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Sample records for reaction center rc

  1. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  2. Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

    DEFF Research Database (Denmark)

    Katona, Gergely; Snijder, Arjan; Gourdon, Pontus Emanuel

    2005-01-01

    In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

  3. A multi-pathway model for photosynthetic reaction center

    International Nuclear Information System (INIS)

    Qin, M.; Shen, H. Z.; Yi, X. X.

    2016-01-01

    Charge separation occurs in a pair of tightly coupled chlorophylls at the heart of photosynthetic reaction centers of both plants and bacteria. Recently it has been shown that quantum coherence can, in principle, enhance the efficiency of a solar cell, working like a quantum heat engine. Here, we propose a biological quantum heat engine (BQHE) motivated by Photosystem II reaction center (PSII RC) to describe the charge separation. Our model mainly considers two charge-separation pathways which is more than that typically considered in the published literature. We explore how these cross-couplings increase the current and power of the charge separation and discuss the effects of multiple pathways in terms of current and power. The robustness of the BQHE against the charge recombination in natural PSII RC and dephasing induced by environments is also explored, and extension from two pathways to multiple pathways is made. These results suggest that noise-induced quantum coherence helps to suppress the influence of acceptor-to-donor charge recombination, and besides, nature-mimicking architectures with engineered multiple pathways for charge separations might be better for artificial solar energy devices considering the influence of environments.

  4. Langmuir-Blodgett and X-ray diffraction studies of isolated photosystem II reaction centers in monolayers and multilayers: physical dimensions of the complex.

    Science.gov (United States)

    Uphaus, R A; Fang, J Y; Picorel, R; Chumanov, G; Wang, J Y; Cotton, T M; Seibert, M

    1997-04-01

    The photosystem II (PSII) reaction center (RC) is a hydrophobic intrinsic protein complex that drives the water-oxidation process of photosynthesis. Unlike the bacterial RC complex, an X-ray crystal structure of the PSII RC is not available. In order to determine the physical dimensions of the isolated PSII RC complex, we applied Langmuir techniques to determine the cross-sectional area of an isolated RC in a condensed monolayer film. Low-angle X-ray diffraction results obtained by examining Langmuir-Blodgett multilayer films of alternating PSII RC/Cd stearate monolayers were used to determine the length (or height; z-direction, perpendicular to the plane of the original membrane) of the complex. The values obtained for a PSII RC monomer were 26 nm2 and 4.8 nm, respectively, and the structural integrity of the RC in the multilayer film was confirmed by several approaches. Assuming a cylindrical-type RC structure, the above dimensions lead to a predicted volume of about 125 nm3. This value is very close to the expected volume of 118 nm3, calculated from the known molecular weight and partial specific volume of the PSII RC proteins. This same type of comparison was also made with the Rhodobacter sphaeroides RC based on published data, and we conclude that the PSII RC is much shorter in length and has a more regular solid geometric structure than the bacterial RC. Furthermore, the above dimensions of the PSII RC and those of PSII core (RC plus proximal antenna) proteins protruding outside the plane of the PSII membrane into the lumenal space as imaged by scanning tunneling microscopy (Seibert, Aust. J. Pl. Physiol. 22, 161-166, 1995) fit easily into the known dimensions of the PSII core complex visualized by others as electron-density projection maps. From this we conclude that the in situ PSII core complex is a dimeric structure containing two copies of the PSII RC.

  5. Tight-binding model of the photosystem II reaction center: application to two-dimensional electronic spectroscopy

    International Nuclear Information System (INIS)

    Gelzinis, Andrius; Valkunas, Leonas; Abramavicius, Darius; Fuller, Franklin D; Ogilvie, Jennifer P; Mukamel, Shaul

    2013-01-01

    We propose an optimized tight-binding electron–hole model of the photosystem II (PSII) reaction center (RC). Our model incorporates two charge separation pathways and spatial correlations of both static disorder and fast fluctuations of energy levels. It captures the main experimental features observed in time-resolved two-dimensional (2D) optical spectra at 77 K: peak pattern, lineshapes and time traces. Analysis of 2D spectra kinetics reveals that specific regions of the 2D spectra of the PSII RC are sensitive to the charge transfer states. We find that the energy disorder of two peripheral chlorophylls is four times larger than the other RC pigments. (paper)

  6. Tight-binding model of the photosystem II reaction center: application to two-dimensional electronic spectroscopy

    Science.gov (United States)

    Gelzinis, Andrius; Valkunas, Leonas; Fuller, Franklin D.; Ogilvie, Jennifer P.; Mukamel, Shaul; Abramavicius, Darius

    2013-07-01

    We propose an optimized tight-binding electron-hole model of the photosystem II (PSII) reaction center (RC). Our model incorporates two charge separation pathways and spatial correlations of both static disorder and fast fluctuations of energy levels. It captures the main experimental features observed in time-resolved two-dimensional (2D) optical spectra at 77 K: peak pattern, lineshapes and time traces. Analysis of 2D spectra kinetics reveals that specific regions of the 2D spectra of the PSII RC are sensitive to the charge transfer states. We find that the energy disorder of two peripheral chlorophylls is four times larger than the other RC pigments.

  7. Moessbauer spectroscopy on the reaction center of Rhodopseudomonas viridis

    International Nuclear Information System (INIS)

    Frolov, E.; Goldanskii, V.I.; Birk, A.; Parak, F.; Fritzsch, G.; Sinning, I.; Michel, H.

    1992-01-01

    Proteins called 'reaction centers' (RC) can be isolated from many photosynthetic bacteria. They have one non-heme iron in a quinone acceptor region. The RC of Rhodopseudomonas viridis contains an additional tightly bound tetra-heme cytochrome c subunit. The electronic configuration of both cytochrome and the non-heme iron has been studied in the crystallized protein by Moessbauer spectroscopy at different redox potentials, pH-values, and with an addition of o-phenanthroline. At high potentials (E h =+500 mV) all heme irons are in the low spin Fe 3+ -state, and at low potential (E h = 1 50 mV) they are low spin Fe 2+ with the same Moessbauer parameters for all hemes independent of pH. Redox titrations change the relative area of the reduced and oxidized states in agreement with other methods. The non-heme iron shows a high spin Fe 2+ configuration independent of E h and pH with parameters comparable to those of Rhodopseudomonas sphaeroides. Surprisingly, there is strong evidence for another non-heme iron species in part of the molecules with a Fe 2+ low spin configuration. Incubation with o-phenanthroline decreases the relative Fe 2+ hs-area and increases the contribution of Fe 2+ ls-area. Above 210 K the mean square displacement, 2 >, of the RC-crystals increases more than linearly with temperature. This may be correlated with the increase of the electron transfer rate and indicates that intramolecular mobility influences the functional activity of a protein. (orig.)

  8. Bio-Photoelectrochemical Solar Cells Incorporating Reaction Center and Reaction Center Plus Light Harvesting Complexes

    Science.gov (United States)

    Yaghoubi, Houman

    Harvesting solar energy can potentially be a promising solution to the energy crisis now and in the future. However, material and processing costs continue to be the most important limitations for the commercial devices. A key solution to these problems might lie within the development of bio-hybrid solar cells that seeks to mimic photosynthesis to harvest solar energy and to take advantage of the low material costs, negative carbon footprint, and material abundance. The bio-photoelectrochemical cell technologies exploit biomimetic means of energy conversion by utilizing plant-derived photosystems which can be inexpensive and ultimately the most sustainable alternative. Plants and photosynthetic bacteria harvest light, through special proteins called reaction centers (RCs), with high efficiency and convert it into electrochemical energy. In theory, photosynthetic RCs can be used in a device to harvest solar energy and generate 1.1 V open circuit voltage and ~1 mA cm-2 short circuit photocurrent. Considering the nearly perfect quantum yield of photo-induced charge separation, efficiency of a protein-based solar cell might exceed 20%. In practice, the efficiency of fabricated devices has been limited mainly due to the challenges in the electron transfer between the protein complex and the device electrodes as well as limited light absorption. The overarching goal of this work is to increase the power conversion efficiency in protein-based solar cells by addressing those issues (i.e. electron transfer and light absorption). This work presents several approaches to increase the charge transfer rate between the photosynthetic RC and underlying electrode as well as increasing the light absorption to eventually enhance the external quantum efficiency (EQE) of bio-hybrid solar cells. The first approach is to decrease the electron transfer distance between one of the redox active sites in the RC and the underlying electrode by direct attachment of the of protein complex

  9. How exciton-vibrational coherences control charge separation in the photosystem II reaction center.

    Science.gov (United States)

    Novoderezhkin, Vladimir I; Romero, Elisabet; van Grondelle, Rienk

    2015-12-14

    In photosynthesis absorbed sun light produces collective excitations (excitons) that form a coherent superposition of electronic and vibrational states of the individual pigments. Two-dimensional (2D) electronic spectroscopy allows a visualization of how these coherences are involved in the primary processes of energy and charge transfer. Based on quantitative modeling we identify the exciton-vibrational coherences observed in 2D photon echo of the photosystem II reaction center (PSII-RC). We find that the vibrations resonant with the exciton splittings can modify the delocalization of the exciton states and produce additional states, thus promoting directed energy transfer and allowing a switch between the two charge separation pathways. We conclude that the coincidence of the frequencies of the most intense vibrations with the splittings within the manifold of exciton and charge-transfer states in the PSII-RC is not occurring by chance, but reflects a fundamental principle of how energy conversion in photosynthesis was optimized.

  10. Alumina plate containing photosystem I reaction center complex oriented inside plate-penetrating silica nanopores.

    Science.gov (United States)

    Kamidaki, Chihiro; Kondo, Toru; Noji, Tomoyasu; Itoh, Tetsuji; Yamaguchi, Akira; Itoh, Shigeru

    2013-08-22

    The photosynthetic photosystem I reaction center complex (PSI-RC), which has a molecular diameter of 21 nm with 100 pigments, was incorporated into silica nanopores with a 100-nm diameter that penetrates an alumina plate of 60-μm thickness to make up an inorganic-biological hybrid photocell. PSI-RCs, purified from a thermophilic cyanobacterium, were stable inside the nanopores and rapidly photoreduced a mediator dye methyl viologen. The reduced dye was more stable inside nanopores suggesting the decrease of dissolved oxygen. The analysis by a cryogenic electron spin paramagnetic resonance indicated the oriented arrangement of RCs inside the 100-nm nanopores, with their surface parallel to the silica wall and perpendicular to the plane of the alumina plate. PSI RC complex in the semicrystalline orientation inside silica nanopores can be a new type of light energy conversion unit to supply strong reducing power selectively to other molecules inside or outside nanopores.

  11. Model photo reaction centers via genetic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhiyu Wang; DiMagno, T.J.; Popov, M.; Norris, J.R. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Chemistry; Chikin Chan; Fleming, G. [Chicago Univ., IL (United States). Dept. of Chemistry; Jau Tang; Hanson, D.; Schiffer, M. [Argonne National Lab., IL (United States)

    1992-12-31

    A series of reaction centers of Rhodococcus capsulatus isolated from a set of mutated organisms modified by site-directed mutagenesis at residues M208 and L181 are described. Changes in the amino acid at these sites affect both the energetics of the systems as well as the chemical kinetics for the initial ET event. Two empirical relations among the different mutants for the reduction potential and the ET rate are presented.

  12. Model photo reaction centers via genetic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhiyu Wang; DiMagno, T.J.; Popov, M.; Norris, J.R. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Chemistry); Chikin Chan; Fleming, G. (Chicago Univ., IL (United States). Dept. of Chemistry); Jau Tang; Hanson, D.; Schiffer, M. (Argonne National Lab., IL (United States))

    1992-01-01

    A series of reaction centers of Rhodococcus capsulatus isolated from a set of mutated organisms modified by site-directed mutagenesis at residues M208 and L181 are described. Changes in the amino acid at these sites affect both the energetics of the systems as well as the chemical kinetics for the initial ET event. Two empirical relations among the different mutants for the reduction potential and the ET rate are presented.

  13. Quinone reduction via secondary B-branch electron transfer in mutant bacterial reaction centers.

    Science.gov (United States)

    Laible, Philip D; Kirmaier, Christine; Udawatte, Chandani S M; Hofman, Samuel J; Holten, Dewey; Hanson, Deborah K

    2003-02-18

    Symmetry-related branches of electron-transfer cofactors-initiating with a primary electron donor (P) and terminating in quinone acceptors (Q)-are common features of photosynthetic reaction centers (RC). Experimental observations show activity of only one of them-the A branch-in wild-type bacterial RCs. In a mutant RC, we now demonstrate that electron transfer can occur along the entire, normally inactive B-branch pathway to reduce the terminal acceptor Q(B) on the time scale of nanoseconds. The transmembrane charge-separated state P(+)Q(B)(-) is created in this manner in a Rhodobacter capsulatus RC containing the F(L181)Y-Y(M208)F-L(M212)H-W(M250)V mutations (YFHV). The W(M250)V mutation quantitatively blocks binding of Q(A), thereby eliminating Q(B) reduction via the normal A-branch pathway. Full occupancy of the Q(B) site by the native UQ(10) is ensured (without the necessity of reconstitution by exogenous quinone) by purification of RCs with the mild detergent, Deriphat 160-C. The lifetime of P(+)Q(B)(-) in the YFHV mutant RC is >6 s (at pH 8.0, 298 K). This charge-separated state is not formed upon addition of competitive inhibitors of Q(B) binding (terbutryn or stigmatellin). Furthermore, this lifetime is much longer than the value of approximately 1-1.5 s found when P(+)Q(B)(-) is produced in the wild-type RC by A-side activity alone. Collectively, these results demonstrate that P(+)Q(B)(-) is formed solely by activity of the B-branch carriers in the YFHV RC. In comparison, P(+)Q(B)(-) can form by either the A or B branches in the YFH RC, as indicated by the biexponential lifetimes of approximately 1 and approximately 6-10 s. These findings suggest that P(+)Q(B)(-) states formed via the two branches are distinct and that P(+)Q(B)(-) formed by the B side does not decay via the normal (indirect) pathway that utilizes the A-side cofactors when present. These differences may report on structural and energetic factors that further distinguish the functional

  14. Assembly of photosynthetic reaction center with ABA tri-block polymersomes: highlights on the protein localization.

    KAUST Repository

    Tangorra, Roberto Rocco

    2015-07-07

    The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i. e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposomes formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.

  15. Assembly of photosynthetic reaction center with ABA tri-block polymersomes: highlights on the protein localization.

    KAUST Repository

    Tangorra, Roberto Rocco; Operamolla, Alessandra; Milano, Francesco; Hassan Omar, Omar; Henrard, John; Comparelli, Roberto; Italiano, Francesca; Agostiano, Angela; De Leo, Vincenzo; Marotta, Roberto; Falqui, Andrea; Farinola, Gianluca; Trotta, Massimo

    2015-01-01

    The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i. e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposomes formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.

  16. Isolated photosystem I reaction centers on a functionalized gated high electron mobility transistor.

    Science.gov (United States)

    Eliza, Sazia A; Lee, Ida; Tulip, Fahmida S; Mostafa, Salwa; Greenbaum, Elias; Ericson, M Nance; Islam, Syed K

    2011-09-01

    In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale (~6 nm) reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs. © 2011 IEEE

  17. Isolated Photosystem I Reaction Centers on a Functionalized Gated High Electron Mobility Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Eliza, Sazia A. [University of Tennessee, Knoxville (UTK); Lee, Ida [ORNL; Tulip, Fahmida S [ORNL; Islam, Syed K [University of Tennessee, Knoxville (UTK); Mostafa, Salwa [University of Tennessee, Knoxville (UTK); Greenbaum, Elias [ORNL; Ericson, Milton Nance [ORNL

    2011-01-01

    In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale nm reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs.

  18. Interplay between excitation kinetics and reaction-center dynamics in purple bacteria

    International Nuclear Information System (INIS)

    Caycedo-Soler, Felipe; RodrIguez, Ferney J; Quiroga, Luis; Johnson, Neil F

    2010-01-01

    Photosynthesis is arguably the fundamental process of life, since it enables energy from the Sun to enter the food chain on the Earth. It is a remarkable non-equilibrium process in which photons are converted to many-body excitations, which traverse a complex biomolecular membrane, where they are captured and fuel chemical reactions within a reaction center (RC) in order to produce nutrients. The precise nature of these dynamical processes-which lie at the interface between quantum and classical behavior and involve both noise and coordination-is still being explored. Here, we focus on a striking recent empirical finding concerning an illumination-driven transition in the biomolecular membrane architecture of the purple bacteria Rsp. photometricum. Using stochastic realizations to describe a hopping rate model for excitation transfer, we show numerically and analytically that this surprising shift in preferred architectures can be traced to the interplay between the excitation kinetics and the RC dynamics. The net effect is that the bacteria profit from efficient metabolism at low illumination intensities while using dissipation to avoid an oversupply of energy at high illumination intensities.

  19. Direct Observation of Energy Detrapping in LH1-RC Complex by Two-Dimensional Electronic Spectroscopy.

    Science.gov (United States)

    Ma, Fei; Yu, Long-Jiang; Hendrikx, Ruud; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

    2017-01-18

    The purple bacterial core light harvesting antenna-reaction center (LH1-RC) complex is the simplest system able to achieve the entire primary function of photosynthesis. During the past decade, a variety of photosynthetic proteins were studied by a powerful technique, two-dimensional electronic spectroscopy (2DES). However, little attention has been paid to LH1-RC, although its reversible uphill energy transfer, trapping, and backward detrapping processes, represent a crucial step in the early photosynthetic reaction dynamics. Thus, in this work, we employed 2DES to study two LH1-RC complexes of Thermochromatium (Tch.) tepidum. By direct observation of detrapping, the complex reversible process was clearly identified and an overall scheme of the excitation evolution in LH1-RC was obtained.

  20. The EPR paradox, the hydrated (solvated) electron, and the reactions of the hydrated electron (Preprint no. RC-02)

    International Nuclear Information System (INIS)

    Gopinathan, C.

    1991-01-01

    Einstein, Podolsky and Rosen pointed out in 1935 a serious flaw in the reasoning behind quantum mechanical modelling. It is shown in this work that this flaw applies to the interpretation of the hydrated electron and its reactions as well. (author). 3 refs

  1. Identification of protein W, the elusive sixth subunit of the Rhodopseudomonas palustris reaction center-light harvesting 1 core complex.

    Science.gov (United States)

    Jackson, Philip J; Hitchcock, Andrew; Swainsbury, David J K; Qian, Pu; Martin, Elizabeth C; Farmer, David A; Dickman, Mark J; Canniffe, Daniel P; Hunter, C Neil

    2018-02-01

    The X-ray crystal structure of the Rhodopseudomonas (Rps.) palustris reaction center-light harvesting 1 (RC-LH1) core complex revealed the presence of a sixth protein component, variably referred to in the literature as helix W, subunit W or protein W. The position of this protein prevents closure of the LH1 ring, possibly to allow diffusion of ubiquinone/ubiquinol between the RC and the cytochrome bc 1 complex in analogous fashion to the well-studied PufX protein from Rhodobacter sphaeroides. The identity and function of helix W have remained unknown for over 13years; here we use a combination of biochemistry, mass spectrometry, molecular genetics and electron microscopy to identify this protein as RPA4402 in Rps. palustris CGA009. Protein W shares key conserved sequence features with PufX homologs, and although a deletion mutant was able to grow under photosynthetic conditions with no discernible phenotype, we show that a tagged version of protein W pulls down the RC-LH1 complex. Protein W is not encoded in the photosynthesis gene cluster and our data indicate that only approximately 10% of wild-type Rps. palustris core complexes contain this non-essential subunit; functional and evolutionary consequences of this observation are discussed. The ability to purify uniform RC-LH1 and RC-LH1-protein W preparations will also be beneficial for future structural studies of these bacterial core complexes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Enriched reaction center preparation from green photosynthetic bacteria. [Chlorobium limicola

    Energy Technology Data Exchange (ETDEWEB)

    Olson, J M; Giddings, Jr, T H; Shaw, E K

    1976-01-01

    Bacteriochlorophyll a reaction-center complex I from Chlorobium limicola f. thiosulfatophilum 6230 (Tassajara) was incubated in 2 M guanidine . HCl and then chromatographed on cross-linked dextran or agarose gel. Two principal components were separated: a larger component with photochemical activity (bacteriochlorophyll a reaction-center complex II) and a smaller component without activity (bacteriochlorophyll a protein). Complex II contains carotenoid, bacteriochlorophyll a, reaction center(s), and cytochromes b and c, but lacks the well characterized bacteriochlorophyll a protein contained in Complex I. Complex II carries out a light-induced reduction of cytochrome b along with an oxidation of cytochrome c.

  3. Redox potential tuning through differential quinone binding in the photosynthetic reaction center of Rhodobacter sphaeroides.

    Science.gov (United States)

    Vermaas, Josh V; Taguchi, Alexander T; Dikanov, Sergei A; Wraight, Colin A; Tajkhorshid, Emad

    2015-03-31

    Ubiquinone forms an integral part of the electron transport chain in cellular respiration and photosynthesis across a vast number of organisms. Prior experimental results have shown that the photosynthetic reaction center (RC) from Rhodobacter sphaeroides is only fully functional with a limited set of methoxy-bearing quinones, suggesting that specific interactions with this substituent are required to drive electron transport and the formation of quinol. The nature of these interactions has yet to be determined. Through parameterization of a CHARMM-compatible quinone force field and subsequent molecular dynamics simulations of the quinone-bound RC, we have investigated and characterized the interactions of the protein with the quinones in the Q(A) and Q(B) sites using both equilibrium simulation and thermodynamic integration. In particular, we identify a specific interaction between the 2-methoxy group of ubiquinone in the Q(B) site and the amide nitrogen of GlyL225 that we implicate in locking the orientation of the 2-methoxy group, thereby tuning the redox potential difference between the quinones occupying the Q(A) and Q(B) sites. Disruption of this interaction leads to weaker binding in a ubiquinone analogue that lacks a 2-methoxy group, a finding supported by reverse electron transfer electron paramagnetic resonance experiments of the Q(A)⁻Q(B)⁻ biradical and competitive binding assays.

  4. Pigment organization and their interactions in reaction centers of photosystem II: optical spectroscopy at 6 K of reaction centers with modified pheophytin composition.

    Science.gov (United States)

    Germano, M; Shkuropatov, A Y; Permentier, H; de Wijn, R; Hoff, A J; Shuvalov, V A; van Gorkom, H J

    2001-09-25

    Photosystem II reaction centers (RC) with selectively exchanged pheophytin (Pheo) molecules as described in [Germano, M., Shkuropatov, A. Ya., Permentier, H., Khatypov, R. A., Shuvalov, V. A., Hoff, A. J., and van Gorkom, H. J. (2000) Photosynth. Res. 64, 189-198] were studied by low-temperature absorption, linear and circular dichroism, and triplet-minus-singlet absorption-difference spectroscopy. The ratio of extinction coefficients epsilon(Pheo)/epsilon(Chl) for Q(Y) absorption in the RC is approximately 0.40 at 6 K and approximately 0.45 at room temperature. The presence of 2 beta-carotenes, one parallel and one perpendicular to the membrane plane, is confirmed. Absorption at 670 nm is due to the perpendicular Q(Y) transitions of the two peripheral chlorophylls (Chl) and not to either Pheo. The "core" pigments, two Pheo and four Chl absorb in the 676-685 nm range. Delocalized excited states as predicted by the "multimer model" are seen in the active branch. The inactive Pheo and the nearby Chl, however, mainly contribute localized transitions at 676 and 680 nm, respectively, although large CD changes indicate that exciton interactions are present on both branches. Replacement of the active Pheo prevents triplet formation, causes an LD increase at 676 and 681 nm, a blue-shift of 680 nm absorbance, and a bleach of the 685 nm exciton band. The triplet state is mainly localized on the Chl corresponding to B(A) in purple bacteria. Both Pheo Q(Y) transitions are oriented out of the membrane plane. Their Q(X) transitions are parallel to that plane, so that the Pheos in PSII are structurally similar to their homologues in purple bacteria.

  5. On RC-spaces

    OpenAIRE

    Bielas, Wojciech; Plewik, Szymon

    2018-01-01

    Following Frink's characterization of completely regular spaces, we say that a regular T_1-space is an RC-space whenever the family of all regular open sets constitutes a regular normal base. Normal spaces are RC-spaces and there exist completely regular spaces which are not RC-spaces. So the question arises, which of the known examples of completely regular and not normal spaces are RC-spaces. We show that the Niemytzki plane and the Sorgenfrey plane are RC-spaces.

  6. Spectral properties of chlorines and electron transfer with their participation in the photosynthetic reaction center of photosystem II

    Science.gov (United States)

    Shchupak, E. E.; Ivashin, N. V.

    2014-02-01

    Structural factors that provide localization of excited states and determine the properties of primary donor and acceptor of electron in the reaction center of photosystem II (PSII RC) are studied. The results of calculations using stationary and time-dependent density functional theory indicate an important role of protein environments of chlorophylls PA, PB, BA, and BB and pheophytins HA and HB in the area with a radius of no greater than ≤10 Å in the formation of excitonic states of PSII RC. When the neighboring elements are taken into account, the wavelength of long-wavelength Q y transition of chlorophyll molecules is varied by about 10 nm. The effect is less developed for pheophytin molecules (Δλ ≅ 2 nm). The following elements strongly affect energy of the transition: HisA198 and HisD197 amino-acid residues that serve as ligands of magnesium atoms affect PA and PB, respectively; MetA183 affects PA; MetA172 and MetD198 affect BA; water molecules that are located above the planes of the BA and BB macrocycles form H bonds with carbonyl groups; and phytol chains of PA and PB affect BA, BB, HA, and HB. The analysis of excitonic states, mutual positions of molecular orbitals of electron donors and acceptors, and matrix elements of electron transfer reaction shows that (i) charge separation between BA and HA and PB and BA is possible in the active A branch of cofactors of PSII RC and (ii) electron transfer is blocked at the BB - HB fragment in inactive B branch of PSII RC.

  7. Orientations of Iron-Sulfur Clusters FA and FB in the Homodimeric Type-I Photosynthetic Reaction Center of Heliobacterium modesticaldum.

    Science.gov (United States)

    Kondo, Toru; Matsuoka, Masahiro; Azai, Chihiro; Itoh, Shigeru; Oh-Oka, Hirozo

    2016-05-12

    Orientations of the FA and FB iron-sulfur (FeS) clusters in a structure-unknown type-I homodimeric heriobacterial reaction center (hRC) were studied in oriented membranes of the thermophilic anaerobic photosynthetic bacterium Heliobacterium modesticaldum by electron paramagnetic resonance (EPR), and compared with those in heterodimeric photosystem I (PS I). The Rieske-type FeS center in the cytochrome b/c complex showed a well-oriented EPR signal. Illumination at 14 K induced an FB(-) signal with g-axes of gz = 2.066, gy = 1.937, and gx = 1.890, tilted at angles of 60°, 60°, and 45°, respectively, with respect to the membrane normal. Chemical reduction with dithionite produced an additional signal of FA(-), which magnetically interacted with FB(-), with gz = 2.046, gy = 1.942, and gx = 1.911 at 30°, 60°, and 90°, respectively. The angles and redox properties of FA(-) and FB(-) in hRC resemble those of FB(-) and FA(-), respectively, in PS I. Therefore, FA and FB in hRC, named after their g-value similarities, seem to be located like FB and FA, not like FA and FB, respectively, in PS I. The reducing side of hRC could resemble those in PS I, if the names of FA and FB are interchanged with each other.

  8. Mathematical Model of Synthesis Catalyst with Local Reaction Centers

    Directory of Open Access Journals (Sweden)

    I. V. Derevich

    2017-01-01

    Full Text Available The article considers a catalyst granule with a porous ceramic passive substrate and point active centers on which an exothermic synthesis reaction occurs. A rate of the chemical reaction depends on the temperature according to the Arrhenius law. Heat is removed from the pellet surface in products of synthesis due to heat transfer. In our work we first proposed a model for calculating the steady-state temperature of a catalyst pellet with local reaction centers. Calculation of active centers temperature is based on the idea of self-consistent field (mean-field theory. At first, it is considered that powers of the reaction heat release at the centers are known. On the basis of the found analytical solution, which describes temperature distribution inside the granule, the average temperature of the reaction centers is calculated, which then is inserted in the formula for heat release. The resulting system of transcendental algebraic equations is transformed into a system of ordinary differential equations of relaxation type and solved numerically to achieve a steady-state value. As a practical application, the article considers a Fischer-Tropsch synthesis catalyst granule with active cobalt metallic micro-particles. Cobalt micro-particles are the centers of the exothermic reaction of hydrocarbons macromolecular synthesis. Synthesis occurs as a result of absorption of the components of the synthesis gas on metallic cobalt. The temperature distribution inside the granule for a single local center and reaction centers located on the same granule diameter is found. It was found that there is a critical temperature of reactor exceeding of which leads to significant local overheating of the centers - thermal explosion. The temperature distribution with the local reaction centers is qualitatively different from the granule temperature, calculated in the homogeneous approximation. It is shown that, in contrast to the homogeneous approximation, the

  9. Unifying principles in homodimeric type I photosynthetic reaction centers: properties of PscB and the FA, FB and FX iron-sulfur clusters in green sulfur bacteria.

    Science.gov (United States)

    Jagannathan, Bharat; Golbeck, John H

    2008-12-01

    The photosynthetic reaction center from the green sulfur bacterium Chlorobium tepidum (CbRC) was solubilized from membranes using Triton X-100 and isolated by sucrose density ultra-centrifugation. The CbRC complexes were subsequently treated with 0.5 M NaCl and ultrafiltered over a 100 kDa cutoff membrane. The resulting CbRC cores did not exhibit the low-temperature EPR resonances from FA- and FB- and were unable to reduce NADP+. SDS-PAGE and mass spectrometric analysis showed that the PscB subunit, which harbors the FA and FB clusters, had become dissociated, and was now present in the filtrate. Attempts to rebind PscB onto CbRC cores were unsuccessful. Mössbauer spectroscopy showed that recombinant PscB contains a heterogeneous mixture of [4Fe-4S]2+,1+ and other types of Fe/S clusters tentatively identified as [2Fe-2S]2+,1+ clusters and rubredoxin-like Fe3+,2+ centers, and that the [4Fe-4S]2+,1+ clusters which were present were degraded at high ionic strength. Quantitative analysis confirmed that the amount of iron and sulfide in the recombinant protein was sub-stoichiometric. A heme-staining assay indicated that cytochrome c551 remained firmly attached to the CbRC cores. Low-temperature EPR spectroscopy of photoaccumulated CbRC complexes and CbRC cores showed resonances between g=5.4 and 4.4 assigned to a S=3/2 ground spin state [4Fe-4S]1+ cluster and at g=1.77 assigned to a S=1/2 ground spin state [4Fe-4S]1+ cluster, both from FX-. These results unify the properties of the acceptor side of the Type I homodimeric reaction centers found in green sulfur bacteria and heliobacteria: in both, the FA and FB iron-sulfur clusters are present on a salt-dissociable subunit, and FX is present as an interpolypeptide [4Fe-4S]2+,1+ cluster with a significant population in a S=3/2 ground spin state.

  10. The three-dimensional structures of bacterial reaction centers.

    Science.gov (United States)

    Olson, T L; Williams, J C; Allen, J P

    2014-05-01

    This review presents a broad overview of the research that enabled the structure determination of the bacterial reaction centers from Blastochloris viridis and Rhodobacter sphaeroides, with a focus on the contributions from Duysens, Clayton, and Feher. Early experiments performed in the laboratory of Duysens and others demonstrated the utility of spectroscopic techniques and the presence of photosynthetic complexes in both oxygenic and anoxygenic photosynthesis. The laboratories of Clayton and Feher led efforts to isolate and characterize the bacterial reaction centers. The availability of well-characterized preparations of pure and stable reaction centers allowed the crystallization and subsequent determination of the structures using X-ray diffraction. The three-dimensional structures of reaction centers revealed an overall arrangement of two symmetrical branches of cofactors surrounded by transmembrane helices from the L and M subunits, which also are related by the same twofold symmetry axis. The structure has served as a framework to address several issues concerning bacterial photosynthesis, including the directionality of electron transfer, the properties of the reaction center-cytochrome c 2 complex, and the coupling of proton and electron transfer. Together, these research efforts laid the foundation for ongoing efforts to address an outstanding question in oxygenic photosynthesis, namely the molecular mechanism of water oxidation.

  11. The calcium-dependent protein kinase RcCDPK2 phosphorylates sucrose synthase at Ser11 in developing castor oil seeds.

    Science.gov (United States)

    Fedosejevs, Eric T; Gerdis, Suzanne A; Ying, Sheng; Pyc, Michal; Anderson, Erin M; Snedden, Wayne A; Mullen, Robert T; She, Yi-Min; Plaxton, William C

    2016-10-15

    Imported sucrose is cleaved by sucrose synthase (SUS) as a critical initial reaction in the biosynthesis of storage end-products by developing seeds. Although SUS is phosphorylated at a conserved seryl residue by an apparent CDPK (Ca 2+ -dependent protein kinase) in diverse plant tissues, the functions and mechanistic details of this process remain obscure. Thus, the native CDPK that phosphorylates RcSUS1 (Ricinus communis SUS1) at Ser 11 in developing COS (castor oil seeds) was highly purified and identified as RcCDPK2 by MS/MS. Purified RcSUS1-K (-kinase) and heterologously expressed RcCDPK2 catalyzed Ca 2+ -dependent Ser 11 phosphorylation of RcSUS1 and its corresponding dephosphopeptide, while exhibiting a high affinity for free Ca 2+ ions [K 0.5 (Ca 2+ ) < 0.4 µM]. RcSUS1-K activity, RcCDPK2 expression, and RcSUS1 Ser 11 phosphorylation peaked during early COS development and then declined in parallel. The elimination of sucrose import via fruit excision triggered RcSUS1 dephosphorylation but did not alter RcSUS1-K activity, suggesting a link between sucrose signaling and posttranslational RcCDPK2 control. Both RcCDPK2-mCherry and RcSUS1-EYFP co-localized throughout the cytosol when transiently co-expressed in tobacco suspension cells, although RcCDPK2-mCherry was also partially localized to the nucleus. Subcellular fractionation revealed that ∼20% of RcSUS1-K activity associates with microsomal membranes in developing COS, as does RcSUS1. In contrast with RcCDPK1, which catalyzes inhibitory phosphorylation of COS bacterial-type phosphoenolpyruvate carboxylase at Ser 451 , RcCDPK2 exhibited broad substrate specificity, a wide pH-activity profile centered at pH 8.5, and insensitivity to metabolite effectors or thiol redox status. Our combined results indicate a possible link between cytosolic Ca 2+ -signaling and the control of photosynthate partitioning during COS development. © 2016 The Author(s); published by Portland Press Limited on behalf of the

  12. The binding of quinone to the photosynthetic reaction centers: kinetics and thermodynamics of reactions occurring at the QB-site in zwitterionic and anionic liposomes.

    Science.gov (United States)

    Mavelli, Fabio; Trotta, Massimo; Ciriaco, Fulvio; Agostiano, Angela; Giotta, Livia; Italiano, Francesca; Milano, Francesco

    2014-07-01

    Liposomes represent a versatile biomimetic environment for studying the interaction between integral membrane proteins and hydrophobic ligands. In this paper, the quinone binding to the QB-site of the photosynthetic reaction centers (RC) from Rhodobacter sphaeroides has been investigated in liposomes prepared with either the zwitterionic phosphatidylcholine (PC) or the negatively charged phosphatidylglycerol (PG) to highlight the role of the different phospholipid polar heads. Quinone binding (K Q) and interquinone electron transfer (L AB) equilibrium constants in the two type of liposomes were obtained by charge recombination reaction of QB-depleted RC in the presence of increasing amounts of ubiquinone-10 over the temperature interval 6-35 °C. The kinetic of the charge recombination reactions has been fitted by numerically solving the ordinary differential equations set associated with a detailed kinetic scheme involving electron transfer reactions coupled with quinone release and uptake. The entire set of traces at each temperature was accurately fitted using the sole quinone release constants (both in a neutral and a charge separated state) as adjustable parameters. The temperature dependence of the quinone exchange rate at the QB-site was, hence, obtained. It was found that the quinone exchange regime was always fast for PC while it switched from slow to fast in PG as the temperature rose above 20 °C. A new method was introduced in this paper for the evaluation of constant K Q using the area underneath the charge recombination traces as the indicator of the amount of quinone bound to the QB-site.

  13. Radiolabelling of RC-160: preliminary results

    International Nuclear Information System (INIS)

    Verdera, E.S.; Balter Binsky, H.S.; Robles, A.M.; Rodriguez, G.; Souto, B.; Laiz, J.; Oliver, P.; Leon, E.

    1998-01-01

    Vapreotide (RC-160) was labelled with 125 I using Chloramine-T and Iodogen methods and with 99m Tc by a direct method with sodium ditionite as reducing agent in the presence of ascorbic acid. Several methods of purification and quality control were evaluated. Yields of the reactions and of purification steps were calculated. The results obtained for the radioiodination reactions showed higher yields when limiting Chloramine-T method was used. Labelling of RC-160 with 99m Tc indicated better yields when high radioactivity concentration of the radionuclide was used. Stability of the products obtained was assessed at different post-labelling times by selected quality control methods: Sep-Pak cartridge as purification method and chromatography by RP-HPLC and ITLC-SG using saline solution as solvent. It was demonstrated that I-125-RC-160 and Tc-99m-RC-160 were stable during five weeks (at -20 deg. C) and 6 hours (at room temperature) respectively. Preliminary biodistribution of Tc-99m-RC-160 in normal rats and mice were done showing different biological behaviour compared with control animals injected with pertechnetate. In conclusion, RC-160 was successfully labelled with both radionuclides, with radiochemical purity higher than 95%. These results encourage further research work in animal models as well as to investigate the biochemical behaviour of radiolabelled peptide. (author)

  14. Quantum measurement corrections to CIDNP in photosynthetic reaction centers

    International Nuclear Information System (INIS)

    Kominis, Iannis K

    2013-01-01

    Chemically induced dynamic nuclear polarization is a signature of spin order appearing in many photosynthetic reaction centers. Such polarization, significantly enhanced above thermal equilibrium, is known to result from the nuclear spin sorting inherent in the radical pair mechanism underlying long-lived charge-separated states in photosynthetic reaction centers. We will show here that the recently understood fundamental quantum dynamics of radical-ion-pair reactions open up a new and completely unexpected pathway toward obtaining chemically induced dynamic nuclear polarization signals. The fundamental decoherence mechanism inherent in the recombination process of radical pairs is shown to produce nuclear spin polarizations of the order of 10 4 times (or more) higher than the thermal equilibrium value at the Earth's magnetic field relevant to natural photosynthesis. This opens up the possibility of a fundamentally new exploration of the biological significance of high nuclear polarizations in photosynthesis. (paper)

  15. Early bacteriopheophytin reduction in charge separation in reaction centers of Rhodobacter sphaeroides.

    Science.gov (United States)

    Zhu, Jingyi; van Stokkum, Ivo H M; Paparelli, Laura; Jones, Michael R; Groot, Marie Louise

    2013-06-04

    A question at the forefront of biophysical sciences is, to what extent do quantum effects and protein conformational changes play a role in processes such as biological sensing and energy conversion? At the heart of photosynthetic energy transduction lie processes involving ultrafast energy and electron transfers among a small number of tetrapyrrole pigments embedded in the interior of a protein. In the purple bacterial reaction center (RC), a highly efficient ultrafast charge separation takes place between a pair of bacteriochlorophylls: an accessory bacteriochlorophyll (B) and bacteriopheophytin (H). In this work, we applied ultrafast spectroscopy in the visible and near-infrared spectral region to Rhodobacter sphaeroides RCs to accurately track the timing of the electron on BA and HA via the appearance of the BA and HA anion bands. We observed an unexpectedly early rise of the HA⁻ band that challenges the accepted simple picture of stepwise electron transfer with 3 ps and 1 ps time constants. The implications for the mechanism of initial charge separation in bacterial RCs are discussed in terms of a possible adiabatic electron transfer step between BA and HA, and the effect of protein conformation on the electron transfer rate. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. The Type 1 Homodimeric Reaction Center in Heliobacterium modesticaldum

    Energy Technology Data Exchange (ETDEWEB)

    Golbeck, John [Pennsylvania State Univ., University Park, PA (United States)

    2018-01-15

    In this funding period, we (i) found that strong illumination of Heliobacterium modesticaldum cells results in saturation of the electron acceptor pool, leading to reduction of the acceptor side and the creation of a back-reacting state that gives rise to delayed fluorescence; (ii) noted that when the FX cluster is reduced in purified reaction centers, no electron transfer occurs beyond A0, even though a quinone is present; (iii) observed by photochemically induced dynamic nuclear polarization (photo-CIDNP) studies of whole cells of Heliobacterium mobilis that primary charge separation is retained even after conversion of the majority of BChl g to Chl aF. ; and (iv) purified a homogeneous preparation of reaction center cores, which led to promising crystallization trials to obtain a three-dimensional structure.

  17. The effects of protein crowding in bacterial photosynthetic membranes on the flow of quinone redox species between the photochemical reaction center and the ubiquinol-cytochrome c2 oxidoreductase.

    Science.gov (United States)

    Woronowicz, Kamil; Sha, Daniel; Frese, Raoul N; Sturgis, James N; Nanda, Vikas; Niederman, Robert A

    2011-08-01

    Atomic force microscopy (AFM) of the native architecture of the intracytoplasmic membrane (ICM) of a variety of species of purple photosynthetic bacteria, obtained at submolecular resolution, shows a tightly packed arrangement of light harvesting (LH) and reaction center (RC) complexes. Since there are no unattributed structures or gaps with space sufficient for the cytochrome bc(1) or ATPase complexes, they are localized in membrane domains distinct from the flat regions imaged by AFM. This has generated a renewed interest in possible long-range pathways for lateral diffusion of UQ redox species that functionally link the RC and the bc(1) complexes. Recent proposals to account for UQ flow in the membrane bilayer are reviewed, along with new experimental evidence provided from an analysis of intrinsic near-IR fluorescence emission that has served to test these hypotheses. The results suggest that different mechanism of UQ flow exist between species such as Rhodobacter sphaeroides, with a highly organized arrangement of LH and RC complexes and fast RC electron transfer turnover, and Phaeospirillum molischianum with a more random organization and slower RC turnover. It is concluded that packing density of the peripheral LH2 antenna in the Rba. sphaeroides ICM imposes constraints that significantly slow the diffusion of UQ redox species between the RC and cytochrome bc(1) complex, while in Phs. molischianum, the crowding of the ICM with LH3 has little effect upon UQ diffusion. This supports the proposal that in this type of ICM, a network of RC-LH1 core complexes observed in AFM provides a pathway for long-range quinone diffusion that is unaffected by differences in LH complex composition or organization.

  18. Energetic change of the primary quinone in photosynthetic reaction center. Mutation, delayed fluorescence and model calculations (Theses of the Ph.D. dissertation)

    International Nuclear Information System (INIS)

    Rinyu, L.

    2007-01-01

    Complete text of publication follows. Photosynthesis is one of the basic metabolic processes of living organisms. Photosynthesizing species (bacteria, algae and higher class plants) convert the energy of light into other forms of free energy (redox potential, electro- chemical potential of ions and protons and phosphate-potential) which are directly suit- able either to cover the energy need of the vital processes of the cell or to storage. In reaction center (RC) protein of photo- synthetic bacteria, electron transfer is initiated upon light excitation from the excited bacteriochlorophyll dimer (P) to the secondary quinone (Q B ) via bacteriopheophytine (Bph) and the primary quinone (Q A ). In Rhodobacter sphaeroides purple bacteria, both quinones are ubiquinone-10, but due to the different protein environment, their electrochemical properties is highly different. Whereas Q A makes one-electron chemistry, Q B can be doubly reduced to form hydroquinone, Q B H 2 by uptake of two protons. Q B H 2 subsequently leaves the RC and is replaced by an oxidized quinone from to membrane pool. The semiquinones are important intermediates in the quinone reduction cycle of the RC. The redox midpoint potentials of the Q/Q - redox pairs (E m ) are also different: the Q A /Q A - has 60 mV more negative potential than the Q B /Q B - couple (pH 8) to make the (interquinone) electron transfer favorable. For fine tuning of the midpoint redox potentials of the quinones, the protein assures appropriate steric and electrostatic environment. The most important aim of this study was the design and production of reaction center mutants in the binding pocket of the primary quinone to investigate the effect of the amino acids of the protein and lipids of the membrane on the thermodynamics of the primary quinone. The first priority was the determination of the absolute free energy gap between the P* and the P + Q A - states in wild type and mutant reaction centers by comparison of the

  19. Regulation of Germinal Center Reactions by B and T Cells

    Directory of Open Access Journals (Sweden)

    Yeonseok Chung

    2013-10-01

    Full Text Available Break of B cell tolerance to self-antigens results in the development of autoantibodies and, thus, leads to autoimmunity. How B cell tolerance is maintained during active germinal center (GC reactions is yet to be fully understood. Recent advances revealed several subsets of T cells and B cells that can positively or negatively regulate GC B cell responses in vivo. IL-21-producing CXCR5+ CD4+ T cells comprise a distinct lineage of helper T cells—termed follicular helper T cells (TFH—that can provide help for the development of GC reactions where somatic hypermutation and affinity maturation take place. Although the function of TFH cells is beneficial in generating high affinity antibodies against infectious agents, aberrant activation of TFH cell or B cell to self-antigens results in autoimmunity. At least three subsets of immune cells have been proposed as regulatory cells that can limit such antibody-mediated autoimmunity, including follicular regulatory T cells (TFR, Qa-1 restricted CD8+ regulatory T cells (CD8+TREG, and regulatory B cells (BREG. In this review, we will discuss our current understanding of GC B cell regulation with specific emphasis on the newly identified immune cell subsets involved in this process.

  20. Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, J; Sener, M; Schulten, K [Department of Physics and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Struempfer, J [Center for Biophysics and Computational Biology and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Qian, P; Hunter, C N, E-mail: kschulte@ks.uiuc.ed [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom)

    2010-08-15

    Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

  1. Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

    International Nuclear Information System (INIS)

    Hsin, J; Sener, M; Schulten, K; Struempfer, J; Qian, P; Hunter, C N

    2010-01-01

    Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

  2. Purple-bacterial photosynthetic reaction centers and quantum-dot hybrid-assemblies in lecithin liposomes and thin films.

    Science.gov (United States)

    Lukashev, Eugeny P; Knox, Petr P; Gorokhov, Vladimir V; Grishanova, Nadezda P; Seifullina, Nuranija Kh; Krikunova, Maria; Lokstein, Heiko; Paschenko, Vladimir Z

    2016-11-01

    Quantum dots (QDs) absorb ultraviolet and long-wavelength visible light energy much more efficiently than natural bacterial light-harvesting proteins and can transfer the excitation energy to photosynthetic reaction centers (RCs). Inclusion of RCs combined with QDs as antennae into liposomes opens new opportunities for using such hybrid systems as a basis for artificial energy-transforming devices that potentially can operate with greater efficiency and stability than devices based only on biological components or inorganic components alone. RCs from Rhodobacter sphaeroides and QDs (CdSe/ZnS with hydrophilic covering) were embedded in lecithin liposomes by extrusion of a solution of multilayer lipid vesicles through a polycarbonate membrane or by dialysis of lipids and proteins dispersed with excess detergent. The efficiency of RC and QD interaction within the liposomes was estimated using fluorescence excitation spectra of the photoactive bacteriochlorophyll of the RCs and by measuring the fluorescence decay kinetics of the QDs. The functional activity of the RCs in hybrid complexes was fully maintained, and their stability was even increased. The efficiency of energy transfer between QDs and RCs and conditions of long-term stability of function of such hybrid complexes in film preparations were investigated as well. It was found that dry films containing RCs and QDs, maintained at atmospheric humidity, are capable of maintaining their functional activity for at least some months as judged by measurements of their spectral characteristics, efficiency of energy transfer from QDs to RCs and RC electron transport activity. Addition of trehalose to the films increases the stability further, especially for films maintained at low humidity. These stable hybrid film structures are promising for further studies towards developing new phototransformation devices for biotechnological applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Effects of Calcium Ions on the Thermostability and Spectroscopic Properties of the LH1-RC Complex from a New Thermophilic Purple Bacterium Allochromatium tepidum.

    Science.gov (United States)

    Kimura, Yukihiro; Lyu, Shuwen; Okoshi, Akira; Okazaki, Koudai; Nakamura, Natsuki; Ohashi, Akira; Ohno, Takashi; Kobayashi, Manami; Imanishi, Michie; Takaichi, Shinichi; Madigan, Michael T; Wang-Otomo, Zheng-Yu

    2017-05-18

    The light harvesting-reaction center (LH1-RC) complex from a new thermophilic purple sulfur bacterium Allochromatium (Alc.) tepidum was isolated and characterized by spectroscopic and thermodynamic analyses. The purified Alc. tepidum LH1-RC complex showed a high thermostability comparable to that of another thermophilic purple sulfur bacterium Thermochromatium tepidum, and spectroscopic characteristics similar to those of a mesophilic bacterium Alc. vinosum. Approximately 4-5 Ca 2+ per LH1-RC were detected by inductively coupled plasma atomic emission spectroscopy and isothermal titration calorimetry. Upon removal of Ca 2+ , the denaturing temperature of the Alc. tepidum LH1-RC complex dropped accompanied by a blue-shift of the LH1 Q y absorption band. The effect of Ca 2+ was also observed in the resonance Raman shift of the C3-acetyl νC═O band of bacteriochlorophyll-a, indicating changes in the hydrogen-bonding interactions between the pigment and LH1 polypeptides. Thermodynamic parameters for the Ca 2+ -binding to the Alc. tepidum LH1-RC complex indicated that this reaction is predominantly driven by the largely favorable electrostatic interactions that counteract the unfavorable negative entropy change. Our data support a hypothesis that Alc. tepidum may be a transitional organism between mesophilic and thermophilic purple bacteria and that Ca 2+ is one of the major keys to the thermostability of LH1-RC complexes in purple bacteria.

  4. Site Energies of Active and Inactive Pheophytins in the Reaction Center of Photosystem II from Chlamydomonas Reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, K.; Neupane, B.; Zazubovich, V.; Sayre, R. T.; Picorel, R.; Seibert, M.; Jankowiak, R.

    2012-03-29

    It is widely accepted that the primary electron acceptor in various Photosystem II (PSII) reaction center (RC) preparations is pheophytin {alpha} (Pheo {alpha}) within the D1 protein (Pheo{sub D1}), while Pheo{sub D2} (within the D2 protein) is photochemically inactive. The Pheo site energies, however, have remained elusive, due to inherent spectral congestion. While most researchers over the past two decades placed the Q{sub y}-states of Pheo{sub D1} and Pheo{sub D2} bands near 678-684 and 668-672 nm, respectively, recent modeling [Raszewski et al. Biophys. J. 2005, 88, 986-998; Cox et al. J. Phys. Chem. B 2009, 113, 12364-12374] of the electronic structure of the PSII RC reversed the assignment of the active and inactive Pheos, suggesting that the mean site energy of Pheo{sub D1} is near 672 nm, whereas Pheo{sub D2} ({approx}677.5 nm) and Chl{sub D1} ({approx}680 nm) have the lowest energies (i.e., the Pheo{sub D2}-dominated exciton is the lowest excited state). In contrast, chemical pigment exchange experiments on isolated RCs suggested that both pheophytins have their Q{sub y} absorption maxima at 676-680 nm [Germano et al. Biochemistry 2001, 40, 11472-11482; Germano et al. Biophys. J. 2004, 86, 1664-1672]. To provide more insight into the site energies of both Pheo{sub D1} and Pheo{sub D2} (including the corresponding Q{sub x} transitions, which are often claimed to be degenerate at 543 nm) and to attest that the above two assignments are most likely incorrect, we studied a large number of isolated RC preparations from spinach and wild-type Chlamydomonas reinhardtii (at different levels of intactness) as well as the Chlamydomonas reinhardtii mutant (D2-L209H), in which the active branch Pheo{sub D1} is genetically replaced with chlorophyll {alpha} (Chl {alpha}). We show that the Q{sub x}-/Q{sub y}-region site energies of Pheo{sub D1} and Pheo{sub D2} are {approx}545/680 nm and {approx}541.5/670 nm, respectively, in good agreement with our previous assignment

  5. Role of Rhodobacter sphaeroides photosynthetic reaction center residue M214 in the composition, absorbance properties, and conformations of H(A) and B(A) cofactors.

    Science.gov (United States)

    Saer, Rafael G; Hardjasa, Amelia; Rosell, Federico I; Mauk, A Grant; Murphy, Michael E P; Beatty, J Thomas

    2013-04-02

    In the native reaction center (RC) of Rhodobacter sphaeroides, the side chain of (M)L214 projects orthogonally toward the plane and into the center of the A branch bacteriopheophytin (BPhe) macrocycle. The possibility that this side chain is responsible for the dechelation of the central Mg(2+) of bacteriochlorophyll (BChl) was investigated by replacement of (M)214 with residues possessing small, nonpolar side chains that can neither coordinate nor block access to the central metal ion. The (M)L214 side chain was also replaced with Cys, Gln, and Asn to evaluate further the requirements for assembly of the RC with BChl in the HA pocket. Photoheterotrophic growth studies showed no difference in growth rates of the (M)214 nonpolar mutants at a low light intensity, but the growth of the amide-containing mutants was impaired. The absorbance spectra of purified RCs indicated that although absorbance changes are associated with the nonpolar mutations, the nonpolar mutant RC pigment compositions are the same as in the wild-type protein. Crystal structures of the (M)L214G, (M)L214A, and (M)L214N mutants were determined (determined to 2.2-2.85 Å resolution), confirming the presence of BPhe in the HA pocket and revealing alternative conformations of the phytyl tail of the accessory BChl in the BA site of these nonpolar mutants. Our results demonstrate that (i) BChl is converted to BPhe in a manner independent of the aliphatic side chain length of nonpolar residues replacing (M)214, (ii) BChl replaces BPhe if residue (M)214 has an amide-bearing side chain, (iii) (M)214 side chains containing sulfur are not sufficient to bind BChl in the HA pocket, and (iv) the (M)214 side chain influences the conformation of the phytyl tail of the BA BChl.

  6. Structure and function of cytochrome c2 in electron transfer complexes with the photosynthetic reaction center of Rhodobacter sphaeroides: optical linear dichroism and EPR.

    Science.gov (United States)

    Drepper, F; Mathis, P

    1997-02-11

    The photosynthetic reaction center (RC) and its secondary electron donor the water-soluble cytochrome (cyt) c2 from the purple bacterium Rhodobacter sphaeroides have been used in cross-linked and non-cross-linked complexes, oriented in compressed gels or partially dried multilayers, to study the respective orientation of the primary donor P (BChl dimer) and of cyt c2. Three methods were used: (i) Polarized optical absorption spectra at 295 and 10 K were measured and the linear dichroism of the two individual transitions (Qx, Qy), which are nearly degenerate within the alpha-band of reduced cyt c2, was determined. Attribution of the polarization directions to the molecular axes within the heme plane yielded the average cyt orientation in the complexes. (ii) Time-resolved flash absorption measurements using polarized light allowed determination of the orientation of cyt c2 in complexes which differ in their kinetics of electron transfer. (iii) EPR spectroscopy of ferricyt c2 in cross-linked RC-cyt c2 complexes was used to determine the angle between the heme and the membrane plane. The results suggest the following structural properties for the docking of cyt c2 to the RC: (i) In cross-linked complexes, the two cytochromes displaying half-lives of 0.7 and 60 micros for electron transfer to P+ are similarly oriented (difference plane is parallel to the symmetry axis of the RC (0 degrees +/- 10 degrees). Moreover, the Qy transition, which is assumed to be polarized within the ring III-ring I direction of the heme plane, makes an angle of 56 degrees +/- 1 degree with the symmetry axis. (iii) The dichroism spectrum for the fast phase (0.7 micros) for the non-cross-linked cyt c2-RC complex suggests an orientation similar to that of cross-linked cyt c2, but the heme plane is tilted about 20 degrees closer to the membrane. An alternative model is that two or more bound states of cyt c2 with heme plane tilt angles between 0 degrees and 30 degrees allow the fast electron

  7. Measuring what matters to rare disease patients - reflections on the work by the IRDiRC taskforce on patient-centered outcome measures.

    Science.gov (United States)

    Morel, Thomas; Cano, Stefan J

    2017-11-02

    Our ability to evaluate outcomes which genuinely reflect patients' unmet needs, hopes and concerns is of pivotal importance. However, much current clinical research and practice falls short of this objective by selecting outcome measures which do not capture patient value to the fullest. In this Opinion, we discuss Patient-Centered Outcomes Measures (PCOMs), which have the potential to systematically incorporate patient perspectives to measure those outcomes that matter most to patients. We argue for greater multi-stakeholder collaboration to develop PCOMs, with rare disease patients and families at the center. Beyond advancing the science of patient input, PCOMs are powerful tools to translate care or observed treatment benefit into an 'interpretable' measure of patient benefit, and thereby help demonstrate clinical effectiveness. We propose mixed methods psychometric research as the best route to deliver fit-for-purpose PCOMs in rare diseases, as this methodology brings together qualitative and quantitative research methods in tandem with the explicit aim to efficiently utilise data from small samples. And, whether one opts to develop a brand-new PCOM or to select or adapt an existing outcome measure for use in a rare disease, the anchors remain the same: patients, their daily experience of the rare disease, their preferences, core concepts and values. Ultimately, existing value frameworks, registries, and outcomes-based contracts largely fall short of consistently measuring the full range of outcomes that matter to patients. We argue that greater use of PCOMs in rare diseases would enable a fast track to Patient-Centered Care.

  8. Equilibration kinetics in isolated and membrane-bound photosynthetic reaction centers upon illumination: a method to determine the photoexcitation rate.

    Science.gov (United States)

    Manzo, Anthony J; Goushcha, Alexander O; Barabash, Yuri M; Kharkyanen, Valery N; Scott, Gary W

    2009-07-01

    Kinetics of electron transfer, following variation of actinic light intensity, for photosynthetic reaction centers (RCs) of purple bacteria (isolated and membrane-bound) were analyzed by measuring absorbance changes in the primary photoelectron donor absorption band at 865 nm. The bleaching of the primary photoelectron donor absorption band in RCs, following a sudden increase of illumination from the dark to an actinic light intensity of I(exp), obeys a simple exponential law with the rate constant alphaI(exp) + k(rec), in which alpha is a parameter relating the light intensity, measured in mW/cm(2), to a corresponding theoretical rate in units of reciprocal seconds, and k(rec) is the effective rate constant of the charge recombination in the photosynthetic RCs. In this work, a method for determining the alpha parameter value is developed and experimentally verified for isolated and membrane-bound RCs, allowing for rigorous modeling of RC macromolecule dynamics under varied photoexcitation conditions. Such modeling is necessary for RCs due to alterations of the forward photoexcitation rates and relaxation rates caused by illumination history and intramolecular structural dynamics effects. It is demonstrated that the classical Bouguer-Lambert-Beer formalism can be applied for the samples with relatively low scattering, which is not necessarily the case with strongly scattering media or high light intensity excitation.

