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  1. 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.

  2. 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.

  3. 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 ...

  4. 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

  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. 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.

  7. Lubricant for cold plastic metal working

    Energy Technology Data Exchange (ETDEWEB)

    Postolov, Yu.M.; Larina, N.F.; Osadchuk, Ye.S.; Proskuryakov, V.A.; Syroyezhko, A.M.; Vikhorev, A.A.; Yakovlev, V.I.

    1980-03-28

    A lubricant is proposed for cold plastic metal working based on fatty acids from the process of pyrolysis of castor oil (ZhKPM) with increased screening properties and which improve the quality of PV of finished parts. The lubricant contains (percent): cyclohexanol 0.5-60, levulinic and/or ketoenanthic acid 0.5-20, ZhKPM up to 100; the content of ketoenanthic acid in mixture with levulinic acid is 20-50 percent. Tests of the number of proposed lubricants were conducted for cold stampling of parts from a metal strip on a 10 ton mechanical press. Tool stability (number of pieces until adhesion) was 1200-1400, purity class Pv-7. In tests under a similar condition of vegetable oil, ZhKPM and a mixture of ZhKPM with esters (nonlubricant) tool stability was 1100, and the purity class Pv-6.

  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. 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)

  10. 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...

  11. 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...

  12. 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.

  13. 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...

  14. 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

  15. 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.

  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. 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.

  19. 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

  20. 46 CFR 160.035-8 - Construction of fibrous glass reinforced plastic (F.R.P.), oar-, hand-, and motor-propelled...

    Science.gov (United States)

    2010-10-01

    ...) Plastic lifeboats shall comply with the general requirements for the construction and arrangement of steel... finish, and there shall be no protruding surface fibers, open voids, pits, cracks, bubbles or blisters... tackiness, and shall show no tendency to delaminate, peel, or craze in any overlay. The laminate shall...

  1. Reduction of the residual stresses in cold expanded thick-walled cylinders by plastic compression

    Institute of Scientific and Technical Information of China (English)

    V.F. SKVORTSOV; A.O. BOZNAK; A.B. KIM; A. Yu ARLYAPOV; A.I. DMITRIEV

    2016-01-01

    We suppose that in order to maintain high accuracy of holes and to lower residual stresses after cold expansion of thick-walled cylinders, which undergo cross-section plastic deformation, it is necessary to perform axial plastic compression and subsequent cold expansion with small interferences. To test this hypothesis, we studied hoop, radial and axial residual stresses in cylinders made of carbon steel AISI 1050 with hole diameter of 5 mm, outer diameter of 15 mm and length of 30 mm by Sachs method as well as accuracy of expanded holes. It is found that double cold expansion with total interference equal to 5.1%generates hoop residual stresses with largest absolute value equal to 284 MPa and ensures high holes accuracy (IT7). After plastic compression with strain equal to 0.5 and 1%the mentioned stresses reduced to 120 and 75 MPa respectively, and accuracy of the holes reduced as well. Subsequent cold expansion with small interference equal to 0.9%helps to restore holes accuracy (IT7) gained by double cold expansion and ensure that absolute value of hoop residual stresses (177 MPa) is lower compared to double cold expansion.

  2. Mechanisms of plastic deformation for powder materials in cold working

    Institute of Scientific and Technical Information of China (English)

    张连洪; 李双义

    2003-01-01

    To deal with the discontinuity of particulate media and subsequent uncertainty of stress, based on the probability theory for mechanics of particulate media, Mohr-Coulomb yield criterion of particulate media, and the theory of crystal deformation, we put forward the statistical mechanisms of deformation of powder materials in cold working and mechanism of texture development of the high temperature superconducting wire/tape. A new yield criterion of powder materials is proposed.

  3. 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.

  4. Generation of Cold Argon Plasma Jet at the End of Flexible Plastic Tube

    CERN Document Server

    Kostov, Konstantin G; Prysiazhnyi, Vadym

    2014-01-01

    This brief communication reports a new method for generation of cold atmospheric pressure plasma jet at the downstream end of a flexible plastic tube. The device consists of a small chamber where dielectric barrier discharge (DBD) is ignited in Argon. The discharge is driven by a conventional low frequency AC power supply. The exit of DBD reactor is connected to a commercial flexible plastic tube (up to 4 meters long) with a thin floating Cu wire inside. Under certain conditions an Ar plasma jet can be extracted from the downstream tube end and there is no discharge inside the plastic tube. The jet obtained by this method is cold enough to be put in direct contact with human skin without electric shock and can be used for medical treatment and decontamination.

  5. Transfer of a cold atmospheric pressure plasma jet through a long flexible plastic tube

    Science.gov (United States)

    Kostov, Konstantin G.; Machida, Munemasa; Prysiazhnyi, Vadym; Honda, Roberto Y.

    2015-04-01

    This work proposes an experimental configuration for the generation of a cold atmospheric pressure plasma jet at the downstream end of a long flexible plastic tube. The device consists of a cylindrical dielectric chamber where an insulated metal rod that serves as high-voltage electrode is inserted. The chamber is connected to a long (up to 4 m) commercial flexible plastic tube, equipped with a thin floating Cu wire. The wire penetrates a few mm inside the discharge chamber, passes freely (with no special support) along the plastic tube and terminates a few millimeters before the tube end. The system is flushed with Ar and the dielectric barrier discharge (DBD) is ignited inside the dielectric chamber by a low frequency ac power supply. The gas flow is guided by the plastic tube while the metal wire, when in contact with the plasma inside the DBD reactor, acquires plasma potential. There is no discharge inside the plastic tube, however an Ar plasma jet can be extracted from the downstream tube end. The jet obtained by this method is cold enough to be put in direct contact with human skin without an electric shock. Therefore, by using this approach an Ar plasma jet can be generated at the tip of a long plastic tube far from the high-voltage discharge region, which provides the safe operation conditions and device flexibility required for medical treatment.

  6. USE OF THE DEVICE TO INCREASE THE PLASTIC PROPERTIES OF COLD-SHAPED FITTINGS

    Directory of Open Access Journals (Sweden)

    T. A. Akhmetov

    2016-01-01

    Full Text Available The subjects of influence of the relationship of a limit of fluidity and full relative lengthening at the maximum load on deformation energy before destruction are considered in the article. Use of the block to decrease of internal tension in production of cold-shaped fittings allows to increase significantly its plastic properties, i. e. a power factor. At the same time combination of such device with the straightening unit similar to one used in production of thin wire and also minimization of specific reduction opens prospects for obtaining all necessary parameters of the fittings of a class «B» produced by cold rolling. 

  7. Cold-atmospheric pressure plasma polymerization of acetylene on wood flour for improved wood plastics composites

    Science.gov (United States)

    Lekobou, William; Pedrow, Patrick; Englund, Karl; Laborie, Marie-Pierre

    2009-10-01

    Plastic composites have become a large class of construction material for exterior applications. One of the main disadvantages of wood plastic composites resides in the weak adhesion between the polar and hydrophilic surface of wood and the non-polar and hydrophobic polyolefin matrix, hindering the dispersion of the flour in the polymer matrix. To improve interfacial compatibility wood flour can be pretreated with environmentally friendly methods such as cold-atmospheric pressure plasma. The objective of this work is therefore to evaluate the potential of plasma polymerization of acetylene on wood flour to improve the compatibility with polyolefins. This presentation will describe the reactor design used to modify wood flour using acetylene plasma polymerization. The optimum conditions for plasma polymerization on wood particles will also be presented. Finally preliminary results on the wood flour surface properties and use in wood plastic composites will be discussed.

  8. 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...

  9. 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.

  10. Warm fish with cold hearts: thermal plasticity of excitation-contraction coupling in bluefin tuna.

    Science.gov (United States)

    Shiels, H A; Di Maio, A; Thompson, S; Block, B A

    2011-01-07

    Bluefin tuna have a unique physiology. Elevated metabolic rates coupled with heat exchangers enable bluefin tunas to conserve heat in their locomotory muscle, viscera, eyes and brain, yet their hearts operate at ambient water temperature. This arrangement of a warm fish with a cold heart is unique among vertebrates and can result in a reduction in cardiac function in the cold despite the elevated metabolic demands of endothermic tissues. In this study, we used laser scanning confocal microscopy and electron microscopy to investigate how acute and chronic temperature change affects tuna cardiac function. We examined the temporal and spatial properties of the intracellular Ca2+ transient (Δ[Ca2+]i) in Pacific bluefin tuna (Thunnus orientalis) ventricular myocytes at the acclimation temperatures of 14°C and 24°C and at a common test temperature of 19°C. Acute (less than 5 min) warming and cooling accelerated and slowed the kinetics of Δ[Ca2+]i, indicating that temperature change limits cardiac myocyte performance. Importantly, we show that thermal acclimation offered partial compensation for these direct effects of temperature. Prolonged cold exposure (more than four weeks) increased the amplitude and kinetics of Δ[Ca2+]i by increasing intracellular Ca2+ cycling through the sarcoplasmic reticulum (SR). These functional findings are supported by electron microscopy, which revealed a greater volume fraction of ventricular SR in cold-acclimated tuna myocytes. The results indicate that SR function is crucial to the performance of the bluefin tuna heart in the cold. We suggest that SR Ca2+ cycling is the malleable unit of cellular Ca2+ flux, offering a mechanism for thermal plasticity in fish hearts. These findings have implications beyond endothermic fish and may help to delineate the key steps required to protect vertebrate cardiac function in the cold.

  11. 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 .

  12. 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

  13. 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.

  14. 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)

  15. 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...

  16. 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.

  17. Influence of stress path change on the resistance to plastic deformation of cold rolled sheets

    Institute of Scientific and Technical Information of China (English)

    Zonghai Ding; Pavel Huml

    2005-01-01

    Flat workpieces have been tested in order to investigate the influence of stress path change (loading mode) while keeping strain path unchanged. These investigations are pertinent to the testing of cold rolled strips and to subsequent forming. The workpieces which first compressed by plane strain compression in thickness direction were then tested in perpendicular direction in order to measure the influence of strain and stress path. The tension workpieces came from flat die compression test at different deformation histories. Two different materials were investigated: 18/8 Ti stainless steel and AW-1050 aluminium. The results show that the plastic flow by tension in lengthwise direction after pre-strain by compression in thickness direction will begin at an appreciably lower stress than that of the workpieces unloaded after pre-compression. Comparing with two materials, it can be seen that both 18/8Ti stainless steel and AW-1050 aluminium behave similarly. The drop in yield stress is lower for AW-1050 aluminium than that for 18/8 Ti stainless steel. However, reloading in different directions than in the precious step results in significantly higher strain hardening.

  18. Atmospheric pressure cold plasma treatment of cellulose based fillers for wood plastic composites

    Science.gov (United States)

    Lekobou, William; Englund, Karl; Pedrow, Patrick; Scudiero, Louis

    2011-10-01

    The main challenge of wood plastic composites (WPC) resides in the low interfacial adhesion due to incompatibility between the cellulose based filler that has a polar surface and most common matrixes, polyolefins which are non-polar. Plasma treatment is a promising technique for surface modification and its implementation into the processing of WPC would provide this industry with a versatile and nearly environmentally benign manufacturing tool. Our investigation aims at designing a cold atmospheric pressure plasma reactor for coating fillers with a hydrophobic material prior to compounding with the matrix. Deposition was achieved with our reactor that includes an array of high voltage needles, a grounded metal mesh, Ar as carrier gas and C2H2 as the precursor molecule. Parameters studied have included gas feed rates and applied voltage; FTIR, ESCA, AFM and SEM imaging were used for film diagnostics. We will also report on deposition rate and its dependence on radial and axial position as well as the effects of plasma-polymerized acetylene on the surface free energy of cellulose based substrates.

  19. Effect of severe plastic deformation on the specific heat and magnetic properties of cold rolled Gd sheets

    Science.gov (United States)

    Taskaev, S.; Skokov, K.; Khovaylo, V.; Buchelnikov, V.; Pellenen, A.; Karpenkov, D.; Ulyanov, M.; Bataev, D.; Usenko, A.; Lyange, M.; Gutfleisch, O.

    2015-03-01

    We report on specific heat and magnetic properties of thin Gd sheets obtained by means of a cold rolling technique. At temperatures well below Curie temperature TC, the cold rolling has a minor impact on the specific heat Cp. However, a well defined λ-type anomaly of Cp seen in the vicinity of TC in a polycrystalline Gd sample is markedly suppressed in the severely deformed samples. Depression of the λ peak is due to a large decrease of magnetization that presumably originates in a local magnetic anisotropy induced by the severe plastic deformation. Results of calculation of magnetocaloric effect from the Cp and magnetization data indicate that the magnetocaloric effect gradually decreases as the degree of plastic deformation increases. This trend is further confirmed by the direct measurements of the adiabatic temperature change ΔTad.

  20. 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.

  1. 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

  2. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  3. 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.

  4. Plastic Mechanisms for Thin-Walled Cold-Formed Steel Members in Eccentric Compression

    Directory of Open Access Journals (Sweden)

    Ungureanu Viorel

    2016-03-01

    Full Text Available The Eurocode 3 concerning thin-walled steel members divides members subjected to compression into four classes, considering their ductility. The representatives of the class C4 are short bars, for which the load-capacity corresponds to the maximum compression stresses less than the yield stress. There are bars prone to local buckling in the elastic range and they do not have a real post-elastic capacity. The failure at ultimate stage of such members, either in compression or bending, always occurs by forming a local plastic mechanism. This fact suggests the possibility to use the local plastic mechanism to characterise the ultimate strength of such members. The present paper is based on previous studies and some latest investigations of the authors, as well as the literature collected data. It represents an attempt to study the plastic mechanisms for members in eccentric compression about minor axis and the evolution of plastic mechanisms, considering several types of lipped channel sections.

  5. Cold plasma inactivates salmonella on grape tomatoes in a commercial PET plastic container without affecting quality

    Science.gov (United States)

    Introduction: The number of outbreaks of foodborne illnesses associated with the consumption of fresh tomatoes has increased. Little research has been conducted on the effects of direct treatment of cold plasma (CP) on the microbial decontamination and preservation of bulk tomatoes packaged in comme...

  6. Modeling texture development during cold rolling of IF steel by crystal plasticity finite element method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With the consideration of slip deformation mechanism and various slip systems of body centered cubic (BCC) metals,Taylor-type and finite element polycrystai models were embedded into the commercial finite element code ABAQUS to realize crystal plasticity finte element modeling,based on the rate dependent crystal constitutive equations.Initial orientations measured by electron backscatter diffraction (EBSD) were directly input into the crystal plasticity finite element model to simulate the development of rolling texture of interstitial-flee steel (IF steel) at various reductions.The modeled results show a good agreement with the experimental results.With increasing reduction,the predicted and experimental rolling textures tend to sharper,and the results simulated by the Taylor-type model are stronger than those simulated by finite element model.Conclusions are obtained that rolling textures calculated with 48 {110}+{ 112}+{123} slip systems are more approximate to EBSD results.

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Influence of Niobium on the Beginning of the Plastic Flow of Material during Cold Deformation

    Directory of Open Access Journals (Sweden)

    Stoja Rešković

    2013-01-01

    Full Text Available Investigations were conducted on low-carbon steel and the steel with same chemical composition with addition of microalloying element niobium. While tensile testing was carried out, the thermographic measurement was tacking place simultaneously. A specific behavior of niobium microalloyed steel was noticed. Test results have shown that, in the elastic deformation region, thermoelastic effect occurs, which is more pronounced in niobium microalloyed steel. Start of plastic flow in steel which is not microalloyed with niobium begins later in comparison to the microalloyed steel, and it is conducted so that, at the point of maximum stress, deformation zone is formed within which stresses grow. In steel microalloyed with niobium after proportionality limit, comes the occurrence of the localized increase in temperature and the occurrence of Lüders band, which propagate along the sample forming a deformation zone.

  14. Influence of niobium on the beginning of the plastic flow of material during cold deformation.

    Science.gov (United States)

    Rešković, Stoja; Jandrlić, Ivan

    2013-01-01

    Investigations were conducted on low-carbon steel and the steel with same chemical composition with addition of microalloying element niobium. While tensile testing was carried out, the thermographic measurement was tacking place simultaneously. A specific behavior of niobium microalloyed steel was noticed. Test results have shown that, in the elastic deformation region, thermoelastic effect occurs, which is more pronounced in niobium microalloyed steel. Start of plastic flow in steel which is not microalloyed with niobium begins later in comparison to the microalloyed steel, and it is conducted so that, at the point of maximum stress, deformation zone is formed within which stresses grow. In steel microalloyed with niobium after proportionality limit, comes the occurrence of the localized increase in temperature and the occurrence of Lüders band, which propagate along the sample forming a deformation zone.

  15. 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.

  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. 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.

  18. 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...

  19. INFLUENCE RESEARCH OF COLD PLASTIC DEFORMATION ON DIFFUSION SATURATION PROCESS BY CARBON AND BORON OF THE LOW-CARBON AND BORON-CONTAINING ALLOYS

    Directory of Open Access Journals (Sweden)

    N. Yu. Filonenko

    2010-06-01

    Full Text Available This work is devoted to the study of influence of cold prestrain with degree of deformation within the range 0…40 % on diffusion saturation with boron and carbon for low-carbon and boron steels. It is determined that the plastic prestrain with degree of deformation 20 % at temperature 750 °С for the low-carbon steel promote increasing of boron-cementation layer thickness by 25 % and microhardness of perlite layer by 20 %.

  20. Fibre Reinforced Plastic Concepts for Structural Chassis Parts

    OpenAIRE

    Deißer, Oliver; Friedrich, Horst E.; Kopp, Gundolf

    2014-01-01

    Abstract Fibre reinforced plastics (FRP) have a high potential for reducing masses of automotive parts, but are seldom used for structural parts in the chassis. If the whole chassis concept is adapted to the new material, then a high weight saving potential can be gained and new body concepts can result. DLR Institute of Vehicle Concepts designed and dimensioned a highly stressed structural part in FRP. A topology optimisation of a defined working space with the estimated loads was perform...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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。

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Robert [Lockheed Martin Corporation, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates, Houston, TX (United States); Johnson, Peter [BMT Scientific Marine Services, Inc., Houston, TX (United States); Shi, Shan [Houston Offshore Engineering, Houston, TX (United States); Marinho, Thiago [Federal Univ. of Rio de Janeiro (Brazil). LabOceano

    2014-05-09

    A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

  13. Electro-bending characterization of adaptive 3D fiber reinforced plastics based on shape memory alloys

    Science.gov (United States)

    Ashir, Moniruddoza; Hahn, Lars; Kluge, Axel; Nocke, Andreas; Cherif, Chokri

    2016-03-01

    The industrial importance of fiber reinforced plastics (FRPs) is growing steadily in recent years, which are mostly used in different niche products, has been growing steadily in recent years. The integration of sensors and actuators in FRP is potentially valuable for creating innovative applications and therefore the market acceptance of adaptive FRP is increasing. In particular, in the field of highly stressed FRP, structural integrated systems for continuous component parts monitoring play an important role. This presented work focuses on the electro-mechanical characterization of adaptive three-dimensional (3D)FRP with integrated textile-based actuators. Here, the friction spun hybrid yarn, consisting of shape memory alloy (SMA) in wire form as core, serves as an actuator. Because of the shape memory effect, the SMA-hybrid yarn returns to its original shape upon heating that also causes the deformation of adaptive 3D FRP. In order to investigate the influences of the deformation behavior of the adaptive 3D FRP, investigations in this research are varied according to the structural parameters such as radius of curvature of the adaptive 3D FRP, fabric types and number of layers of the fabric in the composite. Results show that reproducible deformations can be realized with adaptive 3D FRP and that structural parameters have a significant impact on the deformation capability.

  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. 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.

  16. 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...

  17. 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...

  18. 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.

  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. 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.

  1. 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 ...

  2. 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....

  3. 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.

  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. 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.

  6. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  7. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  8. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable

  9. Neutron diffraction analysis of Cr-Ni-Mo-Ti austenitic steel after cold plastic deformation and fast neutrons irradiation

    Science.gov (United States)

    Voronin, V. I.; Valiev, E. Z.; Berger, I. F.; Goschitskii, B. N.; Proskurnina, N. V.; Sagaradze, V. V.; Kataeva, N. F.

    2015-04-01

    A quantitative assessment is presented of the dislocation density and relative fractions of edge and screw dislocations in reactor-steel samples 16Cr-15Ni-3Mo-1Ti subjected to preliminary cold deformation by rolling and subsequent fast neutron irradiation using neutron diffraction analysis. The Williamson-Hall modified method was used for calculations. It is shown that the fast neutron irradiation leads to a decrease in the density of dislocations that appeared after samples deformation. The applicability of neutron diffraction analysis to the examination of dislocation structure of deformed and irradiated materials is shown.

  10. 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。

  11. Use of pultruded reinforced plastics in energy generation and energy related applications

    Science.gov (United States)

    Anderson, R.

    Applications of pultrusion-formed fiber-reinforced plastics (FRP) in the wind, oil, and coal derived energy industries are reviewed. FRP is noted to be a viable alternative to wood, aluminum, and steel for reasons of availability, price, and weight. Attention is given to the development of FRP wind turbine blades for the DOE 8 kW low cost, high reliability wind turbine program. The blades feature a NACA 23112 profile with a 15 in. chord on the system which was tested at Rocky Flats, CO. Fabricating the blades involved a plus and minus 45 deg roving orientation, a heavy fiber-glass nose piece to assure blade strength, and a separately manufactured foam core. Additional uses for FRP products have been found in the structural members of coal stack scrubbers using a vinyl ester resin in a fire retardant formulation, and as low cost, light weight sucker rods for deep well oil drilling.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling

    Directory of Open Access Journals (Sweden)

    S. Farè

    2011-01-01

    Full Text Available A study was carried out on aging behaviour of a 6082 alloy processed by two different severe plastic deformation techniques: ECAP and asymmetric rolling. Both techniques were able to generate an ultrafine-grained structure in samples processed at room temperature. It was stated that severe straining promotes marked changes in the postdeformation aging kinetics. The peaks of β′′/β′ transition phases were anticipated and of progressively reduced intensity over the coarse grained alloy. A further peak accounting for onset of recrystallization also appeared in the most severely deformed samples. Full consistency in peak shape and position was found when comparing materials processed by ECAP and asymmetric rolling. Isothermal aging treatments performed at 180°C revealed that in the severely deformed samples, aging became so fast that the hardness curves continuously decreased due to overwhelming effects of structure restoration. On the contrary, aging at 130°C offers good opportunities for fully exploiting the precipitate hardening effects in the ultrafine-grained alloy.

  1. 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.)

  2. 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.

  3. 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.

  4. 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.

  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. 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.

  7. The electrostatic properties of Fiber-Reinforced-Plastics double wall underground storage gasoline tanks

    Science.gov (United States)

    Li, Yipeng; Liu, Quanzhen; Meng, He; Sun, Lifu; Zhang, Yunpeng

    2013-03-01

    At present Fiber Reinforced Plastics (FRP) double wall underground storage gasoline tanks are wildly used. An FRP product with a resistance of more than 1011 Ω is a static non-conductor, so it is difficult for the static electricity in the FRP product to decay into the earth. In this paper an experimental system was built to simulate an automobile gasoline filling station. Some electrostatic parameters of the gasoline, including volume charge density, were tested when gasoline was unloaded into a FRP double wall underground storage tank. Measurements were taken to make sure the volume charge density in the oil-outlet was similar to the volume charge density in the tank. In most cases the volume charge density of the gasoline was more than 22.7 μC m-3, which is likely to cause electrostatic discharge in FRP double wall underground storage gasoline tanks. On the other hand, it would be hard to ignite the vapor by electrostatic discharge since the vapor pressure in the tanks is over the explosion limit. But when the tank is repaired or re-used, the operators must pay attention to the static electricity and some measurements should be taken to avoid electrostatic accident. Besides the relaxation time of charge in the FRP double wall gasoline storage tanks should be longer.

  8. 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.

  9. 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

  10. Bond tests of fiberglass-reinforced plastic bars in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, J.; Silva-Rodriquez, R.; Burdette, J.; Harris, B. (Drexel Univ., Philadelphia, PA (United States). Civil and Architectural Engineering Dept.)

    1994-07-01

    Fiberglass Reinforced Plastic (FRP) bars for concrete reinforcement have been commercially available for several years. The main advantage of such bar relative to the conventional steel reinforcing bars is their resistance to corrosion. The reinforced plastic bars are slightly different from the conventional steel bars both geometrically and mechanically. Thus, research is needed to understand their behavior and to be able to use them in concrete reinforcement with adequate reliability. Bond strength of reinforced plastic bars in concrete is one of the mechanical and behavioral differences with the steel bars. This paper presents the results of pullout and beam tests conducted to determine the bond stress-slip behavior of FRP bars in concrete.

