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Sample records for nlo dglap evolution

  1. Decoupling the NLO-coupled QED⊗QCD, DGLAP evolution equations, using Laplace transform method

    NASA Astrophysics Data System (ADS)

    Mottaghizadeh, Marzieh; Eslami, Parvin; Taghavi-Shahri, Fatemeh

    2017-05-01

    We analytically solved the QED⊗QCD-coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next-to-leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform method and then computed the proton structure function in terms of the unpolarized parton distribution functions. Our analytical solutions for parton densities are in good agreement with those from CT14QED (1.2952 < Q2 < 1010) (Ref. 6) global parametrizations and APFEL (A PDF Evolution Library) (2 < Q2 < 108) (Ref. 4). We also compared the proton structure function, F2p(x,Q2), with the experimental data released by the ZEUS and H1 collaborations at HERA. There is a nice agreement between them in the range of low and high x and Q2.

  2. Analytical solutions of the QCD⊗QED DGLAP evolution equations based on the Mellin transform technique in NLO approximation

    NASA Astrophysics Data System (ADS)

    Mottaghizadeh, Marzieh; Taghavi Shahri, Fatemeh; Eslami, Parvin

    2017-10-01

    In this paper we present a new and efficient analytical solutions for evolving the QCD⊗QED DGLAP evolution equations in Mellin space and obtain the parton distribution functions (PDFs) in perturbative QCD including the QED corrections. The validity of our analytical solutions, which have done in the next to leading order QCD and the leading order QED approximations, are checked with the initial parton distributions from newly released CT14QED global analysis code (Schmidt et al., 2016 [9]). The evolved parton distribution functions are in good agreement with CT14QED PDFs set and also with those from APFEL (Bertone et al., 2014 [7]) program. Finally, we derived the impact of the NLO QED corrections to the QCD⊗QED DGLAP evolution equations.

  3. Solution of QCD⊗QED coupled DGLAP equations at NLO

    NASA Astrophysics Data System (ADS)

    Zarrin, S.; Boroun, G. R.

    2017-09-01

    In this work, we present an analytical solution for QCD⊗QED coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at the leading order (LO) accuracy in QED and next-to-leading order (NLO) accuracy in perturbative QCD using double Laplace transform. This technique is applied to obtain the singlet, gluon and photon distribution functions and also the proton structure function. We also obtain contribution of photon in proton at LO and NLO at high energy and successfully compare the proton structure function with HERA data [1] and APFEL results [2]. Some comparisons also have been done for the singlet and gluon distribution functions with the MSTW results [3]. In addition, the contribution of photon distribution function inside the proton has been compared with results of MRST [4] and with the contribution of sea quark distribution functions which obtained by MSTW [3] and CTEQ6M [5].

  4. Phenomenological study of the interplay between IR-improved DGLAP-CS theory and the precision of an NLO ME matched parton shower MC

    SciTech Connect

    Majhi, S.K.; Mukhopadhyay, A.; Ward, B.F.L.; Yost, S.A.

    2014-11-15

    We present a phenomenological study of the current status of the application of our approach of exact amplitude-based resummation in quantum field theory to precision QCD calculations, by realistic MC event generator methods, as needed for precision LHC physics. We discuss recent results as they relate to the interplay of the attendant IR-improved DGLAP-CS theory of one of us and the precision of exact NLO matrix-element matched parton shower MC’s in the Herwig6.5 environment as determined by comparison to recent LHC experimental observations on single heavy gauge boson production and decay. The level of agreement between the new theory and the data continues to be a reason for optimism. In the spirit of completeness, we discuss as well other approaches to the same theoretical predictions that we make here from the standpoint of physical precision with an eye toward the (sub-)1% QCD⊗EW total theoretical precision regime for LHC physics. - Highlights: • Using LHC data, we show that IR-improved DGLAP-CS kernels with exact NLO Shower/ME matching improves MC precision. • We discuss other possible approaches in comparison with ours. • We propose experimental tests to discriminate between competing approaches.

  5. NLO evolution of color dipoles

    SciTech Connect

    Ian Balitsky; Giovanni Chirilli

    2008-01-01

    The small-x deep inelastic scattering in the saturation region is governed by the non-linear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the BK equation for the evolution of color dipoles. In the next-to-leaing order the BK equation gets contributions from quark and gluon loops as well as from the tree gluon diagrams with quadratic and cubic nonlinearities. We calculate the gluon contribution to small-x evolution of Wilson lines (the quark part was obtained earlier).

  6. Decoupling of the DGLAP evolution equations at next-to-next-to-leading order (NNLO) at low- x

    NASA Astrophysics Data System (ADS)

    Boroun, G. R.; Rezaei, B.

    2013-05-01

    We present a set of formulas to extract two second-order independent differential equations for the gluon and singlet distribution functions. Our results extend from the LO up to NNLO DGLAP evolution equations with respect to the hard-Pomeron behavior at low- x. In this approach, both singlet quarks and gluons have the same high-energy behavior at low- x. We solve the independent DGLAP evolution equations for the functions F2s(x,Q2) and G( x, Q 2) as a function of their initial parameterization at the starting scale Q02. The results not only give striking support to the hard-Pomeron description of the low- x behavior, but give a rather clean test of perturbative QCD showing an increase of the gluon distribution and singlet structure functions as x decreases. We compared our numerical results with the published BDM (Block et al. Phys. Rev. D 77:094003 (2008)) gluon and singlet distributions, starting from their initial values at Q02=1 GeV2.

  7. The Green function for the BFKL pomeron and the transition to DGLAP evolution

    NASA Astrophysics Data System (ADS)

    Kowalski, H.; Lipatov, L. N.; Ross, D. A.

    2014-06-01

    We consider the (process-independent) Green function for the BFKL equation with running coupling, and explain how, within the semi-classical approximation, it is related to Green function of the Airy equation. The unique Green function is obtained from a combination of its required ultraviolet behaviour compatible with asymptotic freedom and an infrared limit phase imposed by the non-perturbative sector of QCD. We show that at sufficiently large gluon transverse momenta the corresponding gluon density matches that of the DGLAP analysis, whereas for relatively small values of the gluon transverse momentum the gluon distribution is sensitive to the Regge poles, whose positions are determined both by the non-perturbative QCD dynamics and physics at large transverse momenta.

  8. NLO evolution of color dipoles in N=4 SYM

    SciTech Connect

    Balitsky, Ian; Chirilli, Giovanni

    2009-01-01

    High-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal ${\\cal N}$=4 SYM theory. We define the ``composite dipole operator' with the rapidity cutoff preserving conformal invariance. The resulting M\\"obius invariant kernel agrees with the forward NLO BFKL calculation of Ref. 1

  9. NLO Hierarchy of Wilson Lines Evolution

    SciTech Connect

    Balitsky, Ian

    2015-03-01

    The high-energy behavior of QCD amplitudes can be described in terms of the rapidity evolution of Wilson lines. I present the hierarchy of evolution equations for Wilson lines in the next-to-leading order.

  10. NLO evolution of color dipoles in N=4 SYM

    SciTech Connect

    Chirilli, Giovanni A.; Balitsky, Ian

    2009-07-04

    Here, high-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal ${\\cal N}$=4 SYM theory. We define the "composite dipole operator" with the rapidity cutoff preserving conformal invariance.

  11. NLO evolution of 3-quark Wilson loop operator

    SciTech Connect

    Balitsky, I.; Grabovsky, A. V.

    2015-01-07

    It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in the next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. Thus we also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.

  12. NLO evolution of 3-quark Wilson loop operator

    DOE PAGES

    Balitsky, I.; Grabovsky, A. V.

    2015-01-07

    It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in themore » next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. Thus we also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.« less

  13. NLO evolution of color dipoles in N=4 SYM

    DOE PAGES

    Chirilli, Giovanni A.; Balitsky, Ian

    2009-07-04

    Here, high-energy behavior of amplitudes in a gauge theory can be reformulated in terms of the evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the conformally invariant BK equation for the evolution of color dipoles. In QCD, the next-to-leading order BK equation has both conformal and non-conformal parts, the latter providing the running of the coupling constant. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformalmore » $${\\cal N}$$=4 SYM theory. We define the "composite dipole operator" with the rapidity cutoff preserving conformal invariance.« less

  14. Resummation of soft gluon logarithms in the DGLAP evolution of fragmentation functions

    SciTech Connect

    Albino, S.; Kniehl, B.A.; Kramer, G.; Ochs, W.

    2006-03-01

    We define a general scheme for the evolution of fragmentation functions which resums both soft gluon logarithms and mass singularities in a consistent manner and to any order, and requires no additional theoretical assumptions. Using the double logarithmic approximation and the known perturbative results for the splitting functions, we present our scheme with the complete contribution from the double logarithms, being the largest soft gluon logarithms. We show that the resulting approximation is more complete than the modified leading logarithm approximation even with the fixed order contribution calculated to leading order only, and find, after using it to fit quark and gluon fragmentation functions to experimental data, that this approximation in our scheme gives a good description of the data from the largest x{sub p} values to the peak region in {xi}=ln(1/x{sub p}), in contrast to other approximations. In addition, we develop a treatment of hadron mass effects which gives additional improvements at large {xi}.

  15. Resummation of soft gluon logarithms in the DGLAP evolution of fragmentation functions

    NASA Astrophysics Data System (ADS)

    Albino, S.; Kniehl, B. A.; Kramer, G.; Ochs, W.

    2006-03-01

    We define a general scheme for the evolution of fragmentation functions which resums both soft gluon logarithms and mass singularities in a consistent manner and to any order, and requires no additional theoretical assumptions. Using the double logarithmic approximation and the known perturbative results for the splitting functions, we present our scheme with the complete contribution from the double logarithms, being the largest soft gluon logarithms. We show that the resulting approximation is more complete than the modified leading logarithm approximation even with the fixed order contribution calculated to leading order only, and find, after using it to fit quark and gluon fragmentation functions to experimental data, that this approximation in our scheme gives a good description of the data from the largest xp values to the peak region in ξ=ln⁡(1/xp), in contrast to other approximations. In addition, we develop a treatment of hadron mass effects which gives additional improvements at large ξ.

  16. IR-Improved DGLAP-CS Theory

    DOE PAGES

    Ward, B. F. L.

    2008-01-01

    We show that it is possible to improve the infrared aspects of the standard treatment of the DGLAP-CS evolution theory to take into account a large class of higher-order corrections that significantly improve the precision of the theory for any given level of fixed-order calculation of its respective kernels. We illustrate the size of the effects we resum using the moments of the parton distributions.

  17. Numerical solution of DGLAP equations using Laguerre polynomials expansion and Monte Carlo method.

    PubMed

    Ghasempour Nesheli, A; Mirjalili, A; Yazdanpanah, M M

    2016-01-01

    We investigate the numerical solutions of the DGLAP evolution equations at the LO and NLO approximations, using the Laguerre polynomials expansion. The theoretical framework is based on Furmanski et al.'s articles. What makes the content of this paper different from other works, is that all calculations in the whole stages to extract the evolved parton distributions, are done numerically. The employed techniques to do the numerical solutions, based on Monte Carlo method, has this feature that all the results are obtained in a proper wall clock time by computer. The algorithms are implemented in FORTRAN and the employed coding ideas can be used in other numerical computations as well. Our results for the evolved parton densities are in good agreement with some phenomenological models. They also indicate better behavior with respect to the results of similar numerical calculations.

  18. Markovian Monte Carlo program EvolFMC v.2 for solving QCD evolution equations

    NASA Astrophysics Data System (ADS)

    Jadach, S.; Płaczek, W.; Skrzypek, M.; Stokłosa, P.

    2010-02-01

    We present the program EvolFMC v.2 that solves the evolution equations in QCD for the parton momentum distributions by means of the Monte Carlo technique based on the Markovian process. The program solves the DGLAP-type evolution as well as modified-DGLAP ones. In both cases the evolution can be performed in the LO or NLO approximation. The quarks are treated as massless. The overall technical precision of the code has been established at 5×10. This way, for the first time ever, we demonstrate that with the Monte Carlo method one can solve the evolution equations with precision comparable to the other numerical methods. New version program summaryProgram title: EvolFMC v.2 Catalogue identifier: AEFN_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFN_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including binary test data, etc.: 66 456 (7407 lines of C++ code) No. of bytes in distributed program, including test data, etc.: 412 752 Distribution format: tar.gz Programming language: C++ Computer: PC, Mac Operating system: Linux, Mac OS X RAM: Less than 256 MB Classification: 11.5 External routines: ROOT ( http://root.cern.ch/drupal/) Nature of problem: Solution of the QCD evolution equations for the parton momentum distributions of the DGLAP- and modified-DGLAP-type in the LO and NLO approximations. Solution method: Monte Carlo simulation of the Markovian process of a multiple emission of partons. Restrictions:Limited to the case of massless partons. Implemented in the LO and NLO approximations only. Weighted events only. Unusual features: Modified-DGLAP evolutions included up to the NLO level. Additional comments: Technical precision established at 5×10. Running time: For the 10 6 events at 100 GeV: DGLAP NLO: 27s; C-type modified DGLAP NLO: 150s (MacBook Pro with Mac OS X v.10

  19. Energy evolution of the moments of the hadron distribution in QCD jets including NNLL resummation and NLO running-coupling corrections

    NASA Astrophysics Data System (ADS)

    Pérez-Ramos, Redamy; d'Enterria, David

    2014-08-01

    The moments of the single inclusive momentum distribution of hadrons in QCD jets, are studied in the next-to-modified-leading-log approximation (NMLLA) including next-to-leading-order (NLO) corrections to the αs strong coupling. The evolution equations are solved using a distorted Gaussian parametrisation, which successfully reproduces the spectrum of charged hadrons of jets measured in e + e - collisions. The energy dependencies of the maximum peak, multiplicity, width, kurtosis and skewness of the jet hadron distribution are computed analytically. Comparisons of all the existing jet data measured in e + e - collisions in the range GeV to the NMLLA + NLO* predictions allow one to extract a value of the QCD parameter ΛQCD , and associated two-loop coupling constant at the Z resonance α s(m{Z/2}) = 0.1195 ± 0.0022, in excellent numerical agreement with the current world average obtained using other methods.

  20. Numerical solution of Q evolution equations for fragmentation functions

    NASA Astrophysics Data System (ADS)

    Hirai, M.; Kumano, S.

    2012-04-01

    Semi-inclusive hadron-production processes are becoming important in high-energy hadron reactions. They are used for investigating properties of quark-hadron matters in heavy-ion collisions, for finding the origin of nucleon spin in polarized lepton-nucleon and nucleon-nucleon reactions, and possibly for finding exotic hadrons. In describing the hadron-production cross sections in high-energy reactions, fragmentation functions are essential quantities. A fragmentation function indicates the probability of producing a hadron from a parton in the leading order of the running coupling constant αs. Its Q dependence is described by the standard DGLAP (Dokshitzer-Gribov-Lipatov-Altarelli-Parisi) evolution equations, which are often used in theoretical and experimental analyses of the fragmentation functions and in calculating semi-inclusive cross sections. The DGLAP equations are complicated integro-differential equations, which cannot be solved in an analytical method. In this work, a simple method is employed for solving the evolution equations by using Gauss-Legendre quadrature for evaluating integrals, and a useful code is provided for calculating the Q evolution of the fragmentation functions in the leading order (LO) and next-to-leading order (NLO) of αs. The renormalization scheme is MSbar in the NLO evolution. Our evolution code is explained for using it in one's studies on the fragmentation functions. Catalogue identifier: AELJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELJ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1535 No. of bytes in distributed program, including test data, etc.: 10 191 Distribution format: tar.gz Programming language: Fortran77 Computer: Tested on an HP DL360G5-DC-X5160 Operating system: Linux 2.6.9-42.ELsmp RAM: 130 M

  1. Small-x DIS in NLO

    SciTech Connect

    Ian Balitsky

    2011-04-01

    Deep inelastic scattering in the saturation region (for small $x$ and/or large nucleus) is described by the evolution of color dipoles. In the leading order this evolution is governed by the non-linear BK equation. To see if this equation is relevant for existing or future DIS accelerators (like EIC or LHeC) one needs to know how big are the next-to-leading order (NLO) corrections. I review the calculation of the NLO corrections to high-energy amplitudes in QCD.

  2. Dynamical parton distributions from DGLAP equations with nonlinear corrections

    NASA Astrophysics Data System (ADS)

    Wang, Rong; Chen, Xu-Rong

    2017-05-01

    Determination of proton parton distribution functions is presented under the dynamical parton model assumption by applying DGLAP equations with GLR-MQ-ZRS corrections. We provide two data sets, referred to as IMParton16, which are from two different nonperturbative inputs. One is the naive input of three valence quarks and the other is the input of three valence quarks with flavor-asymmetric sea components. Basically, both data sets are compatible with the experimental measurements at high scale (Q 2 > 2 GeV2). Furthermore, our analysis shows that the input with flavor-asymmetric sea components better reproduces the structure functions at high Q 2. Generally, the parton distribution functions obtained, especially the gluon distribution function, are good options for inputs to simulations of high energy scattering processes. The analysis is performed under the fixed-flavor number scheme for n f = 3, 4, 5. Both data sets start from very low scales, around 0.07 GeV2, where the nonperturbative input is directly connected to the simple picture of the quark model. These results may shed some lights on the origin of the parton distributions observed at high Q 2. Supported by National Basic Research Program (973 Program 2014CB845406) and Century Program of Chinese Academy of Sciences (Y101020BR0)

  3. Monte Carlo simulations using infrared improved DGLAP-CS theory

    NASA Astrophysics Data System (ADS)

    Joseph, Samuel J.

    A large number of Z and W bosons will be produced at the LHC. A careful study of their properties in the presence of QCD background processes, will be important in studying the Standard Model more rigorously and to uncover new physics which may appear through radiative corrections or through new tree level processes with suppressed couplings. In order to reach the 1% attendant theoretical precision tag on processes such as single Z and W production, more precise Monte Carlos need to be developed. As a step towards this goal a new set of infrared (ir) improved DGLAP-CS kernels was developed by Ward. For this work we implemented these infrared improved kernels in HERWIG6.5 to create a new program HERWIRI1.0. We discuss the phenomological implications of our new Monte Carlo HERWIRI1.0. Specifically we compared pp → 2-jets + X and pp → Z/gamma* + X → ℓ+ℓ- + X', with ℓ = e, mu, results obtained by HERWIG6.5 and HERWIRI1.0. The three main quantities that we compared were the pt, energy fraction and rapidity distributions. We made these comparisons at s = 14 TeV, the highest LHC energies. Comparisons were also made for pi + production in pp → 2-jets + X at this energy. As expected, the IR-improved spectra were generally softer. As a test of HERWIRI1.0 a comparison of the pt and rapidity distribution data from FNAL at s = 1.96 TeV for the process pp¯ → Z/gamma* → e+e - + X was made. We found that the softer part of these observed spectra were better described by HERWIRI1.0. This represents a new chapter in precision Monte Carlo simulations for hadron-hadron high energy collisions because the IR-improved kernels do not require an explicit cut-off.

  4. Helac-Nlo

    NASA Astrophysics Data System (ADS)

    Bevilacqua, G.; Czakon, M.; Garzelli, M. V.; van Hameren, A.; Kardos, A.; Papadopoulos, C. G.; Pittau, R.; Worek, M.

    2013-03-01

    Based on the OPP technique and the HELAC framework, HELAC-1LOOP is a program that is capable of numerically evaluating QCD virtual corrections to scattering amplitudes. A detailed presentation of the algorithm is given, along with instructions to run the code and benchmark results. The program is part of the HELAC-NLO framework that allows for a complete evaluation of QCD NLO corrections. Catalogue identifier: AEOC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 290945 No. of bytes in distributed program, including test data, etc.: 3013326 Distribution format: tar.gz Programming language: Fortran (gfortran(http://gcc.gnu.org/fortran/), lahey95 (http://www.lahey.com), ifort3(http://software.intel.com)). Computer: Any. Operating system: Linux, Unix, Mac OS. Classification: 11.1. Nature of problem: The evaluation of virtual one-loop amplitudes for multi-particle scattering is a long-standing problem [1]. In recent years the OPP reduction technique [2] opened the road for a fully numerical approach based on the evaluation of the one-loop amplitude for well-defined values of the loop momentum. Solution method: By using HELAC [3-5] and CutTools [6], HELAC-1LOOP is capable of evaluating QCD virtual corrections [7]. The one-loop n-particle amplitudes are constructed as part of the n+2 tree-order ones, by using the basic recursive algorithm used in HELAC. A Les Houches Event (LHE) file is produced, combining the complete information from tree-order and virtual one-loop contributions. In conjunction with real corrections, obtained with the use of HELAC-DIPOLES [8], the full NLO corrections can be computed. The program has been successfully used in many applications.

  5. Second-order NLO responses of two-cavity inorganic electrides Lin@B20H26 (n = 1, 2): evolutions with increasing excess electron number and various B-B connection sites of B20H26.

    PubMed

    Ma, Nana; Gong, Jinjin; Li, Shujun; Zhang, Jie; Qiu, Yongqing; Zhang, Guisheng

    2017-01-18

    Confining excess electrons in a specific space is an effective strategy to design nonlinear optical (NLO) molecules. The complexants with excess electrons are usually organic compounds, but these compounds are thermally unstable and thus hardly meet the processing requirements of NLO materials. To obtain better thermostability and NLO response molecules, in this work, inorganic compounds of B20H26 isomers containing two cavities were proposed. With the two included cavities, B20H26 can be doped by one or two Li atoms to form electrides of Li@B20H26 and Li2@B20H26. These electrides show larger NLO responses, with respect to the corresponding undoped complexant of B20H26. Particularly, Li2@B20H26 has the largest β0 value of 108 846 a.u. (MP2/6-31+G(d) level) that is 850 times as large as that of corresponding B20H26. Moreover, the change of β0 values with excess electron number is remarkable for two of the isomers, and differences between the β0 values among those isomers are also significant owing to various B-B connection sites between the two cavities. Therefore, the present inorganic electrides have not only better performance due to the magnitude of their β0 values but also better behavior on the molecular-level modulation of NLO.

  6. Photon impact factor in the NLO

    SciTech Connect

    Balitsky, Ian

    2013-04-01

    The photon impact factor for the BFKL pomeron is calculated in the next-to-leading order (NLO) approximation using the operator expansion in Wilson lines. The result is represented as a NLO k{sub T}-factorization formula for the structure functions of small-x deep inelastic scattering.

  7. QCD parton showers and NLO EW corrections to Drell-Yan

    NASA Astrophysics Data System (ADS)

    Richardson, Peter; Sadykov, Renat R.; Sapronov, Andrey A.; Seymour, Michael H.; Skands, Peter Z.

    2012-06-01

    We report on the implementation of an interface between the SANC generator framework for Drell-Yan hard processes, which includes next-to-leading order electroweak (NLO EW) corrections, and the Herwig++ and Pythia8 QCD parton shower Monte Carlos. A special aspect of this implementation is that the initial-state shower evolution in both shower generators has been augmented to handle the case of an incoming photon-in-a- proton, diagrams for which appear at the NLO EW level. The difference between shower algorithms leads to residual differences in the relative corrections of 2-3 % in the p T ( μ) distributions at p T ( μ) ≳ 50 GeV (where the NLO EW correction itself is of order 10 %).

  8. Organic NLO Polymers. 5. Homopolymerization of Indole Based NLO-phore: A Heterocycle Chi(2)NLO Main-Chain Polymer

    DTIC Science & Technology

    1994-05-28

    Lackrltz" and Lee-Yin Liu 2J. 1 wje I Oi School of Chemical SA~giiaeuiat, Purdue Unioersity, Wesit NK InOR Laftbyet ,. A 479071Z26 cHOI, coa 9t Ti (Os3...o /co m. c~ Introduction The design and synthesis of nw NLO materials for i .. CbYt and bucyl optoacave device appli&ctons an be accomplished...through a 2 variety of schemne.’ Tin development of polymeric J" NLO 2Qj:Q1j’TJ materials has boen approached firom a variety od ceative Is on design

  9. NLO QCD Predictions for W+3 jets

    SciTech Connect

    Maitre, Daniel; Berger, Carola F.; Bern, Zvi; Febres Cordero, Fernando; Ita, Harald; Dixon, Lance J.; Forde, Darren; Gleisberg, Tanju; Kosower, David; /Saclay, SPhT

    2009-12-09

    In this contribution we present results from the NLO computation of the production of a W boson in association with three jets in hadronic collisions. The results are obtained by combining two programs: BlackHat for the virtual one-loop matrix elements and Sherpa for the real-emission contributions. We present results for the Tevatron and the LHC, and address the issue of the choice of a common factorization and renormalization scale for this process.

  10. Charm and bottom photoproduction at HERA with MC@NLO

    SciTech Connect

    Toll T.; Frixione, S.

    2011-12-01

    We apply the MC@NLO formalism to the production of heavy-quark pairs in pointlike photon-hadron collisions. By combining this result with its analogue relevant to hadron-hadron collisions, we obtain NLO predictions matched to parton showers for the photoproduction of Q{bar Q} pairs. We compare MC{at}NLO results to the measurements of c- and b-flavored hadron observables performed by the H1 and ZEUS Collaborations at HERA.

  11. Synthesis of Polymers Containing Covalently Bonded NLO Chromophores

    NASA Technical Reports Server (NTRS)

    Denga, Xiao-Hua; Sanghadasa, Mohan; Walton, Connie; Penn, Benjamin B.; Amai, Robert L. S.; Clark, Ronald D.

    1998-01-01

    Polymers containing covalently bonded nonlinear optical (NLO) chromophores are expected to possess special properties such as greater stability, better mechanical processing, and easier film formation than their non-polymeric equivalent. For the present work, polymethylmethacrylate (PMMA) was selected as the basic polymer unit on which to incorporate different NLO chromophores. The NLO components were variations of DIVA {[2-methoxyphenyl methylidene]-propanedinitrile} which we prepared from vanillin derivatives and malononitrile. These were esterified with methacrylic acid and polymerized either directly or with methyl methacrylate to form homopolymers or copolymers respectively. Characterization of the polymers and NLO property studies are underway.

  12. Synthesis of Polymers Containing Covalently Bonded NLO Chromophores

    NASA Technical Reports Server (NTRS)

    Denga, Xiao-Hua; Sanghadasa, Mohan; Walton, Connie; Penn, Benjamin B.; Amai, Robert L. S.; Clark, Ronald D.

    1998-01-01

    Polymers containing covalently bonded nonlinear optical (NLO) chromophores are expected to possess special properties such as greater stability, better mechanical processing, and easier film formation than their non-polymeric equivalent. For the present work, polymethylmethacrylate (PMMA) was selected as the basic polymer unit on which to incorporate different NLO chromophores. The NLO components were variations of DIVA {[2-methoxyphenyl methylidene]-propanedinitrile} which we prepared from vanillin derivatives and malononitrile. These were esterified with methacrylic acid and polymerized either directly or with methyl methacrylate to form homopolymers or copolymers respectively. Characterization of the polymers and NLO property studies are underway.

  13. QCD Evolution in Dense Medium

    NASA Astrophysics Data System (ADS)

    Gay Ducati, M. B.

    The dynamics of the partonic distribution is a main concern in high energy physics, once it provides the initial condition for the Heavy Ion colliders. The determination of the evolution equation which drives the partonic behavior is subject of great interest since is connected to the observables. This lecture aims to present a brief review of the evolution equations that describe the partonic dynamics at high energies. First the linear evolution equations (DGLAP and BFKL) are presented. Then, the formulations developed to deal with the high density effects, which originate the non-linear evolution equations (GLR, AGL, BK, JIMWLK) are discussed, as well as an example of related phenomenology.

  14. NLO error propagation exercise data collection system

    SciTech Connect

    Keisch, B.; Bieber, A.M. Jr.

    1983-01-01

    A combined automated and manual system for data collection is described. The system is suitable for collecting, storing, and retrieving data related to nuclear material control at a bulk processing facility. The system, which was applied to the NLO operated Feed Materials Production Center, was successfully demonstrated for a selected portion of the facility. The instrumentation consisted of off-the-shelf commercial equipment and provided timeliness, convenience, and efficiency in providing information for generating a material balance and performing error propagation on a sound statistical basis.

  15. NLO Jet Physics with BlackHat

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.; /Durham U.

    2010-02-15

    We present several results obtained using the BLACKHAT next-to-leading order QCD program library, in conjunction with SHERPA. In particular, we present distributions for vector boson plus 1,2,3-jet production at the Tevatron and at the asymptotic running energy of the Large Hadron Collider, including new Z + 3-jet distributions. The Z + 2-jet predictions for the second-jet P{sub T} distribution are compared to CDF data. We present the jet-emission probability at NLO in W + 2-jet events at the LHC, where the tagging jets are taken to be the ones furthest apart in pseudorapidity. We analyze further the large left-handed W{sup {+-}} polarization, identified in our previous study, for W bosons produced at high P{sub T} at the LHC.

  16. NLO error propagation exercise: statistical results

    SciTech Connect

    Pack, D.J.; Downing, D.J.

    1985-09-01

    Error propagation is the extrapolation and cumulation of uncertainty (variance) above total amounts of special nuclear material, for example, uranium or /sup 235/U, that are present in a defined location at a given time. The uncertainty results from the inevitable inexactness of individual measurements of weight, uranium concentration, /sup 235/U enrichment, etc. The extrapolated and cumulated uncertainty leads directly to quantified limits of error on inventory differences (LEIDs) for such material. The NLO error propagation exercise was planned as a field demonstration of the utilization of statistical error propagation methodology at the Feed Materials Production Center in Fernald, Ohio from April 1 to July 1, 1983 in a single material balance area formed specially for the exercise. Major elements of the error propagation methodology were: variance approximation by Taylor Series expansion; variance cumulation by uncorrelated primary error sources as suggested by Jaech; random effects ANOVA model estimation of variance effects (systematic error); provision for inclusion of process variance in addition to measurement variance; and exclusion of static material. The methodology was applied to material balance area transactions from the indicated time period through a FORTRAN computer code developed specifically for this purpose on the NLO HP-3000 computer. This paper contains a complete description of the error propagation methodology and a full summary of the numerical results of applying the methodlogy in the field demonstration. The error propagation LEIDs did encompass the actual uranium and /sup 235/U inventory differences. Further, one can see that error propagation actually provides guidance for reducing inventory differences and LEIDs in future time periods.

  17. NLO response of photoswitchable azobenzene-based materials.

    PubMed

    Liaros, Nikolaos; Couris, Stelios; Maggini, Laura; De Leo, Federica; Cattaruzza, Fabrizio; Aurisicchio, Claudia; Bonifazi, Davide

    2013-09-16

    The nonlinear optical (NLO) response of three π-conjugated azobenzene (AB) derivatives was investigated under picosecond laser excitation by means of the Z-scan technique to evaluate the effect of an ethynyl-based conjugated spacer on the NLO properties of ABs. All modules possessed large third-order nonlinearity, but unexpectedly it was the less extended AB derivative that exhibited the largest NLO response. This finding has been confirmed by means of DFT calculations and was attributed to a higher cis/trans ratio of the particular AB derivative in its investigated photoequilibrated state. Furthermore, the influence of the amount of cis isomer on the third-order nonlinear susceptibility [χ((3))] of the less extended AB derivative has been thoroughly investigated. Specifically, modulation of the NLO response has been successfully achieved by tuning the isomeric composition of the investigated photostationary state. These results highlighted the cis-dependent increase of the NLO response to support the general idea that such compounds can be used for multistep switching NLO materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Q 2-evolution of parton densities at small x values. Charm contribution in the combined H1 and ZEUS F 2 data

    NASA Astrophysics Data System (ADS)

    Kotikov, A. V.; Shaikhatdenov, B. G.

    2017-09-01

    The Bessel-inspired behavior of parton densities at small x, obtained in the case of the flat initial conditions for DGLAP evolution equations, is used in the fixed flavor scheme to analyze precise H1 and ZEUS combined data on the structure function F 2.

  19. NLO Vector Boson Production With Light Jets

    SciTech Connect

    Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Hoeche, S.; Ita, H.; Kosower, D.A.; Maitre, D.; Ozeren, K.

    2012-02-15

    In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to be better-behaved as many uncertainties cancel in such ratios. Precise calculation of ratios, along with measurement of one of the two processes in the ratio, can be used in data-driven techniques for estimating backgrounds.

  20. Transverse momentum dependent (TMD) parton distribution functions generated in the modified DGLAP formalism based on the valence-like distributions

    NASA Astrophysics Data System (ADS)

    Hosseinkhani, H.; Modarres, M.; Olanj, N.

    2017-07-01

    Transverse momentum dependent (TMD) parton distributions, also referred to as unintegrated parton distribution functions (UPDFs), are produced via the Kimber-Martin-Ryskin (KMR) prescription. The GJR08 set of parton distribution functions (PDFs) which are based on the valence-like distributions is used, at the leading order (LO) and the next-to-leading order (NLO) approximations, as inputs of the KMR formalism. The general and the relative behaviors of the generated TMD PDFs at LO and NLO and their ratios in a wide range of the transverse momentum values, i.e. kt2 = 10, 102, 104 and 108GeV2 are investigated. It is shown that the properties of the parent valence-like PDFs are imprinted on the daughter TMD PDFs. Imposing the angular ordering constraint (AOC) leads to the dynamical variable limits on the integrals which in turn increase the contributions from the lower scales at lower kt2. The results are compared with our previous studies based on the MSTW2008 input PDFs and it is shown that the present calculation gives flatter TMD PDFs. Finally, a comparison of longitudinal structure function (FL) is made by using the produced TMD PDFs and those that were generated through the MSTW2008-LO PDF from our previous work and the corresponding data from H1 and ZEUS collaborations and a reasonable agreement is found.

  1. Squark production and decay matched with parton showers at NLO

    NASA Astrophysics Data System (ADS)

    Gavin, R.; Hangst, C.; Krämer, M.; Mühlleitner, M.; Pellen, M.; Popenda, E.; Spira, M.

    2015-01-01

    Extending previous work on the predictions for the production of supersymmetric (SUSY) particles at the LHC, we present the fully differential calculation of the next-to-leading order (NLO) SUSY-QCD corrections to the production of squark and squark-antisquark pairs of the first two generations. The NLO cross sections are combined with the subsequent decay of the final state (anti)squarks into the lightest neutralino and (anti)quark at NLO SUSY-QCD. No assumptions on the squark masses are made, and the various subchannels are taken into account independently. In order to obtain realistic predictions for differential distributions the fixed-order calculations have to be combined with parton showers. Making use of the Powheg method we have implemented our results in the Powheg-Box framework and interfaced the NLO calculation with the parton shower Monte Carlo programs Pythia6 and Herwig++. The code is publicly available and can be downloaded from the Powheg-Box webpage. The impact of the NLO corrections on the differential distributions is studied and parton shower effects are investigated for different benchmark scenarios.

  2. NLO QCD method of the polarized semiinclusive DIS data analysis

    SciTech Connect

    Sissakian, A.N.; Shevchenko, O.Yu.; Ivanov, O.N.

    2006-05-01

    Method of polarized semi-inclusive deep inelastic scattering (SIDIS) data analysis in the next to leading order (NLO) QCD is developed. Within the method one first directly extracts in NLO few first truncated (available to measurement) Mellin moments of the quark helicity distributions. Second, using these moments as an input to the proposed modification of the Jacobi polynomial expansion method (MJEM), one eventually reconstructs the local quark helicity distributions themselves. All numerical tests demonstrate that MJEM allows us to reproduce with the high precision the input local distributions even inside the narrow Bjorken x region accessible for experiment. It is of importance that only four first input moments are sufficient to achieve a good quality of reconstruction. The application of the method to the simulated SIDIS data on the pion production is considered. The obtained results encourage one that the proposed NLO method can be successfully applied to the SIDIS data analysis. The analysis of HERMES data on pion production is performed. To this end the pion difference asymmetries are constructed from the measured by HERMES standard semi-inclusive spin asymmetries. The LO results of the valence distribution reconstruction are in a good accordance with the respective leading order SMC and HERMES results, while the NLO results are in agreement with the existing NLO parametrizations on these quantities.

  3. Conformal kernel for NLO BFKL equation in ${\\cal N}$=4 SYM

    SciTech Connect

    Balitsky, Ian; Chirilli, Giovanni

    2009-01-01

    Using the requirement of M\\"{o}bius invariance of ${\\cal N}$=4 SYM amplitudes in the Regge limit we restore the conformal NLO BFKL kernel out of the eigenvalues known from the forward NLO BFKL result.

  4. Global NLO Analysis of Nuclear Parton Distribution Functions

    SciTech Connect

    Hirai, M.; Kumano, S.; Nagai, T.-H.

    2008-02-21

    Nuclear parton distribution functions (NPDFs) are determined by a global analysis of experimental measurements on structure-function ratios F{sub 2}{sup A}/F{sub 2}{sup A{sup '}} and Drell-Yan cross section ratios {sigma}{sub DY}{sup A}/{sigma}{sub DY}{sup A{sup '}}, and their uncertainties are estimated by the Hessian method. The NPDFs are obtained in both leading order (LO) and next-to-leading order (NLO) of {alpha}{sub s}. As a result, valence-quark distributions are relatively well determined, whereas antiquark distributions at x>0.2 and gluon distributions in the whole x region have large uncertainties. The NLO uncertainties are slightly smaller than the LO ones; however, such a NLO improvement is not as significant as the nucleonic case.

  5. Development of Polyimides-Based NLO Materials for Electrooptical Applications

    NASA Technical Reports Server (NTRS)

    Rutherford, Jacqueline; Li, Xiang; Mintz, Eric A.; Bu, Xiu R.

    1998-01-01

    Development of thermally stable optical materials for nonlinear optics have recently focused on the covalent incorporation of NLO chromophores into high performance polymers, especially thermally stable and processable polyamides. One key aspect for the incorporation of robust NLO chromophores into high Tg polymers is to sustain poling induced order. Other advantages include high loading level of chromophores, and elimination of possible phase separation as well as chromophore sublimation at processing or working temperature. We have prepared several polyimide based polymers which are covalently linked with thermally stable chromophores that we have developed, since polyamides generally exhibit high Tg and good film transparency. Here, we report the development and subsequent incorporation of indoline based chromophores into polyamides, leading to thermally stable NLO polymers.

  6. Development of Polyimides-Based NLO Materials for Electrooptical Applications

    NASA Technical Reports Server (NTRS)

    Rutherford, Jacqueline; Li, Xiang; Mintz, Eric A.; Bu, Xiu R.

    1998-01-01

    Development of thermally stable optical materials for nonlinear optics have recently focused on the covalent incorporation of NLO chromophores into high performance polymers, especially thermally stable and processable polyamides. One key aspect for the incorporation of robust NLO chromophores into high Tg polymers is to sustain poling induced order. Other advantages include high loading level of chromophores, and elimination of possible phase separation as well as chromophore sublimation at processing or working temperature. We have prepared several polyimide based polymers which are covalently linked with thermally stable chromophores that we have developed, since polyamides generally exhibit high Tg and good film transparency. Here, we report the development and subsequent incorporation of indoline based chromophores into polyamides, leading to thermally stable NLO polymers.

  7. NLO QCD corrections to graviton induced deep inelastic scattering

    NASA Astrophysics Data System (ADS)

    Stirling, W. J.; Vryonidou, E.

    2011-06-01

    We consider Next-to-Leading-Order QCD corrections to ADD graviton exchange relevant for Deep Inelastic Scattering experiments. We calculate the relevant NLO structure functions by calculating the virtual and real corrections for a set of graviton interaction diagrams, demonstrating the expected cancellation of the UV and IR divergences. We compare the NLO and LO results at the centre-of-mass energy relevant to HERA experiments as well as for the proposed higher energy lepton-proton collider, LHeC, which has a higher fundamental scale reach.

  8. Fully differential NLO predictions for the rare muon decay

    NASA Astrophysics Data System (ADS)

    Pruna, G. M.; Signer, A.; Ulrich, Y.

    2017-02-01

    Using the automation program GoSam, fully differential NLO corrections were obtained for the rare decay of the muon μ → eν ν bar ee. This process is an important Standard Model background to searches of the Mu3e Collaboration for lepton-flavor violation, as it becomes indistinguishable from the signal μ → 3 e if the neutrinos carry little energy. With our NLO program we are able to compute the branching ratio as well as custom-tailored observables for the experiment. With minor modifications, related decays of the tau can also be computed.

  9. Vibronic analysis of NLO spectra of PDA crystals and films

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Debasis; Soos, Zoltan G.

    1995-09-01

    A joint analysis of recent NLO spectra of polydiacetylene films and crystals is presented, using vibronic contributions in the Condon approximation and (pi) -electronic states from Pariser-Parr-Pople theory. Raman resonances are shown to be corrections to average excitations. An even-parity state above the photoconduction edge is found in two-photon absorption of PDA-PTS crystals and nondegenerate four-wave-mixing spectra of PDA- 4BCMU films. We incorporate linear and resonance Raman spectra in the joint NLO analysis and emphasize the different roles of electronic and vibrational contributions.

  10. Highly Non-Linear Optical (NLO) organic crystals

    NASA Technical Reports Server (NTRS)

    Harris, J. Milton

    1987-01-01

    This research project involves the synthesis and characterization of organic materials having powerful nonlinear optical (NLO) properties and the growth of highly ordered crystals and monomolecular films of these materials. Research in four areas is discussed: theoretical design of new materials, characterization of NLO materials, synthesis of new materials and development of coupling procedures for forming layered films, and improvement of the techniques for vapor phase and solution phase growth of high quality organic crystals. Knowledge gained from these experiments will form the basis for experiments in the growth of these crystals.

  11. The dihadron fragmentation function and its evolution

    SciTech Connect

    Majumder, Abhijit; Wang, Xin-Nian

    2004-02-24

    Dihadron fragmentation functions and their evolution arestudied in the process of e+e- annihilation. Under the collinearfactorization approximation and facilitated by the cut-vertex technique,the two hadron inclusive cross section at leading order (LO) is shown tofactorize into a short distance parton cross section and a long distancedihadron fragmentation function. We provide the definition of such adihadron fragmentation function in terms of parton matrix elements andderive its DGLAP evolution equation at leading log. The evolutionequation for the non-singlet quark fragmentation function is solvednumerically with a simple ansatz for the initial condition and resultsare presented for cases of physical interest.

  12. Bimetallic sandwichlike complexes as novel NLO chromophores

    NASA Astrophysics Data System (ADS)

    Heck, Juergen; Brussard, Hugo C.; Dabek, Sven; Meyer-Friedrichsen, Timo; Wong, Hans

    1997-10-01

    Mono- and dinuclear sesquifulvalene-type complexes [{LnM(l5C5H4)}Z{17C7H6)MLtn}mXm+i (m =0, 1 ; X = BF4, PF6) have been synthesized, particularly with regards to their nonlinear optical properties. Z =-: LM = CpFe, M'L' = -, la; LM = CpFe; M'L' = Cr(CO)3, ib; LM = CpFe, ML',, = RuCp, ic; LM = CpFe, L'M' = RUCP*, id; LM = CpRu; M'L' = -, le; LM =CpRu, M'L' RuCp, if, LM = CpRu, M'L' = RuCp*, ig - Z = C2: LM = CpFe, M'L' = Cr(CO)3, 2 - Z = C2H2:LM = CpFe, ML' = -, 3a; LM = CpFe, M'L' = Cr(CO)3, 3b; LM = CpFe, L'M' = RuCp, 3c; LM = Cp*Fe, M'L' = Cr(CO)3, 3d; LM = (Ph4C4)Co, M'L' = - 5; Z = thiophene-1,5-diyl (C4H2S): LM = CpFe, M'L' = -, 4a; LM = CpFe, M'L' = RuCp) (Cp = C5H5, Cp* C5Me5, Ph = C6H5). The ferrocenyl containing complexes reveal UV/vis spectra, showing long wave absorption bands beyond 550 nm which are assigned to a charge transfer (CT) transition between the cyclo-C5 and cyclo-C-, moieties. The corresponding transitions for the ruthenocenyl compounds if and ig are found below 500 nm. The CT transitions exhibit pronounced negative solvatochromism. Cyclic voltammetry studies and structural data of some of these compounds confirm the strong electronic coupling between the cyclo-C5 and the cyclo-C7 moieties. Hyper Rayleigh scattering (HRS) investigations of these mono- and dinuclear sesquifulvalene derivaties to determine the first hyperpolarizability 13 show several different important features: i) the measured 13 values of compounds with an additional spacer Z are the highest ever obtained for sandwich-type NLO chromophores; ii) the B values of the dinuclear sequifulvalene complexes surpass the 13 values of the mononuclear derivatives markedly; iii) the exchange of a monocationic electron accepting group (Cr(CO)3), with a dicationic one (RuCp) enhances 13 considerably, iv) the use of the (cyclobutadiene)(cyclopentadienyl)Co unit reveals a surprisingly large B value although this compound is mononuclear. The large experimental 13 values are in part assigned

  13. Organic NLO Polymers. 2. Main-Chain and Guest-Host Chi(2)NLO Polymers: NLO-phore Structure Versus Poling

    DTIC Science & Technology

    1994-05-28

    34REPORT DOCUMENTATION PAGE Form APProvedT 00146 No. 0704.0188 0.I4( j’qwmol’ * Ufa " ’Of ".i :Ctli f ( tlij mft q r w•a€i€ * t aa ’a l u m, t orDerfewld i...The method of choice to purify the monomers is by crystallization from a mixture of ethyl acetate and hexanes. We prepared a series of NLO-phores and...materials. ’ 41.2 -4NLO- baM 1 0.8- S0.4 Z 0.4 0 0 g00 1000 1600 2000 2600 3000 1M• (au0 Figure L Second order NW response for guest-host PMMA films containng

  14. Graphene in NLO Devices for High Energy Laser Protection

    DTIC Science & Technology

    2009-11-17

    including eye) protection can be achieved by blocking, scattering, diffracting, or absorbing incoming laser light. Current solutions include shutter...noticeable color distortion (filters), narrow band protection (filters), low saturation thresholds (Reverse-Saturable Absorbing (RSA) NLO dyes), and...protecting. Sensor (including eye) protection can be achieved by blocking, scattering, diffracting, or absorbing incoming laser light. Current solutions

  15. Impact factor for exclusive diffractive dijet production with NLO accuracy

    NASA Astrophysics Data System (ADS)

    Boussarie, R.; Grabovsky, A. V.; Szymanowski, L.; Wallon, S.

    2017-03-01

    Relying on the shockwave approach, we present the main steps of the computation of the impact factor for the exclusive diffractive photo- or electro- production of a forward dijet with NLO accuracy. We provide details of the cancellation mechanisms for all the divergences which appear in the intermediate results.

  16. Unifying the Fixed Order Evolution of Fragmentation Functions with the Modified Leading Logarithm Approximation

    NASA Astrophysics Data System (ADS)

    Albino, S.; Kniehl, B. A.; Kramer, G.; Ochs, W.

    An approach which unifies the Double Logarithmic Approximation at small x and the leading order DGLAP evolution of fragmentation functions at large x is presented. This approach reproduces exactly the Modified Leading Logarithm Approximation, but is more complete due to the degrees of freedom given to the quark sector and the inclusion of the fixed order terms. We find that data from the largest x values to the peak region can be better fitted than with other approaches.

  17. NLO cross sections in 4 dimensions without DREG

    NASA Astrophysics Data System (ADS)

    Hernández-Pinto, R. J.; Driencourt-Mangin, F.; Rodrigo, G.; Sborlini, G. F. R.

    2016-10-01

    In this review, we present a new method for computing physical cross sections at NLO accuracy in QCD without using the standard Dimensional Regularisation. The algorithm is based on the Loop-Tree Duality theorem, which allow us to obtain loop integrals as a sum of phase-space integrals; in this way, transforming loop integrals into phase-space integrals, we propose a method to merge virtual and real contributions in order to find observables at NLO in d = 4 space-time dimensions. In addition, the strategy described is used for computing the γ* → qq̅(g) process. A more detailed discussion related on this topic can be found in Ref [1].

  18. NLO electroweak corrections in extended Higgs sectors with RECOLA2

    NASA Astrophysics Data System (ADS)

    Denner, Ansgar; Lang, Jean-Nicolas; Uccirati, Sandro

    2017-07-01

    We present the computer code RECOLA2 along with the first NLO electroweak corrections to Higgs production in vector-boson fusion and updated results for Higgs strahlung in the Two-Higgs-Doublet Model and Higgs-Singlet extension of the Standard Model. A fully automated procedure for the generation of tree-level and one-loop matrix elements in general models, including renormalization, is presented. We discuss the application of the Background-Field Method to the extended models. Numerical results for NLO electroweak cross sections are presented for different renormalization schemes in the Two-Higgs-Doublet Model and the Higgs-Singlet extension of the Standard Model. Finally, we present distributions for the production of a heavy Higgs boson.

  19. Small-x evolution of structure functions in the next-to-leading order

    SciTech Connect

    Giovanni A. Chirilli

    2010-01-01

    The high-energy behavior of amplitudes in gauge theories can be reformulated in terms of the evolution of Wilson-line operators. In the leading order this evolution is governed by the non-linear Balitsky-Kovchegov (BK) equation. In QCD the NLO kernel has both conformal and non-conformal parts. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal N = 4 SYM theory, then we define the "composite dipole operator", and the resulting Mobius invariant kernel for this operator agrees with the forward NLO BFKL calculation.

  20. Graphene in NLO Devices for High Laser Energy Protection

    DTIC Science & Technology

    2010-10-01

    absorbing incoming laser light. Current solutions include shutter systems, fixed-line filters, dyes, and/or reflective technologies. Limitations of these...thresholds (Reverse-Saturable Absorbing (RSA) NLO dyes), and insufficient magnitude of the non-linear effect (metal nano-particles, carbon nanotubes and...scattering, diffracting, or absorbing incoming laser light. Current solutions include shutter systems, fixed-line filters, dyes, and/or reflective

  1. Subtractive Renormalization Group Invariance: Pionless EFT at NLO

    SciTech Connect

    Timoteo, Varese S.; Szpigel, Sergio; Duraes, Francisco O.

    2010-11-12

    We show some results concerning the renormalization group (RG) invariance of the nucleon-nucleon (NN) interaction in pionless effective field theory at next-to-leading order (NLO), using a non-relativistic Callan-Symanzik equation (NRCS) for the driving term of the Lippmann-Schwinger (LS) equation with three recursive subtractions. The phase-shifts obtained for the RG evolved potential are same as those for the original potential, apart from relative differences of order 10{sup -15}.

  2. Subtractive Renormalization Group Invariance: Pionless EFT at NLO

    NASA Astrophysics Data System (ADS)

    Timóteo, Varese S.; Szpigel, Sérgio; Durães, Francisco O.

    2010-11-01

    We show some results concerning the renormalization group (RG) invariance of the nucleon-nucleon (NN) interaction in pionless effective field theory at next-to-leading order (NLO), using a non-relativistic Callan-Symanzik equation (NRCS) for the driving term of the Lippmann-Schwinger (LS) equation with three recursive subtractions. The phase-shifts obtained for the RG evolved potential are same as those for the original potential, apart from relative differences of order 10-15.

  3. A Critical Appraisal of NLO+PS Matching Methods

    SciTech Connect

    Hoeche, Stefan; Krauss, Frank; Schonherr, Marek; Siegert, Frank; /Freiburg U.

    2012-03-19

    In this publication, uncertainties in and differences between the MC{at}NLO and POWHEG methods for matching next-to-leading order QCD calculations with parton showers are discussed. Implementations of both algorithms within the event generator SHERPA are employed to assess the impact on a representative selection of observables. In the MC{at}NLO approach a phase space restriction has been added to subtraction and parton shower, which allows to vary in a transparent way the amount of non-singular radiative corrections that are exponentiated. Effects on various observables are investigated, using the production of a Higgs boson in gluon fusion, with or without an associated jet, as a benchmark process. The case of H+jet production is presented for the first time in an NLO+PS matched simulation. Uncertainties due to scale choices and non-perturbative effects are explored in the production of W{sup {+-}} and Z bosons in association with a jet. Corresponding results are compared to data from the Tevatron and LHC experiments.

  4. NLO QCD Corrections to Electroweak Higgs Boson Production in Association with Three Jets at the LHC

    NASA Astrophysics Data System (ADS)

    Figy, Terrance

    2017-01-01

    In this talk I will discuss the implementation of the next-to-leading order (NLO) perturbative QCD corrections to electroweak Higgs boson plus three jet production at the CERN Large Hadron Collider experiment within the Matchbox framework of the Herwig 7 event generator. Numerical results for integrated cross sections and kinematic distributions will be presented for a fixed-order NLO calculation and for a NLO calculation matched to a parton shower.

  5. NLO vertex for a forward jet plus a rapidity gap at high energies

    SciTech Connect

    Hentschinski, Martin; Madrigal Martínez, José Daniel; Murdaca, Beatrice; Vera, Agustín Sabio

    2015-04-10

    We present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov’s effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green’s function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets)

  6. NLO vertex for a forward jet plus a rapidity gap at high energies

    DOE PAGES

    Hentschinski, Martin; Madrigal Martínez, José Daniel; Murdaca, Beatrice; ...

    2015-04-01

    Here we present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov’s effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green’s function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets).

  7. NLO production of W± and Z0 vector bosons via hadron collisions in the frameworks of Kimber-Martin-Ryskin and Martin-Ryskin-Watt unintegrated parton distribution functions

    NASA Astrophysics Data System (ADS)

    Modarres, M.; Masouminia, M. R.; Aminzadeh Nik, R.; Hosseinkhani, H.; Olanj, N.