  9. Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3-thiophene acetic acid) conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, T.; Magyar, M.; Nagy, L. [Department of Medical Physics and Informatics, University of Szeged, H-6720 Szeged (Hungary); Nemeth, Z.; Hernadi, K. [Department of Applied and Environmental Chemistry, University of Szeged, H-6720 Szeged (Hungary); Endrodi, B.; Bencsik, G.; Visy, Cs. [Department of Physical Chemistry and Materials Science, University of Szeged, H-6720 Szeged (Hungary); Horvath, E.; Magrez, A.; Forro, L. [Institute of Physics of Complex Matter, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

    2012-12-15

    A large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio-nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3-thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Nuclear Reaction Data File for Astrophysics (NRDF/A) in Hokkaido University Nuclear Reaction Data Center

    International Nuclear Information System (INIS)

    Kato, Kiyoshi; Kimura, Masaaki; Furutachi, Naoya; Makinaga, Ayano; Togashi, Tomoaki; Otuka, Naohiko

    2010-01-01

    The activities of the Japan Nuclear Reaction Data Centre is explained. The main task of the centre is data compilation of Japanese nuclear reaction data in collaboration of the International Network of Nuclear Reaction Data Centres. As one of recent activities, preparation of a new database (NRDF/A) and evaluation of astronuclear reaction data are reported. Collaboration in the nuclear data activities among Asian countries is proposed.

  11. Reactions of [WI2(CO)(NCMe)(η2-RC2R)2] (R = Me, Ph) with pyridines and related ligands, X-ray crystal structure of [WI(CO)(bpy)(η2-MeC2Me)2][BPh4

    International Nuclear Information System (INIS)

    Baker, P.K.; Armstrong, E.M.; Drew, M.G.B.

    1988-01-01

    The reactions of the highly versatile bis(alkyne) compounds [WI 2 (CO)(NCMe)(η 2 -RC 2 R) 2 ] (R = Me, Ph) with pyridine and related ligands to give neutral and cationic alkyne complexes are reported. The x-ray structure of [WI 2 (CO)(bpy)(η 2 -MeC 2 Me) 2 ][BPh 4 ] was also measured and is reported. 10 references, 1 figure, 6 tables

  12. B-side charge separation in bacterial photosynthetic reaction centers: nanosecond time scale electron transfer from HB- to QB.

    Science.gov (United States)

    Kirmaier, Christine; Laible, Philip D; Hanson, Deborah K; Holten, Dewey

    2003-02-25

    We report time-resolved optical measurements of the primary electron transfer reactions in Rhodobacter capsulatus reaction centers (RCs) having four mutations: Phe(L181) --> Tyr, Tyr(M208) --> Phe, Leu(M212) --> His, and Trp(M250) --> Val (denoted YFHV). Following direct excitation of the bacteriochlorophyll dimer (P) to its lowest excited singlet state P, electron transfer to the B-side bacteriopheophytin (H(B)) gives P(+)H(B)(-) in approximately 30% yield. When the secondary quinone (Q(B)) site is fully occupied, P(+)H(B)(-) decays with a time constant estimated to be in the range of 1.5-3 ns. In the presence of excess terbutryn, a competitive inhibitor of Q(B) binding, the observed lifetime of P(+)H(B)(-) is noticeably longer and is estimated to be in the range of 4-8 ns. On the basis of these values, the rate constant for P(+)H(B)(-) --> P(+)Q(B)(-) electron transfer is calculated to be between approximately (2 ns)(-)(1) and approximately (12 ns)(-)(1), making it at least an order of magnitude smaller than the rate constant of approximately (200 ps)(-)(1) for electron transfer between the corresponding A-side cofactors (P(+)H(A)(-) --> P(+)Q(A)(-)). Structural and energetic factors associated with electron transfer to Q(B) compared to Q(A) are discussed. Comparison of the P(+)H(B)(-) lifetimes in the presence and absence of terbutryn indicates that the ultimate (i.e., quantum) yield of P(+)Q(B)(-) formation relative to P is 10-25% in the YFHV RC.

  13. Chalcogenide metal centers for oxygen reduction reaction: Activity and tolerance

    International Nuclear Information System (INIS)

    Feng Yongjun; Gago, Aldo; Timperman, Laure; Alonso-Vante, Nicolas

    2011-01-01

    This mini-review summarizes materials design methods, oxygen reduction kinetics, tolerance to small organic molecules and fuel cell performance of chalcogenide metal catalysts, particularly, ruthenium (Ru x Se y ) and non-precious transition metals (M x X y : M = Co, Fe and Ni; X = Se and S). These non-platinum catalysts are potential alternatives to Pt-based catalysts because of their comparable catalytic activity (Ru x Se y ), low cost, high abundance and, in particular, a high tolerance to small organic molecules. Developing trends of synthesis methods, mechanism of oxygen reduction reaction and applications in direct alcohol fuel cells as well as the substrate effect are highlighted.

  14. Structural model and excitonic properties of the dimeric RC-LH1-PufX complex from Rhodobacter sphaeroides

    International Nuclear Information System (INIS)

    Sener, Melih; Hsin, Jen; Trabuco, Leonardo G.; Villa, Elizabeth; Qian, Pu; Hunter, C. Neil; Schulten, Klaus

    2009-01-01

    The light-harvesting apparatus of the purple bacterial photosynthetic unit consists of a pool of peripheral light-harvesting complexes that transfer excitation energy to a reaction center (RC) via the surrounding pigment-protein complex LH1. Recent electron microscopy and atomic force microscopy studies have revealed that RC-LH1 units of Rhodobacter (Rba.) sphaeroides form membrane-bending dimeric complexes together with the polypeptide PufX. We present a structural model for these RC-LH1-PufX dimeric complexes constructed using the molecular dynamics flexible fitting method based on an EM density map. The arrangement of the LH1 BChls displays a distortion near the proposed location of the PufX polypeptide. The resulting atomic model for BChl arrays is used to compute the excitonic properties of the dimeric RC-LH1 complex. A comparison is presented between the structural and excitonic features of the S-shaped dimeric BChl array of Rba. sphaeroides and the circular BChl arrangement found in other purple bacteria

  15. Role of the PufX protein in photosynthetic growth of Rhodobacter sphaeroides. 2. PufX is required for efficient ubiquinone/ubiquinol exchange between the reaction center QB site and the cytochrome bc1 complex.

    Science.gov (United States)

    Barz, W P; Verméglio, A; Francia, F; Venturoli, G; Melandri, B A; Oesterhelt, D

    1995-11-21

    The PufX membrane protein is essential for photosynthetic growth of Rhodobacter sphaeroides because it is required for multiple-turnover electron transfer under anaerobic conditions [see accompanying article; Barz, W. P., Francia, F., Venturoli, G., Melandri, B. A., Verméglio, A., & Oesterhelt, D. (1995) Biochemistry 34, 15235-15247]. In order to understand the molecular role of PufX, light-induced absorption spectroscopy was performed using a pufX- mutant, a pufX+ strain, and two suppressor mutants. We show that the reaction center (RC) requires PufX for its functionality under different redox conditions than the cytochrome bc1 complex: When the kinetics of flash-induced reduction of cytochrome b561 were monitored in chromatophores, we observed a requirement of PufX for turnover of the cytochrome bc1 complex only at high redox potential (Eh > 140 mV), suggesting a function of PufX in lateral ubiquinol transfer from the RC. In contrast, PufX is required for multiple turnover of the RC only under reducing conditions: When the Q pool was partially oxidized in vivo using oxygen or electron acceptors like dimethyl sulfoxide or trimethylamine N-oxide, the deletion of PufX had no effect on light-driven electron flow through the RC. Flash train experiments under anaerobic in vivo conditions revealed that RC photochemistry does not depend on PufX for the first two flash excitations. Following the third and subsequent flashes, however, efficient charge separation requires PufX, indicating an important role of PufX for fast Q/QH2 exchange at the QB site of the RC. We show that the Q/QH2 exchange rate is reduced approximately 500-fold by the deletion of PufX when the Q pool is nearly completely reduced, demonstrating an essential role of PufX for the access of ubiquinone to the QB site. The fast ubiquinone/ubiquinol exchange is partially restored by suppressor mutations altering the macromolecular antenna structure. These results suggest an indirect role of PufX in

  16. 11. IAEA consultants' meeting of the nuclear reaction data centers. Obninsk, 7-11 October 1991

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1992-03-01

    This report summarizes the 1991 co-ordination meeting in Obninsk, Russia, of the national and regional nuclear reaction data centers, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation; the exchanged and documentation of evaluated data libraries in ENDF format, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials

  17. Photosynthetic antennas and reaction centers: Current understanding and prospects for improvement

    Energy Technology Data Exchange (ETDEWEB)

    Blankenship, R.E. [Arizona State Univ., Tempe, AZ (United States)

    1996-09-01

    A brief introduction to the principles, structures and kinetic processes that take place in natural photosynthetic reaction center complexes is presented. Energy is first collected by an antenna system, and is transferred to a reaction center complex where primary electron transfer takes place. Secondary reactions lead to oxidation of water and reduction of CO{sub 2} in some classes of organisms. Antenna systems are highly regulated to maximize energy collection efficiency while avoiding photodamage. Some areas that are presently not well understood are listed.

  18. Co-ordination of the nuclear reaction data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Schwerer, O.; Lemmel, H.D.

    1996-11-01

    This report summarizes the 1996 co-ordination meeting in Brookhaven, U.S.A., of the national and regional nuclear reaction data center, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author). Refs, figs, tabs

  19. Co-ordination of the nuclear reactions data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Pronyaev, V.G.; Schwerer, O.

    1998-07-01

    This report summarizes the 1998 co-ordination meeting at the IAEA Headquarters in Vienna of the regional, national and specialized nuclear reaction data centers, concerned by the IAEA at two-year intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author)

  20. Co-ordination of the nuclear reaction data centers. Report on an IAEA advisory group meeting

    Energy Technology Data Exchange (ETDEWEB)

    Schwerer, O; Lemmel, H D [eds.

    1996-11-01

    This report summarizes the 1996 co-ordination meeting in Brookhaven, U.S.A., of the national and regional nuclear reaction data center, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ``EXFOR`` system, and the further development of this system; the ``CINDA`` system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ``ENDF`` format; the rapid advances of online electronic information technologies, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author). Refs, figs, tabs.

  1. Co-ordination of the nuclear reactions data centers. Report on an IAEA advisory group meeting

    Energy Technology Data Exchange (ETDEWEB)

    Pronyaev, V G; Schwerer, O [eds.

    1998-07-01

    This report summarizes the 1998 co-ordination meeting at the IAEA Headquarters in Vienna of the regional, national and specialized nuclear reaction data centers, concerned by the IAEA at two-year intervals. The main topics are: the international exchange of nuclear reaction data by means of the ``EXFOR`` system, and the further development of this system; the ``CINDA`` system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ``ENDF`` format; the rapid advances of online electronic information technologies, with goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author) Refs, figs, tabs

  2. The breakdown of vinyl ethers as a two-center synchronous reaction

    Science.gov (United States)

    Pokidova, T. S.; Shestakov, A. F.

    2009-11-01

    The experimental data on the molecular decomposition of vinyl ethers of various structures to alkanes and the corresponding aldehydes or ketones in the gas phase were analyzed using the method of intersecting parabolas. The enthalpies and kinetic parameters of decomposition were calculated for 17 reactions. The breakdown of ethers is a two-center concerted reaction characterized by a very high classical potential barrier to the thermally neutral reaction (180-190 kJ/mol). The kinetic parameters (activation energies and rate constants) of back reactions of the formation of vinyl ethers in the addition of aldehydes or ketones to alkanes were calculated using the method of intersecting parabolas. The factors that influenced the activation energy of the decomposition and formation of ethers were discussed. Quantum-chemical calculations of several vinyl ether decomposition reactions were performed. Ether formation reactions were compared with the formation of unsaturated alcohols as competitive reactions, which can occur in the interaction of carbonyl compounds with alkenes.

  3. Molecular electronics of a single photosystem I reaction center: Studies with scanning tunneling microscopy and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, I.; Lee, J.W.; Warmack, R.J.; Allison, D.P.; Greenbaum, E. [Oak Ridge National Lab., TN (United States)

    1995-03-14

    Thylakoids and photosystem I (PSI) reaction centers were imaged by scanning tunneling microscopy. The thylakoids were isolated from spinach chloroplasts, and PSI reaction centers were extracted from thylakoid membranes. Because thylakoids are relatively thick nonconductors, they were sputter-coated with Pd/Au before imaging. PSI photosynthetic centers and chemically platinized PSI were investigated without sputter-coating. They were mounted on flat gold substrates that had been treated with mercaptoacetic acid to help bind the proteins. With tunneling spectroscopy, the PSI centers displayed a semiconductor-like response with a band gap of 1.8 eV. Lightly platinized (platinized for 1 hr) centers displayed diode-like conduction that resulted in dramatic contrast changes between images taken with opposite bias voltages. The electronic properties of this system were stable under long-term storage. 42 refs., 7 figs.

  4. Resident Reactions to Person-Centered Communication by Long-Term Care Staff.

    Science.gov (United States)

    Savundranayagam, Marie Y; Sibalija, Jovana; Scotchmer, Emma

    2016-09-01

    Long-term care staff caregivers who are person centered incorporate the life history, preferences, and feelings of residents with dementia during care interactions. Communication is essential for person-centered care. However, little is known about residents' verbal reactions when staff use person-centered communication. Accordingly, this study investigated the impact of person-centered communication and missed opportunities for such communication by staff on resident reactions. Conversations (N = 46) between staff-resident dyads were audio-recorded during routine care tasks over 12 weeks. Staff utterances were coded for person-centered communication and missed opportunities. Resident utterances were coded for positive reactions, such as cooperation, and negative reactions, such as distress. Linear regression analyses revealed that the more staff used person-centered communication, the more likely that residents reacted positively. Additionally, the more missed opportunities in a conversation, the more likely that the residents reacted negatively. Conversation illustrations elaborate on the quantitative findings and implications for staff training are discussed. © The Author(s) 2016.

  5. Manipulating the Energetics and Rates of Electron Transfer in Rhodobacter capsulatus Reaction Centers with Asymmetric Pigment Content

    Energy Technology Data Exchange (ETDEWEB)

    Faries, Kaitlyn M. [Department; Dylla, Nicholas P. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Hanson, Deborah K. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Holten, Dewey [Department; Laible, Philip D. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Kirmaier, Christine [Department

    2017-07-17

    Seemingly redundant parallel pathways for electron transfer (ET), composed of identical sets of cofactors, are a cornerstone feature of photosynthetic reaction centers (RCs) involved in light-energy conversion. In native bacterial RCs, both A and B branches house one bacteriochlorophyll (BChl) and one bacteriopheophytin (BPh), but the A branch is used exclusively. Described herein are the results-obtained for two Rhodobacter capsulatus RCs with an unnaturally high degree of cofactor asymmetry, two BPh on the RC's B side and two BChl on the A side. These pigment changes derive, respectively, from the His(M180)Leu mutation [a BPh ((Phi(B)) replaces the B-side BChl (BB)], and the Leu(M212)His mutation [a BChl (beta(A))) replaces the A-side BPh (H-A)]. Additionally, Tyr(M208)Phe was employed to disfavor ET to the A branch; in one mutant, Val(M131)Glu creates a hydrogen bond to H-B to enhance ET to H-B. In both Phi(B) mutants, the decay kinetics of the excited primary ET donor (P*) resolve three populations with lifetimes of similar to 9 ps (50-60%), similar to 40 ps (10-20%), and similar to 200 ps (20-30%), with P+Phi(-)(B) formed predominantly from the 9 ps fraction. The 50-60% yield of P+Phi(B)- is the highest yet observed for a Phi(B)-containing RC. The results provide insight into factors needed for efficient multistep ET.

  6. Altitmeter for RC aircraft models

    OpenAIRE

    Švec, Jan

    2012-01-01

    Předmětem mé bakalářské práce je návrh výškoměru, který využívá pro záznam letové polohy modelu RC letadla vyhodnocování aktuálního atmosferického tlaku. Údaje jsou po dobu letu ukládány do paměti, odkud je možné je po skončení záznamu přes rozhraní USB uložit v PC. Software na PC zajišťuje komunikaci se zařízením a přepočet zaznamenaného tlaku na nadmořskou výšku RC modelu. The aim of my bachelor thesis is to design a altimeter, who uses to record the attitude of the model "RC plane" eval...

  7. Vasovagal reactions in whole blood donors at three REDS-II blood centers in Brazil.

    OpenAIRE

    Gonçalez, TT; Sabino, EC; Schlumpf, KS; Wright, DJ; Leao, S; Sampaio, D; Takecian, PL; Proietti, AB; Murphy, E; Busch, M; Custer, B; NHLBI Retrovirus Epidemiology Donor Study-II REDS-II, International Component,

    2012-01-01

    In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids before donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries.A cross-sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 20...

  8. Vasovagal reactions in whole blood donors at 3 REDS-II blood centers in Brazil

    Science.gov (United States)

    Goncalez, T. T.; Sabino, E. C.; Schlumpf, K.S.; Wright, D.J.; Leao, S.; Sampaio, D.; Takecian, P. L.; Carneiro-Proietti, AB; Murphy, E.; Busch, M.; Custer, B.

    2013-01-01

    Background In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids prior to donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries. Methods A cross-sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 2009. Vasovagal reactions (VVRs) along with donor demographic and biometric data were collected. Reactions were defined as any presyncopal or syncopal event during the donation process. Multivariable logistic regression was performed to identify predictors of VVRs. Results Of 724,861 donor presentations, 16,129 (2.2%) VVRs were recorded. Rates varied substantially between the three centers: 53, 290 and 381 per 10,000 donations in Recife, São Paulo and Belo Horizonte, respectively. Although the reaction rates varied, the donor characteristics associated with VVRs were similar [younger age (18–29), replacement donors, first time donors, low estimated blood volume (EBV)]. In multivariable analysis controlling for differences between the donor populations in each city younger age, first-time donor status and lower EBV were the factors most associated with reactions. Conclusion Factors associated with VVRs in other locations are also evident in Brazil. The difference in VVR rates between the three centers might be due to different procedures for identifying and reporting the reactions. Potential interventions to reduce the risk of reactions in Brazil should be considered. PMID:22073941

  9. Biological diversity of photosynthetic reaction centers and the solid-state photo-CIDNP effect

    NARCIS (Netherlands)

    Roy, Esha

    2007-01-01

    Photosynthetic reaction centers (RCs) from plants, heliobacteria and green sulphur bacteria has been investigated with photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR. In photosystem (PS) I of spinach, all signals appear negative which is proposed by a predominance of the

  10. The effects of light-induced reduction of the photosystem II reaction center

    Czech Academy of Sciences Publication Activity Database

    Kutý, Michal

    2009-01-01

    Roč. 8, č. 15 (2009), s. 923-933 ISSN 1610-2940 R&D Projects: GA MŠk(CZ) LC06010 Institutional research plan: CEZ:AV0Z60870520 Keywords : Photosystem II * Reaction center * Pheophytin Subject RIV: CE - Biochemistry Impact factor: 2.336, year: 2009

  11. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  12. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  13. The unusually strong hydrogen bond between the carbonyl of Q(A) and His M219 in the Rhodobacter sphaeroides reaction center is not essential for efficient electron transfer from Q(A)(-) to Q(B).

    Science.gov (United States)

    Breton, Jacques; Lavergne, Jérôme; Wakeham, Marion C; Nabedryk, Eliane; Jones, Michael R

    2007-06-05

    In native reaction centers (RCs) from photosynthetic purple bacteria the primary quinone (QA) and the secondary quinone (QB) are interconnected via a specific His-Fe-His bridge. In Rhodobacter sphaeroides RCs the C4=O carbonyl of QA forms a very strong hydrogen bond with the protonated Npi of His M219, and the Ntau of this residue is in turn coordinated to the non-heme iron atom. The second carbonyl of QA is engaged in a much weaker hydrogen bond with the backbone N-H of Ala M260. In previous work, a Trp side chain was introduced by site-directed mutagenesis at the M260 position in the RC of Rb. sphaeroides, resulting in a complex that is completely devoid of QA and therefore nonfunctional. A photochemically competent derivative of the AM260W mutant was isolated that contains a Cys side chain at the M260 position (denoted AM260(W-->C)). In the present work, the interactions between the carbonyl groups of QA and the protein in the AM260(W-->C) suppressor mutant have been characterized by light-induced FTIR difference spectroscopy of the photoreduction of QA. The QA-/QA difference spectrum demonstrates that the strong interaction between the C4=O carbonyl of QA and His M219 is lost in the mutant, and the coupled CO and CC modes of the QA- semiquinone are also strongly perturbed. In parallel, a band assigned to the perturbation of the C5-Ntau mode of His M219 upon QA- formation in the native RC is lacking in the spectrum of the mutant. Furthermore, a positive band between 2900 and 2400 cm-1 that is related to protons fluctuating within a network of highly polarizable hydrogen bonds in the native RC is reduced in amplitude in the mutant. On the other hand, the QB-/QB FTIR difference spectrum is essentially the same as for the native RC. The kinetics of electron transfer from QA- to QB were measured by the flash-induced absorption changes at 780 nm. Compared to native RCs the absorption transients are slowed by a factor of about 2 for both the slow phase (in the

  14. Reactions of carbon radicals generated by 1,5-transposition of reactive centers

    Directory of Open Access Journals (Sweden)

    ZIVORAD CEKOVIC

    2005-03-01

    Full Text Available Radical intermediates can undergo specific reactions, such as intramolecular rearrangements, i.e., the transpositions of radical centers, which are not known in classical ionic organic reactions. 1,5-Transposition of a radical center to a non-activated carbon atom are of great synthetic importance. It can be successfully applied for the introduction of different functional groups (oxygen, nitrogen, sulfur, halogens onto a carbon atom remote from the present functional group. In addition to functionalization of a remote non-activated carbon atom, the formation of new C-C bonds on the d-carbon atom have also been achieved. 1,5-Transposition of the radical centers takes place from alkoxyl, aminyl and carbon radicals to a remote carbon atom. Relocation of the radical centers preferentially involves 1,5-transfer of a hydrogen atom, although migrations of some other groups are known. The reactions of the carbon radical generated by 1,5-relocation of the radical center are presented and their synthetic applications are reviewed.

  15. Molar extinction coefficients and other properties of an improved reaction center preparation from Rhodopseudomonas viridis

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, R.K.; Clayton, B.J.

    1978-01-01

    Reaction centers have been purified from chromatophores of Rhodopseudomonas viridis by treatment with lauryl dimethyl amine oxide followed by hydroxyapatite chromatography and precipitation with ammonium sulfate. The absorption spectrum at low temperature shows bands at 531 and 543 nm, assigned to two molecules of bacteriopheophytin b. The 600 nm band of bacteriochlorophyll b is resolved at low temperature into components at 601 and 606.5 nm. At room temperature the light-induced difference spectrum shows a negative band centered at 615 nm, where the absorption spectrum shows only a week shoulder adjacent to the 600 nm band. The fluorescence spectrum shows a band at 1000 nm and no fluorescence corresponding to the 830 nm absorption band. Two molecules of cytochrome 558 and three of cytochrome 552 accompany each reaction center. The differential extinction coefficient (reduced minus oxidized) of cytochrome 558 nm was estimated as 20 +- 2 mM/sup -1/.cm/sup -1/ through a coupled reaction with equine cytochrome c. The extinction coefficient of reaction centers at 960 nm was determined to be 123 +- 25 mM/sup -1/.cm/sup -1/ by measuring the light-induced bleaching of P-960 and the coupled oxidation of cytochrome 558. The corresponding extinction coefficient at 830 nm is 300 +- 65 mM/sup -1/.cm/sup -1/. The absorbance ratio ..cap alpha../sub 280nm/..cap alpha../sub 830nm/ in our preparations was 2.1, and there was 190 kg protein per mol of reaction centers. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed three major components of apparent molecular weights 31,000, 37,000, and 41,000.

  16. Selective binding of carotenoids with a shorter conjugated chain to the LH2 antenna complex and those with a longer conjugated chain to the reaction center from Rubrivivax gelatinosus.

    Science.gov (United States)

    Kakitani, Yoshinori; Fujii, Ritsuko; Hayakawa, Yoshihiro; Kurahashi, Masahiro; Koyama, Yasushi; Harada, Jiro; Shimada, Keizo

    2007-06-19

    Rubrivivax gelatinosus having both the spheroidene and spirilloxanthin biosynthetic pathways produces carotenoids (Cars) with a variety of conjugated chains, which consist of different numbers of conjugated double bonds (n), including the C=C (m) and C=O (o) bonds. When grown under anaerobic conditions, the wild type produces Cars for which n = m = 9-13, whereas under semiaerobic conditions, it additionally produces Cars for which n = m + o = 10 + 1, 13 + 1, and 13 + 2. On the other hand, a mutant, in which the latter pathway is genetically blocked, produces only Cars for which n = 9 and 10 under anaerobic conditions and n = 9, 10, and 10 + 1 under semianaerobic conditions. Those Cars that were extracted from the LH2 complex (LH2) and the reaction center (RC), isolated from the wild-type and the mutant Rvi. gelatinosus, were analyzed by HPLC, and their structures were determined by mass spectrometry and 1H NMR spectroscopy. The selective binding of Cars to those pigment-protein complexes has been characterized as follows. (1) Cars with a shorter conjugated chain are selectively bound to LH2 whereas Cars with a longer conjugated chain to the RC. (2) Shorter chain Cars with a hydroxyl group are bound to LH2 almost exclusively. This rule holds either in the absence or in the presence of the keto group. The natural selection of shorter chain Cars by LH2 and longer chain Cars by the RC is discussed, on the basis of the results now available, in relation to the light-harvesting and photoprotective functions of Cars.

  17. Geometric phase and quantum interference in photosynthetic reaction center: Regulation of electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuming, E-mail: ymsun@ytu.edu.cn; Su, Yuehua; Dai, Zhenhong; Wang, WeiTian

    2016-10-20

    Photosynthesis is driven by electron transfer in reaction centers in which the functional unit is composed of several simple molecules C{sub 2}-symmetrically arranged into two branches. In view of quantum mechanism, both branches are possible pathways traversed by the transferred electron. Due to different evolution of spin state along two pathways in transmembrane electric potential (TEP), quantum state of the transferred electron at the bridged site acquires a geometric phase difference dependent on TEP, the most efficient electron transport takes place in a specific range of TEP beyond which electron transfer is dramatically suppressed. What’s more, reaction center acts like elaborately designed quantum device preparing polarized spin dependent on TEP for the transferred electron to regulate the reduction potential at bridged site. In brief, electron transfer generates the TEP, reversely, TEP modulates the efficiency of electron transfer. This may be an important approach to maintaining an appreciable pH environment in photosynthesis.

  18. Electronically tunable RC sinusoidal oscillators

    International Nuclear Information System (INIS)

    Florescu, Valeriu

    2008-01-01

    This paper presents two types of active configurations for realizing electronically tunable RC sinusoidal oscillators. The type-1 network employs two grounded scaled resistances KR 1 and KR 2 , where K is scaling factor. The frequency of oscillation W 0 is controlled conveniently by adjusting K, since W 0 appears in the form W 0 =1/K √ R 1 C 1 R 2 C 2 . For realizing the scaled resistances, an active configuration is proposed, which realizes KR 1 =R 1 /(1+f(V B )), where f(V B ) denotes a function of a controlling voltage V B . Thus the frequency tuning can be effected by controlling a voltage V B . The type-2 oscillator uses two periodically switched conductances. It is shown that the tuning of oscillation frequency can be done by varying the pulse width-to-period ratio (t/T) of the periodically switched conductances. (author)

  19. Nuclear Reaction and Structure Databases of the National Nuclear Data Center

    International Nuclear Information System (INIS)

    Pritychenko, B.; Arcilla, R.; Herman, M. W.; Oblozinsky, P.; Rochman, D.; Sonzogni, A. A.; Tuli, J. K.; Winchell, D. F.

    2006-01-01

    The National Nuclear Data Center (NNDC) collects, evaluates, and disseminates nuclear physics data for basic research and applied nuclear technologies. In 2004, the NNDC migrated all databases into modern relational database software, installed new generation of Linux servers and developed new Java-based Web service. This nuclear database development means much faster, more flexible and more convenient service to all users in the United States. These nuclear reaction and structure database developments as well as related Web services are briefly described

  20. Functional type 2 photosynthetic reaction centers found in the rare bacterial phylum Gemmatimonadetes

    OpenAIRE

    Zeng, Yonghui; Feng, Fuying; Medová, Hana; Dean, Jason; Koblížek, Michal

    2014-01-01

    Photosynthesis is one of the most fundamental biological processes on Earth. To date, species capable of performing (bacterio)chlorophyll-based phototrophy have been reported in six bacterial phyla. Here we report a phototrophic bacterium belonging to the rare and understudied phylum Gemmatimonadetes. This strain, isolated from a freshwater lake in the Gobi Desert, contains fully functional photosynthetic reaction centers. Its photosynthesis genes appear to originate from an ancient horizonta...

  1. Electrostatic dominoes: long distance propagation of mutational effects in photosynthetic reaction centers of Rhodobacter capsulatus.

    Science.gov (United States)

    Sebban, P; Maróti, P; Schiffer, M; Hanson, D K

    1995-07-04

    Two point mutants from the purple bacterium Rhodobacter capsulatus, both modified in the M protein of the photosynthetic reaction center, have been studied by flash-induced absorbance spectroscopy. These strains carry either the M231Arg --> Leu or M43ASN --> Asp mutations, which are located 9 and 15 A, respectively, from the terminal electron acceptor QB. In the wild-type Rb. sphaeroides structure, M231Arg is involved in a conserved salt bridge with H125Glu and H232Glu and M43Asn is located among several polar residues that form or surround the QB binding site. These substitutions were originally uncovered in phenotypic revertants isolated from the photosynthetically incompetent L212Glu-L213Asp --> Ala-Ala site-specific double mutant. As second-site suppressor mutations, they have been shown to restore the proton transfer function that is interrupted in the L212Ala-L213Ala double mutant. The electrostatic effects that are induced in reaction centers by the M231Arg --> Leu and M43Asn --> Asp substitutions are roughly the same in either the double-mutant or wild-type backgrounds. In a reaction center that is otherwise wild type in sequence, they decrease the free energy gap between the QA- and QB- states by 24 +/- 5 and 45 +/- 5 meV, respectively. The pH dependences of K2, the QA-QB QAQB- equilibrium constant, are altered in reaction centers that carry either of these substitutions, revealing differences in the pKas of titratable groups compared to the wild type.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. A single residue controls electron transfer gating in photosynthetic reaction centers

    Czech Academy of Sciences Publication Activity Database

    Shlyk, O.; Samish, I.; Matěnová, M.; Dulebo, A.; Poláková, H.; Kaftan, David; Scherz, A.

    2017-01-01

    Roč. 7, MAR 16 (2017), s. 1-13, č. článku 44580. ISSN 2045-2322 R&D Projects: GA ČR GA15-00703S; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : BACTERIAL REACTION CENTERS * INDUCED STRUCTURAL-CHANGES * ATOMIC-FORCE MICROSCOPE Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.259, year: 2016

  3. Model of deep centers formation and reactions in electron irradiated InP

    International Nuclear Information System (INIS)

    Sibille, A.; Suski, J.; Gilleron, M.

    1986-01-01

    We present a model of the production of deep centers and their reactions following electron irradiations in InP. We propose that the dominant hole traps in p-InP and electron traps in p + n InP junctions are complexes between shallow acceptors and a common intrinsic entity, the phosphorus interstitial or vacancy. The reactions observed below and above room temperature are then due to a local mobility of this entity, which can be obtained as well by thermal as by electronic stimulation of the reactions. This model implies the long-range migration (at least down to 16 K) of this entity, and explains the strongly different behavior of n-InP compared to p-InP samples

  4. Incidence of transfusion reactions: a multi-center study utilizing systematic active surveillance and expert adjudication

    Science.gov (United States)

    Hendrickson, Jeanne E.; Roubinian, Nareg H.; Chowdhury, Dhuly; Brambilla, Don; Murphy, Edward L.; Wu, Yanyun; Ness, Paul M.; Gehrie, Eric A.; Snyder, Edward L.; Hauser, R. George; Gottschall, Jerome L.; Kleinman, Steve; Kakaiya, Ram; Strauss, Ronald G.

    2017-01-01

    Background Prevalence estimates of serious hazards of transfusion vary widely. We hypothesized that the current reporting infrastructure in the United States fails to capture many transfusion reactions, and undertook a multi-center study utilizing active surveillance, data review, and adjudication to test this hypothesis. Study Design and Methods A retrospective record review was completed for a random sample of 17% of all inpatient transfusion episodes over 6 months at 4 academic tertiary care hospitals, with an episode defined as all blood products released to a patient in 6 hours. Data were recorded by trained clinical research nurses, and serious reactions were adjudicated by a panel of transfusion medicine experts. Results Of 4857 transfusion episodes investigated, 1.1% were associated with a serious reaction. Transfusion associated circulatory overload (TACO) was the most frequent serious reaction noted, being identified in 1% of transfusion episodes. Despite clinical notes describing a potential transfusion association in 59% of these cases, only 5.1% were reported to the transfusion service. Suspected transfusion related acute lung injury (TRALI/possible TRALI), anaphylactic, and hypotensive reactions were noted in 0.08%, 0.02%, and 0.02% of transfusion episodes. Minor reactions, including febrile non-hemolytic and allergic, were noted in 0.62% and 0.29% of transfusion episodes, with 30–50% reported to the transfusion service. Conclusion Underreporting of cardiopulmonary transfusion reactions is striking among academic, tertiary care hospitals. Complete and accurate reporting is essential to identify, define, establish pathogenesis, and mitigate/treat transfusion reactions. A better understanding of the failure to report may improve the accuracy of passive reporting systems. PMID:27460200

  5. Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.

    Science.gov (United States)

    Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

    2013-10-01

    Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.

  6. Conformational heterogeneity of the bacteriopheophytin electron acceptor HA in reaction centers from Rhodopseudomonas viridis revealed by Fourier transform infrared spectroscopy and site-directed mutagenesis.

    Science.gov (United States)

    Breton, J; Bibikova, M; Oesterhelt, D; Nabedryk, E

    1999-08-31

    The light-induced Fourier transform infrared (FTIR) difference spectra corresponding to the photoreduction of either the HA bacteriopheophytin electron acceptor (HA-/HA spectrum) or the QA primary quinone (QA-/QA spectrum) in photosynthetic reaction centers (RCs) of Rhodopseudomonas viridis are reported. These spectra have been compared for wild-type (WT) RCs and for two site-directed mutants in which the proposed interactions between the carbonyls on ring V of HA and the RC protein have been altered. In the mutant EQ(L104), the putative hydrogen bond between the protein and the 9-keto C=O of HA should be affected by changing Glu L104 to a Gln. In the mutant WF(M250), the van der Waals interactions between Trp M250 and the 10a-ester C=O of HA should be modified. The characteristic effects of both mutations on the FTIR spectra support the proposed interactions and allow the IR modes of the 9-keto and 10a-ester C=O of HA and HA- to be assigned. Comparison of the HA-/HA and QA-/QA spectra leads us to conclude that the QA-/QA IR signals in the spectral range above 1700 cm-1 are largely dominated by contributions from the electrostatic response of the 10a-ester C=O mode of HA upon QA photoreduction. A heterogeneity in the conformation of the 10a-ester C=O mode of HA in WT RCs, leading to three distinct populations of HA, appears to be related to differences in the hydrogen-bonding interactions between the carbonyls of ring V of HA and the RC protein. The possibility that this structural heterogeneity is related to the observed multiexponential kinetics of electron transfer and the implications for primary processes are discussed. The effect of 1H/2H exchange on the QA-/QA spectra of the WT and mutant RCs shows that neither Glu L104 nor any other exchangeable carboxylic residue changes appreciably its protonation state upon QA reduction.

  7. Japan Nuclear Reaction Data Center (JCPRG), Faculty of Science, Hokkaido University, Steering Committee progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    The Japan Nuclear Reaction Data Center (JCPRG) was approved as an organisation of Faculty of Science, Hokkaido University and established on April 1, 2007. In addition to nuclear data activities carried out by JCPRG (Japan-Charged Particle Nuclear Reaction Data Group), the centre is concerned with the evaluation of nuclear reaction data in nucleosynthesis in the universe. In order efficiently to compile reaction data obtained by using radioactive ion beam, the centre signed a research contract with RIKEN Nishina Center. We are scanning 16 journals for Japanese charged-particle and photo-nuclear nuclear reaction data compilation. From April 2006 to March 2007, CPND and PhND in 45 references (453 records, 1.83 MB) have been newly compiled for NRDF. Usually new data are released at the JCPRG web site several months prior to EXFOR. Since the 2006 NRDC meeting, we have made 104 new entries and have revised or deleted 142 old entries. Intensive numerical data compilations have been done. These data were shown in tabular form in dissertations which are (partially) published in Journals. About 30 new entries were compiled from these data. We have prepared CINDA batches for CPND published in Japan every half year. Each batch covers 6 issues of each of 4 Japanese journals JPJ, PTP, NST and JNRS. Bibliographies for neutron induced reaction data have been compiled by JAEA Nuclear Data Center as before. A new web-based NRDF search and plot system on MySQL was released in July, 2007. New compilation, which has been finalized for NRDF, but not for EXFOR, can be obtained from this site. DARPE (another NRDF search and plot system written in Perl) is also available at http://www.jcprg.org/darpe/. EXFOR/ENDF (http://www.jcprg.org/exfor/) search and plot system is available. We have also developed following utilities: PENDL (http://www.jcprg.org/endf/) and RENORM (http://www.jcprg.org/renorm). We are developing a new search system of CINDA. This is an extension of EXFOR/ENDF search

  8. Spectroscopic properties of reaction center pigments in photosystem II core complexes: revision of the multimer model.

    Science.gov (United States)

    Raszewski, Grzegorz; Diner, Bruce A; Schlodder, Eberhard; Renger, Thomas

    2008-07-01

    Absorbance difference spectra associated with the light-induced formation of functional states in photosystem II core complexes from Thermosynechococcus elongatus and Synechocystis sp. PCC 6803 (e.g., P(+)Pheo(-),P(+)Q(A)(-),(3)P) are described quantitatively in the framework of exciton theory. In addition, effects are analyzed of site-directed mutations of D1-His(198), the axial ligand of the special-pair chlorophyll P(D1), and D1-Thr(179), an amino-acid residue nearest to the accessory chlorophyll Chl(D1), on the spectral properties of the reaction center pigments. Using pigment transition energies (site energies) determined previously from independent experiments on D1-D2-cytb559 complexes, good agreement between calculated and experimental spectra is obtained. The only difference in site energies of the reaction center pigments in D1-D2-cytb559 and photosystem II core complexes concerns Chl(D1). Compared to isolated reaction centers, the site energy of Chl(D1) is red-shifted by 4 nm and less inhomogeneously distributed in core complexes. The site energies cause primary electron transfer at cryogenic temperatures to be initiated by an excited state that is strongly localized on Chl(D1) rather than from a delocalized state as assumed in the previously described multimer model. This result is consistent with earlier experimental data on special-pair mutants and with our previous calculations on D1-D2-cytb559 complexes. The calculations show that at 5 K the lowest excited state of the reaction center is lower by approximately 10 nm than the low-energy exciton state of the two special-pair chlorophylls P(D1) and P(D2) which form an excitonic dimer. The experimental temperature dependence of the wild-type difference spectra can only be understood in this model if temperature-dependent site energies are assumed for Chl(D1) and P(D1), reducing the above energy gap from 10 to 6 nm upon increasing the temperature from 5 to 300 K. At physiological temperature, there are

  9. Proton conduction within the reaction centers of Rhodobacter capsulatus: the electrostatic role of the protein.

    OpenAIRE

    Maróti, P; Hanson, D K; Baciou, L; Schiffer, M; Sebban, P

    1994-01-01

    Light-induced charge separation in the photosynthetic reaction center results in delivery of two electrons and two protons to the terminal quinone acceptor QB. In this paper, we have used flash-induced absorbance spectroscopy to study three strains that share identical amino acid sequences in the QB binding site, all of which lack the protonatable amino acids Glu-L212 and Asp-L213. These strains are the photosynthetically incompetent site-specific mutant Glu-L212/Asp-L213-->Ala-L212/Ala-L213 ...

  10. 47 CFR 95.201 - (R/C Rule 1) What is the Radio Control (R/C) Radio Service?

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false (R/C Rule 1) What is the Radio Control (R/C...) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Radio Control (R/C) Radio Service General Provisions § 95.201 (R/C Rule 1) What is the Radio Control (R/C) Radio Service? The R/C Service is a private...

  11. An efficient synthesis of α-amino-δ-valerolactones by the ugi five-center three-component reaction

    International Nuclear Information System (INIS)

    Kim, Young Bae; Lee, Duck Hyung; Park, Soo Jung; Keum, Gyo Chang; Jang, Min Seok; Kang, Soon Bang; Kim, You Seung

    2002-01-01

    A novel approach to α-amino-δ-valerolactones derivatives 8 by the intramolecular Ugi five-center three-component reaction (U-5C-3CR) using the multifunctional starting material, L-pentahomoserine 5 is described

  12. Engineered Photosystem II reaction centers optimize photochemistry versus photoprotection at different solar intensities.

    Science.gov (United States)

    Vinyard, David J; Gimpel, Javier; Ananyev, Gennady M; Mayfield, Stephen P; Dismukes, G Charles

    2014-03-12

    The D1 protein of Photosystem II (PSII) provides most of the ligating amino acid residues for the Mn4CaO5 water-oxidizing complex (WOC) and half of the reaction center cofactors, and it is present as two isoforms in the cyanobacterium Synechococcus elongatus PCC 7942. These isoforms, D1:1 and D1:2, confer functional advantages for photosynthetic growth at low and high light intensities, respectively. D1:1, D1:2, and seven point mutations in the D1:2 background that are native to D1:1 were expressed in the green alga Chlamydomonas reinhardtii. We used these nine strains to show that those strains that confer a higher yield of PSII charge separation under light-limiting conditions (where charge recombination is significant) have less efficient photochemical turnover, measured in terms of both a lower WOC turnover probability and a longer WOC cycle period. Conversely, these same strains under light saturation (where charge recombination does not compete) confer a correspondingly faster O2 evolution rate and greater protection against photoinhibition. Taken together, the data clearly establish that PSII primary charge separation is a trade-off between photochemical productivity (water oxidation and plastoquinone reduction) and charge recombination (photoprotection). These trade-offs add up to a significant growth advantage for the two natural isoforms. These insights provide fundamental design principles for engineering of PSII reaction centers with optimal photochemical efficiencies for growth at low versus high light intensities.

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

    Science.gov (United States)

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J; Anastasopoulos, Ioannis; Gazetas, George

    2014-12-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation , this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces the nonlinear and inelastic response of both the soil-footing interface and the structure. To this end, a novel scale model RC (1:50 scale) that simulates reasonably well the elastic response and the failure of prototype RC elements is utilized, along with realistic representation of the soil behavior in a geotechnical centrifuge. A variety of seismic ground motions are considered as excitations. They result in consistent demonstrably beneficial performance of the rocking-isolated pier in comparison with the one designed conventionally. Seismic demand is reduced in terms of both inertial load and deck drift. Furthermore, foundation uplifting has a self-centering potential, whereas soil yielding is shown to provide a particularly effective energy dissipation mechanism, exhibiting significant resistance to cumulative damage. Thanks to such mechanisms, the rocking pier survived, with no signs of structural distress, a deleterious sequence of seismic motions that caused collapse of the conventionally designed pier. © 2014 The Authors Published by John Wiley & Sons Ltd.

  14. The rate of second electron transfer to QB(-) in bacterial reaction center of impaired proton delivery shows hydrogen-isotope effect.

    Science.gov (United States)

    Maróti, Ágnes; Wraight, Colin A; Maróti, Péter

    2015-02-01

    The 2nd electron transfer in reaction center of photosynthetic bacterium Rhodobacter sphaeroides is a two step process in which protonation of QB(-) precedes interquinone electron transfer. The thermal activation and pH dependence of the overall rate constants of different RC variants were measured and compared in solvents of water (H2O) and heavy water (D2O). The electron transfer variants where the electron transfer is rate limiting (wild type and M17DN, L210DN and H173EQ mutants) do not show solvent isotope effect and the significant decrease of the rate constant of the second electron transfer in these mutants is due to lowering the operational pKa of QB(-)/QBH: 4.5 (native), 3.9 (L210DN), 3.7 (M17DN) and 3.1 (H173EQ) at pH7. On the other hand, the proton transfer variants where the proton transfer is rate limiting demonstrate solvent isotope effect of pH-independent moderate magnitude (2.11±0.26 (WT+Ni(2+)), 2.16±0.35 (WT+Cd(2+)) and 2.34±0.44 (L210DN/M17DN)) or pH-dependent large magnitude (5.7 at pH4 (L213DN)). Upon deuteration, the free energy and the enthalpy of activation increase in all proton transfer variants by about 1 kcal/mol and the entropy of activation becomes negligible in L210DN/M17DN mutant. The results are interpreted as manifestation of equilibrium and kinetic solvent isotope effects and the structural, energetic and kinetic possibility of alternate proton delivery pathways are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Chemical proprieties of the iron-quinone complex in mutated reaction centers of Rb. sphaeroides

    International Nuclear Information System (INIS)

    Hałas, Agnieszka; Derrien, Valerie; Sebban, Pierre; Matlak, Krzysztof; Korecki, Józef; Kruk, Jerzy; Burda, Kvĕtoslava

    2012-01-01

    We investigated type II bacterial photosynthetic reaction centers, which contain a quinone - iron complex (Q A -Fe-Q B ) on their acceptor side. Under physiological conditions it was observed mainly in a reduced high spin state but its low spin ferrous states were also observed. Therefore, it was suggested that it might regulate the dynamical properties of the iron–quinone complex and the protonation and deprotonation events in its neighbourhood. In order to get insight into the molecular mechanism of the NHFe low spin state formation, we preformed Mössbauer studies of a wild type of Rb. sphaeroides and its two mutated forms. Our Mössbauer measurements show that the hydrophobicity of the Q A binding site can be crucial for stabilization of the high spin ferrous state of NHFe.

  16. Kinetics of several oxygenated carbon-centered free radical reactions with NO2.

    Science.gov (United States)

    Rissanen, Matti P; Arppe, Suula L; Timonen, Raimo S

    2013-05-16

    Five oxygenated carbon-centered free radical reactions with nitrogen dioxide (NO2) have been studied in direct time-resolved measurements. Experiments were conducted in a temperature-controlled flow tube reactor coupled to a 193 nm exciplex laser photolysis and a resonance gas lamp photoionization mass spectrometer. Reactions were investigated under pseudofirst-order conditions, with the NO2 concentrations of the experiments in great excess over the initial radical concentrations ([R]0 CH3CO radical reactions with NO2 and, hence, includes the three smallest hydroxyalkyl radical species (CH2OH, CH2CH2OH, and CH3CHOH). The obtained rate coefficients are high with the temperature-dependent rate coefficients given by a formula k(T) = k300K × (T/300 K)(-n) as (in units of cm(3) molecule(-1) s(-1)): k(CH2OH + NO2) = (8.95 ± 2.70) × 10(-11) × (T/300 K)(-0.54±0.27) (T = 298-363 K), k(CH2CH2OH + NO2) = (5.99 ± 1.80) × 10(-11) × (T/300 K)(-1.49±0.45)(T = 241-363 K), k(CH3CHOH + NO2) = (7.48 ± 2.24) × 10(-11) × (T/300 K)(-1.36±0.41) (T = 266-363 K), k(CH3OCH2 + NO2) = (7.85 ± 2.36) × 10(-11) × (T/300 K)(-0.93±0.28) (T = 243-363 K), and k(CH3CO + NO2) = (2.87 ± 0.57) × 10(-11) × (T/300 K)(-2.45±0.49) (T = 241-363 K), where the uncertainties refer to the estimated overall uncertainties of the values obtained. The determined rate coefficients show negative temperature dependence with no apparent bath gas pressure dependence under the current experimental conditions (241-363 K and about 1-3 Torr helium). This behavior is typical for a radical-radical addition mechanism with no potential energy barrier above the energy of the separated reactants in the entrance channel of the reaction. Unfortunately the absence of detected product signals prevented gaining deeper insight into the reaction mechanism.

  17. Center of gravity estimation using a reaction board instrumented with fiber Bragg gratings

    Science.gov (United States)

    Oliveira, Rui; Roriz, Paulo; Marques, Manuel B.; Frazão, Orlando

    2018-03-01

    The purpose of the present work is to construct a reaction board based on fiber Bragg gratings (FBGs) that could be used for estimation of the 2D coordinates of the projection of center of gravity (CG) of an object. The apparatus is consisted of a rigid equilateral triangular board mounted on three supports at the vertices, two of which have cantilevers instrumented with FBGs. When an object of known weight is placed on the board, the bending strain of the cantilevers is measured by a proportional wavelength shift of the FBGs. Applying the equilibrium conditions of a rigid body and proper calibration procedures, the wavelength shift is used to estimate the vertical reaction forces and moments of force at the supports and the coordinates of the object's CG projection on the board. This method can be used on a regular basis to estimate the CG of the human body or objects with complex geometry and density distribution. An example is provided for the estimation of the CG projection coordinates of two orthopaedic femur bone models, one intact, and the other with a hip stem implant encased. The clinical implications of changing the normal CG location by means of a prosthesis have been discussed.

  18. Impact response of RC rock-shed girder with sand cushion under falling load

    International Nuclear Information System (INIS)

    Bhatti, Abdul Qadir; Kishi, Norimitsu

    2010-01-01

    Research highlights: → An applicability of FE model of RC girders with sand cushion has been investigated. → Experimental and numerical results of Impact force, reaction force and displacement have been performed. → Cracks obtained from numerical models are in good agreement with the experimental ones. → Reaction force-displacement loops agree well between numerical and experimental results. → The configuration of the hysteretic loop at failure of RC girders can be approximated by a parallelogram. - Abstract: In order to establish a proper finite element model of prototype RC girder with sand element for impact response analysis, dynamic response analysis of RC girders with sand cushion subjected to impact force due to weight falling from the height of H = 2.5, 5, 7.5 and 10 m was performed to improve the state of the art of protective design for real scale rock-sheds by using LS-DYNA code. An applicability of proposed model was discussed comparing with experimental results (e.g. impact force, reaction force and displacement waves). From this study, dynamic characteristics of impact response can be better simulated by using the proposed model. As a result, when the sand cushion was set up, the impact force, reaction force, mid-span displacement waves, distribution of reaction force-displacement loops, and crack patterns obtained from the numerical analysis are in good agreement with those from the experimental results.

  19. Fractional-order RC and RL circuits

    KAUST Repository

    Radwan, Ahmed Gomaa

    2012-05-30

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

  20. Protein sequences and redox titrations indicate that the electron acceptors in reaction centers from heliobacteria are similar to Photosystem I

    Science.gov (United States)

    Trost, J. T.; Brune, D. C.; Blankenship, R. E.

    1992-01-01

    Photosynthetic reaction centers isolated from Heliobacillus mobilis exhibit a single major protein on SDS-PAGE of 47 000 Mr. Attempts to sequence the reaction center polypeptide indicated that the N-terminus is blocked. After enzymatic and chemical cleavage, four peptide fragments were sequenced from the Heliobacillus mobilis apoprotein. Only one of these sequences showed significant specific similarity to any of the protein and deduced protein sequences in the GenBank data base. This fragment is identical with 56% of the residues, including both cysteines, found in highly conserved region that is proposed to bind iron-sulfur center Fx in the Photosystem I reaction center peptide that is the psaB gene product. The similarity to the psaA gene product in this region is 48%. Redox titrations of laser-flash-induced photobleaching with millisecond decay kinetics on isolated reaction centers from Heliobacterium gestii indicate a midpoint potential of -414 mV with n = 2 titration behavior. In membranes, the behavior is intermediate between n = 1 and n = 2, and the apparent midpoint potential is -444 mV. This is compared to the behavior in Photosystem I, where the intermediate electron acceptor A1, thought to be a phylloquinone molecule, has been proposed to undergo a double reduction at low redox potentials in the presence of viologen redox mediators. These results strongly suggest that the acceptor side electron transfer system in reaction centers from heliobacteria is indeed analogous to that found in Photosystem I. The sequence similarities indicate that the divergence of the heliobacteria from the Photosystem I line occurred before the gene duplication and subsequent divergence that lead to the heterodimeric protein core of the Photosystem I reaction center.

  1. Structure and function of the tetraheme cytochrome associated to the reaction center of Roseobacter denitrificans.

    Science.gov (United States)

    Garcia, D; Richaud, P; Breton, J; Verméglio, A

    1994-01-01

    We have characterized the tetrahemic RC bound cytochrome isolated from the quasi-photosynthetic bacterium Roseobacter denitrificans in terms of absorption spectrum, redox property and orientation with respect to the membrane plane. The heme, designated H1, which possesses the highest redox midpoint potential (+290 mV), absorbs at 555 nm. Its plane makes an angle of 40 degrees with the membrane plane. The second high potential heme, H2 (+240 mV), peaks at 554 nm and makes a tilt of 55 degrees with the membrane. The two low potential hemes, L1 and L2, present a similar and rather high redox midpoint potential (+90 mV). They absorb at 553 nm and 550 nm. One of these hemes is oriented at 40 degrees while the other makes an angle of 90 degrees with the membrane plane. The soluble cytochrome c551 completes the cyclic electron transfer between the RC and the bc1 complex. Both the oxidation and the re-reduction of cytochrome c551 are diffusible processes. Under semi-aerobic conditions, one of the low potential hemes is photo-oxidized under illumination but only extremely slowly re-reduced. This explains the requirement of high aerobic conditions for growth of Roseobacter denitrificans cells in the light.

  2. Bacterial Reaction Centers Purified with Styrene Maleic Acid Copolymer Retain Native Membrane Functional Properties and Display Enhanced Stability**

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2014-01-01

    Integral membrane proteins often present daunting challenges for biophysical characterization, a fundamental issue being how to select a surfactant that will optimally preserve the individual structure and functional properties of a given membrane protein. Bacterial reaction centers offer a rare opportunity to compare the properties of an integral membrane protein in different artificial lipid/surfactant environments with those in the native bilayer. Here, we demonstrate that reaction centers purified using a styrene maleic acid copolymer remain associated with a complement of native lipids and do not display the modified functional properties that typically result from detergent solubilization. Direct comparisons show that reaction centers are more stable in this copolymer/lipid environment than in a detergent micelle or even in the native membrane, suggesting a promising new route to exploitation of such photovoltaic integral membrane proteins in device applications. PMID:25212490

  3. [High activity antiretroviral therapy change associated to adverse drug reactions in a specialized center in Venezuela].

    Science.gov (United States)

    Subiela, José D; Dapena, Elida

    2016-03-01

    Adverse drug reactions (ADRs) represent the first cause of change of the first-line highly active antiretroviral therapy (HAART) regimen, therefore, they constitute the main limiting factor in the long-term follow up of HIV patients in treatment. A retrospective study was carried out in a specialized center in Lara State, Venezuela, including 99 patients over 18 years of age who had change of first-line HAART regimen due to ADRs, between 2010 and 2013. The aims of this research were to describe the sociodemographic and clinical variables, frequency of ADRs related to change of HAART, duration of the first-line HAART regimen, to determine the drugs associated with ARVs and to identify the risk factors. The ADRs constituted 47.5% of all causes of change of first-line HAART regimen, the median duration was 1.08±0.28 years. The most frequent ADRs were anemia (34.3%), hypersensitivity reactions (20.2%) and gastrointestinal intolerance (13.1%). The most frequent ARV regimen type was the protease inhibitors-based regimen (59.6%), but zidovudine was the ARV most linked to ADRs (41.4%). The regression analysis showed increased risk of ADRs in singles and students in the univariate analysis and heterosexuals and homosexuals in multivariate analysis; and decreased risk in active workers. The present work shows the high prevalence of ADRs in the studied population and represents the first case-based study that describes the pharmacoepidemiology of a cohort of HIV-positive patients treated in Venezuela.

  4. Proton conduction within the reaction centers of Rhodobacter capsulatus: the electrostatic role of the protein.

    Science.gov (United States)

    Maróti, P; Hanson, D K; Baciou, L; Schiffer, M; Sebban, P

    1994-06-07

    Light-induced charge separation in the photosynthetic reaction center results in delivery of two electrons and two protons to the terminal quinone acceptor QB. In this paper, we have used flash-induced absorbance spectroscopy to study three strains that share identical amino acid sequences in the QB binding site, all of which lack the protonatable amino acids Glu-L212 and Asp-L213. These strains are the photosynthetically incompetent site-specific mutant Glu-L212/Asp-L213-->Ala-L212/Ala-L213 and two different photocompetent derivatives that carry both alanine substitutions and an intergenic suppressor mutation located far from QB (class 3 strain, Ala-Ala + Arg-M231-->Leu; class 4 strain, Ala-Ala + Asn-M43-->Asp). At pH 8 in the double mutant, we observe a concomitant decrease of nearly 4 orders of magnitude in the rate constants of second electron and proton transfer to QB compared to the wild type. Surprisingly, these rates are increased to about the same extent in both types of suppressor strains but remain > 2 orders of magnitude smaller than those of the wild type. In the double mutant, at pH 8, the loss of Asp-L213 and Glu-L212 leads to a substantial stabilization (> or = 60 meV) of the semiquinone energy level. Both types of compensatory mutations partially restore, to nearly the same level, the original free energy difference for electron transfer from primary quinone QA to QB. The pH dependence of the electron and proton transfer processes in the double-mutant and the suppressor strains suggests that when reaction centers of the double mutant are shifted to lower pH (1.5-2 units), they function like those of the suppressor strains at physiological pH. Our data suggest that the main effect of the compensatory mutations is to partially restore the negative electrostatic environment of QB and to increase an apparent "functional" pK of the system for efficient proton transfer to the active site. This emphasizes the role of the protein in tuning the

  5. [On the influence of local molecular environment on the redox potential of electron transfer cofactors in bacterial photosynthetic reaction centers].

    Science.gov (United States)

    Krasil'nikov, P M; Noks, P P; Rubin, A B

    2011-01-01

    The addition of cryosolvents (glycerol, dimethylsulfoxide) to a water solution containing bacterial photosynthetic reaction centers changes the redox potential of the bacteriochlorophyll dimer, but does not affect the redox potential of the quinone primary acceptor. It has been shown that the change in redox potential can be produced by changes of the electrostatic interactions between cofactors and the local molecular environment modified by additives entered into the solution. The degree of influence of a solvent on the redox potential of various cofactors is determined by degree of availability of these cofactors for molecules of solvent, which depends on the arrangement of cofactors in the structure of reaction centers.