  11. Ocean thermal energy conversion cold water pipe preliminary design project. Appendices to final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-20

    NOAA/DOE has selected three concepts for a baseline design of the cold water pipe (CWP) for OTEC plants: (1) a FRP CWP of sandwich wall construction suspended from the Applied Physical Laboratory/John Hopkins University (APL/JHU) barge at a site 200 miles east of the coast of Brazil using a horizontal deployment scheme; (2) an elastomer CWP suspended from the APL/JHU barge off the southeast coast of Puerto Rico using either a horizontal or vertical deployment scheme; and (3) a polyethylene CWP (single or multiple pipe) suspended from the Gibbs and Cox spar at the Puerto Rico site using a horizontal deployment scheme. TRW has developed a baseline design for each of these configurations. This volume of the report includes the following appendices: (A) fiberglass reinforced plastic cold water pipe (specification and drawingss); (B) specification for polyethylene CWP; (C) elastomer pipe drawings; (D) drawings for OTEC 10/40 hull/CWP transitions; (E) structural design of OTEC 10/40 CWP support and CWP transitions; (F) universal transition joint for CWP; (G) dynamic spherical seal of CWP; (H) at-sea deployment loads - surface towing loads; (I) OTEC 10/40 CWP deployment up-ending loads; (J) cost estimates for OTEC 10/40 hull/CWP transitions; and (K) OTEC 10/40 CWP deployment scenario and cost estimate. (WHK)

  12. COLD-WORKED HARDWARE

    Directory of Open Access Journals (Sweden)

    N. M. Strizhak

    2007-01-01

    Full Text Available The different types of cold-worked accessory are examined in the article. The necessity of development of such type of accessory in the Republic of Belarus due to requirements of market is shown. High emphasis is placed on the methods of increase of plasticity of cold-worked accessory from usual mill of RUP and CIS countries.

  13. 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...

  14. 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.

  15. 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.

  16. 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...

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. Comparative effects of pyrolytic products of fiber reinforced plastic and wood shavings on the respiratory variables in mice.

    Science.gov (United States)

    Kumar, Pravin; Deb, Utsab; Gautam, Anshoo; Vijayaraghavan, R; Ratna, Debdatta; Chakraborty, B C

    2010-08-01

    Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fiberglass reinforced plastic (FRP) and teak wood shavings were carried out in male Swiss albino mice. The breathing pattern and the respiratory variables were monitored using a computer program that recognizes the modifications of the respiratory pattern. Exposure to the smoke from both the polymers caused a concentration dependent decrease in normal breathing and an increase in sensory irritation measure. The acute lethal concentration 50 values for a 15 min static inhalation exposure to the smoke from FRP and teak wood shavings were found to be > 200.00 and 62.99 g/m(3), respectively. Hence the inhalation toxicity of smoke from FRP sample on a mass basis is approximately one-third that of the smoke from teak wood. The concentration of smoke causing 50% respiratory depression of the exposed animals were found to be 6.877 and 0.106 g/m(3) for FRP and teak wood samples, respectively. Thus the sensory irritancy of the smoke from FRP sample is approximately 65 times lesser than the smoke from teak wood. The higher sensory irritancy potential of wood smoke as compared to FRP smoke may be caused by a greater number of submicron particles (size range of 2 micron and less) and greater percentage of gases present in wood smoke as compared to FRP smoke. Thus in case of accidental fires, synthetic polymers like FRP may be a safer choice for structural parts and interiors than the natural wood.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Effect of the Heat-treatment Temperature on the Mechanical Properties and Microstructural Evolution of Cold-rolled Twinning-induced Plasticity Steel

    Institute of Scientific and Technical Information of China (English)

    LI Dazhao; WEI Yinghui; SONG Jinlu; HOU Lifeng

    2015-01-01

    TWIP steels with 70%cold-rolled reduction were heated at 500, 600, 700, 800, 900, 1000, and 1100℃. Then, the properties before and after heating were examined through tensile and hardness experiments. The microstructures were also analyzed by optical microscopy and transmission electron microscopy. The relationship between the properties and microstructure was examined as well. Finally, the evolution process of cold-rolled microstructures during heating was discussed in detail. Moreover, some conclusions can be drawn, and the heating evolution characteristics are described.

  18. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  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. 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.

  6. 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.

  7. 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

  8. 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.

  9. The extrinsic influence of carbon fibre reinforced plastic laminates to strengthen steel structures

    Indian Academy of Sciences (India)

    A K Patnaik; C L Bauer; T S Srivatsan

    2008-06-01

    The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and discussed in this paper were obtained by closely studying the behaviour of steel beams strengthened with carbon FRP material. An attempt is made to succinctly summarise the findings for two different types of strengthening of the steel beams using carbon FRP laminates. The first type of beams focuses on enhancing the strength of steel in flexure while the second focuses on increasing the shear strength of the beams. Three beams were designed so as to cause them to fail in flexure. Of the beams studied, two were strengthened using carbon FRP strips attached to the tension flange. One of the beams was tested to facilitate comparison of their behaviour to the two beams which are strengthened in flexure. Three other beams were designed such that they failed predominantly in shear. Of these three, two were strengthened with carbon FRP strips attached to the webs while the third beam was used as a control beam for the purpose of drawing comparisons. Preliminary results revealed a noticeable increase in the strength for both the flexure strengthened beams and the beams strengthened in shear. The observed increase in shear strength of the beams was 26% while the increase in strength for the beams tested in flexure was 15%. This study convincingly shows that it is possible to strengthen steel beams using carbon FRP laminates in both flexure and in shear.

  10. 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.

  11. Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing

    Science.gov (United States)

    Ghasemi-Nanesa, H.; Nili-Ahmadabadi, M.; Shirazi, H.

    2010-07-01

    Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was epsilon ~7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

  12. Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi-Nanesa, H; Shirazi, H [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, P.O. Box 14395-731 (Iran, Islamic Republic of); Nili-Ahmadabadi, M, E-mail: sut.caster.81710018@gmail.co, E-mail: nili@ut.ac.i [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, P.O. Box 14395-731 (Iran, Islamic Republic of) and Center of Excellence for High Performance Materials, University of Tehran, P.O. Box 14395-731, Tehran (Iran, Islamic Republic of)

    2010-07-01

    Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was {epsilon} {approx}7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

  13. 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

  14. 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

  15. 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

  16. PHENOLIC RESINS AND THE PLASTICS INDUSTRY: YESTERDAY, TODAY, AND TOMORROW%PHENOLIC RESINS AND THE PLASTICS INDUSTRY:YESTERDAY,TODAY,AND TOMORROW

    Institute of Scientific and Technical Information of China (English)

    Louis Pilato

    2010-01-01

    During 2010,Phenolic Resins celebrate 100years of existence.Dr.Leo Baekeland began commercial production of phenolic resins in May 1910 in Germany and October 1910 in the United States.This activity launched the Plastics Industry as it is recognized today.It is estimated that about 255 million tons of plastics will be produced worldwide in 2010 and consist of thermoplastic,thermosetting and elastomeric materials.Some of these polymeric materials are further transformed into fiber reinforced plastics (FRP) utilizing fibers such as carbon fiber,glass fiber,and organic fibers such as Kevlar,Spectra (ultrahigh molecular weight polyethylene) and others.

  17. Plastic Surgery

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  18. Cold Urticaria

    Science.gov (United States)

    Diseases and Conditions Cold urticaria By Mayo Clinic Staff Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold. Skin that has ... in contact with cold develops reddish, itchy welts (hives). The severity of cold urticaria symptoms varies widely. ...

  19. 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.

  20. 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%.

  1. 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.

  2. 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...

  3. 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...

  4. Analysis of the clinical application of cold eye plastic surgery therapy%眼部整形美容术后冷疗法的临床应用分析

    Institute of Scientific and Technical Information of China (English)

    彭文胜

    2015-01-01

    目的:探讨眼部整形美容术后使用冷疗法的临床应用效果。方法:选取2012年1月-2014年1月接受眼部整形美容手术的患者50例为研究对象。按照术后处理方法的不同将其分为观察组与对照组,每组各25例;观察组术后接受冷疗法处理,对照组术后接受常规处理。对比分析处理后两组患者的疼痛评分、肿胀情况以及不良反应发生率等。结果:观察组的疼痛程度明显比对照组轻;观察组不良反应发生率显著小于对照组;并且观察组术后恢复时间小于对照组;两组以上差异具有统计学意义,P<0.05。结论:眼部整形美容手术后,使用冷疗法处理,能够起到很好的止痛、消肿等作用,从而加快患者术后恢复,避免出现不良反应,提高手术成功率。因此,该方法值得临床推广应用。%Objective To explore the eye plastic surgery clinical application effect of using cold. Methods Selected in January 2012 to January 2012 in our hospital eye plastic surgery patients 50 cases as the research object.According to the postoperative treatment methods of the different divided into observation group and control group, each group of 25 cases.Observation group receied cold therapy treatment,ontrol group receied routine processing.Comparative analysis of two groups of patients after pain score, swelling, and incidence of adverse reactions, etc. Results Pain degree of observation group was obviously lighter than the control group.Observation group of adverse reactions was significantly less than the control group.And the observation group of postoperative recovery time is less than the control group.The more similar between the two groups have statistical significance,P<0.05. Conclusion Eye plastic surgery, the use of cold therapy treatment,can play a role is to pain, swelling,etc,so as to speed up the patients with postoperative recovery,avoid adverse reaction, improve the success rate

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Investigation of primary static recrystallization in a NiTiFe shape memory alloy subjected to cold canning compression using the coupling crystal plasticity finite element method with cellular automaton

    Science.gov (United States)

    Zhang, Yanqiu; Jiang, Shuyong; Hu, Li; Zhao, Yanan; Sun, Dong

    2017-10-01

    The behavior of primary static recrystallization (SRX) in a NiTiFe shape memory alloy (SMA) subjected to cold canning compression was investigated using the coupling crystal plasticity finite element method (CPFEM) with the cellular automaton (CA) method, where the distribution of the dislocation density and the deformed grain topology quantified by CPFEM were used as the input for the subsequent SRX simulation performed using the CA method. The simulation results were confirmed by the experimental ones in terms of microstructures, average grain size and recrystallization fraction, which indicates that the proposed coupling method is well able to describe the SRX behavior of the NiTiFe SMA. The results show that the dislocation density exhibits an inhomogeneous distribution in the deformed sample and the recrystallization nuclei mainly concentrate on zones where the dislocation density is relatively higher. An increase in the compressive deformation degree leads to an increase in nucleation rate and a decrease in grain boundary spaces in the compression direction, which reduces the growth spaces for the SRX nuclei and impedes their further growth. In addition, both the mechanisms of local grain refinement in the incomplete SRX and the influence of compressive deformation degree on the grain size of SRX were vividly illustrated by the corresponding physical models.

  13. 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.

  14. Terahertz Wave Approach and Application on FRP Composites

    Directory of Open Access Journals (Sweden)

    Kwang-Hee Im

    2013-01-01

    Full Text Available Terahertz (THz applications have emerged as one of the most new powerful nondestructive evaluation (NDE techniques. A new T-ray time-domain spectroscopy system was utilized for detecting and evaluating orientation influence in carbon fiber-reinforced plastics (CFRPs composite laminates. Investigation of terahertz time-domain spectroscopy (THz-TDS was made, and reflection and transmission configurations were studied as a nondestructive evaluation technique. Here, the CFRP composites derived their excellent mechanical strength, stiffness, and electrical conductivity from carbon fibers. Especially, the electrical conductivity of the CFRP composites depends on the direction of unidirectional fibers since carbon fibers are electrically conducting while the epoxy matrix is not. In order to solve various material properties, the index of refraction (n and the absorption coefficient (α are derived in reflective and transmission configurations using the terahertz time-domain spectroscopy. Also, for a 48-ply thermoplastic polyphenylene-sulfide-(PPS- based CFRP solid laminate and nonconducting materials, the terahertz scanning images were made at the angles ranged from 0° to 180° with respect to the nominal fiber axis. So, the images were mapped out based on the electrical field (E-field direction in the CFRP solid laminates. It is found that the conductivity (σ depends on the angles of the nominal axis in the unidirectional fiber.

  15. Armazenamento refrigerado da uva de mesa 'Romana' (A1105 cultivada sob cobertura plástica Cold storage of 'Romana' (A1105 table grape cultivated under plastic cover

    Directory of Open Access Journals (Sweden)

    Jorge Lulu

    2005-08-01

    Full Text Available A videira é uma das principais fruteiras cultivadas em todo o mundo e atualmente a preferência por uvas do tipo "sem sementes" ou "apirênicas" vem aumentando gradativamente no mercado interno brasileiro. A cultivar 'Romana' (A1105 tem mostrado grande potencial como nova alternativa de uva de mesa apirênica na região de Jundiaí - SP. No entanto, a qualidade dos cachos tem sido afetada pela ocorrência de chuvas na época da colheita, propiciando a incidência de rachaduras nas bagas ("cracking" e podridões. Visando a solucionar essa dificuldade, foram conduzidos experimentos de campo em vinhedo cultivado em cortina dupla e sob cobertura plástica. Após a colheita, foram coletadas oito amostras com seis cachos cada, que foram armazenadas a 3 ºC e submetidas a avaliações de qualidade por um período máximo de 36 dias. A perda de massa ultrapassou o valor de 6% após três semanas de armazenamento refrigerado, quando apresentou sinais de murchamento das bagas, concluindo-se que o período máximo de armazenamento em câmara fria para a cultivar 'Romana' (A1105 foi de 21 dias.The grapevine is one of the most cultivated fruit crop and nowadays the preference for seedless grapes is gradualy increasing in the Brazilian internal market. The table grape cultivar 'Romana' (A1105 has been showing potential as a new option for the growers from Jundiaí - SP, Brazil, as a seedless grape. However the bunch quality has been affected by rain at the harvest allowing the incidence of cracking and bunch rot. Aiming to solve this problem a field trial was carried out with grapes cultivated under plastic cover and Geneva Double Curtain training system. After harvest, eight samples of six bunches each were taken and stored at 3 ºC and evaluated for quality during a period of 36 days. After three weeks of storage, the weight loss was higher than 6%, showing bunch fade and the rot bunch increased significantly. It was concluded that maximum shelf life for

  16. 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。

  17. 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。

  18. Adaptive changes in the plasticity of body melanisation in generalist, cold and warm adapted Drosophila species%不同气候适应类型果蝇体色黑化可塑性的适应性变化

    Institute of Scientific and Technical Information of China (English)

    Ravi PARKASH; Seema RAMNIWAS; Chanderkala LAMBHOD; Babita KAJLA

    2011-01-01

    变温昆虫果蝇Drosophila深受热选择(即遗传效应)或表型诱导效应(即可塑性)的影响.表型可塑性是不同生物进行适应的有效方法,但是它在不同的果蝇种中较少受到关注.我们分析了不同发育温度范围和地理分布的果蝇的黑化反应模式.嗜凤梨果蝇D.ananassae和蒲桃果蝇D.jambulina对低温敏感,这些物种可在18 ~ 32℃下饲育.相反,D.nepalensis为耐冷且对热敏感的物种,可在12 ~ 25℃下饲育.世界广为分布的黑腹果蝇D.melanogaster的温度范围宽(13~31℃),该物种前3个腹节和后3个腹节的黑化反应模式未见明显差异.D.nepalensis的全部6个腹节(第2~7节)均具有高度的可塑性.不过,黑腹果蝇D.melanogaster只有后3个腹节具有可塑性.相反,热带物种嗜凤梨果蝇D.ananassae的所有腹节均不具有可塑性.世界广为分布的黑腹果蝇,即使来自冷得多的气候环境,其体色也不加深,与D.nepalensis中观察到的体色接近.本研究的目的旨在认识引起体色的形态多样性的过程以及果蝇对不同地理区域的适应性.最后,将体色黑化与物种系统发育谱系的比较表明,在不同的演化谱系中不断发生遗传多态性或表型可塑性两种不同模式的适应.%Ectothermic drosophilids are profoundly affected by thermal selection (i.e.,genetic effects) or through induced effects on phenotype (i.e.,plasticity).Phenotypic plasticity is a powerful means of adaptation in diverse organisms but has received less attention for different drosophilids. We analyzed reaction norms of melanisation in Drosophila species which differ in developmental thermal range and geographical distribution.D.ananassae and D.jambulina are cold sensitive,and these species can be cultured between 18 to 32℃.By contrast,D.nepalensis is cold-tolerant and heat-sensitive species which can be raised between 12 and 25℃.The cosmopolitan species D. melanogaster has a broader thermal range ( 13

  19. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  20. 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.

  1. 新FRP技术加固钢筋混凝土矩形柱改善延性的试验研究%Experimental study on ductility improvement of reinforced concrete rectangular columns retrofitted with a new fiber reinforced plastics method

    Institute of Scientific and Technical Information of China (English)

    刘涛; 冯伟; 张智梅; 欧阳煜

    2008-01-01

    Reinforced concrete (RC) columns lacking adequately detailed transverse reinforcement do not possess the necessaryductility to dissipate seismic energy during a major earthquake without severe strength degradation. In this paper, a newretrofit method, which utilized fiber-reinforced plastics (FRP) confinement mechanism and anchorage of embedded bars, wasdeveloped aiming to retrofit non-ductile large RC rectangular columns to prevent the damage of the plastic hinges. CarbonFRP (CFRP) sheets and glass FRP (GFRP) bars were used in this test, and five scaled RC columns were tested to examinethe function of this new method for improving the ductility of columns. Responses of columns were examined before andafter being retrofitted. Test results indicate that this new composite method can be very effective to improve the anti-seismicbehavior of non-ductile RC columns compared with normal CFRP sheets retrofitted column.

  2. 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.

  3. Common Cold

    Science.gov (United States)

    ... nose, coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In the course of a year, people ... avoid colds. There is no cure for the common cold. For relief, try Getting plenty of rest ...

  4. 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.

  5. 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

  6. Plastic Jellyfish.

    Science.gov (United States)

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  7. Temperature Dependence of Sound Velocity in High-Strength Fiber-Reinforced Plastics

    Science.gov (United States)

    Nomura, Ryuji; Yoneyama, Keiichi; Ogasawara, Futoshi; Ueno, Masashi; Okuda, Yuichi; Yamanaka, Atsuhiko

    2003-08-01

    Longitudinal sound velocity in unidirectional hybrid composites or high-strength fiber-reinforced plastics (FRPs) was measured along the fiber axis over a wide temperature range (from 77 K to 420 K). We investigated two kinds of high-strength crystalline polymer fibers, polyethylene (Dyneema) and polybenzobisoxazole (Zylon), which are known to have negative thermal expansion coefficients and high thermal conductivities along the fiber axis. Both FRPs had very high sound velocities of about 9000 m/s at low temperatures and their temperature dependences were very strong. Sound velocity monotonically decreased with increasing temperature. The temperature dependence of sound velocity was much stronger in Dyneema-FRP than in Zylon-FRP.

  8. 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.

  9. 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

  10. 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).

  11. 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

  12. 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.

  13. Cold Sores

    Science.gov (United States)

    ... Previous Next Related Articles: Canker and Cold Sores Aloe Vera May Help Relieve Mouth Sores Canker Sore or Cold Sore? Mouth Sores: Caused By Student Stress? games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  14. Contour scanning of textile preforms using a light-section sensor for the automated manufacturing of fibre-reinforced plastics

    Science.gov (United States)

    Schmitt, R.; Niggemann, C.; Mersmann, C.

    2008-04-01

    Fibre-reinforced plastics (FRP) are particularly suitable for components where light-weight structures with advanced mechanical properties are required, e.g. for aerospace parts. Nevertheless, many manufacturing processes for FRP include manual production steps without an integrated quality control. A vital step in the process chain is the lay-up of the textile preform, as it greatly affects the geometry and the mechanical performance of the final part. In order to automate the FRP production, an inline machine vision system is needed for a closed-loop control of the preform lay-up. This work describes the development of a novel laser light-section sensor for optical inspection of textile preforms and its integration and validation in a machine vision prototype. The proposed method aims at the determination of the contour position of each textile layer through edge scanning. The scanning route is automatically derived by using texture analysis algorithms in a preliminary step. As sensor output a distinct stage profile is computed from the acquired greyscale image. The contour position is determined with sub-pixel accuracy using a novel algorithm based on a non-linear least-square fitting to a sigmoid function. The whole contour position is generated through data fusion of the measured edge points. The proposed method provides robust process automation for the FRP production improving the process quality and reducing the scrap quota. Hence, the range of economically feasible FRP products can be increased and new market segments with cost sensitive products can be addressed.

  15. 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.

  16. Plastics Technology.

    Science.gov (United States)

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  17. Plastic deformation of nanocrystalline nickel

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline (NC) Ni subject to cold rolling at liquid nitrogen temperature. The activation of grain-boundary-mediated-plasticity is evidenced in NC-Ni, including twinning and formation of stacking fault via partial dislocation slips from the grain boundary. The formation and storage of 60? full dislocations are observed inside NC-grains. The grain/twin boundaries act as the barriers of dislocation slips, leading to dislocation pile-up, severe lattice distortion, and formation of sub-grain boundary. The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation. The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  18. Plastic deformation of nanocrystalline nickel

    Institute of Scientific and Technical Information of China (English)

    WU XiaoLei

    2009-01-01

    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline(NC)Ni subject to cold rolling at liquid nitrogen temperature.The acti vation of grain-boundary-mediated-plasticity is evidenced in NC-Ni,including twinning and formation of stacking fault via partial dislocation slips from the grain boundary.The formation and storage of 60° full dislocations are observed inside NC-grains.The grain/twin boundaries act as the barriers of dislocation slips,leading to dislocation pile-up,severe lattice distortion,and formation of sub-grain boundary.The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation.The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  19. 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.

  20. 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 ...

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Plastic bronchitis

    National Research Council Canada - National Science Library

    Singhi, Anil Kumar; Vinoth, Bharathi; Kuruvilla, Sarah; Sivakumar, Kothandam

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics...

  7. 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.

  8. Plastic Fishes

    CERN Multimedia

    Trettnak, Wolfgang

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

  9. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  10. 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

  11. 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

  12. 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

  13. GREEN PLASTIC: A NEW PLASTIC FOR PACKAGING

    OpenAIRE

    Mr. Pankaj Kumar*, Sonia

    2016-01-01

    This paper gives a brief idea about a new type of plastic called as bio-plastic or green plastic. Plastic is used as a packaging material for various products, but this plastic is made up of non renewable raw materials. There are various disadvantages of using conventional plastic like littering, CO2 production, non-degradable in nature etc. To overcome these problems a new type of plastic is discovered called bio-plastic or green plastic. Bio-plastic is made from renewable resources and also...

  14. Common cold

    Science.gov (United States)

    ... have a low fever or no fever. Young children often run a fever around 100 to 102°F (37.7 to 38.8°C). Depending on which virus caused your cold, you may also have: Cough Decreased appetite Headache Muscle aches Postnasal drip Sore throat

  15. Project COLD.

    Science.gov (United States)

    Kazanjian, Wendy C.

    1982-01-01

    Describes Project COLD (Climate, Ocean, Land, Discovery) a scientific study of the Polar Regions, a collection of 35 modules used within the framework of existing subjects: oceanography, biology, geology, meterology, geography, social science. Includes a partial list of topics and one activity (geodesic dome) from a module. (Author/SK)

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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。

  1. 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.

  2. Plastic condoms.

    Science.gov (United States)

    1968-01-01

    Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

  3. Methods of Cold Soaking, Foam Plastics Enrichment and Inductive Coupling Plasma Atomic Emission Spectrometry%冷浸取--泡塑富集-电感耦合等离子体发射光谱法测定化探样品中的超痕量金铂钯研究

    Institute of Scientific and Technical Information of China (English)

    闵慧英; 袁蕙霞; 郭玉翠

    2015-01-01

    建立了冷浸--泡沫塑料富集,采用 ICP-AES 测定地球化学勘探样品中超痕量金、铂、钯的方法,并试验了冷浸取、泡沫塑料富集时各种因素的影响;确定了采用氯化钠、盐酸和高锰酸钾冷浸取分解试样,以泡沫塑料富集、灰化,残渣用王水溶解,用电感耦合等离子体发射光谱法测定的条件。该方法检出限分别为:Au 0.039ng/g,Pt 0.040ng/g,Pd 0.058ng/g;回收率为95.6%~102.5%之间;测量精密度( RSD%)为:Au 4.85%,Pt 5.76%,Pd 6.45%。采用该方法测定了国家一级地球化学标准物质中的痕量 Au,Pt,Pd,测定值与标准值符合规范要求。%In this paper, we set up the enrichment of cold soaking foam plastics by adopting the method of ICP-AES to test the ultra-trace of gold, platinum and palladium from the geochemical exploration sample and studied all kinds of effective factors in cold soaking foam plastics enrichment. And we confirmed the requirements of using sodi-um chloride, hydrochloric acid and potassium permanganate cold soak-ing to decompose the sample, using foam plastics to enrich and ash, aqua regia to dissolve residue, and measuring by inductive coupling Plasma Atomic Emission Spectrometry. The detection limits of this method are as follows: detection limit: Au 0.039ng/g, Pt 0.040ng/g, Pd 0.058ng/g; recovery rate: between 95.9% and 102.2%; relative stan-dard deviation (RSD%): Au 4.85%,Pt 5.76%,Pd 6.45%.We tested the trace amount of Au, Pt and Pd in the country-level geochemistry stan-dard substance. The measured value is consistent with the normalized value.

