WorldWideScience

Sample records for backbone-only residue pair

  1. Orientation-dependent backbone-only residue pair scoring functions for fixed backbone protein design

    Directory of Open Access Journals (Sweden)

    Bordner Andrew J

    2010-04-01

    Full Text Available Abstract Background Empirical scoring functions have proven useful in protein structure modeling. Most such scoring functions depend on protein side chain conformations. However, backbone-only scoring functions do not require computationally intensive structure optimization and so are well suited to protein design, which requires fast score evaluation. Furthermore, scoring functions that account for the distinctive relative position and orientation preferences of residue pairs are expected to be more accurate than those that depend only on the separation distance. Results Residue pair scoring functions for fixed backbone protein design were derived using only backbone geometry. Unlike previous studies that used spherical harmonics to fit 2D angular distributions, Gaussian Mixture Models were used to fit the full 3D (position only and 6D (position and orientation distributions of residue pairs. The performance of the 1D (residue separation only, 3D, and 6D scoring functions were compared by their ability to identify correct threading solutions for a non-redundant benchmark set of protein backbone structures. The threading accuracy was found to steadily increase with increasing dimension, with the 6D scoring function achieving the highest accuracy. Furthermore, the 3D and 6D scoring functions were shown to outperform side chain-dependent empirical potentials from three other studies. Next, two computational methods that take advantage of the speed and pairwise form of these new backbone-only scoring functions were investigated. The first is a procedure that exploits available sequence data by averaging scores over threading solutions for homologs. This was evaluated by applying it to the challenging problem of identifying interacting transmembrane alpha-helices and found to further improve prediction accuracy. The second is a protein design method for determining the optimal sequence for a backbone structure by applying Belief Propagation

  2. Pair production from residues of complex worldline instantons

    CERN Document Server

    Ilderton, Anton; Wårdh, Jonatan

    2015-01-01

    We use worldline instantons to study nonperturbative electron-positron pair production in strong electric fields. We show that the instantons are complex for fields with lightlike inhomogeneities, and that their contribution to the pair production probability is a contour integral over the instantons themselves. We use this to recast pair production in the language of Cauchy's residue theorem. The instantons contribute residues from the poles they circulate, leading to locality of the effective action. The invariance of complex integrals under contour deformation manifests in the instanton contributions as invariance under a set of generalised, complex, reparameterisations.

  3. Prediction of protein secondary structure based on residue pair types and conformational states using dynamic programming algorithm.

    Science.gov (United States)

    Sadeghi, Mehdi; Parto, Sahar; Arab, Shahriar; Ranjbar, Bijan

    2005-06-20

    We have used a statistical approach for protein secondary structure prediction based on information theory and simultaneously taking into consideration pairwise residue types and conformational states. Since the prediction of residue secondary structure by one residue window sliding make ambiguity in state prediction, we used a dynamic programming algorithm to find the path with maximum score. A score system for residue pairs in particular conformations is derived for adjacent neighbors up to ten residue apart in sequence. The three state overall per-residue accuracy, Q3, of this method in a jackknife test with dataset created from PDBSELECT is more than 70%. PMID:15936021

  4. Determination of residual tensions induced by high speed machinery using an indented pairs method

    International Nuclear Information System (INIS)

    An indented pairs method is used to determine the distribution of residual tensions generated in samples of aluminum AA 6082-T6 and AA 7075-T6 milled at high speed. The method is based on measuring the distance between two collinear indents, before and after thermal treatment. In order to carry out the measuring process for the residual displacements, this method does not need any special equipment, just the use of a universal measuring machine. For this work, an indentation device was added to this measuring machine to reduce the absolute error of measurement. Based on the introduction of very straight longitudinal indents these residual displacements were measured with an absolute error of ±0.3m. This indentation device can be coupled to an electronic sensor that can precisely adjust the depth of the indent. The geometry of the tool and the cutting parameters were selected in order to evaluate the sensitivity of the method. The high speed machinery tests were carried out on a numerically controlled milling machine, using a 63 mm diameter frontal cutter. The inserts on this cutter were made of uncapped tungsten carbide to favor the cutting edges. Longitudinal indents were distributed over the surface of each machined sample to determine the residual tensions at different points of the surface's axis of symmetry. The measurement of the distances between indent pairs was done before and after an annealing thermal treatment, with temperature and time parameters of 573 K and 80 minutes, respectively. The residual tensions obtained show specific patterns in both axes of symmetry. Along the parallel axis in the direction of the advancing movement, the residual tension components that were evaluated display a lineal distribution, with a reduced gradient. Meanwhile, along the normal axis in the advancing direction, the distribution is V-shaped. From these patterns it can be inferred that the mechanisms that operate to generate these tensions are very sensitive to the

  5. Clamping down on weak terminal base pairs: oligonucleotides with molecular caps as fidelity-enhancing elements at the 5′- and 3′-terminal residues

    OpenAIRE

    Narayanan, Sukunath; Gall, Julia; Richert, Clemens

    2004-01-01

    The base-pairing fidelity of oligonucleotides depends on the identity of the nucleobases involved and the position of matched or mismatched base pairs in the duplex. Nucleobases forming weak base pairs, as well as a terminal position favor mispairing. We have searched for 5′-appended acylamido caps that enhance the stability and base-pairing fidelity of oligonucleotides with a 5′-terminal 2′-deoxyadenosine residue using combinatorial synthesis and MALDI-monitored nuclease selections. This pro...

  6. Quantitative analysis of dicamba residues in raw agricultural commodities with the use of ion-pairing reagents in LC-ESI-MS/MS.

    Science.gov (United States)

    Guo, Hongyue; Riter, Leah S; Wujcik, Chad E; Armstrong, Daniel W

    2016-03-01

    A sensitive and selective HPLC-MS/MS method was developed for the quantitative analysis of dicamba residues in raw agricultural commodities (RACs). Instead of analysis in the traditionally used negative electrospray ionization (ESI) mode, these anionic compounds were detected in positive ESI with the use of ion-pairing reagents. In this approach, only a small amount (60µM) of a commercially available dicationic ion-pairing reagent was introduced into the post-column sample stream. This method has been validated in six different types of RACs including corn grain, corn stover, cotton seed, soybean, soy forage and orange with satisfactory quantitative accuracy and precision. The limits of quantitation (LOQ) values for these analytes were 1.0 to 3.0µg/kg. The standard curves were linear over the range of the tested concentrations (3.0 to 500µg/kg), with correlation coefficient (r) values≥0.999. Evaluation of ionization effects in RAC matrix extracts using diluent blanks for comparison showed no significant matrix effects were present. PMID:26717820

  7. An accurate, residue-level, pair potential of mean force for folding and binding based on the distance-scaled, ideal-gas reference state

    OpenAIRE

    Zhang, Chi; Liu, Song; Zhou, Hongyi; Zhou, Yaoqi

    2004-01-01

    Structure prediction on a genomic scale requires a simplified energy function that can efficiently sample the conformational space of polypeptide chains. A good energy function at minimum should discriminate native structures against decoys. Here, we show that a recently developed, residue-specific, all-atom knowledge-based potential (167 atomic types) based on distance-scaled, finite ideal-gas reference state (DFIRE-all-atom) can be substantially simplified to 20 residue types located at sid...

  8. Pair Frames

    OpenAIRE

    Fereydooni, Abolhassan; Safapour, Ahmad

    2011-01-01

    In this paper a new concept related to the frame theory is introduced; the notion of pair frame. By investigating some properties of such frames, it is shown that pair frames are a generalization of ordinary frames. Some classes of of them are introduced such as (p, q)-pair frames and near identity pair frames.

  9. Hairpin loops consisting of single adenine residues closed by sheared A.A and G.G pairs formed by the DNA triplets AAA and GAG: solution structure of the d(GTACAAAGTAC) hairpin.

    Science.gov (United States)

    Chou, S H; Zhu, L; Gao, Z; Cheng, J W; Reid, B R

    1996-12-20

    The DNA undecamers GTACAAAGTAC (AAA 11-mer) and GTACGAGGTAC (GAG 11-mer) have been studied in solution by high-resolution NMR spectroscopy. Both duplexes form stable hairpins containing single deoxyadenosine loops and stems containing five base-pairs that are closed at the loop end by sheared AxA and GxC pairs, respectively. These molecules thus contain new AAA and GAG loop turn motifs. All protons, including the chiral H5'/H5" protons of the loop residues, were assigned using NOESY, DQF-COSY and heteronuclear 1H-31P COSY experiments. The backbone torsion angles were constrained using experimental data from NOE crosspeaks, three-bond 1H-1H coupling constants and four-bond 1H-31P coupling constants and four-bond 1H-31P coupling constants. The AAA and GAG 11-mers form similar structures in solution. The detailed structure of the AAA 11-mer was determined by the combined use of NMR, distance geometry and energy minimization methods. This structure exhibits good stacking of the loop adenosine base on the closing 5Ax7A sheared pair, with the 6A base stacking on the 5A base and the 6A deoxyribose stacking with the 7A base. All sugars in the AAA 11-mer hairpin adopt the typical DNA C2'-endo conformation and a sharp backbone turn occurs between residues 6A and 7A. This loop turn is brought about mainly by a change in the backbone phosphate torsion angles from zeta(g-) alpha(g-) to zeta(g+) alphat(g+) at the turn. The gamma torsion angle of residue 7A in the closing sheared pair also changes from gauche+ to trans. In Pu1NPu2 loop turns of the GCA, AAA and GAG types, the chemical shift of the H4' proton of the loop deoxyribose depends on the nature of Pu2; this reflects the stacking of the loop sugar on the Pu2 base and the different ring current effects of A or G in this position. PMID:9000625

  10. Determination of coumarin anticoagulant rodenticide residues in animal tissue by high-performance liquid chromatography. II. fluorescence detection using ion-pair chromatography.

    Science.gov (United States)

    Hunter, K

    1983-11-18

    A high-performance liquid chromatographic method was developed for the determination of warfarin, coumatetralyl, bromadiolone, difenacoum and brodifacoum in animal tissues using fluorescence detection. Ion-pair chromatography, with the tetrabutylammmonium ion as counter-ion, was used to take full advantage of their native fluorescence. Detection limits in liver tissue after gel permeation clean-up were 0.002 mg kg-1 for coumatetralyl, difenacoum and bromdifacoum, 0.008 mg kg-1 for bromadiolone, and 0.01 mg kg-1 for warfarin. PMID:6655020

  11. H9N2 influenza virus acquires intravenous pathogenicity on the introduction of a pair of di-basic amino acid residues at the cleavage site of the hemagglutinin and consecutive passages in chickens

    Directory of Open Access Journals (Sweden)

    Sakoda Yoshihiro

    2011-02-01

    Full Text Available Abstract Background Outbreaks of avian influenza (AI caused by infection with low pathogenic H9N2 viruses have occurred in poultry, resulting in serious economic losses in Asia and the Middle East. It has been difficult to eradicate the H9N2 virus because of its low pathogenicity, frequently causing in apparent infection. It is important for the control of AI to assess whether the H9N2 virus acquires pathogenicity as H5 and H7 viruses. In the present study, we investigated whether a non-pathogenic H9N2 virus, A/chicken/Yokohama/aq-55/2001 (Y55 (H9N2, acquires pathogenicity in chickens when a pair of di-basic amino acid residues is introduced at the cleavage site of its HA molecule. Results rgY55sub (H9N2, which had four basic amino acid residues at the HA cleavage site, replicated in MDCK cells in the absence of trypsin after six consecutive passages in the air sacs of chicks, and acquired intravenous pathogenicity to chicken after four additional passages. More than 75% of chickens inoculated intravenously with the passaged virus, rgY55sub-P10 (H9N2, died, indicating that it is pathogenic comparable to that of highly pathogenic avian influenza viruses (HPAIVs defined by World Organization for Animal Health (OIE. The chickens inoculated with the virus via the intranasal route, however, survived without showing any clinical signs. On the other hand, an avirulent H5N1 strain, A/duck/Hokkaido/Vac-1/2004 (Vac1 (H5N1, acquired intranasal pathogenicity after a pair of di-basic amino acid residues was introduced into the cleavage site of the HA, followed by two passages by air sac inoculation in chicks. Conclusion The present results demonstrate that an H9N2 virus has the potential to acquire intravenous pathogenicity in chickens although the morbidity via the nasal route of infection is lower than that of H5N1 HPAIV.

  12. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle;

    2006-01-01

    pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  13. Evaluation of residue-residue contact predictions in CASP9

    KAUST Repository

    Monastyrskyy, Bohdan

    2011-01-01

    This work presents the results of the assessment of the intramolecular residue-residue contact predictions submitted to CASP9. The methodology for the assessment does not differ from that used in previous CASPs, with two basic evaluation measures being the precision in recognizing contacts and the difference between the distribution of distances in the subset of predicted contact pairs versus all pairs of residues in the structure. The emphasis is placed on the prediction of long-range contacts (i.e., contacts between residues separated by at least 24 residues along sequence) in target proteins that cannot be easily modeled by homology. Although there is considerable activity in the field, the current analysis reports no discernable progress since CASP8.

  14. Nuclear Scissors Mode with Pairing

    CERN Document Server

    Balbutsev, E B; Urban, M; Vinyes, X

    2007-01-01

    The coupled dynamics of the scissors mode and isovector giant quadrupole resonance are studied using a generalized Wigner function moments method taking into account the pair correlations. Equations of motion for angular momentum, quadrupole moment and other relevant collective variables are derived on the basis of the time dependent Hartree-Fock-Bogoliubov equations. Analytical expressions for energy centroids and transitions probabilities are found for the harmonic oscillator model with the quadrupole-quadrupole residual interaction and monopole pairing force. Deformation dependences of energies and $B(M1)$ values are correctly reproduced. The inclusion of pair correlations leads to a drastic improvement in the description of qualitative and quantitative characteristics of the scissors mode.

  15. Adjoint of Pair Frames

    OpenAIRE

    Fereydooni, Abolhassan; Safapour, Ahmad; Rahimi , Asghar

    2012-01-01

    The concept of (p,q)-pair frames is generalized to (l,l^*)-pair frames. Adjoint (conjugate) of a pair frames for dual space of a Banach space is introduced and some conditions for the existence of adjoint (conjugate) of pair frames are presented.

  16. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  17. EHD3 Protein Is Required for Tubular Recycling Endosome Stabilization, and an Asparagine-Glutamic Acid Residue Pair within Its Eps15 Homology (EH) Domain Dictates Its Selective Binding to NPF Peptides.

    Science.gov (United States)

    Bahl, Kriti; Xie, Shuwei; Spagnol, Gaelle; Sorgen, Paul; Naslavsky, Naava; Caplan, Steve

    2016-06-24

    An elaborate network of dynamic lipid membranes, termed tubular recycling endosomes (TRE), coordinates the process of endocytic recycling in mammalian cells. The C-terminal Eps15 homology domain (EHD)-containing proteins have been implicated in the bending and fission of TRE, thus regulating endocytic recycling. EHD proteins have an EH domain that interacts with proteins containing an NPF motif. We found that NPF-containing EHD1 interaction partners such as molecules interacting with CasL-like1 (MICAL-L1) and Syndapin2 are essential for TRE biogenesis. Also crucial for TRE biogenesis is the generation of phosphatidic acid, an essential lipid component of TRE that serves as a docking point for MICAL-L1 and Syndapin2. EHD1 and EHD3 have 86% amino acid identity; they homo- and heterodimerize and partially co-localize to TRE. Despite their remarkable identity, they have distinct mechanistic functions. EHD1 induces membrane vesiculation, whereas EHD3 supports TRE biogenesis and/or stabilization by an unknown mechanism. While using phospholipase D inhibitors (which block the conversion of glycerophospholipids to phosphatidic acid) to deplete cellular TRE, we observed that, upon inhibitor washout, there was a rapid and dramatic regeneration of MICAL-L1-marked TRE. Using this "synchronized" TRE biogenesis system, we determined that EHD3 is involved in the stabilization of TRE rather than in their biogenesis. Moreover, we identify the residues Ala-519/Asp-520 of EHD1 and Asn-519/Glu-520 of EHD3 as defining the selectivity of these two paralogs for NPF-containing binding partners, and we present a model to explain the atomic mechanism and provide new insight for their differential roles in vesiculation and tubulation, respectively. PMID:27189942

  18. Secure pairing with biometrics

    NARCIS (Netherlands)

    Buhan, I.R.; Boom, B.J.; Doumen, J.M.; Hartel, P.H.; Veldhuis, R.N.J.

    2009-01-01

    Secure pairing enables two devices that share no prior context with each other to agree upon a security association, which they can use to protect their subsequent communication. Secure pairing offers guarantees of the association partner identity and it should be resistant to eavesdropping and to a

  19. Critical Schwinger Pair Production.

    Science.gov (United States)

    Gies, Holger; Torgrimsson, Greger

    2016-03-01

    We investigate Schwinger pair production in spatially inhomogeneous electric backgrounds. A critical point for the onset of pair production can be approached by fields that marginally provide sufficient electrostatic energy for an off-shell long-range electron-positron fluctuation to become a real pair. Close to this critical point, we observe features of universality which are analogous to continuous phase transitions in critical phenomena with the pair-production rate serving as an order parameter: electric backgrounds can be subdivided into universality classes and the onset of pair production exhibits characteristic scaling laws. An appropriate design of the electric background field can interpolate between power-law scaling, essential Berezinskii-Kosterlitz-Thouless-type scaling, and a power-law scaling with log corrections. The corresponding critical exponents only depend on the large-scale features of the electric background, whereas the microscopic details of the background play the role of irrelevant perturbations not affecting criticality. PMID:26991162

  20. Supernovae in paired galaxies

    CERN Document Server

    Nazaryan, T A; Hakobyan, A A; Adibekyan, V Zh; Kunth, D; Mamon, G A; Turatto, M; Aramyan, L S

    2013-01-01

    We investigate the influence of close neighbor galaxies on the properties of supernovae (SNe) and their host galaxies using 56 SNe located in pairs of galaxies with different levels of star formation (SF) and nuclear activity. The mean distance of type II SNe from nuclei of hosts is greater by about a factor of 2 than that of type Ibc SNe. For the first time it is shown that SNe Ibc are located in pairs with significantly smaller difference of radial velocities between components than pairs containing SNe Ia and II. We consider this as a result of higher star formation rate (SFR) of these closer systems of galaxies. SN types are not correlated with the luminosity ratio of host and neighbor galaxies in pairs. The orientation of SNe with respect to the preferred direction toward neighbor galaxy is found to be isotropic and independent of kinematical properties of the galaxy pair.

  1. Tolerance to the Substitution of Buried Apolar Residues by Charged Residues in the Homologous Protein Structures

    OpenAIRE

    Balaji, S.; Aruna, S.; N. Srinivasan

    2003-01-01

    Occurrence and accommodation of charged amino acid residues in proteins that are structurally equivalent to buried non-polar residues in homologues have been investigated. Using a dataset of 1,852 homologous pairs of crystal structures of proteins available at 2A or better resolution, 14,024 examples of apolar residues in the structurally conserved regions replaced by charged residues in homologues have been identified. Out of 2,530 cases of buried apolar residues, 1,677 of the equivalent cha...

  2. Electron pairing without superconductivity

    Science.gov (United States)

    Levy, Jeremy

    Strontium titanate (SrTiO3) is the first and best known superconducting semiconductor. It exhibits an extremely low carrier density threshold for superconductivity, and possesses a phase diagram similar to that of high-temperature superconductors--two factors that suggest an unconventional pairing mechanism. Despite sustained interest for 50 years, direct experimental insight into the nature of electron pairing in SrTiO3 has remained elusive. Here we perform transport experiments with nanowire-based single-electron transistors at the interface between SrTiO3 and a thin layer of lanthanum aluminate, LaAlO3. Electrostatic gating reveals a series of two-electron conductance resonances--paired electron states--that bifurcate above a critical pairing field Bp of about 1-4 tesla, an order of magnitude larger than the superconducting critical magnetic field. For magnetic fields below Bp, these resonances are insensitive to the applied magnetic field; for fields in excess of Bp, the resonances exhibit a linear Zeeman-like energy splitting. Electron pairing is stable at temperatures as high as 900 millikelvin, well above the superconducting transition temperature (about 300 millikelvin). These experiments demonstrate the existence of a robust electronic phase in which electrons pair without forming a superconducting state. Key experimental signatures are captured by a model involving an attractive Hubbard interaction that describes real-space electron pairing as a precursor to superconductivity. Support from AFOSR, ONR, ARO, NSF, DOE and NSSEFF is gratefully acknowledged.

  3. Subradiant split Cooper pairs

    OpenAIRE

    Cottet, Audrey; Kontos, Takis; Yeyati, Alfredo Levy

    2011-01-01

    We suggest a way to characterize the coherence of the split Cooper pairs emitted by a double-quantum-dot based Cooper pair splitter (CPS), by studying the radiative response of such a CPS inside a microwave cavity. The coherence of the split pairs manifests in a strongly nonmonotonic variation of the emitted radiation as a function of the parameters controlling the coupling of the CPS to the cavity. The idea to probe the coherence of the electronic states using the tools of Cavity Quantum Ele...

  4. DNABINDPROT: fluctuation-based predictor of DNA-binding residues within a network of interacting residues

    OpenAIRE

    Ozbek, Pemra; Soner, Seren; Erman, Burak; Haliloglu, Turkan

    2010-01-01

    DNABINDPROT is designed to predict DNA-binding residues, based on the fluctuations of residues in high-frequency modes by the Gaussian network model. The residue pairs that display high mean-square distance fluctuations are analyzed with respect to DNA binding, which are then filtered with their evolutionary conservation profiles and ranked according to their DNA-binding propensities. If the analyses are based on the exact outcome of fluctuations in the highest mode, using a conservation thre...

  5. THE DISTRIBUTION FUNCTION OF RESIDUE-RESIDUE CONTACTS IN PROTEIN MOLECULES

    Institute of Scientific and Technical Information of China (English)

    Xiang-hong Wang; Jian-hong Ke; Zhen-quan Lin

    2005-01-01

    In protein molecules each residue has a different ability to form contacts. In this paper, we calculated the number of contacts per residue and investigated the distribution of residue-residue contacts from 495 globular protein molecules using Contacts of Structural Units (CSU) software. It was found that the probability P(n) of amino acid residues having n pairs of contacts in all contacts fits Gaussian distribution very well. The distribution function of residue-residue contacts can be expressed as: P(n) = P0 + aexp[-b(n - nc)2]. In our calculation, P0 = -0.06, a = 11.4, b = -0.04 and nc = 9.0. According to distribution function, we found that those hydrophobic (H) residues including Leu, Val, Ile, Met, Phe, Tyr, Cys, and Trp residues have large values of the most probable number of contact nc, and hydrophilic (P) residues including Ala, Gly, Thr,His, Glu, Gln, Asp, Asn, Lys, Ser, Arg, and Pro residues have the small ones. We also compare with Fauchere-Pliska hydrophobicity scale (FPH) and the most probable number of contact nc for 20 amino acid residues, and find that there exists a linear relationship between Fauchere-Pliska hydrophobicity scale (FPH) and the most probable number of contact nc,and it is expressed as: nc = a + b × FPH, here a = 8.87, and b = 1.15. It is important to further explain protein folding and its stability from residue-residue contacts.

  6. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    workers from the global South, the first article demonstrates how Facebook can be a fruitful methodological tool in the aspiration to open up the research to new themes of inquiry. However, rather than disregarding the au pairs’ economic problems, the dissertation shows how their family participation and......Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...... pair-sending families in the Philippines, this dissertation examines the long-term trajectories of these young Filipinas. It shows how the au pairs’ local and transnational family relations develop over time and greatly influence their life trajectories. A focal point of the study is how au pairs...

  7. Supernovae in paired galaxies

    CERN Document Server

    Nazaryan, T A; Hakobyan, A A; Adibekyan, V Zh; Kunth, D; Mamon, G A; Turatto, M; Aramyan, L S

    2013-01-01

    We investigate the influence of close neighbor galaxies on the properties of supernovae (SNe) and their host galaxies using 56 SNe located in pairs of galaxies with different levels of star formation (SF) and nuclear activity. The mean distance of type II SNe from nuclei of hosts is greater by about a factor of 2 than that of type Ibc SNe. The distributions and mean distances of SNe are consistent with previous results compiled with the larger sample. For the first time it is shown that SNe Ibc are located in pairs with significantly smaller difference of radial velocities between components than pairs containing SNe Ia and II. We consider this as a result of higher star formation rate (SFR) of these closer systems of galaxies.

  8. Evaluation of residue-residue contact prediction in CASP10

    KAUST Repository

    Monastyrskyy, Bohdan

    2013-08-31

    We present the results of the assessment of the intramolecular residue-residue contact predictions from 26 prediction groups participating in the 10th round of the CASP experiment. The most recently developed direct coupling analysis methods did not take part in the experiment likely because they require a very deep sequence alignment not available for any of the 114 CASP10 targets. The performance of contact prediction methods was evaluated with the measures used in previous CASPs (i.e., prediction accuracy and the difference between the distribution of the predicted contacts and that of all pairs of residues in the target protein), as well as new measures, such as the Matthews correlation coefficient, the area under the precision-recall curve and the ranks of the first correctly and incorrectly predicted contact. We also evaluated the ability to detect interdomain contacts and tested whether the difficulty of predicting contacts depends upon the protein length and the depth of the family sequence alignment. The analyses were carried out on the target domains for which structural homologs did not exist or were difficult to identify. The evaluation was performed for all types of contacts (short, medium, and long-range), with emphasis placed on long-range contacts, i.e. those involving residues separated by at least 24 residues along the sequence. The assessment suggests that the best CASP10 contact prediction methods perform at approximately the same level, and comparably to those participating in CASP9.

  9. Hadronic lepton pair production

    International Nuclear Information System (INIS)

    The author describes a beam dump experiment at the CERN SPS for the study of μ pair production by π+-, K+-, and p(anti p) beams on a copper target at 39.5 GeV/c. The dependence of the cross sections from various parameters is discussed. (HSI)

  10. Paired fuzzy sets

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco de los Ríos, Camilo; Gómez, Daniel;

    2015-01-01

    In this paper we want to stress the relevance of paired fuzzy sets, as already proposed in previous works of the authors, as a family of fuzzy sets that offers a unifying view for different models based upon the opposition of two fuzzy sets, simply allowing the existence of different types of...

  11. Shell Correction and Pairing Energies in the Dinuclear System Model

    Institute of Scientific and Technical Information of China (English)

    WANG Nan; LI Jun-Qing; ZHAO En-Guang

    2008-01-01

    We investigate the dependences of the potential energy surfaces(PES)and the fusion probabilities for some cold fusion reactions leading to super-heavy elements on the nuclear shell effect and pairing energy.It is found that the shell effect plays an important role in the fusion of the super-heavy element while pairing energy's contribution is insignificant.The fusion probabilities and evaporation residue cross sections as functions of the Ge-isotope projectile bombarding 208 Pb are also investigated.It is found that evaporation residue cross sections do not always increase with the increasing neutron number of Ge-isotope.

  12. Pulsational-Pair Instability Supernovae

    CERN Document Server

    Woosley, S E

    2016-01-01

    The final evolution of stars in the mass range 60 - 150 solar masses is explored. Depending upon their mass loss and rotation rates, many of these stars will end their lives as pulsational pair-instability supernovae. Even a non-rotating 70 solar mass star is pulsationally unstable during oxygen shell burning and can power a sub-luminous supernova. Rotation decreases the limit further. For more massive stars, the pulsations are less frequent, span a longer time, and are more powerful. Violent pulsations eject not only any residual low density envelope, but also that fraction of the helium core mass outside about 35 - 50 solar masses. The remaining core of helium and heavy elements continues to evolve, ultimately forming an iron core of about 2.5 solar masses that probably collapses to a black hole. A variety of observational transients result with total durations ranging from days to 10,000 years, and luminosities from 10$^{41}$ to 10$^{44}$ erg s$^{-1}$. Many transients resemble ordinary Type IIp supernovae,...

  13. A CA(+) pair adjacent to a sheared GA or AA pair stabilizes size-symmetric RNA internal loops.

    Science.gov (United States)

    Chen, Gang; Kennedy, Scott D; Turner, Douglas H

    2009-06-23

    RNA internal loops are often important sites for folding and function. Residues in internal loops can have pKa values shifted close to neutral pH because of the local structural environment. A series of RNA internal loops were studied at different pH by UV absorbance versus temperature melting experiments and imino proton nuclear magnetic resonance (NMR). A stabilizing CA pair forms at pH 7 in the CG/AA and CA/AA nearest neighbors when the CA pair is the first noncanonical pair (loop-terminal pair) in 3 x 3 nucleotide and larger size-symmetric internal loops. These CG/AA and CA/AA nearest neighbors, with CA adjacent to a closing Watson-Crick pair, are further stabilized when the pH is lowered from 7 to 5.5. The results are consistent with a significantly larger fraction (from approximately 20% at pH 7 to approximately 90% at pH 5.5) of adenines being protonated at the N1 position to form stabilizing wobble CA+ pairs adjacent to a sheared GA or AA pair. The noncanonical pair adjacent to the GA pair in CG/AA can either stabilize or destabilize the loop, consistent with the sequence-dependent thermodynamics of GA pairs. No significant pH-dependent stabilization is found for most of the other nearest neighbor combinations involving CA pairs (e.g., CA/AG and AG/CA), which is consistent with the formation of various nonwobble pairs observed in different local sequence contexts in crystal and NMR structures. A revised free-energy model, including stabilization by wobble CA+ pairs, is derived for predicting stabilities of medium-size RNA internal loops. PMID:19485416

  14. Coulomb pair-creation

    International Nuclear Information System (INIS)

    Electron-positron pair production in strong Coulomb fields is outlined. It is shown that the singular behaviour of the adiabatic basis can be removed if solutions of the time dependent external field Dirac equation are used as a basis to expand the fermion field operator. This latter 'asymptotic basis' makes it possible to introduce Feynman-propagator. Applying the reduction technique, the computation of all of the basic quantities can be reduced to the solution of an integral equation. The positron spectrum for separable potential model with Lorentzian time dependence and for potential jump is analyzed in the pole approximation. (author)

  15. Physiological aspects of paired stimulation

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1965-01-01

    In this paper some physiological and clinical aspects of paired stimulation are discussed. I) The augmenting effect of paired stimulation on rnyocardial contractility is due to potentiation (increase in speed of restitution) and fusion of two contractions. 2) While using paired stimulation the oxyg

  16. Parallel computation of cryptographic pairings

    International Nuclear Information System (INIS)

    The efficiency of multiprocessor systems for pairing computation has been estimated. Various schemes of efficient implementation of Miller's algorithm for computations of Weyl and Tate pairings in a multiprocessor computing system have been considered. The complexity of pairing computation in uniprocessor and multiprocessor computing systems has been theoretically estimated

  17. Cotorsion Pair Extensions

    Institute of Scientific and Technical Information of China (English)

    De Xu ZHOU

    2009-01-01

    Assume that S is an almost excellent extension of R. Using functors Hom R(S,-) and -(×)R S, we establish some connections between classes of modules (L)R and (L)S, cotorsion pairs ((A)R, (A)R)and ((A)S, (B)S). If (L)S is a T-extension or (and) H-extension of (L)R, we show that (L)S is a (resp., monomorphic, epimorphic, special) preenveloping class if and only if so is (L)R. If (S, S) is a TH-extension of ((A)R,(B)R), we obtain that ((A)S,(B)S) is complete (resp., of finite type, of cofinite type, hereditary, perfect, n-tilting) if and only if so is ((A)R,(B)R).

  18. Pairing in hadron structure

    International Nuclear Information System (INIS)

    A many-body approach to hadron structure is presented, in which we consider two parton species: spin-0 (b-partons), and spin-1/2 (f-partons). We extend a boson and a fermion pairing scheme for the b-, and f-partons respectively, into a Yang-Mills gauge theory. The main feature of this theory is that the gauge field is not identified with the usual gluon field variable in QCD. We study the confinement problem of the hadron constituents, and obtain, for low temperatures, partons that are confined by energy gaps. As the critical temperatures for the corresponding phase transitions are approached, the energy gap gradually disappears, and confinement is lost. The theory goes beyond the non-relativistic harmonic oscillator quark model, in the sense of giving physical reasons why a non-relativistic approximation is adequate in describing the internal dynamics of hadron structure. (author)

  19. Multiprocessor switch with selective pairing

    Energy Technology Data Exchange (ETDEWEB)

    Gara, Alan; Gschwind, Michael K; Salapura, Valentina

    2014-03-11

    System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus

  20. Multiple origins of asteroid pairs

    Science.gov (United States)

    Jacobson, Seth A.

    2016-01-01

    Rotationally fissioned asteroids produce unbound asteroid pairs that have very similar heliocentric orbits. Backward integration of their current heliocentric orbits provides an age of closest proximity that can be used to date the rotational fission event. Most asteroid pairs follow a predicted theoretical relationship between the primary spin period and the mass ratio of the two pair members that is a direct consequence of the YORP-induced rotational fission hypothesis. If the progenitor asteroid has strength, asteroid pairs may have higher mass ratios or faster rotating primaries. However, the process of secondary fission leaves the originally predicted trend unaltered. We also describe the characteristics of pair members produced by four alternative routes from a rotational fission event to an asteroid pair. Unlike direct formation from the event itself, the age of closest proximity of these pairs cannot generally be used to date the rotational fission event since considerable time may have passed.

  1. Stereo Pair, Honolulu, Oahu

    Science.gov (United States)

    2000-01-01

    Honolulu, on the island of Oahu, is a large and growing urban area. This stereoscopic image pair, combining a Landsat image with topography measured by the Shuttle Radar Topography Mission (SRTM), shows how topography controls the urban pattern. This color image can be viewed in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope.Features of interest in this scene include Diamond Head (an extinct volcano near the bottom of the image), Waikiki Beach (just above Diamond Head), the Punchbowl National Cemetary (another extinct volcano, near the image center), downtown Honolulu and Honolulu harbor (image left-center), and offshore reef patterns. The slopes of the Koolau mountain range are seen in the right half of the image. Clouds commonly hang above ridges and peaks of the Hawaiian Islands, but in this synthesized stereo rendition appear draped directly on the mountains. The clouds are actually about 1000 meters (3300 feet) above sea level.This stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with a Landsat 7 Thematic Mapper image collected at the same time as the SRTM flight. The topography data were used to create two differing perspectives, one for each eye. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. The United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota, provided the Landsat data.The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three-dimensional measurements of the Earth

  2. Stereo Pair, Pasadena, California

    Science.gov (United States)

    2000-01-01

    This stereoscopic image pair is a perspective view that shows the western part of the city of Pasadena, California, looking north toward the San Gabriel Mountains. Portions of the cities of Altadena and La Canada Flintridge are also shown. The cluster of large buildings left of center, at the base of the mountains, is the Jet Propulsion Laboratory. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Data shown in this image can be used to predict both how wildfires spread over the terrain and how mudflows are channeled down the canyons.The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation, U. S. Geological Survey digital aerial photography provided the image detail, and the Landsat Thematic Mapper provided the color. The United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota, provided the Landsat data and the aerial photography. The image can be viewed in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope.The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA

  3. Pairing the Volcano

    CERN Document Server

    Ionica, Sorina

    2011-01-01

    Isogeny volcanoes are graphs whose vertices are elliptic curves and whose edges are $\\ell$-isogenies. Algorithms allowing to travel on these graphs were developed by Kohel in his thesis (1996) and later on, by Fouquet and Morain (2001). However, up to now, no method was known, to predict, before taking a step on the volcano, the direction of this step. Hence, in Kohel's and Fouquet-Morain algorithms, many steps are taken before choosing the right direction. In particular, ascending or horizontal isogenies are usually found using a trial-and-error approach. In this paper, we propose an alternative method that efficiently finds all points $P$ of order $\\ell$ such that the subgroup generated by $P$ is the kernel of an horizontal or an ascending isogeny. In many cases, our method is faster than previous methods. This is an extended version of a paper published in the proceedings of ANTS 2010. In addition, we treat the case of 2-isogeny volcanoes and we derive from the group structure of the curve and the pairing ...

  4. Multiple origins of asteroid pairs

    CERN Document Server

    Jacobson, Seth A

    2015-01-01

    Rotationally fissioned asteroids produce unbound daughter asteroids that have very similar heliocentric orbits. Backward integration of their current heliocentric orbits provides an age of closest proximity that can be used to date the rotational fission event. Most asteroid pairs follow a predicted theoretical relationship between the primary spin period and the mass ratio of the two pair members that is a direct consequence of the YORP-induced rotational fission hypothesis. If the progenitor asteroid has strength, asteroid pairs may have high mass ratios with possibly fast rotating primaries. However, secondary fission leaves the originally predicted trend unaltered. We also describe the characteristics of pair members produced by four alternative routes from a rotational fission event to an asteroid pair. Unlike direct formation from the event itself, the age of closest proximity of these pairs cannot generally be used to date the rotational fission event since considerable time may have passed.

  5. Cooper pairs in atomic nuclei

    International Nuclear Information System (INIS)

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  6. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  7. Nanoampere pumping of Cooper pairs

    OpenAIRE

    Vartiainen, Juha J.; Möttönen, Mikko; Pekola, Jukka P.; Kemppinen, Antti

    2007-01-01

    The authors have employed a tunable Cooper-pair transistor, the sluice, with radio frequency control to pump current over a resistive circuit. They find that the charge transferred per pumping cycle can be controlled with the resolution of a single Cooper pair up to hundreds of pairs. The achieved nanoampere current features more than an order of magnitude improvement over the previously reported results and it is close to the theoretical maximum value for the measured sample.

  8. Nanoampere pumping of Cooper pairs

    OpenAIRE

    Vartiainen, Juha J.; Mottonen, Mikko; Pekola, Jukka; Kemppinen, Antti

    2006-01-01

    We have employed a tunable Cooper-pair transistor, the sluice, with radio frequency control to pump current over a resistive circuit. We find that the charge transferred per pumping cycle can be controlled with the resolution of a single Cooper-pair up to hundreds of pairs. The achieved nanoampere current features more than an order of magnitude improvement over the previously reported results and it is close to the theoretical maximum value for the measured sample.

  9. Controversies in kidney paired donation.

    Science.gov (United States)

    Gentry, Sommer E; Montgomery, Robert A; Segev, Dorry L

    2012-07-01

    Kidney paired donation represented 10% of living kidney donation in the United States in 2011. National registries around the world and several separate registries in the United States arrange paired donations, although with significant variations in their practices. Concerns about ethical considerations, clinical advisability, and the quantitative effectiveness of these approaches in paired donation result in these variations. For instance, although donor travel can be burdensome and might discourage paired donation, it was nearly universal until convincing analysis showed that living donor kidneys can sustain many hours of cold ischemia time without adverse consequences. Opinions also differ about whether the last donor in a chain of paired donation transplants initiated by a nondirected donor should donate immediately to someone on the deceased donor wait-list (a domino or closed chain) or should be asked to wait some length of time and donate to start another sequence of paired donations later (an open chain); some argue that asking the donor to donate later may be coercive, and others focus on balancing the probability that the waiting donor withdraws versus the number of additional transplants if the chain can be continued. Other controversies in paired donation include simultaneous versus nonsimultaneous donor operations, whether to enroll compatible pairs, and interactions with desensitization protocols. Efforts to expand public awareness of and participation in paired donation are needed to generate more transplant opportunities. PMID:22732046

  10. Pair Production by Ultraintense Lasers

    International Nuclear Information System (INIS)

    We consider the production of electron-positron pairs by the interaction of relativistic superthermal electrons, generated by ultraintense laser pulses, with high-Z material. We discuss the laser and target parameters required in order to optimize the pair-production rate. We explore the regime when the pairs, if sufficiently confined, can start to exponentiate in number and explore the feasibility of achieving a pair density approaching 1021cm-3 , (1) /(50) th that of solid-ion density. copyright 1998 The American Physical Society

  11. Cooper pairs in atomic nuclei

    CERN Document Server

    Dussel, G G; Dukelsky, J; Sarriguren, P

    2007-01-01

    We consider the development of Cooper pairs in a self-consistent Hartree Fock mean field for the even Sm isotopes. Results are presented at the level of a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson ansatz. While projected BCS captures much of the pairing correlation energy that is absent from BCS, it still misses a sizable correlation energy, typically of order $1 MeV$. Furthermore, because it does not average over the properties of the fermion pairs, the exact Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective.

  12. A two-level solvable model involving competing pairing interactions

    International Nuclear Information System (INIS)

    A model is considered consisting of nucleons moving in two non-degenerate l-shells and interacting through two pairing residual interactions with (S, T) = (1, 0) and (0, 1). These, together with the single particle hamiltonian induce mutually destructive correlations, giving rise to various collective pictures that can be discussed as representing a two-dimensional space of phases. The model is solved exactly using an O(8)xO(8) group theoretical classification scheme. The transfer of correlated pairs and quartets is also discussed. (orig.)

  13. The Simplex in Pair Comparisons

    Science.gov (United States)

    Bloxom, Bruce

    1972-01-01

    Paper develops a model which expresses pair comparisons as a function of (a) affective values which form a perfect simplex, (b) systematic (constant over replications) deviations from the simplex-structured affective values, and (c) errors of measurement for the pair comparisons. (Author)

  14. Kramers Pairs in Configuration Interaction

    DEFF Research Database (Denmark)

    Avery, John Scales; Avery, James Emil

    2003-01-01

    The theory of symmetry-preserving Kramers pair creation operators is reviewed and formulas for applying these operators to configuration interaction calculations are derived. A new and more general type of symmetry-preserving pair creation operator is proposed and shown to commute with the total...

  15. Pairing anti-halo effect

    International Nuclear Information System (INIS)

    We discuss pairing correlations in weakly bound neutron rich nuclei, by using the coordinate-space Hartree-Fock-Bogolyubov approach which allows to take properly into account the coupling to particle continuum. We show that the additional pairing binding energy acts against a development of an infinite rms radius, even in situations when an l=0 single-particle orbital becomes unbound. (author)

  16. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    XuChengqian; ZhaoXiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP)is proposed .A new class of block design-Difference Family Pair (DFP)is also proposed .The relationship between PCSP and DFP,the properties and exising conditions of PCSP and the recursive constructions for PCSP are given.

  17. PERIODIC COMPLEMENTARY BINARY SEQUENCE PAIRS

    Institute of Scientific and Technical Information of China (English)

    Xu Chengqian; Zhao Xiaoqun

    2002-01-01

    A new set of binary sequences-Periodic Complementary Binary Sequence Pair (PCSP) is proposed. A new class of block design-Difference Family Pair (DFP) is also proposed.The relationship between PCSP and DFP, the properties and existing conditions of PCSP and the recursive constructions for PCSP are given.

  18. Assessment Strategies for Pair Programming

    Science.gov (United States)

    Hahn, Jan Hendrik; Mentz, Elsa; Meyer, Lukas

    2009-01-01

    Although pair programming has proved its usefulness in teaching and learning programming skills, it is difficult to assess the individual roles and abilities of students whilst programming in pairs. (Note that within this manuscript, the term assessment refers to evaluating individual student performance.) Assessing only the outcomes of a pair…

  19. Vesícula residual Residual gallbladder

    Directory of Open Access Journals (Sweden)

    Júlio C. U. Coelho

    2002-12-01

    Full Text Available Our objective is to report three patients with recurrent severe upper abdominal pain secondary to residual gallbladder. All patients had been subjected to cholecystectomy from 1 to 20 years before. The diagnosis was established after several episodes of severe upper abdominal pain by imaging exams: ultrasonography, tomography, or endoscopic retrograde cholangiography. Removal of the residual gallbladder led to complete resolution of symptoms. Partial removal of the gallbladder is a very rare cause of postcholecystectomy symptoms.

