The aim of this study was to elucidate the molecular mechanism of cytokinin-modulated rhizoid formation in Rosa canina. Here, we found that cytokinin is a key regulator in the formation of rhizoids. Treatment with cytokinin reduced callus activity and significantly inhibited rhizoid formation in Rosa canina. We further isolated the full-length cDNA of a type-A response regulator gene of cytokinin signaling, RcRR1, from which the deduced amino acid sequence contained the conserved DDK motif. Gene expression analysis revealed that RcRR1 was differentially expressed during rhizoid formation and its expression level was rapidly up-regulated by cytokinin. In addition, the functionality of RcRR1 was tested in Arabidopsis. RcRR1 was found to be localized to the nucleus in GFP-RcRR1 transgenic plants and overexpression of RcRR1 resulted in increased primary root length and lateral root density. More importantly, RcRR1 overexpression transgenic plants also showed reduced sensitivity to cytokinin during root growth; auxin distribution and the expression of auxin efflux carriers PIN genes were altered in RcRR1 overexpression plants. Taken together, these results demonstrate that RcRR1 is a functional type-A response regulator which is involved in cytokinin-regulated rhizoid formation in Rosa canina.

  14. 预制夹芯保温墙体FRP连接件抗拔性能试验研究%PULL-OUT TESTS FOR EVALUATIONS OF ANTI-PULLING BEHAVIOR OF FRP CONNECTORS IN PRECAST SANDWICH INSULATION WALL PANELS

    Institute of Scientific and Technical Information of China (English)

    薛伟辰; 杨佳林; 王君若

    2012-01-01

    预制夹芯保温墙体是集承载与保温一体化的新型预制保温墙体.该墙体由内外叶钢筋混凝土板、中间保温层及纤维增强塑料(FRP)连接件组成,其中FRP连接件是连接内外叶钢筋混凝土板的关键部件,其受力性能直接影响墙体的安全性.本文以上海市某安居工程为背景,基于拔出试验对FRP连接件的抗拔承载力、破坏形态、荷载-滑移关系及荷载-应变关系等进行了较为系统的研究.研究表明,试件均发生了混凝土劈裂破坏;试件的抗拔承载力为23.5kN,为抗拔荷载设计值的14.3倍,满足工程设计要求,并具有较大的安全储备.最后,提出了预制保温墙体FRP连接件的抗拔承载力计算方法.%Precast sandwich insulation wall panel is a new type of insulation wall which performs well both in structural bearing and thermal insulation. This kind of wall is consisted of internal and external concrete wythes, insulating layers and the key component-FRP connectors, which ties two concrete wythes together to provide a distributed fastening system. Taking the model from a practical project in Shanghai as a reference, a series of tests including three pull-out specimens, with emphasis on FRP connectors' pull-out capacity, failure pattern and load-slip curve etc. , were presented. All the tests were terminated by the concrete fracture, and the average pull-out capacity of the connectors was 23. 5kN, about 14. 3 times of the design pull-out load. This means the connector could meet the requirements of the design in the practical project, and has a great safety margin as well. In addition, the calculation method to compute the pull-out capacity of FRP connectors in precast concrete sandwich wall is proposed.

  15. Effect of CFRP Schemes on the Flexural Behavior of RC Beams Modeled by Using a Nonlinear Finite-element Analysis

    Science.gov (United States)

    Al-Rousan, R. Z.

    2015-09-01

    The main objective of this study was to assess the effect of the number and schemes of carbon-fiber-reinforced polymer (CFRP) sheets on the capacity of bending moment, the ultimate displacement, the ultimate tensile strain of CFRP, the yielding moment, concrete compression strain, and the energy absorption of RC beams and to provide useful relationships that can be effectively utilized to determine the required number of CFRP sheets for a necessary increase in the flexural strength of the beams without a major loss in their ductility. To accomplish this, various RC beams, identical in their geometric and reinforcement details and having different number and configurations of CFRP sheets, are modeled and analyzed using the ANSYS software and a nonlinear finite-element analysis.

  16. Improved rolling circle amplification (RCA) of hepatitis B virus (HBV) relaxed-circular serum DNA (RC-DNA).

    Science.gov (United States)

    Martel, Nora; Gomes, Selma A; Chemin, Isabelle; Trépo, Christian; Kay, Alan

    2013-11-01

    For functional analysis of HBV isolates, epidemiological studies and correct identification of recombinant genomes, the amplification of complete genomes is necessary. A method for completely in vitro amplification of full-length HBV genomes starting from serum RC-DNA is described. This uses in vitro completion/ligation of plus-strand HBV RC-DNA and amplification using Rolling-Circle Amplification, eventually followed by a genomic PCR. The method can amplify complete HBV genomes from sera with viral loads ranging from >1.0E+8 IU/ml down to 1.0E+3 IU/ml. The method can be applied to archived sera that have undergone long-term storage or to archived DNA serum extracts. The genomes can easily be cloned. HBV genotypes A-G can all be amplified with no apparent problems. A recombinant subgenotype A3/genotype E genome was identified and fully sequenced.