  4. Plastic Bronchitis.

    Science.gov (United States)

    Rubin, Bruce K

    2016-09-01

    Plastic bronchitis is an uncommon and probably underrecognized disorder, diagnosed by the expectoration or bronchoscopic removal of firm, cohesive, branching casts. It should not be confused with purulent mucous plugging of the airway as seen in patients with cystic fibrosis or bronchiectasis. Few medications have been shown to be effective and some are now recognized as potentially harmful. Current research directions in plastic bronchitis research include understanding the genetics of lymphatic development and maldevelopment, determining how abnormal lymphatic malformations contribute to cast formation, and developing new treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  6. Cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Suk Yong; Sung, Ki Woong; Kang, Joo Sang; Lee, Jong Jik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    So called `cold fusion phenomena` are not confirmed yet. Excess heat generation is very delicate one. Neutron generation is most reliable results, however, the records are erratic and the same results could not be repeated. So there is no reason to exclude the malfunction of testing instruments. The same arguments arise in recording {sup 4}He, {sup 3}He, {sup 3}H, which are not rich in quantity basically. An experiment where plenty of {sup 4}He were recorded is attached in appendix. The problem is that we are trying to search cold fusion which is permitted by nature or not. The famous tunneling effect in quantum mechanics will answer it, however, the most fusion rate is known to be negligible. The focus of this project is on the theme that how to increase that negligible fusion rate. 6 figs, 4 tabs, 1512 refs. (Author).

  7. Plastic fish

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  8. Plastic zonnecellen

    NARCIS (Netherlands)

    Roggen, Marjolein

    1998-01-01

    De zonnecel van de toekomst is in de maak. Onderzoekers van uiteenlopend pluimage werken eendrachtig aan een plastic zonnecel. De basis is technisch gelegd met een optimale, door invallend licht veroorzaakte, vorming van ladingdragers binnen een composiet van polymeren en buckyballs. Nu is het zaak

  9. 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.

  10. Plastic Surgery Statistics

    Science.gov (United States)

    ... PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the American Society of Plastic Surgeons. Statistics by Year Print 2016 Plastic Surgery Statistics 2015 ...

  11. 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 .

  12. 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.

  13. Plastic bronchitis

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singhi

    2015-01-01

    Full Text Available Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding.

  14. 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.

  15. 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.

  16. 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.

  17. New decorative composite construction wall of polymer concrete/FRP%新型聚合物混凝土/玻璃钢复合结构装饰墙体

    Institute of Scientific and Technical Information of China (English)

    师建锋; 郏灵军; 姚小刚

    2000-01-01

    提出一种新型复合结构墙体,该墙体以聚合物混凝土为基层,以玻璃钢为保护层和装饰层,并由树脂渗透层将以上两层紧密结合起来.此复合结构适用于大型墙体装饰,并可达到与天然石材、壁纸、涂料几乎相同的装饰效果.介绍了各层形态及形成机理,并提出了一套较为合理的选材方案及相关技术措施.%A new type of decorative composite construction wall was proposed with polymer concrete as base layer and fibre-glass reinforced plastics (FRP) as protective layer,and resin impregnating layer offers the connection between the two layers. The composite construction is applied to large-scale wall decoration and can get the same ef-fect as that of natural stone,coating and wallpaper,etc. A rational plan for materials-selecting and corresponding technical measures was put forward.

  18. 预制夹芯保温墙体FRP连接件应用进展%STATE-OF-THE-ART OF FIBER REINFORCED PLASTIC CONNECTORS IN PRECAST CONCRETE SANDWICH WALL PANELS

    Institute of Scientific and Technical Information of China (English)

    杨佳林; 薛伟辰

    2012-01-01

    Precast concrete sandwich wall panel is a new type of insulation wall which performs well both in structural bearing and thermal insulation. It is consisted of internal and external concrete wall-board, insulating layers and connectors, etc. According to different material, connector can be divided into three categories: common reinforced connector, alloy metal connector and fiber reinforced plastic ( FRP) connector. FRP connector has the property of low thermal conductivity, good durability and high strength. Which can decrease the heat transfer coefficient of sandwich wall panel, and has bright foreground in engineering applications. This paper introduces classification,research and application, standards and specifications of FRP connector, and offers the prospect for research trend of FRP connector in future.%预制混凝土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,该墙体由内外层混凝土墙板、中间保温层及连接件等组成.按照材料的不同,连接件主要分为普通钢筋连接件、金属合金连接件和纤维塑料(FRP)连接件三种.FRP连接件具有导热系数低、耐久性好、强度高的特点,可有效降低墙体的传热系数,具有广阔的工程应用前景.本文介绍了预制混凝土夹芯保温墙体FRP连接件分类、国内外研究与应用进展和技术规范情况,并对今后FRP连接件研究工作进行了展望.

  19. Analysis on plastic properties of reactive powder concrete continuous beams reinforced with GFRP bars

    Institute of Scientific and Technical Information of China (English)

    LU Shan-shan; ZHENG Wen-zhong

    2010-01-01

    To study the plastic properties of reactive powder concrete continuous beams reinforced with GFRP bars,the calculation programs for moment redistribution coefficients are prepared by using nonlinear analysis methods such as moment-curvature,conjugate beam method and so on.By comparing the test results of existed FRP bars reinforced concrete continuous beams with simulation results,the accuracy of the calculation program is verified.Then 18 simulated GFRP bars reinforced reactive powder concrete continuous beams are selected whose change parameters are reinforcement ratio of mid-span and middle support.Through the nonlinear analysis of simulated beams,moment redistribution coefficients under mid-span concentrated loads,one-third point loads and uniformly distributed loads are obtained respectively.Thus the formula of moment redistribution coefficients is obtained by fitting moment redistribution coefficients and factors.The results show that the reactive powder concrete continuous beams reinforced with GFRP bars have good plastic properties.

  20. Cough & Cold Medicine Abuse

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Cough & Cold Medicine Abuse KidsHealth > For Teens > Cough & Cold Medicine Abuse ... DXM Why Do People Use Cough and Cold Medicines to Get High? There's an ingredient in many ...

  1. 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.

  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. Cold confusion

    Energy Technology Data Exchange (ETDEWEB)

    Chapline, G.

    1989-07-01

    On March 23 two chemists, Martin Fleischmann and Stanley Pons startled the world with a press conference at the University of Utah where they announced that they had achieved nuclear fusion at room temperatures. As evidence they cited the production of ''excess'' amounts of heat in an electrochemical apparatus and observation of neutron production. While the production of heat in a chemical apparatus is not in itself unusual the observation of neutrons is certainly extraordinary. As it turned out, though, careful measurements of the neutron production in electrochemical apparatus similar to that used by Fleischmann and Pons carried out at dozens of other laboratories has shown that the neutron production fails by many orders of magnitude to support the assertion by Fleischmann and Pons that their discovery represents a new and cheap source of fusion power. In particular, independent measurements of the neutron production rate suggest that the actual rate of fusion energy production probably does not exceed 1 trillionth of a watt. This paper discusses the feasibility that cold fusion is actually being achieved. 7 refs.

  4. Overcoming maladaptive plasticity through plastic compensation

    Directory of Open Access Journals (Sweden)

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-08-01

    Full Text Available Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation and two of which do not (standing epigenetic variation, plastic compensation. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change [Current Zoology 59 (4: 526–536, 2013].

  5. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  6. Cold energy

    Science.gov (United States)

    Wallace, John P.

    2015-12-01

    Deviations in Q for resonant superconducting radio frequency niobium accelerator cavities are generally correlated with resistivity loss mechanisms. Field dependent Qs are not well modeled by these classical loss mechanisms, but rather can represent a form of precision cavity surface thermometry. When the field dependent Q variation shows improvement with increasing B field level the classical treatment of this problem is inadequate. To justify this behavior hydrogen as a ubiquitous impurity in niobium, which creates measurable property changes, even at very low concentrations is typically considered the cause of such anomalous behavior. This maybe the case in some instances, but more importantly any system operating with a highly coherent field with a significant time dependent magnetic component at near 2° K will have the ability to organize the remaining free spins within the London penetration depth to form a coupled energy reservoir in the form of low mass spin waves. The niobium resonant cavities are composed of a single isotope with a large nuclear spin. When the other loss mechanisms are stripped away this may be the gain medium activated by the low level residual magnetic fields. It was found that one resonant cavity heat treatment produced optimum surface properties and then functioned as a MASER extracting energy from the 2° K thermal bath while cooling the cavity walls. The cavity operating in this mode is a simulator of what can take place in the wider but not colder universe using the cosmic microwave background (CMB) as a thermal source. The low mass, long lifetimes, and the scale of the magnetic spin waves on the weakly magnetized interstellar medium allows energy to be stored that is many orders of magnitude colder than the cosmic microwave background. A linear accelerator cavity becomes a tool to explore the properties of the long wave length magnetic spin waves that populate this cold low energy regime.

  7. Cold energy

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, John P., E-mail: jpw@castinganalysis.com [Casting Analysis Corp., PO Box 52, Weyers Cave, VA 24486 (United States)

    2015-12-04

    Deviations in Q for resonant superconducting radio frequency niobium accelerator cavities are generally correlated with resistivity loss mechanisms. Field dependent Qs are not well modeled by these classical loss mechanisms, but rather can represent a form of precision cavity surface thermometry. When the field dependent Q variation shows improvement with increasing B field level the classical treatment of this problem is inadequate. To justify this behavior hydrogen as a ubiquitous impurity in niobium, which creates measurable property changes, even at very low concentrations is typically considered the cause of such anomalous behavior. This maybe the case in some instances, but more importantly any system operating with a highly coherent field with a significant time dependent magnetic component at near 2° K will have the ability to organize the remaining free spins within the London penetration depth to form a coupled energy reservoir in the form of low mass spin waves. The niobium resonant cavities are composed of a single isotope with a large nuclear spin. When the other loss mechanisms are stripped away this may be the gain medium activated by the low level residual magnetic fields. It was found that one resonant cavity heat treatment produced optimum surface properties and then functioned as a MASER extracting energy from the 2° K thermal bath while cooling the cavity walls. The cavity operating in this mode is a simulator of what can take place in the wider but not colder universe using the cosmic microwave background (CMB) as a thermal source. The low mass, long lifetimes, and the scale of the magnetic spin waves on the weakly magnetized interstellar medium allows energy to be stored that is many orders of magnitude colder than the cosmic microwave background. A linear accelerator cavity becomes a tool to explore the properties of the long wave length magnetic spin waves that populate this cold low energy regime.

  8. 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.

  9. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  10. Ocean thermal energy conversion cold water pipe preliminary design project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-20

    As part of a DOE goal to develop one or more OTEC Modular Experiment Plants, TRW performed designs, analyses, and evaluations of cold water pipe (CWP) concepts for NOAA. After reviewing the results of the CWP concept selection phase NOAA/DOE selected three concepts for a baseline design: (1) a FRP CWP of sandwich wall construction suspended from the Applied Physics Laboratory/John Hopkins University (APL/JHU) barge at a site 200 miles east of the coast of Brazil using a horizontal deployment scheme (this is TRW's preferred approach); (2) an elastomer CWP suspended from the APL/JHU barge off the southeast coast of Puerto Rico using either a horizontal or vertical deployment scheme; and (3) a polyethylene CWP (single or multiple pipe) suspended from the Gibbs and Cox spar at the Puerto Rico site using a horizontal deployment scheme. TRW has developed a baseline design for each of these configurations. Detailed designs and analyses for the FRP, polyethylene, and elastomer concepts, respectively, are described. A discussion of fabrication plans and processes, schedules for mobilization of facilities and equipment, installation plans, and cost breakdown are given for each concept. (WHK)

  11. 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

  12. Standard practice for examination of fiberglass reinforced plastic fan blades using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examinations of fiberglass reinforced plastic (FRP) fan blades of the type used in industrial cooling towers and heat exchangers. 1.2 This practice uses simulated service loading to determine structural integrity. 1.3 This practice will detect sources of acoustic emission in areas of sensor coverage that are stressed during the course of the examination. 1.4 This practice applies to examinations of new and in-service fan blades. 1.5 This practice is limited to fan blades of FRP construction, with length (hub centerline to tip) of less than 3 m [10 ft], and with fiberglass content greater than 15 % by weight. 1.6 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to evaluate the significance of AE sources. Procedures for other NDE methods are beyond the scope of this practice. 1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as sta...

  13. 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

  14. Recycling of Reinforced Plastics

    Science.gov (United States)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  15. 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.

  16. 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。

  17. Continuous cold therapy in total knee arthroplasty.

    Science.gov (United States)

    Leutz, D W; Harris, H

    1995-01-01

    This article describes a retrospective study that assessed 52 consecutive patients who underwent total knee arthroplasty (TKA) between January 1, 1992 and September 15, 1992. Thirty-three patients underwent TKA and received cold therapy pads placed over a thin dressing in the operating room. Nineteen patients underwent TKA using an identical operative and postoperative procedure, but did not receive continuous cold therapy. Continuous cold therapy consisted of two sterile plastic pads connnected by rubber hoses containing cool water from an electric main unit that maintained a constant temperature of 42 degrees F for the immediate postoperative period. Cold therapy pads were used an average of 3 days and removed with the first dressing change. Patients who had continuous cold therapy averaged a 200 cc decrease in postoperative blood loss. There was no significant difference in the amount of narcotic use, transfusion requirements, or hospital stay between the two groups. Postoperative swelling and range of motion were not consistently recorded. Twenty-eight other variables also examined not significant. Based on these results, we cannot recommend continuous cold therapy or justify the extra expense for all patients who undergo TKA.

  18. 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。

  19. Characteristics of Impact Damage and Post-Impact Strength in Glass-Fibre-Reinforced Plastics with Different Reinforcement Architecture

    Directory of Open Access Journals (Sweden)

    Michał BARCIKOWSKI

    2013-12-01

    Full Text Available Fiber-reinforced plastics (FRP are nowadays used commonly for constructions subjected to impacts of different energies and velocities; therefore, the problem of impact resistance is crucial. This paper presents the results of high-velocity impact tests and post-impact evaluation of damage in glass-fiber-reinforced plastics, depending on the architecture of reinforcing material (different woven fabrics, mat. Composites reinforced with continuous-filament mat, woven roving, roving fabric and twisted-yarn fabric were prepared and subjected to intermediate- and high-velocity impact. After the ballistic impact, damage extent and residual strength, as well as water leakage through the composites, were evaluated. The damage was also investigated under a microscope. The damage extent was confirmed to be linearly dependent on impact energy. The addition of rubber was found to decrease damage extent and increase post-impact residual strength, as well as decrease water leakage rate.

  20. Cold Stress and the Cold Pressor Test

    Science.gov (United States)

    Silverthorn, Dee U.; Michael, Joel

    2013-01-01

    Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

  1. 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.

  2. Cold and Cough Medicines

    Science.gov (United States)

    ... What can you do for your cold or cough symptoms? Besides drinking lots of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

  3. Cold-induced metabolism

    NARCIS (Netherlands)

    van Marken Lichtenbelt, W.D.; Daanen, A.M.

    2003-01-01

    Cold-induced metabolism. van Marken Lichtenbelt WD, Daanen HA. Department of Human Biology, Maastricht University, Maastricht, The Netherlands. PURPOSE OF REVIEW: Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering thermogenesi

  4. Cold nuclear fusion

    National Research Council Canada - National Science Library

    Huang Zhenqiang Huang Yuxiang

    2013-01-01

    ...... And with a magnetic moment of light nuclei controlled cold nuclear collide fusion, belongs to the nuclear energy research and development in the field of applied technology "cold nuclear collide fusion...

  5. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, for example, gutters, window frames, car parts and transportation boxes have long lifetimes and thus appear as waste only many years after they have been introduced on the market. Plastic is constantly being used for new products because of its attractive material properties: relatively cheap, easy to form......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  6. FRP夹强化泡沫芯复合材料的力学性能%Mechanical Properties of Sandwich Composites Made of FRP Panels and Strengthened Foam Cores

    Institute of Scientific and Technical Information of China (English)

    吴琴; 黄争鸣

    2012-01-01

    In this article, mechanical properties of a new type of foam-core sandwich composites are studied. The core was made by inserting thin-walled circular tubes into a PU foam, resulting in a significant reinforcement in its Z-directional properties. The sandwich composites were further fabricated by using FRP (fiber reinforced plastic) panels as surfaces and the strengthened foam as core. Lateral compression, three- point bending and shear tests were carried out for the sandwich composites. Failure mechanisms were analyzed based on fracture modes observed. Theoretical predictions for compression and bending moduli were carried out. The results show that the sandwich materials developed can significantly improve Z-directional mechanical properties, and have a good application prospect.%本文研究一种新型强化泡沫芯夹层复合材料的力学性能。选择在低成本的PU泡沫中置入圆管状结构增强体,使泡沫芯的等效Z向性能大幅提高。对以FRP面板夹这种强化泡沫芯制成的三明治复合材料结构,进行了平压试验、三点弯曲试验和剪切试验,基于其结构破坏模式,分析其破坏机理,并应用三维层板理论和细观力学方法进行了理论模拟。结果表明,这种强化泡沫芯能显著提高三明治板材的Z向力学性能,具有良好的应用前景。

  7. Strain-life method fatigue life analysis of cold extrusion mould based on elastic-plastic FEA%基于弹塑性有限元法的冷挤压模具应变法疲劳寿命分析

    Institute of Scientific and Technical Information of China (English)

    魏志刚; 汤文成

    2011-01-01

    The low-cycle fatigue of a cold extrusion mould was analyzed in this paper. The full strain-time history of the mould in the plastic making process was got by simulation of the plastic making with a coupled thermal-mechanical model. The MSC. Marc post-processing file was modified to filtrate the useless model result data, then the file was re-enveloped. Thus the useful result file was introduced to the professional fatigue analysis software: MSC. Fatigue. The fatigue life was predicted through the strain-life method, and the contour of the mould fatigue life was got. The results make a good agreement with that in the real condition. The result shows this method has a good precision. This method realizes the integrated fatigue life prediction, and provides a whole plan for the mould structure design based on the fatigue life.%对冷挤压模具的低周疲劳破坏进行了寿命分析.首先对模具采用弹塑性热力耦合模型进行了成型过程仿真,获得了成型过程中模具完整的应变-时间历程;然后采用Fortran语言对MSC.Marc分析后处理文件进行修改,删除不需要的模型数据和结果数据,对后处理文件重新进行封装,将需要的弹塑性结果导入到专用疲劳分析软件MSC.Fatigue,使用应变寿命法进行了疲劳寿命预测,获得了模具疲劳寿命分布云图.分析结果与实际情况符合良好,预测寿命具有较高的可信度,实现了挤压模具完整的疲劳寿命预测,为基于疲劳寿命的模具结构设计提供了一整套可行的方法.

  8. Application of self-diagnosis FRP to concrete pile for health monitoring

    Science.gov (United States)

    Nishimura, Hitoshi; Sugiyama, Takeshi; Okuhara, Yoshiki; Shin, Soon-Gi; Matsubara, Hideaki; Yanagida, Hiroaki

    2000-06-01

    The function and performance of the self-diagnosis composites embedded in concrete blocks and piles were investigated by bending tests and electrical resistance measurements. Carbon powder (CP) and carbon fiber (CF) were introduced in glass fiber reinforced plastics composites to obtain electrical conductivity. The CP composite has commonly good performances in various bending tests of block and pile specimens, comparing to the CF composite. The electrical resistance of the CP composite increases in a small strain to response remarkably micro-crack formation at about 200 μ strain and to detect well to smaller deformations before the crack formation. The CP composite posses a continuous resistance change up to a large strain level near the final fracture of concrete structures reinforced by steel bars. It has been concluded that the self-diagnosis composite is fairly useful for the measurement of damage and fracture in concrete blocks and piles.

  9. The Effect of Face Sheet Wrinkle Defects on the Strength of FRP Sandwich Structures

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Christian; Pettersson, Robert

    2007-01-01

    Wrinkle defects may reduce the compressive strength of a face laminate for in-plane loading applied perpendicularly to the line of the wrinkle. To be able to decide whether a repair is needed, it is necessary to know the magnitude of the strength reduction for a given wrinkle geometry....... In the studies reported here, the influence of wrinkle defects on the in-plane compressive strength of quasi-isotropic carbon fiber reinforced plastic (CFRP) laminates used in PVC foam-cored sandwich panels has been investigated by three approaches: testing of sandwich beam specimens in four-point bending......, testing of sandwich panels with inplane compression, and finite element simulation. Wrinkles involving different numbers of plies have been considered. Two different sandwich lay-ups typical of deck and hull bottom panels in naval ships have been included....

  10. 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.

  11. 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.

  12. Deformation mechanism of cold ring rolling in view of texture evolution predicted by a newly proposed polycrystal plasticity model%基于新晶体塑性模型预测织构演化的环件冷轧变形机制

    Institute of Scientific and Technical Information of China (English)

    李宏伟; 冯璐; 杨合

    2013-01-01

    An explicit polycrystal plasticity model was proposed to investigate the deformation mechanism of cold ring rolling in view of texture evolution. The model was created by deducing a set of linear incremental controlling equations within the framework of crystal plasticity theory. It was directly solved by a linear algorithm within a two-level procedure so that its efficiency and stability were guaranteed. A subroutine VUMAT for ABAQUS/Explicit was developed to combine this model with the 3D FE model of cold ring rolling. Results indicate that the model is reliable in predictions of stress-strain response and texture evolution in the dynamic complicated forming process; the shear strain in RD of the ring is the critical deformation mode according to the sharp Goss component ({110}〈100〉) of deformed ring; texture and crystallographic structure of the ring blank do not affect texture type of the deformed ring;texture evolves rapidly at the later stage of rolling, which results in a dramatically increasing deformation of the ring.%提出一种新的多晶体塑性模型以从织构演化角度研究环件冷轧过程的变形机制。该模型是在晶体塑性理论框架内通过推导一套线性增量控制方程建立的。该模型可以用线性求解方法直接求解,并采用一个两步法的求解过程,确保模型计算的效率和稳定性。基于ABAQUS/Explicit平台开发了用户材料子程序VUMAT,以实现该模型与环件冷轧三维有限元模型的结合。结果表明,该模型在预测动态复杂成形过程中的应力应变响应和织构演化方面都是可靠的;从轧制环件中很强的Goss织构{110}〈100〉看出,环件轧向的剪切变形是环件冷轧过程中的主要变形;环坯的织构和晶体结构对轧制环件中的织构类型的影响不大;在冷轧的后期环件织构演化迅速,这导致了这一时期环件的快速长大。

  13. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Science.gov (United States)

    2012-09-06

    ... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A... plastic parts. New information shows that Fortis Plastics is now called Carlyle Plastics and Resins. In... of Carlyle Plastics and Resins, formerly known as Fortis Plastics, a subsidiary of...

  14. The Thickness Design Calculation should be Paid Attention to during the Manufacture of Glass Fiber Reinforced Plastic Tank%玻璃钢储罐生产应重视厚度的设计计算

    Institute of Scientific and Technical Information of China (English)

    谢春良; 骆立刚

    2014-01-01

    Although the quantity of glass fiber reinforced plastic ( FRP) tank increases every year, the quality has not been improved simultaneously, the reasons mostly being insufficient wall thickness and low quality of internal and external surfaces arising from the negligence to relevant quality standards and the insufficient attention to tank thickness design calculation of manufacturing enterprises. Emphasizes the importance of the thickness design calculation of FRP tank and discusses the calculation method, which aims to help improve the quality of FRP tanks and therefore avoid potential accidents due to inferior tank quality.%我国玻璃钢储罐用量逐年增加,但其产品质量并没有同步提升。存在的主要问题是储罐壁厚不足和内外表面质量不符合要求等。原因在于设备制造企业对相关标准的忽视和对玻璃钢储罐厚度设计计算的不重视。强调了玻璃钢储罐厚度设计计算的重要性,并论述了其设计计算方法,以期对提高玻璃钢储罐产品质量及消除事故隐患有所帮助。

  15. Our plastic age

    National Research Council Canada - National Science Library

    Richard C. Thompson; Shanna H. Swan; Charles J. Moore; Frederick S. vom Saal

    2009-01-01

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production...