  20. Property (RD) for Hecke Pairs

    Energy Technology Data Exchange (ETDEWEB)

    Shirbisheh, Vahid, E-mail: shirbisheh@gmail.com

    2012-06-15

    As the first step towards developing noncommutative geometry over Hecke C{sup Asterisk-Operator }-algebras, we study property (RD) (Rapid Decay) for Hecke pairs. When the subgroup H in a Hecke pair (G, H) is finite, we show that the Hecke pair (G, H) has (RD) if and only if G has (RD). This provides us with a family of examples of Hecke pairs with property (RD). We also adapt Paul Jolissant's works in Jolissaint (J K-Theory 2:723-735, 1989; Trans Amer Math Soc 317(1):167-196, 1990) to the setting of Hecke C{sup Asterisk-Operator }-algebras and show that when a Hecke pair (G, H) has property (RD), the algebra of rapidly decreasing functions on the set of double cosets is closed under holomorphic functional calculus of the associated (reduced) Hecke C{sup Asterisk-Operator }-algebra. Hence they have the same K{sub 0}-groups.

  1. Property (RD) for Hecke Pairs

    Science.gov (United States)

    Shirbisheh, Vahid

    2012-06-01

    As the first step towards developing noncommutative geometry over Hecke C ∗-algebras, we study property (RD) (Rapid Decay) for Hecke pairs. When the subgroup H in a Hecke pair ( G, H) is finite, we show that the Hecke pair ( G, H) has (RD) if and only if G has (RD). This provides us with a family of examples of Hecke pairs with property (RD). We also adapt Paul Jolissant's works in Jolissaint (J K-Theory 2:723-735, 1989; Trans Amer Math Soc 317(1):167-196, 1990) to the setting of Hecke C ∗-algebras and show that when a Hecke pair ( G, H) has property (RD), the algebra of rapidly decreasing functions on the set of double cosets is closed under holomorphic functional calculus of the associated (reduced) Hecke C ∗-algebra. Hence they have the same K 0-groups.

  2. Pairing correlations in exotic nuclei

    CERN Document Server

    Sagawa, H

    2012-01-01

    The BCS and HFB theories which can accommodate the pairing correlations in the ground states of atomic nuclei are presented. As an application of the pairing theories, we investigate the spatial extension of weakly bound Ne and C isotopes by taking into account the pairing correlation with the Hartree-Fock-Bogoliubov (HFB) method and a 3-body model, respectively. We show that the odd-even staggering in the reaction cross sections of $^{30,31,32}$Ne and $^{14,15,16}$C are successfully reproduced, and thus the staggering can be attributed to the unique role of pairing correlations in nuclei far from the stability line. A correlation between a one-neutron separation energy and the anti-halo effect is demonstrated for $s$- and p-waves using the HFB wave functions. We also propose effective density-dependent pairing interactions which reproduce both the neutron-neutron ($nn$) scattering length at zero density and the neutron pairing gap in uniform matter. Then, we apply these interactions to study pairing gaps in ...

  3. Viscosity coefficient with pairing interaction

    International Nuclear Information System (INIS)

    In the study of dynamic process (for example, deep-inelastic scattering of heavy ion, nuclear fission), viscosity, which describes the coupling between the intrinsic degrees of freedom and the collective one, is a basic quantity. In this paper, under BCS approximation, we derive a microscopic expression of viscosity coefficient with pairing interaction by means of a linear response theory. Taking the fission process of 236U as an example, we discuss the effect of pairing interaction on the viscosity coefficient. The results show that pairing interaction must be taken into account at lower temperature and can be neglected at a high-temperature region

  4. The q-analogue realization of nucleon-pairing

    International Nuclear Information System (INIS)

    A q-deformed analogue of zero-coupled nucleon pair-states is constructed and the possibility of accounting for pairing correlations examined. For single orbit case, the deformed pairs are found to be more strongly bound than the pairs with zero deformation, when a real valued q parameter is used. It is found that an appropriately scaled deformation parameter reproduces the empirical few nucleon binding energies for nucleons in 1f7/2 orbit and 1g9/2 orbit. The deformed pair Hamiltonian apparently accounts for many-body correlations, the strength of higher order force terms being determined by the deformation parameter q. An extension to the multi shell case, with deformed zero coupled pairs distributed over several single particle orbits, has been realised. An analysis of calculated and experimental ground state energies and the energy spectra of three lowermost 0+ states, for even-A Ca isotopes, reveals that the deformation simulates the effective residual interaction to a large extent. (author)

  5. Pairing mechanisms for binary stars

    CERN Document Server

    Kouwenhoven, M B N; Goodwin, S P; Zwart, S F Portegies; Kaper, L; 10.1002/asna.200811061

    2008-01-01

    Knowledge of the binary population in stellar groupings provides important information about the outcome of the star forming process in different environments. Binarity is also a key ingredient in stellar population studies and is a prerequisite to calibrate the binary evolution channels. In these proceedings we present an overview of several commonly used methods to pair individual stars into binary systems, which we refer to as the pairing function. Many pairing functions are frequently used by observers and computational astronomers, either for the mathematical convenience, or because they roughly describe the expected outcome of the star forming process. We discuss the consequences of each pairing function for the interpretation of observations and numerical simulations. The binary fraction and mass ratio distribution generally depend strongly on the selection of the range in primary spectral type in a sample. These quantities, when derived from a binary survey with a mass-limited sample of target stars, ...

  6. Pairing effects in Sn isotopes

    International Nuclear Information System (INIS)

    An extensive study of pairing effects in the Sn isotopes is carried out. The pairing Hamiltonian is treated by the chain-calculation method which provides practically exact solutions while involving less computational work than a complete-basis diagonalization. The coupling strength is fixed by reproducing the energy of the 9- state in 116Sn, while the single-particle energies have been determined by an analysis of the experimental low-energy spectra of the odd-A isotopes. A detailed comparison of the calculated results with experimental data evidences the importance of neutron pairing correlations in the 50-82 shell. The results of this paper complement those of our previous study of the N=82 isotones. It turns out that the role of pairing correlations is similar to a large extent in both cases. (orig.)

  7. Pairing effects in Sn isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, F. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Coraggio, L. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Covello, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Gargano, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy); Porrino, A. [Naples Univ. (Italy). Dipt. di Scienze Fisiche]|[Istituto Nazionale di Fisica Nucleare, Naples (Italy)

    1996-04-01

    An extensive study of pairing effects in the Sn isotopes is carried out. The pairing Hamiltonian is treated by the chain-calculation method which provides practically exact solutions while involving less computational work than a complete-basis diagonalization. The coupling strength is fixed by reproducing the energy of the 9{sup -} state in {sup 116}Sn, while the single-particle energies have been determined by an analysis of the experimental low-energy spectra of the odd-A isotopes. A detailed comparison of the calculated results with experimental data evidences the importance of neutron pairing correlations in the 50-82 shell. The results of this paper complement those of our previous study of the N=82 isotones. It turns out that the role of pairing correlations is similar to a large extent in both cases. (orig.)

  8. Pseudogap associated with precursor pairing

    OpenAIRE

    De Cao, Tian

    2009-01-01

    This work argues that the off-diagonal long range order (ODLRO) is not necessary for showing superconductivity while the electron pairing around Fermi surface is sufficient for superconductivity. It is shown that there exists the pseudogap state associated with the electron pairing in real space and the high temperature superconductivity could be only found in the metallic region near the Mott metal insulator transition (MIT).

  9. Pair programming: more than just working together in pairs.

    Directory of Open Access Journals (Sweden)

    Elsa Mentz

    2012-03-01

    Full Text Available Pair programming originated in the industry where focus is placed on the development of a programme at the most costand time-effective manner, and within the parameters of quality. In this context, a specific programming code is not developed individually; rather, two people work together in order to ensure a higher quality programming code and to motivate each other to work at a faster pace. The problem with this approach was that novice programmers lacked the social skills to work in pairs as they had not been exposed to this sufficiently at tertiary level. The demand of the industry, especially in terms of programmers needing to be able to programme together, led to the incorporation of pair programming at tertiary level in the late nineties. The pedagogical principles on which any teaching-learning strategy should be built were, however, largely overlooked during this process. This article firstly looks into the semantic and ontological differences between co-operative and collaborative learning and secondly argues that pair programming, within the context of a social constructivist approach to teaching and learning, can be seen as a co-operative teaching-learning strategy. Pair programming is more than just allowing two students to work together on a programming task. The more structured way, in which pair programming needs to be implemented, concur with the principles of co-operative learning. The article concludes that the correct pedagogical application of pair programming as a co-operative teaching-learning strategy in tertiary education will result in improved learning capital.

  10. Pair extended coupled cluster doubles

    CERN Document Server

    Henderson, Thomas M; Scuseria, Gustavo E

    2015-01-01

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreoever, pEC...

  11. Pairing effects in nuclear dynamic

    Science.gov (United States)

    Lacroix, Denis; Scamps, Guillaume; Tanimura, Yusuke

    2016-05-01

    In recent years, efforts have been made to account for super-fluidity in time-dependent mean-field description of nuclear dynamic [1-5]. Inclusion of pairing is important to achieve a realistic description of static properties of nuclei. Here,we show that pairing can also affect the nuclear motion. State of the art TDHF approach can describe from small to large amplitude collective motion as well as the collision between nuclei. Very recently, this microscopic approach has been improved to include pairing either in the BCS or HFB framework. Recent applications of the 3D TDHF + BCS (TDHF+BCS) model introduced in [4] will be presented. The role of super-fluidity on collective motion [6, 7], on one- and two-particle transfer [8] and on fission [9, 10] will be illustrated.

  12. Paired structures in knowledge representation

    DEFF Research Database (Denmark)

    Montero, J.; Bustince, H.; Franco de los Ríos, Camilo;

    2016-01-01

    In this position paper we propose a consistent and unifying view to all those basic knowledge representation models that are based on the existence of two somehow opposite fuzzy concepts. A number of these basic models can be found in fuzzy logic and multi-valued logic literature. Here it is...... paired structures, generated from two paired concepts together with their associated neutrality, all of them to be modeled as fuzzy sets. In this way, paired structures can be viewed as a standard basic model from which different models arise. This unifying view should therefore allow a deeper analysis...... of the relationships between several existing knowledge representation formalisms, providing a basis from which more expressive models can be later developed....

  13. Scoring Function Based on Weighted Residue Network

    Directory of Open Access Journals (Sweden)

    Shan Chang

    2011-12-01

    Full Text Available Molecular docking is an important method for the research of protein-protein interaction and recognition. A protein can be considered as a network when the residues are treated as its nodes. With the contact energy between residues as link weight, a weighted residue network is constructed in this paper. Two weighted parameters (strength and weighted average nearest neighbors’ degree are introduced into this model at the same time. The stability of a protein is characterized by its strength. The global topological properties of the protein-protein complex are reflected by the weighted average nearest neighbors’ degree. Based on this weighted network model and these two parameters, a new docking scoring function is proposed in this paper. The scoring and ranking for 42 systems’ bound and unbounded docking results are performed with this new scoring function. Comparing the results obtained from this new scoring function with that from the pair potentials scoring function, we found that this new scoring function has a similar performance to the pair potentials on some items, and this new scoring function can get a better success rate. The calculation of this new scoring function is easy, and the result of its scoring and ranking is acceptable. This work can help us better understand the mechanisms of protein-protein interactions and recognition.

  14. Orbiting pairs of walking droplets

    Science.gov (United States)

    Siefert, Emmanuel; Bush, John W. M.; Oza, Anand

    2015-11-01

    Droplets may self-propel on the surface of a vibrating fluid bath, pushed forward by their own Faraday pilot-wave field. We present the results of a combined experimental and theoretical investigation of the interaction of pairs of such droplets. Particular attention is given to characterizing the system's dependence on the vibrational forcing of the bath and the impact parameter of the walking droplets. Observed criteria for the capture and stability of orbital pairs are rationalized by accompanying theoretical developments. Thanks to the NSF.

  15. Instantons in lepton pair production

    International Nuclear Information System (INIS)

    We consider QCD instanton-induced contributions to lepton pair production in hadron-hadron collisions. We relate these contributions to those known from deep inelastic scattering and demonstrate that they can be calculated reliably for sufficiently large momentum transfer. We observe that the instanton contribution to the angular distribution of the lepton pairs at finite momentum transfer strongly violates the Lam-Tung relation - a relation between coefficient functions of the angular distribution which is valid within the framework of ordinary perturbation theory. The drastic violation of this relation, as seen in experimental data, might be related to such instanton-induced effects. (Orig.)

  16. Handling of Solid Residues

    International Nuclear Information System (INIS)

    The topic of solid residues is specifically of great interest and concern for the authorities, institutions and community that identify in them a true threat against the human health and the atmosphere in the related with the aesthetic deterioration of the urban centers and of the natural landscape; in the proliferation of vectorial transmitters of illnesses and the effect on the biodiversity. Inside the wide spectrum of topics that they keep relationship with the environmental protection, the inadequate handling of solid residues and residues dangerous squatter an important line in the definition of political and practical environmentally sustainable. The industrial development and the population's growth have originated a continuous increase in the production of solid residues; of equal it forms, their composition day after day is more heterogeneous. The base for the good handling includes the appropriate intervention of the different stages of an integral administration of residues, which include the separation in the source, the gathering, the handling, the use, treatment, final disposition and the institutional organization of the administration. The topic of the dangerous residues generates more expectation. These residues understand from those of pathogen type that are generated in the establishments of health that of hospital attention, until those of combustible, inflammable type, explosive, radio-active, volatile, corrosive, reagent or toxic, associated to numerous industrial processes, common in our countries in development

  17. Thiometon residues in cucumber

    International Nuclear Information System (INIS)

    In the Islamic Republic of Iran, vegetables are treated repeatedly with pesticides to control pests and diseases. Crops harvested shortly after pesticide application are probably contaminated by pesticides that are toxic to humans. Pesticide residues in vegetables are especially important, since these crops are ingested directly by humans. In recent years, farmers have been using more persistent pesticides to protect their crops because of increasing pesticide prices. Field trials were carried out to determine the residues of thiometon, a systemic insecticide used on cucumber. In 1993 and 1994, Ekatin (a 25% thiometon emulsifiable concentrate) was applied with a knapsack sprayer to cucumber (var. Daminus) at late flowering at dilutions of 1:1000 and 2:1000. Plots were 25 m2 in three replicates and were sampled 3, 6, 10, 15, 19 and 24 days after application. The samples were extracted with acetonitrile and cleanup was carried out using thin layer chromatography. Thiometon and two metabolites (thiometon sulphide and thiometon sulphone) were analyzed by gas chromatography. In 1994, the amount of thiometon sulphide determined 24 days treatment was 2 ppm in the peeled cucumber, which exceeded the maximum residue limit of 0.5 ppm. The total thiometon residues were higher in the peeled cucumber than those in the cucumber peel. Thus, peeling is ineffective for reducing the systemic residues of thiometon. Likewise, in this experiment lower dilution caused higher rather than lower thiometon residues in cucumber. The rapid disappearance of thiometon residues 2 weeks after treatment suggests that storing cucumbers at room temperature may be a better strategy for reducing excessive thiometon residues. Alternatively, a contact insecticide could be used. Thus, the bulk of the surface residues could be removed by washing or peeling. (author). 5 refs, 4 figs

  18. Optimized Combination of Residue Hydrodesulfurization and Residue Fluid Catalytic Cracking

    Institute of Scientific and Technical Information of China (English)

    Chen Junwu

    2003-01-01

    @@1 Introduction Combination of residue hydrodesulfurization (HDS) and resi-due fluid catalytic cracking (RFCC) is a unique technologyfor processing high-sulfur residue. This paper discusses theoptimized combination of these two processes.

  19. Scale-free behaviour of amino acid pair interactions in folded proteins

    DEFF Research Database (Denmark)

    Petersen, Steffen B.; Neves-Petersen, Maria Teresa; Mortensen, Rasmus J.;

    2012-01-01

    The protein structure is a cumulative result of interactions between amino acid residues interacting with each other through space and/or chemical bonds. Despite the large number of high resolution protein structures, the ‘‘protein structure code’’ has not been fully identified. Our manuscript...... presents a novel approach to protein structure analysis in order to identify rules for spatial packing of amino acid pairs in proteins. We have investigated 8706 high resolution non-redundant protein chains and quantified amino acid pair interactions in terms of solvent accessibility, spatial and sequence...... are in buried a-helices or b-strands, in a spatial distance of 3.8–4.3A° and in a sequence distance .4 residues. We speculate that the scale free organization of the amino acid pair interactions in the 8D protein structure combined with the clear dominance of pairs of Ala, Ile, Leu and Val is...

  20. Paired Reading: Psycholinguistics in Practice.

    Science.gov (United States)

    Barrett, James Martin

    1987-01-01

    Contends that children need to learn phonic skills, not necessarily through early direct teaching, but through reading experience. Suggests using Paired Reading, which is validated by psycholinguistic reading theory and provides opportunities to learn to read from context and use innate syntactic and semantic knowledge. (SKC)

  1. Direct-photon pair production

    International Nuclear Information System (INIS)

    This paper recalls some general aspects of direct-photon pair production at large Psub(T) in hadron collisions: The basic process qantiq→γγ; contributions from gg→γγ (via the quark box); possible resonant contributions; background problems due to indirect photons. A recent experiment performed at the ISR is finally described

  2. Calculation of two Belyi pairs

    OpenAIRE

    Dremov, V. A.

    2008-01-01

    We calculate two Belyi pairs using the properties of Mulase-Penkava differential. Details are provided including accurate construction of coordinates, variables and equations. The calculation is a part of the work which results in a catalogue arXiv:0710.2658

  3. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients in the...

  4. 1993 Waterfowl Breeding Pair Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Refuge breeding pair survey was conducted on the evening of April 29 from 5:40 pm until sunset at 7:40 pm. Weather consisted of clear skies, cool temperatures,...

  5. Pairing Linguistic and Music Intelligences

    Science.gov (United States)

    DiEdwardo, MaryAnn Pasda

    2005-01-01

    This article describes how music in the language classroom setting can be a catalyst for developing reading, writing, and understanding skills. Studies suggest that pairing music and linguistic intelligences in the college classroom improves students' grades and abilities to compose theses statements for research papers in courses that emphasize…

  6. Guanidinium Pairing Facilitates Membrane Translocation

    Czech Academy of Sciences Publication Activity Database

    Allolio, Christoph; Baxová, Katarína; Vazdar, M.; Jungwirth, Pavel

    2016-01-01

    Roč. 120, č. 1 (2016), s. 143-153. ISSN 1520-6106 R&D Projects: GA ČR GA13-06181S Institutional support: RVO:61388963 Keywords : ab initio molecular dynamics * guanidinium * like charge pairing * membrane Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.302, year: 2014

  7. Pairing interaction and Galilei invariance

    International Nuclear Information System (INIS)

    The relation between Galilei invariance and the energy weighted sum rule for a mass dipole operator is discussed using a monopole pairing interaction. It is found that the energy weighted sum rule for the mass dipole operator changes as much as 18% in medium and heavy nuclei. copyright 1997 The American Physical Society

  8. Paired natural cysteine mutation mapping: aid to constraining models of protein tertiary structure.

    OpenAIRE

    Kreisberg, R.; Buchner, V.; Arad, D.

    1995-01-01

    This paper discusses the benefit of mapping paired cysteine mutation patterns as a guide to identifying the positions of protein disulfide bonds. This information can facilitate the computer modeling of protein tertiary structure. First, a simple, paired natural-cysteine-mutation map is presented that identifies the positions of putative disulfide bonds in protein families. The method is based on the observation that if, during the process of evolution, a disulfide-bonded cysteine residue is ...

  9. Characterization of Hospital Residuals

    International Nuclear Information System (INIS)

    The main objective of this investigation is the characterization of the solid residuals. A description of the handling of the liquid and gassy waste generated in hospitals is also given, identifying the source where they originate. To achieve the proposed objective the work was divided in three stages: The first one was the planning and the coordination with each hospital center, in this way, to determine the schedule of gathering of the waste can be possible. In the second stage a fieldwork was made; it consisted in gathering the quantitative and qualitative information of the general state of the handling of residuals. In the third and last stage, the information previously obtained was organized to express the results as the production rate per day by bed, generation of solid residuals for sampled services, type of solid residuals and density of the same ones. With the obtained results, approaches are settled down to either determine design parameters for final disposition whether for incineration, trituration, sanitary filler or recycling of some materials, and storage politics of the solid residuals that allow to determine the gathering frequency. The study concludes that it is necessary to improve the conditions of the residuals handling in some aspects, to provide the cleaning personnel of the equipment for gathering disposition and of security, minimum to carry out this work efficiently, and to maintain a control of all the dangerous waste, like sharp or polluted materials. In this way, an appreciable reduction is guaranteed in the impact on the atmosphere. (Author)

  10. Examination of pairs in neutrino mixing matrix

    CERN Document Server

    Liu, Dianjing

    2015-01-01

    We exam the pairs of neutrino mixing matrix and suggest pairs that can be used in the construction of new mixing patterns, with "pair" denoting the equality of the modulus of a pair of matrix elements. The results show that the tri-maximal mixing in $\

  11. Tri-residue contact potential: a new knowledge-based energetic method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new knowledge-based potential method, the tri-residue contact potential (TRICP), is proposed. This approach resembles the idea of environment-dependent residue contact energy reported by Zhang et al. We statistically study the 3-dimensional structure of proteins and calculate the knowledge-based contact potential of tri-residue clusters. These contact potentials are carefully compared to pairwise contact potentials (PCP). TRICP helps us to systematically examine the impact on the interactions of residue pairs by the third residue. Moreover, TRICP provides us with many clues to identify high frequency characteristic structural units in protein structures.

  12. How to motivate developers to pair program?

    OpenAIRE

    Haara, Johanna

    2016-01-01

    Many developers are needed to develop large software. Successful development demands communication and teamwork and pair programming improves them. One practice of Extreme Programming is pair programming, which means that developers work together a task. This case study studied how to motivate developers to pair program. The benefits, cost and ways to pair program were studied. In addition, affect of general motivation and Belbin’s team roles to pair programming were studied. The study w...

  13. A plant DNA-binding protein that recognizes 5-methylcytosine residues.

    OpenAIRE

    Zhang, D. L.; Ehrlich, K C; Supakar, P C; Ehrlich, M

    1989-01-01

    A novel, 5-methylcytosine-specific, DNA-binding protein, DBP-m, has been identified in nuclear extracts of peas. DBP-m specifically recognizes 5-methylcytosine residues in DNA without appreciable DNA sequence specificity, unlike a mammalian DNA-binding protein (MDBP), which recognizes 5-methylcytosine residues but only in a related family of 14-base-pair sequences.

  14. Pairing theory of striped superconductivity

    International Nuclear Information System (INIS)

    Striped high-Tc superconductors such as La7/8Ba1/8CuO4 show a fascinating competition between spin and charge order on the one hand and superconductivity on the other. A theory for these systems therefore has to capture both the spin correlations in an antiferromagnet and the pair-correlation of a superconductor. For this purpose we have developed an effective Hartree-Fock theory by merging electron pairing with finite center-of-mass momentum and antiferromagnetism. We show that this theory reproduces the key experimental features such as the formation of the antiferromagnetic stripe patterns at 7/8 band filling or the quasi one-dimensional electronic structure observed by photoemission spectroscopy.

  15. Klt singularities of horospherical pairs

    OpenAIRE

    Pasquier, Boris

    2015-01-01

    Let $X$ be a horospherical $G$-variety and let $D$ be an effective $\\mathbb{Q}$-divisor of $X$ that is stable under the action of a Borel subgroup $B$ of $G$ and such that $D+K\\_X$ is $\\mathbb{Q}$-Cartier. We prove, using Bott-Samelson resolutions, that the pair $(X,D)$ is klt if and only if $\\lfloor D\\rfloor=0$

  16. Differential Bloch Oscillating Transistor Pair

    OpenAIRE

    Sarkar, Jayanta; Puska, Antti; Hassel, Juha; Hakonen, Pertti J.

    2013-01-01

    We examine a Bloch Oscillating Transistor pair as a differential stage for cryogenic low-noise measurements. Using two oppositely biased, nearly symmetric Bloch Oscillating Transistors, we measured the sum and difference signals in the current gain and transconductance modes while changing the common mode signal, either voltage or current. From the common mode rejection ratio we find values $\\sim 20$ dB even under non-optimal conditions. We also characterize the noise properties and obtain ex...

  17. Hyperdimensional analysis of amino acid pair distributions in proteins.

    Directory of Open Access Journals (Sweden)

    Svend B Henriksen

    Full Text Available Our manuscript presents a novel approach to protein structure analyses. We have organized an 8-dimensional data cube with protein 3D-structural information from 8706 high-resolution non-redundant protein-chains with the aim of identifying packing rules at the amino acid pair level. The cube contains information about amino acid type, solvent accessibility, spatial and sequence distance, secondary structure and sequence length. We are able to pose structural queries to the data cube using program ProPack. The response is a 1, 2 or 3D graph. Whereas the response is of a statistical nature, the user can obtain an instant list of all PDB-structures where such pair is found. The user may select a particular structure, which is displayed highlighting the pair in question. The user may pose millions of different queries and for each one he will receive the answer in a few seconds. In order to demonstrate the capabilities of the data cube as well as the programs, we have selected well known structural features, disulphide bridges and salt bridges, where we illustrate how the queries are posed, and how answers are given. Motifs involving cysteines such as disulphide bridges, zinc-fingers and iron-sulfur clusters are clearly identified and differentiated. ProPack also reveals that whereas pairs of Lys residues virtually never appear in close spatial proximity, pairs of Arg are abundant and appear at close spatial distance, contrasting the belief that electrostatic repulsion would prevent this juxtaposition and that Arg-Lys is perceived as a conservative mutation. The presented programs can find and visualize novel packing preferences in proteins structures allowing the user to unravel correlations between pairs of amino acids. The new tools allow the user to view statistical information and visualize instantly the structures that underpin the statistical information, which is far from trivial with most other SW tools for protein structure analysis.

  18. One-dimensional Cooper pairing

    International Nuclear Information System (INIS)

    Exact solutions for electron pairing in a 1D Fermi gas under different separable interactions. Energy dispersion relations for arbitrary values of center-of-mass momenta and interaction strengths. Results reveal linear and roton-like modes. Effects due to finite range parameters in the interaction. We study electron pairing in a one-dimensional (1D) fermion gas at zero temperature under zero- and finite-range, attractive, two-body interactions. The binding energy of Cooper pairs (CPs) with zero total or center-of-mass momentum (CMM) increases with attraction strength and decreases with interaction range for fixed strength. The excitation energy of 1D CPs with nonzero CMM display novel, unique properties. It satisfies a dispersion relation with two branches: a phonon-like linear excitation for small CP CMM; this is followed by roton-like quadratic excitation minimum for CMM greater than twice the Fermi wavenumber, but only above a minimum threshold attraction strength. The expected quadratic-in-CMM dispersion in vacuo when the Fermi wavenumber is set to zero is recovered for any coupling. This paper completes a three-part exploration initiated in 2D and continued in 3D.

  19. Management of NORM Residues

    International Nuclear Information System (INIS)

    The IAEA attaches great importance to the dissemination of information that can assist Member States in the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support the nuclear fuel cycle and nuclear applications, and that address the legacy of past practices and accidents. However, radioactive residues are found not only in nuclear fuel cycle activities, but also in a range of other industrial activities, including: - Mining and milling of metalliferous and non-metallic ores; - Production of non-nuclear fuels, including coal, oil and gas; - Extraction and purification of water (e.g. in the generation of geothermal energy, as drinking and industrial process water; in paper and pulp manufacturing processes); - Production of industrial minerals, including phosphate, clay and building materials; - Use of radionuclides, such as thorium, for properties other than their radioactivity. Naturally occurring radioactive material (NORM) may lead to exposures at some stage of these processes and in the use or reuse of products, residues or wastes. Several IAEA publications address NORM issues with a special focus on some of the more relevant industrial operations. This publication attempts to provide guidance on managing residues arising from different NORM type industries, and on pertinent residue management strategies and technologies, to help Member States gain perspectives on the management of NORM residues

  20. The interacting galaxy pair KPG 390: H$\\alpha$ kinematics

    CERN Document Server

    Repetto, P; Gabbasov, R; Fuentes-Carrera, I

    2010-01-01

    In this work we present scanning Fabry-Perot H$\\alpha$ observations of the isolated interacting galaxy pair NGC 5278/79 obtained with the PUMA Fabry-Perot interferometer. We derived velocity fields and rotation curves for both galaxies. For NGC 5278 we also obtained the residual velocity map to investigate the non-circular motions, and estimated its mass by fitting the rotation curve with a disk+halo components. We test three different types of halo (pseudo-isothermal, Hernquist and Navarro Frenk White) and obtain satisfactory fits to the rotation curve for all profiles. The amount of dark matter required by pseudo-isothermal profile is about ten times smaller than, that for the other two halo distributions. Finally, our kinematical results together with the analysis of dust lanes distribution and of surface brightness profiles along the minor axis allowed us to determine univocally that both components of the interacting pair are trailing spirals.

  1. Pair and single neutron transfer with Borromean 8He

    International Nuclear Information System (INIS)

    Direct observation of the survival of 199Au residues after 2n transfer in the 8He+197Au system and the absence of the corresponding 67Cu in the 8He+65Cu system at various energies are reported. The measurements of the surprisingly large cross sections for 199Au, coupled with the integral cross sections for the various Au residues, is used to obtain the first model-independent lower limits on the ratio of 2n to 1n transfer cross sections from 8He to a heavy target. A comparison of the transfer cross sections for 6,8He on these targets highlights the differences in the interactions of these Borromean nuclei. These measurements for the most neutron-rich nuclei on different targets highlight the need to probe the reaction mechanism with various targets and represent an experimental advance towards understanding specific features of pairing in the dynamics of dilute nuclear systems.

  2. Compton Scattering, Pair Annihilation and Pair Production in a Plasma

    OpenAIRE

    Krishan, Vinod

    1999-01-01

    The square of the four momentum of a photon in vacuum is zero. However, in an unmagnetized plasma it is equal to the square of the plasma frequency. Further, the electron-photon coupling vertex is modified in a plasma to include the effect of the plasma medium. I calculate the cross sections of the three processes - the Compton scattering, electron-positron pair annihilation and production in a plasma. At high plasma densities, the cross sections are found to change significantly. Such high p...

  3. Photon pair generation in multimode optical fibers via intermodal phase matching

    Science.gov (United States)

    Pourbeyram, Hamed; Mafi, Arash

    2016-08-01

    We present a detailed study of photon pair generation in a multimode optical fiber via nonlinear four-wave mixing and intermodal phase matching. We show that in multimode optical fibers, it is possible to generate correlated photon pairs in different fiber modes with large spectral shifts from the pump wavelength, such that the photon pairs are immune to contamination from spontaneous Raman scattering and residual pump photons. We also show that it is possible to generate factorable two-photon states exhibiting minimal spectral correlations between the photon pair components in conventional multimode fibers using commonly available pump lasers. It is also possible to simultaneously generate multiple factorable states from different FWM processes in the same fiber and over a wide range of visible spectrum by varying the pump wavelength without affecting the factorability of the states. Therefore, photon pair generation in multimode optical fibers exhibits considerable potential for producing state engineered photons for quantum communications and quantum information processing applications.

  4. Photon pair generation in multimode optical fibers via intermodal phase-matching

    CERN Document Server

    Pourbeyram, Hamed

    2016-01-01

    We present a detailed study of photon-pair generation in a multimode optical fiber via nonlinear four-wave mixing and intermodal phase-matching. We show that in multimode optical fibers, it is possible to generate correlated photon pairs in different fiber modes with large spectral shifts from the pump wavelength, such that the photon pairs are immune to contamination from spontaneous Raman scattering and residual pump photons. We also show that it is possible to generate factorable two-photon states exhibiting minimal spectral correlations between the photon pair components in conventional multimode fibers using commonly available pump lasers. It is also possible to simultaneously generate multiple factorable states from different FWM processes in the same fiber and over a wide range of visible spectrum by varying the pump wavelength without affecting the factorability of the states. Therefore, photon-pair generation in multimode optical fibers exhibits considerable potential for producing state engineered p...

  5. Top-pair production in hadron collisions at NNLL

    Directory of Open Access Journals (Sweden)

    Ubiali M.

    2013-05-01

    Full Text Available We present results for the total top-pair production cross section at the Tevatron and the LHC. Our predictions supplement fixed-order results with resummation of soft logarithms and Coulomb singularities to next-to-next-to-leading logarithmic accuracy and include top-antitop bound-state effects. The effects of resummation, the dependence on the PDF set used, the residual sources of theoretical uncertainty and their implication for measurements of the top-quark mass are discussed.

  6. Residual-stress measurements

    International Nuclear Information System (INIS)

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author)

  7. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A.N.; Webster, G.A. [Imperial College, London (United Kingdom); Webster, P.J. [Salford Univ. (United Kingdom)

    1997-04-01

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  8. Sharing Residual Liability

    DEFF Research Database (Denmark)

    Carbonara, Emanuela; Guerra, Alice; Parisi, Francesco

    2016-01-01

    Economic models of tort law evaluate the efficiency of liability rules in terms of care and activity levels. A liability regime is optimal when it creates incentives to maximize the value of risky activities net of accident and precaution costs. The allocation of primary and residual liability...... allows policy makers to induce parties to undertake socially desirable care and activity levels. Traditionally, tort law systems have assigned residual liability either entirely on the tortfeasor or entirely on the victim. In this paper, we unpack the cheapest-cost-avoider principle to consider the...

  9. Residues of Chern classes

    OpenAIRE

    Suwa, Tatsuo; 諏訪, 立雄

    2003-01-01

    If we have a finite number of sections of a complex vector bundle E over a manifold M, certain Chern classes of E are localized at the singular set S, i.e., the set of points where the sections fail to be linearly independent. When S is compact, the localizations define the residues at each connected component of S by the Alexander duality. If M itself is compact, the sum of the residues is equal to the Poincaré dual of the corresponding Chern class. This type of theory is also developed for ...

  10. Residues of Chern classes

    OpenAIRE

    Suwa, Tatsuo

    2003-01-01

    If we have a finite number of sections of a complex vector bundle $E$ over a manifold $M$ , certain Chern classes of $E$ are localized at the singular set $S$ , i.e., the set of points where the sections fail to be linearly independent. When $S$ is compact, the localizations define the residues at each connected component of $S$ by the Alexander duality. If $M$ itself is compact, the sum of the residues is equal to the Poincaré dual of the corresponding Chern class. This type of theory is als...

  11. Residual stresses within sprayed coatings

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi; XU Bin-shi; WANG Hai-dou

    2005-01-01

    Some important developments of residual stress researches for coating-based systems were studied. The following topics were included the sources of residual stresses in coatings: error analysis of Stoney's equation in the curvature method used for the measurement of coating residual stress, the modeling of residual stress and some analytical models for predicting the residual stresses in coatings. These topics should provide some important insights for the fail-safe design of the coating-based systems.

  12. Neutron-Proton pairing revisited

    OpenAIRE

    Friedman, W. A.; Bertsch, G. F.

    2007-01-01

    We reexamine neutron-proton pairing as a phenomenon that should be explanable in a microscopic theory of nuclear binding energies. Empirically, there is an increased separation energy when both neutron and proton numbers are even or if they are both odd. The enhancement is present at some level in nearly all nuclei: the separation energy difference has the opposite sign in less than 1% of the cases in which sufficient data exist. We discuss the possible origin of the effect in the context of ...

  13. Working pairs for resorption refrigerator

    International Nuclear Information System (INIS)

    The performances of three chemisorption working pairs operating under the resorption cycle were studied gravimetrically by comparing the desorbed and adsorbed mass of refrigerant in different operation conditions. All pairs used NH3 as refrigerant and MnCl2 in the main reactor, but each one used a different salt for the cooling effect production in the secondary reactor. These salts were NH4Cl or NaBr or BaCl2. The experimental results indicated that the degree of conversion in reaction between the NH3 and BaCl2 was inferior to 25% during cooling production at 0 oC or below, whereas the reactions with the other salts had conversions of at least 80%. When the systems operated with heat source temperature for the main reactor at 155 oC, heat sink temperature for both reactors at 30 oC, and cooling effect production temperature at 0 oC the coefficient of performance (COP) of the system using NH4Cl and the system using NaBr were similar and around 0.30; however, the former system had a specific cooling power (SCP) 5% higher than that of the latter system. Because the reaction in the system with NH4Cl was practically halted in a period much shorter than that used in the experiments, it is possible to expect that if the period of the cooling period was shortened, the difference between the SCP of those systems would be much higher. - Highlights: → The comparison of three different working pairs operating under resorption cycle was conducted. → The three working pairs were NH4Cl/MnCl2, NaBr/MnCl2, BaCl2/MnCl2, respectively. → The mass of refrigerant reacted in different situations were measured and compared. → Among the LTS studied, NH4Cl is the most suitable to be used in a resorption machine at 0 or below 0 oC.

  14. Percentile residual life orders

    OpenAIRE

    Franco Pereira, Alba M.; Lillo, Rosa E.; Romo, Juan; Shaked, Moshe

    2011-01-01

    In this paper we study a family of stochastic orders of random variables defined via the comparison of their percentile residual life functions. Some interpretations of these stochastic orders are given, and various properties of them are derived. The relationships to other stochastic orders are also studied. Finally, some applications in reliability theory and finance are described.

  15. Wood residues in Alberta

    International Nuclear Information System (INIS)

    The forest products industry is the third largest economic sector in Alberta, producing pulp and paper, dimensional lumber, paneling, and value added products, providing some 40,000 jobs . 'Value added' is a key component of expanding economic activity within the forest products sector. Wood residues can play a key role in obtaining more value from forest resources by providing new products, serving as feedstock to energy and chemical production, and playing a role in agriculture and land reclamation. One of the principal roles of the Forest Products Development Branch of the Alberta Economics Department is to encourage the development of the industry by creating new uses for these materials and developing awareness of the scope of the resource. Distances to markets, economic competition from conventional energy sources and coordination of research efforts are substantial barriers to further development that the Forest Products Development Branch has to face daily. Some notable successes in recent years are described. These include the Wood Residue Inventory and the Wood Residue Database that provide data on availability and principal location of wood residues, also a listing of contacts at the mills who produce the materials

  16. Generation of potential/surface density pairs in flat disks Power law distributions

    CERN Document Server

    Hure, J -M; Pierens, A

    2007-01-01

    We report a simple method to generate potential/surface density pairs in flat axially symmetric finite size disks. Potential/surface density pairs consist of a ``homogeneous'' pair (a closed form expression) corresponding to a uniform disk, and a ``residual'' pair. This residual component is converted into an infinite series of integrals over the radial extent of the disk. For a certain class of surface density distributions (like power laws of the radius), this series is fully analytical. The extraction of the homogeneous pair is equivalent to a convergence acceleration technique, in a matematical sense. In the case of power law distributions, the convergence rate of the residual series is shown to be cubic inside the source. As a consequence, very accurate potential values are obtained by low order truncation of the series. At zero order, relative errors on potential values do not exceed a few percent typically, and scale with the order N of truncation as 1/N**3. This method is superior to the classical mul...

  17. Nowitna NWR breeding pair survey, 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a waterfowl breeding pair survey taken on Nowitna National Wildlife Refuge in 1988. The breeding pair survey was conducted 31...

  18. Stability theorems for symplectic and contact pairs

    OpenAIRE

    Bande, G.; Ghiggini, P.; Kotschick, D.

    2004-01-01

    We prove Gray--Moser stability theorems for complementary pairs of forms of constant class defining symplectic pairs, contact-symplectic pairs and contact pairs. We also consider the case of contact-symplectic and contact-contact structures, in which the constant class condition on a one-form is replaced by the condition that its kernel hyperplane distribution have constant class in the sense of E. Cartan.

  19. Pair bonds: arrival synchrony in migratory birds.

    Science.gov (United States)

    Gunnarsson, T G; Gill, J A; Sigurbjörnsson, T; Sutherland, W J

    2004-10-01

    Synchronous arrival of pairs of migratory birds at their breeding grounds is important for maintaining pair bonds and is achieved by pairs that remain together all year round. Here we show that arrival is also synchronized in paired individuals of a migratory shorebird, the black-tailed godwit (Limosa limosa islandica), even though they winter hundreds of kilometres apart and do not migrate together. The mechanisms required to achieve this synchrony and prevent 'divorce' illustrate the complexity of migratory systems. PMID:15470417

  20. Properties of isocalar-pair condensates

    CERN Document Server

    Van Isacker, P; Fallon, P; Zerguine, S

    2016-01-01

    It is pointed out that the ground state of n neutrons and n protons in a single-j shell, interacting through an isoscalar (T=0) pairing force, is not paired, J=0, but rather spin-aligned, J=n. This observation is explained in the context of a model of isoscalar P (J=1) pairs, which is mapped onto a system of p bosons, leading to an approximate analytic solution of the isoscalar-pairing limit in jj coupling.

  1. Drift wave in pair-ion plasma

    Indian Academy of Sciences (India)

    Samiran Ghosh; Nikhil Chakrabarti; Manoranjan Khan; M R Gupta

    2013-02-01

    The conditions for the existence of low-frequency electrostatic drift wave in pair-ion plasma are discussed. It is shown that the temperature and/or mass difference of both species could produce drift wave in a pair-ion plasma. The results are discussed in the context of the fullerene pair-ion plasma experiment.

  2. On one-sided torsion pair

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Motivated by the concept of a torsion pair in a pre-triangulated category induced by Beligiannis and Reiten, the notion of a left (right) torsion pair in the left (right) triangulated category is introduced and investigated. We provide new connections between different aspects of torsion pairs in one-sided triangulated categories, pre-triangulated categories, stable categories and derived categories.

  3. Angular momentum decomposition of Richardson's pairs

    International Nuclear Information System (INIS)

    The angular momentum decomposition of pairs obtained using Richardson's exact solution of the pairing Hamiltonian for the deformed 174Yb nucleus are displayed. The probabilities for low angular momenta of the collective pairs are strikingly different from the ones obtained in the BCS ground state

  4. High spin exotic states and new method for pairing energy

    International Nuclear Information System (INIS)

    We present a new method called 'PSY-MB', initially developed in the framework of abstract group theory for the solution of the problem of strongly interacting multi-fermionic systems with particular to systems in an external rotating field. The validity of the new method (PSY-MB) is tested on model Hamiltonians. A detailed comparison between the obtained solutions and the exact ones is performed. The new method is used in the study of realistic nuclear Hamiltonians based on the Woods-Saxon potential within the cranking approximation to study the influence of residual monopole pairing interactions in the rare-earth mass region. In parallel with this new technique we present original results obtained with the Woods-Saxon mean-field and the self-consistent Hartree-Fock approximation in order to investigate such exotic effects as octupole deformations and hexadecapole C4-polarizing deformations in the framework of high-spin physics. By developing these three approaches in one single work we prepare the ground for the nuclear structure calculations of the new generation - where the residual two-body interactions are taken into account also in the weak pairing limit. (author)

  5. Designing with residual materials

    OpenAIRE

    Walhout, W.; Wever, R; Blom, E.; Addink-Dölle, L.; Tempelman, E.

    2013-01-01

    Many entrepreneurial businesses have attempted to create value based on the residual material streams of third parties. Based on ‘waste’ materials they designed products, around which they built their company. Such activities have the potential to yield sustainable products. Many of such companies remain in the more artistic domain, with relatively labor-intensive products, and small batch sizes. Moving beyond such small-scale activities would likely require a standardized innovation process....

  6. Direct-photon pair production

    International Nuclear Information System (INIS)

    Direct-photon pair production in high-energy hadron collisions is considered. After discussing general aspects of such reactions and giving a brief historical survey of that subject, we present some calculations on the contributions from q anti-q and g g collisions (the latter via the quark box) to the γγ continuum, and on possible resonant contributions. Finally, an estimation of the indirect-photon background (mainly due to π0 and eta decay, and to quark bremsstrahlung) is given for colliding-beam conditions at high energy; assuming both photons to be measured at 900 with equal and opposite momenta, and (within experimental limits) unaccompanied by any hadrons or additional photons, it is shown that this background can be sharply reduced

  7. Perturbations of vortex ring pairs

    CERN Document Server

    Gubser, Steven S; Parikh, Sarthak

    2015-01-01

    We study pairs of co-axial vortex rings starting from the action for a classical bosonic string in a three-form background. We complete earlier work on the phase diagram of classical orbits by explicitly considering the case where the circulations of the two vortex rings are equal and opposite. We then go on to study perturbations, focusing on cases where the relevant four-dimensional transfer matrix splits into two-dimensional blocks. When the circulations of the rings have the same sign, instabilities are mostly limited to wavelengths smaller than a dynamically generated length scale at which single-ring instabilities occur. When the circulations have the opposite sign, larger wavelength instabilities can occur.

