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Sample records for 2cr 1molow cycle

  1. Magnetism, hysteresis cycle, and Ir-substitution doping of Sr2CrIrO6 double perovskite: A Monte Carlo simulation

    El Rhazouani, O.; El Khatabi, M.; Zarhri, Z.; Slassi, A.; Benyoussef, A.; El Kenz, A.

    2016-12-01

    Iridium-based double perovskite (DP) Sr2CrIrO6 is expected to have the highest Curie temperatures (Tc) among all DPs and a high spin-polarization at room temperature, thanks to the more extended 5d orbitals of Ir, which makes it potential candidate in spintronic applications. Several publications have appeared in recent years documenting Ir-based double perovskites, but very few have explored the promising compound Sr2CrIrO6. In this paper, a Monte Carlo simulation has been carried out in the framework of Ising model to make an exploratory study of Sr2CrIrO6. Thermal magnetization, magnetic susceptibility, internal energy and specific heat have been studied. Effect of crystal field of Ir on the magnetic properties has been explored. Magnetic hysteresis cycle has been studied in relation to the exchange coupling values. Effects of Ir-substitution doping by Os "Sr2CrIrxOs1 - xO6" and by Re "Sr2CrIrxRe1 - xO6" (0.1 ≤ x ≤ 0.5) on the magnetic behavior have been investigated.

  2. Type IIIa cracking at 2CrMo welds in 1/2CrMoV pipework

    Brett, S.J.; Smith, P.A. [National Power plc, Swindon (United Kingdom)

    1998-12-31

    The most common form of in-service defect found today on the welds of National Power`s 1/2CrMoV pipework systems is Type IV cracking which occurs in intercritically transformed material at the edge of the heat affected zone. However an alternate form of cracking, termed IIIa, which occurs close to the weld fusion line in fully grain refined heat affected zones, has also been observed. The incidence of Type IIIa cracking has increased in recent years and these defects now constitute a significant part of the total recorded crack population. This presentation describes Type IIIa cracking and compares and contrasts it with the better documented Type IV cracking. Particular reference is made to the role of carbon diffusion at the weld fusion line in promoting Type IIIa damage in preference to Type IV. (orig.) 5 refs.

  3. Transport properties of Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn under high magnetic fields

    Okada, H; Koyama, K; Watanabe, K [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai (Japan); Kusakari, Y; Kanomata, T [Faculty of Engineering, Tohoku Gakuin University, Tagajo (Japan); Matsuoka, E; Onodera, H, E-mail: hironari@imr.tohoku.ac.j [Department of Physics, Graduate School of Science, Sendai (Japan)

    2009-03-01

    We have performed the specific heat and the electrical resistivity measurements under high magnetic fields for Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn. We found that the electrical resistivity for Ru{sub 2}CrGe shows an upturn in the vicinity of 130 K and changes a metallic to a semiconducting-like behavior with decreasing temperature. By applying magnetic field, a negative magnetoresistance was observed below 200 K. On the other hand, the electrical resistivity for Ru{sub 2}CrSn shows a semimetallic-like behavior. The results of the electrical resistivity in Ru{sub 2}CrGe suggest that the compound has a gap-like structure in the electronic structure at the Fermi level. Moreover, it was found that another phase transition occurs in Ru{sub 2}CrGe and Ru{sub 2}CrSn, in addition to the magnetic transition.

  4. Development of the 5-HT2CR-Tango System Combined with an EGFP Reporter Gene.

    Watanabe, Yoshihisa; Tsujimura, Atsushi; Aoki, Miku; Taguchi, Katsutoshi; Tanaka, Masaki

    2016-02-01

    The serotonin 2C receptor (5-HT2CR) is a G-protein-coupled receptor implicated in emotion, feeding, reward, and cognition. 5-HT2CRs are pharmacological targets for mental disorders and metabolic and reward system abnormalities, as alterations in 5-HT2CR expression, RNA editing, and SNPs are involved in these disturbances. To date, 5-HT2CR activity has mainly been measured by quantifying inositol phosphate production and intracellular Ca(2+) release, but these assays are not suitable for in vivo analysis. Here, we developed a 5-HT2CR-Tango assay system, a novel analysis tool of 5-HT2CR activity based on the G-protein-coupled receptor (GPCR)-arrestin interaction. With desensitization of activated 5-HT2CR by arrestin, this system converts the 5-HT2CR-arrestin interaction into EGFP reporter gene signal via the LexA transcriptional activation system. For validation of our system, we measured activity of two 5-HT2CR RNA-editing isoforms (INI and VGV) in HEK293 cells transfected with EGFP reporter gene. The INI isoform displayed both higher basal- and 5-HT-stimulated activities than the VGV isoform. Moreover, an inhibitory effect of 5-HT2CR antagonist SB242084 was also detected by 5-HT2CR-Tango system. This novel tool is useful for in vitro high-throughput targeted 5-HT2CR drug screening and can be applied to future in vivo brain function studies associated with 5-HT2CRs in transgenic animal models.

  5. An unexpected tetranuclear Li2Cr2 trimethylsilylacetylide complex bridged by two μ3-pyrazolates

    WANG Feng; CAO Li; LIAO HongLin; JIANG Jun; JIA XiaoLu; GAO Qian; LI DongFeng

    2012-01-01

    A tetranuclear Li2Cr2 acetylide precursor complex,[Li(Tp)CrⅢ(C≡CSiMe3)2(μ3-pz)]2.(n-pentane)2(Tp =hydridotris(pyrazolyl)borate,pz =pyrazolate)(1)has been synthesized and characterized.The X-ray structure analysis shows that the complex contains a Li2Cr2 core bridged by twoμa-pyrazolates.The magnetic data exhibit the existenceof weak antiferromagnetic interaction in the cluster.

  6. Magnetic properties and phase stability of Co{sub 2}Cr(Ga,Si) Heusler alloys

    Umetsu, R.Y., E-mail: rieume@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Japan Science and Technology Agency-Precursory Research for Embryonic Science and Technology (JST-PREST), Saitama 332-0012 (Japan); Okubo, A.; Xu, X.; Kainuma, R. [Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2014-03-05

    Highlights: • Phase diagram was first established in Co{sub 2}Cr(Ga{sub 1−x}Si{sub x}) Heusler alloys. • Existence region of the single phase in the L2{sub 1}-type was confirmed in x ⩽ 0.5. • Magnetic measurements predict Co{sub 2}Cr(Ga,Si) are half-metallic ferromagnets if the order degree is completely controlled. -- Abstract: The phase diagram, magnetic properties and the region over which the Heusler alloys Co{sub 2}Cr(Ga{sub 1−x}Si{sub x}) occur as a single phase have been established. A single phase was obtained in the composition range of x ⩽ 0.5, in which the order–disorder phase transition temperature from the L2{sub 1} to the B2 phase, T{sub t}{sup L21/B2}, increased almost linearly with increasing x. The value of T{sub t}{sup L21/B2} for the L2{sub 1}-type Co{sub 2}CrSi Heusler alloy, estimated by linear extrapolation from its concentration dependence, was about 1450 K, and therefore higher than that of Co{sub 2}CrAl and Co{sub 2}CrGa. The Curie temperature, T{sub C}, also increased with increasing x becoming 600 K at x = 0.5, thus reflecting an increase in the magnetic moment caused by the change in the number of the valence electrons. The concentration dependence of the spontaneous magnetic moment, M{sub s}, measured at 5 K increased with increasing x, almost following the generalized Slater–Pauling (S.P.) rule predicted by Galanakis et al.

  7. Structural and electronic properties of Y2CrS4 from first-principles study

    Wang, B.-T.; Yin, W.; Li, W.-D.; Wang, F.

    2011-04-01

    We systematically study the structural, electronic, and magnetic properties of chromium sulfide Y2CrS4 by using density-functional theory. We find that antiferromagnetic order is more energetically favorable than ferromagnetic state and near the Fermi level the main occupation is from Cr 3 d states.

  8. Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3

    Yahia, H. Ben; Essehli, R.; Avdeev, M.; Park, J.-B.; Sun, Y.-K.; Al-Maadeed, M. A.; Belharouak, I.

    2016-06-01

    The new compounds NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 crystallize with a stuffed α-CrPO4-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structures of NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 a statistical disorder Ni2+/Cr3+ was observed on both the 8g and 4a atomic positions, whereas in NaCoCr2(PO4)3 the statistical disorder Co2+/Cr3+ was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr2(PO4)3, NaNiCr2(PO4)3, and Na2Ni2Cr(PO4)3 delivered specific capacities of 352, 385, and 368 mA h g-1, respectively, which attests to the electrochemical activity of sodium in these compounds.

  9. Structure, magnetism, and electron-transport properties of Mn2CrGa-based nanomaterials

    Wenyong Zhang

    2016-05-01

    Full Text Available Mn2CrGa in the disordered cubic structure has been synthesized using rapid quenching and subsequent annealing. The cubic phase transforms to a stable tetragonal phase when a fraction of Cr or Ga is replaced by Pt or Al, respectively. All samples are ferrimagnetic with high Curie temperatures (Tc; Mn2CrGa exhibits the highest Tc of about 813 K. The tetragonal samples have appreciable values of magnetocrystalline anisotropy energy, which leads to an increase in coercivity (Hc that approaches about 10 kOe in the Pt-doped sample. The Hc linearly increases with a decrease of temperature, concomitant with the anisotropy change with temperature. All samples are metallic and show negative magnetoresistance with room-temperature resistivities on the order of 1 mΩcm. The magnetic properties including high Tc and low magnetic moment suggest that these tetragonal materials have potential for spin-transfer-torque-based devices.

  10. A neutron scattering study of the crystal and magnetic structure of Sr2CrOsO6

    Krockenberger, Y.; Reehuis, M.; Tovar, M.; Mogare, K.; Jansen, M.; Alff, L.

    2007-03-01

    Recently, the new osmium-based ferrimagnetic double perovskite Sr2CrOsO6 has been reported to have the highest Curie temperature (˜725 K) within this material class [Y. Krockenberger, K. Mogare, M. Reehuis, M. Tovar, M. Jansen, G. Vaitheeswaran, V. Kanchana, A. Delin, F. Wilhelm, A. Rogalev, A. Winkler, L. Alff, preprint, 2006]. Here, we report details about the crystal and magnetic structure of Sr2CrOsO6 as obtained by neutron powder diffraction.

  11. Perpendicular magnetic anisotropy in Fe2Cr1 - xCoxSi Heusler alloy

    Wang, Yu-Pu; Qiu, Jin-Jun; Lu, Hui; Ji, Rong; Han, Gu-Chang; Teo, Kie-Leong

    2014-12-01

    Perpendicular magnetic anisotropy (PMA) was achieved in annealed Fe2Cr1 - xCoxSi (FCCS) Heusler alloys with different Co compositions x. The Co composition is varied to tune the Fermi level in order to achieve both higher spin polarization and better thermal stability. The PMA is thermally stable up to 400 oC for FCCS with x = 0, 0.3, 0.5 and 350 oC for FCCS with x = 0.7, 0.9, 1. The thickness of FCCS films with PMA ranges from 0.6 to 1.2 nm. The annealing temperature and FCCS thickness are found to greatly affect the PMA. The magnetic anisotropy energy density KU is 2.8  ×  106 erg cm-3 for 0.8 nm Fe2CrSi, and decreases as the Co composition x increases, suggesting that the PMA induced at the FCCS/MgO interface is dominated by the contribution of Fe atoms. There is a trade-off between high spin polarization and strong PMA by adjusting the Co composition.

  12. Formation of austenite and dissolution of carbides in Fe-8.2Cr-C alloys

    Shtansky, D.; Nakai, K.; Ohmori, Y. [Ehime Univ., Matsuyama (Japan). Faculty of Engineering

    1999-01-01

    The mechanism of austenite formation and the kinetics of carbide dissolution have been studied in Fe-8.2Cr-0.2C and Fe-8.2Cr-0.96 C (numbers indicate mass%) alloys with ferrite lamellar carbide and ferrite spheroidized carbide initial structures. The morphology of austenite formation in the range of 850 to 900 C has been examined in detail by transmission electron microscopy. The mechanisms of austenite nucleation and growth have been distinguished as they depend on the composition, starting microstructure and austenitizing temperature. The effects of both austenitising temperature in the range of 850 to 1150 C and a time on the M{sub 23}C{sub 6} and M{sub 7}C{sub 3} carbide evolution have also been investigated. Different morphologies of transformation products have been observed. The orientation relationships between ferrite, austenite and carbides were determined. The observed results can be explained by assuming local equilibrium at the moving interfaces during the reactions. (orig.) 47 refs.

  13. Laser induced infrared spectral shift of the MgB2:Cr superconductor films.

    AlZayed, N S; Kityk, I V; Soltan, S; El-Naggar, A M; Shahabuddin, M

    2015-02-01

    During illumination of the MgB2:Cr2O3 films it was established substantial spectral shift of the infrared spectra in the vicinity of 20-50cm(-1). The excitations were performed by nanosecond Er:glass laser operating at 1.54μm and by microsecond 10.6μm CO2 laser. The spectral shifts of the IR maxima were in opposite spectral directions for the two types of lasers. This one observed difference correlates well with spectral shift of their critical temperatures. The possible explanation is given by performance of DFT calculations of the charge density redistribution and the time kinetics of the photovoltaic response. To understand the kinetics of the photoinduced processes the time kinetics of photoresponse was done for the particular laser wavelengths.

  14. Band Structure Simulations of the Photoinduced Changes in the MgB2:Cr Films

    Iwan V. Kityk

    2015-04-01

    Full Text Available An approach for description of the photoinduced nonlinear optical effects in the superconducting MgB2:Cr2O3 nanocrystalline film is proposed. It includes the molecular dynamics step-by-step optimization of the two separate crystalline phases. The principal role for the photoinduced nonlinear optical properties plays nanointerface between the two phases. The first modified layers possess a form of slightly modified perfect crystalline structure. The next layer is added to the perfect crystalline structure and the iteration procedure is repeated for the next layer. The total energy here is considered as a varied parameter. To avoid potential jumps on the borders we have carried out additional derivative procedure.

  15. Study of energy bands and magnetic properties of Co2CrSi Heusler alloy

    Dibya Prakash Rai; Sandeep; M P Ghimire; R K Thapa

    2011-10-01

    The electronic and magnetic properties of Co2CrSi is calculated by using full-potential linearized augmented plane wave (FP–LAPW) method based on density functional theory (DFT). Density of states (DOS), magnetic moment and band structures of the system are presented. For the exchange and correlation energy, local spin density approximation (LSDA+U) with the inclusion of Hubbard potential U is used. Our calculation shows indirect bandgap of 0.91 eV in the minority channel of DOS. This is supported by band structures and hence favoured the half metallic ferromagnetic (HMF) nature of the system. The effective magnetic moment of 4.006 B also supported our conclusion with a near integral value. The DOS of Co and Cr were found to hybridize and was also responsible for the ferromagnetic nature of the system.

  16. Photo-transport properties of Pb2CrO5 single crystals

    Mondal, P. S.; Okazaki, R.; Taniguchi, H.; Terasaki, I.

    2014-11-01

    We report photo-thermoelectric transport phenomena in Pb2CrO5 single crystals. Without illumination, this material exhibits an insulating behavior characterized by an activation-type temperature variation of the electrical conductivity. The Seebeck coefficient contrastingly shows a crossover from high-temperature insulating to low-temperature metallic behavior, which is attributed to degenerate carriers in a donor level. We have found that under illumination, both the conductivity and the Seebeck coefficient increase in magnitude with increasing photon flux density in the degenerate-conduction regime. This result is difficult to understand within a simple photo-doping effect, which usually leads to a decrease in the Seebeck coefficient under illumination. The observed phenomenon is discussed in terms of a two-carrier contribution to the transport properties.

  17. Photo-transport properties of Pb{sub 2}CrO{sub 5} single crystals

    Mondal, P. S.; Okazaki, R., E-mail: okazaki.ryuji@cc.nagoya-u.ac.jp; Taniguchi, H.; Terasaki, I. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2014-11-21

    We report photo-thermoelectric transport phenomena in Pb{sub 2}CrO{sub 5} single crystals. Without illumination, this material exhibits an insulating behavior characterized by an activation-type temperature variation of the electrical conductivity. The Seebeck coefficient contrastingly shows a crossover from high-temperature insulating to low-temperature metallic behavior, which is attributed to degenerate carriers in a donor level. We have found that under illumination, both the conductivity and the Seebeck coefficient increase in magnitude with increasing photon flux density in the degenerate-conduction regime. This result is difficult to understand within a simple photo-doping effect, which usually leads to a decrease in the Seebeck coefficient under illumination. The observed phenomenon is discussed in terms of a two-carrier contribution to the transport properties.

  18. Magnetic and structural characterization of the 2D XY-ferromagnet Rb2CrCl2I2 (abstract)

    Visser, D.; Bramwell, S. T.; Kremer, R. K.

    1991-04-01

    Rb2CrCl2I2 crystallizes with a Jahn-Teller deformed K2NiF4 structure. This results in a ferromagnetic behavior for this compound. Rb2CrCl2I2 orders ferromagnetically at Tc=56.9(2) K. Magnetization and magnetic susceptibility measurements, using a vibrating sample magnetometer, Faraday balance, and SQUID magnetometer, on polycrystalline samples were used for the magnetic characterization. Rb2CrCl2I2 shows a Curie-Weiss behavior between 150 and 300 K. The intraplanar superexchange constant J/k=5.8 K. The intra- and interplanar anisotropy have been obtained from the magnetization curves at 4.2 K and are estimated at Hintra=0.16(2) T and Hinter=4.5(2) T.

  19. Large magnetization and high Curie temperature in highly disordered nanoscale Fe2CrAl thin films

    Dulal, Rajendra P.; Dahal, Bishnu R.; Forbes, Andrew; Pegg, Ian L.; Philip, John

    2017-02-01

    We have successfully grown nanoscale Fe2CrAl thin films on polished Si/SiO2 substrates using an ultra-high vacuum deposition with a base pressure of 9×10-10 Torr. The thickness of thin films ranges from 30 to 100 nm. These films exhibit cubic crystal structure with lattice disorder and display ferromagnetic behavior. The Curie temperature is greater than 400 K, which is much higher than that reported for bulk Fe2CrAl. The magnetic moments of the films varies from 2.5 to 2.8 μB per formula unit, which is larger than the reported bulk values. Thus, the disordered nanoscale Fe2CrAl films exhibit strong Fe-Fe exchange interactions through Fe-Cr-Fe and Fe-Al-Fe layers, resulting in both a large magnetization and a high Curie temperature.

  20. Pycnogenol prevents potassium dichromate K2Cr2O7-induced oxidative damage and nephrotoxicity in rats.

    Parveen, Kehkashan; Khan, Mohd Rashid; Siddiqui, Waseem A

    2009-10-30

    Environmental and occupational exposure to chromium compounds, especially hexavalent chromium [Cr(VI)], is widely recognized as a potential nephrotoxic in humans and animals. Its toxicity is associated with overproduction of free radicals, which induces oxidative damage. Recent evidence indicates that Pycnogenol (PYC), French maritime pine bark extract, exhibits antioxidant potential and protects against various oxidative stressors. The aim of the present study was to examine the modulating impacts of PYC on potassium dichromate K2Cr2O7-induced oxidative damage and nephrotoxicity in rats. Male Wistar rats were divided into four groups. The first group was control, the second group was control plus pre-treated with PYC (10 mg/kg, body weight; in saline; intraperitoneally; once daily for 3 weeks) as drug control and the third group was saline pre-treated plus treated with a single injection of K2Cr2O7 (15 mg/kg, body weight; in saline; intraperitoneally) as toxicant group. The fourth group was PYC pre-treated plus K2Cr2O7 injected. Forty-eight hours after K2Cr2O7-treatment, blood was drawn for estimation of renal injury markers in serum. Rats were then sacrificed, and their kidneys were dissected for biochemical and histopathological assays. K2Cr2O7-treated rats showed significant increases in markers of renal injury in serum, including blood urea nitrogen (BUN), serum creatinine (Scr), and alkaline phosphatase (ALP), which were significantly (P rats with PYC significantly (P rats. These results were also supported and confirmed with histopathological findings. The study suggests that PYC is effective in preventing K2Cr2O7-induced oxidative mediated nephrotoxicity, but more studies are needed to confirm the effects of PYC as a nephroprotective agent.

  1. The effect of chemical pressure on the structure and properties of A2CrOsO6 (A=Sr, Ca) ferrimagnetic double perovskite

    Morrow, Ryan; Soliz, Jennifer R.; Hauser, Adam J.; Gallagher, James C.; Susner, Michael A.; Sumption, Michael D.; Aczel, Adam A.; Yan, Jiaqiang; Yang, Fengyuan; Woodward, Patrick M.

    2016-06-01

    The ordered double perovskites Sr2CrOsO6 and Ca2CrOsO6 have been synthesized and characterized with neutron powder diffraction, electrical transport measurements, and high field magnetization experiments. As reported previously Sr2CrOsO6 crystallizes with R 3 bar symmetry due to a-a-a- octahedral tilting. A decrease in the tolerance factor leads to a-a-b+ octahedral tilting and P21/n space group symmetry for Ca2CrOsO6. Both materials are found to be ferrimagnetic insulators with saturation magnetizations near 0.2 μB. Sr2CrOsO6 orders at 660 K while Ca2CrOsO6 orders at 490 K. Variable temperature magnetization measurements suggest that the magnetization of the Cr3+ and Os3+ sublattices have different temperature dependences in Sr2CrOsO6. This leads to a non-monotonic temperature evolution of the magnetic moment. Similar behavior is not seen in Ca2CrOsO6. Both compounds have similar levels of Os/Cr antisite disorder, with order parameters of η=80.2(4)% for Sr2CrOsO6 and η=76.2(5)% for Ca2CrOsO6, where η=2θ-1 and θ is the occupancy of the osmium ion on the osmium-rich Wyckoff site.

  2. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO{sub 2}(cr)

    Rai, Dhanpat [Rai Enviro-Chem, LLC, Yachats, OR (United States); Kitamura, Akira [Japan Atomic Energy Agency, Ibaraki (Japan); Rosso, Kevin M. [Pacific Northwest National Laboratory, Richland, WA (United States); Sasaki, Takayuki; Kobayashi, Taishi [Kyoto Univ. (Japan)

    2016-11-01

    Solubility studies were conducted with HfO{sub 2}(cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg{sup -1}. These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO{sub 2}(am) suspensions to 90 C to ascertain whether the HfO{sub 2}(am) converts to HfO{sub 2}(cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO{sub 2}(cr) contains a small fraction of less crystalline, but not amorphous, material [HfO{sub 2}(lcr)] and this, rather than the HfO{sub 2}(cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log{sub 10} K{sup 0} values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO{sub 2}(lcr)[HfO{sub 2}(lcr) + 2H{sub 2}O ↔ Hf{sup 4+} + 4OH{sup -}]. The log{sub 10} of the solubility product of HfO{sub 2}(cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  3. Magnetic and structural properties of nanostructured Fe–20Al–2Cr powder mixtures

    Zerniz, N. [Laboratory of Inorganic Materials Chemistry, Chemistry Department, University Badji Mokhtar of Annaba, BP: 12, Annaba 23000 (Algeria); Azzaza, S., E-mail: s.azzaza@gmail.com [Laboratory of Magnetism and Spectroscopy of Solids, Department of Physics, University Badji Mokhtar of Annaba, BP: 12, Annaba 23000 (Algeria); Department of Technology, Faculty of Technology, University 20 Août 1955 of Skikda, B.P.26, Route d' El-Hadaiek, Skikda 21000 (Algeria); Chater, R. [Laboratory of Inorganic Materials Chemistry, Chemistry Department, University Badji Mokhtar of Annaba, BP: 12, Annaba 23000 (Algeria); Abbas, H. [Department of Biology, College of Science, University of Bahrain, PO Box 32038 (Bahrain); Bououdina, M. [Nanotechnology Centre, University of Bahrain, PO Box 32038 (Bahrain); Department of Physics, College of Science, University of Bahrain, PO Box 32038 (Bahrain); Bouchelaghem, W. [Laboratory of Inorganic Materials Chemistry, Chemistry Department, University Badji Mokhtar of Annaba, BP: 12, Annaba 23000 (Algeria)

    2015-02-15

    Nanostructured Fe–20Al–2Cr (wt.%) powders have been prepared using high energy planetary ball-mill. Changes in structural, morphological and magnetic properties of the powders during mechanical alloying (MA) and during subsequent annealing have been examined by X-ray diffraction, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The observed structural and microstructural changes have been related to several processes occurring during MA. After MA, the material becomes significantly disordered and refines to nanoscale grain sizes (~ 14 nm). The obtained bcc α-Fe(Al,Cr) solid solution shows a ferromagnetic behavior. Upon subsequent annealing at 400 °C, α-Fe{sub 2}O{sub 3} and spinel oxides are formed at the surface of particles, while structural defects disappeared as Fe(Al,Cr) solid solution becomes more ordered and grain growth occurs. The saturation magnetization (Ms) shows lower values after annealing, attributed to the formation of metal oxides with low magnetic moment. - Graphical abstract: Display Omitted - Highlights: • Nanostructured Fe–Al–Cr powders were prepared by MA. • Careful analysis of the XRD patterns by using the Rietveld refinement • The lattice distortion is evidenced by the increase of both the lattice parameter and the static Debye Waller parameter. • Annealing at 400 °C stabilizes the microstructure at the nanometer range and leads to the formation of Fe{sub 3}O{sub 4} and Fe{sub 2}O{sub 3} oxides. • Both the milled and annealed samples are ferromagnetic.

  4. The Structure-Function Relationships of Complement Receptor Type 2 (CR2; CD21).

    Hannan, Jonathan Paul

    2016-01-01

    Human complement receptor type 2 (CR2; CD21) is a surface-associated glycoprotein which binds to a variety of endogenous ligands, including the complement component C3 fragments iC3b, C3dg and C3d, the low-affinity IgE receptor CD23, and the type I cytokine, interferon-alpha. CR2 links the innate complement-mediated immune response to pathogens and foreign antigens with the adaptive immune response by binding to C3d that is covalently attached to targets, and which results in a cell signalling phenomenon that lowers the threshold for B cell activation. Variations or deletions of the CR2 gene in humans, or the Cr2 gene in mice associate with a variety of autoimmune and inflammatory conditions. A number of infectious agents including Epstein-Barr virus (EBV), Human Immunodeficiency Virus (HIV) and prions also bind to CR2 either directly or indirectly by means of C3d-targeted immune complexes. In this review we discuss the interactions that CR2 undertakes with its best characterized ligands C3d, CD23 and the EBV gp350/220 envelope protein. To date only a single physiologically relevant complex of CR2 with one of its ligands, C3d, has been elucidated. By contrast, the interactions with CD23 and EBV gp350/220, while being important from physiologic and disease-associated standpoints, respectively, are only incompletely understood. A detailed knowledge of the structure-function relationships that CR2 undergoes with its ligands is necessary to understand the implications of using recombinant CR2 in therapeutic or imaging agents, or alternatively targeting CR2 to down-regulate the antibody mediated immune response in cases of autoimmunity.

  5. Serotonin (5-HT) 5-HT2A Receptor (5-HT2AR):5-HT2CR Imbalance in Medial Prefrontal Cortex Associates with Motor Impulsivity.

    Anastasio, Noelle C; Stutz, Sonja J; Fink, Latham H L; Swinford-Jackson, Sarah E; Sears, Robert M; DiLeone, Ralph J; Rice, Kenner C; Moeller, F Gerard; Cunningham, Kathryn A

    2015-07-15

    A feature of multiple neuropsychiatric disorders is motor impulsivity. Recent studies have implicated serotonin (5-HT) systems in medial prefrontal cortex (mPFC) in mediating individual differences in motor impulsivity, notably the 5-HT2AR receptor (5-HT2AR) and 5-HT2CR. We investigated the hypothesis that differences in the ratio of 5-HT2AR:5-HT2CR protein expression in mPFC would predict the individual level of motor impulsivity and that the engineered loss of the 5-HT2CR would result in high motor impulsivity concomitant with elevated 5-HT2AR expression and pharmacological sensitivity to the selective 5-HT2AR antagonist M100907. High and low impulsive rats were identified in a 1-choice serial reaction time task. Native protein levels of the 5-HT2AR and the 5-HT2CR predicted the intensity of motor impulsivity and the 5-HT2AR:5-HT2CR ratio in mPFC positively correlated with levels of premature responses in individual outbred rats. The possibility that the 5-HT2AR and 5-HT2CR act in concert to control motor impulsivity is supported by the observation that high phenotypic motor impulsivity associated with a diminished mPFC synaptosomal 5-HT2AR:5-HT2CR protein:protein interaction. Knockdown of mPFC 5-HT2CR resulted in increased motor impulsivity and triggered a functional disruption of the local 5-HT2AR:5-HT2CR balance as evidenced by a compensatory upregulation of 5-HT2AR protein expression and a leftward shift in the potency of M100907 to suppress impulsive behavior. We infer that there is an interactive relationship between the mPFC 5-HT2AR and 5-HT2CR, and that a 5-HT2AR:5-HT2CR imbalance may be a functionally relevant mechanism underlying motor impulsivity.

  6. Thermal Shock and Oxidation Behavior of HiPIMS TiAlN Coatings Grown on Ti-48Al-2Cr-2Nb Intermetallic Alloy

    Claudio Badini

    2016-11-01

    Full Text Available A High Power Impulse Magnetron Sputtering (HiPIMS method for depositing TiAlN environmental barrier coatings on the surface of Ti-48Al-2Cr-2Nb alloy was developed in view of their exploitation in turbine engines. Three differently engineered TiAlN films were processed and their performance compared. Bare intermetallic alloy coupons and coated specimens were submitted to thermal cycling under oxidizing atmosphere up to 850 °C or 950 °C, at high heating and cooling rates. For this purpose, a burner rig able to simulate the operating conditions of the different stages of turbine engines was used. Microstructures of the samples were compared before and after each test using several techniques (microscopy, XRD, and XPS. Coating-intermetallic substrate adhesion and tribological properties were investigated too. All the TiAlN films provided a remarkable increase in oxidation resistance. Good adhesion properties were observed even after repeated thermal shocks. HiPIMS pretreatments of the substrate surfaces performed before the coating deposition significantly affected the oxidation rate, the oxide layer composition and the coating/substrate adhesion.

  7. 不同热处理工艺下的2Cr13组织和性能%Microstructure and Properties of 2Cr13 Stainless Steel After Different Heat Treatment

    赵晓磊; 吴志星; 张晓健; 闫昭卓

    2015-01-01

    2Cr13不锈钢进行淬火及不同温度下的回火处理;分析了淬火组织,研究了不同的回火温度对其组织和性能的影响.结果表明:采用960~990℃保温1 h+720℃保温3h的热处理工艺,性能满足API 5CT中L80级的要求.

  8. Experimental Studies on the Sulfide Capacities of CaO-SiO2-CrOx Slags

    Wang, Lijun; Seetharaman, Seshadri

    2010-04-01

    To understand the desulfurization process during the refining of Cr-containing steel grades, this work was initiated to study the reactions between Cr-sulfur and chromium-containing slags. The sulfide capacities of CaO-SiO2-CrOx pseudo-ternary slags were measured using the traditional gas-slag equilibration technique between 1823 K and 1923 K. Sixteen different slag compositions were examined, and two different equilibrium oxygen partial pressures were used to understand the impact of the varying valence of Cr on the sulfide capacities. The results showed that log10 Cs varied linearly with the reciprocal T, and the slope was higher than the corresponding value reported for the binary CaO-SiO2 of corresponding composition. It was difficult to isolate the relative effects of the bi- and trivalent Cr in the slags because the Cr2+/Cr3+ ratio was influenced by the basicity of the slag. By using the equation developed by these authors earlier that related Cr2+/Cr3+ with basicity, oxygen partial pressure, and temperature, it was possible to obtain an approximate trend of the CrO effect on the sulfide capacities; viz. the sulfide shows a decreasing trend as Cr2+ replaces Ca2+ in the slag. With a continued increase of Cr2+ content, indications of the occurrence of a minimum point were observed; beyond which the sulfide capacities showed a slight increasing trend. The latter was attributed, based on slag-structure analysis by Gaskell et al., to the increasing extent of the polymerization reaction releasing oxygen ions for sulfide reactions.

  9. Time course study of oxidative and nitrosative stress and antioxidant enzymes in K2Cr2O7-induced nephrotoxicity

    Saldívar Liliana

    2005-04-01

    Full Text Available Abstract Background Potassium dichromate (K2Cr2O7-induced nephrotoxicity is associated with oxidative and nitrosative stress. In this study we investigated the relation between the time course of the oxidative and nitrosative stress with kidney damage and alterations in the following antioxidant enzymes: Cu, Zn superoxide dismutase (Cu, Zn-SOD, Mn-SOD, glutathione peroxidase (GPx, glutathione reductase (GR, and catalase (CAT. Methods Nephrotoxicity was induced in rats by a single injection of K2Cr2O7. Groups of animals were sacrificed on days 1,2,3,4,6,8,10, and 12. Nephrotoxicity was evaluated by histological studies and by measuring creatinine clearance, serum creatinine, blood urea nitrogen (BUN, and urinary excretion of N-acetyl-β-D-glucosaminidase (NAG and total protein. Oxidative and nitrosative stress were measured by immunohistochemical localization of protein carbonyls and 3-nitrotyrosine, respectively. Cu, Zn-SOD, Mn-SOD, and CAT were studied by immunohistochemical localization. The activity of total SOD, CAT, GPx, and GR was also measured as well as serum and kidney content of chromium and urinary excretion of NO2 -/NO3-. Data were compared by two-way analysis of variance followed by a post hoc test. Results Serum and kidney chromium content increased reaching the highest value on day 1. Nephrotoxicity was made evident by the decrease in creatinine clearance (days 1–4 and by the increase in serum creatinine (days 1–4, BUN (days 1–6, urinary excretion of NAG (days 1–4, and total protein (day 1–6 and by the structural damage to the proximal tubules (days 1–6. Oxidative and nitrosative stress were clearly evident on days 1–8. Urinary excretion of NO2-/NO3- decreased on days 2–6. Mn-SOD and Cu, Zn-SOD, estimated by immunohistochemistry, and total SOD activity remained unchanged. Activity of GPx decreased on days 3–12 and those of GR and CAT on days 2–10. Similar findings were observed by immunohistochemistry of CAT

  10. Simulation of Cooling Rate Effects on Ti-48Al-2Cr-2Nb Crack Formation in Direct Laser Deposition

    Yan, Lei; Li, Wei; Chen, Xueyang; Zhang, Yunlu; Newkirk, Joe; Liou, Frank; Dietrich, David

    2017-03-01

    Transient temperature history is vital in direct laser deposition (DLD) as it reveals the cooling rate at specific temperatures. Cooling rate directly relates to phase transformation and types of microstructure formed in deposits. In this paper, finite element analysis simulation was employed to study the transient temperature history and cooling rate at different experimental setups in the Ti-48Al-2Cr-2Nb DLD process. An innovative prediction strategy was developed to model with a moving Gaussian distribution heat source and element birth and death technology in ANSYS®, and fabricate crack-free deposits. This approach helps to understand and analyze the impact of cooling rate and also explain phase information gathered from x-ray diffraction.

  11. Ferromagnetic Spin Fluctuation and Unconventional Superconductivity in Rb2Cr3As3 Revealed by 75As NMR and NQR

    Yang, J.; Tang, Z. T.; Cao, G. H.; Zheng, Guo-qing

    2015-10-01

    We report 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) studies on the superconductor Rb2Cr3As3 with a quasi-one-dimensional crystal structure. Below T ˜100 K , the spin-lattice relaxation rate (1 /T1 ) divided by temperature, 1 /T1T , increases upon cooling down to Tc=4.8 K , showing a Curie-Weiss-like temperature dependence. The Knight shift also increases with decreasing temperature. These results suggest ferromagnetic spin fluctuation. In the superconducting state, 1 /T1 decreases rapidly below Tc without a Hebel-Slichter peak, and follows a T5 variation below T ˜3 K , which points to unconventional superconductivity with point nodes in the gap function.

  12. Sign reversal of transformation entropy change in Co{sub 2}Cr(Ga,Si) shape memory alloys

    Xu, Xiao, E-mail: xu@material.tohoku.ac.jp; Omori, Toshihiro; Kainuma, Ryosuke [Department of Materials Science, Tohoku University, Sendai 980-8579 (Japan); Nagasako, Makoto [Department of Materials Science, Tohoku University, Sendai 980-8579 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Kanomata, Takeshi [Department of Materials Science, Tohoku University, Sendai 980-8579 (Japan); Research Institute for Engineering and Technology, Tohoku Gakuin University, Tagajo 985-8537 (Japan)

    2015-11-02

    In situ X-ray diffraction (XRD) measurements and compression tests were performed on Co{sub 2}Cr(Ga,Si) shape memory alloys. The reentrant martensitic transformation behavior was directly observed during the in situ XRD measurements. The high-temperature parent phase and low-temperature reentrant parent phase were found to have a continuous temperature dependence of lattice parameter, therefore suggesting that they are the same phase in nature. Moreover, compression tests were performed on a parent-phase single crystal sample; an evolution from normal to inverse temperature dependence of critical stress for martensitic transformation was directly observed. Based on the Clausius-Clapeyron analysis, a sign reversal of entropy change can be expected on the same alloy.

  13. Mössbauer studies of hyperfine fields in disordered Fe2CrAl

    N Lakshmi; K Venugopalan; J Varma

    2002-09-01

    Heusler-like alloy Fe2CrAl was prepared and studied. Structure determination was done by X-ray. The structure was found to conform to the B2 type. Magnetic hyperfine fields in this sample were studied by the Mössbauer effect. The Mössbauer spectra were recorded over a range of temperature from 40 to 296 K. The Mössbauer spectra showed the co-existence of a paramagnetic part with a magnetic hyperfine portion at all recorded temperatures. Even with the distribution in the magnetic hyperfine field, the average hyperfine field follows the $(T=T_{c})^{3/2}$ law. The paramagnetic part of the hyperfine field is explained in terms of the clustering of Cr atoms.

  14. Simulation of Cooling Rate Effects on Ti-48Al-2Cr-2Nb Crack Formation in Direct Laser Deposition

    Yan, Lei; Li, Wei; Chen, Xueyang; Zhang, Yunlu; Newkirk, Joe; Liou, Frank; Dietrich, David

    2016-12-01

    Transient temperature history is vital in direct laser deposition (DLD) as it reveals the cooling rate at specific temperatures. Cooling rate directly relates to phase transformation and types of microstructure formed in deposits. In this paper, finite element analysis simulation was employed to study the transient temperature history and cooling rate at different experimental setups in the Ti-48Al-2Cr-2Nb DLD process. An innovative prediction strategy was developed to model with a moving Gaussian distribution heat source and element birth and death technology in ANSYS®, and fabricate crack-free deposits. This approach helps to understand and analyze the impact of cooling rate and also explain phase information gathered from x-ray diffraction.

  15. Reversed Crystal-Field Splitting and Spin-Orbital Ordering in α-Sr2CrO4

    Ishikawa, Takashi; Toriyama, Tatsuya; Konishi, Takehisa; Sakurai, Hiroya; Ohta, Yukinori

    2017-03-01

    The origin of successive phase transitions observed in the layered perovskite α-Sr2CrO4 is studied by the density-functional-theory-based electronic structure calculation and mean-field analysis of the proposed low-energy effective model. We find that, despite the fact that the CrO6 octahedron is elongated along the c-axis of the crystal structure, the crystal-field level of nondegenerate 3dxy orbitals of the Cr ion is lower in energy than that of doubly degenerate 3dyz and 3dxz orbitals, giving rise to the orbital degrees of freedom in the system with a 3d2 electron configuration. We show that the higher (lower) temperature phase transition is caused by the ordering of the orbital (spin) degrees of freedom.

  16. Rational construction of Z-scheme Ag2CrO4/g-C3N4 composites with enhanced visible-light photocatalytic activity

    Luo, Jin; Zhou, Xiaosong; Ma, Lin; Xu, Xuyao

    2016-12-01

    Novel visible-light driven Z-scheme Ag2CrO4/g-C3N4 composites with different contents of Ag2CrO4 were fabricated by a facile chemical precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence (PL) spectroscopy and photoelectrochemical measurements. Compared with individual g-C3N4 and Ag2CrO4, the Ag2CrO4/g-C3N4 composites displayed much larger photocatalytic activities for the photocatalytic degradation of methyl orange (MO) solution at room temperature under visible light irradiation (λ > 420 nm). Importantly, the optimum photodegradation rate constant of the Ag2CrO4/g-C3N4 composite at a theoretical weight content of 8.0% Ag2CrO4 for the photodegradation of MO was 0.0068 min-1, which was 5.7 and 4.3 times higher than that of pure g-C3N4 and Ag2CrO4, respectively. Such enormous enhancement in photocatalytic performance was predominantly ascribed to the efficient separation and transfer of photogenerated electrons and holes at the Ag2CrO4/g-C3N4 interface imparted through the Z-scheme electron transfer. Furthermore, radical trap experiments depicted that both the holes and superoxide radical anions were thought to dominate oxidative species of the Ag2CrO4/g-C3N4 composite for MO degradation under visible light irradiation. Ultimately, a tentative Z-scheme photodegradation mechanism was proposed. This work may be useful for the rational design of new types of Z-scheme photocatalysts and provide some illuminate insights into the Z-scheme transfer mechanism for application in energy conversion and environmental remediation.

  17. Effect of Ti content on structure and properties of Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy coatings

    Qiu, X.W., E-mail: fallenrain922@163.com [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Sichuan College of Architectural Technology, Deyang 618000 (China); Zhang, Y.P. [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Liu, C.G. [Sichuan College of Architectural Technology, Deyang 618000 (China)

    2014-02-05

    Highlights: • Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy coatings were prepared by laser cladding. • Al{sub 2}CrFeNiCoCuTi{sub x} coatings show excellent corrosion resistance and wear resistance. • Al{sub 2}CrFeNiCoCuTi{sub x} coatings play a good protective effect on Q235 steel. • Ti element promotes the formation of a BCC structure in a certain extent. -- Abstract: The Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy coatings were prepared by laser cladding. The structure, hardness, corrosion resistance, wear resistance and magnetic property were studied by metallurgical microscope, scanning electron microscopy with spectroscopy (SEM/EDS), X-ray diffraction, micro/Vickers hardness tester, electrochemical workstation tribometer and multi-physical tester. The result shows that, Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy samples consist of the cladding zone, bounding zone, heat affected zone and substrate zone. The bonding between the cladding layer and the substrate of a good combination; the cladding zone is composed mainly of equiaxed grains and columnar crystal; the phase structure of Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy coatings simple for FCC, BCC and Laves phase due to high-entropy affect. Ti element promotes the formation of a BCC structure in a certain extent. Compared with Q235 steel, the free-corrosion current density of Al{sub 2}CrFeNiCoCuTi{sub x} high-entropy alloy coatings is reduced by 1–2 orders of magnitude, the free-corrosion potential is more “positive”. With the increasing of Ti content, the corrosion resistance of Al{sub 2}CrFeCoCuNiTi{sub x} high-entropy alloy coatings enhanced in 0.5 mol/L HNO{sub 3} solution. Compared with Q235 steel, the relative wear resistance of Al{sub 2}CrFeCoCuNiTi{sub x} high-entropy alloy coatings has improved greatly; both the hardness and plasticity are affecting wear resistance. Magnetization loop shows that, Ti{sub 0.0} high-entropy alloy is a kind of soft magnetic materials.

  18. Microstructure and properties of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys prepared by laser cladding

    Qiu, Xing-Wu, E-mail: fallenrain922@163.com [Department of Materials Engineering, Sichuan College of Architectural Technology, Deyang 618000 (China); Liu, Chun-Ge [Department of Transportation and Municipal Engineering, Sichuan College of Architectural Technology, Deyang 618000 (China)

    2013-03-15

    Highlights: ► We use a new method (laser cladding) to prepare Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys. ► We studied the effect of Ni content on alloys’ properties. ► Alloys show high microhardness, excellent corrosion resistance and wear resistance. ► The laser cladding layers play a good protective effect on Q235 steel. -- Abstract: The Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys were prepared by laser cladding. Using metallurgical microscope, scanning electron microscopy with spectroscopy (SEM/EDS), X-ray diffraction, micro/Vickers hardness tester, electrochemical workstation and tribometer the structure and hardness, corrosion resistance and wear resistance of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys were tested. The result shows that, Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloy samples consist of the cladding zone, bounding zone and heat affected zone. The bounding zone is between cladding layer and the substrate of a good combination; the cladding zone is composed mainly of axis crystal, nanocrystalline and fine white crystals. The Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating phase structure samples (FCC and BCC structure) due to high-entropy effect. The surface microhardness of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys samples up to 1102 HV, about 4 times as the substrate, and the hardness increases with increasing Ni content. Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating has good corrosion resistance in 1 mol/L NaOH solution and 3.5% NaCl solution. With the increase of Ni content, the corrosion resistance first increases and then decreases. The relative wear resistance of Al{sub 2}CrFeCoCuTiNi{sub x} high-entropy alloys coating shows a first increased and then a decreased trend with the increase of Ni content. Both the hardness and ductility are affected by wear resistance. The coating can play a good protective role on substrate Q235 steel.

  19. ABILITY OF Phanerochaete chrysosporium AND Trametes versicolor TO REMOVE Zn2+, Cr3+, Pb2+ METAL IONS

    Josué Solís Pacheco

    2015-09-01

    Full Text Available The use of fungal biomass as an alternative for removing heavy metals has become increasingly important in recent years, replacing conventional methods based on chemical physical processes. In this study, we evaluated the biosorption of Zn2+, Cr3+ and Pb2+, which were analyzed to determine their effect on growth kinetic parameters of Phanerochaete chrysosporium strain ATCC 32629 and Trametes versicolor ATCC 1267. Growth kinetics were performed in four liquid culture media: 1 Yeast Nitrogen Base (YNB used as control, 2 YNB medium plus Pb2+ (0.25, 1 and 2 mg L-1, 3 YNB medium plus Zn2+ (5, 10 and 20 mg L-1 and 4 YNB medium plus Cr3+ (0.5, 1 and 2 mg L-1. The flasks were incubated at 25 °C with shaking at 150 rpm. Metal concentrations were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES with prior acid digestion of the sample. The results demonstrated that Phanerochaete chrysosporium ATCC 32629 and Trametes versicolor ATCC 12679 are able to grow in the culture medium with Pb2+, Zn2+ and Cr3+ ions at different concentrations. However, P. chrysosporium ATCC 32629 showed greater adaptability and ability to adsorb Cr3+ in the culture medium at concentrations of 0.5 and 1 mg L-1, whereas T. versicolor ATCC 12679 was capable of Pb2+ biosorption at concentrations of 0.25, 1 and 2 mg L-1.

  20. Manganese-mediated ferromagnetism in La2Fe1-Mn2Cr1-O6 perovskite oxides

    R M Tiwari; Mrudul Gadhvi; Abanti Nag; N Y Vasanthacharya; J Gopalakrishnan

    2010-07-01

    We have investigated the structure and magnetic properties of the perovskite oxides of the formula La2Fe1-Mn2Cr1-O6 (0 < < 1.0). For 0 < ≤ 0.5, the members adopt the orthorhombic (Pbnm) structure, where the transition metal atoms are disordered at the 4b sites and the MO6 (M = Fe, Mn, Cr) octahedra become increasingly distorted with increasing . For 0.65 ≤ < 1.0, the members adopt the rhombohedral (R-3c) structure that is similar to LaMnO3+ ( ≥ 0.1) where the MO6 octahedra are undistorted. While the magnetic properties of the latter series are largely similar to the parent LaMnO3+ arising from the double-exchange (DE) between mixed valent MnIII/MnIV, the magnetic properties of the orthorhombic members show a distinct (albeit weak) ferromagnetism (C ∼ 200 K) that seems to arise from a MnIII-mediated superexchange (SE) between FeIII/CrIII in the disordered perovskite structure containing FeIII, MnIII and CrIII.

  1. Ti02-K2Cr207协同体系测定染料.浓度实验条件的正交优化

    张一平

    2013-01-01

    采用纳米Ti02-K2Cr207协同体系光催化氧化,分光光度法测定染料浓度.通过正交实验设计,研究pH值、TiO2用量、K2Cr2O,初始浓度、反应温度、紫外光照时间等因素对染料消解的影响.实验结果表明,各因素的影响程度从大到小依次为pH值〉K2Cr2O7浓度〉rriO:用量〉反应温度〉紫外光照时间;最佳消解条件为pH=1.0,TiO2用量为1.0g·L-1,K2Cr207初始浓度为10mmol·L-1,反应温度为90℃,紫外光照时间为12min.

  2. High-pressure structural behavior of the double perovskite Sr2CrReO6: an experimental and theoretical study

    Olsen, J.S.; Gerward, Leif; Vaitheeswaran, G.;

    2009-01-01

    The high-pressure structural behavior of Sr2CrReO6 has been studied experimentally using synchrotron radiation and the diamond anvil cell and theoretically using density functional theory. The experimental zero-pressure bulk modulus is B0=1704GPa and the pressure derivative is B0'=4.71.0. These r...

  3. Pd基Heusler合金Pd2CrGa和Pd2FeGa的第一性原理研究%First-principles study on Pd-based Heusler alloy Pd2CrGa and Pd2FeGa

    刘国平; 米传同; 钱帅; 余新泉; 赵昆; 于金

    2014-01-01

    运用基因遗传算法的晶格结构预测技术预测Pd基Heusler合金Pd 2 MnSn、Pd 2 CrGa和Pd 2 FeGa的结构;采用基于密度泛函理论(DFT)的投影缀加波(PAW)方法研究Pd 2 CrGa和Pd 2 FeGa的四方变形、磁性、态密度、弹性常数和声子谱线,最后通过Helmholtz自由能的计算预测了Pd 2 CrGa和Pd 2 FeGa的相变温度。结构预测显示:极限条件0 K时,Pd2MnSn以L21立方结构稳定存在,而Pd2CrGa和Pd2FeGa均以四方结构稳定存在。四方变形中,Pd2CrGa、Pd 2 FeGa在c/a<1.0和c/a>1.0处均有一个能量的局域最小值,分别对应一个稳定的结构。Pd 2 CrGa、Pd 2 FeGa在两种状态下均表现为铁磁性,Cr原子和Fe原子是总磁矩的主要贡献者。弹性常数计算结果显示:Pd 2 CrGa和Pd 2 FeGa仅在四方结构时才满足稳定性判据。c/a≈1.24处的四方结构Pd2CrGa转变为立方结构的相变温度在350 K左右, c/a≈1.30处的四方结构Pd2FeGa转变为立方结构的相变温度在130 K左右。%Based on genetic algorithm, the structures of Pd-based Heusler alloy Pd2MnSn, Pd2CrGa and Pd2FeGa were forecasted. The tetragonal distortion, magnetic, DOS elastic constants and phonon dispersion spectra of Pd2CrGa and Pd2FeGa were calculated by first-principles calculation based on DFT with projector augmented wave pseudopotential (PAW). At last, based on the result of Helmholtz free-energy, the phase transition temperatures of Pd2CrGa and Pd2FeGa were predicted. The crystal structure prediction shows that Pd2MnSn is L21 cubic structure, but Pd2CrGa and Pd2FeGa are tetragonal structures at 0 K. The tetragonal distortion analysis show that there are local minimums total energy atc/a1.0, which correspond to stable martensitic phases. Pd2MGa (M=Cr,Fe) are ferromagnetic in these two postures, and M (M=Cr,Fe) is the main magnetic contribution to its alloys, respectively. The elastic constants of Pd2CrGa, Pd2FeGa show that, cubic structure doesn

  4. Expression and modulation of complement receptor 2 (CR2/CD21 in the pathophysiology of rheumatoid arthritis

    Rozaleen Dash

    2016-08-01

    Full Text Available Background: The involvement of B cells, complement activation and subsequent immune complex deposition has been implicated in the pathogenesis of rheumatoid arthritis (RA. Although the reduced expression of complement receptor 2 (CR2, CD21 on the B cells of RA patients is known for long, we aimed at determining the modulation and expression of CR2 on PBMC of healthy individuals and RA patients. Methods: Sixty controls and 57 RA patients were enrolled. PBMC-CR2 transcript levels were correlated with the levels of C3, C3d and circulating immune complexes (CIC in controls and patients and with DAS28 in patients only. CIC levels were determined by PEG precipitation, C3 levels by nephlometry and C3d levels were determined by enzyme linked immunosorbent assay (ELISA. Sixteen patients were recruited for 6 months follow up studies of transcript levels of PBMC correlated with DAS28 score. Appropriate statistical methods were used for the analyses of data. Results: PBMC- CR2 transcript levels were declined in patients as compared to controls. PBMC-CR2 levels correlated negatively with DAS28 score. DAS28 correlated positively with levels of CIC, C3 and C3d. Levels of PBMC -CR2 increased in patients with decline in DAS28 scores in 6 months follow-up patients. Conclusions: Low level of CR2 expression in patients may, thus, contribute significantly to the pathological manifestation of RA. Cause-effect relationships of the up regulation of CR2 on improvement of health condition with the pathophysiology of RA and their importance as putative disease markers is being confirmed.