  6. RC Circuits: Some Computer-Interfaced Experiments.

    Science.gov (United States)

    Jolly, Pratibha; Verma, Mallika

    1994-01-01

    Describes a simple computer-interface experiment for recording the response of an RC network to an arbitrary input excitation. The setup is used to pose a variety of open-ended investigations in network modeling by varying the initial conditions, input signal waveform, and the circuit topology. (DDR)

  7. Kinetics of Several Oxygen-Containing Carbon-Centered Free Radical Reactions with Nitric Oxide.

    Science.gov (United States)

    Rissanen, Matti P; Ihlenborg, Marvin; Pekkanen, Timo T; Timonen, Raimo S

    2015-07-16

    Kinetics of four carbon-centered, oxygen-containing free radical reactions with nitric oxide (NO) were investigated as a function of temperature at a few Torr pressure of helium, employing flow tube reactors coupled to a laser-photolysis/resonance-gas-discharge-lamp photoionization mass spectrometer (LP-RPIMS). Rate coefficients were directly determined from radical (R) decay signals under pseudo-first-order conditions ([R]0 ≪ [NO]). The obtained rate coefficients showed negative temperature dependences, typical for a radical-radical association process, and can be represented by the following parametrizations (all in units of cm(3) molecule(-1) s(-1)): k(CH2OH + NO) = (4.76 × 10(-21)) × (T/300 K)(15.92) × exp[50700/(RT)] (T = 266-363 K, p = 0.79-3.44 Torr); k(CH3CHOH + NO) = (1.27 × 10(-16)) × (T/300 K)(6.81) × exp[28700/(RT)] (T = 241-363 K, p = 0.52-3.43 Torr); k(CH3OCH2 + NO) = (3.58 ± 0.12) × 10(-12) × (T/300 K)(-3.17±0.14) (T = 221-363 K, p = 0.50-0.80 Torr); k(T)3 = 9.62 × 10(-11) × (T/300 K)(-5.99) × exp[-7100/(RT)] (T = 221-473 K, p = 1.41-2.95 Torr), with the uncertainties given as standard errors of the fits and the overall uncertainties estimated as ±20%. The rate of CH3OCH2 + NO reaction was measured in two density ranges due to its observed considerable pressure dependence, which was not found in the studied hydroxyalkyl reactions. In addition, the CH3CO + NO rate coefficient was determined at two temperatures resulting in k298K(CH3CO + NO) = (5.6 ± 2.8) × 10(-13) cm(3) molecule(-1) s(-1). No products were found during these experiments, reasons for which are briefly discussed.

  8. Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method.

    Science.gov (United States)

    Shrestha, Kushal; Jakubikova, Elena

    2015-08-20

    Light-harvesting antennas are protein-pigment complexes that play a crucial role in natural photosynthesis. The antenna complexes absorb light and transfer energy to photosynthetic reaction centers where charge separation occurs. This work focuses on computational studies of the electronic structure of the pigment networks of light-harvesting complex I (LH1), LH1 with the reaction center (RC-LH1), and light-harvesting complex II (LH2) found in purple bacteria. As the pigment networks of LH1, RC-LH1, and LH2 contain thousands of atoms, conventional density functional theory (DFT) and ab initio calculations of these systems are not computationally feasible. Therefore, we utilize DFT in conjunction with the energy-based fragmentation with molecular orbitals method and a semiempirical approach employing the extended Hückel model Hamiltonian to determine the electronic properties of these pigment assemblies. Our calculations provide a deeper understanding of the electronic structure of natural light-harvesting complexes, especially their pigment networks, which could assist in rational design of artificial photosynthetic devices.

  9. Fragment molecular orbital study on electron tunneling mechanisms in bacterial photosynthetic reaction center.

    Science.gov (United States)

    Kitoh-Nishioka, Hirotaka; Ando, Koji

    2012-11-01

    The tunneling mechanisms of electron transfers (ETs) in photosynthetic reaction center of Blastochloris viridis are studied by the ab initio fragment molecular orbital (FMO) method combined with the generalized Mulliken-Hush (GMH) and the bridge Green function (GF) calculations of the electronic coupling T(DA) and the tunneling current method for the ET pathway analysis at the fragment-based resolution. For the ET from batctriopheophytin (H(L)) to menaquinone (MQ), a major tunneling current through Trp M250 and a minor back flow via Ala M215, Ala M216, and His M217 are quantified. For the ET from MQ to ubiquinone, the major tunneling pathway via the nonheme Fe(2+) and His L190 is identified as well as minor pathway via His M217 and small back flows involving His L230, Glu M232, and His M264. At the given molecular structure from X-ray experiment, the spin state of the Fe(2+) ion, its replacement by Zn(2+), or its removal are found to affect the T(DA) value by factors within 2.2. The calculated T(DA) values, together with experimentally estimated values of the driving force and the reorganization energy, give the ET rates in reasonable agreement with experiments.

  10. The gammaTuRC Nanomachine Mechanism and Future Applications

    Science.gov (United States)

    Riehlman, Timothy D.

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

  11. Experimental investigation of the seismic performance of the R/C frames with reinforced masonry infills

    Science.gov (United States)

    Tanjung, Jafril; Maidiawati, Nugroho, Fajar

    2017-10-01

    Intensive studies regarding the investigation of seismic performance of reinforced concrete (R/C) frames which are infilled with brick masonry walls have been carried out by several researchers within the last three-decades. According to authors' field and experimentally experiences conclude that the unreinforced brick masonry infills significantly contributes to increase the seismic performance of the R/C frame structure. Unfortunately, the presence of brick masonry infill walls causes several undesirable effects such as short column, soft-storey, torsion and out of plane collapse. In this study, a strengthening technique for the brick masonry infills were experimentally investigated to improve the seismic performance of the R/C frame structures. For this purpose, four experimental specimens have been prepared, i.e. one of bare R/C frame (BF), one of R/C frame infilled with unreinforced brick-masonry wall (IFUM) and two of R/C frames were infilled with reinforced brick-masonry wall (IFRM-1 and IFRM-2). The bare frame and R/C frame infilled with unreinforced brick-masonry wall represents the typical R/C buildings' construction in Indonesia assuming the brick-masonry wall as the non-structural elements. The brick-masonry wall infills in specimens IFRM-1 and IFRM-2 were strengthened by using embedded ϕ4 plain steel bar on their diagonal and center of brick-masonry wall, respectively. All specimens were laterally pushed-over. The lateral loading and its lateral displacement, failure mechanism and their crack pattern were recorded during experimental works. Comparison of the experimental results of these four specimens conclude that the strengthening of the brick-masonry infills wall gave the significantly increasing of the seismic performance of the R/C frame. The seismic performance was evaluated based on the lateral strength of the R/C specimen. The embedded plain steel bar on brick-masonry also reduces the diagonal crack on the brick-masonry wall. It seems that

  12. Implementation of RC5 and RC6 block ciphers on digital images

    International Nuclear Information System (INIS)

    Belhaj Mohamed, A.; Zaibi, G.; Kachouri, A.

    2011-01-01

    With the fast evolution of the networks technology, the security becomes an important research axis. Many types of communication require the transmission of digital images. This transmission must be safe especially in applications that require a fairly high level of security such as military applications, spying, radars, and biometrics applications. Mechanisms for authentication, confidentiality, and integrity must be implemented within their community. For this reason, several cryptographic algorithms have been developed to ensure the safety and reliability of this transmission. In this paper, we investigate the encryption efficiency of RC5 and RC6 block cipher applied to digital images by including a statistical and differential analysis then, and also we investigate those two block ciphers against errors in ambient noise. The security analysis shows that RC6 algorithm is more secure than RC5. However, using RC6 to encrypt images in rough environment (low signal to noise ratio) leads to more errors (almost double of RC5) and may increase energy consumption by retransmitting erroneous packets. A compromise security/energy must be taken into account for the good choice of encryption algorithm.

  13. Purification and spectroscopic characterization of photosystem II reaction center complexes isolated with or without Triton X-100.

    NARCIS (Netherlands)

    Eijckelhoff, C.; van Roon, H.; Groot, M.L.; van Grondelle, R.; Dekker, J.P.

    1996-01-01

    The pigment composition of the isolated photosystem II reaction center complex in its most stable and pure form currently is a matter of considerable debate. In this contribution, we present a new method based on a combination of gel filtration chromatography and diode array detection to analyze the

  14. Report on the consultants` meeting on technical aspects of the co-operation of nuclear reaction data centers

    Energy Technology Data Exchange (ETDEWEB)

    Lemmel, H D; Schwerer, O; Wienke, H [eds.

    1995-10-01

    The IAEA Nuclear Data Section convenes in annual intervals coordination meetings of the Network of the Nuclear Reaction Data Center. The present meeting dealt with technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Refs, figs and tabs.

  15. A new pathway for transmembrane electron transfer in photosynthetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair.

    NARCIS (Netherlands)

    van Brederode, M.E.; Jones, M.R.; van Mourik, F.; van Stokkum, I.H.M.; van Grondelle, R.

    1997-01-01

    It is generally accepted that electron transfer in bacterial photosynthesis is driven by the first singlet excited state of a special pair of bacteriochlorophylls (P*). We have examined the first steps of electron transfer in a mutant of the Rhodobacter sphaeroides reaction center in which charge

  16. A new pathway for transmembrane electron transfer in photosyntetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair.

    NARCIS (Netherlands)

    van Brederode, M.E.; Jones, M.R.; van Mourik, F.; van Stokkum, I.H.M.; van Grondelle, R.

    1997-01-01

    It is generally accepted that electron transfer in bacterial photosynthesis is driven by the first singlet excited state of a special pair of bacteriochlorophylls (P*). We have examined the first steps of electron transfer in a mutant of the Rhodobacter sphaeroides reaction center in which charge

  17. Report on the consultants' meeting on technical aspects of the co-operation of nuclear reaction data centers

    International Nuclear Information System (INIS)

    Lemmel, H.D.; Schwerer, O.; Wienke, H.

    1995-10-01

    The IAEA Nuclear Data Section convenes in annual intervals coordination meetings of the Network of the Nuclear Reaction Data Center. The present meeting dealt with technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Refs, figs and tabs

  18. Utilizing the dynamic stark shift as a probe for dielectric relaxation in photosynthetic reaction centers during charge separation.

    Science.gov (United States)

    Guo, Zhi; Lin, Su; Woodbury, Neal W

    2013-09-26

    In photosynthetic reaction centers, the electric field generated by light-induced charge separation produces electrochromic shifts in the transitions of reaction center pigments. The extent of this Stark shift indirectly reflects the effective field strength at a particular cofactor in the complex. The dynamics of the effective field strength near the two monomeric bacteriochlorophylls (BA and BB) in purple photosynthetic bacterial reaction centers has been explored near physiological temperature by monitoring the time-dependent Stark shift during charge separation (dynamic Stark shift). This dynamic Stark shift was determined through analysis of femtosecond time-resolved absorbance change spectra recorded in wild type reaction centers and in four mutants at position M210. In both wild type and the mutants, the kinetics of the dynamic Stark shift differ from those of electron transfer, though not in the same way. In wild type, the initial electron transfer and the increase in the effective field strength near the active-side monomer bacteriochlorophyll (BA) occur in synchrony, but the two signals diverge on the time scale of electron transfer to the quinone. In contrast, when tyrosine is replaced by aspartic acid at M210, the kinetics of the BA Stark shift and the initial electron transfer differ, but transfer to the quinone coincides with the decay of the Stark shift. This is interpreted in terms of differences in the dynamics of the local dielectric environment between the mutants and the wild type. In wild type, comparison of the Stark shifts associated with BA and BB on the two quasi-symmetric halves of the reaction center structure confirm that the effective dielectric constants near these cofactors are quite different when the reaction center is in the state P(+)QA(-), as previously determined by Steffen et al. at 1.5 K (Steffen, M. A.; et al. Science 1994, 264, 810-816). However, it is not possible to determine from static, low-temperature measurments if the

  19. 47 CFR 95.221 - (R/C Rule 21) How do I have my R/C transmitter serviced?

    Science.gov (United States)

    2010-10-01

    ... FCC certificated R/C transmitter (see R/C Rule 9) must be made in accord with the Technical... in order to: (1) Adjust a transmitter to an antenna; (2) Detect or measure radiation of energy other...

  20. Comparison of Ground Reaction Forces, Center of Pressure and Body Center of Mass Changes in the Voluntary, Semi-Voluntary and Involuntary Gait Termination in Healthy Young Men

    Directory of Open Access Journals (Sweden)

    behrooz teymourian

    2016-03-01

    Full Text Available Objective: The aim of this study was comparing the ground reaction forces, center of pressure and body center of mass changes in voluntary, semi-voluntary and involuntary gait termination in healthy young men. Methods: In this study, 12 young men performed termination of gait in three different patterns. The variable of peak antero-posterior and vertical forces in two directions at both limbs, the time to reach peak and average forces in every limb in both directions, the center of pressure displacement of medio-lateral and antero-posterior direction for each limb and the net center of pressure and the displacement of the center of mass motion in all three motion plates were recorded using motion analysis system and force plate.The repeated measurements test was used to compare three patterns of gait termination at significance level of p&le0.5. Results: The results showed a significant difference in variables of peak antero-posterior force, the time to reach peak antero-posterior force and mean antero-posterior forces of the leading limb, the peak antero-posterior force of the trialing limbs, the depth force of leading limbs, medio-lateral cop of leading limbs displacement and vertical displacement of the center of mass, among different patterns of gait termination. Conclusion: While walking, the probability of a fall or collision damage, when a sudden or unexpected stop is required, increases. Therefore, more coordination between neuromuscular systems is required.

  1. Fractional RC and LC Electrical Circuits

    Directory of Open Access Journals (Sweden)

    Gómez-Aguilar José Francisco

    2014-04-01

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

  2. Fatigue behavior of RC T-beams

    Directory of Open Access Journals (Sweden)

    Omar A. Farghal

    2014-09-01

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

  3. DISTRIBUTED RC NETWORKS WITH RATIONAL TRANSFER FUNCTIONS,

    Science.gov (United States)

    A distributed RC circuit analogous to a continuously tapped transmission line can be made to have a rational short-circuit transfer admittance and...one rational shortcircuit driving-point admittance. A subcircuit of the same structure has a rational open circuit transfer impedance and one rational ...open circuit driving-point impedance. Hence, rational transfer functions may be obtained while considering either generator impedance or load

  4. Design of the RTO/RC ITER primary pumping system

    International Nuclear Information System (INIS)

    Ladd, P.; Ibbott, C; Janeschitz, G.; Martin, E.

    2000-01-01

    The primary pumping system is needed not only to exhaust helium ash resulting from the DT reaction but also excess fuelling gas injected during the fusion burn, which can extend for 100's to 1000's of seconds, and to perform a variety of other functions. The prevailing environmental conditions, principally nuclear radiation, tritium exposure, magnetic fields, and the need for containment, have a significant impact on the design and selection of equipment. This paper presents the design of the Reduced Technical Objectives/Reduced Cost (RTO/RC) ITER primary pumping system with particular emphasis on the nuclear aspects of the design. Component selection and equipment layout issues to meet established requirements for the system are reviewed together with the R and D that is being undertaken to support the design. In addition, serviceability and maintainability issues related to this system are also discussed

  5. Report compiled by Research Center for Carbonaceous Resources, Institute for Chemical Reaction Science, Tohoku University; Tohoku Daigaku Hanno Kagaku Kenkyusho tanso shigen hanno kenkyu center hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The Research Center for Carbonaceous Resources was established in April 1991 for the purpose of developing a comprehensive process for converting carbonaceous resources into clean fuels or into materials equipped with advanced functions. In this report, the track records etc. of the center are introduced. Under study in the conversion process research department is the organization of a comprehensive coal conversion process which will be a combination of solvent extraction, catalytic decomposition, and catalytic gasification, whose goal is to convert coal in a clean way at high efficiency. Under study in the conversion catalyst research department are the development of a coal denitrogenation method, development of a low-temperature gasification method by use of inexpensive catalysts, synthesis of C{sub 2} hydrocarbons in a methane/carbon dioxide reaction, etc. Other endeavors under way involve the designing and development of new organic materials such as new carbon materials and a study of the foundation on which such efforts stand, that is, the study of the control of reactions between solids. Furthermore, in the study of interfacial reaction control, the contact gasification of coal, brown coal ion exchange capacity and surface conditions, carbonization of cation exchanged brown coal, etc., are being developed. (NEDO)

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

    OpenAIRE

    Nasruddin

    2012-01-01

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

  7. Photochemistry and reactions of OH- defects and F centers in alkali halides

    International Nuclear Information System (INIS)

    Morato, S.P.; Luety, F.

    1978-01-01

    Aditively colored KCl:OH - crystals showed under a combined UV and VIS irradiation, a nearly complete and irreversible destruction of all F centers and visible absorption in the crystal. Only upon heating the crystal above 650 0 C the F center coloration becomes partially restored. The photodissociation of the OH - (under UV light) together with the photoionization of the F center (under VIS light) produces a not effects where all the F centers are converted into U centers. These photoreactions produces high contrast visible images that are completely stable under light at RT. Besides the optical information storage aspect of this effect these photoreaction s can also be used for controlled production of Usub(A) centers if the crystal also contains a foreign metallic impurity such a Na + ion [pt

  8. On the nature of organic and inorganic centers that bifurcate electrons, coupling exergonic and endergonic oxidation-reduction reactions.

    Science.gov (United States)

    Peters, John W; Beratan, David N; Schut, Gerrit J; Adams, Michael W W

    2018-04-19

    Bifurcating electrons to couple endergonic and exergonic electron-transfer reactions has been shown to have a key role in energy conserving redox enzymes. Bifurcating enzymes require a redox center that is capable of directing electron transport along two spatially separate pathways. Research into the nature of electron bifurcating sites indicates that one of the keys is the formation of a low potential oxidation state to satisfy the energetics required of the endergonic half reaction, indicating that any redox center (organic or inorganic) that can exist in multiple oxidation states with sufficiently separated redox potentials should be capable of electron bifurcation. In this Feature Article, we explore a paradigm for bifurcating electrons down independent high and low potential pathways, and describe redox cofactors that have been demonstrated or implicated in driving this unique biochemistry.

  9. Reaction

    African Journals Online (AJOL)

    abp

    19 oct. 2017 ... Reaction to Mohamed Said Nakhli et al. concerning the article: "When the axillary block remains the only alternative in a 5 year old child". .... Bertini L1, Savoia G, De Nicola A, Ivani G, Gravino E, Albani A et al ... 2010;7(2):101-.

  10. Glial reaction in visual centers upon whole-body combined irradiation with microwaves and x-radiation

    International Nuclear Information System (INIS)

    Logvinov, S.V.

    1989-01-01

    A single whole-body preirradiation with thermogenous microwaves modifies the dynamics of the glial reactions of visual centers of ginea pigs induced by median lethal X-radiation doses. A combination of the two factors products the synergistic effect, estimated by the degree of alteration of astrocytes and oligodendroglyocytes at early times after exposure, leads to early activation of microglia, and reduces radiation-induced alterations in glia at later times (25-60 days)

  11. 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...

  12. Resonance Raman spectroscopy of 2H-labelled spheroidenes in petroleum ether and in the Rhodobacter sphaeroides reaction centre.

    Science.gov (United States)

    Kok, P; Köhler, J; Groenen, E J; Gebhard, R; van der Hoef, I; Lugtenburg, J; Farhoosh, R; Frank, H A

    1997-03-01

    As a step towards the structural analysis of the carotenoid spheroidene in the Rhodobacter sphaeroides reaction centre, we present the resonance Raman spectra of 14-2H, 15-2H, 15'-2H, 14'-2H, 14,15'-2H2 and 15-15'-2H2 spheroidenes in petroleum ether and, except for 14,15'-2H2 spheroidene, in the Rb. sphaeroides R26 reaction center (RC). Analysis of the spectral changes upon isotopic substitution allows a qualitative assignment of most of the vibrational bands to be made. For the all-trans spheroidenes in solution the resonance enhancement of the Raman bands is determined by the participation of carbon carbon stretching modes in the centre of the conjugated chain, the C9 to C15' region. For the RC-bound 15,15'-cis spheroidenes, enhancement is determined by the participation of carbon-carbon stretching modes in the centre of the molecule, the C13 to C13' region. Comparison of the spectra in solution and in the RC reveals evidence for an out-of-plane distortion of the RC-bound spheroidene in the central C14 to C14' region of the carotenoid. The characteristic 1240 cm-1 band in the spectrum of the RC-bound spheroidene has been assigned to a normal mode that contains the coupled C12-C13 and C13'-C12' stretch vibrations.

  13. ECE diagnostics for RTO/RC ITER

    International Nuclear Information System (INIS)

    Vayakis, G.; Bartlett, D.V.; Costley, A.E.

    2001-01-01

    This paper presents the current status of the Electron Cyclotron Emission (ECE) diagnostic on the Reduced Technical Objectives/Reduced Cost International Thermonuclear Experimental Reactor (RTO/RC ITER). It discusses the implications of the new machine design on the measurement requirements, the ability of the diagnostic technique to meet these, and the changes in the implementation imposed by the new layout. Finally, it outlines the physics studies, design and R and D work required prior to the detailed design and construction of the diagnostic. Key results are: (i) that the localisation of the measurement is similar to that in ITER-FDR (40-100 mm in X-mode, 60-200 mm in O-mode for the reference scenario), so that the relative spatial resolution degrades in this, smaller, machine, and (ii) the expected effect of transport barriers on the temperature profile in the high temperature region will be poorly resolved, because the effect of the temperature gradient on the outboard side is to degrade the resolution to (∼250 mm in X-mode, ∼350 mm in O-mode). Nevertheless ECE will be able to make a unique and useful contribution to the RTO/RC ITER measurement set

  14. Structural Test and Analysis of RC Slab After Fire Loading

    International Nuclear Information System (INIS)

    Chung, Chulhun; Im, Cho Rong; Park, Jaegyun

    2013-01-01

    In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene) fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber

  15. Structural Test and Analysis of RC Slab After Fire Loading

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chulhun; Im, Cho Rong; Park, Jaegyun [Dankook Univ., Yongin (Korea, Republic of)

    2013-04-15

    In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene) fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber.

  16. Modification of quinone electrochemistry by the proteins in the biological electron transfer chains: examples from photosynthetic reaction centers

    Science.gov (United States)

    Gunner, M. R.; Madeo, Jennifer; Zhu, Zhenyu

    2009-01-01

    Quinones such as ubiquinone are the lipid soluble electron and proton carriers in the membranes of mitochondria, chloroplasts and oxygenic bacteria. Quinones undergo controlled redox reactions bound to specific sites in integral membrane proteins such as the cytochrome bc1 oxidoreductase. The quinone reactions in bacterial photosynthesis are amongst the best characterized, presenting a model to understand how proteins modulate cofactor chemistry. The free energy of ubiquinone redox reactions in aqueous solution and in the QA and QB sites of the bacterial photosynthetic reaction centers (RCs) are compared. In the primary QA site ubiquinone is reduced only to the anionic semiquinone (Q•−) while in the secondary QB site the product is the doubly reduced, doubly protonated quinol (QH2). The ways in which the protein modifies the relative energy of each reduced and protonated intermediate are described. For example, the protein stabilizes Q•− while destabilizing Q= relative to aqueous solution through electrostatic interactions. In addition, kinetic and thermodynamic mechanisms for stabilizing the intermediate semiquinones are compared. Evidence for the protein sequestering anionic compounds by slowing both on and off rates as well as by binding the anion more tightly is reviewed. PMID:18979192

  17. Reduction reactions of water soluble cyano-cobalt(III)-porphyrins: Metal versus ligand centered processes

    International Nuclear Information System (INIS)

    Mosseri, S.; Neta, P.; Harriman, A.; Hambright, P.

    1990-01-01

    Reduction reactions of dicyano-cobalt(III)-porphyrins [potential in vivo cyanide scavenger drugs] were studied by radiolytic and electrochemical methods using the water soluble tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP). For [(CN)2CoIIITPPS]-, reduction occurs stepwise to the CoII, CoI, and finally to the phlorin anion. This behavior is similar to that of the cobalt porphyrins in the absence of cyanide, except that the cyanide ligand shifts the reduction potentials to much more negative values. On the other hand, under radiolytic conditions, [(CN)2CoIIITMPyP]- is reduced on the porphyrin macrocycle by one electron to give the CoIII pi-radical anion, which disproportionates into the initial complex and the two-electron ring reduced CoIII phlorin. The radical anion is also formed by intramolecular electron transfer subsequent to the reaction of CoIITMPyP and cyanide. The results are compared with the chemistry of Vitamin B-12

  18. Density functional theoretical study on the C-F and C-O oxidative addition reaction at an AI center

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Seong [Dept. of Science Education, Kyungnam University, Masan (Korea, Republic of); Cho, Hyun; Hwang, Sungu [Dept. of Nanomechatronics Engineering, Pusan National University, Miryang (Korea, Republic of)

    2017-02-15

    In this study, B3LYP/LACVP** level calculations were chosen because the level of theory was applied successfully to calculations of the thermodynamic and kinetic features of the oxidative addition reactions of alkyl and aryl halides to pincer-type complexes. This study examined the effects of the substituents on the phenyl rings of the Al(I) center. Isopropyl side chains in the phenyl rings attached to N atoms of the pincer ligand were replaced with a methyl (Me) (2) or tertiary butyl ( t Bu) group. The oxidative addition of C[BOND]F and C[BOND]O bonds to an Al (I) center was investigated computationally by DFT calculations. The geometries, thermodynamic, and kinetic features were in good agreement with the experimental data, as in previous studies on the transition metal complexes. The computational results showed that the DFT calculations could provide qualitative insight into the reactivity and thermodynamics of the oxidative addition reactions of C[BOND]F bonds.

  19. Stereoselective synthesis of organosulfur compounds incorporating N-aromatic heterocyclic motifs and quaternary carbon centers via a sulfa-Michael triggered tandem reaction.

    Science.gov (United States)

    Qin, Tianyou; Cheng, Lu; Zhang, Sean Xiao-An; Liao, Weiwei

    2015-06-14

    A novel sulfa-Michael addition (SMA)-triggered tandem reaction was developed by combining a SMA reaction with a simultaneous rearomatization process utilizing a less reactive carbonyl group as an intramolecular electrophile partner, which provided a unique synthetic route to access various organosulfur compounds incorporating an N-aromatic heterocyclic motif and quaternary carbon centers.

  20. Molecular modeling and computational simulation of the photosystem-II reaction center to address isoproturon resistance in Phalaris minor.

    Science.gov (United States)

    Singh, Durg Vijay; Agarwal, Shikha; Kesharwani, Rajesh Kumar; Misra, Krishna

    2012-08-01

    Isoproturon is the only herbicide that can control Phalaris minor, a competitive weed of wheat that developed resistance in 1992. Resistance against isoproturon was reported to be due to a mutation in the psbA gene that encodes the isoproturon-binding D1 protein. Previously in our laboratory, a triazole derivative of isoproturon (TDI) was synthesized and found to be active against both susceptible and resistant biotypes at 0.5 kg/ha but has shown poor specificity. In the present study, both susceptible D1((S)), resistant D1((R)) and D2 proteins of the PS-II reaction center of P. minor have been modeled and simulated, selecting the crystal structure of PS-II from Thermosynechococcus elongatus (2AXT.pdb) as template. Loop regions were refined, and the complete reaction center D1/D2 was simulated with GROMACS in lipid (1-palmitoyl-2-oleoylglycero-3-phosphoglycerol, POPG) environment along with ligands and cofactor. Both S and R models were energy minimized using steepest decent equilibrated with isotropic pressure coupling and temperature coupling using a Berendsen protocol, and subjected to 1,000 ps of MD simulation. As a result of MD simulation, the best model obtained in lipid environment had five chlorophylls, two plastoquinones, two phenophytins and a bicarbonate ion along with cofactor Fe and oxygen evolving center (OEC). The triazole derivative of isoproturon was used as lead molecule for docking. The best worked out conformation of TDI was chosen for receptor-based de novo ligand design. In silico designed molecules were screened and, as a result, only those molecules that show higher docking and binding energies in comparison to isoproturon and its triazole derivative were proposed for synthesis in order to get more potent, non-resistant and more selective TDI analogs.

  1. A Hierarchy of Homodesmotic Reactions for Thermochemistry

    Science.gov (United States)

    Schleyer, Paul v. R.

    2009-01-01

    Chemical equations that balance bond types and atom hybridization to different degrees are often used in computational thermochemistry, for example, to increase accuracy when lower levels of theory are employed. We expose the widespread confusion over such classes of equations and demonstrate that the two most widely used definitions of “homodesmotic” reactions are not equivalent. New definitions are introduced and a consistent hierarchy of reaction classes (RC1 – RC5) for hydrocarbons is constructed: isogyric (RC1) ⊇ isodesmic (RC2) ⊇ hypohomodesmotic (RC3) ⊇ homodesmotic (RC4) ⊇ hyperhomodesmotic (RC5). Each of these successively conserves larger molecular fragments. The concept of isodesmic bond separation reactions is generalized to all classes in this hierarchy, providing a unique sectioning of a given molecule for each reaction type. Several ab initio and density functional methods are applied to the bond separation reactions of 38 hydrocarbons containing five or six carbon atoms. RC4 and RC5 reactions provide bond separation enthalpies with errors consistently less than 0.4 kcal mol−1 across a wide range of theoretical levels, performing significantly better than the other reaction types and far superior to atomization routes. Our recommended bond separation reactions were demonstrated by determining the enthalpies of formation (at 298 K) of 1,3,5-hexatriyne (163.7 ± 0.4 kcal mol−1), 1,3,5,7-octatetrayne (217.6 ± 0.6 kcal mol−1), the larger polyynes C10H2 through C26H2, and an infinite acetylenic carbon chain. PMID:19182999

  2. Vapreotide: BMY 41606, RC 160, Sanvar.

    Science.gov (United States)

    2003-01-01

    Vapreotide [Octastatin, Sanvar, RC 160, BMY 41606] is a somatostatin analogue developed at Tulane University School of Medicine, New Orleans, USA, which holds patent rights for vapreotide. Vapreotide provides a much higher metabolic stability than its parent compound. Vapreotide was licensed to Debiopharm for development in Europe. Vapreotide is usually administered SC although a slow-release IM formulation is also available. Other sustained-release formulations are under development. H3 Pharma plans to sign agreements for all indications in the core markets of North America, Europe and in non-core geographic regions during 2003. H3 Pharma will also seek to obtain registration and early market entry in non-core countries with help from partners. Sanvar Immediate Release (IR) has been submitted for approval within the European Union for the treatment of acute oesophageal variceal bleeding (EVB). Sanvar IR has been awarded orphan drug status in the US for EVB. In July 2003, H3 Pharma received written confirmation from the US FDA that the dossier for Sanvar is fileable for registration in the United States for the treatment of esophageal variceal bleeding (EVB). The Sanvar IR (immediate-release) formulation is expected to enter the US market by late 2004. H3 Pharma expects to file for Latin American registration for this indication in the second half of 2003, with registrations in other regions to follow. Sanvar SR has been submitted for Orphan Drug designation.

  3. Seismic Performance of Precast Polystyrene RC Walls

    Directory of Open Access Journals (Sweden)

    Wibowo Ari

    2017-01-01

    Full Text Available Precast concrete structure such as precast wall is a concept that is growing rapidly these days. However, the earthquake resistance is believed to be one of its drawbacks. Additionally, the large weight of solid elements also increase the building weight significantly which consequently increase the earthquake base shear force as well. Therefore, investigation on the seismic performance of precast concrete wall has been carried out. Three RC wall specimens using wire mesh reinforcement and EPS (Extended Polystyrene System panel have been tested. This wall was designed as a structural wall that was capable in sustaining lateral loads (in-plane yet were lightweight to reduce the total weight of the building. Parameter observed was the ratio of height to width (aspect ratio of wall of 1.0, 1.5 and 2.0 respectively with the aim to study the behaviour of brittle to ductile transition of the wall. Incremental static load tests were conducted until reaching peak load and then followed by displacement control until failure. Several data were measured at every stage of loading comprising lateral load-displacement behaviour, ultimate strength and collapse mechanism. The outcomes showed that precast concrete walls with a steel wire and EPS panel filler provided considerably good resistance against lateral load.

  4. The Second ICASE/LaRC Industry Roundtable: Session Proceedings

    Science.gov (United States)

    Girimaji, Sharath

    1997-01-01

    The second ICASE/LaRC Industry Roundtable was held October 7-9, 1996 at the Williamsburg Hospitality House, Williamsburg, Virginia. Like the first roundtable in 1994, this meeting had two objectives: (1) to expose ICASE and LaRC scientists to industrial research agendas; and (2) to acquaint industry with the capabilities and technology available at ICASE, LaRC and academic partners of ICASE. Nineteen sessions were held in three parallel tracks. Of the 170 participants, over one third were affiliated with various industries. Proceedings from the different sessions are summarized in this report.

  5. High-pressure modulation of the structure of the bacterial photochemical reaction center at physiological and cryogenic temperatures

    Science.gov (United States)

    Timpmann, Kõu; Kangur, Liina; Lõhmus, Ants; Freiberg, Arvi

    2017-07-01

    The optical absorption and fluorescence response to external high pressure of the reaction center membrane chromoprotein complex from the wild-type non-sulfur photosynthetic bacterium Rhodobacter sphaeroides was investigated using the native pigment cofactors as local molecular probes of the reaction center structure at physiological (ambient) and cryogenic (79 K) temperatures. In detergent-purified complexes at ambient temperature, abrupt blue shift and accompanied broadening of the special pair band was observed at about 265 MPa. These reversible in pressure features were assigned to a pressure-induced rupture of a lone hydrogen bond that binds the photo-chemically active L-branch primary electron donor bacteriochlorophyll cofactor to the surrounding protein scaffold. In native membrane-protected complexes the hydrogen bond rupture appeared significantly restricted and occurred close to about 500 MPa. The free energy change associated with the rupture of the special pair hydrogen bond in isolate complexes was estimated to be equal to about 12 kJ mol-1. In frozen samples at cryogenic temperatures the hydrogen bond remained apparently intact up to the maximum utilized pressure of 600 MPa. In this case, however, heterogeneous spectral response of the cofactors from the L-and M-branches was observed due to anisotropic build-up of the protein structure. While in solid phase, the special pair fluorescence as a function of pressure exactly followed the respective absorption spectrum at a constant Stokes shift, at ambient temperature, the two paths began to deviate strongly from one other at the hydrogen bond rupture pressure. This effect was tentatively interpreted by different emission properties of hydrogen-bound and hydrogen-unbound special pair exciton states.

  6. Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

    International Nuclear Information System (INIS)

    Reppert, Mike; Kell, Adam; Pruitt, Thomas; Jankowiak, Ryszard

    2015-01-01

    The vibrational spectral density is an important physical parameter needed to describe both linear and non-linear spectra of multi-chromophore systems such as photosynthetic complexes. Low-temperature techniques such as hole burning (HB) and fluorescence line narrowing are commonly used to extract the spectral density for a given electronic transition from experimental data. We report here that the lineshape function formula reported by Hayes et al. [J. Phys. Chem. 98, 7337 (1994)] in the mean-phonon approximation and frequently applied to analyzing HB data contains inconsistencies in notation, leading to essentially incorrect expressions in cases of moderate and strong electron-phonon (el-ph) coupling strengths. A corrected lineshape function L(ω) is given that retains the computational and intuitive advantages of the expression of Hayes et al. [J. Phys. Chem. 98, 7337 (1994)]. Although the corrected lineshape function could be used in modeling studies of various optical spectra, we suggest that it is better to calculate the lineshape function numerically, without introducing the mean-phonon approximation. New theoretical fits of the P870 and P960 absorption bands and frequency-dependent resonant HB spectra of Rb. sphaeroides and Rps. viridis reaction centers are provided as examples to demonstrate the importance of correct lineshape expressions. Comparison with the previously determined el-ph coupling parameters [Johnson et al., J. Phys. Chem. 94, 5849 (1990); Lyle et al., ibid. 97, 6924 (1993); Reddy et al., ibid. 97, 6934 (1993)] is also provided. The new fits lead to modified el-ph coupling strengths and different frequencies of the special pair marker mode, ω sp , for Rb. sphaeroides that could be used in the future for more advanced calculations of absorption and HB spectra obtained for various bacterial reaction centers

  7. Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

    Energy Technology Data Exchange (ETDEWEB)

    Reppert, Mike; Kell, Adam; Pruitt, Thomas [Department of Chemistry, Kansas State University, Manhattan, Kansas 66506 (United States); Jankowiak, Ryszard, E-mail: ryszard@ksu.edu [Department of Chemistry, Kansas State University, Manhattan, Kansas 66506 (United States); Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States)

    2015-03-07

    The vibrational spectral density is an important physical parameter needed to describe both linear and non-linear spectra of multi-chromophore systems such as photosynthetic complexes. Low-temperature techniques such as hole burning (HB) and fluorescence line narrowing are commonly used to extract the spectral density for a given electronic transition from experimental data. We report here that the lineshape function formula reported by Hayes et al. [J. Phys. Chem. 98, 7337 (1994)] in the mean-phonon approximation and frequently applied to analyzing HB data contains inconsistencies in notation, leading to essentially incorrect expressions in cases of moderate and strong electron-phonon (el-ph) coupling strengths. A corrected lineshape function L(ω) is given that retains the computational and intuitive advantages of the expression of Hayes et al. [J. Phys. Chem. 98, 7337 (1994)]. Although the corrected lineshape function could be used in modeling studies of various optical spectra, we suggest that it is better to calculate the lineshape function numerically, without introducing the mean-phonon approximation. New theoretical fits of the P870 and P960 absorption bands and frequency-dependent resonant HB spectra of Rb. sphaeroides and Rps. viridis reaction centers are provided as examples to demonstrate the importance of correct lineshape expressions. Comparison with the previously determined el-ph coupling parameters [Johnson et al., J. Phys. Chem. 94, 5849 (1990); Lyle et al., ibid. 97, 6924 (1993); Reddy et al., ibid. 97, 6934 (1993)] is also provided. The new fits lead to modified el-ph coupling strengths and different frequencies of the special pair marker mode, ω{sub sp}, for Rb. sphaeroides that could be used in the future for more advanced calculations of absorption and HB spectra obtained for various bacterial reaction centers.

  8. Performance of RC columns with partial length corrosion

    International Nuclear Information System (INIS)

    Wang Xiaohui; Liang Fayun

    2008-01-01

    Experimental and analytical studies on the load capacity of reinforced concrete (RC) columns with partial length corrosion are presented, where only a fraction of the column length was corroded. Twelve simply supported columns were eccentrically loaded. The primary variables were partial length corrosion in tensile or compressive zone and the corrosion level within this length. The failure of the corroded column occurs in the partial length, mainly developed from or located nearby or merged with the longitudinal corrosion cracks. For RC column with large eccentricity, load capacity of the column is mainly influenced by the partial length corrosion in tensile zone; while for RC column with small eccentricity, load capacity of the column greatly decreases due to the partial length corrosion in compressive zone. The destruction of the longitudinally mechanical integrality of the column in the partial length leads to this great reduction of the load capacity of the RC column

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

    Science.gov (United States)

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

    2017-10-01

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

  10. A new NASA LaRC Multi-Purpose Prepregging Unit

    Science.gov (United States)

    Wilkinson, S. P.; Marchello, J. M.; Dixon, D.; Johnston, N. J.

    1993-01-01

    A multi-purpose prepregging machine has been designed and built for NASA Langley Research Center. The machine has numerous advantages over existing units due to its various modular components. Each of these can be used individually or simultaneously depending on the required prepregging method. A reverse roll coater provides the ability to prepare thin films from typical hot-melt thermoset formulations. Also, if necessary, the design allows direct fiber impregnation within the reverse roll coater gap. Included in the impregnation module is a solution dip tank allowing the fabrication of thermoplastic prepregs from solution. The proceeding modules within the unit consist of four nip stations, two hot-plates, a hot-sled option and a high temperature oven. This paper describes the advantages of such a modular construction and discusses the various processing combinations available to the prepregger. A variety of high performance prepreg material systems were produced on IM7 (Hercules) carbon fiber. These included LaRC RP46, a PMR-type resin processed from methanol and two polyamide acids, LaRC IA and LaRC ITPI, prpregged from N-methyl pyrrolidinone (NMP). Parameters involved in the production of these prepreg materials are presented as are the mechanical properties of the resulting good quality laminates. A brief introduction into the existing prepregging science is presented. Topics relating to solution prepregging are identified with a focus on the current research effort and its future development.

  11. Friction correction for model ship resistance and propulsion tests in ice at NRC's OCRE-RC

    Directory of Open Access Journals (Sweden)

    Michael Lau

    2018-05-01

    Full Text Available This paper documents the result of a preliminary analysis on the influence of hull-ice friction coefficient on model resistance and power predictions and their correlation to full-scale measurements. The study is based on previous model-scale/full-scale correlations performed on the National Research Council - Ocean, Coastal, and River Engineering Research Center's (NRC/OCRE-RC model test data. There are two objectives for the current study: (1 to validate NRC/OCRE-RC's modeling standards in regarding to its practice of specifying a CFC (Correlation Friction Coefficient of 0.05 for all its ship models; and (2 to develop a correction methodology for its resistance and propulsion predictions when the model is prepared with an ice friction coefficient slightly deviated from the CFC of 0.05. The mean CFC of 0.056 and 0.050 for perfect correlation as computed from the resistance and power analysis, respectively, have justified NRC/OCRE-RC's selection of 0.05 for the CFC of all its models. Furthermore, a procedure for minor friction corrections is developed. Keywords: Model test, Ice resistance, Power, Friction correction, Correlation friction coefficient

  12. Summary of LaRC 2-inch Erectable Joint Hardware Heritage Test Data

    Science.gov (United States)

    Dorsey, John T.; Watson, Judith J.

    2016-01-01

    As the National Space Transportation System (STS, also known as the Space Shuttle) went into service during the early 1980's, NASA envisioned many missions of exploration and discovery that could take advantage of the STS capabilities. These missions included: large orbiting space stations, large space science telescopes and large spacecraft for manned missions to the Moon and Mars. The missions required structures that were significantly larger than the payload volume available on the STS. NASA Langley Research Center (LaRC) conducted studies to design and develop the technology needed to assemble the large space structures in orbit. LaRC focused on technology for erectable truss structures, in particular, the joint that connects the truss struts at the truss nodes. When the NASA research in large erectable space structures ended in the early 1990's, a significant amount of structural testing had been performed on the LaRC 2-inch erectable joint that was never published. An extensive set of historical information and data has been reviewed and the joint structural testing results from this historical data are compiled and summarized in this report.

  13. The evolutionary pathway from anoxygenic to oxygenic photosynthesis examined by comparison of the properties of photosystem II and bacterial reaction centers.

    Science.gov (United States)

    Allen, J P; Williams, J C

    2011-01-01

    In photosynthetic organisms, such as purple bacteria, cyanobacteria, and plants, light is captured and converted into energy to create energy-rich compounds. The primary process of energy conversion involves the transfer of electrons from an excited donor molecule to a series of electron acceptors in pigment-protein complexes. Two of these complexes, the bacterial reaction center and photosystem II, are evolutionarily related and structurally similar. However, only photosystem II is capable of performing the unique reaction of water oxidation. An understanding of the evolutionary process that lead to the development of oxygenic photosynthesis can be found by comparison of these two complexes. In this review, we summarize how insight is being gained by examination of the differences in critical functional properties of these complexes and by experimental efforts to alter pigment-protein interactions of the bacterial reaction center in order to enable it to perform reactions, such as amino acid and metal oxidation, observable in photosystem II.

  14. Electron transfer. 93. Further reactions of transition-metal-center oxidants with vitamin B12s (Cob(I)alamin)

    International Nuclear Information System (INIS)

    Pillai, G.C.; Ghosh, S.K.; Gould, E.S.

    1988-01-01

    Vitamin B 12s (cob(I)alamin) reduces europium(III), titanium(IV) (TiO(C 2 O 4 ) 2 2- ), and uranium(VI) in aqueous solution. These oxidants undergo one-electron changes, leading in each case to the cobalt product cob(II)alamin (B 12r ). The reduction of Eu 3+ , which is inhibited by TES buffer, but not by glycine, is outer sphere. Its limiting specific rate (1 x 10 2 M -1 s -1 ), incorporated in the Marcus treatment, yields a B 12s ,B 12r self-exchange rate of 10 4.8±0.5 M -1 s -1 . Reductions of TiO(C 2 O 4 ) 2 2- are accelerated by H + and by acetic acid. Kinetic patterns suggest three competing reaction paths involving varying degrees of protonation of the Ti(IV) center or its association with acetic acid. The very rapid reduction of U(VI) (k = 4 x 10 6 M -1 s -1 ) yields U(V) in several buffering media, even when B 12s is taken in excess. The much slower conversion of U(V) to U(IV), although thermodynamically favored, appears to be retarded by the extensive reorganization of the coordination sphere of oxo-bound U(V) that must accompany its acceptance of an additional electron. The observed specific rate for the B 12s -U(VI) reaction is in reasonable agreement, in the framework of the Marcus formalism, with reported values of the formal potential and the self-exchange rate for U(V,VI). 37 references, 4 tables

  15. Electronically stimulated deep-center reactions in electron-irradiated InP: Comparison between experiment and recombination-enhancement theories

    International Nuclear Information System (INIS)

    Sibille, A.

    1987-01-01

    We present a detailed study of the recombination enhancement of several defect reactions involving the main deep centers in low-temperature electron-irradiated InP. A fairly good agreement is obtained with the Weeks-Tully-Kimerling theory for the activation energies of the enhanced process. On the other hand, a thorough investigation of a thermally and electronically stimulated defect transformation shows evidence that one major approximation (local vibrational equilibrium) fails, and that the recently proposed [H. Sumi, Phys. Rev. B 29, 4616 (1984)] mechanism of coherent recombination on deep centers is responsible for altered reaction rates at high injection levels

  16. Menaquinone-7 in the reaction center complex of the green sulfur bacterium Chlorobium vibrioforme functions as the electron acceptor A1

    DEFF Research Database (Denmark)

    Kjaer, B; Frigaard, N-U; Yang, F

    1998-01-01

    Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules of menaqui......Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules...

  17. Molecular insight into γ-γ tubulin lateral interactions within the γ-tubulin ring complex (γ-TuRC)

    Science.gov (United States)

    Suri, Charu; Hendrickson, Triscia W.; Joshi, Harish C.; Naik, Pradeep Kumar

    2014-09-01

    γ-tubulin is essential for the nucleation and organization of mitotic microtubules in dividing cells. It is localized at the microtubule organizing centers and mitotic spindle fibres. The most well accepted hypothesis for the initiation of microtubule polymerization is that α/β-tubulin dimers add onto a γ-tubulin ring complex (γTuRC), in which adjacent γ-tubulin subunits bind to the underlying non-tubulin components of the γTuRC. This template thus determines the resulting microtubule lattice. In this study we use molecular modelling and molecular dynamics simulations, combined with computational MM-PBSA/MM-GBSA methods, to determine the extent of the lateral atomic interaction between two adjacent γ-tubulins within the γTuRC. To do this we simulated a γ-γ homodimer for 10 ns and calculated the ensemble average of binding free energies of -107.76 kcal/mol by the MM-PBSA method and of -87.12 kcal/mol by the MM-GBSA method. These highly favourable binding free energy values imply robust lateral interactions between adjacent γ-tubulin subunits in addition to their end-interactions longitudinally with other proteins of γTuRC. Although the functional reconstitution of γ-TuRC subunits and their stepwise in vitro assembly from purified components is not yet feasible, we nevertheless wanted to recognize hotspot amino acids responsible for key γ-γ interactions. Our free energy decomposition data from converting a compendium of amino acid residues identified an array of hotspot amino acids. A subset of such mutants can be expressed in vivo in living yeast. Because γTuRC is important for the growth of yeast, we could test whether this subset of the hotspot mutations support growth of yeast. Consistent with our model, γ-tubulin mutants that fall into our identified hotspot do not support yeast growth.

  18. Reaction Control System Thruster Cracking Consultation: NASA Engineering and Safety Center (NESC) Materials Super Problem Resolution Team (SPRT) Findings

    Science.gov (United States)

    MacKay, Rebecca A.; Smith, Stephen W.; Shah, Sandeep R.; Piascik, Robert S.

    2005-01-01

    The shuttle orbiter s reaction control system (RCS) primary thruster serial number 120 was found to contain cracks in the counter bores and relief radius after a chamber repair and rejuvenation was performed in April 2004. Relief radius cracking had been observed in the 1970s and 1980s in seven thrusters prior to flight; however, counter bore cracking had never been seen previously in RCS thrusters. Members of the Materials Super Problem Resolution Team (SPRT) of the NASA Engineering and Safety Center (NESC) conducted a detailed review of the relevant literature and of the documentation from the previous RCS thruster failure analyses. It was concluded that the previous failure analyses lacked sufficient documentation to support the conclusions that stress corrosion cracking or hot-salt cracking was the root cause of the thruster cracking and lacked reliable inspection controls to prevent cracked thrusters from entering the fleet. The NESC team identified and performed new materials characterization and mechanical tests. It was determined that the thruster intergranular cracking was due to hydrogen embrittlement and that the cracking was produced during manufacturing as a result of processing the thrusters with fluoride-containing acids. Testing and characterization demonstrated that appreciable environmental crack propagation does not occur after manufacturing.

  19. Pathways and timescales of primary charge separation in the photosystem II reaction center as revealed by a simultaneous fit of time-resolved fluorescence and transient absorption

    NARCIS (Netherlands)

    Novoderezhkin, V.I.; Andrizhiyevskaya, E.G.; Dekker, J.P.; van Grondelle, R.

    2005-01-01

    We model the dynamics of energy transfer and primary charge separation in isolated photosystem II (PSII) reaction centers. Different exciton models with specific site energies of the six core pigments and two peripheral chlorophylls (Chls) in combination with different charge transfer schemes have

  20. Hydrogen bonds in the vicinity of the special pair of the bacterial reaction center probed by hydrostatic high-pressure absorption spectroscopy.

    Science.gov (United States)

    Kangur, Liina; Jones, Michael R; Freiberg, Arvi

    2017-12-01

    Using the native bacteriochlorophyll a pigment cofactors as local probes, we investigated the response to external hydrostatic high pressure of reaction center membrane protein complexes from the photosynthetic bacterium Rhodobacter sphaeroides. Wild-type and engineered complexes were used with a varied number (0, 1 or 2) of hydrogen bonds that bind the reaction center primary donor bacteriochlorophyll cofactors to the surrounding protein scaffold. A pressure-induced breakage of hydrogen bonds was established for both detergent-purified and membrane-embedded reaction centers, but at rather different pressures: between 0.2 and 0.3GPa and at about 0.55GPa, respectively. The free energy change associated with the rupture of the single hydrogen bond present in wild-type reaction centers was estimated to be equal to 13-14kJ/mol. In the mutant with two symmetrical hydrogen bonds (FM197H) a single cooperative rupture of the two bonds was observed corresponding to an about twice stronger bond, rather than a sequential rupture of two individual bonds. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Notable light-free catalytic activity for pollutant destruction over flower-like BiOI microspheres by a dual-reaction-center Fenton-like process.

    Science.gov (United States)

    Wang, Liang; Yan, Dengbiao; Lyu, Lai; Hu, Chun; Jiang, Ning; Zhang, Lili

    2018-10-01

    BiOI is widely used as photocatalysts for pollutant removal, water splitting, CO 2 reduction and organic transformation due to its excellent photoelectric properties. Here, we report for the first time that a light-free catalyst consisting of the flower-like BiOI microspheres (f-BiOI MSs) exposing (1 0 1) and (1 1 0) crystal planes prepared by a hydrothermal method in ethylene glycol environment can rapidly eliminate the refractory BPA within only ∼3 min through a Fenton-like process. The reaction activity is ∼190 times higher than that of the conventional Fenton catalyst Fe 2 O 3 . A series of characterizations and experiments reveal the formation of the dual reaction centers on f-BiOI MSs. The electron-rich O centers efficiently reduce H 2 O 2 to OH, while the electron-poor oxygen vacancies capture electrons from the adsorbed pollutants and divert them to the electron-rich area during the Fenton-like reactions. By these processes, pollutants are degraded and mineralized quickly in a wide pH range. Our findings address the problems of the classical Fenton reaction and are useful for the development of efficient Fenton-like catalysts through constructing dual reaction centers. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Reactive scattering from oriented molecules: The three-center reaction K+ICl --> KI+Cl, KCl+I

    Science.gov (United States)

    Loesch, H. J.; Möller, J.

    1992-12-01

    In a crossed molecular beam experiment, we have measured the angular and time-of-flight (TOF) distributions of the products KCl and KI formed in the reaction K+ICl→KI+Cl, KCl+I at an elevated collision energy of Etr=1.64 eV. Employing the brute force method, we have prepared an oriented ICl beam and studied in addition also the orientation dependence of these distributions. The results are (i) KCl is the dominant product, but also KI is substantially formed with a branching ratio of 4:1; (ii) the double differential reaction cross section in the center-of-mass frame (contour maps) indicates that all products are preferentially forward scattered and constrained to the forward hemisphere; (iii) the KCl flux consists of two distinct components which differ markedly in kinetic energy and dependence on the ICl orientation; there are also indications of the existence of two components of KI; (iv) 65%, 84%, and 64% of the available energy is vested into the internal degrees of freedom for the fast, slow component of KCl and KI, respectively; (v) the existence of two components can be rationalized on the basis of the harpooning mechanism where the jumping electron accesses the ground state or one of the low excited states of the ICl- ion and triggers the subsequent explosion of the ion with more or less kinetic energy of the fragments depending on the initially populated state; (vi) the energies released during dissociation of ICl- in the 2Σ ground state and the first 2Π state are ≤0.19 and ≤1.2 eV, respectively; (vii) the fast KCl component features a negative steric effect suggesting favorable product formation for attacks of K to the I end of ICl, the steric effect of the slow KI component is positive, i.e., attacks to the Cl end form products favorably; the other components exhibit no significant steric effect; (viii) the steric effects can be quantitatively rationalized using the same model as mentioned above; (ix) the magnitude of the steric effect suggests a

  3. Retrieval of ion distributions in RC from TWINS ENA images by CT technique

    Science.gov (United States)

    Ma, S.; Yan, W.; Xu, L.; Goldstein, J.; McComas, D. J.

    2010-12-01

    The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission is the first constellation to employ imagers on two separate spacecraft to measure energetic neutral atoms (ENA) produced by charge exchange between ring current energetic ions and cold exospheric neutral atoms. By applying the 3-D volumetric pixel (voxel) computed tomography (CT) inversion method to TWINS images, parent ion populations in the ring current (RC) and auroral regions are retrieved from their ENA signals. This methodology is implemented for data obtained during the main phase of a moderate geomagnetic storm on 11 October 2008. For this storm the two TWINS satellites were located in nearly the same meridian plane at vantage points widely separated in magnetic local time, and both more than 5 RE geocentric distance from the Earth. In the retrieval process, the energetic ion fluxes to be retrieved are assumed being isotropic with respect to pitch angle. The ENA data used in this study are differential fluxes averaged over 12 sweeps (corresponding to an interval of 16 min.) at different energy levels ranging throughout the full 1--100 keV energy range of TWINS. The ENA signals have two main components: (1) a low-latitude/ high-altitude signal from trapped RC ions and (2) a low-altitude signal from precipitating ions in the auroral/subauroral ionosphere. In the retrieved ion distributions, the main part of the RC component is located around midnight toward dawn sector with L from 3 to 7 or farther, while the subauroral low-altitude component is mainly at pre-midnight. It seems that the dominant energy of the RC ions for this storm is at the lowest energy level of 1-2 keV, with another important energy band centered about 44 keV. The low-altitude component is consistent with in situ observations by DMSP/SSJ4. The result of this study demonstrates that with satellite constellations such as TWINS, using all-sky ENA imagers deployed at multiple vantage points, 3-D distribution of RC ion

  4. R$_{b}$ - R$_{c}$ crisis and new physics

    CERN Document Server

    Bhattacharya, G; Hou Wei Shu; Bhattacharyya, Gautam; Branco, Gustavo C; Hou, Wei Shu

    1996-01-01

    The experimental values of R_b and R_c are the only data which do not seem to agree with Standard Model predictions. Although it is still premature to draw any definite conclusions, it is timely to look for new physics which could explain the excess in R_b and deficit in R_c. We investigate this problem in a simple extension of the Standard Model, where a charge +2/3 isosinglet quark is added to the standard spectrum. Upon the further introduction of an extra scalar doublet, one finds a solution with interesting consequences.

  5. Deformation Analysis of RC Ties Externally Strengthened with FRP Sheets

    Science.gov (United States)

    Gribniak, V.; Arnautov, A. K.; Kaklauskas, G.; Jakstaite, R.; Tamulenas, V.; Gudonis, E.

    2014-11-01

    The current study has two objectives: to validate the ability of the Atena finite-element software to estimate the deformations of reinforced concrete (RC) elements strengthened with fiber-reinforced polymer (FRP) sheets and to assess the effect of FRP-to-concrete bond strength on the results of numerical simulation. It is shown that the bond strength has to be selected according to the overall stiffness of the composite element. The numerical results found are corroborated experimentally by tensile tests of RC elements strengthened with basalt FRP sheets.

  6. Photosynthesis Is Widely Distributed among Proteobacteria as Demonstrated by the Phylogeny of PufLM Reaction Center Proteins

    Directory of Open Access Journals (Sweden)

    Johannes F. Imhoff

    2018-01-01

    Full Text Available Two different photosystems for performing bacteriochlorophyll-mediated photosynthetic energy conversion are employed in different bacterial phyla. Those bacteria employing a photosystem II type of photosynthetic apparatus include the phototrophic purple bacteria (Proteobacteria, Gemmatimonas and Chloroflexus with their photosynthetic relatives. The proteins of the photosynthetic reaction center PufL and PufM are essential components and are common to all bacteria with a type-II photosynthetic apparatus, including the anaerobic as well as the aerobic phototrophic Proteobacteria. Therefore, PufL and PufM proteins and their genes are perfect tools to evaluate the phylogeny of the photosynthetic apparatus and to study the diversity of the bacteria employing this photosystem in nature. Almost complete pufLM gene sequences and the derived protein sequences from 152 type strains and 45 additional strains of phototrophic Proteobacteria employing photosystem II were compared. The results give interesting and comprehensive insights into the phylogeny of the photosynthetic apparatus and clearly define Chromatiales, Rhodobacterales, Sphingomonadales as major groups distinct from other Alphaproteobacteria, from Betaproteobacteria and from Caulobacterales (Brevundimonas subvibrioides. A special relationship exists between the PufLM sequences of those bacteria employing bacteriochlorophyll b instead of bacteriochlorophyll a. A clear phylogenetic association of aerobic phototrophic purple bacteria to anaerobic purple bacteria according to their PufLM sequences is demonstrated indicating multiple evolutionary lines from anaerobic to aerobic phototrophic purple bacteria. The impact of pufLM gene sequences for studies on the environmental diversity of phototrophic bacteria is discussed and the possibility of their identification on the species level in environmental samples is pointed out.