  8. Perturbations of vortex ring pairs

    Science.gov (United States)

    Gubser, Steven S.; Horn, Bart; Parikh, Sarthak

    2016-02-01

    We study pairs of coaxial vortex rings starting from the action for a classical bosonic string in a three-form background. We complete earlier work on the phase diagram of classical orbits by explicitly considering the case where the circulations of the two vortex rings are equal and opposite. We then go on to study perturbations, focusing on cases where the relevant four-dimensional transfer matrix splits into two-dimensional blocks. When the circulations of the rings have the same sign, instabilities are mostly limited to wavelengths smaller than a dynamically generated length scale at which single-ring instabilities occur. When the circulations have the opposite sign, larger wavelength instabilities can occur.

  9. QUANTUM CRYPTOGRAPHY WITH PHOTON PAIRS

    Directory of Open Access Journals (Sweden)

    Anand Sharma,

    2010-07-01

    Full Text Available Quantum cryptographic systems use quantum mechanical concepts that are based on qubit superposition of states, and on the no cloning or no copying theorem to establish unbreakable cipher keys. The basic idea of quantum cryptography is to send the key in the form of photons over a public channel, encoding the zeros and one on quantum states in such a way that any eavesdropping attempt can be detected. Using optical communications the most commonly quantum mechanical property used is the polarization state of photon. However, in most quantum cryptographic algorithms a random polarization state is required. The photons are ideal for low loss transport, either in free space or in optical fibers, i.e. we have the full arsenal of fiber optic technology at our disposal. In this paper we are describing the process of quantum cryptography with photon pairs.

  10. Residual contaminants in milk

    Directory of Open Access Journals (Sweden)

    Nevijo Zdolec

    2006-07-01

    Full Text Available Various chemical agents are used during the whole production chain of milk and dairy products. Production of feedingstuffs is accompanied with pesticide usage, which may remain in environment, thus are transported through feeding into animals, animal products and finally in human organism. Preparation procedure and storage conditions of feed also influence on milk safety in the sense of mycotoxins entering into the food chain. Chemical agents are, on daily basis, used on dairy farms either as detergents or disinfections. The residuals of cleaning agents might remain in milk if the cleaning agents and its dosage are not performed adequately. Besides already mentioned agents, a great influence in milk production can bee seen through veterinary drugs usage, particularly antibacterial drugs (mastitis. Proper application of drugs and by following legal recommendation, a by-reactions can be avoided such as allergic reaction in humans, development of resisting bacteria or even undesirable influence on starter cultures in dairy products manufacture. The maximum residue limits, monitoring plan as well as sampling procedures are set up within the harmonization of Croatian and European legislation, in order to provide official control of residues in foodstuffs of animal origin.

  11. Factors affecting home range of mallard pairs

    Energy Technology Data Exchange (ETDEWEB)

    Riechmann, J.H.

    1976-06-01

    Certain habitat and social factors were investigated for their effect on home range size of mallard (Anas platyhynchos) pairs breeding in a forested region of north-central Minnesota during the spring of 1971--72. Data from 31 radio-marked hens and drakes were used, but primary emphasis was placed on 8 pairs (5 with both members of the pair marked). Pairs were radio-tracked on river marsh areas, river channels, and large sand lakes to provide comparative data for evaluating home range size differences. Home ranges varied from an average of 53 ha for pairs using primarily river habitat to 871 ha for pairs using only large sand lakes. River and lake shorelines varied considerably in species and density of vegetation. Interaction between pairs as well as density of flocked males appeared to be influenced by these habitat differences with resultant effects on home range sizes.

  12. On Minus Paired-Domination in Graphs

    Institute of Scientific and Technical Information of China (English)

    邢化明; 孙良

    2003-01-01

    The study of minus paired-domination of a graph G=(V,E) is initiated. Let SV be any paired-dominating set of G, a minus paired-dominating function is a function of the form f∶V→{-1,0,1} such that f(v)=1 for v∈S, f(v)≤0 for v∈V-S, and f(N[v])≥1 for all v∈V. The weight of a minus paired-dominating function f is w(f)=∑f(v), over all vertices v∈V. The minus paired-domination number of a graph G is γ-p(G)=min{w(f)|f is a minus paired-dominating function of G}. On the basis of the minus paired-domination number of a graph G defined, some of its properties are discussed.

  13. N\\'eron's pairing and relative algebraic equivalence

    CERN Document Server

    Pépin, Cédric

    2011-01-01

    Let R be a complete discrete valuation ring with algebraically closed residue field k and fraction field K. Let X_K be a projective smooth and geometrically connected scheme over K. N\\'eron defined a canonical pairing on X_K between 0-cycles of degree zero and divisors which are algebraically equivalent to zero. When X_K is an abelian variety, and if one restricts to those 0-cycles supported by K-rational points, N\\'eron gave an expression of his pairing involving intersection multiplicities on the N\\'eron model A of A_K over R. When X_K is a curve, Gross and Hriljac gave independantly an analogous description of N\\'eron's pairing, but for arbitrary 0-cycles of degree zero, by means of intersection theory on a proper flat regular R-model X of X_K. In this article, we show that these intersection computations are valid for an arbitrary scheme X_K as above and arbitrary 0-cyles of degree zero, by using a proper flat normal and semi-factorial model X of X_K over R. When X_K=A_K is an abelian variety, and X is a ...

  14. Integrated analysis of residue coevolution and protein structure in ABC transporters.

    Directory of Open Access Journals (Sweden)

    Attila Gulyás-Kovács

    Full Text Available Intraprotein side chain contacts can couple the evolutionary process of amino acid substitution at one position to that at another. This coupling, known as residue coevolution, may vary in strength. Conserved contacts thus not only define 3-dimensional protein structure, but also indicate which residue-residue interactions are crucial to a protein's function. Therefore, prediction of strongly coevolving residue-pairs helps clarify molecular mechanisms underlying function. Previously, various coevolution detectors have been employed separately to predict these pairs purely from multiple sequence alignments, while disregarding available structural information. This study introduces an integrative framework that improves the accuracy of such predictions, relative to previous approaches, by combining multiple coevolution detectors and incorporating structural contact information. This framework is applied to the ABC-B and ABC-C transporter families, which include the drug exporter P-glycoprotein involved in multidrug resistance of cancer cells, as well as the CFTR chloride channel linked to cystic fibrosis disease. The predicted coevolving pairs are further analyzed based on conformational changes inferred from outward- and inward-facing transporter structures. The analysis suggests that some pairs coevolved to directly regulate conformational changes of the alternating-access transport mechanism, while others to stabilize rigid-body-like components of the protein structure. Moreover, some identified pairs correspond to residues previously implicated in cystic fibrosis.

  15. End-to-end and end-to-middle interhelical interactions: new classes of interacting helix pairs in protein structures

    International Nuclear Information System (INIS)

    New classes of helix–helix interactions in protein structures are reported in which interactions only occur at the terminal regions or between the terminal region of one helix and the middle region of another helix. Helix–helix interactions are important for the structure, stability and function of α-helical proteins. Helices that either cross in the middle or show extensive contacts between each other, such as coiled coils, have been investigated in previous studies. Interactions between two helices can also occur only at the terminal regions or between the terminal region of one helix and the middle region of another helix. Examples of such helix pairs are found in aquaporin, H+/Cl− transporter and Bcl-2 proteins. The frequency of the occurrence of such ‘end-to-end’ (EE) and ‘end-to-middle’ (EM) helix pairs in protein structures is not known. Questions regarding the residue preferences in the interface and the mode of interhelical interactions in such helix pairs also remain unanswered. In this study, high-resolution structures of all-α proteins from the PDB have been systematically analyzed and the helix pairs that interact only in EE or EM fashion have been extracted. EE and EM helix pairs have been categorized into five classes (N–N, N–C, C–C, N–MID and C–MID) depending on the region of interaction. Nearly 13% of 5725 helix pairs belonged to one of the five classes. Analysis of single-residue propensities indicated that hydrophobic and polar residues prefer to occur in the C-terminal and N-terminal regions, respectively. Hydrophobic C-terminal interacting residues and polar N-terminal interacting residues are also highly conserved. A strong correlation exists between some of the residue properties (surface area/volume and length of side chains) and their preferences for occurring in the interface of EE and EM helix pairs. In contrast to interacting non-EE/EM helix pairs, helices in EE and EM pairs are farther apart. In these helix

  16. Residue-based Coordinated Selection and Parameter Design of Multiple Power System Stabilizers (PSSs)

    DEFF Research Database (Denmark)

    Su, Chi; Hu, Weihao; Fang, Jiakun; Chen, Zhe

    data from time domain simulations. Then a coordinated approach for multiple PSS selection and parameter design based on residue method is proposed and realized in MATLAB m-files. Particle swarm optimization (PSO) is adopted in the coordination process. The IEEE 39-bus New England system model as the......Residue method is a commonly used approach to design the parameters of a power system stabilizer (PSS). In this paper, a residue identification method is adopted to obtain the system residues for different input-output pairs, using the system identification toolbox in MATLAB with the measurement...

  17. Study on properties of residue-residue contacts in protein

    Institute of Scientific and Technical Information of China (English)

    王向红; 柯见洪; 郑亦庄; 陈爱; 徐银香

    2004-01-01

    Residue-residue contacts are very important in forming protein structure. In this work, we calculated the average probability of residue-residue contacts in 470 globular proteins and analyzed the distribution of contacts in the different interval of residues using Contacts of Structural Units (CSU) and Structural Classification (SCOP) software. It was found that the relationship between the average probability PL and the residue distance L for four structural classes of proteins could be expressed as lgPL=a+b×L, where a and b are coefficients. We also discussed the connection between two aspects of proteins which have equal array residue number and found that the distribution probability was stable (or un-stable) if the proteins had the same (or different) comnact (for examnle svnthase) in the same structural class.

  18. Study on properties of residue-residue contacts in protein

    Institute of Scientific and Technical Information of China (English)

    王向红; 柯见洪; 郑亦庄; 陈爱; 徐银香

    2004-01-01

    Residue-residue contacts are very important in forming protein structure. In this work, we calculated theaverage probability of residue-residue contacts in 470 globular proteins and analyzed the distribution of contacts in thedifferent interval of residues using Contacts of Structural Units (CSU) and Structural Classification (SCOP) software. Itwas found that the relationship between the average probability -PL and the residue distance L for four structural classes ofproteins could be expressed as lgPL=a+b×L, where a and b are coefficients. We also discussed the connection between twoaspects of proteins which have equal array residue number and found that the distribution probability was stable (or un-stable) if the proteins had the same (or different) compact (for example synthase) in the same structural class.

  19. A-Site Residues Move Independently from P-Site Residues in all-Atom Molecular Dynamics Simulations of the 70S Bacterial Ribosome

    OpenAIRE

    Relly Brandman; Yigal Brandman; Pande, Vijay S.

    2012-01-01

    The ribosome is a large macromolecular machine, and correlated motion between residues is necessary for coordinating function across multiple protein and RNA chains. We ran two all-atom, explicit solvent molecular dynamics simulations of the bacterial ribosome and calculated correlated motion between residue pairs by using mutual information. Because of the short timescales of our simulation (ns), we expect that dynamics are largely local fluctuations around the crystal structure. We hypothes...

  20. Report on Pairing-based Cryptography.

    Science.gov (United States)

    Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

    2015-01-01

    This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed. PMID:26958435

  1. Cognitive residues of similarity

    OpenAIRE

    OToole, Stephanie; Keane, Mark T.

    2013-01-01

    What are the cognitive after-effects of making a similarity judgement? What, cognitively, is left behind and what effect might these residues have on subsequent processing? In this paper, we probe for such after-effects using a visual search task, performed after a task in which pictures of real-world objects were compared. So, target objects were first presented in a comparison task (e.g., rate the similarity of this object to another) thus, presumably, modifying some of their features befor...

  2. Bioenergy from sisal residues

    Energy Technology Data Exchange (ETDEWEB)

    Jungersen, G. [Dansk Teknologisk Inst. (Denmark); Kivaisi, A.; Rubindamayugi, M. [Univ. of Dar es Salaam (Tanzania, United Republic of)

    1998-05-01

    The main objectives of this report are: To analyse the bioenergy potential of the Tanzanian agro-industries, with special emphasis on the Sisal industry, the largest producer of agro-industrial residues in Tanzania; and to upgrade the human capacity and research potential of the Applied Microbiology Unit at the University of Dar es Salaam, in order to ensure a scientific and technological support for future operation and implementation of biogas facilities and anaerobic water treatment systems. The experimental work on sisal residues contains the following issues: Optimal reactor set-up and performance; Pre-treatment methods for treatment of fibre fraction in order to increase the methane yield; Evaluation of the requirement for nutrient addition; Evaluation of the potential for bioethanol production from sisal bulbs. The processing of sisal leaves into dry fibres (decortication) has traditionally been done by the wet processing method, which consumes considerable quantities of water and produces large quantities of waste water. The Tanzania Sisal Authority (TSA) is now developing a dry decortication method, which consumes less water and produces a waste product with 12-15% TS, which is feasible for treatment in CSTR systems (Continously Stirred Tank Reactors). (EG)

  3. Pairing and specific heat in hot nuclei

    OpenAIRE

    Gambacurta, Danilo; Lacroix, Denis; Sandulescu, Nicu

    2013-01-01

    The thermodynamics of pairing phase-transition in nuclei is studied in the canonical ensemble and treating the pairing correlations in a finite-temperature variation after projection BCS approach (FT-VAP). Due to the restoration of particle number conservation, the pairing gap and the specific heat calculated in the FT-VAP approach vary smoothly with the temperature, indicating a gradual transition from the superfluid to the normal phase, as expected in finite systems. We have checked that th...

  4. Pair Creation of Black Holes During Inflation

    OpenAIRE

    Bousso, Raphael; Hawking, Stephen W.

    1996-01-01

    Black holes came into existence together with the universe through the quantum process of pair creation in the inflationary era. We present the instantons responsible for this process and calculate the pair creation rate from the no boundary proposal for the wave function of the universe. We find that this proposal leads to physically sensible results, which fit in with other descriptions of pair creation, while the tunnelling proposal makes unphysical predictions. We then describe how the pa...

  5. Dispersion Compensation using a Prism-pair

    OpenAIRE

    Shaked, Yaakov; Yefet, Shai; Pe'er, Avi

    2014-01-01

    A simple and intuitive formulation is reviewed for the Brewster prism-pair - A most common component in spectroscopy-oriented experiments using ultrashort pulses. This review aims to provide students and beginners in the field of spectroscopy with a unified description of a major experimental component. The total spectral phase experienced by a broadband light field is calculated after passing through a pair of Brewster-cut prisms, demonstrating the flexibility of the prism pair to provide tu...

  6. Top pair production distributions at the Tevatron

    Directory of Open Access Journals (Sweden)

    Takeuchi Yuji

    2013-05-01

    Full Text Available At the Tevatron, the top quark is mainly produced in pairs through the strong interaction and decays before forming hadrons. Thus the kinematical distributions at top pair production possess rich information on the tt¯$tar t$ production vertex including polarizations of top and anti-top quarks. In this article, recent measurements on top quark pair production distributions at Tevatron (CDF and DO are presented.

  7. A New Secure Pairing Protocol using Biometrics

    OpenAIRE

    Buhan, I.R.

    2008-01-01

    Secure Pairing enables two devices, which share no prior context with each other, to agree upon a security association that they can use to protect their subsequent communication. Secure pairing offers guarantees of the association partner identity and it should be resistant to eavesdropping or to a man-in-the-middle attack. We propose a user friendly solution to this problem. Keys extracted from biometric data of the participants are used for authentication. Details of the pairing protocol a...

  8. Density dependence of the pairing interaction and pairing correlation in unstable nuclei

    CERN Document Server

    Changizi, S A

    2015-01-01

    This work aims at a global assessment of the effect of the density dependence of the zero-range pairing interaction. Systematic Skyrme-Hartree-Fock-Bogoliubov calculations with the volume, surface and mixed pairing forces are carried out to study the pairing gaps in even-even nuclei over the whole nuclear chart. Calculations are also done in coordinate representation for unstable semi-magic even-even nuclei. The calculated pairing gaps are compared with empirical values from four different odd-even staggering formulae. Calculations with the three pairing interactions are comparable for most nuclei close to $\\beta$-stability line. However, the surface interaction calculations predict neutron pairing gaps in neutron-rich nuclei that are significantly stronger than those given by the mixed and volume pairing. On the other hand, calculations with volume and mixed pairing forces show noticeable reduction of neutron pairing gaps in nuclei far from the stability.

  9. A pair of solar spike emissions

    Institute of Scientific and Technical Information of China (English)

    LIU; Yuying(刘玉英); FU; Qijun(傅其骏); QIN; Zhihai(秦志海); HUANG; Guangli(黄光力); WANG; Ming(汪敏)

    2002-01-01

    Using the 2.6-3.8 GHz solar radio spectrometer of the National Astronomical Observatories of China (NAOC), a pair of microwave millisecond spike (MMS) emissions were observed, and their frequency drift rate was measured. The separatrix frequency of the MMS pair was at 2900 MHz. Its emission layer was about 2×104km above the photosphere. The polarization degree was wave-like variation with an average value of about 25% in LCP. An MMS pair differs greatly from the type III bursts pair. For the latter, in a certain frequency range, there is no emission around separatrix frequency. This phenomenon may help better understand the mechanism of MMS.

  10. Lax pairs for deformed Minkowski spacetimes

    CERN Document Server

    Kyono, Hideki; Yoshida, Kentaroh

    2015-01-01

    We proceed to study Yang-Baxter deformations of 4D Minkowski spacetime based on a conformal embedding. We first revisit a Melvin background and argue a Lax pair by adopting a simple replacement law invented in 1509.00173. This argument enables us to deduce a general expression of Lax pair. Then the anticipated Lax pair is shown to work for arbitrary classical $r$-matrices with Poinca\\'e generators. As other examples, we present Lax pairs for pp-wave backgrounds, the Hashimoto-Sethi background, the Spradlin-Takayanagi-Volovich background.

  11. Lax pairs for deformed Minkowski spacetimes

    Science.gov (United States)

    Kyono, Hideki; Sakamoto, Jun-ichi; Yoshida, Kentaroh

    2016-01-01

    We proceed to study Yang-Baxter deformations of 4D Minkowski spacetime based on a conformal embedding. We first revisit a Melvin background and argue a Lax pair by adopting a simple replacement law invented in 1509.00173. This argument enables us to deduce a general expression of Lax pair. Then the anticipated Lax pair is shown to work for arbitrary classical r-matrices with Poincaré generators. As other examples, we present Lax pairs for pp-wave backgrounds, the Hashimoto-Sethi background, the Spradlin-Takayanagi-Volovich background.

  12. Transrelativistic pair plasmas in AGN jets

    DEFF Research Database (Denmark)

    Bottcher, M.; Pohl, M.; Schlickeiser, R.

    1999-01-01

    Models of relativistic jets filled with ultrarelativistic pair plasma are very successful in explaining the broadband radiation of gamma-ray blazars. Assuming that the initial injection and cooling of ultrarelativistic pair plasma in an AGN jet has occurred, producing the observed high-energy gamma......-ray radiation, we investigate the further evolution of the pair plasma as it continues to move out from the central engine. The effects of thermalization and reacceleration, the emission of pair bremsstrahlung and annihilation radiation and the bulk Compton process, and the possible application to MeV blazars...

  13. Biochemical evidence for the requirement of Hoogsteen base pairing for replication by human DNA polymerase iota.

    Science.gov (United States)

    Johnson, Robert E; Prakash, Louise; Prakash, Satya

    2005-07-26

    Because of the near geometric identity of Watson-Crick (W-C) GxC and AxT base pairs, a given DNA polymerase forms the four possible correct base pairs with nearly identical catalytic efficiencies. However, human DNA polymerase iota (Pol iota), a member of the Y family of DNA polymerases, exhibits a marked template specificity, being more efficient at incorporating the correct nucleotide opposite template purines than opposite pyrimidines. By using 7-deazaadenine and 7-deazaguanine as the templating residues, which disrupt Hoogsteen base pair formation, we show that, unlike the other DNA polymerases belonging to the A, B, or Y family, DNA synthesis by Pol iota is severely inhibited by these N7-modified bases. These observations provide biochemical evidence that, during normal DNA synthesis, template purines adopt a syn conformation in the Pol iota active site, enabling the formation of a Hoogsteen base pair with the incoming pyrimidine nucleotide. Additionally, mutational studies with Leu-62, which lies in close proximity to the templating residue in the Pol iota ternary complex, have indicated that both factors, steric constraints within the active site and the stability provided by the hydrogen bonds in the Hoogsteen base pair, contribute to the efficiency of correct nucleotide incorporation opposite template purines by Pol iota. PMID:16014707

  14. Development of the BNFL Vitrified Residue Transport Flask

    International Nuclear Information System (INIS)

    The BNFL Vitrified Residue Flask has been designed by Nuclear Transport Limited (NTL), an associated company of BNFL. The body comprises a cylindrical shell and base manufactured from forged carbon manganese steel, with a stainless steel lid bolted to it. Silicon rubber neutron shielding is encapsulated in compartments at the flask ends and between the cooling fins. Removable shock absorbers are bolted to both ends, and two pairs of bolted trunnions are fitted for lifting and tie-down. The flask carries 21 vitrified residue containers in a support structure made up of 30 cast aluminium segments secured by a bolting system to the internal flask cavity. This assembled support structure forms seven circular channels to receive the vitrified residue containers. (J.P.N.)

  15. Residual gas analyzer calibration

    Science.gov (United States)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  16. Pair plasma in pulsar magnetospheres

    International Nuclear Information System (INIS)

    The main features of radiation received from pulsars imply that they are neutron stars which contain an extremely intense magnetic field and emit coherently in the radio domain. Most recent studies attribute the origin of the coherence to plasma instabilities arising in pulsar magnetospheres; they mainly concern the linear, or the nonlinear, character of the involved unstable waves. We briefly introduce radio pulsars and specify physical conditions in pulsar emission regions: geometrical properties, magnetic field, pair creation processes and repartition of relativistic charged particles. We point to the main ingredients of the linear theory, extensively explored since the 1970s: (i) a dispersion relation specific to the pulsar case; (ii) the characteristics of the waves able to propagate in relativistic pulsar plasmas; (iii) the different ways in which a two-humped distribution of particles may arise in a pulsar magnetosphere and favour the development of a two-stream instability. We sum up recent improvements of the linear theory: (i) the determination of a 'coupling function' responsible for high values of the wave field components and electromagnetic energy available; (ii) the obtention of new dispersion relations for actually anisotropic pulsar plasmas with relativistic motions and temperatures; (iii) the interaction between a plasma and a beam, both with relativistic motions and temperatures; (iv) the interpretation of observed 'coral' and 'conal' features, associated with the presence of boundaries and curved magnetic field lines in the emission region; (v) the detailed topology of the magnetic field in the different parts of the emission region and its relation to models recently proposed to interpret drifting subpulses observed from PSR 0943+10, showing 20 sub-beams of emission. We relate the nonlinear evolution of the two-stream instability and development of strong turbulence in relativistic pulsar plasmas to the emergence of relativistic solitons, able

  17. A Review of Pair-wise Testing

    OpenAIRE

    Sanchez, Jimi

    2016-01-01

    In software testing, the large size of the input domain makes exhaustively testing the inputs a daunting and often impossible task. Pair-wise testing is a popular approach to combinatorial testing problems. This paper reviews Pair-wise testing and its history, strengths, weaknesses, and tools for generating test cases.

  18. Pair Programming in Education: A Literature Review

    Science.gov (United States)

    Hanks, Brian; Fitzgerald, Sue; McCauley, Renee; Murphy, Laurie; Zander, Carol

    2011-01-01

    This article provides a review of educational research literature focused on pair programming in the undergraduate computer science curriculum. Research suggests that the benefits of pair programming include increased success rates in introductory courses, increased retention in the major, higher quality software, higher student confidence in…

  19. Bonnet Pairs of Surfaces in Minkowski Space

    OpenAIRE

    Grantcharov, G.; Salom, R.

    2012-01-01

    We review some results about Bonnet pairs in Minkowski space obtained using split quaternions and split complex numbers. We present also an example of Bonnet pairs of minimal immersed timelike tori with umbilical points. Such examples do not exists in the Euclidean space.

  20. Superfluid characteristics of induced-pairing model

    International Nuclear Information System (INIS)

    We study electromagnetic and thermodynamic properties of a model coexisting local electron pairs and itinerant carriers coupled via the intersubsystem charge exchange. The calculations of the London penetration depth, energy gap, the magnetic critical fields and the coherence length in the superconducting phase are performed. The effects of reducing binding energy of local pairs are discussed. (author)

  1. A Separable Pairing Force in Nuclear Matter

    Institute of Scientific and Technical Information of China (English)

    TIAN Yuan; MA Zhong-Yu

    2006-01-01

    The method introduced by Duguet is adopted to derive a separable form of the pairing interaction in the 1 S0channel from a bare or an effective nucleon-nucleon (NN) interaction in nuclear matter. With this approach the separable pairing interaction reproduces the pairing properties provided by its corresponding NN interaction. In this work, separable forms of pairing interactions in the 1 S0 channel for the bare NN interaction, Bonn potential and the Gogny effective interaction are obtained. It is found that the separable force of the Gogny effective interaction in the 1 S0 channel has a clear link with the bare NN interaction. With such a simple separable form pairing properties provided by the Gogny force in nuclear matter can be reproduced.

  2. Materials recovery from shredder residues

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, E. J.; Jody, B. J.; Pomykala, J., Jr.

    2000-07-24

    Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources.

  3. Surgical Treatment of Residual Esotropia

    OpenAIRE

    Mravičić, Ivana; Gabrić, Nikica; Pasalić, Adis; Glavota, Vlade; Drača, Nataša

    2011-01-01

    Residual esotropia is a common problem following bilateral medial rectus (MR) recessions for esotropia. The patient was 30 years old men who underwent billateral MR recession of both eyes in the childhood. Recession was repeated on the right eye few years after the first surgery, but residual esotropia progressed. Prior to our surgery residual angle of esotropia was 50PD° with restriction of abduction and elevation of the left eye. Sinechiolysis et myectomia of right MR and sinech...

  4. Microwave emission and crop residues

    Science.gov (United States)

    Jackson, Thomas J.; O'Neill, Peggy E.

    1991-01-01

    A series of controlled experiments were conducted to determine the significance of crop residues or stubble in estimating the emission of the underlying soil. Observations using truck-mounted L and C band passive microwave radiometers showed that for dry wheat and soybeans the dry residue caused negligible attenuation of the background emission. Green residues, with water contents typical of standing crops, did have a significant effect on the background emission. Results for these green residues also indicated that extremes in plant structure, as created using parallel and perpendicular stalk orientations, can cause very large differences in the degree of attenuation.

  5. SRTM Stereo Pair: Fiji Islands

    Science.gov (United States)

    2000-01-01

    image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.This image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (about 200 feet) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.Size: 192 km (119 miles) x 142 km (88 miles) Location: 17.8 deg. South lat., 178.0 deg. East lon. Orientation: North at top Date Acquired: February 19, 2000 Image: NASA/JPL/NIMA

  6. String pair production in non homogeneous backgrounds

    Science.gov (United States)

    Bolognesi, S.; Rabinovici, E.; Tallarita, G.

    2016-04-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  7. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.;

    1999-01-01

    A pair in a string is the occurrence of the same substring twice. A pair is maximal if the two occurrences of the substring cannot be extended to the left and right without making them different. The gap of a pair is the number of characters between the two occurrences of the substring. In this...... paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

  8. P-wave Cooper pair splitting

    Directory of Open Access Journals (Sweden)

    Henning Soller

    2012-07-01

    Full Text Available Background: Splitting of Cooper pairs has recently been realized experimentally for s-wave Cooper pairs. A split Cooper pair represents an entangled two-electron pair state, which has possible application in on-chip quantum computation. Likewise the spin-activity of interfaces in nanoscale tunnel junctions has been investigated theoretically and experimentally in recent years. However, the possible implications of spin-active interfaces in Cooper pair splitters so far have not been investigated.Results: We analyze the current and the cross correlation of currents in a superconductor–ferromagnet beam splitter, including spin-active scattering. Using the Hamiltonian formalism, we calculate the cumulant-generating function of charge transfer. As a first step, we discuss characteristics of the conductance for crossed Andreev reflection in superconductor–ferromagnet beam splitters with s-wave and p-wave superconductors and no spin-active scattering. In a second step, we consider spin-active scattering and show how to realize p-wave splitting using only an s-wave superconductor, through the process of spin-flipped crossed Andreev reflection. We present results for the conductance and cross correlations.Conclusion: Spin-activity of interfaces in Cooper pair splitters allows for new features in ordinary s-wave Cooper pair splitters, that can otherwise only be realized by using p-wave superconductors. In particular, it provides access to Bell states that are different from the typical spin singlet state.

  9. On tide-induced lagrangian residual current and residual transport: 1. Lagrangian residual current

    Science.gov (United States)

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi

    1986-01-01

    Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.

  10. English for au pairs the au pair's guide to learning English

    CERN Document Server

    Curtis, Lucy

    2014-01-01

    English for Au Pairs has interlinked stories about a group of au pairs new to England. Marta, an 18-year-old from Poland arrives in the UK to work as an au pair. Throughout her year-long stay she has many different experiences - some bad, some good - but with the support of her host family she finds new friends and improves her English. English for Au Pairs offers insight into the joys and difficulties of being an au pair while at the same time reinforcing English language learning through grammar explanations and exercises.

  11. Separation of photo-induced radical pair in cryptochrome to a functionally critical distance

    OpenAIRE

    Solov'yov, Ilia A.; Domratcheva, Tatiana; Schulten, Klaus

    2014-01-01

    Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical molecular dynamics calculations. The results reveal how sequential electron transfer, assisted by rearra...

  12. A Curious Pair of Galaxies

    Science.gov (United States)

    2009-03-01

    The ESO Very Large Telescope has taken the best image ever of a strange and chaotic duo of interwoven galaxies. The images also contain some surprises -- interlopers both far and near. ESO PR Photo 11a/09 A Curious Pair of Galaxies ESO PR Video 11a/09 Arp 261 zoom in ESO PR Video 11b/09 Pan over Arp 261 Sometimes objects in the sky that appear strange, or different from normal, have a story to tell and prove scientifically very rewarding. This was the idea behind Halton Arp's catalogue of Peculiar Galaxies that appeared in the 1960s. One of the oddballs listed there is Arp 261, which has now been imaged in more detail than ever before using the FORS2 instrument on ESO's Very Large Telescope. The image proves to contain several surprises. Arp 261 lies about 70 million light-years distant in the constellation of Libra, the Scales. Its chaotic and very unusual structure is created by the interaction of two galaxies that are engaged in a slow motion, but highly disruptive close encounter. Although individual stars are very unlikely to collide in such an event, the huge clouds of gas and dust certainly do crash into each other at high speed, leading to the formation of bright new clusters of very hot stars that are clearly seen in the picture. The paths of the existing stars in the galaxies are also dramatically disrupted, creating the faint swirls extending to the upper left and lower right of the image. Both interacting galaxies were probably dwarfs not unlike the Magellanic Clouds orbiting our own galaxy. The images used to create this picture were not actually taken to study the interacting galaxies at all, but to investigate the properties of the inconspicuous object just to the right of the brightest part of Arp 261 and close to the centre of the image. This is an unusual exploding star, called SN 1995N, that is thought to be the result of the final collapse of a massive star at the end of its life, a so-called core collapse supernova. SN 1995N is unusual because

  13. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi;

    2002-01-01

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling of...

  14. On the average pairing energy in nuclei

    International Nuclear Information System (INIS)

    The macroscopic-microscopic method is applied to calculate the nuclear energies, especially the microscopic shell and pairing corrections. The single-particle levels are obtained with the Yukawa folded mean-field potential. The macroscopic energy is evaluated using the Lublin-Strasbourg Drop model. The shell corrections are obtained using the Strutinsky method with smoothing in nucleon number space. The average nuclear pairing energy is also determined by folding the BCS sums in nucleon number space. The average pairing energy dependence on the nuclear elongation is investigated. (author)

  15. Becoming independent through au pair migration

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    article argues that, despite this critique, au pairing does play an important formative role for young Filipinas because it opens up for experiences abroad that enable them to be recognised as independent adults in Philippine society. Rather than autonomy, however, au pairs define their independence in...... terms of their capacity to assume responsibility for others, thereby achieving a position of social respect. Based on ethnographic fieldwork in Denmark and the Philippines, this article explores how young Filipinas use the social, economic, and cultural resources they gain from their au pair stay abroad...

  16. Categorical Pairs and the Indicative Shift

    OpenAIRE

    Kauffman, Louis H.

    2011-01-01

    This paper introduces the notion of a categorical pair, a pair of categories (C,C') such that every morphism in C is an object in C'. Categorical pairs are precursors to 2-categories. Arrows in C' can express relationships among the morphisms of C. In particular we show that by using a model of the linguistic process of naming, we can ensure that every morphism in C has an indirect self-reference of the form a -----> Fa where this arrow occurs in the category C'. This result is shown to gener...

  17. Hydrologic calibration of paired watersheds using a MOSUM approach

    Science.gov (United States)

    Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.

    2015-01-01

    Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1-3 year intensively managed loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14-15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash-Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.

  18. Hydrologic calibration of paired watersheds using a MOSUM approach

    Directory of Open Access Journals (Sweden)

    H. Ssegane

    2015-01-01

    Full Text Available Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment during the calibration (pre-treatment and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managed loblolly pine (Pinus taeda L. with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum, 14–15 year thinned loblolly pine with natural understory (control, and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.

  19. Implementation of New Pairing Technique for Studying the Effectiveness of Pairs on Persona and Programming

    Directory of Open Access Journals (Sweden)

    HARSIMARJEET KHURANA

    2011-01-01

    Full Text Available This paper reports on a study in which persona for the category of paired and solo students were compared on the parameter like program clarity, presentation, satisfaction level and confidence level, also the effectiveness of pairs in a JAVA programming language and the impact of pairs on each other. In this study same programs were given to all the category of paired and solo students. Finding reported in this paper are that pairing students were more likely to turn in working programs, and these programs were correctly implemented with more required features as compared to solo students. It has been observed that pairing of intelligent, average and poor with themselves has not shown significant differences but we have seen significant differences with combination of pairs.

  20. Statistical inference on residual life

    CERN Document Server

    Jeong, Jong-Hyeon

    2014-01-01

    This is a monograph on the concept of residual life, which is an alternative summary measure of time-to-event data, or survival data. The mean residual life has been used for many years under the name of life expectancy, so it is a natural concept for summarizing survival or reliability data. It is also more interpretable than the popular hazard function, especially for communications between patients and physicians regarding the efficacy of a new drug in the medical field. This book reviews existing statistical methods to infer the residual life distribution. The review and comparison includes existing inference methods for mean and median, or quantile, residual life analysis through medical data examples. The concept of the residual life is also extended to competing risks analysis. The targeted audience includes biostatisticians, graduate students, and PhD (bio)statisticians. Knowledge in survival analysis at an introductory graduate level is advisable prior to reading this book.

  1. Residual stresses in welded structures

    International Nuclear Information System (INIS)

    The nature of residual stresses in welded structures is discussed in terms of their magnitude, directionality, spatial distribution, range and variability. The effects of the following factors on the residual stresses are considered: material properties, material manufacture, structural geometry, fabrication procedure, welding procedure, post-weld treatments and service conditions. Examples are given of residual stress distributions in plate butt welds, circumferential butt welds and weld cladding. These illustrate the different magnitudes and distributions of residual stress that can be found in different joint geometries, and demonstrate the effects of the mechanical, thermal and metallurgical properties of the constituent materials and the sensitivity of residual stresses to pass sequence and to the restraints applied during welding. Further examples for the common case of circumferential butt welds in pipes and pressure vessels are used to illustrate the extent of residual stresses as a function of distance from the weld and the effects of post-weld heat treatment. Measurements or analytical predictions of residual stresses are often subject to significant scatter or variability. This scatter may be due to systematic factors such as variability in measurement location or material properties, or to experimental error in measured data, erroneous assumptions in analytical modelling or unknown factors such as pre-existing residual stresses, inadequately documented welding or fabrication procedures or unrecorded local repairs. Improved prediction and reduction of uncertainty of residual stresses will require better recording of the whole manufacturing and service history of the welded structure and its component materials and better understanding and analysis of the many processes that may affect the residual stresses

  2. A 3-base pair deletion, c.9711_9713del, in DMD results in intellectual disability without muscular dystrophy

    NARCIS (Netherlands)

    de Brouwer, Arjan P. M.; Nabuurs, Sander B.; Verhaart, Ingrid E. C.; Oudakker, Astrid R.; Hordijk, Roel; Yntema, Helger G.; Hordijk-Hos, Jannet M.; Voesenek, Krysta; de Vries, Bert B. A.; van Essen, Ton; Chen, Wei; Hu, Hao; Chelly, Jamel; den Dunnen, Johan T.; Kalscheuer, Vera M.; Aartsma-Rus, Annemieke M.; Hamel, Ben C. J.; van Bokhoven, Hans; Kleefstra, Tjitske

    2014-01-01

    We have identified a deletion of 3 base pairs in the dystrophin gene (DMD), c.9711_9713del, in a family with nonspecific X-linked intellectual disability (ID) by sequencing of the exons of 86 known X-linked ID genes. This in-frame deletion results in the deletion of a single-amino-acid residue, Leu3

  3. Base-Pairing Energies of Protonated Nucleoside Base Pairs of dCyd and m5dCyd: Implications for the Stability of DNA i-Motif Conformations

    Science.gov (United States)

    Yang, Bo; Rodgers, M. T.

    2015-08-01

    Hypermethylation of cytosine in expanded (CCG)n•(CGG)n trinucleotide repeats results in Fragile X syndrome, the most common cause of inherited mental retardation. The (CCG)n•(CGG)n repeats adopt i-motif conformations that are preferentially stabilized by base-pairing interactions of protonated base pairs of cytosine. Here we investigate the effects of 5-methylation and the sugar moiety on the base-pairing energies (BPEs) of protonated cytosine base pairs by examining protonated nucleoside base pairs of 2'-deoxycytidine (dCyd) and 5-methyl-2'-deoxycytidine (m5dCyd) using threshold collision-induced dissociation techniques. 5-Methylation of a single or both cytosine residues leads to very small change in the BPE. However, the accumulated effect may be dramatic in diseased state trinucleotide repeats where many methylated base pairs may be present. The BPEs of the protonated nucleoside base pairs examined here significantly exceed those of Watson-Crick dGuo•dCyd and neutral dCyd•dCyd base pairs, such that these base-pairing interactions provide the major forces responsible for stabilization of DNA i-motif conformations. Compared with isolated protonated nucleobase pairs of cytosine and 1-methylcytosine, the 2'-deoxyribose sugar produces an effect similar to the 1-methyl substituent, and leads to a slight decrease in the BPE. These results suggest that the base-pairing interactions may be slightly weaker in nucleic acids, but that the extended backbone is likely to exert a relatively small effect on the total BPE. The proton affinity (PA) of m5dCyd is also determined by competitive analysis of the primary dissociation pathways that occur in parallel for the protonated (m5dCyd)H+(dCyd) nucleoside base pair and the absolute PA of dCyd previously reported.

  4. Isovectorial pairing in solvable and algebraic models

    International Nuclear Information System (INIS)

    Schematic interactions are useful to gain some insight in the behavior of very complicated systems such as the atomic nuclei. Prototypical examples are, in this context, the pairing interaction and the quadrupole interaction of the Elliot model. In this contribution the interplay between isovectorial pairing, spin-orbit, and quadrupole terms in a harmonic oscillator shell (the so-called pairing-plus-quadrupole model) is studied by algebraic methods. The ability of this model to provide a realistic description of N = Z even-even nuclei in the fp-shell is illustrated with 44Ti. Our calculations which derive from schematic and simple terms confirm earlier conclusions obtained by using realistic interactions: the SU(3) symmetry of the quadrupole term is broken mainly by the spin-orbit term, but the energies depends strongly on pairing.

  5. Robustness of quantum critical pairing against disorder

    Science.gov (United States)

    Kang, Jian; Fernandes, Rafael M.

    2016-06-01

    The remarkable robustness of high-temperature superconductors against disorder remains a controversial obstacle towards the elucidation of their pairing state. Indeed, experiments report a weak suppression rate of the transition temperature Tc with disorder, significantly smaller than the universal value predicted by extensions of the conventional theory of dirty superconductors. However, in many high-Tc compounds, superconductivity appears near a putative magnetic quantum critical point, suggesting that quantum fluctuations, which suppress coherent electronic spectral weight, may also promote unconventional pairing. Here we investigate theoretically the impact of disorder on such a quantum critical pairing state, considering the coupling of impurities both to the low-energy electronic states and to the pairing interaction itself. We find a significant reduction in the suppression rate of Tc with disorder near the magnetic quantum critical point, shedding new light on the nature of unconventional superconductivity in correlated materials.

  6. Large amplitude pairing fluctuations in atomic nuclei

    CERN Document Server

    Vaquero, Nuria López; Rodríguez, Tomás R

    2013-01-01

    Pairing fluctuations are self-consistently incorporated on the same footing as the quadrupole deformations in present state of the art calculations including particle number and angular momentum conservation as well as configuration mixing. The approach is complemented by the use of the finite range density dependent Gogny force which, with a unique source for the particle-hole and particle-particle interactions, guarantees a self-consistent interplay in both channels. We have applied our formalism to study the role of the pairing degree of freedom in the description of the most relevant observables like spectra, transition probabilities, separation energies, etc. We find that the inclusion of pairing fluctuations mostly affects the description of excited states, depending on the excitation energy and the angular momentum. $E0$ transition probabilities experiment rather big changes while $E2$'s are less affected. Genuine pairing vibrations are thoroughly studied with the conclusion that deformations strongly ...

  7. A Pair Polarimeter for High Energy Photons

    Science.gov (United States)

    Tedeschi, David; Wojtsekhowski, B.; Abbott, D.; Vlahovic, B.; Hotta, T.; Kohri, H.; Matsumura, T.; Mibe, T.; Nakano, T.; Yurita, T.; Zegers, R.; Khandaker, M.; Feldman, G.; O'Rielly, G. V.; Wood, M.; Asai, G.; Rudge, A.; Weilhammer, P.

    2001-10-01

    The physics program at the Thomas Jefferson National Accelerator Facility includes fundamental experiments with polarized photon beams in the GeV energy range. To measure the degree of photon polarization, a photon polarimeter based on the detection of e^+e^- pairs has been developed for use in Hall B and was recently tested at the LEPS facility at SPring-8 in Japan. The use of silicon micro-strip detectors allows for the first time the measurement of the angle correlation in electron-positron pair production by high energy photons incident on an amorphous converter. Theoretical calculations of the pair production process show an asymmetry σ_allel/σ_⊥ ~ 1.7 in a wide range of photon energies. Experimental results from the measurement of the pair asymmetry using 2 GeV photons from the SPring-8 facility will be presented.

  8. Four square mile survey pair count instructions

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This standard operating procedure (SOP) provides guidance for conducting bird pair count measurements on wetlands for the HAPETs Four-Square-Mile survey. This set...

  9. Z-related pairs in microtonal systems

    NARCIS (Netherlands)

    Althuis, T.A.; Göbel, F.

    2000-01-01

    Various infinite families of Z-related pairs in microtonal systems are presented. Soderberg's dual inversion is compared to a more special transformation, the one-pitch shift. The material is illustrated by several examples.

  10. Pairing properties of realistic effective interactions

    Directory of Open Access Journals (Sweden)

    Gargano A.

