WorldWideScience

Sample records for non-platinum sequential triplet

  1. Novel non-platinum metal catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel non-platinum metal catalyst material for use in low temperature fuel cells and electrolysers and to fuel cells and electrolysers comprising the novel non-platinum metal catalyst material. The present invention also relates to a novel method for synthesizing...... the novel non-platinum metal catalyst material....

  2. WC as a non-platinum hydrogen evolution electrocatalyst for high temperature PEM water electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    2012-01-01

    Tungsten carbide (WC) nanopowder was tested as a non-platinum cathode electrocatalyst for polymer electrolyte membrane (PEM) water electrolysers, operating at elevated temperatures. It was prepared in thermal plasma reactor with confined plasma jet from WO3 precursor in combination with CH4...... carburizing agent. The results of the investigation showed that the activity of tungsten carbide as cathode electrocatalyst increases significantly with temperature and this effect is more pronounced than for platinum, especially, at 150 °C....

  3. Theoretical studies on membranes and non-platinum catalysts for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ushiyama, Hiroshi [Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan ushiyama@chemsys.t.u-tokyo.ac.jp (Japan)

    2015-12-31

    Mechanism of proton transfer among high-density acid groups in the interface between organic and inorganic materials for polymer electrolyte fuel cells has been theoretically examined. It has been clearly shown that the interactions between the phosphate groups at the surface of the inorganic material, zirconium phosphate (ZrP), and the adsorbed water molecules are relatively large and a strong hydrogen-bond network is generated locally. Because of the strong interactions, water molecules can be attached to ZrP and the O–O distance becomes shorter than that in bulk water systems. Because of the short O–O distances and the delocalized charge of each atom, the activation energy of proton transfer at the ZrP surface decreases and causes high proton conductivity even under conditions of high temperature and low humidity. Based on the above studies, the origin of the high proton conductivity of hybrid electrolytes is also discussed. We will also discuss the mechanism of oxygen reduction reaction on non-platinum catalysts such as Ta{sub 3}N{sub 5}.

  4. Triplet losses in dye lasers

    Energy Technology Data Exchange (ETDEWEB)

    Baczynski, A.; Kossakowski, A.; Marszalek, T. (Uniwersytet Mikolaja Kopernika, Torun (Poland). Instytut Fizyki)

    1977-01-01

    The expression for losses due to triplet states in dye laser considered as a six-level system is given. It is shown that triplet losses depend on pumping parameters and photon number. Depending on molecular and cavity parameters two differe types of behavior of dye lasers are expected. Physical conditions are discussed in which triplet losses as well as photon number undergo a jump at the threshold.

  5. [Comparison of the effectiveness of platinum-based chemotherapy versus non-platinum-based chemotherapy for triple-negative breast cancer with metastases confined to the lungs].

    Science.gov (United States)

    Hong, Ruoxi; Ma, Fei; Shi, Xiuqing; Li, Qing; Zhang, Pin; Yuan, Peng; Wang, Jiayu; Fan, Ying; Cai, Ruigang; Li, Qiao; Xu, Binghe

    2014-10-01

    To compare the effect of first-line treatment with platinum-based chemotherapy and non-platinum-based chemotherapy in patients with lung metastases from triple negative breast cancer (TNBC). Sixty-five eligible patients were divided into platinum-treated group and non-platinum-treated group according to the first-line therapy. Factors predicting the chemotherapeutic efficacy included overall survival (OS), progression-free survival (PFS) and objective response (OR). In the platinum-treated group of 32 patients, 2 cases (6.3%) achieved CR, 16 cases (50.0%) achieved PR, 11 (34.4%) cases achieved SD, and 3 patients (9.4%) achieved PD. In the non-platinum-treated group of 33 patients, 2 cases (6.1%) achieved CR, 6 cases (18.2%) achieved PR, 16 cases (48.5%) achieved SD, and 9 cases (27.3%) achieved PD. Median PFS was significantly longer in the platinum-treated group than in the non-platinum-treated group (10 months vs. 6.0 months, P = 0.012), and OS was also improved (32 months vs. 22 months, P = 0.006). Multivariate analysis of several factors including local-regional lymph node involvement, lung metastasis-related symptoms, first-line platinum-based chemotherapy, disease-free interval, size and number of lung lesions, showed that first-line platinum-based chemotherapy was an independent prognostic factor for TNBC patients with lung metastases. Compared with non-platinum-based chemotherapy, the first-line platinum-based chemotherapy can improve PFS and OS in TNBC patients with metastases confined to the lungs.

  6. Phasic Triplet Markov Chains.

    Science.gov (United States)

    El Yazid Boudaren, Mohamed; Monfrini, Emmanuel; Pieczynski, Wojciech; Aïssani, Amar

    2014-11-01

    Hidden Markov chains have been shown to be inadequate for data modeling under some complex conditions. In this work, we address the problem of statistical modeling of phenomena involving two heterogeneous system states. Such phenomena may arise in biology or communications, among other fields. Namely, we consider that a sequence of meaningful words is to be searched within a whole observation that also contains arbitrary one-by-one symbols. Moreover, a word may be interrupted at some site to be carried on later. Applying plain hidden Markov chains to such data, while ignoring their specificity, yields unsatisfactory results. The Phasic triplet Markov chain, proposed in this paper, overcomes this difficulty by means of an auxiliary underlying process in accordance with the triplet Markov chains theory. Related Bayesian restoration techniques and parameters estimation procedures according to the new model are then described. Finally, to assess the performance of the proposed model against the conventional hidden Markov chain model, experiments are conducted on synthetic and real data.

  7. Study of pyrolyzed hemin/C as non-platinum cathodic catalyst for direct methanol fuel cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Biological reduction of O2 to H2O justifies a serious look at heme as a potential O2 reduction reaction(ORR) catalyst for low temperature fuel cells.In this study,a novel non-platinum electrocatalyst for ORR was prepared through hemin,which is hydrochloride of heme,supported on Black Pearls 2000 carbon black(Hm-BP) pyrolyzed at 700-900℃ in Ar atmosphere.The physical and electrocatalytic properties of as-prepared catalysts were characterized by TGA,XRD,XPS,TEM,rotating disk electrode(RDE) and rotating ring disk electrode(RRDE).It has found that the catalyst treated at 750℃(Hm-BP-750) exhibits the best property among the Hm-BP catalysts prepared.The onset potential of ORR on the Hm-BP-750 at 30℃ was measured ca.0.90 V(vs.RHE) in 0.1 M H2SO4,and mass current density was reached 15.3 mA mg-1 at 0.75 V.It has revealed that O2 could be reduced directly to water in a 4e process between 0.9 and 0.83V,and the yield of H2O2 was 0-18% in the potential range of 0.83-0.63 V.This methanol-tolerant catalyst also presents excellent stability in medium-term test of direct methanol fuel cell at 80℃.

  8. A non-platinum counter electrode, MnNx/C, for dye-sensitized solar cell applications

    Science.gov (United States)

    Kushwaha, Suman; M. P., Karthikayini; Wang, Guanxiong; Mandal, Sudip; Bhobe, Preeti. A.; Ramani, Vijay K.; Priolkar, K. R.; Ramanujam, Kothandaraman

    2017-10-01

    A non-platinum metal catalyst, MnNx/C was synthesized via the high-pressure pyrolysis route. The combination of X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) studies indicated the presence of Mn in +2 oxidation state surrounded by four N atoms. The peak-to-peak separation (ΔEp) of the more negative peak pair observed for I3-/I- redox couple over MnNx/C catalyst was 20 mV lower than that of the Pt catalyst, indicating high reversibility of the redox couple over MnNx/C catalyst. The charge transfer resistance of the MnNx/C electrode, as measured by the impedance spectroscopy, is ∼ 2 Ω higher than that of Pt, which resulted slightly lower short circuit current (Jsc) value for MnNx/C over Pt, however the fill factor (FF) and power conversion efficiency (PCE) values of MnNx/C was slightly higher and comparable to that of Pt respectively. Hence; replacing Pt with MnNx/C would decrease the cost of DSSCs.

  9. Triplet State Resonance Raman Spectroscopy

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N. H.; Pagsberg, Palle Bjørn

    1978-01-01

    Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied......Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied...

  10. Triplets pass their pressure test

    CERN Multimedia

    2007-01-01

    All the LHC inner triplets have now been repaired and are in position. The first ones have passed their pressure tests with flying colours. The repaired inner triplet at LHC Point 1, right side (1R). Ranko Ostojic (on the right), who headed the team responsible for repairing the triplets, shows the magnet to Robert Zimmer, President of the University of Chicago and of Fermi Research Alliance, who visited CERN on 20th August.Three cheers for the triplets! All the LHC inner triplets have now been repaired and are in position in the tunnel. Thanks to the mobilisation of a multidisciplinary team from CERN and Fermilab, assisted by the KEK Laboratory and the Lawrence Berkeley National Laboratory (LBNL), a solution has been found, tested, validated and applied. At the end of March this year, one of the inner triplets at Point 5 failed to withstand a pressure test. A fault was identified in the supports of two out of the three quadruple magne...

  11. Topological Aspects of Triplet Superconductors

    Institute of Scientific and Technical Information of China (English)

    REN Ji-Rong; XU Dong-Hui; ZHANG Xin-Hui; LI Ran

    2007-01-01

    In this paper, using the φ-mapping theory, it is shown that two kinds of topological defects, i.e., the vortex lines and the monopoles exist in the helical configuration of magnetic field in triplet superconductors. And the inner topological structure of these defects is studied. Because the knot solitons in the triplet superconductors are characterized by the Hopf invariant, we also establish a relationship between the Hopf invariant and the linking number of knots family,and reveal the inner topological structure of the Hopf invariant.

  12. Tough Decisions for Premature Triplets.

    Science.gov (United States)

    Hurst, Ashley; Vergales, Brooke D; Paget-Brown, Alix; Mercurio, Mark; Lantos, John D

    2016-02-01

    When infants are born at the borderline of viability, doctors and parents have to make tough decisions about whether to institute intensive care or provide only palliative care. Often, these decisions are made in moments of profound emotional turmoil, and parents receive different information from different health professionals. Communication can become garbled. It may be difficult to tell when and whether the patient's clinical condition has changed enough so that certain choices that had once been permissible become impermissible. In this "Ethics Rounds," we present a case of triplets born at the borderline of viability. We sought comments from the triplets' parents, the doctors and ethicist who were caring for the infants, and a bioethicist/neonatologist from another hospital.

  13. Sequential analysis

    CERN Document Server

    Wald, Abraham

    2013-01-01

    In 1943, while in charge of Columbia University's Statistical Research Group, Abraham Wald devised Sequential Design, an innovative statistical inference system. Because the decision to terminate an experiment is not predetermined, sequential analysis can arrive at a decision much sooner and with substantially fewer observations than equally reliable test procedures based on a predetermined number of observations. The system's immense value was immediately recognized, and its use was restricted to wartime research and procedures. In 1945, it was released to the public and has since revolutio

  14. Triplet Focusing for Recirculating Linear Muon Accelerators

    CERN Document Server

    Keil, Eberhard

    2001-01-01

    Focusing by symmetrical triplets is studied for the linear accelerator lattices in recirculating muon accelerators with several passes where the ratio of final to initial muon energy is about four. Triplet and FODO lattices are compared. At similar acceptance, triplet lattices have straight sections for the RF cavities that are about twice as long as in FODO lat-tices. For the same energy gain, the total lengths of the linear accelerators with triplet lattices are about the same as of those with FODO lattices.

  15. The near elimination of triplets in IVF.

    Science.gov (United States)

    Gerris, Jan

    2007-01-01

    In Antwerp, single embryo transfers (SET) have increased, and this change in policy has seen the incidence of singletons rise from 70 to 90%, twins drop from 25 to 10%, and triplets drop from 1-2% to none at all. At a national and regional level, changes have been much more dramatic as a result of a change in the law in 2003 mandating SET. Data show a huge increase in the number of treatment cycles and a dramatic rise in SET. Rates of twins and triplets have dropped considerably. European data indicate wide differences in the incidence of triplets between countries, varying between 0% (e.g.Slovenia, Iceland, Lithuania) and 4.4% (Hungary), but almost nothing is known about the true incidence of fetal reduction. US data indicate some decrease in triplets during recent years, but certainly nowhere near elimination. These data suggest that in some countries, IVF triplets have almost been eliminated, but the problem is masked by significant fetal reductions. Where SET is not widely used, triplets are still frequent. A correlation appears to exist between the percentage of SET cycles and the incidence of triplets. It is suggested that the solution to almost totally eliminate triplets after IVF is single embryo transfer.

  16. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  17. Diphotons from an Electroweak Triplet-Singlet

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Kiel [Fermilab; Knapen, Simon [UC, Berkeley; Robinson, Dean J. [UC, Berkeley

    2016-03-29

    The neutral component of a real pseudoscalar electroweak (EW) triplet can produce a diphoton excess at 750 GeV, if it is somewhat mixed with an EW singlet pseudoscalar. This triplet-singlet mixing allows for greater freedom in the diboson branching ratios than the singlet-only case, but it is still possible to probe the parameter space extensively with 300 fb$^{-1}$. The charged component of the triplet is pair-produced at the LHC, which results in a striking signal in the form of a pair of $W\\gamma$ resonances with an irreducible rate of 0.27 fb. Other signatures include multiboson final states from cascade decays of the triplet-singlet neutral states. A large class of composite models feature both EW singlet and triplet pseudo-Nambu Goldstone bosons in their spectrum, with the diboson couplings generated by axial anomalies.

  18. Definition and determination of the triplet-triplet energy transfer reaction coordinate

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Felipe; Marazzi, Marco; Castaño, Obis; Frutos, Luis Manuel, E-mail: luisma.frutos@uah.es [Departamento de Química Física, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Acuña, A. Ulises [Instituto de Química Física “Rocasolano”, C.S.I.C., Serrano 119, 28006 Madrid (Spain)

    2014-01-21

    A definition of the triplet-triplet energy transfer reaction coordinate within the very weak electronic coupling limit is proposed, and a novel theoretical formalism is developed for its quantitative determination in terms of internal coordinates The present formalism permits (i) the separation of donor and acceptor contributions to the reaction coordinate, (ii) the identification of the intrinsic role of donor and acceptor in the triplet energy transfer process, and (iii) the quantification of the effect of every internal coordinate on the transfer process. This formalism is general and can be applied to classical as well as to nonvertical triplet energy transfer processes. The utility of the novel formalism is demonstrated here by its application to the paradigm of nonvertical triplet-triplet energy transfer involving cis-stilbene as acceptor molecule. In this way the effect of each internal molecular coordinate in promoting the transfer rate, from triplet donors in the low and high-energy limit, could be analyzed in detail.

  19. Singlet and triplet instability theorems

    Science.gov (United States)

    Yamada, Tomonori; Hirata, So

    2015-09-01

    A useful definition of orbital degeneracy—form-degeneracy—is introduced, which is distinct from the usual energy-degeneracy: Two canonical spatial orbitals are form-degenerate when the energy expectation value in the restricted Hartree-Fock (RHF) wave function is unaltered upon a two-electron excitation from one of these orbitals to the other. Form-degenerate orbitals tend to have isomorphic electron densities and occur in the highest-occupied and lowest-unoccupied molecular orbitals (HOMOs and LUMOs) of strongly correlated systems. Here, we present a mathematical proof of the existence of a triplet instability in a real or complex RHF wave function of a finite system in the space of real or complex unrestricted Hartree-Fock wave functions when HOMO and LUMO are energy- or form-degenerate. We also show that a singlet instability always exists in a real RHF wave function of a finite system in the space of complex RHF wave functions, when HOMO and LUMO are form-degenerate, but have nonidentical electron densities, or are energy-degenerate. These theorems provide Hartree-Fock-theory-based explanations of Hund's rule, a singlet instability in Jahn-Teller systems, biradicaloid electronic structures, and a triplet instability during some covalent bond breaking. They also suggest (but not guarantee) the spontaneous formation of a spin density wave (SDW) in a metallic solid. The stability theory underlying these theorems extended to a continuous orbital-energy spectrum proves the existence of an oscillating (nonspiral) SDW instability in one- and three-dimensional homogeneous electron gases, but only at low densities or for strong interactions.

  20. Kinetic Monte Carlo study of triplet-triplet annihilation in organic phosphorescent emitters

    Science.gov (United States)

    van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

    2015-03-01

    The triplet-triplet annihilation (TTA) rate in organic phosphorescent materials such as used in organic light-emitting diodes is determined predominantly either by the rate of single-step Förster-type triplet-triplet interactions, or by multi-step triplet diffusion. We show how kinetic Monte Carlo simulations may be used to analyze the role of both processes. Under steady state conditions, the effective triplet-triplet interaction rate coefficient, kTT, which is often regarded as a constant, is found to depend actually on the number of excitons lost upon a triplet-triplet interaction process and to show a significant higher-order dependence on the triplet volume density. Under the conditions encountered in transient photoluminescence (PL) studies, kTT is found to be effectively constant in the case of diffusion-dominated TTA. However, for the case of single-step TTA, a strongly different decay of the emission intensity is found, which also deviates from an analytic expression proposed in the literature. We discuss how the transient PL response may be used to make a distinction between both mechanisms. The simulations are applied to recently published work on the dye concentration dependence of the TTA rate in materials based on the archetypal green emitter tris[2-phenylpyridine]iridium (Ir(ppy)3).

  1. Novel Approaches for Concurrent Irradiation in Locally Advanced Cervical Cancer: Platinum Combinations, Non-Platinum-Containing Regimens, and Molecular Targeted Agents

    Directory of Open Access Journals (Sweden)

    Giannis Mountzios

    2013-01-01

    Full Text Available Despite the available prevention and early detection strategies, squamous-cell carcinoma of the uterine cervix is still diagnosed as locally advanced disease in a considerable proportion of patients. As a potent sensitizer of cancer cells, cisplatin has been the “traditional partner” of external beam irradiation in this setting for more than two decades. Induction chemotherapy strategies followed by concurrent chemoradiation or surgery and preoperative concurrent chemoradiation have been recently implemented in clinical trials in an effort to optimize local control and to minimize the risk of distant metastases. In this context, cisplatin has been combined with a number of other potential radiosensitizers, including 5-fluorouracil, capecitabine, and gemcitabine. In patients resistant or intolerant to platinum compounds, numerous non-platinum-containing regimens have been developed, implementing various antimetabolites, taxanes, antineoplastic antibiotics, and topoisomerase II inhibitors. More recently, molecular agents targeting critical pathways in cervical malignant transformation are being assessed in early clinical trials in combination with external-beam irradiation. In the current work, we review the evolving role of cisplatin and other platinum compounds, either alone or in combination regimens, in the context of other potent radiosensitizers. The emerging role of molecular targeted agents, as candidate partners of external beam irradiation, is also discussed.

  2. H{sub 2}/air alkaline membrane fuel cell performance and durability, using novel ionomer and non-platinum group metal cathode catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Piana, Michele; Boccia, Massimiliano; Filpi, Antonio; Flammia, Elisa; Miller, Hamish A.; Orsini, Marco; Salusti, Francesca; Santiccioli, Serena [Acta S.p.A., Fuel cell Technology, via di Lavoria 56/G, I-56042 Crespina (PI) (Italy); Ciardelli, Francesco; Pucci, Andrea [Department of Chemistry and Industrial Chemistry, University of Pisa, Via, Risorgimento 35, I-56126 Pisa (Italy)

    2010-09-15

    The development of H{sub 2}/air alkaline membrane fuel cells (AMFCs) enables the use of non-platinum group metal (PGM) catalysts which are intrinsically stable and have an activity similar to platinum in alkaline media for the oxygen reduction reaction (ORR). As opposed to PEMFCs, the research and development of these types of catalysts for AMFC has had little attention and even less has been given to the development of alkaline membranes and ionomers. Acta S.p.A. has developed recently new non-PGM ORR catalysts with activity higher than Pt in alkaline media. More importantly, a new anionic ionomer derived from cheap starting materials with optimum performance has been produced. In this paper we demonstrate the use of this new ionomer in H{sub 2}/air AMFCs showing the first polarization and durability data, with current densities higher than those recently reported in the literature. Furthermore, we report the effect of CO{sub 2} on AMFC performance, showing the possibility of use of such alkaline devices not only in outer-space applications, but also with atmospheric air for large scale devices. (author)

  3. Triplet absorption spectroscopy and electromagnetically induced transparency

    Science.gov (United States)

    Ghafoor, F.; Nazmitdinov, R. G.

    2016-09-01

    Coherence phenomena in a four-level atomic system, cyclically driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical Stark effect. Two dark lines with a Fano-like profile arise in the triplet absorption spectrum with anomalous dispersions. We provide conditions to control the widths of the transparency windows by means of the relative phase of the driving fields and the intensity of the microwave field, which closes the optical system loop. The effect of Doppler broadening on the results of the triplet absorption spectroscopy is analysed in detail.

  4. Cooper pairs spintronics in triplet spin valves.

    Science.gov (United States)

    Romeo, F; Citro, R

    2013-11-27

    We study a spin valve with a triplet superconductor spacer intercalated between two ferromagnets with noncollinear magnetizations. We show that the magnetoresistance of the triplet spin valve depends on the relative orientations of the d vector, characterizing the superconducting order parameter, and the magnetization directions of the ferromagnetic layers. For devices characterized by a long superconductor, the effects of a polarized current sustained by Cooper pairs only are observed. In this regime, a supermagnetoresistance effect emerges, and the chiral symmetry of the order parameter of the superconducting spacer is easily recognized. Our findings open new perspectives in designing spintronics devices based on the cooperation of ferromagnetic and triplet correlations.

  5. Magnetic Field Effects on Triplet-Triplet Annihilation in Solutions: Modulation of Visible/NIR Luminescence.

    Science.gov (United States)

    Mani, Tomoyasu; Vinogradov, Sergei A

    2013-08-01

    Photon upconversion based on sensitized triplet-triplet annihilation (TTA) presents interest for such areas as photovoltaics and imaging. Usually energy upconversion is observed as p-type delayed fluorescence from molecules whose triplet states are populated via energy transfer from a suitable triplet donor, followed by TTA. Magnetic field effects (MFE) on delayed fluorescence in molecular crystals are well known; however, there exist only a few examples of MFE on TTA in solutions, and all of them are limited to UV-emitting materials. Here we present MFE on TTA-mediated visible and near infrared (NIR) emission, sensitized by far-red absorbing metalloporphyrins in solutions at room temperature. In addition to visible delayed fluorescence from annihilator, we also observed NIR emission from the sensitizer, occurring as a result of triplet-triplet energy transfer back from annihilator, termed "delayed phosphorescence". This emission also exhibits MFE, but opposite in sign to the annihilator fluorescence.

  6. New Heuristics for Rooted Triplet Consistency

    Directory of Open Access Journals (Sweden)

    Soheil Jahangiri

    2013-07-01

    Full Text Available Rooted triplets are becoming one of the most important types of input for reconstructing rooted phylogenies. A rooted triplet is a phylogenetic tree on three leaves and shows the evolutionary relationship of the corresponding three species. In this paper, we investigate the problem of inferring the maximum consensus evolutionary tree from a set of rooted triplets. This problem is known to be APX-hard. We present two new heuristic algorithms. For a given set of m triplets on n species, the FastTree algorithm runs in O(m + α(nn2 time, where α(n is the functional inverse of Ackermann’s function. This is faster than any other previously known algorithms, although the outcome is less satisfactory. The Best Pair Merge with Total Reconstruction (BPMTR algorithm runs in O(mn3 time and, on average, performs better than any other previously known algorithms for this problem.

  7. Delayed Interval Delivery in a Triplet Pregnancy

    Directory of Open Access Journals (Sweden)

    Sheng-Po Kao

    2006-02-01

    Full Text Available Due to a surge in the availability of assisted reproductive techniques (ART, the incidence of multiple pregnancies is increasing. Preterm labor is a major complication in such pregnancies. Preterm delivery of the first fetus is often followed by delivery of the remaining fetuses. However, conservative management and delayed interval delivery in the remaining fetuses might allow for fetal lung maturity and would reduce perinatal morbidities. A 32-year-old female had a quadruplet pregnancy after receiving ART. Fetal reduction to triplet pregnancy was performed at 11 weeks of gestation. The remaining triplet pregnancy was stable until 29 weeks of gestation, when the first triplet was delivered after spontaneous rupture of membranes. Under intensive monitoring, the remaining 2 fetuses were delivered by cesarean section at 31 weeks of gestation. Only the first fetus had retinopathy after discharge. In conclusion, delayed interval delivery of the remaining fetuses should be attempted after preterm delivery of the first fetus.

  8. A code for optimising triplet layout

    CERN Document Server

    Van Riesen-Haupt, Leon; Abelleira, Jose; Cruz Alaniz, Emilia

    2017-01-01

    One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation for a broad parameter scan and MADX for more precise calculations. The thin lens algorithm is significantly faster than a full scan using MADX and relatively precise at indicating the approximate area where the optimum solution lies.

  9. Triplet correlation functions in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Dhabal, Debdas; Chakravarty, Charusita, E-mail: charus@chemistry.iitd.ac.in [Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016 (India); Singh, Murari [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Wikfeldt, Kjartan Thor [Science Institute, University of Iceland, 107 Reykjavik (Iceland)

    2014-11-07

    Triplet correlations have been shown to play a crucial role in the transformation of simple liquids to anomalous tetrahedral fluids [M. Singh, D. Dhabal, A. H. Nguyen, V. Molinero, and C. Chakravarty, Phys. Rev. Lett. 112, 147801 (2014)]. Here we examine triplet correlation functions for water, arguably the most important tetrahedral liquid, under ambient conditions, using configurational ensembles derived from molecular dynamics (MD) simulations and reverse Monte Carlo (RMC) datasets fitted to experimental scattering data. Four different RMC data sets with widely varying hydrogen-bond topologies fitted to neutron and x-ray scattering data are considered [K. T. Wikfeldt, M. Leetmaa, M. P. Ljungberg, A. Nilsson, and L. G. M. Pettersson, J. Phys. Chem. B 113, 6246 (2009)]. Molecular dynamics simulations are performed for two rigid-body effective pair potentials (SPC/E and TIP4P/2005) and the monatomic water (mW) model. Triplet correlation functions are compared with other structural measures for tetrahedrality, such as the O–O–O angular distribution function and the local tetrahedral order distributions. In contrast to the pair correlation functions, which are identical for all the RMC ensembles, the O–O–O triplet correlation function can discriminate between ensembles with different degrees of tetrahedral network formation with the maximally symmetric, tetrahedral SYM dataset displaying distinct signatures of tetrahedrality similar to those obtained from atomistic simulations of the SPC/E model. Triplet correlations from the RMC datasets conform closely to the Kirkwood superposition approximation, while those from MD simulations show deviations within the first two neighbour shells. The possibilities for experimental estimation of triplet correlations of water and other tetrahedral liquids are discussed.

  10. Being Pregnant with Twins, Triplets and Other Multiples

    Science.gov (United States)

    ... twins, triplets and other multiples Being pregnant with twins, triplets and other multiples E-mail to a ... embryos that grow into two or more babies. Twins are called identical when one fertilized egg splits ...

  11. Doublet-Triplet Splitting and Fat Branes

    CERN Document Server

    Maru, N

    2001-01-01

    We consider the doublet-triplet splitting problem in supersymmetric SU(5) grand unified theory in five dimensions where the fifth dimension is non-compact. We point out that an unnatural fine-tuning of parameters in order to obtain the light Higgs doublets is not required due to the exponential suppression of the overlap of the wave functions.

  12. Scalar triplet flavored leptogenesis: a systematic approach

    CERN Document Server

    Sierra, D Aristizabal; Hambye, Thomas

    2014-01-01

    Type-II seesaw is a simple scenario in which Majorana neutrino masses are generated by the exchange of a heavy scalar electroweak triplet. When endowed with additional heavy fields, such as right-handed neutrinos or extra triplets, it also provides a compelling framework for baryogenesis via leptogenesis. We derive in this context the full network of Boltzmann equations for studying leptogenesis in the flavored regime. To this end we determine the relations which hold among the chemical potentials of the various particle species in the thermal bath. This takes into account the SM Yukawa interactions of both leptons and quarks as well as sphaleron processes which, depending on the temperature, may be classified as faster or slower than the Hubble rate. We find that when leptogenesis is enabled by the presence of an extra triplet, lepton flavor effects allow the production of the $B-L$ asymmetry through lepton number conserving CP asymmetries. This scenario becomes dominant as soon as the triplets couple more t...

  13. Improving Fingerprint Verification Using Minutiae Triplets

    Directory of Open Access Journals (Sweden)

    Leopoldo Altamirano-Robles

    2012-03-01

    Full Text Available Improving fingerprint matching algorithms is an active and important research area in fingerprint recognition. Algorithms based on minutia triplets, an important matcher family, present some drawbacks that impact their accuracy, such as dependency to the order of minutiae in the feature, insensitivity to the reflection of minutiae triplets, and insensitivity to the directions of the minutiae relative to the sides of the triangle. To alleviate these drawbacks, we introduce in this paper a novel fingerprint matching algorithm, named M3gl. This algorithm contains three components: a new feature representation containing clockwise-arranged minutiae without a central minutia, a new similarity measure that shifts the triplets to find the best minutiae correspondence, and a global matching procedure that selects the alignment by maximizing the amount of global matching minutiae. To make M3gl faster, it includes some optimizations to discard non-matching minutia triplets without comparing the whole representation. In comparison with six verification algorithms, M3gl achieves the highest accuracy in the lowest matching time, using FVC2002 and FVC2004 databases.

  14. Stacked Sequential Learning

    Science.gov (United States)

    2005-07-01

    a constant factor of K + 2. (To see this, note sequential stacking requires training K+2 classifiers: the classifiers f1, . . . , fK used in cross...on the non- sequential learners (ME and VP) but improves per- formance of the sequential learners (CRFs and VPH - MMs) less consistently. This pattern

  15. Synthesis and Exciton Dynamics of Triplet Sensitized Conjugated Polymers

    KAUST Repository

    Andernach, Rolf

    2015-07-22

    We report the synthesis of a novel polythiophene-based host-guest copolymer incorporating a Pt-porphyrin complex (TTP-Pt) into the backbone for efficient singlet to triplet polymer exciton sensitization. We elucidated the exciton dynamics in thin films of the material by means of Transient Absorption Spectrosopcy (TAS) on multiple timescales and investigated the mechanism of triplet exciton formation. During sensitization, single exciton diffusion is followed by exciton transfer from the polymer backbone to the complex where it undergoes intersystem crossing to the triplet state of the complex. We directly monitored the triplet exciton back transfer from the Pt-porphyrin to the polymer and find that 60% of the complex triplet excitons are transferred with a time constant of 1087 ps. We propose an equilibrium between polymer and porphyrin triplet states as a result of the low triplet diffusion length in the polymer backbone and hence an increased local triplet population resulting in increased triplet-triplet annihilation. This novel system has significant implications for the design of novel materials for triplet sensitized solar cells and up-conversion layers.

  16. Fermiophobia in a Higgs Triplet Model

    CERN Document Server

    Akeroyd, A G; Rivera, Maximiliano A; Romero, Diego

    2010-01-01

    A Fermiophobic Higgs boson can arise in models with an extended Higgs sector, such as models with scalars in an isospin triplet representation. In a specific model with a scalar triplet and spontaneous violation of lepton number induced by a scalar singlet field, we show that fermiophobia is not a fine-tuned situation, unlike in Two Higgs Doublet Models. We study distinctive signals of fermiophobia which can be probed at the LHC. For the case of a small Higgs mass a characteristic signal would be a moderate B(H ->\\gamma\\gamma) accompanied by a large B(H -> JJ) (where J is a Majoron), the latter being an invisible decay. For the case of a large Higgs mass there is the possibility of dominant H -> ZZ, WW and suppressed H -> JJ decay modes. In this situation, B(H -> ZZ) is larger than B(H -> WW), which differs from the SM prediction.

  17. Radiative Neutrino Mass with Scotogenic Scalar Triplet

    CERN Document Server

    Brdar, Vedran; Radovcic, Branimir

    2014-01-01

    We present radiative one-loop neutrino mass model with hypercharge zero scalar triplet in conjunction with another charged singlet scalar and an additional vectorlike lepton doublet. We study three variants of this mass model: the first one without additional beyond-SM symmetry, the second with imposed DM-stabilizing discrete Z_2 symmetry, and the third in which this Z_2 symmetry is promoted to the gauge symmetry U(1)_D. The two latter cases are scotogenic, with a neutral component of the scalar triplet as a dark matter candidate. In first scotogenic model the Z_2-odd dark matter candidate is at the multi-TeV mass scale, so that all new degrees of freedom are beyond the direct reach of the LHC. In second scotogenic setup, with broken U(1)_D symmetry the model may have LHC signatures or be relevant to astrophysical observations, depending on the scale of U(1)_D breaking.

  18. Nickelocene: A universal quencher of organic triplets

    Science.gov (United States)

    Rajadurai, S.; Bhattacharyya, K.; Das, P. K.

    1986-08-01

    Organic triplets, with energies in the range 0.9-3.2 eV, are quenched by nickelocene with rate constants in the limit of diffusion control ((1.3-11) × 109 M-1s-1 in benzene). The efficient quenching, explainable in terms of a combination of energy and electron transfer, suggests the existence of a low-lying spin-forbidden transition (< 0.9 eV) in nickelocene.

  19. Structural basis for triplet repeat disorders

    DEFF Research Database (Denmark)

    Baldi, Pierre; Brunak, Søren; Chauvin, Yves

    1999-01-01

    Motivation: Over a dozen major degenerative disorders, including myotonic distrophy, Huntington's disease and fragile X syndrome result from unstable expansions of particular trinucleotides. Remarkably, only some of all the possible triplets, namely CAG/CTG, CGG/CCG and GAA/TTC, have been associa......, which we predict to have very high flexibility, may play a role in the pathogenesis of the neurodegenerative disorder multiple system atrophy (MSA)....

  20. Twin and Triplet Drugs in Opioid Research

    Science.gov (United States)

    Fujii, Hideaki

    Twin and triplet drugs are defined as compounds that contain respectively two and three pharmacophore components exerting pharmacological effects in a molecule. The twin drug bearing the same pharmacophores is a "symmetrical twin drug", whereas that possessing different pharmacophores is a "nonsymmetrical twin drug." In general, the symmetrical twin drug is expected to produce more potent and/or selective pharmacological effects, whereas the nonsymmetrical twin drug is anticipated to show both pharmacological activities stemming from the individual pharmacophores (dual action). On the other hand, nonsymmetrical triplet drugs, which have two of the same pharmacophores and one different moiety, are expected to elicit both increased pharmacological action and dual action. The two identical portions could bind the same receptor sites simultaneously while the third portion could bind a different receptor site or enzyme. This review will mainly focus on the twin and triplet drugs with an evaluation of their in vivo pharmacological effects, and will also include a description of their pharmacology and synthesis.

  1. Dye-Sensitized Solar Cell with Integrated Triplet-Triplet Annihilation Upconversion System.

    Science.gov (United States)

    Nattestad, Andrew; Cheng, Yuen Yap; MacQueen, Rowan W; Schulze, Tim F; Thompson, Fletcher W; Mozer, Attila J; Fückel, Burkhard; Khoury, Tony; Crossley, Maxwell J; Lips, Klaus; Wallace, Gordon G; Schmidt, Timothy W

    2013-06-20

    Photon upconversion (UC) by triplet-triplet annihilation (TTA-UC) is employed in order to enhance the response of solar cells to sub-bandgap light. Here, we present the first report of an integrated photovoltaic device, combining a dye-sensitized solar cell (DSC) and TTA-UC system. The integrated device displays enhanced current under sub-bandgap illumination, resulting in a figure of merit (FoM) under low concentration (3 suns), which is competitive with the best values recorded to date for nonintegrated systems. Thus, we demonstrate both the compatibility of DSC and TTA-UC and a viable method for device integration.

  2. Integrals over the triplet distribution function without the triplet distribution function

    Science.gov (United States)

    Lado, F.

    While the triplet distribution function of disordered systems appears in a wide variety of problems in statistical mechanics, it does so always under an integral sign. In this paper, we propose a new method of evaluating such integrals that involves only pair functions throughout and avoids altogether the need for any explicit representation of the little-known triplet function. The procedure is based on an extension of integral equation theory of classical fluids. Numerical illustrations of the method are given for integrals that arise in the calculation of moments of a local field distribution.

  3. Odd triplet superconductivity in superconductor ferromagnet structures: a survey

    Energy Technology Data Exchange (ETDEWEB)

    Bergeret, F.S. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica de la Materia Condensada C-V, Madrid (Spain); Volkov, A.F. [Ruhr-Universitaet Bochum, Theoretische Physik III, Bochum (Germany); Russian Academy of Sciences, Institute for Radioengineering and Electronics, Moscow (Russian Federation); Efetov, K.B. [Ruhr-Universitaet Bochum, Theoretische Physik III, Bochum (Germany); L.D. Landau Institute for Theoretical Physics RAS, Moscow (Russian Federation)

    2007-11-15

    We review the main features of odd triplet superconductivity in superconductor-ferromagnet (S/F) structures. We discuss the different types of superconducting condensate that can be experimentally observed and pay special attention to the triplet component induced in a ferromagnet which is in contact with a superconductor. The triplet component is an even function of the momentum and an odd function of the frequency and leads to novel phenomena. (orig.)

  4. Half-metallic superconducting triplet spin valve

    Science.gov (United States)

    Halterman, Klaus; Alidoust, Mohammad

    2016-08-01

    We theoretically study a finite-size S F1N F2 spin valve, where a normal metal (N ) insert separates a thin standard ferromagnet (F1) and a thick half-metallic ferromagnet (F2). For sufficiently thin superconductor (S ) widths close to the coherence length ξ0, we find that changes to the relative magnetization orientations in the ferromagnets can result in substantial variations in the transition temperature Tc, consistent with experimental results [Singh et al., Phys. Rev. X 5, 021019 (2015), 10.1103/PhysRevX.5.021019]. Our results demonstrate that, in good agreement with the experiment, the variations are largest in the case where F2 is in a half-metallic phase and thus supports only one spin direction. To pinpoint the origins of this strong spin-valve effect, both the equal-spin f1 and opposite-spin f0 triplet correlations are calculated using a self-consistent microscopic technique. We find that when the magnetization in F1 is tilted slightly out of plane, the f1 component can be the dominant triplet component in the superconductor. The coupling between the two ferromagnets is discussed in terms of the underlying spin currents present in the system. We go further and show that the zero-energy peaks of the local density of states probed on the S side of the valve can be another signature of the presence of superconducting triplet correlations. Our findings reveal that for sufficiently thin S layers, the zero-energy peak at the S side can be larger than its counterpart in the F2 side.

  5. Powering the High-Luminosity Triplets

    CERN Document Server

    Ballarino, A

    2015-01-01

    The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

  6. Excited triplet state spectroscopy in the infrared

    Science.gov (United States)

    Baiardo, Joseph; Mukherjee, Ranajit; Vala, Martin

    1982-03-01

    A new method for the investigation of the infrared spectra of metastable excitedelectronic states is presented. With a Fourier Transform infrared spectrometer as the probe and a CW Xe lamp source as the pump, the infrared spectrum of the lowest triplet state of triphenylene isolated in a N 2 matrix at 15K has been examined. CH out-of-plane wagging modes are prominent and shifted from their ground state frequencies. It is expected that when fully developed this method will provide important information on excited state force constants and potential energy surfaces.

  7. Toward Triplet Ground State NaLi Molecules

    Science.gov (United States)

    Ebadi, Sepehr; Jamison, Alan; Rvachov, Timur; Jing, Li; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2016-05-01

    The NaLi molecule is expected to have a long lifetime in the triplet ground-state due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. We have mapped the excited state NaLi triplet potential by means of photoassociation spectroscopy. We report on this and our further progress toward the creation of the triplet ground-state molecules using STIRAP. NSF, ARO-MURI, Samsung, NSERC.

  8. Scalar triplet on a domain wall: an exact solution

    CERN Document Server

    Gani, Vakhid A; Radomskiy, Roman V

    2016-01-01

    We study a model with a real scalar Higgs field and a scalar triplet field that allows existence of a topological defect -- a domain wall. The wall breaks the global $O(3)$ symmetry of the model, which gives rise to non-Abelian orientational degrees of freedom. We found an exact analytic solution that describes a domain wall with a localized configuration of the triplet field on it. This solution enables one to calculate contributions to the action from the orientational and translational degrees of freedom of the triplet field. We also study the linear stability of the domain wall with the triplet field switched off.

  9. Sequentializing Parameterized Programs

    Directory of Open Access Journals (Sweden)

    Salvatore La Torre

    2012-07-01

    Full Text Available We exhibit assertion-preserving (reachability preserving transformations from parameterized concurrent shared-memory programs, under a k-round scheduling of processes, to sequential programs. The salient feature of the sequential program is that it tracks the local variables of only one thread at any point, and uses only O(k copies of shared variables (it does not use extra counters, not even one counter to keep track of the number of threads. Sequentialization is achieved using the concept of a linear interface that captures the effect an unbounded block of processes have on the shared state in a k-round schedule. Our transformation utilizes linear interfaces to sequentialize the program, and to ensure the sequential program explores only reachable states and preserves local invariants.

  10. Triplet-triplet energy transfer from chlorophylls to carotenoids in two antenna complexes from dinoflagellate Amphidinium carterae.

    Science.gov (United States)

    Kvíčalová, Zuzana; Alster, Jan; Hofmann, Eckhard; Khoroshyy, Petro; Litvín, Radek; Bína, David; Polívka, Tomáš; Pšenčík, Jakub

    2016-04-01

    Room temperature transient absorption spectroscopy with nanosecond resolution was used to study quenching of the chlorophyll triplet states by carotenoids in two light-harvesting complexes of the dinoflagellate Amphidinium carterae: the water soluble peridinin-chlorophyll protein complex and intrinsic, membrane chlorophyll a-chlorophyll c2-peridinin protein complex. The combined study of the two complexes facilitated interpretation of a rather complicated relaxation observed in the intrinsic complex. While a single carotenoid triplet state was resolved in the peridinin-chlorophyll protein complex, evidence of at least two different carotenoid triplets was obtained for the intrinsic light-harvesting complex. Most probably, each of these carotenoids protects different chlorophylls. In both complexes the quenching of the chlorophyll triplet states by carotenoids occurs with a very high efficiency (~100%), and with transfer times estimated to be in the order of 0.1ns or even faster. The triplet-triplet energy transfer is thus much faster than formation of the chlorophyll triplet states by intersystem crossing. Since the triplet states of chlorophylls are formed during the whole lifetime of their singlet states, the apparent lifetimes of both states are the same, and observed to be equal to the carotenoid triplet state rise time (~5ns).

  11. Higgs Triplet Model with Classically Conformal Invariance

    CERN Document Server

    Okada, Hiroshi; Yagyu, Kei

    2015-01-01

    We discuss an extension of the minimal Higgs triplet model with a classically conformal invariance and with a gauged $U(1)_{B-L}$ symmetry. In our scenario, tiny masses of neutrinos are generated by a hybrid contribution from the type-I and type-II seesaw mechanisms. The shape of the Higgs potential at low energies is determined by solving one-loop renormalization group equations for all the scalar quartic couplings with a set of initial values of parameters at the Planck scale. We find a successful set of the parameters in which the $U(1)_{B-L}$ symmetry is radiatively broken via the Coleman-Weinberg mechanism at the ${\\cal O}$(10) TeV scale, and the electroweak symmetry breaking is also triggered by the $U(1)_{B-L}$ breaking. Under this configuration, we can predict various low energy observables such as the mass spectrum of extra Higgs bosons, and the mixing angles. Furthermore, using these predicted mass parameters, we obtain upper limits on Yukawa couplings among an isospin triplet Higgs field and lepton...