    2016-10-01

    In a series of papers, we have investigated the compatibility of the Kimber-Martin-Ryskin (KMR) and Martin-Ryskin-Watt (MRW) unintegrated parton distribution functions (UPDFs) as well as the description of the experimental data on the proton structure functions. The present work is a sequel to that survey, via calculation of the transverse-momentum distribution of the electroweak gauge vector bosons in the kt-factorization scheme, by the means of the KMR, the leading-order (LO) MRW, and the next-to-leading-order (NLO) MRW UPDF, in the NLO. To this end, we have calculated and aggregated the invariant amplitudes of the corresponding involved diagrams in the NLO and counted the individual contributions in different frameworks. The preparation process for the UPDF utilizes the parton distribution functions of Martin et al., MSTW2008-LO, MSTW2008-NLO, MMHT2014-LO, and MMHT2014-NLO, as the inputs. Afterward, the results have been analyzed against each other as well as the existing experimental data, i.e., D0, CDF, ATLAS, and CMS collaborations. Our calculations show excellent agreement with the experiment data. It is, however, interesting to point out that the calculation using the KMR framework illustrates a stronger agreement with the experimental data, despite the fact that the LO MRW and the NLO MRW formalisms employ a better theoretical description of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation. This is of course due to the use of the different implementation of the angular ordering constraint in the KMR approach, which automatically includes the resummation of ln (1 /x ) , Balitski-Fadin-Kuraev-Lipatov logarithms, in the LO Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation.

  8. Q2-evolution of parton densities at small x values and H1 and ZEUS experimental data

    NASA Astrophysics Data System (ADS)

    Kotikov, A. V.; Shaikhatdenov, B. G.

    2014-07-01

    It is shown that in the leading twist approximation of the Wilson operator product expansion with "frozen" and analytic strong coupling constants, considering the Bessel-inspired behavior of the structure functions F2 and the derivative ∂lnF2/∂ln(1/x) at small x values, obtained for a flat initial condition in the DGLAP evolution equations, leads to a good agreement with the deep inelastic scattering H1 and ZEUS experimental data from HERA.

  9. The SM and NLO Multileg Working Group: Summary Report

    SciTech Connect

    Andersen, J.R.; Archibald, J.; Badger, S.; Ball, R.D.; Bevilacqua, G.; Bierenbaum, I.; Binoth, T.; Boudjema, F.; Boughezal, R.; Bredenstein, A.; Britto, R.; Campanelli, M.; Campbell, J.; Carminati, L.; Chachamis, G.; Ciulli, V.; Cullen, G.; Czakon, M.; Del Debbio, L.; Denner, A.; Dissertori, G.; /Edinburgh U. /Zurich, ETH /Michigan State U. /CAFPE, Granada /CERN /Durham U., IPPP /DESY, Zeuthen /Democritos Nucl. Res. Ctr. /Valencia U., IFIC /Annecy, LAPTH /Zurich U. /KEK, Tsukuba /Saclay, SPhT /University Coll. London /Fermilab /INFN, Milan /Milan U. /PSI, Villigen /Florence U. /INFN, Florence /RWTH Aachen U.

    2012-04-10

    After years of waiting, and after six Les Houches workshops, the era of LHC running is finally upon us, albeit at a lower initial center-of-mass energy than originally planned. Thus, there has been a great sense of anticipation from both the experimental and theoretical communities. The last two years, in particular, have seen great productivity in the area of multi-parton calculations at leading order (LO), next-to-leading order (NLO) and next-to-next-to-leading order (NNLO), and this productivity is reflected in the proceedings of the NLM group. Both religions, Feynmanians and Unitarians, as well as agnostic experimenters, were well-represented in both the discussions at Les Houches, and in the contributions to the write-up. Next-to-leading order (NLO) is the first order at which the normalization, and in some cases the shape, of perturbative cross sections can be considered reliable. This can be especially true when probing extreme kinematic regions, as for example with boosted Higgs searches considered in several of the contributions to this writeup. A full understanding for both standard model and beyond the standard model physics at the LHC requires the development of fast, reliable programs for the calculation of multi-parton final states at NLO. There have been many advances in the development of NLO techniques, standardization and automation for such processes and this is reflected in the contributions to the first section of this writeup. Many calculations have previously been performed with the aid of semi-numerical techniques. Such techniques, although retaining the desired accuracy, lead to codes which are slow to run. Advances in the calculation of compact analytic expressions for Higgs + 2 jets have resulted in the development of much faster codes, which extend the phenomenology that can be conducted, as well as making the code available to the public for the first time. A prioritized list of NLO cross sections was assembled at Les Houches in 2005

  10. Evolution.

    ERIC Educational Resources Information Center

    Mayr, Ernst

    1978-01-01

    Traces the history of evolution theory from Lamarck and Darwin to the present. Discusses natural selection in detail. Suggests that, besides biological evolution, there is also a cultural evolution which is more rapid than the former. (MA)

  11. Evolution.

    ERIC Educational Resources Information Center

    Mayr, Ernst

    1978-01-01

    Traces the history of evolution theory from Lamarck and Darwin to the present. Discusses natural selection in detail. Suggests that, besides biological evolution, there is also a cultural evolution which is more rapid than the former. (MA)

  12. The nonsinglet structure function evolution by Laplace method

    SciTech Connect

    Boroun, G. R. E-mail: boroun@razi.ac.ir; Zarrin, S.

    2015-12-15

    We derive a general scheme for the evolution of the nonsinglet structure function at the leadingorder (LO) and next-to-leading-order (NLO) by using the Laplace-transform technique. Results for the nonsinglet structure function are compared with MSTW2008, GRV, and CKMT parameterizations and also EMC experimental data in the LO and NLO analysis. The results are in good agreement with the experimental data and other parameterizations in the low- and large-x regions.

  13. NLO QCD corrections to ZZ jet production at hadron colliders

    SciTech Connect

    Binoth, T.; Gleisberg, T.; Karg, S.; Kauer, N.; Sanguinetti, G.; /Annecy, LAPTH

    2010-05-26

    A fully differential calculation of the next-to-leading order QCD corrections to the production of Z-boson pairs in association with a hard jet at the Tevatron and LHC is presented. This process is an important background for Higgs particle and new physics searches at hadron colliders. We find sizable corrections for cross sections and differential distributions, particularly at the LHC. Residual scale uncertainties are typically at the 10% level and can be further reduced by applying a veto against the emission of a second hard jet. Our results confirm that NLO corrections do not simply rescale LO predictions.

  14. Characterization and investigation of NLO properties of electrodeposited polythiophenes

    NASA Astrophysics Data System (ADS)

    Figã, V.; Luc, J.; Kulyk, B.; Baitoul, M.; Sahraoui, B.

    2009-04-01

    this work we study the electronic properties of ClO4- doped polythiophenes and discuss the nonlinear optical properties of these organic compounds galvanostatically electrodeposited on ITO glasses. The investigation on the electronic properties (band gap, flat band potential) was performed by means of a non-destructive optical technique, photocurrent spectroscopy (PCS). The investigation on the nonlinear optical response was carried out by means of second and third harmonic generation measurements. In particular, the effect of the oxidation state of the polymeric films was studied by comparing the NLO response of oxidized and reduced polythiophenes. Reduced polymeric films show higher values of the second (?) and third (?) order nonlinear susceptibilities.

  15. Spin polarisation of tt¯γγ production at NLO+PS with GoSam interfaced to MadGraph5_aMC@NLO

    DOE PAGES

    van Deurzen, Hans; Frederix, Rikkert; Hirschi, Valentin; ...

    2016-04-22

    Here, we present an interface between the multipurpose Monte Carlo tool MadGraph5_aMC@NLO and the automated amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections to pp→ tt¯H and pp→ tt¯γγ matched to a parton shower. In the phenomenological analyses of these processes, we focus our attention on observables which are sensitive to the polarisation of the top quarks.

  16. NLO properties of 1, 4-naphthoquinone, Juglone and Lawsone by DFT and Z-scan technique - A detailed study

    NASA Astrophysics Data System (ADS)

    Mande, Prashant; Mathew, Elizabeth; Chitrambalam, Subramaniyan; Joe, Isaac H.; Sekar, Nagaiyan

    2017-10-01

    1, 4-Naphthoquinone, 2-hydroxy-1,4-naphthoquinone (Lawsone) and 5-hydroxy-1,4-naphthoquinone (Juglone) have been investigated for their nonlinear optical (NLO) properties using Z-scan technique and Density Functional Theory (DFT) method. The Z-scan results show that all the three compounds have appreciable NLO properties. Among the three molecules Juglone showed the highest static hyperpolarizability value. The functional CAM-B3LYP performed better than BHHLYP and B3LYP in computing NLO properties. Solvent environment plays a decisive role in NLO properties of naphthoquinone derivatives. Polar solvent environment enhanced the NLO characteristics.

  17. NLO QCD+EW predictions for HV and HV +jet production including parton-shower effects

    NASA Astrophysics Data System (ADS)

    Granata, F.; Lindert, J. M.; Oleari, C.; Pozzorini, S.

    2017-09-01

    We present the first NLO QCD+EW predictions for Higgs boson production in association with a ℓν ℓ or ℓ + ℓ - pair plus zero or one jets at the LHC. Fixed-order NLO QCD+EW calculations are combined with a QCD+QED parton shower using the recently developed resonance-aware method in the POWHEG framework. Moreover, applying the improved MiNLO technique to Hℓν ℓ +jet and Hℓ + ℓ - +jet production at NLO QCD+EW, we obtain predictions that are NLO accurate for observables with both zero or one resolved jet. This approach permits also to capture higher-order effects associated with the interplay of EW corrections and QCD radiation. The behavior of EW corrections is studied for various kinematic distributions, relevant for experimental analyses of Higgsstrahlung processes at the 13 TeV LHC. Exact NLO EW corrections are complemented with approximate analytic formulae that account for the leading and next-to-leading Sudakov logarithms in the high-energy regime. In the tails of transverse-momentum distributions, relevant for analyses in the boosted Higgs regime, the Sudakov approximation works well, and NLO EW effects can largely exceed the ten percent level. Our predictions are based on the POWHEG BOX RES+OpenLoops framework in combination with the Pythia 8.1 parton shower.

  18. NLO+NLL squark and gluino production cross sections with threshold-improved parton distributions.

    PubMed

    Beenakker, Wim; Borschensky, Christoph; Krämer, Michael; Kulesza, Anna; Laenen, Eric; Marzani, Simone; Rojo, Juan

    We present updated predictions for the cross sections for pair production of squarks and gluinos at the LHC Run II. First of all, we update the calculations based on NLO+NLL partonic cross sections by using the NNPDF3.0NLO global analysis. This study includes a full characterization of theoretical uncertainties from higher orders, PDFs and the strong coupling. Then we explore the implications for this calculation of the recent NNPDF3.0 PDFs with NLO+NLL threshold resummation. We find that the shift in the results induced by the threshold-improved PDFs is within the total theory uncertainty band of the calculation based on NLO PDFs. However, we also observe that the central values of the NLO+NLL cross sections are modified both in a qualitative and a quantitative way, illustrating the relevance and impact of using threshold-improved PDFs together with resummed partonic cross sections. The updated NLO+NLL cross sections based on NNPDF3.0NLO are publicly available in the NLL-fast format, and should be an important ingredient for the interpretation of the searches for supersymmetric particles at Run II.

  19. Small-x Evolution of Structure Functions in the Next-to-Leading Order

    SciTech Connect

    Giovanni Antonio Chirilli

    2009-12-01

    The high-energy behavior of amplitudes in gauge theories can be reformulated in terms of the evolution of Wilson-line operators. In the leading order this evolution is governed by the nonlinear Balitsky-Kovchegov (BK) equation. The NLO corrections define the scale of the running coupling constant in the BK equation and in QCD, its kernel has both conformal and non-conformal parts. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal N = 4 SYM theory, then we define the "composite dipole operator" with the rapidity cutoff preserving conformal invariance, and the resulting Möbius invariant kernel for this operator agrees with the forward NLO BFKL calculation. In QCD, the NLO kernel for the composite operators resolves in a sum of the conformal part and the running-coupling part.

  20. Small-x Evolution of Structure Functions in the Next-to-Leading Order

    SciTech Connect

    Chirilli, Giovanni A.

    2009-12-17

    The high-energy behavior of amplitudes in gauge theories can be reformulated in terms of the evolution of Wilson-line operators. In the leading order this evolution is governed by the nonlinear Balitsky-Kovchegov (BK) equation. The NLO corrections define the scale of the running-coupling constant in the BK equation and in QCD, its kernel has both conformal and non-conformal parts. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal N = 4 SYM theory, then we define the 'composite dipole operator' with the rapidity cutoff preserving conformal invariance, and the resulting Moebius invariant kernel for this operator agrees with the forward NLO BFKL calculation.In QCD, the NLO kernel for the composite operators resolves in a sum of the conformal part and the running-coupling part.

  1. Higgs characterisation via vector-boson fusion and associated production: NLO and parton-shower effects.

    PubMed

    Maltoni, Fabio; Mawatari, Kentarou; Zaro, Marco

    Vector-boson fusion and associated production at the LHC can provide key information on the strength and structure of the Higgs couplings to the Standard Model particles. Using an effective field theory approach, we study the effects of next-to-leading order (NLO) QCD corrections matched to a parton shower on selected observables for various spin-0 hypotheses. We find that inclusion of NLO corrections is needed to reduce the theoretical uncertainties on the total rates as well as to reliably predict the shapes of the distributions. Our results are obtained in a fully automatic way via FeynRules and MadGraph5_aMC@NLO.

  2. "H"-shape second order NLO polymers: synthesis and characterization.

    PubMed

    Li, Zhong'an; Hu, Pan; Yu, Gui; Zhang, Wei; Jiang, Zuoquan; Liu, Yunqi; Ye, Cheng; Qin, Jingui; Li, Zhen

    2009-02-28

    In this work, two "H"-shape and one "AB"-type second order nonlinear optical (NLO) polymers were prepared for the first time. The linkage positions of chromophores in the "H"-shape polymers were shoulder-to-shoulder, in which the chromophore moieties were part of the polymeric backbone. The subtle structure could be easily modified by the introduction of different isolation groups, to adjust the property of the resultant polymers. All the polymers exhibited good film-forming ability and thermal stability. The second harmonic generation (SHG) experiments demonstrated that the two "H"-shape polymers (P1 and P2) exhibited large SHG coefficients of d(33) values (up to 90 pm V(-1)), and P2 even demonstrated relatively good long-term temporal stability.

  3. Energy loss at NLO in a high-temperature Quark-Gluon Plasma

    NASA Astrophysics Data System (ADS)

    Ghiglieri, Jacopo

    2016-12-01

    We present an extension of the Arnold-Moore-Yaffe kinetic equations for jet energy loss to NLO in the strong coupling constant. A novel aspect of the NLO analysis is a consistent description of wider-angle bremsstrahlung (semi-collinear emissions), which smoothly interpolates between 2 ↔ 2 scattering and collinear bremsstrahlung. We describe how many of the ingredients of the NLO transport equations (such as the drag coefficient) can be expressed in terms of Wilson line operators and can be computed using a Euclidean formalism or sum rules, both motivated by the analytic properties of amplitudes at light-like separations. We conclude with an outlook on the computation of the shear viscosity at NLO.

  4. ZZ jet and Graviton jet at NLO QCD: recent applications using GOLEM methods

    SciTech Connect

    Karg, Stefan; Binoth, Thomas; Gleisberg, Tanju; Kauer, Nikolas; Sanguinetti, Gregory; Kramer, Michael; Li, Qiang; Zeppenfeld, Dieter; /Karlsruhe U., ITP

    2010-05-26

    In this talk we discuss recent progress concerning precise predictions for hadron colliders. We show results of two applications of tensor reduction using GOLEM methods: the next-to-leading order (NLO) corrections to pp {yields} ZZ + jet as an important background for Higgs particle and new physics searches at hadron colliders, and the NLO corrections to graviton plus jet hadroproduction, which is an important channel for graviton searches at the Tevatron and the LHC.

  5. Reanalysis of the EMC charm production data with extrinsic and intrinsic charm at NLO

    NASA Astrophysics Data System (ADS)

    Harris, B. W.; Smith, J.; Vogt, R.

    1996-02-01

    A calculation of the next-to-leading order exclusive extrinsic charm quark differential distributions in deeply inelastic electroproduction has recently been completed. Using these results we compare the NLO extrinsic contributions to the charm structure function F2( x, Q2, m2c) with the corresponding NLO intrinsic contributions. The results of this analysis are compared with the EMC DIS charm quark data and evidence for an intrinsic charm component in the proton is found.

  6. Donor-acceptor organo-imido polyoxometalates: high transparency, high activity redox-active NLO chromophores.

    PubMed

    Al-Yasari, Ahmed; Van Steerteghem, Nick; El Moll, Hani; Clays, Koen; Fielden, John

    2016-02-21

    We show that polyoxometalates (POMs) are an excellent redox-active acceptor on which to base high performance 2(nd) order non-linear optical (NLO) chromophores. This is demonstrated through three new organoimido-Lindqvist derivatives with HRS β0-values exceeding those of any dipolar organic system with comparable donor, π-system and absorption profile. Thus, organoimido POMs may provide a new generation of high performance, high transparency, and potentially redox-switchable NLO materials.

  7. Organic nanoclusters for nonlinear optics: from model systems to cooperative nanoassemblies with enhanced NLO responses

    NASA Astrophysics Data System (ADS)

    Terenziani, Francesca; Parthasarathy, Venkatakrishnan; Ghosh, Sampa; Pandey, Ravindra; Das, Puspendu K.; Blanchard-Desce, Mireille

    2009-08-01

    While structure-properties relationships are quite actively and successfully investigated at the molecular level of engineering of optical nonlinear responses, supramolecular structure-property relationships are an appealing field. The realization that interchromophoric interactions between strongly polar/polarizable NLO chromophores can significantly affect the NLO response of each chromophoric unit as well as promote associations has opened new dimensions for molecular design. Several elegant routes have been implemented to hinder or counterbalance dipole-dipole interactions between dipolar NLO chromophores for the elaboration of second-order materials (for SHG or electro-optical modulation). At opposite, we have implemented a reverse strategy by confining discrete numbers of NLO push-pull chromophores in close proximity within covalent organic nanoclusters with the aim to exploit interchromophoric interactions in order to achieve enhanced NLO responses. As a proof of concept, we present here the investigation of two-series of multichromophoric covalent assemblies built from NLO push-pull chromophores showing that cooperative enhancement can be achieved both for second-order optical responses (first hyperpolarizabilities) or third-order responses (two-photon absorption cross-sections).

  8. Multi-jet Merging with NLO Matrix Elements

    SciTech Connect

    Siegert, Frank; Hoche, Stefan; Krauss, Frank; Schonherr, Marek; /Dresden, Tech. U.

    2011-08-18

    In the algorithm presented here, the ME+PS approach to merge samples of tree-level matrix elements into inclusive event samples is combined with the POWHEG method, which includes exact next-to-leading order matrix elements in the parton shower. The advantages of the method are discussed and the quality of its implementation in SHERPA is exemplified by results for e{sup +}e{sup -} annihilation into hadrons at LEP, for deep-inelastic lepton-nucleon scattering at HERA, for Drell-Yan lepton-pair production at the Tevatron and for W{sup +}W{sup -}-production at LHC energies. The simulation of hard QCD radiation in parton-shower Monte Carlos has seen tremendous progress over the last years. It was largely stimulated by the need for more precise predictions at LHC energies where the large available phase space allows additional hard QCD radiation alongside known Standard Model processes or even signals from new physics. Two types of algorithms have been developed, which allow to improve upon the soft-collinear approximations made in the parton shower, such that hard radiation is simulated according to exact matrix elements. In the ME+PS approach [1] higher-order tree-level matrix elements for different final-state jet multiplicity are merged with each other and with subsequent parton shower emissions to generate an inclusive sample. Such a prescription is invaluable for analyses which are sensitive to final states with a large jet multiplicity. The only remaining deficiency of such tree-level calculations is the large uncertainty stemming from scale variations. The POWHEG method [2] solves this problem for the lowest multiplicity subprocess by combining full NLO matrix elements with the parton shower. While this leads to NLO accuracy in the inclusive cross section and the exact radiation pattern for the first emission, it fails to describe higher-order emissions with improved accuracy. Thus it is not sufficient if final states with high jet multiplicities are considered

  9. Monte Carlo simulations of Higgs-boson production at the LHC with the KrkNLO method

    NASA Astrophysics Data System (ADS)

    Jadach, S.; Nail, G.; Płaczek, W.; Sapeta, S.; Siódmok, A.; Skrzypek, M.

    2017-03-01

    We present numerical tests and predictions of the KrkNLO method for matching of NLO QCD corrections to hard processes with LO parton-shower Monte Carlo generators (NLO+PS). This method was described in detail in our previous publications, where it was also compared with other NLO+PS matching approaches ( MC@NLO and POWHEG) as well as fixed-order NLO and NNLO calculations. Here we concentrate on presenting some numerical results (cross sections and distributions) for Z/γ ^* (Drell-Yan) and Higgs-boson production processes at the LHC. The Drell-Yan process is used mainly to validate the KrkNLO implementation in the Herwig 7 program with respect to the previous implementation in Sherpa. We also show predictions for this process with the new, complete, MC-scheme parton distribution functions and compare them with our previously published results. Then we present the first results of the KrkNLO method for Higgs production in gluon-gluon fusion at the LHC and compare them with MC@NLO and POWHEG predictions from Herwig 7, fixed-order results from HNNLO and a resummed calculation from HqT, as well as with experimental data from the ATLAS collaboration.

  10. L-Argininium phosphite - a new candidate for NLO materials.

    PubMed

    Ghazaryan, Vahram V; Zakharov, Boris A; Petrosyan, Aram M; Boldyreva, Elena V

    2015-05-01

    In order to investigate the possibility of salt formation in the L-Arg-H3PO3-H2O system, single crystals of L-argininium phosphite, C6H15N4O2(+)·H2PO3(-), were prepared by evaporation of an aqueous solution containing equimolar quantities of L-arginine and phosphorous acid. The asymmetric unit contains one L-argininium(+) cation and one phosphite [HPO2(OH)](-) anion. The phosphite anions form chains parallel to [010] by O-H...O hydrogen bonding, with an O...O distance of 2.630 (3) Å. The protonated amine and guanidyl groups of the L-argininium(+) cations form N-H...O hydrogen bonds with the carboxylate groups and anions. The IR and Raman spectra are discussed in relation to the crystal structure. The salt displays nonlinear optical (NLO) properties. Another salt was obtained from a solution with a 1:2 molar ratio of components, but was characterized by vibrational spectra only.

  11. NLO QCD corrections for J /ψ +c +c ¯ production in photon-photon collision

    NASA Astrophysics Data System (ADS)

    Chen, Zi-Qiang; Chen, Long-Bin; Qiao, Cong-Feng

    2017-02-01

    The γ +γ →J /ψ +c +c ¯ inclusive process is an extremely important subprocess in J /ψ production via photon-photon scattering, like at LEPII or various types of future electron-positron colliders. In this work we perform the next-to-leading order (NLO) QCD corrections to this process in the framework of nonrelativistic QCD (NRQCD) factorization formalism, the first NLO calculation for two projectiles to the 3-body quarkonium inclusive production process. By setting the center-of-mass energy at LEPII, the √{s }=197 GeV , we conduct analyses of the pt2 distribution and total cross section of this process at the NLO accuracy. It turns out that the total cross section is moderately enhanced by the NLO correction with a K factor of about 1.46, and hence the predicted J /ψ inclusive productivity is increased while the DELPHI data still overshoot the theoretical prediction. At the future Circular Electron-Positron Collider, the NLO corrections are found to be more significant, with a K factor of about 1.76.

  12. Carborane tuning on iridium complexes: redox-switchable second-order NLO responses.

    PubMed

    Wang, Jiao; Wang, Wen-Yong; Fang, Xin-Yan; Qiu, Yong-Qing

    2015-04-01

    Much effort has been devoted to investigating the molecular geometries, electronic structures, redox properties and nonlinear optical (NLO) properties of Ir complexes involving o-, m- or p-carborane groups by density functional theory (DFT) methods. Switchable second-order NLO properties were induced by redox processes involving these complexes, and it was found that mainly the coordination bonds of Ir complexes changed during the oxidation process. Our calculations revealed that oxidation reactions have a significant influence on the second-order NLO response owing to the change in charge transfer pattern. The β tot values of oxidized species are at least ∼9 times larger for set I and ∼5 times larger for set II than those of the corresponding parent complexes. Introduction of carborane groups into ppy (phenylpyridine) ligands can enhance the second-order NLO response by 1.2- 1.6 times by a metal-to-ligand charge transfer (MLCT) transition between the Ir atom and carborane. The β tot of complex 2 [(ppy)2Ir(phen)](+) (phen = phenanthroline) is 3.3 times larger than that of complex 1 (ppy)2Ir(acce) (acce = acetylacetonate), which is caused by ligand-to-ligand charge transfer (LLCT) between ppy ligands and the ancillary ligand. Therefore, it can be concluded that the second-order NLO response can be effectively enhanced by oxidation reactions.

  13. Evolution

    NASA Astrophysics Data System (ADS)

    Peter, Ulmschneider

    When we are looking for intelligent life outside the Earth, there is a fundamental question: Assuming that life has formed on an extraterrestrial planet, will it also develop toward intelligence? As this is hotly debated, we will now describe the development of life on Earth in more detail in order to show that there are good reasons why evolution should culminate in intelligent beings.

  14. NLO perturbativity bounds on quartic couplings in renormalizable theories with ϕ4-like scalar sectors

    NASA Astrophysics Data System (ADS)

    Murphy, Christopher W.

    2017-08-01

    The apparent breakdown of unitarity in low order perturbation theory is often is used to place bounds on the parameters of a theory. In this work we give an algorithm for approximately computing the next-to-leading order (NLO) perturbativity bounds on the quartic couplings of a renormalizable theory whose scalar sector is ϕ4-like. By this we mean theories where either there are no cubic scalar interactions, or the cubic couplings are related to the quartic couplings through spontaneous symmetry breaking. The quantity that tests where perturbation theory breaks down itself can be written as a perturbative series, and having the NLO terms allows one to test how well the series converges. We also present a simple example to illustrate the effect of considering these bounds at different orders in perturbation theory. For example, there is a noticeable difference in the viable parameter when the square of the NLO piece is included versus when it is not.

  15. A SUSY GUT of flavour with S 4 × SU(5) to NLO

    NASA Astrophysics Data System (ADS)

    Hagedorn, Claudia; King, Stephen F.; Luhn, Christoph

    2010-06-01

    We construct a Supersymmetric (SUSY) Grand Unified Theory (GUT) of Flavour based on S 4 × SU(5), together with an additional (global or local) Abelian symmetry, and study it to next-to-leading order (NLO) accuracy. The model includes a successful description of quark and lepton masses and mixing angles at leading order (LO) incorporating the Gatto-Sartori-Tonin (GST) relation and the Georgi-Jarlskog (GJ) relations. We study the vacuum alignment arising from F-terms to NLO and such corrections are shown to have a negligible effect on the results for fermion masses and mixings achieved at LO. Tri-bimaximal (TB) mixing in the neutrino sector is predicted very accurately up to NLO corrections of order 0.1%. Including charged lepton mixing corrections implies small deviations from TB mixing described by a precise sum rule, accurately maximal atmospheric mixing and a reactor mixing angle close to three degrees.

  16. Enhancement of nonlinear optical (NLO) properties of indigo through modification of auxiliary donor, donor and acceptor.

    PubMed

    Mahmood, Asif; Abdullah, Muhammad Imran; Khan, Salah Ud-Din

    2015-03-15

    In this study, indigo based dyes with high non-linear optical response have been investigated. Density functional theory (DFT) was used to study non-linear optical properties of indigo and newly designed dyes (IM-Dye-0, IM-Dye-1, IM-Dye-2 and IM-Dye-3). The time dependant density functional theory (TDDFT) was used to calculate the excitation energies. The HOMO-LUMO energy gaps of newly designed dyes were smaller as compare with indigo dye. Absorption maxima of newly designed dyes strongly red shifted as compare with indigo dye. High non-linear optical (NLO) response of newly designed dyes revealed that these materials would be excellent for NLO applications. This theoretical approach of designing will pave the way for experimentalists to synthesize high response NLO compound. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. NLO corrections to c - and b -quark fragmentation into j /ψ and γ

    NASA Astrophysics Data System (ADS)

    Sepahvand, R.; Dadfar, S.

    2017-02-01

    We present the next-to-leading-order (NLO) corrections to the fragmentation process of a heavy quark to a 3S1 wave heavy quarkonium. The virtual and real corrections are calculated by using the dimensional regularization method. The divergences due to virtual NLO corrections are analytically extracted then we explain how the poles from phase-space integrals and from loop integrals are canceled by renormalization. We use the eikonal scheme to evaluate the soft real corrections in 4 -2 ɛ dimensions. Our numerical calculations show the fragmentation function (FF) at NLO is dependent on both the μ scale and the initial quark energy. These corrections have a significant effect on the shape and probability of the FF.

  18. On the maximal use of Monte Carlo samples: re-weighting events at NLO accuracy.

    PubMed

    Mattelaer, Olivier

    2016-01-01

    Accurate Monte Carlo simulations for high-energy events at CERN's Large Hadron Collider, are very expensive, both from the computing and storage points of view. We describe a method that allows to consistently re-use parton-level samples accurate up to NLO in QCD under different theoretical hypotheses. We implement it in MadGraph5_aMC@NLO and show its validation by applying it to several cases of practical interest for the search of new physics at the LHC.

  19. Triple vector boson production through Higgs-Strahlung with NLO multijet merging

    SciTech Connect

    Hoeche, Stefan; Kraus, Frank; Pozzorini, Stephano; Schoenherr, Marek; Thompson, Jennifer M.; Zapp, Korinna C.

    2014-07-25

    Triple gauge boson hadroproduction, in particular the production of three W-bosons at the LHC, is considered at next-to leading order accuracy in QCD. The NLO matrix elements are combined with parton showers. Multijet merging is invoked such that NLO matrix elements with one additional jet are also included. The studies here incorporate both the signal and all relevant backgrounds for V H production with the subsequent decay of the Higgs boson into W– or τ–- pairs. They have been performed using SHERPA+OPENLOOPS in combination with COLLIER.

  20. Diphoton signals in theories with large extra dimensions to NLO QCD at hadron colliders

    NASA Astrophysics Data System (ADS)

    Kumar, M. C.; Mathews, Prakash; Ravindran, V.; Tripathi, Anurag

    2009-02-01

    We present a full next-to-leading order (NLO) QCD corrections to diphoton production at the hadron colliders in both standard model and ADD model. The invariant mass and rapidity distributions of the diphotons are obtained using a semi-analytical two cut-off phase space slicing method which allows for a successful numerical implementation of various kinematical cuts used in the experiments. The fragmentation photons are systematically removed using smooth-cone-isolation cuts on the photons. The NLO QCD corrections not only stabilise the perturbative predictions but also enhance the production cross section significantly.

  1. Self Assembled Spin Coated and Bulk Films of a Novel Polydiacetylene as Second Order NLO Polymers

    DTIC Science & Technology

    1994-05-31

    NLO Polymers 6. AUTHOm(m) R&T Code: 4132016 W.H. Kim, B. Bihari, R. Moody, N. B. Kodali , J.Kumar,S.K. Dr. JoAnn MilUiken Tripathy. 7. PERFORMING...Polymers by W.H. Kim, B. Bihari, R. Moody, N. B. Kodali , J.Kumar,S.K. Tripathy. Submitted to Macromolecules University of Massachusetts Lowell Department...FILMS OF A NOVEL POLYDIACETYLENE AS SECOND ORDER NLO POLYMERS W. H. Kim, B. Bihari+, R. Moody+, N. B. Kodali , J. Kumar+, and S. K. Tripathy, University

  2. NLO predictions for a lepton, missing transverse momentum and dijets at the Tevatron

    SciTech Connect

    Campbell, John M.; Martin, Adam; Williams, Ciaran; /Fermilab

    2011-05-01

    In this paper we investigate the various processes that can contribute to a final state consisting of a lepton, missing transverse momentum, and two jets at next-to-leading order (NLO) at the Tevatron. In particular we consider the production of W/Z+2 jets, diboson pairs, single top, and the t{bar t} process with both fully leptonic and semileptonic decays. We present distributions for the invariant mass of the dijet system and normalizations of the various processes, accurate to NLO.

  3. The NLO QCD corrections to associate production of squarks and charginos at LHC

    SciTech Connect

    Xiao Zhenjun; Jin Ligang; Yu Huan; Cheng Hongmei

    2010-02-10

    In this talk, we present our calculations for the next-to-leading order(NLO) QCD corrections to the cross sections (CS) of the associate production processes pp->gq->q-tilde{sub i}chi-tilde{sub j}{sup +}-+X with q = (u,d) in the constrained minimal supersymmetric standard model in the CERN LHC experiments. The NLO QCD corrections can in general provide a 30-40% enhancement to the corresponding cross sections, and significantly reduce the dependence of the total cross section on the renormalization and factorization scales.

  4. High-generation second-order nonlinear optical (NLO) Dendrimers that contain isolation chromophores: convenient synthesis by using click chemistry and their increased NLO effects.

    PubMed

    Wu, Wenbo; Li, Conggang; Yu, Gui; Liu, Yunqi; Ye, Cheng; Qin, Jingui; Li, Zhen

    2012-08-27

    Herein, high-generation dendrimers G4-NS and G5-NS, which contained 30 and 62 azo-benzene chromophore moieties, respectively, were conveniently prepared in high purity and satisfied yields by a combination of divergent and convergent approaches, coupled with the utilization of the powerful Sharpless click reaction. These dendrimers possessed a regular structure of alternating layers of nitro-based and sulfonyl-based azo chromophores in which the sulfonyl-based azo-chromophore moieties were utilized as co-isolation groups for the nitro-based moieties to achieve larger macroscopic second-order nonlinear optical (NLO) effects. These high-generation dendrimers (G4-NS and G5-NS) displayed very large NLO efficiencies (up to 253.0 pm V(-1)), which is, to the best of our knowledge, the record highest efficiency for simple azo-chromophore moieties. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The effect of secondary structures on the NLO properties of single chain oligopeptides: a comparison between β-strand and α-helix polyglycines.

    PubMed

    Alparone, Andrea

    2013-08-21

    The evolution of the electronic first-order longitudinal hyperpolarizability (βzzz) and the hyperpolarizability aligned along the direction of the dipole moment (βμ) of the α-helix and β-strand single chain H2N-(CH2-CO-NH)n-CH2-COOH (n = 1-9) oligoglycines, were investigated. For this purpose we have used Hartree-Fock, second-order Møller-Plesset perturbation theory and Coulomb-attenuating Density Functional Theory computations. For the longest chain, βμ(β-strand) is one order of magnitude greater than βμ(α-helix), due to the cooperative effect of the α-helices being unfavourable for the NLO properties. The βzzz and βμ values per unit cell of the β-strand conformation were determined, extrapolating the properties in the limit of the polymer. The calculated βzzz values were elucidated using the two-state model involving the characteristic π-π* NV1 electronic transition of peptides. Single chain β-strand polyglycines can be discriminated from the α-helices using second-order NLO effects.

  6. X-Ray Diffraction Analysis of NLO Crystals: Traditional Applications and More New Opportunities

    NASA Technical Reports Server (NTRS)

    Antipin, Mikhail Yu.; Clark, Ronald D.; Nesterov, Vladimir N.

    1998-01-01

    Single crystal X-ray diffraction analysis is one of the more important methods for the molecular and crystal structure determination of matter and therefore it has a great importance in material science including design and engineering of different compounds with non-linear optical (NLO) properties. It was shown in our previous publications that this method provides unique information about molecular structure of NLO compounds, their crystal symmetry and crystal packing arrays, molecular conformation and geometries and many other structural and electronic characteristics that are important for understanding the nature of NLO properties of solids. A very new application of the X-ray diffraction method is related to analysis of the electron density distribution p(r) in crystals and some of its characteristics (atomic and group charges, dipole and higher multipole moments, etc.), that may be obtained directly form the diffraction measurements. In the present work, we will discuss our preliminary low temperature high-resolution X-ray data for the m-nitroaniline (mNA) single crystal (VI). This is one of the "classical" organic NLO materials and electron density distribution analysis in this simple compound has a great scientific interest.

  7. Highly Non-Linear Optical (NLO) organic crystals and films. Electrooptical organic materials

    NASA Technical Reports Server (NTRS)

    Mcmanus, Samuel P.; Rosenberger, Franz; Matthews, John

    1987-01-01

    Devices employing nonlinear optics (NLO) hold great promise for important applications in integrated optics, optical information processing and telecommunications. Properly designed organics possess outstanding optical and electrooptical properties which will substantially advance many technologies including electrooptical switching, optical amplification for communications, and parallel processing for hybrid optical computers. A brief comparison of organic and inorganic materials is given.

  8. W+n-Jet Predictions With MC@NLO in Sherpa

    SciTech Connect

    Hoeche, Stefan; Krauss, Frank; Schonherr, Marek; Siegert, Frank; /Freiburg U.

    2012-03-20

    Results for the production of W-bosons in conjunction with up to three jets including parton shower corrections are presented and compared to recent LHC data. These results consistently incorporate the full next-to leading order QCD corrections through the MC{at}NLO method, as implemented in the SHERPA event generator, with the virtual corrections obtained from the BLACKHAT library.

  9. X-Ray Diffraction Analysis of NLO Crystals: Traditional Applications and More New Opportunities

    NASA Technical Reports Server (NTRS)

    Antipin, Mikhail Yu.; Clark, Ronald D.; Nesterov, Vladimir N.

    1998-01-01

    Single crystal X-ray diffraction analysis is one of the more important methods for the molecular and crystal structure determination of matter and therefore it has a great importance in material science including design and engineering of different compounds with non-linear optical (NLO) properties. It was shown in our previous publications that this method provides unique information about molecular structure of NLO compounds, their crystal symmetry and crystal packing arrays, molecular conformation and geometries and many other structural and electronic characteristics that are important for understanding the nature of NLO properties of solids. A very new application of the X-ray diffraction method is related to analysis of the electron density distribution p(r) in crystals and some of its characteristics (atomic and group charges, dipole and higher multipole moments, etc.), that may be obtained directly form the diffraction measurements. In the present work, we will discuss our preliminary low temperature high-resolution X-ray data for the m-nitroaniline (mNA) single crystal (VI). This is one of the "classical" organic NLO materials and electron density distribution analysis in this simple compound has a great scientific interest.

  10. Small-x Evolution in the Next-to-Leading Order

    SciTech Connect

    Ian Balitsky

    2009-10-01

    The high-energy behavior of amplitudes in gauge theories can be reformulated in terms of the evolution of Wilson-line operators. In the leading order this evolution is governed by the non-linear BK equation. The NLO corrections define the scale of the running-coupling constant in the BK equation and in QCD, its kernel has both conformal and non-conformal parts. To separate the conformally invariant effects from the running-coupling effects, we calculate the NLO evolution of the color dipoles in the conformal N=4 SYM theory, then we define the 'composite dipole operator' with the rapidity cutoff preserving conformal invariance, and the resulting Möbius invariant kernel for this operator agrees with the forward NLO BFKL calculation.

  11. Organometallic NLO Polymers. 3. Copolymerization of Bridged Bis(ferrocenyl) and Bis(cyanoacetate) Monomers Via the Knoevenagel Condensation

    DTIC Science & Technology

    1992-05-10

    Organometallics 1990,9, 853. (b) Wright, M. E.; Toplikar, F_. G. in "Advances in New Materials , Contemporary Topics in Polymer Sicence ,", Salamone, J. C., Riffle...Lindsay and coworkers recently presented the synthesis of a new class of main-chain organic NLO polymers.4 For this new class of NLO materials the polymer...backbone will be aligned into a accordion shape.5 To date, this approach has not been used in the area of organometallic polymeric NLO materials .6

  12. NLO QCD+EW predictions for V + jets including off-shell vector-boson decays and multijet merging

    NASA Astrophysics Data System (ADS)

    Kallweit, S.; Lindert, J. M.; Maierhöfer, P.; Pozzorini, S.; Schönherr, M.

    2016-04-01

    We present next-to-leading order (NLO) predictions including QCD and electroweak (EW) corrections for the production and decay of off-shell electroweak vector bosons in association with up to two jets at the 13 TeV LHC. All possible dilepton final states with zero, one or two charged leptons that can arise from off-shell W and Z bosons or photons are considered. All predictions are obtained using the automated implementation of NLO QCD+EW corrections in the O penLoops matrix-element generator combined with the Munich and Sherpa Monte Carlo frameworks. Electroweak corrections play an especially important role in the context of BSM searches, due to the presence of large EW Sudakov logarithms at the TeV scale. In this kinematic regime, important observables such as the jet transverse momentum or the total transverse energy are strongly sensitive to multijet emissions. As a result, fixed-order NLO QCD+EW predictions are plagued by huge QCD corrections and poor theoretical precision. To remedy this problem we present an approximate method that allows for a simple and reliable implementation of NLO EW corrections in the MePs@Nlo multijet merging framework. Using this general approach we present an inclusive simulation of vector-boson production in association with jets that guarantees NLO QCD+EW accuracy in all phase-space regions involving up to two resolved jets.

  13. Q 2 evolution of parton distributions at small values of x: Effective scale for combined H1 and ZEUS data on the structure function F 2

    NASA Astrophysics Data System (ADS)

    Kotikov, A. V.; Shaikhatdenov, B. G.

    2015-06-01

    An expression for the structure function F 2 in the form of Bessel functions at small values of the Bjorken variable x is used. This expression was derived for a flat initial condition in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations. The argument of the strong coupling constant was chosen in such a way as to annihilate the singular part of the anomalous dimensions in the next-to-leading-order of perturbation theory. This choice, together with the frozen and analytic versions of the strong coupling constant, is used to analyze combined data of the H1 and ZEUS Collaborations obtained recently for the structure function F 2.

  14. A DFT study on NLO response of push-pull hybrid porphyrin-polyoxometalate complexes

    NASA Astrophysics Data System (ADS)

    Yao, Chan; Hu, Bo; Wang, Qingwei; Song, Ping; Su, Zhongmin

    2014-06-01

    Density functional theory (DFT) calculations were carried out to investigate the second-order nonlinear optical (NLO) properties of a series of proposed porphyrin-polyoxometalate-based complexes related to [5-(3,5-dimethyl-4-hexamolybdate amino-phenyl-ethynyl)-15-(4-nitrophenyl-ethynyl)porphinato]zinc(II) which have donor-π conjugated bridge-acceptor (D-π-A) configurations. Our calculations show that these species possess considerably large molecular total second-order polarizability (β0), ˜2000 × 10-30 esu. Furthermore, it can be seen that {W6O18} exhibits stronger electron-donating ability than {Mo6O18}. And two-dimensional (2D) system with A-π-D-π-A structure might be a promising candidate for NLO materials based on the large β0 (4583.5 × 10-30 esu) and in-plane nonlinear anisotropy.

  15. Photophysical studies of fused phenanthrimidazole derivatives as versatile π-conjugated systems for potential NLO applications

    NASA Astrophysics Data System (ADS)

    Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Venkatesh Perumal, Marimuthu

    Two new heterocyclic imidazole derivatives consists of π-conjugated system attached to a phenanthrimidazole moiety have been synthesized in moderate yield by the condensation of 1,10-phenanthroline-5,6-dione with substituted aromatic aldehydes and 4-methoxyaniline in the presence of ammonium acetate in ethanol medium. The photophysical properties of these imidazole derivatives were studied in several solvents. These derivatives were evaluated concerning their solvatochromic properties and molecular optical nonlinearities. Their electric dipole moment (μ) and hyperpolarizability (β) have been calculated theoretically and the results indicate that the extension of the π-framework of the ligands has an effect on the NLO properties of these imidazole derivatives. The non-zero tensor components of these imidazole derivatives reveal that they possess potent non-linear optical (NLO) behavior. The energies of the HOMO and LUMO levels and the molecular electrostatic potential (MEP) energy surface studies have exploited the existence of intramolecular charge transfer (ICT) within the molecule.

  16. Higgs characterisation at NLO in QCD: CP properties of the top-quark Yukawa interaction.

    PubMed

    Demartin, Federico; Maltoni, Fabio; Mawatari, Kentarou; Page, Ben; Zaro, Marco

    At the LHC the CP properties of the top-quark Yukawa interaction can be probed through Higgs production in gluon fusion or in association with top quarks. We consider the possibility for both CP-even and CP-odd couplings to the top quark to be present, and study CP-sensitive observables at next-to-leading order (NLO) in QCD, including parton-shower effects. We show that the inclusion of NLO corrections sizeably reduces the theoretical uncertainties, and confirm that di-jet correlations in [Formula: see text] jet production through gluon fusion and correlations of the top-quark decay products in [Formula: see text] production can provide sensitive probes of the CP nature of the Higgs interactions.

  17. DFT calculations on spectroscopic, structural and NLO properties of silver (I) complex with picolinamide

    NASA Astrophysics Data System (ADS)

    Altürk, Sümeyye; Avci, Davut; Tamer, Ömer; Atalay, Yusuf

    2017-02-01

    The molecular geometry optimization, vibrational frequencies, the molecular static polarizability (α), first-order static hyperpolarizability (β), second-order static hyperpolarizability (γ) and frontier molecular orbital (FMO) energies of silver (I) complex with picolinamide, [Ag(C6H6N2O)2](NO3).H2O, were investigated using density functional theory (DFT) HSEh1PBE and B3LYP methods with LANL2DZ basis set. The molecular hardness (η) and electronegativity (χ) parameters were also obtained by using FMO energies. The NLO parameters of the complex were compared with those of para-Nitroaniline (pNA) and urea which are typical NLO materials. Obtained data showed that there is an agreement between the predicted and experimental data.

  18. Quantum chemical characterization of N-(2-hydroxybenzylidene)acetohydrazide (HBAH): a detailed vibrational and NLO analysis.

    PubMed

    Tamer, Ömer; Avcı, Davut; Atalay, Yusuf

    2014-01-03

    The molecular modeling of N-(2-hydroxybenzylidene)acetohydrazide (HBAH) was carried out using B3LYP, CAMB3LYP and PBE1PBE levels of density functional theory (DFT). The molecular structure of HBAH was solved by means of IR, NMR and UV-vis spectroscopies. In order to find the stable conformers, conformational analysis was performed based on B3LYP level. A detailed vibrational analysis was made on the basis of potential energy distribution (PED). HOMO and LUMO energies were calculated, and the obtained energies displayed that charge transfer occurs in HBAH. NLO analysis indicated that HBAH can be used as an effective NLO material. NBO analysis also proved that charge transfer, conjugative interactions and intramolecular hydrogen bonding interactions occur through HBAH. Additionally, major contributions from molecular orbitals to the electronic transitions were investigated theoretically. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Top-pair production and decay at NLO matched with parton showers

    DOE PAGES

    Campbell, John M.; Ellis, R. Keith; Nason, Paolo; ...

    2015-04-21

    We present a next-to-leading order (NLO) calculation of tt¯ production in hadronic collisions interfaced to shower generators according to the POWHEG method. We start from an NLO result from previous work, obtained in the zero width limit, where radiative corrections to both production and decays are included. The POWHEG interface required an extension of the POWHEG BOX framework, in order to deal with radiation from the decay of resonances. This extension is fully general (i.e. it can be applied in principle to any process considered in the zero width limit), and is here applied for the first time. In ordermore » to perform a realistic simulation, we introduce finite width effects using different approximations, that we validated by comparing with published exact NLO results. We have interfaced our POWHEG code to the PYTHIA8 shower Monte Carlo generator. At this stage, we dealt with novel issues related to the treatment of resonances, especially with regard to the initial scale for the shower that needs to be set appropriately. This procedure affects, for example, the fragmentation function of the b quark, that we have studied with particular attention. We believe that the tool presented here improves over previous generators for all aspects that have to do with top decays, and especially for the study of issues related to top mass measurements that involve B hadrons or b jets. As a result, the work presented here also constitutes a first step towards a fully consistent matching of NLO calculations involving intermediate resonances decaying into coloured particles, with parton showers.« less

  20. NLO QCD corrections to the jet activity in Higgs boson production via vector-boson fusion

    NASA Astrophysics Data System (ADS)

    Figy, Terrance Maynard

    Higgs production plus two jets via vector-boson fusion is expected to provide crucial information on the Higgs boson couplings at the CERN Large Hadron Collider. The achievable statistical accuracy demands comparison with next-to-leading order QCD calculations, which are presented here in the form of a fully flexible partonic Monte Carlo program. QCD corrections are determined for jet distributions and are shown to be modest, of the order of 5%--10% in most cases, but reaching 30% occasionally. Remaining scale uncertainties range from the order of 5% or less for distributions to below +/-2% for the Higgs boson cross section in typical vector-boson fusion search regions. Higgs boson production plus two jets via vector-fusion is sensitive to the tensor of the HVV (V = W, Z ) couplings, which distinguishes loop induced vertices from SM expectations. At the CERN Large Hadron Collider this information shows up in the azimuthal angle correlations of the two forward and backward quark jets which are typical for weak boson fusion. The next-to-leading order QCD corrections to this process, in the presence of anomalous HVV couplings are computed. It is shown that gluon emission does not significantly change the azimuthal jet correlations. For Higgs production via vector boson fusion (VBF), there is suppressed jet activity in the central region of rapidity. Higgs production via VBF in the association of three jets (Hjjj) is computed to NLO accuracy in QCD. K factors for Hjjj are modest, typically, 1.03 to 1.06. Scale uncertainties for the total cross section at NLO are less than 5%. 3-jet ratios for Higgs production via VBF are computed at LO and NLO. The scale dependence of 3-jet ratios is shown to be reduced at NLO.

  1. Diphoton production in the ADD model to NLO + parton shower accuracy at the LHC

    NASA Astrophysics Data System (ADS)

    Frederix, R.; Mandal, Manoj K.; Mathews, Prakash; Ravindran, V.; Seth, Satyajit; Torrielli, P.; Zaro, M.

    2012-12-01

    In this paper, we present the next-to-leading order predictions for diphoton production in the ADD model, matched to the HERWIG parton shower using the MC@NLO formalism. A selection of the results is presented for d = 2-6 extra dimensions, using generic cuts as well as analysis cuts mimicking the search strategies as pursued by the ATLAS and CMS experiments.

  2. Top-pair production and decay at NLO matched with parton showers

    SciTech Connect

    Campbell, John M.; Ellis, R. Keith; Nason, Paolo; Re, Emanuele

    2015-04-21

    We present a next-to-leading order (NLO) calculation of tt¯ production in hadronic collisions interfaced to shower generators according to the POWHEG method. We start from an NLO result from previous work, obtained in the zero width limit, where radiative corrections to both production and decays are included. The POWHEG interface required an extension of the POWHEG BOX framework, in order to deal with radiation from the decay of resonances. This extension is fully general (i.e. it can be applied in principle to any process considered in the zero width limit), and is here applied for the first time. In order to perform a realistic simulation, we introduce finite width effects using different approximations, that we validated by comparing with published exact NLO results. We have interfaced our POWHEG code to the PYTHIA8 shower Monte Carlo generator. At this stage, we dealt with novel issues related to the treatment of resonances, especially with regard to the initial scale for the shower that needs to be set appropriately. This procedure affects, for example, the fragmentation function of the b quark, that we have studied with particular attention. We believe that the tool presented here improves over previous generators for all aspects that have to do with top decays, and especially for the study of issues related to top mass measurements that involve B hadrons or b jets. As a result, the work presented here also constitutes a first step towards a fully consistent matching of NLO calculations involving intermediate resonances decaying into coloured particles, with parton showers.

  3. The chiral S = -1 meson-baryon interaction with new constraints on the NLO contributions

    NASA Astrophysics Data System (ADS)

    Ramos, A.; Feijoo, A.; Magas, V. K.

    2016-10-01

    We present a study of the S = - 1 meson-baryon interaction, employing a chiral SU(3) Lagrangian up to next-to-leading order (NLO) and implementing unitarization in coupled channels. The parameters of the model have been fitted to a large set of experimental scattering data in different two-body channels, to threshold branching ratios, and to the precise SIDDHARTA value of the energy shift and width of kaonic hidrogen. In contrast to other groups, we have taken into consideration the K- p →K+Ξ- ,K0Ξ0 reaction data, since we found in a previous work to be especially sensitive to the NLO parameters of the chiral Lagrangian. In the present work we also include the Born terms, which usually have very little effect, and find them to be non-negligible in the K- p → KΞ channels, correspondingly causing significant modifications to the NLO parameters. We furthermore show that the importance of the Born terms becomes more visible in the isospin projected amplitudes of the K- p → KΞ reactions. The measurement of processes that filter single isospin components, like the KL0 p →K+Ξ0 reaction that could be measured at the proposed secondary KL0 beam at Jlab, would put valuable constraints on the chiral models describing the meson-baryon interaction in the S = - 1 sector.

  4. Solvatochromic benzo[h] coumarins: Synthesis, solvatochromism, NLO and DFT study

    NASA Astrophysics Data System (ADS)

    Warde, Umesh; Sekar, Nagaiyan

    2017-10-01

    Three benzo[h] coumarins were synthesized and analyzed for their potential NLOphoric properties. Coumarins were synthesized using Knoevenagel condensation method by reacting hydroxyl-naphthalene aldehyde with cyano-methylelene-benzazoles containing NH, O and S elements respectively as the active methylene compounds. The absorption maxima for the coumarins are not affected by the solvent polarity but emission maxima does. Emission solvatochromism was analyzed using various solvent polarity functions which highlights the polarity dependency of the emission profile. Coumarins showed satisfactory values for first and second hyperpolarizability which are comparable using solvatochromism and DFT. NLO properties are also compared with the limits of hyperpolarizability calculated using sum rule of quantum mechanics. Results show that the NLO properties predicted by DFT are close to the upper limits of hyperpolarizability. The functional CAM-B3LYP is proven to be suitable for predicting NLO properties for these coumarins compared to functional B3LYP. The present study highlights the importance of such molecules for incorporating in advanced NLOphores.