    2016-01-01

    Full Text Available We investigate the pairing properties of an effective shell-model interaction defined within a model space outside 132Sn and derived by means of perturbation theory from the CD-Bonn free nucleon-nucleon potential. It turns out that the neutron pairing component of the effective interaction is significantly weaker than the proton one, which accounts for the large pairing gap difference observed in the two-valence identical particle nuclei 134Sn and 134Te. The role of the contribution arising from one particle-one hole excitations in determining the pairing force is discussed and its microscopic structure is also analyzed in terms of the multipole decomposition.

  11. Engineering a factorable photon pair source

    Energy Technology Data Exchange (ETDEWEB)

    Zielnicki, Kevin; Kwiat, Paul [University of Illinois, Urbana-Champaign, Illinois 61801 (United States)

    2014-12-04

    Spontaneous parametric downconversion is an important process for producing pairs of photons for quantum optics. We discuss a scheme for eliminating undesired inter-photon correlations inherent in this process, and an efficient characterization of spectral correlations.

  12. Pairing vibrations in semimagic even nuclei

    International Nuclear Information System (INIS)

    The shifts in the energies of pairing vibrations due to the presence of valence nucleons are described in simple terms. Calculations are reported for the Z = 50 isotopes and N = 82 isotones and compared with experiment

  13. Comments on Coulomb pairing in aromatic hydrocarbons

    CERN Document Server

    Huber, D L

    2013-01-01

    Recently reported anomalies in the double-photonionization spectra of aromatic molecules such as benzene, naphthalene, anthracene and coronene are attributed to Coulomb-pair resonances of pi electrons.

  14. Colors of Dynamically Associated Asteroid Pairs

    CERN Document Server

    Moskovitz, Nicholas

    2012-01-01

    Recent dynamical studies have identified pairs of asteroids that reside in nearly identical heliocentric orbits. Possible formation scenarios for these systems include dissociation of binary asteroids, collisional disruption of a single parent body, or spin-up and rotational fission of a rubble-pile. Aside from detailed dynamical analyses and measurement of rotational light curves, little work has been done to investigate the colors or spectra of these unusual objects. A photometric and spectroscopic survey was conducted to determine the reflectance properties of asteroid pairs. New observations were obtained for a total of 34 individual asteroids. Additional photometric measurements were retrieved from the Sloan Digital Sky Survey Moving Object Catalog. Colors or spectra for a total of 42 pair components are presented here. The main findings of this work are: (1) the components in the observed pair systems have the same colors within the uncertainties of this survey, and (2) the color distribution of asteroi...

  15. Discrimination of Single Base Pair Differences Among Individual DNA Molecules Using a Nanopore

    Science.gov (United States)

    Vercoutere, Wenonah; DeGuzman, Veronica

    2003-01-01

    The protein toxin alpha-hemolysin form nanometer scale channels across lipid membranes. Our lab uses a single channel in an artificial lipid bilayer in a patch clamp device to capture and examine individual DNA molecules. This nanopore detector used with a support vector machine (SVM) can analyze DNA hairpin molecules on the millisecond time scale. We distinguish duplex stem length, base pair mismatches, loop length, and single base pair differences. The residual current fluxes also reveal structural molecular dynamics elements. DNA end-fraying (terminal base pair dissociation) can be observed as near full blockades, or spikes, in current. This technique can be used to investigate other biological processes dependent on DNA end-fraying, such as the processing of HIV DNA by HIV integrase.

  16. New nucleotide pairs for stable DNA triplexes stabilized by stacking interaction.

    Science.gov (United States)

    Mizuta, Masahiro; Banba, Jun-ichi; Kanamori, Takashi; Tawarada, Ryuya; Ohkubo, Akihiro; Sekine, Mitsuo; Seio, Kohji

    2008-07-30

    New nucleotide pairs applicable to formation of DNA triplexes were developed. We designed oligonucleotides incorporating 5-aryl deoxycytidine derivatives (dC5Ars) and cyclic deoxycytidine derivatives, dCPPP and dCPPI, having an expanded aromatic area, as the second strand. As pairing partners, two types of abasic residues (C3: propylene linker, phi: abasic base) were chosen. It was concluded that, when the 5-aryl-modified cytosine bases paired with the abasic sites in TFOs in a space-fitting manner, the stability of the resulting triplexes significantly increased. The recognition of C3 toward dC5Ars was selective because of the stacking interactions between their aromatic part and the nucleobases flanking the abasic site. These results indicate the potential utility of new nucleotide triplets for DNA triplex formation, which might expand the variety of structures and sequences and might be useful for biorelated fields such as DNA nanotechnologies. PMID:18611007

  17. Exactly solvable pairing Hamiltonian for heavy nuclei

    International Nuclear Information System (INIS)

    We present a new exactly solvable Hamiltonian with a separable pairing interaction and nondegenerate single-particle energies. It is derived from the hyperbolic family of Richardson-Gaudin models and possesses two free parameters, one related to an interaction cutoff and the other to the pairing strength. These two parameters can be adjusted to give an excellent reproduction of Gogny self-consistent mean-field calculations in the Hartree-Fock basis.

  18. A Cubic Micron of Equilibrium Pair Plasma?

    OpenAIRE

    Katz, J. I.

    1998-01-01

    Is it possible to create a small volume of equilibrium pair plasma in the laboratory with an intense laser pulse? No. The required power would exceed 10^{18} W. The number of seed particles required to absorb the laser energy would approach the number of pairs in the desired plasma, and their radiation in a visible laser field would occur at extremely high frequencies.

  19. Influence of quadrupole pairing on backbending

    International Nuclear Information System (INIS)

    The backbending phenomenon is attributed to the Coriolis antipairing and the rotational alignment effects. We can consider both effects simultaneously by applying the cranked Hartree-Fock-Bogoliubov theory to the description of the rotational motion of nuclei. In usual treatments of the backbending, however, only the monopole pairing force is considered and pairing forces of other types are neglected. This may be the main reason for starting of the backbending at too small total angular momentum in theoretical results. (orig.)

  20. Arithmetic Operators for Pairing-Based Cryptography

    OpenAIRE

    Beuchat, Jean-Luc; Brisebarre, Nicolas; Detrey, Jérémie; Okamoto, Eiji

    2007-01-01

    Since their introduction in constructive cryptographic applications, pairings over (hyper)elliptic curves are at the heart of an ever increasing number of protocols. Software implementations being rather slow, the study of hardware architectures became an active research area. In this paper, we first study an accelerator for the eta_T pairing over F_3[x]/(x^97 + x^12 + 2). Our architecture is based on a unified arithmetic operator which performs addition, multiplication, and cubing over F_3^9...

  1. On the analysis of phylogenetically paired designs

    OpenAIRE

    Funk, Jennifer L.; Rakovski, Cyril S; Macpherson, J Michael

    2015-01-01

    As phylogenetically controlled experimental designs become increasingly common in ecology, the need arises for a standardized statistical treatment of these datasets. Phylogenetically paired designs circumvent the need for resolved phylogenies and have been used to compare species groups, particularly in the areas of invasion biology and adaptation. Despite the widespread use of this approach, the statistical analysis of paired designs has not been critically evaluated. We propose a mixed mod...

  2. Implementing cryptographic pairings at standard security levels

    OpenAIRE

    Enge, Andreas; Milan, Jérôme

    2014-01-01

    This study reports on an implementation of cryptographic pairings in a general purpose computer algebra system. For security levels equivalent to the different AES flavours, we exhibit suitable curves in parametric families and show that optimal ate and twisted ate pairings exist and can be efficiently evaluated. We provide a correct description of Miller's algorithm for signed binary expansions such as the NAF and extend a recent variant due to Boxall et al. to addition-subtraction chains. W...

  3. Pairs trading profitability and style investing

    OpenAIRE

    Franco, Sara das Neves

    2014-01-01

    This dissertation studies the performance of the pairs trading strategy in the US stock market between 1962 and 2013. We find that this strategy remains profitable up to the current days, though these profits have been gradually falling. We show that investors are able to outperform the pure statistical arbitrage strategy, if they restrict the pairs matching to same-industry stocks, as they benefit from permanent links. Foremost, we find that industry, size, momentum and volatility style inve...

  4. Turbulent pair dispersion of inertial particles

    OpenAIRE

    Bec, J; Biferale, L.; Lanotte, A.S.; Scagliarini, A; Toschi, F.

    2009-01-01

    The relative dispersion of pairs of inertial particles in incompressible, homogeneous, and isotropic turbulence is studied by means of direct numerical simulations at two values of the Taylor-scale Reynolds number $Re_{\\lambda} \\sim 200$ and 400. The evolution of both heavy and light particle pairs is analysed at varying the particle Stokes number and the fluid-to-particle density ratio. For heavy particles, it is found that turbulent dispersion is schematically governed by two temporal regim...

  5. Rootless pairs of $EE_8$-lattices

    OpenAIRE

    Griess, Jr., Robert L.; lam, Ching Hung

    2008-01-01

    We describe a classification of pairs $M, N$ of lattices isometric to $EE_8:=\\sqrt 2 E_8$ such that the lattice $M + N$ is integral and rootless and such that the dihedral group associated to them has order at most 12. It turns out that most of these pairs may be embedded in the Leech lattice. Complete proofs will appear in another article. This theory of integral lattices has connections to vertex operator algebra theory and moonshine.

  6. Pairing dynamics and the origin of species

    OpenAIRE

    Puebla, Oscar; Bermingham, Eldredge; Guichard, Frédéric

    2011-01-01

    Whether sexual selection alone can drive the evolution of assortative mating in the presence of gene flow is a long-standing question in evolutionary biology. Here, we report a role for pairing dynamics of individuals when mate choice is mutual, which is sufficient for the evolution of assortative mating by sexual selection alone in the presence of gene flow. Through behavioural observation, individual-based simulation and population genetic analysis, we evaluate the pairing dynamics of coral...

  7. Migration of helium-pair in metals

    Science.gov (United States)

    Cao, J. L.; Geng, W. T.

    2016-09-01

    We have carried out a first-principles density functional theory investigation into the migration of both a single interstitial He and an interstitial He-pair in Fe, Mo, W, Cu, Pd, and Pt. We find the migration trajectories and barriers are determined predominantly by low-energy He-pair configurations which depend mainly on the energy state of a single He in different interstices. The migration barrier for a He-pair in bcc metals is always slightly higher than for a single He. Configurations of a He-pair in fcc metals are very complicated, due to the existence of interstitial sites with nearly identical energy for a single He. The migration barrier for a He-pair is slightly lower than (in Cu), or similar to (in Pd and Pt) a single He. The collective migrations of a He-pair are ensured by strong Hesbnd He interactions with strength-versus-distance forms resembling chemical bonds and can be described with Morse potentials.

  8. Heme A synthase in bacteria depends on one pair of cysteinyls for activity.

    Science.gov (United States)

    Lewin, Anna; Hederstedt, Lars

    2016-02-01

    Heme A is a prosthetic group unique for cytochrome a-type respiratory oxidases in mammals, plants and many microorganisms. The poorly understood integral membrane protein heme A synthase catalyzes the synthesis of heme A from heme O. In bacteria, but not in mitochondria, this enzyme contains one or two pairs of cysteine residues that are present in predicted hydrophilic polypeptide loops on the extracytoplasmic side of the membrane. We used heme A synthase from the eubacterium Bacillus subtilis and the hyperthermophilic archeon Aeropyrum pernix to investigate the functional role of these cysteine residues. Results with B. subtilis amino acid substituted proteins indicated the pair of cysteine residues in the loop connecting transmembrane segments I and II as being essential for catalysis but not required for binding of the enzyme substrate, heme O. Experiments with isolated A. pernix and B. subtilis heme A synthase demonstrated that a disulfide bond can form between the cysteine residues in the same loop and also between loops showing close proximity of the two loops in the folded enzyme protein. Based on the findings, we propose a classification scheme for the four discrete types of heme A synthase found so far in different organisms and propose that essential cysteinyls mediate transfer of reducing equivalents required for the oxygen-dependent catalysis of heme A synthesis from heme O. PMID:26592143

  9. Drug Residues and Food Safety

    OpenAIRE

    Bagley, Clell V, DVM

    2001-01-01

    Complaints and demands from consumers concerning a product usually occur after an incident involving injury, illness or death. However, this was not the case with the Alar scare with apples and it is not the case with the concern for drug residues in food animal products. There has been no increase in drug residues; in fact the rate of violation has steadily decreased. Neither has there been any outbreaks of illness, allergic reactions, or deaths related to residues, nor has there been a decr...

  10. Hydrogen atomic pair-ion production on catalyst surface

    International Nuclear Information System (INIS)

    To generate a hydrogen pair-ion plasma consisting of only hydrogen atomic pair ions, i.e., H+ and H- ions, the efficient production of pair ions is required. When discharged hydrogen plasma is irradiated to a Ni catalyst, pair ions are produced on the catalyst surface. It is clarified that hydrogen chemisorption on the catalyst affects pair-ion production.

  11. Sheared-type G(anti).C(syn) base-pair: a unique d(GXC) loop closure motif.

    Science.gov (United States)

    Chin, Ko-Hsin; Chou, Shan-Ho

    2003-05-30

    Stable DNA loop structures closed by a novel G.C base-pair have been determined for the single-residue d(GXC) loops (X=A, T, G or C) in low-salt solution by high-resolution nuclear magnetic resonance (NMR) techniques. The closing G.C base-pair in these loops is not of the canonical Watson-Crick type, but adopts instead a unique sheared-type (trans Watson-Crick/sugar-edge) pairing, like those occurring in the sheared mismatched G.A or A.C base-pair, to draw the two opposite strands together. The cytidine residue in the closing base-pair is transformed into the rare syn domain to form two H-bonds with the guanine base and to prevent the steric clash between the G 2NH(2) and the C H-5 protons. Besides, the sugar pucker of the syn cytidine is still located in the regular C2'-endo domain, unlike the C3'-endo domain adopted for the pyrimidines of the out-of-alternation left-handed Z-DNA structure. The facile formation of the compact d(GXC) loops closed by a unique sheared-type G(anti).C(syn) base-pair demonstrates the great potential of the single-stranded d(GXC) triplet repeats to fold into stable hairpins. PMID:12758081

  12. Propoxur residues in cocoa beans

    International Nuclear Information System (INIS)

    Pod-bearing Amazon and Amelonado cocoa plants were sprayed with Unden 20% (propoxur, arprocarb, baygon) at the recommended rate of 210 g a.i./ha and twice the recommended rate at monthly intervals from July to October, 1976, and cured beans from the ripe pods analysed for propoxur residues by gas chromatography. In a radiotracer study with 14C-labelled propoxur, the effect of processing methods on residues and systemic uptake of propoxur from insecticide deposits on pod surfaces were also investigated. Residues did not exceed 0.03 ppm. There was no relationship between residues and harvesting time, cocoa type or rate of application. Contamination of beans with insecticide deposits on the pod surface during processing, and systemic uptake of insecticide from pod surfaces were negligible. (author)

  13. Nitrogen availability of biogas residues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed Fouda, Sara

    2011-09-07

    The objectives of this study were to characterize biogas residues either unseparated or separated into a liquid and a solid phase from the fermentation of different substrates with respect to their N and C content. In addition, short and long term effects of the application of these biogas residues on the N availability and N utilization by ryegrass was investigated. It is concluded that unseparated or liquid separated biogas residues provide N at least corresponding to their ammonium content and that after the first fertilizer application the C{sub org}:N{sub org} ratio of the biogas residues was a crucial factor for the N availability. After long term application, the organic N accumulated in the soil leads to an increased release of N.

  14. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi; Chen, D.

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling of...... the ashes. Leaching test, however, must be selected carefully to provide information relevant for the actual disposal scenario and for evaluating the benefits of pre-treating the residues prior to landfilling. This paper describes research at the Technical University of Denmark addressing some of...... these issues focusing on pH-development in landfilled residues, effects of leaching test conditions on Cr leaching and effects of pre-treatment with FeSO4....

  15. Americium recovery from reduction residues

    Science.gov (United States)

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)

  16. Corporate law and Residual Claimants

    OpenAIRE

    Black, Bernard

    1999-01-01

    Common shareholders are not the only important residual claimants on a firm's income. Instead, other claimants, including employees, creditors, preferred shareholders, option holders, suppliers, customers, and the government (as tax collector) also often gain substatially when the firm does well, and suffer when the firm does badly. The conventional contractarian explanation for why only common shareholders vote - that they are the firm's principal residual claima...

  17. Parshin residues via coboundary operators

    OpenAIRE

    Mazin, Mikhail

    2012-01-01

    The article consist of two main parts: an analog of the Leray Theory for Singular Varieties and its application to the Theory of Parshin's Residues. The first part is independent from the second. It uses the theory of Whitney stratifications. The second part is an application of the first. In particular, a geometric and very transparent proof of the Parshin's Reciprocity Law for residues is given.

  18. Improvment of wood-residues conversion technology

    OpenAIRE

    Posharnikov, Feliks; Bazarskaya, Nina; Bulanov, Aleksandr

    2011-01-01

    The problem of wood residues conversion is considered. The sizes-based types of wood residues and results of wood residues conversion are presented. Sawdust-based-cement a new original product is offered

  19. String pair production in non homogeneous backgrounds

    CERN Document Server

    Bolognesi, Stefano; Tallarita, Gianni

    2016-01-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is les...

  20. Pair creation of black holes during inflation

    CERN Document Server

    Bousso, R; Bousso, Raphael; Hawking, Stephen W

    1996-01-01

    Black holes came into existence together with the universe through the quantum process of pair creation in the inflationary era. We present the instantons responsible for this process and calculate the pair creation rate from the no boundary proposal for the wave function of the universe. We find that this proposal leads to physically sensible results, which fit in with other descriptions of pair creation, while the tunnelling proposal makes unphysical predictions. We then describe how the pair created black holes evolve during inflation. In the classical solution, they grow with the horizon scale during the slow roll-down of the inflaton field; this is shown to correspond to the flux of field energy across the horizon according to the First Law of black hole mechanics. When quantum effects are taken into account, however, it is found that most black holes evaporate before the end of inflation. Finally, we consider the pair creation of magnetically charged black holes, which cannot evaporate. In standard Eins...

  1. Pair creation of black holes during inflation

    Science.gov (United States)

    Bousso, Raphael; Hawking, Stephen W.

    1996-11-01

    Black holes came into existence together with the universe through the quantum process of pair creation in the inflationary era. We present the instantons responsible for this process and calculate the pair creation rate from the no boundary proposal for the wave function of the universe. We find that this proposal leads to physically sensible results, which fit in with other descriptions of pair creation, while the tunneling proposal makes unphysical predictions. We then describe how the pair-created black holes evolve during inflation. In the classical solution, they grow with the horizon scale during the slow roll down of the inflaton field; this is shown to correspond to the flux of field energy across the horizon according to the first law of black hole mechanics. When quantum effects are taken into account, however, it is found that most black holes evaporate before the end of inflation. Finally, we consider the pair creation of magnetically charged black holes, which cannot evaporate. In standard Einstein-Maxwell theory we find that their number in the presently observable universe is exponentially small. We speculate how this conclusion may change if dilatonic theories are applied.

  2. Pairing and specific heat in hot nuclei

    CERN Document Server

    Gambacurta, Danilo; Sandulescu, Nicu

    2013-01-01

    The thermodynamics of pairing phase-transition in nuclei is studied in the canonical ensemble and treating the pairing correlations in a finite-temperature variation after projection BCS approach (FT-VAP). Due to the restoration of particle number conservation, the pairing gap and the specific heat calculated in the FT-VAP approach vary smoothly with the temperature, indicating a gradual transition from the superfluid to the normal phase, as expected in finite systems. We have checked that the predictions of the FT-VAP approach are very accurate when compared to the results obtained by an exact diagonalization of the pairing Hamiltonian. The influence of pairing correlations on specific heat is analysed for the isotopes $^{161,162}$Dy and $^{171,172}$Yb. It is shown that the FT-VAP approach, applied with a level density provided by mean field calculations and supplemented, at high energies, by the level density of the back-shifted Fermi gas model, can approximate reasonably well the main properties of specifi...

  3. Cooper-pair splitter: towards an efficient source of spin-entangled EPR pairs

    Science.gov (United States)

    Schonenberger, Christian

    2011-03-01

    In quantum mechanics the properties of two and more particles can be entangled. In basic science pairs of entangled particles, so called Einstein-Podolsky-Rosen (EPR) pairs, play a special role as toy objects for fundamental studies. They provide such things as ``spooky interaction at distance,'' but they also enable secure encoding and teleportation and are thus important for applications in quantum information technology. Whereas EPR pairs of photons can be generated by parametric down conversion (PDC) in a crystal, a similar source for EPR pairs of electrons does not exists yet. In several theory papers, it has been suggested to use a superconductor for this purpose. The superconducting ground state is formed by a condensate of Cooper-pairs which are electron pairs in a spin-singlet state. Since there are many Cooper pairs in a metallic superconductor like Al, the main tasks are to extract Cooper pairs one by one and to split them into different arms. A controlled and efficient splitting is possible if one makes use of Coulomb interaction. This has recently be demonstrated by two groups [2-4] using hybrid quantum-dot devices with both superconducting and normal metal contacts. In the present talk, I will discuss the Cooper-pair splitter results from the Basel-Budapest-Copenhagen team and compare with the other experiments. As an outlook we discuss approaches that aim at entanglement detection. The Cooper pair splitter holds great promises because very large splitting efficiencies approaching 100% and large pair current rates appear feasible. This work has been done by L. Hofstetter, S. Csonka, A. Geresdi, M. Aagesen, J. Nygard and C. Schönenberger

  4. Pair Creation in the Pulsar Magnetosphere

    CERN Document Server

    Eilek, J A

    2002-01-01

    We present numerical simulations of the electron-positron plasma creation process in a simple neutron star magnetosphere. We have developed a set of cascade `kernels', which represent the endpoint of the pair cascades resulting from monoenergetic photon seeds. We explore two popular models by convolving these kernels with the seed photon distributions produced by curvature radiation and by inverse Compton scattering. We find that the pair plasma in either case is well-described in its rest frame by a relativistic Maxwellian distribution with temperature near mc^2/k_B. We present cascade multiplicities and efficiencies for a range of seed particle energies and stellar magnetic fields. We find that the efficiencies and multiplicities of pair creation are often lower than has been assumed in previous work.

  5. Thermodynamics of pairing transition in hot nuclei

    CERN Document Server

    Liu, Lang; Zhao, Peng-Wei

    2014-01-01

    The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.

  6. Complex conjugate pairs in stationary Sturmians

    International Nuclear Information System (INIS)

    Sturmian expansions enable a simply accurate separable specification of two nucleon t matrices based upon realistic two nucleon interactions. Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in that context, and they can be calculated by solving a generalised eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each complex eigenvalues there is a corresponding conjugate partner. In studies using realistic two nucleon potentials, and in certain positive energy intervals, these complex conjugated pairs indeed appear in the Sturmian spectrum. However, it is demonstrated that it is possible to recombine the complex conjugate pairs and corresponding states into a new, (and useful) pair of real eigenvalues and eigenstates with which of effect separable expansions of the (real) two nucleon reactance matrices. 8 refs

  7. Complex conjugate pairs in stationary Sturmian eigenstates

    International Nuclear Information System (INIS)

    Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalized eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each complex eigenvalue there is a corresponding conjugate partner. In studies using realistic nucleon-nucleon potentials, and in certain positive energy intervals, these complex conjugated pairs indeed appear in the Sturmian spectrum. However, as we demonstrate herein, it is possible to recombine the complex conjugate pairs and corresponding states into a new, sign-definite pair of real quantities with which to effect separable expansions of the (real) nucleon-nucleon reactance matrices

  8. Entropy, area, and black hole pairs

    CERN Document Server

    Hawking, Stephen William; Ross, S F; Hawking, S W; Horowitz, Gary T; Ross, Simon F

    1995-01-01

    We clarify the relation between gravitational entropy and the area of horizons. We first show that the entropy of an extreme Reissner-Nordstr\\"om black hole is zero, despite the fact that its horizon has nonzero area. Next, we consider the pair creation of extremal and nonextremal black holes. It is shown that the action which governs the rate of this pair creation is directly related to the area of the acceleration horizon and (in the nonextremal case) the area of the black hole event horizon. This provides a simple explanation of the result that the rate of pair creation of non-extreme black holes is enhanced by precisely the black hole entropy. Finally, we discuss black hole annihilation, and argue that Planck scale remnants are not sufficient to preserve unitarity in quantum gravity.

  9. Entropy, area, and black hole pairs

    Science.gov (United States)

    Hawking, S. W.; Horowitz, Gary T.; Ross, Simon F.

    1995-04-01

    We clarify the relation between gravitational entropy and the area of horizons. We first show that the entropy of an extreme Reissner-Nordström black hole is zero, despite the fact that its horizon has nonzero area. Next, we consider the pair creation of extremal and nonextremal black holes. It is shown that the action which governs the rate of this pair creation is directly related to the area of the acceleration horizon and (in the nonextremal case) the area of the black hole event horizon. This provides a simple explanation of the result that the rate of pair creation of nonextreme black holes is enhanced by precisely the black hole entropy. Finally, we discuss black hole annihilation, and argue that Planck scale remnants are not sufficient to preserve unitarity in quantum gravity.

  10. Theoretical analysis of novel fiber grating pair

    Science.gov (United States)

    Wang, Liao; Jia, Hongzhi; Fang, Liang; You, Bei

    2016-06-01

    A novel fiber grating pair that consists of a conventional long-period fiber grating and a fiber Bragg cladding grating (FBCG) is proposed. The FBCG is a new type of fiber grating in which refractive index modulation is formed in the cladding. Through the coupled-mode theory, we accurately calculate the coupling coefficients between modes supported in the fibers. And some other mode coupling features in the fiber cladding gratings are analyzed in detail. The calculation of the modes involved in this paper is based on a model of three-layer step-index fiber geometry. Then, we have investigated the sensitivity characteristics for variation of the modulation strengths of the fiber Bragg cladding gratings' resonance peaks and the long-period cladding gratings' (LPCGs) dual resonant peaks. Finally, the modulation strength sensitivity of the grating pair's three resonant peaks is demonstrated, and the results indicate that these grating pairs may find potential applications in optical fiber sensing.

  11. Complex Conjugate Pairs in Stationary Sturmians

    CERN Document Server

    Dortmans, P J; Pisent, G; Amos, K A

    1993-01-01

    Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalised eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each complex eigenvalue there is a corresponding conjugate partner. In studies using realistic nucleon--nucleon potentials, and in certain positive energy intervals, these complex conjugated pairs indeed appear in the Sturmian spectrum. However, as we demonstrate herein, it is possible to recombine the complex conjugate pairs and corresponding states into a new, sign--definite pair of real quantities with which to effect separable expansions of the (real) nucleon--nucleon reactance matrices.

  12. The inverse problem for Schwinger pair production

    Directory of Open Access Journals (Sweden)

    F. Hebenstreit

    2016-02-01

    Full Text Available The production of electron–positron pairs in time-dependent electric fields (Schwinger mechanism depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. Owing to this non-linear dependence it is so far unpredictable how to choose a field configuration such that a predetermined momentum distribution is generated. We show that quantum kinetic theory along with optimal control theory can be used to approximately solve this inverse problem for Schwinger pair production. We exemplify this by studying the superposition of a small number of harmonic components resulting in predetermined signatures in the asymptotic momentum spectrum. In the long run, our results could facilitate the observation of this yet unobserved pair production mechanism in quantum electrodynamics by providing suggestions for tailored field configurations.

  13. Hard Photodisintegration of a Proton Pair

    CERN Document Server

    Pomerantz, I; Allada, K; Beck, A; Beck, S; Berman, B L; Boeglin, W; Camsonne, A; Canan, M; Chirapatpimol, K; Cisbani, E; Cusanno, F; De Jager, C W; Dutta, C; Garibaldi, F; Geagla, O; Gilman, R; Glister, J; Higinbotham, D W; Jiang, X; Katramatou, A T; Khrosinkova, E; Lee, B; LeRose, J J; Lindgren, R; McCullough, E; Meekins, D; Michaels, R; Moffit, B; Petratos, G G; Piasetzky, E; Qian, X; Qiang, Y; Rodriguez, I; Ron, G; Saha, A; Sarty, A J; Sawatzky, B; Schulte, E; Shneor, R; Sparveris, N; Subedi, R; Strauch, S; Sulkosky, V; Wang, Y; Wojtsekhowski, B; Yan, X; Yao, H; Zhan, X; Zheng, X

    2009-01-01

    We present the first study of high energy photodisintegration of proton-pairs through the gamma + 3He -> p+p+n channel. Photon energies from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair with high relative momentum and a neutron nearly at rest. An s^{-11} scaling of the cross section was observed, as predicted by the constituent counting rule. The onset of the scaling is at a higher energy and the cross section is significantly lower then for pn pair photodisintegration. For photon energies below the scaling region, the scaled cross section was found to present a strong energy-dependent structure not observed in deuteron photodisintegration.

  14. Pairing effects in N =82 isotones

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, F.; Covello, A.; Gargano, A.; Porrino, A. (Dipartimento di Scienze Fisiche, Universita di Napoli, Napoli (Italy) Istituto Nazionale di Fisica Nucleare, 80125 Napoli (Italy))

    1990-01-01

    The importance of pairing effects in the {ital N}=82 isotones is extensively investigated by studying the string of nuclei with {ital A} ranging from 135 to 151. The pairing Hamiltonian is treated by an equations-of-motion method which is strictly number conserving. The coupling strength is determined by an analysis of the properties of the even-mass isotones. The single-particle energies are extracted from the experimental spectra of {sup 137}Cs and {sup 145}Eu through use of the equations which give the energies of the seniority-one states in a way which is analogous to the inverse gap equation method. A detailed comparison of the calculated results with experimental data in even and odd nuclei provides firm evidence of the prominent role of proton pairing correlations in the 50--82 shell. It is found that non-negligible correlations are present in {sup 146}Gd.

  15. Re-Pair Compression of Inverted Lists

    CERN Document Server

    Claude, Francisco; Navarro, Gonzalo

    2009-01-01

    Compression of inverted lists with methods that support fast intersection operations is an active research topic. Most compression schemes rely on encoding differences between consecutive positions with techniques that favor small numbers. In this paper we explore a completely different alternative: We use Re-Pair compression of those differences. While Re-Pair by itself offers fast decompression at arbitrary positions in main and secondary memory, we introduce variants that in addition speed up the operations required for inverted list intersection. We compare the resulting data structures with several recent proposals under various list intersection algorithms, to conclude that our Re-Pair variants offer an interesting time/space tradeoff for this problem, yet further improvements are required for it to improve upon the state of the art.

  16. Induced Pairing Interaction in Neutron Star Matter

    Science.gov (United States)

    Lombardo, U.; Schulze, H.-J.; Zuo, W.

    2013-01-01

    The three superfluid phases supposed to occur in neutron stars are reviewed in the framework of the generalized BCS theory with the induced interaction. The structure of neutron stars characterized by beta-stable asymmetric nuclear matter in equilibrium with the gravitational force discloses new aspects of the pairing mechanism. Some of them are discussed in this report, in particular the formation in dense matter of Cooper pairs in the presence of three-body forces and the interplay between repulsive and attractive polarization effects on isospin T = 1 Cooper pairs embedded into the neutron and proton environment. Quantitative estimates of the energy gaps are reported and their sensitivity to the medium effects, i.e., interaction and polarization, is explored.

  17. Holographic EPR Pairs, Wormholes and Radiation

    CERN Document Server

    Chernicoff, Mariano; Pedraza, Juan F

    2013-01-01

    As evidence for the ER=EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determines whether the causal structure of the string worldsheet is trivial or not turns out to be the emission of gluonic radiation by the dual quark and antiquark. In the strongly-coupled gauge theory, it is only when radiation is emitted that one obtains an unambiguous separation of the pair into entangled subsystems, and this is what is reflected on the gravity side by the existence of the worldsheet horizon.

  18. Narrowband Photon Pair Source for Quantum Networks

    CERN Document Server

    Monteiro, F; Sanguinetti, B; Zbinden, H; Thew, R T

    2013-01-01

    We demonstrate a compact photon pair source based on a periodically poled lithium niobate nonlinear crystal in a cavity. The cavity parameters are chosen such that the emitted photon pair modes can be matched in the region of telecom ultra dense wavelength division multiplexing (U-DWDM) channel spacings. This approach provides efficient, low-loss, mode selection that is compatible with standard telecommunication networks. Photons with a coherence time of 8.6 ns (116 MHz) are produced and their purity is demonstrated. A source brightness of 134 pairs(s.mW.MHz)$^{-1}$ is reported. The high level of purity and compatibility with standard telecom networks is of great importance for complex quantum communication networks.

  19. Toric CFTs, Permutation Triples and Belyi Pairs

    CERN Document Server

    Jejjala, Vishnu; Rodriguez-Gomez, Diego

    2010-01-01

    Four-dimensional CFTs dual to branes transverse to toric Calabi--Yau threefolds have been described by bipartite graphs on a torus (dimer models). We use the theory of dessins d'enfants to describe these in terms of triples of permutations which multiply to one. These permutations yield an elegant description of zig-zag paths, which have appeared in characterizing the toroidal dimers that lead to consistent SCFTs. The dessins are also related to Belyi pairs, consisting of a curve equipped with a map to P^1, branched over three points on the P^1. We construct explicit examples of Belyi pairs associated to some CFTs, including C^3 and the conifold. Permutation symmetries of the superpotential are related to the geometry of the Belyi pair. The Artin braid group action and a variation thereof play an interesting role. We make a conjecture relating the complex structure of the Belyi curve to R-charges in the conformal field theory.

  20. Categorical Pairs and the Indicative Shift

    CERN Document Server

    Kauffman, Louis H

    2011-01-01

    This paper introduces the notion of a categorical pair, a pair of categories (C,C') such that every morphism in C is an object in C'. Categorical pairs are precursors to 2-categories. Arrows in C' can express relationships among the morphisms of C. In particular we show that by using a model of the linguistic process of naming, we can ensure that every morphism in C has an indirect self-reference of the form a -----> Fa where this arrow occurs in the category C'. This result is shown to generalize and clarify known fixed point theorems in logic and categories, and is applied to Goedel's Incompleteness Theorem, the Cantor Diagonal Process and the Lawvere Fixed Point Theorem. In particular we show that the indirect self-reference that is central to Goedel's Theorem is an instance of a general pattern here called the indicative shift.

  1. An inverse problem for Schwinger pair production

    CERN Document Server

    Hebenstreit, Florian

    2016-01-01

    The production of electron-positron pairs in time-dependent electric fields (Schwinger mechanism) depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. Owing to this non-linear dependence it is so far unpredictable how to choose a field configuration such that a predetermined momentum distribution is generated. We show that quantum kinetic theory along with optimal control theory can be used to approximately solve this inverse problem for Schwinger pair production. We exemplify this by studying the superposition of a small number of harmonic components resulting in predetermined signatures in the asymptotic momentum spectrum. In the long run, our results could facilitate the observation of this yet unobserved pair production mechanism in quantum electrodynamics by providing suggestions for tailored field configurations.

  2. Pair production from an external electric field

    International Nuclear Information System (INIS)

    We solve numerically the problem of pair production from an external electric field in 1 + 1 dimensions including the quantum back-reaction from the produced pairs. We find that in the linear regime our numerical results agree perfectly with analytic calculations. In the strong field regime where tunnelling is uninhibited we determine the time it takes for the electric field to degrade due to energy transfer to the large number of pion field degrees of freedom. The problem has three time scales--the oscillation frequency of the charged quanta, the induced plasma oscillation frequency due to the production of pairs and finally the time scale for energy to be transferred from the electromagnetic field to the pion field. 4 refs., 5 figs

  3. Pairing and the Cooling of Neutron Stars

    CERN Document Server

    Page, Dany

    2012-01-01

    In this review, I present a brief summary of the impact of nucleon pairing at supra-nuclear densities on the cooling of neutron stars. I also describe how the recent observation of the cooling of the neutron star in the supernova remnant Cassiopeia A may provide us with the first direct evidence for the occurrence of such pairing. It also implies a size of the neutron 3P-F2 energy gap of the order of 0.1 MeV.

  4. On Thermal Comptonization in e+- Pair Plasmas

    OpenAIRE

    Ghisellini, Gabriele; Haardt, Francesco

    1994-01-01

    We study $e^{\\pm}$ pair plasmas in pair equilibrium, which emit high energy radiation by thermal Comptonization of soft photons. We find that the maximum luminosity to size ratio of the source (i.e. the compactness) depends not only on the hot plasma temperature, but also on the spectral index of the resulting Comptonized spectrum. In the observationally interesting range, sources of same compactness can be hotter if their spectrum is steeper. Instruments observing in the 50--500 keV energy r...

  5. The BCS Model for General Pair Interaction

    DEFF Research Database (Denmark)

    Hainzl, Christian; Hamza, Eman; Seiringer, Robert;

    2008-01-01

    The Bardeen-Cooper-Schrieffer (BCS) functional has recently received renewed attention as a description of fermionic gases interacting with local pairwise interactions. We present here a rigorous analysis of the BCS functional for general pair interaction potentials. For both zero and positive...... temperature, we show that the existence of a non-trivial solution of the nonlinear BCS gap equation is equivalent to the existence of a negative eigenvalue of a certain linear operator. From this we conclude the existence of a critical temperature below which the BCS pairing wave function does not vanish...

  6. Pairing Phase Transitions of Matter under Rotation

    CERN Document Server

    Jiang, Yin

    2016-01-01

    The phases and properties of matter under global rotation have attracted much interest recently. In this paper we investigate the pairing phenomena in a system of fermions under the presence of rotation. We find that there is a generic suppression effect on pairing states with zero angular momentum. We demonstrate this effect with the chiral condensation and the color superconductivity in hot dense QCD matter as explicit examples. In the case of chiral condensation, a new phase diagram in the temperature-rotation parameter space is found, with a nontrivial critical point.

  7. Non-locality of experimental qutrit pairs

    International Nuclear Information System (INIS)

    The insight due to John Bell that the joint behavior of individually measured entangled quantum systems cannot be explained by shared information remains a mystery to this day. We describe an experiment, and its analysis, displaying non-locality of entangled qutrit pairs. The non-locality of such systems, as compared to qubit pairs, is of particular interest since it potentially opens the door for tests of bipartite non-local behavior independent of probabilistic Bell inequalities, but of deterministic nature. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘50 years of Bell’s theorem’. (paper)

  8. Pracovní spokojenost au-pair

    OpenAIRE

    Tomíšková, Tereza

    2013-01-01

    The topic of the following diploma thesis is the explanation of the concept of job satisfaction while holding an au-pair position. The aim of this thesis is to analyze the job satisfaction young women (or men), who go abroad to work as au-pair, can feel. The first part of the analysis consists in a theoretical assessment of the mentioned topic, that is to say provide the reader with basic terminology and information about this area of domestic work; we will also sketch out the main factors in...

  9. Pairing and realistic shell-model interactions

    OpenAIRE

    Covello, A; Gargano, A.; Kuo, T. T. S.

    2012-01-01

    This paper starts with a brief historical overview of pairing in nuclei, which fulfills the purpose of properly framing the main subject. This concerns the pairing properties of a realistic shell-model effective interaction which has proved very successful in describing nuclei around doubly magic 132Sn. We focus attention on the two nuclei 134Te and 134Sn with two valence protons and neutrons, respectively. Our study brings out the key role of one particle-one hole excitations in producing a ...

  10. Strategies for electron pair reconstruction in CBM

    International Nuclear Information System (INIS)

    Lepton pairs emitted out of the hot and dense stage of relativistic heavy ion collisions are established probes to study the electromagnetic structure of hadrons under extreme conditions. The reconstruction of low-mass vector mesons by means of their electromagnetic decay is one of the experimental goals of the planned compressed baryonic matter (CBM) experiment at the future facility FAIR. We present our strategies to reduce the combinatorial background in electron pair measurements in central Au+Au collisions at 25 AGeV with the CBM experimental setup. A special challenge of the current concept is the fact that electron identification is not provided in front of the magnetic field. (orig.)

  11. Pairing schemes for HFB calculations of nuclei

    CERN Document Server

    Duguet, T; Bonche, P

    2005-01-01

    Several pairing schemes currently used to describe superfluid nuclei through Hartree-Fock-Bogolyubov (HFB) calculations are briefly reviewed. We put a particular emphasis on the regularization recipes used in connection with zero-range forces and on the density dependence which usually complement their definition. Regarding the chosen regularization process, the goal is not only to identify the impact it may or may not have on pairing properties of nuclei through spherical 1D HFB calculations but also to assess its tractability for systematic axial 2D and 3D mean-field and beyond-mean-field calculations.

  12. Nilpotent orbits in real symmetric pairs

    CERN Document Server

    Dietrich, Heiko; Ruggeri, Daniele; Trigiante, Mario

    2016-01-01

    In the classification of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determining the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of SL_2(R)^4 acting on the fourth tensor power of the natural 2-dimensional SL_2(R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model.

  13. Comment on ``Pairing interaction and Galilei invariance''

    Science.gov (United States)

    Arias, J. M.; Gallardo, M.; Gómez-Camacho, J.

    1999-05-01

    A recent article by Dussel, Sofia, and Tonina studies the relation between Galilei invariance and dipole energy weighted sum rule (EWSR). The authors find that the pairing interaction, which is neither Galilei nor Lorentz invariant, produces big changes in the EWSR and in effective masses of the nucleons. They argue that these effects of the pairing force could be realistic. In this Comment we stress the validity of Galilei invariance to a very good approximation in this context of low-energy nuclear physics and show that the effective masses and the observed change in the EWSR for the electric dipole operator relative to its classical value are compatible with this symmetry.

  14. Chemical Nonlinearities and Radical Pair Lifetime Estimation

    Science.gov (United States)

    Robinson, Gregory

    2013-03-01

    Much attention has recently developed around chemical reactions that depend on applied static magnetic fields as weak as earth's. This interest is largely motivated by experiments that implicate the role of spin-selective radical pair recombination in biological magnetic sensing. Existing literature uses a straightforward calculation to approximate the expected lifetime of coherent radical pairs as a function of the minimum RF amplitude that is observed to disrupt magnetic navigation, apparently by decohering the radical pair via electronic Zeeman excitations. But we show that chemical nonlinearities can preclude direct computation of coherent pair lifetime without considering the cellular signalling mechanisms involved, and discuss whether it can explain the surprising fragility of some animals' compass sense. In particular, we demonstrate that an autocatalytic cycle can introduce threshold effects on the disruption sensitivity to applied oscillatory magnetic fields. We will show examples in the mean-field limit and consider the consequences of noise and fluctuations in the Freidlin-Wentzell picture of perturbed dynamical systems.

  15. Pair Production in the Quantum Boltzmann Equation

    OpenAIRE

    Rau, Jochen

    1994-01-01

    A source term in the quantum Boltzmann equation, which accounts for the spontaneous creation of $e^+e^-$-pairs in external electric fields, is derived from first principles and evaluated numerically. Careful analysis of time scales reveals that this source term is generally non-Markovian. This implies in particular that there may be temporary violations of the $H$-theorem.

  16. Effective pair potentials for spherical nanoparticles

    International Nuclear Information System (INIS)

    An effective description for rigid spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, as can occur for some forms of the pair potentials, the effective potential generally has non-analytic points. It is shown that for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Even when only non-overlapping situations are possible, the auxiliary potentials facilitate the formulation of the effective potentials. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered and shown to be related to those for solid nanoparticles. For hollow nanoparticles overlap is more physical, since this covers the case of a smaller particle embedded in a larger, hollow nanoparticle. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London–van der Waals, Morse, Buckingham, and Lennard-Jones potentials. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure

  17. Pair reversal in homogeneous isotropic turbulence

    International Nuclear Information System (INIS)

    We show that the separation of particle pairs in the inertial subrange of homogeneous isotropic turbulence is strongly influenced by the pairs that separate quasi-diffusively. We quantify the influence of the diffusive separators by considering the probability that a pair will 'reverse' direction across a given separation i.e. its separation will decrease (before eventually increasing) and derive an analytical expression for the expected number of reversals across this separation for a quasi-one-dimensional model of relative dispersion in the inertial subrange with Gaussian turbulence. We compare this theoretical result with three different Lagrangian stochastic models in which the influence of the diffusive and ballistic separators (the latter dominated by velocity memory) can be varied by means of the value of C0, the constant of proportionality in the Lagrangian velocity structure function, which appears explicitly in Lagrangian stochastic models. We also compare these results with data from a direct numerical simulation of turbulence. The results indicate the importance of the transverse relative velocity component (i.e. the ability of pairs to rotate), which is absent in Q1D models, in determining the correct quantitative relative dispersion statistics.