  12. Radiative neutrino mass with scotogenic scalar triplet

    Energy Technology Data Exchange (ETDEWEB)

    Brdar, Vedran; Picek, Ivica; Radovčić, Branimir

    2014-01-20

    We present a radiative one-loop neutrino mass model with hypercharge zero scalar triplet in conjunction with another charged singlet scalar and an additional vectorlike lepton doublet. We study three variants of this mass model: the first one without additional beyond-SM symmetry, the second with imposed DM-stabilizing discrete Z{sub 2} symmetry, and the third in which this Z{sub 2} symmetry is promoted to the gauge symmetry U(1){sub D}. The two latter cases are scotogenic, with a neutral component of the scalar triplet as a dark matter candidate. In first scotogenic model the Z{sub 2}-odd dark matter candidate is at the multi-TeV mass scale, so that all new degrees of freedom are beyond the direct reach of the LHC. In second scotogenic setup, with broken U(1){sub D} symmetry the model may have LHC signatures or be relevant to astrophysical observations, depending on the scale of U(1){sub D} breaking.

  13. The superconducting spin valve and triplet superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Garifullin, I.A., E-mail: ilgiz_garifullin@yahoo.com [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Leksin, P.V.; Garif' yanov, N.N.; Kamashev, A.A. [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Fominov, Ya.V. [L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation); Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O.G. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Büchner, B. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoO{sub x}/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers. - Highlights: • We studied a spin switch design F1/F2/S. • We prepared a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). • The full spin switch effect for the superconducting current was realized. • We observed its oscillating behavior as a function of the Fe2-layer thickness. • We obtained direct evidence for the long-range triplet superconductivity.

  14. Reaction of Triplet Phenylnitrene with Molecular Oxygen.

    Science.gov (United States)

    Mieres-Pérez, Joel; Mendez-Vega, Enrique; Velappan, Kavitha; Sander, Wolfram

    2015-12-18

    Triplet carbenes react with molecular oxygen with rates that approach diffusion control to carbonyl O-oxides, whereas triplet nitrenes react much slower. For investigating the reaction of phenylnitrene with O2, the nitrene was generated by flash vacuum thermolysis (FVT) of phenylazide and subsequently isolated in O2-doped matrices. FVT of the azide produces the nitrene in high yield and with only minor contaminations of the rearranged products that are frequently observed if the nitrene is produced by photolysis. The phenylnitrene was isolated in solid Ar, Xe, mixtures of these rare gases with O2, and even in pure solid O2. At temperatures between 30 and 35 K an extremely slow thermal reaction between the nitrene and O2 was observed, whereas at higher temperatures, solid Ar and O2 rapidly evaporate. Only O2-doped Xe matrices allowed us to anneal at temperatures above 40 K, and at these temperatures, the nitrene reacts with O2 to produce nitroso O-oxide mainly in its syn conformation. Upon visible light irradiation (450 nm), the nitroso oxide rapidly rearranges to nitrobenzene.

  15. The neonatal outcome in twin versus triplet and quadruplet pregnancies

    Directory of Open Access Journals (Sweden)

    Fatemeh Nasseri

    2009-02-01

    Full Text Available

    • BACKGROUND: To assess the risk of neonatal mortality and morbidity in twin, triplet and quadruplet pregnancies.
    • METHODS: In a retrospective study, the neonatal outcome of all twin, triplet and quadruplet gestations delivered from October 2001 to September 2006 was reviewed. The neonatal outcome of triples and quadruplets was compared with a matched group of twins for gestational age.
    • RESULTS: During a 5-year period, 511 sets of twin pregnancies, 42 sets of triplet and 5 sets of quadruplet pregnancies were studied. The mean of gestational age for twins, triplets and quadruplets were 33.92 ± 3.5 weeks, 30.92 ± 3.8 weeks and 31.60 ± 2.0 weeks, respectively, (P = 0.0001. Triplets and quadruplets weighed less than twins, (P = 0.0001. Neonatal mortality was 13.5% for twins, 26.8% for triplets and 30% for quadruplets. In vitro fertilization, use of ovulation induction agents, and cesarean delivery in the women with triplet and quadruplet were significantly higher than in those with twin pregnancies, (P = 0.0001. The mean age of mothers with triplets and quadruplets was significantly higher than with twins (P = 0.026. There was not a significant difference in respiratory and non-respiratory short outcomes between triplets, quadruplets and twins when matched for gestational age. Apgar score at 1 and 5 minutes was significantly lower in triplets and quadruplets than twins. There was no influence of birth order on neonatal mortality of triplet pregnancy. Neonatal mortality of triplet births was significantly decreased over the 5 years of the study period.
    • CONCLUSIONS: Triplets and quadruplets have a similar neonatal outcome as twins when matched for gestational age. There is no influence of birth on the neonatal mortality of triplet pregnancy. It appears that outcome is mainly dependent on gestational age.
    • KEYWORDS: Neonatal

    • Time-Varying Triplet State Lifetimes of Single Molecules

      NARCIS (Netherlands)

      Veerman, J.A.; Garcia-Parajo, M.F.; Kuipers, L.; Hulst, van N.F.

      1999-01-01

      It is found that triplet state lifetimes and intersystem crossing yields of individual molecules embedded in a polymer host at room temperature are not constant in time. The range over which the triplet lifetime of a single molecule varies during long observation times shows a strong similarity with

    • Maternal and perinatal complications in triplet compared with twin pregnancy

      NARCIS (Netherlands)

      J.G. Santema (Job); P. Bourdrez (Petra); H.C.S. Wallenburg (Henk)

      1995-01-01

      textabstractObjective: To compare maternal and perinatal complications in triplet and twin pregnancies. Study design: Case-controlled study in the setting of a University Hospital. Each pregnancy of a consecutive series of 40 triplet pregnancies of 20 weeks or more was matched for parity and materna

    • Reversible Triplet Energy Transfer between Neo- Alloocimene and Anthracene

      DEFF Research Database (Denmark)

      Gorman, A. A.; Hamblett, I.; Jensen, Niels-Henrik

      1984-01-01

      The rate constants for triplet energy transfer between neo-alloocimene and anthracene have been redetermined by a combination of pulsed laser photolysi......The rate constants for triplet energy transfer between neo-alloocimene and anthracene have been redetermined by a combination of pulsed laser photolysi...

    • Sequential Back—Propagation

      Institute of Scientific and Technical Information of China (English)

      王晖; 刘大有; 等

      1994-01-01

      In this paper we consider the problem of sequential processing and present a sequential model based on the back-propagation algorithm.This model is intended to deal with intrinsically sequential problems,such as word recognition,speech recognition,natural language understanding.This model can be used to train a network to learn the sequence of input patterns,in a fixed order or a random order.Besides,this model is open- and partial-associative,characterized as “resognizing while accumulating”, which, as we argue, is mental cognition process oriented.

    • Three-Triplet Model with Double SU(3) Symmetry

      Science.gov (United States)

      Han, M. Y.; Nambu, Y.

      1965-01-01

      With a view to avoiding some of the kinematical and dynamical difficulties involved in the single triplet quark model, a model for the low lying baryons and mesons based on three triplets with integral charges is proposed, somewhat similar to the two-triplet model introduced earlier by one of us (Y. N.). It is shown that in a U(3) scheme of triplets with integral charges, one is naturally led to three triplets located symmetrically about the origin of I{sub 3} - Y diagram under the constraint that Nishijima-Gell-Mann relation remains intact. A double SU(3) symmetry scheme is proposed in which the large mass splittings between different representations are ascribed to one of the SU(3), while the other SU(3) is the usual one for the mass splittings within a representation of the first SU(3).

  1. Triplet-triplet annihilation photon-upconversion: towards solar energy applications.

    Science.gov (United States)

    Gray, Victor; Dzebo, Damir; Abrahamsson, Maria; Albinsson, Bo; Moth-Poulsen, Kasper

    2014-06-14

    Solar power production and solar energy storage are important research areas for development of technologies that can facilitate a transition to a future society independent of fossil fuel based energy sources. Devices for direct conversion of solar photons suffer from poor efficiencies due to spectrum losses, which are caused by energy mismatch between the optical absorption of the devices and the broadband irradiation provided by the sun. In this context, photon-upconversion technologies are becoming increasingly interesting since they might offer an efficient way of converting low energy solar energy photons into higher energy photons, ideal for solar power production and solar energy storage. This perspective discusses recent progress in triplet-triplet annihilation (TTA) photon-upconversion systems and devices for solar energy applications. Furthermore, challenges with evaluation of the efficiency of TTA-photon-upconversion systems are discussed and a general approach for evaluation and comparison of existing systems is suggested.

  2. The superconducting spin valve and triplet superconductivity

    Science.gov (United States)

    Garifullin, I. A.; Leksin, P. V.; Garif`yanov, N. N.; Kamashev, A. A.; Fominov, Ya. V.; Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O. G.; Büchner, B.

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers.

  3. Bright Solid State Source of Photon Triplets

    CERN Document Server

    Khoshnegar, Milad; Predojević, Ana; Dalacu, Dan; Prilmüller, Maximilian; Lapointe, Jean; Wu, Xiaohua; Tamarat, Philippe; Lounis, Brahim; Poole, Philip; Weihs, Gregor; Majedi, Hamed

    2015-01-01

    Producing advanced quantum states of light is a priority in quantum information technologies. While remarkable progress has been made on single photons and photon pairs, multipartite correlated photon states are usually produced in purely optical systems by post-selection or cascading, with extremely low efficiency and exponentially poor scaling. Multipartite states enable improved tests of the foundations of quantum mechanics as well as implementations of complex quantum optical networks and protocols. It would be favorable to directly generate these states using solid state systems, for better scaling, simpler handling, and the promise of reversible transfer of quantum information between stationary and flying qubits. Here we use the ground states of two optically active coupled quantum dots to directly produce photon triplets. The wavefunctions of photogenerated excitons localized in these ground states are correlated via molecular hybridization and Coulomb interactions. The formation of a triexciton leads...

  4. Spontaneous Heterotopic Triplet Pregnancy With Tubal Rupture

    Directory of Open Access Journals (Sweden)

    Lima Arsala MBBS, BBMedSci

    2014-04-01

    Full Text Available The recent increase in heterotopic pregnancies has been largely attributed to the increased use of assisted reproduction technologies. We report the rare case of a multiparous woman with a spontaneous conception resulting in a triplet heterotopic pregnancy: a twin intrauterine pregnancy and a single right tubal ectopic pregnancy. Heterotopic pregnancy is a rare and potentially life-threatening condition in which simultaneous gestations occur at 2 or more implantation sites. It is infrequent in natural conception cycles, occurring in 1:30 000 pregnancies. However, the prevalence is rising with the increased use of assisted reproduction techniques to that of 1:100 to 1:500 in these patient subgroups, highlighting the need to incorporate it into a clinician’s diagnostic algorithm.

  5. Magnetic chains on a triplet superconductor.

    Science.gov (United States)

    Sacramento, P D

    2015-11-11

    The topological state of a two-dimensional triplet superconductor may be changed by an appropriate addition of magnetic impurities. A ferromagnetic magnetic chain at the surface of a superconductor with spin-orbit coupling may eliminate the edge states of a finite system giving rise to localized zero modes at the edges of the chain. The coexistence/competition between the two types of zero modes is considered. The reduction of the system to an effective 1d system gives partial information on the topological properties but the study of the two sets of zero modes requires a two-dimensional treatment. Increasing the impurity density from a magnetic chain to magnetic islands leads to a finite Chern number. At half-filling small concentrations are enough to induce chiral modes.

  6. Triplet to Singleton-A Successful Outcome

    Directory of Open Access Journals (Sweden)

    Priya Varshney

    2014-07-01

    Full Text Available We are presenting a case report of triplet pregnancy in a 25 years old lady, in whom single fetal reduction was done at 10 weeks. At 29 weeks, ultrasonography showed fetal demise of second twin. Conservative management was done, after evaluating the status of second twin. Maternal and fetal monitoring was done with PT INR, Ultrasound Doppler weekly till 33 weeks when an emergency cesarean was done due to preterm labour pains. A healthy baby of 1.8 kg was born along with a macerated IUD of 500 gms. Mother and baby are healthy on follow up till date. Hence conservative management should be followed in single fetus demise in twin pregnancy with proper monitoring.

  7. Facile Co-Assembly of a Dipeptide-Based Organogel toward Efficient Triplet-Triplet Annihilation Photonic Upconversion.

    Science.gov (United States)

    Liu, Xingcen; Fei, Jinbo; Zhu, Pengli; Li, Junbai

    2016-10-06

    By one-step molecular co-assembly, a diphenylalanine-based photonic upconversion organogel was constructed within 20 seconds. Impressively, such an assembled system exhibits green-to-blue triplet-triplet annihilation upconversion with a relative quantum yield of 12 % even under ambient conditions.

  8. Triplet-triplet energy transfer and protection mechanisms against singlet oxygen in photosynthesis

    Science.gov (United States)

    Kihara, Shigeharu

    In photosynthesis, (bacterio)chlorophylls ((B)Chl) play a crucial role in light harvesting and electron transport. (B)Chls, however, are known to be potentially dangerous due to the formation of the triplet excited state which forms the singlet oxygen (1O2*) when exposed to the sunlight. Singlet oxygen is highly reactive and all modern organisms incorporate special protective mechanisms to minimize the oxidative damage. One of the conventional photoprotective mechanisms used by photosynthetic organisms is by the nearby carotenoids quenching the excess energy and releasing it by heat. In this dissertation, two major aspects of this process are studied. First, based on experimental data and model calculations, the oxygen content in a functioning oxygenic photosynthetic oxygen cell was determined. These organisms perform water splitting and as a result significant amount of oxygen can be formed within the organism itself. It was found, that contrary to some published estimates, the excess oxygen concentration generated within an individual cell is extremely low -- 0.025 ... 0.25 microM, i.e. about 103-104 times lower than the oxygen concentration in air saturated water. Such low concentrations imply that the first oxygenic photosynthetic cells that evolved in oxygen-free atmosphere of the Earth ~2.8 billion years ago might have invented the water splitting machinery (photosystem II) without the need for special oxygen-protective mechanisms, and the latter mechanisms could have evolved in the next 500 million years during slow rise of oxygen in the atmosphere. This result also suggests that proteins within photosynthetic membranes are not exposed to significant O2 levels and thus can be studied in vitro under the usual O2 levels. Second, the fate of triplet excited states in the Fenna Matthew Olson (FMO) pigment-protein complex is studied by means of time-resolved nanosecond spectroscopy and exciton model simulations. For the first time, the properties of several

  9. Transient photocurrent in molecular junctions: singlet switching on and triplet blocking.

    Science.gov (United States)

    Petrov, E G; Leonov, V O; Snitsarev, V

    2013-05-14

    The kinetic approach adapted to describe charge transmission in molecular junctions, is used for the analysis of the photocurrent under conditions of moderate light intensity of the photochromic molecule. In the framework of the HOMO-LUMO model for the single electron molecular states, the analytic expressions describing the temporary behavior of the transient and steady state sequential (hopping) as well as direct (tunnel) current components have been derived. The conditions at which the current components achieve their maximal values are indicated. It is shown that if the rates of charge transmission in the unbiased molecular diode are much lower than the intramolecular singlet-singlet excitation/de-excitation rate, and the threefold degenerated triplet excited state of the molecule behaves like a trap blocking the charge transmission, a possibility of a large peak-like transient switch-on photocurrent arises.

  10. Sequential stochastic optimization

    CERN Document Server

    Cairoli, Renzo

    1996-01-01

    Sequential Stochastic Optimization provides mathematicians and applied researchers with a well-developed framework in which stochastic optimization problems can be formulated and solved. Offering much material that is either new or has never before appeared in book form, it lucidly presents a unified theory of optimal stopping and optimal sequential control of stochastic processes. This book has been carefully organized so that little prior knowledge of the subject is assumed; its only prerequisites are a standard graduate course in probability theory and some familiarity with discrete-paramet

  11. Epigenetics and triplet repeat neurological diseases

    Directory of Open Access Journals (Sweden)

    Sathiji eNageshwaran

    2015-12-01

    Full Text Available The term ‘junk DNA’ has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterchromatinised resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, with several genes known to require such an environment to permit transcription. Repetitive regions frequently exist as dinucleotide, trinucleotide and tetranucleotide repeats. The association between repetitive regions and disease was emphasised following the discovery of abnormal trinucleotide repeats underlying spinal and bulbar muscular atrophy (Kennedy’s disease and fragile X syndrome of mental retardation (FRAXA in 1991. In this review we provide a brief overview of epigenetic mechanisms and then focus on several diseases caused by DNA triplet-repeat expansions, which exhibit diverse epigenetic effects. It is clear that the emerging field of epigenetics is already generating novel potential therapeutic avenues for this group of largely incurable diseases.

  12. Triplet Pairing in pure neutron matter

    CERN Document Server

    Srinivas, Sarath

    2016-01-01

    We study the zero temperature BCS gaps for the triplet channel in pure neutron matter using Similarity Renormalization Group (SRG) evolved interactions. We use the dependence of the results on the SRG resolution scale, as a tool to analyze medium and many-body corrections. In particular, we study the effects of including the three-body interactions at leading order, which appear at N2LO in the Chiral EFT, as well as that of the first-order self-energy corrections on the zero temperature gap. In addition we also extract the transition temperature as a function of densities and verify the BCS scaling of the zero temperature gaps to the transition temperature. We observe that the self-energy effects are very crucial in order to reduce the SRG resolution scale dependence of the results, while the three-body effects at the leading order do not change the two-body resolution scale dependence. On the other hand, the results depend strongly on the three-body cut-off, emphasizing the importance of the missing higher-o...

  13. Pair Triplet Association Rule Generation in Streams

    Directory of Open Access Journals (Sweden)

    Manisha Thool

    2013-08-01

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

  14. Triplet pairing in pure neutron matter

    Science.gov (United States)

    Srinivas, Sarath; Ramanan, S.

    2016-12-01

    We study the zero-temperature BCS gaps for the triplet channel in pure neutron matter using similarity renormalization group (SRG) evolved interactions. We use the dependence of the results on the SRG resolution scale as a tool to analyze medium and many-body corrections. In particular, we study the effects of including the three-body interactions at leading order, which appear at next-to-next-to leading order (N2LO) in the chiral effective field theory (EFT), as well as that of the first-order self-energy corrections on the zero-temperature gap. In addition we also extract the transition temperature as a function of densities and verify the BCS scaling of the zero-temperature gaps to the transition temperature. We observe that the self-energy effects are very crucial in order to reduce the SRG resolution scale dependence of the results, while the three-body effects at the leading order do not change the two-body resolution scale dependence. On the other hand, the results depend strongly on the three-body cutoff, emphasizing the importance of the missing higher-order three-body effects. We also observe that self-energy effects reduce the overall gap as well as shift the gap closure to lower densities.

  15. Triplet based online track finding in the PANDA-STT

    National Research Council Canada - National Science Library

    Mertens, Marius; Caldeira Balkeståhl, Li; Calén, Hans; Fransson, Kjell; Johansson, Tord; Kupsc, Andrzej; Marciniewski, Pawel; Schönning, Karin; Pettersson, Joachim; Wolke, Magnus; Zmeskal, Johann

    2014-01-01

    .... A variety of tracking algorithms is foreseen to process the different track topologies. The so-called Triplet Finder, which is presented here, is a track finding algorithm based on the central straw tube tracker (STT) of PANDA...

  16. Scalar triplet on a domain wall: an exact solution

    Science.gov (United States)

    Gani, Vakhid A.; Lizunova, Mariya A.; Radomskiy, Roman V.

    2016-04-01

    We study a model with a real scalar Higgs field and a scalar triplet field that allows existence of a topological defect — a domain wall. The wall breaks the global O(3) symmetry of the model, which gives rise to non-Abelian orientational degrees of freedom. We found an exact analytic solution that describes a domain wall with a localized configuration of the triplet field on it. This solution enables one to calculate contributions to the action from the orientational and translational degrees of freedom of the triplet field. We also study the linear stability of the domain wall with the triplet field switched off. We obtain that degrees of freedom localized on the wall can appear or do not appear depending on the parameters of the model.

  17. Rh isoimmunization complicating a triplet gestation. A case report.

    Science.gov (United States)

    Gast, M J; Rigg, L A; Martin, C M

    1991-04-01

    A case occurred of Rh isoimmunization complicating a triplet gestation. Management of that extremely rare situation required careful attention to the problems inherent in both multiple pregnancy and isoimmunization. Amniocentesis and frequent antepartum fetal monitoring were the cornerstones of therapy.

  18. Higher-Spin Triplet Fields and String Theory

    Directory of Open Access Journals (Sweden)

    D. Sorokin

    2010-01-01

    Full Text Available We review basic properties of reducible higher-spin multiplets, called triplets, and demonstrate how they naturally appear as part of the spectrum of String Field Theory in the tensionless limit. We show how in the frame-like formulation the triplet fields are endowed with the geometrical meaning of being components of higher-spin vielbeins and connections and present actions describing their free dynamics.

  19. Decomposition of formyl fluoride on the lowest triplet state surface

    Science.gov (United States)

    Sumathi, R.; Chandra, A. K.

    1992-09-01

    Decomposition of formyl fluoride on the lowest triplet potential energy hypersurface is studied using ab initio quantum chemical methods. Dissociation energies and the barrier to dissociation from the lowest triplet HFCO into H( 2S) and FCO( 2A') are reported. Results reveal that the barrier to dissociation into F( 2P) + HCO( 2A') is very high. The triatomic radical, FCO( 2A') decomposes into F( 2P) + CO( 1Σ) from the high vibrational levels of the C-F stretch.

  20. Triplet exciton dissociation in singlet exciton fission photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Priya J.; Mohanty, Aseema; Bulovic, Vladimir; Baldo, Marc A. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA (United States); Brown, Patrick R. [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA (United States); Thompson, Nicholas [Department of Materials Science, Massachusetts Institute of Technology, Cambridge, MA (United States); Wunsch, Benjamin [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA (United States); Yost, Shane R.; Hontz, Eric; Van Voorhis, Troy; Bawendi, Moungi G. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2012-12-04

    Triplet exciton dissociation in singlet exciton fission devices with three classes of acceptors are characterized: fullerenes, perylene diimides, and PbS and PbSe colloidal nanocrystals. Using photocurrent spectroscopy and a magnetic field probe it is found that colloidal PbSe nanocrystals are the most promising acceptors, capable of efficient triplet exciton dissociation and long wavelength absorption. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Exploring Hyperchargeless Higgs Triplet Model up to the Planck Scale

    CERN Document Server

    Khan, Najimuddin

    2016-01-01

    We examine extended Higgs triplet of Standard Model taking into consideration the Higgs-like particle discovery at the LHC with mass around 125 GeV. We evaluate the bounds on the scalar potential through the unitarity of the scattering-matrix. Considering with and without $Z_2$-symmetry on the extra triplet, we derive constraints on the parameter space. We identify the region of the parameter space that corresponds to the stability and metastability of the electroweak vacuum.

  2. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Paaske, Erik

    1998-01-01

    the iteration process provides the sequential decoders with side information that allows a smaller average load and minimizes the probability of computational overflow. Analytical results for the probability that the first RS word is decoded after C computations are presented. These results are supported...

  3. Sequential memory: Binding dynamics

    Science.gov (United States)

    Afraimovich, Valentin; Gong, Xue; Rabinovich, Mikhail

    2015-10-01

    Temporal order memories are critical for everyday animal and human functioning. Experiments and our own experience show that the binding or association of various features of an event together and the maintaining of multimodality events in sequential order are the key components of any sequential memories—episodic, semantic, working, etc. We study a robustness of binding sequential dynamics based on our previously introduced model in the form of generalized Lotka-Volterra equations. In the phase space of the model, there exists a multi-dimensional binding heteroclinic network consisting of saddle equilibrium points and heteroclinic trajectories joining them. We prove here the robustness of the binding sequential dynamics, i.e., the feasibility phenomenon for coupled heteroclinic networks: for each collection of successive heteroclinic trajectories inside the unified networks, there is an open set of initial points such that the trajectory going through each of them follows the prescribed collection staying in a small neighborhood of it. We show also that the symbolic complexity function of the system restricted to this neighborhood is a polynomial of degree L - 1, where L is the number of modalities.

  4. Improving triplet-triplet-annihilation based upconversion systems by tuning their topological structure

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Jochen, E-mail: jochen.zimmermann@physik.uni-freiburg.de; Wellens, Thomas; Buchleitner, Andreas [Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Mulet, Roberto [Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Group of Complex Systems, Department of Theoretical Physics, Physics Faculty, University of Havana (Cuba); Scholes, Gregory D. [Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Department of Chemistry, Institute for Optical Sciences, and Centre for Quantum Information and Quantum Control, University of Toronto, 80 St George Street, Toronto, Ontario M5S 3H6 (Canada)

    2014-11-14

    Materials capable to perform upconversion of light transform the photon spectrum and can be used to increase the efficiency of solar cells by upconverting sub-bandgap photons, increasing the density of photons able to generate an electron-hole pair in the cell. Incoherent solar radiation suffices to activate upconverters based on sensitized triplet-triplet annihilation, which makes them particularly suited for this task. This process requires two molecular species, sensitizers absorbing low energy photons, and emitters generating higher frequency photons. Successful implementations exist in solutions and solids. However, solid upconverters exhibit lower efficiency than those in solution, which poses a serious problem for real applications. In the present work, we suggest a new strategy to increase the efficiency of sensitized upconverters that exploits the solid nature of the material. We show that an upconversion model system with molecules distributed as clusters outperforms a system with a random distribution of molecules, as used in current upconverters. Our simulations reveal a high potential for improvement of upconverter systems by exploring different structural configurations of the molecules. The implementation of advanced structures can push the performance of solid upconverters further towards the theoretical limit and a step closer to technological application of low power upconversion.

  5. Improving triplet-triplet-annihilation based upconversion systems by tuning their topological structure.

    Science.gov (United States)

    Zimmermann, Jochen; Mulet, Roberto; Scholes, Gregory D; Wellens, Thomas; Buchleitner, Andreas

    2014-11-14

    Materials capable to perform upconversion of light transform the photon spectrum and can be used to increase the efficiency of solar cells by upconverting sub-bandgap photons, increasing the density of photons able to generate an electron-hole pair in the cell. Incoherent solar radiation suffices to activate upconverters based on sensitized triplet-triplet annihilation, which makes them particularly suited for this task. This process requires two molecular species, sensitizers absorbing low energy photons, and emitters generating higher frequency photons. Successful implementations exist in solutions and solids. However, solid upconverters exhibit lower efficiency than those in solution, which poses a serious problem for real applications. In the present work, we suggest a new strategy to increase the efficiency of sensitized upconverters that exploits the solid nature of the material. We show that an upconversion model system with molecules distributed as clusters outperforms a system with a random distribution of molecules, as used in current upconverters. Our simulations reveal a high potential for improvement of upconverter systems by exploring different structural configurations of the molecules. The implementation of advanced structures can push the performance of solid upconverters further towards the theoretical limit and a step closer to technological application of low power upconversion.

  6. Sequential measurements of conjugate observables

    Energy Technology Data Exchange (ETDEWEB)

    Carmeli, Claudio [Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Heinosaari, Teiko [Department of Physics and Astronomy, Turku Centre for Quantum Physics, University of Turku, 20014 Turku (Finland); Toigo, Alessandro, E-mail: claudio.carmeli@gmail.com, E-mail: teiko.heinosaari@utu.fi, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica ' Francesco Brioschi' , Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2011-07-15

    We present a unified treatment of sequential measurements of two conjugate observables. Our approach is to derive a mathematical structure theorem for all the relevant covariant instruments. As a consequence of this result, we show that every Weyl-Heisenberg covariant observable can be implemented as a sequential measurement of two conjugate observables. This method is applicable both in finite- and infinite-dimensional Hilbert spaces, therefore covering sequential spin component measurements as well as position-momentum sequential measurements.

  7. Modelling sequentially scored item responses

    NARCIS (Netherlands)

    Akkermans, W.

    2000-01-01

    The sequential model can be used to describe the variable resulting from a sequential scoring process. In this paper two more item response models are investigated with respect to their suitability for sequential scoring: the partial credit model and the graded response model. The investigation is c

  8. Sequential cloning of chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1991-12-31

    A method for sequential cloning of chromosomal DNA and chromosomal DNA cloned by this method are disclosed. The method includes the selection of a target organism having a segment of chromosomal DNA to be sequentially cloned. A first DNA segment, having a first restriction enzyme site on either side. homologous to the chromosomal DNA to be sequentially cloned is isolated. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  9. Sequential cloning of chromosomes

    Science.gov (United States)

    Lacks, S.A.

    1995-07-18

    A method for sequential cloning of chromosomal DNA of a target organism is disclosed. A first DNA segment homologous to the chromosomal DNA to be sequentially cloned is isolated. The first segment has a first restriction enzyme site on either side. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction (class IIS) enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes. 9 figs.

  10. Birth weight discordance and perinatal mortality among triplets

    Directory of Open Access Journals (Sweden)

    Egić Amira

    2005-01-01

    Full Text Available INTRODUCTION. The incidence of multiple births has increased in the last decade. Perinatal mortality in triplets is significantly greater than in twin and singleton births. OBJECTIVE. The objective of this study was to describe the extent of birth weight discordance among triplets and to identify its association with an increased risk of perinatal mortality. METHOD A retrospective analysis of triplet births, for the period 1993-2003, was conducted at the Gynaecological-Obstetric Clinic "Narodni Front" in Belgrade. Birth weight discordance was defined as the difference in birth weight between the largest and the smallest triplet's weight of more than 20%. RESULTS. The rate of triplets has increased by almost 75% between the first (7.7% and the last (29.6% 5-year period of the last decade. Triplets are becoming more common because of the frequent use of assisted reproductive technology as a treatment for infertility. In the period 1993-2003, there were a total of 40 triplet live births (24 weeks and greater with incidence of 0.06%. There was no clear association between maternal age, parity, method of conception, birth gestational age, and disorders complicating pregnancy with birth discordance more than 20%. Regarding birth weight groups, statistical significance occurred only in the <999 grams group for discordant and in the 2000-2499 grams group for concordant triplets. Overall, the perinatal mortality rate in the group was 10.8%, the foetal mortality rate was 1.7% (2/120, and the neonatal (0-28 days mortality rate was 9.1% (11/120. An odds ratio of 95% confidence interval shows 3 times greater risk for adverse perinatal outcome in the discordant group. However, the difference was not significant. CONCLUSION. Increasing birth weight discordance may increase the risk of adverse perinatal outcome. Triplet pregnancies, being high risk, require intensive antenatal care in order to prevent preterm delivery and ultrasound in order to diagnose foetal

  11. Photolysis of alpha-azidoacetophenones: direct detection of triplet alkyl nitrenes in solution.

    Science.gov (United States)

    Singh, Pradeep N D; Mandel, Sarah M; Robinson, Rachel M; Zhu, Zhendong; Franz, Roberto; Ault, Bruce S; Gudmundsdóttir, Anna D

    2003-10-17

    We report the first detection of triplet alkyl nitrenes in fluid solution by laser flash photolysis of alpha-azido acetophenone derivatives, 1. Alphazides 1 contain an intramolecular triplet sensitizer, which ensures formation of the triplet alkyl nitrene by bypassing the singlet nitrene intermediate. At room temperature, azides 1 cleave to form benzoyl and methyl azide radicals in competition with triplet energy transfer to form triplet alkyl nitrene. The major photoproduct 3 arises from interception of the triplet alkyl nitrene with benzoyl radicals. The triplet alkyl nitrene intermediates are also trapped with molecular oxygen to yield the corresponding 2-nitrophenylethanone. Laser flash photolysis of 1 reveals that the triplet alkyl nitrenes have absorption around 300 nm. The triplet alkyl nitrenes were further characterized by obtaining their UV and IR spectra in argon matrices. (13)C and (15)N isotope labeling studies allowed us to characterize the C-N stretch of the nitrene intermediate at 1201 cm(-)(1).

  12. [Neonatal morbidity and hospital mortality of preterm triplets.

    Science.gov (United States)

    Lamshing-Salinas, Priscilla; Rend Ón-Macías, Mario Enrique; Iglesias-Leboreiro, José; Bernárdez-Zapata, Isabel; Braverman-Bronstein, Ariela

    2013-01-01

    Background: multiple gestations have caused an increase in vulnerable preterm births. Our objective was to analyze neonatal morbidity and mortality in preterm triplets. Methods: we analyzed a cohort of 30 triplets in an obstetrics and gynecology hospital. Data were obtained during pregnancy, childbirth and neonatal period: birth order, sex, weight, height, malformations, advanced resuscitation, assisted ventilation, intraventricular hemorrhage, necrotizing enterocolitis, sepsis, pulmonary hypertension, bronchopulmonary dysplasia, days of hospitalization, and death. Results: 90 infants were analyzed. There was an omphalopagus con-joined twins case; 42 (70 %) had between 30-33 weeks and six between 24-29; 19 (21 %) had low weight for gestational age, and 18 (30 %) had a major malformation; 27 % required ventilatory support, 33 % sepsis, 32 % necrotizing enterocolitis, 21 % pulmonary hypertension, 14 % bronchopulmonary dysplasia and 2 % intraventricular hemorrhage, without statistically significant differences related to the order, presentation at birth, sex and number of placentas and amniotic sacs. Eight 24-week triplets died, four over 28 weeks, and a siamese (p = 38). There was no difference in hospital days between triplets. Conclusions: the triplets mortality is low and mainly associated with extreme prematurity, intrauterine growth restriction and sepsis.

  13. Rates and singlet/triplet ratios from TADF transients

    CERN Document Server

    Nelson, Mitchell C

    2016-01-01

    Thermally activated delayed fluorescence has been reported in a number of OLED emitter materials engineered to have low singlet-triplet energy gaps. Here we derive closed solutions for steady state and transient behaviors and apply these results to data provided in recent reports. Earlier work has used yields, rates and a supplied forward crossing rate to estimate the reverse crossing rate and then obtain the singlet-triplet energy gap in a log-linear fit. In this work we use only the system relaxation times and obtain all five of the system constants: the singlet and triplet relaxation rates, the forward and reverse crossing rates and the singlet-triplet energy gap. These are then used to calculate the fluorescent/phosphorescent ratio and the singlet/triplet population ratio. Good fits are obtained for data from 4CzIPN and from the excimer m-MTDATA:t-Bu-PBD and the results appear to be consistent with the reported behaviors of OLEDS using these materials.

  14. Fat Branes, Orbifolds and Doublet-Triplet Splitting

    CERN Document Server

    Haba, N; Haba, Naoyuki; Maru, Nobuhito

    2003-01-01

    A simple higher dimensional mechanism of the doublet-triplet splitting is presented in a five dimensional supersymmetric SU(5) GUT on S^1/Z_2. The splitting of multiplets is realized by a VEV of the adjoint chiral superfield which breaks SU(5) gauge symmetry. Depending on the sign of the VEV, zero mode Higgs doublets and triplets are localized on the either side of the fixed points. The mass splitting is realized due to the difference of magnitudes of the overlap with a brane localized or a bulk singlet field. No unnatural fine-tuning of parameters is needed. The proton stability is ensured by locality {em without symmetries}. As well as a conventional mass splitting solution, it is shown that the weak scale Higgs triplet is consistent with the proton stability. This result might provide an alternative signature of GUT in future collider experiments.

  15. Ion-Pair States in Triplet Molecular Hydrogen

    Science.gov (United States)

    Setzer, W.; Baker, B. C.; Ashman, S.; Morgan, T. J.

    2016-05-01

    An experimental search is underway to observe the long range triplet ionic states H+ H- of molecular hydrogen. Resonantly enhanced multi-photon ionization of the metastable c 3∏u- 2 pπ state is used access to the R(1)nd1 n = 21 Rydberg state that serves as an intermediate stepping stone state to probe the energy region above the ionization limit with a second tunable laser photon. The metastable state is prepared by electron capture of 6 keV H2+ions in potassium in a molecular beam. Formation of the H+ H- triplet configuration involves triplet excited states of the H- ion, especially the 2p23Pe state, the second bound state of H- predicted to exist with a lifetime long compared to typical auto ionization lifetimes but not yet observed experimentally. Details of the experiment and preliminary results to date will be presented at the conference.

  16. Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter

    CERN Document Server

    Lu, Wen-Bin

    2016-01-01

    We extend the standard model by three types of inert fields including Majorana fermion singlets/triplets, real Higgs singlets/triplets and leptonic Higgs doublets. In the presence of a softly broken lepton number and an exactly conserved Z_2 discrete symmetry, these inert fields together can mediate a one-loop diagram for a Majorana neutrino mass generation. The heavier inert fields can decay to realize a successful leptogenesis while the lightest inert field can provide a stable dark matter candidate. As an example, we demonstrate the leptogenesis by the inert Higgs doublet decays. We also perform a systematic study on the inert Higgs triplet dark matter scenario where the interference between the gauge and Higgs portal interactions can significantly affect the dark matter properties.

  17. Homo- or Hetero- Triplet-Triplet Annihilation? A Case Study with Perylene-Bodipy Dyads/Triads

    KAUST Repository

    Cui, Xiaoneng

    2017-07-06

    The photophysical processes of intramolecular ‘ping-pong’ energy transfers in the iodinated reference dyad BDP-I2-Py, as well as the uniodinated dyad BDP-Py and triad BDP-2Py, were studied. For BDP-I2-Py, a forward Förster resonance energy transfer (FRET) from the perylene (Py) unit to the diiodoBDP unit (7 ps) and a backward triplet energy transfer (TTET, 3 ns) from the diiodoBDP unit to the Py unit were observed. For the BDP-Py and BDP-2Py systems, a FRET (5 ~ 8 ps) and a photo-induced electron transfer (PET) (1-1.5 ns) were observed in acetonitrile. The uniodinated dyad and triad were used as the triplet energy acceptor and emitter for a TTA upconversion with palladium tetraphenyltetrabenzoporphyrin as the triplet photosensitizer. A maximum upconversion quantum yield of 12.6 % was measured. Given that the dyad (BDP-Py) contains one BDP unit and one Py unit, while the triad (BDP-2Py) contains two Py units and one BDP unit, and based on the results from steady-state femtosecond and nanosecond transient optical spectroscopies, it is concluded that neither intramolecular homo- triplet-triplet annihilation (TTA) nor intramolecular hetero-TTA is possible during a TTA upconversion for those upconversion systems.

  18. Forced Sequence Sequential Decoding

    DEFF Research Database (Denmark)

    Jensen, Ole Riis

    In this thesis we describe a new concatenated decoding scheme based on iterations between an inner sequentially decoded convolutional code of rate R=1/4 and memory M=23, and block interleaved outer Reed-Solomon codes with non-uniform profile. With this scheme decoding with good performance is pos...... of computational overflow. Analytical results for the probability that the first Reed-Solomon word is decoded after C computations are presented. This is supported by simulation results that are also extended to other parameters....

  19. Network realization of triplet-type quantum stochastic systems

    Science.gov (United States)

    Zhou, Shaosheng; Fu, Shizhou; Chen, Yuping

    2017-01-01

    This paper focuses on a problem of network synthesis for a class of quantum stochastic systems. The systems under consideration are of triplet-type form and stem from linear quantum optics and linear quantum circuits. A new quantum network realization approach is proposed by generalizing the scattering operator from the scalar form to a unitary matrix in network components. It shows that the triplet-type quantum stochastic system can be approximated by a quantum network which consists of some one-degree-of-freedom generalized open-quantum harmonic oscillators (1DGQHOs) via series, concatenation and feedback connections.

  20. CHROMOSPHERIC POLARIZATION IN THE PHOTOSPHERIC SOLAR OXYGEN INFRARED TRIPLET

    Energy Technology Data Exchange (ETDEWEB)

    Del Pino Alemán, Tanausú; Trujillo Bueno, Javier [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2015-07-20

    We present multilevel radiative transfer modeling of the scattering polarization observed in the solar O i infrared triplet around 777 nm. We demonstrate that the scattering polarization pattern observed on the solar disk forms in the chromosphere, far above the photospheric region where the bulk of the emergent intensity profiles originate. We investigate the sensitivity of the polarization pattern to the thermal structure of the solar atmosphere and to the presence of weak magnetic fields (10{sup −2}–100 G) through the Hanle effect, showing that the scattering polarization signals of the oxygen infrared triplet encode information on the magnetism of the solar chromosphere.

  1. Chromospheric Polarization in the Photospheric Solar Oxygen Infrared Triplet

    CERN Document Server

    Alemán, T del Pino

    2015-01-01

    We present multilevel radiative transfer modeling of the scattering polarization observed in the solar O I infrared triplet around 777 nm. We demonstrate that the scattering polarization pattern observed on the solar disk forms in the chromosphere, far above the photospheric region where the bulk of the emergent intensity profiles originates. We study the sensitivity of the polarization pattern to the thermal structure of the solar atmosphere and to the presence of weak magnetic fields (0.01 - 100 G) through the Hanle effect, showing that the scattering polarization signals of the oxygen infrared triplet encode information on the magnetism of the solar chromosphere.

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

    Directory of Open Access Journals (Sweden)

    J.Spałek

    2008-09-01

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

  3. Analysis of the phosphorescent dye concentration dependence of triplet-triplet annihilation in organic host-guest systems

    Science.gov (United States)

    Zhang, L.; van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

    2016-10-01

    Using a novel method for analyzing transient photoluminescence (PL) experiments, a microscopic description is obtained for the dye concentration dependence of triplet-triplet annihilation (TTA) in phosphorescent host-guest systems. It is demonstrated that the TTA-mechanism, which could be a single-step dominated process or a diffusion-mediated multi-step process, can be deduced for any given dye concentration from a recently proposed PL intensity analysis. A comparison with the results of kinetic Monte Carlo simulations provides the TTA-Förster radius and shows that the TTA enhancement due to triplet diffusion can be well described in a microscopic manner assuming Förster- or Dexter-type energy transfer.

  4. High-efficiency fluorescent organic light-emitting diodes enabled by triplet-triplet annihilation and horizontal emitter orientation

    Energy Technology Data Exchange (ETDEWEB)

    Mayr, Christian, E-mail: Christian.Mayr@physik.uni-augsburg.de; Schmidt, Tobias D.; Brütting, Wolfgang, E-mail: Wolfgang.Bruetting@physik.uni-augsburg.de [Institute of Physics, University of Augsburg, 86135 Augsburg (Germany)

    2014-11-03

    A green organic light-emitting diode with the fluorescent emitter Coumarin 545T shows an external quantum efficiency (η{sub EQE}) of 6.9%, clearly exceeding the classical limit of 5% for fluorescent emitters. The analysis of the angular dependent photoluminescence spectrum of the emission layer reveals that 86% of the transition dipole moments are horizontally oriented. Furthermore, transient electroluminescence measurements demonstrate the presence of a delayed emission originating from triplet-triplet annihilation. A simulation based efficiency analysis reveals quantitatively the origin for the high η{sub EQE}: a radiative exciton fraction higher than 25% and a light-outcoupling efficiency of nearly 30%.

  5. New sets of experimental wavenumber values for triplet-triplet rovibronic transitions of $H_2$ and $D_2$

    CERN Document Server

    Lavrov, Boris P; Umrikhin, Ivan S

    2010-01-01

    New sets of experimental wavenumber values for triplet-triplet rovibronic transitions of $H_2$ and $D_2$ for visible part of spectrum ($400 \\div 700$ nm) have been obtained. The digital intensity registration providing a linear response of the detector gave us the opportunity of digital deconvolution of the recorded line profiles. For line centers that made it possible to reach an accuracy limited only by selfconsistency of various wavenumber standards. New set of data was obtained with accuracy $0.006 \\div 0.05$ cm$^{-1}$.