  17. Implementation analysis of RC5 algorithm on Preneel-Govaerts-Vandewalle (PGV) hashing schemes using length extension attack

    Science.gov (United States)

    Siswantyo, Sepha; Susanti, Bety Hayat

    2016-02-01

    Preneel-Govaerts-Vandewalle (PGV) schemes consist of 64 possible single-block-length schemes that can be used to build a hash function based on block ciphers. For those 64 schemes, Preneel claimed that 4 schemes are secure. In this paper, we apply length extension attack on those 4 secure PGV schemes which use RC5 algorithm in its basic construction to test their collision resistance property. The attack result shows that the collision occurred on those 4 secure PGV schemes. Based on the analysis, we indicate that Feistel structure and data dependent rotation operation in RC5 algorithm, XOR operations on the scheme, along with selection of additional message block value also give impact on the collision to occur.

  18. A simple 1-byte 1-clock RC4 design and its efficient implementation in FPGA coprocessor for secured ethernet communication

    CERN Document Server

    Paul, Rourab; Zaman, Jkm Sadique Uz; Das, Suman; Chakrabarti, Amlan; Ghosh, Ranjan

    2012-01-01

    In the field of cryptography till date the 1-byte in 1-clock is the best known RC4 hardware design [1], while the 1-byte in 3clocks is the best known implementation [2,3]. The design algorithm of 1-byte in 1-clock is complex since it takes two consecutive bytes together. The design of 1-byte in 3-clocks is too much modular and clock hungry. In this paper a simpler embedded system design of RC4 in 1-byte in 1-clock is proposed where two successive sequential tasks are executed as two independent events by using rising and falling edges of the same clock and swapping is done using a MUX-DEMUX combination, thereby increasing its throughput. The encryption and decryption designs are respectively implemented on two FPGA boards to achieve Ethernet communication.

  19. The open, the closed, and the empty: time-resolved fluorescence spectroscopy and computational analysis of RC-LH1 complexes from Rhodopseudomonas palustris.

    Science.gov (United States)

    Beyer, Sebastian R; Müller, Lars; Southall, June; Cogdell, Richard J; Ullmann, G Matthias; Köhler, Jürgen

    2015-01-29

    We studied the time-resolved fluorescence of isolated RC-LH1 complexes from Rhodopseudomonas palustris as a function of the photon fluence and the repetition rate of the excitation laser. Both parameters were varied systematically over 3 orders of magnitude. On the basis of a microstate description we developed a quantitative model for RC-LH1 and obtained very good agreement between experiments and elaborate simulations based on a global master equation approach. The model allows us to predict the relative population of RC-LH1 complexes with the special pair in the neutral state or in the oxidized state P(+) and those complexes that lack a reaction center.

  20. Effects of age and parity on mammary gland lesions and progenitor cells in the FVB/N-RC mice.

    Science.gov (United States)

    Raafat, Ahmed; Strizzi, Luigi; Lashin, Karim; Ginsburg, Erika; McCurdy, David; Salomon, David; Smith, Gilbert H; Medina, Daniel; Callahan, Robert

    2012-01-01

    The FVB/N mouse strain is extensively used in the development of animal models for breast cancer research. Recently it has been reported that the aging FVB/N mice develop spontaneous mammary lesions and tumors accompanied with abnormalities in the pituitary glands. These observations have a great impact on the mouse models of human breast cancer. We have developed a population of inbred FVB/N mice (designated FVB/N-RC) that have been genetically isolated for 20 years. To study the effects of age and parity on abnormalities of the mammary glands of FVB/N-RC mice, twenty-five nulliparous and multiparous (3-4 pregnancies) females were euthanized at 16-22 months of age. Examination of the mammary glands did not reveal macroscopic evidence of mammary gland tumors in either aged-nulliparous or multiparous FVB/N-RC mice (0/25). However, histological analysis of the mammary glands showed rare focal nodules of squamous changes in 2 of the aged multiparous mice. Mammary gland hyperplasia was detected in 8% and 71% of the aged-nulliparous and aged-multiparous mice, respectively. Epithelial contents and serum levels of triiodothyronine were significantly higher in the experimental groups than the 14-wk-old control mice. Immuno-histochemical staining of the pituitary gland pars distalis showed no difference in prolactin staining between the control and the aged mice. Tissue transplant and dilution studies showed no effect of age and/or parity on the ability of putative progenitor cells present among the injected mammary cells to repopulate a cleared fat pad and develop a full mammary gland outgrowth. This FVB/N-RC mouse substrain is suitable to develop mouse models for breast cancer.