  16. Weinig plastic in vissenmaag

    NARCIS (Netherlands)

    Foekema, E.M.

    2012-01-01

    Waar de magen van sommige zeevogels vol plastic zitten, lijken vissen in de Noordzee nauwelijks last te hebben van kunststofafval. Onderzoekers die plastic resten zochten in vissenmagen vonden ze in elk geval nauwelijks.

  17. Ear Plastic Surgery

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  18. 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.

  19. 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

  20. 考虑墙体作用的低层冷弯薄壁型钢轻型房屋住宅体系弹塑性动力分析%ELASTIC-PLASTIC DYNAMIC ANALYSIS OF COLD-FORMED THIN-WALLED STEEL FRAMING SYSTEM OF LOW-RISE RESIDENTIAL BUILDINGS WITH COMPOSITE WALL

    Institute of Scientific and Technical Information of China (English)

    史艳莉; 王文达; 靳垚

    2012-01-01

    低层冷弯薄壁型钢结构住宅体系的抗震性能是进行该类结构推广应用的关键。该文基于ANSYS软件建立了该类结构体系的数值模型,在考虑冷弯薄型钢构件及门窗洞口加强与否、考虑组合墙体作用与否等情况下,分别进行了设防烈度为7度时常遇地震下的静力分析和弹性时程分析和设防烈度分别为7度、8度和9度时罕遇地震下的弹塑性时程分析。结果表明:常遇地震作用时结构弹性层间位移由风荷载控制,罕遇地震作用下结构弹塑性层问侧移则由地震作用控制;是否考虑组合墙体及墙面板材料特性对结构承载力、变形及抗震性能影响显著。在设防烈度分别为7度、8度和9度时的罕遇地震作用下,考虑组合墙体时结构最大弹塑性层间位移角可满足现行抗震规范(GB50011-2010)要求,双面OSB墙面板且角柱进行加强时抗震性能最好。该文结果可为进一步进行此类结构体系的抗震性能研究及应用提供参考。%The seismic behavior of the cold-formed thin-walled steel framing system of low-rise residential buildings is essential for their wide application. A numerical model was developed to simulate the performance of this type of structures using ANSYS. The steel members and the holes at doors or windows with or without the stiffened ribs, and the frames with or without composite walls were considered. Static and elastic dynamic time history analysis were performed under frequent earthquake based on the design earthquake intensity 7, and elastic-plastic dynamic time history analysis was performed under rare earthquake based on the design earthquake intensity 7, 8 and 9, respectively. It is shown that the elastic story-drift of the structure was determined by the wind loads mainly under the loading combination with frequent earthquake action, and the elastic-plastic story-drift was determined by the loading combination with rare

  1. Biodegradability of Plastics

    OpenAIRE

    Yutaka Tokiwa; Calabia, Buenaventurada P.; Charles U. Ugwu; Seiichi Aiba

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical ...

  2. Stored Energy of Plastic Deformation in Tube Bending Processes

    Science.gov (United States)

    Śloderbach, Z.; Pająk, J.

    2013-03-01

    The paper presents an aproximate analytic method for determination of the stored energy of plastic deformation during cold bending of metal tubes at bending machines. Calculations were performed for outer points of the tube layers subjected to tension and compression (the points of maximum strains). The percentage of stored energy related to the plastic strain work was determined and the results were presented in graphs. The influence and importance of the stored energy of plastic deformation on the service life of pipeline bends are discussed.

  3. Chemical Recycle of Plastics

    Directory of Open Access Journals (Sweden)

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  4. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example...

  5. THE RELATIONSHIP AMONG METABOLIC RATE OF TREE SHREWS (TUPAIA BELANGERI) UNDER COLD ACCLIMATION

    OpenAIRE

    Lin Zhang; Wenrong Gao; Wenxiu Jiang; Zhengkun Wang

    2012-01-01

    Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic rate (MMR). However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass ( Mb), basal metabolic rate (BMR), NST, and MMR on a tree shrews (Tupaia belangeri), acclimated to cold (5 ºC) conditions. NST was measured a...

  6. Biodegradability of plastics.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  7. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

  8. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  9. Journal of CHINA PLASTICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Journal of CHINA PLASTICS was authorized and approved by The State Committee of Science and Technology of China and The Bureau of News Press of China, and published by The China Plastics Processing Industry Association,Beijing Technology and Business University and The Institute of Plastics Processing and Application of Light Industry, distributed worldwide. Since its birth in 1987, CHINA PLASTICS has become a leading magazine in plastics industry in China, a national Chinese core journal and journal of Chinese scientific and technological article statistics. It is covered by CA.

  10. Challenges in plastics recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

    2015-01-01

    Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  11. Glassy metallic plastics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature (Tg~25oC to 150oC) and low Young’s modulus (~20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

  12. Standard practice for acoustic emission examination of pressurized containers made of fiberglass reinforced plastic with balsa wood cores

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers guidelines for acoustic emission (AE) examinations of pressurized containers made of fiberglass reinforced plastic (FRP) with balsa cores. Containers of this type are commonly used on tank trailers for the transport of hazardous chemicals. 1.2 This practice is limited to cylindrical shape containers, 0.5 m [20 in.] to 3 m [120 in.] in diameter, of sandwich construction with balsa wood core and over 30 % glass (by weight) FRP skins. Reinforcing material may be mat, roving, cloth, unidirectional layers, or a combination thereof. There is no restriction with regard to fabrication technique or method of design. 1.3 This practice is limited to containers that are designed for less than 0.520 MPa [75.4 psi] (gage) above static pressure head due to contents. 1.4 This practice does not specify a time interval between examinations for re-qualification of a pressure container. 1.5 This practice is used to determine if a container is suitable for service or if follow-up NDT is needed before that...

  13. 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.

  14. 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.

  15. 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。

  16. 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.

  17. 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.

  18. Cold Sores (HSV-1)

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Cold Sores (HSV-1) KidsHealth > For Teens > Cold Sores (HSV-1) A A A What's in this article? ... or around a person's lips, are caused by herpes simplex virus-1 (HSV-1) . But they don't ...

  19. Working in the Cold

    Centers for Disease Control (CDC) Podcasts

    2016-02-08

    During the winter, many workers are outdoors, working in cold, wet, icy, or snowy conditions. Learn how to identify symptoms that tell you there may be a problem and protect yourself from cold stress.  Created: 2/8/2016 by National Institute for Occupational Safety and Health (NIOSH).   Date Released: 2/8/2016.

  20. Cold fusion research

    Energy Technology Data Exchange (ETDEWEB)

    None

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  1. Cold-Weather Sports

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Cold-Weather Sports KidsHealth > For Teens > Cold-Weather Sports A A A What's in this article? ... Equipment Ahh, winter! Shorter days. Frigid temperatures. Foul weather. What better time to be outdoors? Winter sports ...

  2. Coping with Colds

    Science.gov (United States)

    ... have heard that chicken soup can cure a cold. There's no real proof of this, but sick people have been swearing by it for more than 800 years. When Should I Go to the Doctor? Teens who catch colds usually don't get very sick or need ...

  3. Plastic Pollution from Ships

    OpenAIRE

    Čulin, Jelena; Bielić, Toni

    2016-01-01

    The environmental impact of shipping on marine environment includes discharge of garbage. Plastic litter is of particular concern due to abundance, resistance to degradation and detrimental effect on marine biota. According to recently published studies, a further research is required to assess human health risk. Monitoring data indicate that despite banning plastic disposal at sea, shipping is still a source of plastic pollution. Some of the measures to combat the problem are discussed.

  4. Role of Friction in Cold Ring Rolling

    Institute of Scientific and Technical Information of China (English)

    He YANG; Lianggang GUO; Mei ZHAN

    2005-01-01

    Cold ring rolling is an advanced but complex metal forming process under coupled effects with multi-factors, such as geometry sizes of rolls and ring blank, material, forming process parameters and friction, etc. Among these factors,friction between rolls and ring blank plays animportant role in keeping the stable forming of cold ring rolling. An analytical method was firstly presented for proximately determining the critical friction coefficient of stable forming and then a method was proposed to determine thecritical friction coefficient by combining analytical method with numerical simulation. And the influence of friction coefficient on the quality of end-plane and side spread of ring,rolling force, rolling moment and metal flow characteristic in the cold ring rolling process have been explored using the three dimensional (3D) numerical simulation based on the elastic-plastic dynamic finite element method (FEM)under the ABAQUS software environment, and the results show that increasing the friction on the contact surfaces between rolls and ring blank is useful not only for improving the stability of cold ring rolling but also for improving the geometry and dimension precision of deformed ring.

  5. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plasti...... as a knowledge handbook for laser welding of plastic components. This document should provide the information for all aspects of plastic laser welding and help the design engineers to take all critical issues into consideration from the very beginning of the design phase....

  6. Plastics and health risks.

    Science.gov (United States)

    Halden, Rolf U

    2010-01-01

    By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics.

  7. Synaptic Plasticity and Nociception

    Institute of Scientific and Technical Information of China (English)

    ChenJianguo

    2004-01-01

    Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

  8. How Cold is Cold Dark Matter?

    CERN Document Server

    Armendariz-Picon, Cristian

    2013-01-01

    If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models, however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter. The latter imply that its velocity dispersion extrapolated to the present has to be smaller than 56 m/s. Cold dark matter has t...

  9. Influence of geometrical parameters on the flexural rigidity of the LHC dipole cold mass assembly

    CERN Document Server

    Bajko, M; Pardons, A

    2002-01-01

    In order to predict the mechanical behavior of the LHC dipole cold mass in situations such as handling, transport and cool down, a number of important structural parameters are required. The dipole's flexural rigidity determines entirely the mechanical elastic behavior of the cold mass. Therefore, models of a bent cold mass were created to calculate its rigidity. This paper presents a simplified parametric finite element model, created to study the deflection of the cold mass in different situations and supporting conditions. The sensitivity of the models to the supporting conditions is computed. To provide the finite element and the analytical models with input, the deflection of the cold mass under discrete loads in normal condition and then 90-degrees rotated were measured with a laser tracker. By comparing models with measurements, the vertical and transversal rigidity of the cold mass assembly are determined. Additionally, the paper reports on the plastic behavior of the cold mass assembly in the range o...

  10. Powder consolidation using cold spray process modeling and emerging applications

    CERN Document Server

    Moridi, Atieh

    2017-01-01

    This book first presents different approaches to modeling of the cold spray process with the aim of extending current understanding of its fundamental principles and then describes emerging applications of cold spray. In the coverage of modeling, careful attention is devoted to the assessment of critical and erosion velocities. In order to reveal the phenomenological characteristics of interface bonding, severe, localized plastic deformation and material jet formation are studied. Detailed consideration is also given to the effect of macroscopic defects such as interparticle boundaries and subsequent splat boundary cracking on the mechanical behavior of cold spray coatings. The discussion of applications focuses in particular on the repair of damaged parts and additive manufacturing in various disciplines from aerospace to biomedical engineering. Key aspects include a systematic study of defect shape and the ability of cold spray to fill the defect, examination of the fatigue behavior of coatings for structur...

  11. Halos of Plastic

    Institute of Scientific and Technical Information of China (English)

    Maya Reid

    2012-01-01

    The halos that span South Africa's coastline are anything but angelic. Fanning out around four major urban centers-Cape Town, Port Elizabeth, East London and Durban-they are made up of innumerable bits and pieces of plastic. As a form of pollution, their shelflife is unfathomable. Plastic is essentially chemically inactive. It's designed to never break down.

  12. Biodegradation of plastics.

    Science.gov (United States)

    Shimao, M

    2001-06-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  13. DESIGNERS’ KNOWLEDGE IN PLASTICS

    DEFF Research Database (Denmark)

    Eriksen, Kaare

    2013-01-01

    The Industrial designers’ knowledge in plastics materials and manufacturing principles of polymer products is very important for the innovative strength of the industry, according to a group of Danish plastics manufacturers, design students and practicing industrial designers. These three groups...... answered the first Danish national survey, PD13[1], investigating the importance of industrial designers’ knowledge in plastics and the collaboration between designers and the polymer industry. The plastics industry and the industrial designers collaborate well, but both groups frequently experience...... that the designers’ lack of knowledge concerning polymer materials and manufacturing methods can be problematic or annoying, and design students from most Danish design universities express the need for more contact with the industry and more competencies and tools to handle even simple topics when designing plastic...

  14. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  15. Cold Vacuum Drying Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Located near the K-Basins (see K-Basins link) in Hanford's 100 Area is a facility called the Cold Vacuum Drying Facility (CVDF).Between 2000 and 2004, workers at the...

  16. Cold-induced metabolism

    NARCIS (Netherlands)

    Lichtenbelt, W. van Marken; Daanen, H.A.M.

    2003-01-01

    Purpose of review Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering thermogenesis by sympathetic, norepinephrine-induced mitochondrial heat production in brown adipose tissue is a well known component of this metabolic

  17. The cold reading technique.

    Science.gov (United States)

    Dutton, D L

    1988-04-15

    For many people, belief in the paranormal derives from personal experience of face-to-face interviews with astrologers, palm readers, aura and Tarot readers, and spirit mediums. These encounters typically involve cold reading, a process in which a reader makes calculated guesses about a client's background and problems and, depending on the reaction, elaborates a reading which seems to the client so uniquely appropriate that it carries with it the illusion of having been produced by paranormal means. The cold reading process is shown to depend initially on the Barnum effect, the tendency for people to embrace generalized personality descriptions as idiosyncratically their own. Psychological research into the Barnum effect is critically reviewed, and uses of the effect by a professional magician are described. This is followed by detailed analysis of the cold reading performances of a spirit medium. Future research should investigate the degree to which cold readers may have convinced themselves that they actually possess psychic or paranormal abilities.

  18. A Cold Alarm

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Since the end of 2009, north China has been repeatedly struck by arctic-like blasts of cold weather. As temperatures have plummeted to historic lows, they have inflicted considerable suffering as well.

  19. A Cold Alarm

    Institute of Scientific and Technical Information of China (English)

    ZHOU JIANXIONG

    2010-01-01

    @@ Since the end of 2009, north China has been repeatedly struck by arctic-like blasts of cold weather. As temperatures have plummeted to historic lows, they have inflicted considerable suffering as well.

  20. Temperature-induced plasticity in egg size and resistance of eggs to temperature stress in a soil arthropod

    NARCIS (Netherlands)

    Liefting, M.; Weerenbeck, M.; Dooremalen, van C.; Ellers, J.

    2010-01-01

    Keywords:acclimation;cold shock;development rate;egg hatching;heat shock;phenotypic plasticity;Orchesella cincta;oviposition temperature Summary 1. Temperature is considered one of the most important mediators of phenotypic plasticity in ectotherms, resulting in predictable changes in egg size. Howe

  1. An experimental study of plastic deformation of materials

    DEFF Research Database (Denmark)

    Knudsen, Tine

    in the investigated hot deformed samples (lnZ= 27.5 to 32) in general are cell block structures, and that the alignment of the cell block boundaries at low strain depends on the grain orientation, often in the same manner as in cold deformation. Part II investigates the energy stored in the dislocation structure...... after cold deformation by calorimetry and by analysis of the dislocation structure. The stored energy measured by calorimetry is found to be larger than that determined from the dislocation structure by a factor between 1.9 and 2.7, and this factor decreases with the plastic strain. Part III aimed...

  2. Informative document waste plastics

    NARCIS (Netherlands)

    Nagelhout D; Sein AA; Duvoort GL

    1989-01-01

    This "Informative document waste plastics" forms part of a series of "informative documents waste materials". These documents are conducted by RIVM on the indstruction of the Directorate General for the Environment, Waste Materials Directorate, in behalf of the program of

  3. A Plastic Menagerie

    Science.gov (United States)

    Hadley, Mary Jane

    2010-01-01

    Bobble heads had become quite popular, depicting all sorts of sports figures, animals, and even presidents. In this article, the author describes how her fourth graders made bobble head sculptures out of empty plastic drink bottles. (Contains 1 online resource.)

  4. Cortical plasticity and rehabilitation.

    Science.gov (United States)

    Moucha, Raluca; Kilgard, Michael P

    2006-01-01

    The brain is constantly adapting to environmental and endogenous changes (including injury) that occur at every stage of life. The mechanisms that regulate neural plasticity have been refined over millions of years. Motivation and sensory experience directly shape the rewiring that makes learning and neurological recovery possible. Guiding neural reorganization in a manner that facilitates recovery of function is a primary goal of neurological rehabilitation. As the rules that govern neural plasticity become better understood, it will be possible to manipulate the sensory and motor experience of patients to induce specific forms of plasticity. This review summarizes our current knowledge regarding factors that regulate cortical plasticity, illustrates specific forms of reorganization induced by control of each factor, and suggests how to exploit these factors for clinical benefit.

  5. Mechanical plasticity of cells

    Science.gov (United States)

    Bonakdar, Navid; Gerum, Richard; Kuhn, Michael; Spörrer, Marina; Lippert, Anna; Schneider, Werner; Aifantis, Katerina E.; Fabry, Ben

    2016-10-01

    Under mechanical loading, most living cells show a viscoelastic deformation that follows a power law in time. After removal of the mechanical load, the cell shape recovers only incompletely to its original undeformed configuration. Here, we show that incomplete shape recovery is due to an additive plastic deformation that displays the same power-law dynamics as the fully reversible viscoelastic deformation response. Moreover, the plastic deformation is a constant fraction of the total cell deformation and originates from bond ruptures within the cytoskeleton. A simple extension of the prevailing viscoelastic power-law response theory with a plastic element correctly predicts the cell behaviour under cyclic loading. Our findings show that plastic energy dissipation during cell deformation is tightly linked to elastic cytoskeletal stresses, which suggests the existence of an adaptive mechanism that protects the cell against mechanical damage.

  6. Targeting tumour Cell Plasticity

    Institute of Scientific and Technical Information of China (English)

    Elizabeth D. WILLIAMS

    2009-01-01

    @@ Her research is focused on understanding the mechanisms of tumour progression and metastasis, particularly in uro-logical carcinomas (bladder and prostate). Tumour cell plasticity, including epithelial-mesenchymal transition, is a cen-tral theme in Dr Williams' work.

  7. Laser cutting plastic materials

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  8. Localization of plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Rice, J R

    1976-04-01

    The localization of plastic deformation into a shear band is discussed as an instability of plastic flow and a precursor to rupture. Experimental observations are reviewed, a general theoretical framework is presented, and specific calculations of critical conditions are carried out for a variety of material models. The interplay between features of inelastic constitutive description, especially deviations from normality and vertex-like yielding, and the onset of localization is emphasized.

  9. Development of plastic surgery

    Directory of Open Access Journals (Sweden)

    Pećanac Marija Đ.

    2015-01-01

    Full Text Available Introduction. Plastic surgery is a medical specialty dealing with corrections of defects, improvements in appearance and restoration of lost function. Ancient Times. The first recorded account of reconstructive plastic surgery was found in ancient Indian Sanskrit texts, which described reconstructive surgeries of the nose and ears. In ancient Greece and Rome, many medicine men performed simple plastic cosmetic surgeries to repair damaged parts of the body caused by war mutilation, punishment or humiliation. In the Middle Ages, the development of all medical braches, including plastic surgery was hindered. New age. The interest in surgical reconstruction of mutilated body parts was renewed in the XVIII century by a great number of enthusiastic and charismatic surgeons, who mastered surgical disciplines and became true artists that created new forms. Modern Era. In the XX century, plastic surgery developed as a modern branch in medicine including many types of reconstructive surgery, hand, head and neck surgery, microsurgery and replantation, treatment of burns and their sequelae, and esthetic surgery. Contemporary and future plastic surgery will continue to evolve and improve with regenerative medicine and tissue engineering resulting in a lot of benefits to be gained by patients in reconstruction after body trauma, oncology amputation, and for congenital disfigurement and dysfunction.

  10. Differential Metabolic Rearrangements after Cold Storage Are Correlated with Chilling Injury Resistance of Peach Fruits

    Science.gov (United States)

    Bustamante, Claudia A.; Monti, Laura L.; Gabilondo, Julieta; Scossa, Federico; Valentini, Gabriel; Budde, Claudio O.; Lara, María V.; Fernie, Alisdair R.; Drincovich, María F.

    2016-01-01

    Reconfiguration of the metabolome is a key component involved in the acclimation to cold in plants; however, few studies have been devoted to the analysis of the overall metabolite changes after cold storage of fruits prior to consumption. Here, metabolite profiling of six peach varieties with differential susceptibility to develop mealiness, a chilling-injury (CI) symptom, was performed. According to metabolic content at harvest; after cold treatment; and after ripening, either following cold treatment or not; peach fruits clustered in distinct groups, depending on harvest-time, cold treatment, and ripening state. Both common and distinct metabolic responses among the six varieties were found; common changes including dramatic galactinol and raffinose rise; GABA, Asp, and Phe increase; and 2-oxo-glutarate and succinate decrease. Raffinose content after long cold treatment quantitatively correlated to the degree of mealiness resistance of the different peach varieties; and thus, raffinose emerges as a candidate biomarker of this CI disorder. Xylose increase after cold treatment was found only in the susceptible genotypes, indicating a particular cell wall reconfiguration of these varieties while being cold-stored. Overall, results indicate that peach fruit differential metabolic rearrangements due to cold treatment, rather than differential metabolic priming before cold, are better related with CI resistance. The plasticity of peach fruit metabolism renders it possible to induce a diverse metabolite array after cold, which is successful, in some genotypes, to avoid CI. PMID:27746802

  11. Differential metabolic rearrangements after cold storage are correlated with chilling injury resistance of peach fruits

    Directory of Open Access Journals (Sweden)

    Claudia A Bustamante

    2016-09-01

    Full Text Available Reconfiguration of the metabolome is a key component involved in the acclimation to cold in plants; however, few studies have been devoted to the analysis of the overall metabolite changes after cold storage of fruits prior to consumption. Here, metabolite profiling of six peach varieties with differential susceptibility to develop mealiness, a chilling-injury (CI symptom, was performed. According to metabolic content at harvest; after cold treatment; and after ripening, either following cold treatment or not; peach fruits clustered in distinct groups, depending on harvest-time, cold treatment, and ripening state. Both common and distinct metabolic responses among the six varieties were found; common changes including dramatic galactinol and raffinose rise; GABA, Asp and Phe increase; and 2-oxo-glutarate and succinate decrease. Raffinose content after long cold treatment quantitatively correlated to the degree of mealiness resistance of the different peach varieties; and thus, raffinose emerges as a candidate biomarker of this CI disorder. Xylose increase after cold treatment was found only in the susceptible genotypes, indicating a particular cell wall reconfiguration of these varieties while being cold-stored. Overall, results indicate that peach fruit differential metabolic rearrangements due to cold treatment, rather than differential metabolic priming before cold, are better related with CI resistance. The plasticity of peach fruit metabolism renders it possible to induce a diverse metabolite array after cold, which is successful, in some genotypes, to avoid CI

  12. Differential Metabolic Rearrangements after Cold Storage Are Correlated with Chilling Injury Resistance of Peach Fruits.

    Science.gov (United States)

    Bustamante, Claudia A; Monti, Laura L; Gabilondo, Julieta; Scossa, Federico; Valentini, Gabriel; Budde, Claudio O; Lara, María V; Fernie, Alisdair R; Drincovich, María F

    2016-01-01

    Reconfiguration of the metabolome is a key component involved in the acclimation to cold in plants; however, few studies have been devoted to the analysis of the overall metabolite changes after cold storage of fruits prior to consumption. Here, metabolite profiling of six peach varieties with differential susceptibility to develop mealiness, a chilling-injury (CI) symptom, was performed. According to metabolic content at harvest; after cold treatment; and after ripening, either following cold treatment or not; peach fruits clustered in distinct groups, depending on harvest-time, cold treatment, and ripening state. Both common and distinct metabolic responses among the six varieties were found; common changes including dramatic galactinol and raffinose rise; GABA, Asp, and Phe increase; and 2-oxo-glutarate and succinate decrease. Raffinose content after long cold treatment quantitatively correlated to the degree of mealiness resistance of the different peach varieties; and thus, raffinose emerges as a candidate biomarker of this CI disorder. Xylose increase after cold treatment was found only in the susceptible genotypes, indicating a particular cell wall reconfiguration of these varieties while being cold-stored. Overall, results indicate that peach fruit differential metabolic rearrangements due to cold treatment, rather than differential metabolic priming before cold, are better related with CI resistance. The plasticity of peach fruit metabolism renders it possible to induce a diverse metabolite array after cold, which is successful, in some genotypes, to avoid CI.