  6. Intramolecular triplet energy transfer in anthracene-based platinum acetylide oligomers.

    Science.gov (United States)

    Li, Yongjun; Köse, Muhammet E; Schanze, Kirk S

    2013-08-01

    Platinum acetylide oligomers that contain an anthracene moiety have been synthesized and subjected to photophysical characterization. Spectroscopic measurement and DFT calculations reveal that both the singlet and triplet energy levels of the anthracene segment are lower than those of the platinum acetylide segment. Thus, the platinum acetylide segment acts as a sensitizer to populate the triplet state of the anthrancene segment via intramolecular triplet-triplet energy transfer. The objective of this work is to understand the mechanisms of energy-transfer dynamics in these systems. Fluorescence quenching and the dominant triplet absorption that arises from the anthracene segment in the transient absorption spectrum of Pt4An give clear evidence that energy transfer adopts an indirect mechanism, which begins with singlet-triplet energy transfer from the anthracene segment to the platinum acetylide segment followed by triplet-triplet energy transfer to the anthracene segment.

  7. Stability of singlet and triplet trions in carbon nanotubes

    DEFF Research Database (Denmark)

    Rønnow, Troels Frimodt; Pedersen, Thomas Garm; Cornean, Horia

    2009-01-01

    We investigate singlet and triplet trion states in semiconducting carbon nanotubes using a one-dimensional model. It is concluded that singlet trion states in bind up to 13.5% stronger than exciton states, and that they lower the optical transition energy with up to 50% of the tight binding band ...

  8. Properties of the Triplet State of Coumarin Substituted Compounds

    Science.gov (United States)

    Bryantseva, N. G.; Gadirov, R. M.; Nikonov, S. Yu.; Sokolova, I. V.

    2015-03-01

    The absorption spectra of the triplet excited state of coumarin sensitizers are investigated both theoretically and experimentally. The most intense triplet-triplet (TT) absorption bands are determined. The experimental spectra of the T-T absorption are compared with the theoretical T-T transitions. The phosphorescence spectra of five compounds are measured at a temperature of 77 K. The quantum phosphorescence yield is determined by the method of comparison with an etalon (8-methoxypsoralen). The phosphorescence lifetime is determined for the examined molecules at a temperature of 77 K. For 3,4-phenyl-4',5'-cyclohexylpsoralen, 4'-methyl-3,4-cycloheptylpsoralen, and 4'5'-dimethyl-3,4-cyclohexylpsoralen compounds, this time is equal to 1.1, 1.25, and 2.5 s, respectively. The main energy deactivation channel for all examined compounds is the phosphorescence. The positions of the lower excited triplet states, calculated by the quantum-chemical method of intermediate neglect of differential overlap with spectroscopic parameterization (INDO/S), are confirmed by the available experimental data.

  9. The Infrared Ca II triplet as metallicity indicator

    CERN Document Server

    Carrera, Ricardo; Pancino, Elena; Zinn, Robert

    2007-01-01

    From observations of almost 500 RGB stars in 29 Galactic open and globular clusters, we have investigated the behaviour of the infrared Ca II triplet (8498, 8542 and 8662 \\AA) in the age range 13$\\leq$Age/Gyr$\\leq$0.25 and the metallicity range $-2.2\\leq$ [Fe/H] $\\leq$+0.47. These are the widest ranges of ages and metallicities in which the behaviour of the Ca II triplet lines has been investigated in a homogeneous way. We report the first empirical study of the variation of the CaII triplet lines strength, for given metallicities, with respect to luminosity. We find that the sequence defined by each cluster in the Luminosity-$\\Sigma$Ca plane is not exactly linear. However, when only stars in a small magnitude interval are observed, the sequences can be considered as linear. We have studied the the Ca II triplet lines on three metallicities scales. While a linear correlation between the reduced equivalent width ($W'_V$ or $W'_I$) versus metallicity is found in the \\citet{cg97} and \\citet{ki03} scales, a secon...

  10. Mirror and triplet displacement energies within nuclear DFT: numerical stability

    CERN Document Server

    Baczyk, Pawel; Konieczka, Maciej; Nakatsukasa, Takashi; Sato, Koichi; Satula, Wojciech

    2016-01-01

    Isospin-symmetry-violating class II and III contact terms are introduced into the Skyrme energy density functional to account for charge dependence of the strong nuclear interaction. The two new coupling constants are adjusted to available experimental data on triplet and mirror displacement energies, respectively. We present preliminary results of the fit, focusing on its numerical stability with respect to the basis size.

  11. Vector-like quarks with a scalar triplet

    CERN Document Server

    Leskow, Estefania Coluccio; de la Puente, Alejandro

    2014-01-01

    We study a model independent extension to the Standard Model with an addi- tional real scalar triplet, {\\Sigma}, and a single vector-like quark, T . This class of models appear naturally in extensions of the Littlest Higgs model that incorporate dark matter without the need of T -parity. We assume that the triplet does not develop a vacuum expectation value and that all dimension five operators coupling the triplet to Standard Model fields and the vector-like quarks are parametrized by the scale {\\Lambda} at which we expect new physics to arise. We introduce new non-renormalizable interactions between the new scalar sector and fermion sector that allow mixing between the Standard Model third generation up-type quark and the vector-like quark in a way that leads to the cancellation of the leading quadratic divergences to the one-loop corrections to the mass of the Higgs boson. Within this framework, new de- cay modes of the vector-like quark to the real scalar triplet and SM particles arise and bring forth an ...

  12. Triplet State Resonance Raman Spectrum of all-trans-diphenylbutadiene

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Grossman, W.E.L.; Killough, P.M

    1984-01-01

    The resonance Raman spectrum of all-trans-diphenylbutadiene (DPB) in its ground state and the resonance Raman spectrum (RRS) of DPB in its short-lived electronically excited triplet state are reported. Transient spectra were obtained by a pump-probe technique using two pulsed lasers...

  13. Vector-like quarks with a scalar triplet

    Directory of Open Access Journals (Sweden)

    Estefania Coluccio Leskow

    2015-04-01

    Full Text Available We study a minimal extension to the Standard Model with an additional real scalar triplet, Σ, and a single vector-like quark, T. This class of models appear naturally in extensions of the Littlest Higgs model that incorporate dark matter without the need of T-parity. We assume the limit that the triplet does not develop a vacuum expectation value and that all dimension five operators coupling the triplet to Standard Model fields and the vector-like quarks are characterized by the scale Λ at which we expect new physics to arise. We introduce new non-renormalizable interactions between the new scalar sector and fermion sector that allow mixing between the Standard Model third generation up-type quark and the vector-like quark in a way that leads to the cancellation of the leading quadratic divergences to the one-loop corrections from the top quark to the mass of the Higgs boson. Within this framework, new decay modes of the vector-like quark to the real scalar triplet and SM particles arise and bring forth an opportunity to probe this model with existing and future LHC data. We contrast constraints from direct colliders searches with low energy precision measurements and find that heavy vector-like top quarks with a mass as low as 650 GeV are consistent with current experimental constraints in models where new physics arises at scales below 2 TeV.

  14. The fragment spin difference scheme for triplet-triplet energy transfer coupling.

    Science.gov (United States)

    You, Zhi-Qiang; Hsu, Chao-Ping

    2010-08-21

    To calculate the electronic couplings in both inter- and intramolecular triplet energy transfer (TET), we have developed the "fragment spin difference" (FSD) scheme. The FSD was a generalization from the "fragment charge difference" (FCD) method of Voityuk et al. [J. Chem. Phys. 117, 5607 (2002)] for electron transfer (ET) coupling. In FSD, the spin population difference was used in place of the charge difference in FCD. FSD is derived from the eigenstate energies and populations, and therefore the FSD couplings contain all contributions in the Hamiltonian as well as the potential overlap effect. In the present work, two series of molecules, all-trans-polyene oligomers and polycyclic aromatic hydrocarbons, were tested for intermolecular TET study. The TET coupling results are largely similar to those from the previously developed direct coupling scheme, with FSD being easier and more flexible in use. On the other hand, the Dexter's exchange integral value, a quantity that is often used as an approximate for the TET coupling, varies in a large range as compared to the corresponding TET coupling. To test the FSD for intramolecular TET, we have calculated the TET couplings between zinc(II)-porphyrin and free-base porphyrin separated by different numbers of p-phenyleneethynylene bridge units. Our estimated rate constants are consistent with experimentally measured TET rates. The FSD method can be used for both intermolecular and intramolecular TET, regardless of their symmetry. This general applicability is an improvement over most existing methodologies.

  15. The fragment spin difference scheme for triplet-triplet energy transfer coupling

    Science.gov (United States)

    You, Zhi-Qiang; Hsu, Chao-Ping

    2010-08-01

    To calculate the electronic couplings in both inter- and intramolecular triplet energy transfer (TET), we have developed the "fragment spin difference" (FSD) scheme. The FSD was a generalization from the "fragment charge difference" (FCD) method of Voityuk et al. [J. Chem. Phys. 117, 5607 (2002)] for electron transfer (ET) coupling. In FSD, the spin population difference was used in place of the charge difference in FCD. FSD is derived from the eigenstate energies and populations, and therefore the FSD couplings contain all contributions in the Hamiltonian as well as the potential overlap effect. In the present work, two series of molecules, all-trans-polyene oligomers and polycyclic aromatic hydrocarbons, were tested for intermolecular TET study. The TET coupling results are largely similar to those from the previously developed direct coupling scheme, with FSD being easier and more flexible in use. On the other hand, the Dexter's exchange integral value, a quantity that is often used as an approximate for the TET coupling, varies in a large range as compared to the corresponding TET coupling. To test the FSD for intramolecular TET, we have calculated the TET couplings between zinc(II)-porphyrin and free-base porphyrin separated by different numbers of p-phenyleneethynylene bridge units. Our estimated rate constants are consistent with experimentally measured TET rates. The FSD method can be used for both intermolecular and intramolecular TET, regardless of their symmetry. This general applicability is an improvement over most existing methodologies.

  16. Active Sequential Hypothesis Testing

    CERN Document Server

    Naghshvar, Mohammad

    2012-01-01

    Consider a decision maker who is responsible to dynamically collect observations so as to enhance his information in a speedy manner about an underlying phenomena of interest while accounting for the penalty of wrong declaration. The special cases of the problem are shown to be that of variable-length coding with feedback and noisy dynamic search. Due to the sequential nature of the problem, the decision maker relies on his current information state to adaptively select the most "informative" sensing action among the available ones. In this paper, using results in dynamic programming, a lower bound for the optimal total cost is established. Moreover, upper bounds are obtained via an analysis of heuristic policies for dynamic selection of actions. It is shown that the proposed heuristics achieve asymptotic optimality in many practically relevant problems including the problems of variable-length coding with feedback and noisy dynamic search; where asymptotic optimality implies that the relative difference betw...

  17. Intramolecular triplet energy transfer via higher triplet excited state during stepwise two-color two-laser irradiation.

    Science.gov (United States)

    Oseki, Yosuke; Fujitsuka, Mamoru; Sakamoto, Masanori; Majima, Tetsuro

    2007-10-01

    We studied the energy transfer processes in the molecular array consisting of pyrene (Py), biphenyl (Ph2), and bisphthalimidethiophene (ImT), (Py-Ph2)2-ImT, during two-color two-laser flash photolysis (2-LFP). The first laser irradiation predominantly generates ImT in the lowest triplet excited state (ImT(T1)) because of the efficient singlet energy transfer from Py in the lowest singlet excited state to ImT and, then, intersystem crossing of ImT. ImT(T1) was excited to the higher triplet excited state (Tn) with the second laser irradiation. Then, the triplet energy was rapidly transferred to Py via a two-step triplet energy transfer (TET) process through Ph2. The efficient generation of Py(T1) was suggested from the nanosecond-picosecond 2-LFP. The back-TET from Py(T1) to ImT was observed for several tens of microseconds after the second laser irradiation. The estimated intramolecular TET rate from Py(T1) to ImT was as slow as 3.1 x 104 s-1. Hence, long-lived Py(T1) was selectively and efficiently produced during the 2-LFP.

  18. Multi-Attribute Sequential Search

    Science.gov (United States)

    Bearden, J. Neil; Connolly, Terry

    2007-01-01

    This article describes empirical and theoretical results from two multi-attribute sequential search tasks. In both tasks, the DM sequentially encounters options described by two attributes and must pay to learn the values of the attributes. In the "continuous" version of the task the DM learns the precise numerical value of an attribute when she…

  19. Step-Scan FTIR spectroscopy and quantum chemical calculations of xanthone in the triplet state

    Science.gov (United States)

    Buschhaus, L.; Kleinermanns, K.

    2014-10-01

    Step-Scan-FTIR spectroscopy has been used to measure the infrared spectrum of xanthone in the triplet state using chloroform as solvent. Xanthone is an important triplet sensitizer and therefore suitable as model system. Xanthone was excited at 266 nm and its IR triplet spectrum measured in the range 1000-1750 cm-1. The spectrum was analyzed by comparison with DFT/B3LYP/TZVP/COSMO calculations. Further on the results were compared to gas phase IR measurements of triplet xanthone and calculations of isolated xanthone. Mainly based on the calculations we tried to identify the geometry changes from the electronic ground state to the first triplet state.

  20. A Laser Photolysis Study of Triplet Lifetimes and of Triplet–Triplet Annihilation Reactions of Phthalocyanins in DMSO Solutions (Etude des Durées de Vie du Triplet et des Réactions d'Annihilation Triplet–Triplet de Phthalocyanines dans le DMSO par Photolyse Laser)

    OpenAIRE

    Debacker, M. G.; Deleplanque, O.; Van Vlierberge, B.; Sauvage, F. X.

    1988-01-01

    Triplet decay of Mg and Zn phthalocyanins have been studied by laser flash photolysis as a function of concentration. The triplet decay mechanism changes from a near first order in dilute solution to an almost second order in concentrated solutions. This is interpreted in terms of triplet–triplet recombinaison. With the help of a reducing agent, it is shown that the triplet–triplet reaction can lead to charge separation.La décroissance des états excités triplet des phthalocyanines de Mg et de...

  1. Heats of Formation of Triplet Ethylene, Ethylidene, and Acetylene

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, M.T.; Matus, M.H.; Lester Jr, W.A.; Dixon, David A.

    2007-06-28

    Heats of formation of the lowest triplet state of ethylene and the ground triplet state of ethylidene have been predicted by high level electronic structure calculations. Total atomization energies obtained from coupled-cluster CCSD(T) energies extrapolated to the complete basis set limit using correlation consistent basis sets (CBS), plus additional corrections predict the following heats of formation in kcal/mol: Delta H0f(C2H4,3A1) = 80.1 at 0 K and 78.5 at 298 K, and Delta H0f(CH3CH,3A") = 86.8 at 0 K and 85.1 at 298 K, with an error of less than +-1.0 kcal/mol. The vertical and adiabatic singlet-triplet separation energies of ethylene were calculated as Delta ES-T,vert = 104.1 and Delta ES-T,adia = 65.8 kcal/mol. These results are in excellent agreement with recent quantum Monte Carlo (DMC) values of 103.5 +- 0.3 and 66.4 +- 0.3 kcal/mol. Both sets of computational values differ from the experimental estimate of 58 +- 3 kcal/mol for the adiabatic splitting. The computed singlet-triplet gap at 0 K for acetylene is Delta ES-T,adia(C2H2) = 90.5 kcal/mol, which is in notable disagreement with the experimental value of 82.6 kcal/mol. The heat of formation of the triplet is Delta H0f(C2H2,3B2) = 145.3 kcal/mol. There is a systematic underestimation of the singlet-triplet gaps in recent photodecomposition experiments by ~;;7 to 8 kcal/mol. For vinylidene, we predict Delta H0f(H2CC,1A1) = 98.8 kcal/mol at 298 K (exptl. 100.3 +- 4.0), Delta H0f(H2CC,3B2) = 146.2 at 298 K, and an energy gap Delta ES-T-adia(H2CC) = 47.7 kcal/mol.

  2. A sequential tree approach for incremental sequential pattern mining

    Indian Academy of Sciences (India)

    RAJESH KUMAR BOGHEY; SHAILENDRA SINGH

    2016-12-01

    ‘‘Sequential pattern mining’’ is a prominent and significant method to explore the knowledge and innovation from the large database. Common sequential pattern mining algorithms handle static databases.Pragmatically, looking into the functional and actual execution, the database grows exponentially thereby leading to the necessity and requirement of such innovation, research, and development culminating into the designing of mining algorithm. Once the database is updated, the previous mining result will be incorrect, and we need to restart and trigger the entire mining process for the new updated sequential database. To overcome and avoid the process of rescanning of the entire database, this unique system of incremental mining of sequential pattern is available. The previous approaches, system, and techniques are a priori-based frameworks but mine patterns is an advanced and sophisticated technique giving the desired solution. We propose and incorporate an algorithm called STISPM for incremental mining of sequential patterns using the sequence treespace structure. STISPM uses the depth-first approach along with backward tracking and the dynamic lookahead pruning strategy that removes infrequent and irregular patterns. The process and approach from the root node to any leaf node depict a sequential pattern in the database. The structural characteristic of the sequence tree makes it convenient and appropriate for incremental sequential pattern mining. The sequence tree also stores all the sequential patterns with its count and statistics, so whenever the support system is withdrawn or changed, our algorithm using frequent sequence tree as the storage structure can find and detect all the sequential patternswithout mining the database once again.

  3. Sequential Design of Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Anderson-Cook, Christine Michaela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-30

    A sequential design of experiments strategy is being developed and implemented that allows for adaptive learning based on incoming results as the experiment is being run. The plan is to incorporate these strategies for the NCCC and TCM experimental campaigns to be run in the coming months. This strategy for experimentation has the advantages of allowing new data collected during the experiment to inform future experimental runs based on their projected utility for a particular goal. For example, the current effort for the MEA capture system at NCCC plans to focus on maximally improving the quality of prediction of CO2 capture efficiency as measured by the width of the confidence interval for the underlying response surface that is modeled as a function of 1) Flue Gas Flowrate [1000-3000] kg/hr; 2) CO2 weight fraction [0.125-0.175]; 3) Lean solvent loading [0.1-0.3], and; 4) Lean solvent flowrate [3000-12000] kg/hr.

  4. Effect of Förster-mediated triplet-polaron quenching and triplet-triplet annihilation on the efficiency roll-off of organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Eersel, H. van [Simbeyond B.V., P.O. Box 513, NL-5600 MB Eindhoven (Netherlands); Bobbert, P. A.; Janssen, R. A. J.; Coehoorn, R., E-mail: r.coehoorn@tue.nl [Department of Applied Physics and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, NL-5600 MB Eindhoven (Netherlands)

    2016-04-28

    We report the results of a systematic study of the interplay of triplet-polaron quenching (TPQ) and triplet-triplet annihilation (TTA) on the efficiency roll-off of organic light-emitting diodes (OLEDs) with increasing current density. First, we focus on OLEDs based on the green phosphorescent emitter tris[2-phenylpyridine]iridium(III) (Ir(ppy){sub 3}) and the red phosphorescent dye platinum octaethylporphyrin. It is found that the experimental data can be reproduced using kinetic Monte Carlo (kMC) simulations within which TPQ and TTA are due to a nearest-neighbor (NN) interaction, or due to a more long-range Förster-type process. Furthermore, we find a subtle interplay between TPQ and TTA: decreasing the contribution of one process can increase the contribution of the other process, so that the roll-off is not significantly reduced. Furthermore, we find that just analyzing the shape of the roll-off is insufficient for determining the relative role of TPQ and TTA. Subsequently, we investigate the wider validity of this picture using kMC simulations for idealized but realistic symmetric OLEDs, with an emissive layer containing a small concentration of phosphorescent dye molecules in a matrix material. Whereas for NN-interactions the roll-off can be reduced when the dye molecules act as shallow hole and electron traps, we find that such an approach becomes counterproductive for long-range TTA and TPQ. Developing well-founded OLED design rules will thus require that more quantitative information is available on the rate and detailed mechanism of the TPQ and TTA processes.

  5. Effect of Förster-mediated triplet-polaron quenching and triplet-triplet annihilation on the efficiency roll-off of organic light-emitting diodes

    Science.gov (United States)

    van Eersel, H.; Bobbert, P. A.; Janssen, R. A. J.; Coehoorn, R.

    2016-04-01

    We report the results of a systematic study of the interplay of triplet-polaron quenching (TPQ) and triplet-triplet annihilation (TTA) on the efficiency roll-off of organic light-emitting diodes (OLEDs) with increasing current density. First, we focus on OLEDs based on the green phosphorescent emitter tris[2-phenylpyridine]iridium(III) (Ir(ppy)3) and the red phosphorescent dye platinum octaethylporphyrin. It is found that the experimental data can be reproduced using kinetic Monte Carlo (kMC) simulations within which TPQ and TTA are due to a nearest-neighbor (NN) interaction, or due to a more long-range Förster-type process. Furthermore, we find a subtle interplay between TPQ and TTA: decreasing the contribution of one process can increase the contribution of the other process, so that the roll-off is not significantly reduced. Furthermore, we find that just analyzing the shape of the roll-off is insufficient for determining the relative role of TPQ and TTA. Subsequently, we investigate the wider validity of this picture using kMC simulations for idealized but realistic symmetric OLEDs, with an emissive layer containing a small concentration of phosphorescent dye molecules in a matrix material. Whereas for NN-interactions the roll-off can be reduced when the dye molecules act as shallow hole and electron traps, we find that such an approach becomes counterproductive for long-range TTA and TPQ. Developing well-founded OLED design rules will thus require that more quantitative information is available on the rate and detailed mechanism of the TPQ and TTA processes.

  6. Sequential biases in accumulating evidence

    Science.gov (United States)

    Huggins, Richard; Dogo, Samson Henry

    2015-01-01

    Whilst it is common in clinical trials to use the results of tests at one phase to decide whether to continue to the next phase and to subsequently design the next phase, we show that this can lead to biased results in evidence synthesis. Two new kinds of bias associated with accumulating evidence, termed ‘sequential decision bias’ and ‘sequential design bias’, are identified. Both kinds of bias are the result of making decisions on the usefulness of a new study, or its design, based on the previous studies. Sequential decision bias is determined by the correlation between the value of the current estimated effect and the probability of conducting an additional study. Sequential design bias arises from using the estimated value instead of the clinically relevant value of an effect in sample size calculations. We considered both the fixed‐effect and the random‐effects models of meta‐analysis and demonstrated analytically and by simulations that in both settings the problems due to sequential biases are apparent. According to our simulations, the sequential biases increase with increased heterogeneity. Minimisation of sequential biases arises as a new and important research area necessary for successful evidence‐based approaches to the development of science. © 2015 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. PMID:26626562

  7. Measuring oxygen pressures using triplet quenching of Pd-porphine

    Science.gov (United States)

    Sinaasappel, Michiel; Ince, C.; Sanderse, E. A.; Bruining, Hajo A.

    1994-02-01

    A non-invasive optical method for measuring free oxygen in vivo is described. The method, introduced by Wilson and co-workers, is based on the quenching of the triplet state of Pd- porphine by oxygen and is described by the Stern-Volmer relation. The quenching of the triplet state is determined by measurement of the phosphorescence decay following excitation by a pulse of light. Measuring decay times has the advantage that they are independent of the changing optical properties of tissue and concentration of the dye. We describe a setup to measure the phosphorescence decay and present the values of Kq and (tau) o as a function of pH and temperature. Furthermore, some experiments on a rat liver and gut are presented.

  8. Theoretical Investigation on Triplet Excitation Energy Transfer in Fluorene Dimer

    Institute of Scientific and Technical Information of China (English)

    Yu-bing Si; Xin-xin Zhong; Wei-wei Zhang; Yi Zhao

    2011-01-01

    Triplet-triplet energy transfer in fluorene dimer is investigated by combining rate theories with electronic structure calculations.The two key parameters for the control of energy transfer,electronic conpling and reorganization energy,are calculated based on the diabatic states constructed by the constrained density functional theory.The fluctuation of the electronic coupling is further revealed by molecular dynamics simulation.Succeedingly,the diagonal and off-diagonal fluctuations of thc Hamiltonian are mapped from the correlation functions of those parameters,and the rate is then estimated both from the perturbation theory and wavepacket diffusion method.The results manifest that both the static and dynamic fluctuations enhance the rate significantly,but the rate from the dynamic fluctuation is smaller than that from the static fluctuation.

  9. Nonradiative formation of the positron-helium triplet bound state

    Science.gov (United States)

    di Rienzi, Joseph; Drachman, Richard J.

    2007-02-01

    We have previously calculated the cross section for radiative formation of the interesting bound state consisting of a positron bound to helium, where the atomic electrons are in the triplet spin state. That process uses the metastable triplet helium system as target, and, as expected, it has a very small cross section. In this paper we examine a more probable process in which the state of interest is produced in an exchange rearrangement collision between a positronium atom and the singlet helium ground state: Ps+He(Se1)→PsHe+(Se3)+e- . The present calculation is done in the plane-wave Born approximation, using simple initial and final wave functions and compares post and prior forms.

  10. Role of triplet polaron pairs in conjugated polymer photophysics

    Science.gov (United States)

    Wesely, Elizabeth; Rothberg, Lewis; Marchetti, Alfred; Chen, Shaw; Geng, Yanhou; Culligan, Sean

    2007-03-01

    We measure the decay of the long-lived fluorescence of a conjugated oligofluorene at temperatures from 300 K to 20 K. We conclude that nearly all of this emission arises from geminate recombination of photogenerated polaron pairs to reform the singlet exciton, and that charge pair recombination represents a significant contribution to the overall fluorescence quantum yield. The unusual nonmonotonic decay dynamics of the delayed fluorescence can be explained if we assume interconversion between singlet and triplet polaron pairs on the submicrosecond time scale. (˜500 ns.) We are able to model the decay of the delayed fluorescence by assuming activated recombination from a Gaussian energy distribution of singlet polaron pairs centered 0.2 eV below the excited state and having a standard deviation of 0.12 eV. The model is relevant to recent work involving the measurement of singlet-triplet branching ratios and to the yields of electroluminescent devices.

  11. Cloning, characterization, and properties of seven triplet repeat DNA sequences.

    Science.gov (United States)

    Ohshima, K; Kang, S; Larson, J E; Wells, R D

    1996-07-12

    Several neuromuscular and neurodegenerative diseases are caused by genetically unstable triplet repeat sequences (CTG.CAG, CGG.CCG, or AAG.CTT) in or near the responsible genes. We implemented novel cloning strategies with chemically synthesized oligonucleotides to clone seven of the triplet repeat sequences (GTA.TAC, GAT.ATC, GTT.AAC, CAC.GTG, AGG.CCT, TCG.CGA, and AAG.CTT), and the adjoining paper (Ohshima, K., Kang, S., Larson, J. E., and Wells, R. D.(1996) J. Biol. Chem. 271, 16784-16791) describes studies on TTA.TAA. This approach in conjunction with in vivo expansion studies in Escherichia coli enabled the preparation of at least 81 plasmids containing the repeat sequences with lengths of approximately 16 up to 158 triplets in both orientations with varying extents of polymorphisms. The inserts were characterized by DNA sequencing as well as DNA polymerase pausings, two-dimensional agarose gel electrophoresis, and chemical probe analyses to evaluate the capacity to adopt negative supercoil induced non-B DNA conformations. AAG.CTT and AGG.CCT form intramolecular triplexes, and the other five repeat sequences do not form any previously characterized non-B structures. However, long tracts of TCG.CGA showed strong inhibition of DNA synthesis at specific loci in the repeats as seen in the cases of CTG.CAG and CGG.CCG (Kang, S., Ohshima, K., Shimizu, M., Amirhaeri, S., and Wells, R. D.(1995) J. Biol. Chem. 270, 27014-27021). This work along with other studies (Wells, R. D.(1996) J. Biol. Chem. 271, 2875-2878) on CTG.CAG, CGG.CCG, and TTA.TAA makes available long inserts of all 10 triplet repeat sequences for a variety of physical, molecular biological, genetic, and medical investigations. A model to explain the reduction in mRNA abundance in Friedreich's ataxia based on intermolecular triplex formation is proposed.

  12. Updated scalar sector constraints in Higgs triplet model

    CERN Document Server

    Das, Dipankar

    2016-01-01

    We show that in the Higgs triplet model, after the Higgs discovery, the mixing angle in the CP-even sector can be strongly constrained from unitarity. We also discuss how large quantum effects in $h\\to\\gamma\\gamma$ may arise in a SM-like scenario and a certain part of the parameter space can be ruled out from the diphoton signal strength. Using $T$-parameter and diphoton signal strength measurements, we update the bounds on the nonstandard scalar masses.

  13. Sequential Testing: Basics and Benefits

    Science.gov (United States)

    1978-03-01

    103-109 44. A. Wald , Sequential Analysis, John Wiley and Sons, 1947 45. A Wald and J. Wolfowitz , "Optimum Character of The Sequential Probability Ratio...work done by A. Wald [44].. Wald’s work on sequential analysis can be used virtually’without modification in a situation where decisions are made... Wald can be used. The decision to accept, reject, or continue the test depends on: 8 < (8 0/el)r exp [-(1/01 - 1/0 0 )V(t)] < A (1) where 0 and A are

  14. Analysis of Leptogenesis in Supersymmetric Triplet Seesaw Model

    CERN Document Server

    Chun, E J

    2007-01-01

    We analyze leptogenesis in a supersymmetric triplet seesaw scenario that explains the observed neutrino masses, adopting a phenomenological approach where the decay branching ratios of the triplets and the amount of CP--violation in its different decay channels are assumed as free parameters. We find that the solutions of the relevant Boltzmann equations lead to a rich phenomenology, in particular much more complex compared to the non--supersymmetric case, mainly due to the presence of an additional Higgs doublet. Several unexpected and counter--intuitive behaviors emerge from our analysis: the amount of CP violation in one of the decay channels can prove to be be irrelevant to the final lepton asymmetry, leading to successful leptogenesis even in scenarios with a vanishing CP violation in the leptonic sector; gauge annihilations can be the dominant effect in the determination of the evolution of the triplet density up to very high values of its mass, leading anyway to a sizeable final lepton asymmetry, which...

  15. Polaron pair mediated triplet generation in polymer/fullerene blends

    KAUST Repository

    Dimitrov, Stoichko D.

    2015-03-04

    Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whether it involves spin-state mixing is not well understood. In this work, the dynamics of free charge separation competing with recombination to polymer triplet states is studied in two closely related polymer-fullerene blends with differing polymer fluorination and photovoltaic performance. Using time-resolved laser spectroscopic techniques and quantum chemical calculations, we show that lower charge separation in the fluorinated system is associated with the formation of bound electron-hole pairs, which undergo spin-state mixing on the nanosecond timescale and subsequent geminate recombination to triplet excitons. We find that these bound electron-hole pairs can be dissociated by electric fields.

  16. Triplet Energy Transport in Platinum-Acetylide Light Harvesting Arrays.

    Science.gov (United States)

    Chen, Zhuo; Hsu, Hsien-Yi; Arca, Mert; Schanze, Kirk S

    2015-06-18

    Light harvesting and triplet energy transport is investigated in chromophore-functionalized polystyrene polymers featuring light harvesting and energy acceptor chromophores (traps) at varying loading. The series of precision polymers was constructed via reversible addition-fragmentation transfer polymerization and functionalized with platinum acetylide triplet chromophores by using an azide-alkyne "click" reaction. The polymers have narrow polydispersity and degree of polymerization ∼60. The chromophores have the general structure, trans-[-R-C6H4-C≡C-Pt(PBu3)2-C≡C-Ar], where R is the attachment point to the polystyrene backbone and Ar is either -C6H4-C≡C-Ph or -pyrenyl (PE2-Pt and Py-Pt, respectively, with triplet energies of 2.35 and 1.88 eV). The polychromophores contain mainly the high-energy PE2-Pt units (light absorber and energy donor), with randomly distributed Py-Pt units (3-20% loading, energy acceptor). Photophysical methods are used to study the dynamics and efficiency of energy transport from the PE2-Pt to Py-Pt units in the polychromophores. The energy transfer efficiency is >90% for copolymers that contain 5% of the Py-Pt acceptor units. Time-resolved phosphorescence measurements combined with Monte Carlo exciton dynamics simulations suggest that the mechanism of exciton transport is exchange energy transfer hopping between PE2-Pt units.

  17. Renormalization of the Higgs sector in the triplet model

    CERN Document Server

    Aoki, Mayumi; Kikuchi, Mariko; Yagyu, Kei

    2012-01-01

    We study radiative corrections to the mass spectrum and the triple Higgs boson coupling in the model with an additional Y=1 triplet field. In this model, the vacuum expectation value for the triplet field is strongly constrained from the electroweak precision data, under which characteristic mass spectrum appear at the tree level; i.e., $m_{H^{++}}^2-m_{H^+}^2\\simeq m_{H^+}^2-m_A^2$ and $m_A^2\\simeq m_H^2$, where the CP-even ($H$), the CP-odd ($A$) and the doubly-charged ($H^{\\pm\\pm}$) as well as the singly-charged ($H^\\pm$) Higgs bosons are the triplet-like. We evaluate how the tree-level formulae are modified at the one-loop level. The $hhh$ coupling for the standard model-like Higgs boson ($h$) is also calculated at the one-loop level. One-loop corrections to these quantities can be large enough for identification of the model by future precision data at the LHC or the International Linear Collider.

  18. Renormalization of the Higgs sector in the triplet model

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University, Kanazawa 920-1192 (Japan); Kanemura, Shinya; Kikuchi, Mariko [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Yagyu, Kei, E-mail: keiyagyu@jodo.sci.u-toyama.ac.jp [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); National Central University, Physics and Center for Mathematics and Theoretical Physics, No. 300, Jhongda Rd., Jhongli, Taiwan (China)

    2012-08-14

    We study radiative corrections to the mass spectrum and the triple Higgs boson coupling in the model with an additional Y=1 triplet field. In this model, the vacuum expectation value for the triplet field is strongly constrained from the electroweak precision data, under which characteristic mass spectrum appear at the tree level; i.e., m{sub H{sup +}{sup +2}}-m{sub H{sup +2}} Asymptotically-Equal-To m{sub H{sup +2}}-m{sub A}{sup 2} and m{sub A}{sup 2} Asymptotically-Equal-To m{sub H}{sup 2}, where the CP-even (H), the CP-odd (A) and the doubly-charged (H{sup {+-}{+-}}) as well as the singly-charged (H{sup {+-}}) Higgs bosons are the triplet-like. We evaluate how the tree-level formulae are modified at the one-loop level. The hhh coupling for the standard model-like Higgs boson (h) is also calculated at the one-loop level. One-loop corrections to these quantities can be large enough for identification of the model by future precision data at the LHC or the International Linear Collider.

  19. Encapsulated triplet-triplet annihilation-based upconversion in the aqueous phase for sub-band-gap semiconductor photocatalysis.

    Science.gov (United States)

    Kim, Jae-Hyuk; Kim, Jae-Hong

    2012-10-24

    We herein report the first instance of aqueous-phase photosensitization of semiconductor photocatalysts (WO(3) loaded with Pt) through triplet-triplet annihilation (TTA)-based upconversion of sub-band-gap photons. The TTA-based upconversion (UC) was achieved in the aqueous phase by encapsulating the solvent phase containing a benchmark platinum(II) octaethylporphyrin/9,10-diphenylanthracene sensitizer/acceptor pair in a rigid polymer shell in the form of aqueous dispersible microcapsules. A mixture of hexadecane and polyisobutylene was used as the inner solvent phase. This eliminated the need for the deoxygenation step that is essential for existing TTA-based UC processes and enabled stable UC to occur even after a month of exposure to the ambient environment. The photoluminescence properties were examined, and UC-assisted photochemical production of hydroxyl radical from green (532 nm) light irradiation was demonstrated for the first time.

  20. Sequential operators in computability logic

    CERN Document Server

    Japaridze, Giorgi

    2007-01-01

    Computability logic (CL) (see http://www.cis.upenn.edu/~giorgi/cl.html) is a semantical platform and research program for redeveloping logic as a formal theory of computability, as opposed to the formal theory of truth which it has more traditionally been. Formulas in CL stand for (interactive) computational problems, understood as games between a machine and its environment; logical operators represent operations on such entities; and "truth" is understood as existence of an effective solution, i.e., of an algorithmic winning strategy. The formalism of CL is open-ended, and may undergo series of extensions as the study of the subject advances. The main groups of operators on which CL has been focused so far are the parallel, choice, branching, and blind operators. The present paper introduces a new important group of operators, called sequential. The latter come in the form of sequential conjunction and disjunction, sequential quantifiers, and sequential recurrences. As the name may suggest, the algorithmic ...

  1. Entanglement and Metrology with Singlet-Triplet Qubits

    Science.gov (United States)

    Shulman, Michael Dean

    Electron spins confined in semiconductor quantum dots are emerging as a promising system to study quantum information science and to perform sensitive metrology. Their weak interaction with the environment leads to long coherence times and robust storage for quantum information, and the intrinsic tunability of semiconductors allows for controllable operations, initialization, and readout of their quantum state. These spin qubits are also promising candidates for the building block for a scalable quantum information processor due to their prospects for scalability and miniaturization. However, several obstacles limit the performance of quantum information experiments in these systems. For example, the weak coupling to the environment makes inter-qubit operations challenging, and a fluctuating nuclear magnetic field limits the performance of single-qubit operations. The focus of this thesis will be several experiments which address some of the outstanding problems in semiconductor spin qubits, in particular, singlet-triplet (S-T0) qubits. We use these qubits to probe both the electric field and magnetic field noise that limit the performance of these qubits. The magnetic noise bath is probed with high bandwidth and precision using novel techniques borrowed from the field of Hamiltonian learning, which are effective due to the rapid control and readout available in S-T 0 qubits. These findings allow us to effectively undo the undesired effects of the fluctuating nuclear magnetic field by tracking them in real-time, and we demonstrate a 30-fold improvement in the coherence time T2*. We probe the voltage noise environment of the qubit using coherent qubit oscillations, which is partially enabled by control of the nuclear magnetic field. We find that the voltage noise bath is frequency-dependent, even at frequencies as high as 1MHz, and it shows surprising and, as of yet, unexplained temperature dependence. We leverage this knowledge of the voltage noise environment, the

  2. Cooperative Distributed Sequential Spectrum Sensing

    CERN Document Server

    S, Jithin K; Gopalarathnam, Raghav

    2010-01-01

    We consider cooperative spectrum sensing for cognitive radios. We develop an energy efficient detector with low detection delay using sequential hypothesis testing. Sequential Probability Ratio Test (SPRT) is used at both the local nodes and the fusion center. We also analyse the performance of this algorithm and compare with the simulations. Modelling uncertainties in the distribution parameters are considered. Slow fading with and without perfect channel state information at the cognitive radios is taken into account.

  3. Complementary sequential measurements generate entanglement

    OpenAIRE

    Coles, Patrick J.; Piani, Marco

    2013-01-01

    We present a new paradigm for capturing the complementarity of two observables. It is based on the entanglement created by the interaction between the system observed and the two measurement devices used to measure the observables sequentially. Our main result is a lower bound on this entanglement and resembles well-known entropic uncertainty relations. Besides its fundamental interest, this result directly bounds the effectiveness of sequential bipartite operations---corresponding to the mea...

  4. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  5. View Dependent Sequential Point Trees

    Institute of Scientific and Technical Information of China (English)

    Wen-Cheng Wang; Feng Wei; En-Hua Wu

    2006-01-01

    Sequential point trees provide the state-of-the-art technique for rendering point models, by re-arranging hierarchical points sequentially according to geometric errors running on GPU for fast rendering. This paper presents a view dependent method to augment sequential point trees by embedding the hierarchical tree structures in the sequential list of hierarchical points. By the method, two kinds of indices are constructed to facilitate the points rendering in an order mostly from near to far and from coarse to fine. As a result, invisible points can be culled view-dependently in high efficiency for hardware acceleration, and at the same time, the advantage of sequential point trees could be still fully taken. Therefore, the new method can run much faster than the conventional sequential point trees, and the acceleration can be highly promoted particularly when the objects possess complex occlusion relationship and viewed closely because invisible points would be in a high percentage of the points at finer levels.

  6. Mixed Inert Scalar Triplet Dark Matter, Radiative Neutrino Masses and Leptogenesis

    CERN Document Server

    Lu, Wen-Bin

    2016-01-01

    The neutral component of an inert scalar multiplet with hypercharge can provide a stable dark matter particle when its real and imaginary parts have a splitting mass spectrum. Otherwise, a tree-level dark matter-nucleon scattering mediated by the $Z$ boson will be much above the experimental limit. In this paper we focus on a mixed inert scalar triplet dark matter scenario where a complex scalar triplet with hypercharge can mix with another real scalar triplet without hypercharge through their renormalizable coupling to the standard model Higgs doublet. We consider three specified cases that carry most of the relevant features of the full parameter space: (i) the neutral component of the real triplet dominates the dark matter particle, (ii) the neutral component of the complex triplet dominates the dark matter particle; and (iii) the neutral components of the real and complex triplets equally constitute the dark matter particle. Subject to the dark matter relic abundance and direct detection constraint, we pe...

  7. Enhancing triplet superconductivity by the proximity to a singlet superconductor in oxide heterostructures

    Science.gov (United States)

    Horsdal, Mats; Khaliullin, Giniyat; Hyart, Timo; Rosenow, Bernd

    2016-06-01

    We show how in principle a coherent coupling between two superconductors of opposite parity can be realized in a three-layer oxide heterostructure. Due to strong intraionic spin-orbit coupling in the middle layer, singlet Cooper pairs are converted into triplet ones and vice versa. This results in a large enhancement of the triplet superconductivity, persisting well above the native triplet critical temperature.

  8. Distinct properties of the triplet pair state from singlet fission.

    Science.gov (United States)

    Trinh, M Tuan; Pinkard, Andrew; Pun, Andrew B; Sanders, Samuel N; Kumarasamy, Elango; Sfeir, Matthew Y; Campos, Luis M; Roy, Xavier; Zhu, X-Y

    2017-07-01

    Singlet fission, the conversion of a singlet exciton (S1) to two triplets (2 × T1), may increase the solar energy conversion efficiency beyond the Shockley-Queisser limit. This process is believed to involve the correlated triplet pair state (1)(TT). Despite extensive research, the nature of the (1)(TT) state and its spectroscopic signature remain actively debated. We use an end-connected pentacene dimer (BP0) as a model system and show evidence for a tightly bound (1)(TT) state. It is characterized in the near-infrared (IR) region (~1.0 eV) by a distinct excited-state absorption (ESA) spectral feature, which closely resembles that of the S1 state; both show vibronic progressions of the aromatic ring breathing mode. We assign these near-IR spectra to (1)(TT)→Sn and S1→Sn' transitions; Sn and Sn' likely come from the antisymmetric and symmetric linear combinations, respectively, of the S2 state localized on each pentacene unit in the dimer molecule. The (1)(TT)→Sn transition is an indicator of the intertriplet electronic coupling strength, because inserting a phenylene spacer or twisting the dihedral angle between the two pentacene chromophores decreases the intertriplet electronic coupling and diminishes this ESA peak. In addition to spectroscopic signature, the tightly bound (1)(TT) state also shows chemical reactivity that is distinctively different from that of an individual T1 state. Using an electron-accepting iron oxide molecular cluster [Fe8O4] linked to the pentacene or pentacene dimer (BP0), we show that electron transfer to the cluster occurs efficiently from an individual T1 in pentacene but not from the tightly bound (1)(TT) state. Thus, reducing intertriplet electronic coupling in (1)(TT) via molecular design might be necessary for the efficient harvesting of triplets from intramolecular singlet fission.

  9. Three-Nucleon Forces and Triplet Pairing in Neutron Matter

    Science.gov (United States)

    Papakonstantinou, P.; Clark, J. W.