  5. Jet-medium interactions at NLO in a weakly-coupled quark-gluon plasma

    NASA Astrophysics Data System (ADS)

    Ghiglieri, Jacopo; Moore, Guy D.; Teaney, Derek

    2016-03-01

    We present an extension to next-to-leading order in the strong coupling constant g of the AMY effective kinetic approach to the energy loss of high momentum particles in the quark-gluon plasma. At leading order, the transport of jet-like particles is determined by elastic scattering with the thermal constituents, and by inelastic collinear splittings induced by the medium. We reorganize this description into collinear splittings, high-momentum-transfer scatterings, drag and diffusion, and particle conversions (momentum-preserving identity-changing processes). We show that this reorganized description remains valid to NLO in g, and compute the appropriate modifications of the drag, diffusion, particle conversion, and inelastic splitting coefficients. In addition, a new kinematic regime opens at NLO for wider-angle collinear bremsstrahlung. These semi-collinear emissions smoothly interpolate between the leading order high-momentum-transfer scatterings and collinear splittings. To organize the calculation, we introduce a set of Wilson line operators on the light-cone which determine the diffusion and identity changing coefficients, and we show how to evaluate these operators at NLO.

  6. Low mass thermal dilepton production at NLO in a weakly coupled quark-gluon plasma

    NASA Astrophysics Data System (ADS)

    Ghiglieri, Jacopo; Moore, Guy D.

    2014-12-01

    We present a computation, within weakly-coupled thermal QCD, of the production rate of low invariant mass ( M 2 ~ g 2 T 2) dileptons, at next-to-leading order (NLO) in the coupling (which is ). This involves extending the NLO calculation of the photon rate which we recently presented to the case of small nonzero photon invariant mass. Numerical results are discussed and tabulated forms and code are provided for inclusion in hydrodynamical models. We find that NLO corrections can increase the dilepton rate by up to 30-40% relative to leading order. We find that the electromagnetic response of the plasma for real photons and for small invariant mass but high energy dilepton pairs (e.g., M 2 < (300 MeV)2 but p T > 1 GeV) are close enough that dilepton pair measurements really can serve as ersatz photon measurements. We also present a matching a la Ghisoiu and Laine between our results and results at larger invariant masses.

  7. Characterizing the NLO chromophore orientation of polymeric film by electroabsorption spectroscopy[Nonlinear Optical

    SciTech Connect

    Yang, K.; Wang, X.; Kim, W.; Jain, A.; Li, L.; Kumar, J.; Tripathy, S.

    1998-07-01

    The dispersion of third-order nonlinear coefficients {chi}{sub 1133}{sup (3)} and {chi}{sub 3333}{sup (3)} of three different NLO (nonlinear optical) polymer films were determined by electroabsorption spectroscopy. The first material investigated is an epoxy-based polymer BP-2A-NT, with azobenzene NLO chromophore 4-[((4-nitrophenyl)(azo)phenyl)azo]aniline in its side chain. The other materials are two polydiacetylenes, poly(BPOD) and poly(4-BCMU), in which the delocalized polymer chains contribute to the third-order nonlinearity. The complex spectrum of {chi}{sub 3333}{sup (3)} of each material is very similar in shape to corresponding {chi}{sub 1133}{sup (3)} spectrum. The ratio of {chi}{sub 3333}{sup (3)} to {chi}{sub 1133}{sup (3)} is 3.2 for BP-2A-NT, 1.5 for both poly(BPOD) and poly(4-BCMU). These ratios indicate that the distribution of the side-chain NLO chromophores of BP-2A-NT is very close to three-dimensional isotropy, and the distribution of the main-chain chromophores of poly(BPOD) and poly(4-BCMU) is concentrated on the film plane.

  8. Automation of NLO QCD and EW corrections with Sherpa and Recola

    NASA Astrophysics Data System (ADS)

    Biedermann, Benedikt; Bräuer, Stephan; Denner, Ansgar; Pellen, Mathieu; Schumann, Steffen; Thompson, Jennifer M.

    2017-07-01

    This publication presents the combination of the one-loop matrix-element generator Recola with the multipurpose Monte Carlo program Sherpa. Since both programs are highly automated, the resulting Sherpa + Recola framework allows for the computation of - in principle - any Standard Model process at both NLO QCD and EW accuracy. To illustrate this, three representative LHC processes have been computed at NLO QCD and EW: vector-boson production in association with jets, off-shell Z-boson pair production, and the production of a top-quark pair in association with a Higgs boson. In addition to fixed-order computations, when considering QCD corrections, all functionalities of Sherpa, i.e. particle decays, QCD parton showers, hadronisation, underlying events, etc. can be used in combination with Recola. This is demonstrated by the merging and matching of one-loop QCD matrix elements for Drell-Yan production in association with jets to the parton shower. The implementation is fully automatised, thus making it a perfect tool for both experimentalists and theorists who want to use state-of-the-art predictions at NLO accuracy.

  9. Stimuli-responsive NLO properties of tetrathiafulvalene-fused donor-acceptor chromophores.

    PubMed

    Cariati, E; Liu, X; Geng, Y; Forni, A; Lucenti, E; Righetto, S; Decurtins, S; Liu, S-X

    2017-08-23

    The second-order nonlinear optical (NLO) properties of two tetrathiafulvalene (TTF)-fused electron donor-acceptor dyads have been determined using the Electric Field Induced Second Harmonic generation (EFISH) technique and theoretically rationalized. Dyads TTF-dppz (1) and TTF-BTD (2) were obtained by direct fusion of a TTF electron donor unit either with a dipyrido[3,2-a:2',3'-c]phenazine (dppz) or a benzothiadiazole (BTD) electron acceptor moiety. Dyad 1 acts as a reversible acido-triggered NLO switch by protonation/deprotonation at two nitrogen atoms of the dppz acceptor moiety induced by sequential exposure to HCl and ammonia vapors. Dyad 2, on the other hand, displays redox-tunable NLO properties upon two consecutive oxidations to its radical cation 2+˙ and dication 22+ species. The resulting final dication 22+ exhibits an inversion of the sign of β0, due to a completely inverted distribution of the frontier molecular orbitals with respect to those of its neutral species, leading to a scarcely polar species in the excited state, as indicated by the theoretical calculations.

  10. Physicochemical and solvatochromic analysis of an imidazole derivative as NLO material.

    PubMed

    Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Perumal, Marimuthu Venkatesh

    2012-01-01

    Bioactive imidazole derivative, 2-(2,4-difluorophenyl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline, has been synthesized and characterized by IR, UV-vis, NMR and elemental (CHN) analysis. The electric dipole moment (μ) and the hyperpolarizability (β) have been studied both experimentally and theoretically, which reveals that the synthesized imidazole derivative possesses non-linear optical (NLO) behavior. This chromophore possess more appropriate ratio of off-diagonal versus diagonal β tensorial component (r=β(xyy)/β(xxx)=-0.19) which reflects the in plane nonlinearity anisotropy. Since they have largest μβ(0) value, the reported imidazole can be used as potential NLO material. Within this context, reasonable conclusions concerning the steric hindrance in the chromospheres, push-pull character, hyperpolarizability of the imidazole and their application as NLO materials will be drawn. The solvent effect on the absorption and fluorescence bands was analyzed by a multi-component linear regression in which several solvent parameters were analyzed simultaneously. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. NLO perturbativity bounds on quartic couplings in renormalizable theories with Φ4 -like scalar sectors

    DOE PAGES

    Murphy, Christopher W.

    2017-08-17

    The apparent breakdown of unitarity in low order perturbation theory is often is used to place bounds on the parameters of a theory. In this work we give an algorithm for approximately computing the next-to-leading order (NLO) perturbativity bounds on the quartic couplings of a renormalizable theory whose scalar sector is Φ 4 -like. And by this we mean theories where either there are no cubic scalar interactions, or the cubic couplings are related to the quartic couplings through spontaneous symmetry breaking. Furthermore, the quantity that tests where perturbation theory breaks down itself can be written as a perturbative series,more » and having the NLO terms allows one to test how well the series converges. We also present a simple example to illustrate the effect of considering these bounds at different orders in perturbation theory. For example, there is a noticeable difference in the viable parameter when the square of the NLO piece is included versus when it is not.« less

  12. Theoretical investigation on switchable second-order nonlinear optical (NLO) properties of novel cyclopentadienylcobalt linear [4]phenylene complexes.

    PubMed

    Wang, Wen-Yong; Du, Xiao-Feng; Ma, Na-Na; Sun, Shi-Ling; Qiu, Yong-Qing

    2013-04-01

    As a kind of novel organometallic complexes, the cyclopentadienylcobalt (CpCo) linear [4]phenylene complexes (4 = number of benzene rings) display efficient switchable nonlinear optical (NLO) response when CpCo reversibly migrates along the linear [4]phenylene triggered by heating or lighting. In this paper, the second-order NLO properties for CpCo linear [4]phenylene complexes were calculated by using the density functional theory (DFT) methods with four functionals. All of the functionals yield the same order of β tot values: 1<2<4<3. The effect of solvent on second-order NLO properties has been studied using polarized continuum model (PCM) in the tetrahydrofuran (THF) solution. The solvent leads to a slight enhancement of the NLO responses for the studied complexes relevant to their NLO responses in vacuo. The electronic absorption spectra were investigated by the TDDFT methods. The TDDFT calculations indicate that the maximum absorption peaks of complexes 2-4 in the near-infrared spectrum area show the bathochromic shift together with a decreasing intensity compared to complex 1. We have also found that the cobalt (Co) atom acts as a donor in all the organometallic complexes and the d → π* and π → π* charge transfer (CT) transitions contribute to the enhancement of second-order NLO response. Furthermore, two experimentally existing complexes 1 and 3 are found to have a large difference in β tot values. It is our expectation that this difference may stimulate the search for a new type of switchable NLO material based on CpCo linear [4]phenylene complexes.

  13. The role of ion pairs in the second-order NLO response of 4-X-1-methylpiridinium salts.

    PubMed

    Tessore, Francesca; Cariati, Elena; Cariati, Franco; Roberto, Dominique; Ugo, Renato; Mussini, Patrizia; Zuccaccia, Cristiano; Macchioni, Alceo

    2010-02-01

    A series of 4-X-1-methylpyridinium cationic nonlinear optical (NLO) chromophores (X = (E)-CH=CHC(6)H(5); (E)-CH=CHC(6)H(4)-4'-C(CH(3))(3); (E)-CH=CHC(6)H(4)-4'-N(CH(3))(2); (E)-CH=CHC(6)H(4)-4'-N(C(4)H(9))(2); (E,E)-(CH=CH)(2)C(6)H(4)-4'-N(CH(3))(2)) with various organic (CF(3)SO(3)(-), p-CH(3)C(6)H(4)SO(3)(-)), inorganic (I(-), ClO(4)(-), SCN(-), [Hg(2)I(6)](2-)) and organometallic (cis-[Ir(CO)(2)I(2)](-)) counter anions are studied with the aim of investigating the role of ion pairing and of ionic dissociation or aggregation of ion pairs in controlling their second-order NLO response in anhydrous chloroform solution. The combined use of electronic absorption spectra, conductimetric measurements and pulsed field gradient spin echo (PGSE) NMR experiments show that the second-order NLO response, investigated by the electric-field-induced second harmonic generation (EFISH) technique, of the salts of the cationic NLO chromophores strongly depends upon the nature of the counter anion and concentration. The ion pairs are the major species at concentration around 10(-3) M, and their dipole moments were determined. Generally, below 5x10(-4) M, ion pairs start to dissociate into ions with parallel increase of the second-order NLO response, due to the increased concentration of purely cationic NLO chromophores with improved NLO response. At concentration higher than 10(-3) M, some multipolar aggregates, probably of H type, are formed, with parallel slight decrease of the second-order NLO response. Ion pairing is dependent upon the nature of the counter anion and on the electronic structure of the cationic NLO chromophore. It is very strong for the thiocyanate anion in particular and, albeit to a lesser extent, for the sulfonated anions. The latter show increased tendency to self-aggregate.

  14. In Vivo Non Linear Optical (NLO) Imaging in Live Rabbit Eyes Using the Heidelberg Two-Photon Laser Ophthalmoscope

    PubMed Central

    Hao, Ming; Flynn, Kevin; Nien-Shy, Chyong; Jester, Bryan E.; Winkler, Moritz; Brown, Donald J.; La Schiazza, Olivier; Bille, Josef; Jester, James V.

    2010-01-01

    Imaging of non-linear optical (NLO) signals generated from the eye using ultrafast pulsed lasers has been limited to the study of ex vivo tissues because of the use of conventional microscopes with slow scan speeds. The purpose of this study was to evaluate the ability of a novel, high scan rate ophthalmoscope to generate NLO signals using an attached femtosecond laser. NLO signals were generated and imaged in live, anesthetized albino rabbits using a newly designed Heidelberg Two-Photon Laser Ophthalmoscope with attached 25 mW femtosecond laser having a central wavelength of 780 nm, pulsewidth of 75 fs, and a repetition rate of 50 MHz. To assess two-photon excited fluorescent (TPEF) signal generation, cultured rabbit corneal fibroblasts (RCF) were first labeled by Blue-green fluorescent FluoSpheres (1 μm diameter) and then cells were micro-injected into the central cornea. Clumps of RCF cells could be detected by both reflectance and TPEF imaging at 6 hours after injection. By 6 days, RCF containing fluorescent microspheres confirmed by TPEF showed a more spread morphology and had migrated from the original injection site. Overall, this study demonstrates the potential of using NLO microscopy to sequentially detect TPEF signals from live, intact corneas. We conclude that further refinement of the Two-photon laser Ophthalmoscope should lead to the development of an important, new clinical instrument capable of detecting NLO signals from patient corneas. PMID:20558159

  15. In vivo non-linear optical (NLO) imaging in live rabbit eyes using the Heidelberg Two-Photon Laser Ophthalmoscope.

    PubMed

    Hao, Ming; Flynn, Kevin; Nien-Shy, Chyong; Jester, Bryan E; Winkler, Moritz; Brown, Donald J; La Schiazza, Olivier; Bille, Josef; Jester, James V

    2010-08-01

    Imaging of non-linear optical (NLO) signals generated from the eye using ultrafast pulsed lasers has been limited to the study of ex vivo tissues because of the use of conventional microscopes with slow scan speeds. The purpose of this study was to evaluate the ability of a novel, high scan rate ophthalmoscope to generate NLO signals using an attached femtosecond laser. NLO signals were generated and imaged in live, anesthetized albino rabbits using a newly designed Heidelberg Two-Photon Laser Ophthalmoscope with attached 25 mW fs laser having a central wavelength of 780 nm, pulsewidth of 75 fs, and a repetition rate of 50 MHz. To assess two-photon excited fluorescent (TPEF) signal generation, cultured rabbit corneal fibroblasts (RCF) were first labeled by Blue-green fluorescent FluoSpheres (1 mum diameter) and then cells were micro-injected into the central cornea. Clumps of RCF cells could be detected by both reflectance and TPEF imaging at 6 h after injection. By 6 days, RCF containing fluorescent microspheres confirmed by TPEF showed a more spread morphology and had migrated from the original injection site. Overall, this study demonstrates the potential of using NLO microscopy to sequentially detect TPEF signals from live, intact corneas. We conclude that further refinement of the Two-photon laser Ophthalmoscope should lead to the development of an important, new clinical instrument capable of detecting NLO signals from patient corneas. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Two novel bi-functional hybrid materials constructed from POMs and a Schiff base with excellent third-order NLO and catalytic properties.

    PubMed

    Hu, Gonghao; Miao, Hao; Mei, Hua; Zhou, Shuai; Xu, Yan

    2016-05-10

    The first polyoxometalates modified by a porphyrin-resembling planar Schiff base have been successfully designed and synthesized under hydrothermal conditions. The third-order NLO responses indicated that they are excellent third-order NLO materials. Their catalytic performances are also investigated.

  17. Switchable NLO response induced by rotation of metallacarboranes [Ni(III/IV)(C2B9H11)2](-/0) and C-,B-functionalized derivatives.

    PubMed

    Ma, Na-Na; Li, Shu-Jun; Yan, Li-Kai; Qiu, Yong-Qing; Su, Zhong-Min

    2014-04-07

    The rotary motion based on metallacarboranes around a molecular axis can be controlled by simple electron transfer processes, which provides a basis for the structure-property relationship for the nonlinear optical (NLO) switching. However, this phenomenon has not been previously reported in the development of NLO properties of metallacarboranes. In this work, the metallacarboranes [Ni(III/IV)(C2B9H11)2](-/0) and their C-,B-functionalized derivatives are studied by the density functional theory (DFT) method. By calculating relative energies, we obtained the stable states before and after rotation controlled by simple electron transfer. Then, the static and frequency-dependent second-order NLO properties were calculated by several DFT functionals. According to the TDDFT results, the large NLO responses of the studied compounds are mainly caused by substituent group-to-carborane cage charge transfer (L'LCT) and substituent group-to-metal charge transfer (L'MCT) processes. The order of first hyperpolarizabilities (β values) illustrates that the NLO response can be enhanced by introducing a strong electron-donating group. Significantly, the geometric interconversions resulting from the redox reaction of 1C/1T-6C/6T allow the NLO responses to be switched "ON" or "OFF". The B(9,9')-methoxyphenyl-functionalized derivative of nickelacarborane, having low energetic cost and large different NLO responses between two states (from 0 to 20 998 a.u.), can be an excellent switchable NLO material.

  18. The influence of pentafluorophenyl groups on the nonlinear optical (NLO) performance of high generation dendrons and dendrimers

    PubMed Central

    Wu, Wenbo; Wang, Can; Li, Qianqian; Ye, Cheng; Qin, Jingui; Li, Zhen

    2014-01-01

    With the aim to make the influence of pentafluorophenyl groups in the periphery of high generation dendrons and dendrimers on their NLO performance clearly, some NLO dendrons and dendrimers with different chromophore moieties or different end-capped groups were carefully designed and investigated in detail. The results demonstrated that some strong Ar-ArF interactions between the pentafluorophenyl groups in the periphery and the normal phenyl rings of the donors, could influence the topological structures of dendrons or dendrimers, and then affect their NLO performance. Furthermore, the optical transparency and the stability of the dendrons and dendrimers with pentafluorophenyl groups as end-capped moieties were all improved, in comparison with normal dendrons and dendrimers containing phenyl ones as the end-capped groups. PMID:25168867

  19. The influence of pentafluorophenyl groups on the nonlinear optical (NLO) performance of high generation dendrons and dendrimers.

    PubMed

    Wu, Wenbo; Wang, Can; Li, Qianqian; Ye, Cheng; Qin, Jingui; Li, Zhen

    2014-08-29

    With the aim to make the influence of pentafluorophenyl groups in the periphery of high generation dendrons and dendrimers on their NLO performance clearly, some NLO dendrons and dendrimers with different chromophore moieties or different end-capped groups were carefully designed and investigated in detail. The results demonstrated that some strong Ar-Ar(F) interactions between the pentafluorophenyl groups in the periphery and the normal phenyl rings of the donors, could influence the topological structures of dendrons or dendrimers, and then affect their NLO performance. Furthermore, the optical transparency and the stability of the dendrons and dendrimers with pentafluorophenyl groups as end-capped moieties were all improved, in comparison with normal dendrons and dendrimers containing phenyl ones as the end-capped groups.

  20. NLO predictions for Higgs boson pair production with full top quark mass dependence matched to parton showers

    NASA Astrophysics Data System (ADS)

    Heinrich, G.; Jones, S. P.; Kerner, M.; Luisoni, G.; Vryonidou, E.

    2017-08-01

    We present the first combination of NLO QCD matrix elements for di-Higgs production, retaining the full top quark mass dependence, with a parton shower. Results are provided within both the POWHEG-BOX and MadGraph5_aMC@NLO Monte Carlo frameworks. We assess in detail the theoretical uncertainties and provide differential results. We find that, as expected, the shower effects are relatively large for observables like the transverse momentum of the Higgs boson pair, which are sensitive to extra radiation. However, these shower effects are still much smaller than the differences between the Born-improved HEFT approximation and the full NLO calculation in the tails of the distributions.

  1. Scaffold characterization using NLO multimodal microscopy in metrology for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Mortati, Leonardo; Divieto, Carla; Boffitto, Monica; Sartori, Susanna; Ciardelli, Gianluca; Sassi, Maria Paola

    2013-09-01

    Metrology in regenerative medicine aims to develop traceable measurement technologies for characterizing cellular and macromolecule behaviour in regenerative medicine products and processes. One key component in regenerative medicine is using three-dimensional porous scaffolds to guide cells during the regeneration process. The regeneration of specific tissues guided by tissue analogous substrates is dependent on diverse scaffold architectural properties that can be derived quantitatively from scaffolds images. This paper discuss the results obtained with the multimodal NLO microscope recently realized in our laboratory in characterizing 3D tissue engineered (TE) scaffolds colonized from human Mesenchimal stem cells (hMSC), focusing on the study of the three-dimensional metrological parameters.

  2. Physico-chemical studies of fused phenanthrimidazole derivative as sensitive NLO material

    NASA Astrophysics Data System (ADS)

    Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Sathishkumar, Ramalingam; Jayamoorthy, Karunamoorthy

    2013-01-01

    Heterocyclic phenanthrimidazole derivative, 2-(4-fluorophenyl)-1-p-tolyl-1H-imidazo[4,5-f] [1,10] phenanthroline (FPTIP) has been synthesized and characterised by NMR, mass and CHN analysis. The FPTIP was evaluated concerning their solvatochromic properties and molecular optical nonlinearities. Their electric dipole moment (μ), polarizability (α) and hyperpolarizability (β) have been calculated theoretically and the results indicate that the extension of the π-framework of the ligands has an effect on the NLO properties. The energies of the HOMO and LUMO levels and the molecular electrostatic potential (MEP) energy surface studies have exploited the existence of intramolecular charge transfer (ICT) within the molecule.

  3. Multi-jet Cross Sections at NLO with BlackHat and Sherpa

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.

    2009-05-20

    In this talk, we report on a recent next-to-leading order QCD calculation of the production of a W boson in association with three jets at hadron colliders. The computation is performed by combining two programs, BlackHat for the computation of the virtual one-loop matrix elements and Sherpa for the real emission part. The addition of NLO corrections greatly reduces the factorization and renormalization scale dependence of the theory prediction for this process. This result demonstrates the applicability of unitarity-based methods for hadron collider physics.

  4. Structure modulations in nonlinear optical (NLO) materials Cs(2)TB4O9 (T = Ge, Si).

    PubMed

    Zhou, Zhengyang; Xu, Xiang; Fei, Rao; Mao, Jianggao; Sun, Junliang

    2016-04-01

    Incommensurately modulated borate structures of a new type were studied in detail in the nonlinear optical (NLO) materials Cs(2)TB4O9 (T = Ge, Si) using single-crystal X-ray diffraction techniques. The structures were solved by the charge-flipping algorithm in the superspace group I2(αβ0)0. The refinement results strongly suggest that the main structure modulation feature of Cs(2)TB4O9 is the ordering of the O atoms. With these modulated structure models, the unreasonable B-O distances in the average structures were explained as the ordering of BO4 and BO3.

  5. Single crystal EPR study on gamma-irradiated NLO material (2-amino-5-nitropyridinium chloride)

    NASA Astrophysics Data System (ADS)

    Dhanuskodi, S.; Manikandan, S.

    2004-03-01

    A semiorganic nonlinear optical (NLO) material 2-amino-5-nitropyridinium chloride (2A5NPCl) was synthesized. Single crystals were grown following the slow evaporation method and characterized by measuring density, TGA, FT-IR, FT-Raman and X-ray diffraction techniques. The electron paramagnetic resonance (EPR) spectra were recorded for gamma-irradiated single crystals of 2A5NPCl. The angular variation studies of the spectra were observed and the principal values of the g-tensor and A-tensor were determined.

  6. Growth, spectral and thermal studies of an efficient NLO material: Diaquadicinnamatocadmium(II)

    SciTech Connect

    Roy, Sunalya M.; Sudarsanakumar, M. R.; Dhanya, V. S.

    2014-01-28

    A nonlinear metal–organic crystal, diaquadicinnamatocadmium(II) has been grown by controlled gel diffusion technique. Sodium metasilicate was used to prepare the gel. The chemical composition of the crystal has been determined by CHN analysis. Powder X-ray diffraction studies confirm the crystalline nature of the grown crystal. Functional groups present in the compound were identified by FT-IR spectral analysis. The thermal decomposition of the compound was studied using thermogravimetry (TG). The optical transparency range and the lower cut-off wavelength were identified from the UV-Visible-NIR spectrum. The NLO activity of the grown crystal was confirmed using Kurtz and Perry powder test.

  7. Self Assembled Spin Coated and Bulk Films of a Novel Polydiacetylene as Second Order NLO Polymers

    DTIC Science & Technology

    1994-05-31

    T Code: 4132016 W.H. Kim, B. Bihari, R. Moody, N. B. Kodali , J.KumarS.K. Dr. JoAnn Milliken Tripathy. 7. PHI-OUHMING OFH-NIZATION NAMIE(S) AND...Self Assembled Spin Coated and Bulk Films of a Novel Polydiacetylene as Second Order NLO Polymers by W.H. Kim, B. Bihari, R. Moody, N. B. Kodali ...POLYMERS W. H. Kim, B. Bihari+, R. Moody+, N. B. Kodali , J. Kumar+, and S. K. Tripathy, University of Massachusetts-Lowell, Center for Advanced Materials

  8. Octupolar (C3 and S4) Symmetric Cyclized Indole Derivatives: Syntheses, Structures, and NLO Properties.

    PubMed

    Wang, Lei; Fang, Qi; Lu, Qing; Zhang, Shao-jun; Jin, Ying-ying; Liu, Zhi-qiang

    2015-09-04

    Several cyclized indole derivatives have been synthesized, and their structures been determined. The C3-symmetric single-chiral N-phenyltriindole (Tr-Ph3) crystallized in the P1 space group, and the S4-symmetric saddle-like tetraindole (TTr) crystallized in the I4̅ space group. The Tr-Ph3 and TTr crystals exhibit remarkable powder SHG intensities 5 and 11 times that of KH2PO4 (KDP), respectively. TTr is a useful octupolar core to build S4-symmetric molecules and crystals for second-NLO materials.

  9. Diffractive heavy quark production in AA collisions at the LHC at NLO

    SciTech Connect

    Machado, M. M.; Ducati, M. B. Gay; Machado, M. V. T.

    2011-07-15

    The single and double diffractive cross sections for heavy quarks production are evaluated at NLO accuracy for hadronic and heavy ion collisions at the LHC. Diffractive charm and bottom production is the main subject of this work, providing predictions for CaCa, PbPb and pPb collisions. The hard diffraction formalism is considered using the Ingelman-Schlein model where a recent parametrization for the Pomeron structure function (DPDF) is applied. Absorptive corrections are taken into account as well. The diffractive ratios are estimated and theoretical uncertainties are discussed. Comparison with competing production channels is also presented.

  10. APFEL: A PDF evolution library with QED corrections

    NASA Astrophysics Data System (ADS)

    Bertone, Valerio; Carrazza, Stefano; Rojo, Juan

    2014-06-01

    Quantum electrodynamics and electroweak corrections are important ingredients for many theoretical predictions at the LHC. This paper documents APFEL, a new PDF evolution package that allows for the first time to perform DGLAP evolution up to NNLO in QCD and to LO in QED, in the variable-flavor-number scheme and with either pole or MS bar heavy quark masses. APFEL consistently accounts for the QED corrections to the evolution of quark and gluon PDFs and for the contribution from the photon PDF in the proton. The coupled QCD ⊗ QED equations are solved in x-space by means of higher order interpolation, followed by Runge-Kutta solution of the resulting discretized evolution equations. APFEL is based on an innovative and flexible methodology for the sequential solution of the QCD and QED evolution equations and their combination. In addition to PDF evolution, APFEL provides a module that computes Deep-Inelastic Scattering structure functions in the FONLL general-mass variable-flavor-number scheme up to O(αs2) . All the functionalities of APFEL can be accessed via a Graphical User Interface, supplemented with a variety of plotting tools for PDFs, parton luminosities and structure functions. Written in FORTRAN 77, APFEL can also be used via the C/C++ and Python interfaces, and is publicly available from the HepForge repository.

  11. NLO properties of formyl-methoxy derivatives of [2.2]paracyclophane containing the donor group in different positions

    NASA Astrophysics Data System (ADS)

    Puntus, Lada N.; Suponitsky, Kyrill Y.; Antonov, Dmitrii; Pekareva, Irina S.; Lyssenko, Konstantin A.; Kajzar, François

    2014-10-01

    Formyl-methoxy derivatives of [2.2]paracyclophane (pCp) have been synthesized and studied by optical spectroscopy as well as the X-ray diffraction method. These molecules crystallize in acentric space groups. The efficiency of SHG ability of these compounds was measured by the powder technique at 1064 nm fundamental wavelength and average NLO susceptibility for some of them was found comparable with such well-known NLO crystal as NPP. The calculations of molecular and crystalline nonlinearities within density functional theory using M052X/6-31+G* level of approximation were also conducted for the considered series of compounds.

  12. Vector boson production in association with KK modes of the ADD model to NLO in QCD at the LHC

    NASA Astrophysics Data System (ADS)

    Kumar, M. C.; Mathews, Prakash; Ravindran, V.; Seth, Satyajit

    2011-05-01

    Next-to-leading order (NLO) QCD corrections to the associated production of the vector boson (Z/W±) with the Kaluza-Klein (KK) modes of the graviton in large extra-dimensional model at the Large Hadron Collider (LHC) are presented. We have obtained various kinematic distributions using a Monte Carlo code which is based on the two-cutoff phase space slicing method that handles soft and collinear singularities appearing at the NLO level. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorization scale uncertainty when QCD corrections are included.

  13. The first hexadithienylethene-substituted tris(bipyridine)metal complexes as quadratic NLO photoswitches: combined experimental and DFT studies.

    PubMed

    Ordronneau, Lucie; Aubert, Vincent; Guerchais, Véronique; Boucekkine, Abdou; Le Bozec, Hubert; Singh, Anu; Ledoux, Isabelle; Jacquemin, Denis

    2013-05-03

    Flip the NLO switch! A straightforward access to hexadithienylethene-based photochromes by using a coordination-chemistry approach through the combination of bis(dithienylethene)bipyridyl ligands and metal ions (M = Zn, Fe) is reported. The photostability of the isomeric forms of the iron(II) complexes allows the photoswitching of second-order nonlinear optical (NLO) responses (see figure), and the results are rationalized with the help of time-dependent density functional theory. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A nonlinear optical active polymer film based on Pd(ii) dithione/dithiolate second-order NLO chromophores.

    PubMed

    Espa, D; Pilia, L; Marchiò, L; Artizzu, F; Di Carlo, G; Marinotto, D; Serpe, A; Tessore, F; Deplano, P

    2016-11-01

    A film of [Pd(R2pipdt)(dmit)] (1), where R2pipdt = 1,4-didodecyl-piperazine-2,3-dithione (acceptor) and dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate (donor) incorporated into a polymethylmethacrylate (PMMA) matrix, showing a good second-harmonic generation, has been prepared for the first time in the class of dithione-dithiolate 2nd order NLO-chromophores. Moreover full characterization of 1, including molecular second-order NLO properties in solution, is reported.

  15. Spectroscopic analysis, AIM, NLO and VCD investigations of acetaldehyde thiosemicarbazone using quantum mechanical simulations

    NASA Astrophysics Data System (ADS)

    Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Govindarajan, M.; Gnanamuthu, S. Joshua; Pandian, G. V.

    2016-08-01

    The prepared Acetaldehyde thiosemicarbazone (ATSC) have been investigated by both the experimental and theoretical methods; through this work, the essentiality of elucidation of molecular fragments source linear and non-linear optical properties was explored. The stability of the structure and entire calculations have been performed on HF and B3LYP methods with 6-311++G(d,p) level of basis set. The Mulliken charge profile, electronic, optical and hyper polarizability analyses have been carried out in order to evaluate nonlinear optical (NLO) performance of the present compound. The exact optical location of the ATSC was determined by executing UV-Visible calculations on TDSCF method. The existence of the molecular group for the inducement and tuning of NLO properties were thoroughly investigated by performing fundamental vibrational investigation. The optical energy transformation among frontier molecular levels has been described in UV-Visible region. The Gibbs energy coefficient of thermodynamic functions was monitored in different temperature and it was found constant irrespective of temperatures. The appearance of different chemical environment of H and C was monitored from the 1H and 13C NMR spectra. The vibrational optical polarization characteristics with respect to molecular composition in the compound have been studied by VCD spectrum. The bond critical point, Laplacian of electron density, electron kinetic energy density and total electron energy density have calculated and analysed using AIM study.

  16. Penguin-dominated B{yields}PV decays in NLO perturbative QCD

    SciTech Connect

    Li Hsiangnan; Mishima, Satoshi

    2006-11-01

    We study the penguin-dominated B{yields}PV decays, with P (V) representing a pseudoscalar (vector) meson, in the next-to-leading-order (NLO) perturbative QCD (PQCD) formalism, concentrating on the B{yields}K{phi}, {pi}K*, {rho}K, and {omega}K modes. It is found that the NLO corrections dramatically enhance the B{yields}{rho}K, {omega}K branching ratios, which were estimated to be small under the naive factorization assumption. The patterns of the direct CP asymmetries A{sub CP}(B{sup 0}{yields}{rho}{sup {+-}}K{sup {+-}}){approx_equal}A{sub CP}(B{sup {+-}}{yields}{rho}{sup 0}K{sup {+-}}) and A{sub CP}(B{sup 0}{yields}{pi}{sup {+-}}K*{sup {+-}})>A{sub CP}(B{sup {+-}}{yields}{pi}{sup 0}K*{sup {+-}}) are predicted, differing from A{sub CP}(B{sup 0}{yields}{pi}{sup {+-}}K{sup {+-}})>>A{sub CP}(B{sup {+-}}{yields}{pi}{sup 0}K{sup {+-}}). The above patterns, if confirmed by data, will support the source of strong phases from the scalar penguin annihilation in PQCD. The results for the mixing-induced CP asymmetries S{sub f} are consistent with those obtained in the literature, except that our S{sub {rho}{sup 0}}{sub K{sub S}} is as low as 0.5.

  17. Comparative studies on molecular structure, vibrational spectra and hyperpolarizabilies of NLO chromophore Ethyl 4-Dimethylaminobenzoate

    NASA Astrophysics Data System (ADS)

    Amalanathan, M.; Jasmine, G. Femina; Roy, S. Dawn Dharma

    2017-08-01

    The molecular structure, vibrational spectra and polarizabilities of Ethyl 4-Dimethylaminobenzoate (EDAB) was investigated by density functional theory employing Becke's three parameter hybrid exchange functional with Lee-Yang-Parr (B3LYP) co-relational functional involving 6-311++G(d,p) basis set and compared with some other levels. A detailed interpretation of the IR and Raman spectra of EDBA have been reported and analyzed. Complete vibrational assignments of the vibrational modes have been done on the basis of the potential energy distribution (TED) using VEDA software. The molecular electrostatic potential mapped onto total density surface has been obtained. A study on the electronic properties, such as absorption wavelength, and frontier molecular orbitals energy, was performed using DFT approach. The stability of the molecule arising from hyper conjugative interactions and accompanying charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The natural and Mulliken charge also calculated and compared with different level of calculation. The dipole moment, polarizability and first, second order hyperpolarizabilities of the title molecule were calculated and compared with the experimental values. The energy gap between frontier orbitals has been used along with electric moments and first order hyperpolarizability, to understand the non linear optical (NLO) activity of the molecule. The NLO activity of molecule was confirmed by SHG analysis.

  18. Automated NNLL [Formula: see text] NLO resummation for jet-veto cross sections.

    PubMed

    Becher, Thomas; Frederix, Rikkert; Neubert, Matthias; Rothen, Lorena

    In electroweak-boson production processes with a jet veto, higher-order corrections are enhanced by logarithms of the veto scale over the invariant mass of the boson system. In this paper, we resum these Sudakov logarithms at next-to-next-to-leading logarithmic accuracy and match our predictions to next-to-leading-order (NLO) fixed-order results. We perform the calculation in an automated way, for arbitrary electroweak final states and in the presence of kinematic cuts on the leptons produced in the decays of the electroweak bosons. The resummation is based on a factorization theorem for the cross sections into hard functions, which encode the virtual corrections to the boson production process, and beam functions, which describe the low-[Formula: see text] emissions collinear to the beams. The one-loop hard functions for arbitrary processes are calculated using the MadGraph5_aMC@NLO framework, while the beam functions are process independent. We perform the resummation for a variety of processes, in particular for [Formula: see text] pair production followed by leptonic decays of the [Formula: see text] bosons.

  19. {ZZ}\\gamma production in the NLO QCD+EW accuracy at the LHC

    NASA Astrophysics Data System (ADS)

    Yong, Wang; Ren-You, Zhang; Wen-Gan, Ma; Xiao-Zhou, Li; Shao-Ming, Wang; Huan-Yu, Bi

    2017-08-01

    In this paper we present the first study of the impact of the { O }(α ) electroweak (EW) correction to the {pp}\\to {ZZ}γ +X process at the CERN Large Hadron Collider. The subsequent Z-boson leptonic decays are considered at the leading order using the MadSpin method, which takes into account the spin-correlation and off-shell effects from the Z-boson decays. We provide numerical results of the integrated cross section and the kinematic distributions for this process. In coping with final-state photon-jet separation in the QCD real emission and photon-induced processes, we adopt both the Frixione isolated-photon plus jets algorithm and the phenomenological quark-to-photon fragmentation function method for comparison. We find that the next-to-leading order (NLO) EW correction to the {ZZ}γ production can be sizeable and amounts to about -7 % of the integrated cross section, and provides a non-negligible contribution to the kinematic distributions, particularly in the high energy region. We conclude that the NLO EW correction should be included in precision theoretical predictions in order to match future experimental accuracy.

  20. Controlling the growth of porphyrin based nanostructures for tuning third-order NLO properties.

    PubMed

    Wang, Liang; Chen, Yanli; Jiang, Jianzhuang

    2014-01-01

    A series of porphyrin nanospindles with controlled long axis length distributions of 330, 550, 800 nm, and 4 μm have been successfully fabricated via hierarchical self-assembly of cationic porphyrin (H₆TPyP)(4+) with the help of anionic surfactant sodium dodecyl sulfonate (SDS) due to the effective electrostatic interaction. These newly fabricated nanostructures are characterized by TEM and SEM techniques, powder X-ray diffraction analysis, electronic absorption spectroscopy, and confocal laser scanning microscopy (CLSM). The Z-scan technique with a laser duration of 5 ns at the wavelength of 532 nm reveals unreported size-dependent third-order NLO switching properties: the nonlinear absorption changes from saturation absorption to reversed saturation absorption and the nonlinear refraction from self-defocus to self-focus due to the change of the dominant scattering effect, from Rayleigh scattering for nanostructures with a smaller size than the wavelength of laser light, to Mie scattering for nanostructures with a larger size than the laser wavelength. This result is useful for the development of organic nanostructures with desired NLO properties, in particular the optical limiting properties.

  1. Photophysical studies of fused phenanthrimidazole derivatives as versatile π-conjugated systems for potential NLO applications.

    PubMed

    Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Perumal, Marimuthu Venkatesh

    2012-06-15

    Two new heterocyclic imidazole derivatives consists of π-conjugated system attached to a phenanthrimidazole moiety have been synthesized in moderate yield by the condensation of 1,10-phenanthroline-5,6-dione with substituted aromatic aldehydes and 4-methoxyaniline in the presence of ammonium acetate in ethanol medium. The photophysical properties of these imidazole derivatives were studied in several solvents. These derivatives were evaluated concerning their solvatochromic properties and molecular optical nonlinearities. Their electric dipole moment (μ) and hyperpolarizability (β) have been calculated theoretically and the results indicate that the extension of the π-framework of the ligands has an effect on the NLO properties of these imidazole derivatives. The non-zero tensor components of these imidazole derivatives reveal that they possess potent non-linear optical (NLO) behavior. The energies of the HOMO and LUMO levels and the molecular electrostatic potential (MEP) energy surface studies have exploited the existence of intramolecular charge transfer (ICT) within the molecule. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Investigation of nonlinear optical (NLO) properties by charge transfer contributions of amine functionalized tetraphenylethylene

    NASA Astrophysics Data System (ADS)

    Rana, Meenakshi; Singla, Nidhi; Chatterjee, Amrita; Shukla, Abhishek; Chowdhury, Papia

    2016-12-01

    Nonlinear Optical (NLO) properties of amine functionalized tetraphenylethylene (TPE-NH2) have been recorded and analyzed. The structural geometry, bonding features, harmonic vibrational frequencies (FTIR and Raman) of TPE-NH2 have been investigated by B3LYP density functional theory (DFT). Charge (Mulliken and natural) analysis, natural bond orbital (NBO) analysis, frontier molecular orbitals (FMOs), 13C and 1H nuclear magnetic resonance (NMR) and molecular electrostatic potential (MEP) indicate the delocalization of charges over the donor-acceptor region by the increase of C-N bond length. The vibrational analysis on the basis of potential energy distribution (PED) confirms the charge transfer interaction between donor and acceptor groups, and that in turn validates the presence of the larger dipole moment (μ), polarizability and hyperpolarizabilities (α, β and γ) in TPE-NH2. Higher value of ionization potential (IP), electronegativity (χ), hardness (η), chemical potential (CP) and smaller HOMO-LUMO energy gap (Δε) validate TPE-NH2's strong candidature to be used as an NLO active material.

  3. Further enhancement of the second-order nonlinear optical (NLO) coefficient and the stability of NLO polymers that contain isolation chromophore moieties by using the "suitable isolation group" concept and the Ar/Ar(F) self-assembly effect.

    PubMed

    Wu, Wenbo; Ye, Cheng; Qin, Jingui; Li, Zhen

    2013-08-01

    For the first time, a series of second-order NLO poly(arylene-ethynylene)s, in which an isolation chromophore was introduced to enhance the NLO coefficients, were successfully designed and synthesized. Thanks to the isolation chromophore, these polymers demonstrated good NLO activities and optical transparency. To further improve the comprehensive performance of the polymers, different isolation groups of various sizes were introduced to subtly modify the structure of the polymers according to the "suitable isolation group" concept. The naphthalene (Np) group was found to be a "suitable isolation group" in this series of polymers and polymer P3 demonstrated the highest d33 value (122.1 pm V(-1)) of these five polymers. Interestingly, polymer P5, which contained a pentafluorophenyl ring as an isolation group, exhibited a much higher NLO effect and stability than polymer P2, which just contained normal phenyl rings as isolation groups (97.2 versus 62.5 pm V(-1)), thus indicating the advantages of the Ar-Ar(F) self-assembly effect in the field of non-linear optics.

  4. Exploring the influence of carboxylic acids on nonlinear optical (NLO) and dielectric properties of KDP crystal for applications of NLO facilitated photonic devices

    NASA Astrophysics Data System (ADS)

    Anis, Mohd; Muley, G. G.; Hakeem, A.; Shirsat, M. D.; Hussaini, S. S.

    2015-08-01

    The aim of present investigation is to assess the impact of oxalic acid (OA) and maleic acid (MA) on nonlinearity (second and third order) and dielectric behavior of potassium dihydrogen phosphate (KDP) crystal by means of SHG efficiency test, Z-scan analysis and dielectric studies respectively. The enhancement in SHG efficiency of OA and MA doped KDP crystal has been confirmed by means of Kurtz-Perry powder test technique. The close and open aperture Z-scan technique has been employed to study the nature and origin of improved third order NLO behavior of doped KDP crystals at 632.8 nm. The magnitude of third order nonlinear susceptibility (χ3), nonlinear refraction (n2), nonlinear absorption coefficient (β) and figure of merit (FOM) of doped KDP crystals has been calculated using the Z-scan transmittance data to explore the suitability of crystals for distinct laser assisted applications. The dielectric constant and dielectric loss of pure, OA and MA doped KDP crystals were measured at different temperatures by means of dielectric studies.

  5. D-meson enhancement in pp collisions at the LHC due to nonlinear gluon evolution

    SciTech Connect

    Dainese, A.; Vogt, R.; Bondila, M.; Eskola, K.J.; Kolhinen, V.J.

    2004-08-22

    When nonlinear effects on the gluon evolution are included with constraints from HERA, the gluon distribution in the free proton is enhanced at low momentum fractions, x {approx}< 0.01, and low scales, Q{sup 2} {approx}< 10 GeV{sup 2}, relative to standard, DGLAP-evolved, gluon distributions. Consequently, such gluon distributions can enhance charm production in pp collisions at center of mass energy 14 TeV by up to a factor of five at midrapidity, y {approx} 0, and transverse momentum p{sub T} {yields} 0 in the most optimistic case. We show that most of this enhancement survives hadronization into D mesons. Assuming the same enhancement at leading and next-to-leading order, we show that the D enhancement may be measured by D{sup 0} reconstruction in the K{sup -}{pi}{sup +} decay channel with the ALICE detector.

  6. Fluorescence, spectroscopic and NLO properties of green tea extract in deoxyribonucleic acid

    NASA Astrophysics Data System (ADS)

    Manea, Ana-Maria; Rau, Ileana; Kajzar, Francois; Meghea, Aurelia

    2013-11-01

    Natural, purely biological deoxyribonucleic acid (DNA)-green tea extract (GTE) complexes at different concentrations were prepared and characterized for their spectroscopic, fluorescent, linear and nonlinear optical properties. The complexes can be processed into good optical quality thin films by solution casting. They fluoresce when excited in UV absorption band, with a significantly larger quantum yield for the DNA-GTE complex than for a pure GTE solution. The thin film refractive indices were determined by Fabry-Perot (FP) interference patterns. The third-order nonlinear optical (NLO) properties of thin films were determined by the optical third-harmonic generation technique at 1064.2 nm fundamental wavelength. The phase of THG susceptibility was determined from the concentration variation of THG susceptibility. It reveals presence of a two-photon resonance with a band lying in the optical gap.

  7. Off-shell single-top production at NLO matched to parton showers

    SciTech Connect

    Frederix, R.; Frixione, S.; Papanastasiou, A. S.; Prestel, S.; Torrielli, P.

    2016-06-06

    We study the hadroproduction of a Wb pair in association with a light jet, focusing on the dominant t-channel contribution and including exactly at the matrix-element level all non-resonant and off-shell effects induced by the finite top-quark width. Our simulations are accurate to the next-to-leading order in QCD, and are matched to the Herwig6 and Pythia8 parton showers through the MC@NLO method. We present phenomenological results relevant to the 8 TeV LHC, and carry out a thorough comparison to the case of on-shell t-channel single-top production. Furthermore, we formulate our approach so that it can be applied to the general case of matrix elements that feature coloured intermediate resonances and are matched to parton showers.

  8. Computing decay rates for new physics theories with FEYNRULES and MADGRAPH 5_AMC@NLO

    NASA Astrophysics Data System (ADS)

    Alwall, Johan; Duhr, Claude; Fuks, Benjamin; Mattelaer, Olivier; Öztürk, Deniz Gizem; Shen, Chia-Hsien

    2015-12-01

    We present new features of the FEYNRULES and MADGRAPH 5_AMC@NLO programs for the automatic computation of decay widths that consistently include channels of arbitrary final-state multiplicity. The implementations are generic enough so that they can be used in the framework of any quantum field theory, possibly including higher-dimensional operators. We extend at the same time the conventions of the Universal FEYNRULES Output (or UFO) format to include decay tables and information on the total widths. We finally provide a set of representative examples of the usage of the new functions of the different codes in the framework of the Standard Model, the Higgs Effective Field Theory, the Strongly Interacting Light Higgs model and the Minimal Supersymmetric Standard Model and compare the results to available literature and programs for validation purposes.

  9. Preparation, linear and NLO properties of DNA-CTMA-SBE complexes

    NASA Astrophysics Data System (ADS)

    Manea, Ana-Maria; Rau, Ileana; Kajzar, Francois; Meghea, Aurelia

    2013-10-01

    Synthesis of deoxyribonucleic acid (DNA) - was cetyltrimethylammonium (CTMA) - sea buckthorn extract (SBE) at different concentrations is decribed. The complexes were processed into good optical quality thin films by spin coating on different substrates such as: glass, silica and ITO covered glass substrates. SBE contains many bioactive substances that can be used in the treatment of several diseases, such as cardiovascular disease, cancer, and acute mountain sickness. The obtained thin films were characterized for their spectroscopic, fluorescent, linear and nonlinear optical properties as function of SBE concentration. The third-order nonlinear optical (NLO) properties of thin films were determined by the optical third-harmonic generation technique at 1 064.2 nm fundamental wavelength.

  10. Off-shell single-top production at NLO matched to parton showers

    DOE PAGES

    Frederix, R.; Frixione, S.; Papanastasiou, A. S.; ...

    2016-06-06

    We study the hadroproduction of a Wb pair in association with a light jet, focusing on the dominant t-channel contribution and including exactly at the matrix-element level all non-resonant and off-shell effects induced by the finite top-quark width. Our simulations are accurate to the next-to-leading order in QCD, and are matched to the Herwig6 and Pythia8 parton showers through the MC@NLO method. We present phenomenological results relevant to the 8 TeV LHC, and carry out a thorough comparison to the case of on-shell t-channel single-top production. Furthermore, we formulate our approach so that it can be applied to the generalmore » case of matrix elements that feature coloured intermediate resonances and are matched to parton showers.« less

  11. Synthesis and electro-optic properties of the chromophore-containing NLO polyarylate polymers

    NASA Astrophysics Data System (ADS)

    Ren, Haohui; Peng, Chengcheng; Bo, Shuhui; Fan, Guofang; Xu, Guangming; Zhao, Hui; Zhen, Zhen; Liu, Xinhou

    2014-03-01

    Base on the same two monomers, diphenolic acid (DPA) and isophthaloyl chloride (IPC), three chromophore-containing nonlinear optical (NLO) polyarylate polymers were prepared. A tricyanofuran (TCF)-acceptor type chromophore group was in main-chain (mPAR-chr1), side-chain (sPAR-chr1) and side-chain with a 1,1-bis(4-hydroxyphenyl)-1-phenyl-2,2,2-trifluoroethane (BPAPF) group (sPAR-F-chr1), respectively. The obtained polymers were characterized and evaluated by UV-Vis, 1H NMR, DSC and TGA. All the polymers exhibited good electro-optic (EO) activity. The relationship between EO coefficients (r33) and the chromophore concentration of the three polymers were also characterized and discussed. There were no obvious differences found in EO activity between mPAR-chr1 and sPAR-chr1 polyarylates with the same chromophore. The fluorinated block polyarylate sPAR-F-chr1 has the largest r33 value in these three polyarylates which is 52 pm/V at the wavelength of 1310 nm (which is almost twice the r33 value of normal polymers contained the same chormophore at the same content), when the concentration of chromophore 1 is 18wt.%. 85% of the r33 value was retained in the sPAR-F-chr1 after being heated at 85°C for 600 hours. The polymer sPAR-F-chr1, with good solubility, high Tg (above 200 °C) and side functional group at the same time, may probably be a practical NLO material. These properties make the new polyarylates have potential applications in EO devices such as EO modulators and switches.

  12. Vibrational and electronic investigations, NLO, FMO analysis on a hetarylazoindole disperse dye by density functional theory

    NASA Astrophysics Data System (ADS)

    Çatıkkaş, Berna; Aktan, Ebru; Yalçın, Ergin

    2016-08-01

    This work deals with the optimized molecular structure, vibrational spectra, nonlinear optic (NLO) and frontier molecule orbital (FMO) properties of 1-Methyl-2-phenyl-3-(1,3,4-thiadiazol-2-yldiazenyl)-1H-indole (MPI) by quantum chemical calculations. The Fourier transform infrared (FT-MIR and FT-FIR) and Raman spectra of 1-Methyl-2-phenyl-3-(1,3,4-thiadiazol-2-yldiazenyl)-1H-indole (MPI) were recorded in the region (4000-400 cm-1 and 400-30 cm-1) and (3200-92 cm-1), respectively. The analysis and complete vibrational assignments of the fundamental modes of the MPI molecule were carried out by using the observed FT-IR and FT-Raman data and calculated Total Energy Distribution (TED) according to Scaled Quantum Mechanics procedure. The calculated geometrical parameters of the MPI molecule are in agreement with the obtained values from XRD studies. On the other hand, the difference between the scaled and observed wavenumber values of the most of the fundamentals are very small. 1H NMR and 13C NMR chemical shift values, and energy gap between LUMO-HOMO and molecular electrostatic potential (MEP) were investigated by using density functional theory (B3LYP) methods. UV/Visible spectra and λ maximum absorption values, the oscillator strengths in the chloroform, methanol and DMSO solvation in combination with different basis sets were calculated by using the time-dependent density functional theory (TD-DFT). Additionally, the predicted nonlinear optical (NLO) properties of the MPI are quite greater than that of urea at the B3LYP/6-31++G(d,p) level.

  13. Monitoring molecular orientational order in NLO push-pull based polymeric films via photoacoustic measurements

    NASA Astrophysics Data System (ADS)

    Torres-Zúñiga, V.; Castañeda-Guzmán, R.; Morales-Saavedra, O. G.; Pérez-Martínez, A. L.; Ogawa, T.