  5. Optimization of heat treatment process of 60Si2CrVAT spring steel for high-speed trains%提速列车用弹簧钢60Si2CrVAT的热处理工艺优化

    吴华林; 王福明; 李长荣; 程慧静

    2011-01-01

    分析制定了60Si2CrVAT弹簧钢合理的热处理制度,利用正交实验极差分析的方法并结合金相及回火后析出相的分析,研究了热处理工艺参数对60Si2CrVAT弹簧钢力学性能的影响,确定了其最佳热处理工艺。结果表明,回火温度和回火时间对强度的影响较大,回火温度和淬火保温时间对塑性影响较大,60Si2CrVAT弹簧钢最佳热处理工艺为:(900℃+25 min)油淬+(400℃+40 min)回火,水冷。%Heat treatment processes with different processing parameters for 60Si2CrVAT spring steel were designed based on metallurgical principle,and the influence of heat treatment parameters on microstructure and mechanical properties of 60Si2CrVAT spring steel was studied by means of optical microscopy,orthogonal experiments and tensile tests.The heat treatment process was optimized based on the investigation.The results show the relatively significant effect of tempering temperature and tempering time on strength is observed,while tempering temperature and holding time exhibits larger effect on plasticity.The optimum heat treatment process is quenching at 900 ℃ for 25 min in oil and tempering at 400 ℃ for 40 min and then cooling in water for 60Si2CrVAT spring steel.

  6. Structural, magnetic and transport properties of Pb2Cr1+xMo1-xO6 (-1≤x≤1/3)

    Zhao, H. F.; Cao, L. P.; Song, Y. J.; Feng, S. M.; Shen, X.; Ni, X. D.; Yao, Y.; Wang, Y. G.; Wang, R. M.; Jin, C. Q.; Yu, R. C.

    2017-02-01

    Pb2Cr1+xMo1-xO6 (-1≤x≤1/3) samples were synthesized via a high pressure and high temperature route. X-ray diffraction results suggest the samples crystallize in a disordered double perovskite structure (Pm-3m). X-ray photoemission spectroscopy results confirm the presence of Mo4+ for x=-1 and Mo6+ for x=1/3. The measured magnetic and electrical properties exhibit systematic change with increasing x.

  7. 133Cs and 75As NMR investigation of the normal metallic state of quasi-one-dimensional Cs2Cr3As3

    Zhi, Haizhao; Lee, Drake; Imai, Takashi; Tang, Zhangtu; Liu, Yi; Cao, Guanghan

    2016-05-01

    We report 133Cs NMR and 75As nuclear quadrupole resonance (NQR) measurements on the normal metallic state above Tc of a quasi-one-dimensional superconductor Cs2Cr3As3 (Tc<1.6 K). From the 133Cs NMR Knight shift 133K measured at the Cs1 site, we show that the uniform spin susceptibility χspin increases from 295 K to ˜60 K, followed by a mild suppression; χspin then levels off below ˜10 K. In contrast, a vanishingly small magnitude of 133K indicates that Cs2 sites contribute very little to electrical conduction and the exchange interactions between 3d electrons at Cr sites. Low frequency Cr spin dynamics, reflected on 75As1 /T1T (the nuclear spin-lattice relaxation rate 1 /T1 divided by temperature T ), shows an analogous trend as χspin. Comparison with the results of 1 /T1T near Tc with K2Cr3As3 (Tc=6.1 K) and Rb2Cr3As3 (Tc=4.8 K) establishes a systematic trend that substitution of K+ ions with larger alkali ions progressively suppresses Cr spin fluctuations together with Tc.

  8. Structural characterization and complex impedance studies on fast ion conducting mixed system (SbI3)–(Ag2CrO4)1−

    S Austin Suthanthiraraj; S Sarojini

    2013-12-01

    This paper deals with preparation and physico-chemical characterization of a new mixed system, (SbI3)–(Ag2CrO4)1− (0.1 ≤ ≤ 0.9), undertaken with a view to evaluate silver ion transport properties and identify those fast ion conducting compositions. Polycrystalline samples of various compositions were synthesized by rapid melt-quenching method. Powder X-ray diffraction (XRD) analysis in conjunction with differential scanning calorimetry (DSC) and electrical transport evaluation involving silver ionic transport number and temperaturedependent electrical complex impedance measurements were carried out in order to identify the different phases responsible for the conduction mechanism. Realization of a fast ionic conductivity value of 3.2 × 10-2 S cm-1 in the case of the composition, (SbI3)0.3–(Ag2CrO4)0.7, at room temperature due to silver ion transport has been discussed in terms of observed structural and thermal characteristics. A detailed analysis of conductivity spectra pertaining to the best conducting system, (SbI3)0.3–(Ag2CrO4)0.7, has also been presented.

  9. Ab Initio Research on a New Type of Half-Metallic Double Perovskites, A2CrMO6 (A = IVA Group Elements; M = Mo, Re and W

    Yun-Ping Liu

    2014-03-01

    Full Text Available The research based on density functional theory was carried out using generalized gradient approximation (GGA for full-structural optimization and the addition of the correlation effect (GGA + U (Coulomb parameter in a double perovskite structure, A2BB’O6. According to the similar valance electrons between IIA(s2 and IVA(p2, IVA group elements instead of alkaline-earth elements settled on the A-site ion position with fixed BB' combinations as CrM (M = Mo, Re and W. The ferrimagnetic half-metallic (HM-FiM properties can be attributed to the p-d hybridization between the Crd-Mp and the double exchange. All the compounds can be half-metallic (HM materials, except Si2CrMoO6, Ge2CrMo and Ge2CrReO6, because the strong-correlation correction should be considered. For M = W, only A = Sn and Pb are possible candidates as HM materials. Nevertheless, an examination of the structural stability is needed, because Si, Ge, Sn and Pb are quite different from Sr. All compounds are stable, except for the Si-based double perovskite structure.

  10. 汽轮机用钢2Cr11MoVNbN 的锻造工艺及锻后热处理工艺%Forging Process and Heat Treatment Process after Forging of 2Cr11MoVNbN Steel Used for Steam Turbine

    赵森; 黄冬明

    2013-01-01

    2Cr11MoVNbN steel is one of the steel grades with best heat-resistant property among 12% Cr steels, and it is an ideal material used for subcritical and supercritical steam turbine blades .Through smelting with VOD meth-od, drawing with top flat anvil and bottom V type anvil , and upsetting with more than one heat and small percent reduc-tion, the 2Cr11MoVNbN steel blades has been produced successfully to meet technical requirements .%  2Cr11MoVNbN钢是目前12%Cr系耐热性能最好的钢种之一,是一种较为理想的亚临界、超临界汽轮机叶片用材料。通过采用 VOD炼钢,上平砧,下 V型砧拔长下料,多火次,小压下量镦粗工艺,成功锻出2Cr11MoVNbN叶片,质量达到要求。

  11. Biogeochemical Cycling

    Bebout, Brad; Fonda, Mark (Technical Monitor)

    2002-01-01

    This lecture will introduce the concept of biogeochemical cycling. The roles of microbes in the cycling of nutrients, production and consumption of trace gases, and mineralization will be briefly introduced.

  12. TiO2-K2Cr2O7协同光催化氧化体系快速测定染料浓度%Rapid Determination of Dye Concentration Using a Synergistic TiO2-K2 Cr2 07 Photocatalytic Oxidation System

    张一平

    2012-01-01

    As KzCr207 can obtain the photo-induced electrons and thereby enhance the photocatalytic oxidation ability of semiconductor, this paper establishes a simple method of dye concentration determination by using a nano TiO2-K2Cr207 synergistic photocatalytic oxidation system and spectrophotometer. The mecha- nism of photocatalytic oxidation determination of dye concentration is discussed, and the optimal reaction conditions for dye digestion are studied. The optimal digestion conditions are as follows:pH = 1, TiO2 dosage = 1.0 g/L, the initial concentration of K2Cr207 = 8.0 mmol/L, solution temperature = 80℃, and UV irra- diation time = 10 rain. When the Cl- content is less than 1000 mg/L, the relative error is less than 3%.%基于K2Cr2O2能获得光生电子从而提高半导体光催化氧化能力的原理,建立了一种用纳米Ti02-K2Cr2O2协同体系光催化氧化,分光光度法测定染料浓度的简便方法.探讨了光催化氧化测定染料浓度的机理,考察了染料消解的最佳反应条件.最佳的消解条件为pH=1,TiO21.0g/L,K2Cr2O7初始浓度8.0mmol/L,溶液温度80℃,紫外光照时间10min.当Cl^-含量在1000mg/L以内时,相对误差小于3%.

  13. Neutron Scattering Investigation of the Temperature Dependence of Long-Wavelength Spin Waves in Ferromagnetic Rb2CrCI4

    Hutchings, M T; Als-Nielsen, Jens Aage; Lindgård, Per-Anker;

    1981-01-01

    The long-wavelength spin waves in Rb2CrCl4, a nearly two-dimensional ferromagnet, have been investigated at several temperatures below Tc=52.4K using neutron inelastic scattering techniques. The data have been analysed in terms of a Hartree-Fock theory using matching-matrix elements to give...... correctly the effects of anisotropy. Values for the parameters in the spin Hamiltonian have been found, and the theory accounts well for the energy renormalisation of the spin waves and for the transition temperature and variation of magnetic moment with temperature. Due to weak uniaxial anisotropy terms...

  14. Synthesis and Characterization of Ultra-fine Cr2O3 from Hydrogen Reduction of K2CrO4

    BAI Yulan; XU Hongbin; ZHANG Yi; LI Zuohu

    2008-01-01

    As a part of the green process for manufacturing chromium compounds, two steps are involved in the synthesis of ultra-fine Cr2O3 powders: the first is the hydrogen reduction of K2CrO4 into intermediate trivalent (Cr3+) or tetravalent (Cr4+) chromium compounds; the second is the decomposing of the intermediate into Cr2O36 by heat treating. The intermediate is well characterized by means of SEM, XRD, and XPS. The possible reaction mechanism of the process is analyzed.

  15. FES cycling.

    Newham, D J; Donaldson, N de N

    2007-01-01

    Spinal cord injury (SCI) leads to a partial or complete disruption of motor, sensory, and autonomic nerve pathways below the level of the lesion. In paraplegic patients, functional electrical stimulation (FES) was originally widely considered as a means to restore walking function but this was proved technically very difficult because of the numerous degrees of freedom involved in walking. FES cycling was developed for people with SCI and has the advantages that cycling can be maintained for reasonably long periods in trained muscles and the risk of falls is low. In the article, we review research findings relevant to the successful application of FES cycling including the effects on muscle size, strength and function, and the cardiovascular and bone changes. We also describe important practical considerations in FES cycling regarding the application of surface electrodes, training and setting up the stimulator limitations, implanted stimulators and FES cycling including FES cycling in groups and other FES exercises such as FES rowing.

  16. Dependency of microstructure and microhardness on withdrawal rate of Ti-43Al-2Cr-2Nb alloy prepared by electromagnetic cold crucible directional solidification

    Yong-zhe Wang

    2016-07-01

    Full Text Available The intermetallic Ti-43Al-2Cr-2Nb (at.% alloy was directionally solidified in an electromagnetic cold crucible with different withdrawal rates (V ranging from 0.2 to 1.0 mm昺in-1, at a constant temperature gradients (G=18 K昺m-1 . Macrostructures of the alloy were observed by optical microscopy. Microstructures of the alloy were characterized by scanning electron microscopy (SEM in back-scattered electron mode and transmission electron microscopy. Results showed that morphologies of macrostructure depend greatly on the applied withdrawal rate. Continuous columnar grains can be obtained under slow withdrawal rates ranging from 0.2 to 0.6 mm昺in-1. The microstructure of the alloy was composed of ?/?lamellar structures and a small number of mixtures of B2 phases and blocky ?phases. The columnar grain size (d and interlamellar spacing (? decrease with an increasing withdrawal rate. The effect of withdrawal rate on microhardness was also investigated. The microhardness of the directionally solidified Ti-43Al-2Cr-2Nb alloy increases with an increase in withdrawal rate. This is mainly attributed to the increase of B2 and ? phases as well as the refinement of lamellae.

  17. Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag2CrO4

    Difa Xu

    2014-05-01

    Full Text Available Silver chromate (Ag2CrO4 photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic activity of the prepared Ag2CrO4was highly dependent on the preparation methods. The sample prepared by microemulsion method exhibits the highest photocatalytic efficiency on the degradation of methylene blue (MB under visible-light irradiation. The enhanced photocatalytic activity could be ascribed to the smaller particle size, higher surface area, relatively stronger light absorption, and blue-shift absorption edge, which result in the adsorption of more MB molecules, a shorter diffusion process of more photogenerated excitons, and a stronger oxidation ability of the photogenerated holes. Considering the universalities of microemulsion, precipitation, and hydrothermal methods, this work may also provide a prototype for the comparative study of semiconductor based photocatalysis for water purification and environmental remediation.

  18. Correlation between superconductivity and bond angle of CrAs chain in non-centrosymmetric compounds A2Cr3As3 (A = K, Rb)

    Wang, Zhe; Yi, Wei; Wu, Qi; Sidorov, Vladimir A.; Bao, Jinke; Tang, Zhangtu; Guo, Jing; Zhou, Yazhou; Zhang, Shan; Li, Hang; Shi, Youguo; Wu, Xianxin; Zhang, Ling; Yang, Ke; Li, Aiguo; Cao, Guanghan; Hu, Jiangping; Sun, Liling; Zhao, Zhongxian

    2016-11-01

    Non-centrosymmetric superconductors, whose crystal structure is absent of inversion symmetry, have recently received special attentions due to the expectation of unconventional pairings and exotic physics associated with such pairings. The newly discovered superconductors A2Cr3As3 (A = K, Rb), featured by the quasi-one dimensional structure with conducting CrAs chains, belongs to such kind of superconductor. In this study, we are the first to report the finding that superconductivity of A2Cr3As3 (A = K, Rb) has a positive correlation with the extent of non-centrosymmetry. Our in-situ high pressure ac susceptibility and synchrotron x-ray diffraction measurements reveal that the larger bond angle of As-Cr-As (defined as α) in the CrAs chains can be taken as a key factor controlling superconductivity. While the smaller bond angle (defined as β) and the distance between the CrAs chains also affect the superconductivity due to their structural connections with the α angle. We find that the larger value of α-β, which is associated with the extent of the non-centrosymmetry of the lattice structure, is in favor of superconductivity. These results are expected to shed a new light on the underlying mechanism of the superconductivity in these Q1D superconductors and also to provide new perspective in understanding other non-centrosymmetric superconductors.

  19. Correlation between superconductivity and bond angle of CrAs chain in non-centrosymmetric compounds A2Cr3As3 (A = K, Rb)

    Wang, Zhe; Yi, Wei; Wu, Qi; Sidorov, Vladimir A.; Bao, Jinke; Tang, Zhangtu; Guo, Jing; Zhou, Yazhou; Zhang, Shan; Li, Hang; Shi, Youguo; Wu, Xianxin; Zhang, Ling; Yang, Ke; Li, Aiguo; Cao, Guanghan; Hu, Jiangping; Sun, Liling; Zhao, Zhongxian

    2016-01-01

    Non-centrosymmetric superconductors, whose crystal structure is absent of inversion symmetry, have recently received special attentions due to the expectation of unconventional pairings and exotic physics associated with such pairings. The newly discovered superconductors A2Cr3As3 (A = K, Rb), featured by the quasi-one dimensional structure with conducting CrAs chains, belongs to such kind of superconductor. In this study, we are the first to report the finding that superconductivity of A2Cr3As3 (A = K, Rb) has a positive correlation with the extent of non-centrosymmetry. Our in-situ high pressure ac susceptibility and synchrotron x-ray diffraction measurements reveal that the larger bond angle of As-Cr-As (defined as α) in the CrAs chains can be taken as a key factor controlling superconductivity. While the smaller bond angle (defined as β) and the distance between the CrAs chains also affect the superconductivity due to their structural connections with the α angle. We find that the larger value of α-β, which is associated with the extent of the non-centrosymmetry of the lattice structure, is in favor of superconductivity. These results are expected to shed a new light on the underlying mechanism of the superconductivity in these Q1D superconductors and also to provide new perspective in understanding other non-centrosymmetric superconductors. PMID:27886268

  20. Influence of heat treatment process on microstructure and mechanical properties of 60Si2CrVA spring steel%热处理工艺对60Si2CrVA弹簧钢组织及性能的影响

    张占玲; 赵飞; 谭文龙

    2014-01-01

    利用SEM、金相显微镜、X射线应力测定仪、MTS 万能试验机等研究了淬火-等温( Q-I )及淬火-等温-回火( Q-I-T )工艺对60Si2CrVA弹簧钢组织及性能的影响,并与传统工艺进行了比较。结果表明,经Q-I工艺处理的60Si2CrVA弹簧钢具有良好的综合力学性能,抗拉强度可达到2142 MPa,断面收缩率为42.17%,冲击吸收能量达到了43.3 J。 Q-I工艺得到的复相组织中较多的残留奥氏体与下贝氏体是提高材料塑韧性的主要原因。%The influence of quenching-isothermal ( Q-I ) and quenching-isothermal-tempering ( Q-I-T ) processes on microstructure and mechanical properties of 60Si2CrVA steel was studied by SEM, optical microscopy, X-ray stress analyzer, MTS and so on, and compared with the traditional treatment .The results show that the 60Si2CrVA steel treated by Q-I process has fine comprehensive mechanical properties, tensile strength is 2142 MPa, the percentage reduction of area is 42.17%, and the impact absorbed energy is 43.3 J.The duplex microstructure with many retained austenite and bainite obtained by Q-I is the main factor to improve the toughness and ductility .

  1. Corrosion Behaviour of 2Cr13 Stainless Steel in CO2-saturated NaCl Solution in Presence of Acetic Acid%2Cr13不锈钢在含乙酸的C02饱和的NaC1溶液中的腐蚀行为

    陈伟; 彭乔

    2012-01-01

    采用极化曲线、电化学阻抗谱等电化学测试方法,和扫描电镜(SEM)、X射线能谱(EDS)、X射线衍射(XRD)等物理检测方法,研究了乙酸(HAc)对2Cr13不锈钢在60℃下C02饱和的3%NaC1溶液中腐蚀行为的影响,并讨论了腐蚀机理。研究表明,HAc能够直接在电极表面还原,并能促进腐蚀产物FeC(k的形成和溶解,HAc的存在同时加速了金属上的阴极反应和阳极反应,极大促进了2Cr13不锈钢的局部腐蚀和全面腐蚀的发生。%The effect of acetic acid on corrosion behaviour of 2Cr13 stainless steel in CO2-saturated 3 % NaC1 solution at 60 ℃ was investigated by using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). Corrosion mechanism was discussed. With the addition of acetic acid in the solution, both cathodic and anodic reaction rates increase remarkably. It is attributed to the fact that acetic acid adsorbed on electrode surface can be reduced directly by electrochemical reaction, and facilitate the formation and dissolution of ferrous carbonate due to the decrease of solution pH. Acetic acid enhances both localized corrosion and general corrosion attack on 2Cr13 stainless steel.

  2. 焊后热处理对1Cr18Ni9Ti与2Cr13钢焊接接头组织和性能的影响%Effect of post-welding heat treatment on microstructure and mechanical properties of 1Crl8Ni9Ti and 2Cr13 steel welded joints

    赵勇桃; 董俊慧; 刘宗昌; 周军伟

    2012-01-01

    By method of tungsten inert gas welding, 1Crl 8Ni9Ti and 2Cr13 steels were welded, and heat treatment was carried on the welded joint. By OM and SEM, the microstructure of 2Cr13 and 1Crl8Ni9Ti steels welded joints was analyzed before and after heat treatment. Mechanical properties of the welded joints were measured by micro-hardness tester and electronic universal tensile machine. The resuhs show that before heat treatment, 2Cr13 and 1Crl8NigTi steels welded joint is typical columnar crystal, the microstructure is lath martensite + restained austenite + carbide, After heat treatment, the microstructure changes from lath martensite into tempered sorbite, and carbide quantity also increases significantly. The position of fracture is at the heat affected zone of austenitic stainless steel. Before and after heat treatment, the tensile strength of welded joints is about 635.56,649.44 MPa respectively; micro-hardness of welded zone 1Crl8NigTi and 2Cr13 steels is about 276, 222 HV0.5 respectively. After heat treatment,the micro-hardness of all welded joint decreases obviously.%通过钨极氩弧焊方法,对1Cr18Ni9Ti与2Cr13钢实施焊接,并对焊接接头整体进行焊后热处理。采用OM、SEM对2Cr13与1Cr18Ni9Ti钢热处理前后的焊接接头组织进行分析,利用显微硬度计、电子万能拉伸机测量了焊接接头的力学性能。结果表明,1Cr18Ni9Ti和2Cr13钢焊接接头热处理前焊缝组织为典型的柱状晶,组织为板条马氏体+残留奥氏体+碳化物;热处理后焊缝组织为回火索氏体,而且碳化物析出量也明显增多。拉伸时,热处理前后焊接接头断裂的部位都发生在奥氏体不锈钢热影响区一侧,热处理前后焊接接头的抗拉强度分别约为635.56、649.44 MPa;焊缝区的显微硬度分别约为276、222 HV0.5,热处理后焊接接头的整体显微硬度比热处理前的明显降低。

  3. The strain induced band gap modulation from narrow gap semiconductor to half-metal on Ti2CrGe: A first principles study

    Jia Li

    2015-11-01

    Full Text Available The Heusler alloy Ti2CrGe is a stable L21 phase with antiferromagnetic ordering. With band-gap energy (∼ 0.18 eV obtained from a first-principles calculation, it belongs to the group of narrow band gap semiconductor. The band-gap energy decreases with increasing lattice compression and disappears until a strain of −5%; moreover, gap contraction only occurs in the spin-down states, leading to half-metallic character at the −5% strain. The Ti1, Ti2, and Cr moments all exhibit linear changes in behavior within strains of −5%– +5%. Nevertheless, the total zero moment is robust for these strains. The imaginary part of the dielectric function for both up and down spin states shows a clear onset energy, indicating a corresponding electronic gap for the two spin channels.

  4. X-Ray Phase Analysis Of Nitrided Layers Of X2CrNiMo17-12-2 Austenitic Steel

    Frączek T.

    2015-09-01

    Full Text Available This work presents the results of diffraction analyses carried out using X-ray phase analyses (XRD and GIXRD of nitrided layers of X2CrNiMo17-12-2 austenitic steel. Plasma nitriding process was c arried out in the temperature range of 325 ÷ 400 °C and time of 2 ÷ 4 h. Hydrogen-nitrogen plasma was used as reactive atmosphere (H2 75% + N2 25% with pressure of 150 Pa. On the basis of the X-ray analyses it was stated that the obtained nitrided layers consisted of a subsurface layer of chromium nitrides and a zone of nitrogen saturated austenite.

  5. Anomalous physical properties of Heusler-type Co2Cr (Ga,Si) alloys and thermodynamic study on reentrant martensitic transformation

    Xu, Xiao; Nagasako, Makoto; Kataoka, Mitsuo; Umetsu, Rie Y.; Omori, Toshihiro; Kanomata, Takeshi; Kainuma, Ryosuke

    2015-03-01

    Electronic, magnetic, and thermodynamic properties of Co2Cr(Ga,Si) -based shape-memory alloys, which exhibit reentrant martensitic transformation (RMT) behavior, were studied experimentally. For electric resistivity (ER), an inverse (semiconductor-like) temperature dependence in the parent phase was found, along with anomalous behavior below its Curie temperature. A pseudobinary phase diagram was determined, which gives a "martensite loop" clearly showing the reentrant behavior. Differential scanning calorimetry and specific-heat measurements were used to derive the entropy change Δ S between martensite and parent phases. The temperature dependence of the derived Δ S was analyzed thermodynamically to confirm the appearances of both the RMT and normal martensitic transformation. Detailed studies on the specific heat in martensite and parent phases at low temperatures were also conducted.

  6. Negative magnetization and zero-field cooled exchange bias effect in Co0.8Cu0.2Cr2O4 ceramics

    Wang, L. G.; Zhu, C. M.; Tian, Z. M.; Luo, H.; Bao, D. L. G. C.; Yuan, S. L.

    2015-10-01

    The negative magnetization and zero-field cooled exchange bias (ZFC EB) effect are observed in Co0.8Cu0.2Cr2O4 polycrystalline ceramics. 20% Cu substitution for Co in CoCr2O4 leads to the evident magnetization reversal at the compensation temperature (Tcomp ˜ 50 K) with applied magnetic field of 500 Oe. Besides, Tcomp decreases monotonously with increasing applied field, and the negative magnetization finally disappears when the field increases to 9000 Oe. Different temperature dependence of sublattice magnetization at different crystallographic sites is proved to induce the magnetization reversal. In addition, ZFC EB effect can be tuned by measuring temperature and presents the maximum of exchange bias field (HEB) with ˜2300 Oe at 50 K. This unconventional EB effect can be attributed to the coupling interaction between the two sublattices.

  7. Microstructure Evolution of Ti-47Al-2Cr-2Nb Alloy in the Liquid-Metal-Cooling (LMC) Directional-Solidification Process

    XIAO Zhixia; ZHENG Lijing; WANG Lei; YANG Lili; ZHANG Hu

    2011-01-01

    The microstructure evolution of Ti-47Al-2Cr-2Nb alloy was investigated on liquid metal cooling type directional solidified apparatus at high temperature gradient. The analysis shows that it is solidified with primaryβ cells/dendrites, and then α phase is formed through peritectic reaction.Once the columnar grains grow into the steady state, the lameilar orientation inclined with the angle of 45° to the withdrawal direction is more favored than that with parallel to the withdrawal direction. In addition, α phase grain nucleates from β-interdendrite regions, and grows up to the dendritic trunk. If no other α grain hinders its growth, it would occupy the whole dendrite, or it would stop at the dendritic trunk for the weakened motivating drive in theβ dendritic core.

  8. Research on the Ti-48Al-2Cr-2Nb Automobile Exhaust Valve Formed in Permanent Mold during Centrifugal Casting Process

    Wenbin SHENG; Dong LI; Rui YANG; Yuyin LIU; Jingjie GUO; Jun JIA

    2001-01-01

    Ti-48Al-2Cr-2Nb automobile exhaust valves were formed with permanent mold centrifugal cast method and their surface layer structure, microstructure, elements distribution and mechanical properties were analyzed by SEM, XRD and EMPA etc. Furthermore, the HIPped valves were tested on 483Q diesel engine. Results showed that the element distribution of TiAl based alloy exhaust valves was uniform and their microstructure was refined. The typical mechanical properties of HlPped exhaust valves were σb=670 MPa, σ0.2=527.5 MPa and δ=3%. Engine test showed that the valves had excellent airtightness and wear resistance properties and satisfied the requirements of engine successfully.

  9. Sulfide Capacities of CaO-MgO-Al2O3-SiO2-CrO x Slags

    Wang, Lijun; Wang, Yaxian; Chou, Kuo-chih; Seetharaman, Seshadri

    2016-08-01

    The sulfide capacities of CaO-MgO-Al2O3-SiO2-CrO x slags were measured by gas-slag equilibration method in the temperature range of 1823 K to 1898 K (1550 °C to 1625 °C) to reveal the effect of CrO x on the sulfide capacities of slags. Both higher basicity and temperature enhanced sulfide capacities. The CrO x additions in the range of 0 to 5 mass pct increased the sulfide capacity, but, further increase of CrO x contents to 7 pct was found to lower the sulfide capacity. Utilizing the relationship for estimating the ratio of Cr(II)/Cr(III) put forward by the present authors, the influence of Cr(II) on the sulfide capacities of the slags studied is discussed.

  10. Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex K3(TMS)2(H2O)2Cr(CN)6 [TMS = Tetramethylene Sulfone

    CHEN Wei; CHE Yun-Xia; ZHENG Ji-Min

    2005-01-01

    The cyano-bridged bimetallic complex K3(TMS)2(H2O)2Cr(CN)6 with three- dimensional microporous structure was synthesized and characterized. The title complex (C14H20CrK3N, Mr = 601.78) crystallizes in monoclinic, space group C2/c with a = 14.357(4), b = 9.331(3), c = 19.180(6)(A), β = 96.754(5)o, V = 2551.6(13) (A)3, Z = 4, Dc = 1.567 g/m3, μ(MoKα) = 1.141 mm-1, F(000) = 1228, the final R = 0.0440 and wR = 0.0990 for 1760 observed reflections (I > 2σ(I)). In the crystal, two [Cr(CN) 6]3- units, four K+ ions and two oxygen atoms of two TMS molecules are linked to form a sixteen-membered ring and an extended three-dimensional structure.

  11. Fes cycling

    Berkelmans Rik

    2008-01-01

    Full Text Available Many research with functional electrical stimulation (FES has been done to regain mobility and for health benefits. Better results have been reported for FES-cycling than for FES-walking. The majority of the subjects during such research are people with a spinal cord injury (SCI, cause they often lost skin sensation. Besides using surface stimulation also implanted stimulators can be used. This solves the skin sensation problem, but needs a surgery. Many physiological effects of FES-cycling has been reported, e.g., increase of muscles, better blood flow, reduction of pressure ulcers, improved self-image and some reduction of bone mineral density (BMD loss. Also people with an incomplete SCI benefit by FES-cycling, e.g. cycling time without FES, muscle strength and also the walking abilities increased. Hybrid exercise gives an even better cardiovascular training. Presently 4 companies are involved in FES-cycling. They all have a stationary mobility trainer. Two of them also use an outdoor tricycle. One combined with voluntary arm cranking. By optimizing the stimulation parameters the power output and fatigue resistance will increase, but will still be less compared to voluntary cycling.

  12. Identification and characterization of novel associations in the CASP8/ALS2CR12 region on chromosome 2 with breast cancer risk.

    Lin, Wei-Yu; Camp, Nicola J; Ghoussaini, Maya; Beesley, Jonathan; Michailidou, Kyriaki; Hopper, John L; Apicella, Carmel; Southey, Melissa C; Stone, Jennifer; Schmidt, Marjanka K; Broeks, Annegien; Van't Veer, Laura J; Th Rutgers, Emiel J; Muir, Kenneth; Lophatananon, Artitaya; Stewart-Brown, Sarah; Siriwanarangsan, Pornthep; Fasching, Peter A; Haeberle, Lothar; Ekici, Arif B; Beckmann, Matthias W; Peto, Julian; Dos-Santos-Silva, Isabel; Fletcher, Olivia; Johnson, Nichola; Bolla, Manjeet K; Wang, Qin; Dennis, Joe; Sawyer, Elinor J; Cheng, Timothy; Tomlinson, Ian; Kerin, Michael J; Miller, Nicola; Marmé, Frederik; Surowy, Harald M; Burwinkel, Barbara; Guénel, Pascal; Truong, Thérèse; Menegaux, Florence; Mulot, Claire; Bojesen, Stig E; Nordestgaard, Børge G; Nielsen, Sune F; Flyger, Henrik; Benitez, Javier; Zamora, M Pilar; Arias Perez, Jose Ignacio; Menéndez, Primitiva; González-Neira, Anna; Pita, Guillermo; Alonso, M Rosario; Alvarez, Nuria; Herrero, Daniel; Anton-Culver, Hoda; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Lichtner, Peter; Schmutzler, Rita K; Müller-Myhsok, Bertram; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Tessier, Daniel C; Vincent, Daniel; Bacot, Francois; Nevanlinna, Heli; Aittomäki, Kristiina; Blomqvist, Carl; Khan, Sofia; Matsuo, Keitaro; Ito, Hidemi; Iwata, Hiroji; Horio, Akiyo; Bogdanova, Natalia V; Antonenkova, Natalia N; Dörk, Thilo; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Wu, Anna H; Tseng, Chiu-Chen; Van Den Berg, David; Stram, Daniel O; Neven, Patrick; Wauters, Els; Wildiers, Hans; Lambrechts, Diether; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Manoukian, Siranoush; Bonanni, Bernardo; Couch, Fergus J; Wang, Xianshu; Vachon, Celine; Purrington, Kristen; Giles, Graham G; Milne, Roger L; Mclean, Catriona; Haiman, Christopher A; Henderson, Brian E; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Goldberg, Mark S; Labrèche, France; Dumont, Martine; Teo, Soo Hwang; Yip, Cheng Har; Hassan, Norhashimah; Vithana, Eranga Nishanthie; Kristensen, Vessela; Zheng, Wei; Deming-Halverson, Sandra; Shrubsole, Martha J; Long, Jirong; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Kauppila, Saila; Andrulis, Irene L; Knight, Julia A; Glendon, Gord; Tchatchou, Sandrine; Devilee, Peter; Tollenaar, Robert A E M; Seynaeve, Caroline; Van Asperen, Christi J; García-Closas, Montserrat; Figueroa, Jonine; Lissowska, Jolanta; Brinton, Louise; Czene, Kamila; Darabi, Hatef; Eriksson, Mikael; Brand, Judith S; Hooning, Maartje J; Hollestelle, Antoinette; Van Den Ouweland, Ans M W; Jager, Agnes; Li, Jingmei; Liu, Jianjun; Humphreys, Keith; Shu, Xiao-Ou; Lu, Wei; Gao, Yu-Tang; Cai, Hui; Cross, Simon S; Reed, Malcolm W R; Blot, William; Signorello, Lisa B; Cai, Qiuyin; Pharoah, Paul D P; Perkins, Barbara; Shah, Mitul; Blows, Fiona M; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Hartman, Mikael; Miao, Hui; Chia, Kee Seng; Putti, Thomas Choudary; Hamann, Ute; Luccarini, Craig; Baynes, Caroline; Ahmed, Shahana; Maranian, Mel; Healey, Catherine S; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; Mckay, James; Slager, Susan; Toland, Amanda E; Yannoukakos, Drakoulis; Shen, Chen-Yang; Hsiung, Chia-Ni; Wu, Pei-Ei; Ding, Shian-Ling; Ashworth, Alan; Jones, Michael; Orr, Nick; Swerdlow, Anthony J; Tsimiklis, Helen; Makalic, Enes; Schmidt, Daniel F; Bui, Quang M; Chanock, Stephen J; Hunter, David J; Hein, Rebecca; Dahmen, Norbert; Beckmann, Lars; Aaltonen, Kirsimari; Muranen, Taru A; Heikkinen, Tuomas; Irwanto, Astrid; Rahman, Nazneen; Turnbull, Clare A; Waisfisz, Quinten; Meijers-Heijboer, Hanne E J; Adank, Muriel A; Van Der Luijt, Rob B; Hall, Per; Chenevix-Trench, Georgia; Dunning, Alison; Easton, Douglas F; Cox, Angela

    2015-01-01

    Previous studies have suggested that polymorphisms in CASP8 on chromosome 2 are associated with breast cancer risk. To clarify the role of CASP8 in breast cancer susceptibility, we carried out dense genotyping of this region in the Breast Cancer Association Consortium (BCAC). Single-nucleotide polymorphisms (SNPs) spanning a 1 Mb region around CASP8 were genotyped in 46 450 breast cancer cases and 42 600 controls of European origin from 41 studies participating in the BCAC as part of a custom genotyping array experiment (iCOGS). Missing genotypes and SNPs were imputed and, after quality exclusions, 501 typed and 1232 imputed SNPs were included in logistic regression models adjusting for study and ancestry principal components. The SNPs retained in the final model were investigated further in data from nine genome-wide association studies (GWAS) comprising in total 10 052 case and 12 575 control subjects. The most significant association signal observed in European subjects was for the imputed intronic SNP rs1830298 in ALS2CR12 (telomeric to CASP8), with per allele odds ratio and 95% confidence interval [OR (95% confidence interval, CI)] for the minor allele of 1.05 (1.03-1.07), P = 1 × 10(-5). Three additional independent signals from intronic SNPs were identified, in CASP8 (rs36043647), ALS2CR11 (rs59278883) and CFLAR (rs7558475). The association with rs1830298 was replicated in the imputed results from the combined GWAS (P = 3 × 10(-6)), yielding a combined OR (95% CI) of 1.06 (1.04-1.08), P = 1 × 10(-9). Analyses of gene expression associations in peripheral blood and normal breast tissue indicate that CASP8 might be the target gene, suggesting a mechanism involving apoptosis.

  13. Identification and characterization of novel associations in the CASP8/ALS2CR12 region on chromosome 2 with breast cancer risk

    Lin, Wei-Yu; Camp, Nicola J.; Ghoussaini, Maya; Beesley, Jonathan; Michailidou, Kyriaki; Hopper, John L.; Apicella, Carmel; Southey, Melissa C.; Stone, Jennifer; Schmidt, Marjanka K.; Broeks, Annegien; Van't Veer, Laura J.; Th Rutgers, Emiel J.; Muir, Kenneth; Lophatananon, Artitaya; Stewart-Brown, Sarah; Siriwanarangsan, Pornthep; Fasching, Peter A.; Haeberle, Lothar; Ekici, Arif B.; Beckmann, Matthias W.; Peto, Julian; Dos-Santos-Silva, Isabel; Fletcher, Olivia; Johnson, Nichola; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; Sawyer, Elinor J.; Cheng, Timothy; Tomlinson, Ian; Kerin, Michael J.; Miller, Nicola; Marmé, Frederik; Surowy, Harald M.; Burwinkel, Barbara; Guénel, Pascal; Truong, Thérèse; Menegaux, Florence; Mulot, Claire; Bojesen, Stig E.; Nordestgaard, Børge G.; Nielsen, Sune F.; Flyger, Henrik; Benitez, Javier; Zamora, M. Pilar; Arias Perez, Jose Ignacio; Menéndez, Primitiva; González-Neira, Anna; Pita, Guillermo; Alonso, M. Rosario; Álvarez, Nuria; Herrero, Daniel; Anton-Culver, Hoda; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Meindl, Alfons; Lichtner, Peter; Schmutzler, Rita K.; Müller-Myhsok, Bertram; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Tessier, Daniel C.; Vincent, Daniel; Bacot, Francois; Nevanlinna, Heli; Aittomäki, Kristiina; Blomqvist, Carl; Khan, Sofia; Matsuo, Keitaro; Ito, Hidemi; Iwata, Hiroji; Horio, Akiyo; Bogdanova, Natalia V.; Antonenkova, Natalia N.; Dörk, Thilo; Lindblom, Annika; Margolin, Sara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Wu, Anna H.; Tseng, Chiu-Chen; Van Den Berg, David; Stram, Daniel O.; Neven, Patrick; Wauters, Els; Wildiers, Hans; Lambrechts, Diether; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Radice, Paolo; Peterlongo, Paolo; Manoukian, Siranoush; Bonanni, Bernardo; Couch, Fergus J.; Wang, Xianshu; Vachon, Celine; Purrington, Kristen; Giles, Graham G.; Milne, Roger L.; Mclean, Catriona; Haiman, Christopher A.; Henderson, Brian E.; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Goldberg, Mark S.; Labrèche, France; Dumont, Martine; Teo, Soo Hwang; Yip, Cheng Har; Hassan, Norhashimah; Vithana, Eranga Nishanthie; Kristensen, Vessela; Zheng, Wei; Deming-Halverson, Sandra; Shrubsole, Martha J.; Long, Jirong; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Kauppila, Saila; Andrulis, Irene L.; Knight, Julia A.; Glendon, Gord; Tchatchou, Sandrine; Devilee, Peter; Tollenaar, Robert A.E.M.; Seynaeve, Caroline; Van Asperen, Christi J.; García-Closas, Montserrat; Figueroa, Jonine; Lissowska, Jolanta; Brinton, Louise; Czene, Kamila; Darabi, Hatef; Eriksson, Mikael; Brand, Judith S.; Hooning, Maartje J.; Hollestelle, Antoinette; Van Den Ouweland, Ans M.W.; Jager, Agnes; Li, Jingmei; Liu, Jianjun; Humphreys, Keith; Shu, Xiao-Ou; Lu, Wei; Gao, Yu-Tang; Cai, Hui; Cross, Simon S.; Reed, Malcolm W. R.; Blot, William; Signorello, Lisa B.; Cai, Qiuyin; Pharoah, Paul D.P.; Perkins, Barbara; Shah, Mitul; Blows, Fiona M.; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Hartman, Mikael; Miao, Hui; Chia, Kee Seng; Putti, Thomas Choudary; Hamann, Ute; Luccarini, Craig; Baynes, Caroline; Ahmed, Shahana; Maranian, Mel; Healey, Catherine S.; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Sangrajrang, Suleeporn; Gaborieau, Valerie; Brennan, Paul; Mckay, James; Slager, Susan; Toland, Amanda E.; Yannoukakos, Drakoulis; Shen, Chen-Yang; Hsiung, Chia-Ni; Wu, Pei-Ei; Ding, Shian-ling; Ashworth, Alan; Jones, Michael; Orr, Nick; Swerdlow, Anthony J; Tsimiklis, Helen; Makalic, Enes; Schmidt, Daniel F.; Bui, Quang M.; Chanock, Stephen J.; Hunter, David J.; Hein, Rebecca; Dahmen, Norbert; Beckmann, Lars; Aaltonen, Kirsimari; Muranen, Taru A.; Heikkinen, Tuomas; Irwanto, Astrid; Rahman, Nazneen; Turnbull, Clare A.; Waisfisz, Quinten; Meijers-Heijboer, Hanne E. J.; Adank, Muriel A.; Van Der Luijt, Rob B.; Hall, Per; Chenevix-Trench, Georgia; Dunning, Alison; Easton, Douglas F.; Cox, Angela

    2015-01-01

    Previous studies have suggested that polymorphisms in CASP8 on chromosome 2 are associated with breast cancer risk. To clarify the role of CASP8 in breast cancer susceptibility, we carried out dense genotyping of this region in the Breast Cancer Association Consortium (BCAC). Single-nucleotide polymorphisms (SNPs) spanning a 1 Mb region around CASP8 were genotyped in 46 450 breast cancer cases and 42 600 controls of European origin from 41 studies participating in the BCAC as part of a custom genotyping array experiment (iCOGS). Missing genotypes and SNPs were imputed and, after quality exclusions, 501 typed and 1232 imputed SNPs were included in logistic regression models adjusting for study and ancestry principal components. The SNPs retained in the final model were investigated further in data from nine genome-wide association studies (GWAS) comprising in total 10 052 case and 12 575 control subjects. The most significant association signal observed in European subjects was for the imputed intronic SNP rs1830298 in ALS2CR12 (telomeric to CASP8), with per allele odds ratio and 95% confidence interval [OR (95% confidence interval, CI)] for the minor allele of 1.05 (1.03–1.07), P = 1 × 10−5. Three additional independent signals from intronic SNPs were identified, in CASP8 (rs36043647), ALS2CR11 (rs59278883) and CFLAR (rs7558475). The association with rs1830298 was replicated in the imputed results from the combined GWAS (P = 3 × 10−6), yielding a combined OR (95% CI) of 1.06 (1.04–1.08), P = 1 × 10−9. Analyses of gene expression associations in peripheral blood and normal breast tissue indicate that CASP8 might be the target gene, suggesting a mechanism involving apoptosis. PMID:25168388

  14. Glacial cycles

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...

  15. Glacial cycles

    Kaufmann, R. K.; Juselius, Katarina

    and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...

  16. Happy Cycling

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  17. Koszul cycles

    Bruns, Winfreid; Römer, Tim

    2010-01-01

    We prove regularity bounds for Koszul cycles holding for every ideal of dimension at most 1 in a polynomial ring. We generalize the lower bound for the Green-Lazarsfeld index of Veronese rings we proved in arXiv:0902.2431 to the multihomogeneous setting.

  18. Cytogenetic Toxicity of K_2Cr_2O_7 on Rye and Mitigatory Effect of Silicon%重铬酸钾对黑麦的细胞遗传毒性及硅的缓解作用

    张志雯; 陈于和; 秦玲; 林小虎; 秦素平

    2012-01-01

    为了解K2Cr2O7的细胞遗传毒性及硅对铬毒害的缓解作用,采用常规染色体压片技术,观察不同浓度的K2Cr2O7(20、40、60、80、100、120mg.L-1)对黑麦根尖细胞有丝分裂的影响以及硅对铬胁迫缓解效应。结果表明,细胞有丝分裂指数、微核率和染色体畸变率均随K2Cr2O7浓度的升高呈先升后降趋势,在K2Cr2O7浓度为40.0mg.L-1时均达到最大值。与蒸馏水对照相比,6个不同浓度K2Cr2O7胁迫处理的微核率和染色体畸变率均有显著升高。对40mg.L-1 K2Cr2O7胁迫的黑麦根尖分别进行60、120和180mg.L-1的Na2SiO3处理,细胞有丝分裂指数、微核率和染色体畸变率均显著降低,且随硅浓度的增加呈下降趋势。说明K2Cr2O7对黑麦根尖细胞有丝分裂在低浓度时促进,高浓度时抑制,高低浓度处理均对染色体具有明显的致畸效应。外源硅可有效缓解K2Cr2O7对黑麦根尖细胞有丝分裂的不利影响。%Cytogenetic toxicity of K2Cr2O7 on rye and mitigatory effect of silicon were studied.The mitosis index,micronucleus frequency and chromosome aberration rate of root tip cells of rye were investigated under treatments of different concentrations of K2Cr2O7.The results showed that the mitosis index,micronucleus rate and chromosome aberration rate increased gradually in the root tips of rye along with the increasing of K2Cr2O7 concentration in the range of 0~40 mg·L-1,while these index reduced gradually along with the increasing of K2Cr2O7 concentration in the range of 40~120 mg·L-1.There were significant differences between the treatments and the no-treatment.The mitosis index,micronucleus rate and chromosome aberration rate of root tips of rye under K2Cr2O7(40 mg·L-1) stress reduced significantly with increasing concentration of Na2SiO3(0~180 mg·L-1).There were significant differences between Na2SiO3 treatments and the no-treatment.The conclusion of this study was that K2Cr2O7 had obvious

  19. Deficiency of complement receptors CR2/CR1 in Cr2⁻/⁻ mice reduces the extent of secondary brain damage after closed head injury.

    Neher, Miriam D; Rich, Megan C; Keene, Chesleigh N; Weckbach, Sebastian; Bolden, Ashley L; Losacco, Justin T; Patane, Jenée; Flierl, Michael A; Kulik, Liudmila; Holers, V Michael; Stahel, Philip F

    2014-05-24

    Complement activation at the C3 convertase level has been associated with acute neuroinflammation and secondary brain injury after severe head trauma. The present study was designed to test the hypothesis that Cr2-/- mice, which lack the receptors CR2/CD21 and CR1/CD35 for complement C3-derived activation fragments, are protected from adverse sequelae of experimental closed head injury. Adult wild-type mice and Cr2-/- mice on a C57BL/6 genetic background were subjected to focal closed head injury using a standardized weight-drop device. Head-injured Cr2-/- mice showed significantly improved neurological outcomes for up to 72 hours after trauma and a significantly decreased post-injury mortality when compared to wild-type mice. In addition, the Cr2-/- genotype was associated with a decreased extent of neuronal cell death at seven days post-injury. Western blot analysis revealed that complement C3 levels were reduced in the injured brain hemispheres of Cr2-/- mice, whereas plasma C3 levels remained unchanged, compared to wild-type mice. Finally, head-injured Cr2-/- had an attenuated extent of post-injury C3 tissue deposition, decreased astrocytosis and microglial activation, and attenuated immunoglobulin M deposition in injured brains compared to wild-type mice. Targeting of these receptors for complement C3 fragments (CR2/CR1) may represent a promising future approach for therapeutic immunomodulation after traumatic brain injury.

  20. Obtaining and characterization of La0.8Sr0.2CrO3 perovskite by the combustion method

    Morales Rivera, A. M.; Gómez Cuaspud, J. A.; López, E. Vera

    2017-01-01

    This research is focused on the synthesis and characterization of a perovskite oxide based on La0.8Sr0.2CrO3 system by the combustion method. The material was obtained in order to contribute to analyse the effect of synthesis route in the obtaining of advanced anodic materials for solid oxide fuel cells (SOFC). The obtaining of solid was achieved starting from corresponding nitrate dissolutions, which were polymerized by temperature effect in presence of citric acid. The solid precursor as a foam citrate was characterized by infrared (FTIR) and ultraviolet (UV) spectroscopy, confirming the effectiveness in synthesis process. The solid was calcined in oxygen atmosphere at 800°C and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive of X-ray spectroscopy (EDX) and solid state impedance spectroscopy (IS). Results confirm the obtaining of an orthorhombic solid with space group Pnma (62) and cell parameters a=5.4590Å, b=7.7310Å and c=5.5050Å. At morphological level the solid showed a heterogeneous distribution with an optimal correspondence with proposed and obtained stoichiometry. The electrical characterization, confirm a semiconductor behaviour with a value of 2.14eV Band-gap according with previous works.

  1. Laser stimulated kinetics effects on the phase transition of the ferromagnetic/superconducting MgB{sub 2}/(CrO{sub 2}) bilayer thin films

    AlZayed, N.S. [Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Kityk, I.V., E-mail: ikityk@el.pcz.czest.pl [Faculty of Electrical Engineering, Czestochowa University Technology, Armii Krajowej 17, PL-42201 Czestochowa (Poland); Soltan, S. [Max Planck Institute, Solid State Research, D-70569 Stuttgart (Germany); Physics Department, Faculty of Science, Helwan University, 11798 Helwan, Cairo (Egypt); Wojciechowski, A. [Faculty of Electrical Engineering, Czestochowa University Technology, Armii Krajowej 17, PL-42201 Czestochowa (Poland); Fedorchuk, A.O. [Department of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, Pekarska St., 50, 79010 Lviv (Ukraine); Lakshminarayana, G. [Materials Science and Technology Division (MST-7), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Shahabuddin, M. [Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2014-05-01

    Graphical abstract: Dependence of resistance versus temperature for different power densities. The nonzero value is generated from the bottom CrO{sub 2} resistive layer. The onset transition temperature is our reference for the enhancement value. - Highlights: • Photoinduced enhancement of critical temperature in MgB{sub 2}–Cr{sub 2}O{sub 3} films was found. • Crucail role of electron–phonon interacton was shown. • Optimal ratio fundamental/SHG intensities was varied within 4:1 and 6:1. - Abstract: Using bicolor laser treatment by Nd:YAG 20 ns laser (1064–532 nm) and 180 ns CO{sub 2} laser beams (10.6–5.3 μm) it was shown a possibility of critical temperature enhancement in ferromagnetic superconducting MgB{sub 2}/CrO{sub 2} bilayer films. The role of the phonon sub-system effectively interacting with 3d Cr originating localized trapping levels is discussed. The pump–probe laser kinetics for the probing second harmonic generation at 1064 nm is explored in details to show principal role of the localized trapping levels. The relaxation of the processes after the switching off the photo inducing beams show the disappearance of the enhanced superconductivity after the 20–30 s. The temperature dependence of the resistance show nonlinear dependence versus the pumping power and different optimal fundamental to writing power density beams ratio.

  2. Effects of support property on the catalytic performance of CeO2-ZrO2-CrOx for 1,2-dichloroethane oxidation

    陶飞; 杨姗姗; 杨鹏; 石智男; 周仁贤

    2016-01-01

    HZSM-5, Al2O3, TiO2 and SiO2 supported CeO2-ZrO2-CrOx catalysts were prepared by deposition-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane (DCE), as one of the common chlorinated organic pollutants. All the catalysts were characterized by means of N2adsorption-desorption, X-ray photoelectron spectroscopy (XPS), ammonia-temperature- programmed desorption (NH3-TPD) and hydrogen temperature-programmed reduction (H2-TPR). The characterization results re-vealed that there was strongly synergistic effect between the oxidizability of CZCr species and the acidity of supports, which obvi-ously promoted the catalytic activity for DCE degradation. 20%CZCr/HZSM-5 showed the highest activity and good durability dur-ing the long-term continuous test. The catalytic activity decreased in the order: 20%CZCr/HZSM-5>CZCr>20%CZCr/TiO2> 20%CZCr/Al2O3>20%CZCr/SiO2.

  3. Preparation of La0.8Sr0.2Cr0.97V0.03O3-delta films for solid oxide fuel cell application

    Mikkelsen, Lars; Pryds, Nini; Hendriksen, Peter Vang

    2007-01-01

    and to study the material in form of a thin film we have used Pulsed Laser Deposition to obtain a dense, uniform film with the right stochiometry. Investigation of preparation-parameter dependence of the LSC films deposited on a stainless steel substrate during pulsed-laser deposition was carried out. The LSC...... films were deposited with KrF excimer laser (248 nm) on a stainless steel substrate at different oxygen pressure and substrate temperatures. The substrate temperature (873-1073 K) and the oxygen background pressure (5-20 Pa) were varied in order to obtain optimal growth conditions. The surface......La0.8Sr0.2Cr0.97V0.03O3-delta (LSC) is commonly studied as a ceramic interconnect material as well as a coating material for metallic interconnects for solid oxide fuel cell applications. However, it is difficult to sinter this type of material to high density. In order to overcome this problem...