    2017-09-01

    The existence of superfluidity of the neutron component in the core of a neutron star, associated specifically with triplet P- wave pairing, is currently an open question that is central to interpretation of the observed cooling curves and other neutron-star observables. Ab initio theoretical calculations aimed at resolving this issue face unique challenges in the relevant high-density domain, which reaches beyond the saturation density of symmetrical nuclear matter. These issues include uncertainties in the three-nucleon (3N) interaction and in the effects of strong short-range correlations—and more generally of in-medium modification of nucleonic self-energies and interactions. A survey of existing solutions of the gap equations in the triplet channel demonstrates that the net impact on the gap magnitude of 3N forces, coupled channels, and mass renormalization shows extreme variation dependent on specific theoretical inputs, in some cases even pointing to the absence of a triplet gap, thus motivating a detailed analysis of competing effects within a well-controlled model. In the present study, we track the effects of the 3N force and in-medium modifications in the representative case of the ^3P_2 channel, based on the Argonne v_{18} two-nucleon (2N) interaction supplemented by 3N interactions of the Urbana IX family. Sensitivity of the results to the input interaction is clearly demonstrated. We point out consistency issues with respect to the simultaneous treatment of 3N forces and in-medium effects, which warrant further investigation. We consider this pilot study as the first step toward a systematic and comprehensive exploration of coupled-channel ^3P F_2 pairing using a broad range of 2N and 3N interactions from the current generation of refined semi-phenomenological models and models derived from chiral effective field theory.

  10. Superconducting spin-triplet-MRAM with infinite magnetoresistance ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, Daniel; Ullrich, Aladin; Obermeier, Guenter; Mueller, Claus; Krug von Nidda, Hans-Albrecht; Horn, Siegfried; Tidecks, Reinhard [Institut fuer Physik, Universitaet Augsburg, D-86159 Augsburg (Germany); Morari, Roman [Institut fuer Physik, Universitaet Augsburg, D-86159 Augsburg (Germany); D. Ghitsu Institute of Electronic Engineering and Nanotechnologies ASM, Academiei Str. 3/3, MD2028 Kishinev (Moldova, Republic of); Solid State Physics Department, Kazan Federal University, 420008 Kazan (Russian Federation); Zdravkov, Vladimir I. [Institut fuer Physik, Universitaet Augsburg, D-86159 Augsburg (Germany); D. Ghitsu Institute of Electronic Engineering and Nanotechnologies ASM, Academiei Str. 3/3, MD2028 Kishinev (Moldova, Republic of); Institute of Applied Physics and Interdisciplinary Nanoscience Center, Universitaet Hamburg, Jungiusstrasse 9A, D-20355 Hamburg (Germany); Sidorenko, Anatoli S. [D. Ghitsu Institute of Electronic Engineering and Nanotechnologies ASM, Academiei Str. 3/3, MD2028 Kishinev (Moldova, Republic of); Tagirov, Lenar R. [Institut fuer Physik, Universitaet Augsburg, D-86159 Augsburg (Germany); Solid State Physics Department, Kazan Federal University, 420008 Kazan (Russian Federation)

    2016-07-01

    We fabricated a nanolayered hybrid superconductor-ferromagnet spin-valve structure, i.e. the superconducting transition temperature of this structure depends on its magnetic history. The observed spin-valve effect is based on the generation of the long range odd in frequency triplet component, arising from a non-collinear relative orientation of the constituent ferromagnetic layers. We investigated the effect both as a function of the sweep amplitude of the magnetic field, determining the magnetic history, and the applied transport current. Moreover, we demonstrate the possibility of switching the system from the normal o the superconducting state by applying field pulses, yielding an infinite magnetoresistance ratio.

  11. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    Science.gov (United States)

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues.

  12. Status of the LHC inner triplet quadrupole program at Fermilab

    CERN Document Server

    Andreev, N; Bauer, P; Bossert, R; Brandt, J; Carson, J; Caspi, S; Chichili, D R; Chiesa, L; Darve, C; Di Marco, J; Fehér, S; Ghosh, A; Glass, H; Huang, Y; Kerby, J S; Lamm, M J; Markarov, A A; McInturff, A D; Nicol, T H; Nobrega, A; Novitski, I; Ogitsu, T; Orris, D; Ozelis, J P; Page, T; Peterson, T; Rabehl, Roger Jon; Robotham, W; Sabbi, G L; Scanlan, R M; Schlabach, P; Sylvester, C D; Strait, J B; Tartaglia, M; Tompkins, J C; Velev, G V; Yadav, S; Zlobin, A V

    2001-01-01

    Fermilab, in collaboration with LBNL and BNL, is developing a quadrupole for installation in the interaction region inner triplets of the LHC. This magnet is required to have an operating gradient of 215 T/m across a 70 mm coil bore, and operates in superfluid helium at 1.9 K. A 2 m magnet program addressing mechanical, magnetic, quench protection, and thermal issues associated with the design was completed earlier this year, and production of the first full length, cryostatted prototype magnet is underway. This paper summarizes the conclusions of the 2 m program, and the design and status of the first full-length prototype magnet. (11 refs).

  13. Tunneling Conductance in Normal Metal/Insulator/Triplet Superconductor Junction

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Wei

    2005-01-01

    Tunneling conductance in normal metal/insulator/triplet superconductor junctions is studied theoretically as a function of the bias voltage at zero temperature and finite temperature. The results show there are zero-bias conductance peak, zero-bias conductance dip and double-minimum structures in the spectra for p-wave superconductor junctions. The existence of such structures in the conductance spectrum can be taken as evidence that the pairing symmetry of Sr2RuO4 is p-wave symmetry.

  14. String theory triplets and higher-spin curvatures

    CERN Document Server

    Francia, Dario

    2010-01-01

    Unconstrained local Lagrangians for higher-spin gauge theories are bound to involve auxiliary fields, whose integration in the partition function generates geometric, effective actions expressed in terms of curvatures. When applied to the triplets, emerging from the tensionless limit of open string field theory, the same procedure yields interesting alternative forms of geometric Lagrangians, whose rather simple pattern is essentially the same for bosons and fermions. This shows that higher-spin curvatures might play a role in the dynamics, regardless of whether the Fronsdal-Labastida constraints are assumed or not.

  15. String theory triplets and higher-spin curvatures

    Energy Technology Data Exchange (ETDEWEB)

    Francia, Dario, E-mail: francia@apc.univ-paris7.f [AstroParticule et Cosmologie (APC), Universite Paris VII - Campus Paris Rive Gauche, 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France)

    2010-06-07

    Unconstrained local Lagrangians for higher-spin gauge theories are bound to involve auxiliary fields, whose integration in the partition function generates geometric, effective actions expressed in terms of curvatures. When applied to the triplets, emerging from the tensionless limit of open string field theory, the same procedure yields interesting alternative forms of geometric Lagrangians, expressible for both bosons and fermions as squares of field-strengths. This shows that higher-spin curvatures might play a role in the dynamics, regardless of whether the Fronsdal-Labastida constraints are assumed or forgone.

  16. Capturing triplet emission in white organic light emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai [Faculty of EHSE, School of Engineering and IT, B-purple-12, Charles Darwin University, Darwin, NT 0909 (Australia)

    2011-08-15

    The state-of-the art in the white organic light emitting devices (WOLEDs) is reviewed for further developments with a view to enhance the capture of triplet emission. In particular, applying the new exciton-spin-orbit-photon interaction operator as a perturbation, rates of spontaneous emission are calculated in a few phosphorescent materials and compared with experimental results. For iridium based phosphorescent materials the rates agree quite well with the experimental results. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Exploring the triplet parameters space to optimise the final focus of the FCC-hh

    CERN Document Server

    Van Riesen-Haupt, Leon; Seryi, Andrei; Cruz Alaniz, Emilia

    2017-01-01

    One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider (FCC-hh).

  18. The Progression of Sequential Reactions

    Directory of Open Access Journals (Sweden)

    Jack McGeachy

    2010-01-01

    Full Text Available Sequential reactions consist of linked reactions in which the product of the first reaction becomes the substrate of a second reaction. Sequential reactions occur in industrially important processes, such as the chlorination of methane. A generalized series of three sequential reactions was analyzed in order to determine the times at which each chemical species reaches its maximum. To determine the concentration of each species as a function of time, the differential rate laws for each species were solved. The solution of each gave the concentration curve of the chemical species. The concentration curves of species A1 and A2 possessed discreet maxima, which were determined through slope-analysis. The concentration curve of the final product, A3, did not possess a discreet maximum, but rather approached a finite limit.

  19. Clarifying the mechanism of triplet-triplet annihilation in phosphorescent organic host-guest systems: A combined experimental and simulation study

    Science.gov (United States)

    Zhang, L.; van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

    2016-05-01

    At high brightness, triplet-triplet annihilation (TTA) reduces the efficiency of organic light-emitting diodes. Triplet diffusion may considerably enhance this effect, which is otherwise limited by the rate of long-range interactions. Although its role can be clarified by studying the emissive dye concentration dependence of the TTA loss, we demonstrate here the practical applicability of a more direct method, requiring a study for only a single dye concentration. The method uses transient photoluminescence yield measurements, for a wide initial excitation density range. The analysis is applied to an iridium complex and is supported by the results of kinetic Monte Carlo simulations.

  20. Transistor switching and sequential circuits

    CERN Document Server

    Sparkes, John J

    1969-01-01

    Transistor Switching and Sequential Circuits presents the basic ideas involved in the construction of computers, instrumentation, pulse communication systems, and automation. This book discusses the design procedure for sequential circuits. Organized into two parts encompassing eight chapters, this book begins with an overview of the ways on how to generate the types of waveforms needed in digital circuits, principally ramps, square waves, and delays. This text then considers the behavior of some simple circuits, including the inverter, the emitter follower, and the long-tailed pair. Other cha

  1. Complementary sequential measurements generate entanglement

    Science.gov (United States)

    Coles, Patrick J.; Piani, Marco

    2014-01-01

    We present a paradigm for capturing the complementarity of two observables. It is based on the entanglement created by the interaction between the system observed and the two measurement devices used to measure the observables sequentially. Our main result is a lower bound on this entanglement and resembles well-known entropic uncertainty relations. Besides its fundamental interest, this result directly bounds the effectiveness of sequential bipartite operations—corresponding to the measurement interactions—for entanglement generation. We further discuss the intimate connection of our result with two primitives of information processing, namely, decoupling and coherent teleportation.

  2. Sequential Divestiture and Firm Asymmetry

    Directory of Open Access Journals (Sweden)

    Wen Zhou

    2013-01-01

    Full Text Available Simple Cournot models of divestiture tend to generate incentives to divest which are too strong, predicting that firms will break up into an infinite number of divisions resulting in perfect competition. This paper shows that if the order of divestitures is endogenized, firms will always choose sequential, and hence very limited, divestitures. Divestitures favor the larger firm and the follower in a sequential game. Divestitures in which the larger firm is the follower generate greater industry profit and social welfare, but a smaller consumer surplus.

  3. Mode of conception of triplets and high order multiple pregnancies.

    LENUS (Irish Health Repository)

    Basit, I

    2012-03-01

    A retrospective audit was performed of all high order multiple pregnancies (HOMPs) delivered in three maternity hospitals in Dublin between 1999 and 2008. The mode of conception for each pregnancy was established with a view to determining means of reducing their incidence. A total of 101 HOMPs occurred, 93 triplet, 7 quadruplet and 1 quintuplet. Information regarding the mode of conception was available for 78 (81%) pregnancies. Twenty eight (27.7%) were spontaneous, 34 (33.7%) followedlVF\\/ICSI\\/FET treatment (in-vitro fertilisation, intracytoplasmic sperm injection, frozen embryo transfer), 16 (15.8%) resulted from Clomiphene Citrate treatment and 6 (6%) followed ovulation induction with gonadotrophins. Triplet and HOMPs are a major cause of maternal, feta land neonatal morbidity. Many are iatrogenic, arising from fertility treatments including Clomiphene. Reducing the numbers of embryos transferred will address IVF\\/ICSI\\/FET-related multiple pregnancy rates and this is currently happening in Ireland. Clomiphene and gonadotrophins should only be prescribed when appropriate resources are available to monitor patients adequately.

  4. Supersymmetric grand unification with light color-triplet

    Science.gov (United States)

    Berezhiani, Lasha

    2012-05-01

    We construct a natural model of the supersymmetric SU (6) unification, in which the symmetry breaking, down to the standard model gauge group, results in the number of pseudo-Nambu-Goldstone superfields with interesting properties. Namely, besides the Higgs doublet-antidoublet pair which is responsible for the electroweak phase transition, the Nambu-Goldstone sector consists of multiplets in the anti- and fundamental representations of SU (5). While being strictly massless in the supersymmetric limit, they acquire the weak scale masses as a result of its breaking. The color-triplet components of this light sector could, in principle, mediate an unacceptably fast proton decay; however, because of the natural TeV /MGUT suppression of the Yukawa couplings to the light quarks and leptons, their existence is compatible with the experimental bound on proton lifetime. This suppression is made further interesting, since it results in the lifetime, of the lightest of the above-mentioned colored particles from 1 s to 1 day, long enough for it to appear stable in the detector. Furthermore, we argue that the accommodation of the color-triplet pseudo-Nambu-Goldstones, without fine-tuning or contradicting observations, implies SU (6) unification.

  5. Room temperature triplet state spectroscopy of organic semiconductors.

    Science.gov (United States)

    Reineke, Sebastian; Baldo, Marc A

    2014-01-21

    Organic light-emitting devices and solar cells are devices that create, manipulate, and convert excited states in organic semiconductors. It is crucial to characterize these excited states, or excitons, to optimize device performance in applications like displays and solar energy harvesting. This is complicated if the excited state is a triplet because the electronic transition is 'dark' with a vanishing oscillator strength. As a consequence, triplet state spectroscopy must usually be performed at cryogenic temperatures to reduce competition from non-radiative rates. Here, we control non-radiative rates by engineering a solid-state host matrix containing the target molecule, allowing the observation of phosphorescence at room temperature and alleviating constraints of cryogenic experiments. We test these techniques on a wide range of materials with functionalities spanning multi-exciton generation (singlet exciton fission), organic light emitting device host materials, and thermally activated delayed fluorescence type emitters. Control of non-radiative modes in the matrix surrounding a target molecule may also have broader applications in light-emitting and photovoltaic devices.

  6. UGe2: A ferromagnetic spin-triplet superconductor

    Science.gov (United States)

    Huxley, Andrew; Sheikin, Ilya; Ressouche, Eric; Kernavanois, Nolwenn; Braithwaite, Daniel; Calemczuk, Roberto; Flouquet, Jacques

    2001-04-01

    The identification of a spin-triplet superfluid phase in 3He naturally led to more general theoretical predictions that spin triplet superconductivity might occur near to a ferromagnetic instability in some metals. The recent discovery of superconductivity near a ferromagnetic quantum critical point in UGe2 now calls for these predictions to be reexamined experimentally. In this light it initially appears surprising that superconductivity in UGe2 has only been detected in the ferromagnetic phase and not also at pressures above the critical pressure for the suppression of ferromagnetism. In this paper we provide evidence that the superconductivity is indeed a bulk property. We also observe the evolution with pressure of the magnetic order by neutron scattering and find that the ferromagnetic component of the order is still present at a pressure and temperature where superconductivity is found. In resistivity measurements we identify an additional transition within the ferromagnetic state. The characteristic temperature of this transition, Tx, decreases with pressure and disappears at a pressure Px close to the pressure at which the superconductivity is strongest. Evidence is presented that this transition is also induced by a magnetic field at pressures just above Px. An observed unusual reentrant behavior of the superconductivity with field at a pressure of 13.5 kbar is then qualitatively explained. These results suggest that the transition at Px is intricately related to the appearance of superconductivity, which could explain why the superconductivity is apparently confined to the ferromagnetic phase.

  7. Caught in the Act: Discovery of a Physical Quasar Triplet

    CERN Document Server

    Farina, E P; Decarli, R; Fumagalli, M

    2013-01-01

    We present the discovery of a triplet of quasars at z~1.51. The whole system is well accommodated within 25 arcsec (i.e., 200 kpc in projected distance). The velocity differences among the three objects (as measured through the broad MgII emission line) are less than 1000 km/s, suggesting that the quasars belong to the same physical structure. Broad band NIR images of the field do not reveal evidence of galaxies or galaxy clusters that could act as a gravitational lens, ruling out the possibility that two or all the three quasars are multiple images of a single, strongly lensed source. QQQ J1519+0627 is the second triplet of quasars known up to date. We estimate that these systems are extremely rare in terms of simple accidental superposition. The lack of strong galaxy overdensity suggests that this peculiar system is harboured in the seeds of a yet-to-be-formed massive structure. Based on observations collected at the La Silla Observatory with the New Technology Telescope (NTT) of the European Southern Obser...

  8. Excited triplet state photophysics of the sulphonated aluminium phthalocyanines bound to human serum albumin.

    Science.gov (United States)

    Foley, M S; Beeby, A; Parker, A W; Bishop, S M; Phillips, D

    1997-03-01

    The binding of the sulphonated aluminum phthalocyanines to human serum albumin (HSA) in aqueous phosphate buffer solution at 25 degrees C has been studied by measuring the properties of the triplet excited states of these dyes. The triplet lifetimes were measured by triplet-triplet absorption flash photolysis. The triplet lifetime of the disulphonated AlS2Pc (2.5 microM) varies from 500 +/- 30 microseconds in the absence of protein to 1.100 microseconds and longer with HSA concentrations above 100 microM. Under identical conditions, the maximum triplet lifetimes of the mono-, tri- and tetrasulphonated compounds bound to HSA are shorter than those for the disulphonated species. The increase in the triplet state lifetimes is attributed to the ability of the bulk aqueous phase to interact with the sensitizer at the site of binding; the site of binding being dependent on the degree of sulphonation. For AlS2Pc and AlS3Pc at all HSA concentrations, and regardless of the degree of sulphonation, all the triplet state decay profiles follow simple pseudo-first-order kinetics. The exponential decay of the triplet phthalocyanine at all HSA concentrations is ascribed to the rapid association and dissociation of the phthalocyanine-HSA complex on the time-scales of the triplet state lifetimes. A simplified one-step binding model is utilized to describe the results. The association of AlS1Pc with HSA results in substantial quenching of the triplet state quantum yield, and a more complex model is required to analyze the results. The tetrasulphonated compound (AlS4Pc) binds to the protein at a site where it experiences some protection from the aqueous phase.

  9. Sequential triangulation of orbital photography

    Science.gov (United States)

    Rajan, M.; Junkins, J. L.; Turner, J. D.

    1979-01-01

    The feasibility of structuring the satellite photogrammetric triangulation as an iterative Extended Kalman estimation algorithm is demonstrated. Comparative numerical results of the sequential against batch estimation algorithm are presented. Difficulty of accurately modeling of the attitude motion is overcome by utilizing the on-board angular rate measurements. Solutions of the differential equations and the evaluation of state transition matrix are carried out numerically.

  10. Attack Trees with Sequential Conjunction

    NARCIS (Netherlands)

    Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

    2015-01-01

    We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

  11. Sequential triangulation of orbital photography

    Science.gov (United States)

    Rajan, M.; Junkins, J. L.; Turner, J. D.

    1979-01-01

    The feasibility of structuring the satellite photogrammetric triangulation as an iterative Extended Kalman estimation algorithm is demonstrated. Comparative numerical results of the sequential against batch estimation algorithm are presented. Difficulty of accurately modeling of the attitude motion is overcome by utilizing the on-board angular rate measurements. Solutions of the differential equations and the evaluation of state transition matrix are carried out numerically.

  12. Triplet-triplet annihilation upconversion in CdS-decorated SiO2 nanocapsules for sub-bandgap photocatalysis.

    Science.gov (United States)

    Kwon, Oh Seok; Kim, Jae-Hyuk; Cho, Jin Ku; Kim, Jae-Hong

    2015-01-14

    This study reports the first successful nanoscale encapsulation of triplet-triplet annihilation upconversion (TTA-UC) medium within a rigid silica shell using a self-assembly microemulsion process. These newly synthesized nanocapsules present a few critical advances that could be instrumental for a wide range of aqueous-based photonics applications, including photocatalysis, artificial photosynthesis, and bioimaging. The nanocapsules form a homogeneous suspension that can produce intense, diffuse UC emission in water without deoxygenation, closely resembling conventional TTA-UC processes that have been performed in deoxygenated organic solvents. The silica shell provides sites for further surface modification, which allows, when combined with its nanoscale dimension and structural rigidity, this TTA-UC system to acquire various useful functionalities. A benchmark TTA-UC pair, palladium(II) tetraphenyltetrabenzoporphyrin as a sensitizer and perylene as an acceptor, was used to demonstrate efficient red-to-blue (635 nm, 1.95 eV → 470 nm, 2.6 eV) upconversion in the oxygen-rich aqueous phase. The nanocapsule surface was further functionalized with cadmium sulfide nanoparticles (Eg = 2.4 eV) to demonstrate sub-bandgap sensitization and subsequent aqueous-phase catalytic oxidation.

  13. Instability of human TATA-binding protein CAG triplet repeats during amplification by PCR.

    Science.gov (United States)

    Holstege, F C; van der Vliet, P C; Timmers, H T

    1994-09-13

    Polymerase chain reaction (PCR) of a TATA-binding protein cDNA that contains CAG triplet repeats results in heterogeneous products. This is caused by a variable loss in the number of CAG triplets. Sequence analysis of PCR products suggests that instability increases with repeat length.

  14. TripNet: A Heuristic Algorithm for Constructing Rooted Phylogenetic Networks from Triplets

    CERN Document Server

    Poormohammadi, Hadi; Tusserkani, Ruzbeh

    2012-01-01

    The problem of constructing an optimal rooted phylogenetic network from a set of rooted triplets is an NP-hard problem. In this paper, we present a heuristic algorithm called TripNet which tries to construct an optimal rooted phylogenetic network from an arbitrary set of triplets. We prove some theorems to justify the performance of the algorithm.

  15. Dynamic Exchange During Triplet Transport in Nanocrystalline TIPS-Pentacene Films.

    Science.gov (United States)

    Grieco, Christopher; Doucette, Grayson S; Pensack, Ryan D; Payne, Marcia M; Rimshaw, Adam; Scholes, Gregory D; Anthony, John E; Asbury, John B

    2016-12-14

    The multiplication of excitons in organic semiconductors via singlet fission offers the potential for photovoltaic cells that exceed the Shockley-Quiesser limit for single-junction devices. To fully utilize the potential of singlet fission sensitizers in devices, it is necessary to understand and control the diffusion of the resultant triplet excitons. In this work, a new processing method is reported to systematically tune the intermolecular order and crystalline structure in films of a model singlet fission chromophore, 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn), without the need for chemical modifications. A combination of transient absorption spectroscopy and quantitative materials characterization enabled a detailed examination of the distance- and time-dependence of triplet exciton diffusion following singlet fission in these nanocrystalline TIPS-Pn films. Triplet-triplet annihilation rate constants were found to be representative of the weighted average of crystalline and amorphous phases in TIPS-Pn films comprising a mixture of phases. Adopting a diffusion model used to describe triplet-triplet annihilation, the triplet diffusion lengths for nanocrystalline and amorphous films of TIPS-Pn were estimated to be ∼75 and ∼14 nm, respectively. Importantly, the presence of even a small fraction (materials may be essential to efficiently harvest multiplied triplets even when singlet fission occurs on ultrafast time scales.

  16. Delocalisation of photoexcited triplet states probed by transient EPR and hyperfine spectroscopy

    Science.gov (United States)

    Richert, Sabine; Tait, Claudia E.; Timmel, Christiane R.

    2017-07-01

    Photoexcited triplet states play a crucial role in photochemical mechanisms: long known to be of paramount importance in the study of photosynthetic reaction centres, they have more recently also been shown to play a major role in a number of applications in the field of molecular electronics. Their characterisation is crucial for an improved understanding of these processes with a particular focus on the determination of the spatial distribution of the triplet state wavefunction providing information on charge and energy transfer efficiencies. Currently, active research in this field is mostly focussed on the investigation of materials for organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs). As the properties of triplet states and their spatial extent are known to have a major impact on device performance, a detailed understanding of the factors governing triplet state delocalisation is at the basis of the further development and improvement of these devices. Electron Paramagnetic Resonance (EPR) has proven a valuable tool in the study of triplet state properties and both experimental methods as well as data analysis and interpretation techniques have continuously improved over the last few decades. In this review, we discuss the theoretical and practical aspects of the investigation of triplet states and triplet state delocalisation by transient continuous wave and pulse EPR and highlight the advantages and limitations of the presently available techniques and the current trends in the field. Application of EPR in the study of triplet state delocalisation is illustrated on the example of linear multi-porphyrin chains designed as molecular wires.

  17. Direct Measurement of the Triplet Exciton Diffusion Length in Organic Semiconductors

    NARCIS (Netherlands)

    Mikhnenko, Oleksandr V.; Ruiter, Roald; Blom, Paul W. M.; Loi, Maria Antonietta

    2012-01-01

    We present a new method to measure the triplet exciton diffusion length in organic semiconductors. N,N'-di-[(1-naphthyl)-N,N'-diphenyl]-1,1'-biphenyl-4,4'-diamine (NPD) has been used as a model system. Triplet excitons are injected into a thin film of NPD by a phosphorescent thin film, which is opti

  18. Resonance raman and absorption spectra of isomeric retinals in their lowest excited triplet states

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N.-H.; Houee-Levin, C.

    1985-01-01

    implications about the size of the energy barriers separating the various triplet species are discussed. The resonance Raman spectra obtained by using either anthracene (ET = 177.7 kJ mol-1) or naphthalene (ET = 254.8 kJ mol-1) as sensitizers were virtually identical for the corresponding triplet states from...

  19. Prediction of Time to Delivery Week-by-Week in Women with a Triplet Pregnancy

    NARCIS (Netherlands)

    de Mheen, L. van; Ravelli, A. C.; Oudijk, M. A.; Bijvank, S. Nij; Porath, M. M.; Duvekot, J. J.; Scholtenhuis, M. A. G. Holswilder-Olde; Bloemenkamp, K. W. M.; Scheepers, H. C. J.; Woiski, M.; van Pampus, M. G.; de Groot, C. J.; Pajkrt, E.; Mol, B. W. J.

    2016-01-01

    Objective Some clinicians advise prophylactic administration of antenatal steroids for fetal lung maturation in women with a triplet pregnancy. However, the effect of corticosteroids is limited to 10 to 14 days after administration. The aim of this study was to assess the natural course of triplet

  20. Prediction of Time to Delivery Week-by-Week in Women with a Triplet Pregnancy

    NARCIS (Netherlands)

    van de Mheen, L; Ravelli, A C; Oudijk, M A; Bijvank, S Nij; Porath, M M; Duvekot, J J; Scholtenhuis, M A G Holswilder-Olde; Bloemenkamp, K W M; Scheepers, H C J; Woiski, M; Pampus, M G van; Groot, C J de; Pajkrt, E; Mol, B W J

    2016-01-01

    Objective Some clinicians advise prophylactic administration of antenatal steroids for fetal lung maturation in women with a triplet pregnancy. However, the effect of corticosteroids is limited to 10 to 14 days after administration. The aim of this study was to assess the natural course of triplet

  1. GAA triplet-repeats cause nucleosome depletion in the human genome.

    Science.gov (United States)

    Zhao, Hongyu; Xing, Yongqiang; Liu, Guoqing; Chen, Ping; Zhao, Xiujuan; Li, Guohong; Cai, Lu

    2015-08-01

    Although there have been many investigations into how trinucleotide repeats affect nucleosome formation and local chromatin structure, the nucleosome positioning of GAA triplet-repeats in the human genome has remained elusive. In this work, the nucleosome occupancy around GAA triplet-repeats across the human genome was computed statistically. The results showed a nucleosome-depleted region in the vicinity of GAA triplet-repeats in activated and resting CD4(+) T cells. Furthermore, the A-tract was frequently adjacent to the upstream region of GAA triplet-repeats and could enhance the depletion surrounding GAA triplet-repeats. In vitro chromatin reconstitution assays with GAA-containing plasmids also demonstrated that the inserted GAA triplet-repeats destabilized the ability of recombinant plasmids to assemble nucleosomes. Our results suggested that GAA triplet-repeats have lower affinity to histones and can change local nucleosome positioning. These findings may be helpful for understanding the mechanism of Friedreich's ataxia, which is associated with GAA triplet-repeats at the chromatin level.

  2. Triangle Type Trinuclear Copper Complexes with Triplet -excitation Luminescent Property, an Ab Initio Study

    Institute of Scientific and Technical Information of China (English)

    MANG Chao-Yong; ZHANG Ming-Xin; WU Ke-Chen

    2006-01-01

    The luminescent mechanism and properties of a triangular Cu(I) complex, (CuPz)3, have been studied by CIS method. The ground and lowest triplet excitation state geometries were optimized at MP2/SBKJC and CIS/SBKJC levels, respectively. A remarkable geometry distortion of the lowest triplet state was found and believed to cause the emission spectra to red shift.

  3. Two Birds with One Stone: Tailoring Singlet Fission for Both Triplet Yield and Exciton Diffusion Length

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Tong [Department of Chemistry, Purdue University, West Lafayette IN 47907 USA; Wan, Yan [Department of Chemistry, Purdue University, West Lafayette IN 47907 USA; Guo, Zhi [Department of Chemistry, Purdue University, West Lafayette IN 47907 USA; Johnson, Justin [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Huang, Libai [Department of Chemistry, Purdue University, West Lafayette IN 47907 USA

    2016-06-27

    By direct imaging of singlet and triplet populations with ultrafast microscopy, it is shown that the triplet diffusion length and singlet fission yield can be simultaneously optimized for tetracene and its derivatives, making them ideal structures for application in bilayer solar cells.

  4. Codon-triplet context unveils unique features of the Candida albicans protein coding genome

    Directory of Open Access Journals (Sweden)

    Oliveira José L

    2007-11-01

    Full Text Available Abstract Background The evolutionary forces that determine the arrangement of synonymous codons within open reading frames and fine tune mRNA translation efficiency are not yet understood. In order to tackle this question we have carried out a large scale study of codon-triplet contexts in 11 fungal species to unravel associations or relationships between codons present at the ribosome A-, P- and E-sites during each decoding cycle. Results Our analysis unveiled high bias within the context of codon-triplets, in particular strong preference for triplets of identical codons. We have also identified a surprisingly large number of codon-triplet combinations that vanished from fungal ORFeomes. Candida albicans exacerbated these features, showed an unbalanced tRNA population for decoding its pool of codons and used near-cognate decoding for a large set of codons, suggesting that unique evolutionary forces shaped the evolution of its ORFeome. Conclusion We have developed bioinformatics tools for large-scale analysis of codon-triplet contexts. These algorithms identified codon-triplets context biases, allowed for large scale comparative codon-triplet analysis, and identified rules governing codon-triplet context. They could also detect alterations to the standard genetic code.

  5. Generalization of the possible algebraic basis of q-triplets

    Science.gov (United States)

    Tsallis, Constantino

    2017-02-01

    The so called q-triplets were conjectured in 2004 [C. Tsallis, Physica A 340, 1 (2004)] and then found in nature in 2005 [L.F. Burlaga, A.F. Vinas, Physica A 356, 375 (2005)]. A relevant further step was achieved in 2005 [C. Tsallis, M. Gell-Mann, Y. Sato, PNAS 102, 15377 (2005)] when the possibility was advanced that they could reflect an entire infinite algebra based on combinations of the self-dual relations q → 2 - q (additive duality) and q → 1/q (multiplicative duality). The entire algebra collapses into the single fixed point q = 1, corresponding to the Boltzmann-Gibbs entropy and statistical mechanics. For q ≠ 1, an infinite set of indices q appears, corresponding in principle to an infinite number of physical properties of a given complex system describable in terms of the so called q-statistics. The basic idea that is put forward is that, for a given universality class of systems, a small number (typically one or two) of independent q indices exist, the infinite others being obtained from these few ones by simply using the relations of the algebra. The q-triplets appear to constitute a few central elements of the algebra. During the last decade, an impressive amount of q-triplets have been exhibited in analytical, computational, experimental and observational results in natural, artificial and social systems. Some of them do satisfy the available algebra constructed solely with the additive and multiplicative dualities, but some others seem to violate it. In the present work we generalize those two dualities with the hope that a wider set of systems can be handled within. The basis of the generalization is given by the selfdual relation q → qa(q) ≡ ((a+2)-aq) / (a-(a-2)q) (a ∈ R). We verify that qa(1) = 1, and that q2(q) = 2 - q and q0(q) = 1/q. To physically motivate this generalization, we briefly review illustrative applications of q-statistics, in order to exhibit possible candidates where the present generalized algebras could be useful.

  6. Triplet-singlet conversion in ultracold Cs$_2$ and production of ground state molecules

    CERN Document Server

    Bouloufa, Nadia; Aymar, Mireille; Dulieu, Olivier

    2010-01-01

    We propose a process to convert ultracold metastable Cs$_2$ molecules in their lowest triplet state into (singlet) ground state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled $A^{1}\\Sigma_{u}^{+} \\sim b ^{3}\\Pi_{u}$ states. Using spectroscopic data and accurate quantum chemistry calculations for Cs$_2$ potential curves and transition dipole moments, we show that this process has a high rate and competes favorably with the single-photon decay back to the lowest triplet state. In addition, we demonstrate that this conversion process represents a loss channel for vibrational cooling of metastable triplet molecules, preventing an efficient optical pumping cycle down to low vibrational levels.

  7. Supersymmetric Grand Unification with Light Color-Triplet

    CERN Document Server

    Berezhiani, Lasha

    2011-01-01

    We construct a natural model of the supersymmetric SU(6) unification, in which the symmetry breaking, down to the standard model gauge group, results in the number of pseudo-Nambu-Goldstone superfields with interesting properties. Namely, besides the Higgs doublet-antidoublet pair which is responsible for the electroweak phase transition, the Nambu-Goldstone sector consists of multiplets in the anti- and fundamental representations of SU(5). While being strictly massless in the supersymmetric limit, they acquire the weak scale masses as a result of its breaking. The color-triplet components of this light sector could, in principle, mediate an unacceptably fast proton decay; however, because of the natural $\\text{TeV}/M_{\\text{GUT}}$ suppression of the Yukawa couplings to the light quarks and leptons, their existence is compatible with the experimental bound on proton lifetime. This suppression is made further interesting, since it results in the lifetime, of the lightest of the above-mentioned colored particl...

  8. Spectral triplets, emergent geometry and entropy in Moyal plane

    Science.gov (United States)

    Chakraborty, B.; Scholtz, F. G.

    2013-02-01

    It was shown by Doplicher et.al. that the measurement of spacetime intervals of the order of Planck length scale is operationally impossible, as the process of measurement invariably gives rise to a black hole formation. This can be avoided by postulating non-vanishing commutation relations between the coordinates, which are now promoted to the level of operators. Formulation of quantum mechanics in these kinds of spaces through the introduction of Hilbert spaces of Hilbert-Schmidt operators is then shown to allow the construction of spectral triplets a la Connes naturally. The computation of spectral distance between pure and mixed states is then shown to exhibit a deep connection between entropy and geometry.

  9. Demonstration of entanglement of electrostatically coupled singlet-triplet qubits.

    Science.gov (United States)

    Shulman, M D; Dial, O E; Harvey, S P; Bluhm, H; Umansky, V; Yacoby, A

    2012-04-13

    Quantum computers have the potential to solve certain problems faster than classical computers. To exploit their power, it is necessary to perform interqubit operations and generate entangled states. Spin qubits are a promising candidate for implementing a quantum processor because of their potential for scalability and miniaturization. However, their weak interactions with the environment, which lead to their long coherence times, make interqubit operations challenging. We performed a controlled two-qubit operation between singlet-triplet qubits using a dynamically decoupled sequence that maintains the two-qubit coupling while decoupling each qubit from its fluctuating environment. Using state tomography, we measured the full density matrix of the system and determined the concurrence and the fidelity of the generated state, providing proof of entanglement.

  10. Model for Triplet State Engineering in Organic Light Emitting Diodes

    CERN Document Server

    Prodhan, Suryoday; Ramasesha, S

    2014-01-01

    Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions and twisted geometry. The largest system studied is an eighteen carbon polyene which spans a Hilbert space of about 991 million. We show that for reverse intersystem crossing (RISC) process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.

  11. Metrics for phylogenetic networks II: nodal and triplets metrics.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2009-01-01

    The assessment of phylogenetic network reconstruction methods requires the ability to compare phylogenetic networks. This is the second in a series of papers devoted to the analysis and comparison of metrics for tree-child time consistent phylogenetic networks on the same set of taxa. In this paper, we generalize to phylogenetic networks two metrics that have already been introduced in the literature for phylogenetic trees: the nodal distance and the triplets distance. We prove that they are metrics on any class of tree-child time consistent phylogenetic networks on the same set of taxa, as well as some basic properties for them. To prove these results, we introduce a reduction/expansion procedure that can be used not only to establish properties of tree-child time consistent phylogenetic networks by induction, but also to generate all tree-child time consistent phylogenetic networks with a given number of leaves.

  12. Sequential Detection of Digital Watermarking

    Institute of Scientific and Technical Information of China (English)

    LI Li; YU Yu-lian; WANG Pei

    2005-01-01

    The paper analyzed a new watermarking detection paradigm including double detection thresholds based on sequential hypothesis testing. A joint design of watermarking encoding and detection was proposed. The paradigm had good immunity to noisy signal attacks and high detection probability. Many experiments proved that the above algorithm can detect watermarks about 66% faster than popular detectors, which could have significant impact on many applications such as video watermarking detection and watermark-searching in a large database of digital contents.

  13. Galaxy triplets in Sloan Digital Sky Survey Data Release 7 - III. Analysis of Configuration and Dynamics

    CERN Document Server

    Duplancic, Fernanda; Lambas, Diego García; O'Mill, Ana Laura

    2014-01-01

    We analyse the spatial configuration and the dynamical properties of a sample of 92 galaxy triplets obtained from the SDSS-DR7 (SDSS-triplets) restricted to have members with spectroscopic redshifts in the range $0.01\\le z \\le 0.14 $ and absolute r-band luminosities brighter than $M_r=-20.5$. The configuration analysis was performed through Agekyan & Anosova map (AA-map). We estimated dynamical parameters, namely the radius of the system, the velocity dispersion, a dimensionless crossing-time and the virial mass. We compared our results with those obtained for a sample of triplets from the catalogue "Isolated Triplets of Galaxies" (K-triplets) and a sample of Compact Groups. We have also studied a mock catalogue in order to compare real and projected configurations, and to estimate the three dimensional dynamical parameters of the triple systems. We found that the SDSS-triplets prefer alignment configurations while K-triplets present an uniform distribution in the AA-map. From the dynamical analysis we co...

  14. On sequential countably compact topological semigroups

    CERN Document Server

    Gutik, Oleg V; Repovš, Dušan

    2008-01-01

    We study topological and algebraic properties of sequential countably compact topological semigroups similar to compact topological semigroups. We prove that a sequential countably compact topological semigroup does not contain the bicyclic semigroup. Also we show that the closure of a subgroup in a sequential countably compact topological semigroup is a topological group, that the inversion in a Clifford sequential countably compact topological semigroup is continuous and we prove the analogue of the Rees-Suschkewitsch Theorem for simple regular sequential countably compact topological semigroups.

  15. The Lowest Triplet of Tetracyanoquinodimethane via UV-vis Absorption Spectroscopy with Br-Containing Solvents.

    Science.gov (United States)

    Khvostenko, Olga G; Kinzyabulatov, Renat R; Khatymova, Laysan Z; Tseplin, Evgeniy E

    2017-10-05

    This study was undertaken to find the previously unknown lowest triplet of the isolated molecule of tetracyanoquinodimethane (TCNQ), which is a widely used organic semiconductor. The problem is topical because the triplet excitation of this compound is involved in some processes which occur in electronic devices incorporating TCNQ and its derivatives, and information on the TCNQ triplet is needed for better understanding of these processes. The lowest triplet of TCNQ was obtained at 1.96 eV using UV-vis absorption spectroscopy with Br-containing solvents. Production of the triplet band with sufficient intensity in the spectra was provided by the capacity of the Br atom to augment the triplet excitation and through using a 100 mm cuvette. The assignment of the corresponding spectral band to the triplet transition was made by observation that this band appeared only in the spectra recorded in Br-containing solvents but not in spectra recorded in other solvents. Additional support for the triplet assignment came from the overall UV-vis absorption spectra of TCNQ recorded in various solvents, using a 10 mm cuvette, in the 1.38-6.5 eV energy range. Singlet transitions of the neutral TCNQ(o) molecule and doublet transitions of the TCNQ(¯) negative ion were identified in these overall spectra and were assigned with TD B3LYP/6-31G calculations. Determination of the lowest triplet of TCNQ attained in this work may be useful for theoretical studies and practical applications of this important compound.

  16. Molecular hosts for triplet emitters in organic light-emitting diodes and the corresponding working principle

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper summarizes the mechanism and routes for excitation of triplet emitters in dopant emission based phosphorescent organic light-emitting diodes (PhOLEDs),providing a comprehensive overview of recent progress in molecular hosts for triplet emitters in PhOLEDs.Particularly,based on the nature of different hosts,e.g.,hole transporting,electron transporting or bipolar materials,in which the dopant emitters can be hosted to generate phosphorescence,the respective device performances are summarized and compared.Highlights are given to the relationships among the molecular structure,thermal stability,triplet energy,carrier mobility,molecular orbital energy level and their corresponding device performances.

  17. Influence of various functional groups on the relative stability of alkylperoxy triplet cations: A theoretical study

    Science.gov (United States)

    Smith, Kenneth J.; Meloni, Giovanni

    2015-07-01

    CBS-QB3 energy calculations show that the formation of a stable triplet cation for alkylperoxy radicals is dependent on factors other than the stability of the daughter cations exclusively. We have found that in cases where the daughter ions are not capable of stabilizing the cation through hyperconjugation, it is possible for the triplet cation to be bound. In many circumstances, CBS-QB3 calculations have found bound triplet cation states with 'negative dissociation energies.' These results are attributed to the effects that electron donating/withdrawing substituents have on the spin and charge densities of the resulting cations.

  18. Orbifold Grand Unification: A Solution to the Doublet-Triplet Problem

    CERN Document Server

    Jia, Bei

    2014-01-01

    To solve the doublet-triplet splitting problem in SU(5) grand unified theories, we propose a four dimensional orbifold grand unified theory by acting Z2 on the SU(5) gauge group. Without an adjoint Higgs, the orbifold procedure breaks the SU(5) gauge symmetry down to the standard model gauge group, and removes the triplet component of the fundamental SU(5) Higgs. In the supersymmetric framework, we show that the orbifold procedure removes two triplet superfields of the Higgs multiplets and leaves us with the minimal supersymmetric standard model, which also solves the hierarchy problem and realizes gauge coupling unification. We also discuss possible UV completions of the orbifold theories.

  19. Photolysis of alpha-azidoacetophenones: trapping of triplet alkyl nitrenes in solution.

    Science.gov (United States)

    Mandel, S M; Krause Bauer, J A; Gudmundsdottir, A D

    2001-02-22

    [reaction: see text] Selective excitation of the ketone chromophore in alpha-azidoacetophenones, 1, leads to intramolecular triplet energy transfer to the azido group, which forms the corresponding triplet alkyl nitrene, 2. Azides 1 also undergo alpha-cleavage to form benzoyl and methyl azido radicals in competition with nitrene formation. Thus the major photoproduct, 2-benzoylamino-1-phenylethanone, 3, comes from trapping of 2 with a benzoyl radical. This appears to be the first observation of bimolecular trapping of triplet alkyl nitrenes in solution.

  20. Adiabatic and nonadiabatic spin torques induced by a spin-triplet supercurrent

    Science.gov (United States)

    Takashima, Rina; Fujimoto, Satoshi; Yokoyama, Takehito

    2017-09-01

    We study spin-transfer torques induced by a spin-triplet supercurrent in a magnet with the superconducting proximity effect. By a perturbative approach, we show that spin-triplet correlations realize new types of torques, which are analogous to the adiabatic and nonadiabatic (β ) torques, without extrinsic spin-flip scattering. Remarkable advantages compared to conventional spin-transfer torques are highlighted in domain-wall manipulation. Oscillatory motions of a domain wall do not occur for a small Gilbert damping, and the threshold current density to drive its motion becomes zero in the absence of extrinsic pinning potentials due to the nonadiabatic torque controlled by the triplet correlations.