    2011-12-01

    The pulsed-laser photoacoustic-technique (PLPA) was implemented to characterize molecular orientational order and anisotropy in push-pull poled polymeric films as function of temperature and laser polarization. Traditionally, photoacoustic signals are considered to be directly proportional to the linear optical absorption in amorphous media. In this work, however, it is shown that photoacoustic signals can also be highly sensitive to the material anisotropy when convenient polarization dependent photoacoustic analyses are performed. Thus, variation of the molecular orientation in organic films, comprising rod-like polar chromophores, can be unambiguously monitored via rms-analyses performed on the amplitude of the generated opto-acoustical PLPA-signals as function of the incident laser polarization. This result can be useful for the characterization of organic-based nonlinear optical (NLO) poled films and, in general, in studies of anisotropic materials. In fact, in this work we were able to accurately determine the molecular order parameter ( ϕ) of a NLO-active spin-coated polymeric film containing optically active push-pull chromophores. These molecules, previously oriented via an electrical-poling procedure, are capable to exhibit strong second harmonic generation (SHG) effects. The PLPA-measurements were systematically compared to the linear UV-vis optical absorbance spectra while heating the poled film sample in order to monitor the thermally induced molecular disorder, so that the order parameter may be photo-acoustically evaluated via the PLPA-signals generated from the poled to the unpoled film phase. These PLPA-experiments were performed taking into account the UV-vis reference spectra for calibration and comparison purposes in the evaluation of the order parameter. A significant advantage of the PLPA-technique over commonly used optical spectral methodologies is its convenient applicability in samples exhibiting poor or null optical transmission.

  14. Quark contribution to the small-x evolution of color dipole

    SciTech Connect

    Ian Balitsky

    2006-09-11

    The small-x deep inelastic scattering in the saturation region is governed by the non-linear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the BK equation for the evolution of color dipoles. In the NLO the nonlinear equation gets contributions from quark and gluon loops. In this paper I calculate the quark-loop contribution to small-x evolution of Wilson lines in the NLO. It turns out that there are no new operators at the one-loop level--just as at the tree level, the high-energy scattering can be described in terms of Wilson lines. In addition, from the analysis of quark loops I find that the argument of coupling constant in the BK equation is determined by the size of the parent dipole rather than by the size of produced dipoles. These results are to be supported by future calculation of gluon loops.

  15. Spectroscopic study of gel grown L-Valine Zinc Glycine Thiourea Sulfate (VZGTS) crystal: A novel NLO crystal

    NASA Astrophysics Data System (ADS)

    Rathod, Kiran T.; Patel, I. B.

    2017-05-01

    In recent years, organometalic non linear optical (NLO) materials have attained immense appeal form researchers due to its range of technological applications in photonic field and optoelectronic technology. In present research work, novel semi organic NLO L-Valine Zinc Glycine Thiourea Sulfate crystals (VZGTS) with different morphologies were grown by gel method at ambient temperature. Presence and identification of functional groups were confirmed by FITR analysis. Spectroscopic studies were carried out for it. The UV-Vis spectroscopy is recorded for crystal. PL study stats that the crystal has insulating nature. Spectroscopic study shows that this crystal has good transparency in the case of fundamental wavelength of Nd : YAG laser. Second Harmonic Generation (SHG) efficiency was confirmed by Kurtz - Perry powder method. Results are discussed in the paper.

  16. The effects of electronegative substituent atoms on structural, vibrational, electronic and NLO properties of some 4-nitrostilbene derivates.

    PubMed

    Tamer, Ömer; Avcı, Davut; Atalay, Yusuf

    2015-02-05

    Organic compounds which have one or more aromatic systems in conjugated positions show charge transfer interactions which are responsible for the non-linear properties of the compounds. A conjugated π electron system enables a pathway for the entire length of conjugation under the perturbation of an external electric field. When electron donating and withdrawing moieties are located at terminal position of conjugated backbone, nonlinear optical (NLO) properties have been increased significantly which involve the correlated and high delocalized π electron states. Recently synthesized organic complexes, 1-(4-fluorostyryl)-4-nitrostilbene (1), 4-Chloro 4-nitrostilbene (2), 4-Bromo 4-nitrostilbene (3) and 4-Iodo 4-nitrostilbene (4), were simulated using density functional theory (DFT). Based on the optimized geometries, spectroscopic and NLO properties of these complexes were discussed as compared with each other. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Integrated NMR and computational study of push-pull NLO probes: interplay of solvent and structural effects.

    PubMed

    Marini, Alberto; Macchi, Sara; Jurinovich, Sandro; Catalano, Donata; Mennucci, Benedetta

    2011-09-08

    In this study we combined QM calculations and NMR measurements to understand at a detailed level the complex interplay of structural/electronic properties with the effects of the solvent in the NLO activity of push-pull systems, quantified in terms of variations of the static hyperpolarizability. Different parameters (bond lengths and bond length alternation, vibrational frequencies, electronic charge distribution) are introduced and tested to rationalize both the solvent sensitivity of three molecular systems (namely, p-nitroaniline, ethyl 4-ammino benzoate, and 5-nitro-1H-indole) and the differences among them. This analysis has finally allowed us to establish a clear correlation between the charge transfer behavior of the systems, their NLO properties, and NMR parameters also validating simplified but effective chemical analyses based on resonance limit forms.

  18. The second- and third- order nonlinear optical properties and electronic transition of a NLO chromophore: A DFT study

    NASA Astrophysics Data System (ADS)

    Altürk, Sümeyye; Avci, Davut; Tamer, Ömer; Atalay, Yusuf

    2016-03-01

    It is well known that the practical applications of second-order and third-order nonlinear optical (NLO) materials have been reported in modern technology, such as optical data processing, transmission and storage, etc. In this respect, the linear and nonlinear optical parameters (the molecular static polarizability (α), and the first-order static hyperpolarizability (β0), the second-order static hyperpolarizability (γ)), UV-vis spectra and HOMO and LUMO energies of 2-(1'-(4'''-Methoxyphenyl)-5'-(thien-2″-yl)pyrrol-2'-yl)-1,3-benzothiazole were investigated by using the HSEh1PBE/6-311G(d,p) level of density functional theory. The UV-vis spectra were simulated using TD/HSEh1PBE/6- 311G(d,p) level, and the major contributions to the electronic transitions were obtained. The molecular hardness (η) and electronegativity (χ) parameters were also obtained by using molecular frontier orbital energies. The NLO parameters of the title compound were calculated, and obtained data were compared with that of para-Nitroaniline (pNA) which is a typical NLO material and the corresponding experimental data. Obtained data of the chromosphere display significant molecular second-and third-nonlinearity.

  19. The second– and third– order nonlinear optical properties and electronic transition of a NLO chromophore: A DFT study

    SciTech Connect

    Altürk, Sümeyye Avci, Davut Tamer, Ömer Atalay, Yusuf

    2016-03-25

    It is well known that the practical applications of second-order and third-order nonlinear optical (NLO) materials have been reported in modern technology, such as optical data processing, transmission and storage, etc. In this respect, the linear and nonlinear optical parameters (the molecular static polarizability (α), and the first–order static hyperpolarizability (β{sub 0}), the second–order static hyperpolarizability (γ)), UV-vis spectra and HOMO and LUMO energies of 2-(1′-(4’’’-Methoxyphenyl)-5′-(thien-2″-yl)pyrrol-2′-yl)-1,3-benzothiazole were investigated by using the HSEh1PBE/6–311G(d,p) level of density functional theory. The UV–vis spectra were simulated using TD/HSEh1PBE/6– 311G(d,p) level, and the major contributions to the electronic transitions were obtained. The molecular hardness (η) and electronegativity (χ) parameters were also obtained by using molecular frontier orbital energies. The NLO parameters of the title compound were calculated, and obtained data were compared with that of para-Nitroaniline (pNA) which is a typical NLO material and the corresponding experimental data. Obtained data of the chromosphere display significant molecular second-and third-nonlinearity.

  20. Higgs production in association with off-shell top-antitop pairs at NLO EW and QCD at the LHC

    NASA Astrophysics Data System (ADS)

    Denner, Ansgar; Lang, Jean-Nicolas; Pellen, Mathieu; Uccirati, Sandro

    2017-02-01

    We present NLO electroweak corrections to Higgs production in association with off-shell top-antitop quark pairs. The full process ppto {e}+{ν}e{μ}-{overline{ν}}_{μ}boverline{b}H is considered, and hence all interference, off-shell, and non-resonant contributions are taken into account. The electroweak corrections turn out to be below one per cent for the integrated cross section but can exceed 10% in certain phase-space regions. In addition to its phenomenological relevance, the computation constitutes a major technical achievement as the full NLO virtual corrections involving up to 9-point functions have been computed exactly. The results of the full computation are supported by two calculations in the double-pole approximation. These also allow to infer the effect of off-shell contributions and emphasise their importance especially for the run II of the LHC. Finally, we present combined predictions featuring both NLO electroweak and QCD corrections in a common set-up that will help the experimental collaborations in their quest of precisely measuring the aforementioned process.

  1. Synthesis, spectral and redox switchable cubic NLO properties of chiral dinuclear iron cyanide/isocyanide-bridged complexes.

    PubMed

    Ma, Xiao; Lin, Chen-Sheng; Zhang, Hui; Lin, Yi-Ji; Hu, Sheng-Min; Sheng, Tian-Lu; Wu, Xin-Tao

    2013-09-14

    Two chiral dinuclear cyanide/isocyanide-bridged complexes (R)-[Cp(dppe)Fe-CN-Fe(dppp)Cp]PF6 (1[PF6]) and (R)-[Cp(dppe)Fe-NC-Fe(dppp)Cp]PF6 (2[PF6]), and their mono-oxidation products (R)-[Cp(dppe)Fe(II)-CN-Fe(III)(dppp)Cp] [PF6]2 (1[PF6]2) and (R)-[Cp(dppe)Fe(III)-NC-Fe(II)(dppp)Cp][PF6]2 (2[PF6]2) were synthesized and fully characterized. The electronic spectra of both the mixed-valence complexes 1[PF6]2 and 2[PF6]2 exhibit a strong and broad absorption band with two discernable peaks in the NIR region, which are attributed to Fe(II)-Fe(III) IVCT transitions. The attributions are supported by the DFT calculations. Under irradiation with a nanosecond laser at 1064 nm, the measured third-order NLO results of all four cyanide-bridged complexes showed that complexes 1(+) and 2(+) do not exhibit an NLO response, but their one-electron oxidation complexes 1(2+) and 2(2+) exhibit a strong NLO response due to a resonance enhanced effect. In addition, both complexes 1(2+) and 2(2+) display RSA and self-defocusing effects and show good optical limiting behavior in a broadband range.

  2. Second-order NLO switches from molecules to polymer films based on photochromic cyclometalated platinum(II) complexes.

    PubMed

    Boixel, Julien; Guerchais, Véronique; Le Bozec, Hubert; Jacquemin, Denis; Amar, Anissa; Boucekkine, Abdou; Colombo, Alessia; Dragonetti, Claudia; Marinotto, Daniele; Roberto, Dominique; Righetto, Stefania; De Angelis, Roberta

    2014-04-09

    Novel photochromic dithienylethene-based platinum(II) complexes (C^N^N)Pt(C≡C-DTE-C6H4-D) ((C^N^N) = 4,4'-di(n-hexyl)-6-phenyl-2,2'-bipyridine; D = H, NMe2) were prepared and characterized. Their excellent photochromic properties allow the photoinduced switching of their second-order nonlinear optical properties in solution, as measured by the EFISH technique, due to formation of an extended π-conjugated ligand upon suitable electromagnetic radiation. Insights into the electronic structures of the complexes and the nature of their excited states have been obtained by DFT and TD-DFT calculations. These novel Pt(II) complexes were nanoorganized in polymer films which were poled, affording new materials characterized by a good second-order NLO response that can be easily switched, with an excellent NLO contrast. To the best of our knowledge, our compounds allowed designing the very first examples of switchable NLO polymer films based on metal complexes.

  3. Growth and structural analysis of an organic NLO compound: L-lysinium picrate

    NASA Astrophysics Data System (ADS)

    Arthi, D.; Ilango, E.; Mercina, M.; Jayaraman, D.; Joseph, V.

    2017-01-01

    L-lysinium picrate (LLP), an organic material, has been synthesized and grown by solution growth method. The crystal structure of the grown material was solved by single crystal X-ray diffraction analysis and it was found that the material belongs to triclinic system with space group P1. The transmission range of the crystal was measured in the range of 470-1100 nm with lower cut off wavelength at 470 nm using UV-vis-NIR absorption spectrum. The optical band gap of the grown material was found to establish the dielectric behavior of the material. The main functional groups present in the material were identified using FTIR spectral analysis. Thermal stability and decomposition range were studied by means of TGA and DTA analyses. The microstructure of the grown crystal was studied using SEM analysis. The various chemical environments of the protons and carbons were studied by 1H and 13C NMR spectroscopy to confirm the molecular structure of the grown crystal. NLO behavior was confirmed by Kurtz and Perry technique and SHG efficiency was estimated as 1.4 times that of standard KDP.

  4. Constraints on the S=-1 meson-baryon interaction at NLO

    NASA Astrophysics Data System (ADS)

    Feijoo, A.; Magas, V. K.; Ramos, A.

    2017-03-01

    This work contains a study of the meson-baryon interaction in the S = -1 sector by means of a chiral SU(3) Lagrangian up to next-to-leading order (NLO) and implementing unitarization in coupled channels. In order to get more reliable values of the parameters which are present in the model, we performed several fits which take a large set of experimental scattering data in different two-body channels, threshold branching ratios, and the precise SIDDHARTA values of the energy shift and width of kaonic hidrogen into consideration. In previous studies, we had shown that the K- p → KΞ reactions are especially sensitive to the next to Weinberg-Tomozawa (WT) corrections in the hierarchy. In addition, we pointed out the need to employ processes which are described by pure isospin amplitudes as a tool to discern which models are more realistic among those which give small values for the χ2 in the fits. Following the former suggestion, we present results which include data from K- p → ηΛ, ηΣ reactions which have pure isospin I = 0 and I = 1 component respectively. Finally, to check the goodness of the new obtained parametrization of the model, we present a prediction for another process that filters the I = 1 isospin component: the pure I = 1 K_L^ - p \\to {K^ + }{Ξ^0} reaction which could be measured at the proposed secondary K0L beam at Jlab.

  5. Characterization of NLO crystal absorption for wavelengths 1ω to 4ω

    NASA Astrophysics Data System (ADS)

    Mühlig, Ch.; Bublitz, S.

    2016-12-01

    An overview is presented of the characteristic features for the sandwich concept used for NLO crystal bulk absorption measurements. The sandwich concept is a photo-thermal absorption measurement concept based on the laser induced deflection (LID) technique. Besides a strong sensitivity enhancement for photo-thermally insensitive materials, the focus of the paper is on the absolute calibration, one of the key criteria for photo-thermal techniques. Based on experimental results it is proven that absolute bulk absorption calibration is simplified by using the sandwich concept since it is insensitive to sample orientation or dopants. Furthermore, experimental results on a variety of materials reveal that in general the bulk absorption calibration sample can be made of just one material, e.g. Aluminum which is favorable because of its easy mechanical handling. However, for surface/coating calibration a different result is found. Finally, the sandwich concept is applied to characterize the bulk absorption of different nonlinear crystals at the wavelengths 1064, 532, 355 and 266nm.

  6. DFT calculations on spectroscopic and structural properties of a NLO chromophore

    NASA Astrophysics Data System (ADS)

    Altürk, Sümeyye; Avci, Davut; Tamer, Ömer; Atalay, Yusuf

    2016-03-01

    The molecular geometry optimization, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of 2-(1'-(4'''-Methoxyphenyl)-5'-(thien-2″-yl)pyrrol-2'-yl)-1,3-benzothiazole as potential nonlinear optical (NLO) material were calculated using density functional theory (DFT) HSEh1PBE method with 6-311G(d,p) basis set. The best of our knowledge, this study have not been reported to date. Additionally, a detailed vibrational study was performed on the basis of potential energy distribution (PED) using VEDA program. It is noteworthy that NMR chemical shifts are quite useful for understanding the relationship between the molecular structure and electronic properties of molecules. The computed IR and NMR spectra were used to determine the types of the experimental bands observed. Predicted values of structural and spectroscopic parameters of the chromophore were compared with each other so as to display the effects of the different substituents on the spectroscopic and structural properties. Obtained data showed that there is an agreement between the predicted and experimental data.

  7. A new promising nonlinear optical (NLO) crystal for visible and ultraviolet (UV) regions

    SciTech Connect

    Gheorghe, L.; Achim, A.; Voicu, F.

    2012-08-17

    Different La{sub 1−x}Gd{sub x}Sc{sub 3}(BO{sub 3}){sub 4} compounds with 0 ≤ x ≤ 0.5 were synthesized by solid-state reaction method. The X-ray diffraction studies revealed that the compounds containing more than 30 at.% Gd{sup 3+} ions have non-centrosymmetric trigonal structure (space group R32) and, consequently they are optically nonlinear. A crystal of La{sub x}Gd{sub y}Sc{sub z}(BO{sub 3}){sub 4} (x+y+z = 4) – LGSB with La{sub 0.75}Gd{sub 0.5}Sc{sub 2.75}(BO{sub 3}){sub 4} starting melt composition and relatively small dimensions (about 10 mm in diameter and 25 mm in length) was grown by the Czochralski method. In order to confirm the NLO property, the as-grown crystal was subjected to second-harmonic generation (SHG) test. The nonlinear coefficient d{sub 11} of LGSB crystal has been preliminary estimated to be about 1.9 pm/V, which is larger than that of YAl{sub 3}(BO{sub 3}){sub 4} (YAB) crystal. This article has been formally retracted, please refer to the article PDF for the full retraction notice.

  8. NLO predictions for the production of a spin-two particle at the LHC

    NASA Astrophysics Data System (ADS)

    Das, Goutam; Degrande, Céline; Hirschi, Valentin; Maltoni, Fabio; Shao, Hua-Sheng

    2017-07-01

    We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with coloured particles (inclusive, one jet, two jets and t t bar), with vector bosons (Z ,W± , γ) and with the Higgs boson. We present total and differential cross sections as well as branching ratios as a function of the mass and the collision energy also considering the case of non-universal couplings to standard model particles. We find that the next-to-leading order corrections give rise to sizeable K factors for many channels, in some cases exposing the unitarity-violating behaviour of non-universal couplings scenarios, and in general greatly reduce the theoretical uncertainties. Our predictions are publicly available in the MADGRAPH5_aMC@NLO framework and can, therefore, be directly used in experimental simulations of spin-two particle production for arbitrary values of the mass and couplings.

  9. DFT calculations on spectroscopic and structural properties of a NLO chromophore

    SciTech Connect

    Altürk, Sümeyye Avci, Davut Tamer, Ömer Atalay, Yusuf

    2016-03-25

    The molecular geometry optimization, vibrational frequencies and gauge including atomic orbital (GIAO) {sup 1}H and {sup 13}C NMR chemical shift values of 2-(1′-(4’’’-Methoxyphenyl)-5′-(thien-2″-yl)pyrrol-2′-yl)-1,3-benzothiazole as potential nonlinear optical (NLO) material were calculated using density functional theory (DFT) HSEh1PBE method with 6–311G(d,p) basis set. The best of our knowledge, this study have not been reported to date. Additionally, a detailed vibrational study was performed on the basis of potential energy distribution (PED) using VEDA program. It is noteworthy that NMR chemical shifts are quite useful for understanding the relationship between the molecular structure and electronic properties of molecules. The computed IR and NMR spectra were used to determine the types of the experimental bands observed. Predicted values of structural and spectroscopic parameters of the chromophore were compared with each other so as to display the effects of the different substituents on the spectroscopic and structural properties. Obtained data showed that there is an agreement between the predicted and experimental data.

  10. NLO predictions for the production of a spin-two particle at the LHC

    DOE PAGES

    Das, Goutam; Degrande, Céline; Hirschi, Valentin; ...

    2017-05-08

    We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with coloured particles (inclusive, one jet, two jets andmore » $$t\\bar t$$), with vector bosons ($$Z,W^\\pm,\\gamma$$) and with the Higgs boson. Here, we present total and differential cross sections as well as branching ratios as a function of the mass and the collision energy also considering the case of non-universal couplings to standard model particles. We find that the next-to-leading order corrections give rise to sizeable $K$ factors for many channels, in some cases exposing the unitarity-violating behaviour of non-universal couplings scenarios, and in general greatly reduce the theoretical uncertainties. Our predictions are publicly available in the MadGraph5_aMC@NLO framework and can, therefore, be directly used in experimental simulations of spin-two particle production for arbitrary values of the mass and couplings.« less

  11. Investigation of NLO Properties of Fluorescent BORICO Dyes: a Comprehensive Experimental and Theoretical Approach.

    PubMed

    Erande, Yogesh; Warde, Umesh; Sekar, Nagaiyan

    2017-08-22

    BORICO dyes with N, N-diethyl as a strong donor and BF2 complexed iminocoumarin six member core as strong acceptor are investigated as an efficient non linear optical chromophores. Extended π-conjugation over iminocoumarin moiety is useful to make ICT character of BORICO dyes more significant and is established on the scale of Generalised Mulliken Hush analysis scale. Bond length alternation and bond order alternation values for three BORICO chromophores estimates the cyanine like framework for optimal non linear optical response. The frontier molecular orbital diagrams obtained from density functional theory calculations shows that there is charge transfer from donor to accepter as well as effective overlap between them making the basis for optimal NLO response of BORICO chromophores. The theoretical values of linear and non linear optical responses for three BORICO NLOphores obtained by using three different functionals B3LYP, CAMB3LYP and BHandHLYP with 6-311+g(d,p) basis set are quite consistent for the values of static dipole moment (μ), linear polarizability (α) and first hyperpolarizability (β). However in case of the γ values calculation, compare to the similar values obtained by CAMB3LYP and BHandHLYP functionals, B3LYP overestimates the same. The vibrational motions play decisive role in the overall non linear optical properties of BORICO chromophores.

  12. Theoretical studies on the quinoidal thiophene based dyes for dye sensitized solar cell and NLO applications.

    PubMed

    Nithya, R; Senthilkumar, K

    2014-10-21

    A series of quinoidal thiophene based dye molecules were designed and their optoelectronic properties were studied for dye sensitized solar cell (DSSC) applications. The efficiency of the designed dye molecules was analyzed using various parameters such as the HOMO-LUMO energy gap, absorption spectra, light harvesting efficiency (LHE), exciton biding energy (Eb) and free energy change for electron injection (ΔG(inject)). The simulated absorption spectra of the quinoidal thiophene molecules show that the electron withdrawing group substituted molecules exhibit dual band characteristics. We found that the cyano-[5'-(4″-amino benzylidene)-5H-thiophen-2'-ylidene] acetic acid based molecules, QT2B, QT4B, QT5 and QT6, are good candidates for DSSC applications. Furthermore, the study on the polarizability and hyperpolarizability of the designed molecules showed that the electron withdrawing group substituted QT2B-X molecules (X = Cl, Br, CF3, CN and NO2) are good candidates for NLO applications.

  13. Ba6Sn6Se13: a new mixed valence selenostannate with NLO property.

    PubMed

    Feng, Kai; Jiang, Xingxing; Kang, Lei; Yin, Wenlong; Hao, Wenyu; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng; Chen, Chuangtian

    2013-10-07

    A new ternary selenostannate Ba6Sn6Se13 has been synthesized by a high temperature solid-state method. The compound crystallizes in the non-centrosymmetric orthorhombic space group P2(1)2(1)2(1) and may be represented as Ba6Sn5(2+)Sn(4+)Se13 with mixed valence Sn atoms. Sn(4+) cations lie in a tetrahedral environment, while Sn(2+) cations are found in two kinds of coordination environments: the trigonal pyramid and quadrangular pyramid. SnSe(n) (n = 3, 4, 5) polyhedra are further connected to generate a three-dimensional framework with Ba(2+) residing in cavities. Ba6Sn6Se13 shows moderate nonlinear optical response and is the first reported NLO compound in the Ba-Sn-Se system. In addition, diffuse reflectance spectroscopy measurement indicates that the band gap of Ba6Sn6Se13 is 1.52(2) eV and thermal analysis suggests that the compound melts incongruently. The theoretically calculated SHG response and band gap are in good agreement with experimental results.

  14. Structure and NLO properties of halogen (F, Cl) substituted formic acid dimers.

    PubMed

    Umadevi, P; Senthilkumar, L; Gayathri, M; Kolandaivel, P

    2014-11-11

    In this work, using ab initio and density functional theory (DFT) methods halogen substituted formic acid (FA) dimer is studied. The dimer stability is due to the hydrogen bonds, either conventional (OH⋯O, OH⋯F, OH⋯Cl) or non-conventional (CH⋯O, CH⋯F, CH⋯Cl). Among all the dimers, trans-trans form is more stable than the trans-cis, and cis-cis form. Basis set extrapolated counterpoise corrected interaction energy results for the FA dimer are in excellent agreement with BSSE corrected MP2 interaction energy. Symmetry Adopted Perturbation Theory (SAPT) analysis reveals that the electrostatic effect plays a dominant role in stabilization among the dimers with maximum interaction energy. Chlorine substituted FA dimer has high hyperpolarizability, which makes them excellent candidate for nonlinear optical materials (NLO). The halogen substituted formic acid dimers have higher stability and polarizability value than the unsubstituted formic acid dimer. The hyperpolarizability values depend on the geometrical structures of halogenated formic acid dimers than the type of hydrogen bonds. The small excitation energy and HOMO-LUMO gap in the halogenated formic acid dimer has led to the strong nonlinear optical response. The depolarization ratio and Rayleigh scattering increases in formic acid dimer after the halogen atom substitution. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Dipolar NLO Chromophores Bearing Diazine Rings as π-Conjugated Linkers.

    PubMed

    Klikar, Milan; le Poul, Pascal; Růžička, Aleš; Pytela, Oldřich; Barsella, Alberto; Dorkenoo, Kokou D; Robin-le Guen, Françoise; Bureš, Filip; Achelle, Sylvain

    2017-09-15

    The synthesis of a series of push-pull derivatives bearing triphenylamine electron-donating group, cyclopenta[c]thiophen-4,6-dione electron acceptor and various π-linkers including (hetero)aromatic fragments is reported. All target chromophores with systematically varied π-linker structure were further investigated by electrochemistry, absorption measurements, and EFISH experiments in conjunction with DFT calculations. Based on electrochemical and photophysical measurements, when a polarizable 2,5-thienylene moiety is embedded into the chromophore π-backbone the highest intramolecular charge transfer (ICT) is observed. Benzene, pyrimidine, and pyridazine derivatives exhibit lower polarizability and extent of the ICT across these π-linkers. The elongation of the π-conjugated system via additional ethenylene linker results in a significant reduction of the HOMO-LUMO gap and an enhancement of the NLO response. Whereas it does not significantly influence electrochemical and linear optical properties, the orientation of the pyrimidine ring seems to be a key parameter on the μβ value due to significant variation of the dipolar moment (μ) value. In 2a and 2c, pyrimidine is oriented to behave as an acceptor and thus generate dipolar molecule with μ above 5 D, whereas in 2b and 2d ground state dipole moment is significantly reduced. This study seems to indicate a high aromaticity of pyrimidine and pyridazine derivatives, close to the benzene analogues and significantly higher than thiophene analogues.

  16. Relativistic correction to gluon fragmentation function into pseudoscalar quarkonium

    NASA Astrophysics Data System (ADS)

    Gao, Xiangrui; Jia, Yu; Li, Liuji; Xiong, Xiaonu

    2017-02-01

    Inspired by the recent measurements of the ηc meson production at LHC experiments, we investigate the relativistic correction effect for the fragmentation functions of gluon/charm quark fragmenting into ηc, which constitute the crucial nonperturbative element for the ηc production at high p T. Employing three distinct methods, we calculate the next-to-leading-order (NLO) relativistic correction to g → ηc fragmentation function in the NRQCD factorization framework, as well as verifying the existing NLO result for the c → ηc fragmentation function. We also study the evolution behavior of these fragmentation functions with the aid of the DGLAP equation. Supported by National Natural Science Foundation of China (11475188, 11261130311, 11575202, 11222549), IHEP Innovation (Y4545170Y2), State Key Lab for Electronics and Particle Detectors

  17. Synthesis, structure, growth and characterization of a novel organic NLO single crystal: Morpholin-4-ium p-aminobenzoate

    SciTech Connect

    Shanmugam, G.; Ravi Kumar, K.; Sridhar, B.; Brahadeeswaran, S.

    2012-09-15

    Highlights: ► A new organic NLO crystal morpholin-4-ium p-aminobenzoate has been grown for the first time. ► The structure is reported for the first time in the literature. ► Thermal, optical and SHG studies suggest its suitability for various NLO applications. -- Abstract: The title compound, morpholin-4-ium p-aminobenzoate (MPABA)(C{sub 4}H{sub 10}NO{sup +},C{sub 7}H{sub 6}NO{sub 2}{sup −}), has been synthesized for the first time by the addition of morpholine with 4-aminobenzoic acid in equi-molar ratio and good quality single crystals have been grown by solution growth technique using methanol as a solvent. The molecular structure of the compound was solved and refined by Direct Methods using SHELXS97 and full-matrix least-squares technique using SHELXL97, respectively. MPABA crystallizes in a monoclinic system with unit cell parameters, a = 5.948(5) Å, b = 18.033(4) Å, c = 10.577(5) Å, β = 90.40(1)° and non-centrosymmetric space group Cc. The experimentally measured density and chemical compositions were found to be in good agreement with the theoretical values. The phases and functional groups of MPABA have been identified and confirmed through powder X-ray diffraction and Fourier transform infrared (FTIR) studies, respectively. The thermal stability and decomposition details were studied through TG/DTA thermograms. The UV–visible transmission spectra were recorded for the grown crystal and its NLO characteristic was explored by powder second harmonic generation (SHG) studies.

  18. New Meta Nanomaterials Extension II of Optical Enhancement and Photorefractive Two-Beam Coupling - Synthesis and Fabrication of Quantum Dot NLO Polymer Composites

    DTIC Science & Technology

    2015-07-09

    of Quantum Dot NLO Polymer Composites Ronald Ziolo CIQA Final Report 07/09/2015 DISTRIBUTION A: Distribution approved for public release. AF Office...Photorefractive Two-Beam Coupling - Synthesis and Fabrication of Quantum Dot NLO Polymer Composites 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0171 5c...Composites of CdS quantum dots and a new conjugated polymer were prepared by reacting CdS capped with (3-mercaptopropyl)trimethoxysilane (MPS) and a new

  19. Vibrational, NMR and UV-Visible spectroscopic investigation, VCD and NLO studies on Benzophenone thiosemicarbazone using computational calculations

    NASA Astrophysics Data System (ADS)

    Moorthy, N.; Jobe Prabakar, P. C.; Ramalingam, S.; Periandy, S.; Parasuraman, K.

    2016-04-01

    In order to explore the unbelievable NLO property of prepared Benzophenone thiosemicarbazone (BPTSC), the experimental and theoretical investigation has been made. The theoretical calculations were made using RHF and CAM-B3LYP methods at 6-311++G(d,p) basis set. The title compound contains Cdbnd S ligand which helps to improve the second harmonic generation (SHG) efficiency. The molecule has been examined in terms of the vibrational, electronic and optical properties. The entire molecular behavior was studied by their fundamental IR and Raman wavenumbers and was compared with the theoretical aspect. The molecular chirality has been studied by performing vibrational circular dichroism (circularly polarized infrared radiation). The Mulliken charge levels of the compound ensure the perturbation of atomic charges according to the ligand. The molecular interaction of frontier orbitals emphasizes the modification of chemical properties of the compound through the reaction path. The enormous amount of NLO activity was induced by the Benzophenone in thiosemicarbazone. The Gibbs free energy was evaluated at different temperature and from which the enhancement of chemical stability was stressed. The VCD spectrum was simulated and the optical dichroism of the compound has been analyzed.

  20. Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin; Schulze, Markus

    2016-11-01

    We analyze the energy spectra of single b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the "energy peak" as an observable to determine the top quark mass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it concerns higher-order QCD effects or new physics contributions. For a 1% jet energy scale uncertainty, the top quark mass can then be extracted using the energy peak of b-jets with an error ± (1.2 ({exp}) + 0.6({th})) { GeV}. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass.

  1. Growth and characterization of novel organic 3-Hydroxy Benzaldehyde-N-methyl 4 Stilbazolium Tosylate crystals for NLO applications

    NASA Astrophysics Data System (ADS)

    Jagannathan, K.; Umarani, P.; Ratchagar, V.; Ramesh, V.; Kalainathan, S.

    2016-01-01

    The 3-Hydroxy Benzaldehyde-N-methyl 4-Stilbazolium Tosylate (3- HBST) is a new organic NLO crystal and it is a new derivative in stilbazolium tosylate family. In this work we have synthesized 3-HBST and the single crystal was grown by conventional slow cooling method. The structure and lattice parameters of the grown crystal were determined by the single crystal X-ray diffraction (XRD) technique and it is exhibiting good crystalline nature which is observed from the powder XRD. In order to check the crystalline quality the rocking curve was recorded using multi crystal X-ray diffractometer. The functional groups were identified from both FTIR and NMR spectral analyses. The π-π* and n-π* optical transition energy levels were estimated from the absorption peaks. The NLO property was confirmed by measuring relative SHG efficiency by Kurtz powder test; it shows 24 times higher SHG efficiency than that of urea. In order to test the mechanical stability the Vickers and Knoop micro hardness measurement were carried out and found that the micro hardness number decreases with increasing load. The melting point was determined from Differential Scanning Colorimetry (DSC).

  2. Diphoton production at the Tevatron and the LHC in the NLO approximation of the parton Reggeization approach

    NASA Astrophysics Data System (ADS)

    Nefedov, M. A.; Saleev, V. A.

    2015-11-01

    The hadroproduction of prompt isolated photon pairs at high energies is studied in the framework of the parton Reggeization approach. The real part of the NLO corrections is computed (the NLO⋆ approximation), and the procedure for the subtraction of double counting between real parton emissions in the hard-scattering matrix element and unintegrated parton distribution function is constructed for the amplitudes with Reggeized quarks in the initial state. The matrix element of the important next-to-next-to-leading-order subprocess R R →γ γ with full dependence on the transverse momenta of the initial-state Reggeized gluons is obtained. We compare obtained numerical results with diphoton spectra measured at the Tevatron and the LHC and find a good agreement of our predictions with experimental data at the high values of diphoton transverse momentum, pT, and especially at the pT larger than the diphoton invariant mass, M . In this multi-Regge kinematics region, the NLO correction is strongly suppressed, demonstrating the self-consistency of the parton Reggeization approach.

  3. Measurement of the strange - antistrange asymmetry at NLO in QCD from NuTeV dimuon data

    SciTech Connect

    Mason, David Alexander

    2006-03-01

    A measurement of the asymmetry between the strange and antistrange quark distributions, from a next to leading order QCD analysis of dimuon events measured by the NuTeV experiment at Fermilab is presented. Neutrino charged current events with two muons in the final state provide a direct means for studying charm production and measuring the strange sea. NuTeV's sign selected beam allows independent measurement of the strange and antistrange seas. An improved measurement of the neutrino and antineutrino forward dimuon cross section tables, using the complete charged current event sample for normalization is performed. These tables are then analyzed at NLO to measure the strange and antistrange seas. Detector acceptance is modeled using an NLO charm cross section differential in all variables required. The strange quark distribution is found to have an integrated momentum weighted asymmetry of +0.00196 ± 0.00046(stat) ± 0.00045(syst) ± 0.00182(external). The charm mass is found to be 1.41 ± 0.10(stat) ± 0.08(syst) ± 0.12(external) GeV.

  4. NLO QCD result for the gluon polarisation from open-charm D0 meson production at COMPASS

    NASA Astrophysics Data System (ADS)

    Kurek, Krzysztof; Compass Collaboration

    2011-05-01

    One of the main goals of the COMPASS experiment is the measurement of the gluon contribution to the nucleon spin. Among the processes studied by COMPASS, open-charm D0 meson production seems to be the cleanest channel for probing gluons in the energy range covered by the experiment. The gluon polarisation is related to the measured asymmetry for charmed meson production via the analyzing power (asymmetry at the partonic level) calculated in the perturbative QCD frame. The analyzing power for the "photon-gluon fusion" process corresponds to a LO QCD approximation. The significant improvement of the statistical precision and the new, final LO result are presented. The NLO QCD corrections to the partonic cross sections (unpolarised and polarised ones) are now also included into the analysis scheme since these higher order contributions are not negligible. The preliminary NLO QCD result on the gluon polarisation based on a set of measured D0 meson asymmetries in kinematical bins of the D0 energy and transverse momentum is presented.

  5. Growth and characterization of novel organic 3-Hydroxy Benzaldehyde-N-methyl 4 Stilbazolium Tosylate crystals for NLO applications.

    PubMed

    Jagannathan, K; Umarani, P; Ratchagar, V; Ramesh, V; Kalainathan, S

    2016-01-15

    The 3-Hydroxy Benzaldehyde-N-methyl 4-Stilbazolium Tosylate (3- HBST) is a new organic NLO crystal and it is a new derivative in stilbazolium tosylate family. In this work we have synthesized 3-HBST and the single crystal was grown by conventional slow cooling method. The structure and lattice parameters of the grown crystal were determined by the single crystal X-ray diffraction (XRD) technique and it is exhibiting good crystalline nature which is observed from the powder XRD. In order to check the crystalline quality the rocking curve was recorded using multi crystal X-ray diffractometer. The functional groups were identified from both FTIR and NMR spectral analyses. The π-π* and n-π* optical transition energy levels were estimated from the absorption peaks. The NLO property was confirmed by measuring relative SHG efficiency by Kurtz powder test; it shows 24 times higher SHG efficiency than that of urea. In order to test the mechanical stability the Vickers and Knoop micro hardness measurement were carried out and found that the micro hardness number decreases with increasing load. The melting point was determined from Differential Scanning Colorimetry (DSC).

  6. Incorporation of a platinum center in the pi-conjugated core of push-pull chromophores for nonlinear optics (NLO).

    PubMed

    Durand, Raphaël J; Gauthier, Sébastien; Achelle, Sylvain; Kahlal, Samia; Saillard, Jean-Yves; Barsella, Alberto; Wojcik, Laurianne; Le Poul, Nicolas; Robin-Le Guen, Françoise

    2017-02-28

    In this article, we describe the synthesis, redox characteristics, and linear and nonlinear optical (NLO) properties of seven new unsymmetrical push-pull diacetylide platinum-based complexes. These D-π-Pt-π-A complexes incorporate pyranylidene ligands as pro-aromatic donor groups (D), diazine rings as electron-withdrawing groups (A), and various aromatic fragments (styryl or thienylvinyl) as π-linkers separating the platinum diacetylide unit from the donor and the acceptor groups. This is one of the first examples of push-pull chromophores incorporating a platinum center in the π-conjugated core. The NLO properties of these complexes were compared with those of their purely organic analogues. All compounds (organic and organometallic) exhibited positive μβ values, which dramatically increased upon methylation of the pyrimidine fragment. However, this increase was even more significant in the complexes due to the presence of platinum in the π-conjugated core. The effects of the linker on the redox and spectroscopic properties of the complexes are also discussed. In addition, DFT calculations were performed in order to gain further insight into the intramolecular charge transfer (ICT) occurring through the platinum center.

  7. Vibrational, NMR and UV-visible spectroscopic investigation and NLO studies on benzaldehyde thiosemicarbazone using computational calculations

    NASA Astrophysics Data System (ADS)

    Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Pandian, G. V.; Anbusrinivasan, P.

    2016-04-01

    In order to investigate the vibrational, electronic and NLO characteristics of the compound; benzaldehyde thiosemicarbazone (BTSC), the XRD, FT-IR, FT-Raman, NMR and UV-visible spectra were recorded and were analysed with the calculated spectra by using HF and B3LYP methods with 6-311++G(d,p) basis set. The XRD results revealed that the stabilized molecular systems were confined in orthorhombic unit cell system. The cause for the change of chemical and physical properties behind the compound has been discussed makes use of Mulliken charge levels and NBO in detail. The shift of molecular vibrational pattern by the fusing of ligand; thiosemicarbazone group with benzaldehyde has been keenly observed. The occurrence of in phase and out of phase molecular interaction over the frontier molecular orbitals was determined to evaluate the degeneracy of the electronic energy levels. The thermodynamical studies of the temperature region 100-1000 K to detect the thermal stabilization of the crystal phase of the compound were investigated. The NLO properties were evaluated by the determination of the polarizability and hyperpolarizability of the compound in crystal phase. The physical stabilization of the geometry of the compound has been explained by geometry deformation analysis.

  8. Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD

    DOE PAGES

    Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin; ...

    2016-11-21

    Here, we analyze the energy spectra of single b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the “energy peak” as an observable to determine the top quarkmass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it concerns higher-order QCD effects or newmore » physics contributions. For a 1% jet energy scale uncertainty, the top quark mass can then be extracted using the energy peak of b-jets with an error ±(1.2(exp) + 0.6(th)) GeV. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass.« less

  9. The Roles of Molecular Structure and Effective Optical Symmetry in Evolving Dipolar Chromophoric Building Blocks to Potent Octopolar NLO Chromophores

    PubMed Central

    Ishizuka, Tomoya; Sinks, Louise E.; Song, Kai; Hung, Sheng-Ting; Nayak, Animesh; Clays, Koen; Therien, Michael J.

    2011-01-01

    A series of mono-, bis-, tris-, and tetrakis-(porphinato)zinc(II) (PZn)-elaborated ruthenium(II) bis(terpyridine) (Ru) complexes has been synthesized in which an ethyne unit connects the macrocycle meso carbon atom to terpyridyl (tpy) 4-, 4′-, and 4″- positions. These supermolecular chromophores, based on the ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ bis-hexafluorophosphate (RuPZn) archetype, evince strong mixing of the PZn-based oscillator strength with ruthenium terpyridyl charge resonance bands. Potentiometric and linear absorption spectroscopic data indicate that for structures in which multiple PZn moieties are linked via ethynes to a [Ru(tpy)2]2+ core, little electronic coupling is manifest between PZn units, regardless of whether they are located on the same or opposite tpy ligand. Congruent with these experiments, pump-probe transient absorption studies suggest that the individual RuPZn fragments of these structures exhibit, at best, only modest excited-state electronic interactions that derive from factors other than the dipole-dipole interactions of these strong oscillators; this approximate independent character of the component RuPZn oscillators enables fabrication of NLO multipoles with extraordinary hyperpolarizabilities. Dynamic hyperpolarizability (βλ) values and depolarization ratios (ρ) were determined from hyper-Rayleigh light scattering (HRS) measurements carried out at an incident irradiation wavelength (λinc) of 1300 nm. The depolarization ratio data provide an experimental measure of chromophore optical symmetry; appropriate coupling of multiple charge-transfer oscillators produces structures having enormous averaged hyperpolarizabilities (βHRS values), while evolving the effective chromophore symmetry from purely dipolar (e.g., Ru(tpy)[4-(Znporphyrin)ethynyl-tpy](PF6)2, βHRS = 1280 × 10−30 esu, ρ = 3

  10. Evolution of average multiplicities of quark and gluon jets

    SciTech Connect

    Capella, A.; Dremin, I. M.; Gary, J. W.; Nechitailo, V. A.; Tran Thanh Van, J.

    2000-04-01

    The energy evolution of the average multiplicities of quark and gluon jets is studied in perturbative QCD. Higher order (3NLO) terms in the perturbative expansion of equations for the generating functions are found. First and second derivatives of average multiplicities are calculated. The mean multiplicity of gluon jets is larger than that of quark jets and evolves more rapidly with energy. It is shown which quantities are most sensitive to higher order perturbative and nonperturbative corrections. We define the energy regions where the corrections to different quantities are important. The latest experimental data are discussed. (c) 2000 The American Physical Society.

  11. Small-x evolution in the next-to-leading order

    SciTech Connect

    Giovanni Antonio Chirilli

    2009-12-01

    After a brief introduction to Deep Inelastic Scattering in the Bjorken limit and in the Regge Limit we discuss the operator product expansion in terms of non local string operator and in terms of Wilson lines. We will show how the high-energy behavior of amplitudes in gauge theories can be reformulated in terms of the evolution of Wilson-line operators. In the leading order this evolution is governed by the non-linear Balitsky-Kovchegov (BK) equation. In order to see if this equation is relevant for existing or future deep inelastic scattering (DIS) accelerators (like Electron Ion Collider (EIC) or Large Hadron electron Collider (LHeC)) one needs to know the next-to-leading order (NLO) corrections. In addition, the NLO corrections define the scale of the running-coupling constant in the BK equation and therefore determine the magnitude of the leading-order cross sections. In Quantum Chromodynamics (QCD), the next-to-leading order BK equation has both conformal and non-conformal parts. The NLO kernel for the composite operators resolves in a sum of the conformal part and the running-coupling part. The QCD and kernel of the BK equation is presented.

  12. Anion-controlled self-assembly of two NLO-active dinuclear and molecular square Cu(II) enantiomeric pairs: from antiferromagnetic to ferromagnetic coupling.

    PubMed

    Li, Xi-Li; Kang, Jia-Long; Zhang, Xue-Li; Xiao, Hong-Ping; Wang, Ai-Ling; Zhou, Liming; Fang, Shao-Ming; Liu, Cai-Ming

    2014-12-14

    Two second-order nonlinear optically (NLO)-active dinuclear and square Cu(II) enantiomeric pairs were obtained via the self-assemblies of enantiopure linear bis-bidentate ligands with different copper(II) salts under the identical reaction conditions. Their magnetic properties are switched from antiferromagnetic to ferromagnetic coupling.

  13. Q{sub 2} evolution of parton distributions at small values of x: Effective scale for combined H1 and ZEUS data on the structure function F{sub 2}

    SciTech Connect

    Kotikov, A. V. Shaikhatdenov, B. G.

    2015-06-15

    An expression for the structure function F{sub 2} in the form of Bessel functions at small values of the Bjorken variable x is used. This expression was derived for a flat initial condition in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations. The argument of the strong coupling constant was chosen in such a way as to annihilate the singular part of the anomalous dimensions in the next-to-leading-order of perturbation theory. This choice, together with the frozen and analytic versions of the strong coupling constant, is used to analyze combined data of the H1 and ZEUS Collaborations obtained recently for the structure function F{sub 2}.

  14. Study on growth, spectral, optical and thermal characterization of an NLO crystal: 6-Methyl nicotinic acid (6MNA)

    NASA Astrophysics Data System (ADS)

    Delphine, S. Mary; Rani Juliet, A. R. S. Janci; Janarthanan, S.; Samuel, R. Sugaraj

    2017-05-01

    6-methyl-nictinic acid (6MNA), organic non linear optical (NLO) single crystals were grown by slow evaporation solution technique. The cell parameters of 6MNA were confirmed from single crystal X-ray diffraction analysis. The Fourier transforms infrared and proton Nuclear magnetic resonance spectral analysis confirm the presence of various functional groups and the placement of protons respectively in 6MNA compound. UV-vis-NIR spectral studies revealed that the grown 6MNA has good optical transmission in the range of entire visible region. The thermal properties of crystals were evaluated from thermogravimetric (TG) and differential thermal analysis (DTA). It has shown that the grown crystals were stable up to 213°C. The second harmonic generation (SHG) measurements indicated that the efficiency of 6MNA is two times greater than that of the KDP crystals and is suitable for frequency conversion applications.

  15. Conformational analysis, UV-VIS, MESP, NLO and NMR studies of 6-methoxy-1,2,3,4-tetrahydronaphthalene.

    PubMed

    Arivazhagan, M; Kavitha, R; Subhasini, V P

    2014-07-15

    The detailed HF and B3LYP/6-311++G(d,p) comparative studies on the complete FT-IR and FT-Raman spectra of 6-methoxy-1,2,3,4-tetrahydronaphthalene [MTHN] have been studied. In view of the special properties and uses, the present investigation has been undertaken to provide a satisfactorily vibrational analysis of 6-methoxy-1,2,3,4-tetrahydronaphthalene. Therefore, a thorough Raman, IR, molecular electrostatic potential (MESP), non-linear optical (NLO) properties, UV-VIS, HOMO-LUMO and NMR spectroscopic investigation are reported complemented by B3LYP theoretical predictions with basis set 6-311++G(d,p) to provide novel insight on vibrational assignments and conformational stability of MTHN. Potential energy surface scans (PES) of the CH3 group are undertaken to shed light on the rather complicated conformational interchanges in the compound under investigation.

  16. Synthesis, spectral analysis, optical and thermal properties of new organic NLO crystal: N,N'-Diphenylguanidinium Nitrate (DPGN).

    PubMed

    Saravana Kumar, G; Murugakoothan, P

    2014-10-15

    A new organic NLO material N,N'-Diphenylguanidinium Nitrate (DPGN) single crystal was grown by slow evaporation technique using methanol as solvent. Single crystal X-ray diffraction and powder X-ray diffraction experiments were carried out in order to confirm the structure and crystalline nature of DPGN crystal. Wide band gap of 3.9eV with transmittance of 57% up to 800nm is observed for the grown crystal using UV-vis spectral analysis. The chemical bonding and presence of various functional groups were confirmed by the FT-IR and FT-Raman spectral studies. The thermal behavior of DPGN crystal was analyzed by simultaneous TG-DTA studies. The second harmonic generation (SHG) nonlinearity of the grown crystal was measured by Kurtz and Perry powder technique and was found to be comparable with that of the standard reference material potassium dihydrogen phosphate (KDP) crystal. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. [60]Fullerene-porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response.

    PubMed

    Đorđević, L; Marangoni, T; De Leo, F; Papagiannouli, I; Aloukos, P; Couris, S; Pavoni, E; Monti, F; Armaroli, N; Prato, M; Bonifazi, D

    2016-04-28

    By means of different spectroscopic techniques, we investigate a novel series of porphyrin derivatives (H2TPP), connected to dibenzo-24-crown-8 (DB24C8) moieties, which undergo self-assembly with different methano[60]fullerene units bearing dibenzylammonium (DBA) cations. The formation of both [2] and [3]pseudorotaxanes was proved by means of NMR, UV-Vis-NIR absorption and emission spectroscopies. With the support of molecular modelling studies, spectroscopic investigations showed the presence of a secondary interaction between the porphyrin and the C60 chromophores leading to the formation of different types of "face-to-face" assemblies. Remarkably, investigations of the non-linear optical response of these supramolecular systems showed that individual porphyrin and fullerene derivatives exhibit significantly lower second hyperpolarizability values when compared to their pseudorotaxanes functionalised counterparts. This proves that this class of supramolecular materials possesses relevant NLO response, which strongly depends on the structural arrangement of the chromophores in solution.

  18. Singularity-free next-to-leading order ΔS = 1 renormalization group evolution and ɛ K ' /ɛK in the Standard Model and beyond

    NASA Astrophysics Data System (ADS)

    Kitahara, Teppei; Nierste, Ulrich; Tremper, Paul

    2016-12-01

    The standard analytic solution of the renormalization group (RG) evolution for the Δ S = 1 Wilson coefficients involves several singularities, which complicate analytic solutions. In this paper we derive a singularity-free solution of the next-to-leading order (NLO) RG equations, which greatly facilitates the calculation of ɛ K ' , the measure of direct CP violation in K → ππ decays. Using our new RG evolution and the latest lattice results for the hadronic matrix elements, we calculate the ratio ɛ K ' /ɛ K (with ɛ K quantifying indirect CP violation) in the Standard Model (SM) at NLO to ɛ K ' /ɛ K = (1.06 ± 5.07) × 10- 4, which is 2 .8 σ below the experimental value. We also present the evolution matrix in the high-energy regime for calculations of new physics contributions and derive easy-to-use approximate formulae. We find that the RG amplification of new-physics contributions to Wilson coefficients of the electroweak penguin operators is further enhanced by the NLO corrections: if the new contribution is generated at the scale of 1-10 TeV, the RG evolution between the new-physics scale and the electroweak scale enhances these coefficients by 50-100%. Our solution contains a term of order α EM 2 / α s 2 , which is numerically unimportant for the SM case but should be included in studies of high-scale new-physics.

  19. The proton FL dipole approximation in the KMR and the MRW unintegrated parton distribution functions frameworks

    NASA Astrophysics Data System (ADS)

    Modarres, M.; Masouminia, M. R.; Hosseinkhani, H.; Olanj, N.

    2016-01-01

    In the spirit of performing a complete phenomenological investigation of the merits of Kimber-Martin-Ryskin (KMR) and Martin-Ryskin-Watt (MRW) unintegrated parton distribution functions (UPDF), we have computed the longitudinal structure function of the proton, FL (x ,Q2), from the so-called dipole approximation, using the LO and the NLO-UPDF, prepared in the respective frameworks. The preparation process utilizes the PDF of Martin et al., MSTW2008-LO and MSTW2008-NLO, as the inputs. Afterwards, the numerical results are undergone a series of comparisons against the exact kt-factorization and the kt-approximate results, derived from the work of Golec-Biernat and Stasto, against each other and the experimental data from ZEUS and H1 Collaborations at HERA. Interestingly, our results show a much better agreement with the exact kt-factorization, compared to the kt-approximate outcome. In addition, our results are completely consistent with those prepared from embedding the KMR and MRW UPDF directly into the kt-factorization framework. One may point out that the FL, prepared from the KMR UPDF shows a better agreement with the exact kt-factorization. This is despite the fact that the MRW formalism employs a better theoretical description of the DGLAP evolution equation and has an NLO expansion. Such unexpected consequence appears, due to the different implementation of the angular ordering constraint in the KMR approach, which automatically includes the resummation of ln ⁡ (1 / x), BFKL logarithms, in the LO-DGLAP evolution equation.