  13. Sorting Plastic Waste in Hydrocyclone

    Directory of Open Access Journals (Sweden)

    Ernestas Šutinys

    2011-02-01

    Full Text Available The article presents material about sorting plastic waste in hydrocyclone. The tests on sorting plastic waste were carried out. Also, the findings received from the performed experiment on the technology of sorting plastic waste are interpreted applying an experimental model of the equipment used for sorting plastics of different density.Article in Lithuanian

  14. 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.

  15. Cold asymmetrical fermion superfluids

    Energy Technology Data Exchange (ETDEWEB)

    Caldas, Heron

    2003-12-19

    The recent experimental advances in cold atomic traps have induced a great amount of interest in fields from condensed matter to particle physics, including approaches and prospects from the theoretical point of view. In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Here we extend the analysis and verify that in fact, the mixed phase is the preferred ground state of an asymmetrical superfluid in various situations. We predict that the mixed phase can serve as a way of detecting superfluidity and estimating the magnitude of the gap parameter in asymmetrical fermionic systems.

  16. Cold nuclear fusion

    Directory of Open Access Journals (Sweden)

    Huang Zhenqiang Huang Yuxiang

    2013-10-01

    Full Text Available In normal temperature condition, the nuclear force constraint inertial guidance method, realize the combination of deuterium and tritium, helium and lithium... And with a magnetic moment of light nuclei controlled cold nuclear collide fusion, belongs to the nuclear energy research and development in the field of applied technology "cold nuclear collide fusion". According to the similarity of the nuclear force constraint inertial guidance system, the different velocity and energy of the ion beam mixing control, developed ion speed dc transformer, it is cold nuclear fusion collide, issue of motivation and the nuclear power plant start-up fusion and power transfer system of the important equipment, so the merger to apply for a patent

  17. Thermal Tolerance in Widespread and Tropical Drosophila Species: Does Phenotypic Plasticity Increase with Latitude?

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Kristensen, Torsten Nygård; Mitchell, Katherin A

    2011-01-01

    The distribution of insects can often be related to variation in their response to thermal extremes, which in turn may reflect differences in plastic responses or innate variation in resistance. Species with widespread distributions are expected to have evolved higher levels of plasticity than...... for environmental variation and phylogeny. Irrespective of acclimation, cold resistance was higher in the widespread species. Developmental cold acclimation simulating temperate conditions extended cold limits by 2–4C, whereas developmental heat acclimation under simulated tropical conditions increased upper...

  18. 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.

  19. Cold welding sealing of copper-water micro heat pipe ends

    Institute of Scientific and Technical Information of China (English)

    TANG Yong; LU Long-sheng; DENG Da-xiang; YUAN Dong

    2009-01-01

    The quality of micro heat pipe(MHP) is strongly affected by sealing technology. Based on the analysis of requirements of sealing technology, a cold welding technology was presented to seal MHP. In the cold welding process, compression force was used to flatten micro groove copper(MGC) tube. Then the bonding of MGC tube was reached because of intensively plastic deformation of MGC tube under pressure. It is found that the plastic deformation area of the cold welding of MGC tube can be divided into three sections. The deformation of micro grooves in each section was investigated; the influence of the dimensions of cylindrical heads on the weld joint shape and strength was studied; and a comparison between smooth copper tube and MGC tube was done. The results show that a groove compression stage exists in the cold welding of MGC tube besides a flattened stage and a melting stage.

  20. Cold regions isotope applications

    Energy Technology Data Exchange (ETDEWEB)

    Perrigo, L.D.; Divine, T.E.

    1976-04-01

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids. (TFD)

  1. Commemoration of a cold war

    DEFF Research Database (Denmark)

    Farbøl, Rosanna

    2015-01-01

    This article brings together the fields of Cold War studies and memory studies. In Denmark, a remarkable institutionalisation of Cold War memory has taken place in the midst of a heated ideological battle over the past and whether to remember the Cold War as a ‘war’. Using Danish Cold War museums...... and heritage sites as case studies, this article sheds new light on the politics of history involved in Cold War commemoration. It suggests that the Cold War is commemorated as a war, yet this war memory is of a particular kind: it is a war memory without victims....

  2. Detection of cold pain, cold allodynia and cold hyperalgesia in freely behaving rats

    Directory of Open Access Journals (Sweden)

    Woolf Clifford J

    2005-12-01

    Full Text Available Abstract Background Pain is elicited by cold, and a major feature of many neuropathic pain states is that normally innocuous cool stimuli begin to produce pain (cold allodynia. To expand our understanding of cold induced pain states we have studied cold pain behaviors over a range of temperatures in several animal models of chronic pain. Results We demonstrate that a Peltier-cooled cold plate with ± 1°C sensitivity enables quantitative measurement of a detection withdrawal response to cold stimuli in unrestrained rats. In naïve rats the threshold for eliciting cold pain behavior is 5°C. The withdrawal threshold for cold allodynia is 15°C in both the spared nerve injury and spinal nerve ligation models of neuropathic pain. Cold hyperalgesia is present in the spared nerve injury model animals, manifesting as a reduced latency of withdrawal response threshold at temperatures that elicit cold pain in naïve rats. We also show that following the peripheral inflammation produced by intraplantar injection of complete Freund's adjuvant, a hypersensitivity to cold occurs. Conclusion The peltier-cooled provides an effective means of assaying cold sensitivity in unrestrained rats. Behavioral testing of cold allodynia, hyperalgesia and pain will greatly facilitate the study of the neurobiological mechanisms involved in cold/cool sensations and enable measurement of the efficacy of pharmacological treatments to reduce these symptoms.

  3. Cold spray nozzle design

    Science.gov (United States)

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  4. Finger cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.

    2007-01-01

    There are indications that subjects with a reduced finger CIVD response are more prone to get local cold injuries, but more epidemiological research is needed to establish a firm relationship. Although it was observed that an early CIVD onset was associated with initially superior manual performance

  5. Teaching "In Cold Blood."

    Science.gov (United States)

    Berbrich, Joan D.

    1967-01-01

    The Truman Capote nonfiction novel, "In Cold Blood," which reflects for adolescents the immediacy of the real world, illuminates (1) social issues--capital punishment, environmental influence, and the gap between the "haves" and "have-nots," (2) moral issues--the complexity of man's nature, the responsibility of one…

  6. Cold Weather Pet Safety

    Science.gov (United States)

    ... they can be knocked over, potentially starting a fire. Check your furnace before the cold weather sets in to make ... avoided because of the risk of burns or fire. Heated pet mats should also be used ... to burrow, get them back inside quickly because they are showing signs of ...

  7. Cold-induced metabolism

    NARCIS (Netherlands)

    Lichtenbelt, W. van Marken; Daanen, H.A.M.

    2003-01-01

    Purpose of review Cold response can be insulative (drop in peripheral temperature) or metabolic (increase in energy expenditure). Nonshivering thermogenesis by sympathetic, norepinephrine-induced mitochondrial heat production in brown adipose tissue is a well known component of this metabolic respon

  8. Chilling Out With Colds

    Science.gov (United States)

    ... some feel-better tips if you get a cold: Bring on the heat. Hot drinks soothe coughs and sore throats while also clearing mucus. So eat (or drink) your chicken soup! Get steamed up. A steamy shower helps stuffy or irritated noses. Or run a ...

  9. Out in the cold.

    Science.gov (United States)

    Bates, Jane

    2016-05-04

    Every now and then, you say something to a patient and wonder whether you should have kept quiet. On this occasion, a female patient and I were indulging in a moment of shared empathy over an annoying symptom we both experience - permanently cold feet.

  10. Cold War Propaganda.

    Science.gov (United States)

    Bennett, Paul W.

    1988-01-01

    Briefly discusses the development of Cold War propaganda in the United States, Canada, and the USSR after 1947. Presents two movie reviews and a Canadian magazine advertisement of the period which illustrate the harshness of propaganda used by both sides in the immediate postwar years. (GEA)

  11. Recent Cold War Studies

    Science.gov (United States)

    Pineo, Ronn

    2003-01-01

    Cold War historiography has undergone major changes since the 1991 collapse of the Soviet Union. For two years (1992-1993) the principal Soviet archives fell open to scholars, and although some of the richest holdings are now once again closed, new information continues to find its way out. Moreover, critical documentary information has become…

  12. Impact of plastics on fate and transport of organic contaminants in landfills.

    Science.gov (United States)

    Saquing, Jovita M; Saquing, Carl D; Knappe, Detlef R U; Barlaz, Morton A

    2010-08-15

    Factors controlling organic contaminant sorption to common plastics in municipal solid waste were identified. Consumer plastics [drinking water container, prescription drug bottle, soda bottle, disposable cold cup, computer casing, furniture foam, carpet, vinyl flooring, formica sheet] and model polymers [high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene, poly(vinyl chloride) (PVC)] were characterized by X-ray diffractometry, differential scanning calorimetry, and elemental analysis. The material characterization was used to interpret batch isotherm and kinetic data. K(p) values describing toluene sorption to rubbery or "soft" polymers could be normalized by the amorphous polymer fraction (f(amorphous)) but not by the organic carbon fraction (f(oc)). Diffusion coefficients (D) describing the uptake rate of toluene by rubbery plastics (HDPE, drinking water container, prescription drug bottle) were similar (D approximately 10(-10) cm(2)/s), indicating that pure HDPE can be used as a model for rubbery plastics. Toluene diffusivity was similar among glassy or "hard" plastics (PVC, soda bottle, computer casing, disposable cold cup; D approximately 10(-12) cm(2)/s) but lower than for rubbery plastics. Plastics in landfills are potential sinks of hydrophobic organic contaminants (HOCs) because of their higher affinity for HOCs compared to lignocellulosic materials and the slow desorption of HOCs from glassy plastics.

  13. A density-dependent endochronic plasticity for powder compaction processes

    Science.gov (United States)

    Bakhshiani, A.; Khoei, A. R.; Mofid, M.

    This paper is concerned with the numerical modeling of powder cold compaction process using a density-dependent endochronic plasticity model. Endochronic plasticity theory is developed based on a large strain plasticity to describe the nonlinear behavior of powder material. The elastic response is stated in terms of hypoelastic model and endochronic plasticity constitutive equations are stated in unrotated frame of reference. A trivially incrementally objective integration scheme for rate constitutive equations is established. Algorithmic modulus consistent with numerical integration algorithm of constitutive equations is extracted. It is shown how the endochronic plasticity describes the behavior of powder material from the initial stage of compaction to final stage, in which material behaves as solid metals. It is also shown that some commonly used plasticity models for powder material can be derived as special cases of the proposed endochronic theory. Finally, the numerical schemes are examined for efficiency in the modeling of a plain bush, a rotational-flanged and a shaped tablet powder compaction component.

  14. Dynamic Plasticity and Fracture in High Density Polycrystals: Constitutive Modeling and Numerical Simulation

    Science.gov (United States)

    2006-09-01

    polycrystalline WHA specimens on the response under combined compressive -shear loading and found that a certain degree of pre-twisting of the...conducted via isostatic pressing and sintering of a mixture of W, Ni, and Fe powders, followed by annealing to remove absorbed hydrogen and then possible...this ‘‘stored energy of cold work’’ can be viewed as an extension to finite crystal plasticity theory of the macroscopic, linearized elastic–plastic

  15. Herpes Simplex Virus (Cold Sores)

    Science.gov (United States)

    ... Print Share Cold Sores in Children: About the Herpes Simplex Virus Page Content ​A child's toddler and ... Cold sores (also called fever blisters or oral herpes) start as small blisters that form around the ...

  16. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is

  17. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is re

  18. Research on Installation Construction Techniques of Subsea Socket Type Fiberglass Reinforced Plastic Pipelines%海底承插式玻璃钢管道安装施工工艺研究

    Institute of Scientific and Technical Information of China (English)

    上育平; 寇君淑; 房海勃; 李明亮

    2014-01-01

    The installation of large diameter glass reinforced plastic pipes(FRP)under the sea is affected by sea waves , tidal range ,ocean current and seabed geology and so on ,so the construction is difficult with high risks .According to the installation engineering characteristics of large diameter FRP pipes in Sihanouk ,Kampuchea power plant ,the Hough joints were assembled onshore and then the socket joints were connected subsea .During the installation of FRP ,it is very important to control the installation accuracy of the joints ,as well as the construction quality of subsea pipe connection and sealing .The construction result is satisfactory ,which provides some referential value for tsimilar engineering pro-jects .%海底大直径玻璃钢管安装受海上风浪、潮差、海流及海床地质等因素影响,操作技术难度大,操作风险极高。针对柬埔寨西哈努克市火电厂海底大直径玻璃钢管安装工程的特点,采用岸上哈夫接头拼装,水下承插接头安装的施工方法进行安装。在施工中,重点控制岸上接头安装精度、水下管道连接与密封工艺施工质量,取得了很好的效果。本工程施工质量控制措施可为类似工程施工提供重要的技术参考。

  19. SABIC Innovative Plastics: Be the World Best Plastic Resin Manufacturer

    Institute of Scientific and Technical Information of China (English)

    Jenny Du

    2007-01-01

    @@ "SABIC Innovative Plastics is a global supplier of plastic resins, manufacturing and compounding polycarbonate, ABS, SAN, ASA, PPE, PC/ABS, PBT and PEI resins, as well as the LNP* line of high performance specialty compounds," said Hiroshi Yoshida, the Global Market Director for Electronics of SABIC Innovative Plastics based in Tokyo at the press conference held by SABIC Innovative Plastics, November 8th 2007, Shanghai.

  20. Plasticity in thermal tolerance has limited potential to buffer ectotherms from global warming.

    Science.gov (United States)

    Gunderson, Alex R; Stillman, Jonathon H

    2015-06-07

    Global warming is increasing the overheating risk for many organisms, though the potential for plasticity in thermal tolerance to mitigate this risk is largely unknown. In part, this shortcoming stems from a lack of knowledge about global and taxonomic patterns of variation in tolerance plasticity. To address this critical issue, we test leading hypotheses for broad-scale variation in ectotherm tolerance plasticity using a dataset that includes vertebrate and invertebrate taxa from terrestrial, freshwater and marine habitats. Contrary to expectation, plasticity in heat tolerance was unrelated to latitude or thermal seasonality. However, plasticity in cold tolerance is associated with thermal seasonality in some habitat types. In addition, aquatic taxa have approximately twice the plasticity of terrestrial taxa. Based on the observed patterns of variation in tolerance plasticity, we propose that limited potential for behavioural plasticity (i.e. behavioural thermoregulation) favours the evolution of greater plasticity in physiological traits, consistent with the 'Bogert effect'. Finally, we find that all ectotherms have relatively low acclimation in thermal tolerance and demonstrate that overheating risk will be minimally reduced by acclimation in even the most plastic groups. Our analysis indicates that behavioural and evolutionary mechanisms will be critical in allowing ectotherms to buffer themselves from extreme temperatures.

  1. VISUAL SIMULATION OF COLD ROLL-FORMING BASED ON OBJECT ORIENTED PROGRAMMING

    Institute of Scientific and Technical Information of China (English)

    Zhang Lele; Tan Nanlin; Zhang Huadi; Liu Cai

    2004-01-01

    To simulate the process of cold roll-forming process, a new method is adopted.The theoretical foundation of this method is an elastic-plastic large deformation spline finite strip method based on object-oriented programming.Combined with the computer graphics technology, the visual simulation of cold roll-forming is completed and the system is established.By analyzing common channel steel, the process is shown and explained including theory method, model and result display.So the simulation system is already a kind of mature and effective tool to analyze the process of cold roll forming.

  2. Preserving in Plastic.

    Science.gov (United States)

    Wahla, James

    1985-01-01

    Outlines steps for casting insects in permanent molds prepared from commercially available liquid plastic. Also describes dry mountings in glass, acrylic, and petri dishes. The rationale for specimen use, hints for producing quality results, purchasing information, and safety precautions are considered. (DH)

  3. Informative document waste plastics

    NARCIS (Netherlands)

    Nagelhout D; Sein AA; Duvoort GL

    1989-01-01

    This "Informative document waste plastics" forms part of a series of "informative documents waste materials". These documents are conducted by RIVM on the indstruction of the Directorate General for the Environment, Waste Materials Directorate, in behalf of the program of acti

  4. Discrete dislocation plasticity

    NARCIS (Netherlands)

    van der Giessen, E.; Finel, A; Maziere, D; Veron, M

    2003-01-01

    Conventional continuum mechanics models of inelastic deformation processes axe size scale independent. In contrast, there is considerable experimental evidence that plastic flow in crystalline materials is size dependent over length scales of the order of tens of microns and smaller. At present ther

  5. Progress in neural plasticity

    Institute of Scientific and Technical Information of China (English)

    POO; Mu-Ming

    2010-01-01

    One of the properties of the nervous system is the use-dependent plasticity of neural circuits.The structure and function of neural circuits are susceptible to changes induced by prior neuronal activity,as reflected by short-and long-term modifications of synaptic efficacy and neuronal excitability.Regarded as the most attractive cellular mechanism underlying higher cognitive functions such as learning and memory,activity-dependent synaptic plasticity has been in the spotlight of modern neuroscience since 1973 when activity-induced long-term potentiation(LTP) of hippocampal synapses was first discovered.Over the last 10 years,Chinese neuroscientists have made notable contributions to the study of the cellular and molecular mechanisms of synaptic plasticity,as well as of the plasticity beyond synapses,including activity-dependent changes in intrinsic neuronal excitability,dendritic integration functions,neuron-glia signaling,and neural network activity.This work highlight some of these significant findings.

  6. New plastic recycling technology

    Science.gov (United States)

    Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy de...

  7. Persisting Plastic Addiction

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The policy on curbing plastic shopping bag use implemented three years ago has produced mixed results In a bustling farmers’market tucked in a narrow street in Xisanqi residential community in north Beijing,stalls selling vegetables,fruits and other foods line the sidewalk.

  8. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan

    2013-01-01

    opportunities to design new products through joining dissimilar materials. This paper aims to provide an overview of the state of the art in such joining processes, including cold welding, friction stir welding, self-pierce riveting, mechanical clinching and joining by forming. The paper includes description...... of the mechanism of joint formation, and analysis of joint performance and applicability. © 2013 CIRP....

  9. 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。

  10. WISPy cold dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica; Cadamuro, Davide; Redondo, Javier [Max-Planck-Institut fuer Physik, Muenchen (Germany); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2012-01-15

    Very weakly interacting slim particles (WISPs), such as axion-like particles (ALPs) or hidden photons (HPs), may be non-thermally produced via the misalignment mechanism in the early universe and survive as a cold dark matter population until today. We find that, both for ALPs and HPs whose dominant interactions with the standard model arise from couplings to photons, a huge region in the parameter spaces spanned by photon coupling and ALP or HP mass can give rise to the observed cold dark matter. Remarkably, a large region of this parameter space coincides with that predicted in well motivated models of fundamental physics. A wide range of experimental searches - exploiting haloscopes (direct dark matter searches exploiting microwave cavities), helioscopes (searches for solar ALPs or HPs), or light-shining-through-a-wall techniques - can probe large parts of this parameter space in the foreseeable future. (orig.)

  11. "Miniature Cold War?"

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Fu: Relations between America and Russia are one of the most important bilateral ties that could affect the trend of world situation.What's the matter with U. S. -Russia ties? What's wrong with their bilateral relations? People tend to ask these days. Some observers on both sides suggest that post 9/11 honeymoon has turned sour when joint effort against challenges from nontraditional security issues failed to remove original bilateral contradictions over traditional security concerns.Japanese Jiji News Agency saw "a miniature Cold War" evolving and the British Guardian even bluntly pronounced "a new Cold War" on January 3, asserting that disintegration of the former Soviet Union did not terminate bilateral contention, which has only been performed on an international stage more complicated than ever before, with covert scheming against each other replacing overt, direct confrontation. How about starting our discussion with those comments?

  12. Engine Cold Start

    Science.gov (United States)

    2015-09-01

    14. ABSTRACT These fuels were used for testing a GEP 6.5L turbocharged V-8 diesel engine operation in a cold box. This engine architecture is... engines . The U.S. military currently uses petroleum-based jet fuels in diesel engine -powered ground vehicles and is studying the use of alternative jet...to identify a window, or range, of cetane number which would be acceptable to ensure the reliable operation of diesel engine -powered military ground

  13. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  14. The CMS COLD BOX

    CERN Multimedia

    Brice, Maximilien

    2015-01-01

    The CMS detector is built around a large solenoid magnet. This takes the form of a cylindrical coil of superconducting cable that generates a field of 3.8 Tesla: about 100,000 times the magnetic field of the Earth. To run, this superconducting magnet needs to be cooled down to very low temperature with liquid helium. Providing this is the job of a compressor station and the so-called “cold box”.

  15. 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.

  16. Numerical Analysis of a Cold Plate for FM Radio Power Amplifiers

    Science.gov (United States)

    Sabin, M.; Piva, S.

    2014-07-01

    The results of a numerical investigation of heat and fluid flow in a liquid cold plate for FM radio power amplifiers are presented. The objective is to verify, by using a commercial CFD code, the performance of a blister cold plate designed to dissipate the heat generated by a known set of electronic components, in order to limit their maximum temperature during operations. Since in a blister cold-plate mainly the cover is thermally active, the cold-plate is simplified and lightened by using plastics in the base plate. A 3-D conjugate CFD approach, where thermal and fluid flow analyses are combined, is followed. Several design options for the cold plate are examined and the validity of the full 3-D CFD approach in the dimensioning of the cooling systems of electronic equipment is demonstrated.

  17. A QSPR for the plasticization efficiency of polyvinylchloride plasticizers.

    Science.gov (United States)

    Chandola, Mridula; Marathe, Sujata

    2008-01-01

    A simple quantitative structure property relationship (QSPR) for correlating the plasticization efficiency of 25 polyvinylchloride (PVC) plasticizers was obtained using molecular modeling. The plasticizers studied were-aromatic esters (phthalate, terephthalate, benzoate, trimellitate), aliphatic esters (adipate, sebacate, azelate), citrates and a phosphate. The low temperature flex point, Tf, of plasticized polyvinylchloride resins was considered as an indicator of plasticization efficiency. Initially, we attempted to predict plasticization efficiency of PVC plasticizers from physical and structural descriptors derived from the plasticizer molecule alone. However, the correlation of these descriptors with Tf was not very good with R=0.78 and r2=0.613. This implied that the selected descriptors were unable to predict all the interactions between PVC and plasticizer. Hence, to account for these interactions, a model containing two polyvinylchloride (PVC) chain segments along with a plasticizer molecule in a simulation box was constructed, using molecular mechanics. A good QSPR equation correlating physical and structural descriptors derived from the model to Tf of the plasticized resins was obtained with R=0.954 and r2=0.909.

  18. Plastic fiber scintillator response to fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Danly, C. R.; Sjue, S.; Wilde, C. H.; Merrill, F. E.; Haight, R. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    2014-11-15

    The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented.

  19. 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

  20. Bond slip and crack development in FRC and regular concrete specimens longitudinally reinforced with FRP or steel under tension loading

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi; Fischer, Gregor

    2012-01-01

    tensile loading using high definition image analysis in two unique test setups. Two different types of cementitious materials, conventional concrete and highly ductile Engineered Cementitious Composite (ECC), and two types of reinforcement bars, regular steel and Glass Fiber Reinforcement Polymer (GFRP......The governing mechanism in the structural response of reinforced concrete members in tension is the interaction between structural reinforcement and the surrounding concrete matrix. The composite response and the mechanical integrations of reinforced cementitious members were investigated during......), were tested. It was found that the ductile ECC in contrast to regular brittle concrete decreases crack widths significantly which effectively results in decreased bond slip between the reinforcement and surrounding matrix. Furthermore the use of elastic GFRP in comparison to elastic/plastic steel...

  1. X-ray residual stress measurements on cold-drawn steel wire

    NARCIS (Netherlands)

    Willemse, P.F.; Naughton, B.P.; Verbraak, C.A.

    1982-01-01

    The interplanar spacing d{hkl} versus sin2 ψ distributions were measured for the 211, 310, 220 and 200 reflections from severely cold-drawn 0.7% C steel wire with a diameter of 0.25 mm. From the shape of the curves it was concluded that, as well as a 110 fibre texture and elastic anisotropy, plastic

  2. X-ray residual stress measurements on cold-drawn steel wire

    NARCIS (Netherlands)

    Willemse, P.F.; Naughton, B.P.; Verbraak, C.A.