  1. Sequential Beamforming Synthetic Aperture Imaging

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2013-01-01

    Synthetic aperture sequential beamforming (SASB) is a novel technique which allows to implement synthetic aperture beamforming on a system with a restricted complexity, and without storing RF-data. The objective is to improve lateral resolution and obtain a more depth independent resolution...... and a range independent lateral resolution is obtained. The SASB method has been investigated using simulations in Field II and by off-line processing of data acquired with a commercial scanner. The lateral resolution increases with a decreasing F#. Grating lobes appear if F# 6 2 for a linear array with k-pitch...

  2. Vortex lines in a ferromagnetic spin-triplet superconductor

    Institute of Scientific and Technical Information of China (English)

    Zhao Li; Yang Jie; Xie Qun-Ying; Tian Miao; Duan Yi-Shi

    2012-01-01

    Based on Duan's topological current theory,we show that in a ferromagnetic spin-triplet superconductor there is a topological defect of string structures which can be interpreted as vortex lines.Such defects are different from the Abrikosov vortices in one-component condensate systems.We investigate the inner topological structure of the vortex lines.The topological charge density,velocity,and topological current of the vortex lines can all be expressed in terms of δ function,which indicates that the vortices can only arise from the zero points of an order parameter field.The topological charges of vortex lines are quantized in terms of the Hopf indices and Brouwer degrees of φ-mapping.The divergence of the self-induced magnetic field can be rigorously determined by the corresponding order parameter fields and its expression also takes the form of a δ-like function.Finally,based on the implicit function theorem and the Taylor expansion,we conduct detailed studies on the bifurcation of vortex topological current and find different directions of the bifurcation.

  3. Triplet superconductivity in oxide ferromagnetic interlayer of mesa-structure

    Science.gov (United States)

    Ovsyannikov, G. A.; Y Constantinian, K.; Sheerman, A. E.; Shadrin, A. V.; Kislinski, Yu V.; Khaydukov, Yu N.; Mustafa, L.; Kalabukhov, A.; Winkler, D.

    2015-03-01

    We present experimental data on Nb-Au/La0.7Sr0.3MnO3/SrRuO3/YBa2Cu3O7-δ mesa- structure with in plane linear size 10÷50 μm. The mesa-structures were patterned from the epitaxial heterostructures fabricated by pulsed laser ablation and magnetron sputtering. Superconducting critical current was observed for mesa-structures with the interlayer thicknesses up to 50 nm. In the mesa-structures with just one, either La0.7Sr0.3MnO3 or SrRuO3 interlayer with a thickness larger than 10 nm no superconducting current was observed. The registered superconducting current for the mesa-structures with a thinner interlayer is attributed to pinholes. Obtained results are discussed in terms of superconducting long-range triplet generation at interfaces of superconductor and a composite ferromagnet consisting of ferromagnetic materials with non-collinear magnetization.

  4. Triplet based online track finding in the PANDA-STT

    Science.gov (United States)

    Mertens, M. C.; Panda Collaboration

    2014-04-01

    The PANDA-Experiment at the future FAIR facility in Darmstadt will study antiproton-proton collisions in a fixed-target setup with a phase-space cooled antiproton beam with a momentum from 1.5 to 15 GeV/c at a nominal interaction rate of 2 · 107 s-1. The data acquisition of the detectors has to run in a triggerless mode and the physics events of interest are identified by an online event filter. Tracking information is a key input for the event filter to distinguish signal events from background. A variety of tracking algorithms is foreseen to process the different track topologies. The so-called Triplet Finder, which is presented here, is a track finding algorithm based on the central straw tube tracker (STT) of PANDA. The algorithm focuses on mathematical simplicity and robustness to allow an online processing of the incoming detector hits. The algorithm and results of a proof-of-concept implementation are presented.

  5. Radiative corrections to the Higgs couplings in the triplet model

    CERN Document Server

    Kikuchi, Mariko

    2013-01-01

    The feature of extended Higgs models can appear in the pattern of deviations from the Standard Model (SM) predictions in coupling constants of the SM-like Higgs boson ($h$). We can thus discriminate extended Higgs models by precisely measuring the pattern of deviations in the coupling constants of $h$, even when extra bosons are not found directly. In order to compare the theoretical predictions to the future precision data at the ILC, we must evaluate the theoretical predictions with radiative corrections in various extended Higgs models. In this talk, we give our comprehensive study for radiative corrections to various Higgs boson couplings of $h$ in the minimal Higgs triplet model (HTM). First, we define renormalization conditions in the model, and we calculate the Higgs coupling; $g\\gamma\\gamma, hWW, hZZ$ and $hhh$ at the one loop level. We then evaluate deviations in coupling constants of the SM-like Higgs boson from the predictions in the SM. We find that one-loop contributions to these couplings are su...

  6. An atlas of Calcium triplet spectra of active galaxies

    CERN Document Server

    Garcia-Rissmann, A; Asari, N V; Fernandes, R C; Schmitt, H; González-Delgado, R M; Storchi-Bergmann, T

    2005-01-01

    We present a spectroscopic atlas of active galactic nuclei covering the region around the 8498, 8542, 8662 Calcium triplet (CaT) lines. The sample comprises 78 objects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal galaxies. The spectra pertain to the inner ~300 pc in radius, and thus sample the central kinematics and stellar populations of active galaxies. The data are used to measure stellar velocity dispersions (sigma_star) both with cross-correlation and direct fitting methods. These measurements are found to be in good agreement with each-other and with those in previous studies for objects in common. The CaT equivalent width is also measured. We find average values and sample dispersions of W_CaT of 4.6+/-2.0, 7.0 and 7.7+/-1.0 angstrons for Seyfert 1s, Seyfert 2s and normal galaxies, respectively. We further present an atlas of [SIII]\\lambda 9069 emission line profiles for a subset of 40 galaxies. These data are analyzed in a companion paper which addresses the connection between ...

  7. Triplet States of Thioflavin T in Fluorescent Molecular Rotor Model

    Science.gov (United States)

    Kuz‧mitskii, V. A.; Stepuro, V. I.

    2017-01-01

    Quantum-chemical INDO/S calculations of Thiofl avin T have been carried out taking account of variation of the angle φ between the planes of the benzothiazole (BTZ) and dimethylaniline (DMA) rings. It was found that when the angle φ changes from 40° to 90° the energy of the triplet state increases by 4000 cm-1, whereas the energy of the singlet state S 1 decreases by 1900 cm-1 and reaches a minimum. The function {E}_{T_1}(φ) has a minimum at φ = 30°, which is 300 cm-1 less than at φ = 40°. The calculated T 1 S 0 interval at φ = 30-40° amounts to 15,600-16,000 cm-1, which agrees well with the phosphorescence data (17,100-17,400 cm-1). For φ = 80-90° the T 1, T 2 , and T 3 levels ( T 1 and T 2 are lower than S 1 ) are close to the S 1 level. The S 1 and T 3 levels intersect at φ 85°, and at φ = 90° the interval Δ {E}_{S_1{T}_3} amounts to only 100 cm-1 due to the small value of the exchange integral corresponding to electron transfer DMA → BTZ.

  8. Noise filtering of composite pulses for singlet-triplet qubits

    Science.gov (United States)

    Yang, Xu-Chen; Wang, Xin

    2016-01-01

    Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimentally. They are, however, designed under the static-noise model and may be considered as low-frequency filters. In this work, we perform a comprehensive theoretical study of the response of a type of dynamically corrected gates, namely the supcode for singlet-triplet qubits, to realistic 1/f noises with frequency spectra 1/ωα. Through randomized benchmarking, we have found that supcode offers improvement of the gate fidelity for α  1 and the improvement becomes exponentially more pronounced with the increase of the noise exponent in the range 1  α ≤ 3 studied. On the other hand, for small α, supcode will not offer any improvement. The δJ-supcode, specifically designed for systems where the nuclear noise is absent, is found to offer additional error reduction than the full supcode for charge noises. The computed filter transfer functions of the supcode gates are also presented. PMID:27383129

  9. Noise filtering of composite pulses for singlet-triplet qubits

    Science.gov (United States)

    Yang, Xu-Chen; Wang, Xin

    2016-07-01

    Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimentally. They are, however, designed under the static-noise model and may be considered as low-frequency filters. In this work, we perform a comprehensive theoretical study of the response of a type of dynamically corrected gates, namely the SUPCODE for singlet-triplet qubits, to realistic 1/f noises with frequency spectra 1/ωα. Through randomized benchmarking, we have found that SUPCODE offers improvement of the gate fidelity for α  1 and the improvement becomes exponentially more pronounced with the increase of the noise exponent in the range 1  α ≤ 3 studied. On the other hand, for small α, SUPCODE will not offer any improvement. The δJ-SUPCODE, specifically designed for systems where the nuclear noise is absent, is found to offer additional error reduction than the full SUPCODE for charge noises. The computed filter transfer functions of the supcode gates are also presented.

  10. Interplay between singlet and triplet excited states in a conformationally locked donor–acceptor dyad

    KAUST Repository

    Filatov, Mikhail A.

    2015-10-13

    The synthesis and photophysical characterization of a palladium(II) porphyrin – anthracene dyad bridged via short and conformationally rigid bicyclo[2.2.2]octadiene spacer were achieved. A spectroscopic investigation of the prepared molecule in solution has been undertaken to study electronic energy transfer in excited singlet and triplet states between the anthracene and porphyrin units. By using steady-state and time-resolved photoluminescence spectroscopy it was shown that excitation of the singlet excited state of the anthracene leads to energy transfer to the lower-lying singlet state of porphyrin. Alternatively, excitation of the porphyrin followed by intersystem crossing to the triplet state leads to very fast energy transfer to the triplet state of anthracene. The rate of this energy transfer has been determined by transient absorption spectroscopy. Comparative studies of the dynamics of triplet excited states of the dyad and reference palladium octaethylporphyrin (PdOEP) have been performed.

  11. Singlet and triplet excited state properties of natural chlorophylls and bacteriochlorophylls

    Energy Technology Data Exchange (ETDEWEB)

    Niedzwiedzki, Dariusz; Blankenship, R. E.

    2010-11-18

    Ten naturally occurring chlorophylls (a, b, c{sub 2}, d) and bacteriochlorophylls (a, b, c, d, e, g) were purified and studied using the optical spectroscopic techniques of both steady state and time-resolved absorption and fluorescence. The studies were carried out at room temperature in nucleophilic solvents in which the central Mg is hexacoordinated. The comprehensive studies of singlet excited state lifetimes show a clear dependency on the structural features of the macrocycle and terminal substituents. The wide-ranging studies of triplet state lifetime demonstrate the existence of an energy gap law for these molecules. The knowledge of the dynamics and the energies of the triplet state that were obtained in other studies allowed us to construct an energy gap law expression that can be used to estimate the triplet state energies of any (B)chlorophyll molecule from its triplet lifetime obtained in a liquid environment.

  12. The photochemistry of lipoic acid: photoionization and observation of a triplet excited state of a disulfide.

    Science.gov (United States)

    Bucher, Götz; Lu, Changyuan; Sander, Wolfram

    2005-12-09

    Under short-wavelength UV irradiation, lipoic acid (LipSS) and its reduced form, dihydrolipoic acid (DHLA), undergo photoionization processes through a bi- or monophotonic pathway. After ionization, the LipSS radical cation (LipSS*+) and radical anion (LipSS*-) are generated. LipSS*- can be converted to equimolar amounts of LipSS and DHLA through second-order decay. Triplet acetone can be quenched by LipSS and DHLA with a rate close to the diffusion-controlled limit. The mechanism was further confirmed by continuous irradiation experiments. When LipSS is directly irradiated with UVA light, the first excited triplet state of LipSS is observed, with a lifetime tau=75 ns. Characteristic reactions include triplet energy transfer to oxygen and beta-carotene and addition to isoprene. The lifetime of triplet LipSS is also shortened by addition of water and methanol.

  13. The origin of efficient triplet state population in sulfur-substituted nucleobases

    Science.gov (United States)

    Mai, Sebastian; Pollum, Marvin; Martínez-Fernández, Lara; Dunn, Nicholas; Marquetand, Philipp; Corral, Inés; Crespo-Hernández, Carlos E.; González, Leticia

    2016-10-01

    Elucidating the photophysical mechanisms in sulfur-substituted nucleobases (thiobases) is essential for designing prospective drugs for photo- and chemotherapeutic applications. Although it has long been established that the phototherapeutic activity of thiobases is intimately linked to efficient intersystem crossing into reactive triplet states, the molecular factors underlying this efficiency are poorly understood. Herein we combine femtosecond transient absorption experiments with quantum chemistry and nonadiabatic dynamics simulations to investigate 2-thiocytosine as a necessary step to unravel the electronic and structural elements that lead to ultrafast and near-unity triplet-state population in thiobases in general. We show that different parts of the potential energy surfaces are stabilized to different extents via thionation, quenching the intrinsic photostability of canonical DNA and RNA nucleobases. These findings satisfactorily explain why thiobases exhibit the fastest intersystem crossing lifetimes measured to date among bio-organic molecules and have near-unity triplet yields, whereas the triplet yields of canonical nucleobases are nearly zero.

  14. Design and construction of triplet atmospheric cold plasma jet for sterilization

    Directory of Open Access Journals (Sweden)

    F. Sohbatzadeh

    2014-03-01

    Full Text Available In this paper, construction of triplet atmospheric plasma jet using argon, air, oxygen and nitrogen gases is reported. Bactericidal effect of the plasma jet is also investigated. To that end, longitudinal geometric configuration for the electrodes was chosen because it would increase the jet length. Electrical characteristics, jet length dependencies on the applied voltage and gas flow rate were decided, experimentally. Relative concentrations of chemical reactive species such as ozone, atomic oxygen, NOx compounds and hydroxyl were measured using optical emission spectroscopy. It was seen that atomic oxygen and ozone concentrations with triplet plasma jet are more than the concentration of single plasma jet. Triplet plasma jet was also used for sterilization of solid and liquid surfaces to disinfect gram-negative and gram-positive Escherichia coli and Streptococcus pyogenes bacteria. The results verified the effectiveness of the triplet plasma jet for killing bacteria.

  15. Sensitized Triplet Formation of Chlorophyll-A and beta-Carotene

    DEFF Research Database (Denmark)

    Jensen, Nina Mejlhede; Wilbrandt, Robert Walter; Pagsberg, Palle Bjørn

    1980-01-01

    The naphthalene-sensitized formation of triplet excited chlorophyll-a (Chl-a) and all-transß-carotene has been studied by pulse radiolysis. The rate constants for transfer of triplet energy from naphthalene to Chl-a and all-transß-carotene in benzene at 25°C are (3.6 ± 0.6)·109M-1 s-1 and (10.7 ± 1...

  16. Spiro-linked hyperbranched architecture in electrophosphorescent conjugated polymers for tailoring triplet energy back transfer.

    Science.gov (United States)

    Shao, Shiyang; Ma, Zhihua; Ding, Junqiao; Wang, Lixiang; Jing, Xiabin; Wang, Fosong

    2012-04-17

    A spiro-linked hyperbranched architecture has been incorporated into electrophosphorescent conjugated polymers for the first time, aiming at simultaneously tailoring the intra- and intermolecular triplet energy back transfer from the phosphorescent guest to the conjugated polymer host. Based on a prototype with this unique structure, slower decay of triplet excitons, and 5-8 fold enhancement of device efficiencies are obtained compared with the conventional blending counterpart.

  17. Weight growth of triplet infants from birth to twelve years of age.

    Science.gov (United States)

    Yokoyama, Yoshie; Pitkäniemi, Janne; Kaprio, Jaakko; Silventoinen, Karri

    2012-10-01

    We analyzed the characteristics associated with the growth in weight of Japanese triplets from birth to 12 years of age. The study included 376 mothers and their 1,128 triplet children, who were born between 1978 and 2006. Data were collected through a mailed questionnaire sent to the mothers asking for information recorded in medical records. For these births, data on triplets' weight growth, gestational age, sex, parity, maternal age at delivery, maternal height, and maternal body mass index were obtained from records in the Maternal and Child Health Handbooks and records in the school where children receive health check-ups. The weight deficit of the triplets compared to the general population of Japan remained between 10% and 17% until 12 years of age. Moreover, at 12 years of age, the differences of weight between the general population and triplets were approximately -4.75 kg for boys and -6.00 kg for girls. Very low birth weight had the strongest contribution to body weight until 8 years of age. After 8 years of age, maternal body mass index was a significant factor affecting the weight of triplets until 12 years of age.

  18. Exploring Higgs Triplet Models via Vector Boson Scattering at the LHC

    CERN Document Server

    Godfrey, Stephen

    2010-01-01

    We present the results of a study of Higgs triplet boson production arising in the Littlest Higgs, Left-Right Symmetric, and Georgi-Machacek models in the W^\\pm W^\\pm, W^\\pm Z, W^+ W^-, and Z Z channels at the LHC. We focus on the "gold-plated" purely leptonic decay modes and consider the irreducible electroweak, QCD, and t-quark backgrounds, applying a combination of forward-jet-tagging, central-jet-vetoing, and stringent leptonic cuts to suppress the backgrounds. We find that, given the constraints on the triplet vacuum expectation value (vev), considerable luminosity is required to observe Higgs triplet bosons in vector boson scattering. Observing a Higgs triplet at the LHC is most promising in the Georgi-Machacek model due to a weaker constraint on the triplet vev. In this model, we find that a Higgs triplet boson with a mass of 1.0 (1.5) TeV can be observed at the LHC with an integrated luminosity as low as 41 (119) fb^{-1} in the W^\\pm W^\\pm channel and as low as 171 (474) fb^{-1} in the W^\\pm Z channel...

  19. Ab inito study on triplet excitation energy transfer in photosynthetic light-harvesting complexes.

    Science.gov (United States)

    You, Zhi-Qiang; Hsu, Chao-Ping

    2011-04-28

    We have studied the triplet energy transfer (TET) for photosynthetic light-harvesting complexes, the bacterial light-harvesting complex II (LH2) of Rhodospirillum molischianum and Rhodopseudomonas acidophila, and the peridinin-chlorophyll a protein (PCP) from Amphidinium carterae. The electronic coupling factor was calculated with the recently developed fragment spin difference scheme (You and Hsu, J. Chem. Phys. 2010, 133, 074105), which is a general computational scheme that yields the overall coupling under the Hamiltonian employed. The TET rates were estimated based on the couplings obtained. For all light-harvesting complexes studied, there exist nanosecond triplet energy transfer from the chlorophylls to the carotenoids. This result supports a direct triplet quenching mechanism for the photoprotection function of carotenoids. The TET rates are similar for a broad range of carotenoid triplet state energy, which implies a general and robust TET quenching role for carotenoids in photosynthesis. This result is also consistent with the weak dependence of TET kinetics on the type or the number of π conjugation lengths in the carotenoids and their analogues reported in the literature. We have also explored the possibility of forming triplet excitons in these complexes. In B850 of LH2 or the peridinin cluster in PCP, it is unlikely to have triplet exciton since the energy differences of any two neighboring molecules are likely to be much larger than their TET couplings. Our results provide theoretical limits to the possible photophysics in the light-harvesting complexes.

  20. Triplet state in photosystem II reaction centers as studied by 130 GHz EPR

    Energy Technology Data Exchange (ETDEWEB)

    Pashenko, S.V.; Proskuryakov, I.I.; Germano, M.; Gorkom, H.J. van; Gast, P

    2003-11-01

    The triplet state in the reaction centers of photosystem II was studied by high-field/high-frequency (130 GHz) EPR in the temperature range 50-90 K. At 50 K, the zero-field splitting parameters of the EPR spectrum correspond well to those of a chlorophyll monomer, in agreement with earlier studies. In the high magnetic field of 4.6 T employed in this study, the g-anisotropy of the triplet state becomes apparent and leads to a shift of the canonical positions of the triplet EPR spectrum. Assuming that triplet g- and zero-field tensors are coaxial, the principal values of the triplet g-tensor are determined to be 2.00324, 2.00306 and 2.00231 with an error of {+-}0.00004. Lifting this assumption results in higher g-anisotropy. At higher temperatures, the shape of the spectra changes significantly. Triplet excitation hopping involving the accessory chlorophyll B{sub A} and P{sub A} or P{sub B} (equivalents of the special pair bacteriochlorophylls of the bacterial reaction centers) can partially explain those changes, but the most prominent features indicate that also the electron acceptor I{sub A} (a pheophytin molecule) must be involved.

  1. Incidences of Feto-Fetal Transfusion Syndrome and Perinatal Outcomes in Triplet Gestations with Monochorionic Placentation.

    Science.gov (United States)

    Sato, Yuka; Ishii, Keisuke; Yokouchi, Tae; Murakoshi, Takeshi; Kiyoshi, Kenji; Nakayama, Soichiro; Yonetani, Naoto; Mitsuda, Nobuaki

    2016-01-01

    This study aimed to determine the incidences of feto-fetal transfusion syndrome (FFTS) and perinatal outcomes in triplet gestations with monochorionic placentation. In this retrospective cohort study, we evaluated the incidences of FFTS and perinatal outcomes at 28 days of age in cases of triplet gestations with monochorionic placentation who visited our centers before 16 weeks of gestation and delivered over a period of 11 years. In 41 triplet gestations (17 monochorionic triamniotic, 22 dichorionic triamniotic, 1 dichorionic diamniotic, and 1 monochorionic monoamniotic), the incidence of FFTS was 17.1%, and the median gestational age at FFTS diagnosis was 19 weeks. In 123 triplets, the incidences of fetal death and neonatal death at 28 days of age were 8.1 and 0.9%, respectively. None of the surviving infants had grade 3 or 4 intraventricular hemorrhage, while cystic periventricular leukomalacia occurred in 6 of 113 infants (5.3%). The incidence of poor outcomes (death or any major neurological complication at 28 days of age) was 13.8%. Seventeen percent of triplet pregnancies with monochorionic placentation developed FFTS, and 14% had a poor outcome. Therefore, triplet gestations with monochorionic placentation should be followed carefully. © 2016 S. Karger AG, Basel.

  2. The models of proton assisted and the unassisted formation of CGC base triplets.

    Science.gov (United States)

    Medhi, Chitrani

    2002-01-01

    The triple helix is formed by combining a double and a single strand DNAs in low pH and dissociates in high pH. Under such conditions, protonation of cytosine in the single strand is necessary for triplex formation where cytosine-guanine-cytosine (CGC+) base triplet stabilizes the triple helix. The mechanism of CGC+ triplet formation from guanine-cytosine (GC) and a protonated cytosine (C+) shows the importance of N3 proton. Similarly in the case of CGC (unprotonated) triplet, the donor acceptor H-bond at N3 hydrogen of the cytosine analog (C) initiates the interaction with GC. The correspondence between the two models of triplets, CGC+ and CGC, unambiguously assigned that protonation at N3 cytosine in low pH to be the first step in triplet formation, but a donor acceptor triplet (CGC) can be designed without involving a proton in the Hoogsteen H-bond. Further, the bases of cytosine analogue also show the capability of forming Watson Crick (WC) H-bonds with guanine.

  3. Selective formation of triplet alkyl nitrenes from photolysis of beta-azido-propiophenone and their reactivity.

    Science.gov (United States)

    Singh, Pradeep N D; Mandel, Sarah M; Sankaranarayanan, Jagadis; Muthukrishnan, Sivaramakrishnan; Chang, Mingxin; Robinson, Rachel M; Lahti, Paul M; Ault, Bruce S; Gudmundsdóttir, Anna D

    2007-12-26

    Photolysis of beta-azido propiophenone derivatives, 1, with built-in sensitizer units, leads to selective formation of triplet alkyl nitrenes 2 that were detected directly with laser flash photolysis (lambdamax = 325 nm, tau = 27 ms) and ESR spectroscopy (|D/hc| = 1.64 cm-1, |E/hc| = 0.004 cm-1). Nitrenes 2 were further characterized with argon matrix isolation, isotope labeling, and molecular modeling. The triplet alkyl nitrenes are persistent intermediates that do not abstract H-atoms from the solvent but do decay by dimerizing with another triplet nitrene to form azo products, rather than reacting with an azide precursor. The azo dimer tautomerizes and rearranges to form heterocyclic compound 3. Nitrene 2a, with an n,pi* configuration as the lowest triplet excited state of the its ketone sensitizer moiety, undergoes intramolecular 1,4-H-atom abstraction to form biradical 6, which was identified by argon matrix isolation, isotope labeling, and molecular modeling. beta-Azido-p-methoxy-propiophenone, with a pi,pi* lowest excited state of its triplet sensitizer moiety, does not undergo any secondary photoreactions but selectively yields only triplet alkyl nitrene intermediates that dimerize to form 3b.

  4. Triplet excitons in natural photosynthetic and artificial light harvesting systems: Measurement and modeling

    Science.gov (United States)

    Hartzler, Daniel Allen

    Under full sunlight, unprotected (Bacterio)Chlorophyll ((B)Chl) molecules photodegrade in a matter of minutes. This is the result of the generation of highly reactive singlet oxygen (1O2) by energy transfer from the (B)Chl triplet state (3(B)Chl) to the oxygen ground state. Natural photosynthetic systems must protect themselves from 1O2, typically done by positioning carotenoids within a few angstroms of each (B)Chl molecule to quench 3(B)Chl states. Using phosphorescence spectroscopy and computational modeling, we investigated alternative, carotenoid independent, mechanisms which nature may employ to prevent 1O2 sensitization by lowering the energy of 3(B)Chl below that of 1O2. The two proposed triplet lowering mechanisms investigated were: triplet state lowering by strong pigment-pigment interactions (i.e. triplet exciton formation) and triplet state lowering by pigment-protein interactions. Possible natural examples employing these mechanisms are two structures found in green sulfur bacteria: the chlorosome (an antenna containing ~100000 coupled BChl c, d, or e molecules with unexpectedly high photostability) and the Fenna-Matthews-Olson (FMO) complex (an auxiliary antenna containing eight seemingly unprotected BChl a molecules). Measurements performed on linear aggregates of the dye perylene diimide (PDI) show that triplet exciton formation does reduce the triplet state energy. However, direct measurement of triplet state energies for the chlorosome and FMO complex proved experimentally difficult, thus an alternative approach was used to calculate these energies using empirical and excitonic models. Since the use of excitonic modeling requires knowledge of both the pigment site energies and the pigment-pigment interactions (i.e. couplings), work was performed to catalog the monomeric singlet and triplet state energies of all known natural (B)Chl pigments by direct measurement or computational modeling and to characterize the triplet-triplet (T-T) coupling in

  5. Structural features of sequential weak measurements

    Science.gov (United States)

    Diósi, Lajos

    2016-07-01

    We discuss the abstract structure of sequential weak measurement (WM) of general observables. In all orders, the sequential WM correlations without postselection yield the corresponding correlations of the Wigner function, offering direct quantum tomography through the moments of the canonical variables. Correlations in spin-1/2 sequential weak measurements coincide with those in strong measurements, they are constrained kinematically, and they are equivalent with single measurements. In sequential WMs with postselection, an anomaly occurs, different from the weak value anomaly of single WMs. In particular, the spread of polarization σ ̂ as measured in double WMs of σ ̂ will diverge for certain orthogonal pre- and postselected states.

  6. Immediate Sequential Bilateral Cataract Surgery

    DEFF Research Database (Denmark)

    Kessel, Line; Andresen, Jens; Erngaard, Ditte

    2015-01-01

    The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS) with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence......-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were...... performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation). We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery...

  7. Optimization of reversible sequential circuits

    CERN Document Server

    Sayem, Abu Sadat Md

    2010-01-01

    In recent years reversible logic has been considered as an important issue for designing low power digital circuits. It has voluminous applications in the present rising nanotechnology such as DNA computing, Quantum Computing, low power VLSI and quantum dot automata. In this paper we have proposed optimized design of reversible sequential circuits in terms of number of gates, delay and hardware complexity. We have designed the latches with a new reversible gate and reduced the required number of gates, garbage outputs, and delay and hardware complexity. As the number of gates and garbage outputs increase the complexity of reversible circuits, this design will significantly enhance the performance. We have proposed reversible D-latch and JK latch which are better than the existing designs available in literature.

  8. Accessing the Long-Lived Triplet Excited States in Transition-Metal Complexes: Molecular Design Rationales and Applications.

    Science.gov (United States)

    Cui, Xiaoneng; Zhao, Jianzhang; Mohmood, Zafar; Zhang, Caishun

    2016-02-01

    Transition-metal complex triplet photosensitizers are versatile compounds that have been widely used in photocatalysis, photovoltaics, photodynamic therapy (PDT) and triplet-triplet annihilation (TTA) upconversion. The principal photophysical processes in these applications are the intermolecular energy transfer or electron transfer. One of the major challenges facing these triplet photosensitizers is the short triplet-state lifetime, which is detrimental to the above-mentioned photophysical processes. In order to address this challenge, transition-metal complexes showing long-lived triplet excited states are highly desired. This review article summarizes the development of this fascinating area, including the molecular design rationales, the principal photophysical properties, and the applications of these complexes in PDT and TTA upconversion.

  9. Sequential association rules in atonal music

    NARCIS (Netherlands)

    A. Honingh; T. Weyde; D. Conklin

    2009-01-01

    This paper describes a preliminary study on the structure of atonal music. In the same way as sequential association rules of chords can be found in tonal music, sequential association rules of pitch class set categories can be found in atonal music. It has been noted before that certain pitch class

  10. Sequential association rules in atonal music

    NARCIS (Netherlands)

    Honingh, A.; Weyde, T.; Conklin, D.

    2009-01-01

    This paper describes a preliminary study on the structure of atonal music. In the same way as sequential association rules of chords can be found in tonal music, sequential association rules of pitch class set categories can be found in atonal music. It has been noted before that certain pitch class

  11. Sequential auctions, price trends, and risk preferences

    NARCIS (Netherlands)

    Hu, A.; Zou, L.

    2015-01-01

    We analyze sequential auctions in a general environment where bidders are heterogeneous in risk exposures and exhibit non-quasilinear utilities. We derive a pure strategy symmetric equilibrium for the sequential Dutch and Vickrey auctions respectively, with an arbitrary number of identical objects f

  12. Analyzing Sequential Patterns in Retail Databases

    Institute of Scientific and Technical Information of China (English)

    Unil Yun

    2007-01-01

    Finding correlated sequential patterns in large sequence databases is one of the essential tasks in data miningsince a huge number of sequential patterns are usually mined, but it is hard to find sequential patterns with the correlation.According to the requirement of real applications, the needed data analysis should be different. In previous mining approaches,after mining the sequential patterns, sequential patterns with the weak affinity are found even with a high minimum support.In this paper, a new framework is suggested for mining weighted support affinity patterns in which an objective measure,sequential ws-confidence is developed to detect correlated sequential patterns with weighted support affinity patterns. Toefficiently prune the weak affinity patterns, it is proved that ws-confidence measure satisfies the anti-monotone and crossweighted support properties which can be applied to eliminate sequential patterns with dissimilar weighted support levels.Based on the framework, a weighted support affinity pattern mining algorithm (WSMiner) is suggested. The performancestudy shows that WSMiner is efficient and scalable for mining weighted support affinity patterns.

  13. Trial Sequential Methods for Meta-Analysis

    Science.gov (United States)

    Kulinskaya, Elena; Wood, John

    2014-01-01

    Statistical methods for sequential meta-analysis have applications also for the design of new trials. Existing methods are based on group sequential methods developed for single trials and start with the calculation of a required information size. This works satisfactorily within the framework of fixed effects meta-analysis, but conceptual…

  14. Finding Sequential Patterns from Large Sequence Data

    CERN Document Server

    Esmaeili, Mahdi

    2010-01-01

    Data mining is the task of discovering interesting patterns from large amounts of data. There are many data mining tasks, such as classification, clustering, association rule mining, and sequential pattern mining. Sequential pattern mining finds sets of data items that occur together frequently in some sequences. Sequential pattern mining, which extracts frequent subsequences from a sequence database, has attracted a great deal of interest during the recent data mining research because it is the basis of many applications, such as: web user analysis, stock trend prediction, DNA sequence analysis, finding language or linguistic patterns from natural language texts, and using the history of symptoms to predict certain kind of disease. The diversity of the applications may not be possible to apply a single sequential pattern model to all these problems. Each application may require a unique model and solution. A number of research projects were established in recent years to develop meaningful sequential pattern...

  15. Multi-agent sequential hypothesis testing

    KAUST Repository

    Kim, Kwang-Ki K.

    2014-12-15

    This paper considers multi-agent sequential hypothesis testing and presents a framework for strategic learning in sequential games with explicit consideration of both temporal and spatial coordination. The associated Bayes risk functions explicitly incorporate costs of taking private/public measurements, costs of time-difference and disagreement in actions of agents, and costs of false declaration/choices in the sequential hypothesis testing. The corresponding sequential decision processes have well-defined value functions with respect to (a) the belief states for the case of conditional independent private noisy measurements that are also assumed to be independent identically distributed over time, and (b) the information states for the case of correlated private noisy measurements. A sequential investment game of strategic coordination and delay is also discussed as an application of the proposed strategic learning rules.

  16. Laser flash photolysis study on 9-phenylxanthenium tetrafluoroborate: Identification of new features due to the triplet state

    Indian Academy of Sciences (India)

    Sanghamitra Banerjee; Anunay Samanta

    2011-01-01

    Laser flash photolysis study on highly fluorescent and stable salt of 9-phenylxanthenium cation in neutral condition has been carried out for the first time. A new transient absorption band of this extensively studied system that perhaps remained buried under the fluorescence envelope and hitherto undetected has been identified and attributed to the triplet state of the system. This oxygen-insensitive triplet-triplet absorption band in the 480-600 nm range is expected to trigger new studies exploring the reactivity of the triplet state of this system, which has so far received very little attention.

  17. Identification of the sites of chlorophyll triplet quenching in relation to the structure of LHC-II from higher plants. Evidence from EPR spectroscopy.

    Science.gov (United States)

    Di Valentin, Marilena; Biasibetti, Federico; Ceola, Stefano; Carbonera, Donatella

    2009-10-01

    The Chlorophyll a (Chl a) molecules involved in the triplet-triplet energy transfer to the central luteins in trimeric LHC-II are identified by time-resolved and pulse EPR techniques. The concept of spin angular momentum conservation during triplet-triplet energy transfer is exploited for the calculation of the spin polarization of the carotenoid triplet states. The sites with the highest probability of forming triplet states, which are quenched by the central luteins, result to be Chl603 and Chl612. "Unquenched" Chl triplet states are produced by photoexcitation in the LHC-II complex. Putative sites of these triplet states are Chl614, Chl611, Chl604, and Chl613 since they do not contribute to the formation of the observed carotenoid triplet states.

  18. Energy harvesting of non-emissive triplet excitons in tetracene by emissive PbS nanocrystals

    Science.gov (United States)

    Thompson, Nicholas J.; Wilson, Mark W. B.; Congreve, Daniel N.; Brown, Patrick R.; Scherer, Jennifer M.; Bischof, Thomas S.; Wu, Mengfei; Geva, Nadav; Welborn, Matthew; Voorhis, Troy Van; Bulović, Vladimir; Bawendi, Moungi G.; Baldo, Marc A.

    2014-11-01

    Triplet excitons are ubiquitous in organic optoelectronics, but they are often an undesirable energy sink because they are spin-forbidden from emitting light and their high binding energy hinders the generation of free electron-hole pairs. Harvesting their energy is consequently an important technological challenge. Here, we demonstrate direct excitonic energy transfer from ‘dark’ triplets in the organic semiconductor tetracene to colloidal PbS nanocrystals, thereby successfully harnessing molecular triplet excitons in the near infrared. Steady-state excitation spectra, supported by transient photoluminescence studies, demonstrate that the transfer efficiency is at least (90 ± 13)%. The mechanism is a Dexter hopping process consisting of the simultaneous exchange of two electrons. Triplet exciton transfer to nanocrystals is expected to be broadly applicable in solar and near-infrared light-emitting applications, where effective molecular phosphors are lacking at present. In particular, this route to ‘brighten’ low-energy molecular triplet excitons may permit singlet exciton fission sensitization of conventional silicon solar cells.

  19. Matrix genetics, part 1: permutations of positions in triplets and symmetries of genetic matrices

    CERN Document Server

    Petoukhov, Sergey V

    2008-01-01

    The hidden connection between the degeneracy of the vertebrate mitochondria genetic code and the positional permutations inside genetic triplets is described. The Kronecker family of the genetic matrices is investigated, which is based on the genetic matrix [C A; U G], where C, A, U, G are the letters of the genetic alphabet. The natural system of binary numeration of genetic multiplets in the genetic matrices is proposed. The matrix [C A; U G] in the third Kronecker power is the (8*8)-matrix, which contains 64 triplets. When 64 triplets in this matrix are numbered in accordance with the natural system, the coincidence with the famous table of 64 hexagrams of the ancient Chinese book "I Ching" arises. It is significant that peculiarities of the degeneracy of the vertebrate mitochondria genetic code are reflected in the symmetrical black-and-white mosaic of this genetic (8*8)-matrix of 64 triplets. This matrix is reformed into a new mosaic matrix when internal positions in all triplets are permuted simultaneou...

  20. Energy-donor phosphorescence quenching study of triplet–triplet energy transfer between UV absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Azusa; Nakabai, Yuya [Department of Chemistry, Graduate School of Engineering, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan); Oguchi-Fujiyama, Nozomi; Miyazawa, Kazuyuki [Shiseido Research Center, Hayabuchi, Tsuzuki-ku, Yokohama 224-8558 (Japan); Yagi, Mikio, E-mail: yagimiki@ynu.ac.jp [Department of Chemistry, Graduate School of Engineering, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2015-10-15

    The intermolecular triplet–triplet energy transfer from a photounstable UV-A absorber, 4-tert-butyl-4′-methoxydibenzoylmethane (BMDBM), to UV-B absorbers, 2-ethylhexyl 4-methoxycinnamate (octyl methoxycinnamate, OMC), octocrylene (OCR) and dioctyl 4-methoxybenzylidenemalonate (DOMBM) has been observed using a 355 nm laser excitation in rigid solutions at 77 K. The decay curves of the energy-donor phosphorescence in the presence of the UV-B absorbers deviate from the exponential decay at the initial stage of the decay. The Stern–Volmer formulation is not valid in rigid solutions because molecular diffusion is impossible. The experimental results indicate that the rate constant of triplet–triplet energy transfer from BMDBM to the UV-B absorbers, k{sub T–T}, decreases in the following order: k{sub T–T} (BMDBM–DOMBM)>k{sub T–T} (BMDBM–OMC)≥k{sub T–T} (BMDBM–OCR). The presence of DOMBM enhances the photostability of the widely used combination of UV-A and UV-B absorbers, BMDBM and OCR. The effects of the triplet–triplet energy transfer on the photostability of BMDBM are discussed. - Highlights: • The intermolecular triplet–triplet energy transfer between UV absorbers was observed. • The phosphorescence decay deviates from exponential at the initial stage of decay. • The effects of triplet–triplet energy transfer on the photostability are discussed.

  1. Specificity-Determining DNA Triplet Code for Positioning of Human Preinitiation Complex.

    Science.gov (United States)

    Goldshtein, Matan; Lukatsky, David B

    2017-05-23

    The notion that transcription factors bind DNA only through specific, consensus binding sites has been recently questioned. No specific consensus motif for the positioning of the human preinitiation complex (PIC) has been identified. Here, we reveal that nonconsensus, statistical, DNA triplet code provides specificity for the positioning of the human PIC. In particular, we reveal a highly nonrandom, statistical pattern of repetitive nucleotide triplets that correlates with the genomewide binding preferences of PIC measured by Chip-exo. We analyze the triplet enrichment and depletion near the transcription start site and identify triplets that have the strongest effect on PIC-DNA nonconsensus binding. Using statistical mechanics, a random-binder model without fitting parameters, with genomic DNA sequence being the only input, we further validate that the nonconsensus nucleotide triplet code constitutes a key signature providing PIC binding specificity in the human genome. Our results constitute a proof-of-concept for, to our knowledge, a new design principle for protein-DNA recognition in the human genome, which can lead to a better mechanistic understanding of transcriptional regulation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Triplet State Formation in Photovoltaic Blends of DPP-Type Copolymers and PC71BM

    KAUST Repository

    Ochsmann, Julian R.

    2015-04-29

    The exciton dynamics in pristine films of two structurally related low-bandgap diketopyrrolopyrrole (DPP)-based donor–acceptor copolymers and the photophysical processes in bulk heterojunction solar cells using DPP copolymer:PC71BM blends are investigated by broadband transient absorption (TA) pump-probe experiments covering the vis–near-infrared spectral and fs–μs dynamic range. The experiments reveal surprisingly short exciton lifetimes in the pristine poly­mer films in conjunction with fast triplet state formation. An in-depth analysis of the TA data by multivariate curve resolution analysis shows that in blends with fullerene as acceptor ultrafast exciton dissociation creates charge carriers, which then rapidly recombine on the sub-ns timescale. Furthermore, at the carrier densities created by pulsed laser excitation the charge carrier recombination leads to a substantial population of the polymer triplet state. In fact, virtually quantitative formation of triplet states is observed on the sub-ns timescale. However, the quantitative triplet formation on the sub-ns timescale is not in line with the power conversion efficiencies of devices indicating that triplet state formation is an intensity-dependent process in these blends and is reduced under solar illumination conditions, as free charge carriers can be extracted from the photoactive layer in devices.

  3. Investigation of the role of triplet states in the Wulf bands of ozone

    Science.gov (United States)

    Braunstein, M.; Martin, R. L.; Hay, P. J.

    1995-03-01

    Results of spin-orbit interaction calculations on the three lowest triplet states of ozone, 3B2, 3A2, and 3B1, are presented. These calculations use a one-electron, one-center approximation of the spin-orbit operator and a modest number of configurations within a 3s2p1d basis to estimate the amount of singlet character in these predominantly triplet states and triplet character in the predominantly singlet ground state. The results are given in the context of recent studies which predict that one of these triplet states gives rise to the Wulf optical absorption bands of ozone, a series of weak diffuse peaks in the near infrared, just above the O2+O dissociation threshold. Without spin-orbit coupling, these triplet states are spin forbidden from the singlet ozone ground state, 1A1. The present results point to the 3A2 and 3B1 states as playing a possible role in the Wulf bands, but more complete calculations will be needed to confirm this.

  4. Long-lived two-dimensional triplet magnetoexcitons in a Hall insulator

    Science.gov (United States)

    Kulik, L. V.; Gorbunov, A. V.; Zhuravlev, A. S.; Timofeev, V. B.; Kukushkin, I. V.

    2016-03-01

    An experimental technique is developed to perform photoexcitation of an ensemble of translationinvariant triplet excitons, to manipulate this ensemble, and to detect the properties of its components. In particular, the influence of temperature on the radiationless decay during the relaxation of an exciton spin into the ground state of a Hall insulator at a filling factor ν = 2 is studied. The generation of photoexcited electrons and holes is controlled using photoinduced resonance reflection spectra, which makes it possible to estimate the density of light-generated electron-hole pairs and to independently control the self-consistent generation of electrons at the first Landau level and holes (vacancies) at the ground (zero) cyclotron electronic level. The existence of triplet excitons is established from inelastic light scattering spectra, which are used to determine the singlet-triplet exciton splitting. The lifetimes of triplet excitons, which are closely related to the relaxation time of an electron spin, are extremely long: they reach 100 μs in perfect GaAs/AlGaAs heterostructures with a high mobility of two-dimensional electrons at low temperatures. These long spin relaxation times are qualitatively explained, and the expected collective behavior of high-density triplet magnetoexcitons at sufficiently low temperatures, which is related to their Bose nature, is discussed.