  20. A new type of organic-inorganic hybrid NLO-phore with large off-diagonal first hyperpolarizability tensors: a two-dimensional approach.

    PubMed

    Muhammad, Shabbir; Xu, Hongliang; Su, Zhongmin; Fukuda, Kotaro; Kishi, Ryohei; Shigeta, Yasuteru; Nakano, Masayoshi

    2013-11-14

    We report a novel type of organic-inorganic hybrid material with rare two-dimensional nonlinear optical (NLO) properties. The density functional theory (DFT) calculations combined with the finite-field (FF) method show that the designed molecules (6,9 organo-derivatives of B10H14) could carry the characteristic NLO properties of both organic and inorganic materials. Interestingly, due to their unique V-shaped structures, they have large off-diagonal first hyperpolarizability tensors or nonlinear anisotropy, which is an advantage in their practical applications over conventional donor-π-acceptor (D-π-A) NLO-phores. The systematic substitutions of terminal donor/acceptor groups as well as the extension of π-conjugation along the V-shape in these derivatives have been evaluated to guide a purpose-oriented synthesis of NLO material. All the systems in the present study have been categorized into Set-I and Set-II with D-π-A-π-D and A-π-D-π-A configurations, respectively. These designed derivatives show large amplitudes of βz values. For example, systems 3N (6,9-[(N=C=Ph-NO2)2]-B10H12) and 4N (6,9-[((N=C=Ph)2-NO2)2]-B10H12) have βz amplitudes as large as 34.16 and 276.91 × 10(3) a.u. which are 380 and 3000 times larger than those of a typical NLO molecule of urea, respectively. Remarkably, the substitution of nitrogen atoms with 6,9 hydrogen atoms in decaborane is shown to cause a lone pair back donation to vacant p orbitals of 6,9 boron atoms of the decaborane basket. This p orbital overlapping verticalizes the V-arms of the decaborane derivatives and boosts their nonlinear anisotropies due to their larger off-diagonal tensor components. The nonlinear anisotropy values are significantly larger, ranging from 1 (minimum in system 1) to 31.90 (maximum in system 3A) due to their unique V-shape. Comparison of their efficiencies with standard molecules demonstrates that our designed organic-inorganic hybrid molecules have significant potential as excellent

  1. PHYSICS OF ELEMENTARY PARTICLES AND FIELDS: B → ρ(ω, ø)η(') Decays and NLO Contributions in pQCD Approach

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Qing; Xiao, Zhen-Jun

    2009-05-01

    By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next-to-leading-order (NLO) contributions to the two-body charmless hadronic decays B+ → ρ+ η(') and B0 → ρ0 (ω, ø)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B± → ρ±η(') (B0 → ρ0 (ω, ø)η(') decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACPdir(B± → ρ±η(')) are consistent with the data, while the predicted ACP(B0 → ρ0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.

  2. Using two simple methods of Ar-Ar(F) self-assembly and isolation chromophores to further improve the comprehensive performance of NLO dendrimers.

    PubMed

    Wu, Wenbo; Yu, Gui; Liu, Yunqi; Ye, Cheng; Qin, Jingui; Li, Zhen

    2013-01-07

    Herein, through a combination of divergent and convergent approaches, coupled with the utilization of the powerful Sharpless "click chemistry" reaction, two series of high-generation nonlinear optical (NLO) dendrimers have been conveniently prepared in high purity and satisfactory yields. Perfluoroaromatic rings and isolation chromophores were introduced to further improve their comprehensive performance. Thanks to the effects of Ar-Ar(F) self-assembly and the isolation chromophores, coupled with perfect 3D spatial isolation from the highly branched structure of the dendrimer, G5-PFPh-NS displayed very large NLO efficiency (up to 257 pm V(-1)), which is, to the best of our knowledge, the new record highest value reported so far for simple azo chromophore moieties. High-quality wide optical transparency and good stability were also achieved. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Synthesis, growth, structural and HOMO and LUMO, MEP analysis of a new stilbazolium derivative crystal: A enhanced third-order NLO properties with a high laser-induced damage threshold for NLO applications

    NASA Astrophysics Data System (ADS)

    Senthil, K.; Kalainathan, S.; Hamada, F.; Yamada, M.; Aravindan, P. G.

    2015-08-01

    A new organic third-order nonlinear optical crystal from stilbazolium family 2-[2-(4-methoxy-phenyl) vinyl]-1-methyl-pyridinium tetrafluoroborate (4MSTB) has been synthesized and grown by slow evaporation method for the first time. The grown crystal structure was confirmed by single crystal X-ray diffraction analysis, and it is revealed that the grown crystal crystallized in a triclinic crystal system with centrosymmetric space group P 1 bar . The HOMO and LUMO energies were calculated for the grown crystal explains charge transfer takes place within the molecule and confirms the suitability of the title crystal for NLO applications. The presence of various vibration modes of expected functional groups was identified by FT-IR analysis. The transmittance ability of the grown crystal was also analyzed by using UV-Vis-NIR spectral studies and shows that the crystal has no absorption of light in the entire Vis-NIR region. The thermal stability of the title crystal has been investigated by TGA/DTA studies and revealed that the material was thermally stable up to the melting point, 193 °C. The hardness number, Meyer index, yield strength, and elastic stiffness constant has been estimated for the grown 4MSTB crystal using Vickers microhardness tester. Photoluminescence excitation studies showed green emission radiation occurred at 517 nm. The dielectric properties of the grown crystal have been analyzed as a function of temperature over a wide range of frequency (50 Hz-5 MHz) by using LCR meter. The result of ac electrical conductivity of 4MSTB was found to be 5.25 × 10-5 (Ω m)-1. The laser damage threshold (LDT) energy for the grown crystal has been measured by using a Q-switched Nd:YAG laser as a source in single-shot mode (1064 nm, 10 Hz, 420 mJ). The result of LDT indicates that grown title crystal has excellent resistance to laser radiation than those of known some inorganic NLO materials. The chemical etching studies were carried out to assess the perfection of

  4. Laser damage threshold and nonlinear optical studies on guanidinium L - monohydrogen tartrate (GuHT) single crystal for NLO device applications

    NASA Astrophysics Data System (ADS)

    Vivek, P.; Murugakoothan, P.

    2015-06-01

    An organic NLO material guanidinium l - monohydrogen tartrate (GuHT) was grown by the slow evaporation technique using water as a solvent. The GuHT crystal belongs to orthorhombic system with noncentrosymmetric space group P212121. The morphology of the GuHT crystal was studied. The laser induced surface damage threshold behaviour of the GuHT crystal was analyzed in different planes. The second harmonic generation (SHG) effective nonlinearity was confirmed by Kurtz and Perry powder technique.

  5. Ammonium-crown ether supramolecular cation-templated assembly of an unprecedented heterobicluster-metal coordination polymer with enhanced NLO properties.

    PubMed

    Zhang, Jinfang; Jia, Ding; Humphrey, Mark G; Meng, Suci; Zaworotko, Michael J; Cifuentes, Marie P; Zhang, Chi

    2016-03-07

    An ammonium-crown ether host-guest supramolecular cation-templated synthetic methodology has been developed to construct a structurally unprecedented heterobicluster-metal coordination polymer (HCM-CP 1) based on tetranuclear clusters [WS4Cu3](+) with different connection environments, pentanuclear clusters [WS4Cu4](2+), and Cu(+) building metal ions. HCM-CP 1 exhibits enhanced NLO properties, which may be ascribed to the incorporation of diverse building cluster components.

  6. Prediction of robustly large molecular second-order nonlinear optical properties of terpyridine-substituted hexamolybdates: structural modelling towards a rational entry to NLO materials.

    PubMed

    Janjua, Muhammad Ramzan Saeed Ashraf; Guan, Wei; Yan, Likai; Su, Zhong-Min; Ali, Muhammad; Bukhari, Iftikhar Hussain

    2010-06-01

    We have explored an innovative, versatile, and novel molecular hybrid containing polyoxometalate (POM) cluster linked with terpyridine ligand via pi-bridged donor-acceptor (D-A) configuration. The dipole polarizabilities, density of states, and second-order nonlinear optical (NLO) properties of terpyridine-substituted hexamolybdates have been investigated by using time-dependent density functional response theory (TDDFT). This class of organic-inorganic hybrid compounds possesses a robustly large molecular second-order NLO response, especially [Mo(6)O(18)(N(4)C(25)H(16)I(2))](2-) (system 5) and [Mo(6)O(17)(N(4)C(25)H(16)(CN)(2))(N(4)C(25)H(16)(CN)(2))](2-) (system 10) with the static second-order polarizability (beta(vec)) computed to be 1209.25x10(-30)esu and 1622.67x10(-30)esu respectively. Thus, these systems have the possibility to be excellent second-order nonlinear optical materials. Analysis of the major contributions to the beta(vec) value suggests that the charge transfer (CT) from POM-cluster to terpyridine ligand (D-A) along the z-axis plays the key role in the NLO response, POM-cluster (hexamolybdates) acts as a donor (D) whereas terpyridine ligand acts as an acceptor (A) in all the studied systems. The computed beta(vec) values increase by the incorporation of electron acceptors (halogen=F, Cl, Br and I) at the terminus of terpyridine ligand. Furthermore, substitution of trifluoromethoxy (-OCF(3)), trifluoromethyl (-CF(3)), and cyanide (-CN) at the end of terpyridine ligand respectively enhances the optical nonlinearity. Orbital analysis shows that the degree of CT between POM and terpyridine segment was increased in 2D and organometallic/POM hybrid systems. The present investigation provides important and thought provoking insight into the robustly large NLO properties of terpyridine-substituted hexamolybdates. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  7. Phenomenological study of unintegrated parton distribution functions in the frameworks of the Kimber-Martin-Ryskin and Martin-Ryskin-Watt approaches

    NASA Astrophysics Data System (ADS)

    Modarres, M.; Hosseinkhani, H.; Olanj, N.

    2014-02-01

    The aim of the present work is to study the phenomenological behavior of unitegrated parton distribution functions (UPDF) by using the Kimber-Martin-Ryskin (KMR) and Martin-Ryskin-Watt (MRW) formalisms. In the first method, the leading order (LO) UPDF of the KMR prescription is extracted, by taking into account the PDF of Martin et al., i.e., MSTW2008-LO and MRST99-NLO and. While in the second scheme, the next-to-leading order (NLO) UPDF of the (MRW) procedure is generated through the set of MSTW2008-NLO PDFas the inputs. The different aspects of the UPDF in the two approaches, as well as the input PDF are discussed. Then, the deep inelastic proton structure functions, F2(x,Q2), are calculated from the above UPDF in the two schemes, and compared with the data, which are extracted from the ZEUS, NMC, and H1+ZEUS experimental measurements. In general, it is shown that the calculated structure functions based on the UPDF of two schemes, are consistent to the experimental data, and by a good approximation, they are independent to the input PDF. But the proton structure functions, which are extracted from the KMR prescription, have better agreement to the data with respect to that of MRW. Although the MRW formalism is in more compliance with the Dokshitzer-Bribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equation requisites, but it seems in the KMR case, the angular ordering constraint spreads the UPDF to the whole transverse momentum region, and makes the results to sum up the leading DGLAP and Balitski-Fadin-Kuraev-Lipatov (BFKL) Logarithms. This point is under study by the authors.

  8. Solvent Effects on Molecular Structure, Vibrational Frequencies, and NLO Properties of N-(2,3-Dichlorophenyl)-2-Nitrobenzene-Sulfonamide: a Density Functional Theory Study

    NASA Astrophysics Data System (ADS)

    Benhalima, Nadia; Boukabcha, Nourdine; Tamer, Ömer; Chouaih, Abdelkader; Avcı, Davut; Atalay, Yusuf; Hamzaoui, Fodil

    2016-08-01

    Density functional theory (DFT) calculations have been performed to obtain optimized geometries, vibrational wavenumbers, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energies, nonlinear optical (NLO), and thermodynamic properties as well as molecular surfaces for N-(2,3-dichlorophenyl)-2-nitrobenzene-sulfonamide in different solvents. B3LYP level gives similar results for geometric parameters and vibration frequencies in gas phase, water, and ethanol solvents. The most stable structure, which is defined by the highest energy gap between HOMO and LUMO, is obtained in gas phase (∆ E = 10.7376 eV). Obtained small energy gaps between HOMO and LUMO demonstrate the high-charge mobility in the titled compound. The magnitude of first static hyperpolarizability ( β) parameter increases by the decreasing HOMO-LUMO energy gap. The intensive interactions between bonding and antibonding orbitals of titled compound are responsible for movement of π-electron cloud from donor to acceptor, i.e., intramolecular charge transfer (ICT), inducing the nonlinear optical properties. So, the β parameter for title compound is found to be in the range of 5.5255-3.7187 × 10-30 esu, indicating the considerable NLO character. All of these calculations have been performed in gas phase as well as water and ethanol solvents in order to demonstrate solvent effect on molecular structure, vibration frequencies, NLO properties, etc.

  9. The 'partial resonance' of the ring in the NLO crystal melaminium formate: study using vibrational spectra, DFT, HOMO-LUMO and MESP mapping.

    PubMed

    Binoy, J; Marchewka, M K; Jayakumar, V S

    2013-03-01

    The molecular geometry and vibrational spectral investigations of melaminium formate, a potential material known for toxicity and NLO activity, has been performed. The FT IR and FT Raman spectral investigations of melaminium formate is performed aided by the computed spectra of melaminium formate, triazine, melamine, melaminium and formate ion, along with bond orders and PED, computed using the density functional method (B3LYP) with 6-31G(d) basis set and XRD data, to reveal intermolecular interactions of amino groups with neighbor formula units in the crystal, intramolecular H⋯H repulsion of amino group hydrogen with protonating hydrogen, consequent loss of resonance in the melaminium ring, restriction of resonance to N(3)C(1)N(1) moiety leading to special type resonance of the ring and the resonance structure of CO(2) group of formate ion. The 3D matrix of hyperpolarizability tensor components has been computed to quantify NLO activity of melamine, melaminium and melaminium formate and the hyperpolarizability enhancement is analyzed using computed plots of HOMO and LUMO orbitals. A new mechanism of proton transfer responsible for NLO activity has been suggested, based on anomalous IR spectral bands in the high wavenumber region. The computed MEP contour maps have been used to analyze the interaction of melaminium and formate ions in the crystal. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Top-down holographic G-structure glueball spectroscopy at (N)LO in N and finite coupling

    NASA Astrophysics Data System (ADS)

    Sil, Karunava; Yadav, Vikas; Misra, Aalok

    2017-06-01

    The top-down type IIB holographic dual of large- N thermal QCD as constructed in Mia et al. (Nucl Phys B 839:187, 2010) involving a fluxed resolved warped deformed conifold, its delocalized type IIA Strominger-Yau-Zaslow-mirror (SYZ-mirror) as well as its M-theory uplift constructed in Dhuria and Misra (JHEP 1311:001, 2013) - both in the finite coupling (g_s ˜ \\limits ^{<}1)/`MQGP' limit of Dhuria and Misra (JHEP 1311:001, 2013) - were shown explicitly to possess a local SU(3)/G_2-structure in Sil and Misra (Nucl Phys B 910:754, 2016). Glueballs spectra in the finite-gauge-coupling limit (and not just large 't Hooft coupling limit) - a limit expected to be directly relevant to strongly coupled systems at finite temperature such as QGP (Natsuume in String theory and quark-gluon plasma, 2007) - has thus far been missing in the literature. In this paper, we fill this gap by calculating the masses of the 0^{++}, 0^{-+},0^{{-}{-}}, 1^{++}, 2^{++} (`glueball') states (which correspond to fluctuations in the dilaton or complexified two-forms or appropriate metric components) in the aforementioned backgrounds of G-structure in the `MQGP' limit of Dhuria and Misra (JHEP 1311:001, 2013). We use WKB quantization conditions on one hand and impose Neumann/Dirichlet boundary conditions at an IR cut-off (`r_0')/horizon radius (`r_h') on the solutions to the equations of motion on the other hand. We find that the former technique produces results closer to the lattice results. We also discuss the r_h=0 limits of all calculations. In this context we also calculate the 0^{++}, 0^{{-}{-}},1^{++}, 2^{++} glueball masses up to Next to Leading Order (NLO) in N and find a g_sM^2/N(g_sN_f)-suppression similar to and further validating semi-universality of NLO corrections to transport coefficients, observed in Sil and Misra (Eur Phys J C 76(11):618, 2016).

  11. Crystal growth and DFT insight on sodium para-nitrophenolate para-nitrophenol dihydrate single crystal for NLO applications

    NASA Astrophysics Data System (ADS)

    Selvakumar, S.; Boobalan, Maria Susai; Anthuvan Babu, S.; Ramalingam, S.; Leo Rajesh, A.

    2016-12-01

    Single crystals of sodium para-nitrophenolate para-nitrophenol dihydrate (SPPD) were grown by slow evaporation technique and its structure has been studied by FT-IR, FT-Raman and single crystal X-ray diffraction techniques. The optical and electrical properties were characterized by UV-Vis spectrum, and dielectric studies respectively. SPPD was thermally stable up to 128 °C as determined by TG-DTA curves. Using the Kurtz-Perry powder method, the second-harmonic generation efficiency was found to be five times to that of KDP. Third-order nonlinear response was studied using Z-scan technique with a He-Ne laser (632.8 nm) and NLO parameters such as intensity dependent refractive index, nonlinear absorption coefficient and third-order susceptibility were also estimated. The molecular geometry from X-ray experiment in the ground state has been compared using density functional theory (DFT) with appropriate basis set. The first-order hyperpolarizability also calculated using DFT approaches. Stability of the molecule arising from hyperconjugative interactions leading to its nonlinear optical activity and charge delocalization were analyzed using natural bond orbital technique. HOMO-LUMO energy gap value suggests the possibility of charge transfer within the molecule. Based on optimized ground state geometries, Natural bond orbital (NBO) analysis was performed to study donor-acceptor interactions.

  12. NBO, conformational, NLO, HOMO-LUMO, NMR and electronic spectral study on 1-phenyl-1-propanol by quantum computational methods

    NASA Astrophysics Data System (ADS)

    Xavier, S.; Periandy, S.; Ramalingam, S.

    2015-02-01

    In this study, FT-IR, FT-Raman, NMR and UV spectra of 1-phenyl-1-propanol, an intermediate of anti-depressant drug fluoxetine, has been investigated. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been found in good agreement with the corresponding experimental data. 1H and 13C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies are performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The local reactivity of the molecule has been studied using the Fukui function. NLO properties related to polarizability and hyperpolarizability are also discussed.

  13. Synthesis, structural and spectral characterization of a novel NLO crystal N,N‧-diphenylguanidinium picrate: diacetone solvate

    NASA Astrophysics Data System (ADS)

    Shanmugavadivu, T.; Dhandapani, M.; Naveen, S.; Lokanath, N. K.

    2017-09-01

    An organic NLO active material N,N‧-diphenylguanidinium picrate: diacetone solvate (C13H14N3+. C6H2N3O7-. 2C3H6O) (DPGPD) was synthesized and single crystals were grown by slow evaporation-solution growth technique at room temperature. DPGPD crystallizes in monoclinic crystal system with noncentrosymmetric space group, Cc confirmed by single crystal X-ray diffraction analysis. The presence of various functional groups was identified from FT-IR spectral analysis and the proton transfer during the formation of compound was confirmed by NMR spectroscopic techniques. The thermal stability was investigated by TG/DTA analyses. Optical transmittance was measured by UV-Vis-NIR spectroscopy and band gap energy was calculated. Photoluminescence spectrum was used to explore its applicability towards laser diodes. Dielectric property of the material was ascertained at different temperatures and it is found that the grown crystal has higher dielectric constant in low frequencies. Photoconductivity study revealed that DPGPD exhibits positive photoconductivity. SHG property was found to be 0.6 times higher than that of KDP.

  14. Spectroscopic, nonlinear optical and quantum chemical studies on Pyrrolidinium p-Hydroxybenzoate--a phase matchable organic NLO crystal.

    PubMed

    Shanmugam, G; Belsley, M S; Isakov, D; Gomes, E de Matos; Nehru, K; Brahadeeswaran, S

    2013-10-01

    Good quality and bulk single crystals of Pyrrolidinium p-Hydroxybenzoate (PYPHB), a newly identified nonlinear optical material, were grown for the first time. It crystallizes in monoclinic system with an acentric space group Cc. The molecular structure including carbon, proton positions and functional groups has been confirmed through nuclear magnetic resonance and Fourier transform infrared spectra. Its transmission window has been observed for UV-VIS-NIR region along with its theoretical limit. The photoluminescence behavior has been observed by exciting the crystal at 310 nm. The principal refractive indices and second order NLO coefficient of PYPHB are determined by Mach-Zehnder interferometer and Maker-Fringe experiments respectively. The coherence length and phase-matchablility of PYPHB crystals are measured to explore its efficacy towards device fabrications. The dipole moment, polarizability and molecular orbital energy of an isolated PYPHB molecule have also been calculated theoretically and the results are found to corroborate the experimental values. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Investigation of gamma radiation effect on chemical properties and surface morphology of some nonlinear optical (NLO) single crystals

    NASA Astrophysics Data System (ADS)

    Ahlam, M. A.; Ravishankar, M. N.; Vijayan, N.; Govindaraj, G.; Siddaramaiah; Gnana Prakash, A. P.

    2012-05-01

    The effect of Co-60 gamma irradiation on L-alanine cadmium chloride (LACC), L-alanine doped potassium dihydrogen orthophosphate (KDP) and L-arginine doped KDP nonlinear optical (NLO) single crystals were studied in doses ranging from 100 krad to 6 Mrad. The crystals were grown by slow evaporation method at room temperature. The effects of gamma irradiation on the chemical, surface morphology, DC electrical conductivity, thermal and mechanical properties of the grown crystals have been studied. The functional groups of unirradiated and irradiated crystals have been identified and confirmed by Fourier transform infrared (FTIR) studies. Scanning electron microscopy (SEM) of irradiated crystals shows some morphological changes in the crystals. The dc conductivity of LACC and L-alanine doped KDP crystals were found to increase with increase in radiation dose whereas in case of L-arginine doped KDP crystals, the dc conductivity was found to decrease with increase in radiation dose. Differential scanning calorimetry (DSC) thermograms reveals that there is no significant change in the melting point of the crystals after irradiation and the crystals does not decompose as a result of irradiation. The mechanical behavior of both unirradiated and irradiated crystals is explained with the indentation effects using Vicker's microhardness tester. The Vicker's hardness number HV and Mayer's index 'n' has been estimated and confirms that LACC belong to the hard materials.

  16. Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone).

    PubMed

    Rawat, Poonam; Singh, R N

    2015-04-05

    An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm(-1)) and asymmetric (3389, 3382 cm(-1)) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0=23.83×10(-30) esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors--Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule.

  17. Spectroscopic investigation, HOMO-LUMO and NLO studies on L-histidinium maleate based on DFT approach

    NASA Astrophysics Data System (ADS)

    Dhanavel, S.; Stephen, A.; Asirvatham, P. Samuel

    2017-05-01

    The molecular structure of the title compound L-Histidinium Maleate (LHM) was constructed and optimized based on Density Functional Theory method (DFT-B3LYP) with the 6-31G (d,p) basis set. The fundamental vibrational spectral assignment was analyzed with the aid of optimized structure of LHM. The study on electronic properties such as, HOMO-LUMO energies and absorption wavelength were performed using Time dependent DFT (TD-DFT) approach which reveals that energy transfer occur within the molecule. 13C NMR chemical shift values were measured using Gauge independent atomic orbital method (GIAO) and the obtained values are in good agreement with the reported experimental values. Hardness, ionization potential and electrophilicity index also calculated. The electric dipole moment (μtot) and hyperpolarizability (βtot) values of the investigated molecules were computed. The calculated value (β) was 3.7 times higher than that of urea, which confirms the LHM molecule is a potential candidate for NLO applications.

  18. NBO, conformational, NLO, HOMO-LUMO, NMR and electronic spectral study on 1-phenyl-1-propanol by quantum computational methods.

    PubMed

    Xavier, S; Periandy, S; Ramalingam, S

    2015-02-25

    In this study, FT-IR, FT-Raman, NMR and UV spectra of 1-phenyl-1-propanol, an intermediate of anti-depressant drug fluoxetine, has been investigated. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been found in good agreement with the corresponding experimental data. (1)H and (13)C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies are performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The local reactivity of the molecule has been studied using the Fukui function. NLO properties related to polarizability and hyperpolarizability are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Three novel polyoxoanion-supported compounds: confinement of polyoxoanions in Ni-containing rigid concave surfaces with enhanced NLO properties.

    PubMed

    Dong, Yayu; Xu, Xiao; Zhou, Guangpeng; Miao, Hao; Hu, GongHao; Xu, Yan

    2015-11-14

    Three novel polyoxoanion-supported compounds modified by conjugated organic ligand tris(2-benzimidazylmethyl)amine (NTB) and nickel ions, [Ni(NTB)(H2O)]2(H2P2Mo5O23)·9.25H2O (1), [Ni(H2O)(NTB)]2(PMoMo(V)O40)·4.5H2O (2) and [Ni(NTB)]2(Mo8O26)·9H2O (3), have been successfully synthesized under hydrothermal conditions at different pH values. The compounds 1-3 contain similar rigid concave surfaces composed of [Ni(NTB)](2+) cations, which connect with different clusters to form the first examples of metal-NTB-modified polyoxoanion-supported compounds. Transition metal-containing rigid concave surfaces successfully confine polyoxoanions in compounds 1-3. In the synthesis of the three compounds, the pH values play an important role in the formation of polyoxoanions and the stability of the compounds. Additionally, the third-order nonlinear optical properties (NLO) and electrochemical behaviors were also investigated.

  20. Thermally induced crystallization, hole-transport, NLO and photovoltaic activity of a bis-diarylamine-based push-pull molecule.

    PubMed

    Jiang, Yue; Allain, Magali; Gindre, Denis; Dabos-Seignon, Sylvie; Blanchard, Philippe; Cabanetos, Clément; Roncali, Jean

    2017-08-16

    The synthesis of a molecule constituted of two diarylamine-based push-pull chromophores covalently linked via their nitrogen atom is described. Comparison of the electronic properties with the parent monomer shows that dimerization has negligible influence on the electronic properties of the molecule but exerts a dramatic impact on the capacity of the material to self-reorganize. Application of thermal annealing to thin films induces the crystallization under original morphologies, a process accompanied by a partial bleaching of the absorption in the visible range and by a huge increase of hole-mobility. X-ray diffraction data on single crystals reveal the presence of π-stacked organization with a non-centrosymmetric co-facial arrangement of the dipoles which leads to intrinsic 2(nd) order bulk NLO properties of thin films as evidenced by second harmonic generation under 800 nm laser light. The implications of this thermally induced crystallization on the photovoltaic properties of the material are discussed on the basis of preliminary results obtained on simple bilayer organic solar cells.

  1. Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone)

    NASA Astrophysics Data System (ADS)

    Rawat, Poonam; Singh, R. N.

    2015-04-01

    An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm-1) and asymmetric (3389, 3382 cm-1) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0 = 23.83 × 10-30 esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors - Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule.

  2. Techniques for the treatment of IR divergences in decay processes at NLO and application to the top-quark decay.

    PubMed

    Basso, Lorenzo; Dittmaier, Stefan; Huss, Alexander; Oggero, Luisa

    We present the extension of two general algorithms for the treatment of infrared singularities arising in electroweak corrections to decay processes at next-to-leading order: the dipole subtraction formalism and the one-cutoff slicing method. The former is extended to the case of decay kinematics which has not been considered in the literature so far. The latter is generalised to production and decay processes with more than two charged particles, where new "surface" terms arise. Arbitrary patterns of massive and massless external particles are considered, including the treatment of infrared singularities in dimensional or mass regularisation. As an application of the two techniques we present the calculation of the next-to-leading order QCD and electroweak corrections to the top-quark decay width including all off-shell and decay effects of intermediate [Formula: see text] bosons. The result, e.g., represents a building block of a future calculation of NLO electroweak effects to off-shell top-quark pair ([Formula: see text]) production. Moreover, this calculation can serve as the first step towards an event generator for top-quark decays at next-to-leading order accuracy, which can be used to attach top-quark decays to complicated many-particle top-quark processes, such as for [Formula: see text] or [Formula: see text].

  3. NLO+NLL collider bounds, Dirac fermion and scalar dark matter in the B–L model

    DOE PAGES

    Klasen, Michael; Lyonnet, Florian; Queiroz, Farinaldo S.

    2017-05-25

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly-freedom, only combinations of B–L are viable. In this spirit, we investigate possible dark matter realizations in the context of the U(1)B-L model: (i) Dirac fermion with unbroken B–L; (ii) Dirac fermion with broken B–L; (iii) scalar dark matter; (iv) two-component dark matter.We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well-known LEP bound MZ'more » /gBL 7 TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon + dielectron) data at next-to-leading order plus nextto- leading logarithmic accuracy. We show that, for gauge couplings smaller than 0.4, theLHCgives rise to the strongest collider limit. In particular, we find MZ' /gBL > 8.7 TeV for gBL = 0.3. We conclude that the NLO+NLL corrections improve the dilepton bounds on the Z mass and that both dark matter candidates are only viable in the Z' resonance region, with the parameter space for scalar dark matter being fully probed by XENON1T. Lastly, we show that one can successfully have a minimal two-component dark matter model.« less

  4. NLO+NLL collider bounds, Dirac fermion and scalar dark matter in the B-L model

    NASA Astrophysics Data System (ADS)

    Klasen, Michael; Lyonnet, Florian; Queiroz, Farinaldo S.

    2017-05-01

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly-freedom, only combinations of B-L are viable. In this spirit, we investigate possible dark matter realizations in the context of the U(1)_B{-L} model: (i) Dirac fermion with unbroken B-L; (ii) Dirac fermion with broken B-L; (iii) scalar dark matter; (iv) two-component dark matter. We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well-known LEP bound M_{Z^' }}/g_BL ≳ 7 TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon + dielectron) data at next-to-leading order plus next-to-leading logarithmic accuracy. We show that, for gauge couplings smaller than 0.4, the LHC gives rise to the strongest collider limit. In particular, we find M_{Z^' }}/g_BL > 8.7 TeV for g_BL=0.3. We conclude that the NLO+NLL corrections improve the dilepton bounds on the Z^' } mass and that both dark matter candidates are only viable in the Z^' } resonance region, with the parameter space for scalar dark matter being fully probed by XENON1T. Lastly, we show that one can successfully have a minimal two-component dark matter model.

  5. Ultrahigh energy neutrinos and nonlinear QCD dynamics

    SciTech Connect

    Machado, Magno V.T.

    2004-09-01

    The ultrahigh energy neutrino-nucleon cross sections are computed taking into account different phenomenological implementations of the nonlinear QCD dynamics. Based on the color dipole framework, the results for the saturation model supplemented by the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution as well as for the Balitskii-Fadin-Kuraev-Lipatov (BFKL) formalism in the geometric scaling regime are presented. They are contrasted with recent calculations using next-to-leading order DGLAP and unified BFKL-DGLAP formalisms.

  6. Janus second-order nonlinear optical dendrimers: their controllable molecular topology and corresponding largely enhanced performance† †Electronic supplementary information (ESI) available: The structures of dendrimers in the previous study and the related parameters, the synthesis of compounds, NLO measurements including NLO coefficient theories, the preparation of thin films, measurement condition and error analysis, molecular mechanics simulation including calculation method and results, NMR spectra, TOF mass spectra, UV-vis absorption spectra, TGA and DSC thermograms, and UV-vis absorption of thin films before and after poling. See DOI: 10.1039/c6sc02956f Click here for additional data file.

    PubMed Central

    Tang, Runli; Zhou, Shengmin; Cheng, Ziyao; Yu, Gui; Peng, Qian; Zeng, Huiyi; Guo, Guocong; Li, Qianqian

    2017-01-01

    A new type of Janus dendrimers, consisting of two different side dendrons with the dipole orientation of the second-order nonlinear optical (NLO) chromophore moieties partially in a non-centrosymmetric direction, was intelligently designed and synthesized in order to enhance the macroscopic NLO performance and break through the limitation of NLO efficiency in the current molecular topological structure of azo chromophore-based polymers. This kind of Janus dendritic structure was constructed by the combination of convergent and divergent methods, with the utilization of a powerful “click chemistry reaction”. The obtained three dendrimers, D-13N, D-17N and D-21N, show very high NLO performance, especially the dramatically enhanced NLO coefficient of 299 pm V–1 for D-13N, which is the highest value ever reported for polymers containing a simple azo chromophore. The new dendrimers provide a clear structure–properties relationship between high NLO efficiency and the controllable molecular topology with the non-centrosymmetrical alignment of dipole orientation, thus opening up a new avenue for the further development of NLO dendrimers with high performance and more importantly providing some clues for the rational design of functional dendrimers with controllable molecular topology. PMID:28451178

  7. Vibrational spectroscopic and thermo dynamical property studies, Fukui functions, HOMO-LUMO, NLO, NBO and crystal structure analysis of a new Schiff base bearing phenoxy-imine group

    NASA Astrophysics Data System (ADS)

    Ceylan, Ümit; Çapan, Ali; Yalçın, Şerife Pınar; Sönmez, Mehmet; Aygün, Muhittin

    2017-05-01

    This study covers the synthesis, structural characterization by experimental FT-IR, 1H NMR and 13C NMR, UV-Vis and single crystal XRD and comparison with theoretical calculations of a Schiff base compound bearing phenoxy group, C34H28N2O4 by using the DFT method 6-311G(d,p) basis set. The molecular geometry, the dipole moments, electrostatic potential, vibrational frequencies, HOMO-LUMO energy were calculated. NBO, NLO, thermodynamic properties and Fukui function were studied. In this work, theoretical values show good agreement with experimental values.

  8. Synthesis of charged bis-heteroaryl donor-acceptor (D-A+) NLO-phores coupling (π-deficient-π-excessive) heteroaromatic rings.

    PubMed

    Ramirez, Marco Antonio; Custodio, Raul; Cuadro, Ana M; Alvarez-Builla, Julio; Clays, Koen; Asselberghs, Inge; Mendicuti, Francisco; Castaño, Obis; Andrés, José L; Vaquero, Juan J

    2013-11-07

    Charged chromophores based on heteroaromatic cations were prepared by reaction of alkylazinium salts with N-heteroarylstannanes under Stille conditions. This approach provides easy access to potential single donor D-A(+) chromophores in which the acceptor moiety A(+) is the pyridinium cation and the donors are different π-excessive N-heterocycles. The β hyperpolarizabilities were measured in hyper-Rayleigh scattering experiments and the experimental data are supported by a theoretical analysis that combines a variety of computational procedures, including density functional theory and correlated Hartree-Fock-based methods. In some chromophores, the absence of a bridge between donor and acceptor fragments increases the NLO properties.

  9. Electronic structure and nonlinear optical properties (NLO) of 2,4-di-aryl-1,5-benzothiazepine derivatives using DFT approach

    NASA Astrophysics Data System (ADS)

    Moustafa, H.; Elshakre, Mohamed E.; Elramly, Salwa

    2017-05-01

    The electronic structure of and NLO of 2,4-di-aryl-1,5-benzothiazepine and some of its derivatives are investigated theoretically at the B3LYP/6-311G**level of theory. The extent of delocalization and intramolecular charge transfer are estimated and discussed in terms of natural bond orbital analysis (NBO) and second order perturbation interactions between donor and acceptor MOs. The calculated EHOMO and ELUMO energies of the studied compounds can be used to calculate the global properties; chemical hardness (η), softness (S) and electronegativity (χ). The equilibrium geometries of the studied compounds are determined, and it was found that these geometries are non plannar. The choice of these substituents aims at creating a push- pull system on the 1,5-thiazepine basic structure which pave the way to understand their nonlinear optical properties. The calculated nonlinear optical parameters (NLO); polarizability (α), anisotropy of the polarizibility (Δα) and first order hyperpolarizibility (β) of the studied compounds show promising optical properties. 3D-plots of the molecular electrostatic potential (MEP) for some selected molecules are investigated and analyzed showing the distribution of electronic density of orbitals describing the electrophilic and nucleophilic sites of the selected molecules.

  10. Structural characterization, vibrational study, NLO and DFT calculations of a novel organic sulfate monohydrate templated with (S)-(-)-2,6-diammonium-4,5,6,7-tetrahydrobenzothiazole

    NASA Astrophysics Data System (ADS)

    Barhoumi, Abir; Mhiri, Tahar; Dammak, Thameur; Suñol, Joan Josep; Belhouchet, Mohamed

    2017-01-01

    A single crystal of (S)-(-)-2,6-diammonium-4,5,6,7-tetrahydrobenzothiazole sulfate monohydrate has been synthesized and grown at room temperature by slow evaporation of aqueous solution. The studied compound crystallizes in the space group P212121 of the orthorhombic system with cell parameters a = 7.0014(12), b = 8.7631(15), c = 19.773(3) Å. We report the molecular structure and the theoretical and experimental vibrational spectra of the synthesized compound. The atomic arrangement, which is an alternation of organic inorganic layers linked together through hydrogen bonds, gives rise to three types of rings formed by the interconnection of organic-inorganic entities. The experimental FT-IR and the Raman spectra the synthesized compound were recorded and analyzed. The peaks assignment has been made unambiguously from the literature. To confirm the assignment, the experimental spectra were compared with theoretical spectra obtained with the Gaussian 98 program by the Density Functional Theory (DFT) method using B3LYP function with the LanL2DZ basis set. Moreover, to study the nonlinear optical (NLO) property of this compound, the hyperpolarizability βtot, the electric dipole μtot and the polarizability αtot were calculated using the DFT. Based on our calculation the synthesized compound has a non-zero hyperpolarizability suggesting that it may be used in some NLO applications.

  11. Top quark mass determination from the energy peaks of b-jets and B-hadrons at NLO QCD

    SciTech Connect

    Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin; Schulze, Markus

    2016-11-21

    Here, we analyze the energy spectra of single b-jets and B-hadrons resulting from the production and decay of top quarks within the SM at the LHC at the NLO QCD. For both hadrons and jets, we calculate the correlation of the peak of the spectrum with the top quark mass, considering the “energy peak” as an observable to determine the top quarkmass. Such a method is motivated by our previous work where we argued that this approach can have reduced sensitivity to the details of the production mechanism of the top quark, whether it concerns higher-order QCD effects or new physics contributions. For a 1% jet energy scale uncertainty, the top quark mass can then be extracted using the energy peak of b-jets with an error ±(1.2(exp) + 0.6(th)) GeV. In view of the dominant jet energy scale uncertainty in the measurement using b-jets, we also investigate the extraction of the top quark mass from the energy peak of the corresponding B-hadrons which, in principle, can be measured without this uncertainty. The calculation of the B-hadron energy spectrum is carried out using fragmentation functions at NLO. The dependence on the fragmentation scale turns out to be the largest theoretical uncertainty in this extraction of top quark mass.

  12. Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

    NASA Astrophysics Data System (ADS)

    Maltoni, Fabio; Vryonidou, Eleni; Zhang, Cen

    2016-10-01

    We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators ( O tφ , O φG , O tG ) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, Hj and HH production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties at the total as well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.

  13. Strong Infrared NLO Tellurides with Multifunction: CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd).

    PubMed

    Lin, Hua; Liu, Yi; Zhou, Liu-Jiang; Zhao, Hua-Jun; Chen, Ling

    2016-05-02

    Chalcogenides are the most promising mid- and far-infrared materials for nonlinear optical (NLO) applications. Yet, most of them are sulfides and selenides, and tellurides are still rare. Herein, we report three new KCd4Ga5S12-structure type NLO-active tellurides, CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd), synthesized by solid-state reactions. The structure features a 3D diamond-like framework constructed by vertex-sharing asymmetric MTe4 tetrahedra that are stacked along the c-axis. CsCd4In5Te12 exhibits the strongest powder second-harmonic generation (SHG) intensity at 2050 nm (0.61 eV) among tellurides to date, 9 × benchmark AgGaS2 in the range of 46-74 μm particle size. The primary studies reveal the 1.42 eV direct band gap and high absorption coefficient in the visible spectral region for CsCd4In5Te12, suggesting it is a new potential solar cell absorber material. In addition, CsMn4In5Te12 also displays a spin-canted antiferromagnetic property below 50 K.

  14. Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

    SciTech Connect

    Maltoni, Fabio; Vryonidou, Eleni; Zhang, Cen

    2016-10-24

    We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators (O, OφG, OtG) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, Hj and HH production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties at the total as well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Finally, our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.

  15. Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

    DOE PAGES

    Maltoni, Fabio; Vryonidou, Eleni; Zhang, Cen

    2016-10-24

    We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators (Otφ, OφG, OtG) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, Hj and HH production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties at the total asmore » well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Finally, our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.« less

  16. An acido-triggered reversible luminescent and nonlinear optical switch based on a substituted styrylpyridine: EFISH measurements as an unusual method to reveal a protonation-deprotonation NLO contrast.

    PubMed

    Cariati, Elena; Dragonetti, Claudia; Lucenti, Elena; Nisic, Filippo; Righetto, Stefania; Roberto, Dominique; Tordin, Elisa

    2014-02-14

    Diphenyl-(4-{2-[4-(2-pyridin-4-yl-vinyl)-phenyl]-vinyl}-phenyl)-amine (DPVPA) constitutes a novel acido-triggered reversible luminescent and nonlinear optical switch. Remarkably, for the first time the Electric-Field Induced Second Harmonic generation (EFISH) technique is used to reveal a protonation-deprotonation NLO contrast.

  17. NLO Materials Workshop

    DTIC Science & Technology

    1999-09-21

    The Final Proceedings for Workshop on Nonlinear Optical Materials , 20 September 1999 - 21 September 1999. This is an interdisciplinary conference...Topics include: growth, characterization, and applications of chalcopyrites and other nonlinear optical materials for use in the mid-IR.

  18. Investigations on structural, optical, dielectric, laser damage threshold and NLO properties of 2-amino-5-nitropyridinium p-tolunesulfonate (2A5NPT) single crystal

    NASA Astrophysics Data System (ADS)

    Pandian, Muthu Senthil; Sivasubramani, V.; Ramasamy, P.

    2016-05-01

    The highly efficient organic nonlinear optical (NLO) 2-amino-5-nitropyridinium p-tolunesulfonate single crystals have been grown by conventional slow evaporation technique using Millipore water as a solvent in the period of 60 days. The single crystal XRD confirms the unit cell parameters of the grown crystal. The morphology of the grown crystal was analyzed using Bruker-Kappa APEXII single crystal instrument and their planes are identified. The optical transmittance range and the cut-off wavelength are recorded using UV-Visible NIR characterization. The laser damage threshold (LDT) studies were carried out using Nd:YAG laser and LDT value was found to be 3.7 GW/cm2. The dielectric constant and dielectric loss of 2A5NPT single crystals were measured. The SHG efficiency was tested by powder Kurtz-Perry technique and the SHG efficiency is 15 times greater than that of standard KDP material.

  19. Synthesis and characterization of novel push-pull thiophene and thienylpyrrole derivatives functionalized with indanonedicyanovinyl acceptor moiety as efficient NLO-chromophores

    NASA Astrophysics Data System (ADS)

    Batista, Rosa M. F.; Costa, Susana P. G.; Belsley, Michael; Raposo, M. Manuela M.

    2011-05-01

    The synthesis and characterization of new chromophores with second-order nonlinearities containing thienylpyrrole 1a, 2a-b, bithiophene 3 and arylthiophene 4 as π-conjugated bridges and indanonedicyanovinyl acceptor group are reported. The effect of placing the acceptor group at thiophene or pyrrole rings on the optoelectronic properties was also evaluated for thienylpyrrole derivatives 1a and 2a-b. The linear optical properties (absorption and emission) for all compounds were evaluated in dioxane solutions. In addition, the hyperpolarizabilities β of chromophores 1-4 were measured using hyper-Rayleigh scattering in dioxane solutions and thermogravimetric analysis (TGA) was used to evaluate their thermal stability. The experimental results indicate that chromophores 1-4 are endowed with both excellent optical nonlinearities and high thermal stability making them interesting candidates for nonlinear optical (NLO) applications.

  20. Growth and characterization studies of an efficient semiorganic NLO single crystal: 2-Amino 5-nitropyridinium sulfamate (2A5NPS) by assembled temperature reduction (ATR) method

    NASA Astrophysics Data System (ADS)

    Ambrose Rajkumar, M.; Stanly John Xavier, S.; Anbarasu, S.; Devarajan, Prem Anand

    2016-05-01

    Semiorganic crystals of 2-amino 5-nitropyridinium sulfamate (2A5NPS) were grown by slow evaporation and slow cooling method. A asymmetric grown crystal was subjected to single crystal X-ray diffraction and X-ray powder diffraction by using Bruker Kappa APEX11 CCD diffractometer and Philips analytical powder X-ray diffractometer respectively. Vibrational frequency of 1:1 equimolar ratio single crystals of 2-amino 5-nitropyridinium sulfamate (2A5NPS) was measured using FTIR and thermal stability of the grown crystal of 2-amino 5-nitropyridinium sulfamate (2A5NPS) was also measured. Optical properties of the grown crystal and NLO test were also carried out.

  1. Crystal growth, structural, optical, dielectric and thermal studies of an amino acid based organic NLO material: L-Phenylalanine L-phenylalaninium malonate

    NASA Astrophysics Data System (ADS)

    Prakash, M.; Geetha, D.; Lydia Caroline, M.; Ramesh, P. S.

    2011-12-01

    Good transparent single crystals of L-phenylalanine L-phenylalaninium malonate (LPPMA) have been grown successfully by slow evaporation technique from aqueous solution. Single crystal X-ray diffractometer was utilized to measure unit cell parameter and to confirm the crystal structure. The chemical structure of compound was established by FT-NMR technique. The vibrational modes of the molecules of elucidated from FTIR spectra. Its optical behaviour has been examined by UV-vis spectral analysis, which shows the absence of absorbance in the visible region. Thermal properties of the LPPMA crystal were carried out by thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) techniques, which indicate that the material does not decompose before melting. The melting point of grown crystal was observed as 180 °C by melting point apparatus. The NLO property was confirmed by the powder technique of Kurtz and Perry. The dielectric behaviour of the sample was also studied for the first time.

  2. Crystal growth, structural, optical, dielectric and thermal studies of an amino acid based organic NLO material: L-phenylalanine L-phenylalaninium malonate.

    PubMed

    Prakash, M; Geetha, D; Caroline, M Lydia; Ramesh, P S

    2011-12-01

    Good transparent single crystals of L-phenylalanine L-phenylalaninium malonate (LPPMA) have been grown successfully by slow evaporation technique from aqueous solution. Single crystal X-ray diffractometer was utilized to measure unit cell parameter and to confirm the crystal structure. The chemical structure of compound was established by FT-NMR technique. The vibrational modes of the molecules of elucidated from FTIR spectra. Its optical behaviour has been examined by UV-vis spectral analysis, which shows the absence of absorbance in the visible region. Thermal properties of the LPPMA crystal were carried out by thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) techniques, which indicate that the material does not decompose before melting. The melting point of grown crystal was observed as 180°C by melting point apparatus. The NLO property was confirmed by the powder technique of Kurtz and Perry. The dielectric behaviour of the sample was also studied for the first time.

  3. Push-pull 1,3-thiazolium-5-thiolates. Formation via concerted and stepwise pathways, and theoretical evaluation of NLO properties.

    PubMed

    Cantillo, David; Avalos, Martín; Babiano, Reyes; Cintas, Pedro; Jiménez, José L; Light, Mark E; Palacios, Juan C; Rodríguez, Valentín

    2010-12-07

    The transformation of münchnones (mesoionic rings featuring the 1,3-oxazolium-5-olate core) into their sulfur counterparts (1,3-thiazolium-5-thiolates) by reaction with CS(2), pioneered by Huisgen and his group in the early 1970s, has been re-investigated in detail by means of both experimental and theoretical methods. The synthetic strategy can be tuned to incorporate donor and acceptor groups in appropriate positions. Calculations of molecular hyperpolarizabilities together with orbital topologies evidence that these sulfur-containing heterocycles exhibit nonlinear optical responses, thereby pointing to potential applications of mesoionic structures in the NLO field. From a mechanistic viewpoint, modeling of the whole systems at the B3LYP/6-31G(d) level reveals that concerted and stepwise pathways are operative depending on the substitution pattern of the parent münchnone, which also account for the experimental results.

  4. (2-Azoniaethyl)guanidinium dichloride - A promising phase-matchable NLO material employing a simple hydrogen bond acceptor in its structure

    NASA Astrophysics Data System (ADS)

    Matulková, Irena; Solařová, Hana; Štěpnička, Petr; Císařová, Ivana; Janda, Tomáš; Němec, Petr; Němec, Ivan

    2015-04-01

    (2-Azoniaethyl)guanidinium dichloride (AEGCl), a salt of a functional guanidine derivative, was prepared and characterised by single-crystal and powder X-ray diffraction analysis, elemental analysis and by NMR, UV-Vis and vibrational spectroscopy. The crystal structure of AEGCl, which crystallises with the symmetry of the chiral space group P21, is built up via simple and multicentred Nsbnd H⋯Cl hydrogen bonds and further supported by Csbnd H⋯Cl contacts. The compound is thermally robust and exhibits promising NLO properties with powder SHG efficiency better than potassium dihydrogen phosphate. In contrast, (2-azoniaethyl)guanidinium salts with inorganic oxoanions such as (2-azoniaethyl)guanidinium dinitrate and diperchlorate, synthesised for a comparison, form centrosymmetric crystal assemblies having several structurally independent "molecules" in their structures.

  5. Spectroscopic (FT-IR, FT-Raman, UV, NMR, NLO) investigation and molecular docking study of 1-(4-Methylbenzyl) piperazine

    NASA Astrophysics Data System (ADS)

    Subashini, K.; Periandy, S.

    2017-04-01

    The title compound, 1-(4-Methylbenzyl) piperazine, was analyzed by recording FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectra in solid phase, 1H and 13C NMR in CDCl3 (deuterated chloroform) and UV spectrum (200-400 nm) in solid phase and in ethanol solution. The different conformers of the compound and their minimum energies were studied by potential energy surface scan, using semi-empirical method PM6. Density functional theory (DFT) calculation with 6-311++G (d, p) basis set along with B3LYP and B3PW91 functionals have been used to compute ground state molecular geometries and vibrational frequencies. The assignments of the vibrational spectra have carried out with the help of Potential Energy distribution (PED) analysis. Factor group analysis has also been tabulated. Charge distribution, Frontier Molecular Orbitals, UV-Vis spectra, Molecular Electrostatic Potential (MEP) maps, Non-linear optical (NLO) property and thermodynamic properties of the title compound at different temperatures, were determined using B3LYP functional along with 6-311++G (d, p) basis set. The theoretical 1H and 13C NMR chemical shifts were computed using B3LYP functional with 6-311++G (2d, p) basis sets. Natural Bond orbital analysis were computed and possible transitions were correlated with the electronic transitions. The title compound not only exhibits appreciable dipole moment and hyper polarizability (indicating good NLO properties) but also forms a stable complex with Bacillus cereus, (2HUC), with binding affinity -6.7 kcal/mol through molecular docking, suggesting that, it might exhibit inhibitory activity against Bacillus cereus.

  6. DFT calculations on molecular structure, spectral analysis, multiple interactions, reactivity, NLO property and molecular docking study of flavanol-2,4-dinitrophenylhydrazone

    NASA Astrophysics Data System (ADS)

    Singh, Ravindra Kumar; Singh, Ashok Kumar

    2017-02-01

    A new flavanol-2,4-dinitrophenylhydrazone (FDNP) was synthesized and its structure was confirmed by FT-IR, FT-Raman, 1H NMR, mass spectrometry and elemental analysis. All quantum chemical calculations were carried out at level of density functional theory (DFT) with B3LYP functional using 6-311++ G (d,p) basis atomic set. UV-Vis absorption spectra for the singlet-singlet transition computed for fully optimized ground state geometry using Time-Dependent-Density Functional Theory (TD-DFT) with CAM-B3LYP functional was found to be in consistent with that of experimental findings. Analysis of vibrational (FT-IR and FT-Raman) spectrum and their assignments has been done by computing Potential Energy Distribution (PED) using Gar2ped. HOMO-LUMO analysis was performed and reactivity descriptors were calculated. Calculated global electrophilicity index (ω = 7.986 eV) shows molecule to be a strong electrophile. 1H NMR chemical shift calculated with the help of gauge-including atomic orbital (GIAO) approach shows agreement with experimental data. Various intramolecular interactions were analysed by AIM approach. DFT computed total first static hyperpolarizability (β0 = 189.03 × 10-30 esu) indicates that title molecule can be used as attractive future NLO material. Solvent induced effects on the NLO properties studied by using self-consistent reaction field (SCRF) method shows that β0 value increases with increase in solvent polarity. To study the thermal behaviour of title molecule, thermodynamic properties such as heat capacity, entropy and enthalpy change at various temperatures have been calculated and reported. Molecular docking results suggests title molecule to be a potential kinase inhibitor and might be used in future for designing of new anticancer drug.

  7. Theoretical investigation of the structures, stabilities, and NLO responses of calcium-doped pyridazine: alkaline-earth-based alkaline salt electrides.