  7. Overview and evolution of the LeRC PMAD DC test bed

    Science.gov (United States)

    Soeder, James F.; Frye, Robert J.

    1992-01-01

    Since the beginning of the Space Station Freedom Program (SSFP), the Lewis Research Center (LeRC) has been developed electrical power system test beds to support the overall design effort. Through this time, the SSFP has changed the design baseline numerous times, however, the test bed effort has endeavored to track these changes. Beginning in August 1989 with the baseline and an all DC system, a test bed was developed to support the design baseline. The LeRC power measurement and distribution (PMAD) DC test bed and the changes in the restructure are described. The changes included the size reduction of primary power channel and various power processing elements. A substantial reduction was also made in the amount of flight software with the subsequent migration of these functions to ground control centers. The impact of these changes on the design of the power hardware, the controller algorithms, the control software, and a description of their current status is presented. An overview of the testing using the test bed is described, which includes investigation of stability and source impedance, primary and secondary fault protection, and performance of a rotary utility transfer device. Finally, information is presented on the evolution of the test bed to support the verification and operational phases of the SSFP in light of these restructure scrubs.

  8. [Prevalence of reactions secundary to mosquito bites Aedes aegypti at en el Regional Center of Allergy and Clinical Immunology, University Hospital, de Monterrey, Nuevo Leon].

    Science.gov (United States)

    González Diaz, Sandra Nora; Cruz, Alfredo Arias; Sedó Mejía, Giovanni A; Rojas Lozano, Antonio A; Valenzuela, Enrique Avitia; Vidaurri Ojeda, Alma C

    2010-01-01

    although systemic reactions resulting from hymenoptera stings have been studied extensively, the prevalence of allergic reactions to mosquitoes is unknown. to investigate the prevalence of allergic reactions to Aedes aegypti bites in patients seeking treatment at the Allergy and Clinical Immunology Regional Center of Jose E Gonzalez University Hospital in Monterrey, Mexico. we carried out a cross-sectional, descriptive study that included patients receiving skin tests for aeroallergens; skin sensitivity to mosquito bites was also tested. A questionnaire was used to obtain information about previous allergic reactions to mosquito bites. a total of 482 patients between 2 and 60 years of age were included; 53% were female, 407 (84.4%) had a history of local reactions to mosquito bites. Twelve patients (2.4%) stated a history of large local reaction; three (0.6%) of them with a positive skin prick test, one (0.2%) of those had systemic reaction history to mosquito. Eighty five (17.6%) patients had a positive mosquito skin test and 307 (63.6%) had a positive skin test for at least one aeroallergen. Seventy-eight (91.7%) of the 85 patients with a positive mosquito skin test had a history of local skin reactions to mosquito bite (odds ratio: 2.303 [confidence interval (CI) 1.037-5.10]. There was no statistically significance association between allergic diseases and mosquito allergy. adverse reactions and allergic reactions to mosquito bites occur frequently. However mosquito allergy is low. Further studies are required to determine the prevalence of mosquito allergy in the general population.

  9. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

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

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

    DEFF Research Database (Denmark)

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

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

  11. The RC Circuit: An Approach with Fourier Transforms

    Indian Academy of Sciences (India)

    The RC Circuit: An Approach with Fourier Transforms. Classroom Volume 21 Issue 11 November 2016 pp 1029-1042 ... But a lot of things, (including the complex impedanceitself, and some insight into complex analysis) can be understoodbetter if we use the FT approach to solve the differentialequations that come up in ...

  12. Design of RC frames for pre-selected collapse mechanism and ...

    Indian Academy of Sciences (India)

    In this study, total energy of RC frames is calculated and .... curvature relations of RC beam and column members are required for both ..... Case study ..... Turkish Seismic Design Code 2007 Ministry of Public Works and Settlement, Ankara.

  13. Comparison of calculated and experimental isotope edited FTIR difference spectra for purple bacterial photosynthetic reaction centers with different quinones incorporated into the QA binding site.

    Directory of Open Access Journals (Sweden)

    Nan eZhao

    2013-08-01

    Full Text Available Previously we have shown that ONIOM type (QM/MM calculations can be used to simulate isotope edited FTIR difference spectra for neutral ubiquinone in the QA binding site in Rhodobacter sphaeroides photosynthetic reaction centers. Here we considerably extend upon this previous work by calculating isotope edited FTIR difference spectra for reaction centers with a variety of unlabeled and 18O labeled foreign quinones incorporated into the QA binding site. Isotope edited spectra were calculated for reaction centers with 2,3-dimethoxy-5,6-dimethyl-1,4-benzoquinone (MQ0, 2,3,5,6-tetramethyl-1,4-benzoquinone (duroquinone, DQ, and 2,3-dimethyl-l,4-naphthoquinone (DMNQ incorporated, and compared to corresponding experimental spectra. The calculated and experimental spectra agree well, further demonstrating the utility and applicability of our ONIOM approach for calculating the vibrational properties of pigments in protein binding sites.The normal modes that contribute to the bands in the calculated spectra, their composition, frequency and intensity, and how these quantities are modified upon 18O labeling, are presented. This computed information leads to a new and more detailed understanding/interpretation of the experimental FTIR difference spectra. Hydrogen bonding to the carbonyl groups of the incorporated quinones is shown to be relatively weak. It is also shown that there is some asymmetry in hydrogen bonding, accounting for 10-13 cm-1 separation in the frequencies of the carbonyl vibrational modes of the incorporated quinones. The extent of asymmetry H-bonding could only be established by considering the spectra for various types of quinones incorporated into the QA binding site. The quinones listed above are tail-less. Spectra were also calculated for reaction centers with corresponding tail containing quinones incorporated, and it is found that replacement of the quinone methyl group by a phytyl or prenyl chain does not alter ONIOM calculated s

  14. Evolution of direct mechanisms with incident energy from the Coulomb-barrier to relativistic energies. - Two-center effects in nucleon transfer between nuclei. - Signatures of nucleon promotion in heavy ion reactions at barrier energies

    International Nuclear Information System (INIS)

    Oertzen, W. von; Voit, H.; Imanishi, B.

    1988-10-01

    This report contains a review article considering the evolution of direct mechanisms with incident energy in heavy ion reactions and two theoretical articles concerning two-center effects in transfer reactions between heavy ions and the nucleon promotion in heavy ion reactions. See hints under the relevant topics. (HSI)

  15. 75 FR 1356 - RC2 Corporation, Provisional Acceptance of a Settlement Agreement and Order

    Science.gov (United States)

    2010-01-11

    ... primarily at toy stores and various retailers nationwide, and secondarily through RC2's e-commerce websites... various retailers nationwide, and secondarily through RC2's e-commerce Web sites or as `sub-components' of...(e). Published below is a provisionally-accepted Settlement Agreement with RC2 Corporation...

  16. Limit analysis on FRP-strengthened RC members

    Directory of Open Access Journals (Sweden)

    D. De Domenico

    2014-07-01

    Full Text Available Reinforced concrete (RC members strengthened with externally bonded fiber-reinforced-polymer (FRP plates are numerically investigated by a plasticity-based limit analysis approach. The key-concept of the present approach is to adopt proper constitutive models for concrete, steel reinforcement bars (re-bars and FRP strengthening plates according to a multi-yield-criteria formulation. This allows the prediction of concrete crushing, steel bars yielding and FRP rupture that may occur at the ultimate limit state. To simulate such limitstate of the analysed elements, two iterative methods performing linear elastic analyses with adaptive elastic parameters and finite elements (FEs description are employed. The peak loads and collapse mechanisms predicted for FRP-plated RC beams are validated by comparison with the corresponding experimental findings.

  17. GR712RC- Dual-Core Processor- Product Status

    Science.gov (United States)

    Sturesson, Fredrik; Habinc, Sandi; Gaisler, Jiri

    2012-08-01

    The GR712RC System-on-Chip (SoC) is a dual core LEON3FT system suitable for advanced high reliability space avionics. Fault tolerance features from Aeroflex Gaisler’s GRLIB IP library and an implementation using Ramon Chips RadSafe cell library enables superior radiation hardness.The GR712RC device has been designed to provide high processing power by including two LEON3FT 32- bit SPARC V8 processors, each with its own high- performance IEEE754 compliant floating-point-unit and SPARC reference memory management unit.This high processing power is combined with a large number of serial interfaces, ranging from high-speed links for data transfers to low-speed control buses for commanding and status acquisition.

  18. Nuclear Data Center (NDC) of Korea Atomic Energy Research Institute (KAERI). Progress Report to the IAEA Technical Meeting of Nuclear Reaction Data Centers (NRDC)

    International Nuclear Information System (INIS)

    Lee, Young-Ouk

    2012-01-01

    Nuclear Data Center (NDC, former Nuclear Data Evaluation Lab.) of Korea Atomic Energy Research Institute (KAERI) has a director, 10 permanent staffs (2 in evaluation, 1 in measurement, 2 in atomic and molecular data, 2 in processing and validation, 3 in applications), one PhD student and one secretary. KAERI/NDC recently expanded its scope of work into the atomic and molecular data where two permanent staffs are involved. Mission of KAERI/NDC is disseminating outcomes of international network as well as promoting domestic nuclear data activities and related applications.

  19. An experimental investigation for external RC shear wall applications

    Science.gov (United States)

    Kaltakci, M. Y.; Ozturk, M.; Arslan, M. H.

    2010-09-01

    The strength and rigidity of most reinforced concrete (RC) buildings in Turkey, which are frequently hit by destructive earthquakes, is not at a sufficient level. Therefore, the result of earthquakes is a significant loss of life and property. The strengthening method most commonly preferred for these type of RC buildings is the application of RC infilled walls (shear walls) in the frame openings of the building. However, since the whole building has to be emptied and additional heavy costs arise during this type of strengthening, users prefer not to strengthen their buildings despite the heavy risk they are exposed to. Therefore, it is necessary to develop easier-to-apply and more effective methods for the rapid strengthening of housing and the heavily-used public buildings which cannot be emptied during the strengthening process (such as hospitals and schools). This study empirically analyses the different methods of a new system which can meet this need. In this new system, named "external shear wall application", RC shear walls are applied on the external surface of the building, along the frame plane rather than in the building. To this end, 7 test samples in 1/2 and 1/3 geometrical scale were designed to analyse the efficiency of the strengthening technique where the shear wall leans on the frame from outside of the building (external shear wall application) and of the strengthening technique where a specific space is left between the frame and the external shear wall by using a coupling beam to connect elements (application of external shear wall with coupling beam). Test results showed that the maximum lateral load capacity, initial rigidity and energy dissipation behaviours of the samples strengthened with external shear wall were much better than those of the bare frames.

  20. An experimental investigation for external RC shear wall applications

    Directory of Open Access Journals (Sweden)

    M. Y. Kaltakci

    2010-09-01

    Full Text Available The strength and rigidity of most reinforced concrete (RC buildings in Turkey, which are frequently hit by destructive earthquakes, is not at a sufficient level. Therefore, the result of earthquakes is a significant loss of life and property. The strengthening method most commonly preferred for these type of RC buildings is the application of RC infilled walls (shear walls in the frame openings of the building. However, since the whole building has to be emptied and additional heavy costs arise during this type of strengthening, users prefer not to strengthen their buildings despite the heavy risk they are exposed to. Therefore, it is necessary to develop easier-to-apply and more effective methods for the rapid strengthening of housing and the heavily-used public buildings which cannot be emptied during the strengthening process (such as hospitals and schools. This study empirically analyses the different methods of a new system which can meet this need. In this new system, named "external shear wall application", RC shear walls are applied on the external surface of the building, along the frame plane rather than in the building. To this end, 7 test samples in 1/2 and 1/3 geometrical scale were designed to analyse the efficiency of the strengthening technique where the shear wall leans on the frame from outside of the building (external shear wall application and of the strengthening technique where a specific space is left between the frame and the external shear wall by using a coupling beam to connect elements (application of external shear wall with coupling beam. Test results showed that the maximum lateral load capacity, initial rigidity and energy dissipation behaviours of the samples strengthened with external shear wall were much better than those of the bare frames.

  1. Tris(Cyclopentadienyl)Uranium-t-Butyl: Synthesis, reactions, and mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Weydert, M.

    1993-04-01

    Compounds (RC[sub 5]H[sub 4])[sub 3]U(t-Bu) were prepared for R = H, Me, Et. Their decomposition products in aromatic solvents are consistent with a radical decomposition pathway induced by solvent-assisted U-C bond homolysis. NMR was used to study the reactions of (RC[sub 5]H[sub 4])[sub 3]UCl with t-BuLi (R = t-Bu, Me[sub 3]Si). Reactions of (MeC[sub 5]H[sub 4])[sub 3]U(t-Bu) with Lewis bases and fluorocarbons were studied. Analogous reaction chemistry between (RC[sub 5]H[sub 4])[sub 3]ThX systems and t-BuLi was also studied, and reactivity differences between U and Th are discussed. Synthesis of sterically crowded (RC[sub 5]H[sub 4])[sub 4]U compounds is next considered. Reaction of the trivalent (RC[sub 5]H[sub 4])[sub 3]U with (RC[sub 5]H[sub 4])[sub 2]Hg results in formation of (RC[sub 5]H[sub 4])[sub 4]U. Steric congestion, cyclopentadienyl ligand exchange, and electron transfer are discussed. (DLC)

  2. Tris(Cyclopentadienyl)Uranium-t-Butyl: Synthesis, reactions, and mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Weydert, Marc [Univ. of California, Berkeley, CA (United States)

    1993-04-01

    Compounds (RC5H4)3U(t-Bu) were prepared for R = H, Me, Et. Their decomposition products in aromatic solvents are consistent with a radical decomposition pathway induced by solvent-assisted U-C bond homolysis. NMR was used to study the reactions of (RC5H4)3UCl with t-BuLi (R = t-Bu, Me3Si). Reactions of (MeC5H4)3U(t-Bu) with Lewis bases and fluorocarbons were studied. Analogous reaction chemistry between (RC5H4)3ThX systems and t-BuLi was also studied, and reactivity differences between U and Th are discussed. Synthesis of sterically crowded (RC5H4)4U compounds is next considered. Reaction of the trivalent (RC5H4)3U with (RC5H4)2Hg results in formation of (RC5H4)4U. Steric congestion, cyclopentadienyl ligand exchange, and electron transfer are discussed. (DLC)

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

    Directory of Open Access Journals (Sweden)

    Ram Chandra Neupane

    2017-05-01

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

  4. Investigation on the thermographic detection of corrosion in RC structures

    Science.gov (United States)

    Tantele, Elia A.; Votsis, Renos A.; Kyriakides, Nicholas; Georgiou, Panagiota G.; Ioannou, Fotia G.

    2017-09-01

    Corrosion of the steel reinforcement is the main problem of reinforced concrete (RC) structures. Over the past decades, several methods have been developed aiming to detect the corrosion process early in order to minimise the structural damage and consequently the repairing costs. Emphasis was given in developing methods and techniques of non-destructive nature providing fast on-the-spot detection and covering large areas rather that concentrating on single locations. This study, investigates a non-destructive corrosion detection technique for reinforced concrete, which is based on infrared thermography and the difference in thermal characteristics of corroded and non-corroded steel rebars. The technique is based on the principle that corrosion products have poor heat conductivity, and they inhibit the diffusion of heat that is generated in the reinforcing bar due to heating. For the investigation RC specimens, have been constructed in the laboratory using embedded steel bars of different corrosion states. Afterward, one surface of the specimens was heated using an electric device while thermal images were captured at predefined time instants on the opposite surface with an IR camera. The test results showed a clear difference between the thermal characteristics of the corroded and the non-corroded samples, which demonstrates the potential of using thermography in corrosion detection in RC structures.

  5. Characterization of hypersensitivity reactions reported among Andrographis paniculata users in Thailand using Health Product Vigilance Center (HPVC) database.

    Science.gov (United States)

    Suwankesawong, Wimon; Saokaew, Surasak; Permsuwan, Unchalee; Chaiyakunapruk, Nathorn

    2014-12-24

    Andrographis paniculata (andrographis) is one of the herbal products that are widely used for various indications. Hypersensitivity reactions have been reported among subjects receiving Andrographis paniculata in Thailand. Understanding of characteristics of patients, adverse events, and clinical outcomes is essential for ensuring population safety.This study aimed to describe the characteristics of hypersensitivity reactions reported in patients receiving andrographis containing products in Thailand using national pharmacovigilance database. Thai Vigibase data from February 2001 to December 2012 involving andrographis products were used. This database includes the reports submitted through the spontaneous reporting system and intensive monitoring programmes. The database contained patient characteristic, adverse events associated with andrographis products, and details on seriousness, causality, and clinical outcomes. Case reports were included for final analysis if they met the inclusion criteria; 1) reports with andrographis being the only suspected cause, 2) reports with terms consistent with the constellation of hypersensitivity reactions, and 3) reports with terms considered critical terms according to WHO criteria. Descriptive statistics were used. A total of 248 case reports of andrographis-associated adverse events were identified. Only 106 case reports specified andrographis herbal product as the only suspected drug and reported at least one term consistent with constellation of hypersensitivity reactions. Most case reports (89%) came from spontaneous reporting system with no previously documented history of drug allergy (88%). Of these, 18 case reports were classified as serious with 16 cases requiring hospitalization. For final assessment, the case reports with terms consistent with constellation of hypersensitivity reactions and critical terms were included. Thirteen case reports met such criteria including anaphylactic shock (n = 5), anaphylactic

  6. NASA LANGLEY RESEARCH CENTER AND THE TIDEWATER INTERAGENCY POLLUTION PREVENTION PROGRAM

    Science.gov (United States)

    National Aeronautics and Space Administration (NASA)'s Langley Research Center (LaRC) is an 807-acre research center devoted to aeronautics and space research. aRC has initiated a broad-based pollution prevention program guided by a Pollution Prevention Program Plan and implement...

  7. Adverse reactions of Methylphenidate in children with attention deficit-hyperactivity disorder: Report from a referral center

    Science.gov (United States)

    Khajehpiri, Zahra; Mahmoudi-Gharaei, Javad; Faghihi, Toktam; Karimzadeh, Iman; Khalili, Hossein; Mohammadi, Mostafa

    2014-01-01

    Objective: The aim of the current study was to determine various aspects of methylphenidate adverse reactions in children with attention deficit-hyperactivity disorder (ADHD) in Iran. Methods: During the 6 months period, all children under methylphenidate treatment alone or along with other agents attending a university-affiliated psychology clinic were screened regarding all subjective and objective adverse drug reactions (ADRs) of methylphenidate. Causality and seriousness of detected ADRs were assessed by relevant World Health Organization definitions. The Schumock and Thornton questionnaire was used to determine preventability of ADRs. Findings: Seventy-one patients including 25 girls and 46 boys with ADHD under methylphenidate treatment were enrolled within the study period. All (100%) ADHD children under methylphenidate treatment developed at least one ADR. Anorexia (74.3%), irritability (57.1%), and insomnia (47.2%) were the most frequent methylphenidate-related adverse reactions. Except for one, all other detected ADRs were determined to be mild. In addition, no ADR was considered to be preventable and serious. Conclusion: Our data suggested that although methylphenidate related adverse reactions were common in children with ADHD, but they were mainly mild and nonserious. PMID:25535621

  8. Probing the Energy Transfer Dynamics of Photosynthetic Reaction Center Complexes Through Hole-Burning and Single-Complex Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Kerry Joseph [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Photosynthesis is the process by which light energy is used to drive reactions that generate sugars to supply energy for cellular processes. It is one of the most important fundamental biological reactions and occurs in both prokaryotic (e.g. bacteria) and eukaryotic (e.g. plants and algae) organisms. Photosynthesis is also remarkably intricate, requiring the coordination of many different steps and reactions in order to successfully transform absorbed solar energy into a biochemical usable form of energy. However, the net reaction for all photosynthetic organisms can be reduced to the following, deceptively general, equation developed by Van Niel[1] H2 - D + Aimplieshv A - H2 + D where H2-D is the electron donor, e.g. H2O, H2S. A is the electron acceptor, e.g. CO2, and A-H2 is the synthesized sugar. Amazingly, this simple net equation is responsible for creating the oxidizing atmosphere of Earth and the recycling of CO2, both of which are necessary for the sustainment of the global ecosystem.

  9. Reaction of (carbonylimido)sulfur(IV) derivatives with TAS-fluoride, (Me2N)3S+Me3SiF2-.

    Science.gov (United States)

    Lork, E; Viets, D; Mews, R; Oberhammer, H

    2000-10-16

    In the reaction of TAS-fluoride, (Me2N)3S+Me3SiF2-, with carbonyl sulfur difluoride imides RC(O)NSF2 (R = F, CF3), C-N bond, cleavage is observed, and TAS+RC(O)F2- and NSF are the final products. From TASF and RC(O)NS(CF3)F, the salts TAS+RC(O)NS(CF3)F2- (R = F (14), CF3 (15)), with psi-pentacoordinate sulfur centers in the anions, are formed. An X-ray structure investigation of 14 shows that the fluorine atoms occupy axial positions and CF3, NC(O)F, and the sulfur lone pair occupy equatorial positions of the trigonal bipyramid. The -C(O)F group lies in the equatorial plane with the CO bond synperiplanar to the SN bond. According to B3LYP calculations, this structure corresponds to a global minimum and the expected axial orientation of the -C(O)F group represents a transition state. Calculations for the unstable FC(O)NSF3- anion show a different geometry. The -C(O)F group deviates 40 degrees from axial orientation, and the equatorially bonded fluorine is, in contrast to the -CF3 group in 14, syn positioned.

  10. Preliminary study of impact fragility to RC wall subjected to aircraft impact

    International Nuclear Information System (INIS)

    Shin, Sang Shup; Hahm, Dae Gi; Choi, In Kil

    2012-01-01

    International experience has shown that internal and external hazards such as fires, earthquakes, and aircraft impacts can be significant safety contributors to the risk to infrastructures such as nuclear power plants. Since the aircraft accident at the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly of the interest and is one of important categories of an unexpected external hazard field. To date, aircraft impact analyses has most focused on the response analysis to the target structures. However, this preliminary study carried out an impact fragility analysis to reinforced concrete (RC) wall subjected to an aircraft impact. The aircraft velocity is used as the important variable of this study. The impact analysis of the applied Ri era's forcing function is used by Abaqus/Explicit

  11. Magnitude and direction of the change in dipole moment associated with excitation of the primary electron donor in Rhodopseudomonas sphaeroides reaction centers

    Energy Technology Data Exchange (ETDEWEB)

    Lockhart, D.J.; Boxer, S.G.

    1987-02-10

    The magnitude and direction of the change in dipole moment, ..delta mu.., associated with the Q/sub y/ transition of the dimeric primary electron donor (special pair or P870) in Rhodopseudomonas sphaeroides reaction centers have been measured by Stark spectroscopy at 20 /sup 0/C. The magnitude of ..delta mu.. is found to be f/sup -1/ (10.3 +/- 0.7) D, where f is a correction factor for the local dielectric properties of the protein matrix. With the spherical cavity approximation and an effective local dielectric constant of 2, f = 1.2, and absolute value of ..delta mu.. is 8.6 +/- 0.6 D. Absolute value of ..delta mu.. for the Q/sub y/ transition of the special pair is approximately a factor of 3.4 and 2 greater than for the monomeric bacteriochlorophylls and bacteriopheophytins, respectively, in the reaction center. The angle between ..delta mu.. and the transition dipole moment for excitation of the first singlet electron state of the special pair was found to be 24 +/- 2/sup 0/. The measured values are combined to suggest a physical model in which the lowest excited singlet state of the special pair has substantial charge-transfer character and where charge is separated between the two monomers comprising the dimeric special pair. This leads to the hypothesis that the first charge-separated state in bacterial photosynthesis is formed directly upon photoexcitation. These data provide stringent values for comparison with theoretical calculations of the electronic structure of the chromophores in the reaction center.

  12. Conformational differences between the methoxy groups of QA and QB site ubisemiquinones in bacterial reaction centers: a key role for methoxy group orientation in modulating ubiquinone redox potential.

    Science.gov (United States)

    Taguchi, Alexander T; O'Malley, Patrick J; Wraight, Colin A; Dikanov, Sergei A

    2013-07-09

    Ubiquinone is an almost universal, membrane-associated redox mediator. Its ability to accept either one or two electrons allows it to function in critical roles in biological electron transport. The redox properties of ubiquinone in vivo are determined by its environment in the binding sites of proteins and by the dihedral angle of each methoxy group relative to the ring plane. This is an attribute unique to ubiquinone among natural quinones and could account for its widespread function with many different redox complexes. In this work, we use the photosynthetic reaction center as a model system for understanding the role of methoxy conformations in determining the redox potential of the ubiquinone/semiquinone couple. Despite the abundance of X-ray crystal structures for the reaction center, quinone site resolution has thus far been too low to provide a reliable measure of the methoxy dihedral angles of the primary and secondary quinones, QA and QB. We performed 2D ESEEM (HYSCORE) on isolated reaction centers with ubiquinones (13)C-labeled at the headgroup methyl and methoxy substituents, and have measured the (13)C isotropic and anisotropic components of the hyperfine tensors. Hyperfine couplings were compared to those derived by DFT calculations as a function of methoxy torsional angle allowing estimation of the methoxy dihedral angles for the semiquinones in the QA and QB sites. Based on this analysis, the orientation of the 2-methoxy groups are distinct in the two sites, with QB more out of plane by 20-25°. This corresponds to an ≈50 meV larger electron affinity for the QB quinone, indicating a substantial contribution to the experimental difference in redox potentials (60-75 mV) of the two quinones. The methods developed here can be readily extended to ubiquinone-binding sites in other protein complexes.

  13. Report on the consultants` meeting on co-ordination of the nuclear reaction data centers (technical aspects)

    Energy Technology Data Exchange (ETDEWEB)

    Schwerer, O; Wienke, H [eds.

    1997-10-01

    The report summarizes the co-ordination meeting of the network of Nuclear Reaction Data Centres organized by the IAEA in 1997. The meeting was attended by technical staff from ten member centres of the network (representing USA, Russia, China, Japan, Hungary, OECD-NEA and IAEA) to discuss technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Observers from Belgium and Ukraine also attended the meeting. The document includes status reports of all centres and selected working papers. Refs, figs, tabs.

  14. Report on the consultants' meeting on co-ordination of the nuclear reaction data centers (technical aspects)

    International Nuclear Information System (INIS)

    Schwerer, O.; Wienke, H.

    1997-10-01

    The report summarizes the co-ordination meeting of the network of Nuclear Reaction Data Centres organized by the IAEA in 1997. The meeting was attended by technical staff from ten member centres of the network (representing USA, Russia, China, Japan, Hungary, OECD-NEA and IAEA) to discuss technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Observers from Belgium and Ukraine also attended the meeting. The document includes status reports of all centres and selected working papers

  15. Some security results of the RC4+ stream cipher

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Jha, Sonu

    2015-01-01

    to any even 8-bit constant other than 0xAA. Therefore, the question that naturally arises is whether the design of RC4+ can be protected by fixing the pad parameter to some constant odd value. In this paper, we try to answer this very question. We show that the design is still vulnerable by mounting...... in terms of number of faults required and the computational complexity. In fact, we reduce the number of faults by around 11264 on average, and our algorithm is around 26 times faster....

  16. The importance of a hot-sequential mechanism in triplet-state formation by charge recombination in reaction centers of bacterial photosynthesis

    International Nuclear Information System (INIS)

    Saito, K.; Mukai, K.; Sumi, H.

    2006-01-01

    In photosynthesis, pigment-excitation energies in the antenna system produced by light harvesting are transferred among antenna pigments toward the core antenna, where they are captured by the reaction center and initially fixed in the form of a charge separation. Primary charge separation between an oxidized special pair (P + ) and a reduced bacteriopheohytin (H - ) is occasionally intervened by recombination, and a spin-triplet state ( 3 P*) is formed on P in the bacterial reaction center. The 3 P* state is harmful to bio-organisms, inducing the formation of the highly damaging singlet oxygen species. Therefore, understanding the 3 P*-formation mechanism is important. The 3 P* formation is mediated by a state |m> of intermediate charge separation between P and the accessory chlorophyll, which is located between P and H. It will be shown theoretically in the present work that at room temperature, not only the mechanism of superexchange by quantum-mechanical virtual mediation at |m>, but also a hot-sequential mechanism contributes to the mediation. In the latter, although |m> is produced as a real state, the final state 3 P* is quickly formed during thermalization of phonons in the protein matrix in |m>. In the former, the final state is formed more quickly before dephasing-thermalization of phonons in |m>. 3 P* is unistep formed from the charge-separated state in the both mechanisms

  17. Study of the Mn-binding sites in photosystem II using antibodies raised against lumenal regions of the D1 and D2 reaction center proteins

    Energy Technology Data Exchange (ETDEWEB)

    Dalmasso, Enrique Agustin [Univ. of California, Berkeley, CA (United States)

    1992-04-01

    The experiments discussed in this thesis focus on identifying the protein segments or specific amino acids which provide ligands to the Mn cluster of photosystem II (PS II). This Mn cluster plays a central role in the oxygen-evolving complex (OEC) of PS II. The Mn cluster is thought to be bound by lumenal regions of the PS II reaction center proteins known as D1 and D2. First, several peptides were synthesized which correspond to specific lumenal segments of the D1 and D2 proteins. Next, polyclonal antibodies were successfully elicited using three of these peptides. The peptides recognized by these antibodies correspond to protein segments of the spinach reaction center proteins: Ile-321 to Ala-344 of D1 (D1-a), Asp-319 to Arg-334 of D1 (D1-b), and Val-300 to Asn-319 of D2 (D2-a). These antibodies were then used in assays which were developed to structurally or functionally probe the potential Mn-binding regions of the D1 and D2 proteins.

  18. Ultimate capacity and influenced factors analysis of nuclear RC containment subjected to internal pressure

    International Nuclear Information System (INIS)

    Song Chenning; Hou Gangling; Zhou Guoliang

    2014-01-01

    Ultimate compressive bearing capacity, influenced factors and its rules of nuclear RC containment are key problems of safety assessment, accident treatment and structure design, etc. Ultimate compressive bearing capacity of nuclear RC containment is shown by concrete damaged plasticity model and steel double liner model of ABAQUS. The study shows that the concrete of nuclear RC containment cylinder wall becomes plastic when the internal pressure is up to 0.87 MPa, the maximum tensile strain of steel liner exceeds 3000 × 10 6 and nuclear RC containment reaches ultimate status when the internal pressure is up to 1.02 MPa. The result shows that nuclear RC containment is in elastic condition under the design internal pressure and the bearing capacity meets requirement. Prestress and steel liner play key parts in the ultimate internal pressure and failure mode of nuclear RC containment. The study results have value for the analysis of ultimate compressive bearing capacity, structure design and safety assessment. (authors)

  19. Numerical model of RC beam response to corrosion

    Science.gov (United States)

    German, Magdalena; Pamin, Jerzy

    2018-01-01

    The chloride-induced corrosion of reinforcement used to be represented by Tuutti's model with initiation and propagation phases. During the initiation phase chlorides penetrate the concrete cover and accumulate around reinforcement bars. The chloride concentration in concrete increases until it reaches a chloride threshold value, causing deterioration of the passive layer of reinforcement. Then the propagation phase begins. During the propagation phase steel has no natural anti-corrosion protection, a corrosion current flows and this induces the production of rust. A growing volume of corrosion products generates stresses in concrete, which leads to cracking, splitting, delamination and loss of strength. The mechanical response of RC elements to reinforcement corrosion has mostly been examined on the basis of a 2D cross-section analysis. However, with this approach it is not possible to represent both corrosion and static loading. In the paper a 3D finite element model of an RC beam with the two actions applied is presented. Rust is represented as an interface between steel and concrete, considering the volumetric expansion of rust.

  20. Seismic performance of masonry-infilled RC frames

    Directory of Open Access Journals (Sweden)

    Mircea Bârnaure

    2016-09-01

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

  1. Strengthening of RC bridge slabs using CFRP sheets

    Directory of Open Access Journals (Sweden)

    Fahmy A. Fathelbab

    2014-12-01

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

  2. Multi-level nonlinear modeling verification scheme of RC high-rise wall buildings

    OpenAIRE

    Alwaeli, W.; Mwafy, A.; Pilakoutas, K.; Guadagnini, M.

    2017-01-01

    Earthquake-resistant reinforced concrete (RC) high-rise wall buildings are designed and detailed to respond well beyond the elastic range under the expected earthquake ground motions. However, despite their considerable section depth, in terms of analysis, RC walls are still often treated as linear elements, ignoring the effect of deformation compatibility. Due to the limited number of available comprehensive experimental studies on RC structural wall systems subjected to cycling loading, few...

  3. An enhanced chaotic key-based RC5 block cipher adapted to image encryption

    Science.gov (United States)

    Faragallah, Osama S.

    2012-07-01

    RC5 is a block cipher that has several salient features such as adaptability to process different word lengths with a variable block size, a variable number of rounds and a variable-length secret key. However, RC5 can be broken with various attacks such as correlation attack, timing attack, known plaintext correlation attack and differential attacks, revealing weak security. We aimed to enhance the RC5 block cipher to be more secure and efficient for real-time applications while preserving its advantages. For this purpose, this article introduces a new approach based on strengthening both the confusion and diffusion operations by combining chaos and cryptographic primitive operations to produce round keys with better pseudo-random sequences. Comparative security analysis and performance evaluation of the enhanced RC5 block cipher (ERC5) with RC5, RC6 and chaotic block cipher algorithm (CBCA) are addressed. Several test images are used for inspecting the validity of the encryption and decryption algorithms. The experimental results show the superiority of the suggested enhanced RC5 (ERC5) block cipher to image encryption algorithms such as RC5, RC6 and CBCA from the security analysis and performance evaluation points of view.

  4. Data of evolutionary structure change: 1ONAD-2D3RC [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1ONAD-2D3RC 1ONA 2D3R D C ADTIVAVELDTYPNTDIGDPSYPHIGIDIKSVRSKKTAK...WNMQNGKVGTAHIIYNSVDKRLSAVVSYPNADSATVSYDVDLDNVLPEWVRVGLSASTGLYKETNTILSWSFTSKLKT------NALHFMFNQFSKDQKDLILQGDAT... 1ONA D 1ONAD TRVSSN

  5. PIXE analysis of proteins from a photochemical center

    Science.gov (United States)

    Solís, C.; Oliver, A.; Andrade, E.

    1998-03-01

    In oxygen evolving photosynthetic organisms, light is absorbed and its energy used for the conversion of chemical products in two photosystems: PSI and PSII. Each photosystem is composed of a protein core which binds a pigment antenna and a Reaction Center (RC). RC of PSI is considered an "Iron-Sulfur" type. There are six components that participate in the charge separation after light absorption occurs in PSI: the center chlorophyll P700, two acceptors A 0 and A 1 and three FeS centers F X, F A and F B. However, the exact number of polypeptides, their exact molecular weight, their relative abundances and the active components associated to those polypeptides remain still to be completely characterized. In particular the FeS centers have been difficult to detect in a direct way in a gel band, because the amount of centers involved is under the detection limits of the conventional techniques. This study has been under-taken to explore the capability of particle induced X-ray emission (PIXE) to detect in a qualitative way the presence of Fe in some of the protein bands obtained by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) from the PSI complex. The complex was isolated from membranes of thermophilic cyanobacteria: Synechochoccus sp. The polyacrylamide gel electrophoresis of the complex shows eight subunits of 66, 60-65, 14, 13, 9, 8 and 7 KDa. In-air PIXE was performed at 2 MeV and proved to be an adequate tool for direct identification of the iron present in the gel bands.

  6. Separate photosensitizers mediate degradation of the 32-kDa photosystem II reaction center protein in the visible and UV spectral regions

    International Nuclear Information System (INIS)

    Greenberg, B.M.; Gaba, V.; Canaani, O.; Malkin, S.; Mattoo, A.K.; Edelman, M.

    1989-01-01

    A component of the photosystem II reaction center, the 32-kDa protein, is rapidly turned over in the light. The mechanism of its light-dependent metabolism is largely unknown. We quantified the rate of 32-kDa protein degradation over a broad spectral range (UV, visible, and far red). The quantum yield for degradation was highest in the UVB (280-320 nm) region. Spectral evidence demonstrates two distinctly different photosensitizers for 32-kDa protein degradation. The data implicate the bulk photosynthetic pigments (primarily chlorophyll) in the visible and far red regions, and plastoquinone (in one or more of its redox states) in the UV region. A significant portion of 32-kDa protein degradation in sunlight is attributed to UVB irradiance

  7. Correlation of paramagnetic states and molecular structure in bacterial photosynthetic reaction centers: The symmetry of the primary electron donor in Rhodopseudomonas viridis and Rhodobacter sphaeroides R-26

    International Nuclear Information System (INIS)

    Norris, J.R.; Budil, D.E.; Gast, P.; Chang, C.H.; El-Kabbani, O.; Schiffer, M.

    1989-01-01

    The orientation of the principal axes of the primary electron donor triplet state measured in single crystals of photosynthetic reaction centers is compared to the x-ray structures of the bacteria Rhodobacter (Rb.) sphaeroides R-26 and Rhodopseudomonas (Rps.) viridis. The primary donor of Rps. viridis is significantly different from that of Rb. sphaeroides. The measured directions of the axes indicate that triplet excitation is almost completely localized on the L-subunit half of the dimer in Rps. viridis but is more symmetrically distributed on the dimeric donor in Rb. sphaeroides R-26. The large reduction of the zero field splitting parameters relative to monomeric bacteriochlorophyll triplet in vitro suggests significant participation of asymmetrical charge transfer electronic configurations in the special pair triplet state of both organisms

  8. Aborted germinal center reactions and B cell memory by follicular T cells specific for a B cell receptor V region peptide.

    Science.gov (United States)

    Heiser, Ryan A; Snyder, Christopher M; St Clair, James; Wysocki, Lawrence J

    2011-07-01

    A fundamental problem in immunoregulation is how CD4(+) T cells react to immunogenic peptides derived from the V region of the BCR that are created by somatic mechanisms, presented in MHC II, and amplified to abundance by B cell clonal expansion during immunity. BCR neo Ags open a potentially dangerous avenue of T cell help in violation of the principle of linked Ag recognition. To analyze this issue, we developed a murine adoptive transfer model using paired donor B cells and CD4 T cells specific for a BCR-derived peptide. BCR peptide-specific T cells aborted ongoing germinal center reactions and impeded the secondary immune response. Instead, they induced the B cells to differentiate into short-lived extrafollicular plasmablasts that secreted modest quantities of Ig. These results uncover an immunoregulatory process that restricts the memory pathway to B cells that communicate with CD4 T cells via exogenous foreign Ag.

  9. Status of blanket design for RTO/RC ITER

    International Nuclear Information System (INIS)

    Yamada, M.; Ioki, K.; Cardella, A.; Elio, F.; Miki, N.

    2000-01-01

    Design has progressed on the FW/blanket for the RTO/RC (reduced technical objective/ reduced cost) ITER. The basic functions and structures are the same as for the 1998 ITER design. However, design and fabrication methods of the FW/blanket have been improved to achieve ∝ 50% reduction of the construction cost compared to that for the 1998 ITER design. Detailed blanket module designs with flat separable FW panels have been developed to reduce the fabrication cost and the future radioactive waste. Most of the R and D performed so far during the EDA (engineering design activity) is still applicable. Further cost reduction methods are also being investigated and additional R and D is being performed. (orig.)

  10. Present and future activities of TRIGA RC-1 Reactor

    International Nuclear Information System (INIS)

    Festinesi, A.

    1986-01-01

    A summary of reactor activities is presented and discussed. The RC-1 reactor is used by ENEA's laboratories, research institutes and national industries for different aims: research, analysis materials behaviour under neutron flux, etc. To satisfy the requests increase it is important to signalize: - the realization of a new radiochemical laboratory for radioisotopes production, to be used in a medical and/or diagnostic field in general; - the realization of a tritium handling laboratory, to study tritium solubility, release and diffusion in different material (particularly in ceramic breeder as lithium aluminate) to support Italian programs on fusion technology; - a research activity on the reactors computerized control by a console of advanced conception. The aim of this activity is the development of an ergonomic control room that could be a reference point for the planning of the power reactor control rooms

  11. SOIL STRUCTURE INTERACTION EFFECTS ON MULTISTOREY R/C STRUCTURES

    Directory of Open Access Journals (Sweden)

    Muberra ESER AYDEMIR

    2013-01-01

    Full Text Available This paper addresses the behavior of multistorey structures considering soil structure interaction under earthquake excitation. For this purpose, sample 3, 6, 9 storey RC frames are designed based on Turkish Seismic Design Code and analyzed in time domain with incremental dynamic analysis. Strength reduction factors are investigated for generated sample plane frames for 64 different earthquake motions recorded on different site conditions such as rock, stiff soil, soft soil and very soft soil. According to the analysis result, strength reduction factors of sample buildings considering soil structure interaction are found to be almost always smaller than design strength reduction factors given in current seismic design codes, which cause an unsafe design and nonconservative design forces.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    FRPs is about to become common practice. Several guidelines on the subject have been presented during the last decade, e.g. [1-5]. Next step is to further utilize the excellent behaviour of the advanced material, in particular CFRP (Carbon Fiber Reinforced Polymers). CFRPs have mechanical properties...... capacity could be increased, with a carefully applied compressive stress existing open cracks in concrete may be partly closed and it might also be possible to reduce large deflections. In that way the durability of the entire RC (Reinforced Concrete) -structure can be increased. Application of FRPs......As the acceptance for non-stressed FRP (Fibre Reinforced Polymers) increase steadily in the construction industry, the industries susceptibility for new ideas in the material’s usage increase. Improving the performance of a bridge, a parking garage or a multistory building by the use of appropriate...

  13. Design Optimization of Hybrid FRP/RC Bridge

    Science.gov (United States)

    Papapetrou, Vasileios S.; Tamijani, Ali Y.; Brown, Jeff; Kim, Daewon

    2018-04-01

    The hybrid bridge consists of a Reinforced Concrete (RC) slab supported by U-shaped Fiber Reinforced Polymer (FRP) girders. Previous studies on similar hybrid bridges constructed in the United States and Europe seem to substantiate these hybrid designs for lightweight, high strength, and durable highway bridge construction. In the current study, computational and optimization analyses were carried out to investigate six composite material systems consisting of E-glass and carbon fibers. Optimization constraints are determined by stress, deflection and manufacturing requirements. Finite Element Analysis (FEA) and optimization software were utilized, and a framework was developed to run the complete analyses in an automated fashion. Prior to that, FEA validation of previous studies on similar U-shaped FRP girders that were constructed in Poland and Texas is presented. A finer optimization analysis is performed for the case of the Texas hybrid bridge. The optimization outcome of the hybrid FRP/RC bridge shows the appropriate composite material selection and cross-section geometry that satisfies all the applicable Limit States (LS) and, at the same time, results in the lightest design. Critical limit states show that shear stress criteria determine the optimum design for bridge spans less than 15.24 m and deflection criteria controls for longer spans. Increased side wall thickness can reduce maximum observed shear stresses, but leads to a high weight penalty. A taller cross-section and a thicker girder base can efficiently lower the observed deflections and normal stresses. Finally, substantial weight savings can be achieved by the optimization framework if base and side-wall thickness are treated as independent variables.

  14. MASH Test 3-11 on the T131RC Bridge Rail

    Science.gov (United States)

    2012-10-01

    Texas Department of Transportation (TxDOT) currently uses the TxDOT Type T101RC Bridge Rail, : a steel post and beam bridge rail anchored to the top of concrete curbs. The T101RC Bridge Rail is : 27 inches in height and can be anchored to the top of ...

  15. The RC Circuit: An Approach with Fourier Transforms In this article ...

    Indian Academy of Sciences (India)

    CLASSROOM. Mitrajyoti Ghosh. 83, Mitrapara 2nd Lane, Harinavi,. Kolkata 700148, West Bengal,. India. Email: mijospeakingnow@gmail.com. The RC Circuit: An Approach with Fourier Transforms. In this article we shall mathematically analyse the Resistor-. Capacitor (RC) circuit with the help of Fourier transforms. (FT).

  16. Development of an Improved Crack Propagation Model for Corrosion-Induced Cover Cracking in RC Structures

    Science.gov (United States)

    Hilyati, S.; Nizam, Z. M.; Zurisman, M. A. A.; Azhar, A. T. S.

    2017-06-01

    During the last two decades, reinforced concrete (RC) has been extensively used in most of the world as one of the common construction material due to its advantages and durability. However, RC structures exposed to marine environments are subjected to chloride attack. Chlorides from seawater penetrate into RC structures are not only causing severe corrosion problems but also affect the durability and serviceability of such structures. This paper investigates the influence of transverse reinforcement and spacing of reinforcing bars on concrete cover cracking of two-way RC slab specimens using accelerated corrosion tests. The experimental program involved the testing of four RC slab specimens and was generally designed to observe the crack width and the time of crack to propagate. An improved model for predicting the timing of crack propagation based on the experimental data was then developed.

  17. Observation of damage process in RC beams under cucle bending by acoustic emission

    International Nuclear Information System (INIS)

    Shigeishi, Mitsuhiro; Ohtsu, Masayasu; Tsuji, Nobuyuki; Yasuoka, Daisuke

    1997-01-01

    Reinforced concrete (RC) structures are generally applied to construction of buildings and bridges, and are imposed on cyclic loading incessantly. It is considered that detected acoustic emission (AE) waveforms are associated with the damage degree and the fracture mechanisms of RC structures. Therefor, the cyclic bending tests are applied to damaged RC beam specimens. To evaluate the interior of the damaged RC beams, the AE source kinematics are determined by 'SiGMA' procedure for AE moment tensor analysis. By using 'SiGMA' procedure, AE source kinematics, such as source locations, crack types, crack orientations and crack motions, can be identified. The results show the applicability to observation of the fracture process under cyclic bending load and evaluation the degree of damage of RC beam.

  18. Research on the Fatigue Flexural Performance of RC Beams Attacked by Salt Spray

    Science.gov (United States)

    Mao, Jiang-hong; Xu, Fang-yuan; Jin, Wei-liang; Zhang, Jun; Wu, Xi-xi; Chen, Cai-sheng

    2018-04-01

    The fatigue flexural performance of RC beams attacked by salt spray was studied. A testing method involving electro osmosis, electrical accelerated corrosion and salt spray was proposed. This corrosion process method effectively simulates real-world salt spray and fatigue loading exerted by RC components on sea bridges. Four RC beams that have different stress amplitudes were tested. It is found that deterioration by corrosion and fatigue loading reduces the fatigue life of the RC and decreases the ability of deformation. The fatigue life and deflection ability could be reduced by increasing the stress amplitude and the corrosion duration time. The test result demonstrates that this experimental method can couple corrosion deterioration and fatigue loading reasonably. This procedure may be applied to evaluate the fatigue life and concrete durability of RC components located in a natural salt spray environment.

  19. Gamma radiation-induced mutant of NSIC RC144 with broad-spectrum resistance to bacterial blight

    International Nuclear Information System (INIS)

    Alfonso, A.A.; Avellanoza, E.S.; Miranda, R.T.; Espejo, E.O.; Garcia, N.S.

    2014-01-01

    Mutant lines derived from gamma radiation-treated commercial variety NSIC RC144 were produced and screened for novel resistance to bacterial blight, one of the most serious diseases of rice. Preliminary screening of a bulk M2 population through induced method using race 3 of the pathogen Xanthomonas oryzae pv. oryzae (Xoo) resulted in the selection of 89 resistant plants. Subsequent repeated bacterial blight screenings and generation advance for five seasons resulted in the selection of two highly resistant M7 sister lines whose origin can be traced to a single M2 plant. DNA fingerprinting using 63 genome-wide simple sequence repeat (SSR) markers revealed an identical pattern in these lines. Using the same set of markers, they also exhibited 98% similarity to wild type NSIC RC144 indicating that the resistance is due to mutation and not due to genetic admixture or seed impurity. Two seasons of bacterial blight screening using 14 local isolates representing ten races of Xoo revealed an identical reaction pattern in these lines. The reaction pattern was observed to be unique compared to known patterns in four IRBB isolines (IRBB 4, 5, 7 and 21) with strong resistant reaction to bacterial blight suggesting possible novel resistance. The susceptible reaction in F1 testcrosses using Xoo race 6 and the segregation patterns in two F2 populations that fit with the expected 3 susceptible: 1 resistant ratio (P = 0.4, ns) suggest a single-gene recessive mutation in these lines. These mutants are now being used as resistance donor in the breeding program while further molecular characterization to map and characterize the mutated gene is being pursued

  20. X-ray irradiation of RC-MAP pre-stored for various numbers of days. Effect of X-ray irradiation on RC-MAP and reuse of RC-MAP after irradiation

    International Nuclear Information System (INIS)

    Yamada, Naotomo; Nagumo, Fumio; Kawasaki, Seiji; Matsuzaki, Miwako; Tadano, Jutaro

    1995-01-01

    X-ray irradiation is currently in wide use as a means of preventing post-transfusion graft-versus-host disease (PT-GVHD). In this study, we evaluated the effects of X-ray irradiation on RC-MAP pre-stored for various numbers of days, and assessed how long irradiated RC-MAP can be stored. RC-MAP was irradiated at a dosage of 15 Gy at 1, 7, 14, 21 or 28 days after blood collection. These specimens were referred to as group I, II, III, IV and V (X-ray-irradiated groups), respectively. Non-irradiated RC-MAP was used as the control. Results showed that plasma K concentration increased after X-ray irradiation. It is therefore advisable that RC-MAPs be used immediately in infants and in renal failure. However, to maximize the efficiency of blood product use, it seemed possible that groups I and II could be used within two weeks after irradiation, and group III within one week. On the basis of this increase in K concentration, however, groups IV and V plasma should be used immediately after irradiation. (author)

  1. Pulse radiolysis investigations on oxidation reactions of bilirubin in aqueous solutions (Preprint No. RC-3)

    International Nuclear Information System (INIS)

    Mohan, Hari; Gopinathan, C.

    1988-02-01

    The oxidation of bilirubin in aqueous solutions have been investigated by different oxidizing species such as CH 3 I.OH, Br 2 - and CO 3 - . The rate constant for the oxidation of bilirubin has been determined from the formation kinetics of bilirubin cations. (author). 3 refs

  2. Aromatic residues located close to the active center are essential for the catalytic reaction of flap endonuclease-1 from hyperthermophilic archaeon Pyrococcus horikoshii.

    Science.gov (United States)

    Matsui, Eriko; Abe, Junko; Yokoyama, Hideshi; Matsui, Ikuo

    2004-04-16

    Flap endonuclease-1 (FEN-1) possessing 5'-flap endonuclease and 5'-->3' exonuclease activity plays important roles in DNA replication and repair. In this study, the kinetic parameters of mutants at highly conserved aromatic residues, Tyr33, Phe35, Phe79, and Phe278-Phe279, in the vicinity of the catalytic centers of FEN-1 were examined. The substitution of these aromatic residues with alanine led to a large reduction in kcat values, although these mutants retained Km values similar to that of the wild-type enzyme. Notably, the kcat of Y33A and F79A decreased 333-fold and 71-fold, respectively, compared with that of the wild-type enzyme. The aromatic residues Tyr33 and Phe79, and the aromatic cluster Phe278-Phe279 mainly contributed to the recognition of the substrates without the 3' projection of the upstream strand (the nick, 5'-recess-end, single-flap, and pseudo-Y substrates) for the both exo- and endo-activities, but played minor roles in recognizing the substrates with the 3' projection (the double flap substrate and the nick substrate with the 3' projection). The replacement of Tyr33, Phe79, and Phe278-Phe279, with non-charged aromatic residues, but not with aliphatic hydrophobic residues, recovered the kcat values almost fully for the substrates without the 3' projection of the upstream strand, suggesting that the aromatic groups of Tyr33, Phe79, and Phe278-Phe279 might be involved in the catalytic reaction, probably via multiple stacking interactions with nucleotide bases. The stacking interactions of Tyr33 and Phe79 might play important roles in fixing the template strand and the downstream strand, respectively, in close proximity to the active center to achieve the productive transient state leading to the hydrolysis.

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

    Directory of Open Access Journals (Sweden)

    Claudia Viviane Viegas

    2015-09-01

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

  4. Dynamic behavior and functional integrity tests on RC shear walls

    International Nuclear Information System (INIS)

    Akino, Kinji; Nasuda, Toshiaki; Shibata, Akenori.

    1991-01-01

    A project consisting of seven subprojects has been conducted to study the dynamic behavior and functional integrity of reinforced concrete (RC) shear walls in reactor buildings. The objective of this project is to obtain the data to improve and prepare the seismic analysis code regarding the nonlinear structural behavior and integrity of reactor buildings during and after earthquakes. The project started in April, 1986, and will end in March, 1994. Seven subprojects are strain rate test, damping characteristic test, ultimate state response test and the verification test for the test of restoring force characteristics regarding dynamic restoring force characteristics and damping performance; the restoring force characteristic test on the shear walls with openings; and pull-out strength test and the test on air leakage through concrete cracks regarding the functional integrity. The objectives of respective subprojects, the test models and the interim results are reported. Three subprojects have been completed by March, 1990. The results of these projects will be used for the overall evaluation. The strain rate test showed that the ultimate strength of shear walls increased with strain rate. A formula for estimating air flow through the cracks in walls was given by the leakage test. (K.I.)

  5. Seismic performance of existing R.C. framed buildings

    Directory of Open Access Journals (Sweden)

    Sameh A. El-Betar

    2017-08-01

    Full Text Available The earthquakes disasters basically occur due to buildings damage not because of the earth shaking. Therefore, the countries have being updated the seismic codes. The seismic loads for buildings design in Egyptian Code have been changed from (EC-1994 to (ECP-201, 2012. On the other hand, the need is raised to study the vulnerability of existing buildings, which can be divided into the buildings designed to resist the gravity loads only (GLD and the buildings designed according to Egyptian code (EC-1994. Comparison between forces due to Egyptian code for loads (EC-1994 and (ECP-201, 2012 is carried out on the multi-stories R.C. framed buildings which are the most common type of existing buildings in Egypt. To investigate the vulnerability of existing buildings, nonlinear static pushover analysis is conducted to evaluate the real strength of the existing buildings. Moreover, it is considered a useful and effective tool for the performance of three framed buildings: 3, 6 and 10 stories due to expected future earthquakes. Finally, it is found that the vulnerability of existing GLD buildings occurs at expected ground accelerations (ag greater than 0.125 g in Egyptian seismic map, while the EC-94 designed buildings behave elastically up to (ag equals to 0.2 g and above that a slight damage may occur.

  6. Seismic Rehabilitation of RC Frames by Using Steel Panels

    Science.gov (United States)

    Mowrtage, Waiel

    2008-07-01

    Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame. To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.

  7. Explicit expression for effective moment of inertia of RC beams

    Directory of Open Access Journals (Sweden)

    K.A. Patel

    Full Text Available AbstractDeflection is an important design parameter for structures subjected to service load. This paper provides an explicit expression for effective moment of inertia considering cracking, for uniformly distributed loaded reinforced concrete (RC beams. The proposed explicit expression can be used for rapid prediction of short-term deflection at service load. The explicit expression has been obtained from the trained neural network considering concrete cracking, tension stiffening and entire practical range of reinforcement. Three significant structural parameters have been identified that govern the change in effective moment of inertia and therefore deflection. These three parameters are chosen as inputs to train neural network. The training data sets for neural network are generated using finite element software ABAQUS. The explicit expression has been validated for a number of simply supported and continuous beams and it is shown that the predicted deflections have reasonable accuracy for practical purpose. A sensitivity analysis has been performed, which indicates substantial dependence of effective moment of inertia on the selected input parameters.

  8. Finite element analysis of FRP-strengthened RC beams

    Directory of Open Access Journals (Sweden)

    Teeraphot Supaviriyakit

    2004-05-01

    Full Text Available This paper presents a non-linear finite element analysis of reinforced concrete beam strengthened with externally bonded FRP plates. The finite element modeling of FRP-strengthened beams is demonstrated. Concrete and reinforcing bars are modeled together as 8-node isoparametric 2D RC element. The FRP plate is modeled as 8-node isoparametric 2D elastic element. The glue is modeled as perfect compatibility by directly connecting the nodes of FRP with those of concrete since there is no failure at the glue layer. The key to the analysis is the correct material models of concrete, steel and FRP. Cracks and steel bars are modeled as smeared over the entire element. Stress-strain properties of cracked concrete consist of tensile stress model normal to crack, compressive stress model parallel to crack and shear stress model tangential to crack. Stressstrain property of reinforcement is assumed to be elastic-hardening to account for the bond between concrete and steel bars. FRP is modeled as elastic-brittle material. From the analysis, it is found that FEM can predict the load-displacement relation, ultimate load and failure mode of the beam correctly. It can also capture the cracking process for both shear-flexural peeling and end peeling modes similar to the experiment.

  9. Seismic Rehabilitation of RC Frames by Using Steel Panels

    International Nuclear Information System (INIS)

    Mowrtage, Waiel

    2008-01-01

    Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame.To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme

  10. Prediction of Cracking Induced by Indirect Actions in RC Structures

    Science.gov (United States)

    Anerdi, Costanza; Bertagnoli, Gabriele; Gino, Diego; Malavisi, Marzia; Mancini, Giuseppe

    2017-10-01

    Cracking of concrete plays a key role in reinforced concrete (RC) structures design, especially in serviceability conditions. A variety of reasons contribute to develop cracking and its presence in concrete structures is to be considered as almost unavoidable. Therefore, a good control of the phenomenon in order to provide durability is required. Cracking development is due to tensile stresses that arise in concrete structures as a result of the action of direct external loads or restrained endogenous deformations. This paper focuses on cracking induced by indirect actions. In fact, there is very limited literature regarding this particular phenomenon if compared to its high incidence in the construction practice. As a consequence, the correct prediction of the crack opening, width and position when structures are subjected to imposed deformations, such as massive castings or other highly restrained structures, becomes a compelling task, not so much for the structural capacity, as for their durability. However, this is only partially addressed by commonly used design methods, which are usually intended for direct actions. A set of non-linear analysis on simple tie models is performed using the Finite Element Method in order to study the cracking process under imposed deformations. Different concrete grades have been considered and analysed. The results of this study have been compared with the provisions of the most common codes.

  11. Expected damages of retrofitted bridges with RC jacketing

    Science.gov (United States)

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

    2015-07-01

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

  12. Expected damages of retrofitted bridges with RC jacketing

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  13. Model tests on dynamic performance of RC shear walls

    International Nuclear Information System (INIS)

    Nagashima, Toshio; Shibata, Akenori; Inoue, Norio; Muroi, Kazuo.