  18. On a direct superconducting pairing mechanism

    International Nuclear Information System (INIS)

    We suggest that superconductivity can be traced back to a first-order interaction between the charge carriers which does not necessarily involve second-order electron-phonon coupling. For small molecular model systems it is demonstrated that the formation of Cooper pairs can lead to an attenuation of the destabilizing influence of the Pauli antisymmetry principle (PAP). We suggest that this attenuation of a fermionic quantum constraint is the driving force for the superconducting transition. Whenever the PAP is activated in single-particle hoppings of electrons, the corresponding moves reduce the electronic delocalization; they raise the ensemble energy. The stability of a fermionic system is enhanced with decreasing influence of the PAP. Moves of Cooper pairs are not influenced by any quantum constraint of the intersite type. This behaviour differs from the well-known fermionic constraints. The quantum statistics of Cooper pairs is of a mixed type combining a fermionic on-site and a bosonic intersite behaviour. It coincides with the quantum statistics of so-called hard core bosonic ensembles. In the present work Cooper pair formation has been studied for smaller molecular models. The electronic Hamiltonian employed is of the two-parameter Hubbard-type. The solid state phenomenon superconductivity is correlated with the molecular concepts of ''antiaromaticity'' and ''aromaticity''. Arguments are given which support the present interpretation. (orig.)

  19. Abstract polymer models with general pair interactions

    CERN Document Server

    Procacci, Aldo

    2007-01-01

    A convergence criterion of cluster expansion is presented in the case of an abstract polymer system with general pair interactions (i.e. not necessarily hard core or repulsive). As a concrete example, the low temperature disordered phase of the BEG model with infinite range interactions, decaying polynomially as $1/r^{d+\\lambda}$ with $\\lambda>0$, is studied.

  20. A Novel Approach for Collaborative Pair Programming

    Science.gov (United States)

    Goel, Sanjay; Kathuria, Vanshi

    2010-01-01

    The majority of an engineer's time in the software industry is spent working with other programmers. Agile methods of software development like eXtreme Programming strongly rely upon practices like daily meetings and pair programming. Hence, the need to learn the skill of working collaboratively is of primary importance for software developers.…

  1. The mother of all pair potentials

    DEFF Research Database (Denmark)

    Dyre, J. C.; Bacher, Andreas Kvist

    2014-01-01

    This paper presents a computer simulation study of the exponentially repulsive pair potential system. The simulations show that the system has strong virial potential energy correlations in a large part of its thermodynamic phase diagram. Consequences of this are briefly discussed; these include ...

  2. Building a control sample for galaxy pairs

    CERN Document Server

    Perez, Josefa; Blaizot, Jeremy

    2009-01-01

    Several observational works have attempted to isolate the effects of galaxy interactions by comparing galaxies in pairs with isolated galaxies. However, different authors have proposed different ways to build these so-called control samples (CS). By using mock galaxy catalogues of the SDSS-DR4 built up from the Millennium Simulation, we explore how the way of building a CS might introduce biases which could affect the interpretation of results. We make use of the fact that the physics of interactions is not included in the semianalytic model, to infer that any difference between the mock control and pair samples can be ascribed to selection biases. Thus, we find that galaxies in pairs artificially tend to be older and more bulge-dominated, and to have less cold gas and different metallicities than their isolated counterparts. Also because of a biased selection, galaxies in pairs tend to live in higher density environments, and in haloes of larger masses. We find that imposing constraints on redshift, stellar ...

  3. Sfermion Pair Production at $\\mu^{+} \\mu^{-}$ Colliders

    CERN Document Server

    Bartl, Alfred; Kraml, Sabine; Majerotto, Walter; Porod, Werner

    1998-01-01

    We discuss pair production of stops, sbottoms, staus and tau--sneutrinos at a sections and perform a detailed numerical analysis within the Minimal Supersymmetric Standard Model. In particular, we consider sfermion production near $\\sqrt{s} = m_{H^0}$ and $\\sqrt{s} = m_{A^0}$.

  4. Dispersion Compensation with a Prism-pair

    CERN Document Server

    Shaked, Yaakov; Pe'er, Avi

    2014-01-01

    We present a detailed calculation of the total dispersion (spectral phase) from a pair of Brewster-cut prisms. This paper aims to aid advanced students in tracking the operation of this major configuration for dispersion-compensation and phase-control of ultra-short pulses.

  5. Virtual pair creation in nuclear Dirac phenomenology

    International Nuclear Information System (INIS)

    We discuss the importance of virtual nucleon-antinucleon pair (VP) creation in the scalar-vector model of nucleon-nucleus scattering. In a model based upon the Hartree approximation to nuclear matter, we find such VP terms to be crucial in order to reproduce the 'wine-bottle-bottom' shape of the real component of the optical potential. (orig.)

  6. Plasma analog of particle-pair production

    International Nuclear Information System (INIS)

    It is shown that the plasma axial shear flow instability satisfies the Klein-Gordon equation. The plasma instability is then shown to be analogous to spontaneous particle-pair production when a potential energy is present that is greater than twice the particle rest mass energy. Stability criteria can be inferred based on field theoretical conservation laws. (UK)

  7. Evacuation dynamics of asymmetrically coupled pedestrian pairs

    CERN Document Server

    Müller, Frank

    2016-01-01

    We propose and analyze extended floor field cellular automaton models for evacuation dynamics of inhomogeneous pedestrian pairs which are coupled by asymmetric group interactions. Such pairs consist of a leader, who mainly determines the couple's motion and a follower, who has a defined tendency to follow the leader. Examples for such pairs are mother and child or two siblings of different age. We examine the system properties and compare them to the case of a homogeneous crowd. We find a strong impact on evacuation times for the regime of strong pair coupling due to the occurrence of a clogging phenomenon. In addition we obtain a non-trivial dependence of evacuation times on the followers' coupling to the static floor field, which carries the information of the shortest way to the exit location. In particular we find that systems with fully passive followers, who are solely coupled to their leaders, show lower evacuation times than homogeneous systems where all pedestrians have an equal tendency to move towa...

  8. Retardation in the atomic pair polarizability

    NARCIS (Netherlands)

    M.A.J. Michels; L.G. Suttorp

    1977-01-01

    The atomic pair polarizability for hydrogen atoms is calculated within the framework of covariant quantum electrodynamics. Retardation effects are shown to change the dependence on the interatomic separation R from R/sup -6/ to R/sup -7/ for R large compared with a characteristic wavelength of the a

  9. The Lax pairs for the Holt system

    OpenAIRE

    Tsiganov, A. V.

    1998-01-01

    By using non-canonical transformation between the Holt system and the Henon-Heiles system the Lax pairs for all the integrable cases of the Holt system are constructed from the known Lax representations for the Henon-Heiles system.

  10. Near-Ring Radicals and Class Pairs

    Institute of Scientific and Technical Information of China (English)

    L.Godloza; N.J.Groenewald; W.A.Olivier

    2005-01-01

    For near-ring ideal mappings p1 and p2, we investigate radical theoretical properties of and the relationship among the class pairs (p1: p2), (Sp2: Sp1) and (Rp2:Rp1). Conditions on p1 and p2 are given for a general class pair to form a radical class of various types. These types include the Plotkin and KA-radical varieties. A number of examples are shown to motivate the suitability of the theory of Hoehnke-radicals over KA-radicals when radical pairs of near-rings are studied. In particular, it is shown that (pc: P3) forms a KA-radical class, where Pc denotes the class of completely prime nearrings and P3 the class of 3-prime near-rings. This gives another near-ring generalization of the 2-primal ring concept. The theory of radical pairs are also used to show that in general the class of 3-semiprime near-rings is not the semisimple class of the 3-prime radical.

  11. Distinguishing Z' models with polarised top pairs

    OpenAIRE

    Basso, L.; Mimasu, K.; Moretti, S.

    2012-01-01

    We study the sensitivity of top pair production at the Large Hadron Collider (LHC) to the nature of an underlying Z' boson, including full tree level standard model background effects and interferences. We demonstrate that exploiting combinations of asymmetry observables will enable one to distinguish between a selection of `benchmark' Z' models while assuming realistic final state reconstruction efficiencies and error estimates.

  12. Spectral Similarity of Unbound Asteroid Pairs

    CERN Document Server

    Wolters, Stephen D; Christou, Apostolis; Duddy, Samuel R; Lowry, Stephen C

    2014-01-01

    Infrared spectroscopy between 0.8 and 2.5 microns has been obtained for both components of three unbound asteroid pairs, using the NASA-IRTF with the SpeX instrument. Pair primary (2110) Moore-Sitterly is classified as an S-type following the Bus-DeMeo taxonomy; the classification for secondary (44612) 1999 RP27 is ambiguous: S/Sq/Q/K/L-type. Primary (10484) Hecht and secondary (44645) 1999 RC118 are classified as V-types. IR spectra for Moore-Sitterly and Hecht are each linked with available visual photometry. The classifications for primary (88604) 2001 QH293 and (60546) 2000 EE85 are ambiguous: S/Sq/Q/K/L-type. Subtle spectral differences between them suggest the primary may have more weathered material on its surface. Dynamical integrations have constrained the ages of formation: 2110-44612 > 782 kyr; 10484-44645 = 348 (+823,-225) kyr; 88604-60546 = 925 (+842,-754) kyr. The spectral similarity of seven complete pairs is ranked in comparison with nearby background asteroids. Two pairs, 17198-229056 and 192...

  13. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    We demonstrated a new process for recovering plutonium and americium from pyrochemical waste. The method is based on chloride solution anion exchange at low acidity, or acidity that eliminates corrosive HCl fumes. Developmental experiments of the process flow chart concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 62- from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO3-4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO3 precipitation. All filtrates from the process can be discardable as low-level contaminated waste. Production-scale experiments are in progress for MSE residues. Flow charts for actinide recovery from electro-refining and direct oxide reduction residues are presented and discussed

  14. Selective loss of cysteine residues and disulphide bonds in a potato proteinase inhibitor II family.

    Directory of Open Access Journals (Sweden)

    Xiu-Qing Li

    Full Text Available Disulphide bonds between cysteine residues in proteins play a key role in protein folding, stability, and function. Loss of a disulphide bond is often associated with functional differentiation of the protein. The evolution of disulphide bonds is still actively debated; analysis of naturally occurring variants can promote understanding of the protein evolutionary process. One of the disulphide bond-containing protein families is the potato proteinase inhibitor II (PI-II, or Pin2, for short superfamily, which is found in most solanaceous plants and participates in plant development, stress response, and defence. Each PI-II domain contains eight cysteine residues (8C, and two similar PI-II domains form a functional protein that has eight disulphide bonds and two non-identical reaction centres. It is still unclear which patterns and processes affect cysteine residue loss in PI-II. Through cDNA sequencing and data mining, we found six natural variants missing cysteine residues involved in one or two disulphide bonds at the first reaction centre. We named these variants Pi7C and Pi6C for the proteins missing one or two pairs of cysteine residues, respectively. This PI-II-7C/6C family was found exclusively in potato. The missing cysteine residues were in bonding pairs but distant from one another at the nucleotide/protein sequence level. The non-synonymous/synonymous substitution (Ka/Ks ratio analysis suggested a positive evolutionary gene selection for Pi6C and various Pi7C. The selective deletion of the first reaction centre cysteine residues that are structure-level-paired but sequence-level-distant in PI-II illustrates the flexibility of PI-II domains and suggests the functionality of their transient gene versions during evolution.

  15. Recognition of base pair inversions in duplex by chimeric (alpha,beta) triplex-forming oligonucleotides.

    Science.gov (United States)

    Timofeev, Edward N; Goryaeva, Baira V; Florentiev, Vladimir L

    2006-10-01

    DNA recognition by triplex-forming oligonucleotides (TFOs) is usually limited by homopurine-homopyrimidine sequence in duplexes. Modifications of the third strand may overcome this limitation. Chimeric alpha-beta TFOs are expected to form triplex DNA upon binding to non-regular sequence duplexes. In the present study we describe binding properties of chimeric alpha-beta oligodeoxynucleotides in the respect to short DNA duplexes with one, three, and five base pair inversions. Non-natural chimeric TFO's contained alpha-thymidine residues inside (GT) or (GA) core sequences. Modified residues were addressed to AT/TA inversions in duplexes. It was found in the non-denaturing gel-electrophoresis experiments that single or five adjacent base pair inversions in duplexes may be recognized by chimeric alpha-beta TFO's at 10 degrees C and pH 7.8. Three dispersed base pair inversions in the double stranded DNA prevented triplex formation by either (GT) or (GA) chimeras. Estimation of thermal stability of chimeric alpha-beta triplexes showed decrease in T(m) values as compared with unmodified complexes. PMID:16928141

  16. Leaching From Biomass Gasification Residues

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Boldrin, Alessio; Polletini, A.;

    2011-01-01

    composition, and DOC complexation and sorption mechanisms were found to have a great influence on their release. Like wood combustion residues, the analysed ashes could be relevant for recycling in agriculture or forestry because of the potential as liming agent and source of macroelements. However, the high...... geochemical modelling were carried out both on fresh and aged samples. The results showed that the material is comparable to residues from wood combustion and the leaching behaviour was dominated by Ca-containing minerals and solid solutions. Heavy metals were detected in very low concentrations in the bulk...

  17. Peptide iodination on phenylalanine residues

    International Nuclear Information System (INIS)

    Peptide labelling with radioactive isotopes is always a compromise between peptide chemistry, labelling chemistry, and biological receptor tolerance. Therefore new ways for isotope introduction are always useful. The present contribution describes the introduction of iodine isotopes onto synthetic polypeptides by means of the Gattermann/ Sandmeyer reactions. Peptides containing the nitrophenylalanyl residue are reduced to the corresponding aminophenylalanyl, diazolized to the diazonium phenylalanyl peptide and converted to the iodophenylalanyl peptide in the presence of copper. Two examples are presented: angiotensin II and enkephalin. In both cases, the iodophenylalanyl residue is well accepted by the biological target. (author). 13 refs.; 4 figs

  18. Residual Structures in Latent Growth Curve Modeling

    Science.gov (United States)

    Grimm, Kevin J.; Widaman, Keith F.

    2010-01-01

    Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…

  19. Residues for flags of holomorphic foliations

    OpenAIRE

    Brasselet, Jean-Paul; Corrêa, Maurício; Lourenço, Fernando

    2016-01-01

    In this work we prove a Baum-Bott type residues theorem for flags of holomorphic foliations. We prove some relations between the residues of the flag and the residues of their correspondent foliations. We define the Nash residue for flags and we prove that the Bott rationality conjecture holds in this context.

  20. Alternatives to crop residues for soil amendment

    OpenAIRE

    Powell, J.M.; Unger, P.W.

    1997-01-01

    Metadata only record In semiarid agroecosystems, crop residues can provide important benefits of soil and water conservation, nutrient cycling, and improved subsequent crop yields. However, there are frequently multiple competing uses for residues, including animal forage, fuel, and construction material. This chapter discusses the various uses of crop residues and examines alternative soil amendments when crop residues cannot be left on the soil.

  1. Modelling of top quark pairs production in association with Standard Model bosons or heavy quark pairs.

    CERN Document Server

    Moreno Llacer, Maria; The ATLAS collaboration

    2016-01-01

    Production of top quark pairs in association with heavy Standard Model bosons or with heavy flavour quark-pairs is important both as a signal and a background in several ATLAS analyses. Strong constraints on such processes cannot at present be obtained from data, and therefore their modeling by Monte Carlo simulation as well as the associated uncertainties are important. This poster documents the Monte Carlo samples currently being used in ATLAS for the ttH and ttV (V=W,Z vector bosons) and tt+bottom and charm quark pairs processes for sqrt(s)=13 TeV proton-proton collisions.

  2. Neutron pair and proton pair transfer reactions between identical cores in the sulfur region

    International Nuclear Information System (INIS)

    Optical model and exact finite range distorted-wave Born approximation analyses were performed on neutron pair exchange between identical cores for 32S and 34S nuclei and on proton pair exchange between identical cores for 30Si and 32S. The extracted spectroscopic factors were compared with theoretical ones deduced from Hartree-Fock calculations on these pair of nuclei. The enhancement of the experimental cross sections with respect to the theoretical ones strongly suggests evidence for a nuclear Josephson effect. (author). 15 refs., 5 figs., 3 tabs

  3. Solidification process for sludge residue

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, K.L.

    1998-09-10

    This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria.

  4. Solidification process for sludge residue

    International Nuclear Information System (INIS)

    This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria

  5. IMPROVED TECHNIQUES FOR RESIDUAL OZONE

    Science.gov (United States)

    Eight analytical methods for the determination of residual ozone in water are evaluated. Four are iodometric methods based on the reduction of ozone by iodide ion: the iodometric method, the amperometric method, the arsenic (III) back titration method, and the N, N-diethyl-p-phen...

  6. Pyrotechnic reaction residue particle analysis.

    Science.gov (United States)

    Kosanke, Kenneth L; Dujay, Richard C; Kosanke, Bonnie J

    2006-03-01

    Pyrotechnic reaction residue particle (PRRP) production, sampling and analysis are all very similar to that for primer gunshot residue. In both cases, the preferred method of analysis uses scanning electron microscopy to locate suspect particles and then uses energy dispersive x-ray spectroscopy to characterize the particle's constituent chemical elements. There are relatively few times when standard micro-analytical chemistry performed on pyrotechnic residues may not provide sufficient information for forensic investigators. However, on those occasions, PRRP analysis provides a greatly improved ability to discriminate between materials of pyrotechnic origin and other unrelated substances also present. The greater specificity of PRRP analysis is the result of its analyzing a large number of individual micron-sized particles, rather than producing only a single integrated result such as produced using standard micro-analytical chemistry. For example, PRRP analyses are used to demonstrate its ability to successfully (1) discriminate between pyrotechnic residues and unrelated background contamination, (2) identify that two different pyrotechnic compositions had previously been exploded within the same device, and (3) establish the chronology of an incident involving two separate and closely occurring explosions. PMID:16566762

  7. Landfill Mining of Shredder Residues

    DEFF Research Database (Denmark)

    Hansen, Jette Bjerre; Hyks, Jiri; Shabeer Ahmed, Nassera;

    In Denmark, shredder residues (SR) are classified as hazardous waste and until January 2012 the all SR were landfilled. It is estimated that more than 1.8 million tons of SR have been landfilled in mono cells. This paper describes investigations conducted at two Danish landfills. SR were excavated...

  8. Coevolution of amino acid residues in the key photosynthetic enzyme Rubisco

    Directory of Open Access Journals (Sweden)

    Kapralov Maxim V

    2011-09-01

    Full Text Available Abstract Background One of the key forces shaping proteins is coevolution of amino acid residues. Knowing which residues coevolve in a particular protein may facilitate our understanding of protein evolution, structure and function, and help to identify substitutions that may lead to desired changes in enzyme kinetics. Rubisco, the most abundant enzyme in biosphere, plays an essential role in the process of carbon fixation through photosynthesis, thus facilitating life on Earth. This makes Rubisco an important model system for studying the dynamics of protein fitness optimization on the evolutionary landscape. In this study we investigated the selective and coevolutionary forces acting on large subunit of land plants Rubisco using Markov models of codon substitution and clustering approaches applied to amino acid substitution histories. Results We found that both selection and coevolution shape Rubisco, and that positively selected and coevolving residues have their specifically favored amino acid composition and pairing preference. The mapping of these residues on the known Rubisco tertiary structures showed that the coevolving residues tend to be in closer proximity with each other compared to the background, while positively selected residues tend to be further away from each other. This study also reveals that the residues under positive selection or coevolutionary force are located within functionally important regions and that some residues are targets of both positive selection and coevolution at the same time. Conclusion Our results demonstrate that coevolution of residues is common in Rubisco of land plants and that there is an overlap between coevolving and positively selected residues. Knowledge of which Rubisco residues are coevolving and positively selected could be used for further work on structural modeling and identification of substitutions that may be changed in order to improve efficiency of this important enzyme in crops.

  9. Estimation of the Conditional Variance in Paired Experiments

    OpenAIRE

    Abadie, Alberto; Guido W. IMBENS

    2008-01-01

    In paired randomized experiments units are grouped in pairs, often based on covariate information, with random assignment within the pairs. Average treatment effects are then estimated by averaging the within-pair differences in outcomes. Typically the variance of the average treatment effect estimator is estimated using the sample variance of the within-pair differences. However, conditional on the covariates the variance of the average treatment effect estimator may be substantially smaller...

  10. Origins of the residual pulse height deficit in propane-filled gas ionization detectors

    International Nuclear Information System (INIS)

    This work investigates the origins of the residual pulse height deficit in gas ionization detectors. It is motivated by the recent observation that the species dependence of gas detector response cannot be accounted for solely by considering the energy loss of the ions in the detector window and non-ionizing energy loss processes in the detector gas. It was found that the residual pulse height deficit is approximately proportional to the square of the ionization density. However, only a weak dependence of the residual deficit on gas pressure (in the range 70-120mbar) was observed. It is hypothesized that the residual pulse height deficit in gas ionization detectors results from the effect of multiple ionization of individual gas molecules at high ionization densities on the energy required to create an electron-ion pair

  11. Na+ Cl- ion pair association in water-DMSO mixtures: Effect of ion pair model potentials

    Indian Academy of Sciences (India)

    ATANU SARKAR; ANUPAM CHATTERJEE; S C TIWARI; B L TEMBE

    2016-06-01

    Potentials of Mean Force (PMF) for the Na+ Cl- ion pair in water–dimethyl sulfoxide (DMSO)mixtures for three DMSO mole fractions have been computed using constrained Molecular Dynamics (MD)simulations and confirmed by dynamical trajectories and residence times of the ion pair at various inter-ionicseparations. The three ion-ion direct potentials used are 12-6-1, exp-6-1 and exp-8-6-1. The physical picturethat emerges is that there is a strong contact ion pair (CIP) and strong to moderate solvent separated ion pair(SSIP) in these solutions. Analysis of local ion clusters shows that ions are dominantly solvated by watermolecules. The 12-6-1 potential model predicts running coordination numbers closest to experimental data.

  12. Pairing and anti-pairing: a balancing act in the diploid genome

    Science.gov (United States)

    Joyce, Eric F.; Erceg, Jelena; Wu, C.-ting

    2016-01-01

    The presence of maternal and paternal homologs appears to be much more than just a doubling of genetic material. We know this because genomes have evolved elaborate mechanisms that permit homologous regions to sense and then respond to each other. One way in which homologs communicate is to come into contact and, in fact, Dipteran insects such as Drosophila excel at this task, aligning all pairs of maternal and paternal chromosomes, end-to-end, in essentially all somatic tissues throughout development. Here, we reexamine the widely held tenet that extensive somatic pairing of homologous sequences cannot occur in mammals and suggest, instead, that pairing may be a widespread and significant potential that has gone unnoticed in mammals because they expend considerable effort to prevent it. We then extend this discussion to interchromosomal interactions, in general, and speculate about the potential of nuclear organization and pairing to impact inheritance. PMID:27065367

  13. General pairing interactions and pair truncation approximations for fermions in a single-j shell

    CERN Document Server

    Zhao, Y M; Ginocchio, J N; Yoshinaga, N

    2003-01-01

    We investigate Hamiltonians with attractive interactions between pairs of fermions coupled to angular momentum J. We show that pairs with spin J are reasonable building blocks for the low-lying states. For systems with only a J = Jmax pairing interaction, eigenvalues are found to be approximately integers for a large array of states, in particular for those with total angular momenta I le 2j. For I=0 eigenstates of four fermions in a single-j shell we show that there is only one non-zero eigenvalue. We address these observations using the nucleon pair approximation of the shell model and relate our results with a number of currently interesting problems.

  14. Resonant Repulsion of Kepler Planet Pairs

    CERN Document Server

    Lithwick, Yoram

    2012-01-01

    Planetary systems discovered by the Kepler space telescope exhibit an intriguing feature. While the period ratios of adjacent low-mass planets appear largely random, there is a significant excess of pairs that lie just wide of resonances and a deficit on the near side. We demonstrate that this feature naturally arises when two near-resonant planets interact in the presence of weak dissipation that damps eccentricities. The two planets repel each other as orbital energy is lost to heat. This moves near-resonant pairs just beyond resonance, by a distance that reflects the integrated dissipation they experienced over their lifetimes. We find that the observed distances may be explained by tidal dissipation if tides are efficient (tidal quality factor ~10). Once the effect of resonant repulsion is accounted for, the initial orbits of these low mass planets show little preference for resonances. This is a strong constraint on their origin.

  15. Schwinger pair production with ultracold atoms

    Science.gov (United States)

    Kasper, V.; Hebenstreit, F.; Oberthaler, M. K.; Berges, J.

    2016-09-01

    We consider a system of ultracold atoms in an optical lattice as a quantum simulator for electron-positron pair production in quantum electrodynamics (QED). For a setup in one spatial dimension, we investigate the nonequilibrium phenomenon of pair production including the backreaction leading to plasma oscillations. Unlike previous investigations on quantum link models, we focus on the infinite-dimensional Hilbert space of QED and show that it may be well approximated by experiments employing Bose-Einstein condensates interacting with fermionic atoms. Numerical calculations based on functional integral techniques give a unique access to the physical parameters required to realize QED phenomena in a cold atom experiment. In particular, we use our approach to consider quantum link models in a yet unexplored parameter regime and give bounds for their ability to capture essential features of the physics. The results suggest a paradigmatic change towards realizations using coherent many-body states for quantum simulations of high-energy particle physics phenomena.

  16. Top pair production measurements at ATLAS.

    CERN Document Server

    Fabbri, Federica; The ATLAS collaboration

    2016-01-01

    Measurements of the inclusive and differential top-quark pair cross sections in proton-proton collisions at both 8 TeV and 13 TeV with the ATLAS detector at the Large Hadron Collider are presented. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. Differential measurements of the kinematic properties of the top quark production are also discussed. These measurements, including results using boosted tops, probe our understanding of top pair production in the TeV regime. The results, extrapolated to particle and parton level, are compared to Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NNLO QCD calculations.

  17. Dual Resolution Images from Paired Fingerprint Cards

    Science.gov (United States)

    NIST Dual Resolution Images from Paired Fingerprint Cards (PC database for purchase)   NIST Special Database 30 is being distributed for use in development and testing of fingerprint compression and fingerprint matching systems. The database allows the user to develop and evaluate data compression algorithms for fingerprint images scanned at both 19.7 ppmm (500 dpi) and 39.4 ppmm (1000 dpi). The data consist of 36 ten-print paired cards with both the rolled and plain images scanned at 19.7 and 39.4 pixels per mm. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

  18. Instantons For Black Hole Pair Production

    CERN Document Server

    Branoff, P M; Branoff, Paul M.; Brill, Dieter R.

    1998-01-01

    We address the issue of constructing continuous instantons representing the pair creation of black holes in a cosmological context. The recent attempt at constructing such solutions using virtual domain walls is reviewed first. We then explore the existence of continuous instantons in higher curvature gravity theories where the Lagrangian is polynomial in the Ricci scalar. Lastly, we study continuous instanton solutions of ordinary gravity coupled to the Narlikar C-field. For each theory, we first consider the case of finding continuous instanton solutions which represent the "near-annihilation" of a de Sitter universe and its subsequent recreation. In situations where these solutions exist, we then ask whether solutions can be found that represent the "near-annihilation" of a de Sitter spacetime and the subsequent creation of a pair of Schwarzschild-de Sitter black holes.

  19. A search for resonant Z pair production

    Energy Technology Data Exchange (ETDEWEB)

    Boveia, Antonio; /UC, Santa Barbara

    2008-12-01

    I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.

  20. Top Quark Pair Production beyond NNLO

    CERN Document Server

    Muselli, Claudio; Forte, Stefano; Marzani, Simone; Ridolfi, Giovanni

    2015-01-01

    We construct an approximate expression for the total cross section for the production of a heavy quark-antiquark pair in hadronic collisions at next-to-next-to-next-to-leading order (N$^3$LO) in $\\alpha_s$. We use a technique which exploits the analyticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummations, previously introduced and used in the case of Higgs production. We validate our method by comparing to available exact results up to NNLO. We find that N$^3$LO corrections increase the predicted top pair cross section at the LHC by about 4% over the NNLO.

  1. Extra-pair paternity in waved albatrosses.

    Science.gov (United States)

    Huyvaert, K P; Anderson, D J; Jones, T C; Duan, W; Parker, P G

    2000-09-01

    We estimated the rate of extra-pair fertilizations (EPFs) in waved albatrosses (Phoebastria irrorata) on Isla Española, Galápagos, Ecuador, using multilocus minisatellite DNA fingerprinting. Waved albatrosses are socially monogamous, long-lived seabirds whose main population is on Española. Aggressive extra-pair copulation (EPC) attempts have been observed in the breeding colony during the days preceding egg-laying. Our genetic analyses of 16 families (single chicks and their attending parents) revealed evidence of EPFs in four families. In all cases males were the excluded parent. These data suggest that waved albatrosses have an unusually high rate of EPF relative to taxa with similar life histories. Future behavioural observations will determine the extent to which forced vs. unforced EPCs contribute to this high EPF rate. PMID:10972780

  2. Turbulent pair dispersion of inertial particles

    CERN Document Server

    Bec, J; Lanotte, A S; Scagliarini, A; Toschi, F

    2009-01-01

    The relative dispersion of pairs of inertial particles in incompressible, homogeneous, and isotropic turbulence is studied by means of direct numerical simulations at two values of the Taylor-scale Reynolds number $Re_{\\lambda} \\sim 200$ and 400. The evolution of both heavy and light particle pairs is analysed at varying the particle Stokes number and the fluid-to-particle density ratio. For heavy particles, it is found that turbulent dispersion is schematically governed by two temporal regimes. The first is dominated by the presence, at large Stokes numbers, of small-scale caustics in the particle velocity statistics, and it lasts until heavy particle velocities have relaxed towards the underlying flow velocities. At such large scales, a second regime starts where heavy particles separate as tracers particles would do. As a consequence, at increasing inertia, a larger transient stage is observed, and the Richardson diffusion of simple tracers is recovered only at large times and large scales. These features ...

  3. Average prime-pair counting formula

    Science.gov (United States)

    Korevaar, Jaap; Riele, Herman Te

    2010-04-01

    Taking r>0 , let π_{2r}(x) denote the number of prime pairs (p, p+2r) with p≤ x . The prime-pair conjecture of Hardy and Littlewood (1923) asserts that π_{2r}(x)˜ 2C_{2r} {li}_2(x) with an explicit constant C_{2r}>0 . There seems to be no good conjecture for the remainders ω_{2r}(x)=π_{2r}(x)- 2C_{2r} {li}_2(x) that corresponds to Riemann's formula for π(x)-{li}(x) . However, there is a heuristic approximate formula for averages of the remainders ω_{2r}(x) which is supported by numerical results.

  4. REX: Explaining Relationships between Entity Pairs

    CERN Document Server

    Fang, Lujun; Yu, Cong; Bohannon, Philip

    2011-01-01

    Knowledge bases of entities and relations (either constructed manually or automatically) are behind many real world search engines, including those at Yahoo!, Microsoft, and Google. Those knowledge bases can be viewed as graphs with nodes representing entities and edges representing (primary) relationships, and various studies have been conducted on how to leverage them to answer entity seeking queries. Meanwhile, in a complementary direction, analyses over the query logs have enabled researchers to identify entity pairs that are statistically correlated. Such entity relationships are then presented to search users through the "related searches" feature in modern search engines. However, entity relationships thus discovered can often be "puzzling" to the users because why the entities are connected is often indescribable. In this paper, we propose a novel problem called "entity relationship explanation", which seeks to explain why a pair of entities are connected, and solve this challenging problem by integra...

  5. Paired de Bruijn Graphs: A Novel Approach for Incorporating Mate Pair Information into Genome Assemblers

    OpenAIRE

    Medvedev, Paul; Pham, Son; Chaisson, Mark; Tesler, Glenn; Pevzner, Pavel

    2011-01-01

    The recent proliferation of next generation sequencing with short reads has enabled many new experimental opportunities but, at the same time, has raised formidable computational challenges in genome assembly. One of the key advances that has led to an improvement in contig lengths has been mate pairs, which facilitate the assembly of repeating regions. Mate pairs have been algorithmically incorporated into most next generation assemblers as various heuristic post-processing steps to correct ...

  6. Strong pairing approximation in comparison with the exact solutions to the pairing Hamiltonian

    Science.gov (United States)

    Lunyov, A. V.; Mikhajlov, V. M.

    2016-01-01

    Results of the Strong Pairing Approximation (SPA) as a method with the exact particle number conservation are compared with those of the quasiparticle method (QM). It is shown that SPA comes to the same equations as QM for the gap parameter, chemical potential and one- and two-quasiparticle states. Calculations are performed for 14864Gd84 as an example, and compared with the exact solutions to the pairing Hamiltonian.

  7. Radio structures in QSO-galaxy pairs

    International Nuclear Information System (INIS)

    It is now generally agreed that if quasars and nearby low redshift galaxies are associated, then there should be luminous connections between them. However, most of the observational evidence being presented is in the optical domain, whereas such evidence should also exist at radio frequencies. The author is, therefore, investigating some quasar-galaxy pairs at radio frequencies to search for luminous connections and other structural peculiarities. Radio maps of some of these sources are presented

  8. Paired structures and bipolar knowledge representation

    OpenAIRE

    Montero, Javier; Bustince, H.; Franco, C.; Rodríguez, Juan Tinguaro; Gómez, Daniel; Pagola, Miguel; Fernandez, Javier; Barrenechea, Edurne

    2014-01-01

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories which suggests the emergence of a paired structure and its associated type of neutrality, being there three general types of neutral categories, namely indeterminacy, ambivalence and conflict. Hence, ...

  9. Asteroid Systems: Binaries, Triples, and Pairs

    CERN Document Server

    Margot, Jean-Luc; Taylor, Patrick; Carry, Benoît; Jacobson, Seth

    2015-01-01

    In the past decade, the number of known binary near-Earth asteroids has more than quadrupled and the number of known large main belt asteroids with satellites has doubled. Half a dozen triple asteroids have been discovered, and the previously unrecognized populations of asteroid pairs and small main belt binaries have been identified. The current observational evidence confirms that small (20 km) binaries with small satellites are most likely created during large collisions.

  10. Narrowband polarization entangled telecom photon pair source

    OpenAIRE

    Kaiser, Florian; Issautier, Amandine; Alibart, Olivier; Martin, Anthony; Tanzilli, Sébastien

    2011-01-01

    During the last decade, quantum entanglement has paved the way out to of the lab modern applications such as quantum computation and communication. Today, small scale quantum networks exist already, but they are limited to a few 100 km distance, due to intrinsic fiber transmission losses and non perfect detectors. These networks are typically established using photon pair sources based on spontaneous parametric down conversion (SPDC). Widely used entanglement observables are time-bin and pola...

  11. Pair Correlations in Superfluid Helium 3

    OpenAIRE

    Vollhardt, D.

    1997-01-01

    In 1996 Lee, Osheroff and Richardson received the Nobel Prize for their 1971 discovery of superfluid helium 3 -- a discovery which opened the door to the most fascinating system known in condensed matter physics. The superfluid phases of helium 3, originating from pair condensation of helium 3 atoms, turned out to be the ideal test-system for many fundamental concepts of modern physics, such as macroscopic quantum phenomena, (gauge-)symmetries and their spontaneous breakdown, topological defe...

  12. Temporal dependence in longitudinal paired comparisons

    OpenAIRE

    Dittrich, Regina; Francis, Brian; Katzenbeisser, Walter

    2008-01-01

    This paper develops a new approach to the analysis of longitudinal paired comparison data, where comparisons of the same objects by the same judges are made on more than one occasion. As an alternative to other recent approaches to such data, which are based on Kalman filter- ing, our approach treats the problem as one of multivariate multinomial data, allowing dependence terms between comparisons over time to be incorporated. The resulting model can be fitted as a Poisson log-linear model an...

  13. Bjerrum pairing correlations at charged interfaces

    OpenAIRE

    Travesset, A.; Vaknin, D.

    2006-01-01

    Electrostatic correlations play a fundamental role in aqueous solutions. In this letter, we identify transverse and lateral correlations as two mutually exclusive regimes. We show that the transverse regime leads to binding by generalization of Bjerrum pair formation theory, yielding binding constants from first-principle statistical-mechanical calculations. We compare our theoretical predictions with experiments on charged membranes and Langmuir monolayers and find good agreement. We contras...

  14. W+- pairs and neutral currents at ISABELLE

    International Nuclear Information System (INIS)

    A report is presented on two different types of processes which may form part of the weak interactions program. The first is the production of pairs of charged weak bosons in the process pp → W+W-X; the second involves searching for neutral current effects in the rate for ordinary lepton production, without measuring any charge asymmetry or helicities using the reaction pp → l+l-X

  15. Quantum Computation by Pairing Trapped Ultracold Ions

    Institute of Scientific and Technical Information of China (English)

    冯芒; 朱熙文; 高克林; 施磊

    2001-01-01

    Superpositional wavefunction oscillations for the implementation of quantum algorithms modify the desired interference required for the quantum computation. We propose a scheme with trapped ultracold ion-pairs beingqubits to diminish the detrimental effect of the wavefunction oscillations, which is applied to the two-qubitGrover's search. It can be also found that the qubits in our scheme are more robust against the decoherencecaused by the environment, and the model is scalable.

  16. Denitrification in intact sediment cores from a constructed wetland: Examining the isotope pairing technique

    International Nuclear Information System (INIS)

    Constructed wetlands aid in the removal of NO3- from surface waters due to enhanced rates of denitrification. In this study intact sediment cores from a constructed wetland were used to measure denitrification rates via the isotope pairing technique and to compare with denitrification rates measured via a mass balance of NO3- disappearance from the water column. The traditional application of the isotope pairing technique calls for the use of mechanical mixing to ensure the transfer of tracer 15NO3- into the sediments. However, artificial mixing can disrupt natural redox processes near the sediment-water interface, and thus may yield rates that are not representative of field conditions. The objective of this study was to examine the applicability of the isotope pairing technique for intact sediment cores and to determine the adjustments that may be necessary in such applications. The 15NO3- was added to the overlying water of intact sediment cores and was transported into sediments only by natural diffusion processes. Using Br- as a conservative tracer, it was determined that passive diffusion alone allowed 27% of the added compound to reach the zone of denitrification in the sediments. Using these results, the enrichment factor (ε) used in the isotope pairing technique was adjusted to account for this effect. Also, it was determined that agitation of the cores at the end of the incubations was necessary to release residual 15N-labelled N2 gas entrained in the sediment matrix. Only after accounting for these two factors did the denitrification rate from the isotope pairing technique agree with mass balance calculations. The isotope pairing technique can be used to quantify denitrification in intact sediment cores if diffusion limitations are quantified and entrained N2 is released from the sediment matrix before final isotope analyses are conducted

  17. Banach Algebras Associated to Lax Pairs

    Science.gov (United States)

    Glazebrook, James F.

    2015-04-01

    Lax pairs featuring in the theory of integrable systems are known to be constructed from a commutative algebra of formal pseudodifferential operators known as the Burchnall- Chaundy algebra. Such pairs induce the well known KP flows on a restricted infinite-dimensional Grassmannian. The latter can be exhibited as a Banach homogeneous space constructed from a Banach *-algebra. It is shown that this commutative algebra of operators generating Lax pairs can be associated with a commutative C*-subalgebra in the C*-norm completion of the *-algebra. In relationship to the Bose-Fermi correspondence and the theory of vertex operators, this C*-algebra has an association with the CAR algebra of operators as represented on Fermionic Fock space by the Gelfand-Naimark-Segal construction. Instrumental is the Plücker embedding of the restricted Grassmannian into the projective space of the associated Hilbert space. The related Baker and tau-functions provide a connection between these two C*-algebras, following which their respective state spaces and Jordan-Lie-Banach algebras structures can be compared.

  18. Chiral baryon in the coherent pair approximation

    CERN Document Server

    Aly, T S T

    1999-01-01

    We revisit the work of K. Goeke, M. Harvey, F. Grümmer, and J. N. Urbano (Phys. Rev. {\\bf D37}, 754 (1988)) who considered a chiral model for the nucleon based on the linear sigma model with scalar-isoscalar scalar-isovector mesons coupled to quarks and solved using the coherent-pair approximation. In this way the quantum pion field can be treated in a non-perturbative fashion. In this work we review this model and the coherent pair approximation correcting several errors in the earlier work. We minimize the expectation value of the chiral hamiltonian in the ansatz coherent-pair ground state configuration and solve the resulting equations for nucleon quantum numbers. We calculate the canonical set of nucleon observables and compare with the Hedgehog model and experiment. Using the corrected equations yield slightly different values for nucleon observables but do not correct the large virial deviation in the $\\pi$-nucleon coupling. Our results therefore do not significantly alter the conclusions of Goeke, et ...

  19. Population of the giant pairing vibration

    Science.gov (United States)

    Laskin, M.; Casten, R. F.; Macchiavelli, A. O.; Clark, R. M.; Bucurescu, D.

    2016-03-01

    Background: The giant pairing vibration (GPV), a correlated two-nucleon mode in the second shell above the Fermi surface, has long been predicted and expected to be strongly populated in two-nucleon transfer cross sections similar to those of the normal pairing vibration. Recent experiments have provided evidence for this mode in ,15C14 but, despite sensitive studies, it has not been definitively identified in either Sn or Pb nuclei where pairing correlations are known to play a crucial role. Purpose: Our aim is to test whether features inherent to the mixing of bound and unbound levels might account for this and to study the effect in a simple and intuitively clear approach. Method: We study the mixing of unbound levels in a set of toy models that capture the essential physics of the GPV, along with a more realistic calculation including distorted-wave Born approximation transfer amplitudes. Results: The calculated (relative) cross section to populate a simulated GPV state is effectively low, compared to the case of bound levels with no widths Conclusions: The mixing turns out to be only a minor contributor to the weak population. Rather, the main reason is the melting of the GPV peak due to the width it acquires from the low orbital angular momentum single-particle states playing a dominant role in two-nucleon transfer amplitudes. This effect, in addition to a severe Q -value mismatch, may account for the elusive nature of this mode in (t ,p ) and (p ,t ) reactions.