  1. Effects of age and parity on mammary gland lesions and progenitor cells in the FVB/N-RC mice.

    Directory of Open Access Journals (Sweden)

    Ahmed Raafat

    Full Text Available The FVB/N mouse strain is extensively used in the development of animal models for breast cancer research. Recently it has been reported that the aging FVB/N mice develop spontaneous mammary lesions and tumors accompanied with abnormalities in the pituitary glands. These observations have a great impact on the mouse models of human breast cancer. We have developed a population of inbred FVB/N mice (designated FVB/N-RC that have been genetically isolated for 20 years. To study the effects of age and parity on abnormalities of the mammary glands of FVB/N-RC mice, twenty-five nulliparous and multiparous (3-4 pregnancies females were euthanized at 16-22 months of age. Examination of the mammary glands did not reveal macroscopic evidence of mammary gland tumors in either aged-nulliparous or multiparous FVB/N-RC mice (0/25. However, histological analysis of the mammary glands showed rare focal nodules of squamous changes in 2 of the aged multiparous mice. Mammary gland hyperplasia was detected in 8% and 71% of the aged-nulliparous and aged-multiparous mice, respectively. Epithelial contents and serum levels of triiodothyronine were significantly higher in the experimental groups than the 14-wk-old control mice. Immuno-histochemical staining of the pituitary gland pars distalis showed no difference in prolactin staining between the control and the aged mice. Tissue transplant and dilution studies showed no effect of age and/or parity on the ability of putative progenitor cells present among the injected mammary cells to repopulate a cleared fat pad and develop a full mammary gland outgrowth. This FVB/N-RC mouse substrain is suitable to develop mouse models for breast cancer.

  2. Anti-cor osion Performance of FiberglassR einforced Plastic (FRP) under Stimulta ed Conditions of Chimney in Power Plant%模拟火电烟囱工况下乙烯基酯树脂基FRP 的腐蚀性研究

    Institute of Scientific and Technical Information of China (English)

    冯敏; 梁高; 王剑平; 张学双

    2014-01-01

    本文利用含1500 ppm H2 SO4、250 ppm H2 SO3以及250 ppm HCl的混合溶液在65℃加热浸泡试样,再在180℃、200℃高温烘烤试样的实验方法来模拟火电玻璃钢烟囱在运行过程中的腐蚀情况,研究用于火电玻璃钢烟囱设备生产的2种乙烯基酯树脂901和907与相应的纤维增强材料组合的复合材料的耐受性能。结果表明:试样的空泡和分层随实验周期的延长而加剧,空泡和分层的程度与选用的树脂及纤维增强材料的种类相关;酚醛环氧乙烯基酯树脂907比溴化双酚A型环氧乙烯基酯树脂901有更好的耐蚀耐温性能;碳纤维与玻璃纤维复合使用比单纯使用玻璃纤维(C型)的试样具有更好的耐分层和空泡的性能。%Anti-Corrosion performance of specimen made of two types of resin 901 and 907 composited with different types of veil were studied under stimulated conditions which consist of 65℃ soaking in a solution contain 1 500 ppm H2 SO4 ,250 ppm H2 SO3 and 250 ppm HCl and 180℃,200℃baking.Results show that blistering appears to have resulted from a combination of time of exposure to the chemical solution ,the number of shock cycles ,the number and type of veils ,and the thermal shock temperature conditions;FRP based on brominated novolac epoxy vinyl ester resin appears to have better re-sistance to the degradation than FRP based on brominated epoxy vinyl ester resin .Also,a combination of carbon and C-glass veil appeared to perform better than a single C-glass veil alone .

  3. Experimental Research on Seismic of RC Frames with Energy Conservation Masonry Infill Walls%带节能砌体填充墙的 RC 框架抗震试验研究

    Institute of Scientific and Technical Information of China (English)

    黄靓; 易宏伟; 王辉; 蒋文龙

    2014-01-01

    为了研究带节能砌体填充墙的RC框架抗震性能,本试验设计了两个两层单跨的RC框架结构模型,分别为带填充墙的RC框架和不带填充墙的空框架,并对其进行了拟静力试验。对带填充墙的 RC 框架的裂缝开展进行了描述,研究了试件的滞回特性、骨架曲线、刚度退化和强度退化,并和空框架进行了对比分析。分析结果表明:填充墙能够提高框架的承载能力和抗侧刚度,但是相应地降低了框架结构的延性;填充墙的存在使得框架结构的强度和刚度退化加快,然而,带填充墙框架的极限刚度仍然较大,表现出较强的抗倒塌能力。%To investigate the seismic behavior of RC frames with energy conservation masonry infill walls,two RC frame models with two-floor single span,one with infill walls and the other without infill walls (bare frame),were tested with the pseudo-static experiment.The cracking distribution of frame with infill walls was described,and the load-displacement hysteretic curves,skeleton curves,rigidity deg-radation and strength degradation were discussed in comparison with the bare frame.The results show that the lateral load-bearing capacity and structural lateral stiffness of the RC frame,but not the ductility, can be increased by infilling walls in the frame.Due to the presence of the infill walls,the rigidity degrada-tion and strength degradation of the frames will be sped up.However,there is still enough stiffness when the RC frame with infill walls is destroyed,which indicates the good resistance to collapse resistance of the frame with energy conservation masonry infill wall.