    1991-01-01

    For the inelastic dynamic response analysis of a reactor building subjected to earthquakes, it is essentially important to properly evaluate its restoring force characteristics under dynamic loading condition and its damping performance. Reinforced concrete shear walls are the main structural members of a reactor building, and dominate its seismic behavior. In order to obtain the basic information on the dynamic restoring force characteristics and damping performance of shear walls, the dynamic test using a large shaking table, static displacement control test and the pseudo-dynamic test on the models of a shear wall were conducted. In the dynamic test, four specimens were tested on a large shaking table. In the static test, four specimens were tested, and in the pseudo-dynamic test, three specimens were tested. These tests are outlined. The results of these tests were compared, placing emphasis on the restoring force characteristics and damping performance of the RC wall models. The strength was higher in the dynamic test models than in the static test models mainly due to the effect of loading rate. (K.I.)

  14. Pattern of Adverse Drug Reactions in Children Attending the Department of Pediatrics in a Tertiary Care Center: A Prospective Observational Study

    Directory of Open Access Journals (Sweden)

    Kishour Kumar Digra

    2015-01-01

    Full Text Available AIM To study the pattern of various adverse drug reactions (ADRs occurring in children attending the Department of Pediatrics, SMGS Hospital, Jammu over 1 year. Subjects and Methods This was a prospective study, with study population of patients attending Department of Pediatrics over a period of 1 year. A structured format was used to enroll the participants. A pilot study was conducted to test the suitability of the format and feasibility of the study. The study was carried out to review various pattern of ADRs by using the Naranjo probability scale, and severity was assessed by using the Hartwig severity scale. ADRs were classified according to the classification used by the Adverse Drug Reaction Monitoring Center, Central Drugs Standard Control Organization, New Delhi, India. Results In the present study, 104 patients were found to have developed acute drug reactions. Among these, 83.6% were type B, 14.42% type A, and 1.92% were type U. Furthermore, 25.96% ADRs were due to anticonvulsants, followed by antibiotics (22.11%, antipyretics (11.53%, vaccination (8.65%, steroids (6.73%, decongestants (5.67%, snake antivenom and antiemetics (3.84%, and fluids, insulin, and antacids (1.92%. The patients’ dermatological system was involved in 67.30%, followed by the central nervous system (CNS in 11.53% patients. Renal system was involved in 6.73% patients. Cardiac, musculoskeletal, metabolic, and other systems were involved in 4.80%, 3.84%, 2.88%, and 0.96%, respectively. According to the Hartwig severity scale of ADRs, 64.4% patients had moderate ADRs, 29.8% patients had severe ADRs, and 5.76% had mild ADRs. In the present study, 64.4% patients expressed moderate severity, whereas 29.8% expressed high severity and 5.76% expressed mild ADRs. Conclusion ADRs were seen in 71% of the patients between 1 and 5 years of age, 26% in the age group of 5–10 years, and 3% were more than 10 years old. Anticonvulsants (25.96% and antibiotics (22.11% were

  15. Formulation development of retrocyclin 1 analog RC-101 as an anti-HIV vaginal microbicide product.

    Science.gov (United States)

    Sassi, A B; Cost, M R; Cole, A L; Cole, A M; Patton, D L; Gupta, P; Rohan, L C

    2011-05-01

    RC-101 is a synthetic microbicide analog of retrocyclin, which has shown in vitro activity against X4 and R5 HIV-1. In an effort to develop a safe and effective RC-101 vaginal microbicide product, we assessed safety in ex vivo macaque and human models and efficacy using in vitro and ex vivo models. A polyvinyl-alcohol vaginal film containing RC-101 (100 μg/film) was developed. Formulation assessment was conducted by evaluating disintegration, drug content, mechanical properties, and stability. Efficacy was evaluated by in vitro peripheral blood mononuclear cells (PBMC) assay and ex vivo human ectocervical tissue explant model. Ex vivo safety studies were conducted by exposing RC-101 to an excised monkey reproductive tract and excised human ectocervical tissue. RC-101 100 μg films were shown to be safe to human and monkey tissue and effective against HIV-1 in vitro and ex vivo in human ectocervical tissue. The 90% inhibitory concentration (IC90) for RC-101 films at 2,000 μg (IC90=57.5 μM) using an ex vivo model was 10-fold higher than the IC90 observed using an in vitro model (IC90=5.0 μM). RC-101 films were stable for 1 month at 25°C, with in vitro bioactivity maintained for up to 6 months. RC-101 was developed in a quick-dissolve film formulation that was shown to be safe in an ex vivo model and effective in in vitro and ex vivo models. RC-101 film formulations were shown to maintain bioactivity for a period of 6 months. Findings from the present study contribute to the development of a safe and effective topical microbicide product.

  16. Estimation methods of deformational behaviours of RC beams under the unrestrained condition at elevated temperatures

    International Nuclear Information System (INIS)

    Kanezu, Tsutomu; Nakano, Takehiro; Endo, Tatsumi

    1986-01-01

    The estimation methods of free deformations of reinforced concrete (RC) beams at elevated temperatures are investigated based on the concepts of ACI's and CEB/FIP's formulas, which are well used to estimate the flexural deformations of RC beams at normal temperature. Conclusions derived from the study are as follows. 1. Features of free deformations of RC beams. (i) The ratios of the average compressive strains on the top fiber of RC beams to the calculated ones at the cracked section show the inclinations that the ratios once drop after cracking and then remain constant according to temperature rises. (ii) Average compressive strains might be estimated by the average of the calculated strains at the perfect bond section and the cracked section of RC beam. (iii) The ratios of the average tensile strains on the level of reinforcements to the calculated ones at the cracked section are inclined to approach the value of 1.0 monotonically according to temperature rises. The changes of the average tensile strains are caused by the deterioration of bond strength and cracking due to the increase of the differences of expansive strains between reinforcement and concrete. 2. Estimation methods of free deformations of RC beams. (i) In order to estimate the free deformations of RC beams at elevated temperatures, the basic concepts of ACI's and CEB/FIP's formulas are adopted, which are well used to estimate the M-φ relations of RC beams at normal temperature. (ii) It was confirmed that the suggested formulas are able to estimate the free deformations of RC beams, that is, the longitudinal deformation and the curvature, at elevated temperatures. (author)

  17. An optimum design of R-C oscillatory De-Qing circuit

    International Nuclear Information System (INIS)

    Cao Dezhang; Pan Linghe; Yang Tianlu

    1990-01-01

    An optimum design of R-C oscillatory De-Qing circuit has been developed for voltage regulation of the pulse modulator. When a new coefficient T 3 /T is introduced, the selection of De-Qing circuit parameters will become quite simple and the optimum parameters can be calculated directly. The De-Qing circuit parameters calculated will be effective in the whole range of the percentage regulation η from zero to maximum design value. The limit value of η is 0.36 or 0.29, theoretically, when the time constant of the De-Qing circuit is 3RC or 5RC respectively

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

    Directory of Open Access Journals (Sweden)

    Ronaldas Jakubovskis

    2016-12-01

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

  19. Observations on out-of-plane behaviour of URM walls in buildings with RC slabs

    OpenAIRE

    Tondelli, Marco; Beyer, Katrin

    2014-01-01

    In Switzerland many new residential buildings are constructed as unreinforced masonry (URM) structures or as mixed structures where URM walls are coupled with reinforced concrete (RC) walls by RC slabs. At present the boundary conditions of URM walls subjected to out-of-plane accelerations are still not well quantified. In the framework of a large research activity on RC-URM wall structures a shake-table test on a four-storey mixed structure was performed. The test specimen, which was built a...

  20. Electrostatics of the photosynthetic bacterial reaction center. Protonation of Glu L 212 and Asp L 213 - A new method of calculation.

    Science.gov (United States)

    Ptushenko, Vasily V; Cherepanov, Dmitry A; Krishtalik, Lev I

    2015-12-01

    Continuum electrostatic calculation of the transfer energies of anions from water into aprotic solvents gives the figures erroneous by order of magnitude. This is due to the hydrogen bond disruption that suggests the necessity to reconsider the traditional approach of the purely electrostatic calculation of the transfer energy from water into protein. In this paper, the method combining the experimental estimates of the transfer energies from water into aprotic solvent and the electrostatic calculation of the transfer energies from aprotic solvent into protein is proposed. Hydrogen bonds between aprotic solvent and solute are taken into account by introducing an imaginary aprotic medium incapable to form hydrogen bonds with the solute. Besides, a new treatment of the heterogeneous intraprotein dielectric permittivity based on the microscopic protein structure and electrometric measurements is elaborated. The method accounts semi-quantitatively for the electrostatic effect of diverse charged amino acid substitutions in the donor and acceptor parts of the photosynthetic bacterial reaction center from Rhodobacter sphaeroides. Analysis of the volatile secondary acceptor site QB revealed that in the conformation with a minimal distance between quinone QB and Glu L 212 the proton uptake upon the reduction of QB is prompted by Glu L 212 in alkaline and by Asp L 213 in slightly acidic regions. This agrees with the pH dependences of protonation degrees and the proton uptake. The method of pK calculation was applied successfully also for dissociation of Asp 26 in bacterial thioredoxin. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. An under-designed RC frame: Seismic assessment through displacement based approach and possible refurbishment with FRP strips and RC jacketing

    Science.gov (United States)

    Valente, Marco; Milani, Gabriele

    2017-07-01

    Many existing reinforced concrete buildings in Southern Europe were built (and hence designed) before the introduction of displacement based design in national seismic codes. They are obviously highly vulnerable to seismic actions. In such a situation, simplified methodologies for the seismic assessment and retrofitting of existing structures are required. In this study, a displacement based procedure using non-linear static analyses is applied to a four-story existing RC frame. The aim is to obtain an estimation of its overall structural inadequacy as well as the effectiveness of a specific retrofitting intervention by means of GFRP laminates and RC jacketing. Accurate numerical models are developed within a displacement based approach to reproduce the seismic response of the RC frame in the original configuration and after strengthening.

  2. Experiment and simulation of double-layered RC plates under impact loadings. Part 1: Impact tests for double-layered RC plates

    International Nuclear Information System (INIS)

    Shirai, T.; Ueda, M.; Taniguchi, H.; Kambayashi, A.; Ohno, T.; Ishikawa, N.

    1993-01-01

    At a nuclear power plant facility, it should be of interest and important problem to ensure structures against impact loads induced by projectile impacts or plant-internal accidents. It has been well known that local damage consists of spalling of concrete from the impacted area and scabbing of concrete from the back face of the target together with projectile penetration into the target. There are several techniques for improving the impact resistance of RC slabs, that is, lining with a steel plate on the impacted and/or rear face of the slab, making the slab a double-layered composite slab with an elastic absorber and employing a fiber reinforced concrete or a high-strength concrete as the slab materials. Of the many measures available for withstanding impact loads, the use of a double-layered reinforced concrete (RC) slab with absorber is expected to have the higher resistance in reducing or preventing local damage. This paper presents the results of an experimental investigation on the impact resistance of double-layered RC plates subjected to the impact of projectile. In the experiment, the effects of two parameters; the combination of two RC plates having different thicknesses and the existence of an absorber in the middle layer, are mainly investigated. And, the effects of the concrete thickness (7,9 and 11 cm) and the concrete strength (a normal-:35MPa, a lightweight-:40MPa and a high-strength:57MPa) of target were also examined. RC plates, 0.6m-square, were used for test specimens. The projectile has a mass of 0.43kg, made of steel with a flat nose. An average projectile velocity was about 170m/sec. A rubber plate shaped into a square with the same size of RC plate was used for a double-layered specimen as an absorber which was put between two RC plates. It could be concluded that double-layering and presence of an absorber had a considerable effect on the increase of impact resistance of RC plate. In order to reduce local damage, it is more effective to

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

    CERN Document Server

    Yu, Wenjian

    2014-01-01

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

  4. Noise analysis of gate electrode work function engineered recessed channel (GEWE-RC) MOSFET

    International Nuclear Information System (INIS)

    Agarwala, Ajita; Chaujar, Rishu

    2012-01-01

    This paper discusses the noise assessment, using ATLAS device simulation software, of a gate electrode work function engineered recessed channel (GEWE-RC) MOSFET involving an RC and GEWE design integrated onto a conventional MOSFET. Furthermore, the behaviour of GEWE-RC MOSFET is compared with that of a conventional MOSFET having the same device parameters. This paper thus optimizes and predicts the feasibility of a novel design, i.e., GEWE-RC MOSFET for high-performance applications where device and noise reduction is a major concern. The noise metrics taken into consideration are: minimum noise figure and optimum source impedance. The statistical tools auto correlation and cross correlation are also analysed owing to the random nature of noise.

  5. Lewis Research Center R and D Facilities

    Science.gov (United States)

    1991-01-01

    The NASA Lewis Research Center (LeRC) defines and develops advanced technology for high priority national needs. The work of the Center is directed toward new propulsion, power, and communications technologies for application to aeronautics and space, so that U.S. leadership in these areas is ensured. The end product is knowledge, usually in a report, that is made fully available to potential users--the aircraft engine industry, the energy industry, the automotive industry, the space industry, and other NASA centers. In addition to offices and laboratories for almost every kind of physical research in such fields as fluid mechanics, physics, materials, fuels, combustion, thermodynamics, lubrication, heat transfer, and electronics, LeRC has a variety of engineering test cells for experiments with components such as compressors, pumps, conductors, turbines, nozzles, and controls. A number of large facilities can simulate the operating environment for a complete system: altitude chambers for aircraft engines; large supersonic wind tunnels for advanced airframes and propulsion systems; space simulation chambers for electric rockets or spacecraft; and a 420-foot-deep zero-gravity facility for microgravity experiments. Some problems are amenable to detection and solution only in the complete system and at essentially full scale. By combining basic research in pertinent disciplines and generic technologies with applied research on components and complete systems, LeRC has become one of the most productive centers in its field in the world. This brochure describes a number of the facilities that provide LeRC with its exceptional capabilities.

  6. A study on shear behavior of R/C beams subjected to long-term heating

    International Nuclear Information System (INIS)

    Maruta, M.; Yamazaki, M.

    1993-01-01

    In nuclear power plants, many structural members are subjected to long term heating. There are few experimental data available on the behavior especially in shear of reinforced concrete (R/C) members subjected to long term heating. This paper describes a study aimed at experimentally determining the shear behavior of R/C members in nuclear power plant facilities following sustained heating at high temperatures

  7. SEISMICALLY RETROFITTING AND UPGRADING RC-MRF BY USING EXPANDED METAL PANELS

    OpenAIRE

    Phung Ngoc, Dung

    2011-01-01

    Reinforced concrete moment resisting frames (RC-MRFs) have been widely used as the main structural resisting systems for over 30 years based on their capacity in resisting both gravity loads and lateral forces like winds or earthquakes and on low cost of construction. However, there have been still many existing RC-MRFs not designed according to any modern seismic code. This may lead to some undesired failures under a rather low intensity earthquake. There are several existing retrofitting sy...

  8. Modeling the bacterial photosynthetic reaction center. VII. Full simulation of the intervalence hole-transfer absorption spectrum of the special-pair radical cation

    International Nuclear Information System (INIS)

    Reimers, Jeffrey R.; Hush, Noel S.

    2003-01-01

    reaction centers from photosystems I, II, etc., facilitating a deeper understanding of the role of the special pair in initiating primary charge separation during photosynthesis

  9. Study on labelling methods of 125I-RC-160 and its biodistribution in animals

    International Nuclear Information System (INIS)

    Wang Jing; Wang Xiqing; Wang Liangang; Li Fujun; Deng Jinglan

    2002-01-01

    A method for the iodination of peptide RC-160 with high efficiency was developed. RC-160 was iodinated with N-bromosuccinimide (NBS) as oxidant, the conventional chloramine T (Ch-T) method was used as control. The labelling condition of NBS method was optimized and radiolabelled conjugate 125 I-RC-160 was assessed as follows: no further purification was needed, the measured labelling yield of 125 I-RC-160 was 92% and the specific activity was 1.95 x 10 12 Bq/m mol. The yield increased as the amount of NBS increased. The optimal ratio of RC-160 (μg): 125 I (MBq): NBS(μg) was 3:7.4:1. For Ch-T method, the labelling yield is 56% and specific activity was 0.65 x 10 12 Bq/m mol; but after purification by SepPak-C 18 , the labelling yield may reach as high as 92%. 1h after injection, radioactivity in blood decreased by 87.2%. No obvious concentration of 125 I-RC-160 in thyroid or kidney was observed

  10. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Moody, K.J.; Shaughnessy, D.A.; Gostic, J.M.

    2011-01-01

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and

  11. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Moody, K J; Shaughnessy, D A; Gostic, J M

    2011-11-29

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and

  12. LaRC Modeling of Ozone Formation in San Antonio, Texas

    Science.gov (United States)

    Guo, F.; Griffin, R. J.; Bui, A.; Schulze, B.; Wallace, H. W., IV; Flynn, J. H., III; Erickson, M.; Kotsakis, A.; Alvarez, S. L.; Usenko, S.; Sheesley, R. J.; Yoon, S.

    2017-12-01

    Ozone (O3) is one of the most important trace species within the troposphere and results from photochemistry involving emissions from a complex array of sources. Ground-level O3 is detrimental to ecosystems and causes a variety of human health problems including respiratory irritation, asthma and reduction in lung capacity. However, the O3 Design Value in San Antonio, Texas, was in violation of the federal threshold set by the EPA (70 ppb, 8-hr max) based on the average for the most recent three-year period (2014-2016). To understand the sources of high O3 concentrations in this nonattainment area, we assembled and deployed a mobile air quality laboratory and operated it in two locations in the southeast (Traveler's World RV Park) and northwest (University of Texas at San Antonio) of downtown San Antonio during summer 2017 to measure O3 and its precursors, including total nitrogen oxides (NOx) and volatile organic compounds (VOCs). Additional measurements included temperature, relative humidity, pressure, solar radiation, wind speed, wind direction, total reactive nitrogen (NOy), carbon monoxide (CO), and aerosol composition and concentration. We will use the campaign data and the NASA Langley Research Center (LaRC) Zero-Dimensional Box Model (Crawford et al., 1999; Olson et al., 2006) to calculate O3 production rate, NOx and hydroxyl radical chain length, and NOx versus VOCs sensitivity at different times of a day with different photochemical and meteorological conditions. A key to our understanding is to combine model results with measurements of precursor gases, particle chemistry and particle size to support the identification of O3 sources, its major formation pathways, and how the ozone production efficiency (OPE) depends on various factors. The resulting understanding of the causes of high O3 concentrations in the San Antonio area will provide insight into future air quality protection.

  13. Study of RC method on reclamation project in the uranium mine (Joint research)

    International Nuclear Information System (INIS)

    Ishizaka, Kaoru; Tanaka, Masaru; Suzuki, Kazuhiko; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu

    2008-12-01

    To obtain public understanding on the uranium mining sites reclamation at Ningyo-toge Environmental Engineering Center, it is necessary to conduct appropriate Risk Communication (RC). In this study, to discuss the appropriate Risk communication method on the uranium mining sites reclamation, comparative investigation of risk communication cases which concern the siting of solid waste management facilities and nuclear facilities, and questionnaire survey on the risk perception of landfill were conducted. As a result of comparative investigation, information disclosure and the information supplement are important factor to obtain public trust on the siting plan and developer (government and company). However, it is necessary not only to offer information but also to foster information literacy at the same time. In the cases of best practice on consensus-building toward siting of facilities, there was suggestion that is importance to set up the public participation opportunity at an early planning stage to avoid adversary relationship between stakeholders. As assumption of the public participation, it is necessary the safety assurance of the siting plan and regional development plan cover a long period. As a result of questionnaire survey. It was shown that the almost people worried about health and the environmental impact of radioactive waste; moreover, there are a lot of ratios of the peoples who felt a dangerous and scary sensuously. Public trust on government was very low, Over 60 percent does not trust 'countermeasures at the accident' and nearly 70 percent does not trust the information disclosure at the accident'. 'Questions concern on public trust: countermeasures at the accident, information disclosure at the accident, environmental standard, and environmental technology show significant correlation with risk perception of landfill site. (author)

  14. Report on the second consultants' meeting of nuclear reaction data centers Kiev, USSR, 11-16 April 1977. Including the thirteenth four-center meeting and the third meeting on charged particle nuclear data compilation

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1977-10-01

    This second ''NRDC meeting'' combined the 13th ''four centers meeting'' (consultants' meeting of the four neutron nuclear data centers) with the third ''CPND meeting'' (consultants' meeting on charged particle nuclear data compilation). In Part I of the meeting, the neutron data centers held a special session on neutron data matters, in particular on the jointly operated neutron data index CINDA, whereas all items of more general interest, in particular the data exchange system EXFOR, were treated in Part II of the meeting

  15. Implementation of a virtual link between power system testbeds at Marshall Spaceflight Center and Lewis Research Center

    Science.gov (United States)

    Doreswamy, Rajiv

    1990-01-01

    The Marshall Space Flight Center (MSFC) owns and operates a space station module power management and distribution (SSM-PMAD) testbed. This system, managed by expert systems, is used to analyze and develop power system automation techniques for Space Station Freedom. The Lewis Research Center (LeRC), Cleveland, Ohio, has developed and implemented a space station electrical power system (EPS) testbed. This system and its power management controller are representative of the overall Space Station Freedom power system. A virtual link is being implemented between the testbeds at MSFC and LeRC. This link would enable configuration of SSM-PMAD as a load center for the EPS testbed at LeRC. This connection will add to the versatility of both systems, and provide an environment of enhanced realism for operation of both testbeds.

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

    Directory of Open Access Journals (Sweden)

    Hamdy Abou-Elfath

    2017-06-01

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

  17. Evaluation of reuterin production in urogenital probiotic Lactobacillus reuteri RC-14.

    Science.gov (United States)

    Cadieux, Peter; Wind, Anette; Sommer, Philip; Schaefer, Laura; Crowley, Kate; Britton, Robert A; Reid, Gregor

    2008-08-01

    Classified as a distinct species in 1980, Lactobacillus reuteri strains have been used in probiotic formulations for intestinal and urogenital applications. In the former, the primary mechanism of action of L. reuteri SD2112 (ATCC 55730) has been purported to be its ability to produce the antibiotic 3-hydroxypropionaldehyde (3-HPA), also known as reuterin. In the vagina, it has been postulated that probiotic Lactobacillus reuteri RC-14 does not require reuterin production but mediates a restoration of the normal microbiota via hydrogen peroxide, biosurfactant, lactic acid production, and immune modulation. The aim of the present study was to determine whether strain RC-14 produced reuterin. Using PCR and DNA dot blot analyses, numerous Lactobacillus species, including RC-14, were screened for the presence of the gene encoding the large subunit of glycerol dehydratase (gldC), the enzyme responsible for reuterin production. In addition, lactobacilli were grown in glycerol-based media and both high-performance liquid chromatography and a colorimetric assay were used to test for the presence of reuterin. L. reuteri RC-14 was determined to be negative for gldC sequences, as well as for the production of reuterin when cultured in the presence of glycerol. These findings support that the probiotic effects of L. reuteri RC-14, repeatedly demonstrated during numerous studies of the intestine and vagina, are independent of reuterin production.

  18. Tuning cofactor redox potentials: the 2-methoxy dihedral angle generates a redox potential difference of >160 mV between the primary (Q(A)) and secondary (Q(B)) quinones of the bacterial photosynthetic reaction center.

    Science.gov (United States)

    Taguchi, Alexander T; Mattis, Aidas J; O'Malley, Patrick J; Dikanov, Sergei A; Wraight, Colin A

    2013-10-15

    Only quinones with a 2-methoxy group can act simultaneously as the primary (QA) and secondary (QB) electron acceptors in photosynthetic reaction centers from Rhodobacter sphaeroides. (13)C hyperfine sublevel correlation measurements of the 2-methoxy in the semiquinone states, SQA and SQB, were compared with quantum mechanics calculations of the (13)C couplings as a function of the dihedral angle. X-ray structures support dihedral angle assignments corresponding to a redox potential gap (ΔEm) between QA and QB of ~180 mV. This is consistent with the failure of a ubiquinone analogue lacking the 2-methoxy to function as QB in mutant reaction centers with a ΔEm of ≈160-195 mV.

  19. Factors associated with acute oral mucosal reaction induced by radiotherapy in head and neck squamous cell carcinoma: A retrospective single-center experience.

    Science.gov (United States)

    Tao, Zhenchao; Gao, Jin; Qian, Liting; Huang, Yifan; Zhou, Yan; Yang, Liping; He, Jian; Yang, Jing; Wang, Ru; Zhang, Yangyang

    2017-12-01

    To investigate risk factors for acute oral mucosal reaction during head and neck squamous cell carcinoma radiotherapy.A retrospective study of patients with head and neck squamous cell carcinoma who underwent radiotherapy from November 2013 to May 2016 in Anhui Provincial Cancer Hospital was conducted. Data on the occurrence and severity of acute oral mucositis were extracted from clinical records. Based on the Radiation Therapy Oncology Group (RTOG) grading of acute radiation mucosal injury, the patients were assigned into acute reaction (grades 2-4) and minimum reaction (grades 0-1) groups. Preradiotherapy characteristics and treatment factors were compared between the 2 groups. Multivariate logistic regression analysis was used to detect the independent factors associated with acute oral mucosal reactions.Eighty patients completed radiotherapy during the study period. Oral mucosal reactions were recorded as 25, 31, and 24 cases of grades 1, 2, and 3 injuries, respectively. Significant differences between acute reaction and minimum reaction groups were detected in cancer lymph node (N) staging, smoking and diabetes history, pretreatment platelet count and T-Helper/T-Suppressor lymphocyte (Th/Ts) ratio, concurrent chemotherapy, and total and single irradiation doses.Multivariate analysis showed that N stage, smoking history, single dose parapharyngeal irradiation, and pretreatment platelet count were independent risk factors for acute radiation induced oral mucosal reaction. Smoking history, higher grading of N stage, higher single dose irradiation, and lower preirradiation platelet count may increase the risk and severity of acute radiation oral mucosal reaction in radiotherapy of head and neck cancer patients. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Conrads Thomas P

    2011-07-01

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

  1. Hypomethylation of the IL17RC Promoter Associates with Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Lai Wei

    2012-11-01

    Full Text Available Age-related macular degeneration (AMD is the leading cause of irreversible blindness in the elderly population worldwide. Although recent studies have demonstrated strong genetic associations between AMD and SNPs in a number of genes, other modes of regulation are also likely to play a role in the etiology of this disease. We identified a significantly decreased level of methylation on the IL17RC promoter in AMD patients. Furthermore, we showed that hypomethylation of the IL17RC promoter in AMD patients led to an elevated expression of its protein and messenger RNA in peripheral blood as well as in the affected retina and choroid, suggesting that the DNA methylation pattern and expression of IL17RC may potentially serve as a biomarker for the diagnosis of AMD and likely plays a role in disease pathogenesis.

  2. Hypomethylation of IL17RC Promoter Associates with Age-related Macular Degeneration

    Science.gov (United States)

    Wei, Lai; Liu, Baoying; Tuo, Jingsheng; Shen, Defen; Chen, Ping; Li, Zhiyu; Liu, Xunxian; Ni, Jia; Dagur, Pradeep; Sen, H. Nida; Jawad, Shayma; Ling, Diamond; Park, Stanley; Chakrabarty, Sagarika; Meyerle, Catherine; Agron, Elvira; Ferris, Frederick L.; Chew, Emily Y.; McCoy, J. Philip; Blum, Emily; Francis, Peter J.; Klein, Michael L.; Guymer, Robyn H.; Baird, Paul N.; Chan, Chi-Chao; Nussenblatt, Robert B.

    2012-01-01

    SUMMARY Age related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population worldwide. While recent studies have demonstrated strong genetic associations of single nucleotide polymorphisms within a number of genes and AMD, other modes of regulation are also likely to play a role in its etiology. We identified a significantly decreased level of methylation on the IL17RC promoter in AMD patients. Further, we showed that hypomethylation of the IL17RC promoter in AMD patients led to an elevated expression of its protein and mRNA in peripheral blood as well as in the affected retina and choroid, suggesting that the DNA methylation pattern and expression of IL17RC may potentially serve as a biomarker for the diagnosis of AMD and likely plays a role in disease pathogenesis. PMID:23177625

  3. KOMBINASI ALGORITMA AES, RC4 DAN ELGAMAL DALAM SKEMA HYBRID UNTUK KEAMANAN DATA

    Directory of Open Access Journals (Sweden)

    Adi Widarma

    2016-01-01

    Full Text Available Pengiriman atau pertukaran data adalah hal yang sering terjadi dalam dunia teknologi informasi. Data yang dikirim kadang sering berisi data informasi yang penting bahkan sangat rahasia dan harus dijaga keamanannya. Untuk menjaga keamanan data, dapat dilakukan dengan menggunakan teknik kriptografi. Algoritma AES dan RC4 adalah salah satu dari algoritma simetri. Kelemahan dari algoritma simetri adalah proses enkripsi dan dekripsi menggunakan kunci yang sama. Untuk mengatasi tersebut dilakukan dengan menggunakan algoritma Elgamal. Algoritma Elgamal adalah termasuk algoritma asimetri. Algoritma Elgamal digunakan untuk mengamankan kunci dari algoritma AES dan RC4. Peningkatan keamanan pesan dan kunci dilakukan dengan algoritma hybrid. Algoritma hybrid dengan mengkombinasikan beberapa algoritma baik algoritma simetri maupun algortima asimetri akan menambah keamanan sehingga menjadi lebih aman dan powerful (Jain & Agrawal 2014. Penelitian ini akan dilakukan metode hybrid yaitu mengkombinasikan beberapa algoritma kriptografi dengan menggunakan algoritma Advanced Encryption Standard (AES dan RC4 untuk kerahasiaan data serta algoritma Elgamal digunakan untuk enkripsi dan dekripsi kunci.

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

    Directory of Open Access Journals (Sweden)

    Lewiński Paweł M.

    2017-01-01

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

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

    Science.gov (United States)

    Dubey, Shailendra Kumar Damodar; Kute, Sunil

    2014-09-01

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

  6. Out-of-plane ultimate shear strength of RC mat-slab foundations

    International Nuclear Information System (INIS)

    Kumagai, Hitoshi; Nukui, Yasushi; Imamura, Akira; Terayama, Takeshi; Hagiwara, Tetsuya; Kojima, Isao

    2011-01-01

    There have been few studies on the out-of-plane shear in RC mat-slab foundations, and the reasonable method has been demanded to estimate ultimate shear strength of RC mat-slab foundations in the nuclear facilities. In the previous study, the out-of-plane loading tests on the 20 square slab specimens had been performed to collect the fundamental data. In this study, the test results were successfully predicted by 3D non-linear Finite Element Analysis. It has been confirmed that the ultimate shear stress in the slab specimen can be estimated by the Arakawa's formula, which is commonly used to estimate the shear strength of RC beams. (author)

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

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

    2015-01-01

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

  9. 3-D Image Encryption Based on Rubik's Cube and RC6 Algorithm

    Science.gov (United States)

    Helmy, Mai; El-Rabaie, El-Sayed M.; Eldokany, Ibrahim M.; El-Samie, Fathi E. Abd

    2017-12-01

    A novel encryption algorithm based on the 3-D Rubik's cube is proposed in this paper to achieve 3D encryption of a group of images. This proposed encryption algorithm begins with RC6 as a first step for encrypting multiple images, separately. After that, the obtained encrypted images are further encrypted with the 3-D Rubik's cube. The RC6 encrypted images are used as the faces of the Rubik's cube. From the concepts of image encryption, the RC6 algorithm adds a degree of diffusion, while the Rubik's cube algorithm adds a degree of permutation. The simulation results demonstrate that the proposed encryption algorithm is efficient, and it exhibits strong robustness and security. The encrypted images are further transmitted over wireless Orthogonal Frequency Division Multiplexing (OFDM) system and decrypted at the receiver side. Evaluation of the quality of the decrypted images at the receiver side reveals good results.

  10. Immunity to experimental Salmonella typhimurium infections in rats. Transfer of immunity with primed CD45RC+ and CD45RC- CD4 T-cell subpopulations

    DEFF Research Database (Denmark)

    Thygesen, P; Christensen, H B; Hougen, H P

    1996-01-01

    The protective effect of primed CD4 T cells against a lethal dose of Salmonella typhimurium was studied in Lewis rats. Primed CD4 T cells were obtained by inoculating Lewis rats with a non-lethal dose of S. typhimurium. Four weeks after the infection, spleen CD4 T cells were separated by antibody......-induced increase in CD45RC+ cells is most likely due to generation of antigen-specific memory T cells....

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

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-05-01

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

  12. Analysis of an Irregular RC Multi-storeyed Building Subjected to Dynamic Loading

    Science.gov (United States)

    AkashRaut; Pachpor, Prabodh; Dautkhani, Sanket

    2018-03-01

    Many buildings in the present scenario have irregular configurations both in plan and elevation. This in future may subject to devastating earthquakes. So it is necessary to analyze the structure. The present paper is made to study three type of irregularity wiz vertical, mass and plan irregularity as per clause 7.1 of IS 1893 (part1)2002 code. The paper discusses the analysis of RC (Reinforced Concrete) Buildings with vertical irregularity. The study as a whole makes an effort to evaluate the effect of vertical irregularity on RC buildings for which comparison of three parameters namely shear force, bending moment and deflection are taken into account.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Active damping and harmonic compensation are two common challenges faced by LCL-filtered voltage source converters. To manage them holistically, this paper begins by proposing a virtual RC damper in parallel with the passive filter capacitor. The virtual damper is actively inserted by feeding back...... the passive capacitor current through a high-pass filter, which indirectly, furnishes two superior features. They are the mitigation of phase lag experienced by a conventional damper and the avoidance of instability caused by the negative resistance inserted unintentionally. Moreover, with the virtual RC...

  14. The snap-back effect of an RC-IGBT and its simulations

    International Nuclear Information System (INIS)

    Zhang Wenliang; Tian Xiaoli; Zhu Yangjun; Tan Jingfei

    2013-01-01

    The RC-IGBT (reverse conducting insulated gate bipolar transistor) is a new kind of power semiconductor device which has many advantages such as smaller chip size, higher power density, lower manufacturing cost, softer turn off behavior, and better reliability. However, its performance has a number of drawbacks, such as the snap-back effect. In this paper, an introduction about the snap-back effect of the RC-IGBT is given firstly. Then the physical explanations are presented with two simplified models. After that, some numerical simulations are carried out to verify the correctness of the models. (semiconductor devices)

  15. Quick-Reaction Report on the Audit of Defense Base Realignment and Closure Budget Data for Naval Training Center Great Lakes, Illinois

    National Research Council Canada - National Science Library

    Granetto, Paul

    1994-01-01

    .... The Hull Technician School will share building 520 with the Advanced Hull Technician School, which is being realigned from the Naval Training Center San Diego, California, under project P-608T...

  16. Computer tools for systems engineering at LaRC

    Science.gov (United States)

    Walters, J. Milam

    1994-01-01

    The Systems Engineering Office (SEO) has been established to provide life cycle systems engineering support to Langley research Center projects. over the last two years, the computing market has been reviewed for tools which could enhance the effectiveness and efficiency of activities directed towards this mission. A group of interrelated applications have been procured, or are under development including a requirements management tool, a system design and simulation tool, and project and engineering data base. This paper will review the current configuration of these tools and provide information on future milestones and directions.

  17. Introduction to the LaRC central scientific computing complex

    Science.gov (United States)

    Shoosmith, John N.

    1993-01-01

    The computers and associated equipment that make up the Central Scientific Computing Complex of the Langley Research Center are briefly described. The electronic networks that provide access to the various components of the complex and a number of areas that can be used by Langley and contractors staff for special applications (scientific visualization, image processing, software engineering, and grid generation) are also described. Flight simulation facilities that use the central computers are described. Management of the complex, procedures for its use, and available services and resources are discussed. This document is intended for new users of the complex, for current users who wish to keep appraised of changes, and for visitors who need to understand the role of central scientific computers at Langley.

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

    Directory of Open Access Journals (Sweden)

    Raj Senani

    2014-06-01

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

  19. Isolation and molecular characterization of RcSERK1: A Rosa ...

    African Journals Online (AJOL)

    User

    2011-05-16

    May 16, 2011 ... somatic embryogenesis receptor-like kinase; SP, signal peptide; SPP, .... primers used for detecting RcSERK1 gene expression were: for- .... and mainly in the PLBs but weak in the callus and rhi- ... Transformed cells in the bright light (A and E), in the dark for cell nucleuses stained with DAPI (B and F),.

  20. Experimental study on behavior of RC panels covered with steel plates subjected to missile impact

    International Nuclear Information System (INIS)

    Jun Hashimoto; Katsuki Takiguchi; Koshiro Nishimura; Kazuyuki Matsuzawa; Mayuko Tsutsui; Yasuhiro Ohashi; Isao Kojima; Haruhiko Torita

    2005-01-01

    This paper describes an experimental study on the behavior of concrete panels with steel plate subjected to missile impact. Two tests were carried out, divided in accordance with the types of projectile, non-deformable and deformable. In all, 40 specimens of 750 mm square were prepared. The panel specimen was suspended vertically by two steel wire ropes to allow free movement after projectile impact, and was subjected to a projectile. As a result, it is confirmed that a RC panel with steel plate on its back side has higher impact resistance performance than a RC panel and that thickness of concrete panel, thickness of steel plate and the impact velocity of the projectile have a great effect on the failure modes of steel concrete panels. Moreover, based on the experimental results, the quantitative evaluation method for impact resistance performance of RC panels covered with steel plates is examined. The formula for perforation velocity of a half steel concrete panel, proposed in accordance with the bulging height, is effective to evaluate the impact resistance performance of RC panels with steel plates. (authors)

  1. Numerical study on shear resisting mechanism for corroded RC box culverts

    International Nuclear Information System (INIS)

    Matsuo, Toyofumi; Matsumura, Takuro; Iwamori, Akiyuki

    2013-01-01

    This paper discusses the effects of reinforcing steel corrosion on the shear resisting mechanism of RC box culverts and the applicability of the material degradation model in a finite element method. First, in FEM analyses, loss of reinforcement section area and initial tension strain due to reinforcement corrosion, and deteriorated bond characteristics between reinforcement and concrete, were considered. Second, cyclic loading tests using full-scale corroded specimens were numerically analyzed. The analyzed crack patterns and load-displacement relationships up to the maximum load were observed to be in close agreement with the experiment results within the average corrosion ratio of 10% of primary reinforcement. The fact that corrosion cracks can importantly affect the progression of shear cracks and shear strength of RC beams was also found. On the other hand, we established that RC box culverts being statically indeterminate structures, sectional forces are redistributed after cracking damage, and local material deterioration has a minor effect on shear capacity. Furthermore, a parametric study was carried out for corroded RC box culverts using parameters such as size, steel corrosion location, and corrosion level. (author)

  2. Strut and tie modeling for RC short beams with corroded stirrups

    Directory of Open Access Journals (Sweden)

    Ahmed K. El-Sayed

    Full Text Available Corrosion of steel reinforcement is one of the major problems that shorten the service life of reinforced concrete (RC structures. Steel stirrups, due to their location as an outer reinforcement, are more susceptible to corrosion problems and damage. However, there is limited research work in the literature on the effects of stirrup corrosion on the shear strength of RC beams. This paper attempts to evaluate analytically the residual shear strength of RC short beams with corrosion-damaged stirrups. The shear strength of short or deep beams are generally determined using the strut and tie model. The corrosion effects were implemented in the model to make it capable of predicting the residual shear capacity of RC beams with corroded stirrups. The effect of corrosion is implemented considering the reduction in geometry of the concrete cross section due to spalling and reduction in effective compressive strength of concrete due to corrosion cracks. The proposed strut and tie model which accounts for the corrosion effects was verified using the experimental data available in the literature, and good agreement was found.

  3. Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells

    NARCIS (Netherlands)

    Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla Varas, J.

    2012-01-01

    The Klotz Group (KG), an international group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced

  4. Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells

    NARCIS (Netherlands)

    Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla, J.

    2012-01-01

    The Klotz Group (KG), an mtemational group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced

  5. KOMBINASI ALGORITMA AES, RC4 DAN ELGAMAL DALAM SKEMA HYBRID UNTUK KEAMANAN DATA

    Directory of Open Access Journals (Sweden)

    Adi Widarma

    2016-01-01

    Full Text Available Abstrak — Pengiriman atau pertukaran data adalah hal yang sering terjadi dalam dunia teknologi informasi. Data yang dikirim kadang sering berisi data informasi yang penting bahkan sangat rahasia dan harus dijaga keamanannya. Untuk menjaga keamanan data, dapat dilakukan dengan menggunakan teknik kriptografi. Algoritma AES dan RC4 adalah salah satu dari algoritma simetri. Kelemahan dari algoritma simetri adalah proses enkripsi dan dekripsi menggunakan kunci yang sama. Untuk mengatasi tersebut dilakukan dengan menggunakan algoritma Elgamal. Algoritma Elgamal adalah termasuk algoritma asimetri. Algoritma Elgamal  digunakan untuk mengamankan kunci dari algoritma AES dan RC4. Peningkatan keamanan pesan dan kunci dilakukan dengan algoritma hybrid. Algoritma hybrid dengan mengkombinasikan beberapa algoritma baik algoritma simetri maupun algortima asimetri akan menambah keamanan sehingga menjadi lebih aman dan powerful (Jain & Agrawal 2014. Penelitian ini akan dilakukan metode hybrid yaitu mengkombinasikan beberapa algoritma kriptografi dengan menggunakan algoritma Advanced Encryption Standard (AES dan RC4 untuk kerahasiaan data serta algoritma Elgamal digunakan untuk enkripsi dan dekripsi kunci. Kata Kunci :  kriptograpi, algoritma AES, RC4, Elgamal, hybrid

  6. The values of the parameters of some multilayer distributed RC null networks

    Science.gov (United States)

    Huelsman, L. P.; Raghunath, S.

    1974-01-01

    In this correspondence, the values of the parameters of some multilayer distributed RC notch networks are determined, and the usually accepted values are shown to be in error. The magnitude of the error is illustrated by graphs of the frequency response of the networks.

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

    Directory of Open Access Journals (Sweden)

    Fernando Novoa

    2004-06-01

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

  8. Pitting corrosion and structural reliability of corroding RC structures: Experimental data and probabilistic analysis

    International Nuclear Information System (INIS)

    Stewart, Mark G.; Al-Harthy, Ali

    2008-01-01

    A stochastic analysis is developed to assess the temporal and spatial variability of pitting corrosion on the reliability of corroding reinforced concrete (RC) structures. The structure considered herein is a singly reinforced RC beam with Y16 or Y27 reinforcing bars. Experimental data obtained from corrosion tests are used to characterise the probability distribution of pit depth. The RC beam is discretised into a series of small elements and maximum pit depths are generated for each reinforcing steel bar in each element. The loss of cross-sectional area, reduction in yield strength and reduction in flexural resistance are then inferred. The analysis considers various member spans, loading ratios, bar diameters and numbers of bars in a given cross-section, and moment diagrams. It was found that the maximum corrosion loss in a reinforcing bar conditional on beam collapse was no more than 16%. The probabilities of failure considering spatial variability of pitting corrosion were up to 200% higher than probabilities of failure obtained from a non-spatial analysis after 50 years of corrosion. This shows the importance of considering spatial variability in a structural reliability analysis for deteriorating structures, particularly for corroding RC beams in flexure

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

    Science.gov (United States)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Enzo Martinelli

    2014-03-01

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

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

    DEFF Research Database (Denmark)

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

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ahmad Azim Shukri

    2015-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Milev Jordan

    2016-01-01

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

  16. Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

    Science.gov (United States)

    Kerwin, W. J.; Shaffer, C. V.

    1968-01-01

    Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

  17. In RC buildings, the vertical and horizontal members (ie, the beams ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 4. Learning Earthquake Design and Construction - 18. How do Beams in RC Buildings Resist Earthquakes? C V R Murty. Classroom Volume 10 Issue 4 April 2005 pp 87-90 ...

  18. The negative differential resistance characteristics of an RC-IGBT and its equivalent circuit model

    International Nuclear Information System (INIS)

    Zhang Wenliang; Zhu Yangjun; Tian Xiaoli; Lu Shuojin

    2014-01-01

    A simple equivalent circuit model is proposed according to the device structure of reverse conducting insulated gate bipolar transistors (RC-IGBT). Mathematical derivation and circuit simulations indicate that this model can explain the snap-back effect (including primary snap-back effect, secondary snap-back effect, and reverse snap-back effect) and hysteresis effect perfectly. (semiconductor devices)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-15

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

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

    Directory of Open Access Journals (Sweden)

    Sayed Mohamad Soleimani

    2012-01-01

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

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

    Science.gov (United States)

    Shukri, Ahmad Azim; Darain, Kh Mahfuz Ud; Jumaat, Mohd Zamin

    2015-07-08

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

  2. Damage Localization of Severely Damaged RC-Structures Based on Measured Eigenperiods from a Single Response

    DEFF Research Database (Denmark)

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

    This paper deals with the estimation of the damage location of severely damaged Reinforced Concrete (RC) structures excited by earthquakes. It is assumed that the building is instrumented with a sensor measuring the earthquake acceleration signal at ground surface and a sensor measuring only...

  3. Petasis/Diels-Alder/Cyclization Cascade Reactions for the Generation of Scaffolds with Multiple Stereogenic Centers and Orthogonal Handles for Library Production

    DEFF Research Database (Denmark)

    Flagstad, Thomas; Azevedo, Carlos M. G.; Min, Geanna

    2018-01-01

    A new effective strategy for the synthesis of sp3‐rich small molecules for library production is presented. The key steps to generate complexity highlight Petasis 3‐component reaction followed by an intramolecular Diels‐Alder and cyclization to generate a densely enriched tricyclic or tetracyclic...

  4. Kinetic studies on the reaction of cob(II)alamin with hypochlorous acid: Evidence for one electron oxidation of the metal center and corrin ring destruction.

    Science.gov (United States)

    Dassanayake, Rohan S; Farhath, Mohamed M; Shelley, Jacob T; Basu, Soumitra; Brasch, Nicola E

    2016-10-01

    Kinetic and mechanistic studies on the reaction of a major intracellular vitamin B 12 form, cob(II)alamin (Cbl(II)), with hypochlorous acid/hypochlorite (HOCl/OCl - ) have been carried out. Cbl(II) (Co(II)) is rapidly oxidized by HOCl to predominately aquacobalamin/hydroxycobalamin (Cbl(III), Co(III)) with a second-order rate constant of 2.4×10 7 M -1 s -1 (25.0°C). The stoichiometry of the reaction is 1:1. UHPLC/HRMS analysis of the product mixture of the reaction of Cbl(II) with 0.9mol equiv. HOCl provides support for HOCl being initially reduced to Cl and subsequent H atom abstraction from the corrin macrocycle occurring, resulting in small amounts of corrinoid species with two or four H atoms fewer than the parent cobalamin. Upon the addition of excess (H)OCl further slower reactions are observed. Finally, SDS-PAGE experiments show that HOCl-induced damage to bovine serum albumin does not occur in the presence of Cbl(II), providing support for Cbl(II) being an efficient HOCl trapping agent. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Quick-Reaction Report on the Audit of Defense Base Realignment and Closure Budget Data for Naval Training Center Great Lakes, Illinois

    Science.gov (United States)

    1994-05-19

    the audit of project P-608T, Building Modifications, as they relate to project P-557S. Because...project P-608T was addressed in Report No. 94-108, Quick-Reaction Report on the Audit of Defense Base Realignment and Closure Budget Data for Naval Station Treasure Island, California, May 19,

  6. Volume changes and electrostriction in the primary photoreactions of various photosynthetic systems: estimation of dielectric coefficient in bacterial reaction centers and of the observed volume changes with the Drude-Nernst equation.

    Science.gov (United States)

    Mauzerall, David; Hou, Jian-Min; Boichenko, Vladimir A

    2002-01-01

    Photoacoustics (PA) allows the determination of enthalpy and volume changes of photoreactions in photosynthetic reaction centers on the 0.1-10 mus time scale. These include the bacterial centers from Rb. sphaeroides, PS I and PS II centers from Synechocystis and in whole cells. In vitro and in vivo PA data on PS I and PS II revealed that both the volume change (-26 A(3)) and reaction enthalpy (-0.4 eV) in PS I are the same as those in the bacterial centers. However the volume change in PS II is small and the enthalpy far larger, -1 eV. Assigning the volume changes to electrostriction allows a coherent explanation of these observations. One can explain the large volume decrease in the bacterial centers with an effective dielectric coefficient of approximately 4. This is a unique approach to this parameter so important in estimation of protein energetics. The value of the volume contraction for PS I can only be explained if the acceptor is the super- cluster (Fe(4)S(4))(Cys(4)) with charge change from -1 to -2. The small volume change in PS II is explained by sub-mus electron transfer from Y(Z) anion to P(680) cation, in which charge is only moved from the Y(Z) anion to the Q(A) with no charge separation or with rapid proton transfer from oxidized Y(Z) to a polar region and thus very little change in electrostriction. At more acid pH equally rapid proton transfer from a neighboring histidine to a polar region may be caused by the electric field of the P(680) cation.

  7. Monomeric RC-LH1 core complexes retard LH2 assembly and intracytoplasmic membrane formation in PufX-minus mutants of Rhodobacter sphaeroides.

    Science.gov (United States)

    Adams, Peter G; Mothersole, David J; Ng, Irene W; Olsen, John D; Hunter, C Neil

    2011-09-01

    In the model photosynthetic bacterium Rhodobacter sphaeroides domains of light-harvesting 2 (LH2) complexes surround and interconnect dimeric reaction centre-light-harvesting 1-PufX (RC-LH1-PufX) 'core' complexes, forming extensive networks for energy transfer and trapping. These complexes are housed in spherical intracytoplasmic membranes (ICMs), which are assembled in a stepwise process where biosynthesis of core complexes tends to dominate the early stages of membrane invagination. The kinetics of LH2 assembly were measured in PufX mutants that assemble monomeric core complexes, as a consequence of either a twelve-residue N-terminal truncation of PufX (PufXΔ12) or the complete removal of PufX (PufX(-)). Lower rates of LH2 assembly and retarded maturation of membrane invagination were observed for the larger and less curved ICM from the PufX(-) mutant, consistent with the proposition that local membrane curvature, initiated by arrays of bent RC-LH1-PufX dimers, creates a favourable environment for stable assembly of LH2 complexes. Transmission electron microscopy and high-resolution atomic force microscopy were used to examine ICM morphology and membrane protein organisation in these mutants. Some partitioning of core and LH2 complexes was observed in PufX(-) membranes, resulting in locally ordered clusters of monomeric RC-LH1 complexes. The distribution of core and LH2 complexes in the three types of membrane examined is consistent with previous models of membrane curvature and domain formation (Frese et al., 2008), which demonstrated that a combination of crowding and asymmetries in sizes and shapes of membrane protein complexes drives membrane organisation. 2011 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2015-11-01

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

  9. Shear Strengthening of RC Deep Beam Using Externally Bonded GFRP Fabrics

    Science.gov (United States)

    Kumari, A.; Patel, S. S.; Nayak, A. N.

    2018-06-01

    This work presents the experimental investigation of RC deep beams wrapped with externally bonded Glass Fibre Reinforced Polymer (GFRP) fabrics in order to study the Load versus deflection behavior, cracking pattern, failure modes and ultimate shear strength. A total number of five deep beams have been casted, which is designed with conventional steel reinforcement as per IS: 456 (Indian standard plain and reinforced concrete—code for practice, Bureau of Indian Standards, New Delhi, 2000). The spans to depth ratio for all RC deep beams have been kept less than 2 as per the above specification. Out of five RC deep beams, one without retrofitting serves as a reference beam and the rest four have been wrapped with GFRP fabrics in multiple layers and tested with two point loading condition. The first cracking load, ultimate load and the shear contribution of GFRP to the deep beams have been observed. A critical discussion is made with respect to the enhancement of the strength, behaviour and performance of retrofitted deep beams in comparison to the deep beam without GFRP in order to explore the potential use of GFRP for strengthening the RC deep beams. Test results have demonstrated that the deep beams retrofitted with GFRP shows a slower development of the diagonal cracks and improves shear carrying capacity of the RC deep beam. A comparative study of the experimental results with the theoretical ones predicted by various researchers available in the literatures has also been presented. It is observed that the ultimate load of the beams retrofitted with GFRP fabrics increases with increase of number of GFRP layers up to a specific number of layers, i.e. 3 layers, beyond which it decreases.

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

    Directory of Open Access Journals (Sweden)

    Satriyo Satriyo

    2012-01-01

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

  11. Selected ion flow tube (SIFT) studies of the reactions of H3O+, NO+ and O-2(+center dot) with six volatile phytogenic esters

    Czech Academy of Sciences Publication Activity Database

    Sovová, K.; Dryahina, Kseniya; Španěl, Patrik

    2011-01-01

    Roč. 300, č. 1 (2011), s. 31-38 ISSN 1387-3806 R&D Projects: GA ČR GA202/09/0800; GA ČR GA203/09/0256 Institutional research plan: CEZ:AV0Z40400503 Keywords : SIFT-MS * ion-molecule reactions * plant esters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.549, year: 2011

  12. Efficient Destruction of Pollutants in Water by a Dual-Reaction-Center Fenton-like Process over Carbon Nitride Compounds-Complexed Cu(II)-CuAlO2.

    Science.gov (United States)

    Lyu, Lai; Yan, Dengbiao; Yu, Guangfei; Cao, Wenrui; Hu, Chun

    2018-04-03

    Carbon nitride compounds (CN) complexed with the in-situ-produced Cu(II) on the surface of CuAlO 2 substrate (CN-Cu(II)-CuAlO 2 ) is prepared via a surface growth process for the first time and exhibits exceptionally high activity and efficiency for the degradation of the refractory pollutants in water through a Fenton-like process in a wide pH range. The reaction rate for bisphenol A removal is ∼25 times higher than that of the CuAlO 2 . According to the characterization, Cu(II) generation on the surface of CuAlO 2 during the surface growth process results in the marked decrease of the surface oxygen vacancies and the formation of the C-O-Cu bridges between CN and Cu(II)-CuAlO 2 in the catalyst. The electron paramagnetic resonance (EPR) analysis and density functional theory (DFT) calculations demonstrate that the dual reaction centers are produced around the Cu and C sites due to the cation-π interactions through the C-O-Cu bridges in CN-Cu(II)-CuAlO 2 . During the Fenton-like reactions, the electron-rich center around Cu is responsible for the efficient reduction of H 2 O 2 to • OH, and the electron-poor center around C captures electrons from H 2 O 2 or pollutants and diverts them to the electron-rich area via the C-O-Cu bridge. Thus, the catalyst exhibits excellent catalytic performance for the refractory pollutant degradation. This study can deepen our understanding on the enhanced Fenton reactivity for water purification through functionalizing with organic solid-phase ligands on the catalyst surface.

  13. Langley Research Center Strategic Plan for Education

    Science.gov (United States)

    Proctor, Sandra B.

    1994-01-01

    Research assignment centered on the preparation of final draft of the NASA Langley Strategic Plan for Education. Primary research activity consisted of data collection, through interviews with LaRC Office of Education and NASA Headquarters staff, university administrators and faculty, and school administrators / teachers; and documentary analysis. Pre-college and university programs were critically reviewed to assure effectiveness, support of NASA and Langley's mission and goals; National Education Goals; and educational reform strategies. In addition to these mandates, pre-college programs were reviewed to address present and future LaRC activities for teacher enhancement and preparation. University programs were reviewed with emphasis on student support and recruitment; faculty development and enhancement; and LaRC's role in promoting the utilization of educational technologies and distance learning. The LaRC Strategic Plan for Education will enable the Office of Education to provide a focused and well planned continuum of education programs for students, teachers and faculty. It will serve to direct and focus present activities and programs while simultaneously offering the flexibility to address new and emerging directions based on changing national, state, and agency trends.

  14. ADVANCED COMPOSITES TECHNOLOGY CASE STUDY AT NASA LANGLEY RESEARCH CENTER

    Science.gov (United States)

    This report summarizes work conducted at the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC) in Hampton, VA, under the U.S. Environmental Protection Agency’s (EPA) Waste Reduction Evaluations at Federal Sites (WREAFS) Program. Support for...

  15. Workgroup Report by the Joint Task Force Involving American Academy of Allergy, Asthma & Immunology (AAAAI); Food Allergy, Anaphylaxis, Dermatology and Drug Allergy (FADDA) (Adverse Reactions to Foods Committee and Adverse Reactions to Drugs, Biologicals, and Latex Committee); and the Centers for Disease Control and Prevention Botulism Clinical Treatment Guidelines Workgroup-Allergic Reactions to Botulinum Antitoxin: A Systematic Review.