    1982-01-01

    The interplanar spacing d{hkl} versus sin2 ψ distributions were measured for the 211, 310, 220 and 200 reflections from severely cold-drawn 0.7% C steel wire with a diameter of 0.25 mm. From the shape of the curves it was concluded that, as well as a 110 fibre texture and elastic anisotropy, plastic

  3. Sustainable reverse logistics for household plastic waste

    OpenAIRE

    Bing, X

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than that of virgin plastics. Therefore, it is environmentally and economically beneficial to improve the plastic recycling system to ensure more plastic waste from households is properly collected and pr...

  4. Plasticity modeling & computation

    CERN Document Server

    Borja, Ronaldo I

    2013-01-01

    There have been many excellent books written on the subject of plastic deformation in solids, but rarely can one find a textbook on this subject. “Plasticity Modeling & Computation” is a textbook written specifically for students who want to learn the theoretical, mathematical, and computational aspects of inelastic deformation in solids. It adopts a simple narrative style that is not mathematically overbearing, and has been written to emulate a professor giving a lecture on this subject inside a classroom. Each section is written to provide a balance between the relevant equations and the explanations behind them. Where relevant, sections end with one or more exercises designed to reinforce the understanding of the “lecture.” Color figures enhance the presentation and make the book very pleasant to read. For professors planning to use this textbook for their classes, the contents are sufficient for Parts A and B that can be taught in sequence over a period of two semesters or quarters.

  5. Low temperature creep plasticity

    Directory of Open Access Journals (Sweden)

    Michael E. Kassner

    2014-07-01

    Full Text Available The creep behavior of crystalline materials at low temperatures (T < 0.3Tm is discussed. In particular, the phenomenological relationships that describe primary creep are reviewed and analyzed. A discussion of the activation energy for creep at T < 0.3Tm is discussed in terms of the context of higher temperature activation energy. The basic mechanism(s of low temperature creep plasticity are discussed, as well.

  6. Nanocrystalline Metal Hydrides Obtained by Severe Plastic Deformations

    Directory of Open Access Journals (Sweden)

    Jacques Huot

    2012-01-01

    Full Text Available It has recently been shown that Severe Plastic Deformation (SPD techniques could be used to obtain nanostructured metal hydrides with enhanced hydrogen sorption properties. In this paper we review the different SPD techniques used on metal hydrides and present some specific cases of the effect of cold rolling on the hydrogen storage properties and crystal structure of various types of metal hydrides such as magnesium-based alloys and body centered cubic (BCC alloys. Results show that generally cold rolling is as effective as ball milling to enhance hydrogen sorption kinetics. However, for some alloys such as TiV0.9Mn1.1 alloy ball milling and cold rolling have detrimental effect on hydrogen capacity. The exact mechanism responsible for the change in hydrogenation properties may not be the same for ball milling and cold rolling. Nevertheless, particle size reduction and texture seems to play a leading role in the hydrogen sorption enhancement of cold rolled metal hydrides.

  7. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Ocean thermal energy conversion cold water pipe preliminary design project. Task 2. Analysis for concept selection

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-01

    The successful performance of the CWP is of crucial importance to the overall OTEC system; the pipe itself is considered the most critical part of the entire operation. Because of the importance the CWP, a project for the analysis and design of CWP's was begun in the fall of 1978. The goals of this project were to study a variety of concepts for delivering cold water to an OTEC plant, to analyze and rank these concepts based on their relative cost and risk, and to develop preliminary design for those concepts which seemed most promising. Two representative platforms and sites were chosen: a spar buoy of a Gibbs and Cox design to be moored at a site off Punta Tuna, Puerto Rico, and a barge designed by APL/Johns Hopkins University, grazing about a site approximately 200 miles east of the coast of Brazil. The approach was to concentrate on the most promising concepts and on those which were either of general interest or espoused by others (e.g., steel and concrete concepts). Much of the overall attention, therefore, focused on analyzing rigid and compliant wall design, while stockade (except for the special case of the FRP stockade) and bottom-mounted concepts received less attention. A total of 67 CWP concepts were initially generated and subjected to a screening process. Of these, 16 were carried through design analysis, costing, and ranking. Study results are presented in detail. (WHK)

  9. Microelectronics plastic molded packaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R. [Ktech Corp., Albuquerque, NM (United States); Palmer, D.W.; Peterson, D.W. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  10. Paroxysmal cold hemoglobinuria.

    Science.gov (United States)

    Shanbhag, Satish; Spivak, Jerry

    2015-06-01

    Paroxysmal cold hemoglobinuria is a rare cause of autoimmune hemolytic anemia predominantly seen as an acute form in young children after viral illnesses and in a chronic form in some hematological malignancies and tertiary syphilis. It is a complement mediated intravascular hemolytic anemia associated with a biphasic antibody against the P antigen on red cells. The antibody attaches to red cells at colder temperatures and causes red cell lysis when blood recirculates to warmer parts of the body. Treatment is mainly supportive and with red cell transfusion, but immunosuppressive therapy may be effective in severe cases.

  11. Exception in Cold War

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ In the Cold War, India mainly focused its Southeast Asia Strategy on preserving the regional peace and stability, fearing that changes in Southeast Asia would impact India. Generally speaking, India would like to see a relatively strong, stable and independent Southeast Asia, which would guarantee the stability of its east wing. However, fettered by its limited power, its non-alignment policy and its special relation with Soviet Union, India's policy toward Southeast Asia remained relatively passive and its relation with Southeast Asia was, to some extent, trapped in a historical "intermission."

  12. 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.

  13. Crystal plasticity modeling of through-thickness texture heterogeneity in heavily rolled aluminum

    DEFF Research Database (Denmark)

    Delannay, Laurent; Mishin, Oleg V.

    2013-01-01

    The textures measured at different depths inside a cold rolled aluminium sheet are compared to results obtained by crystal plasticity predictions. Different assumptions about the micro-to-macro scale transitions are considered. The input texture reveals a through-thickness gradient that originate...

  14. Interfacial interactions between plastic particles in plastics flotation.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.

  15. Electrochemically enhanced surface plasticity of steels

    Science.gov (United States)

    Gutman, E. M.; Unigovski, Ya.; Shneck, R.; Ye, F.; Liang, Y.

    2016-12-01

    There are serious problems with the formability of alloys which are relatively hard and brittle below ambient temperatures, e.g., in cold extrusion and drawing processes. It is known that electrochemical surface treatment can decrease residual stresses and hardness of the surface layer as a result of the chemomechanical effect (CME), and also improve the plastic deformation ability, e.g., deep drawing of high-strength alloys. Plastic deformation ability of materials can be characterized by hardness measurements. The present study shows some possibilities to improve the surface ductility of carbon steels and FeSi6.5 steel under anodic polarization depending on the current density, composition and pH of acids and chloride electrolytes. The relative Vickers hardness (RVH) amounting to a squared ratio of the penetration depth of a cone indenter in air as compared to that in a solution (hair/hsol)2 was found as a function of the current density and the electrolyte composition. A decrease in hardness of the surface layer as a result of anodic electrochemical polarization was found for different steels.

  16. 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.

  17. Use of recycled plastics in wood plastic composites - a review.

    Science.gov (United States)

    Kazemi Najafi, Saeed

    2013-09-01

    The use of recycled and waste thermoplastics has been recently considered for producing wood plastic composites (WPCs). They have great potential for WPCs manufacturing according to results of some limited researches. This paper presents a detailed review about some essential properties of waste and recycled plastics, important for WPCs production, and of research published on the effect of recycled plastics on the physical and mechanical properties of WPCs.

  18. Direct liquefaction of plastics and coprocessing of coal with plastics

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, G.P.; Feng, Z.; Mahajan, V. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-31

    The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In the coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.

  19. Plastic Surgery and Suicide: A Clinical Guide for Plastic Surgeons.

    Science.gov (United States)

    Reddy, Vikram; Coffey, M Justin

    2016-08-01

    Several studies have identified an increased risk of suicide among patient populations which a plastic surgeon may have a high risk of encountering: women undergoing breast augmentation, cosmetic surgery patients, and breast cancer patients. No formal guidelines exist to assist a plastic surgeon when faced with such a patient, and not every plastic surgery team has mental health clinicians that are readily accessible for consultation or referral. The goal of this clinical guide is to offer plastic surgeons a set of practical approaches to manage potentially suicidal patients. In addition, the authors review a screening tool, which can assist surgeons when encountering high-risk patients.

  20. 浅述玻璃钢制品质量控制%Research on the Quality Control of Fibre Reinforced Plastic Product

    Institute of Scientific and Technical Information of China (English)

    陈瑛卿

    2012-01-01

      Fibre-reinforced plastic (FRP) (also fibre-reinforced polymer) is a composite material made of a polymer matrix reinforced with fibres, which with light quality and high intensity. At present, the integrated quality control system of fibre reinforced plastic technics still not been established in China, to insure the product quality of fibre reinforced plastic, some measures must be taken from the technical training of perspnnel, quality control of raw materials, process control of manufacturing and quality control of final product.%  玻璃钢是一种高性能的纤维增强树脂基复合材料,轻质高强。目前我国的玻璃钢工业尚未建立起完整的质量控制体系,为了确保玻璃钢产品的质量,必须从人员的技术培训、原材料的质量把关,制造过程的工艺控制和成品控制等几方面入手。

  1. Tree plastic bark

    OpenAIRE

    Casado Arroyo, Carlos

    2016-01-01

    “Tree plastic bark" consiste en la realización de una intervención artística en un entorno natural concreto, generando de esta manera un Site Specific(1). Como hace alusión Rosalind Krauss en sus reflexiones “La escultura en el campo expandido”(2), comenta que su origen esta claramente ligado con el concepto de monumentalidad. La escultura es un monumento, se crea para conmemorar algún hecho o personaje relevante y está realizada para una ubicación concreta. La investigación parte de la id...

  2. Fabrication of plastic biochips

    Energy Technology Data Exchange (ETDEWEB)

    Saaem, Ishtiaq; Ma, Kuo-Sheng; Alam, S. Munir; Tian Jingdong [Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States); Department of Medicine and Human Vaccine Institute, Duke University, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering and Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina 27708 (United States)

    2010-07-15

    A versatile surface functionalization procedure based on rf magnetron sputtering of silica was performed on poly(methylmethacrylate), polycarbonate, polypropylene, and cyclic olefin copolymers (Topas 6015). The hybrid thermoplastic surfaces were characterized by x-ray photoelectron spectrometer analysis and contact angle measurements. The authors then used these hybrid materials to perform a sandwich assay targeting an HIV-1 antibody using fluorescent detection and biotinylated peptides immobilized using the bioaffinity of biotin-neutravidin. They found a limit of detection similar to arrays on glass surfaces and believed that this plastic biochip platform may be used for the development of disposable immunosensing and diagnostic applications.

  3. Cold nuclear matter

    CERN Document Server

    Dorso, C O; Nichols, J I; López, J A

    2012-01-01

    We study the behavior of cold nuclear matter near saturation density (\\rho 0) and very low temperature using classical molecular dynamics. We used three different (classical) nuclear interaction models that yield `medium' or `stiff' compressibilities. For high densities and for every model the ground state is a classical crystalline solid, but each one with a different structure. At subsaturation densities, we found that for every model the transition from uniform (crystal) to non-uniform matter occurs at \\rho ~ 0.12 fm^(-3) = 0.75 \\rho 0. Surprisingly, at the non-uniform phase, the three models produce `pasta-like' structures as those allegedly present in neutron star matter but without the long-range Coulomb interaction and with different length scales.

  4. Cold dark matter resuscitated?

    CERN Document Server

    White, M; Silk, J; Davis, M; White, Martin; Scott, Douglas; Silk, Joe; Davis, Marc

    1995-01-01

    The Cold Dark Matter (CDM) model has an elegant simplicitly which makes it very predictive, but when its parameters are fixed at their `canonical' values its predictions are in conflict with observational data. There is, however, much leeway in the initial conditions within the CDM framework. We advocate a re-examination of the CDM model, taking into account modest variation of parameters from their canonical values. We find that CDM models with n=0.8--0.9 and h=0.45--0.50 can fit the available data. Our ``best fit'' CDM model has n=0.9, h=0.45 and C_2^{T}/C_2^{S}=0.7. We discuss the current state of observations which could definitely rule out this model.

  5. Thermal de-acclimation: how permanent are leaf phenotypes when cold-acclimated plants experience warming?

    Science.gov (United States)

    Gorsuch, Peter A; Pandey, Subedar; Atkin, Owen K

    2010-07-01

    We quantified a broad range of Arabidopsis thaliana (Col-0) leaf phenotypes for initially warm-grown (25/20 degrees C day/night) plants that were exposed to cold (5 degrees C) for periods of a few hours to 45 d before being transferred back to the warm, where leaves were allowed to mature. This allowed us to address the following questions: (1) For how long do warm-grown plants have to experience cold before developing leaves become irreversibly cold acclimated? (2) To what extent is the de-acclimation process associated with changes in leaf anatomy and physiology? We show that leaves that experience cold for extended periods during early development exhibit little plasticity in either photosynthesis or respiration, and they do not revert to a warm-associated carbohydrate profile. The eventual expansion rate in the warm was inversely related to the duration of previous cold treatment. Moreover, cold exposure of immature/developing leaves for as little as 5 d resulted in irreversible changes in the morphology of leaves that subsequently matured in the warm, with 15 d cold being sufficient for a permanent alteration of leaf anatomy. Collectively, these results highlight the impact of transitory cold during early leaf development in determining the eventual phenotype of leaves that mature in the warm.

  6. Plastic food packaging and health

    Directory of Open Access Journals (Sweden)

    Raika Durusoy

    2011-02-01

    Full Text Available Plastics have a wide usage in our daily lives. One of their uses is for food packaging and food containers. The aim of this review is to introduce different types of chemicals that can leach from food packaging plastics into foods and cause human exposure and to mention their effects on health. The types of plastics were reviewed under the 13 headings in Turkish Codex Alimentarius and plastics recycling symbols were provided to enable the recognition of the type of plastic when applicable. Chemicals used during the production and that can cause health risks are investigated under the heading of the relevant type of plastic. The most important chemicals from plastic food packaging that can cause toxicity are styrene, 1,3-butadiene, melamine, formaldehyde, acrylamide, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, vinyl chloride and bisphenol A. These chemicals have endocrine disrupting, carcinogenic and/or development disrupting effects. These chemicals may leach into foods depending on the chemical properties of the plastic or food, temperature during packaging, processing and storage, exposure to UV and duration of storage. Contact with fatty/oily or acidic foods, heating of the food inside the container, or drinking hot drinks from plastic cups, use of old and scratched plastics and some detergents increase the risk of leaching. The use of plastic containers and packaging for food and beveradges should be avoided whenever possible and when necessary, less harmful types of plastic should be preferred. [TAF Prev Med Bull 2011; 10(1.000: 87-96

  7. The commercialization of plastic surgery.

    Science.gov (United States)

    Swanson, Eric

    2013-09-01

    The last decade has brought a major challenge to the traditional practice of plastic surgery from corporations that treat plastic surgery as a commercial product and market directly to the public. This corporate medicine model may include promotion of a trademarked procedure or device, national advertising that promises stunning results, sales consultants, and claims of innovation, superiority, and improved safety. This article explores the ethics of this business practice and whether corporate medicine is a desirable model for patients and plastic surgeons.

  8. Structure and mechanical properties of austenitic steel after cold rolling

    Directory of Open Access Journals (Sweden)

    A. Kurc-Lisiecka

    2011-02-01

    Full Text Available Purpose: The aim of the paper is to determine the influence of the cold plastic deformation within the range 18-79% and heat treatment in a temperature range of 500 to 700°C on the microstructure and mechanical properties of austenitic stainless steel grade X5CrNi18-8.Design/methodology/approach: The investigations included observations of the microstructure on a light microscope, researches of mechanical properties in a static tensile test and hardness measurements made by Vickers’s method. The analysis of the phase composition was carried out on the basis of X-ray researches. Whereas, X-ray quantitative phase analysis was carried out by the Averbach Cohen method.Findings: Heat treatment of X5CrNi18-8 stainless steel in the range 500-700°C causes a significant decrease of the mechanical properties (Rm, Rp0.2 and increase of elongation (A. Hardness of investigated steel drops with decrease of cold working degree and increase of heat treatment temperature.Research limitations/implications: The analysis of the obtained results permits to state that the heat treatment causes an essential changes of the microstructure connected with fading of cold deformation. Heating of cold rolled austenitic stainless steels can cause a reverse transformation α’ → γ.Practical implications: Two-phase structure α’+γ of austenitic Cr-Ni steel in deformed state working at elevated temperature undergo a transformation. It significantly influences mechanical properties of steel. Austenite phase undergoes a recrystallization, while martensite α’ phase undergoes reverse transformation.Originality/value: The analytic dependence of the yield point of the investigated steel on the cold working degree in cold rolling process has been confirmed. Revealing this relation is of essential practical importance for the technology of sheetmetal forming of austenitic steel.

  9. Cold gelation of globular proteins

    NARCIS (Netherlands)

    Alting, A.C.

    2003-01-01

    Keywords : globular proteins, whey protein, ovalbumin, cold gelation, disulfide bonds, texture, gel hardnessProtein gelation in food products is important to obtain desirable sensory and textural properties. Cold gelation is a novel method to produce protein-based gels. It is a two step process in w

  10. Cold gelation of globular proteins

    NARCIS (Netherlands)

    Alting, A.C.

    2003-01-01

    Keywords : globular proteins, whey protein, ovalbumin, cold gelation, disulfide bonds, texture, gel hardnessProtein gelation in food products is important to obtain desirable sensory and textural properties. Cold gelation is a novel method to produce protein-based gels. It is a two step process in w

  11. The status of cold fusion

    Science.gov (United States)

    Storms, E.

    This report attempts to update the status of the phenomenon of cold fusion. The new field is continuing to grow as a variety of nuclear reactions are discovered to occur in a variety of chemical environments at modest temperatures. However, it must be cautioned that most scientists consider cold fusion as something akin to UFO's, ESP, and numerology.

  12. Cold Crystal Reflector Filter Concept

    CERN Document Server

    Muhrer, G

    2014-01-01

    In this paper the theoretical concept of a cold crystal reflector filter will be presented. The aim of this concept is to balance the shortcoming of the traditional cold polycrystalline reflector filter, which lies in the significant reduction of the neutron flux right above (in energy space) or right below (wavelength space) the first Bragg edge.

  13. Multiscale modeling and synaptic plasticity.

    Science.gov (United States)

    Bhalla, Upinder S

    2014-01-01

    Synaptic plasticity is a major convergence point for theory and computation, and the process of plasticity engages physiology, cell, and molecular biology. In its many manifestations, plasticity is at the hub of basic neuroscience questions about memory and development, as well as more medically themed questions of neural damage and recovery. As an important cellular locus of memory, synaptic plasticity has received a huge amount of experimental and theoretical attention. If computational models have tended to pick specific aspects of plasticity, such as STDP, and reduce them to an equation, some experimental studies are equally guilty of oversimplification each time they identify a new molecule and declare it to be the last word in plasticity and learning. Multiscale modeling begins with the acknowledgment that synaptic function spans many levels of signaling, and these are so tightly coupled that we risk losing essential features of plasticity if we focus exclusively on any one level. Despite the technical challenges and gaps in data for model specification, an increasing number of multiscale modeling studies have taken on key questions in plasticity. These have provided new insights, but importantly, they have opened new avenues for questioning. This review discusses a wide range of multiscale models in plasticity, including their technical landscape and their implications.

  14. Plastics recycling: challenges and opportunities

    National Research Council Canada - National Science Library

    Jefferson Hopewell; Robert Dvorak; Edward Kosior

    2009-01-01

    .... Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public...

  15. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  16. Innovative cold joining technologies based on tube forming

    Directory of Open Access Journals (Sweden)

    Alves Luis M.

    2015-01-01

    Full Text Available This paper is focused on innovative cold joining technologies for connecting tubes and fixing tubes to sheets. The proposed technologies are based on the utilization of plastic instability waves in thin-walled tubes subjected to axial compression and may be seen as an alternative to conventional joining technologies based on mechanical fixing with fasteners, welding and structural adhesive bonding. Besides allowing connecting dissimilar materials and being successfully employed in fixture conditions that are difficult and costly to achieve by means of conventional joining the new proposed technologies also cope with the growing concerns on the demand, lifecycle and recycling of materials.

  17. [Erythropoietin in plastic surgery].

    Science.gov (United States)

    Günter, C I; Rezaeian, F; Harder, Y; Lohmeyer, J A; Egert, S; Bader, A; Schilling, A F; Machens, H-G

    2013-04-01

    EPO is an autologous hormone, which is known to regulate erythropoiesis. For 30 years it has been used for the therapy of diverse forms of anaemia, such as renal anaemia, tumour-related anaemias, etc. Meanwhile, a multitude of scientific publications were able to demonstrate its pro-regenerative effects after trauma. These include short-term effects such as the inhibition of the "primary injury response" or apoptosis, and mid- and long-term effects for example the stimulation of stem cell recruitment, growth factor production, angiogenesis and re-epithelialisation. Known adverse reactions are increases of thromboembolic events and blood pressure, as well as a higher mortality in patients with tumour anaemias treated with EPO. Scientific investigations of EPO in the field of plastic surgery included: free and local flaps, nerve regeneration, wound healing enhancement after dermal thermal injuries and in chronic wounds.Acute evidence for the clinical use of EPO in the field of plastic surgery is still not satisfactory, due to the insufficient number of Good Clinical Practice (GCP)-conform clinical trials. Thus, the initiation of more scientifically sound trials is indicated.

  18. Optogenetics and synaptic plasticity.

    Science.gov (United States)

    Xie, Yu-feng; Jackson, Michael F; Macdonald, John F

    2013-11-01

    The intricate and complex interaction between different populations of neurons in the brain has imposed limits on our ability to gain detailed understanding of synaptic transmission and its integration when employing classical electrophysiological approaches. Indeed, electrical field stimulation delivered via traditional microelectrodes does not permit the targeted, precise and selective control of neuronal activity amongst a varied population of neurons and their inputs (eg, cholinergic, dopaminergic or glutamatergic neurons). Recently established optogenetic techniques overcome these limitations allowing precise control of the target neuron populations, which is essential for the elucidation of the neural substrates underlying complex animal behaviors. Indeed, by introducing light-activated channels (ie, microbial opsin genes) into specific neuronal populations, optogenetics enables non-invasive optical control of specific neurons with milliseconds precision. These approaches can readily be applied to freely behaving live animals. Recently there is increased interests in utilizing optogenetics tools to understand synaptic plasticity and learning/memory. Here, we summarize recent progress in applying optogenetics in in the study of synaptic plasticity.

  19. Cough and Cold Medicine Abuse (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Cough and Cold Medicine Abuse KidsHealth > For Parents > Cough ... cough and cold medicine. Why Do Kids Abuse Cough and Cold Remedies? Before the U.S. Food and ...

  20. Cold-Weather Sports and Your Family

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Cold-Weather Sports and Your Family KidsHealth > For Parents > Cold- ... once the weather turns frosty. Beating the Cold-Weather Blahs Once a chill is in the air, ...

  1. Understanding Colds: Anatomy of the Nose

    Science.gov (United States)

    ... at least one-half of colds. (5) Cold viruses can only multiply when they are inside of living cells. When on an environmental surface, cold viruses cannot multiply. However, they are still infectious if ...

  2. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than th

  3. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than

  4. Sustainable reverse logistics for household plastic waste

    NARCIS (Netherlands)

    Bing, X.

    2014-01-01

    Summary of the thesis titled “Sustainable Reverse Logistics for Household Plastic Waste” PhD Candidate: Xiaoyun Bing Recycled plastic can be used in the manufacturing of plastic products to reduce the use of virgin plastics material. The cost of recycled plastics is usually lower than th

  5. Plastics recycling: challenges and opportunities.

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-07-27

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3-4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  6. Plastics recycling: challenges and opportunities

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  7. Microstructural Development and Deformation Mechanisms during Cold Rolling of a Medium Stacking Fault Energy TWIP Steel

    Institute of Scientific and Technical Information of China (English)

    K.A. Ofei; L. Zhao; J. Sietsma

    2013-01-01

    The magnetic response,microstructural and texture changes occurring during cold rolling of a Fe-14Mn-0.64C-2.4Al-0.25Si medium stacking fault energy TWlP (twinning induced plasticity) steel have been studied by X-ray diffraction and magnetic techniques.The changes in the sub-grain size (Ds),probability of stacking fault formation (Psf) and microstrain in the material as cold rolling progressed were determined by using a modified version of the Williamson and Hall equation.A strong development of the crystallographic texture with increasing deformation was observed.Deformation-induced formation of a small fraction α'-martensite was observed,indicating that the steel also exhibits y → α'-martensite transformation during cold rolling,which is discussed via the changes of the stacking-fault probability and the texture development during cold rolling.