  5. Preorganized Chromophores Facilitate Triplet Energy Migration, Annihilation and Upconverted Singlet Energy Collection.

    Science.gov (United States)

    Mahato, Prasenjit; Yanai, Nobuhiro; Sindoro, Melinda; Granick, Steve; Kimizuka, Nobuo

    2016-05-25

    Photon upconversion (UC) based on triplet-triplet annihilation (TTA) has the potential to enhance significantly photovoltaic and photocatalytic efficiencies by harnessing sub-bandgap photons, but the progress of this field is held back by the chemistry problem of how to preorganize multiple chromophores for efficient UC under weak solar irradiance. Recently, the first maximization of UC quantum yield at solar irradiance was achieved using fast triplet energy migration (TEM) in metal-organic frameworks (MOFs) with ordered acceptor arrays, but at the same time, a trade-off between fast TEM and high fluorescence efficiency was also found. Here, we provide a solution for this trade-off issue by developing a new strategy, triplet energy migration, annihilation and upconverted singlet energy collection (TEM-UPCON). The porous structure of acceptor-based MOF crystals allows triplet donor molecules to be accommodated without aggregation. The surface of donor-doped MOF nanocrystals is modified with highly fluorescent energy collectors through coordination bond formation. Thanks to the higher fluorescence quantum yield of surface-bound collectors than parent MOFs, the implementation of the energy collector greatly improves the total UC quantum yield. The UC quantum yield maximization behavior at ultralow excitation intensity was retained because the TTA events take place only in the MOF acceptors. The TEM-UPCON concept may be generalized to collectors with various functions and would lead to quantitative harvesting of upconverted energy, which is difficult to achieve in common molecular diffusion-based systems.

  6. Multilevel sequential Monte Carlo samplers

    KAUST Repository

    Beskos, Alexandros

    2016-08-29

    In this article we consider the approximation of expectations w.r.t. probability distributions associated to the solution of partial differential equations (PDEs); this scenario appears routinely in Bayesian inverse problems. In practice, one often has to solve the associated PDE numerically, using, for instance finite element methods which depend on the step-size level . hL. In addition, the expectation cannot be computed analytically and one often resorts to Monte Carlo methods. In the context of this problem, it is known that the introduction of the multilevel Monte Carlo (MLMC) method can reduce the amount of computational effort to estimate expectations, for a given level of error. This is achieved via a telescoping identity associated to a Monte Carlo approximation of a sequence of probability distributions with discretization levels . ∞>h0>h1⋯>hL. In many practical problems of interest, one cannot achieve an i.i.d. sampling of the associated sequence and a sequential Monte Carlo (SMC) version of the MLMC method is introduced to deal with this problem. It is shown that under appropriate assumptions, the attractive property of a reduction of the amount of computational effort to estimate expectations, for a given level of error, can be maintained within the SMC context. That is, relative to exact sampling and Monte Carlo for the distribution at the finest level . hL. The approach is numerically illustrated on a Bayesian inverse problem. © 2016 Elsevier B.V.

  7. Conditions for describing triplet states in reduced density matrix functional theory

    CERN Document Server

    Theophilou, Iris; Helbig, Nicole

    2016-01-01

    We consider necessary conditions for the one body-reduced density matrix (1RDM) to correspond to a triplet wave-function of a two electron system. The conditions concern the occupation numbers and are different for the high spin projections, $S_z=\\pm 1$, and the $S_z=0$ projection. We employ these conditions in reduced density matrix functional theory calculations for the triplet excitations of two electron systems. In addition, we propose that these conditions can be used in the calculation of triplet states of systems with more than two electrons by restricting the active space and assess this procedure in calculations for a few atomic and molecular systems. We show that the quality of the optimal 1RDMs improves by applying the conditions in all the cases we studied.

  8. Exploring two-state reactivity pathways in the cycloaddition reactions of triplet methylene.

    Science.gov (United States)

    Pérez, Patricia; Andrés, J; Safont, V S; Contreras, Renato; Tapia, O

    2005-05-12

    Spin forbidden 1,2-cycloadditions of triplet methylene to alkenes have been theoretically studied as an example of the two-state reactivity paradigm in organic chemistry. The cycloadditions of triplet methylene to ethylene and the (E)- and (Z)-2-butene isomers show spin inversion after the transition state and therefore with no effect on the reaction rate. A local analysis shows that while triplet methylene addition to alkenes leading to the formation of a biradical intermediate is driven by spin polarization, the ring closure step to yield cyclopropane is a pericyclic process. We have found that at the regions in the potential energy surface where the spin crossover is likely to occur, the spin potential in the direction of increasing spin multiplicity, mu(+)(s), tends to equalize the one in the direction of decreasing spin multiplicity, mu(-)(s). This equalization facilitates the spin transfer process driven by changes in the spin density of the system.

  9. A New Track Reconstruction Algorithm suitable for Parallel Processing based on Hit Triplets and Broken Lines

    CERN Document Server

    Schöning, Andre

    2016-01-01

    Track reconstruction in high track multiplicity environments at current and future high rate particle physics experiments is a big challenge and very time consuming. The search for track seeds and the fitting of track candidates are usually the most time consuming steps in the track reconstruction. Here, a new and fast track reconstruction method based on hit triplets is proposed which exploits a three-dimensional fit model including multiple scattering and hit uncertainties from the very start, including the search for track seeds. The hit triplet based reconstruction method assumes a homogeneous magnetic field which allows to give an analytical solutions for the triplet fit result. This method is highly parallelizable, needs fewer operations than other standard track reconstruction methods and is therefore ideal for the implementation on parallel computing architectures. The proposed track reconstruction algorithm has been studied in the context of the Mu3e-experiment and a typical LHC experiment.

  10. Theoretical study of the intensity of chemically induce dynamic electron polarization of radical-triplet pairs

    Institute of Scientific and Technical Information of China (English)

    XU Xin-sheng; ZHANG Xian-yi; ZHANG Wei-jun; CUI Zhi-feng; LU Tong-xing

    2003-01-01

    Considering the interaction between excited triplet molecule and doublet radical, based on the second-order perturbation theory and the motion equation of density matrix, the polarization intensity of RTPM were theoretically calculated with the overpopulated doublet spin states and quartet spin states of radical-triplet pairs as initial conditions respectively. The results of calculation indicate that the net emissive polarization and the net absorptive polarization on the radical result from the zero-field-splitting (zfs) and the multiplet A/E and E/A polarization result from hyperfine (hf) interactions of the triplet molecule. The hyperfine related A+A/E or E+E/A CIDEP on the radical were the overpopulation of the net absorptive or emissive polarization and multiplet A/E or E/A polarization..

  11. A New Track Reconstruction Algorithm suitable for Parallel Processing based on Hit Triplets and Broken Lines

    Science.gov (United States)

    Schöning, André

    2016-11-01

    Track reconstruction in high track multiplicity environments at current and future high rate particle physics experiments is a big challenge and very time consuming. The search for track seeds and the fitting of track candidates are usually the most time consuming steps in the track reconstruction. Here, a new and fast track reconstruction method based on hit triplets is proposed which exploits a three-dimensional fit model including multiple scattering and hit uncertainties from the very start, including the search for track seeds. The hit triplet based reconstruction method assumes a homogeneous magnetic field which allows to give an analytical solutions for the triplet fit result. This method is highly parallelizable, needs fewer operations than other standard track reconstruction methods and is therefore ideal for the implementation on parallel computing architectures. The proposed track reconstruction algorithm has been studied in the context of the Mu3e-experiment and a typical LHC experiment.

  12. Triplet excitons as sensitive spin probes for structure analysis of extended defects in microcrystalline silicon

    Science.gov (United States)

    Meier, Christoph; Teutloff, Christian; Behrends, Jan; Bittl, Robert; Astakhov, Oleksandr; Lips, Klaus

    2016-07-01

    Electrically detected magnetic resonance (EDMR) spectroscopy is employed to study the influence of triplet excitons on the photocurrent in state-of-the-art microcrystalline silicon thin-film solar cells. These triplet excitons are used as sensitive spin probes for the investigation of their electronic and nuclear environment in this mixed-phase material. According to low-temperature EDMR results obtained from solar cells with different triplet excitons reside at extended defects in the crystallites of microcrystalline silicon that give rise to shallow states in the silicon band gap. The excitons possess a rather delocalized wave function, couple to electron spins in conduction band tail states nearby, and take part in a spin-dependent recombination process. Our study shows that extended defects such as grain boundaries or stacking faults in the crystalline part of the material act as charge carrier traps that can influence the material conductivity.

  13. Inelastic collisions of ultracold triplet Rb$_\\textbf{2}$ molecules in the rovibrational ground state

    CERN Document Server

    Drews, Björn; Jachymski, Krzysztof; Idziaszek, Zbigniew; Denschlag, Johannes Hecker

    2016-01-01

    Exploring inelastic and reactive collisions on the quantum level is a main goal of the developing field of ultracold chemistry. We present first experimental studies of inelastic collisions of metastable ultracold triplet molecules in the vibrational ground state. The measurements are performed with nonpolar Rb$_2$ dimers which are prepared in precisely-defined quantum states and trapped in an array of quasi-1D potential tubes. We investigate collisions of molecules in the lowest triplet energy level where any inelastic process requires a relaxation to the singlet state. These are compared to two sets of collision experiments, carried out either with triplet molecules that have two quanta of rotational angular momentum or with vibrationally highly excited Feshbach molecules. We find no evidence for suppression of the inelastic collisions due to the necessary spin-flip, shedding light on this so far unsettled issue. For each of the molecular states studied here, we extract the decay rate constant and compare t...

  14. Monochorionic triamniotic triplets following conventional in vitro fertilization and blastocyst transfer

    Directory of Open Access Journals (Sweden)

    Sumana Gurunath

    2015-01-01

    Full Text Available Multiple pregnancy in in vitro fertilization (IVF is on the decline with a reduction in number of embryos transferred. But the risk of monozygotic splitting persists. The risk of monozygotic twinning in women undergoing IVF is reported to be twice that of natural conception, and monochorionic triplets are even rarer at 100 times more than natural conception. We report a case of monochorionic triamniotic (MCTA triplets following conventional IVF and blastocyst transfer without zona manipulation. This report highlights the possibility of zygotic splitting in IVF in young couples with no family history, in centers with good experience with blastocyst transfer. MCTA triplets carry a high risk of perinatal mortality and morbidity and need multidisciplinary care. Prevention and prediction of zygotic splitting ought to be realized with better reporting and identification of possible risk factors.

  15. iTriplet, a rule-based nucleic acid sequence motif finder

    Directory of Open Access Journals (Sweden)

    Gunderson Samuel I

    2009-10-01

    Full Text Available Abstract Background With the advent of high throughput sequencing techniques, large amounts of sequencing data are readily available for analysis. Natural biological signals are intrinsically highly variable making their complete identification a computationally challenging problem. Many attempts in using statistical or combinatorial approaches have been made with great success in the past. However, identifying highly degenerate and long (>20 nucleotides motifs still remains an unmet challenge as high degeneracy will diminish statistical significance of biological signals and increasing motif size will cause combinatorial explosion. In this report, we present a novel rule-based method that is focused on finding degenerate and long motifs. Our proposed method, named iTriplet, avoids costly enumeration present in existing combinatorial methods and is amenable to parallel processing. Results We have conducted a comprehensive assessment on the performance and sensitivity-specificity of iTriplet in analyzing artificial and real biological sequences in various genomic regions. The results show that iTriplet is able to solve challenging cases. Furthermore we have confirmed the utility of iTriplet by showing it accurately predicts polyA-site-related motifs using a dual Luciferase reporter assay. Conclusion iTriplet is a novel rule-based combinatorial or enumerative motif finding method that is able to process highly degenerate and long motifs that have resisted analysis by other methods. In addition, iTriplet is distinguished from other methods of the same family by its parallelizability, which allows it to leverage the power of today's readily available high-performance computing systems.

  16. Triplet excited state properties in variable gap π-conjugated donor–acceptor–donor chromophores

    KAUST Repository

    Cekli, Seda

    2016-02-12

    A series of variable band-gap donor–acceptor–donor (DAD) chromophores capped with platinum(II) acetylide units has been synthesized and fully characterized by electrochemical and photophysical methods, with particular emphasis placed on probing triplet excited state properties. A counter-intuitive trend of increasing fluorescence quantum efficiency and lifetime with decreasing excited state energy (optical gap) is observed across the series of DAD chromophores. Careful study of the excited state dynamics, including triplet yields (as inferred from singlet oxygen sensitization), reveals that the underlying origin of the unusual trend in the fluorescence parameters is that the singlet–triplet intersystem crossing rate and yield decrease with decreasing optical gap. It is concluded that the rate of intersystem crossing decreases as the LUMO is increasingly localized on the acceptor unit in the DAD chromophore, and this result is interpreted as arising because the extent of spin–orbit coupling induced by the platinum heavy metal centers decreases as the LUMO is more localized on the acceptor. In addition to the trend in intersystem crossing, the results show that the triplet decay rates follow the Energy Gap Law correlation over a 1.8 eV range of triplet energy and 1000-fold range of triplet decay rates. Finally, femtosecond transient absorption studies for the DAD chromophores reveals a strong absorption in the near-infrared region which is attributed to the singlet excited state. This spectral band appears to be general for DAD chromophores, and may be a signature of the charge transfer (CT) singlet excited state.

  17. Diphenylcarbene Protected by Four ortho-Iodine Groups: An Unusually Persistent Triplet Carbene.

    Science.gov (United States)

    Hirai, Katsuyuki; Bessho, Kana; Tsujita, Kosaku; Kitagawa, Toshikazu

    2016-11-15

    Diphenyldiazomethane with four iodine groups at the ortho positions and two tert-butyl groups at the para positions, i.e., bis(4-tert-butyl-2,6-diiodophenyl)diazomethane (1a-N₂), was synthesized as a sterically hindered triplet carbene precursor. Irradiation of 1a-N₂ in solution effectively generated the corresponding triplet diphenylcarbene ³1a, which was characterized by UV-vis spectroscopy at low temperature, along with laser flash photolysis techniques at room temperature. The UV-vis spectrum of ³1a was obtained by irradiating 1a-N₂ in a 2-methyltetrahydrofuran matrix at 77 K. The ESR spectrum showed no triplet carbene signals, while a radical species was observed at the anticipated temperature of the decomposition of triplet carbene ³1a. Transient absorption bands ascribable to ³1a were observed by laser flash photolysis of 1a-N₂ in a degassed benzene solution and decayed very slowly with a second-order rate constant (2k/εl) of 5.5 × 10(-)³·s(-)¹. Steady-state irradiation of 1a-N₂ in degassed benzene afforded 9,10-diarylphenanthrene derivative 2a in a 31% yield. Triplet carbene ³1a was also trapped by either oxygen (kO2 = 6.5 × 10⁵ M(-)¹·s(-)¹) or 1,4-cyclohexadiene (kCHD = 1.5 M(-)¹·s(-)¹) to afford the corresponding ketone 1a-O or the diarylmethane 1a-H₂. The carbene was shown to be much less reactive than the triplet diphenylcarbene that is protected by two ortho-iodo and two ortho-bromo groups, ³1b.

  18. Codon size reduction as the origin of the triplet genetic code.

    Directory of Open Access Journals (Sweden)

    Pavel V Baranov

    Full Text Available The genetic code appears to be optimized in its robustness to missense errors and frameshift errors. In addition, the genetic code is near-optimal in terms of its ability to carry information in addition to the sequences of encoded proteins. As evolution has no foresight, optimality of the modern genetic code suggests that it evolved from less optimal code variants. The length of codons in the genetic code is also optimal, as three is the minimal nucleotide combination that can encode the twenty standard amino acids. The apparent impossibility of transitions between codon sizes in a discontinuous manner during evolution has resulted in an unbending view that the genetic code was always triplet. Yet, recent experimental evidence on quadruplet decoding, as well as the discovery of organisms with ambiguous and dual decoding, suggest that the possibility of the evolution of triplet decoding from living systems with non-triplet decoding merits reconsideration and further exploration. To explore this possibility we designed a mathematical model of the evolution of primitive digital coding systems which can decode nucleotide sequences into protein sequences. These coding systems can evolve their nucleotide sequences via genetic events of Darwinian evolution, such as point-mutations. The replication rates of such coding systems depend on the accuracy of the generated protein sequences. Computer simulations based on our model show that decoding systems with codons of length greater than three spontaneously evolve into predominantly triplet decoding systems. Our findings suggest a plausible scenario for the evolution of the triplet genetic code in a continuous manner. This scenario suggests an explanation of how protein synthesis could be accomplished by means of long RNA-RNA interactions prior to the emergence of the complex decoding machinery, such as the ribosome, that is required for stabilization and discrimination of otherwise weak triplet codon

  19. Adult age differences in learning on a sequentially cued prediction task.

    Science.gov (United States)

    Seaman, Kendra L; Howard, Darlene V; Howard, James H

    2014-09-01

    Much of adaptive behavior relies on the ability to learn and generate predictions about relationships in the environment. Research on aging suggests both that there is an age deficit in the ability to learn sequential relationships and that this deficit in learning could underlie age differences reported in many decision-making tasks. This article introduces the Triplets Prediction Task (TPT) to investigate the learning of sequential relationships that underlies adaptive behavior. In the TPT, participants see 2 successive visual cues and then predict which target will follow. Unknown to participants, there is a predictive relationship between the first cue and the target such that each of 4 cues predicts 1 of 4 targets 85% of the time. Although both age groups demonstrated learning on this task, an age deficit in learning appeared early and performance differences persisted throughout training. There was also evidence of age differences in the learning systems engaged during the task. These results are consistent with previous studies of learning and prediction, and they support the growing literature showing adult age differences in decision making from experience. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Transient absorption probe of intermolecular triplet excimer of naphthalene in fluid solutions: Identification of the species based on comparison to the intramolecular triplet excimers of covalently-linked dimers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Kofron, W.G.; Kong, S.; Rajesh, C.S.; Modarelli, D.A.; Lim, E.C.

    2000-02-24

    The authors report here the observation of the laser-induced transient absorption spectrum of intermolecular triplet excimers of naphthalene in fluid solution. This assignment is confirmed by comparison to the transient absorption spectra of the intramolecular triplet excimers of covalently linked dimers of naphthalene and quinoxaline.

  1. Preferential Nucleosome Assembly at DNA Triplet Repeats from the Myotonic Dystrophy Gene

    Science.gov (United States)

    Wang, Yuh-Hwa; Amirhaeri, Sorour; Kang, Seongman; Wells, Robert D.; Griffith, Jack D.

    1994-07-01

    The expansion of CTG repeats in DNA occurs in or near genes involved in several human diseases, including myotonic dystrophy and Huntington's disease. Nucleosomes, the basic structural element of chromosomes, consist of 146 base pairs of DNA coiled about an octamer of histone proteins and mediate general transcriptional repression. Electron microscopy was used to examine in vitro the nucleosome assembly of DNA containing repeating CTG triplets. The efficiency of nucleosome formation increased with expanded triplet blocks, suggesting that such blocks may repress transcription through the creation of stable nucleosomes.

  2. A case study of brain morphometry in triplets discordant for Down syndrome.

    Science.gov (United States)

    Adeyemi, Elizabeth I; Giedd, Jay N; Lee, Nancy Raitano

    2015-05-01

    Down syndrome, the most common genetic cause of intellectual disability, offers the opportunity to explore the associations between genetics and both neuroanatomic and neuropsychological phenotypes. This case report summarizes the findings of a neuroimaging and neuropsychology study of two adolescent females with Down syndrome and their same-sex discordant triplet siblings (one from each family; n = 4). Using high-resolution magnetic resonance imaging and surface based morphometric approaches, we offer the first in vivo report of cortical surface area reductions and increases in the thickness of the cortical sheet in youth with Down syndrome relative to their typically developing same-sex triplet siblings.

  3. Evidence for Triplet Superconductivity in a Superconductor-Ferromagnet Spin Valve

    Science.gov (United States)

    Leksin, P. V.; Garif'yanov, N. N.; Garifullin, I. A.; Fominov, Ya. V.; Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O. G.; Büchner, B.

    2012-08-01

    We have studied the dependence of the superconducting (SC) transition temperature on the mutual orientation of magnetizations of Fe1 and Fe2 layers in the spin valve system CoOx/Fe1/Cu/Fe2/Pb. We find that this dependence is nonmonotonic when passing from the parallel to the antiparallel case and reveals a distinct minimum near the orthogonal configuration. The analysis of the data in the framework of the SC triplet spin valve theory gives direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the two magnetizations.

  4. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    Science.gov (United States)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  5. Rotational relaxation of 70S ribosomes by a depolarization method using triplet probes.

    Science.gov (United States)

    Lavalette, D; Amand, B; Pochon, F

    1977-01-01

    Rotational relaxation on the microsecond time scale has been followed by a depolarization technique using the properties of the long-lived triplet state of covalently bound labels. Two triplet probes, which efficiently bind to ribosomal proteins, are described. The rotational correlation time of 70S ribosomes of Escherichia coli has been measured. The average hydrodynamic radius of the functionally active 70S particle in solution has been estimated to 147 A. A concentration dependence of the correlation time has been observed, which may result from an association of the 70S ribosomes to form 100S dimers. PMID:323851

  6. Two-step unsymmetrical quantum key distribution protocol using GHZ triplet states

    Institute of Scientific and Technical Information of China (English)

    HUANG Peng; LIU Ye; ZHOU Nan-run; ZENG Gui-hua

    2009-01-01

    The security, efficiency, transmission distance and error rate are important parameters of a quantum key distribution scheme. In this article, the former two parameters are focused on. To reach high efficiency, an unsymmetrical quantum key distribution scheme that employs Greenberger-Horne-Zeilinger (GHZ) triplet states and dense coding mechanism is proposed, in which a GHZ triplet state can be used to share two bits of classical information. The proposed scheme can be employed in a noisy or lossy quantum channel. In addition, a general approach to security analysis against general individual attacks is presented.

  7. Dynamics of excited-state intramolecular proton transfer reactions in piroxicam. Role of triplet states

    Science.gov (United States)

    Cho, Dae Won; Kim, Yong Hee; Yoon, Minjoong; Jeoung, Sae Chae; Kim, Dongho

    1994-08-01

    The picosecond time-resolved fluorescence and transient absorption behavior of piroxicam at room temperature are reported. The keto tautomer in the excited singlet state ( 1K*) formed via the fast intramolecular proton transfer (≈ 20 ps) is observed. The short-lived (7.5 ns) triplet state of keto tauomer ( 3K*) is generated from 1K * in toluene whereas it is hardly observed in ethanol. Consequently, rapid reverse proton transfer takes place from 3K * to the enol triplet state ( 3E *.

  8. A generalized Pauli problem and an infinite family of MUB-triplets in dimension 6

    Energy Technology Data Exchange (ETDEWEB)

    Jaming, Philippe [Universite d' Orleans, Faculte des Sciences, MAPMO - Federation Denis Poisson, BP 6759, F 45067 Orleans Cedex 2 (France); Matolcsi, Mate; Weiner, Mihaly [Alfred Renyi Institute of Mathematics, Hungarian Academy of Sciences POB 127 H-1364 Budapest (Hungary); Mora, Peter [BME Department of Analysis, Egry J. u. 1, H-1111 Budapest (Hungary); Szoellosi, Ferenc [Institute of Mathematics and its Applications, Central European University (CEU), H-1051, Nador u. 9., Budapest (Hungary)], E-mail: philippe.jaming@univ-orleans.fr, E-mail: matomate@renyi.hu, E-mail: morapeter@gmail.com, E-mail: szoferi@gmail.com, E-mail: mweiner@renyi.hu

    2009-06-19

    We exhibit an infinite family of triplets of mutually unbiased bases (MUBs) in dimension 6. These triplets involve the Fourier family of Hadamard matrices, F(a, b). However, in the main result of this paper we also prove that for any values of the parameters (a, b), the standard basis and F(a, b) cannot be extended to a MUB-quartet. The main novelty lies in the method of proof which may successfully be applied in the future to prove that the maximal number of MUBs in dimension 6 is three.

  9. Spin-Selective Generation of Triplet Nitrenes: Olefin Aziridination through Visible-Light Photosensitization of Azidoformates.

    Science.gov (United States)

    Scholz, Spencer O; Farney, Elliot P; Kim, Sangyun; Bates, Desiree M; Yoon, Tehshik P

    2016-02-01

    Azidoformates are interesting potential nitrene precursors, but their direct photochemical activation can result in competitive formation of aziridination and allylic amination products. Herein, we show that visible-light-activated transition-metal complexes can be triplet sensitizers that selectively produce aziridines through the spin-selective photogeneration of triplet nitrenes from azidoformates. This approach enables the aziridination of a wide range of alkenes and the formal oxyamination of enol ethers using the alkene as the limiting reagent. Preparative-scale aziridinations can be easily achieved under continuous-flow conditions.

  10. Simulating Entanglement Dynamics of Singlet-Triplet Qubits Coupled to a Classical Transmission Line Resonator

    Science.gov (United States)

    Wolfe, Michael; Kestner, Jason

    Electrons confined in lateral quantum dots are promising candidates for scalable quantum bits. Particularly, singlet-triplet qubits can entangle electrostatically and offer long coherence times due to their weak interactions with the environment. However, fast two-qubit operations are challenging. We examine the dynamics of singlet triplet qubits capacitively coupled to a classical transmission line resonator driven near resonance. We numerically simulate the dynamics of the von Neumann entanglement entropy and investigate parameters of the coupling element that optimizes the operation time for the qubit.

  11. Scattering and Recombination of Two Triplet Excitons in polymer light-emitting diodes

    CERN Document Server

    Meng, Y; Liu, X J; Wang, Y D; An, Z

    2010-01-01

    The scattering and recombination processes between two triplet excitons in conjugated polymers are investigated by using a nonadiabatic evolution method, based on an extended Su-Schrieffer-Heeger model including interchain interactions. Due to the interchain coupling, the electron and/or hole in the two triplet excitons can exchange. The results show that the recombination induces the formation of singlet excitons, excited polarons and biexcitons. Moreover, we also find the yields of these products, which can contribute to the emission, increase with the interchain coupling strength, in good agreement with results from experiments.

  12. $\\mu \\to e \\gamma$ and $\\tau \\to l \\gamma$ decays in the fermion triplet seesaw model

    CERN Document Server

    Abada, A; Bonnet, F; Gavela, M B; Hambye, T

    2008-01-01

    In the framework of the seesaw models with triplets of fermions, we evaluate the decay rates of $\\mu \\to e \\gamma$ and $\\tau \\to l \\gamma$ transitions. We show that although, due to neutrino mass constraints, those rates are in general expected to be well under the present experimental limits, this is not necessarily always the case. Interestingly enough, the observation of one of those decays in planned experiments would nevertheless contradict bounds stemming from present experimental limits on the $\\mu \\to eee$ and $\\tau \\to 3 l$ decay rates. Such detection of radiative decays would therefore imply that there exist sources of lepton flavour violation not associated to triplet fermions.

  13. A 2-D graphical representation of protein sequences based on nucleotide triplet codons

    Science.gov (United States)

    Bai, Fenglan; Wang, Tianming

    2005-09-01

    Graphical representation of DNA provides a simple way of viewing, sorting and comparing various gene structures. A 2-D graphical representation of protein sequences based on nucleotide triplet codons has been derived for similarity analysis of protein sequences. This approach is based on a graphical representation of triplets of DNA in which the interior of the left half plane of the complex plane is used to accommodate 64 sites for the 64 codons. We associate a directed curve, numerical value, or matrix with a protein as a descriptor. The approach is illustrated on the Homo sapiens X-linked nuclear protein (ATRX) gene.

  14. Spike Inference from Calcium Imaging using Sequential Monte Carlo Methods

    OpenAIRE

    NeuroData; Paninski, L

    2015-01-01

    Vogelstein JT, Paninski L. Spike Inference from Calcium Imaging using Sequential Monte Carlo Methods. Statistical and Applied Mathematical Sciences Institute (SAMSI) Program on Sequential Monte Carlo Methods, 2008

  15. Efficacy of premixed versus sequential administration of ...

    African Journals Online (AJOL)

    an adjuvant to intrathecal hyperbaric bupivacaine in lower limb surgery ... sequential administration in separate syringes on block characteristics, haemodynamic parameters, ... significant side effects and reduces the postoperative analgesic requirement. ... acceptance spinal anaesthesia is fast becoming the procedure of.

  16. Delayed Sequential Coding of Correlated Sources

    CERN Document Server

    Ma, Nan; Ishwar, Prakash

    2007-01-01

    Motivated by video coding applications, we study the problem of sequential coding of correlated sources with (noncausal) encoding and/or decoding frame-delays. The fundamental tradeoffs between individual frame rates, individual frame distortions, and encoding/decoding frame-delays are derived in terms of a single-letter information-theoretic characterization of the rate-distortion region for general inter-frame source correlations and certain types of (potentially frame-specific and coupled) single-letter fidelity criteria. For video sources which are spatially stationary memoryless and temporally Gauss--Markov, MSE frame distortions, and a sum-rate constraint, our results expose the optimality of differential predictive coding among all causal sequential coders. Somewhat surprisingly, causal sequential encoding with one-step delayed noncausal sequential decoding can exactly match the sum-rate-MSE performance of joint coding for all nontrivial MSE-tuples satisfying certain positive semi-definiteness conditio...

  17. A universal property for sequential measurement

    Science.gov (United States)

    Westerbaan, Abraham; Westerbaan, Bas

    2016-09-01

    We study the sequential product the operation p ∗ q = √{ p } q √{ p } on the set of effects, [0, 1]𝒜, of a von Neumann algebra 𝒜 that represents sequential measurement of first p and then q. In their work [J. Math. Phys. 49(5), 052106 (2008)], Gudder and Latrémolière give a list of axioms based on physical grounds that completely determines the sequential product on a von Neumann algebra of type I, that is, a von Neumann algebra ℬ(ℋ) of all bounded operators on some Hilbert space ℋ. In this paper we give a list of axioms that completely determines the sequential product on all von Neumann algebras simultaneously (Theorem 4).

  18. Sequential monitoring with conditional randomization tests

    CERN Document Server

    Plamadeala, Victoria; 10.1214/11-AOS941

    2012-01-01

    Sequential monitoring in clinical trials is often employed to allow for early stopping and other interim decisions, while maintaining the type I error rate. However, sequential monitoring is typically described only in the context of a population model. We describe a computational method to implement sequential monitoring in a randomization-based context. In particular, we discuss a new technique for the computation of approximate conditional tests following restricted randomization procedures and then apply this technique to approximate the joint distribution of sequentially computed conditional randomization tests. We also describe the computation of a randomization-based analog of the information fraction. We apply these techniques to a restricted randomization procedure, Efron's [Biometrika 58 (1971) 403--417] biased coin design. These techniques require derivation of certain conditional probabilities and conditional covariances of the randomization procedure. We employ combinatoric techniques to derive t...

  19. Mining Sequential Patterns In Multidimensional Data

    OpenAIRE

    Plantevit, Marc

    2008-01-01

    Sequential pattern mining is a key technique of data mining with broad applications (user behavior analysis, bioinformatic, security, music, etc.). Sequential pattern mining aims at discovering correlations among events through time. There exist many algorithms to discover such patterns. However, these approaches only take one dimension into account (e.g. product dimension in customer market basket problem analysis) whereas data are multidimensional in nature. In this thesis, we define multid...

  20. Conformational instability of the lowest triplet state of the benzene nucleus: II. p-Xylene, the influence of substituents

    NARCIS (Netherlands)

    J.H. van der Waals; M.C. van Hemert; W.J. Buma

    1990-01-01

    A calculation of the potential-energy surface of the lowest triplet state of p-xylene as a function of the S8(,) distortion coordinate of the benzene skeleton has been made to learn more about the influence of substituents on the vibronically induced distortion of benzene in its metastable triplet s

  1. A smart tailor-made G-clip reporter for sensitive detection of G-triplet-containing sequences.

    Science.gov (United States)

    Cai, Liang-Yuan; Nie, Ji; Zhang, Yi-Wei; Zhang, Fang-Ting; Zhou, Ying-Lin; Zhang, Xin-Xiang

    2015-05-21

    Taking advantage of the intrinsic characteristics of G-triplet-containing sequences, a pioneering tailor-made clip-like reporter containing three-fourths of a G-quadruplex is established. The reporter can clip the G triplet in the target sequence through a recognition process to form a complete G-quadruplex structure.

  2. Synthesis and Exciton Dynamics of Donor-Orthogonal Acceptor Conjugated Polymers: Reducing the Singlet–Triplet Energy Gap

    KAUST Repository

    Freeman, David M. E.

    2017-06-09

    The presence of energetically low-lying triplet states is a hallmark of organic semiconductors. Even though they present a wealth of interesting photophysical properties, these optically dark states significantly limit optoelectronic device performance. Recent advances in emissive charge-transfer molecules have pioneered routes to reduce the energy gap between triplets and

  3. A practical O(n log2 i>n>) time algorithm for computing the triplet distance on binary trees

    DEFF Research Database (Denmark)

    Sand, Andreas; Brodal, Gerth Stølting; Fagerberg, Rolf;

    2013-01-01

    The triplet distance is a distance measure that compares two rooted trees on the same set of leaves by enumerating all sub-sets of three leaves and counting how often the induced topologies of the tree are equal or different. We present an algorithm that computes the triplet distance between two ...

  4. Finding Sequential Patterns from Large Sequence Data

    Directory of Open Access Journals (Sweden)

    Fazekas Gabor

    2010-01-01

    Full Text Available Data mining is the task of discovering interesting patterns from large amounts of data. There are many data mining tasks, such as classification, clustering, association rule mining, and sequential pattern mining. Sequential pattern mining finds sets of data items that occur together frequently in some sequences. Sequential pattern mining, which extracts frequent subsequences from a sequence database, has attracted a great deal of interest during the recent data mining research because it is the basis of many applications, such as: web user analysis, stock trend prediction, DNA sequence analysis, finding language or linguistic patterns from natural language texts, and using the history of symptoms to predict certain kind of disease. The diversity of the applications may not be possible to apply a single sequential pattern model to all these problems. Each application may require a unique model and solution. A number of research projects were established in recent years to develop meaningful sequential pattern models and efficient algorithms for mining these patterns. In this paper, we theoretically provided a brief overview three types of sequential patterns model.

  5. Three-Dimensional Triplet Tracking for LHC and Future High Rate Experiments

    CERN Document Server

    Schöning, Andre

    2014-01-01

    The hit combinatorial problem is a main challenge for track reconstruction and triggering at high rate experiments. At hadron colliders the dominant fraction of hits is due to low momentum tracks for which multiple scattering (MS) effects dominate the hit resolution. MS is also the dominating source for hit confusion and track uncertainties in low energy precision experiments. In all such environments, where MS dominates, track reconstruction and fitting can be largely simplified by using three-dimensional (3D) hit-triplets as provided by pixel detectors. This simplification is possible since track uncertainties are solely determined by MS if high precision spatial information is provided. Fitting of hit-triplets is especially simple for tracking detectors in solenoidal magnetic fields. The over-constrained 3D-triplet method provides a complete set of track parameters and is robust against fake hit combinations. The triplet method is ideally suited for pixel detectors where hits can be treated as 3D-space poi...

  6. Study of the Sextans dwarf spheroidal galaxy from the DART Ca II triplet survey

    NARCIS (Netherlands)

    Battaglia, G.; Tolstoy, E.; Helmi, A.; Irwin, M.; Parisi, P.; Hill, V.; Jablonka, P.

    2011-01-01

    We use Very Large Telescope (VLT)/Fibre Large Array Multi Element Spectrograph (FLAMES) intermediate-resolution (R˜ 6500) spectra of individual red giant branch stars in the near-infrared Ca II triplet (CaT) region to investigate the wide-area metallicity properties and internal kinematics of the Se

  7. Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve

    Science.gov (United States)

    Leksin, P. V.; Garif'yanov, N. N.; Kamashev, A. A.; Validov, A. A.; Fominov, Ya. V.; Schumann, J.; Kataev, V.; Thomas, J.; Büchner, B.; Garifullin, I. A.

    2016-03-01

    We have studied the proximity-induced superconducting triplet pairing in CoOx/Py1/Cu/Py2/Cu/Pb spin-valve structure (where Py = Ni0.81Fe0.19 ). By optimizing the parameters of this structure we found a triplet channel assisted full switching between the normal and superconducting states. To observe an "isolated" triplet spin-valve effect we exploited the oscillatory feature of the magnitude of the ordinary spin-valve effect Δ Tc in the dependence of the Py2-layer thickness dP y 2. We determined the value of dP y 2 at which Δ Tc caused by the ordinary spin-valve effect (the difference in the superconducting transition temperature Tc between the antiparallel and parallel mutual orientation of magnetizations of the Py1 and Py2 layers) is suppressed. For such a sample a "pure" triplet spin-valve effect which causes the minimum in Tc at the orthogonal configuration of magnetizations has been observed.

  8. Computational determination of the dominant triplet population mechanism in photoexcited benzophenone

    NARCIS (Netherlands)

    Sergentu, Dumitru-Claudiu; Maurice, Remi; Havenith, Remco W. A.; Broer, Ria; Roca-Sanjuan, Daniel

    2014-01-01

    In benzophenone, intersystem crossing occurs efficiently between the S-1(n pi(star)) state and the T-1 state of dominant n pi(star) character, leading to excited triplet states after photoexcitation. The transition mechanism between S-1(n pi(star)) and T-1 is still a matter of debate, despite severa

  9. Conformational instability of the lowest triplet state of the benzene nucleus: I. The unsubstituted molecule

    NARCIS (Netherlands)

    van der Waals, J.H.; van Hemert, M.C.; Buma, W.J.

    1990-01-01

    Experiments on benzene have established that its lowest triplet state (3B1u) is conformationally unstable owing to vibronic coupling with the next higher state (3E1u). This instability was found to be critically dependent on the influence of a crystal field. An analogous vibronic coupling is to be

  10. Maternal and Fetal Outcomes of Triplet Gestation in a Tertiary Hospital in Oman

    Directory of Open Access Journals (Sweden)

    Maryam Al-Shukri

    2014-05-01

    Full Text Available Objectives: The aim of this study was to describe the fetal and maternal outcomes of triplet gestation and to report on the maternal characteristics of those pregnancies in a tertiary care centre in Oman. Methods: A retrospective study was undertaken of all triplet pregnancies delivered at Sultan Qaboos University Hospital, Muscat, Oman, between January 2009 and December 2011. Results: Over the three-year study period, there were 9,140 deliveries. Of these, there were 18 triplet pregnancies, giving a frequency of 0.2%. The mean gestational age at delivery was 31.0 ± 3.0 weeks, and the mean birth weight was 1,594 ± 460 g. The most common maternal complications were preterm labour in 13 pregnancies (72.2%, gestational diabetes in 7 (39% and gestational hypertension in 5 (28%. Of the total deliveries, there were 54 neonates. Neonatal complications among these included hyaline membrane disease in 25 neonates (46%, hyperbilirubinaemia in 24 (43%, sepsis in 18 (33% and anaemia in 8 (15%. The perinatal mortality rate was 55 per 1,000 births. Conclusion: The maternal and neonatal outcomes of triplet pregnancies were similar to those reported in other studies.

  11. Photoprotection and triplet energy transfer in higher plants: the role of electronic and nuclear fluctuations.

    Science.gov (United States)

    Cupellini, Lorenzo; Jurinovich, Sandro; Prandi, Ingrid G; Caprasecca, Stefano; Mennucci, Benedetta

    2016-04-28

    Photosynthetic organisms employ several photoprotection strategies to avoid damage due to the excess energy in high light conditions. Among these, quenching of triplet chlorophylls by neighboring carotenoids (Cars) is fundamental in preventing the formation of singlet oxygen. Cars are able to accept the triplets from chlorophylls by triplet energy transfer (TET). We have here studied TET rates in CP29, a minor light-harvesting complex (LHC) of the Photosystem II in plants. A fully atomistic strategy combining classical molecular dynamics of the LHC in its natural environment with a hybrid time-dependent density functional theory/polarizable MM description of the TET is used. We find that the structural fluctuations of the pigment-protein complex can largely enhance the transfer rates with respect to those predicted using the crystal structure, reducing the triplet quenching times in the subnanosecond scale. These findings add a new perspective for the interpretation of the photoprotection function and its relation with structural motions of the LHC.

  12. Conformational instability of the lowest triplet state of the benzene nucleus: I. The unsubstituted molecule

    NARCIS (Netherlands)

    J.H. van der Waals; M.C. van Hemert; W.J. Buma

    1990-01-01

    Experiments on benzene have established that its lowest triplet state (3B1u) is conformationally unstable owing to vibronic coupling with the next higher state (3E1u). This instability was found to be critically dependent on the influence of a crystal field. An analogous vibronic coupling is to be e

  13. Spectrally tunable mollow triplet emission from a coherently excited quantum dot in a microcavity

    DEFF Research Database (Denmark)

    Ulrich, Sven M.; Ates, Serkan; Reitzenstein, Stephan

    2010-01-01

    Resonance fluorescence of excitonic s-shell emission from a coherently pumped single InGaAs/GaAs quantum dot inside a micropillar cavity has been investigated in dependence on optical pump power and laser detuning, respectively. For strong purely resonant excitation, Mollow triplet spectra...

  14. Ultrafast electronic and vibrational dynamics in brominated aluminum corroles: Energy relaxation and triplet formation

    Directory of Open Access Journals (Sweden)

    T. Stensitzki

    2016-07-01

    Full Text Available We combined femtosecond (fs VIS pump–IR probe spectroscopy with fs VIS pump–supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8(py2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80 fs to the S2 and S1 electronic excited states. This is evident from the rise time of the stimulated emission signal in the visible spectral range. On the same time scale, narrowing of broad infrared signals in the C=C stretching region around 1500 cm−1 is observed. Energy redistribution processes are visible in the vibrational and electronic dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is detected with a time constant of (95 ± 3 ps. This is tracked by the complete loss of stimulated emission. Electronic transition of the emerging triplet absorption band overlaps considerably with the singlet excited state absorption. In contrast, two well separated vibrational marker bands for triplet formation were identified at 1477 cm−1 and at 1508 cm−1. These marker bands allow a precise identification of triplet dynamics in corrole systems.

  15. Triplet state dynamics of chlorophylls in photosynthetic reaction centers and model systems.

    NARCIS (Netherlands)

    Wijk, van F.G.H.

    1987-01-01

    In this work the temperature dependence of the lineshape, and more specifically, the electron spin polarization pattern of the Δm = ±1 triplet EPR (Electron Paramagnetic Resonance) spectra from several photosynthetic purple bacteria has been investigated.In Chapter I a general introduction is presen

  16. Triplet exciplexes in reactions of electronically excited chloranil with unsatuated heterocyclic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Petroshenko, K.B.; Frolov, Y.L.; Gorshkov, A.G.; Osipov, S.P.; Turchaninov, V.K.; Vokin, A.I.

    1985-08-10

    In the system indole + chloranil + dioxane the formation has been demonstrated of a triplet exciplex with complete charge transfer and a hydrogen bond between the components. The presence of a hydrogen bond in the dissociative state results in a decrease in the yield of free ion-radicals.

  17. Efficient Algorithms for Computing the Triplet and Quartet Distance Between Trees of Arbitrary Degree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas

    2013-01-01

    degree of any node in the two trees. Within the same time bounds, our framework also allows us to compute the parameterized triplet and quartet distances, where a parameter is introduced to weight resolved (binary) topologies against unresolved (non-binary) topologies. The previous best algorithm...

  18. Ab initio calculations on the structure of pyridine in its lowest triplet state

    NARCIS (Netherlands)

    Buma, W.J.; Groenen, E.J.J.; Schmidt, J.