  4. BEND3 represses rDNA transcription by stabilizing a NoRC component via USP21 deubiquitinase.

    Science.gov (United States)

    Khan, Abid; Giri, Sumanprava; Wang, Yating; Chakraborty, Arindam; Ghosh, Archit K; Anantharaman, Aparna; Aggarwal, Vasudha; Sathyan, Kizhakke M; Ha, Taekjip; Prasanth, Kannanganattu V; Prasanth, Supriya G

    2015-07-01

    Ribosome biogenesis dictates the translational capacity of cells. Several mechanisms establish and maintain transcriptional output from eukaryotic ribosomal DNA (rDNA) loci. rDNA silencing is one such mechanism that ensures the inactivity and hence the maintenance of a silenced state of a subset of rRNA gene copies. Whereas oncogenic agents stimulate rRNA gene transcription, tumor suppressors decrease rRNA gene transcription. We demonstrate in mammalian cells that BANP, E5R, and Nac1 (BEN) domain 3 (BEND3), a quadruple BEN domain-containing protein, localizes in nucleoli and binds to ribosomal RNA gene promoters to help repress rRNA genes. Loss of BEND3 increases histone H3K4 trimethylation and, correspondingly, decreases rDNA promoter DNA methylation, consistent with a role for BEND3 in rDNA silencing. BEND3 associates with the nucleolar-remodeling complex (NoRC), and SUMOylated BEND3 stabilizes NoRC component TTF-1-interacting protein 5 via association with ubiquitin specific protease 21 (USP21) debiquitinase. Our results provide mechanistic insights into how the novel rDNA transcription repressor BEND3 acts together with NoRC to actively coordinate the establishment of rDNA silencing.

  5. 美空军RC-135侦察机最新改进及能力分析

    Institute of Scientific and Technical Information of China (English)

    高莹平; 周长仁

    2007-01-01

    2006年底,美空军1架最新改进型的RC-135“联合铆钉”(Rivet Joint)电子侦察飞机服役。该机是美空军首架采用“基本结构8型”(Baseline 8)制造的飞机,与以前采用“基本结构7型”的RC-135相比,这架新型的RC-135装有新型的导航系统,换装了功率更大的发动机,具有更强的电子情报侦察能力、通信能力与网络中心战能力,且设备可靠性更高,用户界面更友好。

  6. An Efficient Image Encryption Scheme Based on a Peter De Jong Chaotic Map and a RC4 Stream Cipher

    Science.gov (United States)

    Hanchinamani, Gururaj; Kulkarni, Linganagouda

    2015-09-01

    Security is a vital issue in communication and storage of the images and encryption is one of the ways to ensure the security. This paper proposes an efficient image encryption scheme based on a Peter De Jong chaotic map and a RC4 stream cipher. A Peter De Jong map is employed to determine the initial keys for the RC4 stream generator and also during permutation stage. The RC4 stream generator is utilized to generate the pseudo random numbers for the pixel value rotation and diffusion operations. Each encryption round is comprised of three stages: permutation, pixel value rotation and diffusion. The permutation is based on scrambling the rows and columns, in addition, circular rotations of the rows and columns in alternate orientations. The second stage circularly rotates each and every pixel value by utilizing M × N pseudo random numbers. The last stage carries out the diffusion twice by scanning the image in two different ways. Each of the two diffusions accomplishes the diffusion in two orientations (forward and backward) with two previously diffused pixels and two pseudo random numbers. The security and performance of the proposed method is assessed thoroughly by using key space, statistical, differential, entropy and performance analysis. Moreover, two rounds of the call to the encrypt function provide the sufficient security. The experimental results show that the proposed encryption scheme is computationally fast with high security.

  7. Seismic fragility assessment of RC frame structure designed according to modern Chinese code for seismic design of buildings

    Science.gov (United States)

    Wu, D.; Tesfamariam, S.; Stiemer, S. F.; Qin, D.

    2012-09-01

    Following several damaging earthquakes in China, research has been devoted to find the causes of the collapse of reinforced concrete (RC) building sand studying the vulnerability of existing buildings. The Chinese Code for Seismic Design of Buildings (CCSDB) has evolved over time, however, there is still reported earthquake induced damage of newly designed RC buildings. Thus, to investigate modern Chinese seismic design code, three low-, mid- and high-rise RC frames were designed according to the 2010 CCSDB and the corresponding vulnerability curves were derived by computing a probabilistic seismic demand model (PSDM).The PSDM was computed by carrying out nonlinear time history analysis using thirty ground motions obtained from the Pacific Earthquake Engineering Research Center. Finally, the PSDM was used to generate fragility curves for immediate occupancy, significant damage, and collapse prevention damage levels. Results of the vulnerability assessment indicate that the seismic demands on the three different frames designed according to the 2010 CCSDB meet the seismic requirements and are almost in the same safety level.