  20. Photoinduced Charge Separation in Porphyrin Ion Pairs.

    Science.gov (United States)

    Natali, Mirco; Scandola, Franco

    2016-03-10

    Ion pairs between porphyrin-type compounds have been successfully employed for spectral sensitization of semiconductor surfaces and for the preparation of collective binary ionic materials for photonic and (photo)catalytic applications. The understanding of the photophysical processes occurring within ion-paired porphyrin dimers is thus of remarkable importance for the optimization and improvement of such systems. Herein the ion-pair species formed between ZnTMePyP(4+) (Zn1) or H2TMePyP(4+) (H21) and ZnTPPS(4-) (Zn2) or H2TPPS(4-) (H22) in a variety of solvent mixtures are characterized and their photophysics thoroughly investigated by time-resolved techniques. In all the systems studied, very fast and efficient photoinduced charge separation is observed, with the cationic porphyrin being reduced and the anionic one oxidized. Interestingly, despite the very short charge separation distance, the lifetime for charge recombination, depending on the energy gap, can extend into the nanosecond time domain, showing great potential for the utilization of this molecular design within energy conversion schemes. PMID:26905260

  1. Grandmothering life histories and human pair bonding.

    Science.gov (United States)

    Coxworth, James E; Kim, Peter S; McQueen, John S; Hawkes, Kristen

    2015-09-22

    The evolution of distinctively human life history and social organization is generally attributed to paternal provisioning based on pair bonds. Here we develop an alternative argument that connects the evolution of human pair bonds to the male-biased mating sex ratios that accompanied the evolution of human life history. We simulate an agent-based model of the grandmother hypothesis, compare simulated sex ratios to data on great apes and human hunter-gatherers, and note associations between a preponderance of males and mate guarding across taxa. Then we explore a recent model that highlights the importance of mating sex ratios for differences between birds and mammals and conclude that lessons for human evolution cannot ignore mammalian reproductive constraints. In contradiction to our claim that male-biased sex ratios are characteristically human, female-biased ratios are reported in some populations. We consider the likelihood that fertile men are undercounted and conclude that the mate-guarding hypothesis for human pair bonds gains strength from explicit links with our grandmothering life history. PMID:26351687

  2. Tree structure compression with RePair

    CERN Document Server

    Lohrey, Markus; Mennicke, Roy

    2010-01-01

    In this work we introduce a new linear time compression algorithm, called "Re-pair for Trees", which compresses ranked ordered trees using linear straight-line context-free tree grammars. Such grammars generalize straight-line context-free string grammars and allow basic tree operations, like traversal along edges, to be executed without prior decompression. Our algorithm can be considered as a generalization of the "Re-pair" algorithm developed by N. Jesper Larsson and Alistair Moffat in 2000. The latter algorithm is a dictionary-based compression algorithm for strings. We also introduce a succinct coding which is specialized in further compressing the grammars generated by our algorithm. This is accomplished without loosing the ability do directly execute queries on this compressed representation of the input tree. Finally, we compare the grammars and output files generated by a prototype of the Re-pair for Trees algorithm with those of similar compression algorithms. The obtained results show that that our...

  3. Exclusive production of W pairs in CMS

    Directory of Open Access Journals (Sweden)

    Silveira Da

    2014-04-01

    Full Text Available We report the results on the search for exclusive production of W pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at √s = 7 TeV. The analysis comprises the two-photon production of a W pairs, pp → pW+ W− p → p νe± νµ∓ p. Two events are observed in data for pT(ℓ > 4 GeV, |η(ℓ| 20 GeV, in agreement with the standard model prediction of 2.2 ± 0.4 signal events with 0.84 ± 0.15 background events. Moreover, a study of the tail of the lepton pair transverse momentum distribution is performed to search for an evidence of anomalous quartic gauge couplings in the γγ → W+ W− vertex. As no events are observed in data, it results in a model-independent upper limits for the anomalous W quartic gauge couplings aW0,C/Λ2, which are of the order of 10−4.

  4. The paired-domination and the upper paired-domination numbers of graphs

    Directory of Open Access Journals (Sweden)

    Włodzimierz Ulatowski

    2015-01-01

    Full Text Available In this paper we continue the study of paired-domination in graphs. A paired-dominating set, abbreviated PDS, of a graph \\(G\\ with no isolated vertex is a dominating set of vertices whose induced subgraph has a perfect matching. The paired-domination number of \\(G\\, denoted by \\(\\gamma_{p}(G\\, is the minimum cardinality of a PDS of \\(G\\. The upper paired-domination number of \\(G\\, denoted by \\(\\Gamma_{p}(G\\, is the maximum cardinality of a minimal PDS of \\(G\\. Let \\(G\\ be a connected graph of order \\(n\\geq 3\\. Haynes and Slater in [Paired-domination in graphs, Networks 32 (1998, 199-206], showed that \\(\\gamma_{p}(G\\leq n-1\\ and they determine the extremal graphs \\(G\\ achieving this bound. In this paper we obtain analogous results for \\(\\Gamma_{p}(G\\. Dorbec, Henning and McCoy in [Upper total domination versus upper paired-domination, Questiones Mathematicae 30 (2007, 1-12] determine \\(\\Gamma_{p}(P_n\\, instead in this paper we determine \\(\\Gamma_{p}(C_n\\. Moreover, we describe some families of graphs \\(G\\ for which the equality \\(\\gamma_{p}(G=\\Gamma_{p}(G\\ holds.

  5. Radioactive material in residues of health services residues

    International Nuclear Information System (INIS)

    The work presents the operational actions developed by the one organ responsible regulator for the control of the material use radioactive in Brazil. Starting from the appearance of coming radioactive material of hospitals and clinical with services of nuclear medicine, material that that is picked up and transported in specific trucks for the gathering of residuals of hospital origin, and guided one it manufactures of treatment of residuals of services of health, where they suffer radiological monitoring before to guide them for final deposition in sanitary embankment, in the city of Sao Paulo, Brazil. The appearance of this radioactive material exposes a possible one violation of the norms that govern the procedures and practices in that sector in the country. (Author)

  6. Effects of thermal shape fluctuations and pairing fluctuations on the giant dipole resonance in warm nuclei

    CERN Document Server

    Kumar, A K Rhine; Dang, N Dinh

    2015-01-01

    Apart from the higher limits of isospin and temperature, the properties of atomic nuclei are intriguing and less explored at the limits of lowest but finite temperatures. At very low temperatures there is a strong interplay between the shell (quantal fluctuations), statistical (thermal fluctuations), and residual pairing effects as evidenced from the studies on giant dipole resonance (GDR). In our recent work [Phys. Rev. C \\textbf{90}, 044308 (2014)], we have outlined some of our results from a theoretical approach for such warm nuclei where all these effects are incorporated along within the thermal shape fluctuation model (TSFM) extended to include the fluctuations in the pairing field. In this article, we present the complete formalism based on the microscopic-macroscopic approach for determining the deformation energies and a macroscopic approach which links the deformation to GDR observables. We discuss our results for the nuclei $^{97}$Tc, $^{120}$Sn, $^{179}$Au, and $^{208}$Pb, and corroborate with the...

  7. 6-Pyrazolylpurine as an Artificial Nucleobase for Metal-Mediated Base Pairing in DNA Duplexes

    Science.gov (United States)

    Léon, J. Christian; Sinha, Indranil; Müller, Jens

    2016-01-01

    The artificial nucleobase 6-pyrazol-1-yl-purine (6PP) has been investigated with respect to its usability in metal-mediated base pairing. As was shown by temperature-dependent UV spectroscopy, 6PP may form weakly stabilizing 6PP–Ag(I)–6PP homo base pairs. Interestingly, 6PP can be used to selectively recognize a complementary pyrimidine nucleobase. The addition of Ag(I) to a DNA duplex comprising a central 6PP:C mispair (C = cytosine) leads to a slight destabilization of the duplex. In contrast, a stabilizing 6PP–Ag(I)–T base pair is formed with a complementary thymine (T) residue. It is interesting to note that 6PP is capable of differentiating between the pyrimidine moieties despite the fact that it is not as sterically crowded as 6-(3,5-dimethylpyrazol-1-yl)purine, an artificial nucleobase that had previously been suggested for the recognition of nucleic acid sequences via the formation of a metal-mediated base pair. Hence, the additional methyl groups of 6-(3,5-dimethylpyrazol-1-yl)purine may not be required for the specific recognition of the complementary nucleobase. PMID:27089326

  8. Isolated Main Galaxy Pairs from the SDSS Data Release 4

    Institute of Scientific and Technical Information of China (English)

    Xin-Fa Deng; Yi-Qing Chen; Ping Wu; Cheng-Hong Luo; Ji-Zhou He

    2006-01-01

    From the Main galaxy data of the SDSS Data Release 4 (SDSS4), we have identified close galaxy pairs at neighbourhood radius R = 100 kpc by three-dimensional cluster analysis. Using the criterion that an "isolated galaxy pair" must be separated from its "nearest neighbor" by more than 500 kpc, we constructed an isolated galaxy pair sample of 1158 pairs.We also constructed a random pair sample by randomly selecting 1158 galaxy pairs from the Main galaxy sample, which has the same redshift distribution as the isolated galaxy pair sample, and in which the two components of any pair have the same redshifts. Comparative studies of luminosity and size between the members of the galaxy pairs are performed. We find and further confirm there is no tendency for paired galaxies to have similar luminosities or sizes. From the isolated pair sample we also selected a subsample with the magnitude limit of the primary raised by 2 magnitudes, so as to include pairs in which the secondary is 2 magnitudes fainter than the primary. This subsample contains 82 pairs. A random pair sample is similarly constructed.

  9. From one to N Cooper pairs, step by step

    International Nuclear Information System (INIS)

    We suggest a method for the analytical solution of Richardson equations. We reveal a connection between one-pair Cooper problem and BCS superconductivity. The ground state energy is controlled by binding energy of a Cooper pair. The superconducting gap is due to many-body effects induced by Pauli blocking. We extend the one-pair Cooper configuration towards Bardeen-Cooper-Schrieffer (BCS) model of superconductivity by adding one-by-one electron pairs to an energy layer, where a small attraction acts. To do it, we solve Richardson's equations analytically in the dilute limit of pairs on the one-Cooper pair scale. We find, through only keeping the first order term in this expansion, that the N correlated pair energy reads as the energy of N isolated pairs within a N(N-1) correction induced by the Pauli exclusion principle which tends to decrease the average pair binding energy when the pair number increases. Quite remarkably, extension of this first-order result to the dense regime gives the BCS condensation energy exactly. This leads us to suggest a different understanding of the BCS condensation energy with a pair number equal to the number of pairs feeling the potential and an average pair binding energy reduced by Pauli blocking to half the single Cooper pair energy - instead of the more standard but far larger superconducting gap.

  10. Chemical Modification of Tryptophan Residues in Pullulanase

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Tryptophan(Trp)residues in pullulanase have been chemically modified with N-bromossuccinimide(NBS). The results of ultraviolet spectra indicated that there are 18 Trp residues in pullulanase and nine of them are located on the surface of the enzyme. Three of these Trp residues are none-essential residues which showed the fastest reaction speed by Zhou's plot. Two of the seven relative faster reacting residues are essential for the activity of the enzyme. The other eight are none-reactive residues with lowest reaction speed.

  11. The Cauchy method of residues

    CERN Document Server

    Mitrinović, Dragoslav S

    1993-01-01

    Volume 1, i. e. the monograph The Cauchy Method of Residues - Theory and Applications published by D. Reidel Publishing Company in 1984 is the only book that covers all known applications of the calculus of residues. They range from the theory of equations, theory of numbers, matrix analysis, evaluation of real definite integrals, summation of finite and infinite series, expansions of functions into infinite series and products, ordinary and partial differential equations, mathematical and theoretical physics, to the calculus of finite differences and difference equations. The appearance of Volume 1 was acknowledged by the mathematical community. Favourable reviews and many private communications encouraged the authors to continue their work, the result being the present book, Volume 2, a sequel to Volume 1. We mention that Volume 1 is a revised, extended and updated translation of the book Cauchyjev raeun ostataka sa primenama published in Serbian by Nau~na knjiga, Belgrade in 1978, whereas the greater part ...

  12. Residual intersections and some applications

    CERN Document Server

    Wu, X

    1994-01-01

    We give a new residual intersection decomposition for the refined intersection products of Fulton-MacPherson. Our formula refines the celebrated residual intersection formula of Fulton, Kleiman, Laksov, and MacPherson. The new decomposition is more likely to be compatible with the canonical decomposition of the intersection products and each term in the decomposition thus has simple geometric meaning. Our study is motivated by its applications to some geometric problems. In particular, we use the decomposition to find the distribution of limiting linear subspaces in degenerations of hypersurfaces. A family of identities for characteristic classes of vector bundles is also obtained as another consequence. This paper will appear in Duke Math. Jour.

  13. Calcination/dissolution residue treatment

    International Nuclear Information System (INIS)

    Currently, high-level wastes are stored underground in steel-lined tanks at the Hanford site. Current plans call for the chemical pretreatment of these wastes before their immobilization in stable glass waste forms. One candidate pretreatment approach, calcination/dissolution, performs an alkaline fusion of the waste and creates a high-level/low-level partition based on the aqueous solubilities of the components of the product calcine. Literature and laboratory studies were conducted with the goal of finding a residue treatment technology that would decrease the quantity of high-level waste glass required following calcination/dissolution waste processing. Four elements, Fe, Ni, Bi, and U, postulated to be present in the high-level residue fraction were identified as being key to the quantity of high-level glass formed. Laboratory tests of the candidate technologies with simulant high-level residues showed reductive roasting followed by carbonyl volatilization to be successful in removing Fe, Ni, and Bi. Subsequent bench-scale tests on residues from calcination/dissolution processing of genuine Hanford Site tank waste showed Fe was separated with radioelement decontamination factors of 70 to 1,000 times with respect to total alpha activity. Thermodynamic analyses of the calcination of five typical Hanford Site tank waste compositions also were performed. The analyses showed sodium hydroxide to be the sole molten component in the waste calcine and emphasized the requirement for waste blending if fluid calcines are to be achieved. Other calcine phases identified in the thermodynamic analysis indicate the significant thermal reconstitution accomplished in calcination

  14. Residual activity criteria for decommissioning

    International Nuclear Information System (INIS)

    The U.S. Nuclear Regulatory Commission development of criteria for release of facilities and sites for unrestricted use following decommissioning is described. Residual activity limits for both materials and soil are covered. The objectives are: small risk of exposure, consistency with relevant existing standards, and feasibility of demonstration of compliance by measurement. Specific aspects discussed related to establishment of limits are: appropriate risk and dose limits, identification of radionuclides to be considered, dose assessment methodology, and confirmatory measurements

  15. Geotechnical characteristics of residual soils

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, F.C.

    1985-01-01

    Residual soils are products of chemical weathering and thus their characteristics are dependent upon environmental factors of climate, parent material, topography and drainage, and age. These conditions are optimized in the tropics where well-drained regions produce reddish lateritic soils rich in iron and aluminum sesquioxides and kaolinitic clays. Conversely, poorly drained areas tend towards montmorillonitic expansive black clays. Andosols develop over volcanic ash and rock regions and are rich in allophane (amorphous silica) and metastable halloysite. The geological origins greatly affect the resulting engineering characteristics. Both lateritic soils and andosols are susceptible to property changes upon drying, and exhibit compaction and strength properties not indicative of their classification limits. Both soils have been used successfully in earth dam construction, but attention must be given to seepage control through the weathered rock. Conversely, black soils are unpopular for embankments. Lateritic soils respond to cement stabilization and, in some cases, lime stabilization. Andosols should also respond to lime treatment and cement treatments if proper mixing can be achieved. Black expansive residual soils respond to lime treatment by demonstrating strength gains and decreased expansiveness. Rainfall induced landslides are typical of residual soil deposits.

  16. Evaluation of residue drum storage safety risks

    International Nuclear Information System (INIS)

    A study was conducted to determine if any potential safety problems exist in the residue drum backlog at the Rocky Flats Plant. Plutonium residues stored in 55-gallon drums were packaged for short-term storage until the residues could be processed for plutonium recovery. These residues have now been determined by the Department of Energy to be waste materials, and the residues will remain in storage until plans for disposal of the material can be developed. The packaging configurations which were safe for short-term storage may not be safe for long-term storage. Interviews with Rocky Flats personnel involved with packaging the residues reveal that more than one packaging configuration was used for some of the residues. A tabulation of packaging configurations was developed based on the information obtained from the interviews. A number of potential safety problems were identified during this study, including hydrogen generation from some residues and residue packaging materials, contamination containment loss, metal residue packaging container corrosion, and pyrophoric plutonium compound formation. Risk factors were developed for evaluating the risk potential of the various residue categories, and the residues in storage at Rocky Flats were ranked by risk potential. Preliminary drum head space gas sampling studies have demonstrated the potential for formation of flammable hydrogen-oxygen mixtures in some residue drums

  17. Top quark pair production at the LHC

    International Nuclear Information System (INIS)

    One of the most interesting and manifold processes in the Standard Model of elementary particle physics is the top quark pair production. It enabled the discovery of the top quark at the Tevatron in 1995 and the determination of many of its properties. By means of a precise measurement and calculation of the cross section of top quark pair production it is possible to extract the top quark mass. Improvements in the gluon parton distribution functions (important for the Higgs boson production) or improvements in the prediction of the Higgs mass are also closely linked with the top quark pair production. Furthermore, the production process plays an important role in the discovery of new physics. On the one hand the top quark pair decays form the largest part of the background in many BSM models, on the other hand BSM physics can be detected directly in the decay process by investigating the charge symmetry or the invariant mass spectrum. At the LHC it will be possible for the first time to produce a large amount of top quarks; thereby the statistical errors of the observables will be strongly reduced. The enormous increase in the production rate has two reasons. On the one hand, the acceleration energy of the LHC (14 TeV and 7 TeV) is significantly greater than that of the Tevatron (1.96 Tev). This leads to an increase of the cross section by a factor of 100 (∝7.3 pb at the Tevatron to ∝800 pb at 14 TeV LHC). On the other hand, the luminosity of the LHC outperforms the Tevatron by a factor of 10-100. The reduced experimental errors for the observables demand an improvement of the theoretical error. The experimental accuracy of the LHC and the great relevance of the process led to an intensive activity of different research groups in order to improve the calculation of the cross section of top quark pair production. This work presents for the first time a complete numerical result for the full NNLO correction for the top quark pair production in quark anti

  18. Top quark pair production at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Baernreuther, Peter

    2012-06-28

    One of the most interesting and manifold processes in the Standard Model of elementary particle physics is the top quark pair production. It enabled the discovery of the top quark at the Tevatron in 1995 and the determination of many of its properties. By means of a precise measurement and calculation of the cross section of top quark pair production it is possible to extract the top quark mass. Improvements in the gluon parton distribution functions (important for the Higgs boson production) or improvements in the prediction of the Higgs mass are also closely linked with the top quark pair production. Furthermore, the production process plays an important role in the discovery of new physics. On the one hand the top quark pair decays form the largest part of the background in many BSM models, on the other hand BSM physics can be detected directly in the decay process by investigating the charge symmetry or the invariant mass spectrum. At the LHC it will be possible for the first time to produce a large amount of top quarks; thereby the statistical errors of the observables will be strongly reduced. The enormous increase in the production rate has two reasons. On the one hand, the acceleration energy of the LHC (14 TeV and 7 TeV) is significantly greater than that of the Tevatron (1.96 Tev). This leads to an increase of the cross section by a factor of 100 ({proportional_to}7.3 pb at the Tevatron to {proportional_to}800 pb at 14 TeV LHC). On the other hand, the luminosity of the LHC outperforms the Tevatron by a factor of 10-100. The reduced experimental errors for the observables demand an improvement of the theoretical error. The experimental accuracy of the LHC and the great relevance of the process led to an intensive activity of different research groups in order to improve the calculation of the cross section of top quark pair production. This work presents for the first time a complete numerical result for the full NNLO correction for the top quark pair

  19. Paired structures and bipolar knowledge representation

    DEFF Research Database (Denmark)

    Montero, Javier; Bustince, Humberto; Franco, Camilo;

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories...... at the same time the type of neutrality rising in between opposites. Based on this first level of bipolar knowledge representation, paired structures in fact offer the means to characterize a specific bipolar valuation scale depending on the meaning of the concept that has to be verified. In this...

  20. Invisible Decays in Higgs Pair Production

    CERN Document Server

    Banerjee, Shankha; Spannowsky, Michael

    2016-01-01

    Observation of Higgs pair production is an important long term objective of the LHC physics program as it will shed light on the scalar potential of the Higgs field and the nature of electroweak symmetry breaking. While numerous studies have examined the impact of new physics on di-Higgs production, little attention has been given to the well-motivated possibility of exotic Higgs decays in this channel. Here we investigate the consequences of exotic invisible Higgs decays in di-Higgs production. We outline a search sensitive to such invisible decays in the $b\\bar b+{\

  1. Generalized magnetofluid connections in pair plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Asenjo, Felipe A., E-mail: felipe.asenjo@uai.cl [Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Santiago 7941169 (Chile); Comisso, Luca, E-mail: lcomisso@princeton.edu [Department of Astrophysical Sciences and Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544 (United States); Dipartimento Energia, Politecnico di Torino, Torino 10129, Italy and Istituto dei Sistemi Complessi-CNR, Roma 00185 (Italy); Mahajan, Swadesh M., E-mail: mahajan@mail.utexas.edu [Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-12-15

    We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to a general antisymmetric tensor that unifies the electromagnetic and fluid fields. The generalized magnetofluid connections set important constraints on the plasma dynamics by forbidding transitions between configurations with different magnetofluid connectivity. An approximated solution is explicitly shown where the corrections due to current inertial effects are found.

  2. A biometric signcryption scheme without bilinear pairing

    Science.gov (United States)

    Wang, Mingwen; Ren, Zhiyuan; Cai, Jun; Zheng, Wentao

    2013-03-01

    How to apply the entropy in biometrics into the encryption and remote authentication schemes to simplify the management of keys is a hot research area. Utilizing Dodis's fuzzy extractor method and Liu's original signcryption scheme, a biometric identity based signcryption scheme is proposed in this paper. The proposed scheme is more efficient than most of the previous proposed biometric signcryption schemes for that it does not need bilinear pairing computation and modular exponentiation computation which is time consuming largely. The analysis results show that under the CDH and DL hard problem assumption, the proposed scheme has the features of confidentiality and unforgeability simultaneously.

  3. The split decomposition of a tridiagonal pair

    OpenAIRE

    Nomura, Kazumasa; Terwilliger, Paul

    2006-01-01

    Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy (i)--(iv) below: (i) Each of $A$, $A^*$ is diagonalizable. (ii) There exists an ordering $V_{0},V_{1},...,V_{d}$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$, $V_{d+1}=0$. (iii) There exists an ordering $V^*_{0},V^*_{1},...,V^*_{\\delt...

  4. Interacting pion pairs in nuclear matter

    OpenAIRE

    Grion, Nevio

    2000-01-01

    The pion-production $\\pi^+ A \\to \\pi^+\\pi^{\\pm} A'$ reactions were studied on nuclei $^{2}H$, $^{12}C$, $^{40}Ca$ and $^{208}Pb$ at a pion energy of $T_{\\pi^{+}}$=283 MeV using the CHAOS spectrometer. The experimental results are reduced to differential cross sections and compared to both theoretical predictions and reaction phase space. Near the $2m_{\\pi}$ threshold pion pairs couple to $(\\pi\\pi)_{I=J=0}$ when produced in the $\\pi^+\\to \\pi^+\\pi^-$ reaction channel. The $\\cal C$$_{\\pi\\pi}^A$ ...

  5. Matched molecular pair analysis in drug discovery.

    Science.gov (United States)

    Dossetter, Alexander G; Griffen, Edward J; Leach, Andrew G

    2013-08-01

    Multiple parameter optimisation in drug discovery is difficult, but Matched Molecular Pair Analysis (MMPA) can help. Computer algorithms can process data in an unbiased way to yield design rules and suggest better molecules, cutting the number of design cycles. The approach often makes more suggestions than can be processed manually and methods to deal with this are proposed. However, there is a paucity of contextually specific design rules, which would truly make the technique powerful. By combining extracted information from multiple sources there is an opportunity to solve this problem and advance medicinal chemistry in a matter of months rather than years. PMID:23557664

  6. Efficient Certificateless Signcryption Scheme from Weil Pairing

    Directory of Open Access Journals (Sweden)

    Gang Yu

    2011-08-01

    Full Text Available Certificateless signcryption has both the advantage of certificateless public key cryptography, which overcome the escrow problem inherited from identity based cryptography without the use of certificates as in traditional public key cryptography, and signcryption which can fulfill both the functions of signature and encryption in a logical signal step. In this paper, we explicit the security model for certificateless signcryption and propose an efficient certificateless signcryption scheme from Weil pairings. The new scheme not only can be proved to be secure in our model but also can simultaneously provide public verifiability and forward security. Furthermore, compared with existing schemes, the new scheme is more efficient.

  7. Generalized magnetofluid connections in pair plasmas

    Science.gov (United States)

    Asenjo, Felipe A.; Comisso, Luca; Mahajan, Swadesh M.

    2015-12-01

    We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to a general antisymmetric tensor that unifies the electromagnetic and fluid fields. The generalized magnetofluid connections set important constraints on the plasma dynamics by forbidding transitions between configurations with different magnetofluid connectivity. An approximated solution is explicitly shown where the corrections due to current inertial effects are found.

  8. Mated Fingerprint Card Pairs 2 (MFCP2)

    Science.gov (United States)

    NIST Mated Fingerprint Card Pairs 2 (MFCP2) (PC database for purchase)   NIST Special Database 14 is being distributed for use in development and testing of automated fingerprint classification and matching systems on a set of images which approximate a natural horizontal distribution of the National Crime Information Center (NCIC) fingerprint classes. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

  9. Generalized Magnetofluid Connections in Pair Plasmas

    CERN Document Server

    Asenjo, Felipe A; Mahajan, Swadesh M

    2015-01-01

    We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to a general antisymmetric tensor that unifies the electromagnetic and fluid fields. The generalized magnetofluid connections set important constraints on the plasma dynamics by forbidding transitions between configurations with different magnetofluid connectivity. An approximated solution is explicitly shown where the corrections due to current inertial effects are found.

  10. Z Boson Pair-Production at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2003-01-01

    Events stemming from the pair-production of Z bosons in e^+e^- collisions are studied using 217.4 pb^-1 of data collected with the L3 detector at centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events with b quarks is also investigated. Combining these events with those collected at lower centre-of-mass energies, the Standard Model predictions for the production mechanism are verified. In addition, limits are set on anomalous couplings of neutral gauge bosons and on effects of extra space dimensions.

  11. Pair Negotiation When Developing English Speaking Tasks

    Directory of Open Access Journals (Sweden)

    Ingrid Liliana Bohórquez Suárez

    2011-12-01

    Full Text Available This study analyzes what characterizes the negotiations of seventh graders at a public school in Bogotá when working in pairs to develop speaking tasks in EFL classes. The inquiry is a descriptive case study that follows the qualitative paradigm. As a result of analyzing the data, we obtained four consecutive steps that characterize students’ negotiations: Establishing a connection with a partner to work with, proposing practical alternatives, refusing mates’ propositions, and making practical decisions. Moreover, we found that the constant performance of the process of negotiation provokes students to construct a sociolinguistic identity that allows agreements to emerge.

  12. Generalized magnetofluid connections in pair plasmas

    International Nuclear Information System (INIS)

    We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. We show that these connections are related to a general antisymmetric tensor that unifies the electromagnetic and fluid fields. The generalized magnetofluid connections set important constraints on the plasma dynamics by forbidding transitions between configurations with different magnetofluid connectivity. An approximated solution is explicitly shown where the corrections due to current inertial effects are found

  13. Slepton pair production in the POWHEG BOX

    International Nuclear Information System (INIS)

    We present an implementation for slepton pair production at hadron colliders in the POWHEG BOX, a framework for combining next-to-leading order QCD calculations with parton-shower Monte-Carlo programs. Our code provides a SUSY Les Houches Accord interface for setting the supersymmetric input parameters. Decays of the sleptons and parton-shower effects are simulated with PYTHIA. Our Monte-Carlo program allows the generation of events, and thus of arbitrary distributions with appropriate selection cuts. Kinematic distributions of experimentally observable quantities are shown for a representative point in the supersymmetric parameter space.

  14. Topological edge states of bound photon pairs

    CERN Document Server

    Gorlach, Maxim A

    2016-01-01

    We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. Energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. Despite the unexpected breakdown of the Zak phase technique and the edge mixing of internal and center-of-mass motion we link the edge state existence to the two-photon quantum walk graph connectivity, thus uncovering the topological nature of the many-body problem in complex lattices.

  15. Hadroproduction of massive lepton pairs and QCD

    International Nuclear Information System (INIS)

    A survey is presented of some current issues of interest in attempts to describe the production of massive lepton pairs in hadronic collisions at high energies. I concentrate on the interpretation of data in terms of the parton model and on predictions derived from quantum-chromodynamics (QCD), their reliability and their confrontation with experiment. Among topics treated are the connection with deep-inelastic lepton scattering, universality of structure functions, and the behavior of cross-sections as a function of transverse momentum

  16. Polychlorinated Biphenyls (PCB) Residue Effects Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The PCB Residue Effects (PCBRes) Database was developed to assist scientists and risk assessors in correlating PCB and dioxin-like compound residues with toxic...

  17. Effect of welding residual stresson fracture

    OpenAIRE

    Ren, Xiaobo

    2010-01-01

    Residual stresses are unavoidable in welded constructions. How to correctly predict residual stresses and assess their effect on structural integrity is a fundamental issue. One of the most difficult aspects in structural integrity assessment is to incorporate the effect of residual stresses in a safe manner, without making unduly conservative assumptions about the level of stress that may be present. Current structural assessment procedures typically assume upper bound residual stress soluti...

  18. Treatment of pairing correlations based on the equations of motion for zero-coupled pair operators

    International Nuclear Information System (INIS)

    The pairing problem is treated by means of the equations of motion for zero-coupled pair operators. Exact equations for the seniority-v states of N particles are derived. These equations can be solved by a step-by-step procedure which consists of progressively adding pairs of particles to a core. The theory can be applied at several levels of approximation depending on the number of core states which are taken into account. Some numerical applications to the treatment of v = 0, v = 1, and v = 2 states in the Ni isotopes are performed. The accuracy of various approximations is tested by comparison with exact results. For the seniority-one and seniority-two problems it turns out that the results obtained from the first-order theory are very accurate, while those of higher order calculations are practically exact. Concerning the seniority-zero problem, a fifth-order calculation reproduces quite well the three lowest states

  19. Treatment of pairing correlations based on the equations of motion for zero-coupled pair operators

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, F.; Covello, A.; Gargano, A.; Ye, L.J.; Porrino, A.

    1985-07-01

    The pairing problem is treated by means of the equations of motion for zero-coupled pair operators. Exact equations for the seniority-v states of N particles are derived. These equations can be solved by a step-by-step procedure which consists of progressively adding pairs of particles to a core. The theory can be applied at several levels of approximation depending on the number of core states which are taken into account. Some numerical applications to the treatment of v = 0, v = 1, and v = 2 states in the Ni isotopes are performed. The accuracy of various approximations is tested by comparison with exact results. For the seniority-one and seniority-two problems it turns out that the results obtained from the first-order theory are very accurate, while those of higher order calculations are practically exact. Concerning the seniority-zero problem, a fifth-order calculation reproduces quite well the three lowest states.

  20. Synergy between pair coupled cluster doubles and pair density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Garza, Alejandro J.; Bulik, Ireneusz W. [Department of Chemistry, Rice University, Houston, Texas 77251-1892 (United States); Henderson, Thomas M. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Scuseria, Gustavo E. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-01-28

    Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with Kohn–Sham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important. We argue that—as a black-box method with low scaling, size-extensivity, size-consistency, and a simple quasidiagonal two-particle density matrix—pCCD is an excellent match for pair density functionals in this type of fusion of multireference wavefunctions with DFT.

  1. Superluminal Spot Pair Events in Astronomical Settings: Sweeping Beams

    CERN Document Server

    Nemiroff, Robert J

    2014-01-01

    Sweeping beams of light can cast spots moving with superluminal speeds across scattering surfaces. Such faster-than-light speeds are well-known phenomena that do not violate special relativity. It is shown here that under certain circumstances, superluminal spot pair creation and annihilation events can occur that provide unique information to observers. These spot pair events are {\\it not} particle pair events -- they are the sudden creation or annihilation of a pair of relatively illuminated spots on a scattering surface. Real spot pair illumination events occur unambiguously on the scattering surface when spot speeds diverge, while virtual spot pair events are observer dependent and perceived only when real spot radial speeds cross the speed of light. Specifically, a virtual spot pair creation event will be observed when a real spot's speed toward the observer drops below $c$, while a virtual spot pair annihilation event will be observed when a real spot's radial speed away from the observer rises above $c...

  2. Pair emission from bare magnetized strange stars

    CERN Document Server

    Melrose, D B; Peres-Menezes, D

    2006-01-01

    The dominant emission from bare strange stars is thought to be electron-positron pairs, produced through spontaneous pair creation (SPC) in a surface layer of electrons tied to the star by a superstrong electric field. The positrons escape freely, but the electrons are directed towards the star and quickly fill all available states, such that their degeneracy suppresses further SPC. An electron must be reflected and gain energy in order to escape, along with the positron. Each escaping electron leaves a hole that is immediately filled by another electron through SPC. We discuss the collisional processes that produce escaping electrons. When the Landau quantization of the motion perpendicular to the magnetic field is taken into account, electron-electron collisions can lead to an escaping electron only through a multi-stage process involving higher Landau levels. Although the available estimates of the collision rate are deficient in several ways, it appears that the rate is too low for electron-electron colli...

  3. Optimisation of a quantum pair space thruster

    Directory of Open Access Journals (Sweden)

    Valeriu DRAGAN

    2012-06-01

    Full Text Available The paper addresses the problem of propulsion for long term space missions. Traditionally a space propulsion unit has a propellant mass which is ejected trough a nozzle to generate thrust; this is also the case with inert gases energized by an on-board power unit. Unconventional methods for propulsion include high energy LASERs that rely on the momentum of photons to generate thrust. Anti-matter has also been proposed for energy storage. Although the momentum of ejected gas is significantly higher, the LASER propulsion offers the perspective of unlimited operational time – provided there is a power source. The paper will propose the use of the quantum pair formation for generating a working mass, this is different than conventional anti-matter thrusters since the material particles generated are used as propellant not as energy storage.Two methods will be compared: LASER and positron-electron, quantum pair formation. The latter will be shown to offer better momentum above certain energy levels.For the demonstrations an analytical solution is obtained and provided in the form of various coefficients. The implications are, for now, theoretical however the practicality of an optimized thruster using such particles is not to be neglected for long term space missions.

  4. Parenting and Psychopathology in Sibling Pairs

    Directory of Open Access Journals (Sweden)

    Jiri Modestin

    2008-06-01

    Full Text Available Background: The current study explored the relationship between parenting experience in childhood as a specific aspect of the non-shared environment and the amount of psychopathology in adulthood. Sampling and Methods: 27 same-sex sibling pairs were studied. In each pair, one proband was a psychiatric outpatient, the other proband a non-patient. All probands filled in the Parental Bonding Instrument (PBI and the Symptom Checklist-90-Revised (SCL-90-R. Results: The patients rated higher on practically all SCL-90-R scales whereas no significant differences were found with regard to the PBI ratings. With only one exception, there were no significant correlations between PBI and SCL-90-R ratings in the group of patients. In contrast, all SCL-90-R subscales correlated negatively with paternal care and half of them positively with paternal control in patients' healthy siblings. Conclusions: The degree of paternal care seems to be most closely related with lack of mental symptoms in psychiatric non-patients. In contrast, parenting does not seem to play a substantial role in patients, presenting with a higher degree of psychopathology. Obviously, environmental factors become less important, the more pronounced the pathology.

  5. Cooperative interactions between paired domain and homeodomain.

    Science.gov (United States)

    Jun, S; Desplan, C

    1996-09-01

    The Pax proteins are a family of transcriptional regulators involved in many developmental processes in all higher eukaryotes. They are characterized by the presence of a paired domain (PD), a bipartite DNA binding domain composed of two helix-turn-helix (HTH) motifs,the PAI and RED domains. The PD is also often associated with a homeodomain (HD) which is itself able to form homo- and hetero-dimers on DNA. Many of these proteins therefore contain three HTH motifs each able to recognize DNA. However, all PDs recognize highly related DNA sequences, and most HDs also recognize almost identical sites. We show here that different Pax proteins use multiple combinations of their HTHs to recognize several types of target sites. For instance, the Drosophila Paired protein can bind, in vitro, exclusively through its PAI domain, or through a dimer of its HD, or through cooperative interaction between PAI domain and HD. However, prd function in vivo requires the synergistic action of both the PAI domain and the HD. Pax proteins with only a PD appear to require both PAI and RED domains, while a Pax-6 isoform and a new Pax protein, Lune, may rely on the RED domain and HD. We propose a model by which Pax proteins recognize different target genes in vivo through various combinations of their DNA binding domains, thus expanding their recognition repertoire. PMID:8787739

  6. ``Schooling'' of wing pairs in flapping flight

    Science.gov (United States)

    Ramananarivo, Sophie; Zhang, Jun; Ristroph, Leif; AML, Courant Collaboration; Physics NYU Collaboration

    2015-11-01

    The experimental setup implements two independent flapping wings swimming in tandem. Both are driven with the same prescribed vertical heaving motion, but the horizontal motion is free, which means that the swimmers can take up any relative position and forward speed. Experiments show however clearly coordinated motions, where the pair of wings `crystallize' into specific stable arrangements. The follower wing locks into the path of the leader, adopting its speed, and with a separation distance that takes on one of several discrete values. By systematically varying the kinematics and wing size, we show that the set of stable spacings is dictated by the wavelength of the periodic wake structure. The forces maintaining the pair cohesion are characterized by applying an external force to the follower to perturb it away from the `stable wells'. These results show that hydrodynamics alone is sufficient to induce cohesive and coordinated collective locomotion through a fluid, and we discuss the hypothesis that fish schools and bird flocks also represent stable modes of motion.

  7. Convective Polymer Depletion on Pair Particle Interactions

    Science.gov (United States)

    Fan, Tai-Hsi; Taniguchi, Takashi; Tuinier, Remco

    2011-11-01

    Understanding transport, reaction, aggregation, and viscoelastic properties of colloid-polymer mixture is of great importance in food, biomedical, and pharmaceutical sciences. In non-adsorbing polymer solutions, colloidal particles tend to aggregate due to the depletion-induced osmotic or entropic force. Our early development for the relative mobility of pair particles assumed that polymer reorganization around the particles is much faster than particle's diffusive time, so that the coupling of diffusive and convective effects can be neglected. Here we present a nonequilibrium two-fluid (polymer and solvent) model to resolve the convective depletion effect. The theoretical framework is based on ground state approximation and accounts for the coupling of fluid flow and polymer transport to better describe pair particle interactions. The momentum and polymer transport, chemical potential, and local viscosity and osmotic pressure are simultaneously solved by numerical approximation. This investigation is essential for predicting the demixing kinetics in the pairwise regime for colloid-polymer mixtures. This work is supported by NSF CMMI 0952646.

  8. Pair Fireball Precursors of Neutron Star Mergers

    CERN Document Server

    Metzger, Brian D

    2016-01-01

    If at least one neutron star (NS) is magnetized in a binary NS merger, then the orbital motion of the conducting companion through its dipole field during the final inspiral induces a strong voltage and current along the magnetic field lines connecting the two objects. If a modest fraction eta of the electromagnetic power extracted during the inspiral is used to accelerate relativistic particles, the resulting gamma-ray emission in such a compact volume will result in the formation of a thermal electron-positron pair fireball. Applying the steady-state pair wind model of Paczynski (1986), we quantify the luminosities and temperatures of the precursor fireball and its detectability with gamma-ray satellites. Under the assumption that eta ~ 1, the gamma-ray detection horizon of Dmax ~ 20(Bd/1e14 G) is much closer than the Advanced LIGO/Virgo horizon of 200 Mpc, unless the surface magnetic field of the NS is very strong, Bd > 1e15 G. Given the quasi-isotropic nature of the emission, a sub-population of mergers w...

  9. Leptoquark pair production in hadronic interactions

    International Nuclear Information System (INIS)

    The scalar and vector leptoquark pair production cross sections in hadronic collisions are calculated. In a model independent analysis we consider the most general C and P conserving couplings of gluons to both scalar and vector leptoquarks described by an effective low-energy Lagangian which obeys SU(3)c invariance. Analytrical expressions are derived for the differential and integral scattering cross sections including the case of anomalous vector leptoquark couplings, κG and λG, to the gluon field. Numerical predictions are given for the kinematic range of the TEVATRON and LHC. The pair production cross sections are also calculated for the resolved photon contributions to ep → e anti ΦΦX at HERA and LEP x LHC, and for the process γγ → Φ anti ΦX at possible future e+e- linear colliders and γγ colliders. Estimates of the search potential for scalar and vector leptoquarks at present and future high energy colliders are given. (orig.)

  10. Pair Production Constraints on Superluminal Neutrinos Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.

    2012-02-16

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

  11. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1995-01-01

    Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initi...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

  12. Management of post-harvest residue blanket

    Science.gov (United States)

    Timely and effective residue management is essential for maximum sugar yields. Several studies were implemented in 2003 and harvested in 2004 in an effort to increase the effectiveness of residue management practices. Six studies were conducted to determine the effect of residue removal timing a...

  13. 9 CFR 311.39 - Biological residues.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  14. Transitive parallelism of residues in buildings

    OpenAIRE

    Clais, Antoine

    2013-01-01

    We study the buildings in which parallelism of residues is an equivalence relation. If the building admits a group action, we describe how parallel residues are related to residues with equal stabilizers. This permits to retrieve the fact that in a Coxeter group or in a graph product, intersections of parabolic subgroups are parabolic.

  15. Quantum theory of transition radiation and transition pair creation

    OpenAIRE

    Baier, V. N.; Katkov, V. M.

    1998-01-01

    Theory of the transition radiation and the transition pair creation is developed in the frame of QED. The spectral-angular distributions of probability of the transition radiation and of the transition pair creation are found. The total energy losses of and the total probability of pair creation are calculated and analyzed. Features of radiation and pair creation processes in a superdence medium (typical for white dwarfs) are discussed.

  16. From an insulating to a superfluid pair-bond liquid

    OpenAIRE

    Cuoco, Mario; Ranninger, Julius

    2006-01-01

    We study an exchange coupled system of itinerant electrons and localized fermion pairs resulting in a resonant pairing formation. This system inherently contains resonating fermion pairs on bonds which lead to a superconducting phase provided that long range phase coherence between their constituents can be established. The prerequisite is that the resonating fermion pairs can become itinerant. This is rendered possible through the emergence of two kinds of bond-fermions: individual and compo...

  17. SD-pair shell model for even-even systems

    International Nuclear Information System (INIS)

    A nucleon-pair shell model was proposed in 1993 by J. Q. Chen. Due to the success of the interacting boson model, the full shell model space in the nucleon-pair shell model was truncated to SD-pair subspace, called SD-pair shell model. Within this model, the experimental spectra in medium-weight and heavy nuclei, limiting cases in the interacting boson model, phase transitions, etc. can be reproduced approximately. (author)

  18. Diffraction of collinear correlated photon pairs by an ultrasonic wave

    OpenAIRE

    Kwiek, Piotr

    2013-01-01

    The phenomenon of collinear correlated photon pairs diffraction by an ultrasonic wave is investigated for Bragg incidence. A BBO crystal was used for producing collinear correlated photon pairs via type-I spontaneous parametric down-conversion (SPDC I-type). It is shown experimentally that the Bragg angle for photon pairs diffraction is identical to the one corresponding to single photons diffraction. The numbers of single photons and photon pairs counts in discrete diffraction orders were me...

  19. Pairing effect on nuclear level density parameters in 116Sn

    International Nuclear Information System (INIS)

    Pairing correlations have a special importance for many fermion systems. Pairing correlations have been successfully described by the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. In this work, the pairing gap parameters as a function of nuclear temperature for 116Sn have been evaluated. Then the nuclear level density and entropy have been determined using BCS Hamiltonian with inclusion of pairing effects. Also temperature dependence of level density parameters has been investigated.

  20. Residual fMRI sensitivity for identity changes in acquired prosopagnosia

    OpenAIRE

    Fox, Christopher J; Giuseppe eIaria; Duchaine, Bradley C.; Barton, Jason J.S.

    2013-01-01

    While a network of cortical regions contribute to face processing, the lesions in acquired prosopagnosia are highly variable, and likely result in different combinations of spared and affected regions of this network. To assess the residual functional sensitivities of spared regions in prosopagnosia, we designed a rapid event-related functional magnetic resonance imaging (fMRI) experiment that included pairs of faces with same or different identities and same or different expressions. By meas...