    1990-01-01

    Recently we have experimentally shown that pyridine-d5, as a guest in a single crystal of benzene-d6, adopts a boatlike structure upon excitation into the lowest triplet state T0. Here MRDCI ab initio calculations are presented that reveal that the observed nonplanarity of the molecule is not caused

  19. Triplet exciton dissociation and electron extraction in graphene-templated pentacene observed with ultrafast spectroscopy.

    Science.gov (United States)

    McDonough, Thomas J; Zhang, Lushuai; Roy, Susmit Singha; Kearns, Nicholas M; Arnold, Michael S; Zanni, Martin T; Andrew, Trisha L

    2017-02-08

    We compare the ultrafast dynamics of singlet fission and charge generation in pentacene films grown on glass and graphene. Pentacene grown on graphene is interesting because it forms large crystals with the long axis of the molecules "lying-down" (parallel to the surface). At low excitation fluence, spectra for pentacene on graphene contain triplet absorptions at 507 and 545 nm and no bleaching at 630 nm, which we show is due to the orientation of the pentacene molecules. We perform the first transient absorption anisotropy measurements on pentacene, observing negative anisotropy of the 507 and 545 nm peaks, consistent with triplet absorption. A broad feature at 853 nm, observed on both glass and graphene, is isotropic, suggesting hole absorption. At high fluence, there are additional features, whose kinetics and anisotropies are not explained by heating, that we assign to charge generation; we propose a polaron pair absorption at 614 nm. The lifetimes are shorter at high fluence for both pentacene on glass and graphene, indicative of triplet-triplet annihilation that likely enhances charge generation. The anisotropy decays more slowly for pentacene on graphene than on glass, in keeping with the smaller domain size observed via atomic force microscopy. Coherent acoustic phonons are observed for pentacene on graphene, which is a consequence of more homogeneous domains. Measuring the ultrafast dynamics of pentacene as a function of molecular orientation, fluence, and polarization provides new insight to previous spectral assignments.

  20. How disorder controls the kinetics of triplet charge recombination in semiconducting organic polymer photovoltaics.

    Science.gov (United States)

    Bittner, Eric R; Lankevich, Vladimir; Gélinas, Simon; Rao, Akshay; Ginger, David A; Friend, Richard H

    2014-10-14

    Recent experiments by Rao et al. (Nature, 2013, 500, 435-439) indicate that recombination of triplet charge-separated states is suppressed in organic polymer-fullerene based bulk-heterojunction (BHJ) photovoltaic cells exhibiting a high degree of crystallinity in the fullerene phase relative to systems with more disorder. In this paper, we use a series of Frenkel-exciton lattice models to rationalize these results in terms of wave-function localization, interface geometry, and density of states. In one-dimensional co-linear and co-facial models of the interface, increasing local energetic disorder in one phase localizes the interfacial triplet charge-transfer ((3)CT) states and increases the rate at which these states relax to form lower-energy triplet excitons. In two dimensional BHJ models, energetic disorder within the fullerene phase plays little role in further localizing states pinned to the interface. However, inhomogeneous broadening introduces strong coupling between the interfacial (3)CT and nearby fullerene triplet excitons and can enhance the decay of these states in systems with higher degrees of energetic disorder.

  1. Tri-P-LETS: Changing the Face of High School Computer Science

    Science.gov (United States)

    Sherrell, Linda; Malasri, Kriangsiri; Mills, David; Thomas, Allen; Greer, James

    2012-01-01

    From 2004-2007, the University of Memphis carried out the NSF-funded Tri-P-LETS (Three P Learning Environment for Teachers and Students) project to improve local high-school computer science curricula. The project reached a total of 58 classrooms in eleven high schools emphasizing problem solving skills, programming concepts as opposed to syntax,…

  2. Thickness dependence of the triplet spin-valve effect in superconductor-ferromagnet heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, Daniel; Zdravkov, Vladimir I.; Kehrle, Jan; Obermeier, Guenther; Krug von Nidda, Hans-Albrecht; Mueller, Claus; Horn, Siegfried; Tidecks, Reinhard [Institut fuer Physik, Universitaet Augsburg (Germany); Morari, Roman [Institut fuer Physik, Universitaet Augsburg (Germany); D. Ghitsu Institute of Electronic Engineering and Nanotechnologies ASM, Kishinev (Moldova, Republic of); Sidorenko, Anatolie S. [D. Ghitsu Institute of Electronic Engineering and Nanotechnologies ASM, Kishinev (Moldova, Republic of); Tagirov, Lenar [Solid State Physics Department, Kazan Federal University (Russian Federation)

    2015-07-01

    We investigated the triplet spin-valve effect in nanoscale layered S/F{sub 1}/N/F{sub 2}/AF heterostructures with varying F{sub 1}-layer thickness (where S=Nb is a singlet superconducting, F{sub 1}=Cu{sub 41}Ni{sub 59} and F{sub 2}=Co a ferromagnetic, and N a normal-conducting, non-magnetic layer). The theory predicts a long-range, odd-in-frequency triplet component of superconductivity at non-collinear alignment of the magnetizations of F{sub 1} and F{sub 2}. This triplet component exhausts the singlet state and, thus, lowers the superconducting transition temperature, T{sub c}, yielding a global minimum of T{sub c} close to the perpendicular mutual orientations of the magnetizations. We found an oscillating decay of T{sub c} suppression, due to the generation of the triplet component, with increasing F{sub 1} layer thickness, which we discuss in the framework of recent theories.

  3. Study of the Sextans dwarf spheroidal galaxy from the DART CaII triplet survey

    NARCIS (Netherlands)

    Battaglia, G.; Tolstoy, E.; Helmi, A.; Irwin, M.; Parisi, P.; Hill, V.; Jablonka, P.

    2011-01-01

    We use Very Large Telescope (VLT)/Fibre Large Array Multi Element Spectrograph (FLAMES) intermediate-resolution (R similar to 6500) spectra of individual red giant branch stars in the near-infrared Ca ii triplet (CaT) region to investigate the wide-area metallicity properties and internal kinematics

  4. Precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Christoph

    2011-10-19

    In this thesis I report precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules where we use lasers to couple the states in different molecular potentials. We study in detail states of the a {sup 3} sum {sup +}{sub u} and (1) {sup 3} sum {sup +}{sub g} potentials. These states are of great importance for transferring weakly bound molecules to the ro-vibrational triplet ground state via states of the excited potential. As most experiments start from molecules in their X {sup 1} sum {sup +}{sub g} ground state, the triplet states were hard to access via dipole transitions and remained largely unexplored. The measurements presented in this thesis are the first detailed study of diatomic {sup 87}Rb{sub 2} molecules in these states. Our experiments start with an ultracold cloud of {sup 87}Rb atoms. We then load this cloud into an optical lattice where we use a magnetic Feshbach resonance at 1007.4 G to perform a Feshbach association. After we have removed all unbound atoms, we end up with a pure sample of weakly bound Feshbach molecules inside the optical lattice. The optical lattice prevents these molecules from colliding with each other which results in molecular lifetimes on the order of a few hundred milliseconds. In the first set of experiments, we use a laser coupling the Feshbach state to the excited (1) {sup 3} sum {sup +}{sub g} triplet state to map out its low-lying vibrational (v = 0.. 15), rotational, hyperfine, and Zeeman structure. The experimental results are in good agreement with calculations done by Marius Lysebo and Prof. Leif Veseth. We then map out in detail the vibrational, rotational, hyperfine, and Zeeman structure of the a {sup 3} sum {sup +}{sub u} triplet ground state using dark state spectroscopy with levels in the (1) {sup 3} sum {sup +}{sub g} potential as an intermediate state. In this scheme we are able to access molecules in triplet states because our Feshbach state has strong triplet character. Interestingly, it

  5. Modern Sequential Analysis and Its Applications to Computerized Adaptive Testing

    Science.gov (United States)

    Bartroff, Jay; Finkelman, Matthew; Lai, Tze Leung

    2008-01-01

    After a brief review of recent advances in sequential analysis involving sequential generalized likelihood ratio tests, we discuss their use in psychometric testing and extend the asymptotic optimality theory of these sequential tests to the case of sequentially generated experiments, of particular interest in computerized adaptive testing. We…

  6. Quenching excited triplet C{sub 60} fullerene by tetracyanoethylene in benzonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Nadtochenko, V.A.; Denisov, N.N.; Rubtsov, I.V.; Lobach, A.S.; Moravsky, A.P. [Institute of Chemical Physics in Chernogolovka, Moscow (Russian Federation)

    1994-01-01

    The main photophysical properties of C{sub 60} fullerene: The absorption spectra of excited singlet C{sub 60}, the inter-combinational conversion time, the quantum yield of triplet C{sub 60}, the triplet-triplet absorption spectra, and the channels and rate constants of the deactivation of triplet C{sub 60} have been established. The photochemical properties of C{sub 60} fullerene have been investigated to a lesser degree. C{sub 60} is known to be readily reduced (E{sub 1/2} = {minus}0.4 in relation to Ag/Ag{sup +}), in particular, photochemically. For example, photoexcitation of charge-transfer complexes of C{sub 60} with amines gives the radical anion C{sup {minus}}{sub 60} which is also formed in reactions of photoexcited C{sub 60} fullerene. The formation of the radical cation C{sup +}{sub 60} under the action of light has been detected in the reaction with colloidal TiO{sub 2}. The radical ion C{sup +}{sub 60} has been obtained in a homogeneous photochemical process: the reaction of unexcited C{sub 60} with excited singlet N-methylacridinium hexafluorophosphate or with the biphenyl radical cation generated in the reaction with excited singlet N-methylacridinium hexafluorophosphate. The formation of C{sup +}{sub 60} with an electron acceptor in a homogeneous process has not so far been observed. The purpose of this work has been to study the quenching of triplet {sup 3}C{sub 60} with an electron acceptor, tetracyanoethylene (TCNE), which is known to oxidize unsaturated or aromatic hydrocarbons in photochemical reactions.

  7. Modern Sequential Analysis and its Applications to Computerized Adaptive Testing

    CERN Document Server

    Bartroff, Jay; Lai, Tze Leung

    2011-01-01

    After a brief review of recent advances in sequential analysis involving sequential generalized likelihood ratio tests, we discuss their use in psychometric testing and extend the asymptotic optimality theory of these sequential tests to the case of sequentially generated experiments, of particular interest in computerized adaptive testing. We then show how these methods can be used to design adaptive mastery tests, which are asymptotically optimal and are also shown to provide substantial improvements over currently used sequential and fixed length tests.

  8. Sequential dependencies in magnitude scaling of loudness

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Jesteadt, Walt

    2013-01-01

    B were used to program the sone-potentiometer. The knob settings systematically influenced the form of the loudness function. Time series analysis was used to assess the sequential dependencies in the data, which increased with increasing exponent and were greatest for the log-law. It would be possible......, therefore, to choose knob properties that minimized these dependencies. When the sequential dependencies were removed from the data, the slope of the loudness functions did not change, but the variability decreased. Sequential dependencies were only present when the level of the tone on the previous trial...... was higher than on the current trial. According to the attention band hypothesis[Green and Luce, 1974, Perception & Psychophysics] these dependencies arise from a process similar to selective attention, but observations of rapid adaptation of neurons in the inferior colliculus based on stimulus level...

  9. Correlation and Sequential Filtering with Doppler Measurements

    Institute of Scientific and Technical Information of China (English)

    WANGJianguo; HEPeikun; HANYueqiu; WUSiliang

    2004-01-01

    Two sequential filters are developed for Doppler radar measurements in the presence of correlation between range and range rate measurement errors. Two ideal linear measurement equations with the pseudo measurements are constructed via block-partitioned Cholesky factorization and the practical measurement equationswith the pseudo measurements are obtained through the direction cosine estimation and error compensation. The resulting sequential filters make the position measurement be possibly processed before the pseudo measurement and hence the more accurate direction cosine estimate can be obtained from the filtered position estimate rather than the predicted state estimate. The numerical simulations with different rangerange rate correlation coefficients show thatthe proposed two sequential filters are almost equivalent in performance but both superior to the conventional extended Kalman filter for different correlation coefficients.

  10. OLEDs under high current densities. Transient electroluminescence turn-on peaks and singlet-triplet quenching

    Energy Technology Data Exchange (ETDEWEB)

    Kasemann, Daniel

    2012-02-27

    This work focuses on a better understanding of the behavior of organic light emitting devices (OLEDs) under intense electrical excitation. Attaining high exciton densities in organic semiconductors by electrical excitation is of special interest for the field of organic semiconductor lasers (OSLs). In these devices, the high singlet exciton density needed in the active layer to obtain population inversion is easily created by pulsed optical pumping, but direct electrical pumping has not been achieved yet. First, the steps necessary to achieve stable high current densities in organic semiconductors are discussed. After determining the optimal excitation scheme using single p-doped transport layers, the device complexity is increased up to full p-i-n OLEDs with their power dependent emission spectra. For this purpose, two exemplary emitter systems are chosen: the fluorescent laser dye 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) doped into Aluminum(III)bis (2-methyl-8-quinolinato)-4-phenylphenolate (Alq{sub 3}) and the efficient phosphorescent emitter system N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (alpha-NPD) doped by Iridium(III) bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate) (Ir(MDQ){sub 2}(acac)). For pulsed excitation using 50 ns pulses and a repetition rate of 1 kHz, single 100 nm thin p- and n-doped transport layers sustain current densities of over 6 kA/cm{sup 2}. While the maximum current density decreases with increasing device thickness, the full OLEDs still sustain current densities beyond 800 A/cm{sup 2} and exhibit a continuously increasing emission intensity with increasing input power. Next, the time-resolved emission behavior of the singlet and triplet emitter device at high excitation densities is analyzed on the nanosecond scale. Here, the peak emission intensity of the phosphorescent emitter system is found to be more than eight times lower than for the singlet emitter system at comparable current

  11. Sequential Pattern Mining Using Formal Language Tools

    Directory of Open Access Journals (Sweden)

    R. S. Jadon

    2012-09-01

    Full Text Available In present scenario almost every system and working is computerized and hence all information and data are being stored in Computers. Huge collections of data are emerging. Retrieval of untouched, hidden and important information from this huge data is quite tedious work. Data Mining is a great technological solution which extracts untouched, hidden and important information from vast databases to investigate noteworthy knowledge in the data warehouse. An important problem in data mining is to discover patterns in various fields like medical science, world wide web, telecommunication etc. In the field of Data Mining, Sequential pattern mining is one of the method in which we retrieve hidden pattern linked with instant or other sequences. In sequential pattern mining we extract those sequential patterns whose support count are greater than or equal to given minimum support threshold value. In current scenario users are interested in only specific and interesting pattern instead of entire probable sequential pattern. To control the exploration space users can use many heuristics which can be represented as constraints. Many algorithms have been developed in the fields of constraint mining which generate patterns as per user expectation. In the present work we will be exploring and enhancing the regular expression constraints .Regular expression is one of the constraint and number of algorithm developed for sequential pattern mining which uses regular expression as a constraint. Some constraints are neither regular nor context free like cross-serial pattern anbmcndm used in Swiss German Data. We cannot construct equivalent deterministic finite automata (DFA or Push down automata (PDA for such type of patterns. We have proposed a new algorithm PMFLT (Pattern Mining using Formal Language Tools for sequential pattern mining using formal language tools as constraints. The proposed algorithm finds only user specific frequent sequence in efficient

  12. Text Classification: A Sequential Reading Approach

    CERN Document Server

    Dulac-Arnold, Gabriel; Gallinari, Patrick

    2011-01-01

    We propose to model the text classification process as a sequential decision process. In this process, an agent learns to classify documents into topics while reading the document sentences sequentially and learns to stop as soon as enough information was read for deciding. The proposed algorithm is based on a modelisation of Text Classification as a Markov Decision Process and learns by using Reinforcement Learning. Experiments on four different classical mono-label corpora show that the proposed approach performs comparably to classical SVM approaches for large training sets, and better for small training sets. In addition, the model automatically adapts its reading process to the quantity of training information provided.

  13. Self arbitrated VLSI asynchronous sequential circuits

    Science.gov (United States)

    Whitaker, S.; Maki, G.

    1990-01-01

    A new class of asynchronous sequential circuits is introduced in this paper. The new design procedures are oriented towards producing asynchronous sequential circuits that are implemented with CMOS VLSI and take advantage of pass transistor technology. The first design algorithm utilizes a standard Single Transition Time (STT) state assignment. The second method introduces a new class of self synchronizing asynchronous circuits which eliminates the need for critical race free state assignments. These circuits arbitrate the transition path action by forcing the circuit to sequence through proper unstable states. These methods result in near minimum hardware since only the transition paths associated with state variable changes need to be implemented with pass transistor networks.

  14. Asynchronous sequential machine design and analysis

    CERN Document Server

    Tinder, Richard

    2009-01-01

    Asynchronous Sequential Machine Design and Analysis provides a lucid, in-depth treatment of asynchronous state machine design and analysis presented in two parts: Part I on the background fundamentals related to asynchronous sequential logic circuits generally, and Part II on self-timed systems, high-performance asynchronous programmable sequencers, and arbiters.Part I provides a detailed review of the background fundamentals for the design and analysis of asynchronous finite state machines (FSMs). Included are the basic models, use of fully documented state diagrams, and the design and charac

  15. Progress in dynamic study on the triplet excited states and radical ions of DNA and its components

    Institute of Scientific and Technical Information of China (English)

    宋钦华; 林念芸; 姚思德; 张加山

    2000-01-01

    Progress in dynamic study on the triplet excited states and radical ions of DNA and its components is reviewed. It has been found that acetone is the only effective sensitizer for the study of the triplet excited states of DNA components. The transient absorption spectrum of guanyl radical cation resulting from the interaction of triplet acetone and DNA was observed directly, and the original evidence for selective damage of DNA by excited photosensitizer was obtained for the first time, which offered a new pathway for obtaining the main transient species of selective damage of DNA by photonucleases and illustrating initial oxidation mechanism of DNA via electron transfer.

  16. On the hyperfine structure of the triplet $n^{3}S-$states of the four-electron atoms and ions

    CERN Document Server

    Frolov, Alexei M

    2016-01-01

    Hyperfine structures of the triplet $n^3S-$states in the four-electron Be-atom(s) and Be-like ions are considered. It is shown that to determine the hyperfine structure splitting in such atomic systems one needs to know the triplet electron density at the central atomic nucleus $\\rho_T(0)$. We have developed the procedure which allows allows one to determine the triplet electron density $\\rho_T(0)$ for arbitrary four-electron atoms and ions.

  17. Thickness dependence of the triplet spin-valve effect in superconductor–ferromagnet–ferromagnet heterostructures

    Directory of Open Access Journals (Sweden)

    Daniel Lenk

    2016-07-01

    Full Text Available Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature Tc, i.e., a superconducting triplet spin-valve effect, around mutually perpendicular alignment.Results: The superconducting triplet spin valve is realized with S = Nb a singlet superconductor, F1 = Cu41Ni59 and F2 = Co ferromagnetic metals, AF = CoOx an antiferromagnetic oxide, and N = nc-Nb a normal conducting (nc non-magnetic metal, which serves to decouple F1 and F2. The non-collinear alignment of the magnetizations is obtained by applying an external magnetic field parallel to the layers of the heterostructure and exploiting the intrinsic perpendicular easy-axis of the magnetization of the Cu41Ni59 thin film in conjunction with the exchange bias between CoOx and Co. The magnetic configurations are confirmed by superconducting quantum interference device (SQUID magnetic moment measurements. The triplet spin-valve effect has been investigated for different layer thicknesses, dF1, of F1 and was found to decay with increasing dF1. The data is described by an empirical model and, moreover, by calculations using the microscopic theory.Conclusion: The long-range triplet component of superconducting pairing is generated from the singlet component mainly at the N/F2 interface, where the amplitude of the singlet component is suppressed exponentially with increasing distance dF1. The decay length of the empirical model is found to be comparable to twice the electron mean free path of F1 and, thus, to the decay length of the singlet component in F1. Moreover, the obtained data is in qualitative agreement with the microscopic theory, which, however, predicts a (not investigated breakdown of the

  18. Thickness dependence of the triplet spin-valve effect in superconductor–ferromagnet–ferromagnet heterostructures

    Science.gov (United States)

    Zdravkov, Vladimir I; Kehrle, Jan-Michael; Obermeier, Günter; Ullrich, Aladin; Morari, Roman; Krug von Nidda, Hans-Albrecht; Müller, Claus; Kupriyanov, Mikhail Yu; Sidorenko, Anatolie S; Horn, Siegfried; Deminov, Rafael G; Tagirov, Lenar R; Tidecks, Reinhard

    2016-01-01

    Summary Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature T c, i.e., a superconducting triplet spin-valve effect, around mutually perpendicular alignment. Results: The superconducting triplet spin valve is realized with S = Nb a singlet superconductor, F1 = Cu41Ni59 and F2 = Co ferromagnetic metals, AF = CoOx an antiferromagnetic oxide, and N = nc-Nb a normal conducting (nc) non-magnetic metal, which serves to decouple F1 and F2. The non-collinear alignment of the magnetizations is obtained by applying an external magnetic field parallel to the layers of the heterostructure and exploiting the intrinsic perpendicular easy-axis of the magnetization of the Cu41Ni59 thin film in conjunction with the exchange bias between CoOx and Co. The magnetic configurations are confirmed by superconducting quantum interference device (SQUID) magnetic moment measurements. The triplet spin-valve effect has been investigated for different layer thicknesses, d F1, of F1 and was found to decay with increasing d F1. The data is described by an empirical model and, moreover, by calculations using the microscopic theory. Conclusion: The long-range triplet component of superconducting pairing is generated from the singlet component mainly at the N/F2 interface, where the amplitude of the singlet component is suppressed exponentially with increasing distance d F1. The decay length of the empirical model is found to be comparable to twice the electron mean free path of F1 and, thus, to the decay length of the singlet component in F1. Moreover, the obtained data is in qualitative agreement with the microscopic theory, which, however, predicts a (not investigated) breakdown of the

  19. Sequential protein NMR assignments in the liquid state via sequential data acquisition

    Science.gov (United States)

    Wiedemann, Christoph; Bellstedt, Peter; Kirschstein, Anika; Häfner, Sabine; Herbst, Christian; Görlach, Matthias; Ramachandran, Ramadurai

    2014-02-01

    Two different NMR pulse schemes involving sequential 1H data acquisition are presented for achieving protein backbone sequential resonance assignments: (i) acquisition of 3D {HCCNH and HNCACONH} and (ii) collection of 3D {HNCOCANH and HNCACONH} chemical shift correlation spectra using uniformly 13C,15N labelled proteins. The sequential acquisition of these spectra reduces the overall experimental time by a factor of ≈2 as compared to individual acquisitions. The suitability of this approach is experimentally demonstrated for the C-terminal winged helix (WH) domain of the minichromosome maintenance (MCM) complex of Sulfolobus solfataricus.

  20. A triplet-triplet annihilation based up-conversion process investigated in homogeneous solutions and oil-in-water microemulsions of a surfactant.

    Science.gov (United States)

    Penconi, Marta; Gentili, Pier Luigi; Massaro, Giuseppina; Elisei, Fausto; Ortica, Fausto

    2014-01-01

    The triplet-triplet annihilation based up-conversion process, involving a platinum octaethyl-porphyrin (PtOEP) as a sensitizer and tetraphenyl-pyrene (TPPy) as an emitter, has been investigated in homogeneous solutions of toluene, bromobenzene and anisole, and oil-in-water microemulsions of the TX-100 surfactant, where toluene constitutes the non-polar phase. In homogeneous solutions, the highest up-conversion quantum yield (of the order of 20%) has been achieved in toluene, being the solvent that has the lowest viscosity among those explored. The up-conversion emission from the PtOEP-TPPy pair has been then investigated in a toluene based oil-in-water microemulsion at three different concentrations of the solutes, showing quantum yields up to the order of 1%, under the same irradiation conditions, but different deoxygenating procedures. The results herein reported might represent a good starting point for a future investigation in microheterogeneous systems. An optimization of the microemulsion composition, in terms of surfactant, co-surfactant and toluene concentrations, could allow us to increase the sensitizer and emitter concentrations and set up the best operative conditions to obtain even higher up-conversion efficiencies.

  1. Mathematical Problem Solving through Sequential Process Analysis

    Science.gov (United States)

    Codina, A.; Cañadas, M. C.; Castro, E.

    2015-01-01

    Introduction: The macroscopic perspective is one of the frameworks for research on problem solving in mathematics education. Coming from this perspective, our study addresses the stages of thought in mathematical problem solving, offering an innovative approach because we apply sequential relations and global interrelations between the different…

  2. Sequentiality versus simultaneity: Interrelated factor demand

    NARCIS (Netherlands)

    Asphjell, M.K.; Letterie, W.A.; Nilsen, O.A.; Pfann, G.A.

    2014-01-01

    Firms may adjust capital and labor sequentially or simultaneously. In this paper, we develop a structural model of interrelated factor demand subject to nonconvex adjustment costs and estimated by simulated method of moments. Based on Norwegian manufacturing industry plant-level data, parameter

  3. Comprehensive sequential interventional therapy for hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; FAN Wei-jun; HUANG Jin-hua; LI Chuan-xing; ZHAO Ming; WANG Li-gang; TANG Tian

    2009-01-01

    Background Since the 1980s, various approaches to interventional therapy have been developed, with the development and achievement of medical imaging technology. This study aimed to evaluate the effectiveness of comprehensive sequential interventional therapy especially personal therapeutic plan in 53 radical cure patients with hepatocellular carcinoma (HCC).Methods From January 2003 to January 2005, a total of 203 patients with HCC received sequential interventional treatment in our hospital. Fifty-three patients achieved radical cure outcomes. Those patients were treated with transcatheter arterial chemoembolization (TACE), radiofrequency ablation (RFA), percutaneous ethanol injection (PEI), or high intensity focused ultrasound (HIFU), sequentially and in combination depending on their clinical and pathological features. PET-CT was used to evaluate, assess, and guide treatment.Results Based on the imaging and serological data, all the patients had a personal therapeutic plan. The longest follow-up time was 24 months, the shortest was 6 months, and mean survival time was 16.5 months.Conclusion Comprehensive sequential interventional therapy especially personal therapeutic plan for HCC play roles in interventional treatment of HCC in middle or advanced stage.

  4. Sequential spatial processes for image analysis

    NARCIS (Netherlands)

    M.N.M. van Lieshout (Marie-Colette)

    2009-01-01

    htmlabstractWe give a brief introduction to sequential spatial processes. We discuss their definition, formulate a Markov property, and indicate why such processes are natural tools in tackling high level vision problems. We focus on the problem of tracking a variable number of moving objects throug

  5. A Bayesian sequential design with binary outcome.

    Science.gov (United States)

    Zhu, Han; Yu, Qingzhao; Mercante, Donald E

    2017-03-02

    Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha-spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha-spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.

  6. Sequential motor skill: cognition, perception and action

    NARCIS (Netherlands)

    Ruitenberg, M.F.L.

    2013-01-01

    Discrete movement sequences are assumed to be the building blocks of more complex sequential actions that are present in our everyday behavior. The studies presented in this dissertation address the (neuro)cognitive underpinnings of such movement sequences, in particular in relationship to the role

  7. On Sequentially Co-Cohen-Macaulay Modules

    Institute of Scientific and Technical Information of China (English)

    Nguyen Thi Dung

    2007-01-01

    In this paper,we define the notion of dimension filtration of an Artinian module and study a class of Artinian modules,called sequentially co-Cohen-Macaulay modules,which contains strictly all co-Cohen-Macaulay modules.Some characterizations of co-Cohen-Macaulayness in terms of the Matlis duality and of local homology are also given.

  8. Sequential motor skill: cognition, perception and action

    NARCIS (Netherlands)

    Ruitenberg, M.F.L.

    2013-01-01

    Discrete movement sequences are assumed to be the building blocks of more complex sequential actions that are present in our everyday behavior. The studies presented in this dissertation address the (neuro)cognitive underpinnings of such movement sequences, in particular in relationship to the role

  9. Terminating Sequential Delphi Survey Data Collection

    Science.gov (United States)

    Kalaian, Sema A.; Kasim, Rafa M.

    2012-01-01

    The Delphi survey technique is an iterative mail or electronic (e-mail or web-based) survey method used to obtain agreement or consensus among a group of experts in a specific field on a particular issue through a well-designed and systematic multiple sequential rounds of survey administrations. Each of the multiple rounds of the Delphi survey…

  10. A Parallel Programming Model With Sequential Semantics

    Science.gov (United States)

    1996-01-01

    Parallel programming is more difficult than sequential programming in part because of the complexity of reasoning, testing, and debugging in the...context of concurrency. In the thesis, we present and investigate a parallel programming model that provides direct control of parallelism in a notation

  11. Sequential auctions for full truckload allocation

    NARCIS (Netherlands)

    Mes, Martijn R.K.

    2008-01-01

    In this thesis we examine the use of sequential auctions for the dynamic allocation of transportation jobs. For all players, buyers and sellers, we develop strategies and examine their performance both in terms of individual benefits and with respect to the global logistical performance (resource

  12. Sequential Tests for Large Scale Learning

    NARCIS (Netherlands)

    Korattikara, A.; Chen, Y.; Welling, M.

    2016-01-01

    We argue that when faced with big data sets, learning and inference algorithms should compute updates using only subsets of data items. We introduce algorithms that use sequential hypothesis tests to adaptively select such a subset of data points. The statistical properties of this subsampling proce

  13. Sequentiality versus simultaneity: Interrelated factor demand

    NARCIS (Netherlands)

    Asphjell, M.K.; Letterie, W.A.; Nilsen, O.A.; Pfann, G.A.

    2014-01-01

    Firms may adjust capital and labor sequentially or simultaneously. In this paper, we develop a structural model of interrelated factor demand subject to nonconvex adjustment costs and estimated by simulated method of moments. Based on Norwegian manufacturing industry plant-level data, parameter esti

  14. Neutrino dark energy and leptogenesis with TeV scale triplets

    Energy Technology Data Exchange (ETDEWEB)

    Hati, Chandan [Physical Research Laboratory, Ahmedabad (India); Indian Institute of Technology Gandhinagar, Chandkheda, Ahmedabad (India); Sarkar, Utpal [Physical Research Laboratory, Ahmedabad (India)

    2016-05-15

    We propose a realization of mass varying neutrino dark energy in two extensions of the Standard Model (SM) with a dynamical neutrino mass related to the acceleron field while satisfying the naturalness. In the first scenario the SM is extended to include a TeV scale scalar Higgs triplet (ξ) and a TeV scale second Higgs doublet (η), while in the second scenario an extension of the SM with fermion triplet (Σ) is considered. We also point out the possible leptogenesis mechanisms for simultaneously generating the observed baryon asymmetry of the universe in both scenarios and discuss the collider signatures for the TeV scale new fields which make these models testable in the current run of LHC. (orig.)

  15. Experimental investigation of the role of the triplet pairing in the superconducting spin-valve effect

    Science.gov (United States)

    Leksin, P. V.; Kamashev, A. A.; Garif'yanov, N. N.; Validov, A. A.; Fominov, Ya. V.; Schumann, J.; Kataev, V. E.; Büchner, B.; Garifullin, I. A.

    2016-11-01

    An important role of the morphology of a superconducting layer in the superconducting spin-valve effect has been established. The triplet pairing induced by the superconductor/ferromagnet proximity effect has been experimentally investigated for samples CoO x /Py1/Cu/Py2/Cu/Pb (where Py = Ni0.81Fe0.19) with a smooth superconducting layer. The optimization of the parameters of this structure has demonstrated a complete switching between the normal and superconducting states with a change in the relative orientation of magnetizations of the ferromagnetic layers from the antiparallel to orthogonal orientation. A pure triplet contribution has been observed for the sample with a permalloy layer thickness at which the superconducting spin-valve effect vanishes. A direct comparison of the experimental data with the theoretical calculation of the temperature of the transition to the superconducting state has been performed for the first time.

  16. Contribution of satellite lines to temperature diagnostics with He-like triplet lines in photoionized plasma

    Science.gov (United States)

    Wang, Feilu; Han, Bo; Salzmann, David; Zhao, Gang

    2017-04-01

    In the present paper, the He α triplet line ratios (resonance, intercombination, and forbidden lines) are computed for photoionized plasmas, when the contributions of nearby satellite lines are taken into account. The computations have been carried out with our radiative-collisional code, RCF, which is based on the flexible atomic code. The calculations of these line ratios have been done for three materials, namely, silicon, magnesium, and neon. Our calculations are used to derive the plasma temperatures for several astronomical objects, where the spectra are emitted from photoionizing plasmas. It is shown that the incorporation of the satellite lines from doubly excited Li-like ions into the He α triplet lines is necessary to obtain reliable temperature diagnostics for these astrophysical objects.

  17. Quenching of the triplet state of certain porphyrins by cyanocobalamin and co-phthalocyanine

    Science.gov (United States)

    Sapunov, V. V.

    1992-10-01

    The bimolecular exchange-resonance energy transfer efficiency from the triplet level of a number of Pd porphyrins to cyanocobalamin (vitamin B-12) is much lower in ethanol than in aqueous solutions. This is explained by a change in a cyanocobalamin-molecule geometry in ethanol from that in aqueous solutions. This change can be the detachment of the nucleotide from the cobalt ion or a change in the cyanocobalamin-molecule conformation. As a result, stearic hindrance of intermolecular energy transfer arises, or the mobility of the cyanocobalamin molecules decreases. No quenching of the triplet state of tetraphenyl tetrahydroporphin by cyanocobalamine is detected, whereas quenching of Co-phthalocyanine occurs with a high rate constant.

  18. Singlet-triplet annihilation limits exciton yield in poly(3-hexylthiophene)

    CERN Document Server

    Steiner, Florian; Lupton, John M

    2014-01-01

    Control of chain length and morphology in combination with single-molecule spectroscopy techniques provide a comprehensive photophysical picture of excited-state losses in the prototypical conjugated polymer poly(3-hexylthiophene) (P3HT). A universal self-quenching mechanism is revealed, based on singlet-triplet exciton annihilation, which accounts for the dramatic loss in fluorescence quantum yield of a single P3HT chain between its solution (unfolded) and bulk-like (folded) state. Triplet excitons fundamentally limit the fluorescence of organic photovoltaic materials, which impacts on the conversion of singlet excitons to separated charge carriers, decreasing the efficiency of energy harvesting at high excitation densities. Interexcitonic interactions are so effective that a single P3HT chain of >100 kDa weight behaves like a two-level system, exhibiting perfect photon-antibunching.

  19. Triplet FFLO superconductivity in the doped Kitaev-Heisenberg honeycomb model

    Science.gov (United States)

    Liu, Tianhan; Repellin, Cécile; Douçot, Benoît; Regnault, Nicolas; Le Hur, Karyn

    2016-11-01

    We provide analytical and numerical evidence of spin-triplet Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconductivity in the itinerant Kitaev-Heisenberg model (antiferromagnetic Kitaev coupling and ferromagnetic Heisenberg coupling) on the honeycomb lattice around quarter filling. The strong spin-orbit coupling in our model leads to the emergence of six inversion symmetry centers for the Fermi surface at nonzero momenta in the first Brillouin zone. We show how the Cooper pairs condense into these nontrivial momenta, causing spatial modulation of the superconducting order parameter. Applying a Ginzburg-Landau expansion analysis, we find that the superconductivity has three separated degenerate ground states with three different spin-triplet pairings. Exact diagonalizations on finite clusters support this picture while ruling out a spin (charge) density wave.

  20. Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A

    Directory of Open Access Journals (Sweden)

    Lev B. Leinson

    2015-02-01

    Full Text Available In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.

  1. Tailor-made RNAi knockdown against triplet repeat disease-causing alleles.

    Science.gov (United States)

    Takahashi, Masaki; Watanabe, Shoko; Murata, Miho; Furuya, Hirokazu; Kanazawa, Ichiro; Wada, Keiji; Hohjoh, Hirohiko

    2010-12-14

    Nucleotide variations, including SNPs, in the coding regions of disease genes are important targets for RNAi treatment, which is a promising medical treatment for intractable diseases such as triplet repeat diseases. However, the identification of such nucleotide variations and the design of siRNAs conferring disease allele-specific RNAi are quite difficult. In this study we developed a pull-down method to rapidly identify coding SNP (cSNP) haplotypes of triple repeat, disease-causing alleles, and we demonstrated disease allele-specific RNAi that targeted cSNP sites in mutant Huntingtin alleles, each of which possessed a different cSNP haplotype. Therefore, the methods presented here allow for allele-specific RNAi knockdown against disease-causing alleles by using siRNAs specific to disease-linked cSNP haplotypes, and advanced progress toward tailor-made RNAi treatments for triplet repeat diseases.

  2. Inelastic collisions of ultracold triplet Rb2 molecules in the rovibrational ground state

    Science.gov (United States)

    Drews, Björn; Deiß, Markus; Jachymski, Krzysztof; Idziaszek, Zbigniew; Hecker Denschlag, Johannes

    2017-01-01

    Exploring and controlling inelastic and reactive collisions on the quantum level is a main goal of the developing field of ultracold chemistry. For this, the preparation of precisely defined initial atomic and molecular states in tailored environments is necessary. Here we present experimental studies of inelastic collisions of metastable ultracold Rb2 molecules in an array of quasi-1D potential tubes. In particular, we investigate collisions of molecules in the absolute lowest triplet energy level where any inelastic process requires a change of the electronic state. Remarkably, we find similar decay rates as for collisions between rotationally or vibrationally excited triplet molecules where other decay paths are also available. The decay rates are close to the ones for universal reactions but vary considerably when confinement and collision energy are changed. This might be exploited to control the collisional properties of molecules. PMID:28332492

  3. TripNet: A Method for Constructing Phylogenetic Networks from Triplets

    CERN Document Server

    Tusserkani, Ruzbeh; Poormohammadi, Hadi; Azadi, Azin

    2011-01-01

    We present TripNet, a method for constructing phylogenetic networks from triplets. We will present the motivations behind our approach and its theoretical and empirical justification. To demonstrate the accuracy and efficiency of TripNet, we performed two simulations and also applied the method to five published data sets: Kreitman's data, a set of triplets from real yeast data obtained from the Fungal Biodiversity Center in Utrecht, a collection of 110 highly recombinant Salmonella multi-locus sequence typing sequences, and nrDNA ITS and cpDNA JSA sequence data of New Zealand alpine buttercups of Ranunculus sect. Pseudadonis. Finally, we compare our results with those already obtained by other authors using alternative methods. TripNet, data sets, and supplementary files are freely available for download at (www.bioinf.cs.ipm.ir/softwares/tripnet).

  4. Triplet p-wave pairing correlation in low-doped zigzag graphene nanoribbons

    Science.gov (United States)

    Ma, Tianxing; Yang, Fan; Huang, Zhongbing; Lin, Hai-Qing

    2017-02-01

    We reveal an edge spin triplet p–wave superconducting pairing correlation in slightly doped zigzag graphene nanoribbons. By employing a method that combines random-phase approximation, the finite-temperature determinant quantum Monte Carlo approach, and the ground-state constrained-path quantum Monte Carlo method, it is shown that such a spin-triplet pairing is mediated by the ferromagnetic fluctuations caused by the flat band at the edge. The spin susceptibility and effective pairing interactions at the edge strongly increase as the on-site Coulomb interaction increases, indicating the importance of electron-electron correlations. It is also found that the doping-dependent ground-state p-wave pairing correlation bears some similarity to the famous superconducting dome in the phase diagram of a high-temperature superconductor, while the spin correlation at the edge is weakened as the system is doped away from half filling.

  5. Recent emergence of photon upconversion based on triplet energy migration in molecular assemblies.

    Science.gov (United States)

    Yanai, Nobuhiro; Kimizuka, Nobuo

    2016-04-07

    An emerging field of triplet energy migration-based photon upconversion (TEM-UC) is reviewed. Highly efficient photon upconversion has been realized in a wide range of chromophore assemblies, such as non-solvent liquids, ionic liquids, amorphous solids, gels, supramolecular assemblies, molecular crystals, and metal-organic frameworks (MOFs). The control over their assembly structures allows for unexpected air-stability and maximum upconversion quantum yield at weak solar irradiance that has never been achieved by the conventional molecular diffusion-based mechanism. The introduction of the "self-assembly" concept offers a new perspective in photon upconversion research and triplet exciton science, which show promise for numerous applications ranging from solar energy conversion to chemical biology.

  6. Cortical subarachnoid hemorrhage associated with reversible cerebral vasoconstriction syndrome after elective triplet cesarean delivery.

    Science.gov (United States)

    Albano, Beatrice; Del Sette, Massimo; Roccatagliata, Luca; Gandolfo, Carlo; Primavera, Alberto

    2011-06-01

    Reversible cerebral vasoconstriction syndromes (RCVS) comprise a group of disorders characterized by prolonged, but reversible vasoconstriction of the cerebral arteries, usually associated with acute-onset, severe, recurrent headaches, with or without additional neurological signs and symptoms. Various complications of this condition have been observed, such as cortical subarachnoid hemorrhages (cSAH), intracerebral hemorrhages, reversible posterior leukoencephalopathy, ischaemic strokes and transient ischaemic attacks. It is important to include RCVS in thunderclap headache differential diagnosis and among non-aneurismatic subarachnoid hemorrhage causes. In the past years, thanks to the major diffusion of new diagnostic tools such as magnetic resonance, computed tomography and digital subtraction angiography, RCVS have been demonstrated to be more frequent than previously thought. We report an illustrative case of a woman affected by a small cSAH, associated to RCVS, after elective triplet cesarean delivery. To our knowledge, this is the first case of cSAH associated to RCVS after a triplet pregnancy.

  7. Quench Limit Calculation for Steady State Heat Deposits in LHC Inner Triplet Magnets

    CERN Document Server

    Cerutti, F; Esposito, L S; Siemko, A; Bocian, D

    2012-01-01

    In hadron colliders such as the LHC, the energy deposited in the superconductors by the particles lost from the beams or coming from the collision debris may provoke quenches detrimental to the accelerator operation. A Network Model is used to simulate the thermodynamic behavior of the superconducting magnets. In previous papers the validations of network model with measurements performed in the CERN and Fermilab magnet test facilities were presented. This model was subsequently used for thermal analysis of the current LHC inner triplet quadrupole magnets for beam energy of 3.5 TeV and 7.0 TeV. The detailed study of helium cooling channels efficiency for energy deposits simulated with FLUKA was performed. The expected LHC inner triplet magnets quench limit is presented.

  8. Proximity effects in superconducting triplet spin-valve F2/F1/S

    Energy Technology Data Exchange (ETDEWEB)

    Deminov, R.G., E-mail: Raphael.Deminov@kpfu.ru [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Tagirov, L.R. [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Institut für Physik, Universität Augsburg, Augsburg D-86159 (Germany); Gaifullin, R.R. [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Karminskaya, T.Yu.; Kupriyanov, M.Yu. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow 119992 (Russian Federation); Fominov, Ya.V. [Landau Institute for Theoretical Physics RAS, Moscow 119334 (Russian Federation); Golubov, A.A. [Faculty of Science and Technology and MESA+ Institute of Nanotechnology, University of Twente, P.O. Box 217, Enschede 7500 AE (Netherlands)

    2015-01-01

    We investigate the critical temperature T{sub c} of F2/F1/S trilayers (Fi is a ferromagnetic metal and S is a singlet superconductor), where the long-range triplet superconducting component is generated at noncollinear magnetizations of the F layers. In this paper we demonstrate a possibility of the spin-valve effect mode selection (standard switching effect, the triplet spin-valve effect or reentrant T{sub c}(α) dependence) by the variation of the F2/F1 interface transparency. - Highlights: • T{sub c} of FFS trilayer as a function of angle between magnetizations is calculated. • T{sub c} of FFS structure for arbitrary FF interface transparencies γ{sub B} is calculated. • Possibility of the spin-valve effect mode selection by the variation of γ{sub B} is shown.