    PubMed

    Wang, Yin-Feng; Huang, Jiangen; Jia, Li; Zhou, Guangpei

    2014-02-01

    Currently, whether alkaline-earth-doped compounds with electride characteristics are novel candidates for high-performance nonlinear optical (NLO) materials is unknown. In this paper, using quantum chemical computations, we show that: when doping calcium atoms into a family of alkaline-substituted pyridazines, alkaline-earth-based alkaline salt electrides M-H₃C₄N₂⋯Ca (M=H, Li, and K) with distended excess electron clouds are formed. Interestingly, from the triplet to the singlet state, the chemical valence of calcium atom changes from +1 to 0, and the dipole moment direction (μ₀) of the molecule reverses for each M-H₃C₄N₂⋯Ca. Changing pyridazine from without (H₄C₄N₂⋯Ca) to with one alkaline substituent (M-H₃C₄N₂⋯Ca, M=Li and K), the ground state changes from the triplet to the singlet state. The alkaline earth metal doping effect (electride effect) and alkaline salt effect on the static first hyperpolarizabilities (β₀) demonstrates that (1) the β₀ value is increased approximately 1371-fold from 2 (pyridazine, H₄C₄N₂) to 2745au (Ca-doped pyridazine, H₄C₄N₂⋯Ca), (2) the β₀ value is increased approximately 1146-fold from 2 in pyridazine (H₄C₄N₂) to 2294au in an Li-substituted pyridazine (Li-H₃C₄N₂), and (3) the β₀ value is increased 324-(M=Li) and 106-(M=K) fold from 826 (MLi) and 2294au (MK) to 268,679 (M=Li) and 245,878au (M=K), respectively, from the alkalized pyridazine (M-H₃C₄N₂) to the Ca-doped pyridazine (M-H₃C₄N₂⋯Ca). These results may provide a new means for designing high-performance NLO materials.

  8. The growth with energy of exclusive J/Ψ and ϒ photo-production cross-sections and BFKL evolution

    NASA Astrophysics Data System (ADS)

    Hentschinski, Martin

    2017-03-01

    We investigate whether NLO BFKL evolution is capable to describe the energy dependence of the exclusive photo-production cross-section of vector mesons J/Ψ and ϒ on protons. Our description is based on available NLO BFKL fits of the proton impact factor in inclusive DIS, which allow us to construct the necessary scattering amplitude at zero momentum transfer t = 0. Assuming an exponential drop-off with t, this result allows us to calculate the exclusive photoproduction cross-section. Comparing our results with both HERA data (measured by H1 and ZEUS collaborations in ep collision) and LHC data (measured by ALICE, CMS and LHCb collaborations in ultra-peripheral pp and pPb collision) we find that our framework provides a very good description of the energy dependence of the J/Ψ and ϒ photoproduction cross-section, providing therefore further evidence for BFKL evolution at the LHC. The available fits of the proton impact factor require on the other hand an adjustment in the overall normalization.

  9. Teaching Evolution

    ERIC Educational Resources Information Center

    Bryner, Jeanna

    2005-01-01

    Eighty years after the famous 1925 Scopes "monkey trial," which tested a teacher's right to discuss the theory of evolution in the classroom, evolution--and its most recent counterview, called "intelligent design"--are in the headlines again, and just about everyone seems to have an opinion. This past July, President Bush weighed in, telling…

  10. FTS evolution

    NASA Technical Reports Server (NTRS)

    Provost, David E.

    1990-01-01

    Viewgraphs on flight telerobotic servicer evolution are presented. Topics covered include: paths for FTS evolution; frequently performed actions; primary task states; EPS radiator panel installation; generic task definitions; path planning; non-contact alignment; contact planning and control; and human operator interface.

  11. FTS evolution

    NASA Technical Reports Server (NTRS)

    Provost, David E.

    1990-01-01

    Viewgraphs on flight telerobotic servicer evolution are presented. Topics covered include: paths for FTS evolution; frequently performed actions; primary task states; EPS radiator panel installation; generic task definitions; path planning; non-contact alignment; contact planning and control; and human operator interface.

  12. Assessment of long-range corrected and conventional DFT functional for the prediction of second--order NLO properties and other molecular properties of N-(2-cyanoethyl)-N-butylaniline--a vibrational spectroscopy study.

    PubMed

    Anitha, K; Balachandran, V

    2015-07-05

    Vibrational spectral analysis and quantum chemical computations based on density functional theory have been performed on the N-(2-cyanoethyl)-N-butylaniline. The geometry, structural properties, intermolecular hydrogen bond, and harmonic vibrational frequencies of the title molecule have been investigated with the help of DFT (B3LYP) and LC-DFT (CAM-B3LYP) method. Molecular electrostatic potential (MEP) have been performed. The various intramolecular interactions have been exposed by natural bond orbital analysis. The distribution of atomic charges and bending of natural hybrid orbitals also reflect the presence of intramolecular hydrogen bonding. Global reactivity and local reactivity descriptors of the title molecule have been calculated. The analysis of the electron density of HOMO and LUMO gives an idea of the delocalization and low value of energy gap indicated the electron transport in the molecule and thereby NLO activity. The effect of solvent on second-order NLO properties has been studied using polarized continuum model (PCM) in the tetrahydrofuran (THF) solution. The solvent leads to a slight enhancement of the NLO responses for the studied complexes relevant to their NLO responses in gas phase. The electronic absorption spectra were investigated by the TDDFT methods. The frequency-dependent first hyperpolarizabilities of the N-(2-cyanoethyl)-N-butylaniline were also evaluated. The (1)H and (13)C NMR chemical shifts have been calculated by gauge-indepedent atomic orbital (GIAO) method with B3LYP/6-311++G(d, p) approach. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Stellar evolution.

    NASA Technical Reports Server (NTRS)

    Chiu, H.-Y. (Editor); Muriel, A.

    1972-01-01

    Aspects of normal stellar evolution are discussed together with evolution near the main sequence, stellar evolution from main sequence to white dwarf or carbon ignition, the structure of massive main-sequence stars, and problems of stellar stability and stellar pulsation. Other subjects considered include variable stars, white dwarfs, close binaries, novae, early supernova luminosity, neutron stars, the photometry of field horizontal-branch stars, and stellar opacity. Transport mechanisms in stars are examined together with thermonuclear reactions and nucleosynthesis, the instability problem in nuclear burning shells, stellar coalescence, and intense magnetic fields in astrophysics. Individual items are announced in this issue.

  14. The approximation method for calculation of the exponents of the gluon distribution, λ g , and the structure function, λ S ,at low x

    NASA Astrophysics Data System (ADS)

    Boroun, G. R.; Rezaie, B.

    2008-06-01

    We present a set of formulas using the solution of the QCD Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equation to extract of the exponents of the gluon distribution, λ g , and structure function, λ S , from the Regge-like behavior at low x. The exponents are found to be independent of x and to increase linearly with ln Q 2 and are compared with the most data from the H1 Collaboration. We also calculated the structure function F 2( x,Q 2) and the gluon distribution G( x,Q 2) at low x assuming the Regge-like behavior of the gluon distribution function at this limit and compared them with an NLO-QCD fit to theH1 data, two-Pomeron fit, multipole Pomeron exchange fit, and MRST (A.D. Martin, R.G. Roberts, W.J. Stirling, and R.S. Thorne), DL (A. Donnachie and P.V. Landshoff), and NLO GRV (M. Glük, E. Reya, and A. Vogt) fit results.

  15. Simulating Evolution

    ERIC Educational Resources Information Center

    Stebbins, Robert C.; Allen, Brockenbrough

    1975-01-01

    Described are simulations that can be used to illustrate evolution by natural selection. Suggestions for simulating phenomena such as adaptive radiation, color match to background and vision of predators are offered. (BR)

  16. Novel synthetic ester of Brassicasterol, DFT investigation including NBO, NLO response, reactivity descriptor and its intramolecular interactions analyzed by AIM theory

    NASA Astrophysics Data System (ADS)

    Sethi, Arun; Prakash, Rohit

    2015-03-01

    In the present work, Brassicasterol (compound 1) isolated from Allamanda Violacea reacted with the well known NSAID ibuprofen by Steglich esterification yielding a novel steroidal ester, 3β-(2-(4-isobutyl phenyl) propionoxy) 24 methyl cholest-5, 22-dien (compound 2). Identity of synthetic derivative (compound 2) was done with the help of modern spectroscopic techniques like, 1H NMR, IR and UV as well as mass spectrometry. Molecular geometry and vibrational frequencies of compound 2 were calculated using density functional method (DFT/B3LYP) and 6-31(d,p) basis set. NMR chemical shifts of the compound were calculated with GIAO method. Electronic properties such as HOMO-LUMO energies were measured with the help of time dependent DFT method. Natural bond orbital (NBO) analysis was carried out to study hyperconjugative interactions. Non linear optical (NLO) response of compound 2 was also evaluated. Molecular electrostatic potential (MEP) surface has been used to indicate nucleophilic and electrophilic sites. Global reactivity descriptors of compound 1 and 2 were also calculated. Intramolecular interactions were analyzed using Atoms in molecule (AIM) theory.

  17. Synthesis, characterization and theoretical investigations of the structure, electronic properties and third-order nonlinearity optics (NLO) of M(DPIP)2

    NASA Astrophysics Data System (ADS)

    Li, Kang; Tang, Guodong; Kou, ShanShan; Culnane, Lance F.; Zhang, Yu; Song, Yinglin; Li, Rongqing; Wei, Changmei

    2015-03-01

    Three complexes of M(DPIP)2 (M = Cu, Co, Zn as 1, 2, 3) were synthesized and characterized by elemental analysis, IR, UV-Vis, thermogravimetry, and X-ray diffraction. Their nonlinear optical properties were measured by the Z-scan technique and yielded a normalized transmittance of about 70% for complex 1 (45 μJ pulse), and 93% for complex 3 (68 μJ pulse at the focus point). The nonlinear absorption coefficient, β, is 1.4 × 10-11 m/W for 1 and 5.6 × 10-13 m/W for 3, and the third-order nonlinear refraction index, n2, is 1.0 × 10-18 m2/W for 3. Complex 1 shows self-defocusing property, while complex 3 exhibits self-focusing property. The thermogravimetric results show that the frame structure of compounds 1-3 begin to collapse at 400, 250 and 280 °C, respectively, which suggests that they elicit excellent thermal stability. This research aims to provide better understanding of these compounds, and offer preliminary explanations for the significant differences between compounds 1-3, in order to potentially help in the designing of future novel materials with NLO properties.

  18. Molecular structure, vibrational spectra, NLO and MEP analysis of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II)

    NASA Astrophysics Data System (ADS)

    Tanak, Hasan; Toy, Mehmet

    2013-11-01

    The molecular geometry and vibrational frequencies of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II) in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-311G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The energetic and atomic charge behavior of the title compound in solvent media has been examined by applying the Onsager and the polarizable continuum model. To investigate second order nonlinear optical properties of the title compound, the electric dipole (μ), linear polarizability (α) and first-order hyperpolarizability (β) were computed using the density functional B3LYP and CAM-B3LYP methods with the 6-31+G(d) basis set. According to our calculations, the title compound exhibits nonzero (β) value revealing second order NLO behavior. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), frontier molecular orbitals, and thermodynamic properties were performed at B3LYP/6-311G(d,p) level of theory.

  19. Structure, crystal growth, optical and mechanical studies of poly bis (thiourea) silver (I) nitrate single crystal: A new semi organic NLO material

    NASA Astrophysics Data System (ADS)

    Sivakumar, N.; Kanagathara, N.; Varghese, B.; Bhagavannarayana, G.; Gunasekaran, S.; Anbalagan, G.

    2014-01-01

    A new semi organic non linear optical polymeric crystal, bis (thiourea) silver (I) nitrate (TuAgN) with dimension 8 × 7 × 1.5 mm3 has been successfully grown from aqueous solution by slow evaporation solution technique. Single crystal X-ray diffraction study reveals that the crystal belongs to orthorhombic system with non centrosymmetric space group C2221. The crystalline perfection of the crystal was analyzed by high resolution X-ray diffraction (HRXRD) rocking curve measurements. Functional groups present in the crystal were analyzed qualitatively by infrared and Confocal Raman spectral analysis. Effects due to coordination of thiourea with metal ions were also discussed. Optical absorption study on TuAgN crystal shows the minimum absorption in the entire UV-Vis region and the lower cut off wavelength of TuAgN is found to be 318 nm. Thermal analysis shows that the material is thermally stable up to 180 °C. The mechanical strength and its parameters of the grown crystal were estimated by Vicker's microhardness test. The second harmonic generation (SHG) efficiency of the crystal was measured by Kurtz's powder technique infers that the crystal has nonlinear optical (NLO) efficiency 0.85 times that of KDP.

  20. Syntheses, crystal structures, and NLO properties of the quaternary sulfides RE3Sb0.33SiS7 (RE=La, Pr)

    NASA Astrophysics Data System (ADS)

    Zhao, Hua-Jun

    2015-07-01

    Two quaternary sulfides RE3Sb0.33SiS7 (RE=La, Pr) have been prepared from stoichiometric mixtures of elements at 1223 K in an evacuated silica tube. They are the first examples of chalcogenides in the quaternary RE/Si/Sb/Q (RE=rare earth metal; Q=S, Se, Te) system. These two isostructural materials crystallize in the Ce3Al1.67S7 structure type in the hexagonal space group P63. Their structure features one-dimensional chains of face-sharing SbS6 octahedra running parallel to the c direction surrounded by the discrete SiS4 tetrahedra and RE cations. The La3Sb0.33SiS7 exhibits a SHG signal about 0.5 times that of the commercially used IR NLO material AgGaS2 at 2.05 μm laser. The optical gap of 1.92 eV for La3Sb0.33SiS7 was deduced from UV/Vis reflectance spectroscopy.

  1. Growth, optical, thermal, mechanical and dielectric studies of sodium succinate hexahydrate (β phase) single crystal: A promising third order NLO material

    NASA Astrophysics Data System (ADS)

    Mageshwari, P. S. Latha; Priya, R.; Krishnan, S.; Joseph, V.; Das, S. Jerome

    2016-11-01

    A third order nonlinear optical (NLO)single crystals of sodium succinate hexahydrate (SSH) (β phase) has been grown by a slow evaporation growth technique using aqueous solution at ambient temperature. The lattice parameters and morphology of SSH were determined by single crystal X-ray diffraction analysis. SSH crystallizes in centrosymmetric monoclinic system with space group P 21 / c and the crystalline purity was analyzed by powder X-ray diffraction analysis. The UV-vis-NIR spectrum reveals that the crystal is transparent in the entire visible region. The recorded FT-IR spectrum verified the presence of various functional groups in the material. NMR analysis of the grown crystal confirms the structural elucidation and detects the major and minor functional groups present in the title compound. ICP-OES analysis proved the presence of sodium in SSH. TG-DTA/DSCanalysis was used to investigate the thermal stability of the material. The dielectric permittivity and dielectric loss of SSH were carried out as a function of frequency for different temperatures and the results were discussed. The mechanical stability was evaluated from Vicker's microhardness test. The third order nonlinear optical properties of SSH has been investigated employing Z-scan technique with He-Ne laser operating at 632.8 nm wavelength.

  2. Molecular structure, spectroscopic properties, NLO and NBO analysis of 3,4-Lutidine and [Ag(3,4-Lutidine)2NO3] complex

    NASA Astrophysics Data System (ADS)

    Soliman, Saied M.

    2013-09-01

    The molecular structure and electronic properties of 3,4-Lutidine (34Lut) and its silver(I) complex; [Ag(34Lut)2NO3] have been reported. The geometry of the titled compounds was optimized using HF and DFT/B3LYP methods. The calculations predicted a distorted tetrahedral coordination geometry around the Ag(I) ion. The complete vibrational assignments of the 34Lut and [Ag(34Lut)2NO3] complex have been made on the basis of Total Energy Distribution (TED). The vibrational frequencies calculated using DFT/B3LYP method showed better agreement with the experimental values compared to HF method. For [Ag(34Lut)2NO3] complex, the calculations predicted the presence of intramolecular CH⋯O interactions between the oxygen of the nitrate and the neighboring hydrogen atoms of the coordinated 34Lut which is confirmed by the TED analysis of the CH stretching modes. Unexpected blue shift is predicted for the CH stretching modes involved in such interactions. A study on the electronic properties, such as HOMO and LUMO energies as well as the molecular electrostatic potential (MEP) was performed using the same level of theory. Natural charges and natural bond orbital (NBO) analyses of the studied molecules were also calculated and interpreted. The dipole moment, linear polarizability and first hyperpolarizability values were used to describe the NLO properties of the studied compounds.

  3. Molecular conformational analysis, vibrational spectra, NBO, NLO analysis and molecular docking study of bis[(E)-anthranyl-9-acrylic]anhydride based on density functional theory calculations.

    PubMed

    Mary, Y Sheena; Panicker, C Yohannan; Thiemann, Thies; Al-Azani, Mariam; Al-Saadi, Abdulaziz A; Van Alsenoy, C; Raju, K; War, Javeed Ahmad; Srivastava, S K

    2015-01-01

    FT-IR and FT-Raman spectra of bis[(E)-anthranyl-9-acrylic]anhydride were recorded and analyzed. The conformational behavior is also investigated. The vibrational wave numbers were calculated using density functional theory (DFT) quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in Infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The geometrical parameters are compared with related structures. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using Natural Bonding Orbital (NBO) analysis. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) analysis are used to determine the charge transfer within the molecule. Molecular Electrostatic Potential (MEP) was performed by the DFT method. The calculated first hyperpolarizability of the title compound is comparable with the reported values of similar derivatives and is 4.23 times that of the standard nonlinear optical (NLO) material urea and the title compound and its derivatives are an attractive object for future studies of nonlinear optical properties. To evaluate the in silico antitumor activity of the title compound molecular docking studies were carried out against protein Bcl-xL. The (1)H-NMR spectrum is also reported. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Synthesis, characterization and theoretical investigations of the structure, electronic properties and third-order nonlinearity optics (NLO) of M(DPIP)₂.

    PubMed

    Li, Kang; Tang, Guodong; Kou, ShanShan; Culnane, Lance F; Zhang, Yu; Song, Yinglin; Li, Rongqing; Wei, Changmei

    2015-03-15

    Three complexes of M(DPIP)2 (M=Cu, Co, Zn as 1, 2, 3) were synthesized and characterized by elemental analysis, IR, UV-Vis, thermogravimetry, and X-ray diffraction. Their nonlinear optical properties were measured by the Z-scan technique and yielded a normalized transmittance of about 70% for complex 1 (45 μJ pulse), and 93% for complex 3 (68 μJ pulse at the focus point). The nonlinear absorption coefficient, β, is 1.4×10(-11) m/W for 1 and 5.6×10(-13) m/W for 3, and the third-order nonlinear refraction index, n2, is 1.0×10(-18) m(2)/W for 3. Complex 1 shows self-defocusing property, while complex 3 exhibits self-focusing property. The thermogravimetric results show that the frame structure of compounds 1-3 begin to collapse at 400, 250 and 280°C, respectively, which suggests that they elicit excellent thermal stability. This research aims to provide better understanding of these compounds, and offer preliminary explanations for the significant differences between compounds 1-3, in order to potentially help in the designing of future novel materials with NLO properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Molecular structure, vibrational spectra, NLO and MEP analysis of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II).

    PubMed

    Tanak, Hasan; Toy, Mehmet

    2013-11-01

    The molecular geometry and vibrational frequencies of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II) in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-311G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The energetic and atomic charge behavior of the title compound in solvent media has been examined by applying the Onsager and the polarizable continuum model. To investigate second order nonlinear optical properties of the title compound, the electric dipole (μ), linear polarizability (α) and first-order hyperpolarizability (β) were computed using the density functional B3LYP and CAM-B3LYP methods with the 6-31+G(d) basis set. According to our calculations, the title compound exhibits nonzero (β) value revealing second order NLO behavior. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), frontier molecular orbitals, and thermodynamic properties were performed at B3LYP/6-311G(d,p) level of theory. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Conformational stability, vibrational spectra, NLO properties, NBO and thermodynamic analysis of 2-amino-5-bromo-6-methyl-4-pyrimidinol for dye sensitized solar cells by DFT methods.

    PubMed

    Anitha, E Gladis; Vedhagiri, S Joseph; Parimala, K

    2015-04-05

    The Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 2-amino-5-bromo-6-methyl-4-pyrimidinol (ABrMP) were recorded in the region 4000-400 and 3500-100 cm(-1), respectively. The conformational stability, geometrical structure, vibrational frequencies, infrared intensities and Raman activities were carried out by DFT (B3LYP and LSDA) methods with 6-311++G(d,p) basis set. The calculated results show good agreement with observed spectra. The charge delocalization have been analyzed using NBO analysis by LSDA/6-311++G(d,p) level of theory. The NLO properties (μ, α0, Δα, β0 and βvec) have been computed quantum mechanically. The calculated HOMO and LUMO energies show that, the charge transfer occurs within the molecule. The solvent effects have been calculated using TD-DFT and the results are in good agreement with experimental measurements. The other molecular properties like Mulliken population analysis, electrostatic potential (ESP) and thermodynamic properties of the title compound at the different temperatures have been calculated. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Structure, crystal growth, optical and mechanical studies of poly bis (thiourea) silver (I) nitrate single crystal: a new semi organic NLO material.

    PubMed

    Sivakumar, N; Kanagathara, N; Varghese, B; Bhagavannarayana, G; Gunasekaran, S; Anbalagan, G

    2014-01-24

    A new semi organic non linear optical polymeric crystal, bis (thiourea) silver (I) nitrate (TuAgN) with dimension 8×7×1.5 mm(3) has been successfully grown from aqueous solution by slow evaporation solution technique. Single crystal X-ray diffraction study reveals that the crystal belongs to orthorhombic system with non centrosymmetric space group C2221. The crystalline perfection of the crystal was analyzed by high resolution X-ray diffraction (HRXRD) rocking curve measurements. Functional groups present in the crystal were analyzed qualitatively by infrared and Confocal Raman spectral analysis. Effects due to coordination of thiourea with metal ions were also discussed. Optical absorption study on TuAgN crystal shows the minimum absorption in the entire UV-Vis region and the lower cut off wavelength of TuAgN is found to be 318 nm. Thermal analysis shows that the material is thermally stable up to 180°C. The mechanical strength and its parameters of the grown crystal were estimated by Vicker's microhardness test. The second harmonic generation (SHG) efficiency of the crystal was measured by Kurtz's powder technique infers that the crystal has nonlinear optical (NLO) efficiency 0.85 times that of KDP. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Design, synthesis and excellent third-order NLO properties of two new polyoxometalates constructed from Keggin polyanions bonded by a solvent molecule.

    PubMed

    Miao, Hao; Dong, Yayu; Chen, Ziwang; He, Xingxiang; Hu, Gonghao; Xu, Yan

    2016-08-09

    Two new monosubstituted Keggin structural polyoxometalates [H5PMo11O39Zn(C5H5N)]·(C5H5N)5·H2O (1) and [H5PW11O39Co(C5H5N)]·(C5H5N)2·(C6H8N)2·1.5CH3OH (2) have been successfully synthesized under hydrothermal conditions. Structural analysis indicates that the polyoxoanion of compound 1 is a solvent molecule-bonded zinc-monosubstituted Keggin structural cluster, [PMo11O39Zn(C5H5N)](5-), while the polyoxoanion of compound 2 is a cobalt-monosubstituted phosphotungstate polyanion bonded with one pendant pyridine molecule. Both 1 and 2 show 3D supramolecular interpenetrating structures constructed of inorganic polyanion layers and organic layers. Very interestingly, compounds 1 and 2 exhibit excellent third-order NLO properties, and the TPA cross section σ of 1 and 2 is 2571.3 GM and 2876.3 GM, respectively.

  9. Evolution of nonlinear optical properties: from gold atomic clusters to plasmonic nanocrystals.

    PubMed

    Philip, Reji; Chantharasupawong, Panit; Qian, Huifeng; Jin, Rongchao; Thomas, Jayan

    2012-09-12

    Atomic clusters of metals are an emerging class of extremely interesting materials occupying the intermediate size regime between atoms and nanoparticles. Here we report the nonlinear optical (NLO) characteristics of ultrasmall, atomically precise clusters of gold, which are smaller than the critical size for electronic energy quantization (∼2 nm). Our studies reveal remarkable features of the distinct evolution of the optical nonlinearity as the clusters progress in size from the nonplasmonic regime to the plasmonic regime. We ascertain that the smallest atomic clusters do not show saturable absorption at the surface plasmon wavelength of larger gold nanocrystals (>2 nm). Consequently, the third-order optical nonlinearity in these ultrasmall gold clusters exhibits a significantly lower threshold for optical power limiting. This limiting efficiency, which is superior to that of plasmonic nanocrystals, is highly beneficial for optical limiting applications.

  10. Experimental evolution.

    PubMed

    Kawecki, Tadeusz J; Lenski, Richard E; Ebert, Dieter; Hollis, Brian; Olivieri, Isabelle; Whitlock, Michael C

    2012-10-01

    Experimental evolution is the study of evolutionary processes occurring in experimental populations in response to conditions imposed by the experimenter. This research approach is increasingly used to study adaptation, estimate evolutionary parameters, and test diverse evolutionary hypotheses. Long applied in vaccine development, experimental evolution also finds new applications in biotechnology. Recent technological developments provide a path towards detailed understanding of the genomic and molecular basis of experimental evolutionary change, while new findings raise new questions that can be addressed with this approach. However, experimental evolution has important limitations, and the interpretation of results is subject to caveats resulting from small population sizes, limited timescales, the simplified nature of laboratory environments, and, in some cases, the potential to misinterpret the selective forces and other processes at work. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Nonlinear Effects in Gluon Distribution Predicted by GLR-MQ Evolution Equation at Next-to-leading Order in LHC Data

    NASA Astrophysics Data System (ADS)

    Lalung, M.; Phukan, P.; Sarma, J. K.

    2017-09-01

    In this work we have solved the nonlinear GLR-MQ evolution equation upto next-to-leading order (NLO) by considering NLO terms of the gluon-gluon splitting functions and running coupling constant α s (Q 2). Here, we have incorporated a Regge-like behaviour of gluon distribution in order to obtain a solution of the GLR-MQ equation in the range of 5G e V 2 ≤ Q 2 ≤ 25G e V 2. We have studied the Q 2 evolution of the gluon distribution function G(x, Q 2) and its nonlinear effects at small-x. It can be observed from our analysis that the nonlinearities increase with decrease in the correlation radius R of two interacting gluons, as expected. We have compared our result of G(x, Q 2) as Q 2 increases and x decreases, for two different values of R, viz. R = 2G e V -1 and 5 G e V -1. We have also checked the sensitivity of the Regge intercept λ G on our results. We compare our computed results with those obtained by the global analysis to parton distribution functions (PDFs) by various collaborations where LHC data have been included viz. ABM12, CT14, MMHT14, PDF4LHC15, NNPDF3.0 and CJ15. Besides we have also shown comparison of our results with HERA PDF data viz. HERAPDF15.

  12. Security Evolution.

    ERIC Educational Resources Information Center

    De Patta, Joe

    2003-01-01

    Examines how to evaluate school security, begin making schools safe, secure schools without turning them into fortresses, and secure schools easily and affordably; the evolution of security systems into information technology systems; using schools' high-speed network lines; how one specific security system was developed; pros and cons of the…

  13. Art & Evolution

    ERIC Educational Resources Information Center

    Terry, Mark

    2005-01-01

    In this article, the author presents a two-week evolution unit for his biology class. He uses Maria Sybilla Merian (1647-1717) as an example of an Enlightenment mind at work--in this case a woman recognized as one of the great artists and natural scientists of her time. Her representations of butterflies, caterpillars and their pupae, and the…

  14. Silent evolution

    PubMed Central

    OSAWA, Syozo; SU, Zhi-Hui; NISHIKAWA, Masaaki; TOMINAGA, Osamu

    2016-01-01

    Phylogenetic analyses using mitochondrial DNA sequences of several kinds of beetles have shown that their evolution included a silent stage in which no morphological changes took place. We thus propose a new category of evolutionary process called “silent evolution”. PMID:27840392

  15. Art & Evolution

    ERIC Educational Resources Information Center

    Terry, Mark

    2005-01-01

    In this article, the author presents a two-week evolution unit for his biology class. He uses Maria Sybilla Merian (1647-1717) as an example of an Enlightenment mind at work--in this case a woman recognized as one of the great artists and natural scientists of her time. Her representations of butterflies, caterpillars and their pupae, and the…

  16. FTIR, FT-RAMAN, NMR, spectra, normal co-ordinate analysis, NBO, NLO and DFT calculation of N,N-diethyl-4-methylpiperazine-1-carboxamide molecule

    NASA Astrophysics Data System (ADS)

    Muthu, S.; Elamurugu Porchelvi, E.

    2013-11-01

    The Fourier Transform Infrared (FT-IR) and FT-Raman of N,N-diethyl-4-methylpiperazine-1-carboxamide (NND4MC) have been recorded and analyzed. The structure of the compound was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-31G(d,p) and 6-311G(d,p) basis sets. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ* and π* antibonding orbitals and second order delocalization energies (E2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using Density Functional Theory (DFT/B3LYP) with 6-31G(d,p) and 6-311G(d,p) basis sets. The calculated results also show that the NND4MC molecule may have microscopy nonlinear optical (NLO) behavior with non zero values. Mulliken atomic charges of NND4MC were calculated. The 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The UV-Vis spectrum of the compound was recorded. The theoretical electronic absorption spectra have been calculated by using CIS, TD-DFT methods. A study on the electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) were also performed.

  17. The spectroscopic (FT-IR, UV-vis), Fukui function, NLO, NBO, NPA and tautomerism effect analysis of (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile.

    PubMed

    Demircioğlu, Zeynep; Kaştaş, Çiğdem Albayrak; Büyükgüngör, Orhan

    2015-03-15

    A new o-hydroxy Schiff base, (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile was isolated and investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. The vibrational spectral analysis was carried out by using FT-IR spectroscopy in the range of 4000-400cm(-)(1). Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) basis set. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The UV-vis spectrum of the compound was recorded in the region 200-800 nm in several solvents and electronic properties such as excitation energies, and wavelengths were calculated by TD-DFT/B3LYP method. The most prominent transitions were corresponds to π→π∗. Hybrid density functional theory (DFT) was used to investigate the enol-imine and keto-amine tautomers of titled compound. The titled compound showed the preference of enol form, as supported by X-ray and spectroscopic analysis results. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms. Additionally, geometry optimizations in solvent media were performed with the same level of theory by the integral equation formalism polarizable continuum (IEF-PCM). Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.

  18. Spectroscopic (FT-IR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of organic 2,4,5-trichloroaniline.

    PubMed

    Govindarajan, M; Karabacak, M; Periandy, S; Tanuja, D

    2012-11-01

    In this work, the experimental and theoretical study on the molecular structure and vibrational spectra of 2,4,5-trichloroaniline (C(6)H(4)NCl(3), abbreviated as 2,4,5-TClA) were studied. The FT-IR and FT-Raman spectra were recorded. The molecular geometry and vibrational frequencies in the ground state were calculated by using the Hartree-Fock (HF) and density functional theory (DFT) methods (B3LYP) with 6-311++G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of 2,4,5-TClA with calculated results by HF and DFT indicates that B3LYP is superior to HF method for molecular vibrational problems. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and the first hyperpolarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4,5-TClA molecule may have microscopic nonlinear optical (NLO) behavior with non-zero values. Mulliken atomic charges of 2,4,5-TClA was calculated and compared with aniline and chlorobenzene molecules. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. The spectroscopic (FT-IR, UV-vis), Fukui function, NLO, NBO, NPA and tautomerism effect analysis of (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile

    NASA Astrophysics Data System (ADS)

    Demircioğlu, Zeynep; Albayrak Kaştaş, Çiğdem; Büyükgüngör, Orhan

    2015-03-01

    A new o-hydroxy Schiff base, (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile was isolated and investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. The vibrational spectral analysis was carried out by using FT-IR spectroscopy in the range of 4000-400 cm-1. Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) basis set. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The UV-vis spectrum of the compound was recorded in the region 200-800 nm in several solvents and electronic properties such as excitation energies, and wavelengths were calculated by TD-DFT/B3LYP method. The most prominent transitions were corresponds to π → π∗. Hybrid density functional theory (DFT) was used to investigate the enol-imine and keto-amine tautomers of titled compound. The titled compound showed the preference of enol form, as supported by X-ray and spectroscopic analysis results. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms. Additionally, geometry optimizations in solvent media were performed with the same level of theory by the integral equation formalism polarizable continuum (IEF-PCM). Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.

  20. Molecular structure, electronic properties, NLO, NBO analysis and spectroscopic characterization of Gabapentin with experimental (FT-IR and FT-Raman) techniques and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Sinha, Leena; Karabacak, Mehmet; Narayan, V.; Cinar, Mehmet; Prasad, Onkar

    2013-05-01

    Gabapentin (GP), structurally related to the neurotransmitter GABA (gamma-aminobutyric acid), mimics the activity of GABA and is also widely used in neurology for the treatment of peripheral neuropathic pain. It exists in zwitterionic form in solid state. The present communication deals with the quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of GP using density functional (DFT/B3LYP) method with 6-311++G(d,p) basis set. In view of the fact that amino acids exist as zwitterions as well as in the neutral form depending on the environment (solvent, pH, etc.), molecular properties of both the zwitterionic and neutral form of GP have been analyzed. The fundamental vibrational wavenumbers as well as their intensities were calculated and compared with experimental FT-IR and FT-Raman spectra. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The electric dipole moment, polarizability and the first hyperpolarizability values of the GP have been calculated at the same level of theory and basis set. The nonlinear optical (NLO) behavior of zwitterionic and neutral form has been compared. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using natural bond orbital analysis. Ultraviolet-visible (UV-Vis) spectrum of the title molecule has also been calculated using TD-DFT method. The thermodynamic properties of both the zwitterionic and neutral form of GP at different temperatures have been calculated.

  1. FTIR, FT-RAMAN, NMR, spectra, normal co-ordinate analysis, NBO, NLO and DFT calculation of N,N-diethyl-4-methylpiperazine-1-carboxamide molecule.

    PubMed

    Muthu, S; Elamurugu Porchelvi, E

    2013-11-01

    The Fourier Transform Infrared (FT-IR) and FT-Raman of N,N-diethyl-4-methylpiperazine-1-carboxamide (NND4MC) have been recorded and analyzed. The structure of the compound was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-31G(d,p) and 6-311G(d,p) basis sets. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ(*) and π(*) antibonding orbitals and second order delocalization energies (E2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using Density Functional Theory (DFT/B3LYP) with 6-31G(d,p) and 6-311G(d,p) basis sets. The calculated results also show that the NND4MC molecule may have microscopy nonlinear optical (NLO) behavior with non zero values. Mulliken atomic charges of NND4MC were calculated. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The UV-Vis spectrum of the compound was recorded. The theoretical electronic absorption spectra have been calculated by using CIS, TD-DFT methods. A study on the electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) were also performed.

  2. Jet substructure using semi-inclusive jet functions in SCET

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2016-11-01

    We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function {{G}}_i^h(z={ω}_J/ω, {z}_h={ω}_h/{ω}_J,{ω}_J,R,μ ) , which depends on the jet radius R and the large light-cone momenta of the parton ` i' initiating the jet ( ω), the jet ( ω J ), and the hadron h ( ω h ). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function {{G}}_i^h(z,{z}_h,{ω}_J,R,μ ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL R ) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL R results for the hadron distribution inside the jet. We present numerical results for pp → (jet h) X in the new framework, and find excellent agreement with existing LHC experimental data.

  3. Ligand-core NLO-phores: a combined experimental and theoretical approach to the two-photon absorption and two-photon excited emission properties of small-ligated silver nanoclusters.

    PubMed

    Russier-Antoine, Isabelle; Bertorelle, Franck; Calin, Nathalie; Sanader, Željka; Krstić, Marjan; Comby-Zerbino, Clothilde; Dugourd, Philippe; Brevet, Pierre-François; Bonačić-Koutecký, Vlasta; Antoine, Rodolphe

    2017-01-19

    We report a combined experimental and theoretical study of the two-photon absorption and excited emission properties of monodisperse ligand stabilized Ag11, Ag15 and Ag31 nanoclusters in aqueous solutions. The nanoclusters were synthesized using a cyclic reduction under oxidative conditions and separated by vertical gel electrophoresis. The two-photon absorption cross-sections of these protected noble metal nanoclusters measured within the biologically attractive 750-900 nm window are several orders of magnitude larger than that reported for commercially available standard organic dyes. The two-photon excited fluorescence spectra are also presented for excitation wavelengths within the same excitation spectral window. They exhibit size-tunability. Because the fundamental photophysical mechanisms underlying these multiphoton processes in ligand protected clusters with only a few metal atoms are not fully understood yet, a theoretical model is proposed to identify the key driving elements. Elements that regulate the dipole moments and the nonlinear optical properties are the nanocluster size, its structure and the charge distribution on both the metal core and the bound ligands. We coined this new class of NLO materials as "Ligand-Core" NLO-phores.

  4. Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid

    NASA Astrophysics Data System (ADS)

    Venkatesan, Perumal; Thamotharan, Subbiah; Ilangovan, Andivelu; Liang, Hongze; Sundius, Tom

    2016-01-01

    Nonlinear optical (NLO) activity of the compound (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid is investigated experimentally and theoretically using X-ray crystallography and quantum chemical calculations. The NLO activity is confirmed by both powder Second Harmonic Generation (SHG) experiment and first hyper polarizability calculation. The title compound displays 8 fold excess of SHG activity when compared with the standard compound KDP. The gas phase geometry optimization and vibrational frequencies calculations are performed using density functional theory (DFT) incorporated in B3LYP with 6-311G++(d,p) basis set. The title compound crystallizes in non-centrosymmetric space group P21. Moreover, the crystal structure is primarily stabilized through intramolecular N-H···O and O-H···O hydrogen bonds and intermolecular C-H···O and C-H···π interactions. These intermolecular interactions are analyzed and quantified using Hirshfeld surface analysis and PIXEL method. The detailed vibrational assignments are performed on the basis of the potential energy distributions (PED) of the vibrational modes.

  5. Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid.

    PubMed

    Venkatesan, Perumal; Thamotharan, Subbiah; Ilangovan, Andivelu; Liang, Hongze; Sundius, Tom

    2016-01-15

    Nonlinear optical (NLO) activity of the compound (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid is investigated experimentally and theoretically using X-ray crystallography and quantum chemical calculations. The NLO activity is confirmed by both powder Second Harmonic Generation (SHG) experiment and first hyper polarizability calculation. The title compound displays 8 fold excess of SHG activity when compared with the standard compound KDP. The gas phase geometry optimization and vibrational frequencies calculations are performed using density functional theory (DFT) incorporated in B3LYP with 6-311G++(d,p) basis set. The title compound crystallizes in non-centrosymmetric space group P21. Moreover, the crystal structure is primarily stabilized through intramolecular N-H···O and O-H···O hydrogen bonds and intermolecular C-H···O and C-H···π interactions. These intermolecular interactions are analyzed and quantified using Hirshfeld surface analysis and PIXEL method. The detailed vibrational assignments are performed on the basis of the potential energy distributions (PED) of the vibrational modes. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO).

    PubMed

    Rawat, Poonam; Singh, R N; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

    2017-02-11

    As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, (1)H NMR, (13)C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π→π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89×10(-30)esu, (gas phase); 68.79×10(-30) (CHCl3), esu; 76.76×10(-30)esu (CH2Cl2), 85.16×10(-30)esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram

  7. Insect evolution.

    PubMed

    Engel, Michael S

    2015-10-05

    It goes without saying that insects epitomize diversity, and with over a million documented species they stand out as one of the most remarkable lineages in the 3.5-billion-year history of life on earth (Figure 1). This reality is passé to even the layperson and is taken for granted in the same way none of us think much of our breathing as we go about our day, and yet insects are just as vital to our existence. Insects are simultaneously familiar and foreign to us, and while a small fraction are beloved or reviled, most are simply ignored. These inexorable evolutionary overachievers outnumber us all, their segmented body plan is remarkably labile, they combine a capacity for high rates of speciation with low levels of natural extinction, and their history of successes eclipses those of the more familiar ages of dinosaurs and mammals alike. It is their evolution - persisting over vast expanses of geological time and inextricably implicated in the diversification of other lineages - that stands as one of the most expansive subjects in biology.

  8. Syntheses, crystal structures, and NLO properties of the quaternary sulfides RE{sub 3}Sb{sub 0.33}SiS{sub 7} (RE=La, Pr)

    SciTech Connect

    Zhao, Hua-Jun

    2015-07-15

    Two quaternary sulfides RE{sub 3}Sb{sub 0.33}SiS{sub 7} (RE=La, Pr) have been prepared from stoichiometric mixtures of elements at 1223 K in an evacuated silica tube. They are the first examples of chalcogenides in the quaternary RE/Si/Sb/Q (RE=rare earth metal; Q=S, Se, Te) system. These two isostructural materials crystallize in the Ce{sub 3}Al{sub 1.67}S{sub 7} structure type in the hexagonal space group P6{sub 3}. Their structure features one-dimensional chains of face-sharing SbS{sub 6} octahedra running parallel to the c direction surrounded by the discrete SiS{sub 4} tetrahedra and RE cations. The La{sub 3}Sb{sub 0.33}SiS{sub 7} exhibits a SHG signal about 0.5 times that of the commercially used IR NLO material AgGaS{sub 2} at 2.05 μm laser. The optical gap of 1.92 eV for La{sub 3}Sb{sub 0.33}SiS{sub 7} was deduced from UV/Vis reflectance spectroscopy. - Graphical abstract: The RE{sub 3}Sb{sub 0.33}SiS{sub 7} (RE=La, Pr), crystalling in the Ce{sub 3}Al{sub 1.67}S{sub 7} structure type, have been prepared. The La{sub 3}Sb{sub 0.33}SiS{sub 7} exhibits a SHG signal about 0.5 times that of the IR NLO material AgGaS{sub 2}. - Highlights: • The RE{sub 3}Sb{sub 0.33}SiS{sub 7} (RE=La, Pr), crystalling in the Ce{sub 3}Al{sub 1.67}S{sub 7} structure type, have been prepared. • The La{sub 3}Sb{sub 0.33}SiS{sub 7} exhibits a SHG signal about 0.5 times that of the IR NLO material AgGaS{sub 2}. • The optical gap of 1.92 eV for La{sub 3}Sb{sub 0.33}SiS{sub 7} was deduced from UV/Vis reflectance spectroscopy.

  9. EMU evolution

    NASA Technical Reports Server (NTRS)

    Rouen, M.

    1991-01-01

    Evolution of Extravehicular Mobility Unit (EMU) technology is necessary to support the Extravehicular Activity (EVA) requirements of the Space Station Freedom Program and those of the Space Exploration Initiative (SEI). Key qualities supporting long-duration missions include technologies that are highly reliable, durable, minimize logistics requirements, and are in-flight maintainable and serviceable. While these qualities are common to SSF and SEI EVA, development paths will differ where specific mission requirements impose different constraints. Development of reusable, regenerative technologies is necessary to minimize the logistics penalties. Increased battery discharge/recharge cycle life and usable wet life, compact high current density fuel cells, reusable CO2 absorbing media, and thermal radiation coupled with venting heat rejection technologies are just some methods of reducing consumables. Development must strive for durable, reliable systems that are in-flight serviceable and maintainable, which are vital for missions where logistics capabilities are extremely constrained. Key areas include suit components (e.g., gloves, boots, and cooling garments), and life support hardware such as fans, pumps, instrumentation, and emergency O2 systems. Higher pressure suits will reduce EVA prebreathe requirements and pre-EVA operations overall. Many challenges of higher pressure suits have been addressed by on-going development. Emphasis on glove development is necessary to provide low fatigue, dexterous glove mobility at higher suit pressures. Minimum impact hooks and scars which support an advanced SSF EMU have been identified. These accommodations permit upgrades that support servicing of low volume, high pressure oxygen systems, and hydrogen technologies such as fuel cell, and venting hydrogen heat rejection systems.

  10. The nonsinglet spin-dependent structure function evolution by Laplace and characteristics methods

    SciTech Connect

    Boroun, G. R. E-mail: boroun@razi.ac.ir; Zarrin, S.; Dadfar, S.

    2016-03-15

    We evaluate the non-singlet spin-dependent structure function g{sub 1}{sup NS} at leading order (LO) and next-to-leading order (NLO) by using the Laplace-transform technique and method of characteristics and also obtain its first moment at NLO. The polarized non-singlet structure function results are compared with the data from HERMES (A. Airapetian et al., Phys. Rev. D 75, 012007 (2007)) and E143 (K. Abe et al. (E143 Collab.), Phys. Rev. D 58, 112003 (1998)) at LO and NLO analyses and the first-moment the result at NLO is compared with the result of the NLO GRSV2000 fit. Considering the solution, this method is valid at low- and large-x regions.

  11. DFT calculations of the tautomerization and NLO properties of 5-amino-7-(pyrrolidin-1-yl)-2,4,4-trimethyl-1,4-dihydro-1,6-naphthyridine-8-carbonitrile (APNC)

    NASA Astrophysics Data System (ADS)

    Wazzan, Nuha; Safi, Zaki

    2017-09-01

    Amine-imine tautomerization in 5-amino-7-(pyrrolidin-1-yl)-2,4,4-trimethyl-1,4-dihydro-1,6-naphthyridine-8-carbonitrile (APNC) has been studied using the B3LYP, CAM-B3LYP and ωB97XD with 6-311++G(d,p) basis set. Optimum molecular geometries, electronic properties, energetics and electronic densities of these systems have been discussed and compared with the available experimental data. Investigation reveals that one tautomer (the amine tautomer) dominates the gas phase. The photochromic properties of APNC and its two imine tautomers have been studied at the elected DFT-functionals and basis set. The interconversion A1 to I2/I3 is predicted to occur photochemically. The NLO properties were also evaluated and discussed.

  12. NBO, HOMO-LUMO, UV, NLO, NMR and vibrational analysis of veratrole using FT-IR, FT-Raman, FT-NMR spectra and HF-DFT computational methods.

    PubMed

    Suvitha, A; Periandy, S; Gayathri, P

    2015-03-05

    This work deals with FT-IR, FT-Raman and FT-NMR spectral analysis and NBO, NLO, HOMO-LUMO and electronic transitions studies on veratrole. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands were interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree-Fock (HF) and density functional theory (DFT) method with 6-311++G(d, p) basis set. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. In addition, molecular electrostatic potential (MEP), Natural Bond-Orbital (NBO) analysis and thermodynamic properties were performed. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method and compared with experimental chemical shift. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Molecular structures, spectroscopic (FT-IR, NMR, UV) studies, NBO analysis and NLO properties for tautomeric forms of 1,3-dimethyl-5-(phenylazo)-6-aminouracil by density functional method.

    PubMed

    Eşme, Aslı; Sağdınç, Seda Güneşdoğdu

    2018-01-05

    The equilibrium geometry, nuclear magnetic resonance (NMR) and UV-Vis analysis, and vibrational frequencies for the azo and hydrazone isomers of 1,3-dimethyl-5-(phenylazo)-6-aminouracil have been performed using density functional theory (DFT/B3LYP) method with 6-311G(d,p) basis set. A detailed interpretation of the vibrational spectra has been made on the basis of the calculated potential energy distribution (PED) obtained from the Vibrational Energy Distribution Analysis (VEDA4) program. The (1)H NMR chemical shifts with respect to TMS were calculated by the gauge independent atomic orbital (GIAO) method and compared with the experimental data. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Using the TD-DFT method, electronic absorption spectra in CHCl3 solvent of the title compound have been predicted, and good agreement is determined with the experimental one. The NLO properties such as mean polarizability (⟨α⟩), the anisotropy of the polarizability (⟨Δα⟩) and the mean first-order hyperpolarizability (⟨β⟩) were computed by using finite field method. The computed values of μ, α and β for the azo and hydrazone forms of the title molecule are 5.4717 and 3.8905 D, 2.7773×10(-23) and 2.7598×10(-23)esu, and 3.4499×10-(30) and 6.8504×10-(30)esu, respectively. The high β values and non-zero values of μ indicate that the title compound might be a good candidate for NLO material. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Evolution: Help for the Confused.

    ERIC Educational Resources Information Center

    Scheer, Bradley T.

    1979-01-01

    Written in response to an earlier article questioning certain aspects of evolution theory. Discusses ontogeny and phylogeny, the basis of evolution, chance or purpose in evolution, micro and macro-evolution, reversibility, and the evolution processes today. (MA)

  15. Evolution: Help for the Confused.

    ERIC Educational Resources Information Center

    Scheer, Bradley T.

    1979-01-01

    Written in response to an earlier article questioning certain aspects of evolution theory. Discusses ontogeny and phylogeny, the basis of evolution, chance or purpose in evolution, micro and macro-evolution, reversibility, and the evolution processes today. (MA)

  16. Secular Evolution of Galaxies

    NASA Astrophysics Data System (ADS)

    Falcón-Barroso, Jesús; Knapen, Johan H.

    2013-10-01

    Preface; 1. Secular evolution in disk galaxies John Kormendy; 2. Galaxy morphology Ronald J. Buta; 3. Dynamics of secular evolution James Binney; 4. Bars and secular evolution in disk galaxies: theoretical input E. Athanassoula; 5. Stellar populations Reynier F. Peletier; 6. Star formation rate indicators Daniela Calzetti; 7. The evolving interstellar medium Jacqueline van Gorkom; 8. Evolution of star formation and gas Nick Z. Scoville; 9. Cosmological evolution of galaxies Isaac Shlosman.

  17. Understanding Evolution: An Evolution Website for Teachers

    ERIC Educational Resources Information Center

    Scotchmoor, Judy; Janulaw, Al

    2005-01-01

    While many states are facing challenges to the teaching of evolution in their science classrooms, the University of California Museum of Paleontology, working with the National Center for Science Education, has developed a useful web-based resource for science teachers of all grade- and experience-levels. Understanding Evolution (UE) was developed…

  18. Understanding Evolution: An Evolution Website for Teachers

    ERIC Educational Resources Information Center

    Scotchmoor, Judy; Janulaw, Al

    2005-01-01

    While many states are facing challenges to the teaching of evolution in their science classrooms, the University of California Museum of Paleontology, working with the National Center for Science Education, has developed a useful web-based resource for science teachers of all grade- and experience-levels. Understanding Evolution (UE) was developed…

  19. Perspective: reverse evolution.

    PubMed

    Teotónio, H; Rose, M R

    2001-04-01

    For some time, the reversibility of evolution was primarily discussed in terms of comparative patterns. Only recently has this problem been studied using experimental evolution over shorter evolutionary time frames. This has raised questions of definition, experimental procedure, and the hypotheses being tested. Experimental evolution has provided evidence for multiple population genetic mechanisms in reverse evolution, including pleiotropy and mutation accumulation. It has also pointed to genetic factors that might prevent reverse evolution, such as a lack of genetic variability, epistasis, and differential genotype-by-environment interactions. The main focus of this perspective is on laboratory studies and their relevance to the genetics of reverse evolution. We discuss reverse evolution experiments with Drosophila, bacterial, and viral populations. Field studies of the reverse evolution of melanism in the peppered moth are also reviewed.

  20. The Evolution of Design

    ERIC Educational Resources Information Center

    Stebbins, G. Ledyard

    1973-01-01

    Describes the basic logic behind the modern view of evolution theory. Despite gaps in fossil records, evidence is indicative of the origin of life from nonliving molecules and evolution of higher forms of life from simpler forms. (PS)

  1. The Evolution of Design

    ERIC Educational Resources Information Center

    Stebbins, G. Ledyard

    1973-01-01

    Describes the basic logic behind the modern view of evolution theory. Despite gaps in fossil records, evidence is indicative of the origin of life from nonliving molecules and evolution of higher forms of life from simpler forms. (PS)

  2. Mistakes and Molecular Evolution.

    ERIC Educational Resources Information Center

    Trevors, J. T.

    1998-01-01

    Examines the role mistakes play in the molecular evolution of bacteria. Discusses the interacting physical, chemical, and biological factors that cause changes in DNA and play a role in prokaryotic evolution. (DDR)

  3. Mistakes and Molecular Evolution.

    ERIC Educational Resources Information Center

    Trevors, J. T.

    1998-01-01

    Examines the role mistakes play in the molecular evolution of bacteria. Discusses the interacting physical, chemical, and biological factors that cause changes in DNA and play a role in prokaryotic evolution. (DDR)

  4. Evolution and Probability.

    ERIC Educational Resources Information Center

    Bailey, David H.

    2000-01-01

    Some of the most impressive-sounding criticisms of the conventional theory of biological evolution involve probability. Presents a few examples of how probability should and should not be used in discussing evolution. (ASK)

  5. Oxygen and Biological Evolution.

    ERIC Educational Resources Information Center

    Baugh, Mark A.

    1990-01-01

    Discussed is the evolution of aerobic organisms from anaerobic organisms and the accompanying biochemistry that developed to motivate and enable this evolution. Uses of oxygen by aerobic organisms are described. (CW)

  6. Oxygen and Biological Evolution.

    ERIC Educational Resources Information Center

    Baugh, Mark A.

    1990-01-01

    Discussed is the evolution of aerobic organisms from anaerobic organisms and the accompanying biochemistry that developed to motivate and enable this evolution. Uses of oxygen by aerobic organisms are described. (CW)

  7. HIV Evolution and Escape.

    PubMed Central

    Richman, Douglas D.; Little, Susan J.; Smith, Davey M.; Wrin, Terri; Petropoulos, Christos; Wong, Joseph K.