  1. Gene expression profile of residual breast cancer after doxorubicin and cyclophosphamide neoadjuvant chemotherapy.

    Science.gov (United States)

    Koike Folgueira, Maria Aparecida Azevedo; Brentani, Helena; Carraro, Dirce Maria; De Camargo Barros Filho, Mateus; Hirata Katayama, Maria Lucia; Santana de Abreu, Ana Paula; Mantovani Barbosa, Edson; De Oliveira, Célia Tosello; Patrão, Diogo F C; Mota, Louise D; Netto, Mario Mourão; Caldeira, José Roberto Figaro; Brentani, Maria Mitzi

    2009-10-01

    In breast cancer patients, primary chemotherapy is associated with the same survival benefits as adjuvant chemotherapy. Residual tumors represent a clinical challenge, as they may be resistant to additional cycles of the same drugs. Our aim was to identify differential transcripts expressed in residual tumors, after neoadjuvant chemotherapy, that might be related with tumor resistance. Hence, 16 patients with paired tumor samples, collected before and after treatment (4 cycles doxorubicin/cyclophosphamide, AC) had their gene expression evaluated on cDNA microarray slides containing 4,608 genes. Three hundred and eighty-nine genes were differentially expressed (paired Student's t-test, pFDR<0.01) between pre- and post-chemotherapy samples and among the regulated functions were the JNK cascade and cell death. Unsupervised hierarchical clustering identified one branch comprising exclusively, eight pre-chemotherapy samples and another branch, including the former correspondent eight post-chemotherapy samples and other 16 paired pre/post-chemotherapy samples. No differences in clinical and tumor parameters could explain this clustering. Another group of 11 patients with paired samples had expression of selected genes determined by real-time RT-PCR and CTGF and DUSP1 were confirmed more expressed in post- as compared to pre-chemotherapy samples. After neoadjuvant chemotherapy some residual samples may retain their molecular signature while others present significant changes in their gene expression, probably induced by the treatment. CTGF and DUSP1 overexpression in residual samples may be a reflection of resistance to further administration of AC regimen. PMID:19724859

  2. Fountain-Gould Left Orders for Associative Pairs

    Institute of Scientific and Technical Information of China (English)

    José A. ANQUELA; Teresa CORT(E)S; Miguel G(O)MEZ LOZANO; Mercedes SILES MOLINA

    2006-01-01

    In this paper, we introduce a notion of weak Fountain-Gould left order for associative pairs and give a Goldie-like theory of associative pairs which are weak Fountain-Gould left orders in semiprime pairs coinciding with their socles.

  3. Influence of pairing in double beta decay of48Ca

    Indian Academy of Sciences (India)

    Prianka Roy; Shashi K Dhiman

    2010-03-01

    Two-neutrino decay matrix elements and half-life of 48Ca are calculated after including neutron–proton pairing correlations in projected Hartree–Fock–Bogoliubov (PHFB) formalism. The GT matrix elements in 2 decay are reduced due to broader smearing of Fermi surfaces. Half-life results for 2 decay of 48Ca with np pairing are better than without pairing.

  4. Natural radioactivity in petroleum residues

    International Nuclear Information System (INIS)

    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the 238U and 232Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of 226Ra, 228Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for 226Ra, 228Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for 226Ra, 40.5 to 1,550.0 kBq/kg for 228Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  5. Protonation states of histidine and other key residues in deoxy normal human adult hemoglobin by neutron protein crystallography

    International Nuclear Information System (INIS)

    Using neutron diffraction analysis, the protonation states of 35 of 38 histidine residues were determined for the deoxy form of normal human adult hemoglobin. Distal and buried histidines may contribute to the increased affinity of the deoxy state for hydrogen ions and its decreased affinity for oxygen compared with the oxygenated form. The protonation states of the histidine residues key to the function of deoxy (T-state) human hemoglobin have been investigated using neutron protein crystallography. These residues can reversibly bind protons, thereby regulating the oxygen affinity of hemoglobin. By examining the OMIT Fo − Fc and 2Fo − Fc neutron scattering maps, the protonation states of 35 of the 38 His residues were directly determined. The remaining three residues were found to be disordered. Surprisingly, seven pairs of His residues from equivalent α or β chains, αHis20, αHis50, αHis58, αHis89, βHis63, βHis143 and βHis146, have different protonation states. The protonation of distal His residues in the α1β1 heterodimer and the protonation of αHis103 in both subunits demonstrates that these residues may participate in buffering hydrogen ions and may influence the oxygen binding. The observed protonation states of His residues are compared with their ΔpKa between the deoxy and oxy states. Examination of inter-subunit interfaces provided evidence for interactions that are essential for the stability of the deoxy tertiary structure

  6. Process to recycle shredder residue

    Science.gov (United States)

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.

    2001-01-01

    A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

  7. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  8. Modeling within-pair order effects in paired-comparison judgments

    DEFF Research Database (Denmark)

    Wickelmaier, Florian Maria; Choisel, Sylvain

    Prohabilistic choice models which generalize the Bradley-Terry-Luce (BTL) model (Luce, 1959) and the elimination-by- aspects (EBA) model (Tversky, 1972) are presented. These models account for the effect of presentation order within a pair of stimuli, and thereby allow for quantifying judgmental...

  9. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.

    Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... weeks of decomposition, due to high rates of residue N net mineralization and subsequent leaching and denitrification losses of N. Lysimeter experiments showed that pea residues may reduce leaching losses of N, probably due to their effect on the mineralization-immobilizalion turnover of N and...... denitrification. Winter barley succeeding field pea recovered 13% of the incorporated pea residue N by early December; the recovery was found to be 15% at maturity in July. A spring-sown crop of barley recovered less than half the amount of pea residue N recovered by winter barley. The residue N-use efficiencies...

  10. Residual number processing in dyscalculia

    Directory of Open Access Journals (Sweden)

    Marinella Cappelletti

    2014-01-01

    Full Text Available Developmental dyscalculia – a congenital learning disability in understanding numerical concepts – is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia.

  11. Residual number processing in dyscalculia.

    Science.gov (United States)

    Cappelletti, Marinella; Price, Cathy J

    2014-01-01

    Developmental dyscalculia - a congenital learning disability in understanding numerical concepts - is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia. PMID:24266008

  12. Residual Fragments after Percutaneous Nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Kaan Özdedeli

    2012-09-01

    Full Text Available Clinically insignificant residual fragments (CIRFs are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

  13. RESIDUAL STRESSES IN 3013 CONTAINERS

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Dunn, K.

    2009-11-10

    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  14. Frustrated Lewis pairs: Design and reactivity

    Indian Academy of Sciences (India)

    Sanjoy Mukherjee; Pakkirisamy Thilagar

    2015-02-01

    The interaction of a Lewis acid with a Lewis base results in the formation of a Lewis acid–base adduct. Understanding Lewis acids and bases is central to conceptualizing chemical interactions and constitutes a major portion of metal–ligand chemistry. Sterically encumbered/constrained Lewis pairs cannot form acid–base adducts, but such ‘Frustrated Lewis Pairs’ (FLPs), with their unquenched electronic demands can be elegantly used to simultaneously react with a third species, resulting in unusual reactivity of small molecules. Such unusual reactions, explored only in the last few years, have found several applications, e.g., heterolytic splitting of H2, activation of small molecules (CO2, N2O, etc.). FLPs have opened new opportunities in synthetic chemistry, covering organic, main group as well as transition metal chemistry. The design strategies adopted for FLP systems and their unique reactivity are discussed here.

  15. Pairing in bulk nuclear matter beyond BCS

    International Nuclear Information System (INIS)

    The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the 3P2−3F2 coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the 3P2−3F2 coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive

  16. Dust trapping in inviscid vortex pairs

    CERN Document Server

    Angilella, Jean-Regis

    2010-01-01

    The motion of tiny heavy particles transported in a co-rotating vortex pair, with or without particle inertia and sedimentation, is investigated. The dynamics of non-inertial sedimenting particles is shown to be chaotic, under the combined effect of gravity and of the circular displacement of the vortices. This phenomenon is very sensitive to particle inertia, if any. By using nearly hamiltonian dynamical system theory for the particle motion equation written in the rotating reference frame, one can show that small inertia terms of the particle motion equation strongly modify the Melnikov function of the homoclinic trajectories and heteroclinic cycles of the unperturbed system, as soon as the particle response time is of the order of the settling time (Froude number of order unity). The critical Froude number above which chaotic motion vanishes and a regular centrifugation takes place is obtained from this Melnikov analysis and compared to numerical simulations. Particles with a finite inertia, and in the abs...

  17. The stratospheric arrival pair in infrasound propagation.

    Science.gov (United States)

    Waxler, Roger; Evers, Läslo G; Assink, Jelle; Blom, Phillip

    2015-04-01

    The ideal case of a deep and well-formed stratospheric duct for long range infrasound propagation in the absence of tropospheric ducting is considered. A canonical form, that of a pair of arrivals, for ground returns of impulsive signals in a stratospheric duct is determined. The canonical form is derived from the geometrical acoustics approximation, and is validated and extended through full wave modeling. The full caustic structure of the field of ray paths is found and used to determine phase relations between the contributions to the wavetrain from different propagation paths. Finally, comparison with data collected from the 2005 fuel gas depot explosion in Buncefield, England is made. The correspondence between the theoretical results and the observations is shown to be quite good. PMID:25920837

  18. Pairing in bulk nuclear matter beyond BCS

    CERN Document Server

    Ding, D; Dickhoff, W H; Dussan, H; Rios, A; Polls, A

    2014-01-01

    The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the ${}^3P_2-{}^3F_2$ coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.

  19. Diagonal lattices and rootless $EE_8$ pairs

    CERN Document Server

    Griess, Robert L; Lam, Ching Hung

    2011-01-01

    Let E be an integral lattice. We first discuss some general properties of an SDC lattice, i.e., a sum of two diagonal copies of E in E \\bot E. In particular, we show that its group of isometries contains a wreath product. We then specialize this study to the case of E = E_8 and provide a new and fairly natural model for those rootless lattices which are sums of a pair of EE_8-lattices. This family of lattices was classified in [7]. We prove that this set of isometry types is in bijection with the set of conjugacy classes of rootless elements in the isometry group O(E_8), i.e., those h \\in O(E_8) such that the sublattice (h - 1)E_8 contains no roots. Finally, our model gives new embeddings of several of these lattices in the Leech lattice.

  20. Ultracompact quantum splitter of degenerate photon pairs

    CERN Document Server

    He, Jiakun; Casas-Bedoya, Alvaro; Zhang, Yanbing; Xiong, Chunle; Eggleton, Benjamin J

    2015-01-01

    Integrated sources of indistinguishable photons have attracted a lot of attention because of their applications in quantum communication and optical quantum computing. Here, we demonstrate an ultra-compact quantum splitter for degenerate single photons based on a monolithic chip incorporating Sagnac loop and a micro-ring resonator with a footprint of 0.011 mm2, generating and deterministically splitting indistinguishable photon pairs using time-reversed Hong-Ou-Mandel interference. The ring resonator provides enhanced photon generation rate, and the Sagnac loop ensures the photons travel through equal path lengths and interfere with the correct phase to enable the reversed HOM effect to take place. In the experiment, we observed a HOM dip visibility of 94.5 +- 3.3 %, indicating the photons generated by the degenerate single photon source are in a suitable state for further integration with other components for quantum applications, such as controlled-NOT gates.

  1. Dual Origin of Pairing in Nuclei

    CERN Document Server

    Idini, A; Barranco, F; Vigezzi, E; Broglia, R A

    2014-01-01

    An essentially "complete" description of the low-energy nuclear structure of the superfluid nucleus $^{120}$Sn and of its odd-$A$ neighbors is provided by the observations carried out with the help of Coulomb excitation and of one-- and of two-- particle transfer reactions, specific probes of vibrations, quasiparticle and pairing degrees of freedom respectively, and of their mutual couplings. These experimental findings are used to stringently test the predictions of a similarly "complete" description of $^{119,120,121}$Sn carried out in terms of elementary modes of excitation which, through their interweaving, melt together into effective fields, each displaying properties reflecting that of all others, there individuality resulting from the actual relative importance of each one. Its implementation is done by solving the Nambu-Gor'kov equations including, for the first time, all medium polarization effects resulting from the interweaving of quasiparticles, spin and surface vibrations, taking into account, w...

  2. Electroweak boson pair production at the Tevatron

    International Nuclear Information System (INIS)

    Preliminary results from CDF and D OE on Wγ, Zγ and WW, WZ, ZZ boson pair production in √s = 1.8 TeV anti p-p collisions from the 1992--93 collider run are presented. Direct limits on CP-conserving and CP-violating WWγ, WWZ, ZZγ and Zγγ anomalous couplings have been obtained. The results are consistent with Standard Model expectations. In the static limit, the direct experimental limits on WWγ and ZZγ anomalous couplings are related to bounds on the higher-order static (transition) EM moments of the W(Z) bosons. Expectations from the on-going and future Tevatron collider runs are discussed

  3. Authenticating Tripartite Key Agreement Protocol with Pairings

    Institute of Scientific and Technical Information of China (English)

    Sheng-Li Liu; Fang-Guo Zhang; Ke-Fei Chen

    2004-01-01

    In this paper, an authenticated tripartite key agreement protocol is proposed, which is an ID-based one with pairings. This protocol involves only one round. The authenticity of the protocol is assured by a special signature scheme, so that messages carrying the information of two ephemeral keys can be broadcasted authentically by an entity. Consequently, one instance of the protocol results in eight session keys for three entities. In other word, one instance of the protocol generates a session key, which is eight times longer than those obtained from traditional key agreement protocols. Security attributes of the protocol are presented, and the computational overhead and bandwidth of the broadcast messages are analyzed as well.

  4. Stability and size of particle pairs in complex plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nosenko, V., E-mail: V.Nosenko@dlr.de [Deutsches Zentrum für Luft- und Raumfahrt, Forschungsgruppe Komplexe Plasmen, D-82234 Weßling (Germany); Max-Planck-Institut für extraterrestrische Physik, D-85741 Garching (Germany); Ivlev, A. V.; Kompaneets, R. [Max-Planck-Institut für extraterrestrische Physik, D-85741 Garching (Germany); Morfill, G. [Max-Planck-Institut für extraterrestrische Physik, D-85741 Garching (Germany); Centre for Plasma Science and Technology, BMSTU, Moscow (Russian Federation)

    2014-11-15

    Particle pairing in a complex plasma was experimentally studied with the emphasis on pair spatial extent and stability. Micron-size particles were suspended in the (pre)sheath area above the lower electrode in a capacitively coupled radio-frequency discharge in argon. They formed vertical pairs due to the ion wakes created by the flow of ions past particles. We discuss the confinement mechanism for the lower particle, resulting from a combination of the wake field and the field of non-uniform sheath. A model of particle pairs is proposed, which provides good description for the dependence of pair size and stability on experimental parameters.

  5. Scheduler for multiprocessor system switch with selective pairing

    Energy Technology Data Exchange (ETDEWEB)

    Gara, Alan; Gschwind, Michael Karl; Salapura, Valentina

    2015-01-06

    System, method and computer program product for scheduling threads in a multiprocessing system with selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). The method configures the selective pairing facility to use checking provide one highly reliable thread for high-reliability and allocate threads to corresponding processor cores indicating need for hardware checking. The method configures the selective pairing facility to provide multiple independent cores and allocate threads to corresponding processor cores indicating inherent resilience.

  6. Baryon femtoscopy considering residual correlations as a tool to extract strong interaction potentials

    Directory of Open Access Journals (Sweden)

    Szymański Maciej

    2015-01-01

    Full Text Available In this article, the analysis of baryon-antibaryon femtoscopic correlations is presented. In particular, it is shown that taking into account residual correlations is crucial for the description of pΛ¯$\\bar \\Lambda $ and p̄Λ correlation functions measured by the STAR experiment in Au–Au collisions at the centre-of-mass energy per nucleon pair √sNN = 200 GeV. This approach enables to obtain pΛ¯$\\bar \\Lambda $ (p̄Λ source size consistent with the sizes extracted from correlations in pΛ (p̄Λ¯$\\bar \\Lambda $ and lighter pair systems as well as with model predictions. Moreover, with this analysis it is possible to derive the unknown parameters of the strong interaction potential for baryon-antibaryon pairs under several assumptions.

  7. Computational Prediction of Heme-Binding Residues by Exploiting Residue Interaction Network

    OpenAIRE

    Rong Liu; Jianjun Hu

    2011-01-01

    Computational identification of heme-binding residues is beneficial for predicting and designing novel heme proteins. Here we proposed a novel method for heme-binding residue prediction by exploiting topological properties of these residues in the residue interaction networks derived from three-dimensional structures. Comprehensive analysis showed that key residues located in heme-binding regions are generally associated with the nodes with higher degree, closeness and betweenness, but lower ...

  8. Agricultural Residues Based Composites 1. Preparation of Fibrous Agricultural Residues

    International Nuclear Information System (INIS)

    The aim of this study is to use agricultural residues as bagasse, cotton stalks, rice straw, linen and linen fibers, which are produced in Egypt in huge amounts annually to produce composites with cement or gypsum. Also the effect of physical and chemical treatments of the fibers and the addition of some additives to the composites was studied. The mechanical properties of the produced composites also the effect of its firing at temperatures up to 800 degree C was tested after dipping in water for different time intervals (1-90 days). In this paper we considered only the preparation of different types of fibers, its grinding and separation to different fiber lengths (ca. 0.4 to 1.5 mm). The percent of each fiber length and its chemical and physical analysis is found

  9. Part 1: Logging residues in piles - Needle loss and fuel quality. Part 2: Nitrogen leaching under piles of logging residues

    International Nuclear Information System (INIS)

    Part 1: Experimental piles were built in three geographical locations during May-Sept. 1989. Logging residues consisted of 95% spruce and 5% pine. Height of the piles varied between 80 and 230 cm. Needles were collected by placing drawers under 40 randomely chosen piles. The drawers were emptied every two weeks during the storage period. Natural needle loss was between 18 and 32% of the total amount of needles after the first two months of storage. At the end of the storage period, 24-42% of the needles had fallen down to the drawers. At the end of the experiment the total needle fall was 95-100% in the shaken piles. According to the results of this study piles smaller than 150 cm had the most effective needle fall. Piles should be placed on open places where the air and sun heat penetrate and dry them. Needles were the most sensitive fraction to variations in precipitation compared to the other components, such as branches. Piles usually dried quickly, but they also rewet easily. This was especially true in the smaller piles. The lowest moisture content was measured at the end of June. The ash content in needles varied between 4 and 8%. 16 refs., 15 figs. Part 2: Three field experiments were equipped with no-tension humus lysimeters. Pairs of lysimeters with the same humus/field layer vegetation material were placed in pairs, one under a pile of felling residues and another in the open clear felling. Leaching of nitrogen as well as pH and electric conductivity in the leachate was followed through sampling of the leachate at regular intervals. The results from the investigation show that: * the amount of leachate was higher in lysimeters in the open clear felling, * pH in the leachate was initially lower under piles of felling residues, * the amount of nitrogen leached was higher in the open clear felling. Thus, storing of felling residues in piles during the summer season did not cause any increase in nitrogen leaching, which had been considered to be a risk

  10. Pairing reentrance in warm rotating $^{104}$Pd nucleus

    CERN Document Server

    Hung, N Quang; Agrawal, B K; Datar, V M; Mitra, A; Chakrabarty, D R

    2015-01-01

    Pairing reentrance phenomenon in the warm rotating $^{104}$Pd nucleus is studied within the Bardeen-Cooper-Schrieffer (BCS)-based approach (the FTBCS1). The theory takes into account the effect of quasiparticle number fluctuations on the pairing field at finite temperature and angular momentum within the pairing model plus noncollective rotation along the symmetry axis. The numerical calculations for the pairing gaps and nuclear level densities (NLD), of which an anomalous enhancement has been experimentally observed at low excitation energy $E^*$ and high angular momentum $J$, show that the pairing reentrance is seen in the behavior of pairing gap obtained within the FTBCS1 at low $E$ and high $J$. This leads to the enhancement of the FTBCS1 level densities, in good agreement with the experimental observation. This agreement indicates that the observed enhancement of the NLD might be the first experimental detection of the pairing reentrance in a finite nucleus.

  11. Comparing Residue Clusters from Thermophilic and Mesophilic Enzymes Reveals Adaptive Mechanisms

    Science.gov (United States)

    Sammond, Deanne W.; Kastelowitz, Noah; Himmel, Michael E.; Yin, Hang; Crowley, Michael F.; Bomble, Yannick J.

    2016-01-01

    Understanding how proteins adapt to function at high temperatures is important for deciphering the energetics that dictate protein stability and folding. While multiple principles important for thermostability have been identified, we lack a unified understanding of how internal protein structural and chemical environment determine qualitative or quantitative impact of evolutionary mutations. In this work we compare equivalent clusters of spatially neighboring residues between paired thermophilic and mesophilic homologues to evaluate adaptations under the selective pressure of high temperature. We find the residue clusters in thermophilic enzymes generally display improved atomic packing compared to mesophilic enzymes, in agreement with previous research. Unlike residue clusters from mesophilic enzymes, however, thermophilic residue clusters do not have significant cavities. In addition, anchor residues found in many clusters are highly conserved with respect to atomic packing between both thermophilic and mesophilic enzymes. Thus the improvements in atomic packing observed in thermophilic homologues are not derived from these anchor residues but from neighboring positions, which may serve to expand optimized protein core regions. PMID:26741367

  12. Comparing Residue Clusters from Thermophilic and Mesophilic Enzymes Reveals Adaptive Mechanisms.

    Directory of Open Access Journals (Sweden)

    Deanne W Sammond

    Full Text Available Understanding how proteins adapt to function at high temperatures is important for deciphering the energetics that dictate protein stability and folding. While multiple principles important for thermostability have been identified, we lack a unified understanding of how internal protein structural and chemical environment determine qualitative or quantitative impact of evolutionary mutations. In this work we compare equivalent clusters of spatially neighboring residues between paired thermophilic and mesophilic homologues to evaluate adaptations under the selective pressure of high temperature. We find the residue clusters in thermophilic enzymes generally display improved atomic packing compared to mesophilic enzymes, in agreement with previous research. Unlike residue clusters from mesophilic enzymes, however, thermophilic residue clusters do not have significant cavities. In addition, anchor residues found in many clusters are highly conserved with respect to atomic packing between both thermophilic and mesophilic enzymes. Thus the improvements in atomic packing observed in thermophilic homologues are not derived from these anchor residues but from neighboring positions, which may serve to expand optimized protein core regions.

  13. Ferrochelatase from Rhodopseudomonas sphaeroides: substrate specificity and role of sulfhydryl and arginyl residues

    International Nuclear Information System (INIS)

    Purified ferrochelatase from the bacterium Rhodopseudomonas sphaeroides was examined to determine the roles of cationic and sulfhydryl residues in substrate binding. Reaction of the enzyme sulfhydryl residues with N-ethylmaleimide or monobromobimane resulted in a rapid loss of enzyme activity. Ferrous iron, but not porphyrin substrate, had a protective effect against inactivation by these two reagents. Quantitation with 3H-labeled N-ethylmaleimide revealed that inactivation required one to two sulfhydryl groups to be modified. Modification of arginyl residues with either 2,3-butanedione or camphorquinone 10-sulfonate resulted in a loss of ferrochelatase activity. A kinetic analysis of the modified enzyme showed that the K/sub m/ for ferrous iron was not altered but that the K/sub m/ for the prophyrin substrate was increased. These data suggested that arginyl residues may be involved in porphyrin binding, possibly via charge pair interactions between the arginyl residue and the anionic porphyrin propionate side chain. Modification of lysyl residues had no effect on enzyme activity. The authors also examined the ability of bacterial ferrochelatase to use various 2,4-disubstituted porphyrins as substrates. The authors found that 2,4-bis-acetal- and 2,4-disulfonate deuteroporphyrins were effective substrates for the purified bacterial enzyme and that N-methylprotoporphyrin was an effective inhibitor of the enzyme. Data for the ferrochelatase of R. sphaeroides are compared with previously published data for the eucaryotic enzyme

  14. Pairing gaps and Fermi energies at scission for 296Lv alpha-decay

    CERN Document Server

    Mirea, M

    2014-01-01

    The pairing corrections, the single particle occupation numbers, are investigated within density-dependent delta interaction formalism for pairing residual interactions. The potential barrier is computed in the framework of the macroscopic-microscopic model. The microscopic part is based on the Woods-Saxon two center shell model. The alpha-decay of a superheavy element is treated, by paying a special attention to the region of the scission configurations. The sequence of nuclear shapes follows the superasymmetric fission path for alpha decay. It was found that the pairing gaps of the states that reach asymptotically the potential well of the alpha particle have large values at scission but become zero after scission. The 1s1/2 single particle levels of the nascent alpha particle are fully occupied while the superior levels are empties in the scission region and remains in the same states during the penetration of the Coulomb barrier. The projection of the numbers of particle on the two fragments are obtained ...

  15. PHYSICAL PROPERTIES OF CORN RESIDUES

    Directory of Open Access Journals (Sweden)

    Yaning Zhang

    2012-01-01

    Full Text Available Corn residues (cobs, leaves and stalks are abundantly available renewable materials that can be used as an energy source in gasification and combustion systems. Proper understanding of the physical properties of these materials is necessary for their use in thermochemical conversion processes. The physical properties (moisture content, particle size, bulk density and porosity of corn cobs, leaves and stalks were determined in this study. The moisture contents were 6.38, 7.92 and 6.40% of the cobs, leaves and stalks, respectively. The cobs had the highest weight percentage (18.23% of the small particles (0.850 mm. Most of the stalk particles (84.82% were in the range of 0.212-0.850 mm. The cob particle size had a normal concave (inward distribution between particle sizes 0.106 mm (18.23 weight % and 0.925 mm (25.26 weight % with the lowest weight percentage (5.30 weight % at 0.390 mm particle size while the stalk particle size had a normal convex (outward distribution between particle sizes 0.106 mm (8.49 weight % and 0.925 mm (6.69 weight % with the highest weight percentage (23.47 weight % at the 0.605 mm particle size. The leaves had an increasing trend of particle size distribution between the particle sizes 0.106 and 0.925 mm. The average particle sizes for the cobs, leaves and stalks were 0.56, 0.70 and 0.49 mm, respectively. The average bulk density was 282.38, 81.61 and 127.32 kg m-3 for the corn cobs, leaves and stalks, respectively. The average porosity was 67.93, 86.06 and 58.51% for the corn cobs, leaves and stalks, respectively. A positive relationship between the average particle size and the porosity was observed for the corn residues. The differences in the physical properties among the corn residues (cobs, leaves and stalks observed in this study are due to variations in the compositions and structures of these materials.

  16. Mean-field plus various types of pairing interactions and an exact boson mapping of the reduced BCS pairing interaction

    International Nuclear Information System (INIS)

    Exact solutions of Nilsson mean-field plus various type of pairing interactions are briefly reviewed. Some even-odd mass differences and moment of inertia of low-lying states for rare earth and actinide nuclei calculated in nearest-orbit pairing and extended pairing models and comparison with the corresponding experimental data are shown. An exact boson mapping of the reduced BCS pairing Hamiltonian is reported. In the mapping, fermion pair operators are mapped exactly to the corresponding bosons. The image of the mapping results in a Bose-Hubbard model with level dependent hopping. (author)

  17. Residual Liquefaction under Standing Waves

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    This paper summarizes the results of an experimental study which deals with the residual liquefaction of seabed under standing waves. It is shown that the seabed liquefaction under standing waves, although qualitatively similar, exhibits features different from that caused by progressive waves....... The experimental results show that the buildup of pore-water pressure and the resulting liquefaction first starts at the nodal section and spreads towards the antinodal section. The number of waves to cause liquefaction at the nodal section appears to be equal to that experienced in progressive waves for the same...... wave height. Recommendations are made as to how to assess liquefaction potential in standing waves. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE)....

  18. Upgraded wood residue fuels 1995

    International Nuclear Information System (INIS)

    The Swedish market for upgraded residue fuels, i.e. briquettes, pellets and wood powder, has developed considerably during the nineties. The additional costs for the upgrading processes are regained and create a surplus in other parts of the system, e.g. in the form of higher combustion efficiencies, lower investment costs for burning equipment, lower operation costs and a diminished environmental impact. All these factors put together have resulted in a rapid growth of this part of the energy sector. In 1994 the production was 1.9 TWh, an increase of 37 % compared to the previous year. In the forthcoming heating season 1995/96 the production may reach 4 TWh. 57 refs, 11 figs, 6 tabs

  19. Forest residues in cattle feed

    Directory of Open Access Journals (Sweden)

    João Elzeário Castelo Branco Iapichini

    2012-12-01

    Full Text Available The ruminants are capable of converting low-quality food, when they are complementes with high-energy source. Through the use of regional agricultural residues is possible to conduct more economical production systems, since energetic foods have high cost in animal production. There is very abundant availability of residues in agroforestry activities worldwide, so that if a small fraction of them were used with appropriate technical criteria they could largely meet the needs of existing herds in the world and thus meet the demands of consumption of protein of animal origin. The Southwest Region of São Paulo State has large area occupied by reforestation and wide availability of non-timber forest residues, which may represent more concentrated energetic food for ruminant production. This experiment aimed to evaluate the acceptability of ground pine (20, 30 and 40%, replacing part of the energetic food (corn, present in the composition of the concentrate and was performed at the Experimental Station of Itapetininga - Forest Institute / SMA, in the dry season of 2011. It were used four crossbred steers, mean 18 months old, average body weight of 250 kg, housed in a paddock provided with water ad libitum and covered troughs for supplementation with the experimental diet. The adjustment period of the animals was of 07 days and the measurement of the levels of consumption, physiological changes, acceptability and physiological parameters were observed during the following 25 days. The concentrate supplement was formulated based on corn (76.2%, Soybean Meal (20%, urea (2%, Ammonium sulfate (0.4%, calcite (1.4%, Mineral Core (1% and finely ground Pine Cone, replacing corn. In preparing food, the formulas were prepared to make them isoproteic/energetic, containing the following nutrient levels: 22% Crude Protein (CP and 79% of Total Nutrients (TDN. The animals received the supplement in three steps for each level of cone replaced, being offered in the

  20. Mating strategies in dominant meerkats: evidence for extra-pair paternity in relation to genetic relatedness between pair mates.

    Science.gov (United States)

    Leclaire, S; Nielsen, J F; Sharp, S P; Clutton-Brock, T H

    2013-07-01

    Rates of extra-pair paternity (EPP) have frequently been associated with genetic relatedness between social mates in socially monogamous birds. However, evidence is limited in mammals. Here, we investigate whether dominant females use divorce or extra-pair paternity as a strategy to avoid the negative effects of inbreeding when paired with a related male in meerkats Suricata suricatta, a species where inbreeding depression is evident for several traits. We show that dominant breeding pairs seldom divorce, but that rates of EPP are associated with genetic similarity between mates. Although extra-pair males are no more distantly related to the female than social males, they are more heterozygous. Nevertheless, extra-pair pups are not more heterozygous than within-pair pups. Whether females benefit from EPP in terms of increased fitness of the offspring, such as enhanced survival or growth, requires further investigations. PMID:23675879

  1. Les livres pairs d’Alfred Jarry

    Directory of Open Access Journals (Sweden)

    Julien Schuh

    2008-10-01

    Full Text Available Dans les Gestes et opinions du Dr Faustroll, pataphysicien, Alfred Jarry décrit une bibliothèque idéale, composée de 27 ouvrages qu’il nomme mystérieusement des « livres pairs ». Dans cette liste, on trouve aussi bien des œuvres canoniques du symbolisme (Mallarmé, Verlaine, Poe traduit par Baudelaire, des titres des amis de Jarry et des piliers des revues de l’époque (Rachilde, Gustave Kahn, Léon Bloy, que des ouvrages que l’on assimile davantage aux lectures enfantines (un conte de Marceline Desbordes-Valmore, les Mille et une Nuits, le théâtre de Florian ou des textes hors-catégorie (l’œuvre de Rabelais, l’évangile de Luc, les Chants de Maldoror. Beaucoup de critiques se sont interrogés sur la notion de « parité », sur l’égalité supposée entre ces ouvrages n’appartenant pas aux mêmes catégories littéraires. Mais l’intérêt de cette liste n’est pas de fournir un classement, ou d’affirmer l’équivalence de toutes les formes textuelles, comme on l’analyse souvent, en faisant de Jarry un chantre du nihilisme qui chercherait à pervertir les hiérarchies littéraires pour montrer la vacuité du sens. Au contraire, en faisant débuter le Faustroll par une liste d’ouvrages, Jarry met en place les conditions de réception de son texte, dans une posture très littéraire. L’espace délimité par la liste des auteurs pairs fonctionne comme un portrait spirituel de Jarry-littérateur, et livre le contexte selon lequel son discours doit être reçu. La bibliothèque du Dr Faustroll fixe les références que le lecteur pourra voir convoquer dans le texte, et circonscrit l’espace littéraire dans lequel peut fonctionner cet ouvrage.

  2. Natural versus artificial creation of base pairs in DNA: origin of nucleobases from the perspectives of unnatural base pair studies.

    Science.gov (United States)

    Hirao, Ichiro; Kimoto, Michiko; Yamashige, Rie

    2012-12-18

    Since life began on Earth, the four types of bases (A, G, C, and T(U)) that form two sets of base pairs have remained unchanged as the components of nucleic acids that replicate and transfer genetic information. Throughout evolution, except for the U to T modification, the four base structures have not changed. This constancy within the genetic code raises the question of how these complicated nucleotides were generated from the molecules in a primordial soup on the early Earth. At some prebiotic stage, the complementarity of base pairs might have accelerated the generation and accumulation of nucleotides or oligonucleotides. We have no clues whether one pair of nucleobases initially appeared on the early Earth during this process or a set of two base pairs appeared simultaneously. Recently, researchers have developed new artificial pairs of nucleobases (unnatural base pairs) that function alongside the natural base pairs. Some unnatural base pairs in duplex DNA can be efficiently and faithfully amplified in a polymerase chain reaction (PCR) using thermostable DNA polymerases. The addition of unnatural base pair systems could expand the genetic alphabet of DNA, thus providing a new mechanism for the generation novel biopolymers by the site-specific incorporation of functional components into nucleic acids and proteins. Furthermore, the process of unnatural base pair development might provide clues to the origin of the natural base pairs in a primordial soup on the early Earth. In this Account, we describe the development of three representative types of unnatural base pairs that function as a third pair of nucleobases in PCR and reconsider the origin of the natural nucleic acids. As researchers developing unnatural base pairs, they use repeated "proof of concept" experiments. As researchers design new base pairs, they improve the structures that function in PCR and eliminate those that do not. We expect that this process is similar to the one functioning in the

  3. Observing Pair-Work Task in an English Speaking Class

    Directory of Open Access Journals (Sweden)

    Diana Achmad

    2014-01-01

    Full Text Available This paper reports on students’ pair-work interactions to develop their speaking skills in an ELT classroom which consisted of international learners. A number of 16 learners of intermediate proficiency with IELTS score band 5.5 were observed. The teacher had paired those he considered among them to be the more competent ones (hereafter, stronger with the less competent ones (hereafter, weaker; therefore, eight pairs were observed during the lesson. The task given to the students was to express ‘Agree and Disagree’ in the context of giving opinions related to social life. Based on the observations, the task was successfully implemented by six pairs; thus, the two others faced some problems. From the first pair, it was seen that the stronger student had intimated the weaker one into speaking during the task. The other pair, who was both of the same native, did not converse in English as expected and mostly used their native language to speak with one another presumably due to respect from the stronger student towards the weaker one. In situations like this, when pair-work becomes unproductive, rotating pairs is recommended to strengthen information sharing and assigning roles to avoid a student from taking over the activity from his or her pair. In conclusion, pairing international learners with mixed speaking proficiency by teachers must be conducted as effectively as possible by initially identifying their ability and learning culture to profoundly expand the students’ language resources.

  4. Beamlike photon pairs entangled by a 2x2 fiber

    International Nuclear Information System (INIS)

    Polarization-entangled photon pairs have been widely used as a light source of quantum communication. The polarization-entangled photon pairs are generally obtained at the crossing points of the light cones that are generated from a type-II nonlinear crystal. However, it is hard to pick up the photon pairs coming out from the crossing points because of their invisible wavelength and low intensity. In our previous work, we succeeded in generating polarization-entangled photon pairs by overlapping two light paths for the photon-pair generation. The photon pairs could be entangled in all of the generated photon pairs without clipping the crossing points, even with some difficulty in its alignment to overlap the two light paths. In this paper, we have developed an optical system which generates polarization-entangled photon pairs using a beamlike photon pair, without the difficulty in alignment. The measured results show that the photon pairs generated in the system are entangled in their polarizations.

  5. RESIDUES IN CARROTS TREATED WITH LINURON

    DEFF Research Database (Denmark)

    Løkke, Hans

    1974-01-01

    Investigations have been carried out on residues of linuron and its breakdown products in carrots sprayed with Jinuron at 1, 2, or 4 kg a.i./ha, 0, 19, 28, 36 or 60 days after sowing (up to 57 days before harvesting). The extracted residues were separated into three fractions by liquid-liquid par......Investigations have been carried out on residues of linuron and its breakdown products in carrots sprayed with Jinuron at 1, 2, or 4 kg a.i./ha, 0, 19, 28, 36 or 60 days after sowing (up to 57 days before harvesting). The extracted residues were separated into three fractions by liquid......,4-dichloroaniline and iodide ion, followed by gas chromatography with electron capture detector. Only 5-13% of the extract-able residues were breakdown products. Most of the detectable residue (87-95%) was identified as linuron. The relative proportions of linuron and breakdown products in carrots at the time...

  6. Decreasing residual aluminum level in drinking water

    Institute of Scientific and Technical Information of China (English)

    王志红; 崔福义

    2004-01-01

    The relativity of coagulant dosage, residual turbidity, temperature, pH etc. with residual aluminum concentration were investigated, and several important conclusions were achieved. Firstly, dosage of alum-coagulant or PAC1 influences residual aluminum concentration greatly. There is an optimal-dosage-to-aluminum, a bit less than the optimal-dosage-to-turbidity. Secondly, it proposes that decreasing residual aluminum concentration can be theoretically divided into two methods, either decreasing (even removing) the concentration of particulate aluminum component, or decreasing dissolved aluminum. In these tests there is an optimal value of residual turbidity of postprecipitation at 7.0 NTU. Thirdly, residual aluminum level will increase while water temperature goes higher. At the last, optimal pH value corresponds a minimum dissolved aluminum at a given turbidity. Data shows the optimal pH value decreases with water temperature's increasing.

  7. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper;

    2005-01-01

    We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on...... spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the ususal residuals...... plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction....

  8. H2r: Identification of evolutionary important residues by means of an entropy based analysis of multiple sequence alignments

    Directory of Open Access Journals (Sweden)

    Zwick Matthias

    2008-03-01

    Full Text Available Abstract Background A multiple sequence alignment (MSA generated for a protein can be used to characterise residues by means of a statistical analysis of single columns. In addition to the examination of individual positions, the investigation of co-variation of amino acid frequencies offers insights into function and evolution of the protein and residues. Results We introduce conn(k, a novel parameter for the characterisation of individual residues. For each residue k, conn(k is the number of most extreme signals of co-evolution. These signals were deduced from a normalised mutual information (MI value U(k, l computed for all pairs of residues k, l. We demonstrate that conn(k is a more robust indicator than an individual MI-value for the prediction of residues most plausibly important for the evolution of a protein. This proposition was inferred by means of statistical methods. It was further confirmed by the analysis of several proteins. A server, which computes conn(k-values is available at http://www-bioinf.uni-regensburg.de. Conclusion The algorithms H2r, which analyses MSAs and computes conn(k-values, characterises a specific class of residues. In contrast to strictly conserved ones, these residues possess some flexibility in the composition of side chains. However, their allocation is sensibly balanced with several other positions, as indicated by conn(k.

  9. Riboswitch Structure: an Internal Residue Mimicking the Purine Ligand

    Energy Technology Data Exchange (ETDEWEB)

    Delfosse, V.; Bouchard, P; Bonneau, E; Dagenais, P; Lemay, J; Lafontaine, D; Legault, P

    2009-01-01

    The adenine and guanine riboswitches regulate gene expression in response to their purine ligand. X-ray structures of the aptamer moiety of these riboswitches are characterized by a compact fold in which the ligand forms a Watson-Crick base pair with residue 65. Phylogenetic analyses revealed a strict restriction at position 39 of the aptamer that prevents the G39-C65 and A39-U65 combinations, and mutational studies indicate that aptamers with these sequence combinations are impaired for ligand binding. In order to investigate the rationale for sequence conservation at residue 39, structural characterization of the U65C mutant from Bacillus subtilis pbuE adenine riboswitch aptamer was undertaken. NMR spectroscopy and X-ray crystallography studies demonstrate that the U65C mutant adopts a compact ligand-free structure, in which G39 occupies the ligand-binding site of purine riboswitch aptamers. These studies present a remarkable example of a mutant RNA aptamer that adopts a native-like fold by means of ligand mimicking and explain why this mutant is impaired for ligand binding. Furthermore, this work provides a specific insight into how the natural sequence has evolved through selection of nucleotide identities that contribute to formation of the ligand-bound state, but ensures that the ligand-free state remains in an active conformation.

  10. Curvature and Residual Stress Analysis in Rotational Leveling of Bars

    Institute of Scientific and Technical Information of China (English)

    Yong-qin WANG; Zhi-fang LIU; Hen-gan OU; Yuan-xin LUO; Xing-chun YAN

    2016-01-01

    Leveling process plays an important role in delivering the desired material properties and product stand-ards.An analytical method for the rotational leveling process of bars was presented.First,each cross section of the bar in the leveling area was discretized with the roller gap-curvature relations established in both planes XY and XZ. Second,a numerical procedure with two steps was developed to simulate both pressing and leveling processes.This approach can be easily implemented to produce simulation results of the curvature and traj ectory distributions during the leveling process,as well as the bending and residual stresses.It is found that curvature and traj ectory distribu-tions follow a sine-shape due to the characteristic of rotational movement,which also results in a helical pattern of residual stress after leveling.Based on the results obtained,it is also observed that the rotational movement is benefi-cial for adding the number of bending cycle.This is the reason why there are only a few pairs of rollers on the bar leveler.

  11. Escherichia coli DegP Protease Cleaves between Paired Hydrophobic Residues in a Natural Substrate: the PapA Pilin

    OpenAIRE

    Jones, C. Hal; Dexter, Paul; Evans, Amy K.; Liu, Christopher; Hultgren, Scott J.; Hruby, Dennis E.

    2002-01-01

    The DegP protein, a multifunctional chaperone and protease, is essential for clearance of denatured or aggregated proteins from the inner-membrane and periplasmic space in Escherichia coli. To date, four natural targets for DegP have been described: colicin A lysis protein, pilin subunits and MalS from E. coli, and high-molecular-weight adherence proteins from Haemophilus influenzae. In vitro, DegP has shown weak protease activity with casein and several other nonnative substrates. We report ...

  12. Pair Triplet Association Rule Generation in Streams

    Directory of Open Access Journals (Sweden)

    Manisha Thool

    2013-08-01

    Full Text Available Many applications involve the generation and analysis of a new kind of data, called stream data, where data flows in and out of an observation platform or window dynamically. Such data streams have the unique features such as huge or possibly infinite volume, dynamically changing, flowing in or out in a fixed order, allowing only one or a small number of scans. An important problem in data stream mining is that of finding frequent items in the stream. This problem finds application across several domains such as financial systems, web traffic monitoring, internet advertising, retail and e-business. This raises new issues that need to be considered when developing association rule mining technique for stream data. The Space-Saving algorithm reports both frequent and top-k elements with tight guarantees on errors. We also develop the notion of association rules in streams of elements. The Streaming-Rules algorithm is integrated with Space-Saving algorithm to report 1-1 association rules with tight guarantees on errors, using minimal space, and limited processing per element and we are using Apriori algorithm for static datasets and generation of association rules and implement Streaming-Rules algorithm for pair, triplet association rules. We compare the top- rules of static datasets with output of stream datasets and find percentage of error.