  8. 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.

  9. 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.

  10. Cold plasma decontamination of foods.

    Science.gov (United States)

    Niemira, Brendan A

    2012-01-01

    Cold plasma is a novel nonthermal food processing technology that uses energetic, reactive gases to inactivate contaminating microbes on meats, poultry, fruits, and vegetables. This flexible sanitizing method uses electricity and a carrier gas, such as air, oxygen, nitrogen, or helium; antimicrobial chemical agents are not required. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization process. A wide array of cold plasma systems that operate at atmospheric pressures or in low pressure treatment chambers are under development. Reductions of greater than 5 logs can be obtained for pathogens such as Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. Effective treatment times can range from 120 s to as little as 3 s, depending on the food treated and the processing conditions. Key limitations for cold plasma are the relatively early state of technology development, the variety and complexity of the necessary equipment, and the largely unexplored impacts of cold plasma treatment on the sensory and nutritional qualities of treated foods. Also, the antimicrobial modes of action for various cold plasma systems vary depending on the type of cold plasma generated. Optimization and scale up to commercial treatment levels require a more complete understanding of these chemical processes. Nevertheless, this area of technology shows promise and is the subject of active research to enhance efficacy.

  11. Plastic in North Sea Fish

    NARCIS (Netherlands)

    Foekema, E.M.; Gruijter, de C.; Mergia, M.T.; Franeker, van J.A.; Murk, A.J.; Koelmans, A.A.

    2013-01-01

    To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, wh

  12. The scope of plastic surgery

    African Journals Online (AJOL)

    2013-08-03

    Aug 3, 2013 ... areas of surgery (especially general surgery), plastic surgeons are arguably the .... Who do you feel are experts in laparoscopic surgery? e (general surgeons) a. Maxillofacial .... of pressure sore. ORIF = open reduction internal fixation. ... Plastic versus cosmetic surgery: What's the difference? Plast Reconstr.

  13. New Life for Old Plastics

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Recycling joint venture utilizes innovative technology to reuse plastics Recycling,despite its green connotations,can be a messy business.In China,more than 400,000 companies are engaged in plastic recycling,but 70 percent of them are family enterprises,

  14. Computational strain gradient crystal plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2014-01-01

    of plane crystal plasticity are studied: pure shear of a single crystal between rigid platens as well as plastic deformation around cylindrical voids in hexagonal close packed and face centered cubic crystals. Effective in-plane constitutive slip parameters for plane strain deformation of specifically...

  15. Architecture of European Plastic Surgery

    NARCIS (Netherlands)

    Nicolai, J. -P. A.; Banic, A.; Molea, G.; Mazzola, R.; Poell, J. G.

    2006-01-01

    The architecture of European Plastic Surgery was published in 1996 [Nicolai JPA, Scuderi N. Plastic surgical Europe in an organogram. Eur J Plast Surg 1996; 19: 253-6.] It is the objective of this paper to update information of that article. Continuing medical education (CME), science, training,

  16. 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.

  17. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  18. Cold-sterilization of copper IUDs.

    Science.gov (United States)

    1982-03-01

    The International Fertility Research Program (IFRP) conducted a study to identify a feasible method for cold-sterilization of copper IUDs. 5 classes of disinfectants were selected for preliminary laboratory trials because of their known disinfectant activity and general product attributes. The types of disinfectants tested for both antibacterial and sporicidal ability were a formaldehyde, an alkaline glutaraldehyde, 2 experimental chlorine-liberating compounds, an iodophor, and quaternary ammonium salts. Initially, tests were conducted on plastic, noncopper bearing IUDs. The different disinfectants were evaluated for their ability to kill Staphylococcus aureus or Escherichia coli vegetative bacteria within 10 minutes. The formaldehyde solution destroyed both types of bacteria in 1 minute. Both chlorine-liberating compounds and the quaternary ammonium salts destroyed the bacteria within 5 minutes. When used on copper IUDs, only formaldehyde or glutaraldehyde solutions proved to be effective sporicides and, therefore, appropriate for cold-sterilization. The 2 chlorine-liberating compounds were sporicidal if exposed for more than 1 hour, but when immersed in the disinfectant for that period of time the copper corroded. In a subsequent study, 2 commercial glutaraldehydes were compared to a formaldehyde for both antibacterial and sporicidal activity. In this 2nd study, copper bearing IUDs were inoculated with the same microorganisms as used previously. Against the vegetative bacteria, all 3 disinfectants were effective within 10 minutes. Against Bacillus globigii spores, each of these 3 disinfectants was an effective sporicidal agent after 5 hours immersion. An important findint that is relevant to field use is that Sporicidin can be mixed with tap water in a 1:5 dilution, and remain sporicidal after an exposure time of 6 3/4 hours. This eliminates the need for sterile water in preparing the solution.

  19. Friendly units for coldness

    CERN Document Server

    Fraundorf, P

    2006-01-01

    Measures of temperature that center around human experience get lots of use. Of course thermal physics insights of the last century have shown that reciprocal temperature (1/kT) has applications that temperature addresses less well. In addition to taking on negative absolute values under population inversion (e.g. of magnetic spins), bits and bytes turn 1/kT into an informatic measure of the thermal ambient for developing correlations within any complex system. We show here that, in the human-friendly units of bytes and food Calories, water freezes when 1/kT ~200 ZB/Cal or kT ~5 Cal/YB. Casting familiar benchmarks into these terms shows that habitable human space requires coldness values (part of the time, at least) between 0 and 40 ZB/Cal with respect body temperature ~100 degrees F, a range in kT of ~1 Cal/YB. Insight into these physical quantities underlying thermal equilibration may prove useful for budding scientists, as well as the general public, in years ahead.

  20. Zitterbewegung in Cold Atoms

    Science.gov (United States)

    Penteado, Poliana; Egues, J. Carlos

    2013-03-01

    In condensed matter systems, the coupling between spatial and spin degrees of freedom through the spin-orbit (SO) interaction offers the possibility of manipulating the electron spin via its orbital motion. The proposal by Datta and Das of a `spin transistor' for example, highlights the use of the SO interaction to control the electron spin via electrical means. Recently, arrangements of crossed lasers and magnetic fields have been used to trap and cool atoms in optical lattices and also to create light-induced gauge potentials, which mimic the SO interactions in real solids. In this work, we investigate the Zitterbewegung in cold atoms by starting from the effective SO Hamiltonian derived in Ref.. Cross-dressed atoms as effective spins can provide a proper setting in which to observe this effect, as the relevant parameter range of SO strengths may be more easily attainable in this context. We find a variety of peculiar Zitterbewegung orbits in real and pseudo-spin spaces, e.g., cycloids and ellipses - all of which obtained with realistic parameters. This work is supported by FAPESP, CAPES and CNPq.

  1. Universal features of amorphous plasticity

    Science.gov (United States)

    Budrikis, Zoe; Castellanos, David Fernandez; Sandfeld, Stefan; Zaiser, Michael; Zapperi, Stefano

    2017-07-01

    Plastic yielding of amorphous solids occurs by power-law distributed deformation avalanches whose universality is still debated. Experiments and molecular dynamics simulations are hampered by limited statistical samples, and although existing stochastic models give precise exponents, they require strong assumptions about fixed deformation directions, at odds with the statistical isotropy of amorphous materials. Here, we introduce a fully tensorial, stochastic mesoscale model for amorphous plasticity that links the statistical physics of plastic yielding to engineering mechanics. It captures the complex shear patterning observed for a wide variety of deformation modes, as well as the avalanche dynamics of plastic flow. Avalanches are described by universal size exponents and scaling functions, avalanche shapes, and local stability distributions, independent of system dimensionality, boundary and loading conditions, and stress state. Our predictions consistently differ from those of mean-field depinning models, providing evidence that plastic yielding is a distinct type of critical phenomenon.

  2. Phenotypic Plasticity and Species Coexistence.

    Science.gov (United States)

    Turcotte, Martin M; Levine, Jonathan M

    2016-10-01

    Ecologists are increasingly interested in predicting how intraspecific variation and changing trait values impact species interactions and community composition. For many traits, much of this variation is caused by phenotypic plasticity, and thus the impact of plasticity on species coexistence deserves robust quantification. Partly due to a lack of sound theoretical expectations, empirical studies make contradictory claims regarding plasticity effects on coexistence. Our critical review of this literature, framed in modern coexistence theory, reveals that plasticity affects species interactions in ways that could impact stabilizing niche differences and competitive asymmetries. However, almost no study integrates these measures to quantify the net effect of plasticity on species coexistence. To address this challenge, we outline novel empirical approaches grounded in modern theory.

  3. Imaging brain plasticity after trauma

    Institute of Scientific and Technical Information of China (English)

    Zhifeng Kou; Armin Iraji

    2014-01-01

    The brain is highly plastic after stroke or epilepsy;however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrat-ed both structural reorganization as well as functional compensation by the recruitment of other brain regions. However, the large scale brain network alterations after TBI are still unknown, and the ifeld is still short of proper means on how to guide the choice of TBI rehabilitation or treat-ment plan to promote brain plasticity. The authors also point out the new direction of brain plas-ticity investigation.

  4. Size effects in crystal plasticity

    DEFF Research Database (Denmark)

    Borg, Ulrik

    2007-01-01

    Numerical analyses of plasticity size effects have been carried out for different problems using a developed strain gradient crystal plasticiy theory. The theory employs higher order stresses as work conjugates to slip gradients and uses higher order boundary conditions. Problems on localization...... of plastic flow in a single crystal, grain boundary effects in a bicrystal, and grain size effects in a polycrystal are studied. Single crystals containing micro-scale voids have also been analyzed at different loading conditions with focus on the stress and deformation fields around the voids, on void...... growth and interaction between neighboring voids, and on a comparison between the developed strain gradient crystal plasticity theory and a discrete dislocation plasticity theory. Furthermore, voids and rigid inclusions in isotropic materials have been studied using a strain gradient plasticity theory...

  5. Cold-formed steel design

    CERN Document Server

    Yu, Wei-Wen

    2010-01-01

    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  6. Nano-Ceramic Coated Plastics

    Science.gov (United States)

    Cho, Junghyun

    2013-01-01

    Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

  7. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  8. Plasticity and beyond microstructures, crystal-plasticity and phase transitions

    CERN Document Server

    Hackl, Klaus

    2014-01-01

    The book presents the latest findings in experimental plasticity, crystal plasticity, phase transitions, advanced mathematical modeling of finite plasticity and multi-scale modeling. The associated algorithmic treatment is mainly based on finite element formulations for standard (local approach) as well as for non-standard (non-local approach) continua and for pure macroscopic as well as for directly coupled two-scale boundary value problems. Applications in the area of material design/processing are covered, ranging from grain boundary effects in polycrystals and phase transitions to deep-drawing of multiphase steels by directly taking into account random microstructures.

  9. PANDA: Cold three axes spectrometer

    Directory of Open Access Journals (Sweden)

    Astrid Schneidewind

    2015-08-01

    Full Text Available The cold three axes spectrometer PANDA, operated by JCNS, Forschungszentrum Jülich, offers high neutron flux over a large dynamic range keeping the instrumental background comparably low.

  10. Flu and Colds: In Depth

    Science.gov (United States)

    ... studies have evaluated the use of American ginseng (Panax quinquefolius) to prevent colds. A 2011 evaluation of ... E561. Seida JK, Durec T, Kuhle S. North American (Panax quinquefolius) and Asian ginseng (Panax ginseng) preparations for ...

  11. Review on Cold Spray Process and Technology: Part I—Intellectual Property

    Science.gov (United States)

    Irissou, Eric; Legoux, Jean-Gabriel; Ryabinin, Anatoly N.; Jodoin, Bertrand; Moreau, Christian

    2008-12-01

    The number of research papers as well as of patents and patent applications on cold spray and cold spray related technologies has grown exponentially in the current decade. This rapid growth of activity brought a tremendous amount of information on this technology in a short period of time. The main motivation for this review is to summarize the rapidly expanding common knowledge on cold spray to help researchers and engineers already or soon to be involved for their future endeavors with this new technology. Cold spray is one of the various names for describing an all-solid-state coating process that uses a high-speed gas jet to accelerate powder particles toward a substrate where they plastically deform and consolidate upon impact. Cold gas dynamic spray, cold spray, kinetic spray, supersonic particle deposition, dynamic metallization or kinetic metallization are all terminologies found in the literature that designate the above-defined coating process. This review on cold spray technology is divided into two parts. In this article, Part I, patents and patent applications related to this process are reviewed, starting from the first few mentions of the idea at the beginning of the 20th century to its practical discovery in Russia in the 1980s and its subsequent occidental development and commercialization. The patent review encompasses Russian and USA patents and patent applications. Part II will review the scientific literature giving a general perspective of the current understanding and capability of this process.

  12. International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): A review.

    Science.gov (United States)

    Xanthos, Dirk; Walker, Tony R

    2017-02-18

    Marine plastic pollution has been a growing concern for decades. Single-use plastics (plastic bags and microbeads) are a significant source of this pollution. Although research outlining environmental, social, and economic impacts of marine plastic pollution is growing, few studies have examined policy and legislative tools to reduce plastic pollution, particularly single-use plastics (plastic bags and microbeads). This paper reviews current international market-based strategies and policies to reduce plastic bags and microbeads. While policies to reduce microbeads began in 2014, interventions for plastic bags began much earlier in 1991. However, few studies have documented or measured the effectiveness of these reduction strategies. Recommendations to further reduce single-use plastic marine pollution include: (i) research to evaluate effectiveness of bans and levies to ensure policies are having positive impacts on marine environments; and (ii) education and outreach to reduce consumption of plastic bags and microbeads at source.

  13. Cold nuclear fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tsyganov, E.N., E-mail: edward.tsyganov@coldfusion-power.com [Cold Fusion Power, International (United States); Bavizhev, M.D. [LLC “Radium”, Moscow (Russian Federation); Buryakov, M.G. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation); Dabagov, S.B. [RAS P.N. Lebedev Physical Institute, Leninsky pr. 53, 119991 Moscow (Russian Federation); National Research Nuclear University MEPhI, Kashirskoe shosse 31, 115409 Moscow (Russian Federation); Golovatyuk, V.M.; Lobastov, S.P. [Joint Institute for Nuclear Research (JINR), Dubna (Russian Federation)

    2015-07-15

    If target deuterium atoms were implanted in a metal crystal in accelerator experiments, a sharp increase in the probability of DD-fusion reaction was clearly observed when compared with the reaction’s theoretical value. The electronic screening potential, which for a collision of free deuterium atoms is about 27 eV, reached 300–700 eV in the case of the DD-fusion in metallic crystals. These data leads to the conclusion that a ban must exist for deuterium atoms to be in the ground state 1s in a niche filled with free conduction electrons. At the same time, the state 2p whose energy level is only 10 eV above that of state 1s is allowed in these conditions. With anisotropy of 2p, 3p or above orbitals, their spatial positions are strictly determined in the lattice coordinate system. When filling out the same potential niches with two deuterium atoms in the states 2p, 3p or higher, the nuclei of these atoms can be permanently positioned without creating much Coulomb repulsion at a very short distance from each other. In this case, the transparency of the potential barrier increases dramatically compared to the ground state 1s for these atoms. The probability of the deuterium nuclei penetrating the Coulomb barrier by zero quantum vibration of the DD-system also increases dramatically. The so-called cold nuclear DD-fusion for a number of years was registered in many experiments, however, was still rejected by mainstream science for allegedly having no consistent scientific explanation. Finally, it received the validation. Below, we outline the concept of this explanation and give the necessary calculations. This paper also considers the further destiny of the formed intermediate state of {sup 4}He{sup ∗}.

  14. Endogenous neurotrophins and plasticity following spinal deafferentation.

    Science.gov (United States)

    Ramer, Matt S

    2012-05-01

    Neurons intrinsic to the spinal cord dorsal horn receive input from various classes of long-distance projection systems. Two of the best known of these are primary afferent and descending monoaminergic axons. Together with intrinsic interneurons, activity in these axonal populations shapes the early part of the sensory experience before it is transmitted to supraspinal structures via ascending projection axons. Injury to dorsal roots, which contain the centrally projecting branches of primary afferent axons, results in their permanent disconnection from the spinal cord, as well as sensory dysfunction such as pain. In animals, experimental dorsal root injuries affecting a small number of roots produce dynamic behavioural changes, providing evidence for the now familiar concept that sensory processing at the level of the spinal cord is not hard-wired. Changes in behaviour following rhizotomy suggest changes in spinal sensory circuitry, and we and others have shown that the density of spinal serotonergic axons as well as processes of inhibitory interneurons increases following rhizotomy. Intact primary afferent axons are less apt to sprout into denervated territory. Recent work from our group has asked (1) what is the stimulus that induces sprouting of serotonergic (and other) axons and (2) what prevents spared primary afferent axons from occupying the territory of those lost to injury. This article will review the evidence that a single factor upregulated by dorsal root injury, brain-derived neurotrophic factor (BDNF), underpins both serotonergic sprouting and a lack of primary afferent plasticity. BDNF also differentially modulates some of the behavioural consequences of dorsal root injury: antagonizing endogenous BDNF improves spontaneous mechanosensory recovery but prevents recovery from rhizotomy-induced hypersensitivity to cold. These findings reinforce the notion that in disease states as complex and variable as spinal cord injury, single pharmacological

  15. FEM Analysis of Rolling Pressure Along Strip Width in Cold Rolling Process

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-hua; SHI Xu; LI Shan-qing; XU Jian-yong; WANG Guo-dong

    2007-01-01

    Using 3-D elastic-plastic FEM, the cold strip rolling process in a 4-high mill was simulated. The elastic deformation of rolls, the plastic deformation of the strip, and the pressure between the work roll and the backup roll were taken into account. The distribution of rolling pressure along the strip width was obtained. Based on the simulation results, the peak value of rolling pressure and the location of the peak were analyzed under different rolling conditions. The effects of the roll bending force and the strip width on the distribution of rolling pressure along the width direction were determined.

  16. Phenotypic plasticity, costs of phenotypes, and costs of plasticity

    DEFF Research Database (Denmark)

    Callahan, Hilary S; Maughan, Heather; Steiner, Uli

    2008-01-01

    Why are some traits constitutive and others inducible? The term costs often appears in work addressing this issue but may be ambiguously defined. This review distinguishes two conceptually distinct types of costs: phenotypic costs and plasticity costs. Phenotypic costs are assessed from patterns...... of covariation, typically between a focal trait and a separate trait relevant to fitness. Plasticity costs, separable from phenotypic costs, are gauged by comparing the fitness of genotypes with equivalent phenotypes within two environments but differing in plasticity and fitness. Subtleties associated with both...... types of costs are illustrated by a body of work addressing predator-induced plasticity. Such subtleties, and potential interplay between the two types of costs, have also been addressed, often in studies involving genetic model organisms. In some instances, investigators have pinpointed the mechanistic...

  17. Biodegradable plastics from renewable sources.

    Science.gov (United States)

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  18. Plastics recycling: challenges and opportunities

    OpenAIRE

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to pro...

  19. Circadian Regulation of Synaptic Plasticity

    Directory of Open Access Journals (Sweden)

    Marcos G. Frank

    2016-07-01

    Full Text Available Circadian rhythms refer to oscillations in biological processes with a period of approximately 24 h. In addition to the sleep/wake cycle, there are circadian rhythms in metabolism, body temperature, hormone output, organ function and gene expression. There is also evidence of circadian rhythms in synaptic plasticity, in some cases driven by a master central clock and in other cases by peripheral clocks. In this article, I review the evidence for circadian influences on synaptic plasticity. I also discuss ways to disentangle the effects of brain state and rhythms on synaptic plasticity.

  20. PLASMA GASIFICATION OF WASTE PLASTICS

    Directory of Open Access Journals (Sweden)

    Tadeusz Mączka

    2013-01-01

    Full Text Available The article presents the process of obtaining liquid fuels and fuel gas in the process of plasma processing of organic materials, including waste plastics. The concept of plasma pyrolysis of plastics was presented and on its basis a prototype installation was developed. The article describes a general rule of operating the installation and its elements in the process and basic operation parameters determined during its start-up. Initial results of processing plastics and the directions further investigations are also discussed. The effect of the research is to be the design of effective technology of obtaining fuels from gasification/pyrolysis of organic waste and biomass.

  1. In-package inhibition of E.coli 0157:H7 on bulk romaine lettuce using cold plasma

    Science.gov (United States)

    Dielectric barrier discharge atmospheric cold plasma (DACP) treatment was evaluated for the inactivation of Escherichia coli O157:H7, surface morphology, color, carbon dioxide generation, and weight loss of bulk Romaine lettuce in a commercial plastic clamshell container. The lettuce samples were pa...

  2. Epoxidized Vegetable Oils Plasticized Poly(lactic acid Biocomposites: Mechanical, Thermal and Morphology Properties

    Directory of Open Access Journals (Sweden)

    Buong Woei Chieng

    2014-10-01

    Full Text Available Plasticized poly(lactic acid PLA with epoxidized vegetable oils (EVO were prepared using a melt blending method to improve the ductility of PLA. The plasticization of the PLA with EVO lowers the Tg as well as cold-crystallization temperature. The tensile properties demonstrated that the addition of EVO to PLA led to an increase of elongation at break, but a decrease of tensile modulus. Plasticized PLA showed improvement in the elongation at break by 2058% and 4060% with the addition of 5 wt % epoxidized palm oil (EPO and mixture of epoxidized palm oil and soybean oil (EPSO, respectively. An increase in the tensile strength was also observed in the plasticized PLA with 1 wt % EPO and EPSO. The use of EVO increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The SEM micrograph of the plasticized PLA showed good compatible morphologies without voids resulting from good interfacial adhesion between PLA and EVO. Based on the results of this study, EVO may be used as an environmentally friendly plasticizer that can improve the overall properties of PLA.

  3. Characteristics of materials and thermal treatments applied to gearwheels obtained by plastic deformation

    Science.gov (United States)

    Bostan, I.; Dulgheru, V.; Trifan, N.

    2016-08-01

    A variety of materials are used in the manufacture of gearwheels. These materials satisfy various working conditions for gears. Such gears are made of metallic materials - ferrous, non-ferrous and from plastic materials. Among ferrous materials the following are used: irons; cast, forged and rolled steels; among non-ferrous materials the following are used: bronze, aluminium alloys, brass, etc., and of plastics the following are used: textolite, polyamide, polyacetal. In the practice of exploitation and in the process of special research it was established that the permissible load, according to teeth contact resistance, is generally determined by the hardness of the material. The highest hardness and respectively, the smallest sizes and reduced mass of the transmission can be obtained in the manufacture of steel gears via thermal treatment. It is obvious that by plastic deformation at cold it cannot be obtained gearwheels with complicated configuration as deformed plastic metal will form cracks caused by low plasticity. To improve processability by plastic deformation the mouldings for gearwheels are heated. With increasing the heating temperature, plasticity increases and resistance to deformation decreases.

  4. 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.

  5. Garlic for the common cold.

    Science.gov (United States)

    Lissiman, Elizabeth; Bhasale, Alice L; Cohen, Marc

    2014-11-11

    Background Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have six to eight colds per year and adults have two to four.Objectives To determine whether garlic (Allium sativum) is effective for the prevention or treatment of the common cold, when compared to placebo, no treatment or other treatments.Search methods We searched CENTRAL (2014, Issue 7),OLDMEDLINE (1950 to 1965),MEDLINE (January 1966 to July week 5, 2014), EMBASE(1974 to August 2014) and AMED (1985 to August 2014).Selection criteria Randomised controlled trials of common cold prevention and treatment comparing garlic with placebo, no treatment or standard treatment.Data collection and analysis Two review authors independently reviewed and selected trials from searches, assessed and rated study quality and extracted relevant data.Main results In this updated review, we identified eight trials as potentially relevant from our searches. Again, only one trial met the inclusion criteria.This trial randomly assigned 146 participants to either a garlic supplement (with 180 mg of allicin content) or a placebo (once daily)for 12 weeks. The trial reported 24 occurrences of the common cold in the garlic intervention group compared with 65 in the placebo group (P value garlic group compared with the placebo group (111 versus 366). The number of days to recovery from an occurrence of the common cold was similar in both groups (4.63 versus 5.63). Only one trial met the inclusion criteria, therefore limited conclusions can be drawn. The trial relied on self reported episodes of the common cold but was of reasonable quality in terms of randomisation and allocation concealment. Adverse effects included rash and odour. Authors' conclusions There is insufficient clinical trial evidence

  6. Effect of Heat Treatment Temperature on Properties of Chinese Calcined Flint Clay Based Plastic Refractories

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; DAI Wenyong; YU Xinfeng; LI Liang

    2009-01-01

    Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material,aluminum sulfate and fireclay as binding system.The results showed that with temperature rising,Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded.The modulus of rupture (MOR) and the cold crushing strength (CCS) increased firstly and then decreased from 110 ℃ to 600 ℃,then increased obviously.Thermal expansion coefficient increased from 110 ℃ to 760 ℃,decreased from 760 ℃ to 1 300 ℃,and increased from 1 300 ℃ to 1 500 ℃.