  4. Structural investigations of La{sub 0.8}Sr{sub 0.2}CrO{sub 3} by X-ray and neutron scattering

    Patra, A.K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Nair, Sathi [Energy Conversion Materials Section, Bhabha Atomic Research Centre, Vashi Complex, Navi Mumbai 400705 (India); Sastry, P.U. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: aktyagi@barc.gov.in

    2009-05-05

    Effect of heat treatment on pore microstructure of La{sub 0.8}Sr{sub 0.2}CrO{sub 3} compacts was investigated by small angle neutron scattering (SANS) over the scattering wave-vector range of 0.003-3.5 nm{sup -1}. Phase and composition of the powder synthesized by gel combustion method were characterized by X-ray diffraction. Agglomerate size distribution was measured by laser diffraction. Average agglomerate size (D{sub 50}) was found to be 950 nm. Analysis of SANS data showed that pores in the green compact follow power law distribution. Pores in sintered compacts follow log-normal size distribution. Though there was decrease in porosity of the compact with increasing sintering temperature, a shift in size distribution of pores towards higher side was observed. Scaling of SANS profiles of sintered compacts using Rg as characteristic length indicated that morphological pattern of the pores in the system look nearly similar at different temperatures.

  5. Forming Mechanism of Gaseous Defect in Ti-48A1-2Cr-2Nb Exhaust Valves Formed with Permanent Mold Centrifugal Casting Method

    2001-01-01

    A method combining theoretical analysis with experiment is adopted and the flowing process of Ti-48AI-2Cr-2Nb alloy melt poured in a permanent mould during the centrifugal casting process has been analyzed. A mathematical model of the filling process is established and the forming mechanism of internal gaseous defect is summarized. The results of calculation show that the melt fills the mould with varying cross-section area and inclined angle. The filling speed of the cross-section is a function of filling time. The cross-section area is directly proportional to the filling speed and the inclined angle is inversely proportional to the filling speed at a given rotating speed of the platform. Both of them changes more obvious near the mould entrance.The gaseous defect can be formed in several ways and the centrifugal field has an important influence on the formation of the defect. In addition, the filling process in centrifugal field has been verified by wax experiments and the theoretical analysis are consistent with experimental results.

  6. Ultrasonic-assisted preparation of novel ternary ZnO/Ag3VO4/Ag2CrO4 nanocomposites and their enhanced visible-light activities in degradation of different pollutants

    Pirhashemi, Mahsa; Habibi-Yangjeh, Aziz

    2016-05-01

    Novel ternary ZnO/Ag3VO4/Ag2CrO4 nanocomposites were successfully fabricated via preparation of ZnO/Ag3VO4 followed by coupling of it with Ag2CrO4 through facile ultrasonic-assisted method. The resultant samples were carefully characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of X-rays, UV-vis diffuse reflectance spectroscopy, Fourier transform-infrared spectroscopy, and photoluminescence techniques. Photocatalytic activity for degradation of organic dyes, including rhodamine B, methylene blue, and methyl orange was examined under visible-light irradiation. Among the prepared samples, the ternary nanocomposite with 20% of Ag2CrO4 demonstrated the superior activity. This nanocomposite showed 10.6, 2.9, and 3.0-folds greater activity compared to ZnO, ZnO/Ag2CrO4, and ZnO/Ag3VO4, respectively. The enhanced activity was attributed to more harvesting of the visible-light irradiation and efficiently separation of the photogenerated charge carriers in the ternary nanocomposites. To understand efficiently separation of the charge carriers, a plausible diagram was proposed based on formation of tandem n-n heterojunctions.

  7. Electronic, magnetic, and optical characteristics of half-semiconductor double perovskite oxide Sr2CrOsO6 governed by 3d (t2g3)-5d (t2g3) antiferromagnetic coupling

    H.-E., M. Musa Saad

    2016-07-01

    In this study, motivated by observations of the remarkable magnetic insulating nature and high Curie temperature (TC=725 K) of double perovskite oxide Sr2CrOsO6, the electronic, magnetic, and optical characteristics of Sr2CrOsO6 were determined using the full potential linear muffin-tin orbital method according to density functional theory. The spin-orbit coupling contribution was included in the local spin density approximation (LSDA) and generalized gradient approximation (GGA). In addition, the Coulomb repulsion (U) and Hund's exchange (J) energies were considered in both methods (LSDA+U and GGA+U). Full structural optimization confirmed that the ground state of Sr2CrOsO6 is face-centered cubic (Fm-3m symmetry). Calculations predicted that Sr2CrOsO6 is ferrimagnetic half-semiconductive (HSC) due to the vertical hopping of t2g electrons via antiferromagnetic coupling [Cr3+ (t2g3↑)-O (2pπ)-Os5+ (t2g3↓)], which agreed with the experimental results. The HSC energy-gaps originate from the splitting of three partially occupied Os5+ (5d) bands into two fully filled bands and one empty spin-down band. The real ε1 (ω) and imaginary ε2 (ω) parts of the dielectric function ε (ω) and energy-loss spectrum L (ω) were calculated, analyzed, and compared with the electronic results.

  8. Safe cycling!

    Anaïs Schaeffer

    2012-01-01

    The HSE Unit will be running a cycling safety campaign at the entrances to CERN's restaurants on 14, 15 and 16 May. Pop along to see if they can persuade you to get back in the saddle!   With summer on its way, you might feel like getting your bike out of winter storage. Well, the HSE Unit has come up with some original ideas to remind you of some of the most basic safety rules. This year, the prevention campaign will be focussing on three themes: "Cyclists and their equipment", "The bicycle on the road", and "Other road users". This is an opportunity to think about the condition of your bike as well as how you ride it. From 14 to 16 May, representatives of the Swiss Office of Accident Prevention and the Touring Club Suisse will join members of the HSE Unit at the entrances to CERN's restaurants to give you advice on safe cycling (see box). They will also be organising three activity stands where you can test your knowle...

  9. Effect of Heat Treatment on Fracture Microstructure and Image of 1Cr18Ni9Ti and 2Cr13 Steel Welded Joints%热处理对1Cr18Ni9Ti与2Cr13钢焊接接头断口组织形貌的影响

    赵勇桃; 董俊慧; 刘宗昌; 周军伟

    2012-01-01

    By TIG, under certain welding craft conditions, lCrl8Ni9Ti and 2Crl3 was welded, and certain heat treatment was carried out to welded joint The fracture image and properties of 2Cr13 and lCrl8Ni9Ti welded joints before and after heat treatment were observed by OM, SEM, electronic universal tensile machine and tensile experiments. The results show that before heat treatment, 2Crl3 and lCrl8Ni9Ti welded joints is columnar crystal, the microstructure is lath martensite + austenite + carbide. After heat treatment, the structure changes from lath martensite into tempered sorbite. After tensile,the fracture position of welded joints is HAZ of austenitic stainless steel, belong to toughness fracture. Before heat treatment, the dimple size and distribution are not uniform; after heat treatment, they are uniform. Before heat treatment, the tensile strength of the welded joints is about 635 Mpa, elongation is 26%, reduction of area is 44%; after heat treatment, the tensile strength of the welded joints is about 645 Mpa, elongation is 24%, reduction of area is 44%.%通过钨极氩弧焊方法,在一定工艺条件下对1Cr18Ni9Ti与2Cr13实施焊接,后对焊接接头进行焊后热处理.通过万能拉伸机对热处理前后的焊接接头进行拉伸试验,采用OM、SEM对1Cr18Ni9Ti与2Cr13钢热处理前后的焊接接头进行断口组织形貌观察及分析.结果表明,1Cr18Ni9Ti和2Cr13焊接接头热处理前焊缝组织为典型的柱状晶,组织为板条马氏体+残余奥氏体+碳化物;热处理后焊缝组织转变为回火索氏体.拉伸时,热处理前后焊接接头断裂部位都发生在奥氏体不锈钢热影响区一侧,均属于韧性断裂,热处理前韧窝大小、分布不均匀;热处理后韧窝变小,分布均匀,大小尺寸均等.热处理前,焊接接头的抗拉强度约为635 MPa,伸长率约为26%,断面收缩率约为44%;热处理后,焊接接头的抗拉强度约为645 MPa,伸长率约为24%,断面收缩率约为44%.

  10. High-cycle Fatigue Fracture Behavior of Ultrahigh Strength Steels

    Weijun HUI; Yihong NIE; Han DONG; Yuqing WENG; Chunxu WANG

    2008-01-01

    The fatigue fracture behavior of four ultrahigh strength steels with different melting processes and therefore different inclusion sizes were studied by using a rotating bar two-point bending fatigue machine in the high-cycle regime up to 107 cycles of loading. The fracture surfaces were observed by field emission scanning electron microscopy (FESEM). It was found that the size of inclusion has significant effect on the fatigue behavior.For AISI 4340 steel in which the inclusion size is smaller than 5.5 μm, all the fatigue cracks except one did not initiated from inclusion but from specimen surface and conventional S-N curve exists. For 65Si2MnWE and Aermet 100 steels in which the average inclusion sizes are 12.2 and 14.9 μm, respectively, fatigue cracks initiated from inclusions at lower stress amplitudes and stepwise S-N curves were observed. The S-N curvedisplays a continuous decline and fatigue failures originated from large oxide inclusion for 60Si2CrVA steel in which the average inclusion size is 44.4 μm. In the case of internal inclusion-induced fractures at cycles beyond about 1×106 for 65Si2MnWE and 60Si2CrVA steels, inclusion was always found inside the fish-eye and a granular bright facet (GBF) was observed in the vicinity around the inclusion. The GBF sizes increasewith increasing the number of cycles to failure Nf in the long-life regime. The values of stress intensity factor range at crack initiation site for the GBF are almost constant with Nf, and are almost equal to that for the surface inclusion and the internal inclusion at cycles lower than about 1×106. Neither fish-eye nor GBF was observed for Aermet 100 steel in the present study.

  11. Giant magnetoimpedance intrinsic impedance and voltage sensitivity of rapidly solidified Co66Fe2Cr4Si13B15 amorphous wire for highly sensitive sensors applications

    Das, Tarun K.; Banerji, Pallab; Mandal, Sushil K.

    2016-11-01

    We report a systematic study of the influence of wire length, L, dependence of giant magneto-impedance (GMI) sensitivity of Co66Fe2Cr4Si13B15 soft magnetic amorphous wire of diameter ~100 µm developed by in-water quenching technique. The magnetization behaviour (hysteresis loops) of the wire with different length ( L = 1, 2, 3, 5, 8 and 10 cm) has been evaluated by fuxmetric induction method. It was observed that the behaviour of the hysteresis loops change drastically with the wire length, being attributed to the existence of a critical length, L C, found to be around 3 cm. GMI measurements have been taken using automated GMI measurement system and the GMI sensitivities in terms of intrinsic impedance sensitivity ( S Ω/Am -1) and voltage sensitivity ( S V/Am -1) of the wire have been evaluated under optimal bias field and excitation current. It was found that the maximum ( S Ω/Am -1) max ≈ 0.63 Ω/kAm-1/cm and ( S V/Am -1) max ≈ 3.10 V/kAm-1/cm were achieved at a critical length L C ~ 3 cm of the wire for an AC current of 5 mA and a frequency of 5 MHz. These findings provide crucial insights for optimization of the geometrical dimensions of magnetic sensing elements and important practical guidance for designing high sensitive GMI sensors. The relevant combinations of magnetic material parameters and operating conditions that optimize the sensitivity are highlighted.

  12. Isolating the Epstein-Barr virus gp350/220 binding site on complement receptor type 2 (CR2/CD21).

    Young, Kendra A; Chen, Xiaojiang S; Holers, V Michael; Hannan, Jonathan P

    2007-12-14

    Complement receptor type 2 (CR2/CD21) is essential for the attachment of Epstein-Barr virus (EBV) to the surface of B-lymphocytes in an interaction mediated by the viral envelope glycoprotein gp350. The heavily glycosylated structure of EBV gp350 has recently been elucidated by x-ray crystallography, and the CR2 binding site on this protein has been characterized. To identify the corresponding gp350 binding site on CR2, we have undertaken a site-directed mutagenesis study targeting regions of CR2 that have previously been implicated in the binding of CR2 to the C3d/C3dg fragments of complement component C3. Wild-type or mutant forms of CR2 were expressed on K562 cells, and the ability of these CR2-expressing cells to bind gp350 was measured using flow cytometry. Mutations directed toward the two N-terminal extracellular domains of CR2 (SCR1-2) reveal that a large contiguous surface of CR2 SCR1-2 is involved in gp350 binding, including a number of positively charged residues (Arg-13, (Arg-28, (Arg-36, Lys-41, Lys-57, Lys-67, and Arg-83). These data appear to complement the CR2 binding site on gp350, which is characterized by a preponderance of negative charge. In addition to identifying the importance of charge in the formation of a CR2-gp350 complex, we also provide evidence that both SCR1 and SCR2 make contact with gp350. Specifically, two anti-CR2 monoclonal antibodies, designated as monoclonal antibodies 171 and 1048 whose primary epitopes are located within SCR2, inhibit binding of wild-type CR2 to EBV gp350; with regard to SCR1, both K562 cells expressing an S15P mutation and recombinant S15P CR2 proteins exhibit diminished gp350 binding.

  13. The effect of heat treatment on the corrosion resistance of 440C stainless steel in 20% HNO3 + 2.5% Na2Cr2O7 solution

    Savas, Terence P.; Wang, Allen Yi-Lan; Earthman, James C.

    2003-04-01

    The effect of heat treatment on the corrosion resistance of 440C stainless steel was investigated in a 20% HNO3 + 2.5% Na2Cr2O7 solution using electrochemical noise (ECN) measurements, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) examinations. The noise resistance ( Rn), which has been found to be inversely related to the localized corrosion rate, was measured to be 5.7E + 08 Ω-cm2, 4.2E + 08 Ω-cm2, and 3.7E + 04 Ω-cm2 for the oil-quenched, air-quenched, and vacuum furnace cooled (VFC) samples, respectively, after 1200 s exposures. The Rn for all heat treat conditions stabilized within a range of 1.0E + 07 Ω-cm2 to 3.2E + 08 Ω-cm2 after 2 h exposures. The EIS response showed a polarization resistance ( R p) on the order of 6.6E + 04 Ω-cm2, 5.3E + 04 Ω-cm2, and 1.1E + 04 Ω-cm2 for the oil-quenched, air-quenched, and VFC samples, respectively, after 2 h exposures. The EIS data are in good agreement with ECN data and indicate that after longer exposures, general corrosion mechanisms dominate and the corrosion rates are comparable. SEM examinations of specimens subjected to 1200 s exposures revealed that severity of pitting and intergranular corrosion damage was consistent with trends in the Rn data. Specifically, the electrochemical noise data as well as SEM examinations of specimens revealed a higher localized corrosion resistance of the hardened specimens during the early stages of passivation. This greater resistance to localized corrosion can be attributed to an increased stability of the natural passive film resulting from a higher concentration of chromium atoms in solution for the martensite phase.

  14. Mutational analysis of the complement receptor type 2 (CR2/CD21)-C3d interaction reveals a putative charged SCR1 binding site for C3d.

    Hannan, Jonathan P; Young, Kendra A; Guthridge, Joel M; Asokan, Rengasamy; Szakonyi, Gerda; Chen, Xiaojiang S; Holers, V Michael

    2005-02-25

    We have characterized the interaction between the first two short consensus repeats (SCR1-2) of complement receptor type 2 (CR2, CD21) and C3d in solution, by utilising the available crystal structures of free and C3d-bound forms of CR2 to create a series of informative mutations targeting specific areas of the CR2-C3d complex. Wild-type and mutant forms of CR2 were expressed on the surface of K562 erythroleukemia cells and their binding ability assessed using C3dg-biotin tetramers complexed to fluorochrome conjugated streptavidin and measured by flow cytometry. Mutations directed at the SCR2-C3d interface (R83A, R83E, G84Y) were found to strongly disrupt C3dg binding, supporting the conclusion that the SCR2 interface reflected in the crystal structure is correct. Previous epitope and peptide mapping studies have also indicated that the PILN11GR13IS sequence of the first inter-cysteine region of SCR1 is essential for the binding of iC3b. Mutations targeting residues within or in close spatial proximity to this area (N11A, N11E, R13A, R13E, Y16A, S32A, S32E), and a number of other positively charged residues located primarily on a contiguous face of SCR1 (R28A, R28E, R36A, R36E, K41A, K41E, K50A, K50E, K57A, K57E, K67A, K67E), have allowed us to reassess those regions on SCR1 that are essential for CR2-C3d binding. The nature of this interaction and the possibility of a direct SCR1-C3d association are discussed extensively. Finally, a D52N mutant was constructed introducing an N-glycosylation sequence at an area central to the CR2 dimer interface. This mutation was designed to disrupt the CR2-C3d interaction, either directly through steric inhibition, or indirectly through disruption of a physiological dimer. However, no difference in C3dg binding relative to wild-type CR2 could be observed for this mutant, suggesting that the dimer may only be found in the crystal form of CR2.

  15. Molecular basis of the interaction between complement receptor type 2 (CR2/CD21) and Epstein-Barr virus glycoprotein gp350.

    Young, Kendra A; Herbert, Andrew P; Barlow, Paul N; Holers, V Michael; Hannan, Jonathan P

    2008-11-01

    The binding of the Epstein-Barr virus glycoprotein gp350 by complement receptor type 2 (CR2) is critical for viral attachment to B lymphocytes. We set out to test hypotheses regarding the molecular nature of this interaction by developing an enzyme-linked immunosorbent assay (ELISA) for the efficient analysis of the gp350-CR2 interaction by utilizing wild-type and mutant forms of recombinant gp350 and also of the CR2 N-terminal domains SCR1 and SCR2 (designated CR2 SCR1-2). To delineate the CR2-binding site on gp350, we generated 17 gp350 single-site substitutions targeting an area of gp350 that has been broadly implicated in the binding of both CR2 and the major inhibitory anti-gp350 monoclonal antibody (MAb) 72A1. These site-directed mutations identified a novel negatively charged CR2-binding surface described by residues Glu-21, Asp-22, Glu-155, Asp-208, Glu-210, and Asp-296. We also identified gp350 amino acid residues involved in non-charge-dependent interactions with CR2, including Tyr-151, Ile-160, and Trp-162. These data were supported by experiments in which phycoerythrin-conjugated wild-type and mutant forms of gp350 were incubated with CR2-expressing K562 cells and binding was assessed by flow cytometry. The ELISA was further utilized to identify several positively charged residues (Arg-13, Arg-28, Arg-36, Lys-41, Lys-57, Lys-67, Arg-83, and Arg-89) within SCR1-2 of CR2 that are involved in the binding interaction with gp350. These experiments allowed a comparison of those CR2 residues that are important for binding gp350 to those that define the epitope for an effective inhibitory anti-CR2 MAb, 171 (Asn-11, Arg-13, Ser-32, Thr-34, Arg-36, and Tyr-64). The mutagenesis data were used to calculate a model of the CR2-gp350 complex using the soft-docking program HADDOCK.

  16. Magnetic tunneling junctions with the Heusler compound Co{sub 2}Cr{sub 0.6}Fe{sub 0.4}Al

    Conca Parra, A.

    2007-07-20

    Materials with large spin polarization are required for applications in spintronics devices. For this reason, major research efforts are directed to study the properties of compounds which are expected to be half metals, i.e. materials with 100% spin polarization. Half metals are expected to have a gap in the density of states at the Fermi energy for one spin band while the other spin band is metallic leading to a completely spin polarized current. The ferromagnetic full Heusler alloy Co{sub 2}Cr{sub 0.6}Fe{sub 0.4}Al (CCFA) has attracted great interest in the field of spintronics. The high Tc (800 K) and the expected half metallicity make CCFA a good candidate for applications in spintronic devices such as magnetic tunneling junctions (MTJs). This thesis presents the results of the study of the electronic and structural properties of CCFA thin films. The films were implemented in magnetic tunneling junctions and the tunneling magnetoresistance effect (TMR) was investigated. The main objectives were the measurement of the spin polarisation of the CCFA alloy and to obtain information about its electronic structure. The influence of the deposition conditions on the thin film properties and on the surface crystalline order and their respective influence on the TMR ratio was investigated. Epitaxial CCFA thin films with two alternative growth orientations were deposited on different substrates and buffer layers. An annealing step was used to improve the crystalline properties of the thin films. In the tunneling junctions, Al{sub 2}O{sub 3} was used as a barrier material and Co was chosen as counter electrode. The multilayer systems were patterned in Mesa structures using lithographic techniques. In the framework of the Julliere model, a maximum spin polarisation of 54% at 4K was measured in tunneling junctions with epitaxial CCFA electrodes. A strong influence of the annealing temperature on the TMR ratio was determined. The increase of the TMR ratio could be correlated

  17. Numerical adiabatic potentials of orthorhombic Jahn-Teller effects retrieved from ultrasound attenuation experiments. Application to the SrF2:Cr crystal

    Zhevstovskikh, I. V.; Bersuker, I. B.; Gudkov, V. V.; Averkiev, N. S.; Sarychev, M. N.; Zherlitsyn, S.; Yasin, S.; Shakurov, G. S.; Ulanov, V. A.; Surikov, V. T.

    2016-06-01

    A methodology is worked out to retrieve the numerical values of all the main parameters of the six-dimensional adiabatic potential energy surface (APES) of a polyatomic system with a quadratic T-term Jahn-Teller effect (JTE) from the ultrasound experiments. The method is based on a verified assumption that ultrasound attenuation and speed encounter anomalies when the direction of propagation and polarization of its wave of strain coincides with the characteristic directions of symmetry breaking in the JTE. For the SrF2:Cr crystal, employed as a basic example, we observed anomaly peaks in the temperature dependence of attenuation of ultrasound at frequencies of 50-160 MHz in the temperature interval of 40-60 K for the wave propagating along the [110] direction, for both the longitudinal and the shear modes, the latter with two polarizations along the [001] and [1 1 ¯ 0 ] axes, respectively. We show that these anomalies are due to the ultrasound relaxation by the system of non-interacting Cr2+ JT centers with orthorhombic local distortions. The interpretation of the experimental findings is based on the T2 g⊗(eg+t2 g) JTE problem including the linear and the quadratic terms of vibronic interactions in the Hamiltonian and the same-symmetry modes reduced to one interaction mode. Combining the experimental results with a theoretical analysis, we show that on the complicated six-dimensional APES of this system with three tetragonal, four trigonal, and six orthorhombic extrema points, the latter are global minima, while the former are saddle points, and we estimate numerically all the main parameters of this surface, including the linear and quadratic vibronic coupling constants, the primary force constants, the coordinates of all the extrema points and their energies, the energy barrier between the orthorhombic minima, and the tunneling splitting of the ground vibrational states. To our knowledge, such a based-on-experimental-data numerical reconstruction of the APES

  18. Cu-Mn-Ni-Ag钎料高频感应钎焊2Cr13不锈钢接头的显微组织与性能%Microstructure andperformance of 2Cr13stainless steel joint by high frequency induction brazing usingCu-Mn-Ni-Agfiller alloy

    郑义; 颜家振; 李宁; 曹永同; 帅帆

    2016-01-01

    The characteristic of Cu-Mn-Ni-Ag filler alloy and the microstructure and mechanical properties of the 2Cr13 stainless steel joint brazed by high frequency induction brazing using Cu-Mn-Ni-Ag filler alloywerestudied. The results show that the melting point of the Cu-Mn-Ni-Ag filler alloy is 880℃and it is composed of Ag-rich phase, Cu-Mn-Ni solid solution and a little Ni-Mn-Si compound; a layer of Fe-Mn-Ni-Cr-Cu solid solution forms at the interface between the filler alloy and base metal, and the brazing seam zone is composed of Ag-rich phase, Cu-Mn-Ni solid solution and a little Ni-Mn-Si compound. The brazing jointsfailsin the inside Cu-Mn-Ni solid solution and Ag-rich phase, and the fracture mode of the joints is mainly ductile dimple fracture, the best shear strength of the brazing joint at room temperature is 369 MPa, the high temperature shear strength of the brazing joints at 400℃, 500℃and 600℃are 251 MPa, 208 MPa and 84 MPa,respectively.%采用新型的Cu-Mn-Ni-Ag中温铜基钎料高频感应钎焊2Cr13不锈钢,并对钎料的工艺特性、钎焊接头的显微组织以及测试温度对钎焊接头力学性能的影响进行研究。结果表明:Cu-Mn-Ni-Ag钎料的熔点约为880℃,由富Ag相、Cu-Mn-Ni固溶体以及少量的Ni-Mn-Si化合物组成;钎料与2Cr13不锈钢产生良好的冶金结合,且钎焊接头组织致密;界面反应区的组织为Fe-Mn-Ni-Cr-Cu固溶体,钎缝区组织由富Ag相、Cu-Mn-Ni固溶体和少量的Ni-Mn-Si化合物组成;钎焊接头断裂于钎缝中间的富Ag相和CuMnNi固溶体上,为以剪切韧窝为主的韧性断裂,室温剪切强度最大可达369 MPa,在400℃、500℃和600℃下接头的剪切强度分别为251 MPa、208 MPa和84 MPa。

  19. Vacancy-induced insulator – direct spin gapless semiconductor – half-metal transition in double perovskite La{sub 2}CrFeO{sub 6}: A first-principles study

    Wu, Haiping, E-mail: mrhpwu@njust.edu.cn [Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, 210094 (China); State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012 (China); Qian, Yan, E-mail: qianyan@njust.edu.cn [Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, 210094 (China); Tan, Weishi; Kan, Erjun; Lu, Ruifeng; Deng, Kaiming [Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, 210094 (China)

    2015-11-06

    Double perovskite oxide La{sub 2}CrFeO{sub 6} with the characteristic of ferrimagnetic insulator has been reported by Chakraverty and Lee et al. Engineering the physical properties of materials, including obtaining unusual properties, can be achieved by some measures, and defect-tuning has been one of the most efficient measures. Here, by using density-functional calculations, La vacancy is introduced in La{sub 2}CrFeO{sub 6} and special properties are obtained successfully. The results show that the magnetic phase of La{sub 2}CrFeO{sub 6} would transfer from ferrimagnetic to ferromagnetic ordering as long as La vacancy is introduced. Furthermore, La{sub 1.75}CrFeO{sub 6} shows direct spin gapless semiconductor, and La{sub 1.5}CrFeO{sub 6} behaves as half-metal with the half-metallic gap of 0.42 eV. In the whole range of La vacancy, the electronic configurations of both Cr and Fe ions exhibit high-spin states, the magnetic moment of Fe remains 4.20 μ{sub B}, while that of Cr ions decreases from 2.66 to 1.97 μ{sub B} with increasing the amount of La vacancy. This work opens an alternative way to design spintronic materials, especially for direct spin gapless semiconductors which have never been reported in perovskite oxides. - Highlights: • La vacancy is introduced in La{sub 2}CrFeO{sub 6}. • La{sub 1.75}CrFeO{sub 6} shows the direct spin gapless semiconductor. • La{sub 1.5}CrFeO{sub 6} behaves as half-metal with the half-metallic gap of 0.42 eV.

  20. Deposition of La0.8Sr0.2Cr0.97V0.03O3 and MnCr2O4 thin films on ferritic alloy for solid oxide fuel cell application

    Mikkelsen, Lars; Chen, Ming; Hendriksen, Peter Vang;

    2007-01-01

    Single layer dense films of La0.8Sr0.2Cr0.97V0.03O3 (LSC) and MnCr2O4 with a thickness of 500 nm were deposited on a commercially available ferritic alloy (Crofer 22APU) by large-area Pulsed Laser Deposition. The deposited samples were subsequently oxidized at 1173 K for 500 h in humidified air...

  1. 金属型离心铸造Ti-48%Al-2%Cr-2%Nb合金汽车排气阀的研制%Research on Ti-48%Al-2%Cr-2%Nb Automobile Exhaust Valve Cast by Centrifugal Casting Process in Permanent Mold

    盛文斌; 李东; 杨锐; 郭景杰; 刘羽寅; 苏彦庆; 贾均

    2001-01-01

    In this paper, Ti-48Al-2Cr-2Nb automobile exhaust valve was castby the centrifugal casting method in permanent mold and its surface layer structure, microstructure, element distribution , mechanical properties etc were analyzed by SEM, XRD and EMPA . Furthermore, the valves treated by HIP were tested on 483Q diesel engine platform. Results showed that the distribution of alloying elements in Ti-Al based alloy for exhaust valve was uniform and its microstructure was refined to a certain extent. The mechanical properties of exhaust valve cast by centrifugal permanent mold then treated by HIP were that the σb = 670MPa, σ0.2 =527.5MPa and δ=3%. Result of the engine platform test showed that the valve had excellent air-tightness and wear-resistant properties, so could successfully satisfy requirements of the engine.%本文利用离心铸造的方法,在金属型中浇铸了Ti-48%Al-2%Cr-2%Nb合金汽车排气阀,通过SEM、XRD和EMPA等分析手段,对排气阀坯件的表面层结构、组织形态、成分分布和力学性能等特征进行了检测,并将热等静压(HIP)处理后的排气阀安装到483Q型柴油发动机上进行了台架试验。结果表明,金属型离心浇铸Ti-Al基合金排气阀,在保证阀体成分均匀性的同时,可在一定程度上细化铸件的显微组织。HIP处理后排气阀的平均力学性能为:σb=670MPa,σ0.2=527.5MPa和δ=3%。进一步的台架测试结果表明,排气阀在测试过程中表现出了优异的密封性和耐磨性,完全满足发动机的性能要求。

  2. Synthesis and X-ray structural investigation of (C{sub 3}N{sub 6}H{sub 7}){sub 4}(CN{sub 3}H{sub 6}){sub 2}[UO{sub 2}(CrO{sub 4}){sub 4}] . 4H{sub 2}O and (H{sub 3}O){sub 6}[UO{sub 2}(CrO{sub 4}){sub 4}

    Serezhkina, L. B., E-mail: lserezh@ssu.samara.ru [Samara State University (Russian Federation); Peresypkina, E. V.; Virovets, A. V. [Russian Academy of Sciences, Nikolaev Institute of Inorganic Chemistry, Siberian Branch (Russian Federation); Verevkin, A. G.; Pushkin, D. V. [Samara State University (Russian Federation)

    2009-03-15

    Single crystals of the compounds (C{sub 3}N{sub 6} H{sub 7}){sub 4}(CN{sub 3}H{sub 6}){sub 2}[UO{sub 2}(CrO{sub 4}){sub 4}] . 4H{sub 2}O (I) and (H{sub 3}O){sub 6}[UO{sub 2}(CrO{sub 4}){sub 4}] (II) are synthesized, and their structures are investigated using X-ray diffraction. Compound I crystallizes in the triclinic system with the unit cell parameters a = 6.3951(8) A, b = 10.8187(16) A, c = 16.9709(18) A, {alpha} = 93.674(4){sup o}, {beta} = 97.127(4){sup o}, {gamma} = 92.020(4){sup o}, space group, P1-barZ = 1, V = 1161.6(3) A{sup 3}, and R = 0.0470. Crystals of compound II belong to the monoclinic system with the unit cell parameters a = 14.3158(4) A, b = 11.7477(3) A, c = 13.1351(4) A, {beta}= 105.836(1){sup o}, space group C2/c, Z = 4, V = 2125.2(1) A{sup 3}, and R = 0.0213. The uranium-containing structural units of crystals I and II are mononuclear anionic complexes of the composition [UO{sub 2}(CrO{sub 4}){sub 4}]{sup 6-} with an island structure, which belong to the crystal-chemical group Am{sub 1}{sup 4} (A = UO{sub 2+}{sup 2}, M{sup 1} = CrO{sub 2-}{sup 4}) of the uranyl complexes. The [UO{sub 2}(CrO{sub 4}){sub 4}]{sup 6-} anionic complexes are joined into a three-dimensional framework through the electrostatic interactions with outer-sphere cations and a system of hydrogen bonds.

  3. Mechanisms and rates of proton transfer to coordinated carboxydithioates: studies on [Ni(S2CR){PhP(CH2CH2PPh2)2}](+) (R = Me, Et, Bu(n) or Ph).

    Alwaaly, Ahmed; Clegg, William; Henderson, Richard A; Probert, Michael R; Waddell, Paul G

    2015-02-21

    The complexes [Ni(S2CR)(triphos)]BPh4 (R = Me, Et, Bu(n) or Ph; triphos = PhP{CH2CH2PPh2}2) have been prepared and characterised. X-ray crystallography (for R = Et, Ph, C6H4Me-4, C6H4OMe-4 and C6H4Cl-4) shows that the geometry of the five-coordinate nickel in the cation is best described as distorted trigonal bipyramidal, containing a bidentate carboxydithioate ligand with the two sulfur atoms spanning axial and equatorial sites, the other axial site being occupied by the central phosphorus of triphos. The reactions of [Ni(S2CR)(triphos)](+) with mixtures of HCl and Cl(-) in MeCN to form equilibrium solutions containing [Ni(SH(S)CR)(triphos)](2+) have been studied using stopped-flow spectrophotometry. The kinetics show that proton transfer is slower than the diffusion-controlled limit and involves at least two coupled equilibria. The first step involves the rapid association between [Ni(S2CR)(triphos)](+) and HCl to form the hydrogen-bonded precursor, {[Ni(S2CR)(triphos)](+)HCl} (K) and this is followed by the intramolecular proton transfer (k) to produce [Ni(SH(S)CR)(triphos)](2+). In the reaction of [Ni(S2CMe)(triphos)](+) the rate law is consistent with the carboxydithioate ligand undergoing chelate ring-opening after protonation. It seems likely that chelate ring-opening occurs for all [Ni(S2CR)(triphos)](+), but only with [Ni(S2CMe)(triphos)](+) is the protonation step sufficiently fast that chelate ring-opening is rate-limiting. With all other systems, proton transfer is rate-limiting. DFT calculations indicate that protonation can occur at either sulfur atom, but only protonation at the equatorial sulfur results in chelate ring-opening. The ways in which protonation of either sulfur atom complicates the analyses and interpretation of the kinetics are discussed.

  4. Dependence of the chemical properties of macrocyclic [Ni(II)(2)L(μ-O(2)CR)](+) complexes on the basicity of the carboxylato coligands (L(2-) = macrocyclic N(6)S(2) ligand).

    Lehmann, Ulrike; Klingele, Julia; Lozan, Vasile; Steinfeld, Gunther; Klingele, Marco H; Käss, Steffen; Rodenstein, Axel; Kersting, Berthold

    2010-12-01

    The dependence of the properties of mixed ligand [Ni(II)(2)L(μ-O(2)CR)](+) complexes (where L(2-) represents a 24-membered macrocyclic hexaamine-dithiophenolato ligand) on the basicity of the carboxylato coligands has been examined. For this purpose 19 different [Ni(II)(2)L(μ-O(2)CR)](+) complexes (2-20) incorporating carboxylates with pK(b) values in the range 9 to 14 have been prepared by the reaction of [Ni(II)(2)L(μ-Cl)](+) (1) and the respective sodium or triethylammonium carboxylates. The resulting carboxylato complexes, isolated as ClO(4)(-) or BPh(4)(-) salts, have been fully characterized by elemental analyses, IR, UV/vis spectroscopy, and X-ray crystallography. The possibility of accessing the [Ni(II)(2)L(μ-O(2)CR)](+) complexes by carboxylate exchange reactions has also been examined. The main findings are as follows: (i) Substitution reactions between 1 and NaO(2)CR are not affected by the basicity or the steric hindrance of the carboxylate. (ii) Complexes 2-20 form an isostructural series of bisoctahedral [Ni(II)(2)L(μ-O(2)CR)](+) compounds with a N(3)Ni(μ-SR)(2)(μ-O(2)CR)NiN(3) core. (iii) They are readily identified by their ν(as)(CO) and ν(s)(CO) stretching vibration bands in the ranges 1684-1576 cm(-1) and 1428-1348 cm(-1), respectively. (iv) The spin-allowed (3)A(2g) → (3)T(2g) (ν(1)) transition of the NiOS(2)N(3) chromophore is steadily red-shifted by about 7.5 nm per pK(b) unit with increasing pK(b) of the carboxylate ion. (v) The less basic the carboxylate ion, the more stable the complex. The stability difference across the series, estimated from the difference of the individual ligand field stabilization energies (LFSE), amounts to about 4.2 kJ/mol [Δ(LFSE)(2,18)]. (vi) The "second-sphere stabilization" of the nickel complexes is not reflected in the electronic absorption spectra, as these forces are aligned perpendicularly to the Ni-O bonds. (vii) Coordination of a basic carboxylate donor to the [Ni(II)(2)L](2+) fragment weakens

  5. Bipolar mood cycles and lunar tidal cycles.

    Wehr, T A

    2017-01-24

    In 17 patients with rapid cycling bipolar disorder, time-series analyses detected synchronies between mood cycles and three lunar cycles that modulate the amplitude of the moon's semi-diurnal gravimetric tides: the 14.8-day spring-neap cycle, the 13.7-day declination cycle and the 206-day cycle of perigee-syzygies ('supermoons'). The analyses also revealed shifts among 1:2, 1:3, 2:3 and other modes of coupling of mood cycles to the two bi-weekly lunar cycles. These shifts appear to be responses to the conflicting demands of the mood cycles' being entrained simultaneously to two different bi-weekly lunar cycles with slightly different periods. Measurements of circadian rhythms in body temperature suggest a biological mechanism through which transits of one of the moon's semi-diurnal gravimetric tides might have driven the patients' bipolar cycles, by periodically entraining the circadian pacemaker to its 24.84-h rhythm and altering the pacemaker's phase-relationship to sleep in a manner that is known to cause switches from depression to mania.Molecular Psychiatry advance online publication, 24 January 2017; doi:10.1038/mp.2016.263.

  6. PLASMA-BASED LOW-ENERGY NITROGEN ION IMPLANTATION OF 2Cr13 MARTENSITIC STAINLESS STEEL USED IN PUMPS AND VALVES%泵阀用2Cr13马氏体不锈钢等离子体基低能氮离子注入研究

    雷明凯; 王克胜; 欧伊翔; 张磊

    2011-01-01

    采用等离子体基低能氮离子注入技术,在450℃,4h改性处理核电站泵阀零部件用2Cr13马氏体不锈钢,获得了深度为10-12 μm的改性层,超高氮过饱和浓度为35%-40%(原子分数),由hcp结构的ε-Fe2-3N相组成.改性层的硬度最大值为15.7 GPa,球-盘式摩擦学实验测定的改性层摩擦系数由原始不锈钢的1.0减至0.85,耐磨性显著提高.在3.5%NaCl溶液中,改性层的阳极极化曲线由原始不锈钢的活化溶解转化为自钝化-孔蚀击穿特征,自腐蚀电位增加至-185 mV(vs SCE),维钝电流密度为10-1 μA/cm2,孔蚀击穿电位为-134 mV(vs SCE),抗孔蚀性能明显改善.表面改性2Cr13马氏体不锈钢满足泵阀零部件耐磨损抗腐蚀的需求.%The 2Crl3 martensitic stainless steel used in pumps and valves was modified by plasma-based low-energy nitrogen ion implantation at a processing temperature of 450 ℃ for a treatment time of 4 h. The modified layer on the 2Crl3 stainless steel had a thickness range of 10- 12 μm. The modified layer consisted of monophase and has a high supersaturated nitrogen concentration up to 35%-40% (atomic fraction). The microhardness of the e-Fe2-3N phase layer was measured to be 15.7 Gpa, and the increased wear resistance of the modified layer was obtained on a ball on disc tribometer with a decreased friction coefficient from 1.0 of the original stainless steel to 0.85. A typical course from self-passivation to pitting corrosion of the modified layer in 3.5%NaCl solution was observed with a corrosion potential of -185 raV(vs SCE), a passive current density of 10-1μ/A/cm2, and a pitting potential of -134 mV(vs SCE). The pitting corrosion resistance of the modified layer was improved in comparison with that of the original stainless steel with non anodic passivation. It was found that the plasma-based low-energy nitrogen ion implantation of 2Crl3 martensitic stainless steel could meet the wear and corrosion resistance requirement for use

  7. The Solar Cycle

    Hathaway, David H

    2015-01-01

    The Solar Cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  8. The Solar Cycle.

    Hathaway, David H

    The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  9. Solar cycle 25: another moderate cycle?

    Cameron, Robert H; Schuessler, Manfred

    2016-01-01

    Surface flux transport simulations for the descending phase of cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipole moment around 2020 $(2.5\\pm1.1\\,$G) is comparable to that observed at the end of cycle 23 (about $2\\,$G). The empirical correlation between the dipole moment during solar minimum and the strength of the subsequent cycle thus suggests that cycle 25 will be of moderate amplitude, not much higher than that of the current cycle. However, the intrinsic uncertainty of such predictions resulting from the random scatter of the source properties is considerable and fundamentally limits the reliability with which such predictions can be made before activity minimum is reached.

  10. Proliferation in cycle

    Piao Yunsong [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: yspiao@gucas.ac.cn

    2009-06-15

    In the contracting phase with w{approx_equal}0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w{approx_equal}0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

  11. Transformation and Precipitation Reactions by Metal Active Gas Pulsed Welded Joints from X2CrNiMoN22-5-3 Duplex Stainless Steels

    Ion-Dragos Utu

    2016-07-01

    Full Text Available The high alloying degree of Duplex stainless steels makes them susceptible to the formation of intermetallic phases during their exposure to high temperatures. Precipitation of these phases can lead to a decreasing of the corrosion resistance and sometimes of the toughness. Starting from the advantages of the synergic Metal Active Gas (MAG pulsed welding process, this paper analyses the structure formation particularities of homogeneous welded joints from Duplex stainless steel. The effect of linear welding energy on the structure morphology of the welded joints was revealed by macro- and micrographic examinations, X-ray energy dispersion analyses, measurements of ferrite proportion and X-ray diffraction analysis. The results obtained showed that the transformation of ferrite into austenite is associated with the chromium, nickel, molybdenum and nitrogen distribution between these two phases and their redistribution degree is closely linked to the overall heat cycle of the welding process. The adequate control of the energy inserted in the welded components provides an optimal balance between the two microstructural constituents (Austenite and Ferrite and avoids the formation of undesirable intermetallic phases.

  12. Cycling in Sydney, Australia

    Alexis Zander

    2013-01-01

    Full Text Available Introduction. Cycling can be an enjoyable way to meet physical activity recommendations and is suitable for older people; however cycling participation by older Australians is low. This qualitative study explored motivators, enablers, and barriers to cycling among older people through an age-targeted cycling promotion program. Methods. Seventeen adults who aged 50–75 years participated in a 12-week cycling promotion program which included a cycling skills course, mentor, and resource pack. Semistructured interviews at the beginning and end of the program explored motivators, enablers, and barriers to cycling. Results. Fitness and recreation were the primary motivators for cycling. The biggest barrier was fear of cars and traffic, and the cycling skills course was the most important enabler for improving participants’ confidence. Reported outcomes from cycling included improved quality of life (better mental health, social benefit, and empowerment and improved physical health. Conclusions. A simple cycling program increased cycling participation among older people. This work confirms the importance of improving confidence in this age group through a skills course, mentors, and maps and highlights additional strategies for promoting cycling, such as ongoing improvement to infrastructure and advertising.

  13. Life cycle assessment (LCA)

    Thrane, Mikkel; Schmidt, Jannick Andresen

    2004-01-01

    The chapter introduces Life Cycle Assessment (LCA) and its application according to the ISO 1404043 standards.......The chapter introduces Life Cycle Assessment (LCA) and its application according to the ISO 1404043 standards....

  14. Chromium substitution in mullite type bismuth aluminate: Bi{sub 2}Cr{sub x}Al{sub 4−x}O{sub 9} with 0≤x≤2.0

    Debnath, Tapas, E-mail: debnath@du.ac.bd [Department of Chemistry, University of Dhaka, Dhaka (Bangladesh); Ullah, Ahamed [Department of Chemistry, University of Dhaka, Dhaka (Bangladesh); Rüscher, Claus H. [Institute of Mineralogy, Leibniz University of Hannover, Hannover (Germany); Hussain, Altaf [Department of Chemistry, University of Dhaka, Dhaka (Bangladesh)

    2014-12-15

    Nominal compositions Bi{sub 2}Cr{sub x}Al{sub 4−x}O{sub 9} with 0.0≤x≤2.0 (Δx=0.2) were prepared using appropriate amounts of nitrates dissolved in glycerine and heated at 800 °C for 24 h as we previously used for the preparation of solid solution series Bi{sub 2}M{sub x}/M′{sub 4−x}O{sub 9} (M/M′=Fe/Al, Ga/Al and Fe/Ga). The samples were characterized using XRD, FTIR and optical microscopic techniques. Analyses of XRD data show mullite type single phase can be prepared up to x=1.2. The lattice parameters (a, b and c) increases with increasing Cr content. Further increase in x (i.e., x≥1.4) show the presence of some additional phases indicating a limiting value for Cr doping is in the range of 1.2≤x<1.4. The effect of Cr incorporation could also be observed in the infrared absorption spectra via systematic hard mode shifts of certain lattice modes, e.g. the Bi–O related vibration changes from 96 cm{sup −1} to 93 cm{sup −1} with increasing x up to 1.2 and certain intensity changes together with shift in peak positions. Interestingly, the absence of any splitting and shift of the high energy IR absorption peak at 821 cm{sup −1} as assigned to the characteristic tetrahedral type dimer, Al{sub 2}O{sub 7}, indicate that the Cr thus partially substitutes only the octahedrally coordinated Al. This is confirmed by Rietveld structure refinements, too. - Graphical abstract: Structural model of Cr doped bismuth aluminate, Bi{sub 2}Cr{sub x}Al{sub 4−x}O{sub 9}. - Highlights: • Chromium doped bismuth aluminate, Bi{sub 2}Cr{sub x}Al{sub 4−x}O{sub 9} with mullite type structure are synthesized. • The samples are characterized by XRD and FTIR techniques. • Cr can replace only certain amount of octahedrally coordinated Al in Bi{sub 2}Al{sub 4}O{sub 9} under present experimental conditions.

  15. HIV Life Cycle

    HIV Overview The HIV Life Cycle (Last updated 9/13/2016; last reviewed 9/8/2016) Key Points HIV gradually destroys the immune ... life cycle. What is the connection between the HIV life cycle and HIV medicines? Antiretroviral therapy (ART) ...

  16. Cycling To Awareness.

    Kozak, Stan

    1999-01-01

    Encourages environmental and outdoor educators to promote bicycling. In the community and the curriculum, cycling connects environmental issues, health and fitness, law and citizenship, appropriate technology, and the joy of being outdoors. Describes the Ontario Cycling Association's cycling strategy and its four components: school cycling…

  17. Hereditary urea cycle abnormality

    ... vitro so the specific genetic cause is known. Teamwork between parents, the affected child, and doctors can help prevent severe illness. Alternative Names Abnormality of the urea cycle - hereditary; Urea cycle - hereditary abnormality Images Male urinary system Urea cycle References Lichter-Konecki ...

  18. Effects of stress ratio on the temperature-dependent high-cycle fatigue properties of alloy steels

    Lü, Zhi-yang; Wan, Ao-shuang; Xiong, Jun-jiang; Li, Kuang; Liu, Jian-zhong

    2016-12-01

    This paper addresses the effects of stress ratio on the temperature-dependent high-cycle fatigue (HCF) properties of alloy steels 2CrMo and 9CrCo, which suffer from substantial vibrational loading at small stress amplitude, high stress ratio, and high frequency in the high-temperature environments in which they function as blade and rotor spindle materials in advanced gas or steam turbine engines. Fatigue tests were performed on alloy steels 2CrMo and 9CrCo subjected to constant-amplitude loading at four stress ratios and at four and three temperatures, respectively, to determine their temperature-dependent HCF properties. The interaction mechanisms between high temperature and stress ratio were deduced and compared with each other on the basis of the results of fractographic analysis. A phenomenological model was developed to evaluate the effects of stress ratio on the temperature-dependent HCF properties of alloy steels 2CrMo and 9CrCo. Good correlation was achieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed method.

  19. Effects of stress ratio on the temperature-dependent high-cycle fatigue properties of alloy steels

    Zhi-yang L; Ao-shuang Wan; Jun-jiang Xiong; Kuang Li; Jian-zhong Liu

    2016-01-01

    This paper addresses the effects of stress ratio on the temperature-dependent high-cycle fatigue (HCF) properties of alloy steels 2CrMo and 9CrCo, which suffer from substantial vibrational loading at small stress amplitude, high stress ratio, and high frequency in the high-temperature environments in which they function as blade and rotor spindle materials in advanced gas or steam turbine engines. Fatigue tests were performed on alloy steels 2CrMo and 9CrCo subjected to constant-amplitude loading at four stress ratios and at four and three temperatures, respectively, to determine their temperature-dependent HCF properties. The interaction mechanisms between high temperature and stress ratio were deduced and compared with each other on the basis of the results of fractographic analysis. A phenomenological model was developed to evaluate the effects of stress ratio on the temperature-dependent HCF properties of alloy steels 2CrMo and 9CrCo. Good correlation was achieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed method.

  20. The effect of austenitizing treatments on the microstructure and creep properties of commercial and high purity 1/2Cr-1/2Mo-1/4V steels

    Varma, R.K.; Tipler, H.R.

    1980-08-01

    Techniques used to produce specimens with specific creep properties from two types of 1/2 Cr 1/2 Mo 1/4 V steel, i.e., high purity and commercial purity, having different hardening and grain growth characteristics are described. The production of steels with identical microstructures was desired to provide material for an investigation of the effect of complex stresses in creep. Material for samples was produced by hot rolling at 1050 C. In general the high purity steel has better hardening characteristics and is also more prone to grain growth. Consequently, it was necessary to investigate the effects of various austenitizing conditions and of different rates of cooling on the microstructures obtained. The results of unlaxial creep tests are consistent with those previously obtained on similar steels. (ESA)

  1. Oxidation Behaviour and Mechansim of MoSi2-CrSi2-SiC-Si Coating for Carbon/Carbon Composites from Room Temperature to 1873 K

    Feng Tao

    2015-01-01

    Full Text Available A MoSi2-CrSi2-SiC-Si coating was prepared on the surface of carbon/carbon (C/C composites by a two-step pack cementation method. The microstructure and oxidation behaviour of the coating were studied. These results illustrated that the coating could effectively protect C/C composites from oxidation from oxidation in air above 1600 K, due to the protection of the compound glass. The weight loss of the coated C/C specimens was only 0.4% after oxidation at 1873 K for more than 150 h. The coating lacked effective oxidation resistance for C/C composites from 800 to 1600 K, as no obvious glass layer covered the coating surface and the cracks cannot be sealed because of the high viscosity of the compound glass.

  2. Effect of Post-Weld Heat Treatment on Mechanical and Electrochemical Properties of Gas Metal Arc-Welded 316L (X2CrNiMo 17-13-2) Stainless Steel

    Muhammad, F.; Ahmad, A.; Farooq, A.; Haider, W.

    2016-10-01

    In the present research work, corrosion behavior of post-weld heat-treated (PWHT) AISI 316L (X2CrNiMo 17-13-2) specimens joined by gas metal arc welding is compared with as-welded samples by using potentiodynamic polarization technique. Welded samples were PWHT at 1323 K for 480 s and quenched. Mechanical properties, corrosion behavior and microstructures of as-welded and PWHT specimens were investigated. Microstructural studies have shown grain size refinement after PWHT. Ultimate tensile strength and yield strength were found maximum for PWHT samples. Bend test have shown that PWHT imparted ductility in welded sample. Fractographic analysis has evidenced ductile behavior for samples. Potentiodynamic polarization test was carried out in a solution composed of 1 M H2SO4 and 1 N NaCl. Corrosion rate of weld region was 127.6 mpy, but after PWHT, it was decreased to 13.12 mpy.

  3. The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

    Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke

    2002-01-01

    Normal human B lymphocytes are known to activate the alternative pathway (AP) of complement, leading to C3-fragment deposition and membrane attack complex (MAC) formation. The process is mediated via complement receptor type 2 (CR2, CD21), with complement receptor type 1 (CR1, CD35) playing...... a subsidiary role. In this study, we examine the relative contributions of CR1 and CR2 to the deposition of C3 fragments and MAC on B lymphocytes under circumstances where all complement pathways are operational. C3-fragment deposition and MAC formation were assessed on human peripheral B lymphocytes......) bearing CR1, however, markedly reduced both C3-fragment deposition and MAC formation. Our data suggest that C3-fragment deposition and MAC formation on B lymphocytes in vivo may involve both AP and classical pathway activation, with CR1 contributing significantly to the latter. On the other hand...