    Science.gov (United States)

    Schussler, Edith; Sobel, Jeremy; Hsu, Joy; Yu, Patricia; Meaney-Delman, Dana; Grammer, Leslie C; Nowak-Wegrzyn, Anna

    2017-12-27

    Naturally occurring botulism is rare, but a large number of cases could result from unintentional or intentional contamination of a commercial food. Despeciated, equine-derived, heptavalent botulinum antitoxin (HBAT) is licensed in the United States. Timely treatment reduces morbidity and mortality, but concerns that botulinum antitoxin can induce anaphylaxis exist. We sought to quantify the allergy risk of botulinum antitoxin treatment and the usefulness of skin testing to assess this risk. We conducted a systematic review of (1) allergic reactions to botulinum antitoxin and (2) the predictive value of skin testing (ST) before botulinum antitoxin administration. We searched 5 scientific literature databases, reviewed articles' references, and obtained data from the HBAT manufacturer and from the Centers for Disease Control and Prevention. Anaphylaxis incidence was determined for HBAT and previously employed botulinum antitoxins. We calculated the positive predictive value (PPV) and negative predictive value (NPV) of ST for anaphylaxis related to HBAT and other botulinum antitoxins. Seven articles were included. Anaphylaxis incidence was 1.64% (5/305 patients) for HBAT and 1.16% (8/687 patients) for all other botulinum antitoxins (relative risk, 1.41 [95% confidence interval, .47-4.27]; P = .5). Observed values for both PPV and NPV for HBAT-ST (33 patients) were 100%. Observed PPVs and NPVs of ST for other botulinum antitoxins (302 patients) were 0-56% and 50%-100%, respectively. There were no reports of fatal anaphylaxis. Considering the <2 % rate of anaphylaxis, fatal outcomes, modest predictive value of ST, resource requirements for ST, and the benefits of early treatment, data do not support delaying HBAT administration to perform ST in a mass botulinum toxin exposure. Anaphylactic reactions may occur among 1%-2% of botulinum antitoxin recipients and will require epinephrine and antihistamine treatment and, possibly, intensive care. Published by Oxford

  16. Mouse RC/BTB2, a Member of the RCC1 Superfamily, Localizes to Spermatid Acrosomal Vesicles

    Science.gov (United States)

    Shen, Xuening; Nagarkatti-Gude, David R.; Hess, Rex A.; Henderson, Scott C.; Strauss, Jerome F.; Zhang, Zhibing

    2012-01-01

    Mouse RC/BTB2 is an unstudied protein of the RCC1 (Regulator of Chromosome Condensation) superfamily. Because of the significant remodeling of chromatin that occurs during spermiogenesis, we characterized the expression and localization of mouse RC/BTB2 in the testis and male germ cells. The Rc/btb2 gene yields two major transcripts: 2.3 kb Rc/btb2-s, present in most somatic tissues examined; and 2.5 kb Rc/btb2-t, which contains a unique non-translated exon in its 5′-UTR that is only detected in the testis. During the first wave of spermatogenesis, Rc/btb2-t mRNA is expressed from day 8 after birth, reaching highest levels of expression at day 30 after birth. The full-length protein contains three RCC1 domains in the N-terminus, and a BTB domain in the C-terminus. In the testis, the protein is detectable from day 12, but is progressively up-regulated to day 30 and day 42 after birth. In spermatids, some of the protein co-localizes with acrosomal markers sp56 and peanut lectin, indicating that it is an acrosomal protein. A GFP-tagged RCC1 domain is present throughout the cytoplasm of transfected CHO cells. However, both GFP-tagged, full-length RC/BTB2 and a GFP-tagged BTB domain localize to vesicles in close proximity to the nuclear membrane, suggesting that the BTB domain might play a role in mediating full-length RC/BTB2 localization. Since RCC1 domains associate with Ran, a small GTPase that regulates molecular trafficking, it is possible that RC/BTB2 plays a role in transporting proteins during acrosome formation. PMID:22768142

  17. Practical stress evaluation method of RC slab for bending moment in consideration of additional in-plane stress caused by boundary condition

    International Nuclear Information System (INIS)

    Kobayashi, Toshio; Adachi, Naohito; Masuda, Kiyoshi

    1998-01-01

    In a design of a thick RC slab such as a basemat of a nuclear reactor building, the design method as same as for RC column is usually used. In this method, bending moment and axial force which are obtained by linear Finite Element Method (FEM) for external force are considered. But the assumption for linear FEM in which concrete participates for tensile stress is different from that for reinforcement design in which concrete does not participate for tensile stress. This difference of the assumption results that in-plane tensile strain at the center of the slab depth in the reinforcement design is larger than that in linear FEM. Some effects will appear in stress distribution if this tensile strain is constrained by boundary condition. In this paper, a practical method to evaluate the boundary constrain effects for this in-plane tensile strain is proposed and a simulation analysis of a thick reinforced concrete slab with a large opening for out-of-plane force is also reported. (author)

  18. Learning Abstract Physical Concepts from Experience: Design and Use of an RC Circuit

    Science.gov (United States)

    Parra, Alfredo; Ordenes, Jorge; de la Fuente, Milton

    2018-05-01

    Science learning for undergraduate students requires grasping a great number of theoretical concepts in a rather short time. In our experience, this is especially difficult when students are required to simultaneously use abstract concepts, mathematical reasoning, and graphical analysis, such as occurs when learning about RC circuits. We present a simple experimental model in this work that allows students to easily design, build, and analyze RC circuits, thus providing an opportunity to test personal ideas, build graphical descriptions, and explore the meaning of the respective mathematical models, ultimately gaining a better grasp of the concepts involved. The result suggests that the simple setup indeed helps untrained students to visualize the essential points of this kind of circuit.

  19. Flexural repair/strengthening of pre-damaged R.C. beams using embedded CFRP rods

    Directory of Open Access Journals (Sweden)

    Alaa M. Morsy

    2015-12-01

    Full Text Available Many reinforced concrete R.C. elements need either strengthening due to the need of increasing the service loads or repair due to overloading stress or environmental deterioration affecting these elements. In this paper an experimental program is presented to investigate the effect of using embedded CFRP rod as NSM reinforcement for strengthening/repairing R.C. beams pre-damaged by loading to different loading levels and comparing the results to those of non-preloaded beams. A total of five beams were cast and six beams were tested under four point loading. The main objective of this paper was to investigate the effect of providing one 12 mm diameter CFRP rod in addition to the existing steel reinforcement. Three beams were tested to failure directly without any preloading, whereas the other three beams were firstly subjected to preloading to different load levels. Following that these three beams were strengthened and were tested up to failure.

  20. Development of a relational database for nuclear material (NM) accounting in RC and I Group

    International Nuclear Information System (INIS)

    Yadav, M.B.; Ramakumar, K.L.; Venugopal, V.

    2011-01-01

    A relational database for the nuclear material accounting in RC and I Group has been developed with MYSQL for Back-End and JAVA for Front-End development. Back-End has been developed to avoid any data redundancy, to provide random access of the data and to retrieve the required information from database easily. JAVA Applet and Java Swing components of JAVA programming have been used in the Front-End development. Front-End has been developed to provide data security, data integrity, to generate inventory status report at the end of accounting period, and also to have a quick look of some required information on computer screen. The database has been tested for the data of three quarters of the year 2009. It has been implemented from 1st January, 2010 for the accounting of nuclear material in RC and I Group. (author)

  1. Development of a relational database for nuclear material (NM) accounting in RC and I Group

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, M B; Ramakumar, K L; Venugopal, V [Radioanalytical Chemistry Division, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre, Mumbai (India)

    2011-07-01

    A relational database for the nuclear material accounting in RC and I Group has been developed with MYSQL for Back-End and JAVA for Front-End development. Back-End has been developed to avoid any data redundancy, to provide random access of the data and to retrieve the required information from database easily. JAVA Applet and Java Swing components of JAVA programming have been used in the Front-End development. Front-End has been developed to provide data security, data integrity, to generate inventory status report at the end of accounting period, and also to have a quick look of some required information on computer screen. The database has been tested for the data of three quarters of the year 2009. It has been implemented from 1st January, 2010 for the accounting of nuclear material in RC and I Group. (author)

  2. Experimental study on fatigue crack propagation rate of RC beam strengthened with carbon fiber laminate

    Science.gov (United States)

    Huang, Peiyan; Liu, Guangwan; Guo, Xinyan; Huang, Man

    2008-11-01

    The experimental research on fatigue crack propagation rate of reinforced concrete (RC) beams strengthened with carbon fiber laminate (CFL) is carried out by MTS system in this paper. The experimental results show that, the main crack propagation on strengthened beam can be summarized into three phases: 1) fast propagation phase; 2) steady propagation and rest phase; 3) unsteady propagation phase. The phase 2-i.e. steady propagation and rest stage makes up about 95% of fatigue life of the strengthened beam. The propagation rate of the main crack, da/dN, in phase 2 can be described by Paris formula, and the constant C and m can be confirmed by the fatigue crack propagation experiments of the RC beams strengthened with CFL under three-point bending loads.

  3. Development of Shear Capacity Prediction Model for FRP-RC Beam without Web Reinforcement

    Directory of Open Access Journals (Sweden)

    Md. Arman Chowdhury

    2016-01-01

    Full Text Available Available codes and models generally use partially modified shear design equation, developed earlier for steel reinforced concrete, for predicting the shear capacity of FRP-RC members. Consequently, calculated shear capacity shows under- or overestimation. Furthermore, in most models some affecting parameters of shear strength are overlooked. In this study, a new and simplified shear capacity prediction model is proposed considering all the parameters. A large database containing 157 experimental results of FRP-RC beams without shear reinforcement is assembled from the published literature. A parametric study is then performed to verify the accuracy of the proposed model. Again, a comprehensive review of 9 codes and 12 available models is done, published back from 1997 to date for comparison with the proposed model. Hence, it is observed that the proposed equation shows overall optimized performance compared to all the codes and models within the range of used experimental dataset.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-15

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

  5. A 500-600 MHz GaN power amplifier with RC-LC stability network

    Science.gov (United States)

    Ma, Xinyu; Duan, Baoxing; Yang, Yintang

    2017-08-01

    A 500-600 MHz high-efficiency, high-power GaN power amplifier is designed and realized on the basis of the push-pull structure. The RC-LC stability network is proposed and applied to the power amplifier circuit for the first time. The RC-LC stability network can significantly reduce the high gain out the band, which eliminates the instability of the power amplifier circuit. The developed power amplifier exhibits 58.5 dBm (700 W) output power with a 17 dB gain and 85% PAE at 500-600 MHz, 300 μs, 20% duty cycle. It has the highest PAE in P-band among the products at home and abroad. Project supported by the National Key Basic Research Program of China (No. 2014CB339901).

  6. The response of an RC line MWPC to primary cosmic rays. [Multi-Wire Proportional Counter

    Science.gov (United States)

    Gregory, J. C.; Selig, W. J.; Austin, R. W.; Derrickson, J. H.; Parnell, T. A.

    1978-01-01

    A simple 50 x 50 sq cm MWPC plane was arranged as an RC-line and flown on a balloon flight with the MSFC-UAH Cosmic Ray experiment. Positions of primary cosmic ray tracks in the RC-line were determined by the risetime method and compared with the expected position as indicated by a best line fitted through four planes of the conventional MWPC hodoscope. Mean errors were estimated for sea-level muons, and CNO group and iron group particles. It is believed that the delta-rays accompanying the primaries degraded the position resolution. Measured standard deviations allowing for uncertainty in the true track position are of the order of 1 cm or less in the primary charge region between 7 and 26.

  7. Behavior of Insulated Carbon-FRP-Strengthened RC Beams Exposed to Fire

    Science.gov (United States)

    Sayin, B.

    2014-09-01

    There are two main approaches to improving the fire resistance of fiber-reinforced polymer (FRP) systems. While the most common method is to protect or insulate the FRP system, an other way is to use fibers and resins with a better fire performance. This paper presents a numerical investigation into the five protection behavior of insulated carbon-fiber-reinforced-polymer (CFRP)-strengthened reinforced concrete (RC) beams. The effects of external loading and thermal expansion of materials at elevated temperatures are taken into consideration in a finite-element model. The validity of the numerical model is demonstrated with results from an existing experimental study on insulated CFRP-strengthened RC beams. Conclusions of this investigation are employed to predict the structural behavior of CFRP-strengthened concrete structures.

  8. RC structures strengthened by metal shear panels: experimental and numerical analysis

    International Nuclear Information System (INIS)

    De Matteis, G.; Formisano, A.; Mazzolani, F. M.

    2008-01-01

    Metal shear panels (MSPs) may be effectively used as a lateral load resisting system for framed structures. In the present paper, such a technique is applied for the seismic protection of existing RC buildings, by setting up a specific design procedure, which has been developed on the basis of preliminary full-scale experimental tests. The obtained results allowed the development of both simplified and advanced numerical models of both the upgraded structure and the applied shear panels. Also, the proposed design methodology, which is framed in the performance base design philosophy, has been implemented for the structural upgrading of a real Greek existing multi-storey RC building. The results of the numerical analysis confirmed the effectiveness of the proposed technique, also emphasising the efficiency of the implemented design methodology

  9. Flexural Behavior of RC Slabs Strengthened in Flexure with Basalt Fabric-Reinforced Cementitious Matrix

    Directory of Open Access Journals (Sweden)

    Sugyu Lee

    2018-01-01

    Full Text Available This paper presents both experimental and analytical research results for predicting the flexural capacity of reinforced concrete (RC slabs strengthened in flexure with basalt fabric-reinforced cementitious matrix (FRCM. A total of 13 specimens were fabricated to evaluate the flexural behavior of RC slabs strengthened with basalt FRCM composite and were tested under four-point loading. The fiber type, tensile reinforcement ratio, and the number of fabric layers were chosen as experimental variables. The maximum load of FRCM-strengthened specimens increased from 11.2% to 98.2% relative to the reference specimens. The energy ratio and ductility of the FRCM-strengthened specimens decreased with the higher amount of fabric and tensile reinforcement. The effective stress level of FRCM fabric can be accurately predicted by a bond strength of ACI 549 and Jung’s model.

  10. Homogenized global nonlinear constitutive model for RC panels under cyclic loadings

    International Nuclear Information System (INIS)

    Huguet, Miquel; Voldoire, Francois; Kotronis, Panagiotis; Erlicher, Silvano

    2014-01-01

    A new nonlinear stress resultant global constitutive model for RC panels is presented. Concrete damage, concrete stress transfer at cracks and bond-slip stress are the main nonlinear effects identified at the local scale that constitute the basis for the construction of the stress resultant global model through an analytical homogenization technique. The closed form solution is obtained using general functions for the previous phenomena. (authors)

  11. Dynamics model for real time diagnostics of Triga RC-1 system

    International Nuclear Information System (INIS)

    Gadomski, A.M.; Nanni, V.; Meo, G.

    1988-01-01

    This paper presents dynamics model of TRIGA RC-1 reactor system. The model is dedicated to the real-time early fault detection during a reactor operation in one week exploitation cycle. The algorithms are specially suited for real-time, long time and also accelerated simulations with assumed diagnostic oriented accuracy. The approximations, modular structure, numerical methods and validation are discussed. The elaborated model will be build in the TRIGA Supervisor System and TRIGA Diagnostic Simulator

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

    DEFF Research Database (Denmark)

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

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

  13. ENEA TRIGA RC-1 reactor activities in the fields of nuclear medicine and neutron radiography

    International Nuclear Information System (INIS)

    Chiesa, Gianni; Festinesi, Armando; Palomba, Mario; Rosa, Roberto; Rossi, Gabriela; Sangiovanni, Gino; Santoro, Emilio; Sedda, Antioco Franco; Storelli, Lucio

    2008-01-01

    In the last three years, TRIGA RC-1 plant staff is involved in collaborations with some roman hospitals for the production of particular radioisotopes for the diagnosis and therapy in the field of human cancer. Further, the thermal column of TRIGA reactor has been prepared for neutron radiography and tomography. For another channel, instruments and equipment above neutron radiography and tomography are in preparation phase. This paper includes an overview of the experimental equipment properly developed by TRIGA staff. (authors)

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

    Directory of Open Access Journals (Sweden)

    Elodie ePEYROUX

    2014-06-01

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

  15. Sustainable RC Beam-Column Connections with Headed Bars: A Formula for Shear Strength Evaluation

    Directory of Open Access Journals (Sweden)

    Minh-Tung Tran

    2018-02-01

    Full Text Available Beam-column joints are critical regions for reinforced concrete (RC frames subjected to earthquakes. The steel reinforcement is, in general, highly concentrated in these zones. This is why in many cases, headed bars are used. A headed bar is a longitudinal steel reinforcement whose end has a special button added to reduce the bonding length of the steel rebar. This paper establishes a formula predicting the shear strength of exterior RC beam-column connections where the beam longitudinal reinforcements use headed bars. A database was collected, which contained 30 experimental data about the exterior beam-column joints using headed bars and subjected to quasi-static cyclic loading. First, from the collected database, a statistical study was carried out to identify the most influencing parameters on the shear strength of the beam-column joints tested. The three most important parameters were identified and an empirical modified formula was developed based on the formula existing in the standards. The study showed that the results obtained from the modified formula proposed in the present study were closer to the experimental results than that obtained from the formula existing in the standards. Finally, a numerical study was performed on two T-form RC structures and the numerical results were compared with the prediction calculated from the modified formula proposed. For two investigated cases, the proposed formula provided the results in the safety side and the differences with the numerical results were less than 20%. Thus, the proposed formula can be used for a rapid assessment of the shear strength of RC joints using headed bars.

  16. Loads experiments study on two-story RC box and truncated conical walls

    International Nuclear Information System (INIS)

    Asega, H.; Iizuka, S.; Kurihara, I.; Kubo, T.

    1987-01-01

    The failure modes of the two specimens were the sliding shear failure. The two specimens showed almost equal deformation at the maximum shear strength. The ratio of the flexural deformation in the deformation of the truncated conical was larger than that of the box wall. The ratio of the shear deformation in the deformation of the two-story RC box wall was larger than that of the flexural deformation. (orig./HP)

  17. A proposal for seismic evaluation index of mid-rise existing RC buildings in Afghanistan

    Science.gov (United States)

    Naqi, Ahmad; Saito, Taiki

    2017-10-01

    Mid-rise RC buildings gradually rise in Kabul and entire Afghanistan since 2001 due to rapid increase of population. To protect the safety of resident, Afghan Structure Code was issued in 2012. But the building constructed before 2012 failed to conform the code requirements. In Japan, new sets of rules and law for seismic design of buildings had been issued in 1981 and severe earthquake damage was disclosed for the buildings designed before 1981. Hence, the Standard for Seismic Evaluation of RC Building published in 1977 has been widely used in Japan to evaluate the seismic capacity of existing buildings designed before 1981. Currently similar problem existed in Afghanistan, therefore, this research examined the seismic capacity of six RC buildings which were built before 2012 in Kabul by applying the seismic screening procedure presented by Japanese standard. Among three screening procedures with different capability, the less detailed screening procedure, the first level of screening, is applied. The study founds an average seismic index (IS-average=0.21) of target buildings. Then, the results were compared with those of more accurate seismic evaluation procedures of Capacity Spectrum Method (CSM) and Time History Analysis (THA). The results for CSM and THA show poor seismic performance of target buildings not able to satisfy the safety design limit (1/100) of the maximum story drift. The target buildings are then improved by installing RC shear walls. The seismic indices of these retrofitted buildings were recalculated and the maximum story drifts were analyzed by CSM and THA. The seismic indices and CSM and THA results are compared and found that building with seismic index larger than (IS-average =0.4) are able to satisfy the safety design limit. Finally, to screen and minimize the earthquake damage over the existing buildings, the judgement seismic index (IS-Judgment=0.5) for the first level of screening is proposed.

  18. Comparative Analysis of Existing RC Columns Jacketed with CFRP or FRCC

    Directory of Open Access Journals (Sweden)

    Marta Del Zoppo

    2018-03-01

    Full Text Available Reinforced concrete (RC columns typical of existing structures often exhibit premature failures during seismic events (i.e., longitudinal bars buckling and shear interaction mechanisms due to the poor quality concrete and the absence of proper seismic details in the potential plastic hinge region. The Fiber Reinforced Polymers (FRP externally bonded reinforcement is known to be a valid technique to improve the shear capacity or the ductility of existing RC columns. However, few experimental tests have proven its effectiveness in the case of columns affected by shear interaction mechanisms. In this work, the behavior of existing RC columns with border line behavior between flexure and shear have been investigated in the case of poor quality concrete and light FRP strengthening with local jacketing and medium quality concrete and strong FRP strengthening with local jacketing, in order to highlight the effect of concrete strength on the effectiveness of the retrofit intervention. As an alternative to FRP jacketing; the effectiveness of the Fiber Reinforced Cementitious Composite (FRCC jacketing for the seismic strengthening of columns with highly deteriorated concrete cover or columns already damaged by an earthquake is also evaluated. Six full-scale RC columns have been tested under cyclic loading: one was used as a control specimen; four were strengthened in the potential plastic hinge region with carbon FRP (CFRP; and one was fully jacketed with FRCC. The comparison between poor and medium quality concrete columns showed that the CFRP local jacketing is more effective in the case of poor quality concrete. The FRCC jacketing appears to be a sound repair strategy and a suitable alternative to the FRP jacketing in case of poor quality; however, more experimental research is needed for improving this retrofit technique.

  19. A three-layer distributed RC network with two transmission zeros

    Science.gov (United States)

    Huelsman, L. P.

    1974-01-01

    This report describes the properties of a three-layer distributed RC network consisting of two resistive layers separated by a dielectric which may be used to realize two zeros of transmission on the j-omega axis of the complex frequency plane. The relative location of the two zeros is controlled by the location of a contact placed on one of the resistive layers.

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

    Science.gov (United States)

    2014-06-06

    5a. CONTRACT NUMBER Risk Quantification for Sustaining Coastal Military Installation Asset and Mission Capabilities (RC-1701) 5b. GRANT NUMBER...Planetary Boundary Layer (PBL) wind model TC96 (Thompson and Cardone 1996), 2) Surge has been simulated using the ADvanced CIRCulation model ADCIRC...coefficient, and h is the depth of the PBL (Thompson and Cardone 1996). The cyclone pressure is defined by an axisymmetrical exponential pressure or by

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

    Science.gov (United States)

    Peyroux, Elodie; Franck, Nicolas

    2014-01-01

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

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

    Science.gov (United States)

    Peyroux, Elodie; Franck, Nicolas

    2014-01-01

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

  3. A hybrid Rankine cycle (HyRC) with ambient pressure combustion (APC)

    International Nuclear Information System (INIS)

    Wu, Lijun; Thimsen, David; Clements, Bruce; Zheng, Ligang; Pomalis, Richard

    2014-01-01

    The main losses in thermal power generation include heat in exhaust flue gas, heat rejected through steam condensation of low-pressure turbine, and exergy destruction in heat exchange process etc. To the extent that the heat losses are significantly greater in temperature than either air or water coolant resources, these losses also represent exergy losses which might be exploited to improve plant capacity and efficiency. This paper presents a hybrid Rankine cycle (HyRC) with an ambient pressure combustion (APC) boiler to address the recovery potential of these losses within the steam Rankine cycle (SRC). The APC–HyRC concept employs an organic Rankine cycle (ORC) to supplement SRC and to reduce cycle energy losses to the atmosphere since organic fluids are capable of lowering cycle condensation temperature when a very low temperature heat sink is available. The case studies based on a 399 MW SRC unit show that the APC–HyRC configurations have better thermodynamic performance than its base case SRC at a cycle condensation temperature of 30 °C and below. The best APC–HyRC configuration generates up to 14% more power than the baseline steam cycle which is a 5.45% increase in overall gross efficiency with a cycle condensation temperature at 4 °C. - Highlights: • A hybrid Rankine cycle with water and organic fluid is presented. • Heat losses in exhaust flue gas and exhaust steam are reduced. • Exergy losses in regeneration process are reduced. • Efficiency improvements are made to the conventional steam Rankine cycle. • Issues in design/construction of greenfield and repowering project are discussed

  4. Dynamics model for real time diagnostics of TRIGA RC-1 system

    International Nuclear Information System (INIS)

    Gadomski, A.M.; Nanni, V.; Meo, G.B.

    1986-01-01

    This paper presents dynamics model of TRIGA RC-1 reactor system. The model is dedicated to the real-time early fault detection during a reactor operation in one week exploitation cycle. The algorithms are specially suited for real-time, long time and also accelerated simulations with assumed diagnostic oriented accuracy. The approximations, modular structure, numerical methods and validation are discussed. The elaborated model will be build in the TRIGA Supervisory System and TRIGA Diagnostic Simulator. (author)

  5. Vibronic coupling in ionized organic molecules. Structural distortions and chemical reactions

    International Nuclear Information System (INIS)

    Williams, F.

    2002-01-01

    Complete text of publication follows. Ionized organic molecules (radical cations, RC) are prone to undergo vibronic coupling whenever there is a relatively small energy gap ( 2v point group of the neutral parent molecule by twisting at the olefinic π bond to the lower C 2 symmetry in the RC (Chem. Eur. J. 2002, 8, 1074). These experiments clearly revealed a double minimum in the potential energy surface along the a 2 torsional mode. This is in accord with the coupling of the 2 B 1 and 2 B 2 Born-Oppenheimer states in C 2v symmetry, this mixing of the 2 B 1 π-ionized ground state and the 2 B 2 δ-ionized excited state being facilitated by the low (∼ 1.0 eV) gap between these states, as estimated from photoelectron spectroscopy. Turning to the second class of RC where unimolecular rearrangement reactions are promoted by vibronic interaction, several cases have emerged where the rearrangement would not be expected if it were based only on the ground-state properties of the RC. It was found (Chem. Phy. Lett. 1988, 143, 521) that the ethylene oxide RC undergoes C-C ring opening to the oxallyl species despite the fact that the ground state corresponds to ionization from the nonbonding oxygen π lone-pair orbital. The reaction develops excited-state character as a result of the vibronic mixing so that the activation barrier to ring opening is lowered. We will discuss the unusual rearrangements of the bicyclo[1.1.1.]pentane and [1.1.1]propellane RC from a similar perspective, emphasis being placed on the decisive role of symmetry in predicting the course of these rearrangements. We illustrate how this approach can reconcile conflicting considerations on some of the 'unexpected' reaction pathways followed by highly strained organic RC

  6. Impact of Cyclic Loading on Chloride Diffusivity and Mechanical Performance of RC Beams under Seawater Corrosion

    Directory of Open Access Journals (Sweden)

    Sen Pang

    2017-01-01

    Full Text Available An experimental study was conducted to investigate the impact of cyclic loading on the mechanical performance and chloride diffusivity of RC beams exposed to seawater wet-dry cycles. To induce initial damage to RC beam specimen, cyclic loading controlled by max load and cycles was applied. Then beam specimens underwent 240 wet-dry cycles of seawater. Results show that the chloride content increased as max load and cycle increased. The chloride content at steel surface increased approximatively linearly as average crack width increased. Moreover, the max load had more influence on chloride content at steel surface than cycle. The difference of average chloride diffusion coefficient between tension and compression concrete was little at uncracked position. Average chloride diffusion coefficient increased as crack width increased when crack width was less than 0.11 mm whereas the increasing tendency was weak when crack width exceeded 0.11 mm. The residual yield load and ultimate load of RC beams decreased as max load and cycle increased. Based on univariate analysis of variance, the max load had more adverse effect on yield load and ultimate load than cycle.

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

    Science.gov (United States)

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

    2017-08-01

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

  8. A Novel Image Encryption Scheme Based on Intertwining Chaotic Maps and RC4 Stream Cipher

    Science.gov (United States)

    Kumari, Manju; Gupta, Shailender

    2018-03-01

    As the systems are enabling us to transmit large chunks of data, both in the form of texts and images, there is a need to explore algorithms which can provide a higher security without increasing the time complexity significantly. This paper proposes an image encryption scheme which uses intertwining chaotic maps and RC4 stream cipher to encrypt/decrypt the images. The scheme employs chaotic map for the confusion stage and for generation of key for the RC4 cipher. The RC4 cipher uses this key to generate random sequences which are used to implement an efficient diffusion process. The algorithm is implemented in MATLAB-2016b and various performance metrics are used to evaluate its efficacy. The proposed scheme provides highly scrambled encrypted images and can resist statistical, differential and brute-force search attacks. The peak signal-to-noise ratio values are quite similar to other schemes, the entropy values are close to ideal. In addition, the scheme is very much practical since having lowest time complexity then its counterparts.

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

    Directory of Open Access Journals (Sweden)

    Syed Zubair Iman

    2016-01-01

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

  10. The IL-17F/IL-17RC Axis Promotes Respiratory Allergy in the Proximal Airways

    Directory of Open Access Journals (Sweden)

    Antonella De Luca

    2017-08-01

    Full Text Available The interleukin 17 (IL-17 cytokine and receptor family is central to antimicrobial resistance and inflammation in the lung. Mice lacking IL-17A, IL-17F, or the IL-17RA subunit were compared with wild-type mice for susceptibility to airway inflammation in models of infection and allergy. Signaling through IL-17RA was required for efficient microbial clearance and prevention of allergy; in the absence of IL-17RA, signaling through IL-17RC on epithelial cells, predominantly by IL-17F, significantly exacerbated lower airway Aspergillus or Pseudomonas infection and allergic airway inflammation. In contrast, following infection with the upper respiratory pathogen Staphylococcus aureus, the IL-17F/IL-17RC axis mediated protection. Thus, IL-17A and IL-17F exert distinct biological effects during pulmonary infection; the IL-17F/IL-17RC signaling axis has the potential to significantly worsen pathogen-associated inflammation of the lower respiratory tract in particular, and should be investigated further as a therapeutic target for treating pathological inflammation in the lung.

  11. Direct displacement-based design of special composite RC shear walls with steel boundary elements

    Directory of Open Access Journals (Sweden)

    H. Kazemi

    2016-06-01

    Full Text Available Special composite RC shear wall (CRCSW with steel boundary elements is a kind of lateral force resisting structural system which is used in earthquake-prone regions. Due to their high ductility and energy dissipation, CRCSWs have been widely used in recent years by structural engineers. However, there are few studies in the literature on the seismic design of such walls. Although there are many studies in the literature on the Direct Displacement-Based Design (DDBD of RC structures, however, no study can be found on DDBD of CRCSWs. Therefore, the aim of present study is to evaluate the ability of DDBD method for designing CRCSWs. In this study, four special composite reinforced concrete shear walls with steel boundary elements of 4, 8, 12 and 16 story numbers were designed using the DDBD method for target drift of 2%. The seismic behavior of the four CRCSWs was studied using nonlinear time-history dynamic analyses. Dynamic analyses were performed for the mentioned walls using 7 selected earthquake records. The seismic design parameters considered in this study includes: lateral displacement profile, inelastic dynamic inter-story drift demand, failure pattern and the composite RC shear walls overstrength factor. For each shear wall, the overall overstrength factor was calculated by dividing the ultimate dynamic base shear demand (Vu by the base shear demand (Vd as per the Direct Displacement Based-Design (DDBD method. The results show that the DDBD method can be used to design CRCSWs safely in seismic regions with predicted behavior.

  12. Prediction of the Fundamental Period of Infilled RC Frame Structures Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Panagiotis G. Asteris

    2016-01-01

    Full Text Available The fundamental period is one of the most critical parameters for the seismic design of structures. There are several literature approaches for its estimation which often conflict with each other, making their use questionable. Furthermore, the majority of these approaches do not take into account the presence of infill walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period. In the present paper, artificial neural networks (ANNs are used to predict the fundamental period of infilled reinforced concrete (RC structures. For the training and the validation of the ANN, a large data set is used based on a detailed investigation of the parameters that affect the fundamental period of RC structures. The comparison of the predicted values with analytical ones indicates the potential of using ANNs for the prediction of the fundamental period of infilled RC frame structures taking into account the crucial parameters that influence its value.

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

    Science.gov (United States)

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

    2017-01-01

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

  14. Assessment of Seismic Vulnerability of Steel and RC Moment Buildings Using HAZUS and Statistical Methodologies

    Directory of Open Access Journals (Sweden)

    Iman Mansouri

    2017-01-01

    Full Text Available Designer engineers have always the serious challenge regarding the choice of the kind of structures to use in the areas with significant seismic activities. Development of fragility curve provides an opportunity for designers to select a structure that will have the least fragility. This paper presents an investigation into the seismic vulnerability of both steel and reinforced concrete (RC moment frames using fragility curves obtained by HAZUS and statistical methodologies. Fragility curves are employed for several probability parameters. Fragility curves are used to assess several probability parameters. Furthermore, it examines whether the probability of the exceedence of the damage limit state is reduced as expected. Nonlinear dynamic analyses of five-, eight-, and twelve-story frames are carried out using Perform 3D. The definition of damage states is based on the descriptions provided by HAZUS, which gives the limit states and the associated interstory drift limits for structures. The fragility curves show that the HAZUS procedure reduces probability of damage, and this reduction is higher for RC frames. Generally, the RC frames have higher fragility compared to steel frames.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Jiho Moon

    2017-01-01

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

  17. Investigation of the fittest shear transfer model used to FEM analysis of RC structures

    International Nuclear Information System (INIS)

    Endo, Tatumi; Aoyagi, Masao; Endo, Takao

    1988-01-01

    In order to rationalize the design method of reinforced concrete (RC) structures in the nuclear power plant, the structural analysis, which is able to simulate the seismic behavior of RC structures, should be established. In this report, the investigation of shear transfer model at shear plane to be applied to FEM analysis is performed. Main conclusions obtained within the limit of the study are as follows. 1. Development of the shear transfer model at shear plane. 1) Two shear transfer models are developed to be used to the 2-dimensional nonlinear FEM analysis. 2) In one model suggested, reinforcements are modeled by plate elements and the nonlinearity of concrete surrounding reinforcement but the properties of bond-slip relation between concrete and reinforcements is also considered. 3) In another model, reinforcements are modeled by equivalent concrete properties, in which axial regidity and dowel effects of reinforcements are considered. 2. Verification of the suggested model. 1) It is confirmed that the computational results using the above-mentioned model could simulate the experimental ones fairly well. 2) Considering the application to the analysis of RC structures in the design, the model, in which reinforcement are modeled by equivalent concrete properties, is useful in view point of accuracy and simplicity. (author)

  18. Interfacial stresses in damaged RC beams strengthened with externally bonded CFRP plate

    International Nuclear Information System (INIS)

    Benrahou, K.H.; Adda bedia, E.A.; Benyoucef, S.; Tounsi, A.; Benguediab, M.

    2006-01-01

    A theoretical method to predict the interfacial stresses in the adhesive layer of damaged reinforced concrete beams strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) plate is presented. The adopted model is developed including the adherend shear deformations by assuming a linear shear stress through the depth of the RC beam [A. Tounsi, Int. J. Solids Struct., in press], while all existing solutions neglect this effect [e.g. S. Benyoucef, A. Tounsi, S.A. Meftah, E.A. Adda Bedia, Compos. Interfaces, in press; S.T. Smith, J.G. Teng, Eng. Struct. 23 (7) (2001) 857-871; T.M. Roberts, Struct. Eng. 67 (12) (1989) 229-233; A. Tounsi, S. Benyoucef, Int. J. Adhes. Adhes., in press; T. Stratford, J. Cadei, Construct. Building Mater. 20 (2006) 34-35]. In addition, in the present study the anisotropic damage model is adopted to describe the damage of the RC beams. It is shown that the damage has a significant effect on the interfacial stresses in FRP-damaged RC beam

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

    Science.gov (United States)

    Kalkan, E.; Yuksel, S.B.

    2008-01-01

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

  20. Identifying the public's concerns and the Centers for Disease Control and Prevention's reactions during a health crisis: An analysis of a Zika live Twitter chat.

    Science.gov (United States)

    Glowacki, Elizabeth M; Lazard, Allison J; Wilcox, Gary B; Mackert, Michael; Bernhardt, Jay M

    2016-12-01

    The arrival of the Zika virus in the United States caused much concern among the public because of its ease of transmission and serious consequences for pregnant women and their newborns. We conducted a text analysis to examine original tweets from the public and responses from the Centers for Disease Control and Prevention (CDC) during a live Twitter chat hosted by the CDC. Both the public and the CDC expressed concern about the spread of Zika virus, but the public showed more concern about the consequences it had for women and babies, whereas the CDC focused more on symptoms and education. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  1. Retrospective analysis of non-laboratory-based adverse drug reactions induced by intravenous radiocontrast agents in a Joint Commission International-accredited academic medical center hospital in China

    Directory of Open Access Journals (Sweden)

    Chen QL

    2017-04-01

    Full Text Available Qin-lan Chen,1 Xiao-ying Zhao,2 Xiao-mi Wang,1 Na Lv,2 Ling-ling Zhu,3 Hui-min Xu,4 Quan Zhou4 1Radiology Nursing Unit, Division of Nursing, 2Department of Quality Management, 3Geriatric VIP Care Ward, Division of Nursing, 4Department of Pharmacy, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China Abstract: The authors retrospectively analyzed the pattern and characteristics of non-laboratory-based adverse drug reactions (ADRs induced by intravenous radiocontrast agents in a large-scale hospital in China during 2014–2015. There were 314 ADR cases among 118,208 patients receiving enhanced CT or MRI examinations. The frequency of moderate/severe ADRs defined by Chinese Society of Radiology (ie, severe vomiting, systematic urticaria, facial swelling, dyspnea, vasovagal reaction, laryngeal edema, seizure, trembling, convulsions, unconsciousness, shock, death, and other unexpected adverse reactions was rare (0.0431%, whereas the mild ADRs were uncommon (0.2225% and accounted for 83.76% of ADRs. Frequency of ADRs induced by iodinated contrast agents was related with examination site, sex, and type of patient settings (P<0.01 and was higher compared with gadolinium contrast agents (0.3676% vs 0.0504%, P<0.01. From 2014 to 2015, frequencies of total and moderate/severe ADRs induced by iodinated contrast agents decreased significantly (0.4410% vs 0.2947%, P<0.01; 0.0960% vs 0.0282%, P<0.01, respectively. Frequency of ADRs differed among different iodinated contrast and gadolinium contrast (P<0.05 agents. Iopromide’s ADR frequency in 2014 was significantly higher compared with iopamidol, ioversol, or iohexol (P<0.01. Frequency of moderate/severe ADRs induced by iodixanol was 4.1–5.4 times that of iohexol, iopromide, or iopamidol. Rash was the predominant ADR subtype (84.39% and occurred more frequently with iodixanol compared with iohexol, iopamidol, or ioversol (P<0

  2. Theoretical studies of the nucleophilic substitution of halides and amine at a sulfonyl center.

    Science.gov (United States)

    Sung, Dae Dong; Kim, Tae Joon; Lee, Ikchoon

    2009-06-25

    Gas-phase nucleophilic substitution reactions, F(-) + CH(3)SO(2)F, Cl(-) + CH(3)SO(2)Cl, Cl(-) + CH(3)SO(2)F, and NH(3) + CH(3)SO(2)Cl, have been investigated at the B3LYP/6-311+G** and MP2/6-31+G* levels of theory. A very shallow well for the reaction intermediate in a triple-well potential energy surface (PES) was observed for the identity fluoride exchange, but double well PESs were obtained for the other three reactions with three different PES profiles. NBO analyses of the transition states showed substantial charge transfer interactions in all cases which provided a much larger amount of stabilization energy compared with the corresponding species at the carbon center of methyl halides. This difference is primarily caused by the strong electropositive nature of the sulfur center. The F-S-F axial linkage in the distorted TBP type intermediate in the identity fluoride exchange reaction exhibited a weak three-center, four-electron omega-bonding, which is considered to provide stability of the intermediate. All the reactant (RC) and product complexes (PC) have Cs symmetry. The symmetry plane bisects angles HCH (of methyl group), OSO (of sulfonyl group), and HNH (of ammonia). Vicinal charge transfer interactions between the two out-of-plane C-H, S-O, and N-H bonds provide extra stabilization to the ion-dipole complexes together with H-bond formation of in-plane H atom with the nucleophile and/or leaving group.

  3. A Program of Research and Education in Astronautics at the NASA Langley Research Center

    Science.gov (United States)

    Tolson, Robert H.

    2000-01-01

    The objectives of the Program were to conduct research at the NASA Langley Research Center in the area of astronautics and to provide a comprehensive education program at the Center leading to advanced degrees in Astronautics. We believe that the program has successfully met the objectives and has been of significant benefit to NASA LaRC, the GWU and the nation.

  4. Reaction dynamics of the four-centered elimination CH2OH + --> CHO + +H2: Measurement of kinetic energy release distribution and classical trajectory calculation

    Science.gov (United States)

    Lee, Tae Geol; Park, Seung C.; Kim, Myung Soo

    1996-03-01

    Mass-analyzed ion kinetic energy (MIKE) spectrum of CHO+ generated in the unimolecular dissociation of CH2OH+ was measured. Kinetic energy release distribution (KERD) was evaluated by analyzing the spectrum according to the algorithm developed previously. The average kinetic energy release evaluated from the distribution was extraordinarily large, 1.63 eV, corresponding to 75% of the reverse barrier of the reaction. A global analytical potential energy surface was constructed such that the experimental energetics was represented and that various features in the ab initio potential energy surface were closely reproduced. Classical trajectory calculation was carried out with the global analytical potential energy surface to investigate the causes for the extraordinarily large kinetic energy release. Based on the detailed dynamical calculations, it was found that the strained bending forces at the transition state and strengthening of the CO bond from double to triple bond character were mainly responsible for such a significant kinetic energy release. In addition, the dissociation products H2 and CHO+ ion were found to be rotationally excited in the trajectory calculations. This was attributed to the asymmetry of the transition state and the release of asymmetric bending forces. Also, the bending vibrational modes of CHO+ and the H2 stretching mode, which are coupled with the bending coordinates, were found to be moderately excited.

  5. Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, W.D.

    2009-09-02

    This report summarizes research conducted in conjunction with a project entitled “Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center”, which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2.

  6. CD45RC isoform expression identifies functionally distinct T cell subsets differentially distributed between healthy individuals and AAV patients.

    Directory of Open Access Journals (Sweden)

    Laurence Ordonez

    Full Text Available In animal models of anti-neutrophil cytoplasmic antibody (ANCA-associated vasculitis (AAV, the proportion of CD45RC T cell subsets is important for disease susceptibility. Their human counterparts are, however, functionally ill defined. In this report, we studied their distribution in healthy controls (HC, AAV patients and in Systemic lupus erythematous (SLE patients as disease controls. We showed that CD45RC expression level on human CD4 and CD8 T cells identifies subsets that are highly variable among individuals. Interestingly, AAV patients exhibit an increased proportion of CD45RC(low CD4 T cells as compared to HC and SLE patients. This increase is stable over time and independent of AAV subtype, ANCA specificity, disease duration, or number of relapses. We also analyzed the cytokine profile of purified CD4 and CD8 CD45RC T cell subsets from HC, after stimulation with anti-CD3 and anti-CD28 mAbs. The CD45RC subsets exhibit different cytokine profiles. Type-1 cytokines (IL-2, IFN-gamma and TNF-alpha were produced by all CD45RC T cell subsets, while the production of IL-17, type-2 (IL-4, IL-5 and regulatory (IL-10 cytokines was restricted to the CD45RC(low subset. In conclusion, we have shown that CD45RC expression divides human T cells in functionally distinct subsets that are imbalanced in AAV. Since this imbalance is stable over time and independent of several disease parameters, we hypothesize that this is a pre-existing immune abnormality involved in the etiology of AAV.

  7. Structural studies on reaction centers from thermophilic photosynthetic bacteria and its functional utilizations. Tainetsusei kogosei saikin ni yuraisuru kogosei hanno chushin no kozo kaimei to kino kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, T; Morishita, Y; Kobayashi, M; Kanno, S [Tohoku University, Sendai (Japan). Faculty of Engineering

    1992-10-31

    This paper describes the results of the experiment in which crystallization of protein of reactive center purified from the photosynthetic film of thermophilic purple sulfur photosynthetic bacterium Chromatium tepidum whose hyrogen donor in photosynthesis is H2S instead of H2O was attempted. Crystallization was carried out by the vapor diffusion method and particularly by using ethylene glycol as precipitator at 4[degree]C after various investigations on the conditions of crystallization. By X-ray diffraction, this crystal was found to belong to the rhombic system, and it was estimated that the lattice constants, a, b, c equal to 140[angstrom], 190[angstrom] and 80[angstrom] respectively. This bacterium is a thermophilic bacterium having the optimum growth temperature of 48-50 [degree]C and utilizes CO2 or H2CO3 as corbon source, ammonium, urea etc. as nitrogen source and thiosulfate as sulfur source. Moreover, another purpose of this investigation was to determine the thermophilic location by elucidating its configuration (although, as a result, the analysis of configuration had no sufficient resolution). It was confirmed that the enzyme system of photosynthetic film and its cytoplasm obtained by ultrasonic spallation of this cell have CO2 fixing activity utilizing light energy. 23 refs., 14 figs., 3 tabs.

  8. Concurrent validity and reliability of using ground reaction force and center of pressure parameters in the determination of leg movement initiation during single leg lift.

    Science.gov (United States)

    Aldabe, Daniela; de Castro, Marcelo Peduzzi; Milosavljevic, Stephan; Bussey, Melanie Dawn

    2016-09-01

    Postural adjustment evaluations during single leg lift requires the initiation of heel lift (T1) identification. T1 measured by means of motion analyses system is the most reliable approach. However, this method involves considerable workspace, expensive cameras, and time processing data and setting up laboratory. The use of ground reaction forces (GRF) and centre of pressure (COP) data is an alternative method as its data processing and setting up is less time consuming. Further, kinetic data is normally collected using frequency samples higher than 1000Hz whereas kinematic data are commonly captured using 50-200Hz. This study describes the concurrent-validity and reliability of GRF and COP measurements in determining T1, using a motion analysis system as reference standard. Kinematic and kinetic data during single leg lift were collected from ten participants. GRF and COP data were collected using one and two force plates. Displacement of a single heel marker was captured by means of ten Vicon(©) cameras. Kinetic and kinematic data were collected using a sample frequency of 1000Hz. Data were analysed in two stages: identification of key events in the kinetic data, and assessing concurrent validity of T1 based on the chosen key events with T1 provided by the kinematic data. The key event presenting the least systematic bias, along with a narrow 95% CI and limits of agreement against the reference standard T1, was the Baseline COPy event. Baseline COPy event was obtained using one force plate and presented excellent between-tester reliability. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Loss Characteristics of 6.5 kV RC-IGBT Applied to a Traction Converter

    Directory of Open Access Journals (Sweden)

    Xianjin Huang

    2017-07-01

    Full Text Available 6.5 kV level IGBT (Insulated Gate Bipolar Transistor modules are widely applied in megawatt locomotive (MCUs traction converters, to achieve an upper 3.5 kV DC link, which is beneficial for decreasing power losses and increasing the power density. Reverse Conducting IGBT (RC-IGBT constructs the conventional IGBT function and freewheel diode function in a single chip, which has a greater flow ability in the same package volume. In the same cooling conditions, RC-IGBT allows for a higher operating temperature. In this paper, a mathematic model is developed, referring to the datasheets and measurement data, to study the 6.5 kV/1000 A RC-IGBT switching features. The relationship among the gate desaturated pulse, conducting losses, and recovery losses is discussed. Simulations and tests were carried out to consider the influence of total losses on the different amplitudes and durations of the desaturated pulse. The RC-IGBT traction converter system with gate pulse desaturated control is built, and the simulation and measurements show that the total losses of RC-IGBT with desaturated control decreased comparing to the RC-IGBT without desaturated control or conventional IGBT. Finally, a proportional small power platform is developed, and the test results prove the correction of the theory analysis.

  10. Retrospective analysis of multiplex polymerase chain reaction-based molecular diagnostics (SES in 70 patients with suspected central nervous system infections: A single-center study

    Directory of Open Access Journals (Sweden)

    Rama Krishnan Tiruppur Chinnappan Ramalingam

    2016-01-01

    Full Text Available Background: Central nervous system (CNS infections present a grave health care challenge due to high morbidity and mortality. Clinical findings and conventional laboratory assessments are not sufficiently distinct for specific etiologic diagnosis. Identification of pathogens is a key to appropriate therapy. Aim: In this retrospective observational study, we evaluated the efficacy and clinical utility of syndrome evaluation system (SES for diagnosing clinically suspected CNS infections. Materials and Methods: This retrospective analysis included inpatients in our tertiary level neurointensive care unit (NICU and ward from February 2010 to December 2013. Cerebrospinal fluid (CSF samples of 70 patients, clinically suspected of having CNS infections, were subjected to routine laboratory tests, culture, imaging, and SES. We analyzed the efficacy of SES in the diagnosis of CNS infections and its utility in therapeutic decision-making. Results: SES had a clinical sensitivity of 57.4% and clinical specificity of 95.6%. Streptococcus pneumoniae and Pseudomonas aeruginosa were the top two bacterial pathogens, whereas Herpes simplex virus (HSV was the most common viral pathogen. Polymicrobial infections were detected in 32.14% of SES-positive cases. SES elicited a change in the management in 30% of the patients from initial empiric therapy. At discharge, 51 patients recovered fully while 11 patients had partial recovery. Three-month follow-up showed only six patients to have neurological deficits. Conclusion: In a tertiary care center, etiological microbial diagnosis is central to appropriate therapy and outcomes. Sensitive and accurate multiplex molecular diagnostics play a critical role in not only identifying the causative pathogen but also in helping clinicians to institute appropriate therapy, reduce overuse of antimicrobials, and ensure superior clinical outcomes.

  11. Retrospective analysis of multiplex polymerase chain reaction-based molecular diagnostics (SES) in 70 patients with suspected central nervous system infections: A single-center study.

    Science.gov (United States)

    Ramalingam, Rama Krishnan Tiruppur Chinnappan; Chakraborty, Dipanjan

    2016-01-01

    Central nervous system (CNS) infections present a grave health care challenge due to high morbidity and mortality. Clinical findings and conventional laboratory assessments are not sufficiently distinct for specific etiologic diagnosis. Identification of pathogens is a key to appropriate therapy. In this retrospective observational study, we evaluated the efficacy and clinical utility of syndrome evaluation system (SES) for diagnosing clinically suspected CNS infections. This retrospective analysis included inpatients in our tertiary level neurointensive care unit (NICU) and ward from February 2010 to December 2013. Cerebrospinal fluid (CSF) samples of 70 patients, clinically suspected of having CNS infections, were subjected to routine laboratory tests, culture, imaging, and SES. We analyzed the efficacy of SES in the diagnosis of CNS infections and its utility in therapeutic decision-making. SES had a clinical sensitivity of 57.4% and clinical specificity of 95.6%. Streptococcus pneumoniae and Pseudomonas aeruginosa were the top two bacterial pathogens, whereas Herpes simplex virus (HSV) was the most common viral pathogen. Polymicrobial infections were detected in 32.14% of SES-positive cases. SES elicited a change in the management in 30% of the patients from initial empiric therapy. At discharge, 51 patients recovered fully while 11 patients had partial recovery. Three-month follow-up showed only six patients to have neurological deficits. In a tertiary care center, etiological microbial diagnosis is central to appropriate therapy and outcomes. Sensitive and accurate multiplex molecular diagnostics play a critical role in not only identifying the causative pathogen but also in helping clinicians to institute appropriate therapy, reduce overuse of antimicrobials, and ensure superior clinical outcomes.

  12. Two-center three-electron bonding in ClNH{sub 3} revealed via helium droplet infrared laser Stark spectroscopy: Entrance channel complex along the Cl + NH{sub 3} → ClNH{sub 2} + H reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Christopher P.; Douberly, Gary E., E-mail: douberly@uga.edu [Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556 (United States); Xie, Changjian; Guo, Hua [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Kaufmann, Matin [Department of Physical Chemistry II, Ruhr-University Bochum, D-44801 Bochum (Germany)

    2016-04-28

    Pyrolytic dissociation of Cl{sub 2} is employed to dope helium droplets with single Cl atoms. Sequential addition of NH{sub 3} to Cl-doped droplets leads to the formation of a complex residing in the entry valley to the substitution reaction Cl + NH{sub 3} → ClNH{sub 2} + H. Infrared Stark spectroscopy in the NH stretching region reveals symmetric and antisymmetric vibrations of a C{sub 3v} symmetric top. Frequency shifts from NH{sub 3} and dipole moment measurements are consistent with a ClNH{sub 3} complex containing a relatively strong two-center three-electron (2c–3e) bond. The nature of the 2c–3e bonding in ClNH{sub 3} is explored computationally and found to be consistent with the complexation-induced blue shifts observed experimentally. Computations of interconversion pathways reveal nearly barrierless routes to the formation of this complex, consistent with the absence in experimental spectra of two other complexes, NH{sub 3}Cl and Cl–HNH{sub 2}, which are predicted in the entry valley to the hydrogen abstraction reaction Cl + NH{sub 3} → HCl + NH{sub 2}.

  13. RC-3095, a Selective Gastrin-Releasing Peptide Receptor Antagonist, Does Not Protect the Lungs in an Experimental Model of Lung Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Vera L. Oliveira-Freitas

    2015-01-01

    Full Text Available RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR, RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P<0.001. The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P=0.005. Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P<0.013. No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β (P=0.159 and TNF-α (P=0.260, as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis.

  14. Design issues and cost implications of RTO/RC-ITER divertor

    International Nuclear Information System (INIS)

    Ibbott, C.; Antipenkov, A.; Chiocchio, S.; Federici, G.; Heidl, H.; Janeschitz, G.; Martin, E.; Tivey, R.

    2000-01-01

    This paper reports on the conceptual divertor design developed for the reduced technical objectives/reduced cost-international thermonuclear experimental reactor (RTO/RC-ITER). The cost drivers are discussed and a number of cost-reducing measures identified. Scaled costs, based on industrial estimates of the 1998 ITER design (Technical Basis for the ITER Final Design Report, Cost Review and Safety Analysis (FDR). ITER EDA Documentation Series No. 16. IAEA, Vienna, 1998), give for the RTO/RC-ITER ∼60% of the FDR costs. Plasma facing components (PFCs) account for 75% of the total divertor costs. Hence, PFC design simplifications are outlined in the paper showing the possibility of achieving a cost reduction of 50%. The design proposals, outlined in the paper, focus on minimising the number of sub-components and simplifying the manufacturing cycle. These changes contribute to improved reliability based on a more robust coolant design layout. The reduced space allocated to the divertor (G. Janeschitz, A. Antipenkov, V. Barabash, S. Chiocchio, G. Federici, C. Ibbott, E. Martin, R. Tivey, Overview of the Divertor Design and its Integration into RTO/RC-ITER, this conference) requires changes to the design that minimise the cassette body thickness, relocate the cassette attachments and revise the remote handling philosophy. Results of supporting electro-magnetic, neutron shielding, thermo-hydraulic and pumping conductance analyses are reported, qualifying the cassette design. A reduction in the coolant inlet temperature to 100-120 deg. C is discussed in terms of thermal-hydraulic performance and fatigue life of the heat sink. Finally, an R and D plan sets out the work needed: (1) to develop the cost saving measures of the new design; and (2) to demonstrate the reliability of the chosen technologies

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

    Directory of Open Access Journals (Sweden)

    Yuri Ariyanto

    2009-01-01

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

  16. Effect of web openings on the structural behavior of RC beams subjected to pure torsion

    Directory of Open Access Journals (Sweden)

    Abdo Taha

    2017-01-01

    Full Text Available In the construction of modern buildings, the presence of openings became a necessity nowadays in order to accommodate the many pipes and ducts required for the different services. On the other hand, the presence of these openings in RC beams affects their structural behavior. One important behavior that needs further study would be torsion. Currently, there are no guide lines available to analyze or design RC beams with web openings under pure torsion. Thus, the main objective of this research is to investigate the behavior of simply supported RC beams with openings subjected to pure torsion. In the first part of this paper, an experimental study is conducted on seven beams subjected to pure torsion loading in order to investigate the effect of the number of openings, the spacing between stirrups, and beam depth. All beams have a constant clear span length of 1800 mm and a constant beam width of 150 mm. The beams have varying opening number and stirrups arrangement as well as varying beam depth in order to investigate the effect of these parameters on the behavior of the beams. Systematic measurements such as the cracking torque, the ultimate torque, the angle of rotation of the beam at cracking, and the angle of rotation of the beam at the ultimate load are conducted for further understanding of the beam behavior under torsion. In the second part of the paper, the experimental results are compared with the numerical results obtained using the non-linear finite element analysis program, ANSYS. Good agreement between the experimental and numerical results is found.

  17. Biochemical and Molecular Characterization of RcSUS1, a Cytosolic Sucrose Synthase Phosphorylated in Vivo at Serine 11 in Developing Castor Oil Seeds*

    Science.gov (United States)

    Fedosejevs, Eric T.; Ying, Sheng; Park, Joonho; Anderson, Erin M.; Mullen, Robert T.; She, Yi-Min; Plaxton, William C.

    2014-01-01

    Sucrose synthase (SUS) catalyzes the UDP-dependent cleavage of sucrose into UDP-glucose and fructose and has become an important target for improving seed crops via metabolic engineering. A UDP-specific SUS homotetramer composed of 93-kDa subunits was purified to homogeneity from the triacylglyceride-rich endosperm of developing castor oil seeds (COS) and identified as RcSUS1 by mass spectrometry. RcSUS1 transcripts peaked during early development, whereas levels of SUS activity and immunoreactive 93-kDa SUS polypeptides maximized during mid-development, becoming undetectable in fully mature COS. The cytosolic location of the enzyme was established following transient expression of RcSUS1-enhanced YFP in tobacco suspension cells and fluorescence microscopy. Immunological studies using anti-phosphosite-specific antibodies revealed dynamic and high stoichiometric in vivo phosphorylation of RcSUS1 at its conserved Ser-11 residue during COS development. Incorporation of 32Pi from [γ-32P]ATP into a RcSUS1 peptide substrate, alongside a phosphosite-specific ELISA assay, established the presence of calcium-dependent RcSUS1 (Ser-11) kinase activity. Approximately 10% of RcSUS1 was associated with COS microsomal membranes and was hypophosphorylated relative to the remainder of RcSUS1 that partitioned into the soluble, cytosolic fraction. Elimination of sucrose supply caused by excision of intact pods of developing COS abolished RcSUS1 transcription while triggering the progressive dephosphorylation of RcSUS1 in planta. This did not influence the proportion of RcSUS1 associated with microsomal membranes but instead correlated with a subsequent marked decline in SUS activity and immunoreactive RcSUS1 polypeptides. Phosphorylation at Ser-11 appears to protect RcSUS1 from proteolysis, rather than influence its kinetic properties or partitioning between the soluble cytosol and microsomal membranes. PMID:25313400

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

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

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

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

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

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

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

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

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

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

    Directory of Open Access Journals (Sweden)

    P.A. De Sousa

    2016-03-01

    Full Text Available The human embryonic stem cell line RCe012-A (RC-8 was derived from a frozen and thawed day 5 embryo cultivated to the blastocyst stage. The embryo was voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyotype and microsatellite PCR identity, HLA and blood group typing data is available.

  2. Overview of the divertor design and its integration into RTO/RC-ITER

    International Nuclear Information System (INIS)

    Janeschitz, G.; Tivey, R.; Antipenkov, A.; Barabash, V.; Chiocchio, S.; Federici, G.; Heidl, H.; Ibbott, C.; Martin, E.

    2000-01-01

    The design of the divertor and its integration into the reduced technical objectives/reduced cost-international thermonuclear energy reactor (RTO/RC-ITER) is based on the experience gained from the 1998 design of international thermonuclear energy reactor (ITER) and on the research and development performed throughout the engineering design activities (EDA). This paper gives an overview of the layout and functional design of the RTO/RC-ITER divertor, including the integration into the machine and the remote replacement of the divertor cassettes. Design guidelines are presented which have allowed quick preparation of divertor layouts suitable for further study using the B2-EIRENE edge plasma code. As in the 1998 design, the divertor is segmented into cassettes, and the segmentation, which is three per sector, is driven by access through the divertor level ports. Maintaining this access and avoiding interference with poloidal field coils means that the divertor level ports need to be inclined (7 deg.). This opens up the possibility of incorporating inboard and outboard baffles into the divertor cassettes. The cassettes are transported in-vessel by making use of the toroidal rails onto which the cassettes are finally clamped in position. Significant reduction of the space available between the X-point and the vacuum vessel results in re-positioning of the toroidal rails in order to retain sufficient depth for the inner and outer divertor legs. This, in turn, requires some changes to the remote handling (RH) concept. Remote handling (RH) is now based on using a cantilevered articulated gripper during the radial movement of the cassettes inside the RH ports. However, the principle to use a cassette toroidal mover (CTM) for in vessel handling is unchanged, hence maintaining the validity of previous EDA research and development. The space previously left below the cassettes for RH was also used for pumping. Elimination of this space has led to re-siting of the pumping

  3. Vibration based structural assessment of the rehabilitation intervention in r.c. segmental bridge

    OpenAIRE

    Franchetti Paolo; Frizzarin Michele; Leonardi Andrea; Zeni Fabio

    2015-01-01

    A vibration based structural assessment campaign was carried out on a r.c. segmental bridge in North East Italy. The bridge has a cantilever static scheme, fixed at the top of the piers and with a hinge at the centre of the span. The particular configuration of the hinge consists in a couple of steel elements, each one composed by a tongue and groove joint. Since the year 1960, the hinge was subjected to consumption and degradation, that caused a malfunctioning of the device. An intervention ...