    2004-01-01

    Human immunodeficiency virus (HIV) exemplifies the principles of Darwinian evolution with a telescoped chronology. Because of its high mutation rate and remarkably high rates of replication, evolution can be appreciated over periods of days in contrast to the durations conceived of by Darwin. Certain selective pressures that drive the evolution of HIV include chemotherapy, anatomic compartmentalization and the immune response. Examples of these selective forces on HIV evolution are described. Images Fig. 5 PMID:17060974

  8. Inlet Geomorphology Evolution

    DTIC Science & Technology

    2015-04-01

    APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Inlet Geomorphology Evolution 5a. CONTRACT NUMBER 5b...Std Z39-18 Coastal Inlets Research Program Inlet Geomorphology Evolution The Inlet Geomorphology Evolution work unit of the CIRP evaluates

  9. Evolution & Diversity in Plants.

    ERIC Educational Resources Information Center

    Pearson, Lorentz C.

    1988-01-01

    Summarizes recent findings that help in understanding how evolution has brought about the diversity of plant life that presently exists. Discusses basic concepts of evolution, diversity and classification, the three-line hypothesis of plant evolution, the origin of fungi, and the geologic time table. Included are 31 references. (CW)

  10. Arguing for Evolution.

    ERIC Educational Resources Information Center

    Ayala, Francisco J.

    2000-01-01

    Discusses the Kansas State Board of Education's decision to remove references to evolution and cosmology from the state's education standards and assessment. Advocates the need to teach evolution in high schools for a meaningful biology education. Addresses the question whether the teaching of evolution poses a threat to Christianity or other…

  11. Arguing for Evolution.

    ERIC Educational Resources Information Center

    Ayala, Francisco J.

    2000-01-01

    Discusses the Kansas State Board of Education's decision to remove references to evolution and cosmology from the state's education standards and assessment. Advocates the need to teach evolution in high schools for a meaningful biology education. Addresses the question whether the teaching of evolution poses a threat to Christianity or other…

  12. Evolution & Diversity in Plants.

    ERIC Educational Resources Information Center

    Pearson, Lorentz C.

    1988-01-01

    Summarizes recent findings that help in understanding how evolution has brought about the diversity of plant life that presently exists. Discusses basic concepts of evolution, diversity and classification, the three-line hypothesis of plant evolution, the origin of fungi, and the geologic time table. Included are 31 references. (CW)

  13. The semi-inclusive jet function in SCET and small radius resummation for inclusive jet production

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo; Ringer, Felix; Vitev, Ivan

    2016-10-01

    We introduce a new kind of jet function: the semi-inclusive jet function J i ( z, ω J , μ), which describes how a parton i is transformed into a jet with a jet radius R and energy fraction z = ω J /ω, with ω J and ω being the large light-cone momentum component of the jet and the corresponding parton i that initiates the jet, respectively. Within the framework of Soft Collinear Effective Theory (SCET) we calculate both J q ( z, ω J , μ) and J g ( z, ω J , μ) to the next-to-leading order (NLO) for cone and anti-kT algorithms. We demonstrate that the renormalization group (RG) equations for J i ( z, ω J , μ) follow exactly the usual DGLAP evolution, which can be used to perform the ln R resummation for inclusive jet cross sections with a small jet radius R. We clarify the difference between our RG equations for J i ( z, ω J , μ) and those for the so-called unmeasured jet functions J i ( ω J , μ), widely used in SCET for exclusive jet production. Finally, we present applications of the new semi-inclusive jet functions to inclusive jet production in e + e - and pp collisions. We demonstrate that single inclusive jet production in these collisions shares the same short-distance hard functions as single inclusive hadron production, with only the fragmentation functions D i h ( z, μ) replaced by J i ( z, ω J , μ). This can facilitate more efficient higher-order analytical computations of jet cross sections. We further match our ln R resummation at both LL R and NLL R to fixed NLO results and present the phenomenological implications for single inclusive jet production at the LHC.

  14. Frontiers of stellar evolution

    NASA Technical Reports Server (NTRS)

    Lambert, David L. (Editor)

    1991-01-01

    The present conference discusses theoretical and observational views of star formation, spectroscopic constraints on the evolution of massive stars, very low mass stars and brown dwarfs, asteroseismology, globular clusters as tests of stellar evolution, observational tests of stellar evolution, and mass loss from cool evolved giant stars. Also discussed are white dwarfs and hot subdwarfs, neutron stars and black holes, supernovae from single stars, close binaries with evolved components, accretion disks in interacting binaries, supernovae in binary systems, stellar evolution and galactic chemical evolution, and interacting binaries containing compact components.

  15. Evolution prediction from tomography

    NASA Astrophysics Data System (ADS)

    Dominy, Jason M.; Venuti, Lorenzo Campos; Shabani, Alireza; Lidar, Daniel A.

    2017-03-01

    Quantum process tomography provides a means of measuring the evolution operator for a system at a fixed measurement time t. The problem of using that tomographic snapshot to predict the evolution operator at other times is generally ill-posed since there are, in general, infinitely many distinct and compatible solutions. We describe the prediction, in some "maximal ignorance" sense, of the evolution of a quantum system based on knowledge only of the evolution operator for finitely many times 0<τ 1evolution at times away from the measurement times. Even if the original evolution is unitary, the predicted evolution is described by a non-unitary, completely positive map.

  16. New acceptor-bridge-donor strategy for enhancing NLO response with long-range excess electron transfer from the NH2...M/M3O donor (M = Li, Na, K) to inside the electron hole cage C20F19 acceptor through the unusual σ chain bridge (CH2)4.

    PubMed

    Bai, Yang; Zhou, Zhong-Jun; Wang, Jia-Jun; Li, Ying; Wu, Di; Chen, Wei; Li, Zhi-Ru; Sun, Chia-Chung

    2013-04-04

    Using the strong electron hole cage C20F19 acceptor, the NH2...M/M3O (M = Li, Na, and K) complicated donors with excess electron, and the unusual σ chain (CH2)4 bridge, we construct a new kind of electride molecular salt e(-)@C20F19-(CH2)4-NH2...M(+)/M3O(+) (M = Li, Na, and K) with excess electron anion inside the hole cage (to be encapsulated excess electron-hole pair) serving as a new A-B-D strategy for enhancing nonlinear optical (NLO) response. An interesting push-pull mechanism of excess electron generation and its long-range transfer is exhibited. The excess electron is pushed out from the (super)alkali atom M/M3O by the lone pair of NH2 in the donor and further pulled inside the hole cage C20F19 acceptor through the efficient long σ chain (CH2)4 bridge. Owing to the long-range electron transfer, the new designed electride molecular salts with the excess electron-hole pair exhibit large NLO response. For the e(-)@C20F19-(CH2)4-NH2...Na(+), its large first hyperpolarizability (β0) reaches up to 9.5 × 10(6) au, which is about 2.4 × 10(4) times the 400 au for the relative e(-)@C20F20...Na(+) without the extended chain (CH2)4-NH2. It is shown that the new strategy is considerably efficient in enhancing the NLO response for the salts. In addition, the effects of different bridges and alkali atomic number on β0 are also exhibited. Further, three modulating factors are found for enhancing NLO response. They are the σ chain bridge, bridge-end group with lone pair, and (super)alkali atom. The new knowledge may be significant for designing new NLO materials and electronic devices with electrons inside the cages. They may also be the basis of establishing potential organic chemistry with electron-hole pair.

  17. Vibrational analysis using FT-IR, FT-Raman spectra and HF-DFT methods and NBO, NLO, NMR, HOMO-LUMO, UV and electronic transitions studies on 2,2,4-trimethyl pentane.

    PubMed

    Suvitha, A; Periandy, S; Govindarajan, M; Gayathri, P

    2015-03-05

    In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000cm(-1)and 50-4000cm(-1), respectively, for 2,2,4-Trimethyl Pentane, TMP (C8H18) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree Fock (HF) and density functional theory (DFT) method with 6-311++G(d,p) basis set. The scaled B3LYP/6-311++G(d,p) results shows the best agreement with the experimental values over the other method. The calculated HOMO and LUMO energies shows that charge transfer within the molecule. The physical reactions of single bond hydrocarbon TMP were investigated. The results of the calculations were applied to simulate spectra of the title compound, which shows the excellent agreement with observed spectra. Besides, Mulliken atomic charges, UV, frontier molecular orbital (FMO), MEP, NLO activity, Natural Bond-Orbital (NBO) analysis, NMR and thermodynamic properties of title molecule were also performed. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Vibrational analysis using FT-IR, FT-Raman spectra and HF-DFT methods and NBO, NLO, NMR, HOMO-LUMO, UV and electronic transitions studies on 2,2,4-trimethyl pentane

    NASA Astrophysics Data System (ADS)

    Suvitha, A.; Periandy, S.; Govindarajan, M.; Gayathri, P.

    2015-03-01

    In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000 cm-1and 50-4000 cm-1, respectively, for 2,2,4-Trimethyl Pentane, TMP (C8H18) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree Fock (HF) and density functional theory (DFT) method with 6-311++G(d,p) basis set. The scaled B3LYP/6-311++G(d,p) results shows the best agreement with the experimental values over the other method. The calculated HOMO and LUMO energies shows that charge transfer within the molecule. The physical reactions of single bond hydrocarbon TMP were investigated. The results of the calculations were applied to simulate spectra of the title compound, which shows the excellent agreement with observed spectra. Besides, Mulliken atomic charges, UV, frontier molecular orbital (FMO), MEP, NLO activity, Natural Bond-Orbital (NBO) analysis, NMR and thermodynamic properties of title molecule were also performed.

  19. Vibrational spectroscopic studies, Fukui functions, HOMO-LUMO, NLO, NBO analysis and molecular docking study of (E)-1-(1,3-benzodioxol-5-yl)-4,4-dimethylpent-1-en-3-one, a potential precursor to bioactive agents

    NASA Astrophysics Data System (ADS)

    Al-Wabli, Reem I.; Resmi, K. S.; Sheena Mary, Y.; Yohannan Panicker, C.; Attia, Mohamed I.; El-Emam, Ali A.; Van Alsenoy, C.

    2016-11-01

    The FT-IR and FT-Raman spectra of (E)-1-(1,3-benzodioxol-5-yl)-4,4-dimethylpent-1-en-3-one were recorded and analyzed experimentally and theoretically. The observed experimental and theoretical wavenumbers were assigned using potential energy distribution. The NLO properties were evaluated by the determination of first and second hyperpolarizabilities of the title compound. From the frontier molecular orbital study, the HOMO centers over the entire molecule except the methyl groups, while the LUMO is over the entire molecule except the CH2 group with the dioxole ring and one of the methyl groups. From the MEP plot, it is evident that the negative region covers the carbonyl and Cdbnd C groups and the positive region is over CH2 groups. The Fukui functions are also reported. The calculated geometrical parameters are in agreement with the XRD results. From the molecular docking study, the docked ligand title compound forms a stable complex with the androgen receptor and gives a binding affinity value of -8.1 kcal/mol and the results suggest that the compound might exhibit inhibitory activity against androgen receptor.

  20. Synthesis, characterization, crystal structure and NLO properties of a new mixed crystal potassium sodium ammonium dihydrogenphosphate K0.23Na0.23(NH4)0.54H2PO4

    NASA Astrophysics Data System (ADS)

    Ramasamy, G.; Meenakshisundaram, Subbiah

    2012-08-01

    Potassium sodium ammonium dihydrogenphosphate K0.23Na0.23(NH4)0.54H2PO4 (KSADP), a new mixed crystal has been grown in aqueous medium by the slow evaporation of equimolar mixture of ammonium dihydrogenphosphate (ADP), potassium dihydrogenphosphate (KDP) and sodium dihydrogenphosphate (SDP). Crystal composition as determined by single crystal X-ray diffraction analysis reveals that it belongs to the tetragonal system with noncentrosymmetric space group I-42d and it is structurally similar to ADP with cell parameter values, a=7.4794(4) Å; b=7.4794(4) Å; c=7.2974(11) Å; υ=408.23(7) Å3; z=4. The presence of sodium and potassium in ADP matrix was confirmed by inductively coupled plasma emission spectrometry and energy dispersive X-ray spectroscopy. The partial cationic substitution results in defect centers influencing the physical properties. Slight shifts in vibrational patterns could be attributed to strains in the lattice. Refinement of structure by single crystal XRD analysis reveals that potassium, sodium and ammonium coexist in the mixed crystal. The surface morphology of the as-grown specimen, which is changed as a result of cationic incorporation, was studied by scanning electron microscopy. The relative second harmonic generation (SHG) efficiency measurements revealed that the mixed crystal has a superior NLO activity than ADP.

  1. Spectroscopic (FT-IR, FT-Raman, and UV-visible) and quantum chemical studies on molecular geometry, Frontier molecular orbitals, NBO, NLO and thermodynamic properties of 1-acetylindole.

    PubMed

    Shukla, Vikas K; Al-Abdullah, Ebtehal S; El-Emam, Ali A; Sachan, Alok K; Pathak, Shilendra K; Kumar, Amarendra; Prasad, Onkar; Bishnoi, Abha; Sinha, Leena

    2014-12-10

    Quantum chemical calculations of ground state energy, geometrical structure and vibrational wavenumbers of 1-acetylindole were carried out using density functional (DFT/B3LYP) method with 6-311++G(d,p) basis set. The FT-IR and FT-Raman spectra were recorded in the condensed state. The fundamental vibrational wavenumbers were calculated and a good correlation between experimental and scaled calculated wavenumbers has been accomplished. Electric dipole moment, polarizability and first static hyperpolarizability values of 1-acetylindole have been calculated at the same level of theory and basis set. The results show that the 1-acetylindole molecule possesses nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. UV-Visible spectrum of the molecule was recorded in the region 200-500nm and the electronic properties like HOMO and LUMO energies and composition were obtained using TD-DFT method. The calculated energies and oscillator strengths are in good correspondence with the experimental data. The thermodynamic properties of the compound under investigation were calculated at different temperatures. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Synthesis, crystal structure and NLO property of a nonmetal pentaborate [C{sub 6}H{sub 13}N{sub 2}][B{sub 5}O{sub 6}(OH){sub 4}

    SciTech Connect

    Liu Huanxin; Liang Yunxiao Jiang Xiao

    2008-12-15

    A nonmetal pentaborate [C{sub 6}H{sub 13}N{sub 2}][B{sub 5}O{sub 6}(OH){sub 4}] (1) has been synthesized by 1,4-diazabicyclo[2.2.2] octane (DABCO) and boric acid, and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system with space group Cc (no. 9), a=10.205(2) A, b=14.143(3) A, c=11.003(2) A, {beta}=113.97(3){sup o}, V=1451.1(5) A{sup 3}, Z=4. The anionic units, [B{sub 5}O{sub 6}(OH){sub 4}]{sup -}, are interlinked via hydrogen bonding to form a three-dimensional (3D) supramolecular network containing large channels, in which the protonated [C{sub 6}H{sub 13}N{sub 2}]{sup +} cations are located. Second-harmonic generation (SHG) measurements on the powder samples reveal that 1 exhibits SHG efficiency approximately 0.9 times that of potassium dihydrogen phosphate (KDP). - Graphical abstract: The protonated [C{sub 6}H{sub 13}N{sub 2}]{sup +} cations and the polyanions [B{sub 5}O{sub 6}(OH){sub 4}]{sup -} form a 3D supramolecular network by extensive hydrogen bonds and electrostatic attraction. This compound shows NLO properties and the SHG efficiency is approximately 0.9 times that of KDP.

  3. Synthesis, crystal structure analysis, spectral IR, NMR UV-Vis investigations, NBO and NLO of 2-benzoyl-N-(4-chlorophenyl)-3-oxo-3-phenylpropanamide with use of X-ray diffractions studies along with DFT calculations

    NASA Astrophysics Data System (ADS)

    Demir, Sibel; Sarioğlu, Ahmet Oral; Güler, Semih; Dege, Necmi; Sönmez, Mehmet

    2016-08-01

    The title compound, 2-benzoyl-N-(4-chlorophenyl)-3-oxo-3-phenylpropanamide compound (C22H16NO3Cl) has been synthesized and characterized by X-ray diffraction, IR, 1H and 13C NMR and UV-Vis spectra. Optimized geometrical structure, harmonic vibrational frequencies and chemical shifts were computed using hybrid-DFT (B3LYP and B3PW91) methods and 6-311G(d,p) as the basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The calculated optimized geometries, vibrational frequencies and 1H NMR chemical shift values are in strong agreement with experimentally measured values. UV-Vis spectrum of the title compound, was also recorded and the electronic properties, such as calculated energies, excitation energies, oscillator strengths, dipole moments and frontier orbital energies and band gap energies were computed with TDDFT-B3LYP methodolgy and using 6-311G(d,p) as the basis set. Furthermore, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP), natural bond orbital (NBO) and non linear optical (NLO) properties were performed by using B3LYP/6-311G(d,p) level for the title compound.

  4. Molecular conformational analysis, vibrational spectra, NBO, NLO, HOMO-LUMO and molecular docking studies of ethyl 3-(E)-(anthracen-9-yl)prop-2-enoate based on density functional theory calculations.

    PubMed

    Mary, Y Sheena; Varghese, Hema Tresa; Panicker, C Yohannan; Thiemann, Thies; Al-Saadi, Abdulaziz A; Popoola, Saheed A; Van Alsenoy, C; Al Jasem, Yosef

    2015-11-05

    FT-IR and FT-Raman spectra of ethyl 3-(E)-(anthracen-9-yl)prop-2-enoate were recorded and analyzed. The conformational behavior of the molecule was also investigated. The vibrational wavenumbers were calculated using DFT quantum chemical calculations. The data obtained from the wavenumber calculations were used to assign vibrational bands obtained experimentally. The geometrical parameters are in agreement with XRD data. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis were used to determine the charge transfer within the molecule and quantum chemical parameters related to the title compound. From the MEP analysis, it is clear that the negative electrostatic potential regions are mainly localized over the carbonyl groups and anthracene ring and are possible sites for electrophilic attack and the positive regions are localized at all the hydrogen atoms as possible sites for nucleophilic attack. NLO and NMR studies are also reported. Molecular docking studies suggest that the title compound might exhibit inhibitory activity against IDE and may act as an insulysin inhibitor. Conformational analysis is also reported. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Molecular structure, NLO, MEP, NBO analysis and spectroscopic characterization of 2,5-dimethylanilinium dihydrogen phosphate with experimental (FT-IR and FT-Raman) techniques and DFT calculations.

    PubMed

    Guidara, Sameh; Feki, Habib; Abid, Younes

    2014-12-10

    Single crystals of 2,5-dimethylanilinium dihydrogen phosphate were grown by slow evaporation method at room temperature. The synthesized compound was characterized by powder X-ray diffraction analysis to confirm its crystalline nature. The optimized molecular structure, vibrational spectra and the optical properties were calculated by the density functional theory (DFT) method using the B3LYP function with the 6-31G(d,p) basis set. Theoretical simulation of infrared and Raman spectra led to excellent overall agreement with the observed spectral patterns. The complete assignments of the vibrational spectra were carried out with the aid of potential energy distribution (PED). The stability of the molecule arising from hyperconjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis leading to high nonlinear optical (NLO) activity. The lowering in the HOMO and LUMO energy gap explains the eventual charge transfer interactions that take place within the molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Structural, thermal, laser damage, photoconductivity, NLO and mechanical properties of modified vertical Bridgman method grown AgGa0.5In0.5Se2 single crystal

    NASA Astrophysics Data System (ADS)

    Vijayakumar, P.; Ramasamy, P.

    2016-08-01

    AgGa0.5In0.5Se2 single crystal was grown using modified vertical Bridgman method. The structural perfection of the AgGa0.5In0.5Se2 single crystal has been analyzed by high-resolution X-ray diffraction rocking curve measurements. The structural and compositional uniformities of AgGa0.5In0.5Se2 were studied using Raman scattering spectroscopy at room temperature. The FWHM of the Γ1 (W1) and Γ5L (Γ15) measured at different regions of the crystal confirms that the composition throughout its length is fairly uniform. Thermal properties of the as-grown crystal, including specific heat, thermal diffusivity and thermal conductivity have been investigated. The multiple shot surface laser damage threshold value was measured using Nd:YAG laser. Photoconductivity measurements with different temperatures have confirmed the positive photoconducting behavior. Second harmonic generation (SHG) on powder samples has been measured using the Kurtz and Perry technique and the results display that AgGa0.5In0.5Se2 is a phase-matchable NLO material. The hardness behavior has been measured using Vickers micro hardness measurement and the indentation size effect has been observed. The classical Meyer's law, propositional resistance model and modified propositional resistance model have been used to analyse the micro hardness behavior.

  7. Spectroscopic, DNA binding ability, biological activity, DFT calculations and non linear optical properties (NLO) of novel Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes with ONS Schiff base

    NASA Astrophysics Data System (ADS)

    Abdel Aziz, Ayman A.; Elantabli, Fatma M.; Moustafa, H.; El-Medani, Samir M.

    2017-08-01

    The reaction of Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) with the synthesized N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol Schiff base ligand (H2L) at room temperature resulted in the formation of the five complexes; [Co(HL)2]H2O, 1; [M(HL)2] (M = Cu, Zn and Cd), (2-4) and [Hg(HL)Cl], 5. The ligand and its complexes were characterized based on elemental analyses, IR, 1H NMR, magnetic measurement, molar conductance, and thermal analysis. Coats and Redfern method was used to compute the kinetic and thermodynamic parameters. Antimicrobial activities of H2L and its complexes have been studied. The binding of Co(II), Cu(II) and Zn(II) complexes to calf thymus DNA (CT-DNA) has been investigated using UV-Vis and fluorescence absorption spectra. The results indicated that the ligand and its complexes may bind to DNA by intercalation modes, with a much higher binding affinity of the complexes than that of the ligand. The equilibrium geometries of the studied complexes are investigated theoretically at the B3LYP/LANL2DZ level of theory, and it was found that these geometries are non-linear. The calculated EHOMO and ELUMO energies of the studied complexes can be used to calculate the global properties. The calculated nonlinear optical parameters (NLO); first order hyperpolarizibility (β) of the studied complexes show promising optical properties.

  8. Oxygen evolution reaction catalysis

    DOEpatents

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  9. The Evolution of DEOMI

    DTIC Science & Technology

    2017-09-15

    THE EVOLUTION DE MI DEFENSE EQU AL OPPORTU NITY MANAG EMENT INST ITUTE IDENTITY TITLE: Dr. G · NAME: William Ga ry Mc u1re RACE: White NDER...The Evolution of DEOMI Defense Equal Opportunity Management Institute Research Directorate Written by William Gary McGuire, PhD...organization of NTL gives an accurate (although sketchy) picture of the evolution of laboratory practice both in the varying demands of its changing clientele

  10. Speeding up evolution

    NASA Astrophysics Data System (ADS)

    Hoff, Wouter

    Proteins and cells offer great opportunities for green chemistry and renewable energy. However, few of these possible applications have been put into practice because of details that turn out to be major barriers to cost-efficient implementation and that prove difficult to solve by genetic engineering. A better understanding of molecular evolution promises a novel approach to addressing these important challenges. While major advances have been made, major gaps remain in understanding the evolution of proteins. Different approaches to accelerating molecular evolution into targeted directions will be discussed, including recent progress on evolution in non-homogeneous environments.

  11. Comparative analysis of analytical solutions for F2P(x ,t ) in the DGLAP approach

    NASA Astrophysics Data System (ADS)

    Choudhury, D. K.; Borah, Neelakshi N. K.

    2017-01-01

    Coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations involving singlet quark and gluon distributions are explored by a Taylor expansion at small x as two first-order partial differential equations in two variables: Bjorken x and t (t =l n Q/2Λ2). The system of equations are then solved by Lagrange's method and the method of characteristics. We obtain the proton structure function F2P(x ,t ) by combining the corresponding nonsinglet and singlet structure functions with both methods. Analytical solutions for F2P(x ,t ) thus obtained are compared with the recent data published by the H1 and ZEUS Collaborations as well as with NNPDF3.0 parametrization, and their compatibility is checked. Comparative analysis favors the analytical solution by Lagrange's method; the plausible reasons behind that are also discussed.

  12. Evolution: functional evolution of nuclear structure.

    PubMed

    Wilson, Katherine L; Dawson, Scott C

    2011-10-17

    The evolution of the nucleus, the defining feature of eukaryotic cells, was long shrouded in speculation and mystery. There is now strong evidence that nuclear pore complexes (NPCs) and nuclear membranes coevolved with the endomembrane system, and that the last eukaryotic common ancestor (LECA) had fully functional NPCs. Recent studies have identified many components of the nuclear envelope in living Opisthokonts, the eukaryotic supergroup that includes fungi and metazoan animals. These components include diverse chromatin-binding membrane proteins, and membrane proteins with adhesive lumenal domains that may have contributed to the evolution of nuclear membrane architecture. Further discoveries about the nucleoskeleton suggest that the evolution of nuclear structure was tightly coupled to genome partitioning during mitosis.

  13. Evolution's Erratic Pace

    ERIC Educational Resources Information Center

    Gould, Stephen Jay

    1977-01-01

    Offers an opposing view to Darwin's statement that evolution occurs through gradual change, using fossil species and modes of evolution to lend support to the author's model of "punctuated equilibria," in which... "Lineages change little during most of their history, but events of rapid speciation occasionally punctuate this…

  14. Treatment of Evolution Inconsistent

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2005-01-01

    State standards for academic content vary enormously in how well they cover the topic of evolution, with many of those documents either ignoring or giving scant treatment to the core principles of that established scientific theory. This article presents the analysis of Education Week on state's standards treatment of evolution. Nearly all the…

  15. Self and Evolution.

    ERIC Educational Resources Information Center

    Csikszentmihalyi, Mihaly

    1998-01-01

    Suggests the time has come for humans to direct their own individual evolution and the evolution of the entire species. Argues that ways must be found to encourage individuals, families, and cultures to discover and develop their differentiating characteristics and help these groups integrate with other cultures, customs, and belief systems.…

  16. Treatment of Evolution Inconsistent

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2005-01-01

    State standards for academic content vary enormously in how well they cover the topic of evolution, with many of those documents either ignoring or giving scant treatment to the core principles of that established scientific theory. This article presents the analysis of Education Week on state's standards treatment of evolution. Nearly all the…

  17. Evolution: Theory or Dogma?

    ERIC Educational Resources Information Center

    Mayer, William V.

    In this paper the author examines the question of whether evolution is a theory or a dogma. He refutes the contention that there is a monolithic scientific conspiracy to present evolution as dogma and suggests that his own presentation might be more appropriately entitled "Creationism: Theory or Dogma." (PEB)

  18. Framing Evolution Discussion Intellectually

    ERIC Educational Resources Information Center

    Oliveira, Alandeom W.; Cook, Kristin; Buck, Gayle A.

    2011-01-01

    This study examines how a first-year biology teacher facilitates a series of whole-class discussions about evolution during the implementation of a problem-based unit. A communicative theoretical perspective is adopted wherein evolution discussions are viewed as social events that the teacher can frame intellectually (i.e., present or organize as…

  19. State Standards and Evolution

    ERIC Educational Resources Information Center

    Moore, Randy

    2004-01-01

    Throughout the United States various individuals and groups have tried to subvert science education by removing or weakening the treatment of evolution in state science-education standards. Most states' science-education standards support the teaching of evolution, but many in the general public and some policymakers want science classrooms to…

  20. Evolution of Constructivism

    ERIC Educational Resources Information Center

    Liu, Chu Chih; Chen, I Ju

    2010-01-01

    The contrast between social constructivism and cognitive constructivism are depicted in different ways in many studies. The purpose of this paper is to summarize the evolution of constructivism and put a focus on social constructivism from the perception of Vygotsky. This study provides a general idea of the evolution of constructivism for people…

  1. Evolution & Intelligent Design

    ERIC Educational Resources Information Center

    Staver, John R.

    2003-01-01

    Advocates of Intelligent Design (ID) theory argue that evolution is a theory in crisis, ID is a legitimate scientific theory, and biology teachers should teach the controversy. Supporters of evolutionary theory testify that ID is a religious, not scientific, concept, and evolution is in no danger of bankruptcy, having survived 140 years of…

  2. Framing Evolution Discussion Intellectually

    ERIC Educational Resources Information Center

    Oliveira, Alandeom W.; Cook, Kristin; Buck, Gayle A.

    2011-01-01

    This study examines how a first-year biology teacher facilitates a series of whole-class discussions about evolution during the implementation of a problem-based unit. A communicative theoretical perspective is adopted wherein evolution discussions are viewed as social events that the teacher can frame intellectually (i.e., present or organize as…

  3. Evolution for Young Victorians

    ERIC Educational Resources Information Center

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  4. Thermodynamical Arguments against Evolution

    ERIC Educational Resources Information Center

    Rosenhouse, Jason

    2017-01-01

    The argument that the second law of thermodynamics contradicts the theory of evolution has recently been revived by anti-evolutionists. In its basic form, the argument asserts that whereas evolution implies that there has been an increase in biological complexity over time, the second law, a fundamental principle of physics, shows this to be…

  5. Hydrogen evolution reaction catalyst

    DOEpatents

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  6. Evolution - A Theory Evolving

    ERIC Educational Resources Information Center

    Weinberg, Janet H.

    1975-01-01

    Presented is an explanation of a non-Darwinian theory of evolution based on the premise that functional differences are the result of many small mutations such as the substitution of one amino acid for another in a large protein molecule. A brief overview of Darwinian evolution and other theories are presented. (EB)

  7. The Nature of Evolution

    ERIC Educational Resources Information Center

    Alles, David L.

    2005-01-01

    The nature of evolution, the historical change in the universe, and the change that is caused by the workings of the dynamic processes at the smallest and largest scales are studied. It is viewed that the cumulative change in the historical systems is caused by evolution, which is a type of causal relationship and evolutionary processes could be…

  8. Reconciling Evolution and Creation.

    ERIC Educational Resources Information Center

    Tax, Sol

    1983-01-01

    Proposes a way to reconcile evolution with creationism by hypothesizing that the universe was created when the scientific evidence shows, speculating that this was when God began the series of creations described in Genesis, and assuming that God gave humans intelligence to uncover the methods by which he ordained scientific evolution. (Author/MJL)

  9. Science, Evolution, and Creationism

    ERIC Educational Resources Information Center

    National Academies Press, 2008

    2008-01-01

    How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable. In the book "Science, Evolution, and…

  10. Evolution & Intelligent Design

    ERIC Educational Resources Information Center

    Staver, John R.

    2003-01-01

    Advocates of Intelligent Design (ID) theory argue that evolution is a theory in crisis, ID is a legitimate scientific theory, and biology teachers should teach the controversy. Supporters of evolutionary theory testify that ID is a religious, not scientific, concept, and evolution is in no danger of bankruptcy, having survived 140 years of…

  11. State Standards and Evolution

    ERIC Educational Resources Information Center

    Moore, Randy

    2004-01-01

    Throughout the United States various individuals and groups have tried to subvert science education by removing or weakening the treatment of evolution in state science-education standards. Most states' science-education standards support the teaching of evolution, but many in the general public and some policymakers want science classrooms to…

  12. Evolution Under Attack

    ERIC Educational Resources Information Center

    Muench, David; Newell, Norman D.

    1974-01-01

    The article points out the growing attempts by creationists to have special creation presented with evolution in any educational discussion of the origin of life. The evolution theory is shown to be consistent with known scientific facts while the theory of special creation does not adequately account for these facts. (LS)

  13. Reconciling Evolution and Creation.

    ERIC Educational Resources Information Center

    Tax, Sol

    1983-01-01

    Proposes a way to reconcile evolution with creationism by hypothesizing that the universe was created when the scientific evidence shows, speculating that this was when God began the series of creations described in Genesis, and assuming that God gave humans intelligence to uncover the methods by which he ordained scientific evolution. (Author/MJL)

  14. New Insights into Evolution.

    ERIC Educational Resources Information Center

    Stronck, David R.

    1992-01-01

    Presents insights on the controversial issues regarding evolution. This article partitions into the following sections: (1) Mechanisms explaining how evolution happened; (2) Creationist Confusion; (3) Literal Interpretation of the Bible; (4) Public demand for Creationism; (5) No Basis for Debating; and (6) Scientific Creationism is Bible Study.…

  15. EVOLUTION OF INDIVIDUAL CUMULUS,

    DTIC Science & Technology

    In this paper, the evolution of individual cumulus is studied with basic equations involving the drag effect of water droplets and the phase...the thermal conditions and other properties in the evolution process. It is shown that the drag and phase transformation effects on cloud

  16. Science, Evolution, and Creationism

    ERIC Educational Resources Information Center

    National Academies Press, 2008

    2008-01-01

    How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable. In the book "Science, Evolution, and…

  17. The Nature of Evolution

    ERIC Educational Resources Information Center

    Alles, David L.

    2005-01-01

    The nature of evolution, the historical change in the universe, and the change that is caused by the workings of the dynamic processes at the smallest and largest scales are studied. It is viewed that the cumulative change in the historical systems is caused by evolution, which is a type of causal relationship and evolutionary processes could be…

  18. Evolution's Erratic Pace

    ERIC Educational Resources Information Center

    Gould, Stephen Jay

    1977-01-01

    Offers an opposing view to Darwin's statement that evolution occurs through gradual change, using fossil species and modes of evolution to lend support to the author's model of "punctuated equilibria," in which... "Lineages change little during most of their history, but events of rapid speciation occasionally punctuate this…

  19. Evolution for Young Victorians

    ERIC Educational Resources Information Center

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  20. Organic chemical evolution

    NASA Technical Reports Server (NTRS)

    Chang, S.

    1981-01-01

    The course of organic chemical evolution preceding the emergence of life on earth is discussed based on evidence of processes occurring in interstellar space, the solar system and the primitive earth. Following a brief review of the equilibrium condensation model for the origin and evolution of the solar system, consideration is given to the nature and organic chemistry of interstellar clouds, comets, Jupiter, meteorites, Venus and Mars, and the prebiotic earth. Major issues to be resolved in the study of organic chemical evolution on earth are identified regarding condensation and accretion in the solar nebula, early geological evolution, the origin and evolution of the atmosphere, organic production rates, organic-inorganic interactions, environmental fluctuations, phase separation and molecular selectivity.

  1. TIDEV: Tidal Evolution package

    NASA Astrophysics Data System (ADS)

    Cuartas-Restrepo, P.; Melita, M.; Zuluaga, J.; Portilla, B.; Sucerquia, M.; Miloni, O.

    2016-09-01

    TIDEV (Tidal Evolution package) calculates the evolution of rotation for tidally interacting bodies using Efroimsky-Makarov-Williams (EMW) formalism. The package integrates tidal evolution equations and computes the rotational and dynamical evolution of a planet under tidal and triaxial torques. TIDEV accounts for the perturbative effects due to the presence of the other planets in the system, especially the secular variations of the eccentricity. Bulk parameters include the mass and radius of the planet (and those of the other planets involved in the integration), the size and mass of the host star, the Maxwell time and Andrade's parameter. TIDEV also calculates the time scale that a planet takes to be tidally locked as well as the periods of rotation reached at the end of the spin-orbit evolution.

  2. How Can Evolution Learn?

    PubMed

    Watson, Richard A; Szathmáry, Eörs

    2016-02-01

    The theory of evolution links random variation and selection to incremental adaptation. In a different intellectual domain, learning theory links incremental adaptation (e.g., from positive and/or negative reinforcement) to intelligent behaviour. Specifically, learning theory explains how incremental adaptation can acquire knowledge from past experience and use it to direct future behaviours toward favourable outcomes. Until recently such cognitive learning seemed irrelevant to the 'uninformed' process of evolution. In our opinion, however, new results formally linking evolutionary processes to the principles of learning might provide solutions to several evolutionary puzzles - the evolution of evolvability, the evolution of ecological organisation, and evolutionary transitions in individuality. If so, the ability for evolution to learn might explain how it produces such apparently intelligent designs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Organic chemical evolution

    NASA Technical Reports Server (NTRS)

    Chang, S.

    1981-01-01

    The course of organic chemical evolution preceding the emergence of life on earth is discussed based on evidence of processes occurring in interstellar space, the solar system and the primitive earth. Following a brief review of the equilibrium condensation model for the origin and evolution of the solar system, consideration is given to the nature and organic chemistry of interstellar clouds, comets, Jupiter, meteorites, Venus and Mars, and the prebiotic earth. Major issues to be resolved in the study of organic chemical evolution on earth are identified regarding condensation and accretion in the solar nebula, early geological evolution, the origin and evolution of the atmosphere, organic production rates, organic-inorganic interactions, environmental fluctuations, phase separation and molecular selectivity.

  4. Cultural Evolution and SETI

    NASA Astrophysics Data System (ADS)

    Dick, S. J.

    2009-12-01

    The Drake Equation for the number of radio communicative technological civilizations in the Galaxy encompasses three components of cosmic evolution: astronomical, biological and cultural. Of these three, cultural evolution totally dominates in terms of the rapidity of its effects. Yet, SETI scientists do not take cultural evolution into account, perhaps for understandable reasons, since cultural evolution is not well-understood even on Earth and is unpredictable in its outcome. But the one certainty for technical civilizations billions, millions, or even thousands of years older than ours is that they will have undergone cultural evolution. Cultural evolution potentially takes place in many directions, but this paper argues that its central driving force is the maintenance, improvement and perpetuation of knowledge and intelligence, and that to the extent intelligence can be improved, it will be improved. Applying this principle to life in the universe, extraterrestrials will have sought the best way to improve their intelligence. One possibility is that they may have long ago advanced beyond flesh-and-blood to artificial intelligence, constituting a postbiological universe. Although this subject has been broached, it has not been given the attention it is due from its foundation in cultural evolution. Nor has the idea of a postbiological universe been carried to its logical conclusion, including a careful analysis of the implications for SETI. SETI scientists, social scientists, and experts in AI should consider the strengths and weaknesses of this new paradigm.

  5. The evolution of airplanes

    NASA Astrophysics Data System (ADS)

    Bejan, A.; Charles, J. D.; Lorente, S.

    2014-07-01

    The prevailing view is that we cannot witness biological evolution because it occurred on a time scale immensely greater than our lifetime. Here, we show that we can witness evolution in our lifetime by watching the evolution of the flying human-and-machine species: the airplane. We document this evolution, and we also predict it based on a physics principle: the constructal law. We show that the airplanes must obey theoretical allometric rules that unite them with the birds and other animals. For example, the larger airplanes are faster, more efficient as vehicles, and have greater range. The engine mass is proportional to the body size: this scaling is analogous to animal design, where the mass of the motive organs (muscle, heart, lung) is proportional to the body size. Large or small, airplanes exhibit a proportionality between wing span and fuselage length, and between fuel load and body size. The animal-design counterparts of these features are evident. The view that emerges is that the evolution phenomenon is broader than biological evolution. The evolution of technology, river basins, and animal design is one phenomenon, and it belongs in physics.

  6. Evolution of thymus organogenesis.

    PubMed

    Ge, Qing; Zhao, Yong

    2013-01-01

    The thymus is the primary organ for functional T lymphocyte development in jawed vertebrates. A new study in the jawless fish, lampreys, indicates the existence of a primitive thymus in these surviving representatives of the most ancient vertebrates, providing strong evidence of co-evolution of T cells and thymus. This review summarizes the wealth of data that have been generated towards understanding the evolution of the thymus in the vertebrates. Progress in identifying genetic networks and cellular mechanisms that control thymus organogenesis in mammals and their evolution in lower species may inspire the development of new strategies for medical interventions targeting faulty thymus functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Evolution of biological complexity.

    PubMed

    Adami, C; Ofria, C; Collier, T C

    2000-04-25

    To make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that, because natural selection forces genomes to behave as a natural "Maxwell Demon," within a fixed environment, genomic complexity is forced to increase.

  8. Evolution of biological complexity

    PubMed Central

    Adami, Christoph; Ofria, Charles; Collier, Travis C.

    2000-01-01

    To make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that, because natural selection forces genomes to behave as a natural “Maxwell Demon,” within a fixed environment, genomic complexity is forced to increase. PMID:10781045

  9. Galactic chemical evolution

    NASA Astrophysics Data System (ADS)

    Mollá, M.; Cavichia, O.; da Costa, R.; Gibson, B. K.; Díaz, A. I.

    2017-03-01

    We analyze the evolution of oxygen abundance radial gradients resulting from our chemical evolution models calculated with different prescriptions for the star formation rate (SFR) and for the gas infall rate, in order to assess their respective roles in shaping gradients. We also compare with cosmological simulations and confront all with recent observational datasets, in particular with abundances inferred from planetary nebulae. We demonstrate the critical importance in isolating the specific radial range over which a gradient is measured, in order for their temporal evolution to be useful indicators of disk growth with redshift.

  10. The evolution of vision.

    PubMed

    Gehring, Walter J

    2014-01-01

    In this review, the evolution of vision is retraced from its putative origins in cyanobacteria to humans. Circadian oscillatory clocks, phototropism, and phototaxis require the capability to detect light. Photosensory proteins allow us to reconstruct molecular phylogenetic trees. The evolution of animal eyes leading from an ancestral prototype to highly complex image forming eyes can be deciphered on the basis of evolutionary developmental genetic experiments and comparative genomics. As all bilaterian animals share the same master control gene, Pax6, and the same retinal and pigment cell determination genes, we conclude that the different eye-types originated monophyletically and subsequently diversified by divergent, parallel, or convergent evolution.

  11. Evolution without evolution and without ambiguities

    NASA Astrophysics Data System (ADS)

    Marletto, C.; Vedral, V.

    2017-02-01

    In quantum theory it is possible to explain time, and dynamics, in terms of entanglement. This is the timeless approach to time, which assumes that the universe is in a stationary state, where two noninteracting subsystems, the "clock" and the "rest," are entangled. As a consequence, by choosing a suitable observable of the clock, the relative state of the rest of the universe evolves unitarily with respect to the variable labeling the clock observable's eigenstates, which is then interpreted as time. This model for an "evolution without evolution" (Page and Wootters, 1983), albeit elegant, has never been developed further, because it was criticized for generating severe ambiguities in the dynamics of the rest of the universe. In this paper we show that there are no such ambiguities; we also update the model, making it amenable to possible new applications.

  12. Heredity in Evolution & Evolution of Heredity

    NASA Astrophysics Data System (ADS)

    Rivoire, Olivier

    2015-03-01

    The inheritance of characteristics induced by the environment has often been opposed to the theory of evolution by natural selection. However, although evolution by natural selection requires new heritable traits to be produced and transmitted, it does not prescribe, per se, the mechanisms by which this is operated. The mechanisms of inheritance are not, however, unconstrained, because they are themselves subject to natural selection. We introduce a schematic, analytically solvable mathematical model to compare the adaptive value of different schemes of inheritance. Our model allows for variations to be inherited, randomly produced, or environmentally induced, and, irrespectively, to be either transmitted or not during reproduction. The adaptation of the different schemes for processing variations is quantified for a range of fluctuating environments, following an approach that links quantitative genetics with stochastic control theory.

  13. Evolution of models for evolution. [of life

    NASA Technical Reports Server (NTRS)

    Rohlfing, D. L.

    1974-01-01

    The paper discusses models of evolution and their values, and some critiques of these models and the value of these critiques. A model is investigated which involves the formation of prebiotic protein from amino acids. Its formation by four theoretical critiques that suggest alternative environmental conditions is discussed. Experiments are reviewed so as to illustrate the experimental testing of the possible weaknesses of a model for a single molecular evolutionary phase and to suggest some necessary changes in the model.

  14. Evolution of models for evolution. [of life

    NASA Technical Reports Server (NTRS)

    Rohlfing, D. L.

    1974-01-01

    The paper discusses models of evolution and their values, and some critiques of these models and the value of these critiques. A model is investigated which involves the formation of prebiotic protein from amino acids. Its formation by four theoretical critiques that suggest alternative environmental conditions is discussed. Experiments are reviewed so as to illustrate the experimental testing of the possible weaknesses of a model for a single molecular evolutionary phase and to suggest some necessary changes in the model.

  15. Comment on the paper "Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material" by P.M. Dinakaran, S. Kalainathan [Spectrochim. Acta A 111 (2013) 123-130].

    PubMed

    Srinivasan, Bikshandarkoil R; Dhuri, Sunder N; Nadkarni, V S

    2014-01-03

    We argue that (trans)-4-chloro-4'-nitrostilbene is not a new organic nonlinear optical material as claimed by Dinakaran and Kalainathan [P.M. Dinakaran, S. Kalainathan, Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-Chloro 4-Nitrostilbene (CONS): a potential NLO material, Spectrochim. Acta A 111 (2013) 123-130], but instead a well-known compound whose synthesis, spectral data, single crystal structure and second harmonic generation (SHG) efficiency are well documented in the literature. The title paper is completely erroneous. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Co-Evolution.

    ERIC Educational Resources Information Center

    McGhee, Robert

    2002-01-01

    Discusses the role of techniques of DNA analysis in assessing the genetic relationships between various species. Focuses on wolf-dog evolution using DNA evidence and historical data about human/wolf-dog relationships. (DDR)

  17. Stochasticity in evolution.

    PubMed

    Lenormand, Thomas; Roze, Denis; Rousset, François

    2009-03-01

    The debate over the role of stochasticity is central in evolutionary biology, often summarised by whether or not evolution is predictable or repeatable. Here we distinguish three types of stochasticity: stochasticity of mutation and variation, of individual life histories and of environmental change. We then explain when stochasticity matters in evolution, distinguishing four broad situations: stochasticity contributes to maladaptation or limits adaptation; it drives evolution on flat fitness landscapes (evolutionary freedom); it might promote jumps from one fitness peak to another (evolutionary revolutions); and it might shape the selection pressures themselves. We show that stochasticity, by directly steering evolution, has become an essential ingredient of evolutionary theory beyond the classical Wright-Fisher or neutralist-selectionist debates.

  18. Experimental evolution gone wild.

    PubMed

    Scheinin, M; Riebesell, U; Rynearson, T A; Lohbeck, K T; Collins, S

    2015-05-06

    Because of their large population sizes and rapid cell division rates, marine microbes have, or can generate, ample variation to fuel evolution over a few weeks or months, and subsequently have the potential to evolve in response to global change. Here we measure evolution in the marine diatom Skeletonema marinoi evolved in a natural plankton community in CO2-enriched mesocosms deployed in situ. Mesocosm enclosures are typically used to study how the species composition and biogeochemistry of marine communities respond to environmental shifts, but have not been used for experimental evolution to date. Using this approach, we detect a large evolutionary response to CO2 enrichment in a focal marine diatom, where population growth rate increased by 1.3-fold in high CO2-evolved lineages. This study opens an exciting new possibility of carrying out in situ evolution experiments to understand how marine microbial communities evolve in response to environmental change.

  19. The evolution of galaxies

    NASA Technical Reports Server (NTRS)

    Gunn, J. E.

    1982-01-01

    The recent observational evidence on the evolution of galaxies is reviewed and related to the framework of current ideas for galaxy formation from primordial density fluctuations. Recent strong evidence for the evolution of the stellar population in ellipticals is presented, as well as evidence that not all ellipticals behave as predicted by any simple theory. The status of counts of faint galaxies and the implications for the evolution of spirals is discussed, together with a discussion of recent work on the redshift distribution of galaxies at faint magnitudes and a spectroscopic investigation of the Butcher-Oemler blue cluster galaxies. Finally a new picture for the formation and evolution of disk galaxies which may explain most of the features of the Hubble sequence is outlined.

  20. Co-Evolution.

    ERIC Educational Resources Information Center

    McGhee, Robert

    2002-01-01

    Discusses the role of techniques of DNA analysis in assessing the genetic relationships between various species. Focuses on wolf-dog evolution using DNA evidence and historical data about human/wolf-dog relationships. (DDR)

  1. Evolution of oncolytic viruses.

    PubMed

    Sanjuán, Rafael; Grdzelishvili, Valery Z

    2015-08-01

    Owing to their replicative capacity, oncolytic viruses (OVs) can evolve under the action of natural selection. Reversion to virulence and recombination with wild-type strains may compromise OV safety, therefore requiring evolutionary risk assessment studies. On the other hand, evolution can be directed in the laboratory to create more potent and safer OVs. Previous work in the experimental evolution field provides a background for OV directed evolution, and has identified interesting exploitable features. While genetic engineering has greatly advanced the field of oncolytic virotherapy, this approach is sometimes curtailed by the complexity and diversity of virus-host interactions. Directed evolution provides an alternative approach that may help to obtain new OVs without prejudice toward the underlying molecular mechanisms involved. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Evolution: Always New

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2005-01-01

    The changes in the evolution due to changes in science are explored. These changes are frustrating to paleontologists, especially when they are trying to date a singular event, like a cataclysm that precipitated a mass extinction.

  3. Experimental evolution gone wild

    PubMed Central

    Scheinin, M.; Riebesell, U.; Rynearson, T. A.; Lohbeck, K. T.; Collins, S.

    2015-01-01

    Because of their large population sizes and rapid cell division rates, marine microbes have, or can generate, ample variation to fuel evolution over a few weeks or months, and subsequently have the potential to evolve in response to global change. Here we measure evolution in the marine diatom Skeletonema marinoi evolved in a natural plankton community in CO2-enriched mesocosms deployed in situ. Mesocosm enclosures are typically used to study how the species composition and biogeochemistry of marine communities respond to environmental shifts, but have not been used for experimental evolution to date. Using this approach, we detect a large evolutionary response to CO2 enrichment in a focal marine diatom, where population growth rate increased by 1.3-fold in high CO2-evolved lineages. This study opens an exciting new possibility of carrying out in situ evolution experiments to understand how marine microbial communities evolve in response to environmental change. PMID:25833241

  4. Evolution, epigenetics and cooperation.

    PubMed

    Bateson, Patrick

    2014-04-01

    Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

  5. Stellar evolution. VI.

    NASA Technical Reports Server (NTRS)

    Iben, I., Jr.

    1967-01-01

    Evolution of low mass Population I stars from main sequence to red giant branch in Hertzsprung- Russell diagram, through energy generation phases of p-p chain reactions /dominating over C-N cycle reactions/ and hydrogen burning

  6. Baculovirus phylogeny and evolution.

    PubMed

    Herniou, Elisabeth A; Jehle, Johannes A

    2007-10-01

    The family Baculoviridae represents one of the largest and most diverse groups of viruses and a unique model for studying the forces driving the evolution and biodiversity of double-stranded DNA viruses with large genomes. With the advent of comparative genomics, the phylogenetic relationships of baculoviruses have been put on solid bases. This, as well as improved bioinformatic approaches, has provided a detailed picture of baculovirus phylogeny and evolution. According to the present knowledge, baculoviruses can be classified into at least four evolutionary lineages: the most ancestral dipteran nucleopolyhedroviruses, the hymenopteran nucleopolyhedroviruses and the lepidopteran nucleopolyhedroviruses and granuloviruses. Despite the growing understanding of baculovirus phylogeny and macro-evolution, our knowledge of the micro-evolutionary processes within baculovirus species and virus populations is still limited. Here we present the state of the art on baculovirus phylogeny and evolution.

  7. Grand Views of Evolution.

    PubMed

    de Vladar, Harold P; Santos, Mauro; Szathmáry, Eörs

    2017-05-01

    Despite major advances in evolutionary theories, some aspects of evolution remain neglected: whether evolution: would come to a halt without abiotic change; is unbounded and open-ended; or is progressive and something beyond fitness is maximized. Here, we discuss some models of ecology and evolution and argue that ecological change, resulting in Red Queen dynamics, facilitates (but does not ensure) innovation. We distinguish three forms of open-endedness. In weak open-endedness, novel phenotypes can occur indefinitely. Strong open-endedness requires the continual appearance of evolutionary novelties and/or innovations. Ultimate open-endedness entails an indefinite increase in complexity, which requires unlimited heredity. Open-ended innovation needs exaptations that generate novel niches. This can result in new traits and new rules as the dynamics unfolds, suggesting that evolution is not fully algorithmic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Physical Principles of Evolution

    NASA Astrophysics Data System (ADS)

    Schuster, Peter

    Theoretical biology is incomplete without a comprehensive theory of evolution, since evolution is at the core of biological thought. Evolution is visualized as a migration process in genotype or sequence space that is either an adaptive walk driven by some fitness gradient or a random walk in the absence of (sufficiently large) fitness differences. The Darwinian concept of natural selection consisting in the interplay of variation and selection is based on a dichotomy: All variations occur on genotypes whereas selection operates on phenotypes, and relations between genotypes and phenotypes, as encapsulated in a mapping from genotype space into phenotype space, are central to an understanding of evolution. Fitness is conceived as a function of the phenotype, represented by a second mapping from phenotype space into nonnegative real numbers. In the biology of organisms, genotype-phenotype maps are enormously complex and relevant information on them is exceedingly scarce. The situation is better in the case of viruses but so far only one example of a genotype-phenotype map, the mapping of RNA sequences into RNA secondary structures, has been investigated in sufficient detail. It provides direct information on RNA selection in vitro and test-tube evolution, and it is a basis for testing in silico evolution on a realistic fitness landscape. Most of the modeling efforts in theoretical and mathematical biology today are done by means of differential equations but stochastic effects are of undeniably great importance for evolution. Population sizes are much smaller than the numbers of genotypes constituting sequence space. Every mutant, after all, has to begin with a single copy. Evolution can be modeled by a chemical master equation, which (in principle) can be approximated by a stochastic differential equation. In addition, simulation tools are available that compute trajectories for master equations. The accessible population sizes in the range of 10^7le Nle 10

  9. Manipulation of quantum evolution

    NASA Technical Reports Server (NTRS)

    Cabera, David Jose Fernandez; Mielnik, Bogdan

    1994-01-01

    The free evolution of a non-relativistic charged particle is manipulated using time-dependent magnetic fields. It is shown that the application of a programmed sequence of magnetic pulses can invert the free evolution process, forcing an arbitrary wave packet to 'go back in time' to recover its past shape. The possibility of more general operations upon the Schrodinger wave packet is discussed.