  4. Sucrose-aided combustion synthesis of nanosized LiMn{sub 1.99-y}Li{sub y}M{sub 0.01}O{sub 4} (M = Al{sup 3+}, Ni{sup 2+}, Cr{sup 3+}, Co{sup 3+}, y = 0.01 and 0.06) spinels. Characterization and electrochemical behavior at 25 and at 55 C in rechargeable lithium cells

    Amarilla, J.M.; Pico, F.; Rojo, J.M.; Rojas, R.M. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz no. 3, Cantoblanco, 28049 Madrid (Spain); Petrov, K.; Avdeev, G. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2009-06-15

    Doubly doped LiMn{sub 1.99-y}Li{sub y}M{sub 0.01}O{sub 4} (M = Al{sup 3+}, Ni{sup 2+}, Cr{sup 3+}, Co{sup 3+}; y = 0.01 and 0.06) spinels have been synthesized by the sucrose-aided combustion method. Combined TG/DTA and XRD studies have shown that stoichiometric single-phase spinels are formed after annealing of the samples at 700 C for 1 h. The samples obtained are nanocrystalline materials having a narrow size-distribution and a coherent domain size between 40 and 60 nm, depending on the amount of fuel (sucrose) used in the synthesis. The influence of the Li-excess, the type of M{sup n+}-dopant cation and the amount of fuel used in the synthesis on the electrochemical behavior of the spinels in a Li-cell at room and at elevated temperature (55 C) has been studied. At 25 C all the spinels synthesized have a good capacity retention after 100 cycles, QRt-100 > 92%. At 55 C the increase of the Li-excess improves the cycling performances. Rate capability studies show that the spinels retain >90% of their capacity even at 5C rate. The synergic effect of the Li-excess and the particle size on the electrochemical properties of the spinels as cathode material has been settled. The LiMn{sub 1.93}Li{sub 0.06}M{sub 0.01}O{sub 4}, (M = Al{sup 3+}, Ni{sup 2+}) spinels, with cyclabilities >99.9% by cycle at both 25 and 55 C, and high rate capabilities, are the ones that show the best electrochemical properties. (author)

  5. Driving and engine cycles

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  6. Menstrual Cycle: Basic Biology

    Hawkins, Shannon M.; Matzuk, Martin M.

    2010-01-01

    The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its complexities can be easily perturbed by environmental factors such as stress, extreme exercise, eating disorders, and obesity. Furthermore, genetic influences such as fragile X premutations (Chapter X), X chromosome abnormalities (Chapter X), and galactose-1-phosphate uridyltransferase (GALT) point mutations (galactosemia) also contribute to perturbations of the menstrual cycle. Although not perfect, mouse model have helped to identify and confirm additional components and pathways in menstrual cycle function and dysfunction in humans. PMID:18574203

  7. Edgeworth cycles revisited

    Doyle, Joseph [MIT Sloan School of Management, 50 Memorial Drive, E52-447, Cambridge MA 02142 (United States); Muehlegger, Erich [John F. Kennedy School of Government, Harvard University, Mailbox 25, 79 JFK Street, Cambridge, MA 02138 (United States); Samphantharak, Krislert [Graduate School of International Relations and Pacific Studies, University of California at San Diego, 9500 Gilman Drive 1519, La Jolla, CA 92093 (United States)

    2010-05-15

    Some gasoline markets exhibit remarkable price cycles, where price spikes are followed by a series of small price declines: a pattern consistent with a model of Edgeworth cycles described by Maskin and Tirole. We extend the model and empirically test its predictions with a new dataset of daily station-level prices in 115 US cities. Consistent with the theory, and often in contrast with previous empirical work, we find the least and most concentrated markets are much less likely to exhibit cycling behavior both within and across cities; areas with more independent convenience-store gas stations are also more likely to cycle. (author)

  8. Power Plant Cycling Costs

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  9. Nutrient cycling strategies.

    Breemen, van N.

    1995-01-01

    This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil fertili

  10. Teaching the Krebs Cycle.

    Akeroyd, F. Michael

    1983-01-01

    Outlines a simple but rigorous treatment of the Krebs Cycle suitable for A-level Biology students. The importance of the addition of water molecules in various stages of the cycle is stressed as well as the removal of hydrogen atoms by the oxidizing enzymes. (JN)

  11. Life Cycle Environmental Management

    Pedersen, Claus Stig; Jørgensen, Jørgen; Pedersen, Morten Als

    1996-01-01

    processes. The discipline of life cycle environmental management (LCEM) focuses on the incorporation of environmental criteria from the life cycles of products and other company activities into the company management processes. This paper introduces the concept of LCEM as an important element...

  12. Life cycle management (LCM)

    2004-01-01

    The chapter gives an introduction to Life Cycle Management (LCM) and shows how LCM can be practiced in different contexts and at different ambition levels.......The chapter gives an introduction to Life Cycle Management (LCM) and shows how LCM can be practiced in different contexts and at different ambition levels....

  13. Stability through cycles

    E.A. de Groot (Bert); Ph.H.B.F. Franses (Philip Hans)

    2006-01-01

    textabstractEconomic variables like GDP growth, employment, interest rates and consumption show signs of cyclical behavior. Many variables display multiple cycles, with lengths ranging in between 5 to even up to 100 years. We argue that multiple cycles can be associated with long-run stability of th

  14. Stability through cycles

    Groot, de E.A. (Bert); Franses, P.H.P.H.

    2008-01-01

    Economic variables like GDP growth, employment, interest rates and consumption show signs of cyclical behavior. Many variables display multiple cycles, with periods ranging in between 5 to even up to 100 years. We argue that multiple cycles can be associated with long-run stability of the economic s

  15. Stability through cycles

    Groot, de E.A. (Bert); Franses, P.H.P.H.

    2006-01-01

    Economic variables like GDP growth, employment, interest rates and consumption show signs of cyclical behavior. Many variables display multiple cycles, with lengths ranging in between 5 to even up to 100 years. We argue that multiple cycles can be associated with long-run stability of the economic s

  16. Two Quantum Polytropic Cycles

    Arias-Hernández, L. A.; Morales-Serrano, A. F.

    2002-11-01

    In this work we follow the Bender et al paper [1] to study the quantum analogues of the Stirling and Ericsson polytropic cycles. In the context of the classical thermodynamics, the Stirling and Ericsson cycles correspond to reversible heat engines with two isothermal processes joined by two polytropic branches which occur in a device called regenerator. If this device is an ideal one, the efficiency of these cycles is the Carnot efficiency. Here, we introduce the quantum analogues of the Stirling and Ericsson cycles, the first one based on a double square potential well with a finite potential barrier, since in this system the tunnel effect could be the analogue to the regeneration classical process, therefore the isochoric quantum branches would really correspond to an internal energy storage, and the last one with an unknown system where the isobaric quantum processes don't induce changes in its quantum state. With these systems the quantum engines have cycles consisting of polytropic and isothermal quantum processes analogues to the corresponding classical processes. We show that in both cases the quantum cycles have an efficiency given by ηCQM = 1 - EC/EH, which is the same expression for the quantum analogue of the Carnot cycle studied by Bender.

  17. Applied physiology of cycling.

    Faria, I E

    1984-01-01

    Historically, the bicycle has evolved through the stages of a machine for efficient human transportation, a toy for children, a finely-tuned racing machine, and a tool for physical fitness development, maintenance and testing. Recently, major strides have been made in the aerodynamic design of the bicycle. These innovations have resulted in new land speed records for human powered machines. Performance in cycling is affected by a variety of factors, including aerobic and anaerobic capacity, muscular strength and endurance, and body composition. Bicycle races range from a 200m sprint to approximately 5000km. This vast range of competitive racing requires special attention to the principle of specificity of training. The physiological demands of cycling have been examined through the use of bicycle ergometers, rollers, cycling trainers, treadmill cycling, high speed photography, computer graphics, strain gauges, electromyography, wind tunnels, muscle biopsy, and body composition analysis. These techniques have been useful in providing definitive data for the development of a work/performance profile of the cyclist. Research evidence strongly suggests that when measuring the cyclist's aerobic or anaerobic capacity, a cycling protocol employing a high pedalling rpm should be used. The research bicycle should be modified to resemble a racing bicycle and the cyclist should wear cycling shoes. Prolonged cycling requires special nutritional considerations. Ingestion of carbohydrates, in solid form and carefully timed, influences performance. Caffeine appears to enhance lipid metabolism. Injuries, particularly knee problems which are prevalent among cyclists, may be avoided through the use of proper gearing and orthotics. Air pollution has been shown to impair physical performance. When pollution levels are high, training should be altered or curtailed. Effective training programmes simulate competitive conditions. Short and long interval training, blended with long

  18. Life Cycle Sustainability Dashboard

    Traverso, Marzia; Finkbeiner, Matthias; Jørgensen, Andreas

    2012-01-01

    One method to assess the sustainability performance of products is life cycle sustainability assessment (LCSA), which assesses product performance considering the environmental,economic, and social dimensions of the life cycle. The results of LCSA can be used to compare different products...... of sustainability is the communicability of the results by means of a graphical representation (a cartogram), characterized by a suitable chromatic scale and ranking score. The integration of LCSA and the dashboard of sustainability into a so-called Life Cycle Sustainability Dashboard (LCSD) is described here...

  19. Dzyaloshinsky-Moriya Interaction and the Ground State in S = 3/2 Perfect Kagome Lattice Antiferromagnet KCr3(OH)6(SO4)2 (Cr-Jarosite) Studied by X-Band and High-Frequency ESR

    Okubo, Susumu; Nakata, Ryohei; Ikeda, Shohei; Takahashi, Naoki; Sakurai, Takahiro; Zhang, Wei-Min; Ohta, Hitoshi; Shimokawa, Tokuro; Sakai, Tôru; Okuta, Koji; Hara, Shigeo; Sato, Hirohiko

    2017-02-01

    A single-crystal S = 3/2 perfect kagome lattice antiferromagnet, KCr3(OH)6(SO4)2 (Cr-jarosite), has been studied by X-band and high-frequency electron spin resonance (ESR). The g-values perpendicular to the kagome plane (c-axis) and in the plane were determined to be gc = 1.9704 ± 0.0002 and gξ = 1.9720 ± 0.0003, respectively, by high-frequency ESR observed at 265 K. Antiferromagnetic resonances (AFMRs) with an antiferromagnetic gap of 120 GHz were observed at 1.9 K, which is below TN = 4.5 K. The analysis of AFMR modes using the conventional molecular field theory gave dp = 0.27 K and dz = 0.07 K, where dp and dz are in-plane and out-of-plane components of d vector of the Dzyaloshinsky-Moriya (DM) interaction, respectively. On the basis of these results and the exchange interaction of J = 6.15 K estimated by Okuta et al., the ground state of Cr-jarosite was discussed in connection with the Monte Carlo simulation results with classical Heisenberg spins on the kagome lattice by Elhajal et al. Finally, the angular dependence of the linewidth and lineshape observed at 296 K by X-band ESR showed the typical behavior of a two-dimensional Heisenberg antiferromagnet, suggesting the good two-dimensionality of Cr-jarosite.

  20. Analysis of tandem E-box motifs within human Complement receptor 2 (CR2/CD21) promoter reveals cell specific roles for RP58, E2A, USF and localized chromatin accessibility.

    Cruickshank, Mark N; Dods, James; Taylor, Rhonda L; Karimi, Mahdad; Fenwick, Emily J; Quail, Elizabeth A; Rea, Alexander J; Holers, V Michael; Abraham, Lawrence J; Ulgiati, Daniela

    2015-07-01

    Complement receptor 2 (CR2/CD21) plays an important role in the generation of normal B cell immune responses. As transcription appears to be the prime mechanism via which surface CR2/CD21 expression is controlled, understanding transcriptional regulation of this gene will have broader implications to B cell biology. Here we report opposing, cell-context specific control of CR2/CD21 promoter activity by tandem E-box elements, spaced 22 bp apart and within 70 bp of the transcription initiation site. We have identified E2A and USF transcription factors as binding to the distal and proximal E-box sites respectively in CR2-positive B-cells, at a site that is hypersensitive to restriction enzyme digestion compared to non-expressing K562 cells. However, additional unidentified proteins have also been found to bind these functionally important elements. By utilizing a proteomics approach we have identified a repressor protein, RP58, binding the distal E-box motif. Co-transfection experiments using RP58 overexpression constructs demonstrated a specific 10-fold repression of CR2/CD21 transcriptional activity mediated through the distal E-box repressor element. Taken together, our results indicate that repression of the CR2/CD21 promoter can occur through one of the E-box motifs via recruitment of RP58 and other factors to bring about a silenced chromatin context within CR2/CD21 non-expressing cells.

  1. Structural characterization and electron density distribution studies of (La0.8Ca0.2)(Cr0.9-xCo0.1Mnx)O3

    Saravanan, R.; Thenmozhi, N.; Fu, Yen-Pei

    2016-07-01

    The doped lanthanum chromite (La0.8Ca0.2)(Cr0.9-xCo0.1Mnx)O3 (x=0.03, 0.06, 0.09 and 0.12) were synthesized by solid state reaction technique. The samples have been characterized by X-ray diffraction for structural and charge density analysis. XRD data show that the grown samples are orthorhombic in structure with single phase. The spatial charge density distribution in the unit cell for the synthesized samples has been studied using maximum entropy method. Further, the samples were analyzed by UV-visible spectrometry for optical properties and scanning electron microscopy for surface morphology. From the optical data, it was found that the direct band gap of the samples range from 2.27 to 2.46 eV. The samples were also investigated by vibrating sample magnetometry for magnetic properties. From VSM data, it is inferred that all the samples in this series are found to be predominantly antiferromagnetic in nature. Since the doped lanthanum chromites have good mechanical properties and electrical conductivity at high temperature, these materials are used in solid oxide fuel cells (SOFC).

  2. Cycles in graphs

    Alspach, BR

    1985-01-01

    This volume deals with a variety of problems involving cycles in graphs and circuits in digraphs. Leading researchers in this area present here 3 survey papers and 42 papers containing new results. There is also a collection of unsolved problems.

  3. Offshore Rankine Cycles

    Brandsar, Jo

    2012-01-01

    The title of the thesis - "Offshore Rankine Cycles" - is very general and cover a large range of engineering fields, e.g. thermodynamic cycles (Rankine, ORC, Brayton, Kalina, etc.), mechanical equipment (gas/steam turbine, heat exchangers and additional equipment) and safety concerns (flammable and/or toxic fluids, high temperature and pressures), to name the most important.The thesis try to give a brief overview of all critical points and alternatives, concerning employment of a wa...

  4. Menstrual Cycle: Basic Biology

    2008-01-01

    The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its complexities can be easily perturbed by environmental factors such as stress, extreme exercise, eating disorders, and obesity. Furthermore, genetic influences such as fragile X premutations (Chapter X), X chromosome abnormalities (Chapter X), and galactose-1-phosphate uridyltransferase (GALT) point mutati...

  5. Diurnal Cycle Computations

    Covey, Curt [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Doutriaux, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-01

    Directory /export_backup/covey1/CMIP5/Precipitation/DiurnalCycle/GridpointTimeseries/CMCCBCM_etal/ on crunchy.llnl.gov contains Python / UV-CDAT scripts compositeDiurnalStatistics.py and fourierDiurB nalAllGrid.py. compositeDiurnalStatistics.py reads high-time-frequency climate data from one or more years and computes 24 hour composite-mean and composite-standard-deviation cycles for one requested month.

  6. Animating the Carbon Cycle

    2014-01-01

    Understanding the biogeochemical processes reg- ulating carbon cycling is central to mitigating atmospheric CO2 emissions. The role of living organisms has been accounted for, but the focus has traditionally been on contributions of plants and microbes. We develop the case that fully ‘‘animating’’ the carbon cycle requires broader consideration of the functional role of animals in mediating biogeochemical processes and quanti- fication of their effects on carbon storage and exchange among ter...

  7. Solar Cycle Predictions

    Pesnell, William Dean

    2012-01-01

    Solar cycle predictions are needed to plan long-term space missions; just like weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as you consume the reduced propellant load more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5-20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations how those predictions could be made more accurate in the future will be discussed.

  8. Quantifying the adaptive cycle

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  9. Initiation and growth of thermal fatigue crack networks in an AISI 304 L type austenitic stainless steel (X2 CrNi18-09); Amorcage et propagation de reseaux de fissures de fatigue thermique dans un acier inoxydable austenitique de type X2 CrNi18-09 (AISI 304 L)

    Maillot, V

    2004-07-01

    We studied the behaviour of a 304 L type austenitic stainless steel submitted to thermal fatigue. Using the SPLASH equipment of CEA/SRMA we tested parallelepipedal specimens on two sides: the specimens are continuously heated by Joule effect, while two opposites faces are cyclically. cooled by a mixed spray of distilled water and compressed air. This device allows the reproduction and the study of crack networks similar to those observed in nuclear power plants, on the inner side of circuits fatigued by mixed pressurized water flows at different temperatures. The crack initiation and the network constitution at the surface were observed under different thermal conditions (Tmax = 320 deg C, {delta}T between 125 and 200 deg C). The experiment produced a stress gradient in the specimen, and due to this gradient, the in-depth growth of the cracks finally stopped. The obtained crack networks were studied quantitatively by image analysis, and different parameters were studied: at the surface during the cycling, and post mortem by step-by-step layer removal by grinding. The maximal depth obtained experimentally, 2.5 mm, is relatively coherent with the finite element modelling of the SPLASH test, in which compressive stresses appear at a depth of 2 mm. Some of the crack networks obtained by thermal fatigue were also tested in isothermal fatigue crack growth under 4-point bending, at imposed load. The mechanisms of the crack selection, and the appearance of the dominating crack are described. Compared to the propagation of a single crack, the crack networks delay the propagation, depending on the severity of the crack competition for domination. The dominating crack can be at the network periphery, in that case it is not as shielded by its neighbours as a crack located in the center of the network. It can also be a straight crack surrounded by more sinuous neighbours. Indeed, on sinuous cracks, the loading is not the same all along the crack path, leading to some

  10. Helium process cycle

    Ganni, Venkatarao

    2007-10-09

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  11. Historicising the Hydrosocial Cycle

    Jeremy J. Schmidt

    2014-02-01

    Full Text Available This paper examines the historical claims made in support of the hydrosocial cycle. In particular, it considers how arguments advancing the hydrosocial cycle make historical claims regarding modernist conceptions of what water is (i.e. H2O and its fit with society. The paper gives special emphasis to the society/nature dualism and to the notion of agency as key sites of contest in arguments regarding the hydrosocial cycle. It finds that, while several versions of the hydrosocial cycle seek to advance a political ecology more sensitive to non-human actions, these same accounts often do not address the robust account of non-human agency in the historical record. Evidence is presented regarding water’s agency amongst late 19th and early 20th century architects of key water management norms in the United States. This evidence troubles accounts of the hydrosocial cycle that critique the US experience and suggests new directions for rethinking the role of historical and institutional norms in water policy.

  12. Giant magnetoimpedance intrinsic impedance and voltage sensitivity of rapidly solidified Co{sub 66}Fe{sub 2}Cr{sub 4}Si{sub 13}B{sub 15} amorphous wire for highly sensitive sensors applications

    Das, Tarun K.; Mandal, Sushil K. [CSIR - National Metallurgical Laboratory, NDE and Magnetic Materials Group, MST Division, Jamshedpur (India); Banerji, Pallab [Indian Institute of Technology, Kharagpur, Materials Science Centre, Kharagpur (India)

    2016-11-15

    We report a systematic study of the influence of wire length, L, dependence of giant magneto-impedance (GMI) sensitivity of Co{sub 66}Fe{sub 2}Cr{sub 4}Si{sub 13}B{sub 15} soft magnetic amorphous wire of diameter ∝ 100 μm developed by in-water quenching technique. The magnetization behaviour (hysteresis loops) of the wire with different length (L = 1, 2, 3, 5, 8 and 10 cm) has been evaluated by fuxmetric induction method. It was observed that the behaviour of the hysteresis loops change drastically with the wire length, being attributed to the existence of a critical length, L{sub C}, found to be around 3 cm. GMI measurements have been taken using automated GMI measurement system and the GMI sensitivities in terms of intrinsic impedance sensitivity (S{sub Ω/Am}{sup -1}) and voltage sensitivity (S{sub V/Am}{sup -1}) of the wire have been evaluated under optimal bias field and excitation current. It was found that the maximum (S{sub Ω/Am}{sup -1}){sub max} ∼ 0.63 Ω/kAm{sup -1}/cm and (S{sub V/Am}{sup -1}){sub max} ∼ 3.10 V/kAm{sup -1}/cm were achieved at a critical length L{sub C} ∝ 3 cm of the wire for an AC current of 5 mA and a frequency of 5 MHz. These findings provide crucial insights for optimization of the geometrical dimensions of magnetic sensing elements and important practical guidance for designing high sensitive GMI sensors. The relevant combinations of magnetic material parameters and operating conditions that optimize the sensitivity are highlighted. (orig.)

  13. {[Na1(μ-H2ONa2]2[(C2O42Cr(μ-OH2Cr(C2O42]·H2O}n, a novel hydrated form

    Michel M. Bélombé

    2010-08-01

    Full Text Available The unit cell of the title compound, poly[[μ-aqua-μ-hydroxido-di-μ-oxalato-chromium(IIIdisodium] monohydrate], {[CrNa2(C2O42(OH(H2O]·H2O}n, contains four [Na1(μ-H2ONa2][(C2O42Cr(μ-OH·H2O] formula units, each of which consists of two crystallographically independent Na+ sites (bridged by one aqua ligand, one half of a centrosymmetric di-μ-hydroxido-bis[cis-bis(oxalatochromate(III] dimer, [(C2O42Cr(μ-OH2Cr(C2O42]4−, and one uncoordinated water molecule. The structure is best described as a coordination polymer in which the three-dimensional lattice framework is realized by the interconnection of the metallic atoms via the O atoms of the aqua, hydroxide and oxalate ligands. One Na atom is heptacoordinated by one water, one hydroxide and five oxalate O atoms, whilst the other is pentacoordinated by one water and four oxalate O atoms. The coordination around the Cr3+ sites is pseudo-octahedral, involving four aqua and two hydroxide O atoms. Adjacent Na atoms are separated by 3.593 (2 Å, whereas the intradimer Cr...Cr spacing is 2.978 (1 Å. The crystal structure is consolidated by extended relatively weak O—H...O hydrogen bonding with O...O distances ranging from 2.808 (4 to 3.276 (5 Å.

  14. Advanced heat pump cycle

    Groll, E.A.; Radermacher, R.

    1993-07-01

    The desorption and absorption process of a vapor compression heat pump with a solution circuit (VCHSC) proceeds at gliding temperature intervals, which can be adjusted over a wide range. In case that the gliding temperature intervals in the desorber and the absorber overlap, a modification of the VCHSC employing a desorber/absorber heat exchange (DAHX) can be introduced, which results in an extreme reduction of the pressure ratio. Although the DAHX-cycle has features of a two-stage cycle, it still requires only one solution pump, one separator and one compressor. Such a cycle for the working pair ammonia/water is built in the Energy Laboratory of the Center for Environmental Energy Engineering at the University of Maryland. The experimental results obtained with the research plant are discussed and compared to those calculated with a simulation program. The possible temperature lift between heat source and heat sink depending on the achievable COP are presented.

  15. Superfluid thermodynamic cycle refrigerator

    Swift, Gregory W.; Kotsubo, Vincent Y.

    1992-01-01

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

  16. Cycles in fossil diversity

    Rohde, Robert A.; Muller, Richard A.

    2004-10-20

    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

  17. Revenue cycle management.

    Manley, Ray; Satiani, Bhagwan

    2009-11-01

    With the widening gap between overhead expenses and reimbursement, management of the revenue cycle is a critical part of a successful vascular surgery practice. It is important to review the data on all the components of the revenue cycle: payer contracting, appointment scheduling, preregistration, registration process, coding and capturing charges, proper billing of patients and insurers, follow-up of accounts receivable, and finally using appropriate benchmarking. The industry benchmarks used should be those of peers in identical groups. Warning signs of poor performance are discussed enabling the practice to formulate a performance improvement plan.

  18. Menstrual cycle pattern and fertility

    Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik;

    1999-01-01

    To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss.......To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss....

  19. Big Data and Cycling

    Romanillos, Gustavo; Zaltz Austwick, Martin; Ettema, Dick; De Kruijf, Joost

    2016-01-01

    Big Data has begun to create significant impacts in urban and transport planning. This paper covers the explosion in data-driven research on cycling, most of which has occurred in the last ten years. We review the techniques, objectives and findings of a growing number of studies we have classified

  20. 90-Day Cycle Handbook

    Park, Sandra; Takahashi, Sola

    2013-01-01

    90-Day Cycles are a disciplined and structured form of inquiry designed to produce and test knowledge syntheses, prototyped processes, or products in support of improvement work. With any type of activity, organizations inevitably encounter roadblocks to improving performance and outcomes. These barriers might include intractable problems at…

  1. Life Cycle Collection Management

    Helen Shenton

    2003-09-01

    Full Text Available Life cycle collection management is a way of taking a long-term approach to the responsible stewardship of the British Library's collections and is one of the Library's strategic strands. It defines the different stages in a collection item's existence over time. These stages range from selection and acquisitions processing, cataloguing and press marking, through to preventive conservation, storage and retrieval. Life cycle collection management seeks to identify the costs of each stage in order to show the economic interdependencies between the phases over time. It thereby aims to demonstrate the long-term consequences of what the library takes into its collections, by making explicit the financial and other implications of decisions made at the beginning of the life cycle for the next 100 plus years. This paper describes the work over the past year at the British Library on this complex and complicated subject. It presents the emerging findings and suggests how it can be used for practical reasons (by individual curators and selectors and for economic, governance and political purposes. The paper describes the next steps in the project, for example, on a predictive data model. The British Library is seeking to benchmark itself against comparable organisations in this area. It intends to work with others on specific comparison for example, of life cycle costing of electronic and paper journals, as a prelude to eliding digital and 'traditional' formats.

  2. Educational Business Cycles

    Tepe, Markus; Vanhuysse, Pieter

    Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...

  3. Educational Business Cycles

    Tepe, Markus; Vanhuysse, Pieter

    2009-01-01

    Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...

  4. Stellar magnetic cycles

    Baliunas, S. L.

    2004-05-01

    Is hope for understanding the solar magnetic cycle to be found in stars? Observations of stars with significant sub-surface convective zones -- masses smaller than about 1.5 solar masses on the lower main sequence and many types of cool, post-main-sequence stars -- indicate the presence of surface and atmospheric inhomogeneities analogous to solar magnetic features, making stellar magnetic activity a cosmically widespread phenomenon. Observations have been made primarily in visible wavelengths, and important information has also been derived from the ultraviolet and x-ray spectrum regions. Interannual to interdecadal variability of spectrum indicators of stellar magnetic features is common, and in some cases similar in appearance to the 11-year sunspot cycle. Successful models of the physical processes responsible for stellar magnetic cycles, typically cast as a magnetohydrodynamic dynamo, require advances in understanding not only convection but also the magnetic field's interaction with it. The observed facts that underpin the hope for models will be summarized. Properties of stellar magnetic cycles will be compared and contrasted with those of the sun, including inferences from paleo-environmental reservoirs that contain information on solar century- to millennial-scale magnetic variability. Partial support of this research came from NASA NAG5-7635, NRC COBASE, CRDF 322, MIT-MSG 5710001241, JPL 1236821, AF 49620-02-1-0194, Richard Lounsberry Foundation, Langley-Abbot, Rollins, Scholarly Studies and James Arthur Funds (Smithsonian Institution) and several generous individuals.

  5. MERCURY CYCLING AND BIOMAGNIFICATION

    Mercury cycling and biomagnification was studied in man-made ponds designed for watering livestock on the Cheyenne River Sioux Reservation in South Dakota. Multiple Hg species were quantified through multiple seasons for 2 years in total atmospheric deposition samples, surface wa...

  6. Re-Cycling

    Brown, Robert W.; Covault, Corbin E.

    2015-01-01

    An old comedy routine on Saturday Night Live by Father Guido Sarducci introduced a "Five-Minute University," because five minutes is all that's remembered after graduation anyway. In counterpoint, we discuss "cycling," a teaching method for memory enhancement. Our principal implementation consists of offering a simple version…

  7. Assisted Cycling Tours

    Hollingsworth, Jan Carter

    2008-01-01

    This article discusses Assisted Cycling Tours (ACT), a Westminster, Colorado based 501(c)3, non-profit that is offering the joy of bicycle tours in breathtaking, scenic locations to children and adults with developmental and physical disabilities and their families. ACT was founded by Bob Matter and his son David with a goal of opening up the…

  8. The Science of Cycling

    Crompton, Zoe; Daniels, Shelley

    2014-01-01

    Children are engaged by finding out about science in the real world (Harlen, 2010). Many children will be cyclists or will have seen or heard about the success of British cyclists in the Olympics and the Tour de France. This makes cycling a good hook to draw children into learning science. It is also a good cross-curricular topic, with strong…

  9. The Pneumocystis life cycle

    Cécile-Marie Aliouat-Denis

    2009-05-01

    Full Text Available First recognised as "schizonts" of Trypanosoma cruzi, Pneumocystis organisms are now considered as part of an early-diverging lineage of Ascomycetes. As no robust long-term culture model is available, most data on the Pneumocystis cell cycle have stemmed from ultrastructural images of infected mammalian lungs. Although most fungi developing in animals do not complete a sexual cycle in vivo, Pneumocystis species constitute one of a few exceptions. Recently, the molecular identification of several key players in the fungal mating pathway has provided further evidence for the existence of conjugation and meiosis in Pneumocystisorganisms. Dynamic follow-up of stage-to-stage transition as well as studies of stage-specific proteins and/or genes would provide a better understanding of the still hypothetical Pneumocystislife cycle. Although difficult to achieve, stage purification seems a reasonable way forward in the absence of efficient culture systems. This mini-review provides a comprehensive overview of the historical milestones leading to the current knowledge available on the Pneumocystis life cycle.

  10. Skills, sunspots and cycles

    Busato, Francesco; Marchetti, Enrico

    This paper explores the ability of a class of one-sector,multi-input models to generate indeterminate equilibrium paths, andendogenous cycles, without relying on factors' hoarding. The modelpresents a novel theoretical economic mechanism that supportssunspot-driven expansions without requiring up...

  11. The global water cycle

    Oki, Taikan; Entekhabi, Dara; Harrold, Timothy Ives

    The global water cycle consists of the oceans, water in the atmosphere, and water in the landscape. The cycle is closed by the fluxes between these reservoirs. Although the amounts of water in the atmosphere and river channels are relatively small, the fluxes are high, and this water plays a critical role in society, which is dependent on water as a renewable resource. On a global scale, the meridional component of river runoff is shown to be about 10% of the corresponding atmospheric and oceanic meridional fluxes. Artificial storages and water withdrawals for irrigation have significant impacts on river runoff and hence on the overall global water cycle. Fully coupled atmosphere-land-river-ocean models of the world's climate are essential to assess the future water resources and scarcities in relation to climate change. An assessment of future water scarcity suggests that water shortages will worsen, with a very significant increase in water stress in Africa. The impact of population growth on water stress is shown to be higher than that of climate change. The virtual water trade, which should be taken into account when discussing the global water cycle and water scarcity, is also considered. The movement of virtual water from North America, Oceania, and Europe to the Middle East, North West Africa, and East Asia represents significant global savings of water. The anticipated world water crisis widens the opportunities for the study of the global water cycle to contribute to the development of sustainability within society and to the solution of practical social problems.

  12. Archaea in biogeochemical cycles.

    Offre, Pierre; Spang, Anja; Schleper, Christa

    2013-01-01

    Archaea constitute a considerable fraction of the microbial biomass on Earth. Like Bacteria they have evolved a variety of energy metabolisms using organic and/or inorganic electron donors and acceptors, and many of them are able to fix carbon from inorganic sources. Archaea thus play crucial roles in the Earth's global geochemical cycles and influence greenhouse gas emissions. Methanogenesis and anaerobic methane oxidation are important steps in the carbon cycle; both are performed exclusively by anaerobic archaea. Oxidation of ammonia to nitrite is performed by Thaumarchaeota. They represent the only archaeal group that resides in large numbers in the global aerobic terrestrial and marine environments on Earth. Sulfur-dependent archaea are confined mostly to hot environments, but metal leaching by acidophiles and reduction of sulfate by anaerobic, nonthermophilic methane oxidizers have a potential impact on the environment. The metabolisms of a large number of archaea, in particular those dominating the subsurface, remain to be explored.

  13. Gap Cycling for SWIFT

    Corum, Curtis A; Snyder, Carl J; Garwood, Michael

    2013-01-01

    Purpose: SWIFT (SWeep Imaging with Fourier Transformation) is a non- Cartesian MRI method with unique features and capabilities. In SWIFT, radiofrequency (RF) excitation and reception are performed nearly simultaneously, by rapidly switching between transmit and receive during a frequency-swept RF pulse. Because both the transmitted pulse and data acquisition are simultaneously amplitude-modulated in SWIFT (in contrast to continuous RF excitation and uninterrupted data acquisition in more familiar MRI sequences), crosstalk between different frequency bands occurs in the data. This crosstalk leads to a "bulls-eye" artifact in SWIFT images. We present a method to cancel this inter-band crosstalk by cycling the pulse and receive gap positions relative to the un-gapped pulse shape. We call this strategy "gap cycling." Methods: We carry out theoretical analysis, simulation and experiments to characterize the signal chain, resulting artifacts, and their elimination for SWIFT. Results: Theoretical analysis reveals t...

  14. Sen cycles and externalities

    Piggins, Ashley; Salerno, Gillian

    2016-01-01

    It has long been understood that externalities of some kind are responsible for Sen’s (1970) theorem on the impossibility of a Paretian liberal. However, Saari and Petron (2006) show that for any social preference cycle generated by combining the weak Pareto principle and individual decisiveness, every decisive individual must suffer at least one strong negative externality. We show that this fundamental result only holds when individual preferences are strict. Building on their contribution,...

  15. Stirling cycle engine

    Lundholm, Gunnar

    1983-01-01

    In a Stirling cycle engine having a plurality of working gas charges separated by pistons reciprocating in cylinders, the total gas content is minimized and the mean pressure equalization among the serial cylinders is improved by using two piston rings axially spaced at least as much as the piston stroke and by providing a duct in the cylinder wall opening in the space between the two piston rings and leading to a source of minimum or maximum working gas pressure.

  16. FUZZY REASONING IN CYCLES

    曹立明

    1990-01-01

    By the similarity between the syllogism in logic and a path proposition in graph theory,a new concept,fuzzy reasoning graph G has been given in this paper. Transitive closure has been studied and used to do reasoning related to self-loop in G,and an algorithm has been designed to cope with reasoning in other cycles in G. Both approaches are applicable and efficient.

  17. Forests and water cycle

    Iovino F

    2009-06-01

    Full Text Available Based on a comprehensive literature analysis, a review on factors that control water cycle and water use in Mediterranean forest ecosystems is presented, including environmental variables and silvicultural treatments. This important issue is considered in the perspective of sustainable forest management of Mediterranean forests, with special regard to crucial environmental hazards such as forest fires and desertification risks related to climate change.

  18. [Microbial geochemical calcium cycle].

    Zavarzin, G A

    2002-01-01

    The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites.

  19. International Business Cycle

    Marek Lubiński

    2007-04-01

    Full Text Available Prime stylized facts of international business cycle theory refer to positive correlation in the cyclical components of important macroeconomic variables across countries. However a number of indicators of business cycle synchronization do not point to clear trends. It can be ascribed to the fact that different forces influence level of business cycle correlation. When investigating into the forces behind the commonness in aggregate fluctuations economic research seems to have pointed in two directions. One strand of the literature examines the idea of common exogenous shocks that affect economies simultaneously. In addition to that economic interdependencies such as trade in goods and services or capital account transactions may serve as the channels through which disturbances spill over across countries.The observed degree of output co movement reflects both the nature of the shocks that have occurred and the degree of economic interdependence. In the periods when common shocks prevail level of synchronization is usually higher than in times of transmission dominance.

  20. Terrestrial Carbon Cycle Variability

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1), and

  1. Bifurcation of limit cycles near equivariant compound cycles

    2007-01-01

    In this paper we study some equivariant systems on the plane. We first give some criteria for the outer or inner stability of compound cycles of these systems. Then we investigate the number of limit cycles which appear near a compound cycle of a Hamiltonian equivariant system under equivariant perturbations. In the last part of the paper we present an application of our general theory to show that a Z3 equivariant system can have 13 limit cycles.

  2. Geomicrobiological cycling of antimony

    Kulp, T. R.; Terry, L.; Dovick, M. A.; Braiotta, F.

    2013-12-01

    Microbiologically catalyzed oxidation and reduction of toxic metalloids (e.g., As, Se, and Te) generally proceeds much faster than corresponding abiotic reactions. These microbial transformations constitute biogeochemical cycles that control chemical speciation and environmental behavior of metalloids in aqueous environments. Particular progress has been made over the past two decades in documenting microbiological biotransformations of As, which include anaerobic respiratory reduction of As(V) to As(III), oxidation of As(III) to As(V) linked to chemoautotrophy or photoautotrophy, and cellular detoxification pathways. By contrast, microbial interactions with Sb, As's group 15 neighbor and a toxic element of emerging global concern, are poorly understood. Our work with sediment microcosms, enrichment cultures, and bacterial isolates suggests that prokaryotic metabolisms may be similarly important to environmental Sb cycling. Enrichment cultures and isolates from a Sb-contaminated mine site in Idaho exhibited Sb(V)-dependent heterotrophic respiration under anaerobic conditions and Sb(III)-dependent autotrophic growth in the presence of air. Live, anoxic cultures reduced 2 mM Sb(V) to Sb(III) within 5 d, while no activity occurred in killed controls. Sb(V) reduction was stimulated by lactate or acetate and was quantitatively coupled to the oxidation of lactate. The oxidation of radiolabeled 14C-acetate (monitored by GC-GPC) demonstrated Sb(V)-dependent oxidation to 14CO2, suggesting a dissimilatory process. Sb(V) dependent growth in cultures was demonstrated by direct counting. Microbiological reduction of Sb(V) also occurred in anerobic sediment microcosms from an uncontaminated suburban lake, but did not appear to be linked to growth and is interpreted as a mechanism of biological detoxification. Aerobic microcosms and cultures from the Idaho mine oxidized 2 mM Sb(III) to Sb(V) within 7 d and coupled this reaction to cell growth quantified by direct counting. An

  3. Cycling Joule Thomson refrigerator

    Tward, E.

    1983-01-01

    A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander, or valve, interposed between the legs thereof for providing a, efficient refrigeration cycle is described. The system further includes a plurality of gas operational heat switches adapted selectively to transfer heat from a thermal load and to transfer or discharge heat through a heat projector, such as a radiator or the like. The heat switches comprise heat pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.

  4. Quantum thermodynamic cooling cycle

    Palao, J P; Gordon, J M; Palao, Jose P.; Kosloff, Ronnie; Gordon, Jeffrey M.

    2001-01-01

    The quantum-mechanical and thermodynamic properties of a 3-level molecular cooling cycle are derived. An inadequacy of earlier models is rectified in accounting for the spontaneous emission and absorption associated with the coupling to the coherent driving field via an environmental reservoir. This additional coupling need not be dissipative, and can provide a thermal driving force - the quantum analog of classical absorption chillers. The dependence of the maximum attainable cooling rate on temperature, at ultra-low temperatures, is determined and shown to respect the recently-established fundamental bound based on the second and third laws of thermodynamics.

  5. The software life cycle

    Ince, Darrel

    1990-01-01

    The Software Life Cycle deals with the software lifecycle, that is, what exactly happens when software is developed. Topics covered include aspects of software engineering, structured techniques of software development, and software project management. The use of mathematics to design and develop computer systems is also discussed. This book is comprised of 20 chapters divided into four sections and begins with an overview of software engineering and software development, paying particular attention to the birth of software engineering and the introduction of formal methods of software develop

  6. Elementary cycles of time

    Dolce Donatello

    2013-09-01

    Full Text Available Elementary particles, i.e. the basic constituents of nature, are characterized by quantum recurrences in time. The flow of time of every physical system can be therefore decomposed in elementary cycles of time. This allows us to enforce the local nature of relativistic time, yielding interesting unified descriptions of fundamental aspects of modern physics, as shown in recent publications. Every particle can be regarded as a reference clock with time resolution of the order of the Compton time particle, many orders of magnitude more accurate than the atomic clocks. Here we report basic implications about the resulting notion of time.

  7. Revenue cycle management: part I.

    Crew, Matt

    2006-01-01

    The revenue cycle starts long before a patient is seen and continues until a claim is completely resolved. Each step in the revenue cycle must be clearly defined and easy to follow. Use of various tools such as templates, forms, reports, spreadsheets, and components of your practice management system will help to provide the consistency you need for profitable revenue cycle management.

  8. Sometimes "Newton's Method" Always "Cycles"

    Latulippe, Joe; Switkes, Jennifer

    2012-01-01

    Are there functions for which Newton's method cycles for all non-trivial initial guesses? We construct and solve a differential equation whose solution is a real-valued function that two-cycles under Newton iteration. Higher-order cycles of Newton's method iterates are explored in the complex plane using complex powers of "x." We find a class of…

  9. Paths and cycles of hypergraphs

    王建方; Tony; T.Lee

    1999-01-01

    Hypergraphs are the most general structures in discrete mathematics. Acyclic hypergraphs have been proved very useful in relational databases. New systems of axioms for paths, connectivity and cycles of hypergraphs are constructed. The systems suit the structure properties of relational databases. The concepts of pseudo cycles and essential cycles of hypergraphs are introduced. They are relative to each other. Whether a family of cycles of a hypergraph is dependent or independent is defined. An enumeration formula for the maximum number of independent essential cycles of a hypergraph is given.

  10. Menstrual cycle pattern and fertility

    Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik;

    1999-01-01

    OBJECTIVE: To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss. DESIGN: Prospective follow-up study. SETTING: Healthy couples recruited throughout Denmark. PATI...... 0.09-0.68). When the combined effect of cycle variation and cycle length was assessed, cycle variation was a persistent strong predictor of fecundity. CONCLUSION(S): The mechanisms of the present findings probably are female functional disturbances in ovulation, conception, implantation...

  11. Krebs Cycle Wordsearch

    Helser, Terry L.

    2001-04-01

    This puzzle embeds 46 names, terms, abbreviations, and acronyms about the citric acid (Krebs) cycle in a 14- x 17-letter matrix. A descriptive narrative beside it describes important features of the pathway. All the terms a student needs to find are embedded there with the first letter followed by underlined blanks to be completed. Therefore, the students usually must find the terms to know how to spell them, correctly fill in the blanks in the narrative with the terms, and then find and highlight the terms in the letter matrix. When all are found, the 24 unused letters complete a sentence that describes a major feature of this central pathway. The puzzle may be used as homework, an extra-credit project, or a group project in the classroom in any course where basic metabolism is learned. It disguises as fun the hard work needed to learn the names of the intermediates, enzymes, and cofactors.

  12. The supercontinent cycle

    Nance, R.D.; Worsley, T.R.; Moody, J.B.

    1988-07-01

    This paper discusses a new theory of plate tectonics which proposes that Pangaea was only the most recent in a series of supercontinents that have been breaking up and reassembling every 500 million years or so. The cycle, driven by heat percolating up from the mantle, splits continents and drives interrelated processes that shape the earth's geology and climate and play a role in biological evolution. The framework of the supercontinent theory makes it possible to understand the timing of changes in sea level that have taken place in the past 570 million years, and also helps to explain periods of intense mountain building, episodes of glaciation, and changes in the nature of life on the earth.

  13. Open cycle thermoacoustics

    Reid, Robert Stowers [Georgia Inst. of Technology, Atlanta, GA (United States)

    2000-01-01

    A new type of thermodynamic device combining a thermodynamic cycle with the externally applied steady flow of an open thermodynamic process is discussed and experimentally demonstrated. The gas flowing through this device can be heated or cooled in a series of semi-open cyclic steps. The combination of open and cyclic flows makes possible the elimination of some or all of the heat exchangers (with their associated irreversibility). Heat is directly exchanged with the process fluid as it flows through the device when operating as a refrigerator, producing a staging effect that tends to increase First Law thermodynamic efficiency. An open-flow thermoacoustic refrigerator was built to demonstrate this concept. Several approaches are presented that describe the physical characteristics of this device. Tests have been conducted on this refrigerator with good agreement with a proposed theory.

  14. Measurement of single cycle and sub-cycle pulse duration

    Zhenglie Gong(龚正烈); Wenzhuo Ge(葛文卓); Guizhong Zhang(张贵忠); Wanghua Xiang(向望华)

    2004-01-01

    This paper suggests that the linear interferometric correlation (LFC) can be used to measure pulse duration of a few cycles, single cycle or even sub-cycle light pulse. The relations between pulsewidth and LFC curve are derived for Gaussian- and hyperbolic secant-shaped pules. This new method abandons focusing,frequency doubling and filtering in the traditional second order correlation method, meanwhile the signalto-noise ratio (SNR) is improved.

  15. Overview of cycling injuries: results of a cycling club survey.

    Decalzi, Javier F; Narvy, Steven J; Vangsness, C Thomas

    2013-04-01

    Participation in competitive bicycling has increased substantially over the past decade, and bicycle injuries have increased accordingly. Cycling has been reported in several studies to have higher rates of injury than other sports and recreational activities; accordingly, riders must be cognizant of the potential for injury and protect themselves appropriately. The purpose of the current study was to survey an established competitive Los Angeles-based road cycling team to determine the epidemiology of and circumstances for traumatic cycling injuries.

  16. Removing Cycles in Esterel Programs

    Lukoschus Jan

    2007-01-01

    Full Text Available Esterel belongs to the family of synchronous programming languages, which are affected by cyclic signal dependencies. This prohibits a static scheduling, limiting the choice of available compilation techniques for programs with such cycles. This work proposes an algorithm that, given a constructive synchronous Esterel program, performs a semantics-preserving source code level transformation that removes cyclic signal dependencies. The transformation is divided into two parts: detection of cycles and iterative resolution of these cycles. It is based on the replacement of cycle signals by a signal expression involving no other cycle signals, thereby breaking the cycle. This transformation of cyclic Esterel programs enables the use of efficient compilation techniques, which are only available for acyclic programs. Furthermore, experiments indicate that the code transformation can even improve code quality produced by compilers that can already handle cyclic programs.

  17. Removing Cycles in Esterel Programs

    Reinhard von Hanxleden

    2007-05-01

    Full Text Available Esterel belongs to the family of synchronous programming languages, which are affected by cyclic signal dependencies. This prohibits a static scheduling, limiting the choice of available compilation techniques for programs with such cycles. This work proposes an algorithm that, given a constructive synchronous Esterel program, performs a semantics-preserving source code level transformation that removes cyclic signal dependencies. The transformation is divided into two parts: detection of cycles and iterative resolution of these cycles. It is based on the replacement of cycle signals by a signal expression involving no other cycle signals, thereby breaking the cycle. This transformation of cyclic Esterel programs enables the use of efficient compilation techniques, which are only available for acyclic programs. Furthermore, experiments indicate that the code transformation can even improve code quality produced by compilers that can already handle cyclic programs.

  18. Numerical study of thermomagnetic cycle

    Almanza, Morgan; Pasko, Alexandre; Mazaleyrat, Frédéric; LoBue, Martino

    2017-03-01

    We estimate the efficiency and power of a thermal energy harvesting thermodynamic cycle using a magnetocaloric material as active substance. The thermodynamic cycle is computed using an equation of state, either extrapolated from experimental data or deduced using a phenomenological Landau model. The magnetic work is then compared to the maximum work. Afterwards power is estimated using a simple thermal exchange model. Simulations of different cycles for different working points illustrate the tradeoff between power and efficiency.

  19. Entrepreneurship and the business cycle

    Thurik, Roy

    2014-01-01

    Entrepreneurship has a cyclical component, raising two questions. Is the entrepreneurship cycle related to the business cycle? And is there causality? A two-way relationship between entrepreneurship and the business cycle would be in line with the two faces of entrepreneurs: as agents of change creating upswings (opportunity entrepreneurship) and as rational actors escaping unemployment by setting up a business (necessity entrepreneurship). Nascent entrepreneurship can indeed be precyclical, ...

  20. Regenerative superheated steam turbine cycles

    Fuller, L. C.; Stovall, T. K.

    1980-01-01

    PRESTO computer program was developed to analyze performance of wide range of steam turbine cycles with special attention given to regenerative superheated steam turbine cycles. It can be used to model standard turbine cycles, including such features as process steam extraction, induction and feedwater heating by external sources, peaking, and high back pressure. Expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses are used to calculate cycle heat rate and generator output. Program provides power engineer with flexible aid for design and analysis of steam turbine systems.

  1. Biomass Gasification Combined Cycle

    Judith A. Kieffer

    2000-07-01

    Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

  2. Organic rankine cycle fluid

    Brasz, Joost J.; Jonsson, Ulf J.

    2006-09-05

    A method of operating an organic rankine cycle system wherein a liquid refrigerant is circulated to an evaporator where heat is introduced to the refrigerant to convert it to vapor. The vapor is then passed through a turbine, with the resulting cooled vapor then passing through a condenser for condensing the vapor to a liquid. The refrigerant is one of CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2, (CF.sub.3).sub.2 CFC(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.2C(O)CF(CF.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.3C(O)CF(CG.sub.3).sub.2, CF.sub.3(CF.sub.2).sub.5C(O)CF.sub.3, CF.sub.3CF.sub.2C(O)CF.sub.2CF.sub.2CF.sub.3, CF.sub.3C(O)CF(CF.sub.3).sub.2.

  3. The earth's hydrological cycle

    Bonnet, R-M; Calisto, M; Destouni, G; Gurney, R; Johannessen, J; Kerr, Y; Lahoz, WA; Rast, M

    2014-01-01

    This book gives a comprehensive presentation of our present understanding of the Earth's Hydrological cycle and the problems, consequences and impacts that go with this topic. Water is a central component in the Earth's system. It is indispensable for life on Earth in its present form and influences virtually every aspect of our planet's life support system. On relatively short time scales, atmospheric water vapor interacts with the atmospheric circulation and is crucial in forming the Earth's climate zones. Water vapor is the most powerful of the greenhouse gases and serves to enhance the tropospheric temperature. The dominant part of available water on Earth resides in the oceans. Parts are locked up in the land ice on Greenland and Antarctica and a smaller part is estimated to exist as groundwater. If all the ice over the land and all the glaciers were to melt, the sea level would rise by some 80 m. In comparison, the total amount of water vapor in the atmosphere is small; it amounts to ~ 25 kg/m2, or the ...

  4. The Global Nitrogen Cycle

    Galloway, J. N.

    2003-12-01

    Once upon a time nitrogen did not exist. Today it does. In the intervening time the universe was formed, nitrogen was created, the Earth came into existence, and its atmosphere and oceans were formed! In this analysis of the Earth's nitrogen cycle, I start with an overview of these important events relative to nitrogen and then move on to the more traditional analysis of the nitrogen cycle itself and the role of humans in its alteration.The universe is ˜15 Gyr old. Even after its formation, there was still a period when nitrogen did not exist. It took ˜300 thousand years after the big bang for the Universe to cool enough to create atoms; hydrogen and helium formed first. Nitrogen was formed in the stars through the process of nucleosynthesis. When a star's helium mass becomes great enough to reach the necessary pressure and temperature, helium begins to fuse into still heavier elements, including nitrogen.Approximately 10 Gyr elapsed before Earth was formed (˜4.5 Ga (billion years ago)) by the accumulation of pre-assembled materials in a multistage process. Assuming that N2 was the predominate nitrogen species in these materials and given that the temperature of space is -270 °C, N2 was probably a solid when the Earth was formed since its boiling point (b.p.) and melting point (m.p.) are -196 °C and -210 °C, respectively. Towards the end of the accumulation period, temperatures were probably high enough for significant melting of some of the accumulated material. The volcanic gases emitted by the resulting volcanism strongly influenced the surface environment. Nitrogen was converted from a solid to a gas and emitted as N2. Carbon and sulfur were probably emitted as CO and H2S (Holland, 1984). N2 is still the most common nitrogen volcanic gas emitted today at a rate of ˜2 TgN yr-1 (Jaffee, 1992).Once emitted, the gases either remained in the atmosphere or were deposited to the Earth's surface, thus continuing the process of biogeochemical cycling. The rate of

  5. Reproductive cycle of goats.

    Fatet, Alice; Pellicer-Rubio, Maria-Teresa; Leboeuf, Bernard

    2011-04-01

    Goats are spontaneously ovulating, polyoestrous animals. Oestrous cycles in goats are reviewed in this paper with a view to clarifying interactions between cyclical changes in tissues, hormones and behaviour. Reproduction in goats is described as seasonal; the onset and length of the breeding season is dependent on various factors such as latitude, climate, breed, physiological stage, presence of the male, breeding system and specifically photoperiod. In temperate regions, reproduction in goats is described as seasonal with breeding period in the fall and winter and important differences in seasonality between breeds and locations. In tropical regions, goats are considered continuous breeders; however, restricted food availability often causes prolonged anoestrous and anovulatory periods and reduced fertility and prolificacy. Different strategies of breeding management have been developed to meet the supply needs and expectations of consumers, since both meat and milk industries are subjected to growing demands for year-round production. Hormonal treatments, to synchronize oestrus and ovulation in combination with artificial insemination (AI) or natural mating, allow out-of-season breeding and the grouping of the kidding period. Photoperiodic treatments coupled with buck effect now allow hormone-free synchronization of ovulation but fertility results after AI are still behind those of hormonal treatments. The latter techniques are still under study and will help meeting the emerging social demand of reducing the use of hormones for the management of breeding systems.