  8. Lateral Pressure of RC Silos with Static and Dynamic Granular Materials

    Institute of Scientific and Technical Information of China (English)

    Lingkai Meng

    2015-01-01

    This paper aims at analyzing material⁃induced lateral pressure of RC cylinder silo in both static and dynamic condition using the finite element method (FEM).In the finite element software ABAQUS, concrete material is modeled by concrete damaged plasticity model, and stored materials in silo is modeled by the hypoplastic theory.In terms of numerical model, shell elements (S4R) and solid elements (C3D8) are applied for model silo wall and stored materials respectively. The interaction between silo wall and stored materials is simulated by Coulomb friction model and penalty contact constrain provided by ABAQUS.The numerical results are verified with the existing experimental data that are designed to ensure the validation of such numerical model using FEM and it obtains good agreements between numerical results and experimental data. Then the material parameters are analyzed in both static and dynamic condition.According to the analysis, it is clear that critical friction angle, initial void ratio and minimum void ratio have an obvious effect on static lateral pressure while all the material parameters affect dynamic lateral pressure at different levels. In addition, differences of silo wall between elastic and plastic state are analyzed in dynamic condition. The numerical results show that it contributes to increasing dynamic pressure when silo wall enters into the plastic state. Finally, this paper discusses the time⁃history lateral pressure at different heights along silo wall, and analytical results indicate that larger acceleration values play main roles in producing the maximum lateral pressure at higher part of the silo wall.

  9. NASA LaRC airborne high spectral resolution lidar aerosol measurements during MILAGRO: observations and validation

    Directory of Open Access Journals (Sweden)

    L. I. Kleinman

    2009-07-01

    Full Text Available The NASA Langley Research Center (LaRC airborne High Spectral Resolution Lidar (HSRL measures vertical profiles of aerosol extinction, backscatter, and depolarization at both 532 nm and 1064 nm. In March of 2006 the HSRL participated in the Megacity Initiative: Local and Global Research Observations (MILAGRO campaign along with several other suites of instruments deployed on both aircraft and ground based platforms. This paper presents high spatial and vertical resolution HSRL measurements of aerosol extinction and optical depth from MILAGRO and comparisons of those measurements with similar measurements from other sensors and model predictions. HSRL measurements coincident with airborne in situ aerosol scattering and absorption measurements from two different instrument suites on the C-130 and G-1 aircraft, airborne aerosol optical depth (AOD and extinction measurements from an airborne tracking sunphotometer on the J-31 aircraft, and AOD from a network of ground based Aerosol Robotic Network (AERONET sun photometers are presented as a validation of the HSRL aerosol extinction and optical depth products. Regarding the extinction validation, we find bias differences between HSRL and these instruments to be less than 3% (0.01 km−1 at 532 nm, the wavelength at which the HSRL technique is employed. The rms differences at 532 nm were less than 50% (0.015 km−1. To our knowledge this is the most comprehensive validation of the HSRL measurement of aerosol extinction and optical depth to date. The observed bias differences in ambient aerosol extinction between HSRL and other measurements is within 15–20% at visible wavelengths, found by previous studies to be the differences observed with current state-of-the-art instrumentation (Schmid et al., 2006.

  10. NASA LaRC airborne high spectral resolution lidar aerosol measurements during MILAGRO: observations and validation

    Directory of Open Access Journals (Sweden)

    R. R. Rogers

    2009-04-01

    Full Text Available The NASA Langley Research Center (LaRC airborne High Spectral Resolution Lidar (HSRL measures vertical profiles of aerosol extinction, backscatter, and depolarization at both 532 nm and 1064 nm. In March of 2006 the HSRL participated in the Megacity Initiative: Local and Global Research Observations (MILAGRO campaign along with several other suites of instruments deployed on both aircraft and ground based platforms. This paper presents high spatial and vertical resolution HSRL measurements of aerosol extinction and optical depth from MILAGRO and comparisons of those measurements with similar measurements from other sensors and model predictions. HSRL measurements coincident with airborne in situ aerosol scattering and absorption measurements from two different instrument suites on the C-130 and G-1 aircraft, airborne aerosol optical depth (AOD and extinction measurements from an airborne tracking sunphotometer on the J-31 aircraft, and AOD from a network of ground based Aerosol Robotic Network (AERONET sun photometers are presented as a validation of the HSRL aerosol extinction and optical depth products. Regarding the extinction validation, we find bias differences between HSRL and these instruments to be less than 3% (0.01 km−1 at 532 nm, the wavelength at which the HSRL technique is employed. The rms differences at 532 nm were less than 50% (0.015 km−1. To our knowledge this is the most comprehensive validation of the HSRL measurement of aerosol extinction and optical depth to date. The observed bias differences in ambient aerosol extinction between HSRL and other measurements is within 15–20% at visible wavelengths, found by previous studies to be the differences observed with current state-of-the-art instrumentation (Schmid et al., 2006.

  11. Smart RC elements for long-life monitoring of civil infrastructures

    Science.gov (United States)

    Zonta, Daniele; Pozzi, Matteo; Forti, Marco; Bursi, Oreste S.