  7. Martensitic transformation in nanostructured TiNi shape memory alloy formed via severe plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, K. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan)]. E-mail: tsuchiya@pse.tut.ac.jp; Inuzuka, M. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Tomus, D. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Hosokawa, A. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Nakayama, H. [Department of Mechanical Engineering, University of Washington (United States); Morii, K. [Research and Development Laboratory, Daido Steel, Co., Ltd. (Japan); Todaka, Y. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Umemoto, M. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan)

    2006-11-25

    Martensitic transformation and mechanical behavior was investigated on TiNi shape memory alloy subjected to severe plastic deformation by cold rolling. Transmission electron microscopy revealed the sample to be a mixture of nanocrystalline and amorphous material after 40% cold rolling. Diffrential scaning calorimetry measurements and X-ray diffractometry suggested that the martensitic transformation was suppressed when the thickness reduction was over 25%. The pseudoelastic stress-strain curves of nanocrystalline/amorphous TiNi are characterized by the absence of a stress-plateau and by small hysteresis.

  8. Finger and toe temperature response to cold water and cold air exposure

    NARCIS (Netherlands)

    Struijs, N.R. van der; Es, E.M. van; Raymann, R.J.E.M.; Daanen, H.A.M.

    2008-01-01

    Introduction: Subjects with a weak cold-induced vasodilatation response (CIVD) to experimental cold-water immersion of the fingers in a laboratory setting have been shown to have a higher risk for local cold injuries when exposed to cold in real life. Most of the cold injuries in real life, however,

  9. Plasticity and creep of metals

    CERN Document Server

    Rusinko, Andrew

    2011-01-01

    Here is a systematic presentation of the postulates, theorems and principles of mathematical theories of plasticity and creep in metals, and their applications. Special attention is paid to analysis of the advantages and shortcomings of the classical theories.

  10. American Society of Plastic Surgeons

    Science.gov (United States)

    ... PRS PRS GO PSN PSEN GRAFT Contact Us Cosmetic Surgery New procedures and advanced technologies offer plastic surgery ... David Berman MD 14 Pidgeon Hill Drive Berman Cosmetic Surgery & S... Sterling, VA 20165 Website Franklin Richards MD Suite ...

  11. Exceptional plasticity of silicon nanobridges

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Tadashi; Sato, Takaaki; Toshiyoshi, Hiroshi; Collard, Dominique; Fujita, Hiroyuki [University of Tokyo, Institute of Industrial Science, 4-6-1 Komaba Meguro, Tokyo 153-8505 (Japan); Cleri, Fabrizio [Institut d' Electronique Microelectronique et Nanotechnologie (CNRS UMR 8520), Universite de Lille I, Avenue Poincare BP60069 59652 Villeneuve d' Ascq (France); Kakushima, Kuniyuki [Tokyo Institute of Technology, 4259, Nagatsuda, Midori, Yokohama, Kanagawa 226-8502 (Japan); Mita, Makoto [Department of Spacecraft Engineering, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Miyata, Masaki; Itamura, Noriaki; Sasaki, Naruo [Department of Materials and Life Sciences, Seikei University, 3-3-1, Kitamachi, Kichijoji, Musashino, Tokyo 180-8633 (Japan); Endo, Junji, E-mail: tadashii@iis.u-tokyo.ac.jp [FK Optical laboratory, 1-13-4 Nakano Niiza Saitama, 352-0005 (Japan)

    2011-09-02

    The plasticity of covalently bonded materials is a subject at the forefront of materials science, bearing on a wide range of technological and fundamental aspects. However, covalent materials fracture in a brittle manner when the deformation exceeds just a few per cent. It is predicted that a macroscopically brittle material like silicon can show nanoscale plasticity. Here we report the exceptional plasticity observed in silicon nanocontacts ('nanobridges') at room temperature using a special experimental setup combining a transmission electron microscope and a microelectromechanical system. When accounting for surface diffusion, we succeeded in elongating the nanocontact into a wire-like structure, with a fivefold increase in volume, up to more than twenty times the original length. Such a large plasticity was caused by the stress-assisted diffusion and the sliding of the intergranular, amorphous-like material among the nanocrystals.

  12. Globally Oriented Chinese Plastics Industry

    Institute of Scientific and Technical Information of China (English)

    Liao Zhengpin

    2004-01-01

    @@ Through continued endeavor and persistent opening to the whole world the Chinese plastics industry has been developed into a comprehensive industrial system that forms the basic material industries side by side with the steel, cement and the timber industry.

  13. Computational materials science: Nanoscale plasticity

    DEFF Research Database (Denmark)

    Jacobsen, Karsten Wedel; Schiøtz, Jakob

    2002-01-01

    How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour.......How does plastic deformation of polycrystalline materials with grain sizes less than 100 nm look at the atomic scale? A large-scale molecular dynamics simulation of nanocrystalline alluminium reveals some surprising behaviour....

  14. Sorting Techniques for Plastics Recycling

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents the basic principles of three different types of separating methods and a general guideline for choosing the most effective method for sorting plastic mixtures. It also presents the results of the tests carried out for separation of PVC, ABS and PET from different kinds of plastic mixtures in order to improve the grade of the raw input used in mechanical or feedstock recycling.

  15. [Modern neuroimaging of brain plasticity].

    Science.gov (United States)

    Kasprian, G; Seidel, S

    2010-02-01

    Modern neuroimaging methods offer new insights into the plasticity of the human brain. As the techniques of functional MRI and diffusion tensor imaging are increasingly being applied in a clinical setting, the examiner is now frequently confronted with the interpretation of imaging findings related to regenerative processes in response to lesions of the central and also of the peripheral nervous system. In this article individual results of modern neuroimaging studies are discussed in the context of structural and functional plasticity of the CNS.

  16. Plastic bronchitis: a management challenge.

    Science.gov (United States)

    Eberlein, Michael H; Drummond, Michael B; Haponik, Edward F

    2008-02-01

    Plastic bronchitis is an uncommon and underdiagnosed entity, characterized by recurrent expectoration of large, branching bronchial casts. We describe a 39-year-woman with no prior lung disease who had episodic wheezing, severe dyspnea with expectoration of large and thick secretions, branching in appearance, which she described as resembling squid. A comprehensive evaluation revealed no specific cause and a diagnosis of idiopathic plastic bronchitis was made. In plastic bronchitis the bronchial casts may vary in size from small segmental casts of a bronchus to casts filling the airways of an entire lung. Plastic bronchitis can therefore present as an acute life-threatening emergency if mechanical obstruction of major airways occurs. The casts are differentiated into type I, inflammatory casts, or type II, acellular casts. The type I inflammatory casts are often associated with bronchial disease and often have an acute presentation. The acellular type of cast production is often chronic or recurrent. Numerous systemic illnesses are associated with plastic bronchitis, but often, as in our patient, no underlying cause can be identified. The treatment of plastic bronchitis includes acute therapy to aid the removal and expectoration of casts, and specific short- or long-term treatments attempting to address the underlying hypersecretory process. The therapeutic options are supported only by anecdotal evidence based on case reports as the rarity and heterogeneity of plastic bronchitis confounds systematic investigations of its treatment. Improved understanding of the regulation of mucus production may allow for new treatment options in plastic bronchitis and other chronic lung diseases characterized by hypersecretion of mucus.

  17. ARE PLASTIC GROCERY BAGS SACKING THE ENVIRONMENT?

    OpenAIRE

    Mangal Gogte

    2009-01-01

    This paper is oriented on analysis impacts of plastic bags on environment. In this paper is analyzed did plastic bags are so harmful, and what are the main ingredients of it. One part of this paper is oriented on effects of plastic bags and management of their usage. There is also made comparative analysis between impacts of plastic and paper bags on environment.

  18. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

    1996-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  19. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

    1999-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  20. 49 CFR 192.281 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  1. 49 CFR 192.59 - Plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  2. The Story of the Plastics Industry.

    Science.gov (United States)

    Masson, Don, Ed.

    This is an illustrated informative booklet, designed to serve members of the Society of the Plastics Industry, Inc., and the plastics industry as a whole. It provides basic information about the industry's history and growth, plastics raw materials, typical uses of plastics, properties, and methods of processing and fabricating. (Author/DS)

  3. The role of local strains from prior cold work on stress corrosion cracking of α-brass in Mattsson's solution

    Energy Technology Data Exchange (ETDEWEB)

    Ulaganathan, Jaganathan, E-mail: jagan.ulaganathan@mail.utoronto.ca; Newman, Roger C., E-mail: roger.newman@utoronto.ca

    2014-06-01

    The dynamic strain rate ahead of a crack tip formed during stress corrosion cracking (SCC) under a static load is assumed to arise from the crack propagation. The strain surrounding the crack tip would be redistributed as the crack grows, thereby having the effect of dynamic strain. Recently, several studies have shown cold work to cause accelerated crack growth rates during SCC, and the slip-dissolution mechanism has been widely applied to account for this via a supposedly increased crack-tip strain rate in cold worked material. While these interpretations consider cold work as a homogeneous effect, dislocations are generated inhomogeneously within the microstructure during cold work. The presence of grain boundaries results in dislocation pile-ups that cause local strain concentrations. The local strains generated from cold working α-brass by tensile elongation were characterized using electron backscatter diffraction (EBSD). The role of these local strains in SCC was studied by measuring the strain distributions from the same regions of the sample before cold work, after cold work, and after SCC. Though, the cracks did not always initiate or propagate along boundaries with pre-existing local strains from the applied cold work, the local strains surrounding the cracked boundaries had contributions from both the crack propagation and the prior cold work. - Highlights: • Plastic strain localization has a complex relationship with SCC susceptibility. • Surface relief created by cold work creates its own granular strain localization. • Cold work promotes crack growth but several other factors are involved.

  4. Deformation mechanisms of plasticized starch materials.

    Science.gov (United States)

    Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P

    2014-12-19

    The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch.

  5. Evolution of phenotypic plasticity in colonizing species.

    Science.gov (United States)

    Lande, Russell

    2015-05-01

    I elaborate an hypothesis to explain inconsistent empirical findings comparing phenotypic plasticity in colonizing populations or species with plasticity from their native or ancestral range. Quantitative genetic theory on the evolution of plasticity reveals that colonization of a novel environment can cause a transient increase in plasticity: a rapid initial increase in plasticity accelerates evolution of a new optimal phenotype, followed by slow genetic assimilation of the new phenotype and reduction of plasticity. An association of colonization with increased plasticity depends on the difference in the optimal phenotype between ancestral and colonized environments, the difference in mean, variance and predictability of the environment, the cost of plasticity, and the time elapsed since colonization. The relative importance of these parameters depends on whether a phenotypic character develops by one-shot plasticity to a constant adult phenotype or by labile plasticity involving continuous and reversible development throughout adult life. © 2014 John Wiley & Sons Ltd.

  6. Laser spectroscopy of cold molecules

    CERN Document Server

    Borri, Simone

    2016-01-01

    This paper reviews the recent results in high-resolution spectroscopy on cold molecules. Laser spectroscopy of cold molecules addresses issues of symmetry violation, like in the search for the electric dipole moment of the electron and the studies on energy differences in enantiomers of chiral species; tries to improve the precision to which fundamental physical constants are known and tests for their possible variation in time and space; tests quantum electrodynamics, and searches for a fifth force. Further, we briefly review the recent technological progresses in the fields of cold molecules and mid-infrared lasers, which are the tools that mainly set the limits for the resolution that is currently attainable in the measurements.

  7. COLD-SAT dynamic model

    Science.gov (United States)

    Adams, Neil S.; Bollenbacher, Gary

    1992-01-01

    This report discusses the development and underlying mathematics of a rigid-body computer model of a proposed cryogenic on-orbit liquid depot storage, acquisition, and transfer spacecraft (COLD-SAT). This model, referred to in this report as the COLD-SAT dynamic model, consists of both a trajectory model and an attitudinal model. All disturbance forces and torques expected to be significant for the actual COLD-SAT spacecraft are modeled to the required degree of accuracy. Control and experimental thrusters are modeled, as well as fluid slosh. The model also computes microgravity disturbance accelerations at any specified point in the spacecraft. The model was developed by using the Boeing EASY5 dynamic analysis package and will run on Apollo, Cray, and other computing platforms.

  8. Nanofriction in cold ion traps.

    Science.gov (United States)

    Benassi, A; Vanossi, A; Tosatti, E

    2011-01-01

    Sliding friction between crystal lattices and the physics of cold ion traps are so far non-overlapping fields. Two sliding lattices may either stick and show static friction or slip with dynamic friction; cold ions are known to form static chains, helices or clusters, depending on the trapping conditions. Here we show, based on simulations, that much could be learnt about friction by sliding, through, for example, an electric field, the trapped ion chains over a corrugated potential. Unlike infinite chains, in which the theoretically predicted Aubry transition to free sliding may take place, trapped chains are always pinned. Yet, a properly defined static friction still vanishes Aubry-like at a symmetric-asymmetric structural transition, found for decreasing corrugation in both straight and zig-zag trapped chains. Dynamic friction is also accessible in ringdown oscillations of the ion trap. Long theorized static and dynamic one-dimensional friction phenomena could thus become accessible in future cold ion tribology.

  9. Cold Tolerance of Plants Used for Cold-Regions Revegetation

    Science.gov (United States)

    1990-10-01

    from tempted to transfer the rye cold-tolerance genome to increased concentrations of solutes in cells and extra- wheat in hybrids. While the gene...Journal, 76: 516-517. Tryon, E.H. and R.P. True (1952) Blister shake of Yelenosky, G. (1988) Capacity of citrus flowers to yellow poplar. Bulletin of the

  10. The effect of Qingbi Tablet on the KLF6-FRP regulation system of rheumatoid arthritis process%清痹片对类风湿关节炎KLF6-FRP调控体系的干预作用

    Institute of Scientific and Technical Information of China (English)

    刘维; 吴沅皞; 刘晓亚; 张磊; 薛斌; 陈英俊

    2011-01-01

    Objective: The project intends to investigate the role of KLF6-FRP regulation system of rheumatoid arthritis process, then to illuminate the possible ati-arthritis mechanism of the Qingbi Tablet, as a scientific basis for the research and application of the antiarthritic traditional Chinese medicine. Methods: Focusing on the Qingbi tablet with the formulating principle of dispelling toxins and dredging collaterals, under the guidance of TCM theory, the experimental research used collagen-induced arthritis (CIA) as the experimental animal models with the incisiveness point of the KLF6-TGFpl-FRP network (Kruppel like transcription factor 6-Transforming growth factor β1-Follistatin related protein). Comparating with normal group, the CIA rats were divided randomly into 5 groups, treating with or without the Qingbi tablets of low, middle, high dosage (0.36gkg -1-d-1, lg-kg-1-d-1 or 1.8g-kg-1-d-1) or Methotrexate. One half of rats were sacrificed on the 35th or the 49th day. The wrist joints were collected for measuring the KLF6 and FRP by Western Blotting. And the ankle joints were collected for measuring the TGFβ1, TNFα, IL-1β and MMP-3 with the immunohistochemistry assay. Results: The expression levels of KLF6, FRP, TGFβ1, TNFα, IL-ip, MMP-3 of CIA in rats were higher significantly compared with the normal ones (P<0.01). With a dose dependent, the expressions of KLF6 in the rats treating with Qingbi tablets of lg-kg-1-d-1 or 1.8g-kg-1-d-1 were lower significantly compared with the model group but of FRP are higher (P<0.01). The expression levels of TGFpi, TNFα, IL-1β, MMP-3 in treated groups are significantly lower than the model group (P<0.01). The expression levels of TNFα, IL-1β, MMP-3 of Qingbi high dosage group were power than the MTX group (P<0.01). Conclusion: The Qingbi Tablet has the effects of intervening the expression the KLF6-FRP regulation system and related factors on the RA process effectively.%目的:探讨清痹片对KLF6-FRP调控体系

  11. 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

  12. Microstructures and properties of cold drawn and annealed submicron crystalline Cu-5%Cr alloy

    Institute of Scientific and Technical Information of China (English)

    HE Wen-xiong; YU Yang; WANG Er-de; SUN Hong-fei; HU Lian-xi; CHEN Hui

    2009-01-01

    The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.

  13. The relationship among metabolic rate of tree shrews (Tupaia belangeri under cold acclimation

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2012-11-01

    Full Text Available Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST and thermoregulatory maximum metabolic rate (MMR. However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass ( Mb, basal metabolic rate (BMR, NST, and MMR on a tree shrews (Tupaia belangeri, acclimated to cold (5 ºC conditions. NST was measured as the maximum response of metabolic rate (NSTmax after injection of norepinephrine (NE in thermoneutrality minus BMR. Maximum metabolic rate was assessed in animals exposed to enhanced heat-loss atmosphere (He-O2 connected with an open-flow respirometer. Body mass and metabolic variables increased significantly after cold acclimation with respect to control group but to a high extent (BMR, 87.97%; NST, 69.77%; and MMR, 32.35%. However, aerobic scope (MMR/BMR, and calculated shivering thermogenesis (ST did not significantly change with control group. Our data suggest: 1. The body mass and the capacity of heat production in the cold acclimated group were higher; 2. The increase of BMR and MMR during cold acclimation was the main pattern of heat production in the tree shrews.

  14. Avionics Box Cold Plate Damage Prevention

    Science.gov (United States)

    Stambolian, Damon B.; Larchar, Steven W.; Henderson, Gena; Tran, Donald; Barth, Tim

    2012-01-01

    Problem Introduction: 1. Prevent Cold Plate Damage in Space Shuttle. 1a. The number of cold plate problems had increased from an average of 16.5 per/year between 1990 through 2000, to an average of 39.6 per year between 2001through 2005. 1b. Each complete set of 80 cold plates cost approximately $29 million, an average of $362,500 per cold plate. 1c It takes four months to produce a single cold plate. 2. Prevent Cold Plate Damage in Future Space Vehicles.

  15. Smartphones and the plastic surgeon.

    Science.gov (United States)

    Al-Hadithy, Nada; Ghosh, Sudip

    2013-06-01

    Surgical trainees are facing limited training opportunities since the introduction of the European Working Time Directive. Smartphone sales are increasing and have usurped computer sales for the first time. In this context, smartphones are an important portable reference and educational tool, already in the possession of the majority of surgeons in training. Technology in the palm of our hands has led to a revolution of accessible information for the plastic surgery trainee and surgeon. This article reviews the uses of smartphones and applications for plastic surgeons in education, telemedicine and global health. A comprehensive guide to existing and upcoming learning materials and clinical tools for the plastic surgeon is included. E-books, podcasts, educational videos, guidelines, work-based assessment tools and online logbooks are presented. In the limited resource setting of modern clinical practice, savvy plastic surgeons can select technological tools to democratise access to education and best clinical care. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. Mechanisms of GABAergic Homeostatic Plasticity

    Directory of Open Access Journals (Sweden)

    Peter Wenner

    2011-01-01

    Full Text Available Homeostatic plasticity ensures that appropriate levels of activity are maintained through compensatory adjustments in synaptic strength and cellular excitability. For instance, excitatory glutamatergic synapses are strengthened following activity blockade and weakened following increases in spiking activity. This form of plasticity has been described in a wide array of networks at several different stages of development, but most work and reviews have focussed on the excitatory inputs of excitatory neurons. Here we review homeostatic plasticity of GABAergic neurons and their synaptic connections. We propose a simplistic model for homeostatic plasticity of GABAergic components of the circuitry (GABAergic synapses onto excitatory neurons, excitatory connections onto GABAergic neurons, cellular excitability of GABAergic neurons: following chronic activity blockade there is a weakening of GABAergic inhibition, and following chronic increases in network activity there is a strengthening of GABAergic inhibition. Previous work on GABAergic homeostatic plasticity supports certain aspects of the model, but it is clear that the model cannot fully account for some results which do not appear to fit any simplistic rule. We consider potential reasons for these discrepancies.

  17. Mitochondria, synaptic plasticity, and schizophrenia.

    Science.gov (United States)

    Ben-Shachar, Dorit; Laifenfeld, Daphna

    2004-01-01

    The conceptualization of schizophrenia as a disorder of connectivity, i.e., of neuronal?synaptic plasticity, suggests abnormal synaptic modeling and neuronal signaling, possibly as a consequence of flawed interactions with the environment, as at least a secondary mechanism underlying the pathophysiology of this disorder. Indeed, deficits in episodic memory and malfunction of hippocampal circuitry, as well as anomalies of axonal sprouting and synapse formation, are all suggestive of diminished neuronal plasticity in schizophrenia. Evidence supports a dysfunction of mitochondria in schizophrenia, including mitochondrial hypoplasia, and a dysfunction of the oxidative phosphorylation system, as well as altered mitochondrial-related gene expression. Mitochondrial dysfunction leads to alterations in ATP production and cytoplasmatic calcium concentrations, as well as reactive oxygen species and nitric oxide production. All of the latter processes have been well established as leading to altered synaptic strength or plasticity. Moreover, mitochondria have been shown to play a role in plasticity of neuronal polarity, and studies in the visual cortex show an association between mitochondria and synaptogenesis. Finally, mitochondrial gene upregulation has been observed following synaptic and neuronal activity. This review proposes that mitochondrial dysfunction in schizophrenia could cause, or arise from, anomalies in processes of plasticity in this disorder.

  18. 大型玻璃钢渔船帽型骨架剖面参数的力学分析%Mechanics Analysis for Section Parameters of Cap- shape Frames of Large FRP Fishing Vessels

    Institute of Scientific and Technical Information of China (English)

    蒋丰; 沈叔曾

    2000-01-01

    In this paper, the section parameters of the cap - shape frame of the large FRP fishing vessel is analyzed by elastic stability theory. Both two models of thin rectangle plates on compression and shear stability are established. The section parameter b/t1 and h/t are obtained in four cases that is the four combinations for two materials (1: 1FRP and 4:1 FRP) and two boundaries (all edges simply supported and all edges clamped). The ranges are from 18.0 to 26. 2 and from 28.7 to 44.2 respectively. The results provide theory basis for the optimal design of section parameters of the cap - shape frame and the revision of relevant standard.%本文对大型玻璃钢渔船帽型骨架剖面参数,进行了在不利受力情况下正交各向异性玻璃钢薄板稳定的力学分析,建立了骨架受力分析--受压区的矩形薄板压缩稳定和腹板的矩形薄板剪切稳定两种力学模型,解得这两种力学模型,在两种材料(1:1玻璃钢和4:1玻璃钢)与两种边界条件(四边简支和四边固支)组合的四种条件下,骨架剖面参数的b/t1和h/t的取值范围,它们依次为18.0~26.2和28.7~44.2。文中分析结果为帽型骨架剖面参数的优化设计和相关规范的修订提供了理论依据。

  19. Simulation of Multiple Cold Rolls Progressive Forming for Non-symmetrical Channel Section

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In cold roll forming process, the sheet is progressively formed into a very complex three dimensional surface. The design procedure for the roll formed products, forming rolls, and roll pass sequences was considered more an art than a science. Good roll pass design was the key to successful roll forming. In order to reduce forming defects and trial production cost, computer simulation of cold roll forming was employed. Based on the Updated-Lagrange method in the deformation mechanics, a theoretical model of elastic-plastic large deformation spline finite strip method is proposed in this paper. The method is employed to analyze the progressive forming process of non-symmetrical section, and the displacement, the stress and the strain along rolling direction during the multiple cold rolls forming process are got. This program written in C Language can be used to analyze other simple cross sectional profiles also.

  20. MECHANICS ANALYSIS ON PRECISE FORMING PROCESS OF EXTERNAL SPLINE COLD ROLLING

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dawei; LI Yongtang; FU Jianhua; ZHENG Quangang

    2007-01-01

    According to the suitable assumption, the deformation process of external spline cold rolling is analyzed. By the graphing method, the slip-line field of plastically deforming area in process of external spline cold rolling is set up. Different friction-conditions are used in different contact areas in order to realistically reflect the actual situation. The unit average pressure on contact surface of the rolling process is solved according to the stress filed theory of slip-line. And the formulae of the rolling-force and rolling-moment are established. The theoretical result is well consistent with the finite element analysis. A theoretical basis is provided for the precise forming process of spline cold rolling and the production of external splined shafts.