  6. The Photosynthetic Cycle

    Calvin, Melvin

    1955-03-21

    A cyclic sequence of transformations, including the carboxylation of RuDP (ribulose diphosphate) and its re-formation, has been deduced as the route for the creation of reduced carbon compounds in photosynthetic organisms. With the demonstration of RuDP as substrate for the carboxylation in a cell-free system, each of the reactions has now been carried out independently in vitro. Further purification of this last enzyme system has confirmed the deduction that the carboxylation of RuDP leads directly to the two molecules of PGA (phosphoglyceric acid) involving an internal dismutation and suggesting the name "carboxydismutase" for the enzyme. As a consequence of this knowledge of each of the steps in the photosynthetic CO{sub 2} reduction cycle, it is possible to define the reagent requirements to maintain it. The net requirement for the reduction of one molecule of CO{sub 2} is four equivalents of [H]and three molecules of ATP (adenine triphosphate). These must ultimately be supplied by the photochemical reaction. Some possible ways in which this may be accomplished are discussed.

  7. Enhancing the Oxygen Permeation Rate of Zr0.84Y0.16O1.92 - La0.8Sr0.2Cr0.5Fe0.5O3-δ Dual-Phase Hollow Fiber Membrane by Coating with Ce0.8Sm0.2O1.9 Nanoparticles

    Liu, Tong; Wang, Yao; Yuan, Ronghua; Gao, Jianfeng; Chen, Chusheng; Bouwmeester, H.J.M.

    2013-01-01

    Zr0.84Y0.16O1.92−La0.8Sr0.2Cr0.5Fe0.5O3−δ (YSZ-LSCrF) dual-phase composite hollow fiber membranes were prepared by a combined phase-inversion and sintering method. The shell surface of the hollow fiber membrane was modified with Ce0.8Sm0.2O1.9 (SDC) via a drop−coating method. As the rate of oxygen p

  8. 'Benefits cycle' replacing premium cycle as consumerism takes hold.

    2002-05-01

    The traditional premium cycle of ups and downs in rates is giving way to a new phenomenon--driven by the advent of consumerism in health care--termed the "benefits cycle" by one consultant. Rather than shifts in rates, he argues, the future will see shifts in benefits packages.

  9. Life Cycle of Stars

    1999-01-01

    In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper left of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2.

  10. Variations on the Zilch Cycle

    Binder, P.-M.; Tanoue, C. K. S.

    2013-01-01

    Thermo dynamic cycles in introductory physics courses are usually made up from a small number of permutations of isothermal, adiabatic, and constant-pressure and volume quasistatic strokes, with the working fluid usually being an ideal gas. Among them we find the Carnot, Stirling, Otto, Diesel, and Joule-Brayton cycles; in more advanced courses,…

  11. Drought and ecosystem carbon cycling

    Molen, van der M.K.; Dolman, A.J.; Ciais, P.; Eglin, T.; Gobron, N.; Law, B.E.; Meir, P.; Peters, W.; Philips, O.L.; Hurk, van den B.J.J.M.; Jeu, M.; Kruijt, B.; Teuling, A.J.; Werf, van der G.R.; Wang, G.

    2011-01-01

    Drought as an intermittent disturbance of the water cycle interacts with the carbon cycle differently than the ‘gradual’ climate change. During drought plants respond physiologically and structurally to prevent excessive water loss according to species-specific water use strategies. This has consequ

  12. Emissions from photovoltaic life cycles

    Fthenakis, V.M.; Kim, H.C.; Alsema, E.A.

    2008-01-01

    Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004–2006, this study presents the life-cycle greenhou

  13. Quadratic reactivity fuel cycle model

    Lewins, J.D.

    1985-11-01

    For educational purposes it is highly desirable to provide simple yet realistic models for fuel cycle and fuel economy. In particular, a lumped model without recourse to detailed spatial calculations would be very helpful in providing the student with a proper understanding of the purposes of fuel cycle calculations. A teaching model for fuel cycle studies based on a lumped model assuming the summability of partial reactivities with a linear dependence of reactivity usefully illustrates fuel utilization concepts. The linear burnup model does not satisfactorily represent natural enrichment reactors. A better model, showing the trend of initial plutonium production before subsequent fuel burnup and fission product generation, is a quadratic fit. The study of M-batch cycles, reloading 1/Mth of the core at end of cycle, is now complicated by nonlinear equations. A complete account of the asymptotic cycle for any order of M-batch refueling can be given and compared with the linear model. A complete account of the transient cycle can be obtained readily in the two-batch model and this exact solution would be useful in verifying numerical marching models. It is convenient to treat the parabolic fit rho = 1 - tau/sup 2/ as a special case of the general quadratic fit rho = 1 - C/sub tau/ - (1 - C)tau/sup 2/ in suitably normalized reactivity and cycle time units. The parabolic results are given in this paper.

  14. The LifeCycle model

    Krink, Thiemo; Løvbjerg, Morten

    2002-01-01

    Adaptive search heuristics are known to be valuable in approximating solutions to hard search problems. However, these techniques are problem dependent. Inspired by the idea of life cycle stages found in nature, we introduce a hybrid approach called the LifeCycle model that simultaneously applies...

  15. Activity Cycle of Solar Filaments

    K. J. Li; Q. X. Li; P. X. Gao; J. Mu; H. D. Chen; T. W. Su

    2007-06-01

    Long-term variation in the distribution of the solar filaments observed at the Observatorie de Paris, Section de Meudon from March 1919 to December 1989 is presented to compare with sunspot cycle and to study the periodicity in the filament activity, namely the periods of the coronal activity with the Morlet wavelet used. It is inferred that the activity cycle of solar filaments should have the same cycle length as sunspot cycle, but the cycle behavior of solar filaments is globally similar in profile with, but different in detail from, that of sunspot cycles. The amplitude of solar magnetic activity should not keep in phase with the complexity of solar magnetic activity. The possible periods in the filament activity are about 10.44 and 19.20 years. The wavelet local power spectrum of the period 10.44 years is statistically significant during the whole consideration time. The wavelet local power spectrum of the period 19.20 years is under the 95% confidence spectrum during the whole consideration time, but over the mean red-noise spectrum of = 0.72 before approximate Carrington rotation number 1500, and after that the filament activity does not statistically show the period. Wavelet reconstruction indicates that the early data of the filament archive (in and before cycle 16) are more noiseful than the later (in and after cycle 17).

  16. Economic growth and business cycles

    Canton, E.J.F.

    1997-01-01

    This thesis contains five essays on economic growth and business cycles. The main focus is on the interaction between economic growth and the cycle: is cyclical variability good or bad for the long-run rate of economic growth? The introduction aims to provide some empirical evidence for an investmen

  17. Prospects for Predicting Cycle 24

    Arnab Rai Choudhuri

    2008-03-01

    Although we have reliable data of solar polar fields only from the mid-1970s, it seems that the polar field at a minimum is well correlated with the next cycle, but the strength of the cycle is not correlated with the polar field produced at its end. We explain this by suggesting that the Babcock–Leighton mechanism of poloidal field generation from tilted active regions involves randomness, whereas the other aspects of the dynamo process are more ordered. To model actual cycles, we have to ‘correct’ our theoretical dynamo model by ‘feeding’ information about the polar field at the minima. Following this process, we find that our model fits the observed sunspot numbers of cycles 21–23 reasonably well and predicts that cycle 24 will be the weakest in a century.

  18. Limit cycles in quantum systems

    Niemann, Patrick

    2015-04-27

    In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

  19. Life cycle of mobile devices

    T.V. Rohal

    2011-12-01

    Full Text Available Article is devoted features of life cycle of mobile devices. The article highlighted a number of disadvantages associated with managing the life cycle of the product. Disadvantages include the orientation is not on the quality of mobile devices and their design, the obsolescence of digital products. The article drew attention to the need for process improvement life cycle management of mobile devices. For since this type of product is now the most popular among the population, consumers are interested, first of all, quality, and only then, look good.

  20. Introducing Life Cycle Impact Assessment

    Hauschild, Michael Zwicky; Huijbregts, Mark AJ

    2015-01-01

    This chapter serves as an introduction to the presentation of the many aspects of life cycle impact assessment (LCIA) in this volume of the book series ‘LCA Compendium’. It starts with a brief historical overview of the development of life cycle impact assessment driven by numerous national LCIA...... methodology projects and presents the international scientific discussions and methodological consensus attempts in consecutive working groups under the auspices of the Society of Environmental Toxicology and Chemistry (SETAC) as well as the UNEP/ SETAC Life Cycle Initiative, and the (almost) parallel...

  1. Digital daily cycles of individuals

    Aledavood, Talayeh; Jørgensen, Sune Lehmann; Saramäki, Jari

    2015-01-01

    Humans, like almost all animals, are phase-locked to the diurnal cycle. Most of us sleep at night and are active through the day. Because we have evolved to function with this cycle, the circadian rhythm is deeply ingrained and even detectable at the biochemical level. However, within the broader...... day-night pattern, there are individual differences: e.g., some of us are intrinsically morning-active, while others prefer evenings. In this article, we look at digital daily cycles: circadian patterns of activity viewed through the lens of auto-recorded data of communication and online activity. We...

  2. Life-cycle cost analysis of adsorption cycles for desalination

    Thu, Kyaw

    2010-08-01

    This paper presents the thermo-economic analysis of the adsorption desalination (AD) cycle that is driven by low-temperature waste heat from exhaust of industrial processes or renewable sources. The AD cycle uses an adsorbent such as the silica gel to desalt the sea or brackish water. Based on an experimental prototype AD plant, the life-cycle cost analysis of AD plants of assorted water production capacities has been simulated and these predictions are translated into unit cost of water production. Our results show that the specific energy consumption of the AD cycle is 1.38 kWh/m3 which is the lowest ever reported. For a plant capacity of 1000 m3/d, the AD cycle offers a unit cost of $0.457/m3 as compared to more than $0.9 for the average RO plants. Besides being cost-effective, the AD cycle is also environment-friendly as it emits less CO2 emission per m3 generated, typically 85% less, by comparison to an RO process. © 2010 Desalination Publications.

  3. National Urea Cycle Disorders Foundation

    ... triggers undiagnosed fatal urea cycle disorder in Tennessee wife and teacher. Story . More information about bariatric surgery ... with sodium phenylbutyrate may decrease liver dysfunction in patients with ASA. Details "IN TRIBUTE TO HER SON, ...

  4. Air Quality Management Process Cycle

    Air quality management are activities a regulatory authority undertakes to protect human health and the environment from the harmful effects of air pollution. The process of managing air quality can be illustrated as a cycle of inter-related elements.

  5. Total Product Life Cycle (TPLC)

    U.S. Department of Health & Human Services — The Total Product Life Cycle (TPLC) database integrates premarket and postmarket data about medical devices. It includes information pulled from CDRH databases...

  6. Glacial Cycles and Milankovitch Forcing

    Raghuraman, Shiv Priyam

    2015-01-01

    Using a recent conceptual model of the glacial-interglacial cycles we present more evidence of Milankovitch cycles being the trigger for retreat and forming of ice sheets in the cycles. This model is based on a finite approximation of an infinite dimensional model which has three components: Budyko's energy balance model describing the annual mean temperatures at latitudes, Widiasih's ODE which describes the behavior of the edge of the ice sheet, and Walsh et al. who introduced a snow line to account for glacial accumulation and ablation zones. Certain variables in the model are made to depend on the Milankovitch cycles, in particular, the obliquity of the Earth's axis and the eccentricity of the Earth's orbit. We see as a result that deglaciation and glaciation do occur mostly due to obliquity and to some extent eccentricity.

  7. (Auto)Ethnographies and Cycling

    Larsen, Jonas

    2014-01-01

    , habits and affective capacities of cycling are cultivated and performed. The article argues that autoethnography is particularly apt at illuminating the embodied qualities of movement, and it sits within established ethnographies of ‘excising’ and ‘mobile bodies’. In the second part of the article, I......This article discusses the formation, salience and reformation of everyday bodily routines and resources in relation to cycling; it also examines how we can study them ethnographically in different places. I discuss forms of embodied, sensuous and mobile ethnography that can illuminate how routines...... draw upon ongoing autoethnographies of cycling in a familiar place (my hometown, Copenhagen) and by learning to cycle ‘out-of-place’ (in London) and ‘in-a-new–way’ (when commuting long distance on a racer bike). The study challenges static notions of the body by analysing how cyclists’ (and researchers...

  8. Revenue cycle management, Part II.

    Crew, Matt

    2007-01-01

    The proper management of your revenue cycle requires the application of "best practices" and the continual monitoring and measuring of the entire cycle. The correct technology will enable you to gain the insight and efficiencies needed in the ever-changing healthcare economy. The revenue cycle is a process that begins when you negotiate payor contracts, set fees, and schedule appointments and continues until claims are paid in full. Every single step in the cycle carries equal importance. Monitoring all phases and a commitment to continually communicating the results will allow you to achieve unparalleled success. In part I of this article, we explored the importance of contracting, scheduling, and case management as well as coding and clinical documentation. We will now take a closer look at the benefits charge capture, claim submission, payment posting, accounts receivable follow-up, and reporting can mean to your practice.

  9. Endogenous, Imperfectly Competitive Business Cycles

    Whitta-Jacobsen, Hans Jørgen

    by monopolistic competition. An implicit assumption of barriers to entry justifies that the number of firms is fixed even when positive profits occur. It turns out that both market power of firms on the product markets and market power of unions on the labor markets make the occurrence of cycles more likely......We investigate how imperfect competition affects the occurrence and the properties of endogenous, rational expectations business cycles in an overlapping generations model with constant returns to scale in production. The model has explicit product and labor markets all characterized....... In particular, imperfect competition on the product markets and the positive profits associated with it may have the effect that there is a cycle even if the labor supply curve is increasing in the real-wage rate. For competitive cycles is required not only a decreasing labor supply curve, but a wage elasticity...

  10. Towards Life Cycle Sustainability Assessment

    Marzia Traverso

    2010-10-01

    Full Text Available Sustainability is nowadays accepted by all stakeholders as a guiding principle for both public policy making and corporate strategies. However, the biggest challenge for most organizations remains in the real and substantial implementation of the sustainability concept. The core of the implementation challenge is the question, how sustainability performance can be measured, especially for products and processes. This paper explores the current status of Life Cycle Sustainability Assessment (LCSA for products and processes. For the environmental dimension well established tools like Life Cycle Assessment are available. For the economic and social dimension, there is still need for consistent and robust indicators and methods. In addition to measuring the individual sustainability dimensions, another challenge is a comprehensive, yet understandable presentation of the results. The “Life Cycle Sustainability Dashboard” and the “Life Cycle Sustainability Triangle” are presented as examples for communication tools for both experts and non expert stakeholders.

  11. Venus Altitude Cycling Balloon Project

    National Aeronautics and Space Administration — The ISTAR Group ( IG) and team mate Thin Red Line Aerospace (TRLA) propose a Venus altitude cycling balloon (Venus ACB), an innovative superpressure balloon...

  12. Mirador - Carbon Cycle and Ecosystems

    National Aeronautics and Space Administration — Earth Science data access made simple. This Focus Area deals with the cycling of carbon in reservoirs and ecosystems as it changes naturally, is changed by humans,...

  13. Corporate governance cycles during transition

    Mygind, Niels; Demina, Natalia; Gregoric, Aleksandra

    2004-01-01

    -nancial system. To provide simple hypothesis tests, we use Russian enterprise data for 1995-2003 and Slovenian data covering 1998-2003. In spite of differences in institutional development, con-cerning privatization and development of corporate governance institutions, we find that govern-ance cycles are broadly...... of ownership on managers, external domestic and foreign owners. JEL-codes: G3, J5, P2, P3 - Keywords: corporate governance, life-cycle, privatization, ownership change, transition economies, Russia and Slovenia.......Ownership is determined by firm specific factors and the environment. Firms change over their life-cycle. The governance cycle - here defined as changes in identity of the dominant owner and own-ership concentration - is marked by key phases including start-up, growth, and possibly a restructur...

  14. On acyclicity of games with cycles

    Andersson, Klas Olof Daniel; Hansen, Thomas Dueholm; Gurvich, Vladimir

    2010-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (di-graphs) that may contain directed cycles (di-cycles). We assume that all these di-cycles form one outcome c, for example, a draw. We obtain criteria of re...

  15. Detonation Jet Engine. Part 1--Thermodynamic Cycle

    Bulat, Pavel V.; Volkov, Konstantin N.

    2016-01-01

    We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. The efficiency advantages of thermodynamic detonative combustion cycle over Humphrey combustion cycle at constant volume and Brayton combustion cycle at constant pressure were demonstrated. An ideal Ficket-Jacobs detonation cycle, and…

  16. Life cycle and textiles recycling

    2011-01-01

    Within the vision of development of European textile and clothing industry for 2020 from the standpoint of the European Technology Platform (ETP), the paper analyzes a segment which includes life cycle and recycling of textiles. It is the fact that the complexity of new textile and clothing product has caused the development of new-higher standards. For this reason in development of highly innovative products, today is included also quality assurance during his whole life cycle starting from ...

  17. Integrated coal gasification combined cycle

    Richards, P. C.; Wijffels, J.-B.; Zuideveld, P. L.

    Features of the integrated coal gasification combined cycle power plants are described against the backdrop of the development and first commercial application of the shell coal gasification process. Focus is on the efficiency and excellent environmental performance of the integrated coal gasification combined power plants. Current IGCC projects are given together with an outline of some of the options for integrating coal gasification with combined cycles and also other applications of synthesis gas.

  18. Serotype cycles in cholera dynamics

    Koelle, Katia; Pascual, Mercedes; Yunus, Md.

    2006-01-01

    Interest in understanding strain diversity and its impact on disease dynamics has grown over the past decade. Theoretical disease models of several co-circulating strains indicate that incomplete cross-immunity generates conditions for strain-cycling behaviour at the population level. However, there have been no quantitative analyses of disease time-series that are clear examples of theoretically expected strain cycling. Here, we analyse a 40-year (1966–2005) cholera time-series from Banglade...

  19. Limit cycle vibrations in turbomachinery

    Ryan, S. G.

    1991-01-01

    The focus is on an examination of rotordynamic systems which are simultaneously susceptible to limit cycle instability and subharmonic response. Characteristics of each phenomenon are determined as well as their interrelationship. A normalized, single mass rotor model is examined as well as a complex model of the high pressure fuel turbopump and the Space Shuttle Main Engine. Entrainment of limit cycle instability by subharmonic response is demonstrated for both models. The nonuniqueness of the solution is also demonstrated.

  20. On Cycles in AS Relationships

    Dimitropoulos, Xenofontas; Krioukov, Dmitri

    2008-01-01

    Several users of our AS relationship inference data (http://www.caida.org/data/active/as-relationships/), released with cs/0604017, asked us why it contained AS relationship cycles, e.g., cases where AS A is a provider of AS B, B is a provider of C, and C is a provider of A, or other cycle types. Having been answering these questions in private communications, we have eventually decided to write down our answers here for future reference.

  1. Secular Cycles and Millennial Trends

    Andrey Korotayev

    2016-12-01

    Full Text Available In the current paper we investigate the relation between secular cycles and millennial trends. The tests we have performed suggest that the structure of millennial trends cannot be adequately understood without secular cycles being taken into consideration. At a certain level of analysis millennial trends turn out to be a virtual byproduct of the demographic cycle mechanisms, which turn out to incorporate certain trend-creating mechanisms. Demographic-political cycle models can serve as a basis for the development and testing of models accounting not only for cycles but also for secular trends. In order to do this, we suggest to alter the basic assumptions of the earlier generations of demographic cycle models (that both the carrying capacity of land and the polity size are constant. The variables such as carrying capacity of land, cultural complexity, and empire sizes are actually not constant, but rather experience long-term trend dynamics in the rise, and the new generation of models needs to account for this fact.

  2. The NEWS Water Cycle Climatology

    Rodell, Matthew; Beaudoing, Hiroko Kato; L'Ecuyer, Tristan; William, Olson

    2012-01-01

    NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the first phase of the NEWS Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project was a multi-institutional collaboration with more than 20 active contributors. This presentation will describe the results of the water cycle component of the first phase of the project, which include seasonal (monthly) climatologies of water fluxes over land, ocean, and atmosphere at continental and ocean basin scales. The requirement of closure of the water budget (i.e., mass conservation) at various scales was exploited to constrain the flux estimates via an optimization approach that will also be described. Further, error assessments were included with the input datasets, and we examine these in relation to inferred uncertainty in the optimized flux estimates in order to gauge our current ability to close the water budget within an expected uncertainty range.

  3. Solar Cycle Predictions (Invited Review)

    Pesnell, W. Dean

    2012-11-01

    Solar cycle predictions are needed to plan long-term space missions, just as weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on low-Earth orbit spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as the reduced propellant load is consumed more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5 - 20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations of how those predictions could be made more accurate in the future are discussed.

  4. A biogeochemical cycle for aluminium?

    Exley, Christopher

    2003-09-15

    The elaboration of biogeochemical cycles for elements which are known to be essential for life has enabled a broad appreciation of the homeostatic mechanisms which underlie element essentiality. In particular they can be used effectively to identify any part played by human activities in element cycling and to predict how such activities might impact upon the lithospheric and biospheric availability of an element in the future. The same criteria were the driving force behind the construction of a biogeochemical cycle for aluminium, a non-essential element which is a known ecotoxicant and a suspected health risk in humans. The purpose of this exercise was to examine the concept of a biogeochemical cycle for aluminium and not to review the biogeochemistry of this element. The cycle as presented is rudimentary and qualitative though, even in this nascent form, it is informative and predictive and, for these reasons alone, it is deserving of future quantification. A fully fledged biogeochemical cycle for aluminium should explain the biospheric abundance of this element and whether we should expect its (continued) active involvement in biochemical evolution.

  5. What cycles the cell? -Robust autonomous cell cycle models.

    Lavi, Orit; Louzoun, Yoram

    2009-12-01

    The cell cycle is one of the best studied cellular mechanisms at the experimental and theoretical levels. Although most of the important biochemical components and reactions of the cell cycle are probably known, the precise way the cell cycle dynamics are driven is still under debate. This phenomenon is not atypical to many other biological systems where the knowledge of the molecular building blocks and the interactions between them does not lead to a coherent picture of the appropriate dynamics. We here propose a methodology to develop plausible models for the driving mechanisms of embryonic and cancerous cell cycles. We first define a key property of the system (a cyclic behaviour in the case of the embryonic cell cycle) and set mathematical constraints on the types of two variable simplified systems robustly reproducing such a cyclic behaviour. We then expand these robust systems to three variables and reiterate the procedure. At each step, we further limit the type of expanded systems to fit the known microbiology until a detailed description of the system is obtained. This methodology produces mathematical descriptions of the required biological systems that are more robust to changes in the precise function and rate constants. This methodology can be extended to practically any type of subcellular mechanism.

  6. Thermodynamic properties of bis-({eta}{sup 6}-cumene)chromium fulleride [({eta}{sup 6}-PhCH(CH{sub 3}){sub 2}){sub 2}Cr]{sup {center_dot}+}[C{sub 60}]{sup {center_dot}-} over the range from T {yields} (0 to 310) K

    Markin, A.V., E-mail: markin@calorimetry-center.ru [Chemistry Institute, Nizhny Novgorod State University, Prospekt Gagarina 23/5, 603950 Nizhny Novgorod (Russian Federation); Ruchenin, V.A.; Smirnova, N.N. [Chemistry Institute, Nizhny Novgorod State University, Prospekt Gagarina 23/5, 603950 Nizhny Novgorod (Russian Federation); Abakumov, G.A.; Markin, G.V.; Shevelev, Yu.A.; Kuropatov, V.A.; Lopatin, M.A.; Cherkasov, V.K.; Domrachev, G.A. [Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Tropinin Str. 49, 603950 Nizhny Novgorod (Russian Federation)

    2011-10-15

    Highlights: > Heat capacity and thermodynamic properties of crystalline bis-({eta}{sup 6}-cumene)chromium fulleride between T = (6 and 310) K. > Temperature dependence of EPR signal parameters of bis-({eta}{sup 6}-cumene)chromium fulleride over the range from T = (120 to 290) K. > The reversible dimerization of fullerene fragments and thermodynamic characteristics of the transformation.. > The stability of dimeric dianions (C{sub 60}{sup -}){sub 2} depends significantly on the nature of substituent. - Abstract: In the present research, the temperature dependence of heat capacity C{sub p,m}{sup 0}=f(T) of crystalline bis-({eta}{sup 6}-cumene)chromium fulleride [({eta}{sup 6}-PhCH(CH{sub 3}){sub 2}){sub 2}Cr]{sup {center_dot}+}[C{sub 60}]{sup {center_dot}-} has been measured between T = (6 and 310) K in the precision adiabatic vacuum calorimeter and reported for the first time. Also, for the first time, the temperature dependence of EPR signal parameters of bis-({eta}{sup 6}-cumene)chromium fulleride over the range from T = (120 to 290) K was investigated by electron paramagnetic resonance. In the interval from T = (196 to 240) K the reversible endothermic transformation was detected and its thermodynamic characteristics were estimated. This transformation was caused by dissociation of dimer (C{sub 60}{sup -}){sub 2} and formation of fulleride [({eta}{sup 6}-PhCH(CH{sub 3}){sub 2}){sub 2}Cr]{sup {center_dot}+}[C{sub 60}]{sup {center_dot}-} during heating. The experimental results have been used to calculate the standard (p{sup {center_dot}} = 0.1 MPa) thermodynamic functions C{sub p,m}{sup 0}/R, {Delta}{sub T{sub 1}}{sup T{sub 2}}H{sub m}{sup 0}/RT, {Delta}{sub T{sub 1}}{sup T{sub 2}}S{sub m}{sup 0}/R, and {Phi}{sub m}{sup 0}/R={Delta}{sub T{sub 1}}{sup T{sub 2}}S{sub m}{sup 0}/R-{Delta}{sub T{sub 1}}{sup T{sub 2}}H{sub m}{sup 0}/RT (where R is the universal gas constant) for dimeric fulleride over the range from T {yields} (0 to 196) K and for monomeric complex

  7. The Water Cycle Solutions Network

    Houser, P.; Belvedere, D.; Imam, B.; Schiffer, R.; Schlosser, C.; Gupta, H.; Welty, C.; Vörösmarty, C.; Matthews, D.; Lawford, R.

    2006-12-01

    The goal of the Water cycle Solutions Network is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend research results to augment decision support tools and meet national needs. WaterNet will engage relevant NASA water cycle research resources and community-of-practice organizations, to develop what we term an "actionable database" that can be used to communicate and connect water cycle research results (WCRs) towards the improvement of water-related Decision Support Tools (DSTs). An actionable database includes enough sufficient knowledge about its nodes and their heritage so that connections between these nodes are identifiable and robust. Recognizing the many existing highly valuable water-related science and application networks, we will focus the balance of our efforts on enabling their interoperability in a solutions network context. We will initially focus on identification, collection, and analysis of the two end points, these being the WCRs and water related DSTs. We will then develop strategies to connect these two end points via innovative communication strategies, improved user access to NASA resources, improved water cycle research community appreciation for DST requirements, improved policymaker, management and stakeholder knowledge of NASA research and application products, and improved identification of pathways for progress. Finally, we will develop relevant benchmarking and metrics, to understand the network's characteristics, to optimize its performance, and to establish sustainability. The WaterNet will deliver numerous pre-evaluation reports that will identify the pathways for improving the collective ability of the water cycle community to routinely harness WCRs that address crosscutting water cycle challenges.

  8. Focused training boosts revenue cycle skills, accountability.

    Richmond, Craig

    2011-09-01

    In 2009, the MetroHealth System took its first steps toward creating a comprehensive revenue cycle university, with the goal of developing revenue cycle staff talent and achieving best-in-class revenue cycle operations. MetroHealth became a beta site for HFMA's online Credentialed Revenue Cycle Representative (CRCR) program, and asked its revenue cycle leaders to present classes on key revenue cycle issues. As of June 2011, 62 percent of 122 revenue cycle employees who had taken the CRCR course passed the exam. The CRCR designation is now a prerequisite for career advancement in certain revenue cycle areas at MetroHealth.

  9. Antifreeze life cycle assessment (LCA

    Kesić Jelena

    2005-01-01

    Full Text Available Antifreeze based on ethylene glycol is a commonly used commercial product The classification of ethylene glycol as a toxic material increased the disposal costs for used antifreeze and life cycle assessment became a necessity. Life Cycle Assessment (LCA considers the identification and quantification of raw materials and energy inputs and waste outputs during the whole life cycle of the analyzed product. The objectives of LCA are the evaluation of impacts on the environment and improvements of processes in order to reduce and/or eliminate waste. LCA is conducted through a mathematical model derived from mass and energy balances of all the processes included in the life cycle. In all energy processes the part of energy that can be transformed into some other kind of energy is called exergy. The concept of exergy considers the quality of different types of energy and the quality of different materials. It is also a connection between energy and mass transformations. The whole life cycle can be described by the value of the total loss of exergy. The physical meaning of this value is the loss of material and energy that can be used. The results of LCA are very useful for the analyzed products and processes and for the determined conditions under which the analysis was conducted. The results of this study indicate that recycling is the most satisfactory solution for the treatment of used antifreeze regarding material and energy consumption but the re-use of antifreeze should not be neglected as a solution.

  10. Origins of the supercontinent cycle

    R. Damian Nance

    2013-07-01

    Full Text Available The supercontinent cycle, by which Earth history is seen as having been punctuated by the episodic assembly and breakup of supercontinents, has influenced the rock record more than any other geologic phenomena, and its recognition is arguably the most important advance in Earth Science since plate tectonics. It documents fundamental aspects of the planet's interior dynamics and has charted the course of Earth's tectonic, climatic and biogeochemical evolution for billions of years. But while the widespread realization of the importance of supercontinents in Earth history is a relatively recent development, the supercontinent cycle was first proposed thirty years ago and episodicity in tectonic processes was recognized long before plate tectonics provided a potential explanation for its occurrence. With interest in the supercontinent cycle gaining momentum and the literature expanding rapidly, it is instructive to recall the historical context from which the concept developed. Here we examine the supercontinent cycle from this perspective by tracing its development from the early recognition of long-term episodicity in tectonic processes, through the identification of tectonic cycles following the advent of plate tectonics, to the first realization that these phenomena were the manifestation of episodic supercontinent assembly and breakup.

  11. Air bottoming cycle, an alternative to combined cycles. Final report

    Kaikko, J. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    2002-02-01

    In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

  12. Air bottoming cycle, an alternative to combined cycles. Final report

    Kaikko, J. [Royal Inst. of Techn., Stockholm (Sweden). Dept. of Energy Technology

    2001-10-01

    In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

  13. Modeling the Nuclear Fuel Cycle

    Jacob J. Jacobson; A. M. Yacout; G. E. Matthern; S. J. Piet; A. Moisseytsev

    2005-07-01

    The Advanced Fuel Cycle Initiative is developing a system dynamics model as part of their broad systems analysis of future nuclear energy in the United States. The model will be used to analyze and compare various proposed technology deployment scenarios. The model will also give a better understanding of the linkages between the various components of the nuclear fuel cycle that includes uranium resources, reactor number and mix, nuclear fuel type and waste management. Each of these components is tightly connected to the nuclear fuel cycle but usually analyzed in isolation of the other parts. This model will attempt to bridge these components into a single model for analysis. This work is part of a multi-national laboratory effort between Argonne National Laboratory, Idaho National Laboratory and United States Department of Energy. This paper summarizes the basics of the system dynamics model and looks at some results from the model.

  14. Proliferation resistance fuel cycle technology

    Lee, J. S.; Ko, W. I

    1999-02-01

    The issues of dual use in nuclear technology are analysed for nuclear fuel cycle with special focus on uranium enrichment and spent fuel reprocessing which are considered as the most sensitive components in terms of vulnerability to diversion. Technical alternatives to mitigrate the vulnerability, as has been analysed in depth during the NASAP and INFCE era in the late seventies, are reviewed to characterize the DUPIC fuel cycle alternative. On the other hand, the new realities in nuclear energy including the disposition of weapon materials as a legacy of cold war are recast in an angle of nuclear proliferation resistance and safeguards with a discussion on the concept of spent fuel standard concept and its compliance with the DUPIC fuel cycle technology. (author)

  15. Optimization of data life cycles

    Jung, C.; Gasthuber, M.; Giesler, A.; Hardt, M.; Meyer, J.; Rigoll, F.; Schwarz, K.; Stotzka, R.; Streit, A.

    2014-06-01

    Data play a central role in most fields of science. In recent years, the amount of data from experiment, observation, and simulation has increased rapidly and data complexity has grown. Also, communities and shared storage have become geographically more distributed. Therefore, methods and techniques applied to scientific data need to be revised and partially be replaced, while keeping the community-specific needs in focus. The German Helmholtz Association project "Large Scale Data Management and Analysis" (LSDMA) aims to maximize the efficiency of data life cycles in different research areas, ranging from high energy physics to systems biology. In its five Data Life Cycle Labs (DLCLs), data experts closely collaborate with the communities in joint research and development to optimize the respective data life cycle. In addition, the Data Services Integration Team (DSIT) provides data analysis tools and services which are common to several DLCLs. This paper describes the various activities within LSDMA and focuses on the work performed in the DLCLs.

  16. Measuring risky adolescent cycling behaviour.

    Feenstra, Hans; Ruiter, Robert A C; Schepers, Jan; Peters, Gjalt-Jorn; Kok, Gerjo

    2011-09-01

    Adolescents are at a greater risk of being involved in traffic accidents than most other age groups, even before they start driving cars. This article aims to determine the factor structure of a self-report questionnaire measuring adolescent risky cycling behaviour, the ACBQ (Adolescent Cycling Behaviour Questionnaire). The questionnaire's structure was based on the widely used Driver Behaviour Questionnaire (DBQ). A sample of secondary school students (N = 1749; age range: 13-18 years) filled out the questionnaire. Factor analysis revealed a three-factor structure underlying the questionnaire, which was confirmed on two equally large portions of the entire sample. These three underlying factors were identified as errors, common violations and exceptional violations. The ACBQ is a useful instrument for measuring adolescents' risky cycling behaviour.

  17. Modeling road-cycling performance.

    Olds, T S; Norton, K I; Lowe, E L; Olive, S; Reay, F; Ly, S

    1995-04-01

    This paper presents a complete set of equations for a "first principles" mathematical model of road-cycling performance, including corrections for the effect of winds, tire pressure and wheel radius, altitude, relative humidity, rotational kinetic energy, drafting, and changed drag. The relevant physiological, biophysical, and environmental variables were measured in 41 experienced cyclists completing a 26-km road time trial. The correlation between actual and predicted times was 0.89 (P road-cycling performance are maximal O2 consumption, fractional utilization of maximal O2 consumption, mechanical efficiency, and projected frontal area. The model is then applied to some practical problems in road cycling: the effect of drafting, the advantage of using smaller front wheels, the effects of added mass, the importance of rotational kinetic energy, the effect of changes in drag due to changes in bicycle configuration, the normalization of performances under different conditions, and the limits of human performance.

  18. Corporate governance cycles during transition

    Jones, Derek C.; Mygind, Niels

    2004-01-01

    is faster in Estonia and this can be explained by the relatively fast pace of institutional change and evolution of important gov-ernance institutions, including tough bankruptcy legislation and advances in the financial system. JEL-codes: G3, J5, P2, P3 Keywords: corporate governance, life......We begin by identifying a typical governance life-cycle, defined as changes in ownership structure, and including both the identity of the major owner and ownership concentration. The cycle is marked by key events and phases including start-up, initial growth, mature growth, and possibly a crisis...... and restructuring stage or exit stage. The governance cycle for transitional countries reflects some specific characteristics -e.g. often privatization produces specific initial ownership structures, with an unusually high proportion of insider, especially, employee ownership. Subsequently pres...

  19. ALMA Cycle 0 Publication Statistics

    Stoehr, Felix; Meakins, Silvia; Bishop, Marsha; Uchida, Ayako; Testi, Leonardo; Iono, Daisuke; Tatematsu, Kenichi; Wootten, Al

    2016-01-01

    The scientific impact of a facility is the most important measure of its success. Monitoring and analysing the scientific return can help to modify and optimise operations and adapt to the changing needs of scientific research. The methodology that we have developed to monitor the scientific productivity of the ALMA Observatory, as well as the first results, are described. We focus on the outcome of the first cycle (Cycle 0) of ALMA Early Science operations. Despite the fact that only two years have passed since the completion of Cycle 0 and operations have already changed substantially, this analysisconfirms the effectiveness of the underlying concepts. We find that ALMA is fulfilling its promise as a transformational facility for the observation of the Universe in the submillimetre.

  20. SIRTF Cycle-1 Research Opportunities

    Soifer, B. T.; Bicay, M. D.

    2003-12-01

    The Space InfraRed Telescope Facility (SIRTF), the fourth and final element in NASA's family of Great Observatories, was successfully launched into an Earth-trailing heliocentric orbit on August 25, 2003. The SIRTF Science Center (SSC) at Caltech is now soliciting Cycle-1 research proposals from the worldwide scientific community. Proposals must be submitted electronically to the SSC by February 14, 2004. A preliminary version of the Cycle-1 Call for Proposals (CP) was issued by the SSC in November 2002. A CP Update and supporting technical documentation, which incorporates the on-orbit performance of the observatory, were released in December 2003. Investigations may be proposed for new SIRTF observations, through the General Observer (GO) program, or for archival research. About 3700 hours of observing time is being offered for the Cycle-1 GO Program, in small (less than 50 hours) and medium (50 to 200 hours) categories. More than \\15 million in NASA data analysis support is available to qualified GO investigators. For GO proposals, a detailed list of proposed observations, generated by the SIRTF Planning Observations Tool, must accompany the research proposal. The Archival Research (AR) Program in Cycle-1 is limited to the analysis of data from the First-Look Survey, a 100-hour program to be executed by the SSC at the start of the science mission. Up to \\750,000 in NASA data analysis support is available to qualified AR investigators. All documents supporting the Cycle-1 solicitation are available online in the Proposal Kit section of the SSC public Web site (http://sirtf.caltech.edu/SSC/). Questions pertaining to the Cycle-1 CP should be sent electronically to the SSC HelpDesk at sirtf@ipac.caltech.edu. SIRTF is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  1. Tricarboxylic-acid-cycle intermediates and cycle endurance capacity.

    Brown, Amy C; Macrae, Holden S H; Turner, Nathan S

    2004-12-01

    The purpose of this study was to determine whether ingestion of a multinutrient supplement containing 3 tricarboxylic-acid-cycle intermediates (TCAIs; pyridoxine-alpha-ketoglutarate, malate, and succinate) and other substances potentially supporting the TCA cycle (such as aspartate and glutamate) would improve cyclists' time to exhaustion during a submaximal endurance-exercise test (approximately 70 % to 75 % VO2peak) and rate of recovery. Seven well-trained male cyclists (VO2max 67.4 2.1 mL x kg(-1) x in(-1), 28.6 +/- 2.4 y) participated in a randomized, double-blind crossover study for 7 wk. Each took either the treatment or a placebo 30 min before and after their normal training sessions for 3 wk and before submaximal exercise tests. There were no significant differences between the TCAI group (KI) and placebo group (P) in time to exhaustion during cycling (KI = 105 +/- 18, P = 113 +/- 11 min); respiratory-exchange ratio at 20-min intervals; blood lactate and plasma glucose before, after, and at 30-min intervals during exercise; perceived exertion at 20-min intervals during exercise; or time to fatigue after the 30-min recovery (KI = 16.1 +/- 3.2, P = 15 +/- 2 min). Taking a dietary sport supplement containing several TCAIs and supporting substances for 3 wk does not improve cycling performance at 75 % VO2peak or speed recovery from previously fatiguing exercise.

  2. Optimal Life Cycle Portfolio Choice with Housing Market Cycles

    Fischer, Marcel; Stamos, Michael Z.

    2013-01-01

    In recent decades U.S. households have experienced residential house prices moving persistently, that is, returns being positively serially correlated. We set up a realistically calibrated life cycle model with slow-moving time variation in expected housing returns, showing that not only age, lab...

  3. Biogeochemical cycling and remote sensing

    Peterson, D. L.

    1985-01-01

    Research is underway at the NASA Ames Research Center that is concerned with aspects of the nitrogen cycle in terrestrial ecosystems. An interdisciplinary research group is attempting to correlate nitrogen transformations, processes, and productivity with variables that can be remotely sensed. Recent NASA and other publications concerning biogeochemical cycling at global scales identify attributes of vegetation that could be related or explain the spatial variation in biologically functional variables. These functional variables include net primary productivity, annual nitrogen mineralization, and possibly the emission rate of nitrous oxide from soils.

  4. Business Cycles in Developing Countries

    Rand, John; Tarp, Finn

    2002-01-01

    This paper demonstrates that developing countries differ considerably from their developed counterparts when focus is on the nature and characteristics of short run macroeconomic fluctuations. Cycles are generally shorter, and the stylized facts of business cycles across countries are more diverse...... than those of the rather uniform industrialized countries. Supply-side models are generally superior in explaining changes in output, but a “one-size fits all” approach in formulating policy is inappropriate. Our results also illustrate the critical importance of understanding business regularities...... as a stepping-stone in the process of designing appropriate stabilization policy and macroeconomic management in developing countries....

  5. Properties of stellar activity cycles

    Korhonen, Heidi

    2015-01-01

    The current photometric datasets, that span decades, allow for studying long-term cycles on active stars. Complementary Ca H&K observations give information also on the cycles of normal solar-like stars, which have significantly smaller, and less easily detectable, spots. In the recent years, high precision space-based observations, for example from the Kepler satellite, have allowed also to study the sunspot-like spot sizes in other stars. Here I review what is known about the properties of the cyclic stellar activity in other stars than our Sun.

  6. Life cycle of remanufactured engines

    YANG Ming; CHEN Ming

    2005-01-01

    The life cycle index of remanufactured engines was assessed by using the method of life cycle assessment (LCA). A remanufactured engine of a certain domestic brand was taken as researching object. Engine reproducing engineering was investigated from three aspects which were energy, material and environment. The application of LCA on remanufacturing engines was discussed in detail with a practical case. The results indicate that remanufackg CO2 , 6.09 kg CO, 1.01 kg NOx, 3. 985 kg SOx and 288. 725 kg solid waste. The remanufacturing of engines possesses great economic value and practicability.

  7. Digital calculations of engine cycles

    Starkman, E S; Taylor, C Fayette

    1964-01-01

    Digital Calculations of Engine Cycles is a collection of seven papers which were presented before technical meetings of the Society of Automotive Engineers during 1962 and 1963. The papers cover the spectrum of the subject of engine cycle events, ranging from an examination of composition and properties of the working fluid to simulation of the pressure-time events in the combustion chamber. The volume has been organized to present the material in a logical sequence. The first two chapters are concerned with the equilibrium states of the working fluid. These include the concentrations of var

  8. SNMR pulse sequence phase cycling

    Walsh, David O; Grunewald, Elliot D

    2013-11-12

    Technologies applicable to SNMR pulse sequence phase cycling are disclosed, including SNMR acquisition apparatus and methods, SNMR processing apparatus and methods, and combinations thereof. SNMR acquisition may include transmitting two or more SNMR pulse sequences and applying a phase shift to a pulse in at least one of the pulse sequences, according to any of a variety cycling techniques. SNMR processing may include combining SNMR from a plurality of pulse sequences comprising pulses of different phases, so that desired signals are preserved and indesired signals are canceled.

  9. Ramsey Results for Cycle Spectra

    Brandt, S.; Joos, F.; Muttel, J.;

    2013-01-01

    Let C(G) denote the set of lengths of cycles of a graph G of order n and let (G) over bar denote the complement of G. We show that if n >= 6, then C(G) boolean OR C((G) over bar) contains all odd l with 3......Let C(G) denote the set of lengths of cycles of a graph G of order n and let (G) over bar denote the complement of G. We show that if n >= 6, then C(G) boolean OR C((G) over bar) contains all odd l with 3...

  10. A short note on Reitlinger thermodynamic cycles

    Sparavigna, Amelia Carolina

    2015-01-01

    It is well known that Carnot cycle is the thermodynamic cycle which has the best thermal efficiency. However, an entire class of cycles exists that can have the same maximum efficiency: this class is that of the regenerative Reitlinger cycles. Here we discuss them.

  11. Interchange graphs and the Hamiltonian cycle polytope

    Sierksma, G

    1998-01-01

    This paper answers the (non)adjacency question for the whole spectrum of Hamiltonian cycles on the Hamiltonian cycle polytope (HC-polytope), also called the symmetric traveling salesman polytope, namely from Hamiltonian cycles that differ in only two edges through Hamiltonian cycles that are edge di

  12. H gas turbine combined cycle

    Corman, J. [General Electric Co., Schenectady, NY (United States)

    1995-10-01

    A major step has been taken in the development of the Next Power Generation System - {open_quotes}H{close_quotes} Technology Combined Cycle. This new gas turbine combined-cycle system increases thermal performance to the 60% level by increasing gas turbine operating temperature to 1430 C (2600 F) at a pressure ratio of 23 to 1. Although this represents a significant increase in operating temperature for the gas turbine, the potential for single digit NOx levels (based upon 15% O{sub 2}, in the exhaust) has been retained. The combined effect of performance increase and environmental control is achieved by an innovative closed loop steam cooling system which tightly integrates the gas turbine and steam turbine cycles. The {open_quotes}H{close_quotes} Gas Turbine Combined Cycle System meets the goals and objectives of the DOE Advanced Turbine System Program. The development and demonstration of this new system is being carried out as part of the Industrial/Government cooperative agreement under the ATS Program. This program will achieve first commercial operation of this new system before the end of the century.

  13. Sorption Refrigeration / Heat Pump Cycles

    Saha, Bidyut Baran; Alam, K. C. Amanul; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    Over the past few decades there have been considerable efforts to use adsorption (solid/vapor) for cooling and heat pump applications, but intensified efforts were initiated only since the imposition of international restrictions on the production and use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Up to now, only the desiccant evaporative cooling system of the open type has achieved commercial use, predominantly in the United States. Closed-type adsorption refrigeration and heat pump systems are rarely seen in the market, or are still in the laboratory testing stage. Promising recent development have been made in Japan for the use of porous metal hydrides and composite adsorbents. In this paper, a short description of adsorption theories along with an overview of present status and future development trends of thermally powered adsorption refrigeration cycles are outlined putting emphasis on experimental achievements. This paper also addressed some advanced absorption cycles having relatively higher COP, and also summarizes fundamental concepts of GAX cycles and various GAX cycles developed for heat pump applications.

  14. The product life cycle revisited

    Ulhøi, John Parm

    1995-01-01

    Efter et introduktionsafsnit følger afsnit II, hvor der gives en historisk analyse af Life Cycle Assessment (LCA) og Environmental Impact Assessment (EIA). I afsnit III munder analysen ud i en vurdering af ligheder og forskelle mellem LCA analyser og EIA analyser, og en diskussion følger af...

  15. Menopause: A Life Cycle Transition.

    Evarts, Barbara Kess; Baldwin, Cynthia

    1998-01-01

    Family therapists need to address the issue of menopause proactively to be of benefit to couples and families during this transitional period in the family life cycle. Physical, psychological, and psychosocial factors affecting the menopausal woman and her family, and ways to address these issues in counseling are discussed. (Author/EMK)

  16. Nuclear Fuel Cycle Introductory Concepts

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-02

    The nuclear fuel cycle is a complex entity, with many stages and possibilities, encompassing natural resources, energy, science, commerce, and security, involving a host of nations around the world. This overview describes the process for generating nuclear power using fissionable nuclei.

  17. Business Cycle Dependent Unemployment Insurance

    Andersen, Torben M.; Svarer, Michael

    The consequences of business cycle contingencies in unemployment insurance systems are considered in a search-matching model allowing for shifts between "good" and "bad" states of nature. We show that not only is there an insurance argument for such contingencies, but there may also be an incentive...

  18. Time Cycles in Indian Cosmology

    Narayan, R H

    2007-01-01

    In this article we review some key time cycles in ancient Indian astronomy, especially those that have emerged from researches in the past couple of decades expressing knowledge of the changing frame of earth's axis. The article also briefly reviews the philosophy related to the interconnection between the inner and the outer cosmos that was used in the analytical narrative related to this astronomy.

  19. Autoradiography and the Cell Cycle.

    Jones, C. Weldon

    1992-01-01

    Outlines the stages of a cell biology "pulse-chase" experiment in which the students apply autoradiography techniques to learn about the concept of the cell cycle. Includes (1) seed germination and plant growth; (2) radioactive labeling and fixation of root tips; (3) feulgen staining of root tips; (4) preparation of autoradiograms; and…

  20. Single-cycle nonlinear optics

    Max-Planck-Institut fur Quantenoptik; Goulielmakis, E.; Schultze, M.; Hofstetter, M.; Yakovlev, V. S.; Gagnon, J.; Uiberacker, M.; Aquila, A. L.; gullikson, E. M.; attwood, D. T.; Kienberger, R.; Krausz, F.; Kleineberg, U.

    2008-11-05

    Nonlinear optics plays a central role in the advancement of optical science and laser-based technologies. We report on the confinement of the nonlinear interaction of light with matter to a single wave cycle and demonstrate its utility for time-resolved and strong-field science. The electric field of 3.3-femtosecond, 0.72-micron laser pulses with a controlled and measured waveform ionizes atoms near the crests of the central wave cycle, with ionization being virtually switched off outside this interval. Isolated sub-100-attosecond pulses of extreme ultraviolet light (photon energy {approx} 80 electron volts), containing {approx} 0.5 nanojoule of energy, emerge from the interaction with a conversion efficiency of {approx} 10{sup -6}. These tools enable the study of the precision control of electron motion with light fields and electron-electron interactions with a resolution approaching the atomic unit of time ({approx} 24 attoseconds).

  1. Soleus stretch reflex during cycling

    Grey, Michael James; Pierce, C. W.; Milner, T. E.

    2001-01-01

    The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions during...... the crank cycle, producing ankle dorsiflexion perturbations of similar trajectory. The stretch reflex was greatest during the power phase of the crank cycle and was decreased to the level of background EMG during recovery. Matched perturbations were induced under static conditions at the same crank angle...... and background soleus EMG as recorded during the power phase of active pedaling. The magnitude of the stretch reflex was not statistically different from that during the static condition throughout the power phase of the movement. The results of this study indicate that the stretch reflex is not depressed during...

  2. Life cycle assessment of turbines

    NONE

    2004-10-15

    This report forms part of the final reporting of the project 'LCA and turbines, which has been carried out as a cooperation between Vestas Wind Systems A/S and Tech-wise A/S on behalf of Elsam A/S. The goal of the project was to create a life cycle model for a big Vestas offshore turbine. Based on the offshore model an analysis has been prepared and this analysis will show the most significant environmental impacts a turbine will be subject to during its life cycle. Furthermore we have prepared a recommendation on how an improvement strategy on a selected area can be drafted. Finally, a preliminary environmental declaration of contents will be prepared for the turbine in question and 1 kWh generated from here. (BA)

  3. Swimming as a limit cycle

    Jacobs, Henry O

    2012-01-01

    Steady swimming can be characterized as both periodic and stable. These characteristics are the very definition of limit cycles, and so we ask "Can we view swimming as a limit cycle?" In this paper we will find that the answer is "yes". We will define a class of dissipative systems which correspond to the passive dynamics of a body immersed in a Navier-Stokes fluid (i.e. the dynamics of a dead fish). Upon performing reduction by symmetry we will find a hyperbolically stable fixed point which corresponds to the stability of a dead fish in stagnant water. Given a periodic force on the shape of the body we will invoke the persistence theorem to assert the existence of a loop which approximately satisfies the exact equations of motion. If we lift this loop with a phase reconstruction formula we will find that the lifted loops are not loops, but stable trajectories which represent regular periodic motion reminiscent of swimming.

  4. THE CANADIAN POLITICAL BUSINESS CYCLE

    Barbara Libby

    2000-01-01

    Full Text Available This paper will discuss the existence of a Canadian Political Business Cycle (PBC during the period 1946-1989. Logit analysis was used to determine if changes in the unemployment rate, growth of real GNE and the rate of inflation are significantly different in the period before an election than during the rest of the electoral term. It was found that the rate of growth in the unemployment rate declines and the rate of growth of real GNP increases in the four quarters before an election. The behavior of these variables reverses in the period after an election. These findings are consistent with a political business cycle. Policy variables, under a majority government, also behave in a manner associated with a PBC, with the government stimulating the economy approximately two years into its term so that good economic news will occur before it has to call an election. Minority governments tend to simulate the economy immediately after taking office.

  5. HTGR fuel and fuel cycle technology

    Lotts, A.L.; Coobs, J.H.

    1976-08-01

    The status of fuel and fuel cycle technology for high-temperature gas-cooled reactors (HTGRs) is reviewed. The all-ceramic core of the HTGRs permits high temperatures compared with other reactors. Core outlet temperatures of 740/sup 0/C are now available for the steam cycle. For advanced HTGRs such as are required for direct-cycle power generation and for high-temperature process heat, coolant temperatures as high as 1000/sup 0/C may be expected. The paper discusses the variations of HTGR fuel designs that meet the performance requirements and the requirements of the isotopes to be used in the fuel cycle. Also discussed are the fuel cycle possibilities, which include the low-enrichment cycle, the Th-/sup 233/U cycle, and plutonium utilization in either cycle. The status of fuel and fuel cycle development is summarized.