    2005-05-01

    A research effort has been launched at the University of Trento, aimed at developing an innovative distributed construction system based on smart prefabricated concrete elements allowing for real-time condition assessment of civil infrastructures. So far, two reduced-scale prototypes have been produced, each consisting of a 0.2 by 0.3 by 5.6m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optics Sensors (FOS) at the lower edge. The sensors employed are Fiber Bragg Grating (FBG) -based and can measure finite displacements both in statics and dynamics. The acquisition module uses a single commercial interrogation unit and a software-controlled optical switch, allowing acquisition of dynamic multi-channel signals from FBG-FOS, with a sample frequency of 625 Hz per channel. The performance of the system underwent validation I n the laboratory. The scope of the experiment was to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen was dynamically characterized in the undamaged state and in various damage conditions, simulating different cracking levels and recurrent deterioration scenarios, including concrete cover spalling and partial corrosion of the reinforcement. The location and the extent of damage are evaluated by calculating damage indices which take account of changes in frequency and in strain-mode-shapes. This paper presents in detail the results of the experiment and demonstrates how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.

  12. Determining the Number of Parallel RC Branches in Polarization / Depolarization Current Modeling for XLPE Cable Insulation

    Directory of Open Access Journals (Sweden)

    S. Sulaiman

    2017-06-01

    Full Text Available An important element in the electric power distribution system is the underground cable. However continuous applications of high voltages unto the cable, may lead to insulation degradations and subsequent cable failure. Since any disruption to the electricity supply may lead to economic losses as well as lowering customer satisfaction, the maintenance of cables is very important to an electrical utility company. Thus, a reliable diagnostic technique that is able to accurately assess the condition of cable insulation operating is critical, in order for cable replacement exercise to be done. One such diagnostic technique to assess the level of degradation within the cable insulation is the Polarization / Depolarization Current (PDC analysis. This research work attempts to investigate PDC behaviour for medium voltage (MV cross-linked polyethylene (XLPE insulated cables, via baseline PDC measurements and utilizing the measured data to simulate for PDC analysis. Once PDC simulations have been achieved, the values of conductivity of XLPE cable insulations can be approximated. Cable conductivity serves as an indicator to the level of degradation within XLPE cable insulation. It was found that for new and unused XLPE cables, the polarization and depolarization currents have almost overlapping trendlines, as the cable insulation’s conduction current is negligible. Using a linear dielectric circuit equivalence model as the XLPE cable insulation and its corresponding governing equations, it is possible to optimize the number of parallel RC branches to simulate PDC analysis, with a very high degree of accuracy. The PDC simulation model has been validated against the baseline PDC measurements.

  13. Ginsenoside Rc from Korean Red Ginseng (Panax ginseng C.A. Meyer) Attenuates Inflammatory Symptoms of Gastritis, Hepatitis and Arthritis.

    Science.gov (United States)

    Yu, Tao; Rhee, Man Hee; Lee, Jongsung; Kim, Seung Hyung; Yang, Yanyan; Kim, Han Gyung; Kim, Yong; Kim, Chaekyun; Kwak, Yi-Seong; Kim, Jong-Hoon; Cho, Jae Youl

    2016-01-01

    Korean Red Ginseng (KRG) is an herbal medicine prescribed worldwide that is prepared from Panax ginseng C.A. Meyer (Araliaceae). Out of ginseng's various components, ginsenosides are regarded as the major ingredients, exhibiting anticancer and anti-inflammatory activities. Although recent studies have focused on understanding the anti-inflammatory activities of KRG, compounds that are major anti-inflammatory components, precisely how these can suppress various inflammatory processes has not been fully elucidated yet. In this study, we aimed to identify inhibitory saponins, to evaluate the in vivo efficacy of the saponins, and to understand the inhibitory mechanisms. To do this, we employed in vitro lipopolysaccharide-treated macrophages and in vivo inflammatory mouse conditions, such as collagen (type II)-induced arthritis (CIA), EtOH/HCl-induced gastritis, and lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-triggered hepatitis. Molecular mechanisms were also verified by real-time PCR, immunoblotting analysis, and reporter gene assays. Out of all the ginsenosides, ginsenoside Rc (G-Rc) showed the highest inhibitory activity against the expression of tumor necrosis factor (TNF)-[Formula: see text], interleukin (IL)-1[Formula: see text], and interferons (IFNs). Similarly, this compound attenuated inflammatory symptoms in CIA, EtOH/HCl-mediated gastritis, and LPS/D-galactosamine (D-GalN)-triggered hepatitis without altering toxicological parameters, and without inducing gastric irritation. These anti-inflammatory effects were accompanied by the suppression of TNF-[Formula: see text] and IL-6 production and the induction of anti-inflammatory cytokine IL-10 in mice with CIA. G-Rc also attenuated the increased levels of luciferase activity by IRF-3 and AP-1 but not NF-[Formula: see text]B. In support of this phenomenon, G-Rc reduced TBK1, IRF-3, and ATF2 phosphorylation in the joint and liver tissues of mice with hepatitis. Therefore, our results strongly suggest that

  14. FRP加固框架节点的受力影响因素的数值模拟%Numerical simulation of the stress influence factors of FRP reinforcement frame joints

    Institute of Scientific and Technical Information of China (English)