  10. Population genetics and evolution

    SciTech Connect

    De Jong, G.

    1988-01-01

    This volume reevaluates the position of population genetics in evolutionary biology by using population genetics as the tool to study the role of development and adaptation in evolution. The emphasis is on the organismic process of selection, and on how the study of selection means connecting variation at the molecular, biochemical, and phenotypic levels of organization with the resulting variation in fitness. This book illustrates that the tendency to view single locus differences in isolation as the building blocks of evolution is disappearing.

  11. Topology of viral evolution.

    PubMed

    Chan, Joseph Minhow; Carlsson, Gunnar; Rabadan, Raul

    2013-11-12

    The tree structure is currently the accepted paradigm to represent evolutionary relationships between organisms, species or other taxa. However, horizontal, or reticulate, genomic exchanges are pervasive in nature and confound characterization of phylogenetic trees. Drawing from algebraic topology, we present a unique evolutionary framework that comprehensively captures both clonal and reticulate evolution. We show that whereas clonal evolution can be summarized as a tree, reticulate evolution exhibits nontrivial topology of dimension greater than zero. Our method effectively characterizes clonal evolution, reassortment, and recombination in RNA viruses. Beyond detecting reticulate evolution, we succinctly recapitulate the history of complex genetic exchanges involving more than two parental strains, such as the triple reassortment of H7N9 avian influenza and the formation of circulating HIV-1 recombinants. In addition, we identify recurrent, large-scale patterns of reticulate evolution, including frequent PB2-PB1-PA-NP cosegregation during avian influenza reassortment. Finally, we bound the rate of reticulate events (i.e., 20 reassortments per year in avian influenza). Our method provides an evolutionary perspective that not only captures reticulate events precluding phylogeny, but also indicates the evolutionary scales where phylogenetic inference could be accurate.

  12. Energy and Evolution

    NASA Astrophysics Data System (ADS)

    Porter, George

    I have called my lecture Energy and Evolution, and that embraces Physics and Biology. I suppose that what I have in mind are the great things that have happened in the last 135 years since Charles Darwin; and the great problems that we have in this field today. In 1859 Charles Darwin wrote history on a grand scale and he gave mankind an intellectual shock which changed our concept of ourselves and our place in the world. Rather suddenly we have come to realize that the process of natural evolution which he described and which has served the world for three billion years may be about to cease or least to change in a profound way. The Darwinian changes of evolution occurred slowly, unnoticed by participants who had very little to say about the forms that their descendants would take. They merely flocked to survive and if they survived they had one privilege only and that was the privilege of handing on their genes. The situation has changed drastically in the last few years. One species, man now so dominates the earth that it is in his part to eliminate most of the other species if he so wishes. Those who do survive do so only because man finds them interesting and useful and he is busy with the natural evolution even of these. It is the end of the evolution, as Darwin knew it. Far greater powers to play God will soon be in our hands. Genetic Engineering will enable us to eliminate conquered genes and other unfavorable genetic information and even to change the nature of mankind. We may not wish to do this but it will become possible. What we see happening is a rapid transfer of responsibility for the future evolution into the hands of ourselves, the hands of one species, homosapiens. We are no longer pawns in the game of evolution. We are not even the kings and queens, we are the players.

  13. Creationism, Evolution, and Science Education

    SciTech Connect

    Scott, Eugenie C.

    2005-06-22

    Many topics in the curriculum of American schools are controversial, but perhaps the one with the longest tenure is evolution. Three arguments are made against evolution: that it is allegedly weak science ('evolution is a theory in crisis'); that it is incompatible with religion; and that it is only 'fair' to 'balance' evolution with creationism. Regardless of the appropriateness of their application to science education, all three of the arguments are made to try to restrict the teaching of evolution. Variants of the fairness argument such as balancing evolution with 'scientific alternatives to evolution' or balancing evolution with 'arguments against evolution' have in fact become the current predominant antievolutionist strategy. Current events in the creationism/evolution controversy will be reviewed, and suggestions made for how to promote sound science education in the schools.

  14. The evolution of language

    PubMed Central

    Nowak, Martin A.; Krakauer, David C.

    1999-01-01

    The emergence of language was a defining moment in the evolution of modern humans. It was an innovation that changed radically the character of human society. Here, we provide an approach to language evolution based on evolutionary game theory. We explore the ways in which protolanguages can evolve in a nonlinguistic society and how specific signals can become associated with specific objects. We assume that early in the evolution of language, errors in signaling and perception would be common. We model the probability of misunderstanding a signal and show that this limits the number of objects that can be described by a protolanguage. This “error limit” is not overcome by employing more sounds but by combining a small set of more easily distinguishable sounds into words. The process of “word formation” enables a language to encode an essentially unlimited number of objects. Next, we analyze how words can be combined into sentences and specify the conditions for the evolution of very simple grammatical rules. We argue that grammar originated as a simplified rule system that evolved by natural selection to reduce mistakes in communication. Our theory provides a systematic approach for thinking about the origin and evolution of human language. PMID:10393942

  15. The Evolution of Language

    NASA Astrophysics Data System (ADS)

    Nowak, Martin A.; Krakauer, David C.

    1999-07-01

    The emergence of language was a defining moment in the evolution of modern humans. It was an innovation that changed radically the character of human society. Here, we provide an approach to language evolution based on evolutionary game theory. We explore the ways in which protolanguages can evolve in a nonlinguistic society and how specific signals can become associated with specific objects. We assume that early in the evolution of language, errors in signaling and perception would be common. We model the probability of misunderstanding a signal and show that this limits the number of objects that can be described by a protolanguage. This "error limit" is not overcome by employing more sounds but by combining a small set of more easily distinguishable sounds into words. The process of "word formation" enables a language to encode an essentially unlimited number of objects. Next, we analyze how words can be combined into sentences and specify the conditions for the evolution of very simple grammatical rules. We argue that grammar originated as a simplified rule system that evolved by natural selection to reduce mistakes in communication. Our theory provides a systematic approach for thinking about the origin and evolution of human language.

  16. Workshop on Molecular Evolution

    NASA Technical Reports Server (NTRS)

    Cummings, Michael P.

    2004-01-01

    Molecular evolution has become the nexus of many areas of biological research. It both brings together and enriches such areas as biochemistry, molecular biology, microbiology, population genetics, systematics, developmental biology, genomics, bioinformatics, in vitro evolution, and molecular ecology. The Workshop provides an important contribution to these fields in that it promotes interdisciplinary research and interaction, and thus provides a glue that sticks together disparate fields. Due to the wide range of fields addressed by the study of molecular evolution, it is difficult to offer a comprehensive course in a university setting. It is rare for a single institution to maintain expertise in all necessary areas. In contrast, the Workshop is uniquely able to provide necessary breadth and depth by utilizing a large number of faculty with appropriate expertise. Furthermore, the flexible nature of the Workshop allows for rapid adaptation to changes in the dynamic field of molecular evolution. For example, the 2003 Workshop included recently emergent research areas of molecular evolution of development and genomics.

  17. Study of HERA e p data at low Q2 and low xBj and the need for higher-twist corrections to standard perturbative QCD fits

    NASA Astrophysics Data System (ADS)

    Abt, I.; Cooper-Sarkar, A. M.; Foster, B.; Myronenko, V.; Wichmann, K.; Wing, M.

    2016-08-01

    A detailed comparison of HERA data at low Bjorken-x and low four-momentum-transfer squared, Q2, with predictions based on ln Q2 evolution (DGLAP) in perturbative quantum chromodynamics suggests inadequacies of this framework. The standard DGLAP evolution was augmented by including an additional higher-twist term in the description of the longitudinal structure function, FL. This additional term, FLALHT/Q2 , improves the description of the reduced cross sections significantly. The resulting predictions for FL suggest that further corrections are required for Q2 less than about 2 GeV2 .

  18. Evolution and Christian Faith

    NASA Astrophysics Data System (ADS)

    Roughgarden, J. E.

    2006-12-01

    My recent book, Evolution and Christian Faith explores how evolutionary biology can be portrayed from the religious perspective of Christianity. The principal metaphors for evolutionary biology---differential success at breeding and random mutation, probably originate with the dawn of agriculture and clearly occur in the Bible. The central narrative of evolutionary biology can be presented using Biblical passages, providing an account of evolution that is inherently friendly to a Christian perspective. Still, evolutionary biology is far from complete, and problematic areas pertain to species in which the concept of an individual is poorly defined, and to species in which the expression of gender and sexuality depart from Darwin's sexual-selection templates. The present- day controversy in the US about teaching evolution in the schools provides an opportunity to engage the public about science education.

  19. B-chromosome evolution.

    PubMed Central

    Camacho, J P; Sharbel, T F; Beukeboom, L W

    2000-01-01

    B chromosomes are extra chromosomes to the standard complement that occur in many organisms. They can originate in a number of ways including derivation from autosomes and sex chromosomes in intra- and interspecies crosses. Their subsequent molecular evolution resembles that of univalent sex chromosomes, which involves gene silencing, heterochromatinization and the accumulation of repetitive DNA and transposons. B-chromosome frequencies in populations result from a balance between their transmission rates and their effects on host fitness. Their long-term evolution is considered to be the outcome of selection on the host genome to eliminate B chromosomes or suppress their effects and on the B chromosome's ability to escape through the generation of new variants. Because B chromosomes interact with the standard chromosomes, they can play an important role in genome evolution and may be useful for studying molecular evolutionary processes. PMID:10724453

  20. Experimental evolution of multicellularity

    PubMed Central

    Ratcliff, William C.; Denison, R. Ford; Borrello, Mark; Travisano, Michael

    2012-01-01

    Multicellularity was one of the most significant innovations in the history of life, but its initial evolution remains poorly understood. Using experimental evolution, we show that key steps in this transition could have occurred quickly. We subjected the unicellular yeast Saccharomyces cerevisiae to an environment in which we expected multicellularity to be adaptive. We observed the rapid evolution of clustering genotypes that display a novel multicellular life history characterized by reproduction via multicellular propagules, a juvenile phase, and determinate growth. The multicellular clusters are uniclonal, minimizing within-cluster genetic conflicts of interest. Simple among-cell division of labor rapidly evolved. Early multicellular strains were composed of physiologically similar cells, but these subsequently evolved higher rates of programmed cell death (apoptosis), an adaptation that increases propagule production. These results show that key aspects of multicellular complexity, a subject of central importance to biology, can readily evolve from unicellular eukaryotes. PMID:22307617

  1. Dust evolution from comets

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1977-01-01

    The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of the evolution of cometary dust. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tails is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

  2. Dust evolution from comets

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1976-01-01

    The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of evolution. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tail is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

  3. Ethics, evolution and culture.

    PubMed

    Mesoudi, Alex; Danielson, Peter

    2008-08-01

    Recent work in the fields of evolutionary ethics and moral psychology appears to be converging on a single empirically- and evolutionary-based science of morality or ethics. To date, however, these fields have failed to provide an adequate conceptualisation of how culture affects the content and distribution of moral norms. This is particularly important for a large class of moral norms relating to rapidly changing technological or social environments, such as norms regarding the acceptability of genetically modified organisms. Here we suggest that a science of morality/ethics can benefit from adopting a cultural evolution or gene-culture coevolution approach, which treats culture as a second, separate evolutionary system that acts in parallel to biological/genetic evolution. This cultural evolution approach brings with it a set of established theoretical concepts (e.g. different cultural transmission mechanisms) and empirical methods (e.g. evolutionary game theory) that can significantly improve our understanding of human morality.

  4. Characterizing gene family evolution

    PubMed Central

    Liberles, David A.

    2008-01-01

    Gene families are widely used in comparative genomics, molecular evolution, and in systematics. However, they are constructed in different manners, their data analyzed and interpreted differently, with different underlying assumptions, leading to sometimes divergent conclusions. In systematics, concepts like monophyly and the dichotomy between homoplasy and homology have been central to the analysis of phylogenies. We critique the traditional use of such concepts as applied to gene families and give examples of incorrect inferences they may lead to. Operational definitions that have emerged within functional genomics are contrasted with the common formal definitions derived from systematics. Lastly, we question the utility of layers of homology and the meaning of homology at the character state level in the context of sequence evolution. From this, we move forward to present an idealized strategy for characterizing gene family evolution for both systematic and functional purposes, including recent methodological improvements. PMID:19461954

  5. QCD Evolution 2016

    NASA Astrophysics Data System (ADS)

    The QCD Evolution 2016 workshop was held at the National Institute for Subatomic Physics (Nikhef) in Amsterdam, May 30 - June 3, 2016. The workshop is a continuation of a series of workshops held during five consecutive years, in 2011, 2012, 2013, 2015 at Jefferson Lab, and in 2014 in Santa Fe, NM. With the rapid developments in our understanding of the evolution of parton distributions including low-x, TMDs, GPDs, higher-twist correlation functions, and the associated progress in perturbative QCD, lattice QCD and effective field theory techniques, we look forward to yet another exciting meeting in 2016. The program of QCD Evolution 2016 will pay special attention to the topics of importance for ongoing experiments, in the full range from Jefferson Lab energies to LHC energies or future experiments such as a future Electron Ion Collider, recently recommended as a highest priority in U.S. Department of Energy's 2015 Long Range Plan for Nuclear Science.

  6. Computational evolution: taking liberties.

    PubMed

    Correia, Luís

    2010-09-01

    Evolution has, for a long time, inspired computer scientists to produce computer models mimicking its behavior. Evolutionary algorithm (EA) is one of the areas where this approach has flourished. EAs have been used to model and study evolution, but they have been especially developed for their aptitude as optimization tools for engineering. Developed models are quite simple in comparison with their natural sources of inspiration. However, since EAs run on computers, we have the freedom, especially in optimization models, to test approaches both realistic and outright speculative, from the biological point of view. In this article, we discuss different common evolutionary algorithm models, and then present some alternatives of interest. These include biologically inspired models, such as co-evolution and, in particular, symbiogenetics and outright artificial operators and representations. In each case, the advantages of the modifications to the standard model are identified. The other area of computational evolution, which has allowed us to study basic principles of evolution and ecology dynamics, is the development of artificial life platforms for open-ended evolution of artificial organisms. With these platforms, biologists can test theories by directly manipulating individuals and operators, observing the resulting effects in a realistic way. An overview of the most prominent of such environments is also presented. If instead of artificial platforms we use the real world for evolving artificial life, then we are dealing with evolutionary robotics (ERs). A brief description of this area is presented, analyzing its relations to biology. Finally, we present the conclusions and identify future research avenues in the frontier of computation and biology. Hopefully, this will help to draw the attention of more biologists and computer scientists to the benefits of such interdisciplinary research.

  7. Bulk growth of undoped and Nd3+ doped zinc thiourea chloride (ZTC) monocrystal: Exploring the remarkably enhanced structural, optical, electrical and mechanical performance of Nd3+ doped ZTC crystal for NLO device applications

    NASA Astrophysics Data System (ADS)

    Anis, Mohd; Muley, Gajanan. G.

    2017-05-01

    In current scenario good quality crystals are demanded for NLO device application hence present communication is aimed to grow bulk crystal and investigate the doping effect of rare earth element Nd3+ on structural, linear-nonlinear optical, luminescence, mechanical and dielectric properties of zinc thiourea chloride (ZTC) crystal. The ZTC crystal of dimension 21×10×8 mm3 and the Nd3+ doped ZTC crystal of dimension 27×17×5 mm3 have been grown from aqueous solution by slow evaporation technique. The elemental analysis of Nd3+ doped ZTC single crystal has been performed by means of energy dispersive spectroscopic technique. The powder X-ray diffraction technique has been employed to confirm the crystalline phase and identify the effect of Nd3+ doping on structural dimensions of ZTC crystal. The grown crystals have been characterized by UV-Vis-NIR study in the range of 190-1100 nm to ascertain the enhancement in optical transparency of ZTC crystal facilitated by dopant Nd3+. The recorded transmittance data has been utilized to investigate the vital optical constants of grown crystals. The second order nonlinear optical behavior of grown crystals has been evaluated by means of Kurtz-Perry test and the second harmonic generation efficiency of Nd3+ doped ZTC crystal is found to be 1.24 times higher than ZTC crystal. The luminescence analysis has been performed to examine the electronic purity and the color centered photoluminescence emission nature of pure and Nd3+ doped ZTC crystals. The influence of Nd3+ ion on mechanical behavior of ZTC crystal has been investigated by means of microhardness studies. The nature of dielectric constant and dielectric loss of pure and Nd3+ doped ZTC crystal has been examined in the range of 40-100 °C under dielectric study. The Z-scan technique has been employed using the He-Ne laser to investigate the third order nonlinear optical (TONLO) nature of Nd3+ doped ZTC single crystal. The magnitude of TONLO susceptibility, absorption

  8. Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO) studies on pyrrole-isonicotinyl hydrazine

    NASA Astrophysics Data System (ADS)

    Rawat, Poonam; Singh, R. N.; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

    2017-05-01

    As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7 kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, 1H NMR, 13C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π → π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89 × 10- 30 esu, (gas phase); 68.79 × 10- 30 (CHCl3), esu; 76.76 × 10- 30 esu (CH2Cl2), 85.16 × 10- 30 esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram

  9. Some thoughts on evolution.

    PubMed

    Conyers, R A; Fazzalari, N L

    1980-01-01

    The sparsity of transitional forms and the abrupt appearance of higher taxa in the fossil record are enigmas for the neo-Darwinian theory of evolution. If the cell is considered to be a steady state system then mutations affecting non-regulatory proteins will have far less effect on the steady state than mutations affecting regulatory proteins. This latter type of mutation, when expressed in multicellular biological systems, is a sufficient explanation for the discontinuities observed between species. Such a mechanism, however, has its own implications for any theory of evolution.

  10. On quasar evolution.

    NASA Technical Reports Server (NTRS)

    Cavaliere, A.; Morrison, P.; Wood, K.

    1971-01-01

    We examine the consequences for quasar statistics of a class of models describing the evolution of individual strong sources. The continuity equation for the change of density and luminosity with cosmological epoch determines the population, once a model for the evolution of an individual object is chosen. A dynamical model of spinning objects seems to agree satisfactorily with the present observational sample, both in density and in luminosity function; such a model requires that an individual object strongly brightens as time goes on. A genetic relationship between quasars and radio galaxies which qualitatively fits the observations is suggested by the model.

  11. Macrothermodynamics of Biological Evolution:

    NASA Astrophysics Data System (ADS)

    Gladyshev, Georgi P.

    The author sets forth general considerations pertaining to the thermodynamic theory of biological evolution and the aging of living organisms. It becomes much easier to comprehend the phenomenon of life scrutinizing the formation of structural hierarchies of biological matter applying different temporal scales. These scales are 'identified' by nature itself, and this is reflected in the law of temporal hierarchies. The author discusses some misunderstandings in thermodynamics and evolutionary biology. A simple physicochemical model of biological evolution and the development of living beings is proposed. The considered theory makes it possible to use physicochemical evaluations to develop effective anti-aging diets.

  12. Calibrating bacterial evolution

    PubMed Central

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A.

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal application to all bacteria. However, there is evidence that bacteria have a constant genome-wide mutation rate on an evolutionary time scale but that this rate differs dramatically from the rate estimated by experimental methods. PMID:10535975

  13. [Biological evolution and specialization].

    PubMed

    Luo, Weizhen; Wang, Deli

    2003-12-01

    There were some disputes about the concept and mechanism of biological evolution. This paper tried to give more explanations on the key concepts. The biological adaptability was distinguished into two different concepts: biological evolution and specialization. The former was defined as the process of biologically gradual evolvement, and the latter was considered as the process of species formation at horizontal development. Moreover, a new conceptual framework was applied to the popular biological theories known by people, and the previous research results or discoveries were explained over again.

  14. Evolution and social epidemiology.

    PubMed

    Nishi, Akihiro

    2015-11-01

    Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Evolution of proteins.

    NASA Technical Reports Server (NTRS)

    Dayhoff, M. O.

    1971-01-01

    The amino acid sequences of proteins from living organisms are dealt with. The structure of proteins is first discussed; the variation in this structure from one biological group to another is illustrated by the first halves of the sequences of cytochrome c, and a phylogenetic tree is derived from the cytochrome c data. The relative geological times associated with the events of this tree are discussed. Errors which occur in the duplication of cells during the evolutionary process are examined. Particular attention is given to evolution of mutant proteins, globins, ferredoxin, and transfer ribonucleic acids (tRNA's). Finally, a general outline of biological evolution is presented.

  16. Software evolution. What kind of evolution?

    NASA Astrophysics Data System (ADS)

    Torres-Carbonell, J. J.; Parets-Llorca, J.

    2001-06-01

    Most Software Systems capable of adapting to the environment or of performing some kind of adaptive activity (such as pattern learning, behavior simulations and the like) use concepts and models from Biology. Nevertheless, such approaches are based on the Modern Synthesis, i.e., Darwinism plus Mendelism, and this implies preadaptive mutations in, and subsequent selection of the better adapted individuals. These pre-adaptive changes usually do not produce the desired effect, are virtually useless and require some kind of backtracking for the system to obtain profit from adaptation. It is our contention that an evolutionary approach in Software Systems development cannot be based on pre-adaptive mutations, but rather on post-adaptive ones, that is, anticipatory mutations and modifications (Lamarkism). A novel way of understanding evolution in Software Systems based on applied Lamarkism is presented and a framework that allows the incorporation of modifications according to the necessities of the system and the will of the modeller is proposed.

  17. The Evolution of Empathy

    ERIC Educational Resources Information Center

    Hackney, Harold

    1978-01-01

    Therapeutic empathy has been an often-used construct by counseling professionals. Through that usage, the term has evolved in meaning and significance from its original presentation by Carl Rogers. This article traces that evolution by identifying its users and contributors over the past 20 years. (Author)

  18. Technologies for ECLSS Evolution

    NASA Technical Reports Server (NTRS)

    Diamant, Bryce L.

    1990-01-01

    Viewgraphs and discussion on technologies for Environmental Control and Life Support System (ECLSS) evolution are presented. Topics covered include: atmosphere revitalization including CO2 removal, CO2 reduction, O2 generation, and trace contaminant control; water recovery and management including urine processing, hygiene water processing, and potable water processing; and waste management. ECLSS technology schematics, process diagrams, and fluid interfaces are included.

  19. The Evolution of Darwinism.

    ERIC Educational Resources Information Center

    Stebbins, G. Ledyard; Ayala, Francisco J.

    1985-01-01

    Recent developments in molecular biology and new interpretations of the fossil record are gradually altering and adding to Charles Darwin's theory, which has been the standard view of the process of evolution for 40 years. Several of these developments and interpretations are identified and discussed. (JN)

  20. Darwinism: Evolution or Revolution?

    ERIC Educational Resources Information Center

    Holt, Niles R.

    1989-01-01

    Maintains that Darwin's theory of evolution was more than a science versus religion debate; rather it was a revolutionary concept that influenced numerous social and political ideologies and movements throughout western history. Traces the impact of Darwin's work historically, utilizing a holistic approach. (RW)

  1. Tectonic Evolution of Mars

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.

    1992-01-01

    The Final Technical Report on tectonic evolution of Mars is presented. Two papers and an abstract are included. Topics addressed include: scientific rationale and requirements for a global seismic network on Mars, permanent uplift in magmatic systems with application to the Tharsis Region of Mars, and the geophysical signal of the Martian global dichotomy.

  2. Darwinism: Evolution or Revolution?

    ERIC Educational Resources Information Center

    Holt, Niles R.

    1989-01-01

    Maintains that Darwin's theory of evolution was more than a science versus religion debate; rather it was a revolutionary concept that influenced numerous social and political ideologies and movements throughout western history. Traces the impact of Darwin's work historically, utilizing a holistic approach. (RW)

  3. Evolution of Osmolyte Systems.

    ERIC Educational Resources Information Center

    Banfalvi, Gaspar

    1991-01-01

    Osmotic aspects of aqueous solutions that are usually disregarded in biochemistry textbooks are presented. This article discusses the osmolarity of seawater, evolution of organisms over geological time, ionic adaptation of cells, ionic concentrations in bacteria, osmolytes and blood electrolytes in water-stressed organisms and land vertebrates,…

  4. The Evolution of Behavior.

    ERIC Educational Resources Information Center

    Smith, John Maynard

    1978-01-01

    The topic of altruistic behavior is an important one in studying the evolution of behavior. It is questioned whether natural selection can actually favor patterns of behavior that apparently do not favor the survival of the individual. Game theory models are presented to help explore the problem. (MA)

  5. Cluster Physics & Evolution

    NASA Astrophysics Data System (ADS)

    Nagai, Daisuke; Arnaud, Monique; Dasadia, Sarthak; McDonald, Michael; Mitsuishi, Ikuyuki; Morandi, Andrea

    Recent advances in X-ray and microwave observations have provided unprecedented insights into the structure and evolution of the hot X-ray emitting plasma from their cores to the virialization region in outskirts of galaxy clusters. Recent Sunyaev-Zel'dovich (SZ) surveys (ACT, Planck, SPT) have provided new cluster catalogs, significantly expanding coverage of the mass-redshift plane, while Chandra and XMM-Newton X-ray follow-up programs have improved our understanding of cluster physics and evolution as well as the surveys themselves. However, the current cluster-based cosmological constraints are still limited by uncertainties in cluster astrophysics. In order to exploit the statistical power of the current and upcoming X-ray and microwave cluster surveys, it is critical to improve our understanding of the structure and evolution of the hot X-ray emitting intracluster medium (ICM). In this session, we discussed recent advances in observations and simulations of galaxy clusters, with highlights on (i) the evolution of ICM profiles and scaling relations, (ii) physical processes operating in the outskirts of galaxy clusters, and (iii) impact of mergers on the ICM structure in groups and clusters.

  6. Evolution in Action

    ERIC Educational Resources Information Center

    Dennis, Mike; Duggan, Adrienne; McGregor, Deb

    2014-01-01

    Evolution and inheritance appear in the new National Science Curriculum for England, which comes into effect from September 2014. In the curriculum documents, it is expected that pupils in year 6 (ages 10-11) should be taught to: (1) recognise that living things have changed over time; (2) recognise that living things produce offspring of the same…

  7. Evolution. Teacher's Guide.

    ERIC Educational Resources Information Center

    Bershad, Carol

    This teacher's guide was developed to assist teachers in the use of multimedia resources for the Public Broadcasting System (PBS) program, "Evolution." Each unit uses an inquiry-based approach to meet the National Science Education Standards. Units include: (1) "What is the Nature of Science?"; (2) "Who Was Charles Darwin?"; (3) "What is the…

  8. The Evolution of Darwinism.

    ERIC Educational Resources Information Center

    Stebbins, G. Ledyard; Ayala, Francisco J.

    1985-01-01

    Recent developments in molecular biology and new interpretations of the fossil record are gradually altering and adding to Charles Darwin's theory, which has been the standard view of the process of evolution for 40 years. Several of these developments and interpretations are identified and discussed. (JN)

  9. Human Development, Human Evolution.

    ERIC Educational Resources Information Center

    Smillie, David

    One of the truly remarkable events in human evolution is the unprecedented increase in the size of the brain of "Homo" over a brief span of 2 million years. It would appear that some significant selective pressure or opportunity presented itself to this branch of the hominid line and caused a rapid increase in the brain, introducing a…

  10. Evolution Projects Yield Results

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2010-01-01

    When a federal court in 2005 rejected an attempt by the Dover, Pennsylvania, school board to introduce intelligent design as an alternative to evolution to explain the development of life on Earth, it sparked a renaissance in involvement among scientists in K-12 science instruction. Now, some of those teaching programs, studies, and research…

  11. The timetable of evolution

    PubMed Central

    Knoll, Andrew H.; Nowak, Martin A.

    2017-01-01

    The integration of fossils, phylogeny, and geochronology has resulted in an increasingly well-resolved timetable of evolution. Life appears to have taken root before the earliest known minimally metamorphosed sedimentary rocks were deposited, but for a billion years or more, evolution played out beneath an essentially anoxic atmosphere. Oxygen concentrations in the atmosphere and surface oceans first rose in the Great Oxygenation Event (GOE) 2.4 billion years ago, and a second increase beginning in the later Neoproterozoic Era [Neoproterozoic Oxygenation Event (NOE)] established the redox profile of modern oceans. The GOE facilitated the emergence of eukaryotes, whereas the NOE is associated with large and complex multicellular organisms. Thus, the GOE and NOE are fundamental pacemakers for evolution. On the time scale of Earth’s entire 4 billion–year history, the evolutionary dynamics of the planet’s biosphere appears to be fast, and the pace of evolution is largely determined by physical changes of the planet. However, in Phanerozoic ecosystems, interactions between new functions enabled by the accumulation of characters in a complex regulatory environment and changing biological components of effective environments appear to have an important influence on the timing of evolutionary innovations. On the much shorter time scale of transient environmental perturbations, such as those associated with mass extinctions, rates of genetic accommodation may have been limiting for life. PMID:28560344

  12. The Evolution of Cooperation.

    ERIC Educational Resources Information Center

    Dugatkin, Lee Alan

    1997-01-01

    Outlines the four paths to the evolution and maintenance of cooperative behavior and provides two stories highlighting each path. Discusses reciprocity, byproduct mutualism, kin-selected cooperation, and group-selected cooperation. Presents some thoughts on where the study of animal cooperation might head in the future. Contains 67 references.…

  13. Evolution of lifespan.

    PubMed

    Neill, David

    2014-10-07

    Present-day evolutionary theory, modern synthesis and evo-devo, appear to explain evolution. There remain however several points of contention. These include: biological time, direction, macroevolution verses microevolution, ageing and the extent of internal as opposed to external mediation. A new theoretical model for the control of biological time in vertebrates/bilaterians is introduced. Rather than biological time being controlled solely by a molecular cascade domino effect, it is suggested there is also an intracellular oscillatory clock. This clock (life's timekeeper) is synchronised across all cells in an organism and runs at a constant frequency throughout life. Slower frequencies extend lifespan, increase body/brain size and advance behaviour. They also create a time void which could aid additional evolutionary change. Faster frequencies shorten lifespan, reduce body/brain size and diminish behaviour. They are therefore less likely to mediate evolution in vertebrates/mammals. It is concluded that in vertebrates, especially mammals, there is a direction in evolution towards longer lifespan/advanced behaviour. Lifespan extension could equate with macroevolution and subsequent modifications with microevolution. As life's timekeeper controls the rate of ageing it constitutes a new genetic theory of ageing. Finally, as lifespan extension is internally mediated, this suggests a major role for internal mediation in evolution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Evolution and Flow.

    ERIC Educational Resources Information Center

    Csikszentmihalyi, Mihaly

    1997-01-01

    Presents flow theory in the context of evolution. Defines the elements of "flow" and contends that flow results in an optimal state of inner harmony which improves one's chance for survival. Identifies consequences of flow for creativity, peak performance, talent development, productivity, self-esteem, and stress reduction. Examines the…

  15. Evolution Perception with Metaphors

    ERIC Educational Resources Information Center

    Yilmaz, Fatih

    2016-01-01

    The main objective of this research is to find out how the teacher candidates who graduated from the Faculty of Theology and study in pedagogical formation program perceive the theory of evolution. Having a descriptive characteristic, this research is conducted with 63 Faculty of Theology graduate teacher candidates of which 36 is women and 27 is…

  16. Voices for Evolution.

    ERIC Educational Resources Information Center

    McCollister, Betty, Ed.

    The creation/evolution controversy can be best thought of as a contest over control of a portion of educational policy. Scientists do not dispute the right of fundamentalist Christians to believe that Genesis is a history and a science textbook. The difficulty arises when fundamentalists seek to bring their sectarian religious faith into biology…

  17. Evolution and Friendship

    ERIC Educational Resources Information Center

    Mena-Werth, Jose

    2005-01-01

    In 1925, Williams Jennings Bryan, a former congressman from Nebraska and a former Secretary of State under Woodrow Wilson, spent two agonizing weeks defending his religious faith that cost him his life a month after. Bryan was a prosecutor of high school teacher John Scopes, who had violated Tennessee state law by teaching the theory of evolution.…

  18. Crustal Evolution Introduced.

    ERIC Educational Resources Information Center

    Stoever, Edward C., Jr.; Korporaal, Arie R.

    1979-01-01

    Detailed are the origins, development, and implementation of the Crustal Evolution Education Project (CEEP). This group has produced, for use in earth science and other classes in grades 8-10, a series of instructional modules based on current scientific research in the composition, history, and processes of the earth's crust. (BT)

  19. Collection Evaluation and Evolution

    NASA Technical Reports Server (NTRS)

    Habermann, Ted; Kozimor, John

    2017-01-01

    We will review metadata evaluation tools and share results from our most recent CMR analysis. We will demonstrate results using Google spreadsheets and present new results in terms of number of records that include specific content. We will show evolution of UMM-compliance over time and also show results of comparing various CMR collections (NASA, non-NASA, and SciOps).

  20. Software Architecture Evolution

    ERIC Educational Resources Information Center

    Barnes, Jeffrey M.

    2013-01-01

    Many software systems eventually undergo changes to their basic architectural structure. Such changes may be prompted by new feature requests, new quality attribute requirements, changing technology, or other reasons. Whatever the causes, architecture evolution is commonplace in real-world software projects. Today's software architects, however,…

  1. Evolution: Sex Limits Adaptation.

    PubMed

    Nosil, Patrik

    2015-07-20

    Evolution is affected by survival of individuals and by mate choice, but how sexual selection affects adaptation remains unclear. A new study finds that sexual selection can limit adaptation by causing male-induced harm to females and thus opposing natural selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Early cellular evolution.

    NASA Technical Reports Server (NTRS)

    Margulis, L.

    1972-01-01

    Study of the evolutionary developments that occurred subsequent to the origin of ancestral cells. Microbial physiology and ecology are potential sharp tools for shaping concepts of microbial evolution. Some popular unjustified assumptions are discussed. It is considered that certain principles derived mainly from the advances of molecular biology can be used to order the natural groups (genera) of extant prokaryotes and their patterns phylogenetically.

  3. The timetable of evolution.

    PubMed

    Knoll, Andrew H; Nowak, Martin A

    2017-05-01

    The integration of fossils, phylogeny, and geochronology has resulted in an increasingly well-resolved timetable of evolution. Life appears to have taken root before the earliest known minimally metamorphosed sedimentary rocks were deposited, but for a billion years or more, evolution played out beneath an essentially anoxic atmosphere. Oxygen concentrations in the atmosphere and surface oceans first rose in the Great Oxygenation Event (GOE) 2.4 billion years ago, and a second increase beginning in the later Neoproterozoic Era [Neoproterozoic Oxygenation Event (NOE)] established the redox profile of modern oceans. The GOE facilitated the emergence of eukaryotes, whereas the NOE is associated with large and complex multicellular organisms. Thus, the GOE and NOE are fundamental pacemakers for evolution. On the time scale of Earth's entire 4 billion-year history, the evolutionary dynamics of the planet's biosphere appears to be fast, and the pace of evolution is largely determined by physical changes of the planet. However, in Phanerozoic ecosystems, interactions between new functions enabled by the accumulation of characters in a complex regulatory environment and changing biological components of effective environments appear to have an important influence on the timing of evolutionary innovations. On the much shorter time scale of transient environmental perturbations, such as those associated with mass extinctions, rates of genetic accommodation may have been limiting for life.

  4. Human Development, Human Evolution.

    ERIC Educational Resources Information Center

    Smillie, David

    One of the truly remarkable events in human evolution is the unprecedented increase in the size of the brain of "Homo" over a brief span of 2 million years. It would appear that some significant selective pressure or opportunity presented itself to this branch of the hominid line and caused a rapid increase in the brain, introducing a…

  5. Decentralized Software Evolution

    DTIC Science & Technology

    2003-09-01

    Institute for Software Research University of California, Irvine www.isr.uci.edu/tech-reports.html Peyman Oreizy University of California, Irvine... Peyman Oreizy and Richard N. Taylor Institute for Software Research University of California, Irvine Irvine, CA 92697-3425 USA {peymano, taylor...mechanisms that enforce cooperation among Decentralized Software Evolution Peyman Oreizy and Richard N. Taylor Institute for Software Research

  6. Evolution: Skipping School

    PubMed Central

    Bell, Alison M.

    2014-01-01

    Some individual fish like to be close together in ‘schools’, while other individuals like to be alone. A pair of recent papers dissects the genetic basis of schooling behavior, showing that genetic changes in sensory systems are involved when this social behavior is lost during evolution. PMID:24112981

  7. Evolution Projects Yield Results

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2010-01-01

    When a federal court in 2005 rejected an attempt by the Dover, Pennsylvania, school board to introduce intelligent design as an alternative to evolution to explain the development of life on Earth, it sparked a renaissance in involvement among scientists in K-12 science instruction. Now, some of those teaching programs, studies, and research…

  8. Early cellular evolution.

    NASA Technical Reports Server (NTRS)

    Margulis, L.

    1972-01-01

    Study of the evolutionary developments that occurred subsequent to the origin of ancestral cells. Microbial physiology and ecology are potential sharp tools for shaping concepts of microbial evolution. Some popular unjustified assumptions are discussed. It is considered that certain principles derived mainly from the advances of molecular biology can be used to order the natural groups (genera) of extant prokaryotes and their patterns phylogenetically.

  9. Evolution of Osmolyte Systems.

    ERIC Educational Resources Information Center

    Banfalvi, Gaspar

    1991-01-01

    Osmotic aspects of aqueous solutions that are usually disregarded in biochemistry textbooks are presented. This article discusses the osmolarity of seawater, evolution of organisms over geological time, ionic adaptation of cells, ionic concentrations in bacteria, osmolytes and blood electrolytes in water-stressed organisms and land vertebrates,…

  10. The Evolution of Empathy

    ERIC Educational Resources Information Center

    Hackney, Harold

    1978-01-01

    Therapeutic empathy has been an often-used construct by counseling professionals. Through that usage, the term has evolved in meaning and significance from its original presentation by Carl Rogers. This article traces that evolution by identifying its users and contributors over the past 20 years. (Author)

  11. Evolution and Friendship

    ERIC Educational Resources Information Center

    Mena-Werth, Jose

    2005-01-01

    In 1925, Williams Jennings Bryan, a former congressman from Nebraska and a former Secretary of State under Woodrow Wilson, spent two agonizing weeks defending his religious faith that cost him his life a month after. Bryan was a prosecutor of high school teacher John Scopes, who had violated Tennessee state law by teaching the theory of evolution.…

  12. Evolution and the Law

    ERIC Educational Resources Information Center

    Mayer, William V.

    1973-01-01

    Some court cases and legislative bills have been filed in states to legalize the use of the creationist view (of life forms on earth) in biology textbooks superseding the organic theory of evolution. The law has not yet accepted the religious viewpoint. (PS)

  13. Evolution in Action

    ERIC Educational Resources Information Center

    Dennis, Mike; Duggan, Adrienne; McGregor, Deb

    2014-01-01

    Evolution and inheritance appear in the new National Science Curriculum for England, which comes into effect from September 2014. In the curriculum documents, it is expected that pupils in year 6 (ages 10-11) should be taught to: (1) recognise that living things have changed over time; (2) recognise that living things produce offspring of the same…

  14. Evolution and Religion

    ERIC Educational Resources Information Center

    Strickberger, Monroe W.

    1973-01-01

    The relationship between the two concepts (evolution, religion) from an historical and social view is discussed. The concepts are seen to respond differently to the various needs of society, with considerable conflict between them in areas which involve the justification of religious beliefs. (Author/EB)

  15. Titan Polar Landscape Evolution

    NASA Technical Reports Server (NTRS)

    Moore, Jeffrey M.

    2016-01-01

    With the ongoing Cassini-era observations and studies of Titan it is clear that the intensity and distribution of surface processes (particularly fluvial erosion by methane and Aeolian transport) has changed through time. Currently however, alternate hypotheses substantially differ among specific scenarios with respect to the effects of atmospheric evolution, seasonal changes, and endogenic processes. We have studied the evolution of Titan's polar region through a combination of analysis of imaging, elevation data, and geomorphic mapping, spatially explicit simulations of landform evolution, and quantitative comparison of the simulated landscapes with corresponding Titan morphology. We have quantitatively evaluated alternate scenarios for the landform evolution of Titan's polar terrain. The investigations have been guided by recent geomorphic mapping and topographic characterization of the polar regions that are used to frame hypotheses of process interactions, which have been evaluated using simulation modeling. Topographic information about Titan's polar region is be based on SAR-Topography and altimetry archived on PDS, SAR-based stereo radar-grammetry, radar-sounding lake depth measurements, and superposition relationships between geomorphologic map units, which we will use to create a generalized topographic map.

  16. Software Architecture Evolution

    ERIC Educational Resources Information Center

    Barnes, Jeffrey M.

    2013-01-01

    Many software systems eventually undergo changes to their basic architectural structure. Such changes may be prompted by new feature requests, new quality attribute requirements, changing technology, or other reasons. Whatever the causes, architecture evolution is commonplace in real-world software projects. Today's software architects, however,…

  17. Glossogeny and phylogeny: cultural evolution meets genetic evolution.

    PubMed

    Fitch, W Tecumseh

    2008-08-01

    Evolutionary theorists since Darwin have been interested in the parallels and interactions between biological and cultural evolution. Recent applications of empirical techniques originally developed to analyze molecular genetic data to linguistic data offer new insights into the historical evolution of language, revealing fascinating parallels between language change and biological evolution. This work offers considerable potential toward unified theories of genetic and cultural change.

  18. Evolution as Fact and Theory.

    ERIC Educational Resources Information Center

    Gould, Stephen Jay

    1981-01-01

    This essay by a Harvard evolutionist presents viewpoints concerning the creationists' arguments against evolutionary biology. Semantics regarding "facts" and "theory" of evolution are examined, examples are cited of creationist argument, and arguments for evolution are presented. (CS)

  19. Viral Evolution Core | FNLCR Staging

    Cancer.gov

    Brandon F. Keele, Ph.D. PI/Senior Principal Investigator, Retroviral Evolution Section Head, Viral Evolution Core Leidos Biomedical Research, Inc. Frederick National Laboratory for Cancer Research Frederick, MD 21702-1201 Tel: 301-846-173

  20. "New" Persuasive Evidence for Evolution.

    ERIC Educational Resources Information Center

    Max, Edward E.

    1998-01-01

    Discusses some new evidence for evolution that might be useful in persuading students who question the scientific basis for evolution. Draws on findings from the fields of molecular biology and genetics. (DDR)

  1. Evolution as Fact and Theory.

    ERIC Educational Resources Information Center

    Gould, Stephen Jay

    1981-01-01

    This essay by a Harvard evolutionist presents viewpoints concerning the creationists' arguments against evolutionary biology. Semantics regarding "facts" and "theory" of evolution are examined, examples are cited of creationist argument, and arguments for evolution are presented. (CS)

  2. Evolution of Brain and Language

    ERIC Educational Resources Information Center

    Schoenemann, P. Thomas

    2009-01-01

    The evolution of language and the evolution of the brain are tightly interlinked. Language evolution represents a special kind of adaptation, in part because language is a complex behavior (as opposed to a physical feature) but also because changes are adaptive only to the extent that they increase either one's understanding of others, or one's…

  3. Evolution of Brain and Language

    ERIC Educational Resources Information Center

    Schoenemann, P. Thomas

    2009-01-01

    The evolution of language and the evolution of the brain are tightly interlinked. Language evolution represents a special kind of adaptation, in part because language is a complex behavior (as opposed to a physical feature) but also because changes are adaptive only to the extent that they increase either one's understanding of others, or one's…

  4. Expanding the Understanding of Evolution

    ERIC Educational Resources Information Center

    Musante, Susan

    2011-01-01

    Originally designed for K-12 teachers, the Understanding Evolution (UE) Web site ("www.understandingevolution.org") is a one-stop shop for all of a teacher's evolution education needs, with lesson plans, teaching tips, lists of common evolution misconceptions, and much more. However, during the past five years, the UE project team learned that…

  5. Expanding the Understanding of Evolution

    ERIC Educational Resources Information Center

    Musante, Susan

    2011-01-01

    Originally designed for K-12 teachers, the Understanding Evolution (UE) Web site ("www.understandingevolution.org") is a one-stop shop for all of a teacher's evolution education needs, with lesson plans, teaching tips, lists of common evolution misconceptions, and much more. However, during the past five years, the UE project team learned that…

  6. Type Evolution and Instance Adaptation

    DTIC Science & Technology

    1992-06-01

    Schema evolution support is an important facility for object-oriented database (OODB) systems. While existing OODB systems provide for limited forms...of evolution , including modification to the database schema and reorganization of affected instances, we find their support insufficient. Specific... evolution of class definitions and the adaptation of existing, persistent instances to those new definitions.

  7. Fla. Panel's Evolution Vote Hailed

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2008-01-01

    This article reports on how the compromise hammered out in Florida recently over the treatment of evolution in the state's science classrooms is winning praise from scientists and educators. The new science standards will refer to evolution as the "scientific theory of evolution." These changes will replace more-general language in the…

  8. The evolution of helicopters

    NASA Astrophysics Data System (ADS)

    Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

    2016-07-01

    Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

  9. Kamikazes and cultural evolution.

    PubMed

    Allen-Hermanson, Sean

    2017-02-01

    Is cultural evolution needed to explain altruistic selfsacrifice? Some contend that cultural traits (e.g. beliefs, behaviors, and for some "memes") replicate according to selection processes that have "floated free" from biology. One test case is the example of suicide kamikaze attacks in wartime Japan. Standard biological mechanisms-such as reciprocal altruism and kin selection-might not seem to apply here: The suicide pilots did not act on the expectation that others would reciprocate, and they were supposedly sacrificing themselves for country and emperor, not close relatives. Yet an examination of both the historical record and the demands of evolutionary theory suggest the kamikaze phenomenon does not cry out for explanation in terms of a special non-biological selection process. This weakens the case for cultural evolution, and has interesting implications for our understanding of altruistic self-sacrifice.

  10. The metaphysics of evolution

    PubMed Central

    2017-01-01

    This paper briefly describes process metaphysics, and argues that it is better suited for describing life than the more standard thing, or substance, metaphysics. It then explores the implications of process metaphysics for conceptualizing evolution. After explaining what it is for an organism to be a process, the paper takes up the Hull/Ghiselin thesis of species as individuals and explores the conditions under which a species or lineage could constitute an individual process. It is argued that only sexual species satisfy these conditions, and that within sexual species the degree of organization varies. This, in turn, has important implications for species' evolvability. One important moral is that evolution will work differently in different biological domains. PMID:28839921

  11. The metaphysics of evolution.

    PubMed

    Dupré, John

    2017-10-06

    This paper briefly describes process metaphysics, and argues that it is better suited for describing life than the more standard thing, or substance, metaphysics. It then explores the implications of process metaphysics for conceptualizing evolution. After explaining what it is for an organism to be a process, the paper takes up the Hull/Ghiselin thesis of species as individuals and explores the conditions under which a species or lineage could constitute an individual process. It is argued that only sexual species satisfy these conditions, and that within sexual species the degree of organization varies. This, in turn, has important implications for species' evolvability. One important moral is that evolution will work differently in different biological domains.

  12. Anatomy of Scientific Evolution

    PubMed Central

    Yun, Jinhyuk; Kim, Pan-Jun; Jeong, Hawoong

    2015-01-01

    The quest for historically impactful science and technology provides invaluable insight into the innovation dynamics of human society, yet many studies are limited to qualitative and small-scale approaches. Here, we investigate scientific evolution through systematic analysis of a massive corpus of digitized English texts between 1800 and 2008. Our analysis reveals great predictability for long-prevailing scientific concepts based on the levels of their prior usage. Interestingly, once a threshold of early adoption rates is passed even slightly, scientific concepts can exhibit sudden leaps in their eventual lifetimes. We developed a mechanistic model to account for such results, indicating that slowly-but-commonly adopted science and technology surprisingly tend to have higher innate strength than fast-and-commonly adopted ones. The model prediction for disciplines other than science was also well verified. Our approach sheds light on unbiased and quantitative analysis of scientific evolution in society, and may provide a useful basis for policy-making. PMID:25671617

  13. Thermal evolution of Venus

    NASA Technical Reports Server (NTRS)

    Arkani-Hamed, J.; Toksoz, M. N.

    1984-01-01

    A modification of the Boussinesq fluid assumption is the basis of the present theory of three-dimensional and finite amplitude convection in a viscous spherical shell with temperature- and pressure-dependent physical parameters. The theory is applied to the definition of thermal evolution models for Venus which emphasize the effects of certain physical parameters on thermal evolution, rather than the specific thermal history of the planet. It is suggested that a significant portion of the present temperature in the mantle and surface heat flux of Venus is due to the decay of a high temperature that was established in the planet at the completion of its core formation, and that Venus has been highly convective over the course of its history, until about 0.5 Ga ago.

  14. Evolution of intrafamilial interactions.

    PubMed Central

    Lynch, M

    1987-01-01

    A theory for the evolution of behavioral interactions among relatives is developed that allows for genetic correlations between the types of behavior that are expressed in different social contexts. Both theoretical and empirical considerations indicate that such genetic constraints will almost certainly be common in natural populations. It is shown that when genetic correlations between elements of social behavior exist, Hamilton's rule inaccurately describes the conditions for evolution by way of kin selection. The direction in which social organization evolves is a delicate function of the genetic covariance structure among behaviors expressed as an offspring, sibling, parent, etc. A change in this covariance structure caused by random genetic drift or by a change in environment for a population exhibiting genotype-environment interaction can cause the population to suddenly cross a threshold into a new selective domain. Consequently, radical changes in social organization may arise between closely related species without any major shift in selective pressures external to the population. Images PMID:3479804

  15. Epigenetics and brain evolution.

    PubMed

    Keverne, Eric B

    2011-04-01

    Fundamental aspects of mammalian brain evolution occurred in the context of viviparity and placentation brought about by the epigenetic regulation of imprinted genes. Since the fetal placenta hormonally primes the maternal brain, two genomes in one individual are transgenerationally co-adapted to ensure maternal care and nurturing. Advanced aspects of neocortical brain evolution has shown very few genetic changes between monkeys and humans. Although these lineages diverged at approximately the same time as the rat and mouse (20 million years ago), synonymous sequence divergence between the rat and mouse is double that when comparing monkey with human sequences. Paradoxically, encephalization of rat and mouse are remarkably similar, while comparison of the human and monkey shows the human cortex to be three times the size of the monkey. This suggests an element of genetic stability between the brains of monkey and man with a greater emphasis on epigenetics providing adaptable variability.

  16. Algorithms, games, and evolution

    PubMed Central

    Chastain, Erick; Livnat, Adi; Papadimitriou, Christos; Vazirani, Umesh

    2014-01-01

    Even the most seasoned students of evolution, starting with Darwin himself, have occasionally expressed amazement that the mechanism of natural selection has produced the whole of Life as we see it around us. There is a computational way to articulate the same amazement: “What algorithm could possibly achieve all this in a mere three and a half billion years?” In this paper we propose an answer: We demonstrate that in the regime of weak selection, the standard equations of population genetics describing natural selection in the presence of sex become identical to those of a repeated game between genes played according to multiplicative weight updates (MWUA), an algorithm known in computer science to be surprisingly powerful and versatile. MWUA maximizes a tradeoff between cumulative performance and entropy, which suggests a new view on the maintenance of diversity in evolution. PMID:24979793

  17. QCD Evolution 2015

    NASA Astrophysics Data System (ADS)

    These are the proceedings of the QCD Evolution 2015 Workshop which was held 26-30 May, 2015 at Jefferson Lab, Newport News, Virginia, USA. The workshop is a continuation of a series of workshops held during four consecutive years 2011, 2012, 2013 at Jefferson Lab, and in 2014 in Santa Fe, NM. With the rapid developments in our understanding of the evolution of parton distributions including low-x, TMDs, GPDs, higher-twist correlation functions, and the associated progress in perturbative QCD, lattice QCD and effective field theory techniques we look forward with great enthusiasm to the 2015 meeting. A special attention was also paid to participation of experimentalists as the topics discussed are of immediate importance for the JLab 12 experimental program and a future Electron Ion Collider.

  18. Evolution of catalytic function

    NASA Technical Reports Server (NTRS)

    Joyce, G. F.

    1993-01-01

    An RNA-based evolution system was constructed in the laboratory and used to develop RNA enzymes with novel catalytic function. By controlling the nature of the catalytic task that the molecules must perform in order to survive, it is possible to direct the evolving population toward the expression of some desired catalytic behavior. More recently, this system has been coupled to an in vitro translation procedure, raising the possibility of evolving protein enzymes in the laboratory to produce novel proteins with desired catalytic properties. The aim of this line of research is to reduce darwinian evolution, the fundamental process of biology, to a laboratory procedure that can be made to operate in the service of organic synthesis.

  19. Evolution of catalytic function

    NASA Technical Reports Server (NTRS)

    Joyce, G. F.

    1993-01-01

    An RNA-based evolution system was constructed in the laboratory and used to develop RNA enzymes with novel catalytic function. By controlling the nature of the catalytic task that the molecules must perform in order to survive, it is possible to direct the evolving population toward the expression of some desired catalytic behavior. More recently, this system has been coupled to an in vitro translation procedure, raising the possibility of evolving protein enzymes in the laboratory to produce novel proteins with desired catalytic properties. The aim of this line of research is to reduce darwinian evolution, the fundamental process of biology, to a laboratory procedure that can be made to operate in the service of organic synthesis.

  20. Evolution of mycorrhiza systems

    NASA Astrophysics Data System (ADS)

    Cairney, J. W. G.

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200million years ago) and ericoid mycorrhizas (about 100million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change.