  6. Phase lags of solar hemispheric cycles

    Muraközy, J

    2013-01-01

    The North-South asymmetry of solar activity is variable in time and strength. We analyse the long-term variation of the phase lags of hemispheric cycles and check a conjectured relationship between these phase lags and the hemispheric cycle strengths. Sunspot data are used from cycles 12-23 in which the separation of northern and southern hemispheres is possible. The centers of mass of the hemispheric cycle profiles were used to study the phase relations and relative strengths of the hemispheric cycles. This approach considers a cycle as a whole and disregards the short-term fluctuations of the cycle time profile. The phase of the hemispheric cycles shows an alternating variation: the northern cycle leads in 4 cycles and follows in 4 cycles. No significant relationship is found between the phase and strength differences of the hemispheric cycles. The period of 4+4 cycles appears to be close to the Gleissberg cycle and may provide a key to its physical background. It may raise a new aspect in the solar dynamo ...

  7. Biomechanics of Counterweighted One-Legged Cycling.

    Elmer, Steven J; McDaniel, John; Martin, James C

    2016-02-01

    One-legged cycling has served as a valuable research tool and as a training and rehabilitation modality. Biomechanics of one-legged cycling are unnatural because the individual must actively lift the leg during flexion, which can be difficult to coordinate and cause premature fatigue. We compared ankle, knee, and hip biomechanics between two-legged, one-legged, and counterweighted (11.64 kg) one-legged cycling. Ten cyclists performed two-legged (240 W), one-legged (120 W), and counterweighted one-legged (120 W) cycling (80 rpm). Pedal forces and limb kinematics were recorded to determine work during extension and flexion. During counterweighted one-legged cycling relative ankle dorsiflexion, knee flexion, and hip flexion work were less than one-legged but greater than two-legged cycling (all P cycling were greater than one-legged but less than two-legged cycling (all P cycling reduced but did not eliminate differences in joint flexion and extension actions between one- and two-legged cycling. Even with these differences, counterweighted one-legged cycling seemed to have advantages over one-legged cycling. These results, along with previous work highlighting physiological characteristics and training adaptations to counterweighted one-legged cycling, demonstrate that this exercise is a viable alternative to one-legged cycling.

  8. Biogeochemical Cycles in Degraded Lands

    Davidson, Eric A.; Vieira, Ima Celia G.; ReisdeCarvalho, Claudio Jose; DeanedeAbreuSa, Tatiana; deSouzaMoutinho, Paulo R.; Figueiredo, Ricardo O.; Stone, Thomas A.

    2004-01-01

    The objectives of this project were to define and describe the types of landscapes that fall under the broad category of "degraded lands" and to study biogeochemical cycles across this range of degradation found in secondary forests. We define degraded land as that which has lost part of its capacity of renovation of a productive ecosystem, either in the context of agroecosystems or as native communities of vegetation. This definition of degradation permits evaluation of biogeochemical constraints to future land uses.

  9. Automatic Dehumanization Across Menstrual Cycle

    Piccoli, Valentina; Carnaghi, Valentina; Foroni, Francesco; Hvastja Stefani, Loredana

    2014-01-01

    In the current study we address the role of hormonal fluctuations across menstrual cycle in female dehumanization of women and men. Using a sequential priming procedure in a lexical decision task, we test whether increased levels of conception risk lead to dehumanization of other women and men on both animal and human dimensions. Results showed that for word woman as the prime, animal words were more accessible in the high than in the low conception risk of the menstru...

  10. Containing revenue-cycle costs.

    Geer, Robert; Burton, Eric

    2003-04-01

    Healthcare organizations can achieve revenue-cycle improvement while maintaining optimum staffing levels by taking a three-step approach-developing a plan, measuring costs, and using benchmarks to measure performance. Planned cost reductions can be achieved without a negative impact on the organization. Cost-reduction strategies should look at purchased services, staffing, and the cost-to-collect ratio. Healthcare organizations should reach target performance levels before implementing a cost-reduction strategy.

  11. Technology cycles and technology revolutions

    Paganetto, Luigi; Scandizzo, Pasquale Lucio

    2010-09-15

    Technological cycles have been characterized as the basis of long and continuous periods economic growth through sustained changes in total factor productivity. While this hypothesis is in part consistent with several theories of growth, the sheer magnitude and length of the economic revolutions experienced by humankind seems to indicate surmise that more attention should be given to the origin of major technological and economic changes, with reference to one crucial question: role of production and use of energy in economic development.

  12. Self-Fulfilling Credit Cycles

    Costas Azariadis; Leo Kaas

    2012-01-01

    This paper argues that self-fulfilling beliefs in credit conditions can generate endogenously persistent business cycle dynamics. We develop a tractable dynamic general equilibrium model with idiosyncratic firm productivity shocks. Capital from less productive firms is lent to more productive ones in the form of credit secured by collateral and also as unsecured credit based on reputation. A dynamic complementarity between current and future credit constraints permits uncorrelated sunspot sho...

  13. Short-Cycle Adsorption Refrigerator

    Chan, C. K.

    1988-01-01

    Modular adsorption/Joule-Thomson-effect refrigerator offers fast regeneration; adsorption/desorption cycle time expected to be 1 minute. Pressurized hydrogen generated by bank of compressor modules during heating phase passes through system of check valves and expands in Joule-Thomson junction as it enters refrigeration chamber. Hydrogen absorbs heat from load before it is sucked out by another bank of compressor modules in cooling phase.

  14. Fundamental cycles and graph embeddings

    2009-01-01

    In this paper, we investigate fundamental cycles in a graph G and their relations with graph embeddings. We show that a graph G may be embedded in an orientable surface with genus at least g if and only if for any spanning tree T , there exists a sequence of fundamental cycles C1, C2, . . . , C2g with C2i-1 ∩ C2i≠ф for 1≤ i ≤g. In particular, among β(G) fundamental cycles of any spanning tree T of a graph G, there are exactly 2γM (G) cycles C1, C2, . . . , C2γM (G) such that C2i-1 ∩ C2i≠ф for 1 ≤i≤γM (G), where β(G) and γM (G) are the Betti number and the maximum genus of G, respectively. This implies that it is possible to construct an orientable embedding with large genus of a graph G from an arbitrary spanning tree T (which may have very large number of odd components in G\\E(T )). This is different from the earlier work of Xuong and Liu, where spanning trees with small odd components are needed. In fact, this makes a common generalization of Xuong, Liu and Fu et al. Furthermore, we show that (1) this result is useful for locating the maximum genus of a graph having a specific edge-cut. Some known results for embedded graphs are also concluded; (2) the maximum genus problem may be reduced to the maximum matching problem. Based on this result and the algorithm of Micali-Vazirani, we present a new efficient algorithm to determine the maximum genus of a graph in O((β(G)) 25 ) steps. Our method is straight and quite different from the algorithm of Furst, Gross and McGeoch which depends on a result of Giles where matroid parity method is needed.

  15. ZPC Matrices and Zero Cycles

    Marina Arav

    2009-01-01

    Full Text Available Let H be an m×n real matrix and let Zi be the set of column indices of the zero entries of row i of H. Then the conditions |Zk∩(∪i=1k−1Zi|≤1 for all k  (2≤k≤m are called the (row Zero Position Conditions (ZPCs. If H satisfies the ZPC, then H is said to be a (row ZPC matrix. If HT satisfies the ZPC, then H is said to be a column ZPC matrix. The real matrix H is said to have a zero cycle if H has a sequence of at least four zero entries of the form hi1j1,hi1j2,hi2j2,hi2j3,…,hikjk,hikj1 in which the consecutive entries alternatively share the same row or column index (but not both, and the last entry has one common index with the first entry. Several connections between the ZPC and the nonexistence of zero cycles are established. In particular, it is proved that a matrix H has no zero cycle if and only if there are permutation matrices P and Q such that PHQ is a row ZPC matrix and a column ZPC matrix.

  16. Solar storms, cycles and topology

    Lundstedt H.

    2010-12-01

    Full Text Available Solar storms are produced due to plasma processes inside and between coronal loops. These loops are topologically examined using knot and braid theory. Solar cycles are topologically explored with a complex generalization of the three ordinary differential equations studied by Lorenz. By studying the Poincaré map we give numerical evidence that the flow has an attractor with fractal structure. The period is defined as the time needed for a point on a hyperplane to return to the hyperplane again. The periods are distributed in an interval. For large values of the Dynamo number there is a long tail toward long periods and other interesting comet-like features. We also found a relationship between the intensity of a cycle and the length for the previous cycle. Maunder like minima are also appearing. These general relations found for periods can further be physically interpreted with improved helioseismic estimates of the parameters used by the dynamical systems. Solar Dynamic Observatory is expected to offer such improved measurements.

  17. Advanced Fuel Cycle Cost Basis

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2009-12-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  18. Advanced Fuel Cycle Cost Basis

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert

    2007-04-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 26 cost modules—24 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, and high-level waste.

  19. Advanced Fuel Cycle Cost Basis

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2008-03-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  20. Product development cycle time reduction

    Farran, Robin

    1992-05-01

    We are facing here today the key issues that face us in the competitive environment. North American companies are struggling to compete in the global marketplace. Gone are the days when presence ensured success. Then, sales and earnings were guaranteed. Today the competition is intense. Many manufacturing and service companies are no longer competitive. Traditionally, manufacturing companies have created the most wealth for the community and economy. Losing this ability to create wealth is tragic and unnecessary. A company can only be successful by focusing on customer satisfaction at competitive costs. Revenue growth and earnings growth require a continuous stream of products that anticipate the customers' needs, result from shorter and shorter innovation cycles, continually improve in quality, and are produced at improved costs on each cycle. The best opportunities for increased quality and decreased costs are with new products. Sure, work on quality and costs everyday. The biggest changes, however, will come through the new product development cycle. We must improve our development processes to provide leadership products which result in high levels of customer satisfaction. This is a prerequisite for business success. When presence in the marketplace was a virtual guarantee of success for a North American company, technology tended to drive the products, and the customers bought virtually everything that was produced. Functional excellence was stressed within companies ... and that was enough. Effective planning processes were not a prerequisite for success. Today success demands highly developed business research and planning processes, and functional excellence combined with organizational capabilities that ensure commercialization excellence.

  1. Endoreversible Meletis-Georgiou cycle

    Chang Liu, Lingen Chen, Fengrui Sun

    2012-01-01

    Full Text Available An endoreversible Meletis-Georgiou (MG cycle model with constant specific heat of working fluid is established and the analytical formulae of performance parameters including working fluid temperatures, work output and efficiency are derived using the finite time thermodynamic theory. The performance of the endoreversible MG cycle is analyzed and optimized. The characteristics of the work output versus compression ratio, efficiency versus compression ratio, and work output versus efficiency are obtained, respectively, by detailed numerical examples, and the effects of changeover ratio, over-expansion ratio, heating value of fuel, heat transfer loss coefficient, initial temperature of working fluid, and the transferred volume ratio on the relationship mentioned above are also discussed. The maximum work output and the corresponding optimal compression ratio, changeover ratio, over-expansion ratio as well as the maximum efficiency and the corresponding optimal changeover ratio and over-expansion ratio are obtained by taking the cycle work output and efficiency as the optimization objectives, respectively. Moreover, the effects of the parameters such as the heating value of fuel, heat transfer loss coefficient, initial temperature of working fluid, and the transferred volume ratio on the maximum work output, the maximum efficiency and the corresponding optimal ratios are analyzed. The results may provide guidelines for the optimal design of practical MG engine.

  2. Digital Daily Cycles of Individuals

    Talayeh eAledavood

    2015-10-01

    Full Text Available Humans, like almost all animals, are phase-locked to the diurnal cycle. Most of us sleep at night and are active through the day. Because we have evolved to function with this cycle, the circadian rhythm is deeply ingrained and even detectable at the biochemical level. However, within the broader day-night pattern, there are individual differences: e.g., some of us are intrinsically morning-active, while others prefer evenings. In this article, we look at digital daily cycles: circadian patterns of activity viewed through the lens of auto-recorded data of communication and online activity. We begin at the aggregate level, discuss earlier results, and illustrate differences between population-level daily rhythms in different media. Then we move on to the individual level, and show that there is a strong individual-level variation beyond averages: individuals typically have their distinctive daily pattern that persists in time. We conclude by discussing the driving forces behind these signature daily patterns, from personal traits (morningness/eveningness to variation in activity level and external constraints, and outline possibilities for future research.

  3. Nutrient Cycling in Piermont Marsh

    Reyes, N.; Gribbin, S.; Newton, R.; Diaz, K.; Laporte, N.; Trivino, G.; Ortega, J.; McKee, K.; Sambrotto, R.

    2011-12-01

    We investigate the cycling of nutrients through a brackish tidal wetland about 40 km north of Manhattan in the Hudson River estuary. As part of a long-term ecological study of Piermont Marsh, a NOAA reference wetland managed by the NY State DEC, we are measuring dissolved inorganic nutrients on the Marsh surface and its drainage channels. The marsh occupies 400 acres along the southwest corner of Haverstraw Bay with approximately 2 km frontage to the estuary. It is supplied with nutrient-rich water and drained primarily along several tidal creeks and the hundreds of rivulets that feed them. During most tidal cycles the silty berm bounding the marsh is not topped. Human influence in the marsh's surrounding area has had profound effects, one of the most fundamental of which has been the shift from native grass species, predominantly Spartina alterniflora, to an invasive genotype of common reed, Phragmites australis. Along with this shift there have been changes in the root bed, the effective marsh interior and berm heights, the hydroperiod and, as a result, the ability of the marsh to be utilized by various types of Hudson estuary fish. The vegetative shift is believed to be anthropogenic, but the connection is not well understood, and it is not known what role biogeochemical perturbations are playing. We present two field seasons of nitrate, phosphate and silicate measurements from Sparkill Creek, a freshwater stream draining the surrounding highlands constitutes the northern boundary, two tidally driven creeks transect the Marsh from West to East: the Crumkill and an unnamed creek we have dubbed the "Tidal", Ludlow Ditch, a no-longer-maintained drainage channel grading gently from the northern part of the marsh to the South terminates in a wide tidal outlet that is its southern boundary. Net tidal cycle fluxes and fluxes resulting from runoff events are presented. Deviations from Redfield ratios and limiting nutrients are analyzed. Piermont Marsh data is compared

  4. BUSINESS CYCLES, ELECTORAL CYCLES. TOWARD A THEORETICAL FRAME OF INTERACTION

    BOGDAN-LUCIAN DOSPINESCU

    2015-06-01

    Full Text Available The idea of cyclical movement of a system: be it political, economic, institutional, is one of the constants of critical thinking. In this sense, there is a natural cyclic movement that cannot be avoided (only amplified or diminished and is connected with the nature of these systems. The economy follows a cyclical movement; a period of growth follows a period of decline, and so on. So does popularity for political parties or leaders. In this paper, I explore the links between the business cycles and electoral cycles. For this purpose, I introduce the concept of electoral perception cycles. My hypothesis is that popularity of political parties and leaders follow a cyclical evolution, both on short and long term. I show how perception cycles can impact the “political business cycle theory”. There is great interest in political science literature for the factors that influence the fluctuations in Presidents’ popularity, especially from United States. However, very little has been said about Romania’s case. I investigate the hypothesis of electoral perception cycles looking at the popularity of former president Traian Basescu, over his two terms. The variable used to measure popularity is favorability, measured in national surveys, done face to face, on representative samplez, of around 1000 subjects. I’ve correlated the fluctuations in favorability over time, with key public events or political decisions taken by Traian Băsescu. The main findings are as follows. Firstly, there are significant short term fluctuations (short term perception cycles and they are correlated with major events on the agenda. I would point the following key moments: 1. The referendum for dismissal of the President in May 2007 – Traian Băsescu’s favorability increased by 7 percentage points; 2. The referendum for unicameral Parliament with 300 MPs in the fall of 2009. Coupled with victory in the presidential election, it lead to an increase of 10 percentage

  5. The nuclear fuel cycle; Le cycle du combustible nucleaire

    NONE

    1998-05-01

    After a short introduction about nuclear power in the world, fission physics and the French nuclear power plants, this brochure describes in a digest way the different steps of the nuclear fuel cycle: uranium prospecting, mining activity, processing of uranium ores and production of uranium concentrates (yellow cake), uranium chemistry (conversion of the yellow cake into uranium hexafluoride), fabrication of nuclear fuels, use of fuels, reprocessing of spent fuels (uranium, plutonium and fission products), recycling of energetic materials, and storage of radioactive wastes. (J.S.)

  6. Biogeochemical cycles: Interactions in global metabolism

    Moore, B., III; Morowitz, H.; Dastoor, M. N.

    1984-01-01

    A science that chooses the globe as it fundamental biogeophysical unit forces extraordinary conceptual difficulties. The roles of energy flow, matter cycles, carbon cycle, air pollution, global effects, air water interactions are discussed.

  7. Life cycle management in product development

    Skelton, Kristen; Pattis, Anna

    The integration of Life Cycle Thinking (LCT) and Life Cycle Management (LCM) into business operations poses great challenges, as it requires a wider range of environmental responsibility often extending beyond a company's immediate control. Simultaneously, it offers many opportunities...

  8. High performance heat pump absorption cycles

    Lazzarin, R.; Longo, G.; Rossetto, L.

    1988-10-01

    Absorption heat pumps can provide high performances when operating in suitable cycles with multiple effects. This report describes some multistage cycles and evaluates the coefficient of performance realistically obtainable both in winter and summer working conditions.

  9. Not all counterclockwise thermodynamic cycles are refrigerators

    Dickerson, R. H.; Mottmann, J.

    2016-06-01

    Clockwise cycles on PV diagrams always represent heat engines. It is therefore tempting to assume that counterclockwise cycles always represent refrigerators. This common assumption is incorrect: most counterclockwise cycles cannot be refrigerators. This surprising result is explored here for quasi-static ideal gas cycles, and the necessary conditions for refrigeration cycles are clarified. Three logically self-consistent criteria can be used to determine if a counterclockwise cycle is a refrigerator. The most fundamental test compares the counterclockwise cycle with a correctly determined corresponding Carnot cycle. Other criteria we employ include a widely accepted description of the functional behavior of refrigerators, and a corollary to the second law that limits a refrigerator's coefficient of performance.

  10. Terminology gap in hydrological cycle

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Water is central to life on Earth. People have been trying to understand how water moves in the hydrosphere throughout the human history. In the 9th century BC, the famous Greek poet Homer described the hydrological cycle in Iliad as "okeanos whose stream bends back in a circle" with a belief that rivers are ocean-fed from subterranean seas. Later, Aristotle (4th century BC) claimed that most of the water came from underground caverns in which air was transformed into water. It was only until 1674, French scientist Perrault developed the correct concept of the water cycle. In modern times, scientists are interested in understanding the individual processes of the hydrological cycle with a keen focus on runoff which supplies water to rivers, lakes, and oceans. Currently, the prevailing concepts on runoff processes include 'infiltration excess runoff' and 'saturation excess runoff'. However, there is no term to describe another major runoff due to the excess beyond the soil water holding capacity (i.e., the field capacity). We argue that a new term should be introduced to fill this gap, and it could be called 'holding excess runoff' which is compatible with the convention. This new term is significant in correcting a half-century misnomer where 'holding excess runoff' has been incorrectly named as 'saturation excess runoff', which was introduced by the Xinanjiang model in China in 1960s. Similar concept has been adopted in many well-known hydrological models such as PDM and HBV in which the saturation refers to the field capacity. The term 'holding excess runoff' resolves such a common confusion in the hydrological community.

  11. Politics and the life cycle.

    Kinder, Donald R

    2006-06-30

    The study of politics and the life cycle began with a rather single-minded focus on childhood and the family-on the idea, as Tocqueville famously put it, that the entire person could be "seen in the cradle of the child." Politics does begin in childhood, and parents do influence their offspring, but change takes place over the entire span of life. I take up the early emergence of partisanship and essentialism, the formation of generations, politically consequential transitions in adulthood, and the rising of politics and its final decline.

  12. Carnot cycle for an oscillator

    Arnaud, Jacques; Chusseau, Laurent; Philippe, Fabrice

    2002-09-01

    In 1824 Carnot established that the efficiency of cyclic engines operating between a hot bath at absolute temperature Thot and a bath at a lower temperature Tcold cannot exceed 1 - Tcold/Thot. We show that linear oscillators alternately in contact with hot and cold baths obey this principle in the quantum as well as classical regime. The expression of the work performed is derived from a simple prescription. Reversible and non-reversible cycles are illustrated. The paper begins with historical considerations and is essentially self-contained.

  13. Rankine cycle system and method

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-09-09

    A Rankine cycle waste heat recovery system uses a receiver with a maximum liquid working fluid level lower than the minimum liquid working fluid level of a sub-cooler of the waste heat recovery system. The receiver may have a position that is physically lower than the sub-cooler's position. A valve controls transfer of fluid between several of the components in the waste heat recovery system, especially from the receiver to the sub-cooler. The system may also have an associated control module.

  14. Structural characterization and electron density distribution studies of (La{sub 0.8}Ca{sub 0.2})(Cr{sub 0.9−x}Co{sub 0.1}Mn{sub x})O{sub 3}

    Saravanan, R. [Research Centre and Post Graduate Department of physics, The Madura College, Madurai 625011 (India); Thenmozhi, N., E-mail: thenmozhi.n6@gmail.com [PG and Research Department of Physics, NMSSVN College, Nagamalai, Madurai 625019 (India); Fu, Yen-Pei [Department of materials Science and Engineering, National Dong-Hwa University, Shou-Feng, Hualien 974, Taiwan (China)

    2016-07-15

    The doped lanthanum chromite (La{sub 0.8}Ca{sub 0.2})(Cr{sub 0.9−x}Co{sub 0.1}Mn{sub x})O{sub 3} (x=0.03, 0.06, 0.09 and 0.12) were synthesized by solid state reaction technique. The samples have been characterized by X-ray diffraction for structural and charge density analysis. XRD data show that the grown samples are orthorhombic in structure with single phase. The spatial charge density distribution in the unit cell for the synthesized samples has been studied using maximum entropy method. Further, the samples were analyzed by UV–visible spectrometry for optical properties and scanning electron microscopy for surface morphology. From the optical data, it was found that the direct band gap of the samples range from 2.27 to 2.46 eV. The samples were also investigated by vibrating sample magnetometry for magnetic properties. From VSM data, it is inferred that all the samples in this series are found to be predominantly antiferromagnetic in nature. Since the doped lanthanum chromites have good mechanical properties and electrical conductivity at high temperature, these materials are used in solid oxide fuel cells (SOFC).

  15. Kinetic models of conjugated metabolic cycles

    Ershov, Yu. A.

    2016-01-01

    A general method is developed for the quantitative kinetic analysis of conjugated metabolic cycles in the human organism. This method is used as a basis for constructing a kinetic graph and model of the conjugated citric acid and ureapoiesis cycles. The results from a kinetic analysis of the model for these cycles are given.

  16. Combined cycles with gas turbine engines

    Najjar, Y.S.H.; Akyurt, M. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Mechanical Engineering Dept.)

    1994-03-01

    Simple cycle gas turbine engines suffer from limited efficiencies and consequential dominance of fuel prices on generation costs. Combined cycles, however. exploit the waste heat from exhaust gases to boost power output, resulting in overall efficiencies around 50%, which are significantly above those of steam power plants. This paper reviews various types of combined cycles, including repowering, integrated gasification and other advanced systems. (author)

  17. [The menstrual cycle in women with gonorrhea].

    Kuntsevich, L D

    1989-01-01

    Various abnormalities of the menstrual cycle have been revealed in 9.57% of the 763 patients with gonorrhea. When the disease takes a chronic course, a wider spectrum of the cycle abnormalities develops, because of hypoestrogenia characteristic of a prolonged course of a gonococcal infection. Menstrual cycle disorders are more frequent in the women with manifest gonorrhea.

  18. Dormancy cycling in seeds: mechanisms and regulation

    Claessens, S.M.C.

    2012-01-01

    The life cycle of most plants starts, and ends, at the seed stage. In most species mature seeds are shed and dispersed on the ground. At this stage of its life cycle the seed may be dormant and will, by definition, not germinate under favourable conditions (Bewley, 1997). Seasonal dormancy cycling

  19. The next generation of revenue cycle management.

    Hammer, David C

    2007-07-01

    The revenue cycle management environment is dynamic. Revenue cycle leaders are now responsible for additional functional areas and have to deal with new financing arrangements that expose the organization to greater financial risk. Financial managers can use key performance indicators and the suggested practice processes checklist to determine whether their revenue cycle operations are in good shape or need shaping up.

  20. Multiple Limit Cycles in an Immune System

    Xun-cheng Huang; Le-min Zhu; Minaya Villasana

    2008-01-01

    The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.

  1. Constructing Dense Graphs with Unique Hamiltonian Cycles

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  2. "Constructing" the Cell Cycle in 3D

    Koc, Isil; Turan, Merve

    2012-01-01

    The cycle of duplication and division, known as the "cell cycle," is the essential mechanism by which all living organisms reproduce. This activity allows students to develop an understanding of the main events that occur during the typical eukaryotic cell cycle mostly in the process of mitotic phase that divides the duplicated genetic material…

  3. On Acyclicity of Games with Cycles

    Andersson, Daniel; Gurvich, Vladimir; Hansen, Thomas Dueholm

    2009-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (digraphs) that may contain cycles. We obtain criteria of restricted improvement acyclicity (ri-acyclicity) in two cases: for n = 2 and for acyclic digraphs. We...

  4. Technology development life cycle processes.

    Beck, David Franklin

    2013-05-01

    This report and set of appendices are a collection of memoranda originally drafted in 2009 for the purpose of providing motivation and the necessary background material to support the definition and integration of engineering and management processes related to technology development. At the time there was interest and support to move from Capability Maturity Model Integration (CMMI) Level One (ad hoc processes) to Level Three. As presented herein, the material begins with a survey of open literature perspectives on technology development life cycles, including published data on %E2%80%9Cwhat went wrong.%E2%80%9D The main thrust of the material presents a rational expose%CC%81 of a structured technology development life cycle that uses the scientific method as a framework, with further rigor added from adapting relevant portions of the systems engineering process. The material concludes with a discussion on the use of multiple measures to assess technology maturity, including consideration of the viewpoint of potential users.

  5. Social Life Cycle Assessment Revisited

    Ruqun Wu

    2014-07-01

    Full Text Available To promote the development of Social Life Cycle Assessment (SLCA, we conducted a comprehensive review of recently developed frameworks, methods, and characterization models for impact assessment for future method developers and SLCA practitioners. Two previous reviews served as our foundations for this review. We updated the review by including a comprehensive list of recently-developed SLCA frameworks, methods and characterization models. While a brief discussion from goal, data, and indicator perspectives is provided in Sections 2 to 4 for different frameworks/methods, the focus of this review is Section 5 where discussion on characterization models for impact assessment of different methods is provided. The characterization models are categorized into two types following the UNEP/SETAC guidelines: type I models without impact pathways and type II models with impact pathways. Different from methods incorporating type I/II characterization models, another LCA modeling approach, Life Cycle Attribute Assessment (LCAA, is also discussed in this review. We concluded that methods incorporating either type I or type II models have limitations. For type I models, the challenge lies in the systematic identification of relevant stakeholders and materiality issues; while for type II models, identification of impact pathways that most closely and accurately represent the real-world causal relationships is the key. LCAA may avoid these problems, but the ultimate questions differ from those asked by the methods using type I and II models.

  6. Limit cycle behaviour in FELIX

    Jaroszynski, D. A.; Bakker, R. J.; Oepts, D.; van der Meer, A. F. G.; van Amersfoort, P. W.

    1993-07-01

    The free electron laser for infrared experiments (FELIX) operates at wavelengths up to λ = 110 μm. A radio-frequency linear accelerator is used to produce electron micropulses with a duration of about 3 ps. With N = 38 undulator periods, this puts FELIX well into the regime where the slippage length, Nλ, exceeds the electron micropulse length, and prominent short pulse effects are expected. One of these effects, stable limit cycle oscillations of the pulse energy, has not been detected experimentally before. Such oscillations occur when the saturated optical pulses move away from the electron pulses, due to the changing balance between lethargy and desynchronism, while new subpulses grow periodically. In FELIX, limit cycle behaviour is clearly demonstrated. The observations are in agreement with numerical simulations of the pulse propagation, and the oscillation period is given by a simple formula containing the slippage length and the desynchronism between optical and electron pulses. We also show how lethargic behaviour can be used to reduce the optical bandwidth of the FEL and to store optical energy in the optical cavity without saturation limiting the energy stored.

  7. Life Cycle Assessment of Concrete

    Sjunnesson, Jeannette

    2005-09-15

    This is an environmental study on concrete that follows the standard protocol of life cycle assessment (LCA). The study is done for two types of concrete, ordinary and frost-resistant concrete, and has an extra focus on the superplasticizers used as admixtures. The utilization phase is not included in this study since the type of construction for which the concrete is used is not defined and the concrete is assumed to be inert during this phase. The results show that it is the production of the raw material and the transports involved in the life cycle of concrete that are the main contributors to the total environmental load. The one single step in the raw material production that has the highest impact is the production of cement. Within the transportation operations the transportation of concrete is the largest contributor, followed by the transportation of the cement. The environmental impact of frost-resistant concrete is between 24-41 % higher than that of ordinary concrete due to its higher content of cement. Superplasticizers contribute with approximately 0.4-10.4 % of the total environmental impact of concrete, the least to the global warming potential (GWP) and the most to the photochemical ozone creation potential (POCP). Also the toxicity of the superplasticizers is investigated and the conclusion is that the low amount of leakage of superplasticizers from concrete leads to a low risk for the environment and for humans.

  8. MHD Integrated Topping Cycle Project

    1992-03-01

    The Magnetohydrodynamics (MHD) Integrated Topping Cycle (ITC) Project represents the culmination of the proof-of-concept (POC) development stage in the US Department of Energy (DOE) program to advance MHD technology to early commercial development stage utility power applications. The project is a joint effort, combining the skills of three topping cycle component developers: TRW, Avco/TDS, and Westinghouse. TRW, the prime contractor and system integrator, is responsible for the 50 thermal megawatt (50 MW{sub t}) slagging coal combustion subsystem. Avco/TDS is responsible for the MHD channel subsystem (nozzle, channel, diffuser, and power conditioning circuits), and Westinghouse is responsible for the current consolidation subsystem. The ITC Project will advance the state-of-the-art in MHD power systems with the design, construction, and integrated testing of 50 MW{sub t} power train components which are prototypical of the equipment that will be used in an early commercial scale MHD utility retrofit. Long duration testing of the integrated power train at the Component Development and Integration Facility (CDIF) in Butte, Montana will be performed, so that by the early 1990's, an engineering data base on the reliability, availability, maintainability and performance of the system will be available to allow scaleup of the prototypical designs to the next development level. This Sixteenth Quarterly Technical Progress Report covers the period May 1, 1991 to July 31, 1991.

  9. Produtividade e eficiência econômica de sistemas de produção de cria, recria e engorda de bovinos de corte na região sul do estado da Bahia Economic efficiency and productivity of life-cycle beef cattle production systems in the South of Bahia

    F.A. Barbosa

    2010-06-01

    Full Text Available Estudaram-se a produtividade e a eficiência econômica de quatro sistemas de bovinos de corte, por meio de simulação, que diferiram quanto à taxa de natalidade (TN. A pesquisa foi realizada em uma fazenda de ciclo completo (SCC com TN de 87%, e mais três sistemas simulados: -4TN com TN de 83%; -2TN com TN de 85%; e +2TN com TN de 89%. O SCC foi baseado em dados de um sistema de cria, recria e engorda com média de 3.453 cabeças, localizado no sul da Bahia, no período de janeiro de 2000 a dezembro de 2002. As TN foram ajustadas à demanda energética dos animais em cada sistema e à evolução do rebanho durante três anos. A quantidade de carne vendida foi de 149, 146, 144, 141 kg/ha/ano para -4TN, -2TN, SCC e +2TN, respectivamente. O lucro total acumulado, na mesma ordem de citação, foi de R$780.695,42; R$737.526,16; R$727.031,52 e R$703.907,58. O retorno do capital investido acumulado foi de 7,8; 7,4; 7,3 e 7,0% para -4 TN, -2TN, SCC e +2TN, respectivamente. A variação da TN na atividade de cria, recria e engorda de bovinos alterou a produtividade e a eficiência econômica dos sistemas simulados. As respostas em produtividade e eficiência econômica diminuíram com o aumento da taxa de natalidade.Economic efficiency and productivity of life-cycle cattle raising systems were studied by simulations that differed in calving rates (CR. The study was conducted on a life-cycle cattle production system (SCC with 87% CR, and three simulated systems: -4CR with 83% CR, -2CR with 85% CR, and +2CR with 89% CR. The SCC was based on data from a life-cycle cattle system of 3,453 animals in the South of Bahia State, from January 2000 to December 2002. CR was adjusted according to energy requirement and herd composition in SCC during three years. Meat amount sold was 149, 146, 144, and 141kg/ha/year for -4CR, -2CR, SCC, and +2CR, respectively. Accumulated profit and return on invested capital were R$ 780,695.42 and 7.8%; R$ 737,526.16 and 7.4%; R

  10. When Product Life Cycle Meets Customer Activity Cycle

    Tan, Adrian Ronald

    2007-01-01

    to shift market strategies from a transactional approach to an approach based on the establishment and management of customer relationships (Grönroos, 1999). A growing number of studies and research programmes have focused on the potentials of business strategies based on providing the value of utility...... project in a global office furniture manufacturer, this paper attempts to uncover how a manufacturing company is making the move from selling office furniture to selling the benefit of workspace performance. A significant insight is that the definition of value is core to both relationship marketing...... of products throughout their life cycle by designing integrated solutions of products and services. This approach has been dubbed ‘product/service-systems (PSS)’ (Mont, 2004). Although relationship marketing and product/service-system design have their roots in each their own research fields - marketing...

  11. [The M-cycle of crime].

    Antholz, Birger

    2012-01-01

    Crime development measured by means of the changes in police recorded crime statistics (criminal offences per 100.000 inhabitants) shows periodical cycles, which can be described by the capital letter M. Starting from a low rate of criminality, crime rises over 1-3 years followed by an interim decline lasting for about one year. Then crime increases again for approximately 2 years to a second peak. After that, crime strongly declines to the next low point over a period of about two years. The course of this development is not uniform with equal amplitudes, but resembles an M-curve. Since 1950, seven such M-cycles have been observed with the 3rd M-cycle from 1965-1973, the 4th M-cycle from 1973-1984, the 5th M-cycle from 1984-1994, the 6th M-cycle from 1994-2005 and the 7th M-cycle from 2005-2010 being particularly distinct. The M-curve of crime may be explained by the M-form of the business cycle. Since World War II, the M-cycle of crime and the M-cycle of the economy have run approximately parallel. Up to the first large oil crisis, the M-cycle of crime preceded the economic situation by 1-2 years, whereas since 1976 it has followed the economic development with a time lag of one to two years.

  12. VISION: Verifiable Fuel Cycle Simulation Model

    Jacob J. Jacobson; Abdellatif M. Yacout; Gretchen E. Matthern; Steven J. Piet; David E. Shropshire

    2009-04-01

    The nuclear fuel cycle is a very complex system that includes considerable dynamic complexity as well as detail complexity. In the nuclear power realm, there are experts and considerable research and development in nuclear fuel development, separations technology, reactor physics and waste management. What is lacking is an overall understanding of the entire nuclear fuel cycle and how the deployment of new fuel cycle technologies affects the overall performance of the fuel cycle. The Advanced Fuel Cycle Initiative’s systems analysis group is developing a dynamic simulation model, VISION, to capture the relationships, timing and delays in and among the fuel cycle components to help develop an understanding of how the overall fuel cycle works and can transition as technologies are changed. This paper is an overview of the philosophy and development strategy behind VISION. The paper includes some descriptions of the model and some examples of how to use VISION.

  13. Design and Fabrication of Eu-Cycle

    A.Venkat Sai

    2014-10-01

    Full Text Available EU-Cycle is a self balancing electric unicycle. A regular unicycle is powered by pedal and is balanced by a rider, whilst the EU-Cycle runs by an electric motor and balance by control system in the roll direction. The simple thing to do by rider is to lean forward for acceleration, to lean backward for braking. EU-Cycle is designed as to be a fast and portable means of transport among crowded area, home and office. Therefore, The EU-Cycle gives tough challenge to the unicycle. EU-Cycle has attracted print media including future stories in radio, television. Thus in addition to successful development of EU-Cycle in urban use, the project has to implement the EU-cycle as an educative device.

  14. Fuel Cycle System Analysis Handbook

    Steven J. Piet; Brent W. Dixon; Dirk Gombert; Edward A. Hoffman; Gretchen E. Matthern; Kent A. Williams

    2009-06-01

    This Handbook aims to improve understanding and communication regarding nuclear fuel cycle options. It is intended to assist DOE, Campaign Managers, and other presenters prepare presentations and reports. When looking for information, check here. The Handbook generally includes few details of how calculations were performed, which can be found by consulting references provided to the reader. The Handbook emphasizes results in the form of graphics and diagrams, with only enough text to explain the graphic, to ensure that the messages associated with the graphic is clear, and to explain key assumptions and methods that cause the graphed results. Some of the material is new and is not found in previous reports, for example: (1) Section 3 has system-level mass flow diagrams for 0-tier (once-through), 1-tier (UOX to CR=0.50 fast reactor), and 2-tier (UOX to MOX-Pu to CR=0.50 fast reactor) scenarios - at both static and dynamic equilibrium. (2) To help inform fast reactor transuranic (TRU) conversion ratio and uranium supply behavior, section 5 provides the sustainable fast reactor growth rate as a function of TRU conversion ratio. (3) To help clarify the difference in recycling Pu, NpPu, NpPuAm, and all-TRU, section 5 provides mass fraction, gamma, and neutron emission for those four cases for MOX, heterogeneous LWR IMF (assemblies mixing IMF and UOX pins), and a CR=0.50 fast reactor. There are data for the first 10 LWR recycle passes and equilibrium. (4) Section 6 provides information on the cycle length, planned and unplanned outages, and TRU enrichment as a function of fast reactor TRU conversion ratio, as well as the dilution of TRU feedstock by uranium in making fast reactor fuel. (The recovered uranium is considered to be more pure than recovered TRU.) The latter parameter impacts the required TRU impurity limits specified by the Fuels Campaign. (5) Section 7 provides flows for an 800-tonne UOX separation plant. (6) To complement 'tornado' economic

  15. The effect of turbo trainer cycling on pedalling technique and cycling efficiency.

    Arkesteijn, M; Hopker, J; Jobson, S A; Passfield, L

    2013-06-01

    Cycling can be performed on the road or indoors on stationary ergometers. The purpose of this study was to investigate differences in cycling efficiency, muscle activity and pedal forces during cycling on a stationary turbo trainer compared with a treadmill. 19 male cyclists cycled on a stationary turbo trainer and on a treadmill at 150, 200 and 250 W. Cycling efficiency was determined using the Douglas bags, muscle activity patterns were determined using surface electromyography and pedal forces were recorded with instrumented pedals. Treadmill cycling induced a larger muscular contribution from Gastrocnemius Lateralis, Biceps Femoris and Gluteus Maximus of respectively 14%, 19% and 10% compared with turbo trainer cycling (pcycling induced larger muscular contribution from Vastus Lateralis, Rectus Femoris and Tibialis Anterior of respectively 7%, 17% and 14% compared with treadmill cycling (pcycling was observed. These results suggest that cycling technique and type of ergometer can be altered without affecting cycling efficiency.

  16. Business cycles in oil economies

    Al-Mutairi, N.H.

    1991-01-01

    This study examines the impact of oil price shocks on output fluctuations of several oil-exporting economies. In most studies of business cycles, the role of oil price is ignored; the few studies that use oil price as one of the variables in the system focus on modeling oil-importing economies. The vector autoregression (VAR) technique is used to consider the cases of Norway, Nigeria, and Mexico. Both atheoretical and structural' VARs are estimated to determine the importance of oil price impulses on output variations. The study reports two types of results: variance decomposition and impulse response functions, with particular emphasis on the issues of stationarity and co-integration among the series. The empirical results suggest that shocks to oil price are important in explaining output variations. In most cases, shocks to oil price are shown to explain more than 20% of the forecast variance of output over a 40-quarter horizon.

  17. Thorium nuclear fuel cycle technology

    Eom, Tae Yoon; Do, Jae Bum; Choi, Yoon Dong; Park, Kyoung Kyum; Choi, In Kyu; Lee, Jae Won; Song, Woong Sup; Kim, Heong Woo

    1998-03-01

    Since thorium produces relatively small amount of TRU elements after irradiation in the reactor, it is considered one of possible media to mix with the elements to be transmuted. Both solid and molten-salt thorium fuel cycles were investigated. Transmutation concepts being studied involved fast breeder reactor, accelerator-driven subcritical reactor, and energy amplifier with thorium. Long-lived radionuclides, especially TRU elements, could be separated from spent fuel by a pyrochemical process which is evaluated to be proliferation resistance. Pyrochemical processes of IFR, MSRE and ATW were reviewed and evaluated in detail, regarding technological feasibility, compatibility of thorium with TRU, proliferation resistance, their economy and safety. (author). 26 refs., 22 figs

  18. Violence as a Vicious Cycle

    Huseyin Gulec

    2012-03-01

    Full Text Available Since the conclusion that the violence as a behavior is not (cannot be determined within an absolute genetic determinism has been reached for long years, environmental factors are increasingly examined. We witness that human behavior in society can easily convert into coping with stressful events with violence. Individual or social violence as a behavior has a similar pattern with violence committed in primitive society and by children. After a brief review of violence, its description, etiological theories and types, this article majorly focuses on children and their early and late response to violence. The purpose here is to draw attention to the individuals who were previously exposed to violence (either directly or indirectly resort to violence, perpetuating a vicious cycle.

  19. Custom formed orthoses in cycling.

    O'Neill, Brendan C; Graham, Kenneth; Moresi, Mark; Perry, Philip; Kuah, Donald

    2011-11-01

    To assess the effects of currently used prescribed in-shoe custom foot orthoses (CFOs) on a number of biomechanical variables during the power phase of cycling, including: hip adduction, knee abduction and tibial internal rotation. Before and after cross-over study recording subjects' biomechanical variables with and without their CFOs. Twelve competitive cyclists, currently using prescribed in-shoe CFOs, performed two exercise bouts on a stationary trainer, with 3-dimensional data recorded on an 8 camera Vicon Mx system. 2-way ANOVA statistical analysis of Null vs Orthotic condition, and left leg vs right leg. No systematic effects from the CFOs were seen. A trend towards reduced tibial internal rotation range of movement was found (Pcycling biomechanics. Significant subject-specific biomechanical effects can be produced by CFOs utilizing rearfoot and/or forefoot wedges. An individualised approach to orthotic prescription, and attention to the forefoot-rearfoot relationship, is recommended.

  20. Canard cycles in global dynamics

    Vidal, Alexandre

    2009-01-01

    Fast-slow systems are studied usually by "geometrical dissection". The fast dynamics exhibit attractors which may bifurcate under the influence of the slow dynamics which is seen as a parameter of the fast dynamics. A generic solution comes close to a connected component of the stable invariant sets of the fast dynamics. As the slow dynamics evolves, this attractor may lose its stability and the solution eventually reaches quickly another connected component of attractors of the fast dynamics and the process may repeat. This scenario explains quite well relaxation and bursting oscillations. More recently, in relation both with theory of dynamical systems and with applications to physiology, a new interest has emerged in canard cycles. These orbits share the property that they remain for a while close to an unstable invariant set (either singular set or periodic orbits of the fast dynamics). Although canards were first discovered when the transition points are folds, in this article, we focus on the case where...

  1. Ferroelectric Stirling-Cycle Refrigerator

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    1999-01-01

    A Stirling-cycle refrigerator has a three-pump configuration and pumping sequence, in which one pump serves as a compressor. one pump serves as an expander, and one pump serves as a displacer. The pumps are ferroelectrically actuated diaphragm pumps which are coordinated by synchronizing the ferroelectric-actuator voltages in such a way that the net effect of the displacer is to reduce the deleterious effect of dead space; that is, to circulate a greater fraction of the working fluid through the heat exchangers than would be possible by use of the compressor and expander alone. In addition. the displacer can be controlled separately to make the flow of working fluid in the heat exchangers turbulent (to increase the rate of transfer of heat at the cost of greater resistance to flow) or laminar (to decrease the resistance to flow at the cost of a lower heat-transfer rate).

  2. MHD Integrated Topping Cycle Project

    1992-07-01

    This seventeenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period August 1, 1991 to October 31, 1991. Manufacturing of the prototypical combustor pressure shell has been completed including leak, proof, and assembly fit checking. Manufacturing of forty-five cooling panels was also completed including leak, proof, and flow testing. All precombustor internal components (combustion can baffle and swirl box) were received and checked, and integration of the components was initiated. A decision was made regarding the primary and backup designs for the 1A4 channel. The assembly of the channel related prototypical hardware continued. The cathode wall electrical wiring is now complete. The mechanical design of the diffuser has been completed.

  3. Life cycle of cytosolic prions.

    Hofmann, Julia; Vorberg, Ina

    2013-01-01

    Prions are self-templating protein aggregates that were originally identified as the causative agent of prion diseases in mammals, but have since been discovered in other kingdoms. Mammalian prions represent a unique class of infectious agents that are composed of misfolded prion protein. Prion proteins usually exist as soluble proteins but can refold and assemble into highly ordered, self-propagating prion polymers. The prion concept is also applicable to a growing number of non-Mendelian elements of inheritance in lower eukaryotes. While prions identified in mammals are clearly pathogens, prions in lower eukaryotes can be either detrimental or beneficial to the host. Prion phenotypes in fungi are transmitted vertically from mother to daughter cells during cell division and horizontally during mating or abortive mating, but extracellular phases have not been reported. Recent findings now demonstrate that in a mammalian cell environment, protein aggregates derived from yeast prion domains exhibit a prion life cycle similar to mammalian prions propagated ex vivo. This life cycle includes a soluble state of the protein, an induction phase by exogenous prion fibrils, stable replication of prion entities, vertical transmission to progeny and natural horizontal transmission to neighboring cells. Our data reveal that mammalian cells contain all co-factors required for cytosolic prion propagation and dissemination. This has important implications for understanding prion-like properties of disease-related protein aggregates. In light of the growing number of identified functional amyloids, cell-to-cell propagation of cytosolic protein conformers might not only be relevant for the spreading of disease-associated proteins, but might also be of more general relevance under non-disease conditions.

  4. Prior muscular exercise affects cycling pattern.

    Bieuzen, F; Hausswirth, C; Couturier, A; Brisswalter, J

    2008-05-01

    The aim of this study was to investigate the effect of concentric or eccentric fatiguing exercise on cycling pattern. Eleven well trained cyclists completed three sessions of cycling (control cycling test [CTRL], cycling following concentric [CC] or eccentric [ECC] knee contractions) at a mean power of 276.8 +/- 26.6 Watts. Concentric and eccentric knee contractions were performed at a load corresponding to 80 % of one repetition maximum with both legs. Before and after CTRL, CC or ECC knee contractions and after cycling, a maximal voluntary contraction (MVC) test was performed. Cardiorespiratory, mechanical and electromyographic activity (EMG) of the rectus femoris, vastus lateralis and biceps femoris muscles were recorded during cycling. A significant decrease in MVC values was observed after CC and ECC exercises and after the cycling. ECC exercise induced a significant decrease in EMG root mean square during MVC and a decrease in pedal rate during cycling. EMG values of the three muscles were significantly higher during cycling exercise following CC exercise when compared to CTRL. The main finding of this study was that a prior ECC exercise induces a greater neuromuscular fatigue than a CC exercise, and changes in cycling pattern.

  5. Thermodynamic Analysis of Combined Cycle Power Plant

    A.K.Tiwari,

    2010-04-01

    Full Text Available Air Bottoming Cycle (ABC can replace the heat recovery steam generator and the steam turbine of the conventionalcombined cycle plant. The exhaust energy of the topping gas turbine of existing combine cycle is sent to gas-air heat exchange, which heats the air in the secondary gas turbine cycle. In 1980’s the ABC was proposed as an alternative for the conventional steam bottoming cycle. In spite of the cost of reducing hardware installations it could achieve a thermal efficiency of 80%. The complete thermodynamic analysis of the system has been performed by using specially designed programme, enabling the variation of main independent variables. The result shows the gain in net work output as well as efficiency of combined cycle is 35% to 68%.

  6. Short Time Cycles of Purely Quantum Refrigerators

    Feldmann, Tova

    2012-01-01

    Four stroke Otto refrigerator cycles with no classical analogue are studied. Extremely short cycle times with respect to the internal time scale of the working medium characterize these refrigerators. Therefore these cycles are termed sudden. The sudden cycles are characterized by the stable limit cycle which is the invariant of the global cycle propagator. During their operation the state of the working medium possesses significant coherence which is not erased in the equilibration segments due to the very short time allocated. This characteristic is reflected in a difference between the energy entropy and the Von Neumann entropy of the working medium. A classification scheme for sudden refrigerators is developed allowing simple approximations for the cooling power and coefficient of performance.

  7. Nuclear reactors and fuel cycle

    NONE

    2014-07-01

    fulfill its mission that is to contribute in improving the quality of life of the Brazilian people. The nuclear fuel cycle is a series of steps involved in the production and use of fuel for nuclear reactors. The Laboratories of Chemistry and Environmental Diagnosis Center, CQMA, support the demand of Nuclear Fuel Cycle Program providing chemical characterization of uranium compounds and other related materials. In this period the Research Reactor Center (CRPq) concentrated efforts on improving equipment and systems to enable the IEA-R1 research reactor to operate at higher power, increasing the capacity of radioisotopes production, samples irradiation, tests and experiments. (author)

  8. Life cycle of transformer oil

    Đurđević Ksenija R.

    2008-01-01

    Full Text Available The consumption of electric power is constantly increasing due to industrialization and population growth. This results in much more severe operating conditions of transformers, the most important electrical devices that make integral parts of power transmission and distribution systems. The designed operating life of the majority of worldwide transformers has already expired, which puts the increase of transformer reliability and operating life extension in the spotlight. Transformer oil plays a very important role in transformer operation, since it provides insulation and cooling, helps extinguishing sparks and dissolves gases formed during oil degradation. In addition to this, it also dissolves moisture and gases from cellulose insulation and atmosphere it is exposed to. Further and by no means less important functions of transformer are of diagnostic purpose. It has been determined that examination and inspection of insulation oil provide 70% of information on transformer condition, which can be divided in three main groups: dielectric condition, aged transformer condition and oil degradation condition. By inspecting and examining the application oil it is possible to determine the condition of insulation, oil and solid insulation (paper, as well as irregularities in transformer operation. All of the above-mentioned reasons and facts create ground for the subject of this research covering two stages of transformer oil life cycle: (1 proactive maintenance and monitoring of transformer oils in the course of utilization with reference to influence of transformer oil condition on paper insulation condition, as well as the condition of the transformer itself; (2 regeneration of transformer oils for the purpose of extension of utilization period and paper insulation revitalization potential by means of oil purification. The study highlights advantages of oil-paper insulation revitalization over oil replacement. Besides economic, there are

  9. The spatial dimension of cycle logistics

    Vitale Brovarone, Elisabetta; Staricco, Luca

    2016-01-01

    Cycle logistics is emerging as a promising alternative in urban freight transport. Compared to fossil fuelled vans, the use of cycles for delivering goods within urban areas offers advantages in terms of environmental friendliness, economic efficiency, flexibility, and liveability of urban neighbourhood. At the same time, cycle logistics has to face limits in terms of weight and volume of goods that can be delivered, distances that can be covered, and spatial urban structures that can be serv...

  10. Variants of closing the nuclear fuel cycle

    Andrianova, E. A.; Davidenko, V. D.; Tsibulskiy, V. F.; Tsibulskiy, S. V.

    2015-12-01

    Influence of the nuclear energy structure, the conditions of fuel burnup, and accumulation of new fissile isotopes from the raw isotopes on the main parameters of a closed fuel cycle is considered. The effects of the breeding ratio, the cooling time of the spent fuel in the external fuel cycle, and the separation of the breeding area and the fissile isotope burning area on the parameters of the fuel cycle are analyzed.

  11. Epigenetic dynamics across the cell cycle

    Kheir, Tony Bou; Lund, Anders H.

    2010-01-01

    Progression of the mammalian cell cycle depends on correct timing and co-ordination of a series of events, which are managed by the cellular transcriptional machinery and epigenetic mechanisms governing genome accessibility. Epigenetic chromatin modifications are dynamic across the cell cycle...... a correct inheritance of epigenetic chromatin modifications to daughter cells. In this chapter, we summarize the current knowledge on the dynamics of epigenetic chromatin modifications during progression of the cell cycle....

  12. Should We Rely on Intelligence Cycle?

    2015-01-01

    Intelligence cycle is a systematic process which is usually applied in order to obtain intelligence from raw data. Today the world has been experiencing dazzling changes on many fields as well as technology. With the help of the new emerging technologies the data that have to be handled for intelligence is much more than ever. In addition to new technological contributions, there are discussions about intelligence cycle whether it’s being out-dated and old fashioned. Intelligence cycle was ma...