    余登华; 黄志强; 梁芳

    2014-01-01

    FRP (Fiber Reinforced Plastics) fiber reinforced concrete frame joints was carried out a numerical analysis with finite element analysis software RFPA (Realistic Failure Process Analysis).It explored the effect of reinforcing from the concrete strength,fiber paste length and thickness.Finite element analysis results show that the reinforcement of the frame joints withstand the load and deformation capacity has improved signifi-cantly.%利用有限元分析软件RFPA (Realistic Failure Process Analysis)对FRP (Fiber Reinforced Plastics)纤维加固混凝土框架节点进行了数值分析,从混凝土强度、纤维布粘贴长度、纤维布粘贴厚度三方面探讨对加固效果的影响。有限元分析结果表明,加固了的框架节点所能承受的荷载和变形能力都有了显著提高。

  15. Application of FRP Wrapped Tanks to Anti-corrosion of Nonferrous Metallurgy in Jinchuan%玻璃钢缠绕贮罐在金川有色冶金生产中的应用

    Institute of Scientific and Technical Information of China (English)

    吴培德

    2011-01-01

    The fundamental using condition, manufacturing process, structure and properties of glass fiber reinforced plastics(FRP) wrapped tanks are introduced, and the application of 100 m3, 200 m3, 270 m3 and 400 m3 FRP wrapped tanks to non-ferrous metallurgical industry in Jinchuan is introduced. This kind of tanks provides a new way to store up acid corrosion medium in non-ferrous metallurgical industry.%介绍了玻璃钢缠绕贮罐的使用条件、制造工艺、结构和性能等,以及100m3、200m3、270m3、400m3玻璃钢缠绕贮罐在金川有色冶金生产中的应用情况,该罐适合于有色湿法冶金工业酸性溶液腐蚀性介质的贮存。

  16. 高轴压比CFRP约束钢筋混凝土圆柱抗震性能试验与有限元分析%Experiment and finite element analysis of the seismic behavior of CFRP-confined RC circular columns with high axial compression ratio

    Institute of Scientific and Technical Information of China (English)

    王震宇; 王代玉; 吕大刚

    2011-01-01

    To investigate the seismic behavior of FRP-confined circular RC columns with high axial compression ratio, six columns confined with Carbon Fiber-Reinforced Polymer (CFRP) at plastic hinge region and two control columns were tested under constant axial load and cyclic lateral force. Test results demonstrated marked improvement in the ductility and energy dissipation of the columns due to CFRP wrapping in the plastic hinge region and the contribution of hoops to the confining effect should not be ignored under the condition of high axial compression ratio. A nonlinear analytical procedure was developed using fiber model method based on OpenSees (Open System for Earthquake Engineering Simulation). The simulation results agree well with the experimental results for axial compression ratios less than O. 45. Inclusion of the confining effects of both the hoop~ and CFRP results in better simulation of the test results if the .axial compression ratio exceeds 0.45. Finally, influences of axial compression ratio and length of CFRP in the plastic hinge region on the seismic performance of FRP-confined columns were analyzed. The results indicate that the lateral loading capacity of columns begins to decrease when axial compression in the plastic hinge region exceeds 1.2 times the column diameter, the wrapped columns. ratio exceeds 0.6. If the length of wrapped CFRP performance could be equivalent to that with fully%为研究高轴压比下FRP约束钢筋混凝土圆柱的抗震性能,对6根碳纤维约束钢筋混凝土圆柱及2根对比柱进行伪静力试验。结果表明:塑性铰区包裹碳纤维可显著改善高轴压比柱的抗震性能,轴压比较高时不应忽略箍筋对核心混凝土的约束贡献。基于OpenSees中的纤维模型,对柱水平力.位移滞回曲线进行有限元模拟。轴压比小于0.45时,数值模拟与试验结果吻合较好;轴压比大于0.45时,考虑核心混凝土受箍筋及FRP双重约束的计

  17. 'IRDiRC Recognized Resources': a new mechanism to support scientists to conduct efficient, high-quality research for rare diseases.

    Science.gov (United States)

    Lochmüller, Hanns; Le Cam, Yann; Jonker, Anneliene H; Lau, Lilian Pl; Baynam, Gareth; Kaufmann, Petra; Lasko, Paul; Dawkins, Hugh Js; Austin, Christopher P; Boycott, Kym M

    2017-02-01

    The International Rare Diseases Research Consortium (IRDiRC) has created a quality label, 'IRDiRC Recognized Resources', formerly known as 'IRDiRC Recommended'. It is a peer-reviewed quality indicator process established based on the IRDiRC Policies and Guidelines to designate resources (ie, standards, guidelines, tools, and platforms) designed to accelerate the pace of discoveries and translation into clinical applications for the rare disease (RD) research community. In its first year of implementation, 13 resources successfully applied for this designation, each focused on key areas essential to IRDiRC objectives and to the field of RD research more broadly. These included data sharing for discovery, knowledge organisation and ontologies, networking patient registries, and therapeutic development. 'IRDiRC Recognized Resources' is a mechanism aimed to provide community-approved contributions to RD research higher visibility, and encourage researchers to adopt recognised standards, guidelines, tools, and platforms that facilitate research advances guided by the principles of interoperability and sharing.