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    the arrival of the first earthquake from non-destructive vibration tests or via structural analysis. The previous excitation and displacement response time series is employed for the identification of the instantaneous softening using an ARMA model. The hysteresis parameters are updated after each earthquake....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

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

    DEFF Research Database (Denmark)

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

    1994-01-01

    the arrival of the first earthquake from non-destructive vibration tests or via structural analysis. The previous excitation and displacement response time series is employed for the identification of the instantaneous softening using an ARMA model. The hysteresis parameters are updated after each earthquake....... The proposed model is next generalized for the MDOF system. Using the adapted models for the structure and the global damage state, the global damage in a future earthquake can then be estimated when a suitable earthquake model is applied. The performance of the model is illustrated on RC frames which were...

  6. Human geminin promotes pre-RC formation and DNA replication by stabilizing CDT1 in mitosis

    DEFF Research Database (Denmark)

    Ballabeni, Andrea; Melixetian, Marina; Zamponi, Raffaella

    2004-01-01

    -mediated degradation by inhibiting its ubiquitination. In particular, Geminin ensures basal levels of CDT1 during S phase and its accumulation during mitosis. Consistently, inhibition of Geminin synthesis during M phase leads to impairment of pre-RC formation and DNA replication during the following cell cycle....... Moreover, we show that inhibition of CDK1 during mitosis, and not Geminin depletion, is sufficient for premature formation of pre-RCs, indicating that CDK activity is the major mitotic inhibitor of licensing in human cells. Taken together with recent data from our laboratory, our results demonstrate...

  7. A numerical design approach for single amplifier, Active-RC Butterworth filter of order 5

    OpenAIRE

    Gaunholt, Hans

    2007-01-01

    A design method is presented for the design of all pole lowpass active-RC filters applying operational amplifiers. The operational amplifier model used is the integrator model: omegat/s where omegat is the unity gain frequency. The design method is used for the design of a fifth order Butterworth filter applying just one operational amplifier coupled as a unity gain amplifier. It is shown that the influence from the real operational amplifier may be reduced by trimming just one resistor in th...

  8. AERODYNAMIC CHARACTERISTICS CALCULATION ON SINGLE ROTOR BLADE USING FLOEFD, ANSYS FLUENT AND RC-VTOL

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The results of computational simulation of helicopter rotor's single blade flow, for which experimental (model test data are published, are represented in this article. The calculations were made in the universal software package of CFD modeling FloEFD, which was based on the solution of averaged equations' system of Navier-Stocks, as well as in the program software RC-VTOL using the vortex method. The obtained results are compared with experimental data and modeling results in the program software ANSYS Fluent (license of TsAGI Nr. 501024. The work shows satisfactory, and in some cases good calculation data reconciliation getting with different techniques including experimental.

  9. Together with Research Centers and Universities

    Directory of Open Access Journals (Sweden)

    Nuno Domingos Garrido

    2016-10-01

    Full Text Available The Journal Motricidade has always been walking in parallel with the scientific communities. We found that the affiliation of most authors has, nearly always, a University (Uni or a Research Center (RC. In fact it is almost impossible to conduct research outside these two universes. In this sense, Uni and RC feed the most, if not all, of scientific journals worldwide. By this I mean that is in the interest of Motricidade to be associated with high-quality RC and Uni equally recognized. With regard to RC, Motricidade will publish this year a supplement of the International Congress of Research Centre in Sports Sciences, Health Sciences and Human Development (CIDESD. This RC has conducted research in a variety of areas within the Sport Sciences and Health and always with high recognition and associated publications. It was not by chance that this RC was evaluated with ‘very good’ by the Portuguese Foundation for Science and Technology (FCT panel and has been granted funding. This Congress, which takes place every two years, targets to converge research and high level practices within these three areas: Sports, Health and Human Development. The 2016 CIDESD edition is dedicated to "Exercise and Health, Sports and Human Development" and will be held at the University of Évora, between 11 and 12 November of 2016. The readers can check the program in the following link http://gdoc.uevora.pt/450120 and get more information in the Congress Site available at http://www.cidesd2016.uevora.pt/. With regard to Uni, Motricidade signed a cooperation protocol with the University of Beira Interior (UBI in May of 2016, involving the development and dissemination of scientific knowledge in Sports Sciences, Psychology, Human Development and Health. At the present, UBI hosts more than 6,000 students spread across five faculties - Arts & Letters, Sciences, Health Sciences, Humanities and Social Sciences and Engineering. When looking at the rankings, for instance

  10. Development of a hysteresis model for R/C columns subjected to bi-axial lateral loading

    International Nuclear Information System (INIS)

    Dutta, Sekhar Chandra; Chowdhury, Rajib; Roy, Raghupati; Reddy, G. Rami

    2003-01-01

    Recent investigations on dynamic response of reinforced concrete (R/C) structures have confirmed that the R/C structural members undergo much more inelastic deformation in each of the two mutually perpendicular directions under bi-directional seismic loading, than that observed only under unidirectional ground motion. To predict the seismic response of R/C structure with fair accuracy demands, a faithful model that can incorporate the effect of biaxial bending interaction in column. This model should not have high computational demand but should adequately reflect the stiffness degrading and strength deterioration characteristics of R/C structural members. Present study is an effort to develop such a bi-directional hysteresis model accounting the effect of interaction between lateral loadings in two orthogonal directions. The development of the present model is based on the yield surface approach and it can incorporate both strength and stiffness degradation characteristics, which is unavoidable in R/C structures during cyclic loading. The performance of the proposed model/ is demonstrated through the prediction of available experimental results of a reinforced concrete column, subjected to biaxial loading. (author)

  11. Lactobacillus rhamnosus RC007 intended for feed additive: immune-stimulatory properties and ameliorating effects on TNBS-induced colitis.

    Science.gov (United States)

    Dogi, C; García, G; De Moreno de LeBlanc, A; Greco, C; Cavaglieri, L

    2016-09-01

    Lactobacillus rhamnosus RC007 is a potential probiotic bacterium that can exert beneficial effects as supplement for animal feed, by improving the immune status in healthy host, and by providing therapeutic benefits to infected/inflamed animals. The aim of the present work was to evaluate in vivo the beneficial properties of L. rhamnosus RC007, intended for animal feed, when administered to healthy and trinitro-benzene-sulfonic-acid (TNBS) colitis induced BALB/c mice. The administration of L. rhamnosus RC007 to healthy mice during 10 days increased the phagocytic activity of peritoneal macrophages and the number of immunoglobulin A+ cells in the lamina proper of the small intestine. Significant increases of monocyte chemotactic protein 1, interleukin (IL)-10 and tumour necrosis factor alpha (TNF-α) concentrations, and in the ratio between anti- and pro-inflammatory cytokines (IL-10/TNF-α) were observed in intestinal fluids after administration of bacteria. In the inflammation model, less body weight loss, macroscopic and histological damages in the large intestine were accompanied by increased IL-10/TNF-α ratio in the intestinal fluids of mice from the L. rhamnosus-TNBS group when compared to the TNBS group. In a healthy host, the oral administration of L. rhamnosus RC007 kept the gut immune system stimulated allowing a faster response to noxious stimulus. Mice that received L. rhamnosus RC007 also decreased the severity of the intestinal inflammation.

  12. Fuel cycle design evolution from FDR-ITER to RTO/RC-ITER

    International Nuclear Information System (INIS)

    Murdoch, D.K.; Glugla, M.; Kveton, O.

    2000-01-01

    Instantaneous fuelling and plasma exhaust flow rates for the reduced technical objective/reduced cost version of International Thermonuclear Experimental Reactor (RTO/RC-ITER) are similar to those described in the Final Design Report (FDR) of ITER, despite the reduction in fusion power by a factor of about two. However, the reduced pulse length and the lower fraction of campaign time spent in burn mode, together with the lower integrated operating lifetime proposed, will generate cost savings in several systems of the fuel cycle. As the quantity of tritium handled per pulse is now smaller, this could be buffered, allowing systems in the tritium plant still to operate in steady state mode as in the FDR design, thereby increasing the potential for downsizing of system capacities. The lower operating time fraction will increase performance margins for some systems, for example, the Torus Exhaust Gas Processing System (TEGPS) which was designed to meet a specified daily release rate for the FDR design conditions which were more onerous than RTO/RC-ITER. As no break through of tritium into cooling water is now expected, the duties of the Water and Atmosphere Detritiation Systems are considerably reduced, and design concepts which are simpler, cheaper and more amenable to modular implementation can be adopted

  13. Shear Resistance Capacity of Interface of Plate-Studs Connection between CFST Column and RC Beam

    Directory of Open Access Journals (Sweden)

    Qianqian Wang

    2017-01-01

    Full Text Available The combination of a concrete-filled steel tube (CFST column and reinforced concrete (RC beam produces a composite structural system that affords good structural performance, functionality, and workability. The effective transmission of moments and shear forces from the beam to the column is key to the full exploitation of the structural performance. The studs of the composite beam transfer the interfacial shear force between the steel beam and the concrete slab, with the web bearing most of the vertical shear force of the steel beam. In this study, the studs and vertical steel plate were welded to facilitate the transfer of the interfacial shear force between the RC beam and CFST column. Six groups of a total of 18 specimens were used to investigate the shear transfer mechanism and failure mode of the plate-studs connection, which was confirmed to effectively transmit the shear forces between the beam and column. The results of theoretical calculations were also observed to be in good agreement with the experimental measurements.

  14. A More Sustainable Way for Producing RC Sandwich Panels On-Site and in Developing Countries

    Directory of Open Access Journals (Sweden)

    Lorenzo Graziani

    2017-03-01

    Full Text Available The purpose of this work is to assess if traditionally used welded connectors for joining the two skins of reinforced concrete (RC sandwich panels, used as structural walls and horizontal structural elements, can be substituted with bent ones. In this way, the scope of the effort is to reduce drastically the energy required during manufacturing, thus having a much more sustainable building product. Wire mesh on site production, in fact, requires a large amount of energy for the welding process, as stated by several Environmental Product Declaration (EPD. In addition, the production of sandwich panels with bent connectors requires a low level of automation and no qualified labor allowing the diffusion in developing countries. The procedures used to execute the work were both experimental and numerical. Structural performances were examined by testing full-scale sandwich panels under (axial and eccentric compression and flexural loads. Additionally, a Finite Element (FE study was developed to investigate and to optimize the dimension of welded mesh and the number of connectors. The major findings show that it is possible to substitute welded connectors with bent ones without compromising the structural performance of the tested RC sandwich panels, thus having a more sustainable way for producing these last ones.

  15. Quasistatic Seismic Damage Indicators for RC Structures from Dissipating Energies in Tangential Subspaces

    Directory of Open Access Journals (Sweden)

    Wilfried B. Krätzig

    2014-01-01

    Full Text Available This paper applies recent research on structural damage description to earthquake-resistant design concepts. Based on the primary design aim of life safety, this work adopts the necessity of additional protection aims for property, installation, and equipment. This requires the definition of damage indicators, which are able to quantify the arising structural damage. As in present design, it applies nonlinear quasistatic (pushover concepts due to code provisions as simplified dynamic design tools. Substituting so nonlinear time-history analyses, seismic low-cycle fatigue of RC structures is approximated in similar manner. The treatment will be embedded into a finite element environment, and the tangential stiffness matrix KT in tangential subspaces then is identified as the most general entry for structural damage information. Its spectra of eigenvalues λi or natural frequencies ωi of the structure serve to derive damage indicators Di, applicable to quasistatic evaluation of seismic damage. Because det KT=0 denotes structural failure, such damage indicators range from virgin situation Di=0 to failure Di=1 and thus correspond with Fema proposals on performance-based seismic design. Finally, the developed concept is checked by reanalyses of two experimentally investigated RC frames.

  16. 3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

    Directory of Open Access Journals (Sweden)

    Francesco Bencardino

    2016-05-01

    Full Text Available The purpose of this study is to evaluate, through a nonlinear Finite Element (FE analysis, the structural behavior of Reinforced Concrete (RC beams externally strengthened by using Steel Reinforced Grout (SRG and Steel Reinforced Polymer (SRP systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

  17. Prediction of RC multi-story construction performance with a new proposed design spectrum approach

    Directory of Open Access Journals (Sweden)

    James Haido

    2016-02-01

    Full Text Available The consideration of novel response spectrum analysis to check the reinforced concrete RC buildings resistance towards the seismic risks in Iraq has not been investigated so far. Due to the increasing of frequent earthquakes with moderate intensity in north of Iraq, caution should be taken into account in building design especially with considering the design codes. Where, there are no specific Iraqi standards of earthquake for building design. Thus, the proposing of new response spectrum relationship matching the properties of Kurdistan region (north of Iraq soil is considered essential with considering of novel stiffness or inertia reduction factors for concrete sections. Present endeavor is devoted to develop new design spectra dynamic analysis of RC multistory building located in Duhok city-Iraq. Influence of proposed concrete section reduction factors on the analysis outcomes has been investigated also. Great role has been observed for introducing of stiffness reduction factors in present seismic analysis represent in magnifying of lateral deformation of building of more than 50%. Proper matching was obtained between current proposed spectrum design outputs and that for other analytical approaches.

  18. RC beams shear-strengthened with fabric-reinforced-cementitious-matrix (FRCM) composite

    Science.gov (United States)

    Loreto, Giovanni; Babaeidarabad, Saman; Leardini, Lorenzo; Nanni, Antonio

    2015-12-01

    The interest in retrofit/rehabilitation of existing concrete structures has increased due to degradation and/or introduction of more stringent design requirements. Among the externally-bonded strengthening systems fiber-reinforced polymers is the most widely known technology. Despite its effectiveness as a material system, the presence of an organic binder has some drawbacks that could be addressed by using in its place a cementitious binder as in fabric-reinforced cementitious matrix (FRCM) systems. The purpose of this paper is to evaluate the behavior of reinforced concrete (RC) beams strengthened in shear with U-wraps made of FRCM. An extensive experimental program was undertaken in order to understand and characterize this composite when used as a strengthening system. The laboratory results demonstrate the technical viability of FRCM for shear strengthening of RC beams. Based on the experimental and analytical results, FRCM increases shear strength but not proportionally to the number of fabric plies installed. On the other hand, FRCM failure modes are related with a high consistency to the amount of external reinforcement applied. Design considerations based on the algorithms proposed by ACI guidelines are also provided.

  19. Interaction between corrosion crack width and steel loss in RC beams corroded under load

    International Nuclear Information System (INIS)

    Malumbela, Goitseone; Alexander, Mark; Moyo, Pilate

    2010-01-01

    This paper presents results and discussions on an experimental study conducted to relate the rate of widening of corrosion cracks with the pattern of corrosion cracks as well as the level of steel corrosion for RC beams (153 x 254 x 3000 mm) that were corroded whilst subjected to varying levels of sustained loads. Steel corrosion was limited to the tensile reinforcement and to a length of 700 mm at the centre of the beams. The rate of widening of corrosion cracks as well as strains on uncracked faces of RC beams was constantly monitored during the corrosion process, along the corrosion region and along other potential cracking faces of beams using a demec gauge. The distribution of the gravimetric mass loss of steel along the corrosion region was measured at the end of the corrosion process. The results obtained showed that: the rate of widening of each corrosion crack is dependent on the overall pattern of the cracks whilst the rate of corrosion is independent of the pattern of corrosion cracks. A mass loss of steel of 1% was found to induce a corrosion crack width of about 0.04 mm.

  20. Semi-Active Control of Precast RC Columns under Seismic Action

    Science.gov (United States)

    Caterino, Nicola; Spizzuoco, Mariacristina

    2017-10-01

    This work is inspired by the idea of dissipating seismic energy at the base of prefabricated RC columns via semi-active (SA) variable dampers exploiting the base rocking. It was performed a wide numerical campaign to investigate the seismic behaviour of a pre-cast RC column with a variable base restraint. The latter is based on the combined use of a hinge, elastic springs, and magnetorheological (MR) dampers remotely controlled according to the instantaneous response of the structural component. The MR devices are driven by a SA control algorithm purposely written to modulate the dissipative capability so as to reduce base bending moment without causing excessive displacement at the top. The proposed strategy results to be really promising, since the base restraint relaxation, that favours the base moment demand reduction, is accompanied by a high enhancement of the dissipated energy due to rocking that can be even able to reduce top displacement in respect to the “fixed base rotation” conditions.

  1. Predicting the seismic performance of typical R/C healthcare facilities: emphasis on hospitals

    Science.gov (United States)

    Bilgin, Huseyin; Frangu, Idlir

    2017-09-01

    Reinforced concrete (RC) type of buildings constitutes an important part of the current building stock in earthquake prone countries such as Albania. Seismic response of structures during a severe earthquake plays a vital role in the extent of structural damage and resulting injuries and losses. In this context, this study evaluates the expected performance of a five-story RC healthcare facility, representative of common practice in Albania, designed according to older codes. The design was based on the code requirements used in this region during the mid-1980s. Non-linear static and dynamic time history analyses were conducted on the structural model using the Zeus NL computer program. The dynamic time history analysis was conducted with a set of ground motions from real earthquakes. The building responses were estimated in global levels. FEMA 356 criteria were used to predict the seismic performance of the building. The structural response measures such as capacity curve and inter-story drift under the set of ground motions and pushover analyses results were compared and detailed seismic performance assessment was done. The main aim of this study is considering the application and methodology for the earthquake performance assessment of existing buildings. The seismic performance of the structural model varied significantly under different ground motions. Results indicate that case study building exhibit inadequate seismic performance under different seismic excitations. In addition, reasons for the poor performance of the building is discussed.

  2. Barometrický výškoměr pro RC modely letadel

    OpenAIRE

    Dujíček, Martin

    2012-01-01

    Cílem této práce je návrh barometrického výškoměru určeného pro RC modely letadel. Během letu je zaznamenávána hodnota ze snímacího prvku do paměti. Po ukončení letu a po připojení zařízení k počítači je možné data přečíst nebo smazat. Přijatá data je dále možné zpracovat například do grafické podoby. The aim of this thesis is to design barometric altimeter for RC plane models. During the flight the value from sensing element is stored in memory. After the flight and connect to computer it...

  3. Full Scale RC Beam-Column Joints Strengthened with Steel Reinforced Polymer Systems

    Science.gov (United States)

    De Vita, Alessandro; Napoli, Annalisa; Realfonzo, Roberto

    2017-07-01

    This paper presents the results of an experimental campaign performed at the Laboratory of Materials and Structural Testing of the University of Salerno (Italy) in order to investigate the seismic performance of RC beam-column joints strengthened with Steel Reinforced Polymer (SRP) systems. With the aim to represent typical façade frames’ beam-column subassemblies found in existing RC buildings, specimens were provided with two short beam stubs orthogonal to the main beam and were designed with inadequate seismic details. Five members were strengthened by using two different SRP layouts while the remaining ones were used as benchmarks. Once damaged, two specimens were also repaired, retrofitted with SRP and subjected to cyclic test again. The results of cyclic tests performed on SRP strengthened joints are examined through a comparison with the outcomes of the previous experimental program including companion specimens not provided with transverse beam stubs and strengthened by Carbon Fiber Reinforced Polymer (CFRP) systems. In particular, both qualitative and quantitative considerations about the influence of the confining effect provided by the secondary beams on the joint response, the suitability of all the adopted strengthening solutions (SRP/CFRP systems), the performances and the failure modes experienced in the several cases studied are provided.

  4. A monolithic constant-fraction discriminator using distributed R-C delay-line shaping

    International Nuclear Information System (INIS)

    Simpson, M.L.; Young, G.R.; Xu, M.

    1995-01-01

    A monolithic, CMOS, constant-fraction discriminator (CFD) was fabricated in the Orbit Semiconductor, 1.2 μ N-well process. This circuit uses an on-chip, distributed, R-C delay-line to realize the constant-fraction shaping. The delay-line is constructed from a narrow, 500-μ serpentine layer of polysilicon above a wide, grounded, second layer of polysilicon. This R-C delay-line generates about 1.1 ns of delay for 5 ns risetime signals with a slope degradation of only ≅ 15% and an amplitude reduction of about 6.1%. The CFD also features an automatic walk adjustment. The entire circuit, including the delay line, has a 200 μ pitch and is 950 μ long. The walk for a 5 ns risetime signal was measured as ± 100 ps over the 100:1 dynamic range from -15 mV to -1.5 mV. to -1.5 V. The CFD consumes 15 mW

  5. Effect of discrete glass fibers on the behavior of R.C. Beams exposed to fire

    Directory of Open Access Journals (Sweden)

    Magdy Riad

    2017-08-01

    Full Text Available The main objective of this paper is to investigate the effect of adding discrete glass fibers on the behavior of reinforced concrete (RC beams under different fire and cooling conditions. Eighteen beams with different concrete compressive strengths were tested to study the behavior of reinforced concrete (RC beams containing discrete glass fibers when exposed to different fire and cooling conditions. Nine beams were prepared from normal strength concrete (NSC with compressive strength equal to 35 MPa while the other beams were prepared from high strength concrete (HSC with compressive strength equal to 60 MPa. The beams contained different contents of discrete glass fibers. The modes of failure of tested specimens show that the crack patterns change according to fire condition and fiber content. Analysis of test results show that adding discrete glass fibers to NSC increased the residual stiffness of the tested specimens after firing and decreased the rate of the deflection gain during firing. Also adding fibers to concrete has a limited positive effect on the ultimate strength of the specimens compared to the control specimens. Its effect on deflection due to fire is more pronounced. Finally, the recommended optimum ratio of discrete glass fibers is not more than 0.5% of the total concrete weight.

  6. Effect of CFRP and TRM Strengthening of RC Slabs on Punching Shear Strength

    Directory of Open Access Journals (Sweden)

    Husain Abbas

    Full Text Available Abstract The paper presents experiments involving punching of RC slabs strengthened using externally bonded carbon fiber reinforced polymer (CFRP sheet and textile reinforced mortar (TRM. Twelve RC slab specimens of two concrete grades (39.9 and 63.2 MPa and employing two strengthening schemes (CFRP and TRM were tested. Specimens were supported on two opposite edges. Experimental load-displacement variations show two peak loads in strengthened slabs and one peak followed by a plateau in control. Second peak or the plateau corresponds to the combined action of aggregate interlock and the dowel action of back face rebars and strengthening layers. The dowel action of back face rebars and strengthening layers had no role in ultimate punching load (i.e. first peak. Strengthened slabs showed 9-18% increase in ultimate punching load (i.e. first peak whereas there was significant increase in the second peak load (190-276% for CFRP; 55-136% for TRM and energy absorption (~66% for CFRP and 22-56% for TRM. An analytical model was also developed for predicting the punching shear strength (first and second peaks of strengthened slabs showing good comparison with experiments.

  7. Prestress Loss of CFL in a Prestressing Process for Strengthening RC Beams

    Directory of Open Access Journals (Sweden)

    Xinyan Guo

    2017-01-01

    Full Text Available A prestressing system was designed to strengthen reinforced concrete (RC beams with prestressed carbon fiber laminate (CFL. During different prestressing processes, prestress loss was measured using strain gauges attached on the surface of CFL along the length direction. The prestress loss was 50–68% of the whole prestress loss, which is typically associated with CFL slipping between the grip anchors. Approximately 20–27% of the prestress loss was caused by the elastic shortening of the RC beam. An analytical model using linear-elastic theory was constructed to calculate the prestress loss caused by CFL slipping between the anchors and the elastic shortening of the strengthened beams. The compared results showed that the analytical model of prestress loss can describe the experimental data well. Methods of reducing the prestress loss were also suggested. Compared to other experiments, the prestressing system proposed by this research group was effective because the maximum percentage of prestress loss was 14.9% and the average prestress loss was 12.5%.

  8. Scientific Performance Analysis of the SYZ Telescope Design versus the RC Telescope Design

    Science.gov (United States)

    Ma, Donglin; Cai, Zheng

    2018-02-01

    Recently, Su et al. propose an innovative design, referred as the “SYZ” design, for China’s new project of a 12 m optical-infrared telescope. The SYZ telescope design consists of three aspheric mirrors with non-zero power, including a relay mirror below the primary mirror. SYZ design yields a good imaging quality and has a relatively flat field curvature at Nasmyth focus. To evaluate the science-compatibility of this three-mirror telescope, in this paper, we thoroughly compare the performance of SYZ design with that of Ritchey–Chrétien (RC) design, a conventional two-mirror telescope design. Further, we propose the Observing Information Throughput (OIT) as a metric for quantitatively evaluating the telescopes’ science performance. We find that although a SYZ telescope yields a superb imaging quality over a large field of view, a two-mirror (RC) telescope design holds a higher overall throughput, a better diffraction-limited imaging quality in the central field of view (FOV < 5‧) which is better for the performance of extreme Adaptive Optics (AO), and a generally better scientific performance with a higher OIT value. D. Ma & Z. Cai contributed equally to this paper.

  9. Effect of URM infills on seismic vulnerability of Indian code designed RC frame buildings

    Science.gov (United States)

    Haldar, Putul; Singh, Yogendra; Paul, D. K.

    2012-03-01

    Unreinforced Masonry (URM) is the most common partitioning material in framed buildings in India and many other countries. Although it is well-known that under lateral loading the behavior and modes of failure of the frame buildings change significantly due to infill-frame interaction, the general design practice is to treat infills as nonstructural elements and their stiffness, strength and interaction with the frame is often ignored, primarily because of difficulties in simulation and lack of modeling guidelines in design codes. The Indian Standard, like many other national codes, does not provide explicit insight into the anticipated performance and associated vulnerability of infilled frames. This paper presents an analytical study on the seismic performance and fragility analysis of Indian code-designed RC frame buildings with and without URM infills. Infills are modeled as diagonal struts as per ASCE 41 guidelines and various modes of failure are considered. HAZUS methodology along with nonlinear static analysis is used to compare the seismic vulnerability of bare and infilled frames. The comparative study suggests that URM infills result in a significant increase in the seismic vulnerability of RC frames and their effect needs to be properly incorporated in design codes.

  10. Seismic Retrofitting: Reinforced Concrete (RC shear wall versus Reinforcement of RC element by Carbon Fiber Reinforced Polymer (CFRP using PUSHOVER analysis

    Directory of Open Access Journals (Sweden)

    Yahya RIYAD

    2016-12-01

    Full Text Available Seismic retrofitting of constructions vulnerable to earthquakes is a current problem of great political and social relevance. During the last sixty years, moderate to severe earthquakes have occurred in Morocco (specifically in Agadir 1960 and Hoceima 2004. Such events have clearly shown the vulnerability of the building stock in particular and of the built environment in general. Hence, it is very much essential to retrofit the vulnerable building to cope up for the next damaging earthquake. In this paper, the focus will be on a comparative study between two techniques of seismic retrofitting, the first one is a reinforcement using carbon fiber reinforced polymer (CFRP applied to RC elements by bonding , and the second one is a reinforcement with a shear wall. For this study, we will use a non-linear static analysis -also known as Pushover analysis - on a reinforced concrete structure consisting of beams and columns, and composed from eight storey with a gross area of 240 m², designed conforming to the Moroccan Seismic code[1].

  11. Localization of Low Copy Number Plasmid pRC4 in Replicating Rod and Non-Replicating Cocci Cells of Rhodococcus erythropolis PR4.

    Directory of Open Access Journals (Sweden)

    Divya Singhi

    Full Text Available Rhodococcus are gram-positive bacteria, which can exist in two different shapes rod and cocci. A number of studies have been done in the past on replication and stability of small plasmids in this bacterium; however, there are no reports on spatial localization and segregation of these plasmids. In the present study, a low copy number plasmid pDS3 containing pRC4 replicon was visualized in growing cells of Rhodococcus erythropolis PR4 (NBRC100887 using P1 parS-ParB-GFP system. Cells were initially cocci and then became rod shaped in exponential phase. Cocci cells were found to be non-replicating as evident by the presence of single fluorescence focus corresponding to the plasmid and diffuse fluorescence of DnaB-GFP. Rod shaped cells contained plasmid either present as one fluorescent focus observed at the cell center or two foci localized at quarter positions. The results suggest that the plasmid is replicated at the cell center and then it goes to quarter position. In order to observe the localization of plasmid with respect to nucleoid, plasmid segregation was also studied in filaments where it was found to be replicated at the cell center in a nucleoid free region. To the best of our knowledge, this is the first report on segregation of small plasmids in R. erythropolis.

  12. Nonlinear interaction analysis of RC cylindrical tank with subsoil by adopting two kinds of constitutive models for ground and structure

    Science.gov (United States)

    Lewiński, Paweł M.; Dudziak, Sławomir

    2018-01-01

    In the paper, two kinds of constitutive models for ground and structure were adopted for the nonlinear interaction analysis of the RC cylindrical tank with subsoil. The paper discusses deformational and incremental approaches to a nonlinear FE analysis of soil-structure interaction including the description of behaviour of the RC structure and the subsoil under short-term loading. Moreover, a non-linear elastic-brittle-plastic analysis of RC axisymmetric structures using finite element iterative techniques is presented. The constitutive laws for concrete and subsoil are developed in compliance with the deformational and plastic flow theories of plasticity. Two examples of an FE analysis of soil-structure interaction were performed and the results were analysed.

  13. A comparative mathematical analysis of RL and RC electrical circuits via Atangana-Baleanu and Caputo-Fabrizio fractional derivatives

    Science.gov (United States)

    Abro, Kashif Ali; Memon, Anwar Ahmed; Uqaili, Muhammad Aslam

    2018-03-01

    This research article is analyzed for the comparative study of RL and RC electrical circuits by employing newly presented Atangana-Baleanu and Caputo-Fabrizio fractional derivatives. The governing ordinary differential equations of RL and RC electrical circuits have been fractionalized in terms of fractional operators in the range of 0 ≤ ξ ≤ 1 and 0 ≤ η ≤ 1. The analytic solutions of fractional differential equations for RL and RC electrical circuits have been solved by using the Laplace transform with its inversions. General solutions have been investigated for periodic and exponential sources by implementing the Atangana-Baleanu and Caputo-Fabrizio fractional operators separately. The investigated solutions have been expressed in terms of simple elementary functions with convolution product. On the basis of newly fractional derivatives with and without singular kernel, the voltage and current have interesting behavior with several similarities and differences for the periodic and exponential sources.

  14. Shake-table testing of a self-centering precast reinforced concrete frame with shear walls

    Science.gov (United States)

    Lu, Xilin; Yang, Boya; Zhao, Bin

    2018-04-01

    The seismic performance of a self-centering precast reinforced concrete (RC) frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls (SPCW), which utilize a combination of unbonded prestressed post-tensioned (PT) tendons and mild steel reinforcing bars for flexural resistance across base joints. The structures concentrated deformations at the bottom joints and the unbonded PT tendons provided the self-centering restoring force. A 1/3-scale model of a five-story self-centering RC frame with shear walls was designed and tested on a shake-table under a series of bi-directional earthquake excitations with increasing intensity. The acceleration response, roof displacement, inter-story drifts, residual drifts, shear force ratios, hysteresis curves, and local behaviour of the test specimen were analysed and evaluated. The results demonstrated that seismic performance of the test specimen was satisfactory in the plane of the shear wall; however, the structure sustained inter-story drift levels up to 2.45%. Negligible residual drifts were recorded after all applied earthquake excitations. Based on the shake-table test results, it is feasible to apply and popularize a self-centering precast RC frame with shear walls as a structural system in seismic regions.

  15. Identification of an Equivalent Linear Model for a Non-Linear Time-Variant RC-Structure

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    are investigated and compared with ARMAX models used on a running window. The techniques are evaluated using simulated data generated by the non-linear finite element program SARCOF modeling a 10-storey 3-bay concrete structure subjected to amplitude modulated Gaussian white noise filtered through a Kanai......This paper considers estimation of the maximum softening for a RC-structure subjected to earthquake excitation. The so-called Maximum Softening damage indicator relates the global damage state of the RC-structure to the relative decrease of the fundamental eigenfrequency in an equivalent linear...

  16. An implementation of super-encryption using RC4A and MDTM cipher algorithms for securing PDF Files on android

    Science.gov (United States)

    Budiman, M. A.; Rachmawati, D.; Parlindungan, M. R.

    2018-03-01

    MDTM is a classical symmetric cryptographic algorithm. As with other classical algorithms, the MDTM Cipher algorithm is easy to implement but it is less secure compared to modern symmetric algorithms. In order to make it more secure, a stream cipher RC4A is added and thus the cryptosystem becomes super encryption. In this process, plaintexts derived from PDFs are firstly encrypted with the MDTM Cipher algorithm and are encrypted once more with the RC4A algorithm. The test results show that the value of complexity is Θ(n2) and the running time is linearly directly proportional to the length of plaintext characters and the keys entered.

  17. Preloading Effect on Strengthening Efficiency of RC Beams Strengthened with Non- and Pretensioned NSM Strips

    Directory of Open Access Journals (Sweden)

    Renata Kotynia

    2018-02-01

    Full Text Available The near surface mounted (NSM technique has been shown to be one of the most promising methods for upgrading reinforced concrete (RC structures. Many tests carried out on RC members strengthened in flexure with NSM fiber-reinforced polymer (FRP systems have demonstrated greater strengthening efficiency than the use of externally-bonded (EB FRP laminates. Strengthening with simultaneous pretensioning of the FRP results in improvements in the serviceability limit state (SLS conditions, including the increased cracking moment and decreased deflections. The objective of the reported experimental program, which consisted of two series of RC beams strengthened in flexure with NSM CFRP strips, was to investigate the influence of a number of parameters on the strengthening efficiency. The test program focused on an analysis of the effects of preloading on the strengthening efficiency which has been investigated very rarely despite being one of the most important parameters to be taken into account in strengthening design. Two preloading levels were considered: the beam self-weight only, which corresponded to stresses on the internal longitudinal reinforcement of 25% and 14% of the yield stress (depending on a steel reinforcement ratio, and the self-weight with the additional superimposed load, corresponding to 60% of the yield strength of the unstrengthened beam and a deflection equal to the allowable deflection at the SLS. The influence of the longitudinal steel reinforcement ratio was also considered in this study. To reflect the variability seen in existing structures, test specimens were varied by using different steel bar diameters. Finally, the impact of the composite reinforcement ratio and the number of pretensioned FRP strips was considered. Specimens were divided into two series based on their strengthening configuration: series “A” were strengthened with one pretensioned and two non-pretensioned carbon FRP (CFRP strips, while series

  18. Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center, Subproject to Co-PI Eric E. Roden. Final Report

    International Nuclear Information System (INIS)

    Roden, Eric E.

    2011-01-01

    This report summarizes research conducted in conjunction with a project entitled 'Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center', which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2.

  19. Impact differences in ground reaction force and center of mass between the first and second landing phases of a drop vertical jump and their implications for injury risk assessment.

    Science.gov (United States)

    Bates, Nathaniel A; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

    2013-04-26

    The drop vertical jump (DVJ) task is commonly used to assess biomechanical performance measures that are associated with ACL injury risk in athletes. Previous investigations have solely assessed the first landing phase. We examined the first and second landings of a DVJ for differences in the magnitude of vertical ground reaction force (vGRF) and position of center of mass (CoM). A cohort of 239 adolescent female basketball athletes completed a series of DVJ tasks from an initial box height of 31 cm. Dual force platforms and a three dimensional motion capture system recorded force and positional data for each trial. There was no difference in peak vGRF between landings (p=0.445), but side-to-side differences increased from the first to second landing (p=0.007). Participants demonstrated a lower minimum CoM during stance in the first landing than the second landing (p<0.001). The results have important implications for the future assessment of ACL injury risk behaviors in adolescent female athletes. Greater side-to-side asymmetry in vGRF and higher CoM during impact indicate the second landing of a DVJ may exhibit greater perturbation and better represent in-game mechanics associated with ACL injury risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  1. Performance of a multi-section ICRF array for a RTO/RC ITER

    International Nuclear Information System (INIS)

    Bosia, Giuseppe; Brambilla, Marco

    1999-01-01

    In an RTO/RC ITER, the Ion Cyclotron (IC) Heating and Current Drive System would need to operate at a power density of 6.5 MW/m 2 , (or about twice the design value adopted in the ITER Final Design Report), in order to provide the required total power output of 40 MW of RF power from two equatorial ports. A significant upgrade of the original IC array design is necessary, in order to keep the operating RF voltage at the plasma interface within acceptable limits. This is in principle possible by increasing the number of array elements and by operating them in parallel. In the paper the prospects of this modifications and the implications on the array layout are discussed

  2. Calibrating and validating a FE model for long-term behavior of RC beams

    Directory of Open Access Journals (Sweden)

    Tošić Nikola D.

    2014-01-01

    Full Text Available This study presents the research carried out in finding an optimal finite element (FE model for calculating the long-term behavior of reinforced concrete (RC beams. A multi-purpose finite element software DIANA was used. A benchmark test in the form of a simply supported beam loaded in four point bending was selected for model calibration. The result was the choice of 3-node beam elements, a multi-directional fixed crack model with constant stress cut-off, nonlinear tension softening and constant shear retention and a creep and shrinkage model according to CEB-FIP Model Code 1990. The model was then validated on 14 simply supported beams and 6 continuous beams. Good agreement was found with experimental results (within ±15%.

  3. Comparative Application of Capacity Models for Seismic Vulnerability Evaluation of Existing RC Structures

    International Nuclear Information System (INIS)

    Faella, C.; Lima, C.; Martinelli, E.; Nigro, E.

    2008-01-01

    Seismic vulnerability assessment of existing buildings is one of the most common tasks in which Structural Engineers are currently engaged. Since, its is often a preliminary step to approach the issue of how to retrofit non-seismic designed and detailed structures, it plays a key role in the successful choice of the most suitable strengthening technique. In this framework, the basic information for both seismic assessment and retrofitting is related to the formulation of capacity models for structural members. Plenty of proposals, often contradictory under the quantitative standpoint, are currently available within the technical and scientific literature for defining the structural capacity in terms of force and displacements, possibly with reference to different parameters representing the seismic response. The present paper shortly reviews some of the models for capacity of RC members and compare them with reference to two case studies assumed as representative of a wide class of existing buildings

  4. A Plastic Design Method for RC Moment Frame Buildings against Progressive Collapse

    Directory of Open Access Journals (Sweden)

    Hadi Faghihmaleki

    2017-04-01

    Full Text Available In this study, progressive collapse potential of generic 3-, 8- and 12-storey RC moment frame buildings designed based on IBC-2006 code was investigated by performing non-linear static and dynamic analyses. It was observed that the model structures had high potential for progressive collapse when the second floor column was suddenly removed. Then, the size of beams required to satisfy the failure criteria for progressive collapse was obtained by using the virtual work method; i.e., using the equilibrium of the external work done by gravity load due to loss of a column and the internal work done by plastic rotation of beams. According to the nonlinear dynamic analysis results, the model structures designed only for normal load turned out to have strong potential for progressive collapse whereas the structures designed by plastic design concept for progressive collapse satisfied the failure criterion recommended by the GSA code. 

  5. BUTREN-RC an hybrid system for the recharges optimization of nuclear fuels in a BWR

    International Nuclear Information System (INIS)

    Ortiz S, J.J.; Castillo M, J.A.; Valle G, E. del

    2004-01-01

    The obtained results with the hybrid system BUTREN-RC are presented that obtains recharges of nuclear fuel for a BWR type reactor. The system has implemented the methods of optimization heuristic taboo search and neural networks. The optimization it carried out with the technique of taboo search, and the neural networks, previously trained, were used to predict the behavior of the recharges of fuel, in substitution of commercial codes of reactor simulation. The obtained recharges of nuclear fuel correspond to 5 different operation cycles of the Laguna Verde Nuclear Power plant, Veracruz in Mexico. The obtained results were compared with the designs of this cycles. The energy gain with the recharges of fuel proposals is of approximately 4.5% with respect to those of design. The time of compute consumed it was considerably smaller that when a commercial code for reactor simulation is used. (Author)

  6. Application of system-process-goal approach for description of TRIGA RC-1 system

    International Nuclear Information System (INIS)

    Gadomski, Adam M.

    1986-01-01

    The new methodology of the goal oriented description of an artificial system is presented. In the SPG approach (System-Process-Goal) it is assumed that the knowledge necessary for achieving the goal is available but it is not ordered or ordered for other purposes. The aim of SPG is to give the description of the analyzed system in form of network by decomposition of goal-system relationships using uniform and mathematical formalism. The SPG approach is useful to build a reactor operator aid system. This paper presents the conception of the application of the SPG approach to the decomposition of TRIGA RC-1 dynamics and for designing of TRIGA diagnostic algorithms. (author)

  7. FW/Blanket and vacuum vessel for RTO/RC ITER

    International Nuclear Information System (INIS)

    Ioki, K.; Barabash, V.; Cardella, A.; Elio, F.; Iida, H.; Johnson, G.; Kalinin, G.; Miki, N.; Onozuka, M.; Sannazzaro, G.; Utin, Y.; Yamada, M.

    2000-01-01

    The design has progressed on the vacuum vessel and First Wall (FW)/blanket for the Reduced Technical Objective/Reduced Cost (RTO/RC) ITER. The basic functions and structures are the same as for the 1998 ITER design. The design has been improved to achieve, along with the size reduction, ∼50% target reduction of the fabrication cost. The number of blanket modules has been minimized according to smaller dimensions of the machine and a higher payload capacity of the blanket Remote Handling tool. A concept without the back plate has been designed and assessed. The blanket module concept with flat separable FW panels has been developed to reduce the fabrication cost and future radioactive waste

  8. Response Analysis of an RC Cooling Tower Under Seismic and Windstorm Effects

    Directory of Open Access Journals (Sweden)

    D. Makovička

    2006-01-01

    Full Text Available The paper compares the RC structure of a cooling tower unit under seismic loads and under strong wind loads. The calculated values of the envelopes of the displacements and the internal forces due to seismic loading states are compared with the envelopes of the loading states due to the dead, operational and live loads, wind and temperature actions. The seismic effect takes into account the seismic area of ground motion 0.3 g and the ductility properties of a relatively rigid structure. The ductility is assessed as the reduction in seismic load. In this case the actions of wind pressure are higher than the seismicity effect under ductility correction. The seismic effects, taking into account the ductility properties of the structure, are lower than the actions of the wind pressure. The other static loads, especially temperature action due to the environment and surface insulation are very important for the design of the structure. 

  9. FW/Blanket and vacuum vessel for RTO/RC ITER

    Energy Technology Data Exchange (ETDEWEB)

    Ioki, K. E-mail: iokik@itereu.de; Barabash, V.; Cardella, A.; Elio, F.; Iida, H.; Johnson, G.; Kalinin, G.; Miki, N.; Onozuka, M.; Sannazzaro, G.; Utin, Y.; Yamada, M

    2000-11-01

    The design has progressed on the vacuum vessel and First Wall (FW)/blanket for the Reduced Technical Objective/Reduced Cost (RTO/RC) ITER. The basic functions and structures are the same as for the 1998 ITER design. The design has been improved to achieve, along with the size reduction, {approx}50% target reduction of the fabrication cost. The number of blanket modules has been minimized according to smaller dimensions of the machine and a higher payload capacity of the blanket Remote Handling tool. A concept without the back plate has been designed and assessed. The blanket module concept with flat separable FW panels has been developed to reduce the fabrication cost and future radioactive waste.

  10. Bonding techniques for flexural strengthening of R.C. beams using CFRP laminates

    Directory of Open Access Journals (Sweden)

    Alaa Morsy

    2013-09-01

    Full Text Available This paper presents an experimental study of an alternative method of attaching FRP laminates to reinforced concrete beams by the way of fasting steel rivets through the FRP laminate and concrete substrate. Five full scale R.C. beams were casted and strengthened in flexural using FRP laminate bonded with conventional epoxy and compared with other beams strengthened with FRP laminate and bonded with fastener “steel rivets” of 50 mm length and 10 mm diameter. Based on experimental evidence the beam strengthened with conventional bonding methods failed due to de-bonding with about 13% increase over the un-strengthened beam. On the other hand, the beams strengthened with FRP laminate and bonded by four steel fastener rivets only failed by de-bonding also but at higher flexural capacity with increase 19% over the un-strengthened beam.

  11. Smart aggregate based damage detection of circular RC columns under cyclic combined loading

    International Nuclear Information System (INIS)

    Moslehy, Yashar; Belarbi, Abdeldjelil; Mo, Y L; Gu, Haichang; Song, Gangbing

    2010-01-01

    Structural health monitoring is an important issue for the maintenance of large-scale civil infrastructures, especially for bridge columns. In this paper, an innovative piezoceramic-based approach is developed for the structural health monitoring of reinforced concrete columns. An innovative piezoceramic-based device, the smart aggregate, is utilized as a transducer for the purpose of health monitoring. To investigate the seismic behavior of reinforced concrete (RC) bridge columns, structural health monitoring tests were performed on two bridge columns under combined reversed cyclic loading at the Missouri University of Science and Technology. The proposed smart aggregate based approach successfully evaluated the health status of concrete columns during the loading procedure. Sensor energy plots and 3D normalized sensor energy plots demonstrated that the damage inside attenuated the transmitted energy. The wavelet packet based damage index and sensor history damage index evaluate the damage development in concrete columns under cyclic loading

  12. Lateral stiffness and vibration characteristics of composite plated RC shear walls with variable fibres spacing

    International Nuclear Information System (INIS)

    Meftah, S.A.; Yeghnem, R.; Tounsi, A.; Adda Bedia, E.A.

    2008-01-01

    In this paper, a finite element model for static and free vibration analysis of reinforced concrete (RC) shear walls structures strengthened with thin composite plates having variable fibres spacing is presented. An efficient analysis method that can be used regardless to the sizes and location of the bonded plates is proposed in this study. In the numerical formulation, the adherents and the adhesives are all modelled as shear wall elements, using the mixed finite element method. Several test problems are examined to demonstrate the accuracy and effectiveness of the proposed method. Numerical results are obtained for six nonuniform distributions of E-glass, graphite and boron fibres in epoxy matrices. The fibre redistributions of the bonded plates are seen to increase the frequencies modes and reduce substantially the lateral displacements

  13. Active RC filter based implementation analysis part of two channel hybrid filter bank

    Directory of Open Access Journals (Sweden)

    Stojanović Vidosav

    2014-01-01

    Full Text Available In the present paper, a new design method for continuous-time powersymmetric active RC filters for Hybrid Filter Bank (HFB is proposed. Some theoretical properties of continious-time power-symmetric filters bank in a more general perspective are studied. This includes the derivation of a new general analytical form, and a study of poles and zeros locations in s-plane. In the proposed design method the analytic solution of filter coefficients is solved in sdomain using only one nonlinear equation Finally, the proposed approximation is compared to standard approximations. It was shown that attenuation and group delay characteristic of the proposed filter lie between Butterworth and elliptic characteristics. [Projekat Ministarstva nauke Republike Srbije, br. 32009TR

  14. Intestinal toxicity of deoxynivalenol is limited by Lactobacillus rhamnosus RC007 in pig jejunum explants.

    Science.gov (United States)

    García, Gisela Romina; Payros, Delphine; Pinton, Philippe; Dogi, Cecilia Ana; Laffitte, Joëlle; Neves, Manon; González Pereyra, María Laura; Cavaglieri, Lilia Renée; Oswald, Isabelle P

    2018-02-01

    Probiotics have been explored to stimulate gut health in weaned pigs, when they started to consume solid diet where mycotoxins could be present. The aim of this study was to evaluate the effect of Lactobacillus rhamnosus RC007 on the intestinal toxicity of deoxynivalenol (DON) in an ex vivo model. Jejunal explants, obtained from 5-week-old crossbred castrated male piglets, were kept as control, exposed for 3 h to 10 μM DON, incubated for 4 h with 10 9 CFU/mL L. rhamnosus, or pre-incubated 1 h with 10 9 L. rhamnosus and exposed to DON. Histological lesions were observed, para- and transcellular intestinal permeability was measured in Ussing chambers. The expression levels of mRNA encoding six inflammatory cytokines (CCL20, IL-10, IL-1β, TNFα, IL-8 and IL-22) were determined by RT-PCR. The expressions of the phosphorylated MAP kinases p42/p44 and p38 were assessed by immunoblotting. Exposure to DON induced histological changes, significantly increased the expression of CCL20, IL-1β, TNFα, IL-8, IL-22 and IL-10, increased the intestinal paracellular permeability and activated MAP kinases. Incubation with L. rhamnosus alone did not have any significant effect. By contrast, the pre-incubation with L. rhamnosus reduced all the effects of DON: the histological alterations, the pro-inflammatory response, the paracellular permeability and the phosphorylation of MAP kinases. Of note, L. rhamnosus did not adsorb DON and only slightly degrade the toxin. In conclusion, L. rhamnosus RC007 is a promising probiotic which, included as feed additive, can decrease the intestinal toxicity of DON.

  15. Evaluation method for corrosion level of rebar in RC with electrical impedance measurement

    Science.gov (United States)

    Sasamoto, Akira

    2018-04-01

    The author reported that the impedance measurement using the 4-terminal method on the RC surface for diagnosing corrosion of internal rebar. The difference between the maximum value at 0.01 Hz and the minimum value around 10 Hz indicates the corrosion level of rebar in that report. This is successive report on a signal processing method for estimating the corrosion level by the measured impedance data to obtain more high accuracy. In the dielectric, a graph of frequency and dielectric constant (Cole-Cole plot diagram by KS Cole and RH Cole article of 1941) draws a shape of circle if the dielectric is independent of frequency but it draws a shape of ellipse in reality due to frequency dependency. Havriliak and Negami have also presented Havriliak-Negami model which introduced parameter into dielectric constant equation which deforms Cole-Cole plot diagram and showed that acquired dielectric data of polymer materials fit to this model with proper parameters. In this report, we first consider electric model connected with resistance and capacitance as a rough model of RC concrete. If the capacitance in this model circuit has some loss of dielectric, it is stated that graph in impedance plot is expected to take as similar deformation in the dielectric Cole-Cole plot. Then a numerical optimization computer code for obtaining parameters in the Cole-Cole plot diagram and Havriliak-Negami model is constructed, and the correlation between the deformation parameter of each model and corrosion is shown by this code. These results are feasibility study for diagnosis of corrosion level of rebar by associated parameters to a shape of impedance graph.

  16. Seismic design and performance of nuclear safety related RC structures based on new seismic design principle

    International Nuclear Information System (INIS)

    Murugan, R.; Sivathanu Pillai, C.; Chattopadhyaya, S.; Sundaramurthy, C.

    2011-01-01

    Full text: Seismic design of safety related Reinforced Concrete (RC) structures of Nuclear power plants (NPP) in India as per the present AERB codal procedures tries to ensure predominantly elastic behaviour under OBE so that the features of Nuclear Power Plant (NPP) necessary for continued safe operation are designed to remain functional and prevent accident (collapse) of NPP under SSE for which certain Structures, Systems and Components (SSCs) those are necessary to ensure the capability to shut down the reactor safely, are designed to remain functional. While the seismic design principles of non safety related structures as per Indian code (IS 1893-2002) are ensuring elastic behaviour under DBE and inelastic behaviour under MCE by utilizing ductility and energy dissipation capacity of the structure effectively. The design principle of AERB code is ensuring elastic behaviour under OBE and is not enlightening much inference about the overall structural behaviour under SSE (only ensuring the capability of certain SSCs required for safe shutdown of reactor). Various buildings and structures of Indian Nuclear power plant are classified from the basis of associated safety functions in a descending order in according with their roles in preventions and mitigation of an accident or support functions for prevention. This paper covers a comprehensive seismic analysis and design methodology based on the AERB codal provisions followed for safety related RC structure taking Diesel Generator Building of PFBR as a case study and study and investigates its performance under OBE and SSE by carrying out Non-linear static Pushover analysis. Based on the analysis, observed variations, recommendations are given for getting the desired performance level so as to implement performance based design in the future NPP design

  17. Final Report for SERDP Project RC-1649: Advanced Chemical Measurements of Smoke from DoD-prescribed Burns

    Science.gov (United States)

    T.J. Johnson; R.J. Yokelson; S.K. Akagi; I.R. Burling; D.R. Weise; S.P. Urbanski; C.E. Stockwell; J. Reardon; E.N. Lincoln; L.T.M. Profeta; A. Mendoza; M.D.W. Schneider; R.L. Sams; S.D. Williams; C.E. Wold; D.W.T. Griffith; M. Cameron; J.B. Gilman; C. Warneke; J.M. Roberts; P. Veres; W.C. Kuster; J de Gouw

    2014-01-01

    Project RC-1649, "Advanced Chemical Measurement of Smoke from DoD-prescribed Burns" was undertaken to use advanced instrumental techniques to study in detail the particulate and vapor-phase chemical composition of the smoke that results from prescribed fires used as a land management tool on DoD bases, particularly bases in the southeastern U.S. The statement...

  18. Seismic reliability assessment of RC structures including soil–structure interaction using wavelet weighted least squares support vector machine

    International Nuclear Information System (INIS)

    Khatibinia, Mohsen; Javad Fadaee, Mohammad; Salajegheh, Javad; Salajegheh, Eysa

    2013-01-01

    An efficient metamodeling framework in conjunction with the Monte-Carlo Simulation (MCS) is introduced to reduce the computational cost in seismic reliability assessment of existing RC structures. In order to achieve this purpose, the metamodel is designed by combining weighted least squares support vector machine (WLS-SVM) and a wavelet kernel function, called wavelet weighted least squares support vector machine (WWLS-SVM). In this study, the seismic reliability assessment of existing RC structures with consideration of soil–structure interaction (SSI) effects is investigated in accordance with Performance-Based Design (PBD). This study aims to incorporate the acceptable performance levels of PBD into reliability theory for comparing the obtained annual probability of non-performance with the target values for each performance level. The MCS method as the most reliable method is utilized to estimate the annual probability of failure associated with a given performance level in this study. In WWLS-SVM-based MCS, the structural seismic responses are accurately predicted by WWLS-SVM for reducing the computational cost. To show the efficiency and robustness of the proposed metamodel, two RC structures are studied. Numerical results demonstrate the efficiency and computational advantages of the proposed metamodel for the seismic reliability assessment of structures. Furthermore, the consideration of the SSI effects in the seismic reliability assessment of existing RC structures is compared to the fixed base model. It shows which SSI has the significant influence on the seismic reliability assessment of structures.

  19. Simplified unified analysis of switched-RC passive mixers, samplers, and N -Path filters using the adjoint network

    NARCIS (Netherlands)

    Pavan, Shanthi; Klumperink, Eric A.M.

    2017-01-01

    Recent innovations in software defined CMOS radio transceiver architectures heavily rely on high linearity switched-RC sampler and passive-mixer circuits, driven by digitally programmable multiphase clocks. Although seemingly simple, the frequency domain analysis of these linear periodically time

  20. An Experimental Study on Hybrid Noncompression CF Bracing and GF Sheet Wrapping Reinforcement Method to Restore Damaged RC Structures

    Directory of Open Access Journals (Sweden)

    Kang Seok Lee

    2015-01-01

    Full Text Available We describe a novel technique for restoration of reinforced concrete (RC structures that have sustained damage during an earthquake. The reinforcement scheme described here is a hybrid seismic retrofitting technique that combines noncompression X-bracing using CF with externally bonded GF sheets to strengthen RC structures that have sustained damage following an earthquake. The GF sheet is used to improve the ductility of columns, and the noncompression CF X-bracing system, which consists of CF bracing and anchors to replace the conventional steel bracing and bolt connections, is used to increase the lateral strength of the framing system. We report seismic restoration capacity, which enables reuse of the damaged RC frames via the hybrid CF X-bracing and GF sheet wrapping system. Cyclic loading tests were carried out to investigate hysteresis of the lateral load-drift relations, as well as the ductility. The GF sheet significantly improved the ductility of columns, resulting in a change in failure mode. The strengthening effect of conventional CF sheets used in columns is not sufficient with respect to lateral strength and stiffness. However, this study results in a significant increase in the strength of the structure due to the use of CF X-bracing and inhibited buckling failure of the bracing. This result can be exploited to develop guidelines for the application of the reinforcement system to restore damaged RC structures.

  1. Humidity build-up in electronic enclosures exposed to different geographical locations by RC modelling and reliability prediction

    DEFF Research Database (Denmark)

    Conseil-Gudla, H.; Staliulionis, Z.; Mohanty, S.

    2018-01-01

    according to this steady state (25 °C and 60% RH) have been calculated for the different climates, and the protection offered by the enclosures has been estimated under different casing materials and resistor-capacitor (RC) simulation. This method offers a way to predict the average value of failure rate...

  2. Seismic assessment of existing RC buildings under alternative ground motion ensembles compatible to EC8 and NTC 2008

    NARCIS (Netherlands)

    Tanganelli, Marco; Viti, Stefania; Mariani, V.; Pianigiani, Maria

    2017-01-01

    This work investigates the effects of the choice of different ensembles of ground motions on the seismic assessment of existing RC buildings through nonlinear dynamic analysis. Nowadays indeed, all the main International Seismic Codes provide a soil classification which is based on the shear wave

  3. A case of hyperkalemia after transfusion of irradiated red cell concentrate in mannitol-adenine-phosphate (RC-MAP)

    International Nuclear Information System (INIS)

    Fukui, Akira; Yokota, Kimio; Aoki, Masanori; Sari, Atsuo

    1998-01-01

    A 72-year-old male, 45 kg in weight, underwent anterior and posterior fixations of the lumbar vertebra. Preanesthetic blood chemistry was within normal range. Following transfusion of 400 ml of RC-MAP in two hours (11 days after blood collection and 2 days after irradiation at a dose of 20 Gy), and then another 100 ml of 400 ml RC-MAP (12 days after blood collection and 2 days after irradiation at a dose of 20 Gy), the patient's serum kalium value increased from 4.8 to 5.5 mEq/l. Even though the transfusion was immediately discontinued, the level continued to rise to 6.0 mEq/l. It subsequently fell to the normal level with glucose-insulin therapy. The hyperkalemia in this case could have been attributable to the period of storage after irradiation, the transfusion of salvaged autologous blood, and the storage state of RC-MAP. However, since the kalium values of RC-MAP and the salvaged autologous blood were not measured in this case, the exact cause was unknown. In conclusion, hyperkalemia can occur in patients during transfusion of irradiated blood. Therefore, kalium levels should be monitored carefully. (author)

  4. Time-variant flexural reliability of RC beams with externally bonded CFRP under combined fatigue-corrosion actions

    International Nuclear Information System (INIS)

    Bigaud, David; Ali, Osama

    2014-01-01

    Time-variant reliability analysis of RC highway bridges strengthened with carbon fibre reinforced polymer CFRP laminates under four possible competing damage modes (concrete crushing, steel rupture after yielding, CFRP rupture and FRP plate debonding) and three degradation factors is analyzed in terms of reliability index β using FORM. The first degradation factor is chloride-attack corrosion which induces reduction in steel area and concrete cover cracking at characteristic key times (corrosion initiation, severe surface cover cracking). The second degradation factor considered is fatigue which leads to damage in concrete and steel rebar. Interaction between corrosion and fatigue crack growth in steel reinforcing bars is implemented. The third degradation phenomenon is the CFRP properties deterioration due to aging. Considering these three degradation factors, the time-dependent flexural reliability profile of a typical simple 15 m-span intermediate girder of a RC highway bridge is constructed under various traffic volumes and under different corrosion environments. The bridge design options follow AASHTO-LRFD specifications. Results of the study have shown that the reliability is very sensitive to factors governing the corrosion. Concrete damage due to fatigue slightly affects reliability profile of non-strengthened section, while service life after strengthening is strongly related to fatigue damage in concrete. - Highlights: • We propose a method to follow the time-variant reliability of strengthened RC beams. • We consider multiple competing failure modes of CFRP strengthened RC beams. • We consider combined degradation mechanisms (corrosion, fatigue, ageing of CFRP)

  5. Glass Fiber Reinforced Polymer (GFRP Bars for Enhancing the Flexural Performance of RC Beams Using Side-NSM Technique

    Directory of Open Access Journals (Sweden)

    Md. Akter Hosen

    2017-05-01

    Full Text Available Reinforced concrete (RC structures require strengthening for numerous factors, such as increased load, modification of the structural systems, structural upgrade or errors in the design and construction stages. The side near-surface mounted (SNSM strengthening technique with glass fiber-reinforced polymer (GFRP bars is a relatively new emerging technique for enhancing the flexural capacities of existing RC elements. Nine RC rectangular beams were flexurally strengthened with this technique and tested under four-point bending loads until failure. The main goal of this study is to optimize the structural capacity of the RC beams by varying the amount of strengthening reinforcement and bond length. The experimental test results showed that strengthening with SNSM GFRP bars significantly enhanced the flexural responses of the specimens compared with the control specimen. The first cracking and ultimate loads, energy absorption capacities, ductility and stiffness were remarkably enhanced by the SNSM technique. It was also confirmed that the bond length of the strengthened reinforcement greatly influences the energy absorption capacities, ductility and stiffness. The effect of the bond length on these properties is more significant compared to the amount of strengthening reinforcement.