  13. Policy paper no. 1 : Pedestrians and cycling

    Zbogar, H. [City of Brampton, ON (Canada)

    2004-06-01

    The City of Brampton's Transportation and Transit Master Plan includes a workable plan to promote walking and cycling facilities in the area. This paper reviewed existing policies, programs and practices in the City of Brampton that pertain to cycling and walking. Walking and cycling issues and trends were also reviewed with reference to the principles that improve the pedestrian and cycling environment, such as safety, security, convenience, continuity, comfort, coherence and attractiveness. The recreation, health and fitness benefits of walking and cycling were also outlined along with transportation, environmental, and economic benefits. The official plan for the city was included with reference to walking and cycling sections in the city. It was noted that effective pathways should be customer driven and respond to the needs of residents. They should also accommodate all uses, including walking, jogging, cycling and in-line skating. Experience of other jurisdictions in Ontario in providing walking and cycling facilities were also reviewed. It was noted that walking and cycling are significant elements of an intermodal transportation system and have a strong bearing on a city's vision for urban street design. 11 refs., 2 tabs., 3 figs.

  14. Combined rankine and vapor compression cycles

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  15. Open cycle cooling systems using solar energy

    Lazzarin, R.; Sovrano, M.

    Open cycle cooling systems are particularly suitable for utilizing solar energy. In all these systems the adsorption and absorption phenomena are very important, hence they are described separately. The cycles used are essentially two: the Baum-Kakabaev cycle using liquid absorbers and the dehumidification/humidification cycle where also adsorbent substances can be utilized. Solar energy is used in the regeneration process of dehumidifying substances. Reactivation modes can be various: suitability of one mode or the other can depend on the climate of the site where the system is installed.

  16. Irreversible cycle in linear irreversible thermodynamics

    Wang, Xian-Zhi

    2010-10-01

    The reversible Carnot cycle in reversible thermodynamics is composed of two reversible heat exchange processes and two reversible adiabatic processes. We construct an irreversible cycle in linear irreversible thermodynamics by analogy with the reversible Carnot cycle. The irreversible cycle is composed of two linear irreversible heat exchange processes and two linear irreversible adiabatic processes. It is found that the Curzon-Alhborn efficiency can be attained if the power for each of the four linear irreversible processes reaches its maximum. The maximum efficiency is the Carnot efficiency. The strong coupling condition is prerequisite for the respective attainment of the Curzon-Alhborn efficiency and the Carnot efficiency.

  17. Nonlinear solar cycle forecasting: theory and perspectives

    A. L. Baranovski

    2008-02-01

    Full Text Available In this paper we develop a modern approach to solar cycle forecasting, based on the mathematical theory of nonlinear dynamics. We start from the design of a static curve fitting model for the experimental yearly sunspot number series, over a time scale of 306 years, starting from year 1700 and we establish a least-squares optimal pulse shape of a solar cycle. The cycle-to-cycle evolution of the parameters of the cycle shape displays different patterns, such as a Gleissberg cycle and a strong anomaly in the cycle evolution during the Dalton minimum. In a second step, we extract a chaotic mapping for the successive values of one of the key model parameters – the rate of the exponential growth-decrease of the solar activity during the n-th cycle. We examine piece-wise linear techniques for the approximation of the derived mapping and we provide its probabilistic analysis: calculation of the invariant distribution and autocorrelation function. We find analytical relationships for the sunspot maxima and minima, as well as their occurrence times, as functions of chaotic values of the above parameter. Based on a Lyapunov spectrum analysis of the embedded mapping, we finally establish a horizon of predictability for the method, which allows us to give the most probable forecasting of the upcoming solar cycle 24, with an expected peak height of 93±21 occurring in 2011/2012.

  18. Back Work Ratio of Brayton Cycle

    Malaver de la Fuente M.

    2010-07-01

    Full Text Available This paper analizes the existing relation between temperatures, back work ratio and net work of Brayton cycle, a cycle that describes gas turbine engines performance. The application of computational soft ware helps to show the influence of back work ratio or coupling ratio, compressor and turbine in let temperatures in an ideal thermodynamical cycle. The results lead to deduce that the maximum value reached in back work ratio will depend on the ranges of maximum and minimal temperatures of Brayton cycle.

  19. Aromatase inhibitors in stimulated IVF cycles

    Papanikolaou, Evangelos G; Polyzos, Nikolaos P; Humaidan, Peter;

    2011-01-01

    are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears...... to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels....

  20. Cycle slipping in phase synchronization systems

    Yang, Ying; Huang, Lin

    2007-02-01

    Cycle slipping is a characteristically nonlinear phenomenon in phase synchronization systems, which is highly dependent of the initial state of the system. Slipping a cycle means that the phase error is increased to such an extent that the generator to be synchronized slips one complete cycle with respect to the input phase. In this Letter, a linear matrix inequality (LMI) based approach is proposed and the estimation of the number of cycles which slips a solution of the system is obtained by solving a quasi-convex optimization problem of LMI. Applications to phase locked loops demonstrate the validity of the proposed approach.

  1. Kalina cycle. Thermodynamic principles and feasibility

    Gajewski, W.; Lezuo, A.; Nuernberg, R.; Rukes, B.; Vesper, H.

    1989-05-01

    The Kalina cycle belongs to the group of absorption cycles. It is operated with the two substances H/sub 2/O/NH/sub 3/. For combined gas- and steam power plants using the Kalina retrofit cycle in place of the normal water/steam cycle an increase in efficiency by about 2 to 3 percentage points can be expected. The advantage in efficiency contrasts with the high additional expenditure in capital costs. In addition operating difficulties as a result of partial decomposition of the ammonia are to be expected.

  2. An integrated life cycle inventory for demolition processes in the context of life cycle sustainability assessment

    Bozhilova-Kisheva, Kossara Petrova; Hu, Mingming; van Roekel, Eric

    2012-01-01

    According to the Life Cycle Assessment in Building and Construction: State-of-the-Art Report (2003), the dismantling and demolition stage of the building life cycle is only sometimes included in the Life Cycle Inventory (LCI) when doing Life Cycle Assessments (LCA). The reason that it is less...... inventoried in a traditional LCA maybe because this stage is expected to have a negligible environmental impact comparing to other stages in the life cycle of the buildings. When doing a life cycle sustainability assessment considering not only environmental but also economic and social impacts, the impacts...

  3. Mercury cycling in terrestrial watersheds

    Shanley, James B.; Bishop, Kevin; Banks, Michael S.

    2012-01-01

    This chapter discusses mercury cycling in the terrestrial landscape, including inputs from the atmosphere, accumulation in soils and vegetation, outputs in streamflow and volatilization, and effects of land disturbance. Mercury mobility in the terrestrial landscape is strongly controlled by organic matter. About 90% of the atmospheric mercury input is retained in vegetation and organic matter in soils, causing a buildup of legacy mercury. Some mercury is volatilized back to the atmosphere, but most export of mercury from watersheds occurs by streamflow. Stream mercury export is episodic, in association with dissolved and particulate organic carbon, as stormflow and snowmelt flush organic-rich shallow soil horizons. The terrestrial landscape is thus a major source of mercury to downstream aquatic environments, where mercury is methylated and enters the aquatic food web. With ample organic matter and sulfur, methylmercury forms in uplands as well—in wetlands, riparian zones, and other anoxic sites. Watershed features (topography, land cover type, and soil drainage class) are often more important than atmospheric mercury deposition in controlling the amount of stream mercury and methylmercury export. While reductions in atmospheric mercury deposition may rapidly benefit lakes, the terrestrial landscape will respond only over decades, because of the large stock and slow turnover of legacy mercury. We conclude with a discussion of future scenarios and the challenge of managing terrestrial mercury.

  4. MHD Integrated Topping Cycle Project

    1992-02-01

    This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the proposed anode design are presented. Sidewall confirmation tests, which were used to select the proposed gas-side design, were conducted. The design for the full scale CDIF system was completed. A test program was initiated to investigate the practicality of using Avco current controls for current consolidation in the power takeoff (PTO) regions and to determine the cause of past current consolidation failures. Another important activity was the installation of 1A4-style coupons in the 1A1 channel. A description of the coupons and their location with 1A1 channel is presented herein.

  5. Material Flows and Carbon Cycles

    Worrell, E.

    2003-12-01

    The industrial sector emits almost 43 percent of the global anthropogenic carbon dioxide emissions to produce materials and products. Furthermore, energy is used to move materials and products and process the waste. Hence, a large amount of energy is consumed and CO2 is emitted to sustain our materials system. Until recently, studies investigating mitigation options focused on changes in the energy system. For industrial processes most studies evaluate how the current materials system can be maintained producing fewer greenhouse gas emissions. Three elements of a strategy to improve the long-term materials productivity are the reduction of dissipative uses of non-biodegradable materials, secondly, the re-design of products to use less material or design for re-use or recycling, and thirdly, develop more efficient technologies for material conversion and recycling. This will reduce or eliminate the need to extract virgin materials from the environment, and reduce CO2 emissions from the energy-intensive production processes. To assess measures to reduce materials consumption, fossil fuels consumption and CO2 emissions, detailed understanding of the material system is needed. The lifecycle of materials has to be investigated including all branches of industry with all the inputs and outputs. We start with a discussion of materials and the carbon cycle focusing on the contribution of materials to anthropogenic carbon flows. We discuss CO2 emissions from energy use in materials extraction and production, fossil (e.g. plastics) and biomass carbon (e.g. lumber, paper) used as feedstock of materials, and mineral sources (e.g. cement). We discuss opportunities to reduce CO2 emissions by improving the efficiency with which society uses materials through product design, material substitution, product reuse and material recycling.

  6. Science Illiteracy: Breaking the Cycle

    Lebofsky, L. A.; Lebofsky, N. R.

    2003-12-01

    At the University of Arizona, as at many state universities and colleges, the introductory science classes for non-science majors may be the only science classes that future K--8 teachers will take. The design of the UA's General Education program requires all future non-science certified teachers to take the General Education science classes. These classes are therefore an ideal venue for the training of the state's future teachers. Many students, often including future teachers, are ill-prepared for college, i.e., they lack basic science content knowledge, basic mathematics skills, and reading and writing skills. They also lack basic critical thinking skills and study skills. It is within this context that our future teachers are trained. How do we break the cycle of science illiteracy? There is no simple solution, and certainly not a one-size-fits-all panacea that complements every professor's style of instruction. However, there are several programs at the University of Arizona, and also principles that I apply in my own classes, that may be adaptable in other classrooms. Assessment of K--12 students' learning supports the use of inquiry-based science instruction. This approach can be incorporated in college classes. Modeling proven and productive teaching methods for the future teachers provides far more than ``just the facts,'' and all students gain from the inquiry approach. Providing authentic research opportunities employs an inquiry-based approach. Reading (outside the textbook) and writing provide feedback to students with poor writing and critical thinking skills. Using peer tutors and an instant messaging hot line gives experience to the tutors and offers "comfortable" assistance to students.

  7. The terrestrial uranium isotope cycle.

    Andersen, Morten B; Elliott, Tim; Freymuth, Heye; Sims, Kenneth W W; Niu, Yaoling; Kelley, Katherine A

    2015-01-15

    Changing conditions on the Earth's surface can have a remarkable influence on the composition of its overwhelmingly more massive interior. The global distribution of uranium is a notable example. In early Earth history, the continental crust was enriched in uranium. Yet after the initial rise in atmospheric oxygen, about 2.4 billion years ago, the aqueous mobility of oxidized uranium resulted in its significant transport to the oceans and, ultimately, by means of subduction, back to the mantle. Here we explore the isotopic characteristics of this global uranium cycle. We show that the subducted flux of uranium is isotopically distinct, with high (238)U/(235)U ratios, as a result of alteration processes at the bottom of an oxic ocean. We also find that mid-ocean-ridge basalts (MORBs) have (238)U/(235)U ratios higher than does the bulk Earth, confirming the widespread pollution of the upper mantle with this recycled uranium. Although many ocean island basalts (OIBs) are argued to contain a recycled component, their uranium isotopic compositions do not differ from those of the bulk Earth. Because subducted uranium was probably isotopically unfractionated before full oceanic oxidation, about 600 million years ago, this observation reflects the greater antiquity of OIB sources. Elemental and isotope systematics of uranium in OIBs are strikingly consistent with previous OIB lead model ages, indicating that these mantle reservoirs formed between 2.4 and 1.8 billion years ago. In contrast, the uranium isotopic composition of MORB requires the convective stirring of recycled uranium throughout the upper mantle within the past 600 million years.

  8. Preliminary Modelling Results for an Otto Cycle/Stirling Cycle Hybrid-engine-based Power Generation System

    Cullen, Barry; McGovern, Jim; Feidt, Michel; Petrescu, Stoian

    2009-01-01

    This paper presents preliminary data and results for a system mathematical model for a proposed Otto Cycle / Stirling Cycle hybrid-engine-based power generation system. The system is a combined cycle system with the Stirling cycle machine operating as a bottoming cycle on the Otto cycle exhaust. The application considered is that of a stationary power generation scenario wherein the Stirling cycle engine operates as a waste heat recovery device on the exhaust stream of the Otto cycle engine. ...

  9. 25 MeV Solar Proton Events in Cycle 24 and Previous Cycles

    Richardson, I. G.; Cane, H. V.; von Rosenvinge, T. T.

    2014-12-01

    We summarize observations of nearly 1000 solar energetic particle events that include 25 MeV protons made by Goddard instruments on various spacecraft (IMPs IV, V, 7, 8, ISEE-3) and by other instruments on SOHO, since 1967, encompassing solar cycles 20 to 24. We also include recent observations of such events from the STEREO spacecraft. These extended observations place studies focusing on Cycles 23 and 24 in a broader context. For example, the time distribution of 25 MeV proton events varies from cycle to cycle such that each cycle is unique. In the current cycle, ~25 MeV proton events were absent during the preceding solar minimum, whereas earlier minima showed occasional, often reasonably intense events, and there have been, so far, fewer exceptionally intense events compared to Cycles 22 and 23, though Cycle 21 also apparently lacked such events.

  10. How people with low vision cycle safely

    Jelijs, Bart; Melis-Dankers, Bart; de Waard, Dick; Heutink, Jochem

    2015-01-01

    In the Netherlands, the ability to cycle safely and responsibly is important for independent mobility across the lifespan. In addition, cycling can be important in maintaining physical health. But when can a visually challenged person use a bicycle safely? Opinions vary, but there are no reliable -

  11. Synchronisation of the reproductive cycle in pigs

    Hazeleger, W.; Kirkwood, R.N.; Soede, N.M.

    2001-01-01

    An outline of procedures to synchronise oestrus and ovulation in pigs is described. The oestrus cycle of pigs can be synchronised depending on the stage of the reproductive cycle of these animals. Non-cyclic gilts shortly before puberty, can easily be synchronised by treatments with a mixture of 400

  12. Supermarket Defrost Cycles As Flexible Reserve

    Pedersen, Rasmus; Sloth, Christoffer; Wisniewski, Rafal

    2015-01-01

    This work analyses how supermarket defrost cycles can be used as flexible reserve in a smart grid context. The consumption flexibility originates from being able to shift defrost cycles in time, while adhering to the underlying refrigeration systems constraints. It is shown how this time constrai...

  13. General framework for bridge life cycle design

    Junhai MA; Airong CHEN; Jun HE

    2009-01-01

    Based on a detailed illustration for bridge life cycle design which comprises the processes of service life design, aesthetics design, performance design, environ-mental and ecological design, inspection, maintenance and repair design as well as cost analysis, this paper presented a general framework for bridge life cycle design comprising three design phases and six design processes.

  14. LIFE CYCLE ASSESSMENT: PRINCIPLES AND PRACTICE

    The following document provides an introductory overview of Life Cycle Assessment (LCA) and describes the general uses and major components of LCA. This document is an update and merger of two previous EPA documents on LCA ("Life Cycle Assessment: Inventory Guidelines and Princip...

  15. Nash-Williams’ cycle-decomposition theorem

    Thomassen, Carsten

    2016-01-01

    We give an elementary proof of the theorem of Nash-Williams that a graph has an edge-decomposition into cycles if and only if it does not contain an odd cut. We also prove that every bridgeless graph has a collection of cycles covering each edge at least once and at most 7 times. The two results...

  16. Nationally Appropriate Mitigation Action: Understanding NAMA Cycle

    Sharma, Sudhir; Desgain, Denis DR

    There is no internationally defined or agreed Nationally Appropriate Mitigation Action(NAMA) cycle, as was the case, for example, with the Clean Development Mechanisms (CDM) project cycle. However, there are some common steps that NAMA identification, formulation, and implementation will all go...

  17. Removing Preconceptions with a "Learning Cycle."

    Gang, Su

    1995-01-01

    Describes a teaching experiment that uses the Learning Cycle to achieve the reorientation of physics' students conceptual frameworks away from commonsense perspectives toward scientifically rigorous outlooks. Uses Archimedes' principle as the content topic while using the Learning Cycle to remove students' nonscientific preconceptions. (JRH)

  18. Finite Feedback Cycling in Structural Equation Models

    Hayduk, Leslie A.

    2009-01-01

    In models containing reciprocal effects, or longer causal loops, the usual effect estimates assume that any effect touching a loop initiates an infinite cycling of effects around that loop. The real world, in contrast, might permit only finite feedback cycles. I use a simple hypothetical model to demonstrate that if the world permits only a few…

  19. Integrating hospital and physician revenue cycle operations.

    Lockett, Kevin M

    2014-03-01

    Standardized revenue cycle processes should be a key component of the coordinated care delivery strategy organizations will require to complete the transition to population health management. Integrating hospital and physician revenue cycle operations can help organizations better navigate new payment models, reduce costs, and improve value. The most comprehensive approach involves integrating patient access and registration, coding operations, and receivables management across different settings.

  20. What makes a physician revenue cycle tick.

    Freeman, Thomas; Stephen, Stan

    2011-09-01

    Hospitals should boost the revenue cycle performance of acquired physician practices by: Effectively assimilating the physician practice into the overall organization. Standardizing revenue cycle processes, policies, and tools between the hospital and physician practice. Enhancing physician/patient scheduling policies and procedures. Regularly auditing physician documentation and periodically comparing hospital charges against practice charges. Improving procedures for responding to denials.

  1. Uncertainty Analyses of Advanced Fuel Cycles

    Laurence F. Miller; J. Preston; G. Sweder; T. Anderson; S. Janson; M. Humberstone; J. MConn; J. Clark

    2008-12-12

    The Department of Energy is developing technology, experimental protocols, computational methods, systems analysis software, and many other capabilities in order to advance the nuclear power infrastructure through the Advanced Fuel Cycle Initiative (AFDI). Our project, is intended to facilitate will-informed decision making for the selection of fuel cycle options and facilities for development.

  2. Thermal Cycle Lifetest of Swaged Cathode Heaters

    Polk, Jay; Ramesham, Rajeshuni

    2007-01-01

    This viewgraph presentation reviews the thermal cycling test for the Dawn mission. The flight system, the mission requirements, and the Ion Propulsion System (IPS) are shown. The Dawn mission requires periodic thruster shutdown for data transmission and coast periods. The thermal cycling test is designed to simulate approximately three complete mission profiles. The results of the tests are reviewed.

  3. Some Graphs Containing Unique Hamiltonian Cycles

    Lynch, Mark A. M.

    2002-01-01

    In this paper, two classes of graphs of arbitrary order are described which contain unique Hamiltonian cycles. All the graphs have mean vertex degree greater than one quarter the order of the graph. The Hamiltonian cycles are detailed, their uniqueness proved and simple rules for the construction of the adjacency matrix of the graphs are given.…

  4. Effective risk management SOGO life cycle management

    Ali, Mohamed Omar

    2012-01-01

    After new or upgrade projects the offshore installation gets maintenance or support through the life cycle management organization at Siemens. Small to medium modification projects are executed by the life cycle management. Risk assessment on these projects show different risks when it comes to estimation and pricing of projects, planning and executing, resource management, competence and knowledge.

  5. Nature's third cycle a story of sunspots

    Choudhuri, Arnab Rai

    2015-01-01

    The cycle of day and night and the cycle of seasons are two familiar natural cycles around which many human activities are organized. But is there a third natural cycle of importance for us humans? On 13 March 1989, six million people in Canada went without electricity for many hours: a large explosion on the sun was discovered as the cause of this blackout. Such explosions occur above sunspots, dark features on the surface of the Sun that have been observed through telescopes since the time of Galileo. The number of sunspots has been found to wax and wane over a period of 11 years. Although this cycle was discovered less than two centuries ago, it is becoming increasingly important for us as human society becomes more dependent on technology. For nearly a century after its discovery, the cause of the sunspot cycle remained completely shrouded in mystery. The 1908 discovery of strong magnetic fields in sunspots made it clear that the 11-year cycle is the magnetic cycle of the sun. It is only during the last ...

  6. Cycle-maximal triangle-free graphs

    Durocher, Stephane; Gunderson, David S.; Li, Pak Ching;

    2015-01-01

    Abstract We conjecture that the balanced complete bipartite graph K ⌊ n / 2 ⌋ , ⌈ n / 2 ⌉ contains more cycles than any other n -vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds...

  7. Few-optical-cycle dissipative solitons

    Leblond, H [Laboratoire de Photonique d' Angers EA 4464, Universite d' Angers, 2 Bd. Lavoisier, 49045 Angers Cedex 01 (France); Mihalache, D, E-mail: herve.leblond@univ-angers.f [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor, Magurele-Bucharest, 077125 (Romania)

    2010-09-17

    By using a powerful reductive perturbation technique, or multiscale analysis, a generalized modified Korteweg-de Vries partial differential equation is derived, which describes the physics of few-optical-cycle dissipative solitons beyond the slowly varying envelope approximation. Numerical simulations of the formation of stable dissipative solitons from arbitrary breather-like few-cycle pulses are also given.

  8. Questions, Curiosity and the Inquiry Cycle

    Casey, Leo

    2014-01-01

    This article discusses the conceptual relationship between questions, curiosity and learning as inquiry elaborated in the work of Chip Bruce and others as the Inquiry Cycle. The Inquiry Cycle describes learning in terms of a continuous dynamic of ask, investigate, create, discuss and reflect. Of these elements "ask" has a privileged…

  9. Helioseismic Solar Cycle Changes and Splitting Coefficients

    S. C. Tripathy; Kiran Jain; A. Bhatnagar

    2000-09-01

    Using the GONG data for a period over four years, we have studied the variation of frequencies and splitting coefficients with solar cycle. Frequencies and even-order coefficients are found to change significantly with rising phase of the solar cycle. We also find temporal variations in the rotation rate near the solar surface.

  10. Associations between urban form and cycling

    Nielsen, Thomas Alexander Sick; Olafsson, Anton Stahl; Carstensen, Trine Agervig

    The bikeability project has analysed the environmental correlates of cycling based on Danish National Transportation Survey data transportation and urban form micro-data; and based on a smaller sample of primary data which included housing preferences, policy and attitude variables. Analysis...... on environmental features can be added to the set of influential environmental factors. Attractive conditions for using public transportation or walking are related to less cycling. Highly relevant in the context of the promotion of cycling, the results suggest different effects of urban form on the probability...... and residential preferences indicated that environmental/urban form correlations or impacts upon cycling persist even when attitudes and transportation preferences related to the choice of residence is taken into consideration. Attitudes/preferences seem to be highly important in explaining weekly cycling rates...

  11. Plutonium in an enduring fuel cycle

    Pillay, K.K.S.

    1998-05-01

    Nuclear fuel cycles evolved over the past five decades have allowed many nations of the world to enjoy the benefits of nuclear energy, while contributing to the sustainable consumption of the world`s energy resources. The nuclear fuel cycle for energy production suffered many traumas since the 1970s because of perceived risks of proliferation of nuclear weapons. However, the experience of the past five decades has shown that the world community is committed to safeguarding all fissile materials and continuing the use of nuclear energy resources. Decisions of a few nations to discard spent nuclear fuels in geologic formations are contrary to the goals of an enduring nuclear fuel cycle and sustainable development being pursued by the world community. The maintenance of an enduring nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including spent fuels.

  12. The glutamate/GABA-glutamine cycle

    Bak, Lasse K; Schousboe, Arne; Waagepetersen, Helle S

    2006-01-01

    Neurons are metabolically handicapped in the sense that they are not able to perform de novo synthesis of neurotransmitter glutamate and gamma-aminobutyric acid (GABA) from glucose. A metabolite shuttle known as the glutamate/GABA-glutamine cycle describes the release of neurotransmitter glutamate....... Discussions of stoichiometry, the relative role of glutamate vs. GABA and pathological conditions affecting the glutamate/GABA-glutamine cycling are presented. Furthermore, a section is devoted to the accompanying ammonia homeostasis of the glutamate/GABA-glutamine cycle, examining the possible means...... of intercellular transfer of ammonia produced in neurons (when glutamine is deamidated to glutamate) and utilized in astrocytes (for amidation of glutamate) when the glutamate/GABA-glutamine cycle is operating. A main objective of this review is to endorse the view that the glutamate/GABA-glutamine cycle must...

  13. Cycle 23 Variation in Solar Flare Productivity

    Hudson, Hugh; McTiernan, Jim

    2014-01-01

    The NOAA listings of solar flares in cycles 21-24, including the GOES soft X-ray magnitudes, enable a simple determination of the number of flares each flaring active region produces over its lifetime. We have studied this measure of flare productivity over the interval 1975-2012. The annual averages of flare productivity remained approximately constant during cycles 21 and 22, at about two reported M or X flares per region, but then increased significantly in the declining phase of cycle 23 (the years 2004-2005). We have confirmed this by using the independent RHESSI flare catalog to check the NOAA events listings where possible. We note that this measure of solar activity does not correlate with the solar cycle. The anomalous peak in flare productivity immediately preceded the long solar minimum between cycles 23 and 24.

  14. Life-cycle assessment of semiconductors

    Boyd, Sarah B

    2012-01-01

    Life-Cycle Assessment of Semiconductors presents the first and thus far only available transparent and complete life cycle assessment of semiconductor devices. A lack of reliable semiconductor LCA data has been a major challenge to evaluation of the potential environmental benefits of information technologies (IT). The analysis and results presented in this book will allow a higher degree of confidence and certainty in decisions concerning the use of IT in efforts to reduce climate change and other environmental effects. Coverage includes but is not limited to semiconductor manufacturing trends by product type and geography, unique coverage of life-cycle assessment, with a focus on uncertainty and sensitivity analysis of energy and global warming missions for CMOS logic devices, life cycle assessment of flash memory and life cycle assessment of DRAM. The information and conclusions discussed here will be highly relevant and useful to individuals and institutions. The book also: Provides a detailed, complete a...

  15. Cycles and Clustering in Multiplex Networks

    Baxter, Gareth J; Dorogovtsev, Sergey N; Mendes, José F F

    2016-01-01

    In multiplex networks, cycles cannot be characterized only by their length, as edges may occur in different layers in different combinations. We define a classification of cycles by the number of edges in each layer and the number of switches between layers. We calculate the expected number of cycles of each type in the configuration model of a large sparse multiplex network. Our method accounts for the full degree distribution including correlations between degrees in different layers. In particular, we obtain the numbers of cycles of length 3 of all possible types. Using these, we give a complete set of clustering coefficients and their expected values. We show that correlations between the degrees of a vertex in different layers strongly affect the number of cycles of a given type, and the number of switches between layers. Both increase with assortative correlations and are strongly decreased by disassortative correlations. The effect of correlations on clustering coefficients is equally pronounced.

  16. Income inequality and the business cycle

    Shahee Mostafa

    2015-01-01

    Full Text Available This paper first examines the relationship between ordinary least squares estimators of consumption and investment for 36 selected countries with their respective Gini indices. The analysis shows that income inequality is consistent with a smaller estimator of consumption and a greater estimator of investment. Second, the cycles of GDP, consumption and investment are dated separately to determine how the deepness and duration of cycles of those variables are correlated with the Gini indices of countries. The results show that income inequality leads to a deeper and longer decline of GDP, which causes a greater cumulative income loss of GDP during recession, and a somewhat faster speed of recovery during expansion. Likewise, the result of a correlation between Gini indices and the number of cycles in consumption, investment and GDP indicate that income inequality is associated with a greater number of cycles in consumption and GDP and a lower number of cycles in investment.

  17. NiH2 Cycle Life Study

    Hollandsworth, Roger P.; Armantrout, Jon D.; Rao, Gopalakrishna M.

    2002-01-01

    Cycle life studies have been performed at Eagle Picher Technologies (EPT), on HST Mantech design cells with various pedigrees of slurry and dry sinter processed electrodes, to evaluate peak load voltage performance during generic load profile testing. These tests provide information for determining voltage and capacity fade (degradation) mechanisms, and their impact on nickel hydrogen cell cycle life. Comparison of peak load voltage fade, as a function of State of Charge and cycle life, with capacity data from HST indicates that the cycle life limiting mechanism is due to impedance growth, and formation of a second discharge plateau. With a second plateau on discharge, capacity from the cell is still available, but at an unacceptable low voltage of 0.8 V per cell (17.6 V battery). Data shows that cell impedance increases with cycle number and depth of discharge, as expected.

  18. A comparison of advanced heat recovery power cycles in a combined cycle for large ships

    Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

    2014-01-01

    Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus in...

  19. Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

    Greene, William D. (Inventor)

    2008-01-01

    A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

  20. The spatial dimension of cycle logistics

    Luca Staricco

    2016-08-01

    Full Text Available Cycle logistics is emerging as a promising alternative in urban freight transport. Compared to fossil fuelled vans, the use of cycles for delivering goods within urban areas offers advantages in terms of environmental friendliness, economic efficiency, flexibility, and liveability of urban neighbourhood. At the same time, cycle logistics has to face limits in terms of weight and volume of goods that can be delivered, distances that can be covered, and spatial urban structures that can be served. This latter issue has till now received less attention in the scientific literature: it is generally recognized that cycle logistics performs at its best in inner urban areas, but no systematic study has been realized to identify specific spatial requisites for the effectiveness of cycle logistics. This paper provides a brief review of the main issues that emerge from the literature over cycle logistics, and contributes to stimulate the debate over the spatial dimension of cycle logistics: it presents a classification of cycle logistics schemes, on the basis of their integration with other urban logistic facilities and of the spatial structure of delivery operations. A three-level classification is proposed, depending on the type of goods consolidation: only distribution without consolidation, consolidation in a fixed urban consolidation centre, or consolidation in a mobile depot; for each level, operational examples and case studies are provided. This systematizing typology could support both public and private operators in decisions about the organization of cycle logistics facilities, such as the location of urban consolidation centres or the composition of cycle fleets.

  1. The timing of the cognitive cycle.

    Tamas Madl

    Full Text Available We propose that human cognition consists of cascading cycles of recurring brain events. Each cognitive cycle senses the current situation, interprets it with reference to ongoing goals, and then selects an internal or external action in response. While most aspects of the cognitive cycle are unconscious, each cycle also yields a momentary "ignition" of conscious broadcasting. Neuroscientists have independently proposed ideas similar to the cognitive cycle, the fundamental hypothesis of the LIDA model of cognition. High-level cognition, such as deliberation, planning, etc., is typically enabled by multiple cognitive cycles. In this paper we describe a timing model LIDA's cognitive cycle. Based on empirical and simulation data we propose that an initial phase of perception (stimulus recognition occurs 80-100 ms from stimulus onset under optimal conditions. It is followed by a conscious episode (broadcast 200-280 ms after stimulus onset, and an action selection phase 60-110 ms from the start of the conscious phase. One cognitive cycle would therefore take 260-390 ms. The LIDA timing model is consistent with brain evidence indicating a fundamental role for a theta-gamma wave, spreading forward from sensory cortices to rostral corticothalamic regions. This posteriofrontal theta-gamma wave may be experienced as a conscious perceptual event starting at 200-280 ms post stimulus. The action selection component of the cycle is proposed to involve frontal, striatal and cerebellar regions. Thus the cycle is inherently recurrent, as the anatomy of the thalamocortical system suggests. The LIDA model fits a large body of cognitive and neuroscientific evidence. Finally, we describe two LIDA-based software agents: the LIDA Reaction Time agent that simulates human performance in a simple reaction time task, and the LIDA Allport agent which models phenomenal simultaneity within timeframes comparable to human subjects. While there are many models of reaction time

  2. Pipeline bottoming cycle study. Final report

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  3. Fuel cell hybrid taxi life cycle analysis

    Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

    2011-09-15

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  4. Cell cycle gene expression under clinorotation

    Artemenko, Olga

    2016-07-01

    Cyclins and cyclin-dependent kinase (CDK) are main regulators of the cell cycle of eukaryotes. It's assumes a significant change of their level in cells under microgravity conditions and by other physical factors actions. The clinorotation use enables to determine the influence of gravity on simulated events in the cell during the cell cycle - exit from the state of quiet stage and promotion presynthetic phase (G1) and DNA synthesis phase (S) of the cell cycle. For the clinorotation effect study on cell proliferation activity is the necessary studies of molecular mechanisms of cell cycle regulation and development of plants under altered gravity condition. The activity of cyclin D, which is responsible for the events of the cell cycle in presynthetic phase can be controlled by the action of endogenous as well as exogenous factors, but clinorotation is one of the factors that influence on genes expression that regulate the cell cycle.These data can be used as a model for further research of cyclin - CDK complex for study of molecular mechanisms regulation of growth and proliferation. In this investigation we tried to summarize and analyze known literature and own data we obtained relatively the main regulators of the cell cycle in altered gravity condition.

  5. Heat driven refrigeration cycle at low temperatures

    HE Yijian; HONG Ronghua; CHEN Guangming

    2005-01-01

    Absorption refrigeration cycle can be driven by low-grade thermal energy, such as solar energy, geothermal energy and waste heat. It is beneficial to save energy and protect environment. However, the applications of traditional absorption refrigeration cycle are greatly restricted because they cannot achieve low refrigeration temperature. A new absorption refrigeration cycle is investigated in this paper, which is driven by low-grade energy and can get deep low refrigeration temperature. The mixture refrigerant R23+R134a and an absorbent DMF are used as its working fluid. The theoretical results indicate that the new cycle can achieve -62℃ refrigeration temperature when the generation temperature is only 160℃. This refrigeration temperature is much lower than that obtained by traditional absorption refrigeration cycle. Refrigeration temperature of -47.3℃ has been successfully achieved by experiment for this new cycle at the generation temperature of 157℃, which is the lowest temperature obtained by absorption refrigeration system reported in the literature up to now. The theoretical and experimental results prove that new cycle can achieve rather low refrigeration temperature.

  6. Performance of an irreversible quantum refrigeration cycle

    He Ji-Zhou; Ouyang Wei-Pin; Wu Xin

    2006-01-01

    A new model of a quantum refrigeration cycle composed of two adiabatic and two isomagnetic field processes is established. The working substance in the cycle consists of many non-interacting spin-1/2 systems. The performance of the cycle is investigated, based on the quantum master equation and semi-group approach. The general expressions of several important performance parameters, such as the coefficient of performance, cooling rate, and power input, are given. It is found that the coefficient of performance of this cycle is in the closest analogy to that of the classical Carnot cycle. Furthermore, at high temperatures the optimal relations of the cooling rate and the maximum cooling rate are analysed in detail. Some performance characteristic curves of the cycle are plotted, such as the cooling rate versus the maximum ratio between high and low "temperatures" of the working substances, the maximum cooling rate versus the ratio between high and low "magnetic fields" and the "temperature" ratio between high and low reservoirs. The obtained results are further generalized and discussed, so that they may be directly applied to describing the performance of the quantum refrigerator using spin-J systems as the working substance. Finally, the optimum characteristics of the quantum Carnot and Ericsson refrigeration cycles are derived by analogy.

  7. Performance comparison of magnetic refrigeration cycles

    Chen, F.C.; Chen, G.L.; Murphy, R.W.; Mei, V.C.

    1990-01-01

    Magnetic refrigeration has been used for cryogenic cooling at temperatures near absolute zero for many years. In these cases, a single-step adiabatic demagnetization method that does not provide continuous refrigeration is commonly used. The possibilities of providing continuous cooling through magnetic refrigeration cycles and of extending the range of applications above near-absolute-zero temperatures have been investigated only in recent years. This paper reports the results of a parametric performance study of three magnetic refrigeration cycles using four rare-earth magnetic materials operating near their respective Curie temperatures. The thermodynamic cycles employed are the magnetic-equivalent Carnot, Ericsson, and ideal regenerative cycles, and the four magnetic materials are terbium, holmium, erbium, and thulium. Our findings show that the Carnot cycle is not possible for cases of temperature lift beyond 10 K for a magnetic field variation of Tesla, that the performance and capacity of an ideal regenerative cycle are higher than that of the corresponding Ericsson cycle, and that the magnetocaloric effects of erbium and thulium seem to be too weak for practical applications. 14 refs., 14 figs.

  8. Waste Stream Analyses for Nuclear Fuel Cycles

    N. R. Soelberg

    2010-08-01

    A high-level study was performed in Fiscal Year 2009 for the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) Advanced Fuel Cycle Initiative (AFCI) to provide information for a range of nuclear fuel cycle options (Wigeland 2009). At that time, some fuel cycle options could not be adequately evaluated since they were not well defined and lacked sufficient information. As a result, five families of these fuel cycle options are being studied during Fiscal Year 2010 by the Systems Analysis Campaign for the DOE NE Fuel Cycle Research and Development (FCRD) program. The quality and completeness of data available to date for the fuel cycle options is insufficient to perform quantitative radioactive waste analyses using recommended metrics. This study has been limited thus far to qualitative analyses of waste streams from the candidate fuel cycle options, because quantitative data for wastes from the front end, fuel fabrication, reactor core structure, and used fuel for these options is generally not yet available.

  9. Nucleosome architecture throughout the cell cycle.

    Deniz, Özgen; Flores, Oscar; Aldea, Martí; Soler-López, Montserrat; Orozco, Modesto

    2016-01-28

    Nucleosomes provide additional regulatory mechanisms to transcription and DNA replication by mediating the access of proteins to DNA. During the cell cycle chromatin undergoes several conformational changes, however the functional significance of these changes to cellular processes are largely unexplored. Here, we present the first comprehensive genome-wide study of nucleosome plasticity at single base-pair resolution along the cell cycle in Saccharomyces cerevisiae. We determined nucleosome organization with a specific focus on two regulatory regions: transcription start sites (TSSs) and replication origins (ORIs). During the cell cycle, nucleosomes around TSSs display rearrangements in a cyclic manner. In contrast to gap (G1 and G2) phases, nucleosomes have a fuzzier organization during S and M phases, Moreover, the choreography of nucleosome rearrangements correlate with changes in gene expression during the cell cycle, indicating a strong association between nucleosomes and cell cycle-dependent gene functionality. On the other hand, nucleosomes are more dynamic around ORIs along the cell cycle, albeit with tighter regulation in early firing origins, implying the functional role of nucleosomes on replication origins. Our study provides a dynamic picture of nucleosome organization throughout the cell cycle and highlights the subsequent impact on transcription and replication activity.

  10. Sustainability Features of Nuclear Fuel Cycle Options

    Stefano Passerini

    2012-09-01

    Full Text Available The nuclear fuel cycle is the series of stages that nuclear fuel materials go through in a cradle to grave framework. The Once Through Cycle (OTC is the current fuel cycle implemented in the United States; in which an appropriate form of the fuel is irradiated through a nuclear reactor only once before it is disposed of as waste. The discharged fuel contains materials that can be suitable for use as fuel. Thus, different types of fuel recycling technologies may be introduced in order to more fully utilize the energy potential of the fuel, or reduce the environmental impacts and proliferation concerns about the discarded fuel materials. Nuclear fuel cycle systems analysis is applied in this paper to attain a better understanding of the strengths and weaknesses of fuel cycle alternatives. Through the use of the nuclear fuel cycle analysis code CAFCA (Code for Advanced Fuel Cycle Analysis, the impact of a number of recycling technologies and the associated fuel cycle options is explored in the context of the U.S. energy scenario over 100 years. Particular focus is given to the quantification of Uranium utilization, the amount of Transuranic Material (TRU generated and the economics of the different options compared to the base-line case, the OTC option. It is concluded that LWRs and the OTC are likely to dominate the nuclear energy supply system for the period considered due to limitations on availability of TRU to initiate recycling technologies. While the introduction of U-235 initiated fast reactors can accelerate their penetration of the nuclear energy system, their higher capital cost may lead to continued preference for the LWR-OTC cycle.

  11. The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24

    Solheim, Jan-Erik; Humlum, Ole

    2012-01-01

    Relations between the length of a sunspot cycle and the average temperature in the same and the next cycle are calculated for a number of meteorological stations in Norway and in the North Atlantic region. No significant trend is found between the length of a cycle and the average temperature in the same cycle, but a significant negative trend is found between the length of a cycle and the temperature in the next cycle. This provides a tool to predict an average temperature decrease of at least 1.0 "C from solar cycle 23 to 24 for the stations and areas analyzed. We find for the Norwegian local stations investigated that 25-56% of the temperature increase the last 150 years may be attributed to the Sun. For 3 North Atlantic stations we get 63-72% solar contribution. This points to the Atlantic currents as reinforcing a solar signal.

  12. Cardiac Biomarkers and Cycling Race

    Caroline Le Goff, Jean-François Kaux, Sébastien Goffaux, Etienne Cavalier

    2015-06-01

    Full Text Available In cycling as in other types of strenuous exercise, there exists a risk of sudden death. It is important both to understand its causes and to see if the behavior of certain biomarkers might highlight athletes at risk. Many reports describe changes in biomarkers after strenuous exercise (Nie et al., 2011, but interpreting these changes, and notably distinguishing normal physiological responses from pathological changes, is not easy. Here we have focused on the kinetics of different cardiac biomarkers: creatin kinase (CK, creating kinase midbrain (CK-MB, myoglobin (MYO, highly sensitive troponin T (hs-TnT and N-terminal brain natriuretic peptide (NT-proBNP. The population studied was a group of young trained cyclists participating in a 177-km cycling race. The group of individuals was selected for maximal homogeneity. Their annual training volume was between 10,000 and 16,000 kilometers. The rhythm of races is comparable and averages 35 km/h, depending on the race’s difficulty. The cardiac frequency was recorded via a heart rate monitor. Three blood tests were taken. The first blood test, T0, was taken approximately 2 hours before the start of the race and was intended to gather values which would act as references for the following tests. The second blood test, T1, was realized within 5 minutes of their arrival. The third and final blood test, T3, was taken 3 hours following their arrival. The CK, CK-MB, MYO, hs-TnT and NT-proBNP were measured on the Roche Diagnostic modular E (Manhein, Germany. For the statistical analysis, an ANOVA and post hoc test of Scheffé were calculated with the Statistica Software version 9.1. We noticed an important significant variation in the cardiac frequency between T0 and T1 (p < 0.0001, T0 and T3 (p < 0.0001, and T1 and T3 (p < 0.01. Table 1 shows the results obtained for the different biomarkers. CK and CK-MB showed significant variation between T0-T1 and T0-T3 (p < 0.0001. Myoglobin increased significantly

  13. International Nuclear Fuel Cycle Fact Book

    Leigh, I.W.; Patridge, M.D.

    1991-05-01

    As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source of information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained in the International Nuclear Fuel Cycle Fact Book has been obtained from many unclassified sources: nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECN/NEA activities reports; not reflect any one single source but frequently represent a consolidation/combination of information.

  14. Globalisation of the nuclear fuel cycle

    Rougeau, J.-P.; Durret, L.-F.

    1995-12-31

    Three main features of the globalisation of the nuclear fuel cycle are identified and discussed. The first is an increase in the scale of the nuclear fuel cycle materials and services markets in the past 20 years. This has been accompanied by a growth in the sophistication of the fuel cycle. Secondly, the nuclear industry is now more vulnerable to outside pressures; it is no longer possible to make strategic decisions on the industry within a country solely on national considerations. Thirdly, there are changes in the decision-making process at the political, regulatory, operational and industrial level which are the consequence of global factors. (UK).

  15. Closed power cycles thermodynamic fundamentals and applications

    Invernizzi, Costante Mario

    2013-01-01

    With the growing attention to the exploitation of renewable energies and heat recovery from industrial processes, the traditional steam and gas cycles are showing themselves often inadequate. The inadequacy is due to the great assortment of the required sizes power and of the large kind of heat sources. Closed Power Cycles: Thermodynamic Fundamentals and Applications offers an organized discussion about the strong interaction between working fluids, the thermodynamic behavior of the cycle using them and the technological design aspects of the machines. A precise treatment of thermal engines op

  16. Fission Yeast Cell Cycle Synchronization Methods.

    Tormos-Pérez, Marta; Pérez-Hidalgo, Livia; Moreno, Sergio

    2016-01-01

    Fission yeast cells can be synchronized by cell cycle arrest and release or by size selection. Cell cycle arrest synchronization is based on the block and release of temperature-sensitive cell cycle mutants or treatment with drugs. The most widely used approaches are cdc10-129 for G1; hydroxyurea (HU) for early S-phase; cdc25-22 for G2, and nda3-KM311 for mitosis. Cells can also be synchronized by size selection using centrifugal elutriation or a lactose gradient. Here we describe the methods most commonly used to synchronize fission yeast cells.

  17. Recent developments in Life Cycle Assessment

    Finnveden, Göran; Hauschild, Michael Zwicky; Ekvall, Tomas

    2009-01-01

    Life Cycle Assessment is a tool to assess the environmental impacts and resources used throughout a product’s life cycle, i.e., from raw material acquisition, via production and use phases, to waste management. The methodological development in LCA has been strong, and LCA is broadly applied...... on Life Cycle Impact Assessment we discuss the characteristics of the modelling as well as some recent developments for specific impact categories and weighting. In relation to the Interpretation the focus is on uncertainty analysis. Finally, we discuss recent developments in relation to some...

  18. Correspondence Between Astronomical Periods and Sedimentary Cycles

    Cheng Rihui; You Haitao

    2000-01-01

    It is shown from detailed study that there are some genetic relationships between outer events of celestial bodies and inner geological events of the earth, such as some kinds of correspondences between astronomical periods and sedimentary cycles. The time spans of movement periods of the solar system around the center of the galaxy and cross the plain of the galaxy, the periods of the earth orbit (Milankovitch period) and periods of sunspot are coincided with that of respective sedimentary cycles. It is suggested that the gravity and magnetic changes of the earth leading up to the global climatic and sea level changes are the dynamics of sedimentary cycles.

  19. Cycle-maximal triangle-free graphs

    Durocher, Stephane; Gunderson, David S.; Li, Pak Ching

    2015-01-01

    Abstract We conjecture that the balanced complete bipartite graph K ⌊ n / 2 ⌋ , ⌈ n / 2 ⌉ contains more cycles than any other n -vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds...... on the numbers of cycles in graphs depending on numbers of vertices and edges, girth, and homomorphisms to small fixed graphs; and use the bounds to show that among regular graphs, the conjecture holds. We also consider graphs that are close to being regular, with the minimum and maximum degrees differing...

  20. Blender cycles lighting and rendering cookbook

    Iraci, Bernardo

    2013-01-01

    An in-depth guide full of step-by-step recipes to explore the concepts behind the usage of Cycles. Packed with illustrations, and lots of tips and tricks; the easy-to-understand nature of the book will help the reader understand even the most complex concepts with ease.If you are a digital artist who already knows your way around Blender, and you want to learn about the new Cycles' rendering engine, this is the book for you. Even experts will be able to pick up new tips and tricks to make the most of the rendering capabilities of Cycles.

  1. Comparison of Gas-Turbine Cycles for Space Applications

    English, Robert E.; Slone, Henry O.

    1960-01-01

    On the basis of the radiator area required for rejecting cycle waste heat, Rankine vapor cycles are far superior to the basic Brayton gas cycle for space turbogenerating powerplants. The present analysis considers modifications of the basic Brayton cycle and compares the modified cycles to the basic cycle with radiator area as the criterion of merit. The results indicate that reductions in radiator area attainable by modifying the basic Brayton cycle are small, and thus the competitive position of gasturbine cycles relative to Rankine vapor cycles is unchanged.

  2. Free Energy and Internal Combustion Engine Cycles

    Harris, William D

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  3. Structures closed into cycles in globular proteins.

    Efimov, A V

    2011-12-01

    Different types of structures closed into cycles are widespread at all the levels of structural organization of proteins. β-Hairpins, triple-stranded β-sheets, and βαβ-units represent simple structural motifs closed into cycles by systems of hydrogen bonds. Secondary closing of these simple motifs into larger cycles by means of different superhelices, split β-hairpins, or SS-bridges results in formation of complex structural motifs such as abcd-units, φ-motifs, five- and seven-segment α/β-motifs, etc. At the level of tertiary structure many proteins and domains fold into structures closed into cylinders. Apparently, closing the motifs and domains into cycles and cylinders results in formation of more cooperative and stable structures as compared with open ones, and this may be the reason for high frequencies of occurrence of the motifs in proteins.

  4. Solar Wind Variation with the Cycle

    I. S. Veselovsky; A. V. Dmitriev; A. V. Suvorova; M. V. Tarsina

    2000-09-01

    The cyclic evolution of the heliospheric plasma parameters is related to the time-dependent boundary conditions in the solar corona. "Minimal" coronal configurations correspond to the regular appearance of the tenuous, but hot and fast plasma streams from the large polar coronal holes. The denser, but cooler and slower solar wind is adjacent to coronal streamers. Irregular dynamic manifestations are present in the corona and the solar wind everywhere and always. They follow the solar activity cycle rather well. Because of this, the direct and indirect solar wind measurements demonstrate clear variations in space and time according to the minimal, intermediate and maximal conditions of the cycles. The average solar wind density, velocity and temperature measured at the Earth's orbit show specific decadal variations and trends, which are of the order of the first tens per cent during the last three solar cycles. Statistical, spectral and correlation characteristics of the solar wind are reviewed with the emphasis on the cycles.

  5. The glacial cycles and cosmic rays

    Kirkby, Jasper; Müller, R A

    2004-01-01

    The cause of the glacial cycles remains a mystery. The origin is widely accepted to be astronomical since paleoclimatic archives contain strong spectral components that match the frequencies of Earth's orbital modulation. Milankovitch insolation theory contains similar frequencies and has become established as the standard model of the glacial cycles. However, high precision paleoclimatic data have revealed serious discrepancies with the Milankovitch model that fundamentally challenge its validity and re-open the question of what causes the glacial cycles. We propose here that the ice ages are initially driven not by insolation cycles but by cosmic ray changes, probably through their effect on clouds. This conclusion is based on a wide range of evidence, including results presented here on speleothem growth in caves in Austria and Oman, and on a record of cosmic ray flux over the past 220 kyr obtained from the 10Be composition of deep-ocean sediments.

  6. Reversible Carnot cycle outside a black hole

    Deng Xi-Hao; Gao Si-Jie

    2009-01-01

    A Carnot cycle outside a Schwarzschild black hole is investigated in detail. We propose a reversible Carnot cycle with a black hole being the cold reservoir. In our model, a Carnot engine operates between a hot reservoir with temperature T1 and a black hole with Hawking temperature Th. By naturally extending the ordinary Carnot cycle to the black hole system, we show that the thermal efficiency for a reversible process can reach the maximal efficiency 1-TH/T1 Consequently, black holes can be used to determine the thermodynamic temperature by means of the Carnot cycle. The role of the atmosphere around the black hole is discussed. We show that the thermal atmosphere provides a necessary mechanism to make the process reversible.

  7. Presentation of a modified double reheat cycle

    Kjaer, Sven; Drinhaus, Frank [DONG ENERGY A/S, Frederica (Denmark)

    2008-07-01

    It may be concluded that the Master Cycle offers an excellent opportunity to gain a heat rate improvement in the range of 3% (or an efficiency improvement in the range of 1(1)/(2) %- point) at economic viable capital cost compared with a single reheat cycle. Furthermore, there is no impact on the thermal flexibility of the plant and the erosion and corrosion problems of the last stages of the LP-turbines disappear. Most technical departments of the turbine companies we have talked with recognise the new ideas of the Master cycle but the market departments are still asking for the market possibilities. Therefore, despite of many technical advantages the success of the Master Cycle can only be guaranteed if other power generators than DONG Energy show their interest, and we hereby strongly encourage those power generators being interested in improving efficiencies of coal-fired power generation to contact us and we will share our experiences with you. (orig.)

  8. Rapid Update Cycle (RUC) [13 km

    National Oceanic and Atmospheric Administration, Department of Commerce — The Rapid Update Cycle (RUC) weather forecast model was developed by the National Centers for Environmental Prediction (NCEP). On May 1, 2012, the RUC was replaced...

  9. Rapid Update Cycle (RUC) [20 km

    National Oceanic and Atmospheric Administration, Department of Commerce — The Rapid Update Cycle (RUC) weather forecast model was developed by the National Centers for Environmental Prediction (NCEP). On May 1, 2012, the RUC was replaced...

  10. Developing the Social Life Cycle Assessment

    Jørgensen, Andreas

    This thesis seeks to add to the development of the Social Life Cycle Assessment (SLCA), which can be defined as an assessment method for assessing the social impacts connected to the life cycle of a product, service or system. In such development it is important to realise that the SLCA is only...... appealing to the extent that it does what it is supposed to do. In this thesis, this goal of SLCA is defined as to support improvements of the social conditions for the stakeholders throughout the life cycle of the assessed product, system or service. This effect should arise through decision makers......, it was also shown that the companies’ ability to obtain data throughout their products’ life cycles was very limited, for example because suppliers were unwilling to hand over this information to the companies or because the goods were bought on open markets furnished by a large number of unidentified...