  18. ‘IRDiRC Recognized Resources': a new mechanism to support scientists to conduct efficient, high-quality research for rare diseases

    Science.gov (United States)

    Lochmüller, Hanns; Le Cam, Yann; Jonker, Anneliene H; Lau, Lilian PL; Baynam, Gareth; Kaufmann, Petra; Lasko, Paul; Dawkins, Hugh JS; Austin, Christopher P; Boycott, Kym M

    2017-01-01

    The International Rare Diseases Research Consortium (IRDiRC) has created a quality label, ‘IRDiRC Recognized Resources', formerly known as ‘IRDiRC Recommended'. It is a peer-reviewed quality indicator process established based on the IRDiRC Policies and Guidelines to designate resources (ie, standards, guidelines, tools, and platforms) designed to accelerate the pace of discoveries and translation into clinical applications for the rare disease (RD) research community. In its first year of implementation, 13 resources successfully applied for this designation, each focused on key areas essential to IRDiRC objectives and to the field of RD research more broadly. These included data sharing for discovery, knowledge organisation and ontologies, networking patient registries, and therapeutic development. ‘IRDiRC Recognized Resources' is a mechanism aimed to provide community-approved contributions to RD research higher visibility, and encourage researchers to adopt recognised standards, guidelines, tools, and platforms that facilitate research advances guided by the principles of interoperability and sharing. PMID:27782107

  19. Ginsenoside Rc from Panax ginseng exerts anti-inflammatory activity by targeting TANK-binding kinase 1/interferon regulatory factor-3 and p38/ATF-2.

    Science.gov (United States)

    Yu, Tao; Yang, Yanyan; Kwak, Yi-Seong; Song, Gwan Gyu; Kim, Mi-Yeon; Rhee, Man Hee; Cho, Jae Youl

    2017-04-01

    Ginsenoside Rc (G-Rc) is one of the major protopanaxadiol-type saponins isolated from Panax ginseng, a well-known medicinal herb with many beneficial properties including anticancer, anti-inflammatory, antiobesity, and antidiabetic effects. In this study, we investigated the effects of G-Rc on inflammatory responses in vitro and examined the mechanisms of these effects. The in vitro inflammation system used lipopolysaccharide-treated macrophages, tumor necrosis factor-α/interferon-γ-treated synovial cells, and HEK293 cells transfected with various inducers of inflammation. G-Rc significantly inhibited the expression of macrophage-derived cytokines, such as tumor necrosis factor-α and interleukin-1β. G-Rc also markedly suppressed the activation of TANK-binding kinase 1/IκB kinase ε/interferon regulatory factor-3 and p38/ATF-2 signaling in activated RAW264.7 macrophages, human synovial cells, and HEK293 cells. G-Rc exerts its anti-inflammatory actions by suppressing TANK-binding kinase 1/IκB kinase ε/interferon regulatory factor-3 and p38/ATF-2 signaling.

  20. Computational fluid dynamics analysis of a twisted airfoil shaped two-bladed H-Darrieus rotor made from fibreglass reinforced plastic (FRP

    Directory of Open Access Journals (Sweden)

    Rajat Gupta, Sukanta Roy, Agnimitra Biswas

    2010-11-01

    Full Text Available H-Darrieus rotor is a lift type device having two to three blades designed as airfoils. The blades are attached vertically to the central shaft through support arms. The support to vertical axis helps the rotor maintain its shape. In this paper, Computational Fluid Dynamics (CFD analysis of an airfoil shaped two-bladed H-Darrieus rotor using Fluent 6.2 software was performed. Based on the CFD results, a comparative study between experimental and computational works was carried out. The H-Darrieus rotor was 20cm in height, 5cm in chord and twisted with an angle of 30° at the trailing end. The blade material of rotor was Fiberglass Reinforced Plastic (FRP. The experiments were earlier conducted in a subsonic wind tunnel for various height-to-diameter (H/D ratios. A two dimensional computational modeling was done with the help of Gambit tool using unstructured grid. Realistic boundary conditions were provided for the model to have synchronization with the experimental conditions. Two dimensional steady-state segregated solver with absolute velocity formulation and cell based grid was considered, and a standard k-epsilon viscous model with standard wall functions was chosen. A first order upwind discretization scheme was adopted for pressure velocity coupling of the flow. The inlet velocities and rotor rotational speeds were taken from the experimental results. From the computational analysis, power coefficient (Cp and torque coefficient (Ct values at ten different H/D ratios namely 0.85, 1.0, 1.10, 1.33, 1.54, 1.72, 1.80, 1.92, 2.10 and 2.20 were calculated in order to predict the performances of the twisted H-rotor. The variations of Cp and Ct with tip speed ratios were analyzed and compared with the experimental results. The standard deviations of computational Cp and Ct from experimental Cp and Ct were obtained. From the computational analysis, the highest values of Cp and Ct were obtained at H/D ratios of 1.0 and 1.54 respectively. The