  13. An Identity Based Aggregate Signature from Pairings

    Directory of Open Access Journals (Sweden)

    Yike Yu

    2011-04-01

    Full Text Available An aggregate signature is a useful digital signature that supports aggregation: Given n signatures on n distinct messages from n distinct users, aggregate signature scheme is possible to aggregate all these signature into a single short signature. This single signature, along with the n original messages will convince any verifier that the n users did indeed sign the n original messages respectively (i.e., for i=1,...,n user i signed message  mi. In this paper, we propose an identity based aggregate signature scheme which requires constant pairing operations in the verification and the size of aggregate signature is independent of the number of signers. We prove that the proposed signature scheme is secure against existential forgery under adaptively chosen message and identity attack in the random oracle model assuming the intractability of the computational Diffie-Hellman problem.

  14. Unifying projected entangled pair state contractions

    International Nuclear Information System (INIS)

    The approximate contraction of a tensor network of projected entangled pair states (PEPS) is a fundamental ingredient of any PEPS algorithm, required for the optimization of the tensors in ground state search or time evolution, as well as for the evaluation of expectation values. An exact contraction is in general impossible, and the choice of the approximating procedure determines the efficiency and accuracy of the algorithm. We analyze different previous proposals for this approximation, and show that they can be understood via the form of their environment, i.e. the operator that results from contracting part of the network. This provides physical insight into the limitation of various approaches, and allows us to introduce a new strategy, based on the idea of clusters, that unifies previous methods. The resulting contraction algorithm interpolates naturally between the cheapest and most imprecise and the most costly and most precise method. We benchmark the different algorithms with finite PEPS, and show how the cluster strategy can be used for both the tensor optimization and the calculation of expectation values. Additionally, we discuss its applicability to the parallelization of PEPS and to infinite systems

  15. AGT, Burge pairs and minimal models

    CERN Document Server

    Bershtein, M

    2014-01-01

    We consider the AGT correspondence in the context of the conformal field theory M^{p, p'} x M^H, where M^{p, p'} is the minimal model based on the Virasoro algebra V^{p, p'} labeled by two co-prime integers {p, p'}, 1 < p < p', and M^H is the free boson theory based on the Heisenberg algebra H. Using Nekrasov's instanton partition functions without modification to compute conformal blocks in M^{p, p'} x M^H leads to ill-defined or incorrect expressions. Let B^{p, p', H}_n be a conformal block in M^{p, p'} x M^H, with n consecutive channels \\chi_{\\i}, \\i = 1, ..., n, and let \\chi_{\\i} carry states from H^{p, p'}_{r_{\\i}, s_{\\i}} x F, where H^{p, p'}_{r_{\\i}, s_{\\i}} is an irreducible highest-weight V^{p, p'}-representation, labeled by two integers {r_{\\i}, s_{\\i}}, 0 < r_{\\i} < p, 0 < s_{\\i} < p', and F is the Fock space of H. We show that restricting the states that flow in \\chi_{\\i}, \\i = 1, ..., n, to states labeled by partition pairs {Y_1^{\\i}, Y_2^{\\i}} that satisfy Y^{\\i, T}_{2, \\sigma}...

  16. Particle Acceleration in Pair-Starved Pulsars

    CERN Document Server

    Harding, A G M A K

    2004-01-01

    We investigate the physical situation above the pulsar polar cap (PC) where the accelerating primaries (electrons) are not capable of producing sufficient numbers of electron-positron pairs at low altitudes (within 1-2 stellar radii above the PC surface) to screen the accelerating electric field, and continue accelerating up to, at least, very high altitudes nearly approaching the light cylinder. We derive an analytic solution for the parallel electric field valid at high altitudes. The solution is based on the physical condition of asymptotic vanishing of the rotationally induced transverse electric field within the magnetic flux tube. This condition constrains the asymptotic value of the effective space charge that determines the distribution of the parallel electric field within the magnetic tube. Our estimates of low- to high-altitude values of the parallel electric field imply the occurrence of a regime of primary acceleration (with the characteristic Lorentz factor up to 1-2 X 10^7) all the way from the...

  17. Investigation of tau pair production at PETRA

    International Nuclear Information System (INIS)

    The reaction e+e- -> tau+tau- has been measured at center of mass energies around 34 GeV. The selection is sensitive to 93% of the tau pair decays, thus making possible a high identification efficiency of proportional 70% over a large solid angle. The total cross section has been measured to Rsub(tau) = sigmasub(tautau)/sigmasub(point) = .94 +- .06(stat.) +- .06(syst.). In the differential cross section a charge asymmetry of Asub(tau) = (-(9.0 +- 6.6)% was observed, corresponding to a tau axial vector coupling to the weak neutral current of asub(tau) = -.94 +- 0.69. Moreover, final states from the decays tau -> πν, tau -> eνν, and tau -> μνν have been isolated and branching ratios into these channels have been determined. From the inclusive momentum spectra of the observed decay products (including the channel tau -> rhoν) the forward backward asymmetry of tau polarization has been determined to Asub(p,tau) = -(1 +- 22)% which corresponds to vsub(tau) = -.1 +- 2.9. Tests on factorization are discussed. (orig.)

  18. Nebular spectra of pair-instability supernovae

    CERN Document Server

    Jerkstrand, A; Heger, A

    2015-01-01

    If very massive stars (M >~ 100 Msun) can form and avoid too strong mass loss during their evolution, they are predicted to explode as pair-instability supernovae (PISNe). One critical test for candidate events is whether their nucleosynthesis yields and internal ejecta structure, being revealed through nebular-phase spectra at t >~ 1 yr, match those of model predictions. Here we compute theoretical spectra based on model PISN ejecta at 1-3 years post-explosion to allow quantitative comparison with observations. The high column densities of PISNe lead to complete gamma-ray trapping for t >~ 2 years which, combined with fulfilled conditions of steady state, leads to bolometric supernova luminosities matching the 56Co decay. Most of the gamma-rays are absorbed by the deep-lying iron and silicon/sulphur layers. The ionization balance shows a predominantly neutral gas state, which leads to emission lines of Fe I, Si I, and S I. For low-mass PISNe the metal core expands slowly enough to produce a forest of distinc...

  19. Bayesian nonparametric regression with varying residual density

    OpenAIRE

    Pati, Debdeep; Dunson, David B.

    2013-01-01

    We consider the problem of robust Bayesian inference on the mean regression function allowing the residual density to change flexibly with predictors. The proposed class of models is based on a Gaussian process prior for the mean regression function and mixtures of Gaussians for the collection of residual densities indexed by predictors. Initially considering the homoscedastic case, we propose priors for the residual density based on probit stick-breaking (PSB) scale mixtures and symmetrized ...

  20. Residual Energies after Slow Quantum Annealing

    OpenAIRE

    Suzuki, Sei; Okada, Masato

    2005-01-01

    Features of the residual energy after the quantum annealing are investigated. The quantum annealing method exploits quantum fluctuations to search the ground state of classical disordered Hamiltonian. If the quantum fluctuation is reduced sufficiently slowly and linearly by the time, the residual energy after the quantum annealing falls as the inverse square of the annealing time. We show this feature of the residual energy by numerical calculations for small-sized systems and derive it on th...

  1. Structure of residual interaction in spherical nuclei

    OpenAIRE

    Kamchatnov, A. M.; Nosov, V. G.

    2003-01-01

    The effect of residual interaction between nucleons (quasiparticles) on shell oscillations of the masses of spherical nuclei is considered. The singularity of the ground state energy of the system in the vicinity of nucleon magic numbers is analyzed for various types of the dependence of residual interaction on orbital momentum of the quasiparticle. It is shown that only the perturbation band width of the Fermi distribution due to residual interaction which is proportional to the square of th...

  2. Maintaining Arc Consistency with Multiple Residues

    OpenAIRE

    Lecoutre, Christophe; Likitvivatanavong, Chavalit; Shannon, Scott; Yap, Roland; Zhang, Yuanlin

    2008-01-01

    International audience Exploiting residual supports (or residues) has proved to be one of the most cost-effective approaches for Maintaining Arc Consistency during search (MAC). While MAC based on optimal AC algorithm may have better theoretical time complexity in some cases, in practice the overhead for maintaining required data structure during search outweighs the benefit, not to mention themore complicated implementation. Implementing MAC with residues, on the other hand, is trivial. I...

  3. Computational Prediction of Hot Spot Residues

    OpenAIRE

    Morrow, John Kenneth; Zhang, Shuxing

    2012-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has pr...

  4. Residues : The gateway to higher arithmetic I

    OpenAIRE

    Siebeneicher, Christian

    2012-01-01

    Residues to a given modulus have been introduced to mathematics by Carl Friedrich Gauss with the definition of congruence in the `Disquisitiones Arithmeticae'. Their extraordinary properties provide the basis for a change of paradigm in arithmetic. By restricting residues to remainders left over by divison Peter Gustav Lejeune Dirichlet - Gauss's successor in G\\"ottingen - eliminated in his `Lectures on number theory' the fertile concept of residues and attributed with the number-theoretic ap...

  5. Identification of kinetically hot residues in proteins.

    OpenAIRE

    M. C. Demirel; Atilgan, A. R.; Jernigan, R. L.; Erman, B; Bahar, I

    1998-01-01

    A number of recent studies called attention to the presence of kinetically important residues underlying the formation and stabilization of folding nuclei in proteins, and to the possible existence of a correlation between conserved residues and those participating in the folding nuclei. Here, we use the Gaussian network model (GNM), which recently proved useful in describing the dynamic characteristics of proteins for identifying the kinetically hot residues in folded structures. These are t...

  6. Particulate residue separators for harvesting devices

    Science.gov (United States)

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, John R.

    2010-06-29

    A particulate residue separator and a method for separating a particulate residue stream may include a plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams which are formed by the harvesting device and which travel, at least in part, along the plenum and in a direction of the second, exhaust end; and a baffle assembly which is located in partially occluding relation relative to the plenum, and which substantially separates the first and second particulate residue air streams.

  7. Methods of separating particulate residue streams

    Science.gov (United States)

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, J. Richard

    2011-04-05

    A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

  8. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper;

    residuals generalise the well-known residuals for point processes in time, used in signal processing and survival analysis. An important difference is that the conditional intensity or hazard rate of the temporal point process must be replaced by the Papangelou conditional intensity $lambda$ of the spatial....... The conditional intensity $lambda$ plays the role of the mean response. Elaborating this analogy gives us recommendations for diagnostic plots and model criticism using these residuals. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend...

  9. Carbaryl residues in maize and processed products

    International Nuclear Information System (INIS)

    Carbaryl residues in two local maize varieties were determined using a colorimetric method. No significant differences were observed for residues of the two varieties which ranged between 12.0 to 13.75 mg/kg in the crude oil, and averaged 1.04 and 0.67 mg/kg in the flour and cake respectively. In whole maize plants, carbaryl residues declined to approximately 2 mg/kg 35 days after treatment. Cooking in aqueous, oil or aqueous-oil media led to 63-83% loss of carbaryl residues, after 30 minutes. (author)

  10. High temperature reaction of insoluble residue

    International Nuclear Information System (INIS)

    The dissolution and vaporization of insoluble residue in overheated nitric acid, and the oxidation and vaporization of insoluble residue in air were investigated. Only 8% of Ru in the insoluble residue was dissolved into boiling azeotropic nitric acid in 48 hours. The amount of dissolved Ru increases its concentration only by 10% from normal condition. No significant vaporization of Ru was observed. In the air, insoluble residue was not oxidized by 400degC. The metal of Ru started to be oxidized from 550degC, but was not vaporized below 1000degC. (author)

  11. Strength of a multipole residual interaction

    International Nuclear Information System (INIS)

    The consequences of assuming different radial dependences for the multipole residual interaction are explored, using macroscopic and microscopic arguments. Calculations are done both for schematic and realistic cases

  12. Modeling of Residual Stresses In Toughened Glass

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik

    2006-01-01

    -depth knowledge of the residual stresses in toughened glass near holes and edges where the total stress state is a combination of contact stresses and residual stresses. The present paper, presenting the derivation and results for a model predicting the residual stresses in a glass plate far from edges and holes......, is a step towards such a model. The model is based on the Instant Freeze concept with a few modifications. Current work, using a partial differential equation approach for the modeling and state-of-the-art in modeling residual stresses in glass is briefly presented, and a short description of the...

  13. RESIDUES IN CARROTS TREATED WITH LINURON

    DEFF Research Database (Denmark)

    Løkke, Hans

    1974-01-01

    Investigations have been carried out on residues of linuron and its breakdown products in carrots sprayed with Jinuron at 1, 2, or 4 kg a.i./ha, 0, 19, 28, 36 or 60 days after sowing (up to 57 days before harvesting). The extracted residues were separated into three fractions by liquid......,4-dichloroaniline and iodide ion, followed by gas chromatography with electron capture detector. Only 5-13% of the extract-able residues were breakdown products. Most of the detectable residue (87-95%) was identified as linuron. The relative proportions of linuron and breakdown products in carrots at the time of...

  14. Spin polarization transfer by the radical pair mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Zarea, Mehdi, E-mail: m-zarea@northwestern.edu; Ratner, Mark A.; Wasielewski, Michael R. [Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University, Evanston, Illinois 60208-3113 (United States)

    2015-08-07

    In a three-site representation, we study a spin polarization transfer from radical pair spins to a nearby electron or nuclear spin. The quantum dynamics of the radical pair spins is governed by a constant exchange interaction between the radical pair spins which have different Zeeman frequencies. Radical pair spins can recombine to the singlet ground state or to lower energy triplet states. It is then shown that the coherent dynamics of the radical pair induces spin polarization on the nearby third spin in the presence of a magnetic field. The spin polarization transfer depends on the difference between Zeeman frequencies, the singlet and triplet recombination rates, and on the exchange and dipole-dipole interactions between the different spins. In particular, the sign of the polarization depends on the exchange coupling between radical pair spins and also on the difference between singlet and triplet recombination rate constants.

  15. Analysis of food pairing in regional cuisines of India

    CERN Document Server

    Jain, Anupam; Bagler, Ganesh

    2015-01-01

    Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient ...

  16. An ensemble of SVM classifiers based on gene pairs.

    Science.gov (United States)

    Tong, Muchenxuan; Liu, Kun-Hong; Xu, Chungui; Ju, Wenbin

    2013-07-01

    In this paper, a genetic algorithm (GA) based ensemble support vector machine (SVM) classifier built on gene pairs (GA-ESP) is proposed. The SVMs (base classifiers of the ensemble system) are trained on different informative gene pairs. These gene pairs are selected by the top scoring pair (TSP) criterion. Each of these pairs projects the original microarray expression onto a 2-D space. Extensive permutation of gene pairs may reveal more useful information and potentially lead to an ensemble classifier with satisfactory accuracy and interpretability. GA is further applied to select an optimized combination of base classifiers. The effectiveness of the GA-ESP classifier is evaluated on both binary-class and multi-class datasets. PMID:23668348

  17. Diffraction of collinear correlated photon pairs by an ultrasonic wave

    CERN Document Server

    Kwiek, Piotr

    2013-01-01

    The phenomenon of collinear photon pairs diffraction by an ultrasonic wave is investigated for Bragg incidence. A BBO crystal was used for producing collinear correlated photon pairs via type-I spontaneous parametric down-conversion. The experimental setup for diffraction of collinear correlated photon pairs was tested based on Malus' law for pairs of photons. The obtained results do not support the L. B. Deng's theory of 2012, presented in his work entitled "Diffraction of entangled photon pairs by ultrasonic waves" [Front. Phys. 7, 239 (2012)] . An alternative simple theoretical description of interaction of collinear photon pairs with ultrasonic waves is shown in the present paper which reveals very good agreement with corresponding experimental data.

  18. Water-Mediated Ion Pairing: Occurrence and Relevance

    DEFF Research Database (Denmark)

    van der Vegt, Nico F.A.; Haldrup, Kristoffer; Roke, Sylvie;

    2016-01-01

    We present an overview of the studies of ion pairing in aqueous media of the past decade. In these studies, interactions between ions, and between ions and water, are investigated with relatively novel approaches, including dielectric relaxation spectroscopy, far-infrared (terahertz) absorption...... spectroscopy, femtosecond mid-infrared spectroscopy, and X-ray spectroscopy and scattering, as well as molecular dynamics simulation methods. With these methods, it is found that ion pairing is not a rare phenomenon only occurring for very particular, strongly interacting cations and anions. Instead, for many...... salt solutions and their interfaces, the measured and calculated structure and dynamics reveal the presence of a distinct concentration of contact ion pairs (CIPs), solvent shared ion pairs (SIPs), and solvent-separated ion pairs (2SIPs). We discuss the importance of specific ion-pairing interactions...

  19. Spin polarization transfer by the radical pair mechanism

    International Nuclear Information System (INIS)

    In a three-site representation, we study a spin polarization transfer from radical pair spins to a nearby electron or nuclear spin. The quantum dynamics of the radical pair spins is governed by a constant exchange interaction between the radical pair spins which have different Zeeman frequencies. Radical pair spins can recombine to the singlet ground state or to lower energy triplet states. It is then shown that the coherent dynamics of the radical pair induces spin polarization on the nearby third spin in the presence of a magnetic field. The spin polarization transfer depends on the difference between Zeeman frequencies, the singlet and triplet recombination rates, and on the exchange and dipole-dipole interactions between the different spins. In particular, the sign of the polarization depends on the exchange coupling between radical pair spins and also on the difference between singlet and triplet recombination rate constants

  20. Pairing Nambu-Goldstone Modes within Nuclear Density Functional Theory

    Science.gov (United States)

    Hinohara, Nobuo; Nazarewicz, Witold

    2016-04-01

    We show that the Nambu-Goldstone formalism of the broken gauge symmetry in the presence of the T =1 pairing condensate offers a quantitative description of the binding-energy differences of open-shell superfluid nuclei. We conclude that the pairing-rotational moments of inertia are excellent pairing indicators, which are free from ambiguities attributed to odd-mass systems. We offer a new, unified interpretation of the binding-energy differences traditionally viewed in the shell model picture as signatures of the valence nucleon properties. We present the first systematic analysis of the off-diagonal pairing-rotational moments of inertia and demonstrate the mixing of the neutron and proton pairing-rotational modes in the ground states of even-even nuclei. Finally, we discuss the importance of mass measurements of neutron-rich nuclei for constraining the pairing energy density functional.

  1. Pairing Nambu-Goldstone modes within nuclear density functional theory

    CERN Document Server

    Hinohara, Nobuo

    2016-01-01

    We show that the Nambu-Goldstone formalism of the broken gauge symmetry in the presence of the $T=1$ pairing condensate offers a quantitative description of the binding energy differences of open-shell superfluid nuclei. We conclude that the pairing rotational moments of inertia are excellent pairing indicators, which are free from ambiguities attributed to odd-mass systems. We offer a new, unified interpretation of the binding-energy differences traditionally viewed in the shell model picture as signatures of the valence nucleon properties. We present the first systematic analysis of the off-diagonal pairing rotational moments of inertia, and demonstrate the mixing of the neutron and proton pairing rotational modes in the ground states of even-even nuclei. Finally, we discuss the importance of mass measurements of neutron-rich nuclei for constraining the pairing energy density functional.

  2. Classes of source pairs in interference and diffraction

    CERN Document Server

    Castaneda, R

    2003-01-01

    A description of interference and diffraction based on the concept of class of source pairs is presented. It is the set of pairs of sources whose contributions to the interference or diffraction patterns exhibit the same phase difference. Each class of source pairs provides a specific cosine-like modulation on the intensity distribution of pattern, in such a way that the set provides an expansion of the intensity distribution of the pattern in an orthogonal basis. From this point of view, the classes of source pairs are the effective elementary sources for those intensity distributions. The characteristics of the classes of source pairs can be accurately determined by Fourier transforming the intensity distribution of the patterns. The central value of this Fourier spectrum is related to the number of individual sources. The remaining values will provide two crucial descriptors of the classes: their positions on the Fourier transform domain will be corresponding to the separation vector of the class of pairs ...

  3. Paired teaching for faculty professional development in teaching

    CERN Document Server

    Stang, Jared B

    2015-01-01

    Paired (or co-)teaching is an arrangement in which two faculty are collaboratively responsible for all aspects of teaching a course. By pairing an instructor experienced in research-based instructional strategies (RBIS) with an instructor with little or no experience in RBIS, paired teaching can be used to promote the adoption of RBIS. Using data from post-course interviews with the novice instructors of four such arrangements, we seek to understand the factors that make for effective professional development in teaching via paired teaching. Learning about teaching for the novice instructors was found to be mediated both by the approach of the novice instructor to the paired teaching and the previous teaching experience of the novice instructor. Additionally, the structure of the pair-taught course and the sequence of teaching assignments for the novice instructor both play roles in lowering the barrier to novice instructors adopting RBIS.

  4. Pair Cascades and Deathlines in Offset Magnetic Dipole Fields

    Science.gov (United States)

    Harding, Alice; Muslimov, Alex

    2010-01-01

    We investigate electron-positron pair cascades in a dipole magnetic field whose axis is offset from the neutron star center. In such a field geometry, the polar cap is displaced from the neutron star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the polar cap of an offset dipole, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset parameter. We find that the pair multiplicity can change dramatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity.

  5. Pair Production In Near Extremal Charged Black Holes

    CERN Document Server

    Chen, Chiang-Mei; Tang, Fu-Yi

    2015-01-01

    We study the spontaneous pair production, including the Schwinger mechanism and the Hawking radiation, of charged scalar and spinor particles from the near horizon region of (near) extremal charged black holes in the probe field limit. The pair production rate and the absorption cross section, as well as the retarded Green's functions of the probe fields are analytically computed. Moreover, the holographic description dual to the pair production is discussed.

  6. Compression of Soliton Pairs in Dispersion-Decreasing Fibres

    Institute of Scientific and Technical Information of China (English)

    CUI Hu; XU Wen-Cheng; LIU Song-Hao

    2004-01-01

    @@ The compression of soliton pairs in fibres with decreasing dispersion is studied. The results show that generation of high-quality stable pedestal-free pulses is strongly affected by the interaction between soliton pairs. The initial phase difference between two solitons can modify soliton interaction and can make the neighbouring solitons never collide periodically. The soliton pairs can be compressed selectively so that one of the two solitons can achieve enhanced compression by controlling the initial phase difference.

  7. Impact of pairing correlations on the orientation of the nuclear

    OpenAIRE

    Zhao, P. W.; Zhang, S.Q.; Meng, J

    2015-01-01

    For the first time, the tilted axis cranking covariant density functional theory with pairing correlations has been formulated and implemented in a fully self-consistent and microscopic way to investigate the evolution of the spin axis and the pairing effects in rotating triaxial nuclei. The measured energy spectrum and transition probabilities for the Nd-135 yrast band are reproduced well without any ad hoc renormalization factors when pairing effects are taken into account. A transition fro...

  8. Paired structures and other opposite-based models

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco, Camilo; Gómez, Daniel;

    2015-01-01

    In this paper we present a new class of fuzzy sets, paired fuzzy sets, that tries to overcome any conflict between families of fuzzy sets that share a main characteristic: that they are generated from two basic opposite fuzzy sets. Hence, the first issue is to formalize the notion of opposition, ...... viewed as a particular paired structure when the classical fuzzy negation is considered; on the other hand, the relationship of this model with bipolarity is reconsidered from our paired view....

  9. Photon-exchange effects on photon-pair transmission

    OpenAIRE

    Resch, K. J.; Lapaire, G. G.; Lundeen, J. S.; Sipe, J. E.; Steinberg, A. M.

    2003-01-01

    It has been proposed that photon-exchange effects in atom-photon interactions could lead to greatly enhanced optical nonlinearities. These might have widespread application (e.g. quantum information). Here we demonstrate experimentally that such exchange effects can indeed enhance the probability of real absorption of photon pairs. Using nonclassical pairs of photons with variable time separation, we observe a maximum suppression of pair transmission by at least 5% with respect to the result ...

  10. PANDAseq: paired-end assembler for illumina sequences

    OpenAIRE

    Masella Andre P; Bartram Andrea K; Truszkowski Jakub M; Brown Daniel G; Neufeld Josh D

    2012-01-01

    Abstract Background Illumina paired-end reads are used to analyse microbial communities by targeting amplicons of the 16S rRNA gene. Publicly available tools are needed to assemble overlapping paired-end reads while correcting mismatches and uncalled bases; many errors could be corrected to obtain higher sequence yields using quality information. Results PANDAseq assembles paired-end reads rapidly and with the correction of most errors. Uncertain error corrections come from reads with many lo...

  11. Particle vs. pair condensation in attractive Bose liquids

    OpenAIRE

    Nozières, P.; Saint James, D.

    1982-01-01

    The competition between particle and pair condensation in Bose liquids is studied using a mean field variational ground state that comprises both the Bogoliubov approximation for weakly interacting Bose gases and the Valatin-Butler pair state. We first consider structureless bosons, disregarding the fact that an attractive gas will necessarily collapse. We show that a pair state occurs only if the attraction is strong enough to bind two bosons together. The limit of low densities is treated e...

  12. Single pairs of time-bin entangled photons

    CERN Document Server

    Versteegh, Marijn A M; Berg, Aafke A van den; Juska, Gediminas; Dimastrodonato, Valeria; Gocalinska, Agnieszka; Pelucchi, Emanuele; Zwiller, Val

    2015-01-01

    Time-bin entangled photons are ideal for long-distance quantum communication via optical fibers. Here we present a source where, even at high creation rates, each excitation pulse generates at most one time-bin entangled pair. This is important for the accuracy and security of quantum communication. Our site-controlled quantum dot generates single polarization-entangled photon pairs, which are then converted, without loss of entanglement strength, into single time-bin entangled photon pairs.

  13. Pairing Nambu-Goldstone Modes within Nuclear Density Functional Theory

    OpenAIRE

    Hinohara, Nobuo; Nazarewicz, Witold

    2016-01-01

    We show that the Nambu-Goldstone formalism of the broken gauge symmetry in the presence of the $T=1$ pairing condensate offers a quantitative description of the binding-energy differences of open-shell superfluid nuclei. We conclude that the pairing-rotational moments of inertia are excellent pairing indicators, which are free from ambiguities attributed to odd-mass systems. We offer a new, unified interpretation of the binding-energy differences traditionally viewed in the shell model pictur...

  14. Recognition of triplex forming oligodeoxynucleotides incorporating abasic sites by 5-arylcytosine residues in duplex DNAs.

    Science.gov (United States)

    Mizuta, Masahiro; Banba, Jun-Ichi; Kanamori, Takashi; Ohkubo, Akihiro; Sekine, Mitsuo; Seio, Kohji

    2007-01-01

    In this paper, we reported our attempt to use a 5arylcytosine (dC(ar)) and the abasic site () as an artificial base pair for DNA triplex. The idea was confirmed by the molecular modeling studied in which the aromatic group of (ph) which protrudes in the major groove was buried into the cleft formed by the residue in the TFO. We synthesized three kinds of dC(ar) and the oligonucleotides incorporating them. Our UV-melting experiments revealed that the DNA triplex containing the dC(ph).phi was more stable than that containing dC.phi pair. Moreover, the dC.phi pair was more stable than any other dC.Y pairs such as dC(ph).G, dC(ph).C, dC(ph).T and dC(ph).A. These results indicated the possibility that the appropriate pair of dC(Ar) and could be the new sequence code of DNA triplex. We also carried out the Tm analyses of other TFOs incorporating dC(Ar) and , and clarified the stability of these triplexes. PMID:18029568

  15. On extensions of wavelet systems to dual pairs of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2015-01-01

    It is an open problem whether any pair of Bessel sequences with wavelet structure can be extended to a pair of dual frames by adding a pair of singly generated wavelet systems. We consider the particular case where the given wavelet systems are generated by the multiscale setup with trigonometric...... masks and provide a positive answer under extra assumptions. We also identify a number of conditions that are necessary for the extension to dual (multi-) wavelet frames with any number of generators, and show that they imply that an extension with two pairs of wavelet systems is possible. Along the way...

  16. Excluded volume effect enhances the homology pairing of model chromosomes

    CERN Document Server

    Takamiya, Kazunori; Isami, Shuhei; Nishimori, Hiraku; Awazu, Akinori

    2015-01-01

    To investigate the structural dynamics of the homology pairing of polymers, we mod- eled the scenario of homologous chromosome pairings during meiosis in Schizosaccharomyces pombe, one of the simplest model organisms of eukaryotes. We consider a simple model consist- ing of pairs of homologous polymers with the same structures that are confined in a cylindrical container, which represents the local parts of chromosomes contained in an elongated nucleus of S. pombe. Brownian dynamics simulations of this model showed that the excluded volume effects among non-homological chromosomes and the transitional dynamics of nuclear shape serve to enhance the pairing of homologous chromosomes.

  17. Nature of strong hole pairing in doped Mott antiferromagnets.

    Science.gov (United States)

    Zhu, Zheng; Jiang, Hong-Chen; Sheng, D N; Weng, Zheng-Yu

    2014-01-01

    Cooper pairing instability in a Fermi liquid is well understood by the BCS theory, but pairing mechanism for doped Mott insulators still remains elusive. Previously it has been shown by density matrix renormalization group (DMRG) method that a single doped hole is always self-localized due to the quantum destructive interference of the phase string signs hidden in the t-J ladders. Here we report a DMRG investigation of hole binding in the same model, where a novel pairing-glue scheme beyond the BCS realm is discovered. Specifically, we show that, in addition to spin pairing due to superexchange interaction, the strong frustration of the phase string signs on the kinetic energy gets effectively removed by pairing the charges, which results in strong binding of two holes. By contrast, if the phase string signs are "switched off" artificially, the pairing strength diminishes significantly even if the superexchange coupling remains the same. In the latter, unpaired holes behave like coherent quasiparticles with pairing drastically weakened, whose sole origin may be attributed to the resonating-valence-bond (RVB) pairing of spins. Such non-BCS pairing mechanism is therefore beyond the RVB picture and may shed important light on the high-T(c) cuprate superconductors. PMID:24957467

  18. On the interpolation properties of certain quasilinearizable pairs

    International Nuclear Information System (INIS)

    For a quasilinearizable pair of reflexive spaces {A0,A1}, the interpolation properties of the derived pair {A0+A1, A0 intersection A1} are studied. A real interpolation formula is proved that connects the interpolation spaces of the pairs {A0,A1} and {A0+A1, A0 intersection A1}. In particular, it turns out that the corresponding interpolation spaces coincide for θ1/2 . The results are applied to generalized Nikol'skii-Besov spaces (the quasilinearizability of a pair {Bp,q1(μ0), Bp,q1(μ1)} of such spaces is proved beforehand)

  19. Ion-pair formation in electron recombination with molecular ions

    International Nuclear Information System (INIS)

    By studying ion-pair formation in electron recombination with molecular ions, fundamental knowledge on the molecular dynamics can be obtained. In order to study these types of reactions, both the electron recombination as well as the dynamics all the way to the asymptotic limits must be well described. We have used the wave packet technique to study ion-pair formation in electron recombination with HeH+, HD+, H3+ and HF+. We here discuss what will determine the general shape of the ion-pair cross section, the threshold effects, possible interference effects as well as the ratio of the cross sections of ion-pair formation to dissociative recombination

  20. On the random sampling of pairs, with pedestrian examples

    OpenAIRE

    Arratia, Richard; DeSalvo, Stephen

    2015-01-01

    Suppose one desires to randomly sample a pair of objects such as socks, hoping to get a matching pair. Even in the simplest situation for sampling, which is sampling with replacement, the innocent phrase "the distribution of the color of a matching pair" is ambiguous. One interpretation is that we condition on the event of getting a match between two random socks; this corresponds to sampling two at a time, over and over without memory, until a matching pair is found. A second interpretation ...

  1. Effective t-J model of pairing: singlet versus triplet

    Directory of Open Access Journals (Sweden)

    J.Spałek

    2008-09-01

    Full Text Available The t-J model is regarded as a canonical model of spin-singlet pairing induced by the kinetic exchange interaction also responsible for an antiferromagnetic ordering in the strongly correlated narrow-band systems. In the orbitally degenerate systems both ferromagnetic and antiferromagnetic kinetic exchange interactions occur. I briefly review the analogy between the singlet and triplet types of pairing, as well as draw some general conclusions about the pairing induced by these exchange interactions. The general discussion is also illustrated with a concrete case of a two-dimensional lattice with the spin triplet pairing.

  2. Communication: Improved pair approximations in local coupled-cluster methods

    International Nuclear Information System (INIS)

    In local coupled cluster treatments the electron pairs can be classified according to the magnitude of their energy contributions or distances into strong, close, weak, and distant pairs. Different approximations are introduced for the latter three classes. In this communication, an improved simplified treatment of close and weak pairs is proposed, which is based on long-range cancellations of individually slowly decaying contributions in the amplitude equations. Benchmark calculations for correlation, reaction, and activation energies demonstrate that these approximations work extremely well, while pair approximations based on local second-order Møller-Plesset theory can lead to errors that are 1-2 orders of magnitude larger

  3. Mated Fingerprint Card Pairs (Volumes 1-5)

    Science.gov (United States)

    NIST Mated Fingerprint Card Pairs (Volumes 1-5) (PC database for purchase)   The NIST database of mated fingerprint card pairs (Special Database 9) consists of multiple volumes. Currently five volumes have been released. Each volume will be a 3-disk set with each CD-ROM containing 90 mated card pairs of segmented 8-bit gray scale fingerprint images (900 fingerprint image pairs per CD-ROM). A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

  4. Alexander-equivalent Zariski pairs of irreducible sextics

    DEFF Research Database (Denmark)

    Eyral, Christophe; Oka, Mutsuo

    2009-01-01

    The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by Degtyarev. However, no explicit example of such a pair is available (only the existence is known) in the literature. In this paper, we construct the first concrete example.......The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by Degtyarev. However, no explicit example of such a pair is available (only the existence is known) in the literature. In this paper, we construct the first concrete example....

  5. DSAM lifetime measurements for the chiral pair in 194Tl

    International Nuclear Information System (INIS)

    Most important for the identification of chiral symmetry in atomic nuclei is to establish a pair of bands that are near-degenerate in energy, but also in B(M1) and B(E2) transition probabilities. Dedicated lifetime measurements were performed for four bands of 194Tl, including the pair of four-quasiparticle chiral bands with close near-degeneracy, considered as a prime candidate for best chiral symmetry pair. The lifetime measurements confirm the excellent near-degeneracy in this pair and indicate that a third band may be involved in the chiral symmetry scenario. (orig.)

  6. Nucleon-pair approximation to the nuclear shell model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.M., E-mail: ymzhao@sjtu.edu.cn [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Arima, A. [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Musashi Gakuen, 1-26-1 Toyotamakami Nerima-ku, Tokyo 176-8533 (Japan)

    2014-12-01

    Atomic nuclei are complex systems of nucleons–protons and neutrons. Nucleons interact with each other via an attractive and short-range force. This feature of the interaction leads to a pattern of dominantly monopole and quadrupole correlations between like particles (i.e., proton–proton and neutron–neutron correlations) in low-lying states of atomic nuclei. As a consequence, among dozens or even hundreds of possible types of nucleon pairs, very few nucleon pairs such as proton and neutron pairs with spin zero, two (in some cases spin four), and occasionally isoscalar spin-aligned proton–neutron pairs, play important roles in low-energy nuclear structure. The nucleon-pair approximation therefore provides us with an efficient truncation scheme of the full shell model configurations which are otherwise too large to handle for medium and heavy nuclei in foreseeable future. Furthermore, the nucleon-pair approximation leads to simple pictures in physics, as the dimension of nucleon-pair subspace is always small. The present paper aims at a sound review of its history, formulation, validity, applications, as well as its link to previous approaches, with the focus on the new developments in the last two decades. The applicability of the nucleon-pair approximation and numerical calculations of low-lying states for realistic atomic nuclei are demonstrated with examples. Applications of pair approximations to other problems are also discussed.

  7. Stereo Pair, Salt Lake City, Utah

    Science.gov (United States)

    2002-01-01

    The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This image pair provides a stereoscopic map view of north central Utah that includes all of these Olympic sites. In the south, next to Utah Lake, Provo hosts the ice hockey competition. In the north, northeast of the Great Salt Lake, Ogden hosts curling and the nearby Snowbasin ski area hosts the downhill events. In between, southeast of the Great Salt Lake, Salt Lake City hosts the Olympic Village and the various skating events. Further east, across the Wasatch Mountains, the Park City ski resort hosts the bobsled, ski jumping, and snowboarding events. The Winter Olympics are always hosted in mountainous terrain. This view shows the dramatic landscape that makes the Salt Lake City region a world-class center for winter sports.This stereoscopic image was generated by draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR

  8. Modification of pion pairs in nuclear matter

    International Nuclear Information System (INIS)

    In this work the quasifree photoproduction of pion pairs on bound nucleons is analyzed for the solid targets carbon, calcium and lead. These measurements allow an isospin dependent determination of the in medium properties of pion pairs. The invariant mass distributions showed a shift in strength towards the threshold region with increasing atomic number of the targets in case of an isoscalar ππ meson system. According to theoretical predictions this effect was interpreted as a positive signature of a partial restoration of chiral symmetry. A pioneering experiment with photon beams was performed by the TAPS collaboration at the accelerator facility MAMI-B in Mainz in 1995. This measurement observed an invariant mass shift of the isoscalar π0π0 channel with increasing atomic number. In the π±π0 channel this effect was not observed. This observation confirmed the former experiments, since final state interactions of the pions would affect in first order both isospin channels in a similar way. Due to the poor statistics, the significance of the data was however limited. The experiment described in this work reached a much higher statistical significance, allowing a review of the old data and a study of the dependence of the signal from parameters like the momenta of the ππ system or the single pions. In this experiment, the TAPS detector was used as a forward wall in combination with the Crystal Ball detector to achieve a 4π solid angle coverage for photon detection at the MAMI accelerator facility. The new readout electronics for the BaF2 crystals was used for the first time. The new data analysis confirms the previously measured and published data. However, the shift of the invariant π0π0 mass to the threshold region is less pronounced than in the published data. By performing cuts on the individual pion momenta, resulting in a maximum mean free path of the pions, the shift towards lower masses is enhanced. BUU transport calculations can not describe the

  9. Hidden Pair of Supermassive Black Holes

    Science.gov (United States)

    Kohler, Susanna

    2015-08-01

    Could a pair of supermassive black holes (SMBHs) be lurking at the center of the galaxy Mrk 231? A recent study finds that this may be the case and the unique spectrum of this galaxy could be the key to discovering more hidden binary SMBH systems.Where Are the Binary Supermassive Black Holes?Its believed that most, if not all, galaxies have an SMBH at their centers. As two galaxies merge, the two SMBHs should evolve into a closely-bound binary system before they eventually merge. Given the abundance of galaxy mergers, we would expect to see the kinematic and visual signatures of these binary SMBHs among observed active galactic nuclei yet such evidence for sub-parsec binary SMBH systems remains scarce and ambiguous. This has led researchers to wonder: is there another way that we might detect these elusive systems?A collaboration led by Chang-Shuo Yan (National Astronomical Observatories, Chinese Academy of Sciences) thinks that there is. The group suggests that these systems might have distinct signatures in their optical-to-UV spectra, and they identify a system that might be just such a candidate: Mrk 231.A Binary CandidateProposed model of Mrk 231. Two supermassive black holes, each with their own mini-disk, orbit each other in the center of a circumbinary disk. The secondary black hole has cleared gap in the circumbinary disk as a result of its orbit around the primary black hole. [Yan et al. 2015]Mrk 231 is a galaxy with a disturbed morphology and tidal tails strong clues that it might be in the final stages of a galactic merger. In addition to these signs, Mrk 231 also has an unusual spectrum for a quasar: its continuum emission displays an unexpected drop in the near-UV band.Yan and her collaborators propose that the odd behavior of Mrk 231s spectrum can be explained if the center of the galaxy houses a pair of SMBHs each with its own mini accretion disk surrounded by a circumbinary accretion disk. As the secondary SMBH orbits the primary SMBH (with a

  10. Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

    Energy Technology Data Exchange (ETDEWEB)

    Murray, A.M.

    1999-02-10

    This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS).

  11. Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

    International Nuclear Information System (INIS)

    This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS)

  12. HYDROTHERMAL CRACKING OF RESIDUAL OILS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrothermal cracking of heavy oils, such as Canadian oil sand bitumen and Arabian heavy vacuum residue, as well as their model compound were performed over sulfided Ni/Al2O3 and NiMo/Al2O3 catalysts under 663~703 K and 6.0~8.0 MPa of hydrogen pressure in a batch autoclave reactor. According to the reaction mechanism of hydrothermal cracking, a small amount of free redical initiators, such as di-tert-peroxide, sulfur, etc., was added into the feed to generate free redicals at lower temperature, and obviously showed promotional effect on the conversion of hydrocarbons. The reaction mechanisms of hydrothermal cracking as well as the enhancing effect of initiators were studied by a probe reaction with 1-phenyldodecane as a model compound. The hydrothermal cracking of hydrocarbon proceeded via free redical mechanism and hydrogenating quench. The initiators might easily generate free redicals under reaction temperature, these redicals might abstract H from hydrocarbon molecule and reasonably initiate the chain reactions, therefore, promote the conversion of hydrocarbon even at lower reaction temperature.

  13. Thermal Insulation from Hardwood Residues

    Science.gov (United States)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  14. Expanding the Horizons of Educational Pair Programming: A Methodological Review of Pair Programming in Computer Science Education Research

    OpenAIRE

    Rimington, Keith B.

    2010-01-01

    Educators and researchers continue to explore the benefits, real or imagined, of implementing pair programming as part of the computer science pedagogy. Current reviews of computer science educational research practices do not focus on educational pair programming. This thesis presents a review of the research methods used in recent educational pair programming research. The primary purpose of this review is to inform the ongoing dialogue about and to provide evidence-based recommendations fo...

  15. Crop Residues: The Rest of the Story

    Science.gov (United States)

    A recent scientific publication stated that to remove CO2 from the atmosphere, the most permanent and rapid solution would be to sink crop residues to the ocean floor where they would be buried in deep ocean sediments. However, mitigating rising atmospheric CO2 concentrations by removing crop residu...

  16. Soil water evaporation and crop residues

    Science.gov (United States)

    Crop residues have value when left in the field and also when removed from the field and sold as a commodity. Reducing soil water evaporation (E) is one of the benefits of leaving crop residues in place. E was measured beneath a corn canopy at the soil suface with nearly full coverage by corn stover...

  17. RECOVERY OF URANIUM VALUES FROM RESIDUES

    Science.gov (United States)

    Schaap, W.B.

    1959-08-18

    A process is described for the recovery of uranium from insoluble oxide residues resistant to repeated leaching with mineral acids. The residue is treated with gaseous hydrogen fluoride, then with hydrogen and again with hydrogen fluoride, preferably at 500 to 700 deg C, prior to the mineral acid leaching.

  18. Densification of FL Chains via Residuated Frames

    Czech Academy of Sciences Publication Activity Database

    Baldi, Paolo; Terui, K.

    2016-01-01

    Roč. 75, č. 2 (2016), s. 169-195. ISSN 0002-5240 R&D Projects: GA ČR GAP202/10/1826 Keywords : densifiability * standard completeness * residuated lattices * residuated frames * fuzzy logic Subject RIV: BA - General Mathematics Impact factor: 0.442, year: 2014

  19. Word Problem for Knotted Residuated Lattices

    Czech Academy of Sciences Publication Activity Database

    Horčík, Rostislav

    2015-01-01

    Roč. 219, č. 5 (2015), s. 1548-1563. ISSN 0022-4049 R&D Projects: GA ČR GAP202/11/1632 Institutional support: RVO:67985807 Keywords : residuated lattice * knotted rule * word problem * residuated frame * semi-Thue system * square-free word Subject RIV: BA - General Mathematics Impact factor: 0.474, year: 2014

  20. Distribution of veterinary drug residues among muscles

    Science.gov (United States)

    The U.S. Food and Drug Administration sets tolerances for veterinary drug residues in muscle, but does not specify which muscle should be sampled for analysis. The goal of this research was to determine if antibiotic residue levels are dependent on muscle type. In this study, penicillin G (Pen G) d...