  6. Ion distributions in RC at different energy levels retrieved from TWINS ENA images by voxel CT tech

    Science.gov (United States)

    Ma, S. Y.; McComas, David; Xu, Liang; Goldstein, Jerry; Yan, Wei-Nan

    2012-07-01

    Distributions of energetic ions in the RC regions in different energy levels are retrieved by using 3-D voxel CT inversion method from ENA measurements onboard TWINS constellation during the main phase of a moderate geomagnetic storm. It is assumed that the ion flux distribution in the RC is anisotropic in regard to pitch angle which complies with the adiabatic invariance of the magnetic moment as ion moving in the dipole magnetic mirror field. A semi-empirical model of the RC ion distribution in the magnetic equator is quoted to form the ion flux distribution shape at off-equatorial latitudes by mapping. For the concerned time interval, the two satellites of the TWINS flying in double Molnia orbits were located in nearly the same meridian plane at vantage points widely separated in magnetic local time, and both more than 5 RE geocentric distance from the Earth. The ENA data used in this study are differential fluxes averaged over 12 sweeps (corresponding to an interval of 16 min.) at different energy levels ranging from about 1 to 100 keV. The retrieved ion distributions show that in total the main part of the RC is located in the region with L value larger than 4, tending to increase at larger L. It reveals that there are two distinct dominant energy bands at which the ion fluxes are significantly larger magnitude than at other energy levels, one is at lower level around 2 keV and the other at higher level of 30-100 keV. Furthermore, it is very interesting that the peak fluxes of the RC ions at the two energy bands occurred in different magnetic local time, low energy ions appear preferentially in after midnight, while the higher energy ions mainly distributed around midnight and pre-midnight. This new profile is worthy of further study and needs to be demonstrated by more cases.

  7. Comparison of Path Length and Ranges of Movement of the Center of Pressure and Reaction Time and Between Paired-Play and Solo-Play of a Virtual Reality Game.

    Science.gov (United States)

    Portnoy, Sigal; Hersch, Ayelet; Sofer, Tal; Tresser, Sarit

    2017-06-01

    To test whether paired-play will induce longer path length and ranges of movement of the center of pressure (COP), which reflects on balance performance and stability, compared to solo-play and to test the difference in the path length and ranges of movement of the COP while playing the virtual reality (VR) game with the dominant hand compared to playing it with the nondominant hand. In this cross-sectional study 20 children (age 6.1 ± 0.7 years old) played an arm movement controlled VR game alone and with a peer while each of them stood on a pressure measuring pad to track the path length and ranges of movement of the COP. The total COP path was significantly higher during the paired-play (median 295.8 cm) compared to the COP path during the solo-play (median 189.2 cm). No significant differences were found in the reaction time and the mediolateral and anterior-posterior COP ranges between solo-play and paired-play. No significant differences were found between the parameters extracted during paired-play with the dominant or nondominant hand. Our findings imply that the paired-play is advantageous compared to solo-play since it induces a greater movement for the child, during which, higher COP velocities are reached that may contribute to improving the balance control of the child. Apart from the positive social benefits of paired-play, this positive effect on the COP path length is a noteworthy added value in the clinical setting when treating children with balance disorder.

  8. Accelerator Center for Energy Research (ACER)

    Data.gov (United States)

    Federal Laboratory Consortium — The Accelerator Center for Energy Research (ACER) exploits radiation chemistry techniques to study chemical reactions (and other phenomena) by subjecting samples to...

  9. Quasielastic reactions

    International Nuclear Information System (INIS)

    Henning, W.

    1979-01-01

    Quasielastic reaction studies, because of their capability to microscopically probe nuclear structure, are still of considerable interest in heavy-ion reactions. The recent progress in understanding various aspects of the reaction mechanism make this aim appear closer. The relation between microscopic and macroscopic behavior, as suggested, for example, by the single proton transfer data to individual final states or averaged excitation energy intervals, needs to be explored. It seems particularly useful to extend measurements to higher incident energies, to explore and understand nuclear structure aspects up to the limit of the energy range where they are important

  10. Design and analysis of the vacuum vessel for RTO/RC-ITER

    International Nuclear Information System (INIS)

    Onozuka, M.; Ioki, K.; Johnson, G.; Kodama, T.; Sannazzaro, G.; Utin, Y.

    2000-01-01

    Recent progress in design and analysis of the vacuum vessel (VV) for the reduced technical objectives/reduced cost International Thermonuclear Experimental Reactor (RTO/RC-ITER) is presented. The basic VV design is similar to the previous ITER VV. However, because the back plate for the blanket modules could be eliminated, its previous functions could be transferred to the VV. For this option, the blanket modules are supported directly by the VV and the blanket coolant channels are structurally part of the VV double wall structure. In addition, a 'tight fitting' configuration is required to correctly position the modules' first wall. Although such modifications of the VV complicate its structure and increase its fabrication cost, the design of the VV is considered to be still feasible. The structural analyses of the VV have been conducted using several FE models of the VV, including global and local models. Although further assessment is required, based on the analyses performed to date, the structural aspects of the VV for the case without the back plate appear feasible

  11. RTO/RC ITER plasma performance: inductive and steady-state operation

    International Nuclear Information System (INIS)

    Mukhovatov, V.; Boucher, D.; Fujisawa, N.; Shimada, M.; Vayakis, G.; Janeschitz, G.; Matsumoto, H.; Leonov, V.; Polevoy, A.

    2000-01-01

    The plasma performance in two design options of the reduced-technical objectives/reduced cost (RTO/RC) ITER, i.e. IAM (intermediate aspect ratio machine) and LAM (low aspect ratio machine) is analysed. It is shown that Q=P fus /P aux ∼10 can be obtained in both options at inductively driven ELMy H-mode operation. The operation domain in LAM is found to be marginally larger than that in IAM. The non-inductive operation with Q approx.= 5 will be possible in both machines, provided a large amount of power with a high current drive efficiency is applied, or substantial improvement of the energy confinement time relative to the ELMy H-mode (H H =1.2-1.4) is obtained. The required values of H H and β N are marginally smaller in IAM. The IAM-like machine, ITER-FEAT (fusion energy advanced tokamak), proposed for a detailed engineering design is discussed in brief. (author)

  12. Material activation assessment for waste analysis of the EU design of RC/RTO ITER

    International Nuclear Information System (INIS)

    Cambi, G.; Cepraga, D.G.; Frisoni, M.

    2001-01-01

    This paper presents the results of Sn radiation transport and activation calculations related to the ITER RC/RTO EU-I design, performed in support of safety and waste management analyses. The activation characteristics (included the clearance levels) have been estimated for the different materials/zones of the equatorial plane up to 10 5 years after plasma operations. The Bonami-XSDNRPM sequence of the Scale 4.4 code system (using Vitamin-ENEA library, based on ENDF/B-VI data) has been used for radiation transport analyses. The ANITA-4M activation code (with FENDL/A-2 and FENDL/D-2 activation and decay data libraries) is used for the activation calculation. The unconditional clearance level data library is based on IAEA-TECDOC-855. First, a sensitivity analysis to optimise the radial spatial meshing for the neutron flux distribution evaluation and, accordingly, for the activation calculation, has been performed. Then, the clearance indexes of vessel and ex-vessel zones/materials have been calculated. The results are presented and discussed. A design option that considers copper instead of superconductor material for TFC winding pack has also been considered and assessed

  13. Masonry Infilling Effect On Seismic Vulnerability and Performance Level of High Ductility RC Frames

    International Nuclear Information System (INIS)

    Ghalehnovi, M.; Shahraki, H.

    2008-01-01

    In last years researchers preferred behavior-based design of structure to force-based one for designing and construction of the earthquake-resistance structures, this method is named performance based designing. The main goal of this method is designing of structure members for a certain performance or behavior. On the other hand in most of buildings, load bearing frames are infilled with masonry materials which leads to considerable changes in mechanical properties of frames. But usually infilling wall's effect has been ignored in nonlinear analysis of structures because of complication of the problem and lack of simple logical solution. As a result lateral stiffness, strength, ductility and performance of the structure will be computed with less accuracy. In this paper by use of Smooth hysteretic model for masonry infillings, some high ductile RC frames (4, 8 stories including 1, 2 and 3 spans) designed according to Iranian code are considered. They have been analyzed by nonlinear dynamic method in two states, with and without infilling. Then their performance has been determined with criteria of ATC 40 and compared with recommended performance in Iranian seismic code (standard No. 2800)

  14. A multi-standard active-RC filter with accurate tuning system

    International Nuclear Information System (INIS)

    Ma Heping; Yuan Fang; Shi Yin; Dai, F F

    2009-01-01

    A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 μm 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm 2 and 0.11 mm 2 (calibration circuit excluded), respectively.

  15. Security devices and experiment facilities at ENEA TRIGA RC-1 reactor

    International Nuclear Information System (INIS)

    Bianchi, P.; Festinesi, A.; Santoro, E.; Tardani, G.; Magli, M.; Reis, G.

    1990-01-01

    RC-1 TRIGA operating exercise staff has produced some auxiliary security devices. These are the neutron source automatic handling device, irradiated samples rabbit connection rotating rack, and auxiliary equipment for transferring hot fuel elements. The reactor electronic control instrumentation system includes various instrumentation channels, the operating capability of which must be verified by the licensee as per Italian regulations. In order to obtain automatic and repeatable operations, TEMAV designed and constructed a remotely-driven source transfer device, based on requirements, performance specifications and technical data supplied by ENEA-TIB. The pneumatic irradiating system for short lived materials allows extraction of radiated samples in a time no longer than 4 seconds. To optimize the system, both as to operability and health protection, a specific rotating rack for the connection of irradiated samples with pneumatic transfer (RABBIT) was produced. To permit 1 MW hot fuel element storage in pits it is necessary to remove hot 100 KW fuel elements and transfer them to a re-treatment plant. Feasibility studies showed the impossibility of using heavy trucks inside the reactor hall. To avoid problems trucks are left outside the reactor hall and only the PEGASO container is removed with a special device that runs on rails. Movement from Rail truck is assured by an electromotor driving pull device and security cable

  16. Vibration based structural assessment of the rehabilitation intervention in r.c. segmental bridge

    Directory of Open Access Journals (Sweden)

    Franchetti Paolo

    2015-01-01

    Full Text Available A vibration based structural assessment campaign was carried out on a r.c. segmental bridge in North East Italy. The bridge has a cantilever static scheme, fixed at the top of the piers and with a hinge at the centre of the span. The particular configuration of the hinge consists in a couple of steel elements, each one composed by a tongue and groove joint. Since the year 1960, the hinge was subjected to consumption and degradation, that caused a malfunctioning of the device. An intervention of rehabilitation of the bridge led to a reinforcement of the existing hinges with the coupling of new metallic devices: new tongue and groove hinges were applied, that by one side allow the horizontal displacements and rotation, by the other side strongly reduce the relative vertical displacements of the two parts of the bridge. A dynamic test campaign was set up in order to assess the effectiveness of the intervention. The principal dynamic parameters were calculated and analysed with respect to the intervention that was realized. The tests clearly showed the effectiveness of the intervention, and helped the designer to have a better understanding of the structural behaviour of the bridge.

  17. Improved seismic response of rc frame structures by using fluid viscous dampers

    International Nuclear Information System (INIS)

    Khan, Q.S.; Qazi, A.U.; Ilyas, M.

    2013-01-01

    In modern era passive control devices are used to improve the seismic response of structures during large magnitude earthquakes. In this research an analytical study is carried out on commercial FEM program SAP 2000 by modeling five, seven and nine storey RC frame structures. Response to four earthquake ground motions on modeled frame structures is studied and is effectively controlled by varying the characteristic properties of Fluid viscous dampers (FVD). Response in terms of frequency, displacement, velocity, acceleration, storey drift, base shear and energy dissipation is studied. Quantitatively in the modeled frames damage in terms of percentage change in global stiffness and natural frequency is determined. Qualitatively damage in terms of performance levels as per ATC-40 and FEMA-440 is considered. With an increase in Additional Stiffness Ratio of FVD corresponding increase in natural frequency and reduction in dynamic response is observed. FVDs significantly improve structural performance level of frames from Completely Damage to Immediate Occupancy/Operational Level during large magnitude earthquakes. (author)

  18. Variation of over strength factor for mid-rise R.C. moment resisting frames

    International Nuclear Information System (INIS)

    Tasnimi, A. A.; Mahmoodi Sahebi, M.

    2001-01-01

    The over strength of a multi-storey structure (as a multi-degree of freedom system) is one of the parameters playing the evaluation of the behaviour factor. This is an important property when the structure exhibits inelastic behaviour and is described by over strength factor. The over strength factor and strength reduction factor due to ductility are considered in most seismic design codes of practice to reduce the elastic strength demand of the structure. In spite the importance of the over strength, its influence has not yet been quantified. This paper is a part of an investigation from which the first part was published in Amirkabir Journal No.36/Winter 1998, entitled as E stimation of over strength of low-ri sed flexural R.C. frames using nonlinear analysis . This paper investigates the variation of over strength factor for reinforced concrete moment resisting frames, having several stories (5 to 15) with various spans (3 to 5) and located in high seismicity regions using non-linear inelastic analysis. The results indicate that the over strength factor of these systems efforts 25 to 40 percent reduction in the elastic strength demand of such frames

  19. SEISMIC FRAGILITY ANALYSIS OF IMPROVED RC FRAMES USING DIFFERENT TYPES OF BRACING

    Directory of Open Access Journals (Sweden)

    HAMED HAMIDI JAMNANI

    2017-04-01

    Full Text Available Application of bracings to increase the lateral stiffness of building structures is a technique of seismic improvement that engineers frequently have recourse to. Accordingly, investigating the role of bracings in concrete structures along with the development of seismic fragility curves are of overriding concern to civil engineers. In this research, an ordinary RC building, designed according to the 1st edition of Iranian seismic code, was selected for examination. According to FEMA 356 code, this building is considered to be vulnerable. To improve the seismic performance of this building, 3 different types of bracings, which are Concentrically Braced Frames, Eccentrically Braced Frames and Buckling Restrained Frames were employed, and each bracing element was distributed in 3 different locations in the building. The researchers developed fragility curves and utilized 30 earthquake records on the Peak Ground Acceleration seismic intensity scale to carry out a time history analysis. Tow damage scale, including Inter-Story Drifts and Plastic Axial Deformation were also used. The numerical results obtained from this investigation confirm that Plastic Axial Deformation is more reliable than conventional approaches in developing fragility curves for retrofitted frames. In lieu of what is proposed, the researchers selected the suitable damage scale and developed and compared log-normal distribution of fragility curves first for the original and then for the retrofitted building.

  20. Implementasi Aplikasi Kriptografi Pada Layanan Pesan Singkat (SMS Menggunakan Algoritma RC6 Berbasis Android

    Directory of Open Access Journals (Sweden)

    Widi Puji Atmojo

    2016-08-01

    Full Text Available Security is a very important aspect in data communication. In the last decade, there was a rapid development in mobile phone technology. Smartphone have been equipped with various features and one of them is the short message service (SMS. However, messages sent via mobile phone networks pose threat to be accessed by people who do not have any authorization. Therefore, it is necessary to do research on the development of software to enhance the security of messages through message encryption and decryption features. This application uses Java programming language with SDK (Software Development Kit Android and Android Studio 1.3.1 as an editor. The initial step of this research is to encrypt the original message to produce the ciphertext message. The second step is to decrypt ciphertext incoming messages to become genuine message. Results from this research are an Android-based application that can perform encryption and decryption of the SMS messages using the RC6 algorithm. With the application of cryptography for SMS messages, the expected level of information security of the message can be improved so that the message will be more secure from unauthorized access.

  1. Flexural and Shear Behavior of RC Concrete Beams Reinforced with Fiber Wire Mesh

    Directory of Open Access Journals (Sweden)

    Rafea Flaih Hassan

    2018-02-01

    Full Text Available This work aims to study  the effect of using fiber wire mesh on the flexural and shear properties of RC concrete beams. Six reinforced concrete beams (120*180*1220mm were tested under two load points. Fiber wire mesh was applied with two manners, first one is three layers as U shape around the section of the beam, the second one is four layers around overall section of beam. The test results indicated that using of fiber wire mesh as additional reinforcement can increase the ultimate load of about (1.85-3.58% in the case of flexural and (17.7-23.7% in case of shear. Also,  results showed that an increasing in  first cracking  load is obtained from  (42.8-85.7% in case of flexural and from (41.2-76.5% in case of shear. Also the shear behavior of beams becomes more ductile when the fiber wire mesh was used in beams. The cracks of shrinkage was disappeared when the fiber wire mesh surround the section of the beam. 

  2. Design and analysis of the vacuum vessel for RTO/RC-ITER

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M. E-mail: onozukm@itereu.de; Ioki, K.; Johnson, G.; Kodama, T.; Sannazzaro, G.; Utin, Y

    2000-11-01

    Recent progress in design and analysis of the vacuum vessel (VV) for the reduced technical objectives/reduced cost International Thermonuclear Experimental Reactor (RTO/RC-ITER) is presented. The basic VV design is similar to the previous ITER VV. However, because the back plate for the blanket modules could be eliminated, its previous functions could be transferred to the VV. For this option, the blanket modules are supported directly by the VV and the blanket coolant channels are structurally part of the VV double wall structure. In addition, a 'tight fitting' configuration is required to correctly position the modules' first wall. Although such modifications of the VV complicate its structure and increase its fabrication cost, the design of the VV is considered to be still feasible. The structural analyses of the VV have been conducted using several FE models of the VV, including global and local models. Although further assessment is required, based on the analyses performed to date, the structural aspects of the VV for the case without the back plate appear feasible.

  3. Estimating the behavior of RC beams strengthened with NSM system using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Seyed Rohollah Hosseini Vaez

    2017-12-01

    Full Text Available In the last decade, conventional materials such as steel and concrete are being replaced by fiber reinforced polymer (FRP materials for the strengthening of concrete structures. Among the strengthening techniques based on Fiber Reinforced Polymer composites, the use of near-surface mounted (NSM FRP rods is emerging as a promising technology for increasing flexural and shear strength of deficient concrete, masonry and timber members. An artificial neural network is an information processing tool that is inspired by the way biological nervous systems (such as the brain process the information. The key element of this tool is the novel structure of the information processing system. In engineering applications, a neural network can be a vector mapper which maps an input vector to an output one. In the present study, a new approach is developed to predict the behavior of strengthened concrete beam using a large number of experimental data by applying artificial neural networks. Having parameters used as input nodes in ANN modeling such as elastic modulus of the FRP reinforcement, the ratio of the steel longitudinal reinforcement, dimensions of the beam section, the ratio of the NSM-FRP reinforcement and characteristics of concrete, the output node was the flexural strength of beams. The idealized neural network was employed to generate empirical charts and equations to be used in design. The aim of this study is to investigate the behavior of strengthened RC beam using artificial neural networks.

  4. Development of a rocking R/C shear wall system implementing repairable structural fuses

    Science.gov (United States)

    Parsafar, Saeed; Moghadam, Abdolreza S.

    2017-09-01

    In the last decades, the concept of earthquake resilient structural systems is becoming popular in which the rocking structure is considered as a viable option for buildings in regions of high seismicity. To this end, a novel wall-base connection based on the " repairable structure" approach is proposed and evaluated. The proposed system is made of several steel plates and high strength bolts act as a friction connection. To achieve the desired rocking motion in the proposed system, short-slotted holes are used in vertical directions for connecting the steel plates to the shear wall (SW). The experimental and numerical studies were performed using a series of displacement control quasi-static cyclic tests on a reference model and four different configurations of the proposed connection installed at the wall corners. The seismic response of the proposed system is compared to the conventional SW in terms of energy dissipation and damage accumulation. In terms of energy dissipation, the proposed system depicted better performance with 95% more energy dissipation capability compared to conventional SW. In terms of damage accumulation, the proposed SW system is nearly undamaged compared to the conventional wall system, which was severely damaged at the wall-base region. Overall, the introduced concept presents a feasible solution for R/C structures when a low-damage design is targeted, which can improve the seismic performance of the structural system significantly.

  5. Pencil-on-Paper Capacitors for Hand-Drawn RC Circuits and Capacitive Sensing

    Directory of Open Access Journals (Sweden)

    Jonathan E. Thompson

    2017-01-01

    Full Text Available Electronic capacitors were constructed via hand-printing on paper using pencil graphite. Graphite traces were used to draw conductive connections and capacitor plates on opposing sides of a sheet of standard notebook paper. The paper served as the dielectric separating the plates. Capacitance of the devices was generally < 1000 pF and scaled with surface area of the plate electrodes. By combining a pencil-drawn capacitor with an additional resistive pencil trace, an RC low-pass filter was demonstrated. Further utility of the pencil-on-paper devices was demonstrated through description of a capacitive force transducer and reversible chemical sensing. The latter was achieved for water vapor when the hygroscopic cellulose matrix of the paper capacitor’s dielectric adsorbed water. The construction and demonstration of pencil-on-paper capacitive elements broadens the scope of paper-based electronic circuits while allowing new opportunities in the rapidly expanding field of paper-based sensors.

  6. Simulation of Shear and Bending Cracking in RC Beam: Material Model and its Application to Impact

    Science.gov (United States)

    Mokhatar, S. N.; Sonoda, Y.; Zuki, S. S. M.; Kamarudin, A. F.; Noh, M. S. Md

    2018-04-01

    This paper presents a simple and reliable non-linear numerical analysis incorporated with fully Lagrangian method namely Smoothed Particle Hydrodynamics (SPH) to predict the impact response of the reinforced concrete (RC) beam under impact loading. The analysis includes the simulation of the effects of high mass low-velocity impact load falling on beam structures. Three basic ideas to present the localized failure of structural elements are: (1) the accurate strength of concrete and steel reinforcement during the short period (dynamic), Dynamic Increase Factor (DIF) has been employed for the effect of strain rate on the compression and tensile strength (2) linear pressure-sensitive yield criteria (Drucker-Prager type) with a new volume dependent Plane-Cap (PC) hardening in the pre-peak regime is assumed for the concrete, meanwhile, shear-strain energy criterion (Von-Mises) is applied to steel reinforcement (3) two kinds of constitutive equation are introduced to simulate the crushing and bending cracking of the beam elements. Then, these numerical analysis results were compared with the experimental test results.

  7. Anchorage strength models for end-debonding predictions in RC beams strengthened with FRP composites

    Science.gov (United States)

    Nardini, V.; Guadagnini, M.; Valluzzi, M. R.

    2008-05-01

    The increase in the flexural capacity of RC beams obtained by externally bonding FRP composites to their tension side is often limited by the premature and brittle debonding of the external reinforcement. An in-depth understanding of this complex failure mechanism, however, has not yet been achieved. With specific regard to end-debonding failure modes, extensive experimental observations reported in the literature highlight the important distinction, often neglected in strength models proposed by researchers, between the peel-off and rip-off end-debonding types of failure. The peel-off failure is generally characterized by a failure plane located within the first few millimetres of the concrete cover, whilst the rip-off failure penetrates deeper into the concrete cover and propagates along the tensile steel reinforcement. A new rip-off strength model is described in this paper. The model proposed is based on the Chen and Teng peel-off model and relies upon additional theoretical considerations. The influence of the amount of the internal tensile steel reinforcement and the effective anchorage length of FRP are considered and discussed. The validity of the new model is analyzed further through comparisons with test results, findings of a numerical investigation, and a parametric study. The new rip-off strength model is assessed against a database comprising results from 62 beams tested by various researchers and is shown to yield less conservative results.

  8. Recent improvements to RC-line encoded position-sensitive proportional counters

    International Nuclear Information System (INIS)

    Borkowski, C.J.; Kopp, M.K.

    1977-01-01

    Continuing research on the principles of position encoding with RC lines has advanced the design of position-sensitive proportional counters (PSPCs) to meet the requirements for high count rates (>10 5 counts/sec) and good spatial resolution (>10 4 spatial elements) in small-angle scattering experiments with x rays and neutrons. Low-noise preamplifiers were developed with pole-zero cancellation in the feedback circuit and modular linear amplifiers with passive RCL shaping which, compared to previous designs, reduce output saturation at high count rates approx.20 times and shorten the position signal processing time to 2 ) for low-energy ( 800 x 800 mm 2 ) for the measurement of small-angle scattering with neutrons. The method of electronic thickness discrimination was applied to change the effective thickness of an area PSPC from 12 to 2 cm whenever the molybdenum target of an x-ray generator was changed to a copper target. This thickness adjustment increased the signal-to-background ratio by a factor of approx.6 for the 8-keV photons from the copper target, while maintaining a >90% detection efficiency

  9. Hausdorff-Based RC and IESIL Combined Positioning Algorithm for Underwater Geomagnetic Navigation

    Directory of Open Access Journals (Sweden)

    Lin Yi

    2010-01-01

    Full Text Available This paper presents a primitive solution with novel scheme and algorithm for Underwater geoMagnetic Navigation (UMN, which now occurs as the hot-point in the research field of navigation. UMN as an independent or supplementary technique can theoretically supply accurate locations for marine vehicles, but in practice there are plenty of restrictions for UMN's application (e.g., geomagnetic daily variation. After analysis of the theoretical model of geomagnetic positioning in the correlation-matching mode from the viewpoint of pattern recognition, this paper proposed an appropriate matching scenario and a combined positioning algorithm for UMN. The subalgorithm of Hausdorff-based Relative Correlation (RC corresponding to the pattern classification module implements the coarse positioning, and the subalgorithm of Isograms Equidistance-Segmenting theIntersection Lines (IESILs associated with the module of feature extraction continues the fine positioning. The experiments based on the simulation platform and the real-surveyed data both validate the new algorithm, and its efficiency and accuracy are also discussed. It can be concluded that the work introduced in this paper gives an initial and real validation of UMN's potentiality.

  10. Prediction of strain values in reinforcements and concrete of a RC frame using neural networks

    Science.gov (United States)

    Vafaei, Mohammadreza; Alih, Sophia C.; Shad, Hossein; Falah, Ali; Halim, Nur Hajarul Falahi Abdul

    2018-03-01

    The level of strain in structural elements is an important indicator for the presence of damage and its intensity. Considering this fact, often structural health monitoring systems employ strain gauges to measure strains in critical elements. However, because of their sensitivity to the magnetic fields, inadequate long-term durability especially in harsh environments, difficulties in installation on existing structures, and maintenance cost, installation of strain gauges is not always possible for all structural components. Therefore, a reliable method that can accurately estimate strain values in critical structural elements is necessary for damage identification. In this study, a full-scale test was conducted on a planar RC frame to investigate the capability of neural networks for predicting the strain values. Two neural networks each of which having a single hidden layer was trained to relate the measured rotations and vertical displacements of the frame to the strain values measured at different locations of the frame. Results of trained neural networks indicated that they accurately estimated the strain values both in reinforcements and concrete. In addition, the trained neural networks were capable of predicting strains for the unseen input data set.

  11. 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.

  12. Analysis of Foundation of Tall R/C Chimney Incorporating Flexibility of Soil

    Science.gov (United States)

    Jayalekshmi, B. R.; Jisha, S. V.; Shivashankar, R.

    2017-09-01

    Three dimensional Finite Element (FE) analysis was carried out for 100 and 400 m high R/C chimneys having piled annular raft and annular raft foundations considering the flexibility of soil subjected to across-wind load. Stiffness of supporting soil and foundation were varied to evaluate the significance of Soil-Structure Interaction (SSI). The integrated chimney-foundation-soil system was analysed by finite element software ANSYS based on direct method of SSI assuming linear elastic material behaviour. FE analyses were carried out for two cases of SSI namely, (1) chimney with annular raft foundation and (2) chimney with piled annular raft foundation. The responses in raft such as bending moments and settlements were evaluated for both the cases and compared to those obtained from the conventional method of analysis of annular raft foundation. It is found that the responses in raft vary considerably depending on the stiffness of the underlying soil and the stiffness of foundation. Piled raft foundations are better suited for tall chimneys to be constructed in loose or medium sand.

  13. A multi-standard active-RC filter with accurate tuning system

    Energy Technology Data Exchange (ETDEWEB)

    Ma Heping; Yuan Fang; Shi Yin [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Dai, F F, E-mail: hpma@semi.ac.c [Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849-5201 (United States)

    2009-09-15

    A low-power, highly linear, multi-standard, active-RC filter with an accurate and novel tuning architecture is presented. It exhibits IEEE 802.11 a/b/g (9.5 MHz) and DVB-H (3 MHz, 4 MHz) application. The filter exploits digitally-controlled polysilicon resistor banks and a phase lock loop type automatic tuning system. The novel and complex automatic frequency calibration scheme provides better than 4 corner frequency accuracy, and it can be powered down after calibration to save power and avoid digital signal interference. The filter achieves OIP3 of 26 dBm and the measured group delay variation of the receiver filter is 50 ns (WLAN mode). Its dissipation is 3.4 mA in RX mode and 2.3 mA (only for one path) in TX mode from a 2.85 V supply. The dissipation of calibration consumes 2 mA. The circuit has been fabricated in a 0.35 {mu}m 47 GHz SiGe BiCMOS technology; the receiver and transmitter filter occupy 0.21 mm{sup 2} and 0.11 mm{sup 2} (calibration circuit excluded), respectively.

  14. Flexural Strengthening of RC Slabs with Prestressed CFRP Strips Using Different Anchorage Systems

    Directory of Open Access Journals (Sweden)

    José Sena-Cruz

    2015-10-01

    Full Text Available Externally Bonded Reinforcement (EBR technique has been widely used for flexural strengthening of concrete structures by using carbon fiber-reinforced polymers (CFRP. EBR technique offers several structural advantages when the CFRP material is prestressed. This paper presents an experimental and numerical study on reinforced (RC slabs strengthened in flexure with prestressed CFRP strips as a structural strengthening system. The strips are applied as an externally bonded reinforcement (EBR and anchored with either a mechanical or a gradient anchorage. The former foresees metallic anchorage plates fixed to the concrete substrate, while the latter is based on an accelerated epoxy resin curing followed by a segment-wise prestress force decrease at the strip ends. Both anchorage systems, in combination with different CFRP strip geometries, were subjected to static loading tests. It could be demonstrated that the composite strip’s performance is better exploited when prestressing is used, with slightly higher overall load carrying capacities for mechanical anchorages than for the gradient anchorage. The performed investigations by means of a cross-section analysis supported the experimental observation that in case a mechanical anchorage is used, progressive strip debonding changes the fully bonded configuration to an unbonded end-anchored system. The inclusion of defined debonding criteria for both the anchorage zones and free length between the anchorage regions allowed to precisely capture the ultimate loading forces.

  15. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology,. Hyderabad ... thus obtained are helpful to model the regioselectivity ... compromise to model Diels–Alder reactions involving ...... acceptance.

  16. Hydrogen abstraction reactions by amide electron adducts

    International Nuclear Information System (INIS)

    Sevilla, M.D.; Sevilla, C.L.; Swarts, S.

    1982-01-01

    Electron reactions with a number of peptide model compounds (amides and N-acetylamino acids) in aqueous glasses at low temperature have been investigated using ESR spectroscopy. The radicals produced by electron attachment to amides, RC(OD)NDR', are found to act as hydrogen abstracting agents. For example, the propionamide electron adduct is found to abstract from its parent propionamide. Electron adducts of other amides investigated show similar behavior except for acetamide electron adduct which does not abstract from its parent compound, but does abstract from other amides. The tendency toward abstraction for amide electron adducts are compared to electron adducts of several carboxylic acids, ketones, aldehydes and esters. The comparison suggests the hydrogen abstraction tendency of the various deuterated electron adducts (DEAs) to be in the following order: aldehyde DEA > acid DEA = approximately ester DEA > ketone DEA > amide DEA. In basic glasses the hydrogen abstraction ability of the amide electron adducts is maintained until the concentration of base is increased sufficiently to convert the DEA to its anionic form, RC(O - )ND 2 . In this form the hydrogen abstracting ability of the radical is greatly diminished. Similar results were found for the ester and carboxylic acid DEA's tested. (author)

  17. The Intercomparison of 3D Radiation Codes (I3RC): Showcasing Mathematical and Computational Physics in a Critical Atmospheric Application

    Science.gov (United States)

    Davis, A. B.; Cahalan, R. F.

    2001-05-01

    The Intercomparison of 3D Radiation Codes (I3RC) is an on-going initiative involving an international group of over 30 researchers engaged in the numerical modeling of three-dimensional radiative transfer as applied to clouds. Because of their strong variability and extreme opacity, clouds are indeed a major source of uncertainty in the Earth's local radiation budget (at GCM grid scales). Also 3D effects (at satellite pixel scales) invalidate the standard plane-parallel assumption made in the routine of cloud-property remote sensing at NASA and NOAA. Accordingly, the test-cases used in I3RC are based on inputs and outputs which relate to cloud effects in atmospheric heating rates and in real-world remote sensing geometries. The main objectives of I3RC are to (1) enable participants to improve their models, (2) publish results as a community, (3) archive source code, and (4) educate. We will survey the status of I3RC and its plans for the near future with a special emphasis on the mathematical models and computational approaches. We will also describe some of the prime applications of I3RC's efforts in climate models, cloud-resolving models, and remote-sensing observations of clouds, or that of the surface in their presence. In all these application areas, computational efficiency is the main concern and not accuracy. One of I3RC's main goals is to document the performance of as wide a variety as possible of three-dimensional radiative transfer models for a small but representative number of ``cases.'' However, it is dominated by modelers working at the level of linear transport theory (i.e., they solve the radiative transfer equation) and an overwhelming majority of these participants use slow-but-robust Monte Carlo techniques. This means that only a small portion of the efficiency vs. accuracy vs. flexibility domain is currently populated by I3RC participants. To balance this natural clustering the present authors have organized a systematic outreach towards

  18. Ductility Analysis of RC Beams Considering the Concrete Confinement Effect Produced by the Shear Reinforcement: a Numerical Approach

    Directory of Open Access Journals (Sweden)

    Caio Gorla Nogueira

    Full Text Available Abstract In this paper, a simplified numerical approach to study the influence of the confinement effect provided by transversal reinforcement on the ductility behavior of RC beams in bending is proposed. A unidimensional FEM mechanical model coupled to the Mazars’ damage model to simulate concrete behavior was adopted to assess ductility curvatures at the ultimate limit state. The confinement effect was incorporated to the numerical model through a calibration process of the damage internal parameters, based on the Least Square Method and an analytical law proposed by Kent and Park (1971. Several numerical analyses were carried out considering different designs of RC beams according to a parametric study varying the neutral axis position, concrete compressive strength and the volumetric transversal reinforcement ratio. The obtained results showed the importance of the amount of transversal reinforcement on the ductility behavior, increasing the ductility factor even for the cases with inappropriate neutral axis position.

  19. A new 4π(LS)-γ coincidence counter at NCBJ RC POLATOM with TDCR detector in the beta channel.

    Science.gov (United States)

    Ziemek, T; Jęczmieniowski, A; Cacko, D; Broda, R; Lech, E

    2016-03-01

    A new 4π(LS)-γ coincidence system (TDCRG) was built at the NCBJ RC POLATOM. The counter consists of a TDCR detector in the beta channel and scintillation detector with NaI(Tl) crystal in the gamma channel. The system is equipped with a digital board with FPGA, which records and analyses coincidences in the TDCR detector and coincidences between the beta and gamma channels. The characteristics of the system and a scheme of the FPGA implementation with behavioral simulation are given. The TDCRG counter was validated by activity measurements on (14)C and (60)Co solutions standardized in RC POLATOM using previously validated methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Effects of age and parity on mammary gland lesions and progenitor cells in the FVB/N-RC mice.

    Directory of Open Access Journals (Sweden)

    Ahmed Raafat

    Full Text Available The FVB/N mouse strain is extensively used in the development of animal models for breast cancer research. Recently it has been reported that the aging FVB/N mice develop spontaneous mammary lesions and tumors accompanied with abnormalities in the pituitary glands. These observations have a great impact on the mouse models of human breast cancer. We have developed a population of inbred FVB/N mice (designated FVB/N-RC that have been genetically isolated for 20 years. To study the effects of age and parity on abnormalities of the mammary glands of FVB/N-RC mice, twenty-five nulliparous and multiparous (3-4 pregnancies females were euthanized at 16-22 months of age. Examination of the mammary glands did not reveal macroscopic evidence of mammary gland tumors in either aged-nulliparous or multiparous FVB/N-RC mice (0/25. However, histological analysis of the mammary glands showed rare focal nodules of squamous changes in 2 of the aged multiparous mice. Mammary gland hyperplasia was detected in 8% and 71% of the aged-nulliparous and aged-multiparous mice, respectively. Epithelial contents and serum levels of triiodothyronine were significantly higher in the experimental groups than the 14-wk-old control mice. Immuno-histochemical staining of the pituitary gland pars distalis showed no difference in prolactin staining between the control and the aged mice. Tissue transplant and dilution studies showed no effect of age and/or parity on the ability of putative progenitor cells present among the injected mammary cells to repopulate a cleared fat pad and develop a full mammary gland outgrowth. This FVB/N-RC mouse substrain is suitable to develop mouse models for breast cancer.

  1. Implementation of Highly-Flowable Strain Hardening Fiber Reinforced Concrete in New RC Beam-Column Joints

    Directory of Open Access Journals (Sweden)

    Liao Wen-Cheng

    2018-01-01

    Full Text Available The purpose of New RC project was aimed to reduce the member sections and increase the available space of high rise buildings by using high strength concrete (f’c > 70 MPa and high strength rebars (fy > 685 MPa. Material consumptions and member section sizes can be further reduced owing to the upgrade of strength. However, the nature of brittleness of high strength may also cause early cover spalling and other ductility issues. Addition of steel fibers is an alternative as transverse reinforcement. Highly flowable strain hardening fiber reinforced concrete (HF-SHFRC has excellent workability in the fresh state and exhibits the strain-hardening and multiple cracking characteristics of high performance fiber reinforced cementitious composites (HPFRCC in their hardened state. The objective of this study is to investigate the feasibility of implementing HF-SHFRC in New RC building systems, particularly for beam-column joints as an alternative of transverse reinforcements. Four full-scale exterior beam-column joints, including two specimens with intensive transverse reinforcements and two specimens made of HF-SHFRC without any stirrup, are tested. Test results show that the HF-SHFRC specimens perform as well as specimens with intensive transverse reinforcements regarding failure mode, ductility, energy dissipation and crack width control. Integration of New RC building systems and HF-SHFRC can assuring construction qualities and further diminish labor work and give infrastructure longer service life, and eventually lower the life-cycle cost.

  2. Evaluation on effects of chloride-induced deterioration on mechanical properties of RC beams with cracking damage

    International Nuclear Information System (INIS)

    Matsuo, Toyofumi; Matsumura, Takuro; Otsuka, Taku

    2015-01-01

    This paper discusses the influence of chloride-induced deterioration on mechanical properties of aging reinforced concrete (RC) structures and the applicability of the material degradation model that takes reinforcing steel corrosion into consideration for finite element analysis. We conducted the corrosion tests under the simulated tidal environment and the flexural loading tests for the RC beams with cracking damage and initial defects. Then, the experimental results were numerically correlated to validate the devised modeling. The obtained results were summarized as follows: (a) The cracking damage in specimens caused a minor effect on the reinforcing steel corrosion in the case where the thickness of cover concrete was 40 mm and main rebars did not yield before chloride attack. On the other hand the maximum corrosion ratio of the deteriorated part became considerably larger than that of the non-cracking part in the specimens where the cover concrete were removed partially to simulate spalling by the severe corrosion. (b) Based on the test results, we derived the corrosion velocity of reinforcing steel corresponding to cracking damage degrees. (c) In FEM analyses, we showed that the above modeling can estimate the flexural strength of RC beams in consideration of the degradation in elongation performance of reinforcing steel due to corrosion. (author)

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

    Directory of Open Access Journals (Sweden)

    Abdulla Jabr

    2017-01-01

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

  4. Direct Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Austern, N. [University of Pittsburgh, Pittsburgh, PA (United States)

    1963-01-15

    In order to give a unified presentation of one point of view, these lectures are devoted only to a detailed development of the standard theories of direct reactions, starting from basic principles. Discussion is given of the present status of the theories, of the techniques used for practical calculation, and of possible future developments. The direct interaction (DI) aspects of a reaction are those which involve only a few of the many degrees of freedom of a nucleus. In fact the minimum number of degrees of freedom which must be involved in a reaction are those required to describe the initial and final channels, and DI studies typically consider these degrees of freedom and no others. Because of this simplicity DI theories may be worked out in painstaking detail. DI processes concern only part of the wave function for a problem. The other part involves complicated excitations of many degrees of freedom, and gives the compound nucleus (CN) effects. While it is extremely interesting to learn how to separate DI and CN effects in an orderly manner, if they are both present in a reaction, no suitable method has yet been found. Instead, current work stresses the kinds of reactions and the kinds of final states in which DI effects dominate and in which CN effects may almost be forgotten. The DI cross-sections which are studied are often extremely large, comparable to elastic scattering cross-sections. (author)

  5. Factors controlling the redox potential of ZnCe6 in an engineered bacterioferritin photochemical 'reaction centre'.

    Science.gov (United States)

    Mahboob, Abdullah; Vassiliev, Serguei; Poddutoori, Prashanth K; van der Est, Art; Bruce, Doug

    2013-01-01

    Photosystem II (PSII) of photosynthesis has the unique ability to photochemically oxidize water. Recently an engineered bacterioferritin photochemical 'reaction centre' (BFR-RC) using a zinc chlorin pigment (ZnCe6) in place of its native heme has been shown to photo-oxidize bound manganese ions through a tyrosine residue, thus mimicking two of the key reactions on the electron donor side of PSII. To understand the mechanism of tyrosine oxidation in BFR-RCs, and explore the possibility of water oxidation in such a system we have built an atomic-level model of the BFR-RC using ONIOM methodology. We studied the influence of axial ligands and carboxyl groups on the oxidation potential of ZnCe6 using DFT theory, and finally calculated the shift of the redox potential of ZnCe6 in the BFR-RC protein using the multi-conformational molecular mechanics-Poisson-Boltzmann approach. According to our calculations, the redox potential for the first oxidation of ZnCe6 in the BRF-RC protein is only 0.57 V, too low to oxidize tyrosine. We suggest that the observed tyrosine oxidation in BRF-RC could be driven by the ZnCe6 di-cation. In order to increase the efficiency of tyrosine oxidation, and ultimately oxidize water, the first potential of ZnCe6 would have to attain a value in excess of 0.8 V. We discuss the possibilities for modifying the BFR-RC to achieve this goal.

  6. Estimation of the behavior factor of existing RC-MRF buildings

    Science.gov (United States)

    Vona, Marco; Mastroberti, Monica

    2018-01-01

    In recent years, several research groups have studied a new generation of analysis methods for seismic response assessment of existing buildings. Nevertheless, many important developments are still needed in order to define more reliable and effective assessment procedures. Moreover, regarding existing buildings, it should be highlighted that due to the low knowledge level, the linear elastic analysis is the only analysis method allowed. The same codes (such as NTC2008, EC8) consider the linear dynamic analysis with behavior factor as the reference method for the evaluation of seismic demand. This type of analysis is based on a linear-elastic structural model subject to a design spectrum, obtained by reducing the elastic spectrum through a behavior factor. The behavior factor (reduction factor or q factor in some codes) is used to reduce the elastic spectrum ordinate or the forces obtained from a linear analysis in order to take into account the non-linear structural capacities. The behavior factors should be defined based on several parameters that influence the seismic nonlinear capacity, such as mechanical materials characteristics, structural system, irregularity and design procedures. In practical applications, there is still an evident lack of detailed rules and accurate behavior factor values adequate for existing buildings. In this work, some investigations of the seismic capacity of the main existing RC-MRF building types have been carried out. In order to make a correct evaluation of the seismic force demand, actual behavior factor values coherent with force based seismic safety assessment procedure have been proposed and compared with the values reported in the Italian seismic code, NTC08.

  7. Experimental investigation on full scale RC beam-column joint of NPP structures

    International Nuclear Information System (INIS)

    Thandavamoorthy, T.S.; Lakshmanan, N.; Reddy, G.R.; Kushwaha, H.S.

    2003-01-01

    The Nuclear Power Plant (NPP) structures in India are constructed using reinforced concrete. The beam-column joint in these structures are critical sub-assemblages because they ensure continuity of a structure and transfer forces from one element to another. Under seismic excitation, the beam-column joint region is subjected to horizontal and vertical shear forces whose magnitudes are typically many times higher than those within the adjacent beams and columns. In view of the increased incidence of seismicity in the country, the safety of these structures against earthquake loading assumes greater significance. There is a growing need to look into the seismic safety aspect of existing RC frame type structures in NPPs, which have been designed as per codes prevalent at the time of their construction. Seismic performance of such joints has not been studied extensively in India. Therefore experimental testing of full scale joint identical to those available in the existing NPP structures, was carried out to study its behaviour and evaluate its capacity. The size of the beam of the joint was 2000 mm x 610 mm x 915 mm and column 2915 mm x 610 mm x 915 mm. The percentage reinforcement of the beam was 4.95 and column 1.5. Such full scale and heavily reinforced concrete joint was cast successfully in the laboratory and tested under monotonic loading. The paper presents a complete description of the experimental testing, observations made during testing as for cracking, deflection and rotation of joint, discussion of results obtained, etc. Conclusions drawn from the investigation are also presented. (author)

  8. IL-17A, IL-17RC polymorphisms and IL17 plasma levels in Tunisian patients with rheumatoid arthritis

    Science.gov (United States)

    Chahbi, Mayssa; Haouami, Youssra; Sfar, Imen; Abdelmoula, Leila; Ben Abdallah, Taieb; Gorgi, Yousr

    2018-01-01

    Background Interleukin-17 (IL-17), a cytokine mainly secreted by Th17 cells, seems to play a significant role in the pathogenesis of rheumatoid arthritis (RA). Functional genetic polymorphisms in IL-17 and its receptor genes can influence either qualitatively or quantitatively their functions. Therefore, we aimed to study the impact of IL17-A and IL17RC polymorphisms on plasma level of IL-17 and RA susceptibility and severity. Methods In this context, IL-17A*rs2275913 and IL-17RC*rs708567 polymorphisms were investigated together with the quantification of IL17 plasma level in 115 RA patients and 91 healthy control subjects matched in age, sex and ethnic origin. Results There were no statistically significant associations between IL-17A and IL-17RC studied polymorphisms and RA susceptibility. In contrast, IL-17A plasma levels were significantly higher in patients (55.07 pg/ml) comparatively to controls (4.75 pg/ml), p<10E-12. A ROC curve was used to evaluate the performance of plasma IL-17 in detecting RA. Given 100% specificity, the highest sensitivity of plasma IL-17A was 61.7% at a cut-off value of 18.25 pg/ml; p < 10E-21, CI = [0.849–0.939]. Analytic results showed that the IgM-rheumatoid factor and anti-CCP antibodies were significantly less frequent in patients with the IL-17RC*A/A genotype than those carrying *G/G and *G/A genotypes; p = 0.013 and p = 0.015, respectively. Otherwise, IL-17 plasma levels’ analysis showed a significant association with the activity of RA (DAS28≥5.1 = 74.71 pg/ml vs. DAS28<5.1 = 11.96 pg/ml), p<10E-6. Conclusion IL-17A*rs2275913 (G/A) and IL-17RC*rs708567 (G/A) polymorphisms did not seem to influence RA susceptibility in Tunisian population. This result agrees with those reported previously. Plasma IL-17A level seems to be predictive of severe RA occurrence. PMID:29584788

  9. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  10. Sociální vztahy a postoje v ženském ragbyovém týmu RC Tatra Smíchov

    OpenAIRE

    Kadavá, Tereza

    2014-01-01

    Title: Social Relationships and Attitudes in Women's RC Tatra Smichov Rugby Team Objectives: The main objective of this thesis is to analyze social relations and attitudes in the women's RC Tatra Smichov rugby team and to create the profiles of the players. The analysis should help the new coach to get to know the players well, focusing mainly on their career, ambition, motivation, and feelings during trainings and matches. At the same time, it should shed light on how they perceive themselve...

  11. Experimental investigations on a cascaded steam-/organic-Rankine-cycle (RC/ORC) system for waste heat recovery (WHR) from diesel engine

    International Nuclear Information System (INIS)

    Yu, Guopeng; Shu, Gequn; Tian, Hua; Huo, Yongzhan; Zhu, Weijie

    2016-01-01

    Highlights: • A novel cascaded RC/ORC system was constructed for WHR of a heavy-duty diesel engine. • The RC/ORC system was experimentally investigated under engine operating conditions. • Good system stability and satisfying thermal states of working fluids were observed. • The power increment can reach up to 5.6% by equipping the novel cascaded RC/ORC system. - Abstract: A novel cascaded RC/ORC system that comprises a steam Rankine cycle as the high-temperature loop (H-RC) and an organic Rankine cycle as the low-temperature loop (L-ORC) was constructed and experimentally investigated to recover waste heat from exhaust gas of a heavy-duty diesel engine (DE). By monitoring key parameters of the RC/ORC system against time, good system stability and satisfying thermal states of working fluids were observed. Impacts that the engine operations have on this proposed waste-heat-recovery (WHR) system were studied, indicating that waste heat recovered from the gas increases gradually and greatly as the engine load increases, yet decreases slightly as the speed grows. At full loads at speeds lower than 2050 rpm, up to 101.5 kW of waste heat can be abstracted from the gas source, showing a promising heat transfer potential. Besides, observations of key exergy states as well as estimations and comparisons of potential output power were carried out stepwise. Results indicated that up to 12.7 kW of output power could be obtained by the novel RC/ORC system under practical estimations. Comparing to the basic diesel engine, the power increment reaches up to 5.6% by equipping the cascaded RC/ORC system.

  12. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  13. A higher risk of acute rejection of human kidney allografts can be predicted from the level of CD45RC expressed by the recipients' CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Laurence Ordonez

    Full Text Available Although transplantation is the common treatment for end-stage renal failure, allograft rejection and marked morbidity from the use of immunosuppressive drugs remain important limitations. A major challenge in the field is to identify easy, reliable and noninvasive biomarkers allowing the prediction of deleterious alloreactive immune responses and the tailoring of immunosuppressive therapy in individuals according to the rejection risk. In this study, we first established that the expression of the RC isoform of the CD45 molecule (CD45RC on CD4 and CD8 T cells from healthy individuals identifies functionally distinct alloreactive T cell subsets that behave differently in terms of proliferation and cytokine secretion. We then investigated whether the frequency of the recipients CD45RC T cell subsets before transplantation would predict acute graft rejection in a cohort of 89 patients who had undergone their first kidney transplantation. We showed that patients exhibiting more than 54.7% of CD8 CD45RC(high T cells before transplantation had a 6 fold increased risk of acute kidney graft rejection. In contrast, the proportions of CD4 CD45RC T cells were not predictive. Thus, a higher risk of acute rejection of human kidney allografts can be predicted from the level of CD45RC expressed by the recipients' CD8 T cells.

  14. Conformational dependence of a protein kinase phosphate transfer reaction

    Science.gov (United States)

    Labute, Montiago; Henkelman, Graeme; Tung, Chang-Shung; Fenimore, Paul; McMahon, Ben

    2007-03-01

    Atomic motions and energetics for a phosphate transfer reaction catalyzed by the cAMP-dependent protein kinase have been calculated using plane-wave density functional theory, starting from structures of proteins crystallized in both the reactant conformation (RC) and the transition-state conformation (TC). In TC, we calculate that the reactants and products are nearly isoenergetic with a 20-kJ/mol barrier, whereas phosphate transfer is unfavorable by 120 kJ/mol in the RC, with an even higher barrier. Our results demonstrate that the phosphate transfer reaction occurs rapidly and reversibly in a particular conformation of the protein, and that the reaction can be gated by changes of a few tenths of an angstrom in the catalytic site [1]. [1] G.H. Henkelman, M.X. LaBute, C.-S. Tung, P.W. Fenimore, B.H. McMahon, Proc. Natl. Acad. Sci. USA vol. 102, no. 43:15347-15351 (2005).

  15. Usage Center

    DEFF Research Database (Denmark)

    Kleinaltenkamp, Michael; Plewa, Carolin; Gudergan, Siegfried

    2017-01-01

    Purpose: The purpose of this paper is to advance extant theorizing around resourceintegration by conceptualizing and delineating the notion of a usage center. Ausage center consists of a combination of interdependent actors that draw onresources across their individual usage processes to create v...

  16. Evaluation equivalent pulse of pulse-like ground motion to estimate the response of RC moment-resisting frames

    Directory of Open Access Journals (Sweden)

    Seyed Rohollah Hosseini Vaez

    2017-08-01

    Full Text Available In this study the ability of equivalent pulse extracted by a mathematical model from pulse-like ground motion is investigated in order to estimate the response of RC moment-resisting frames. By examining the mathematical model, it is obvious that the model-based elastic response spectra are compatible with the actual pulse-like record. Also, the model simulates the long-period portion of actual pulse-like records by a high level of precision. The results indicate that the model adequately simulates the components of time histories. In order to investigate the ability of equivalent pulse of pulse-like ground motion in estimating the response of RC moment-resisting frames, five frame models including 3, 6, 9, 12 and 15 stories analyzed under actual record and simulated one. The results of the base shear demand, the maximum value of the inter-story drift and the distribution of inter-story drift along the height of the structures in three levels of design ductility is investigated. According to the results of this study, the equivalent pulses can predict accurately the response of regular RC moment-resisting frames when the fundamental period of the structure is equal to or greater than the equivalent pulse of the record. For the ground motion with high-frequency content the difference is high; but with increasing the number of stories and approaching pulse period to the fundamental period of the structure and increasing the level of design ductility of structure, more accurately predict the structural response.

  17. RC-IAL: linhagem celular contínua de rim de coelho - características e substrato para replicação de vírus RC-IAL: rabbit kidney cell line - characteristics and substrate for viral multiplication

    Directory of Open Access Journals (Sweden)

    Aurea Silveira Cruz

    1992-12-01

    Full Text Available Uma linhagem celular de rim de coelho (denominada RC-IAL, que foi isolada em 1976, e que atualmente está na 150ª passagem, teve suas características analisadas. As células apresentaram morfologia semelhante aos fibroblastos desde o início de seu cultivo. A proporção de crescimento celular não se alterou desde seu isolamento, com uma eficiência de clonagem ao redor de 9%. A linhagem mostrou crescimento dependente de ancoragem, e a análise cromossômica apresentou o número modal da espécie com pequenas variações para mais ou menos um cromossomo, resultando uma somatória de 50%. Sua espécie de origem foi comprovada através da reação de imunofluorescência indireta e a susceptibilidade da linhagem a alguns vírus, com demonstração do efeito citopático, foi verificada com os vírus da vacínia, cowpox, herpes simples tipo 1 e 2 e da rubéola. Esse substrato celular está livre de contaminantes, satisfazendo assim, as condições para seu uso em trabalhos científicos, principalmente os relacionadas à saúde pública.A rabbit kidney cell line RC-IAL, isolated in 1976 and at apresent at 150ª passage, has had its characteristics analysed. The cells presented morphology similar to fibroblasto throughout their culture. The cellular growth proportion remained unaltered from its isolation, with a cloning efficiency of around 9%. The line showed growth dependent on anchorage and chromosomic analysis presented the modal number of the species with small variations to about one chromosome, to a total of about 50%. The line's species of origin was confirmed through indirect imunofluorescence reaction and susceptibility to some viruses with cytopatic effect was verified with vaccinia, cowpox, herpes simplex types 1 and 2 and rubella viruses. This cellular substract is free from contaminating agents, thus satisfying the conditions for its use in scientific work, especially that relating to public health.

  18. A selected ion flow tube study of the reactions of H3O+, NO+ and O-2(+center dot) with seven isomers of hexanol in support of SIFT-MS

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Sovová, Kristýna; Španěl, Patrik

    2012-01-01

    Roč. 319, MAY 1 2012 (2012), s. 25-30 ISSN 1387-3806 R&D Projects: GA ČR GA203/09/0256 Institutional support: RVO:61388955 Keywords : selected ion flow tube mass spectrometry * proton transfer * ion molecule reaction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.142, year: 2012

  19. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

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

    1997-01-01

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...

  20. Case Study of Local Damage Indicators for a 2-Bay, 6-Storey RC-Frame subject to Earthquakes

    DEFF Research Database (Denmark)

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

    A simulation study of a 2-bay, 6storey model test RC-frame(scale 1:5) subject to earthquakes is considered in this paper. Based on measured (simulated) storey accelerations and ground surface accelerations several indices for the storey damage, including interstorey drift, flexural damage ratios......, normalized cumulative dissipated energy, Park and Ang's indicator, a low-cycle fatigue damage index and a recently proposed local softening damage index estimated from time-varying eigenfrequencies are used to evaluate the damage state of the structure after the earthquake. Storey displacements are obtained...