  11. Solar Cycle 24: is the peak coming?

    Sello, Stefano

    2012-01-01

    Solar cycle activity forecasting, mainly its magnitude and timing, is an essential issue for numerous scientific and technological applications: in fact, during an active solar period, many strong eruptions occur on the Sun with increasing frequency, such as flares, coronal mass ejections, high velocity solar wind photons and particles, which can severely affect the Earth's ionosphere and the geomagnetic field, with impacts on the low atmosphere. Thus it is very important to develop reliable solar cycle prediction methods for the incoming solar activity. The current solar cycle 24 appeared unusual from many points of view: an unusually extended minimum period, and a global low activity compared to those of the previous three or four cycles. Currently, there are many different evidences that the peak in the northern hemisphere already occurred at 2011.6 but not yet in the southern hemisphere. In this brief note we update the peak prediction and its timing, based on the most recent observations.

  12. Demographic cycles, cohort size, and earnings.

    Berger, M C

    1989-05-01

    This article examines whether position in the demographic cycle is an important factor in determining earnings and earnings growth. Earnings equations for white males are estimated by using March Current Population Survey data. Position in the demographic cycle is captured by including both measures of own cohort size and the size of surrounding cohorts in the estimated earnings equations. Position in the demographic cycle matters. Increases in own cohort size lead to flatter earnings profiles, whereas increases in the size of surrounding cohorts are associated with steeper earnings profiles. The net effect is that those who enter the labor market before or after the peak of the demographic cycle start out with lower earnings but experience faster earnings growth. This pattern is uniform across all schooling groups: high school dropouts, high school graduates, those with some college, and college graduates.

  13. Developing mathematical practices through reflection cycles

    Reinholz, Daniel L.

    2016-09-01

    This paper focuses on reflection in learning mathematical practices. While there is a long history of research on reflection in mathematics, it has focused primarily on the development of conceptual understanding. Building on notion of learning as participation in social practices, this paper broadens the theory of reflection in mathematics learning. To do so, it introduces the concept of reflection cycles. Each cycle begins with prospective reflection, which guides one's actions during an experience, and ends with retrospective reflection, which consolidates the experience and informs the next reflection cycle. Using reflection cycles as an organizing framework, this paper synthesizes the literature on reflective practices at a variety of levels: (1) metacognition, (2) self-assessment, (3) noticing, and (4) lifelong learning. These practices represent a spectrum of reflection, ranging from the micro level (1) to macro level (4).

  14. Cycle 22 COS/NUV Fold Distribution

    Wheeler, T.; Welty, A.

    2016-09-01

    We summarize the Cycle 22 COS/NUV Fold Distribution for the Cosmic Origins Spectrograph's (COS) MAMA detector on the Hubble Space Telescope. The detector micro-channel plate's health state is determined and the results are presented.

  15. Capacity fade of Sony 18650 cells cycled at elevated temperatures. Part I. Cycling performance

    Ramadass, P.; Haran, Bala; White, Ralph; Popov, Branko N.

    The capacity fade of Sony 18650 Li-ion cells increases with increase in temperature. After 800 cycles, the cells cycled at RT and 45 °C showed a capacity fade of 30 and 36%, respectively. The cell cycled at 55 °C showed a capacity loss of about 70% after 490 cycles. The rate capability of the cells continues to decrease with cycling. Impedance measurements showed an overall increase in the cell resistance with cycling and temperature. Impedance studies of the electrode materials showed an increased positive electrode resistance when compared to that of the negative electrode for cells cycled at RT and 45 °C. However, cells cycled at 50 and 55 °C exhibit higher negative electrode resistance. The increased capacity fade for the cells cycled at high temperatures can be explained by taking into account the repeated film formation over the surface of anode, which results in increased rate of lithium loss and also in a drastic increase in the negative electrode resistance with cycling.

  16. African primary care research: Quality improvement cycles

    Claire Van Deventer

    2014-01-01

    Full Text Available Improving the quality of clinical care and translating evidence into clinical practice is commonly a focus of primary care research. This article is part of a series on primary care research and outlines an approach to performing a quality improvement cycle as part of a research assignment at a Masters level. The article aims to help researchers design their quality improvement cycle and write their research project proposal.

  17. African primary care research: quality improvement cycles.

    van Deventer, Claire; Mash, Bob

    2014-04-24

    Improving the quality of clinical care and translating evidence into clinical practice is commonly a focus of primary care research. This article is part of a series on primary care research and outlines an approach to performing a quality improvement cycle as part of a research assignment at a Masters level. The article aims to help researchers design their quality improvement cycle and write their research project proposal.

  18. Gitz Cycling - Lancering af et nyt brand

    Priisholm Petersen, Andreas; Borch Jacobsen, Adam

    2014-01-01

    This project seeks to answer the struggles that an upcoming business can face, when approaching an existing market. This also includes the many aspects they might face when launching a new brand. This is done through a case study of the company Gitz Cycling. They have a new offer to the cycling market - an exclusive brand and design. Upon their entrance to the existing market, they have planned to market themselves through social media. Therefore this paper will also evolve around what proble...

  19. Life Cycle Assessment of Slurry Management Technologies

    Wesnæs, Marianne; Wenzel, Henrik; Petersen, Bjørn Molt

    This report contains the results of Life Cycle Assessments of two slurry management technologies - acidification and decentred incineration. The LCA foundation can be used by the contributing companies for evaluating the environmental sustainability of a specific technology from a holistic Life...... Cycle perspective. Through this the companies can evaluate the environmental benefits and disadvantages of introducing a specific technology for slurry management. From a societal perspective the results can contribute to a clarification of which slurry management technologies (or combination...

  20. Evolution of the global phosphorus cycle

    Reinhard, Christopher T.; Noah J. Planavsky; Gill, Benjamin C.; Ozaki, Kazumi; Robbins, Leslie J.; Lyons, Timothy W.; Fischer, Woodward W.; Wang, Chunjiang; Cole, Devon B.; Konhauser, Kurt O.

    2016-01-01

    The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth’s history and therefore whether the phosphorus cycle has consistently modulated biospheric productivity and ocean–atmosphere oxygen levels over time. Here we present a compilation o...

  1. Cycles through subsets with large degree sums

    Broersma, Hajo; Li, Hao; Li, Jianping; Tian, Feng; Veldman, Henk Jan

    1997-01-01

    Let G be a 2-connected graph on n vertices and let X V(G). We say that G is X-cyclable if G has an X-cycle, i.e., a cycle containing all vertices of X. We denote by ¿(X) the maximum number of pairwise nonadjacent vertices in the subgraph G[X] of G induced by X. If G[X] is not complete, we denote by

  2. Applications of mathematical models of road cycling

    Dahmen, Thorsten; Saupe, Dietmar; Wolf, Stefan

    2012-01-01

    This contribution discusses several use cases of mathematical models for road cycling. A mechanical model for the pedaling forces is the basis for an accurate indoor ergometer simulation of road cycling on real-world tracks. Together with a simple physiological model for the exertion of the athlete as a function of his/her accumulated power output, an optimal riding strategy for time trials on mountain ascents is computed. A combination of the two models leads to a mathematical optimization p...

  3. Spatial placement of state cycling routes

    Milovanović, Klemen

    2009-01-01

    The national strategy and the traffic policy stimulate the development of unmotorized traffic, cycling infrastructure and the use of bicycles wherever possible. Regarding state interests, traffic engineer expert opinion and community involvment, the first draft of state cycling routes network was presented. Due to the document's merely informative nature, detailed spatial palacement studies are necessary. The main object of this Graduation Thesis is to define a detailed course,...

  4. Trusted Computing Exemplar: Life Cycle Management Plan

    2014-12-12

    Informal “An informal specification is written as prose in natural language...(e.g., Dutch, English, French, German). An informal specification is not...informal) prose . The restricted syntax language may be a natural language with restricted sentence structure and keywords with special meaning, or it may...accompanied by supporting explanatory (informal) prose .” [4] TCX: Life Cycle Management Plan NPS-CAG-14-002 4 2 Life Cycle Phases and Activities

  5. The demographic cycle and optimal schooling choices.

    Jeon, B P; Berger, M C

    1996-10-01

    A model is developed that enables the authors to estimate the effects of demographic cycles on both earnings and schooling. The model is tested using data from the 1991 Korean Occupational Wage Survey. The results indicate that cohorts following large birth cohorts in the cycle choose relatively less formal schooling compared to pre-peak cohorts, and that post-peak cohorts also have lower incomes. This result concerning South Korea is consistent with findings from previous studies concerning the United States.

  6. Strategies for successful revenue cycle outsourcing.

    Lisowski, Duane A; Sanderson, Brian

    2013-09-01

    Revenue cycle outsourcing can offer hospitals and health systems many advantages, including cost savings and revenue gains, but it also carries risks. Some organizations may choose to outsource revenue cycle to third-party service providers; others may opt to develop internal centers of excellence. Hospitals and health systems should consider IT system compatibility, payment arrangements, and incentive and value alignment when selecting an outsourcing partner.

  7. Statistical tests of simple earthquake cycle models

    DeVries, Phoebe M. R.; Evans, Eileen L.

    2016-12-01

    A central goal of observing and modeling the earthquake cycle is to forecast when a particular fault may generate an earthquake: a fault late in its earthquake cycle may be more likely to generate an earthquake than a fault early in its earthquake cycle. Models that can explain geodetic observations throughout the entire earthquake cycle may be required to gain a more complete understanding of relevant physics and phenomenology. Previous efforts to develop unified earthquake models for strike-slip faults have largely focused on explaining both preseismic and postseismic geodetic observations available across a few faults in California, Turkey, and Tibet. An alternative approach leverages the global distribution of geodetic and geologic slip rate estimates on strike-slip faults worldwide. Here we use the Kolmogorov-Smirnov test for similarity of distributions to infer, in a statistically rigorous manner, viscoelastic earthquake cycle models that are inconsistent with 15 sets of observations across major strike-slip faults. We reject a large subset of two-layer models incorporating Burgers rheologies at a significance level of α = 0.05 (those with long-term Maxwell viscosities ηM 4.6 × 1020 Pa s) but cannot reject models on the basis of transient Kelvin viscosity ηK. Finally, we examine the implications of these results for the predicted earthquake cycle timing of the 15 faults considered and compare these predictions to the geologic and historical record.

  8. External cost assessment for nuclear fuel cycle

    Park, Byung Heung [Korea National University of Transportation, Chungju (Korea, Republic of); Ko, Won Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    Nuclear power is currently the second largest power supply method in Korea and the number of nuclear power plants are planned to be increased as well. However, clear management policy for spent fuels generated from nuclear power plants has not yet been established. The back-end fuel cycle, associated with nuclear material flow after nuclear reactors is a collection of technologies designed for the spent fuel management and the spent fuel management policy is closely related with the selection of a nuclear fuel cycle. Cost is an important consideration in selection of a nuclear fuel cycle and should be determined by adding external cost to private cost. Unlike the private cost, which is a direct cost, studies on the external cost are focused on nuclear reactors and not at the nuclear fuel cycle. In this research, external cost indicators applicable to nuclear fuel cycle were derived and quantified. OT (once through), DUPIC (Direct Use of PWR SF in CANDU), PWR-MOX (PWR PUREX reprocessing), and Pyro-SFR (SFR recycling with pyroprocessing) were selected as nuclear fuel cycles which could be considered for estimating external cost in Korea. Energy supply security cost, accident risk cost, and acceptance cost were defined as external cost according to precedent and estimated after analyzing approaches which have been adopted for estimating external costs on nuclear power generation.

  9. Evaporative cycles - in theory and in practise

    Rosen, P.M.

    2000-08-01

    The thesis is based on applied research, rather closed to industrial development. The developed simulation model, for pre-design of evaporative gas turbine cycles, has been validated in a 600 kW pilot plant and in rebuilt turbo-charged diesel engines. Besides of the work with the thesis including theoretical modelling and hardware development concerning wet cycles, the work has also resulted in three patents dealing with the technique studied. The main feature of the evaporative cycles is the way the integration between the gas and liquid flows is executed, combined with using low-level heat gathered into the liquid phase which is later used to evaporate the liquid itself in a humidification tower. In this tower, the mass- and heat transfer take place under stable physical laws, and if the tower is properly designed, the distilling effect in the tower will also be high. Today the combined cycle has the best thermal efficiency to generate electricity from fuels. Every new power cycle, including the evaporative cycles, will therefore be compared with power stations based on combined cycles. In evaporative cycles, the steam bottoming cycle of the combined cycles has been eliminated. Instead the 'steam' cycle is integrated into the gas cycle. This action has a favourable effect on thermal efficiency and on NO{sub x} formation in the combustion zone. The major part of this thesis is about the EvGT-project. At Lund University, the major objective of this project was to develop, design, erect and operate the world's first evaporative gas turbine unit. The objective was accomplished in 1999, and in the process of reaching the objective, rather large modelling errors, both thermodynamic and dimensioning of the humidification tower, have been detected in the open literature. It seems as if the pressure dependency of the humidification process has been underestimated in the models used today. The EvGT-pilot plant at Lund University was built and taken into

  10. Measuring business cycles in The Netherlands, 1815-1913: a comparison of business cycle dating methods

    Bonenkamp, Jan; Jacobs, Jan; Kuper, Gerard H.

    2001-01-01

    This paper compares different business cycle dating methods both on theoretical and practical grounds. Weighing the pros and cons of these methods, and based on a new data set for The Netherlands in the nineteenth century, we finally recommend two preferred methods for doing further business cycle research on the economy of the Netherlands. With respect to the methods for finding turning points in the level of economic activity, the classical cycle definition, we prefer the Bry-Boschan algori...

  11. Transitions between refrigeration regions in extremely short quantum cycles

    Feldmann, Tova; Kosloff, Ronnie

    2016-05-01

    The relation between the geometry of refrigeration cycles and their performance is explored. The model studied is based on a coupled spin system. Small cycle times, termed sudden refrigerators, develop coherence and inner friction. We explore the interplay between coherence and energy of the working medium employing a family of sudden cycles with decreasing cycle times. At the point of maximum coherence the cycle changes geometry. This region of cycle times is characterized by a dissipative resonance where heat is dissipated both to the hot and cold baths. We rationalize the change of geometry of the cycle as a result of a half-integer quantization which maximizes coherence. From this point on, increasing or decreasing the cycle time, eventually leads to refrigeration cycles. The transition point between refrigerators and short circuit cycles is characterized by a transition from finite to singular dynamical temperature. Extremely short cycle times reach a universal limit where all cycles types are equivalent.

  12. Thermodynamic cycles of nuclear power plants; Les cycles thermodynamiques des centrales nucleaires

    Normand, T.; Andreani, J.; Tejedor, V.

    2010-07-01

    Above all a nuclear power plant is a thermal system whose efficiency relies on the thermodynamic cycle that turns the heat produced by the fission of uranium nuclei into electricity. The thermodynamic yield is an essential parameter to dimension a power plant. This book is dedicated to the presentation of the thermodynamic cycles that have been chosen in the different types of French PWR: CP0, P4, N4 and EPR. These cycles are classical steam cycles that have been used and optimized for 40 years, but they are physically limited and do not respond to the expectations of future generations of reactors. The last part deals with the thermodynamic cycles that might be involved in the fourth generation of nuclear reactors: cycles with super-critical steam, direct cycles for high temperature gas, indirect gas cycles, and cycles with super-critical CO{sub 2}. The first part of the book gives an account of the situation of nuclear power in France. (A.C.)

  13. Comparison Between helium cycle and Supercritical CO{sub 2} Cycle for MMR and AMR

    Bae, Seong Jun; Lee, Jeong Ik; Ahn, Yoon Han; Lee, Je Kyoung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    Korea Atomic Energy Research Institute (KAERI) started the development of Mobile Multi-Purpose Reactor (MMR), which is a 10MWth gas-cooled reactor. MMR is aiming for maximizing mobility, high performance, durability and safety. This is in order to use the MMR for many purposes such as ship propulsion, train engine and so on. MMR generally uses helium Brayton cycle as a power conversion system since it can obtain very simple system arrangement with direct cycle. However, some researchers have proposed that the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle can be more efficient energy converting cycle for the high temperature gas cooled reactor (HTGR) and the very high temperature reactor (VHTR) system as well. Thus, this paper is to compare helium Brayton cycle to the S-CO{sub 2} Brayton cycle in terms of the efficiency while varying turbine inlet temperature (T. I. T). A cascaded S-CO{sub 2} cycle which had been proposed by Argonne National laboratory (ANL) was used as the S-CO{sub 2} Brayton cycle configuration. This cycle is to overcome the mismatch of temperature drop between reactor coolant and CO{sub 2} through the reactor heat exchanger (RHX). Our research team reviewed the ANL research by using the in-house codes developed by the Korea Advanced institute of Science and Technology (KAIST) research team. The calculation error between the in-house code and previous result was -0.36%.

  14. Theoretical Study on CO2 Transcritical Cycle Combined Ejector Cycle Refrigeration System

    卢苇; 马一太; 李敏霞; 查世彤

    2003-01-01

    Chlorofluorocarbons(CFCs) or hydrochlorofluorocarbons(HCFCs) are as main refrigerants used in traditional refrigeration systems driven by electricity from burning fossil fuels, which is regarded as one of the major reasons for ozone depletion (man-made refrigerants emission) and global warming (CO2 emission). So people pay more and more attention to natural refrigerants and energy saving technologies. An innovative system combining CO2 transcritical cycle with ejector cycle is proposed in this paper. The CO2 compression sub-cycle is powered by electricity with the characteristics of relatively high temperature in the gas cooler (defined as an intercooler by the proposed system). In order to recover the waste heat, an ejector sub-cycle operating with the natural refrigerants (NH3, H2O) is employed. The two sub-cycles are connected by an intercooler. This combined cycle joins the advantages of the two cycles together and eliminates the disadvantages. The influences of the evaporation temperature in CO2 compression sub-cycle, the evaporation temperature in the ejector sub-cycle, the temperature in the intercooler and the condensation temperature in the proposed system performance are discussed theoretically in this study. In addition, some unique features of the system are presented.

  15. Does a low solar cycle minimum hint at a weak upcoming cycle?

    Zhan-Le Du; Hua-Ning Wang

    2010-01-01

    The maximum amplitude (Rm) of a solar cycle, in the term of mean sunspot numbers, is well-known to be positively correlated with the preceding minimum (Rmin). So far as the long term trend is concerned, a low level of Rmin tends to be followed by a weak Rm, and vice versa. We found that the evidence is insufficient to infer a very weak Cycle 24 from the very low Rmin in the preceding cycle. This is concluded by analyzing the correlation in the temporal variations of parameters for two successive cycles.

  16. Drivers of cycling demand and cycling futures in the Danish context

    Analysis of the time trend in cycling mode share based on longest possible time series. Logistic regression model of cycling as mode choice as basis for studying ‘driver variables’ contribution to time trend. Describing important vectors of change behind the time trend.......Analysis of the time trend in cycling mode share based on longest possible time series. Logistic regression model of cycling as mode choice as basis for studying ‘driver variables’ contribution to time trend. Describing important vectors of change behind the time trend....

  17. IS SOLAR CYCLE 24 PRODUCING MORE CORONAL MASS EJECTIONS THAN CYCLE 23?

    Wang, Y.-M.; Colaninno, R., E-mail: yi.wang@nrl.navy.mil, E-mail: robin.colaninno@nrl.navy.mil [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  18. Tectonometamorphic Cycles in Different Geodynamic Conditions

    2000-01-01

    Formation and attenuation of crust thermal anomalies, accompanied by development of geological structures, are governed by special laws, together with metamorphism and other endogenic process, form tectonometamorphic cycle (TMC). Because of rock rheology under metamorphic conditions, the structures, concurring with metamorphism, reflect geodynamic conditions much more perfect than those of the structures of nonmetamorphosed rocks. For this reason, structural investigations open wide, sometimes unique, possibilities for geodynamic research into regional metamorphosed terrains. The TMC features under different geodynamic conditions are shown with examples of California (subduction), Himalaya and Junggar Alatau (collision), and Northwest environs of the White Sea (polycyclic development). The analysis of these units serves as basis of some general conclusions. TMC, the steady pattern of crust thermal anomalies manifestation, does not practically depend on peculiarities of metamorphism. At lower and middle crust levels, occur the high-temperature complete cycles that include following two stages. The first is represented by nappes and paragenes of parallel bedding flow, the second, by linear folds, domes and faults. At top levels of fold complexes display the low-temperature reduced cycles, expressed only by structures of the second stage. There are gradual transitions between the complete and reduced cycles. Thermal anomalies in the first stage of complete cycles devolop against the background of large horizontal displacements at contacts between interacting plates or are genetically connected with their gently sloping fault planes. Of all structural elements of the cycles, in compressional environments (nappes, linear folds, domes etc. ), only the structures of the first stage of complete cycles can be considered as indications of plate tectonics. Presence of such structures at the most ancient supracrustal complexes point to existence of plate tectonics already at

  19. THE BIMODAL STRUCTURE OF THE SOLAR CYCLE

    Du, Z. L., E-mail: zldu@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2015-05-01

    Some properties of the 11 yr solar cycle can be explained by the current solar dynamo models. However, some other features remain not well understood such as the asymmetry of the cycle, the double-peaked structure, and the “Waldmeier effect” that a stronger cycle tends to have less rise time and a shorter cycle length. We speculate that the solar cycle is governed by a bi-dynamo model forming two stochastic processes depicted by a bimodal Gaussian function with a time gap of about 2 yr, from which the above features can be reasonably explained. The first one describes the main properties of the cycle dominated by the current solar dynamo models, and the second one occurs either in the rising phase as a short weak explosive perturbation or in the declining phase as a long stochastic perturbation. The above function is the best one selected from several in terms of the Akaike information criterion. Through analyzing different distributions, one might speculate about the dominant physical process inside the convection zone. The secondary (main) process is found to be closely associated with complicated (simple) active ranges. In effect, the bi-dynamo model is a reduced form of a multi-dynamo model, which could occur from the base of the convection zone through its envelope and from low to high heliographic latitude, reflecting the active belts in the convection zone. These results are insensitive to the hemispheric asymmetry, smoothing filters, and distribution functions selected and are expected to be helpful in understanding the formation of solar and stellar cycles.

  20. Effects of eccentric cycling and endurance training versus low cadence cycling and endurance training on muscle strength and cycling performance in trained individuals

    Eidsheim, Hedda Øyeflaten

    2016-01-01

    Background: Recent studies have shown a positive effect of concurrent strength and endurance training on performance in cycling. Still, few studies have investigated the effect of eccentric cycling (ECC) and low cadence cycling (LCC) on muscle strength and determinants of cycling performance. Aim: Compare the effect of concurrent ECC and endurance training with concurrent LCC and endurance training on strength development, muscle thickness, and cycling performance in trained...

  1. The cell cycle rallies the transcription cycle: Cdc28/Cdk1 is a cell cycle-regulated transcriptional CDK.

    Chymkowitch, Pierre; Enserink, Jorrit M

    2013-01-01

    In the budding yeast Saccharomyces cerevisiae, the cyclin-dependent kinases (CDKs) Kin28, Bur1 and Ctk1 regulate basal transcription by phosphorylating the carboxyl-terminal domain (CTD) of RNA polymerase II. However, very little is known about the involvement of the cell cycle CDK Cdc28 in the transcription process. We have recently shown that, upon cell cycle entry, Cdc28 kinase activity boosts transcription of a subset of genes by directly stimulating the basal transcription machinery. Here, we discuss the biological significance of this finding and give our view of the kinase-dependent role of Cdc28 in regulation of RNA polymerase II.

  2. Aromatase inhibitors in stimulated IVF cycles

    Tournaye Herman

    2011-06-01

    Full Text Available Abstract Aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with PCOS. Although several randomized trials have been conducted regarding their use as ovulation induction agents, only few trials are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears to have the potential to increase clinical pregnancy rates when combined with gonadotropins, whereas at the same time reduces the total gonadotropin dose required for ovarian stimulation. However, given that in all of the trials letrozole has been administered in GnRH antagonist cycles, it is intriguing to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels

  3. POLITICAL BUDGET CYCLES: EVIDENCE FROM TURKEY

    FİLİZ ERYILMAZ

    2015-04-01

    Full Text Available The theorical literature on “Political Business Cycles” presents important insights on the extent to which politicians attempt to manipulate government monetary and fiscal policies to influence electoral outcomes, in particular, with the aim of re-election. In recent years “Political Budget Cycles” is the one of the most important topics in Political Business Cycles literature. According to Political Budget Cycles Theory, some components of the government budget are influenced by the electoral cycle and consequently an increase in government spending or decrease in taxes in an election year, leading to larger fiscal deficit. This incumbent’s fiscal manipulation is a tool that governments possess to increase their changes for re-election. In this paper we investigate the presence of Political Budget Cycles using a data set of budget balance, total expenditure and total revenue over the period 1994–2012. Our findings suggest that incumbents in Turkey use fiscal policy to increase their popularity and win elections, therefore fiscal manipulation was rewarded rather than punished by Turkish voters. The meaning of this result is that Political Budget Cycles Theory is valid for Turkey between 1994 and 2012.

  4. A cycle timer for testing electric vehicles

    Soltis, R. F.

    1978-01-01

    A cycle timer was developed to assist the driver of an electric vehicle in more accurately following and repeating SAE driving schedules. These schedules require operating an electric vehicle in a selected stop-and-go driving cycle and repeating this cycle pattern until the vehicle ceases to meet the requirements of the cycle. The heart of the system is a programmable read-only memory (PROM) that has the required test profiles permanently recorded on plug-in cards, one card for each different driving schedule. The PROM generates a direct current analog signal that drives a speedometer displayed on one scale of a dual movement meter. The second scale of the dual movement meter displays the actual speed of the vehicle as recorded by the fifth wheel. The vehicle operator controls vehicle speed to match the desired profile speed. The PROM controls the recycle start time as well as the buzzer activation. The cycle programmer is powered by the test vehicle's 12-volt accessory battery, through a 5-volt regulator and a 12-volt dc-to-dc converter.

  5. Giant half-cycle attosecond pulses

    Wu, H -C

    2011-01-01

    Half-cycle picosecond pulses have been produced from thin photo-conductors, when applying an electric field across the surface and switching on conduction by a short laser pulse. Then the transverse current in the wafer plane emits half-cycle pulses in normal direction, and pulses of 500 fs duration and 1e6 V/m peak electric field have been observed. Here we show that single half-cycle pulses of 50 as duration and up to 1e13 V/m can be produced when irradiating a double foil target by intense few-cycle laser pulses. Focused onto an ultra-thin foil, all electrons are blown out, forming a uniform sheet of relativistic electrons. A second layer, placed at some distance behind, reflects the drive beam, but lets electrons pass straight. Under oblique incidence, beam reflection provides the transverse current, which emits intense half-cycle pulses. Such a pulse may completely ionize even heavier atoms. New types of attosecond pump-probe experiments will become possible.

  6. Nuclear Fuel Cycle Evaluation and Real Options

    L. Havlíček

    2008-01-01

    Full Text Available The first part of this paper describes the nuclear fuel cycle. It is divided into three parts. The first part, called Front-End, covers all activities connected with fuel procurement and fabrication. The middle part of the cycle includes fuel reload design activities and the operation of the fuel in the reactor. Back-End comprises all activities ensuring safe separation of spent fuel and radioactive waste from the environment. The individual stages of the fuel cycle are strongly interrelated. Overall economic optimization is very difficult. Generally, NPV is used for an economic evaluation in the nuclear fuel cycle. However the high volatility of uranium prices in the Front-End, and the large uncertainty of both economic and technical parameters in the Back-End, make the use of NPV difficult. The real option method is able to evaluate the value added by flexibility of decision making by a company under conditions of uncertainty. The possibility of applying this method to the nuclear fuel cycle evaluation is studied. 

  7. Lactobacillus decelerates cervical epithelial cell cycle progression.

    Katarina Vielfort

    Full Text Available We investigated cell cycle progression in epithelial cervical ME-180 cells during colonization of three different Lactobacillus species utilizing live cell microscopy, bromodeoxyuridine incorporation assays, and flow cytometry. The colonization of these ME-180 cells by L. rhamnosus and L. reuteri, originating from human gastric epithelia and saliva, respectively, was shown to reduce cell cycle progression and to cause host cells to accumulate in the G1 phase of the cell cycle. The G1 phase accumulation in L. rhamnosus-colonized cells was accompanied by the up-regulation and nuclear accumulation of p21. By contrast, the vaginal isolate L. crispatus did not affect cell cycle progression. Furthermore, both the supernatants from the lactic acid-producing L. rhamnosus colonies and lactic acid added to cell culture media were able to reduce the proliferation of ME-180 cells. In this study, we reveal the diversity of the Lactobacillus species to affect host cell cycle progression and demonstrate that L. rhamnosus and L. reuteri exert anti-proliferative effects on human cervical carcinoma cells.

  8. Exercise efficiency of low power output cycling.

    Reger, M; Peterman, J E; Kram, R; Byrnes, W C

    2013-12-01

    Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations.

  9. Influence of Thermal Cycling on Cryogenic Thermometers

    Balle, C; Rieubland, Jean Michel; Suraci, A; Togny, F; Vauthier, N

    1999-01-01

    The stringent requirements on temperature control of the superconducting magnets for the Large Hadron Collider (LHC), impose that the cryogenic temperature sensors meet compelling demands such as long-term stability, radiation hardness, readout accuracy better than 5 mK at 1.8 K and compatibility with industrial control equipment. This paper presents the results concerning long-term stability of resistance temperature sensors submitted to cryogenic thermal cycles. For this task a simple test facility has been designed, constructed and put into operation for cycling simultaneously 115 cryogenic thermometers between 300 K and 4.2 K. A thermal cycle is set to last 71/4 hours: 3 hours for either cooling down or warming up the sensors and 1 respectively 1/4 hour at steady temperature conditions at each end of the temperature cycle. A Programmable Logic Controller (PLC) drives automatically this operation by reading 2 thermometers and actuating on 3 valves and 1 heater. The first thermal cycle was accomplished in a...

  10. Comparing the Life Cycle Energy Consumption, Global ...

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability

  11. Global water cycle and solar activity variations

    Al-Tameemi, Muthanna A.; Chukin, Vladimir V.

    2016-05-01

    The water cycle is the most active and most important component in the circulation of global mass and energy in the Earth system. Furthermore, water cycle parameters such as evaporation, precipitation, and precipitable water vapour play a major role in global climate change. In this work, we attempt to determine the impact of solar activity on the global water cycle by analyzing the global monthly values of precipitable water vapour, precipitation, and the Solar Modulation Potential in 1983-2008. The first object of this study was to calculate global evaporation for the period 1983-2008. For this purpose, we determined the water cycle rate from satellite data, and precipitation/evaporation relationship from 10 years of Planet Simulator model data. The second object of our study was to investigate the relationship between the Solar Modulation Potential (solar activity index) and the evaporation for the period 1983-2008. The results showed that there is a relationship between the solar modulation potential and the evaporation values for the period of study. Therefore, we can assume that the solar activity has an impact on the global water cycle.

  12. International Nuclear Fuel Cycle Fact Book

    Leigh, I.W.

    1992-05-01

    As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need exists costs for a ready source of information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book has been compiled to meet that need. The information contained in the International Nuclear Fuel Cycle Fact Book has been obtained from many unclassified sources: nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECD/NMEA activities reports; and proceedings of conferences and workshops. The data listed typically do not reflect any single source but frequently represent a consolidation/combination of information.

  13. International Nuclear Fuel Cycle Fact Book

    Leigh, I W; Mitchell, S J

    1990-01-01

    As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source of information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained in the International Nuclear Fuel Cycle Fact Book has been obtained from many unclassified sources: nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECD/NEA activities reports; proceedings of conferences and workshops, etc. The data listed do not reflect any one single source but frequently represent a consolidation/combination of information.

  14. Methods and compositions for rapid thermal cycling

    Beer, Neil Reginald; Benett, William J.; Frank, James M.; Deotte, Joshua R.; Spadaccini, Christopher

    2015-10-27

    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  15. New Realization of Periodic Cycled Separation

    Toftegard, Bjarne; Clausen, Charlotte H.; Jørgensen, Sten B.;

    2016-01-01

    A new realization of periodic cycled gas/liquid separation is presented. Separation factors and column efficiencies are compared for a column stripping ammonia from water with air, using three different sets of internals: conventional sieve trays, Sulzer BX gauze packings, and periodically cycled...... trays. The proposed new periodic trays are shown to be advantageous compared to their continuous alternatives. It is demonstrated experimentally that periodic tray efficiencies of up to 300% are achievable. With the proposed new tray design, a new operation form is also introduced in which the trays...... are drained sequentially rather than simultaneously, such that the vapor flow is not interrupted during the liquid drainage. For different ratios of counter-current vapor/liquid flow rates, column efficiencies for periodically cycled columns are shown experimentally to be two times greater than those...

  16. Does an irreversible chemical cycle support equilibrium?

    Banerjee, Kinshuk

    2013-01-01

    The impossibility of attaining equilibrium for cyclic chemical reaction networks with irreversible steps is apparently due to a divergent entropy production rate. A deeper reason seems to be the violation of the detailed balance condition. In this work, we discuss how the standard theoretical framework can be adapted to include irreversible cycles, avoiding the divergence. With properly redefined force terms, such systems are also seen to reach and sustain equilibria that are characterized by the vanishing of the entropy production rate, though detailed balance is not maintained. Equivalence of the present formulation with Onsager's original prescription is established for both reversible and irreversible cycles, with a few adjustments in the latter case. Further justification of the attainment of true equilibrium is provided with the help of the minimum entropy production principle. All the results are generalized for an irreversible cycle comprising of N number of species.

  17. Dynamo Models of the Solar Cycle

    Charbonneau Paul

    2005-06-01

    Full Text Available This paper reviews recent advances and current debates in modeling the solar cycle as a hydromagnetic dynamo process. Emphasis is placed on (relatively simple dynamo models that are nonetheless detailed enough to be comparable to solar cycle observations. After a brief overview of the dynamo problem and of key observational constraints, we begin by reviewing the various magnetic field regeneration mechanisms that have been proposed in the solar context. We move on to a presentation and critical discussion of extant solar cycle models based on these mechanisms. We then turn to the origin of fluctuations in these models, including amplitude and parity modulation, chaotic behavior, and intermittency. The paper concludes with a discussion of our current state of ignorance regarding various key questions, the most pressing perhaps being the identification of the physical mechanism(s responsible for the generation of the Sun's poloidal magnetic field component.

  18. Comparative myoanatomy of cycliophoran life cycle stages

    Neves, Ricardo C.; Cunha, Marina R; Funch, Peter

    2010-01-01

    The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic...... on the dorsal side, whereas on the ventral side, longitudinal muscles and a V-shaped muscle structure are present. These muscles are complemented by additional dorsoventral muscles. The mesodermal muscle fibers attach to the cuticle via the epidermis in all life cycle stages studied herein. The musculature...... of the female is similar to that of the Pandora larva of Symbion americanus and includes dorsoventral muscles and longitudinal muscles that run in the dorsal and ventral body region. Overall, our results reveal striking similarities in the muscular arrangement of the life cycle stages of both Symbion species. J...

  19. Implementing Life Cycle Assessment in Product development

    Bhander, Gurbakhash Singh

    2003-01-01

    The overall aim of the paper is to provide an understanding of the environmental issues involved in the early stages of product development and the capacity of life cycle assessment techniques to address these issues. The paper aims to outline the problems for the designer in evaluating......, and of the opportunities for introducing environmental criteria in the design process through meeting the information requirements of the designer on the different life cycle stages, producing an in-depth understanding of the attitudes of practitioners among product developers to the subject area, and an understanding...... of possible future directions for product development. An Environmentally Conscious Design method is introduced and trade-offs are presented between design degrees of freedom and environmental solutions. Life cycle design frameworks and strategies are addressed. The paper collects experiences and ideas around...

  20. Life Cycle Assessment and Risk Assessment

    Olsen, Stig Irving

    Life Cycle Assessment (LCA) is a tool for environmental assessment of product and systems – over the whole life cycle from acquisition of raw materials to the end-of-life of the product – and encompassing all environmental impacts of emissions and resource usage, e.g. global warming, acidification...... and toxicity. Whereas Risk Assessment (RA) aims to identify absolute risks, LCA assess potential or relative impacts. LCA is readily applicable to nanotechnologies and several studies have been carried out, but LCA faces large problems when addressing toxic impacts of nanomaterials emitted during the life...... cycle. The models for assessing toxic impacts in LCA are to a large extent based on those developed for RA, e.g. EUSES, and require basic information about the inherent properties of the emissions like solubility, LogKow,ED50 etc. Additionally, it is a prerequisite to know how to characterize...

  1. Asset Allocation Over the Life Cycle

    Fischer, Marcel; Kraft, Holger; Munk, Claus

    2013-01-01

    We study the welfare effect of tax-optimizing portfolio decisions in a life cycle model with unspanned labor income and realization-based capital gain taxation. For realistic parameterizations of our model, certainty equivalent welfare gains from fully tax-optimized portfolio decisions are less...... and instead assumes mark-to-market taxation, these gains are less than 0.5%. That is, our work provides a justification for ignoring taxes in life cycle portfolio choice problems - a wide-spread assumption in that literature. However, if capital gains are forgiven at death (as in the U.S.), investors...... with strong bequest motives face substantial welfare costs when not tax-optimizing their portfolio decisions towards the end of the life cycle....

  2. Biological phosphorus cycling in dryland regions

    Belnap, Jayne; Bunemann, Else; Oberson, Astrid; Frossard, Emmanuel

    2011-01-01

    The relatively few studies done on phosphorus (P) cycling in arid and semiarid lands (drylands) show many factors that distinguish P cycling in drylands from that in more mesic regions. In drylands, most biologically relevant P inputs and losses are from the deposition and loss of dust. Horizontal and vertical redistribution of P is an important process. P is concentrated at the soil surface and thus vulnerable to loss via erosion. High pH and CaCO3 limit P bioavailability, and low rainfall limits microbe and plant ability to free abiotically bound P via exudates, thus making it available for uptake. Many invasive plants are able to access recalcitrant P more effectively than are native plants. As P availability depends on soil moisture and temperature, climate change is expected to have large impacts on P cycling

  3. Air Conditioning System using Rankine Cycle

    Nagatomo, Shigemi; Yamaguchi, Hiroichi; Hattori, Hitoshi; Futamura, Motonori

    Natural gas is used as the energy source to cope with the recent situation of increasing demand for electricity especially in summer. In this paper, the performance of a Rankine cycle air conditioning system driven by natural gas was studied. The following results were obtained : (1) Basic equations of performance, refrigerant mass flow rate and expander volume were developed by using the values of heating efficiency, regeneration efficiency, expander efficiency and compressor efficiency. (2) R134a refrigerant has been considered to be suitable for the Rankine cycle air conditioning system, compared with other refrigerants. (3)A Rankine cycle cooling system using R134a refrigerant as a single working fluid was developed. System COP of 0.47 was attained at typical operating condition.

  4. Methods and compositions for rapid thermal cycling

    Beer, Neil Reginald; Benett, William J.; Frank, James M.; Deotte, Joshua R.; Spadaccini, Christopher

    2015-10-27

    The rapid thermal cycling of a material is targeted. A microfluidic heat exchanger with an internal porous medium is coupled to tanks containing cold fluid and hot fluid. Fluid flows alternately from the cold tank and the hot tank into the porous medium, cooling and heating samples contained in the microfluidic heat exchanger's sample wells. A valve may be coupled to the tanks and a pump, and switching the position of the valve may switch the source and direction of fluid flowing through the porous medium. A controller may control the switching of valve positions based on the temperature of the samples and determined temperature thresholds. A sample tray for containing samples to be thermally cycled may be used in conjunction with the thermal cycling system. A surface or internal electrical heater may aid in heating the samples, or may replace the necessity for the hot tank.

  5. Chemical Oceanography and the Marine Carbon Cycle

    Emerson, Steven; Hedges, John

    The principles of chemical oceanography provide insight into the processes regulating the marine carbon cycle. The text offers a background in chemical oceanography and a description of how chemical elements in seawater and ocean sediments are used as tracers of physical, biological, chemical and geological processes in the ocean. The first seven chapters present basic topics of thermodynamics, isotope systematics and carbonate chemistry, and explain the influence of life on ocean chemistry and how it has evolved in the recent (glacial-interglacial) past. This is followed by topics essential to understanding the carbon cycle, including organic geochemistry, air-sea gas exchange, diffusion and reaction kinetics, the marine and atmosphere carbon cycle and diagenesis in marine sediments. Figures are available to download from www.cambridge.org/9780521833134. Ideal as a textbook for upper-level undergraduates and graduates in oceanography, environmental chemistry, geochemistry and earth science and a valuable reference for researchers in oceanography.

  6. Brayton-cycle heat exchanger technology program

    Killackey, J. J.; Coombs, M. G.; Graves, R. F.; Morse, C. J.

    1976-01-01

    The following five tasks designed to advance this development of heat exchanger systems for close loop Brayton cycle power systems are presented: (1) heat transfer and pressure drop data for a finned tubular heat transfer matrix. The tubes are arranged in a triangular array with copper stainless steel laminate strips helically wound on the tubes to form a disk fin geometry; (2) the development of a modularized waste heat exchanger. Means to provide verified double containment are described; (3) the design, fabrication, and test of compact plate fin heat exchangers representative of full scale Brayton cycle recuperators; (4) the analysis and design of bellows suitable for operation at 1600 F and 200 psia for 1,000 cycles and 50,000 hours creep life; and (5) screening tests used to select a low cost braze alloy with the desirable attributes of a gold base alloy. A total of 22 different alloys were investigated; the final selection was Nicrobraz 30.

  7. Searching for Political Fiscal Cycles in Hungary

    Endrit Lami

    2013-12-01

    Full Text Available Hungary has had a remarkably high public debt throughout the transition, and it has continued to increase during recent years, exceeding 80% of the GDP. Its debt and fiscal deficit were the highest among the Visegrád countries during the transition. One factor triggering the debt increase may be elections-related fiscal policies. By analyzing quarterly data for Hungary, we found clear empirical evidence of fiscal expansion before elections and contractions afterwards. These events are widely known as political fiscal cycles. We observed statistically significant incremental increases in fiscal deficits as elections approach, both in nominal and in GDP ratios, followed by contractions after elections. Thus, it can be concluded that incumbents in Hungary are engaged in opportunistic political fiscal cycles by embracing expansionary fiscal policy before parliamentary elections. Our findings also suggest that political fiscal cycles in Hungary may be an underlying factor contributing to the accumulation of public debt.

  8. International nuclear fuel cycle fact book

    Leigh, I.W.

    1988-01-01

    As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source or information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained has been obtained from nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECD/NEA activities reports; proceedings of conferences and workshops; and so forth. Sources do not agree completely with each other, and the data listed herein does not reflect any one single source but frequently is consolidation/combination of information. Lack of space as well as the intent and purpose of the Fact Book limit the given information to that pertaining to the Nuclear Fuel Cycle and to data considered of primary interest or most helpful to the majority of users.

  9. Nuclear Fusion Fuel Cycle Research Perspectives

    Chung, Hongsuk; Koo, Daeseo; Park, Jongcheol; Kim, Yeanjin [KAERI, Daejeon (Korea, Republic of); Yun, Sei-Hun [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    As a part of the International Thermonuclear Experimental Reactor (ITER) Project, we at the Korea Atomic Energy Research Institute (KAERI) and our National Fusion Research Institute (NFRI) colleagues are investigating nuclear fusion fuel cycle hardware including a nuclear fusion fuel Storage and Delivery System (SDS). To have a better knowledge of the nuclear fusion fuel cycle, we present our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). To have better knowledge of the nuclear fusion fuel cycle, we presented our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). Our efforts to enhance the tritium confinement will be continued for the development of cleaner nuclear fusion power plants.

  10. Carbon cycle in advanced coal chemical engineering.

    Yi, Qun; Li, Wenying; Feng, Jie; Xie, Kechang

    2015-08-07

    This review summarizes how the carbon cycle occurs and how to reduce CO2 emissions in highly efficient carbon utilization from the most abundant carbon source, coal. Nowadays, more and more attention has been paid to CO2 emissions and its myriad of sources. Much research has been undertaken on fossil energy and renewable energy and current existing problems, challenges and opportunities in controlling and reducing CO2 emission with technologies of CO2 capture, utilization, and storage. The coal chemical industry is a crucial area in the (CO2 value chain) Carbon Cycle. The realization of clean and effective conversion of coal resources, improving the utilization and efficiency of resources, whilst reducing CO2 emissions is a key area for further development and investigation by the coal chemical industry. Under a weak carbon mitigation policy, the value and price of products from coal conversion are suggested in the carbon cycle.

  11. Implementing Life Cycle Assessment in systems development

    Bhander, Gurbakhash Singh; Hauschild, Michael Zwicky; McAloone, Timothy Charles

    2003-01-01

    derived from products and system, and calculate resource consumptions. However, the complexity of LCA poses restrictions to its use in current product and system development given the need for a reduction in product development cycle time which is needed to meet the increasing competitive pressures....... The paper reviews the current environmental evaluation practices with respect to product life cycles. As a number of deficiencies in LCA are identified, strategies are presented to provide a solution to many of the deficiencies. The result of the paper is a definition of the requirements for performance...... measurement techniques and a performance measurement environment necessary to support life cycle evaluation throughout the evaluation of early stages of a product system....

  12. Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk

    Rasmussen, Martin G; Grøntved, Anders; Blond, Kim;

    2016-01-01

    BACKGROUND: Cycling is a recreational activity and mode of commuting with substantial potential to improve public health in many countries around the world. The aim of this study was to examine prospective associations between recreational and commuter cycling, changes in cycling habits, and risk...... to recreational and commuter cycling and changes in cycling habits, with adjustment for a priori known T2D risk factors. During 743,245.4 person-years of follow-up (mean follow-up 14.2 y), 6,779 incident cases of T2D were documented. Multivariable adjusted HRs (95% confidence interval [CI]) were 1, 0.87 (0.82, 0.......80 (0.76, 0.85) for non-cyclists, seasonal cyclists (those cycling only in summer or winter), and those cycling during both summer and winter, respectively. How changes in total cycling from baseline to the second examination affected risk was also investigated, and multivariable adjusted HRs (95% CI...

  13. Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

    Rokni, Masoud

    2014-01-01

    steam in a HRSG (heat recovery steam generator). The bottoming steam cycle was modeled with two configurations: (1) a simple single pressure level and (2) a dual pressure level with both a reheat and a pre-heater. The SOFC stacks in the present SOFC-ST hybrid cycles were not pressurized. The dual...

  14. Cell cycle phase regulates glucocorticoid receptor function.

    Laura Matthews

    Full Text Available The glucocorticoid receptor (GR is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors. In contrast to many other nuclear receptors, GR is thought to be exclusively cytoplasmic in quiescent cells, and only translocate to the nucleus on ligand binding. We now demonstrate significant nuclear GR in the absence of ligand, which requires nuclear localisation signal 1 (NLS1. Live cell imaging reveals dramatic GR import into the nucleus through interphase and rapid exclusion of the GR from the nucleus at the onset of mitosis, which persists into early G(1. This suggests that the heterogeneity in GR distribution is reflective of cell cycle phase. The impact of cell cycle-driven GR trafficking on a panel of glucocorticoid actions was profiled. In G2/M-enriched cells there was marked prolongation of glucocorticoid-induced ERK activation. This was accompanied by DNA template-specific, ligand-independent GR transactivation. Using chimeric and domain-deleted receptors we demonstrate that this transactivation effect is mediated by the AF1 transactivation domain. AF-1 harbours multiple phosphorylation sites, which are consensus sequences for kinases including CDKs, whose activity changes during the cell cycle. In G2/M there was clear ligand independent induction of GR phosphorylation on residues 203 and 211, both of which are phosphorylated after ligand activation. Ligand-independent transactivation required induction of phospho-S211GR but not S203GR, thereby directly linking cell cycle driven GR modification with altered GR function. Cell cycle phase therefore regulates GR localisation and post-translational modification which selectively impacts GR activity. This suggests that cell cycle phase is an important determinant in the cellular response to Gc, and that mitotic index contributes to tissue Gc sensitivity.

  15. Solar Cycle 24 and the Solar Dynamo

    Pesnell, W. D.; Schatten, K.

    2007-01-01

    We will discuss the polar field precursor method for solar activity prediction, which predicts cycle 24 will be significantly lower than recent activity cycles, and some new ideas rejuvenating Babcock's shallow surface dynamo. The polar field precursor method is based on Babcock and Leighton's dynamo models wherein the polar field at solar minimum plays a major role in generating the next cycle's toroidal field and sunspots. Thus, by examining the polar fields of the Sun near solar minimum, a forecast for the next cycle's activity is obtained. With the current low value for the Sun's polar fields, this method predicts solar cycle 24 will be one of the lowest in recent times, with smoothed F10.7 radio flux values peaking near 135 plus or minus 35 (2 sigma), in the 2012-2013 timeframe (equivalent to smoothed Rz near 80 plus or minus 35 [2 sigma]). One may have to consider solar activity as far back as the early 20th century to find a cycle of comparable magnitude. We discuss unusual behavior in the Sun's polar fields that support this prediction. Normally, the solar precursor method is consistent with the geomagnetic precursor method, wherein geomagnetic variations are thought to be a good measure of the Sun's polar field strength. Because of the unusual polar field, the Earth does not appear to be currently bathed in the Sun's extended polar field (the interplanetary field), hence negating the primal cause behind the geomagnetic precursor technique. We also discuss how percolation may support Babcock's original shallow solar dynamo. In this process ephemeral regions from the solar magnetic carpet, guided by shallow surface fields, may collect to form pores and sunspots.

  16. AFIP-6 MKII First Cycle Report

    N.E. Woolstenhulme

    2012-03-01

    The first fuel plate frame assembly of the AFIP-6 MKII experiment was irradiated as planned from December, 2011 through February, 2012 in the center flux trap of the Advanced Test Reactor during cycle 151A. Following irradiation in this cycle and while reconfiguring the experiment in the ATR canal, a non-fueled component (the bottom plate) of the first fuel plate frame assembly became separated from the rail sides. There is no evidence that the fueled region of the fuel plate frame assembly was compromised by this incident or the irradiation conditions. The separation of this component was determined to have been caused by flow induced vibrations, where vortex shedding frequencies were resonant with a natural frequency of the bottom plate component. This gave way to amplification, fracture, and separation from the assembly. Although parallel flow induced vibrations were analyzed, vortex shedding flow induced vibrations was an unfamiliar failure mode that was difficult to identify. Both the once-irradiated first fuel plate and un-irradiated second fuel plate frame assemblies were planned for irradiation in the subsequent cycle 151B. The AFIP-6 MKII experiment was excluded from irradiation in cycle 151B because non-trivial design modifications would be needed to mitigate this type of incident during the second irradiation cycle. All items of the experiment hardware were accounted for and cycle 151B occurred with a non-fueled AFIP backup assembly in the center flux trap. Options for completion of the AFIP-6 MKII experiment campaign are presented and future preventative actions are recommended.

  17. Maximisation of Combined Cycle Power Plant Efficiency

    Janusz Kotowicz

    2015-12-01

    Full Text Available The paper presents concepts for increasing the efficiency of a modern combined cycle power plant. Improvement of gas turbine performance indicators as well as recovering heat from the air cooling the gas turbine’s flow system enable reaching gross electrical efficiencies of around 65%. Analyses for a wide range of compressor pressure ratios were performed. Operating characteristics were developed for the analysed combined cycle plant, for different types of open air cooling arrangements of the gas turbine’s expander: convective, transpiration and film.

  18. Optimal Orientations of the Generalized Cycles

    2005-01-01

    Optimal orientations of the generalized cycles are studied. For a graph G, let D(G) be the family of the strong orientations of G,d(G)=min{d(D)|D∈D(x)(G)} and ρ(G)=d(G)-d(G), where d(G) and d(D) are the diameters of G and D respectively. Evaluate the value of ρ(G) is evaluated by reduction to absurdity when G is a generalized cycle Cn([Km]), and a complete result is obtained.

  19. Breaking the cycle of family violence

    Heikkinen, Eeva

    2009-01-01

    ABSTRACT Heikkinen Eeva. Breaking the cycle of family violence. Järvenpää, Autumn 2009, 51 pages, 2 appendices. Diaconia University of Applied Sciences, Diak South, Järvenpää. Degree Programme in Social Services. The research was done in a shelter for battered family members, a place where families can go, when they are unable to stay at home because of violence. The aim of the research was to find out the role of the shelter in breaking the cycle of family violence and to ...

  20. Life cycle assessment of renewable energy sources

    Singh, Anoop; Olsen, Stig Irving

    2013-01-01

    Governments are setting challenging targets to increase the production of energy and transport fuel from sustainable sources. The emphasis is increasingly on renewable sources including wind, solar, geothermal, biomass based biofuel, photovoltaics or energy recovery from waste. What are the environmental consequences of adopting these other sources? How do these various sources compare to each other? Life Cycle Assessment of Renewable Energy Sources tries to answer these questions based on the universally adopted method of Life Cycle Assessment (LCA). This book introduces the concept and impor