  9. Unexpected effect of substituents on the zero-field splitting of triplet phenyl nitrenes

    Science.gov (United States)

    Korchagin, Denis V.; Akimov, Alexander V.; Yureva, Elena A.; Aldoshin, Sergei M.; Misochko, Eugenii Ya.

    2016-08-01

    The EPR spectrum of triplet 2,4,6-tribromophenyl nitrene was obtained in glassy methylcyclohexane at 15 K. Surprisingly, the zero-field splitting parameter D = 0.989 cm-1 derived from this spectrum is much lower than that reported previously for triplet 3,5-diazido-2,4,6-tribromophenyl nitrene and has the same value as in phenyl nitrenes composed with light atoms. DFT calculations of the zero-field splitting parameters support this unexpected experimental observation. Experimental and theoretical data provide evidence that the enhanced by bromine atoms spin-orbit contribution to the parameter D (the so called ;heavy-atom effect;) is strongly modulated by other substituents attached to the aromatic cycle.

  10. Triplet p-wave pairing correlation in low-doped zigzag graphene nanoribbons

    Science.gov (United States)

    Ma, Tianxing; Yang, Fan; Huang, Zhongbing; Lin, Hai-Qing

    2017-01-01

    We reveal an edge spin triplet p–wave superconducting pairing correlation in slightly doped zigzag graphene nanoribbons. By employing a method that combines random-phase approximation, the finite-temperature determinant quantum Monte Carlo approach, and the ground-state constrained-path quantum Monte Carlo method, it is shown that such a spin-triplet pairing is mediated by the ferromagnetic fluctuations caused by the flat band at the edge. The spin susceptibility and effective pairing interactions at the edge strongly increase as the on-site Coulomb interaction increases, indicating the importance of electron-electron correlations. It is also found that the doping-dependent ground-state p-wave pairing correlation bears some similarity to the famous superconducting dome in the phase diagram of a high-temperature superconductor, while the spin correlation at the edge is weakened as the system is doped away from half filling. PMID:28186185

  11. Photopolymer material sensitized by xanthene dyes for holographic recording using forbidden singlet-triplet electronic transitions

    Science.gov (United States)

    Shelkovnikov, Vladimir; Vasiljev, Evgeny; Russkih, Vladimlen; Berezhnaya, Viktoria

    2016-07-01

    A new holographic photopolymer material is developed. The photopolymer material is sensitized by dyes of xanthene and thioxanthene series which contain iodine and bromine heavy atoms. Holographic recording was carried out during excitation of forbidden singlet-triplet electron transitions of dyes. Thioerythrosin triethylammonium was identified as the most effective sensitizer among a number of tested dyes. The spectral absorption area of the singlet-triplet electronic transition of the dye is conveyed in the red spectral range from 600 to 700 nm. The sensitivity of the photopolymer material to radiation with 633 nm wavelength is 180 mJ cm-2. Optimization of concentration of the main components of the photopolymer compositions was carried out in order to achieve maximum efficiency of holographic recording.

  12. Magnetoelectric Andreev Effect due to Proximity-Induced Nonunitary Triplet Superconductivity in Helical Metals

    Science.gov (United States)

    Tkachov, G.

    2017-01-01

    Noncentrosymmetric superconductors exhibit the magnetoelectric effect, which manifests itself in the appearance of the magnetic spin polarization in response to a dissipationless electric current (supercurrent). While much attention has been dedicated to the thermodynamic version of this phenomenon (Edelstein effect), nonequilibrium transport magnetoelectric effects have not been explored yet. We propose the magnetoelectric Andreev effect (MAE), which consists in the generation of spin-polarized triplet Andreev conductance by an electric supercurrent. The MAE stems from the spin polarization of the Cooper-pair condensate due to a supercurrent-induced nonunitary triplet pairing. We propose the realization of such a nonunitary pairing and MAE in superconducting proximity structures based on two-dimensional helical metals—strongly spin-orbit-coupled electronic systems with the Dirac spectrum such as the topological surface states. Our results uncover an unexplored route towards electrically controlled superconducting spintronics and are a smoking gun for induced unconventional superconductivity in spin-orbit-coupled materials.

  13. Triplet repeat DNA structures and human genetic disease: dynamic mutations from dynamic DNA

    Indian Academy of Sciences (India)

    Richard R Sinden; Vladimir N Potaman; Elena A Oussatcheva; Christopher E Pearson; Yuri L Lyubchenko; Luda S Shlyakhtenko

    2002-02-01

    Fourteen genetic neurodegenerative diseases and three fragile sites have been associated with the expansion of (CTG)n•(CAG)n, (CGG)n•(CCG)n, or (GAA)n•(TTC)n repeat tracts. Different models have been proposed for the expansion of triplet repeats, most of which presume the formation of alternative DNA structures in repeat tracts. One of the most likely structures, slipped strand DNA, may stably and reproducibly form within triplet repeat sequences. The propensity to form slipped strand DNA is proportional to the length and homogeneity of the repeat tract. The remarkable stability of slipped strand DNA may, in part, be due to loop-loop interactions facilitated by the sequence complementarity of the loops and the dynamic structure of three-way junctions formed at the loop-outs.

  14. Singlet-Triplet Transitions of a P(o)schl-Teller Quantum Dot

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    We study the energy spectra of a two-dimensional two-electron quantum dot (QD) with P(o)schl-Teller confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation. A ground-state behavior (spin singlet-triplet transitions) as a function of the strength of a magnetic field is found. We find that the dot radius R of a P(o)schl-Teller potential is important for the ground-state transition and the feature of ground-state for a P(o)schl-Teller QD and a parabolic QD is similar when R is larger. The larger the well depth, the higher the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in a P(o)schl-Teller QD.

  15. Using less Quantum Resource for Probabilistic Controlled Teleportation of a Triplet W State

    Directory of Open Access Journals (Sweden)

    Xian-Ming Wang

    2012-10-01

    Full Text Available In a recent paper [CHIN. PHYS. LETT. Vol.26,No.7(2009070306 ], DONG et al. proposed a scheme for probabilistic controlled teleportation of a triplet W state using combined non-maximally entangled channel of two Einstein–Podolsky–Rosen (EPR states and one Greenberger–Horne–Zeilinger (GHZ state. In this paper ,only using one Einstein–Podolsky–Rosen (EPR state and one Greenberger–Horne–Zeilinger (GHZ state,the scheme for probabilistic controlled teleportation of a triplet W state is presented. Furthermore, Comparing with the widely used Bell-State measurement, Alice performs orthogonal complete basis measurement in the current work. Then Bob can faithfully reconstruct the original state by performing relevant unitary transformations. The total probability of successful teleportation is only dependent on channel coefficients of EPR state and GHZ state.  

  16. Fusion Rules of the ${\\cal W}_{p,q}$ Triplet Models

    CERN Document Server

    Wood, Simon

    2009-01-01

    In this paper we determine the fusion rules of the logarithmic ${\\calW}_{p,q}$ triplet theory and construct the Grothendieck group with subgroups for which consistent product structures can be defined. The fusion rules are then used to determine projective covers. This allows us also to write down a candidate for a modular invariant partition function. Our results demonstrate that recent work on the ${\\cal W}_{2,3}$ model generalises naturally to arbitrary (p,q).

  17. Quantum Computing via Singlet-Triplet Spin Qubits in Nanowire Double Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    XUE Peng

    2011-01-01

    We propose a new structure for quantum computing via spin qubits with high fidelity.Each spin qubit corresponds to two electrons in a nanowire double quantum dot,with the singlet and one of the triplets as the logical qubit states.The entangling gate is effected by virtual charge dipole transitions.We include noise to show the feasibility of this scheme under current experimental conditions.

  18. Beginning Chemistry Teachers Use of the Triplet Relationship During their First Three Years in the Classroom

    Science.gov (United States)

    Adams, Krista

    Pedagogical content knowledge (PCK) has been described as the knowledge teachers' use in the process of designing and implementing lessons to a particular group of students. This includes the most effective representations that make the content understandable to students, together with the preconceptions and misconceptions that students hold. For chemistry, students have been found to have difficulty with the discipline due to its reliance upon three levels of representation called the triplet: the macro, the submicro, and the symbolic. This study examines eight beginning chemistry teachers' depiction of the chemistry content through the triplet relationship and modifications as a result of considering students' understanding across the teacher's first three years in the classroom. The data collected included classroom observations, interviews, and artifacts for the purpose of triangulation. The analysis of the data revealed that beginning chemistry teachers utilized the abstract components, submicro and symbolic, primarily in the first year. However, the teachers began to engage more macro representations over time building a more developed instructional repertoire. Additionally, teachers' developed an awareness of and responded to their students' understanding of learning atomic structure during the second and third year teaching. The results of this study call for preservice and induction programs to help novice chemistry teachers build a beginning repertoire that focuses on the triplet relationship. In so doing, the teachers enter the classroom with a repertoire that allows them to address the needs of their students. Finally, the study suggests that the triplet relationship framework should be revisited to include an additional component that frames learning to account for socioscientific issues and historical contributions.

  19. Implications of the discovery of a Higgs triplet on electroweak right-handed neutrinos

    CERN Document Server

    Aranda, Alfredo; Hung, P Q

    2008-01-01

    Electroweak scale active right-handed neutrinos such as those proposed in a recent model necessitate the enlargement of the SM Higgs sector to include Higgs triplets with doubly charged scalars. The search for and constraints on such Higgs sector has implications not only on the nature of the electroweak symmetry breaking but also on the possibility of testing the seesaw mechanism at colliders such as the LHC and the ILC.

  20. Photoinduced charge injection from excited triplet hypocrellin B into TiO2 colloid in ethanol

    Institute of Scientific and Technical Information of China (English)

    SHEN, Jian-Quan; SHEN, Tao; ZHANG, Man-Hua; LI, Wen; SONG, Ai-Min

    2000-01-01

    Photosensitization of TiO2 colloid by hypocrellin B (HB), a natural photodynamic pigment with extremely high plhotosta bility, has been studied by surface enhanced Raman spec troscorpy (SERS), laser flash photolysis and electron param agnetic resonance (EPR) techniques. The photosensitization of TiO2 occurred practically from the excited triplet dye and the electron injection rate constant is 1.3 × 106 s-1. The influ ences of donor and acceptor on the eleciron injection were in vestigated.

  1. Structure analysis of photo-induced triplet phenylnitrene using synchrotron radiation

    CERN Document Server

    Kawano, M; Uekusa, H; Ohashi, Y; Ozawa, Y; Matsubara, K; Imabayashi, H; Mitsumi, M; Toriumi, K

    2003-01-01

    The crystal structures of [(PhCH sub 2) sub 2 NH sub 2] sup + [m-C sub 6 H sub 4 (N sub 3)-(COO)] sup - before and after UV-irradiation were analyzed at 25 K by using an X-ray vacuum camera set up at the synchrotron laboratory (SPring-8). The C-N (nitrene) bond distance in the triplet state of the photo-induced m-carboxyphenylnitrene is determined to be 1.34(4) A.

  2. Identification of redundant and synergetic circuits in triplets of electrophysiological data

    Science.gov (United States)

    Erramuzpe, Asier; Ortega, Guillermo J.; Pastor, Jesus; de Sola, Rafael G.; Marinazzo, Daniele; Stramaglia, Sebastiano; Cortes, Jesus M.

    2015-12-01

    Objective. Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. While correlations and mutual information are commonly used to characterize these dependencies, our objective here is to extend interactions to triplets of variables to better detect and characterize dynamic information transfer. Approach. Our approach relies on the measure of interaction information (II). The sign of II provides information as to the extent to which the interaction of variables in triplets is redundant (R) or synergetic (S). Three variables are said to be redundant when a third variable, say Z, added to a pair of variables (X, Y), diminishes the information shared between X and Y. Similarly, the interaction in the triplet is said to be synergetic when conditioning on Z enhances the information shared between X and Y with respect to the unconditioned state. Here, based on this approach, we calculated the R and S status for triplets of electrophysiological data recorded from drug-resistant patients with mesial temporal lobe epilepsy in order to study the spatial organization and dynamics of R and S close to the epileptogenic zone (the area responsible for seizure propagation). Main results. In terms of spatial organization, our results show that R matched the epileptogenic zone while S was distributed more in the surrounding area. In relation to dynamics, R made the largest contribution to high frequency bands (14-100 Hz), while S was expressed more strongly at lower frequencies (1-7 Hz). Thus, applying II to such clinical data reveals new aspects of epileptogenic structure in terms of the nature (redundancy versus synergy) and dynamics (fast versus slow rhythms) of the interactions. Significance. We expect this methodology, robust and simple, can reveal new aspects beyond pair-interactions in networks of interacting units in other

  3. The low lying modes of triplet-condensed neutron matter and their effective theory

    CERN Document Server

    Bedaque, Paulo F

    2013-01-01

    The condensation of neutrons into a 3P2 superfluid phase occurs at densities relevant for the interior of neutron stars. The triplet pairing breaks rotational symmetry spontaneously and leads to the existence of gapless modes (angulons) that are relevant for many transport coefficients and to the star's cooling properties. We derive the leading terms of the low energy effective field theory, including the leading coupling to electroweak currents, valid for a variety of possible 3P2 phases.

  4. Vibrational states of the triplet electronic state of H3+. The role of non-adiabatic coupling and geometrical phase

    CERN Document Server

    Alijah, Alexander

    2015-01-01

    Vibrational energies and wave functions of the triplet state of the H3+ ion have been determined. In the calculations, the ground and first excited triplet electronic states are included as well as the non-Born-Oppenheimer coupling between them. A diabatization procedure transforming the two adiabatic ab initio potential energy surfaces of the triplet-H3+ state into a 2x2 matrix is employed. The diabatization takes into account the non-Born-Oppenheimer coupling and the effect of the geometrical phase due to the conical intersection between the two adiabatic potential surfaces. The results are compared to the calculation involving only the lowest adiabatic potential energy surface of the triplet-H3+ ion and neglecting the geometrical phase. The energy difference between results with and without the non-adiabatic coupling and the geometrical phase is about a wave number for the lowest vibrational levels.

  5. Singlet-triplet fission of carotenoid excitation in light-harvesting LH2 complexes of purple phototrophic bacteria.

    Science.gov (United States)

    Klenina, I B; Makhneva, Z K; Moskalenko, A A; Gudkov, N D; Bolshakov, M A; Pavlova, E A; Proskuryakov, I I

    2014-03-01

    The current generally accepted structure of light-harvesting LH2 complexes from purple phototrophic bacteria conflicts with the observation of singlet-triplet carotenoid excitation fission in these complexes. In LH2 complexes from the purple bacterium Allochromatium minutissimum, a drop in the efficiency of carotenoid triplet generation is demonstrated, which correlates with the extent of selective photooxidation of bacteriochlorophylls absorbing at ~850 nm. We conclude that singlet-triplet fission of carotenoid excitation proceeds with participation of these excitonically coupled bacteriochlorophylls. In the framework of the proposed mechanism, the contradiction between LH2 structure and photophysical properties of carotenoids is eliminated. The possibility of singlet-triplet excitation fission involving a third mediator molecule was not considered earlier.

  6. Non-Linear Advanced Control of the LHC Inner Triplet Heat Exchanger Test Unit

    CERN Document Server

    Blanco-Viñuela, E; De Prada-Moraga, C; Cristea, S

    2002-01-01

    The future Large Hadron Collider (LHC) at CERN will include eight interaction region final focus magnet systems, the so-called "Inner Triplet", one on each side of the four beam collision points. The Inner Triplets will be cooled in a static bath of pressurized He II nominally at 1.9 K. This temperature is a control parameter and has very severe constraints in order to avoid the transition from the superconducting to normal resistive state. The main difference in these special zones with respect to a regular LHC cell is higher dynamic heat load unevenly distributed which modifies largely the process characteristics and hence the controller performance. Several control strategies have already been tested at CERN in a pilot plant (LHC String Test) which reproduced a LHC half-cell. In order to validate a common control structure along the whole LHC ring, a Nonlinear Model Predictive Control (NMPC) has been developed and implemented in the Inner Triplet Heat Exchanger Unit (IT-HXTU) at CERN. Automation of the Inn...

  7. HLA class I donor-specific triplet antibodies detected after renal transplantation.

    Science.gov (United States)

    Varnavidou-Nicolaidou, A; Doxiadis, I I N; Iniotaki-Theodoraki, A; Patargias, T; Stavropoulos-Giokas, C; Kyriakides, G K

    2004-01-01

    The purpose of this study was to investigate whether IgG, non-donor-specific anti-HLA class I antibodies (HLAabI) detected after renal transplantation recognize immunogenic amino acid triplets expressed on the foreign graft. In addition, we sought to evaluate the effect of these antibodies as well as other posttransplant HLAabI on graft outcome. Posttransplant sera from 264 renal recipients were tested for the presence of IgG HLAabI and HLA class II-specific alloantibodies (HLAabII) by ELISA. The HLAMatchmaker computer algorithm was used to define the HLA class I non-donor-specific antibodies, which seem to recognize immunogenic amino acid triplets. Donor-specific triplet antibodies (DSTRab) were detected in 16 of 22 (72.7%) recipients based on at least one HLA-A or -B mismatched antigen with the donor. DSTRab were found either without (n = 7) or with (n = 9) HLA donor-specific antibodies (HLA-DSA). The presence of DSTRab alone in the periphery was associated with acute rejection, whereas the presence of both DSTRab and HLA-DSA was associated with chronic rejection and graft failure.

  8. Dichorionic triamniotic triplet pregnancy complicated by twin anemia polycythemia sequence: the place of fetal therapy.

    Science.gov (United States)

    Griersmith, Thérèse H; Fung, Alison M; Walker, Susan P

    2014-12-01

    Monochorionic twins as part of a high order multiple pregnancy can be an unintended consequence of the increasingly common practice of blastocyst transfer for couples requiring in vitro fertilisation (IVF) for infertility. Dichorionic triamniotic (DCTA) triplets is the most common presentation, and these pregnancies are particularly high risk because of the additional risks associated with monochorionicity. Surveillance for twin-to-twin transfusion syndrome, including twin anemia polycythemia sequence, may be more difficult, and any intervention to treat the monochorionic pair needs to balance the proposed benefits against the risks posed to the unaffected singleton. Counseling of families with DCTA triplets is therefore complex. Here, we report a case of DCTA triplets, where the pregnancy was complicated by threatened preterm labour, and twin anemia polycythemia sequence (TAPS) was later diagnosed at 28 weeks. The TAPS was managed with a single intraperitoneal transfusion, enabling safe prolongation of the pregnancy for over 2 weeks until recurrence of TAPS and preterm labour supervened. Postnatal TAPS was confirmed, and all three infants were later discharged home at term corrected age, and were normal at follow-up. This case highlights that in utero therapy has an important role in multiple pregnancies of mixed chorionicity, and can achieve safe prolongation of pregnancy at critical gestations.

  9. Time-resolved spectroscopic studies of sulphonated aluminium phthalocyanine triplet states

    Science.gov (United States)

    Simpson, Mary S. C.; Beeby, A.; Bishop, Steven M.; MacRobert, Alexander J.; Parker, Andrew W.; Phillips, David

    1992-04-01

    The photophysical and photochemical properties of sulphonated aluminum and zinc phthalocyanines have been investigated in a range of solvents and model biological systems. Anomalous effects are observed upon deuteration of the solvent and addition of fluoride ions. In D2O the excited singlet and triplet state lifetimes and quantum yields of fluorescence and triplet state formation are increased relative to H2O. No solvent isotope effect is observed between CH3OH and CH3OD. It is proposed that relaxation of the excited state involves a tunnelling type interaction in which the phthalocyanine's highly energetic metal-axial ligand stretching vibrations are coupled to the HO-H or DO-D stretching vibrations. A significant increase in triplet lifetimes of phthalocyanine sensitizers bound to protein substrates is observed which is a function of the degree of sulphonation. The implications of these results to the determination of the quantum yields of singlet oxygen formation in D2O and lipophilic environments are discussed.

  10. Analysis of Triplet Exciton Loss Pathways in PTB7:PC71BM Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Kraus, Hannes; Heiber, Michael C.; Väth, Stefan; Kern, Julia; Deibel, Carsten; Sperlich, Andreas; Dyakonov, Vladimir

    2016-07-01

    A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway.

  11. Genome-Wide Demethylation Promotes Triplet Repeat Instability Independently of Homologous Recombination

    Science.gov (United States)

    Dion, Vincent; Lin, Yunfu; Price, Brandee A.; Fyffe, Sharyl L.; Seluanov, Andrei; Gorbunova, Vera; Wilson, John H.

    2008-01-01

    Trinucleotide repeat instability is intrinsic to a family of human neurodegenerative diseases. The mechanism leading to repeat length variation is unclear. We previously showed that treatment with the demethylating agent 5-aza-2′-deoxycytidine (5-aza-CdR) dramatically increases triplet repeat instability in mammalian cells. Based on previous reports that demethylation increases homologous recombination (HR), and our own observations that HR destabilizes triplet repeats, we hypothesized that demethylation alters repeat stability by stimulating HR. Here, we test that hypothesis at the Aprt (adenosine phosphoribosyl transferase) locus in CHO cells, where CpG demethylation and HR have both been shown to increase CAG repeat instability. We find that the rate of HR at the Aprt locus is not altered by demethylation. The spectrum of recombinants, however, was shifted from the usual 6:1 ratio of conversions to crossovers to more equal proportions in 5-aza-CdR-treated cells. The subtle influences of demethylation on HR at the Aprt locus are not sufficient to account for its dramatic effects on repeat instability. We conclude that 5-aza-CdR promotes triplet repeat instability independently of HR. PMID:18083071

  12. Experimental evidences of singlet to triplet transition in a spin cluster compound

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Tanmoy [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India); Experimental Physics III, Fakultät Physik, TU Dortmund, 44221 Dortmund (Germany); Singh, Harkirat [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India); Department of Condensed Matter Physics and Material Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Mitra, Chiranjib, E-mail: chiranjib@iiserkol.ac.in [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India)

    2015-12-15

    Experimental realization of magnetic field induced singlet to triplet transition is reported for NH{sub 4}CuPO{sub 4}·H{sub 2}O, a two spin cluster material with isotropic Heisenberg interaction. Experimental magnetization and specific heat data have been collected as a function of temperature and magnetic field. Experimental data have been analyzed in terms of Heisenberg dimer model. Two quantum complementary observables representing local and non-local properties of the spins are constructed using the experimental data and a clear evidence of singlet to triplet transition is observed through partial quantum information sharing when the magnetic field is swept through a particular value. Signature of this transition has also been captured when specific heat is measured as a function of magnetic field. Furthermore, using the experimental specific heat data, magnetic energy values are calculated and their variations are captured as a function of magnetic field and temperature. - Highlights: • Magnetic field induced energy level crossing is reported for NH{sub 4}CuPO{sub 4}·H{sub 2}O. • Magnetic data are analyzed within the framework of spin 1/2 dimer model. • Singlet-triplet transition is captured employing quantum complementarity principle. • Field dependent specific heat data also provides the signature of the transition.

  13. Charge transfer and triplet states in OPV materials and devices (Presentation Recording)

    Science.gov (United States)

    Dyakonov, Vladimir

    2015-10-01

    Electron back transfer (EBT), potentially occurring after electron transfer from donor to acceptor may populate the lower lying donor or acceptor triplet state and serve as recombination channel.[1] Here we report on studies of charge transfer and triplet states in blends of highly efficient benzodithiophene PTB7 polymer in combination with the fullerene-derivative PC71BM using the spin sensitive optically detected magnetic resonance (ODMR) technique and compare the results with those obtained in P3HT (poly(3- hexylthiophene):PC61BM blends. Although PTB7:PC71BM absorbers yield much higher power conversion efficiencies in solar cells exceeding 7%, we found a significant increase of triplet exciton generation, which was absent in the P3HT based blends. We discuss this observation within the EBT scenario with the emphasis on the influence of morphology, fullerene load, HOMO/LUMO energy and presence of additives (DIO). Suppressing the EBT process by morphology and/or energetics of polymer and molecules is important to achieve the full potential of highly efficient OPV materials. [1] M. Liedtke, et al., JACS 133, 9088 (2011).

  14. Triplet state dissolved organic matter in aquatic photochemistry: reaction mechanisms, substrate scope, and photophysical properties.

    Science.gov (United States)

    McNeill, Kristopher; Canonica, Silvio

    2016-11-09

    Excited triplet states of chromophoric dissolved organic matter ((3)CDOM*) play a major role among the reactive intermediates produced upon absorption of sunlight by surface waters. After more than two decades of research on the aquatic photochemistry of (3)CDOM*, the need for improving the knowledge about the photophysical and photochemical properties of these elusive reactive species remains considerable. This critical review examines the efforts to date to characterize (3)CDOM*. Information on (3)CDOM* relies mainly on the use of probe compounds because of the difficulties associated with directly observing (3)CDOM* using transient spectroscopic methods. Singlet molecular oxygen ((1)O2), which is a product of the reaction between (3)CDOM* and dissolved oxygen, is probably the simplest indicator that can be used to estimate steady-state concentrations of (3)CDOM*. There are two major modes of reaction of (3)CDOM* with substrates, namely triplet energy transfer or oxidation (via electron transfer, proton-coupled electron transfer or related mechanisms). Organic molecules, including several environmental contaminants, that are susceptible to degradation by these two different reaction modes are reviewed. It is proposed that through the use of appropriate sets of probe compounds and model photosensitizers an improved estimation of the distribution of triplet energies and one-electron reduction potentials of (3)CDOM* can be achieved.

  15. The protein's role in triplet energy transfer in bacterial reaction centers.

    Energy Technology Data Exchange (ETDEWEB)

    Laible, P. D.

    1998-08-14

    When photosynthetic organisms are subjected to high-light conditions in nature, electron transfer becomes blocked as the rate of conversion of light into charge-separated states in the reaction center (RC) exceeds the capacity of the soluble carriers involved in cyclic electron transfer. In that event, a well-characterized T{sub 0}-polarized triplet state {sup T}P, is formed on the primary donor, P, from the P{sup +}H{sub A}{sup {minus}} state (reviewed in [1]). In an aerobic or semi-aerobic environment, the major role of the carotenoid (C), also bound by the RC, is to quench {sup T}P prior to its sensitization of the {sup 1}{Delta}{sub g} singlet state of oxygen--a potentially damaging biological oxidant. The carotenoid performs this function efficiently in most bacterial RCs by rapidly accepting the triplet state from P and dissipating this excited-state energy into heat through internal conversion. The lowest-lying triplet states of P and the carotenoid are sufficiently different that {sup T}P can promote oxygen to its excited singlet state whereas {sup T}C can quench the {sup T}P state (reviewed in [2]).

  16. Helical Self-Assembly-Induced Singlet-Triplet Emissive Switching in a Mechanically Sensitive System.

    Science.gov (United States)

    Wu, Hongwei; Zhou, Yunyun; Yin, Liyuan; Hang, Cheng; Li, Xin; Ågren, Hans; Yi, Tao; Zhang, Qing; Zhu, Liangliang

    2017-01-18

    In nanoscience, chirality has shown a significant ability to tune materials' electronic properties, whereas imposing macrochirality into the regulation of singlet-triplet features of organic optoelectronics remains a challenging research topic. Since the tuning for singlet and triplet excited-state properties in a single π-functional molecule connects to its multicolor luminescent application and potential improvement of internal quantum efficiency, we here report that supramolecular chirality can be employed to toggle the singlet and triplet emissions in a well-designed asterisk-shaped molecule. Employing a hexathiobenzene-based single luminophore as a prototype and functionalizing it with chiral α-lipoiate side groups, we find that helical nanoarchitectures can accordingly form in mixed DMF/H2O solution. On this basis, switching between fluorescence and phosphorescence of the material can be realized upon helical self-assembly and dissociation. Such a behavior can be attributed to a helical-conformation-dependent manipulation of the intersystem crossing. Furthermore, reversible mechanoluminescence of the corresponding solid sample was also observed to rely on an analogous molecular self-assembly alternation. These results can probably provide new visions for the development of next-generation supramolecular chiral functional materials.

  17. Magnetic dipolar interaction between correlated triplets created by singlet fission in tetracene crystals

    CERN Document Server

    Wang, Rui; Zhang, Bo; Liu, Yunlong; Wang, Xiaoyong; Xiao, Min

    2015-01-01

    Singlet fission (SF) can potentially break the Shockley-Queisser efficiency limit in single-junction solar cells by splitting one photo-excited singlet exciton (S1) into two triplets (2T1) in organic semiconductors. A dark multi-exciton (ME) state has been proposed as the intermediate connecting S1 to 2T1. However, the exact nature of this ME state, especially how the doubly-excited triplets interact, remains elusive. Here, we report a quantitative study on the magnetic dipolar interaction between SF-induced correlated triplets in tetracene crystals by monitoring quantum beats relevant to the ME sublevels at room temperature. The resonances of ME sublevels approached by tuning an external magnetic field are observed to be avoided, which agrees well with the theoretical predictions considering a magnetic dipolar interaction of ~ 0.008 GHz. Our work paves a way to quantify the magnetic dipolar interaction in organic materials and marks an important step towards understanding the underlying physics of the ME sta...

  18. Quantum dynamics study of singlet-triplet transitions in s-trans-1,3-butadiene

    Science.gov (United States)

    Nikoobakht, Behnam; Köppel, Horst

    2016-05-01

    The intersystem crossing dynamics of s-trans-1,3-butadiene in its lowest singlet and triplet states is studied theoretically, employing a fully quantal approach for the first time. The electronic states 21Ag, 11Bu, 13Bu and 13Ag, which interact vibronically and via the spin-orbit coupling are treated in the calculation, thus covering the lowest spin-forbidden electronic transitions. Up to five nuclear degrees of freedom, including out-of-plane dihedral angles are included in our investigation. The calculation of potential energy surfaces relies on the CASPT2 method, and the evaluation of spin-orbit coupling matrix elements using the full two-electron Breit-Pauli Hamiltonian is performed by utilizing the MRCI wavefunction. The latter dependence on the nuclear coordinates is included for the first time. An electronic population transfer on the sub-picosecond time scale due to intersystem crossing is obtained, a mechanism that can contribute to the singlet-triplet transitions in the electron energy loss spectrum of s-trans-1, 3-butadiene. It is found that the dependence of the spin-orbit coupling on the out-of-plane coordinates plays a dominant role in these singlet-triplet transitions. The amount of population transfer to the 13Ag and 13Bu states is roughly of the same order of magnitude.

  19. Fluorescence via Reverse Intersystem Crossing from Higher Triplet States in a Bisanthracene Derivative

    CERN Document Server

    Sato, Tohru; Haruta, Naoki; Pu, Yong-Jin

    2016-01-01

    To elucidate the high external quantum efficiency observed for organic light-emitting diodes using a bisanthracene derivative, BD1, as the emitting molecule, off-diagonal vibronic coupling constants (VCCs) between the excited states of BD1, which govern non-radiative transition rates, were calculated employing time-dependent density functional theory. The VCCs were analysed based on the concept of vibronic coupling density. The VCC calculations suggest a fluorescence via higher triplets (FvHT) mechanism, which entails the conversion of a T$_4$ exciton generated during electrical excitation into an S$_2$ exciton via reverse intersystem crossing (RISC); moreover, the S$_2$ exciton relaxes to a fluorescent S$_1$ exciton because of large vibronic coupling between S$_2$ and S$_1$. This mechanism is valid as long as the relaxation of triplet states higher than T$_1$ to lower states is suppressed. The symmetry-controlled thermally activated delayed fluorescence (SC-TADF) and inverted singlet and triplet (iST) struct...

  20. Phenomenology of a Higgs triplet model at future $e^{+}e^{-}$ colliders

    CERN Document Server

    Blunier, Sylvain; Díaz, Marco Aurelio; Koch, Benjamin

    2016-01-01

    In this work, we investigate the prospects of future $e^{+}e^{-}$ colliders in testing a Higgs triplet model with a scalar triplet and a scalar singlet under $SU(2)$. The parameters of the model are fixed so that the lightest $CP-$even state corresponds to the Higgs particle observed at the LHC at around $125$ GeV. This study investigates if the second heaviest $CP-$even, the heaviest $CP-$odd and the singly charged states can be observed at existing and future colliders by computing their accessible production and decay channels. In particular, the LHC is not well equipped to produce a Higgs boson which is not mainly doublet-like, so we turn our focus to lepton colliders. We find distinctive features of this model in cases when the second heaviest $CP-$even Higgs is triplet-like, singlet-like or a mixture. These features could distinguish the model from other scenarios at future $e^{+}e^{-}$ colliders.

  1. Lamb shift in radical-ion pairs produces a singlet-triplet energy splitting in photosynthetic reaction centers

    OpenAIRE

    Vitalis, K. M.; Kominis, I. K.

    2013-01-01

    Radical-ion pairs, fundamental for understanding photosynthesis and the avian magnetic compass, were recently shown to be biological open quantum systems. We here show that the coupling of the radical-pair's spin degrees of freedom to its decohering vibrational reservoir leads to a shift of the radical-pair's magnetic energy levels. The Lamb shift Hamiltonian is diagonal in the singlet-triplet basis, and results in a singlet-triplet energy splitting physically indistinguishable from an exchan...

  2. Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10: I. Stellar populations and emission line analysis

    CERN Document Server

    Costa-Duarte, M V; Duplancic, F; Sodré, L; Lambas, D G

    2016-01-01

    We identify isolated galaxy triplets in a volume-limited sample from the Sloan Digital Sky Survey Data Release 10. Our final sample has 80 galaxy systems in the redshift range 0.04$\\le$z$\\le$0.1, brighter than $M_r = -20.5 + 5\\log h_{70}$. Spectral synthesis results and WHAN and BPT diagnostic diagrams were employed to classify the galaxies in these systems as star-forming, active nuclei, or passive/retired. Our results suggest that the brightest galaxies drive the triplet evolution, as evidenced by the strong correlations between properties as mass assembly and mean stellar population age with triplet properties. Galaxies with intermediate luminosity or the faintest one within the triplet seem to play a secondary role. Moreover, the relation between age and stellar mass of galaxies is similar for these galaxies but different for the brightest galaxy in the system. Most of the triplet galaxies are passive or retired, according to the WHAN classification. Low mass triplets present different fractions of WHAN c...

  3. EPR characterisation of the triplet state in photosystem II reaction centers with singly reduced primary acceptor Q(A).

    Science.gov (United States)

    Feikema, W Onno; Gast, Peter; Klenina, Irina B; Proskuryakov, Ivan I

    2005-09-05

    The triplet states of photosystem II core particles from spinach were studied using time-resolved cw EPR technique at different reduction states of the iron--quinone complex of the reaction center primary electron acceptor. With doubly reduced primary acceptor, the well-known photosystem II triplet state characterised by zero-field splitting parameters |D|=0.0286 cm(-1), |E|=0.0044 cm(-1) was detected. When the primary acceptor was singly reduced either chemically or photochemically, a triplet state of a different spectral shape was observed, bearing the same D and E values and characteristic spin polarization pattern arising from RC radical pair recombination. The latter triplet state was strongly temperature dependent disappearing at T=100 K, and had a much faster decay than the former one. Based on its properties, this triplet state was also ascribed to the photosystem II reaction center. A sequence of electron-transfer events in the reaction centers is proposed that explains the dependence of the triplet state properties on the reduction state of the iron--quinone primary acceptor complex.

  4. Photo-assisted intersystem crossing: The predominant triplet formation mechanism in some isolated polycyclic aromatic molecules excited with pulsed lasers

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Philip M., E-mail: Philip.johnson@stonybrook.edu [Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400 (United States); Sears, Trevor J. [Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400 (United States); Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2015-07-28

    Naphthalene, anthracene, and phenanthrene are shown to have very long-lived triplet lifetimes when the isolated molecules are excited with nanosecond pulsed lasers resonant with the lowest singlet state. For naphthalene, triplet state populations are created only during the laser pulse, excluding the possibility of normal intersystem crossing at the one photon level, and all molecules have triplet lifetimes greater than hundreds of microseconds, similar to the behavior previously reported for phenylacetylene. Although containing 7–12 thousand cm{sup −1} of vibrational energy, the triplet molecules have ionization thresholds appropriate to vibrationless T{sub 1} states. The laser power dependences (slopes of log-log power plots) of the excited singlet and triplet populations are about 0.7 for naphthalene and about 0.5 for anthracene. Kinetic modeling of the power dependences successfully reproduces the experimental results and suggests that the triplet formation mechanism involves an enhanced spin orbit coupling caused by sigma character in states at the 2-photon level. Symmetry adapted cluster-configuration interaction calculations produced excited state absorption spectra to provide guidance for estimating kinetic rates and the sigma character present in higher electronic states. It is concluded that higher excited state populations are significant when larger molecules are excited with pulsed lasers and need to be taken into account whenever discussing the molecular photodynamics.

  5. Spin-state dependent radical stabilization in nitrenes: the unusually small singlet-triplet splitting in 2-furanylnitrene.

    Science.gov (United States)

    Wenthold, Paul G

    2012-01-06

    Geometries and energies of the triplet and singlet states of 2-furanylnitrene and 3-furanylnitrene have been calculated by using spin-flip coupled-cluster methods. Calculations with triple-ζ basis sets predict a singlet-triplet splitting of 10.9 kcal/mol for 2-furanylnitrene, 4.5 kcal/mol smaller than that in phenylnitrene. In contrast, the singlet-triplet splitting in 3-furanylnitrene is computed to be 1.9 kcal/mol larger than that in phenylnitrene. The differences in the singlet-triplet splittings for the furanylnitrenes are attributed to the differences in the radical stabilizing abilities of the 2-furanyl- and 3-furanyl-groups compared to a phenyl ring. Comparison of the singlet-triplet splittings of more than 20 substituted aromatic nitrenes and the radical stabilizing ability of the aromatic systems reveals a high degree of correlation between the singlet-triplet splitting and the radical stabilizing ability, indicating that singlet states of aromatic nitrenes are preferentially stabilized by radical stabilizing substituents. The preferential stabilization of the singlet states is attributed to the decrease in electron pair repulsion resulting from increased delocalization of the radical electron.

  6. Prediction of plant promoters based on hexamers and random triplet pair analysis

    Directory of Open Access Journals (Sweden)

    Noman Nasimul

    2011-06-01

    Full Text Available Abstract Background With an increasing number of plant genome sequences, it has become important to develop a robust computational method for detecting plant promoters. Although a wide variety of programs are currently available, prediction accuracy of these still requires further improvement. The limitations of these methods can be addressed by selecting appropriate features for distinguishing promoters and non-promoters. Methods In this study, we proposed two feature selection approaches based on hexamer sequences: the Frequency Distribution Analyzed Feature Selection Algorithm (FDAFSA and the Random Triplet Pair Feature Selecting Genetic Algorithm (RTPFSGA. In FDAFSA, adjacent triplet-pairs (hexamer sequences were selected based on the difference in the frequency of hexamers between promoters and non-promoters. In RTPFSGA, random triplet-pairs (RTPs were selected by exploiting a genetic algorithm that distinguishes frequencies of non-adjacent triplet pairs between promoters and non-promoters. Then, a support vector machine (SVM, a nonlinear machine-learning algorithm, was used to classify promoters and non-promoters by combining these two feature selection approaches. We referred to this novel algorithm as PromoBot. Results Promoter sequences were collected from the PlantProm database. Non-promoter sequences were collected from plant mRNA, rRNA, and tRNA of PlantGDB and plant miRNA of miRBase. Then, in order to validate the proposed algorithm, we applied a 5-fold cross validation test. Training data sets were used to select features based on FDAFSA and RTPFSGA, and these features were used to train the SVM. We achieved 89% sensitivity and 86% specificity. Conclusions We compared our PromoBot algorithm to five other algorithms. It was found that the sensitivity and specificity of PromoBot performed well (or even better with the algorithms tested. These results show that the two proposed feature selection methods based on hexamer frequencies

  7. Charge Carrier Generation Followed by Triplet State Formation, Annihilation, and Carrier Recreation in PBDTTT-C:PC 60 BM Photovoltaic Blends

    KAUST Repository

    Gehrig, Dominik W.

    2015-05-22

    Triplet state formation after photoexcitation of low-bandgap polymer:fullerene blends has recently been demonstrated, however, the precise mechanism and its impact on solar cell performance is still under debate. Here, we study exciton dissociation, charge carrier generation and triplet state formation in low-bandgap polymer PBDTTT-C:PC60BM bulk heterojunction photovoltaic blends by a combination of fs-µs broadband Vis-NIR transient absorption (TA) pump-probe spectroscopy and multivariate curve resolution (MCR) data analysis. We found sub-ps exciton dissociation and charge generation followed by sub-ns triplet state creation. The carrier dynamics and triplet state dynamics exhibited a very pronounced intensity dependence indicating non-geminate recombination of free carriers is the origin of triplet formation in these blends. Triplets were found to be the dominant state present on the nanosecond timescale. Surprisingly, the carrier population increased again on the ns-µs timescale. We attribute this to triplet-triplet annihilation and the formation of higher energy excited states that subsequently underwent charge transfer. This unique dip and recovery of the charge population is a clear indication that triplets are formed by non-geminate recombination, as such a kinetic is incompatible with a monomolecular triplet state formation process.

  8. Sequential Analysis in High Dimensional Multiple Testing and Sparse Recovery

    OpenAIRE

    Malloy, Matthew; Nowak, Robert

    2011-01-01

    This paper studies the problem of high-dimensional multiple testing and sparse recovery from the perspective of sequential analysis. In this setting, the probability of error is a function of the dimension of the problem. A simple sequential testing procedure is proposed. We derive necessary conditions for reliable recovery in the non-sequential setting and contrast them with sufficient conditions for reliable recovery using the proposed sequential testing procedure. Applications of the main ...

  9. Sequential motif profile of natural visibility graphs

    CERN Document Server

    Iacovacci, Jacopo

    2016-01-01

    The concept of sequential visibility graph motifs -subgraphs appearing with characteristic frequencies in the visibility graphs associated to time series- has been advanced recently along with a theoretical framework to compute analytically the motif profiles associated to Horizontal Visibility Graphs (HVGs). Here we develop a theory to compute the profile of sequential visibility graph motifs in the context of Natural Visibility Graphs (VGs). This theory gives exact results for deterministic aperiodic processes with a smooth invariant density or stochastic processes that fulfil the Markov property and have a continuous marginal distribution. The framework also allows for a linear time numerical estimation in the case of empirical time series. A comparison between the HVG and the VG case (including evaluation of their robustness for short series polluted with measurement noise) is also presented.

  10. SMCTC: Sequential Monte Carlo in C++

    Directory of Open Access Journals (Sweden)

    Adam M. Johansen

    2009-04-01

    Full Text Available Sequential Monte Carlo methods are a very general class of Monte Carlo methodsfor sampling from sequences of distributions. Simple examples of these algorithms areused very widely in the tracking and signal processing literature. Recent developmentsillustrate that these techniques have much more general applicability, and can be appliedvery eectively to statistical inference problems. Unfortunately, these methods are oftenperceived as being computationally expensive and dicult to implement. This articleseeks to address both of these problems.A C++ template class library for the ecient and convenient implementation of verygeneral Sequential Monte Carlo algorithms is presented. Two example applications areprovided: a simple particle lter for illustrative purposes and a state-of-the-art algorithmfor rare event estimation.

  11. Quantitative perceived depth from sequential monocular decamouflage.

    Science.gov (United States)

    Brooks, K R; Gillam, B J

    2006-03-01

    We present a novel binocular stimulus without conventional disparity cues whose presence and depth are revealed by sequential monocular stimulation (delay > or = 80 ms). Vertical white lines were occluded as they passed behind an otherwise camouflaged black rectangular target. The location (and instant) of the occlusion event, decamouflaging the target's edges, differed in the two eyes. Probe settings to match the depth of the black rectangular target showed a monotonic increase with simulated depth. Control tests discounted the possibility of subjects integrating retinal disparities over an extended temporal window or using temporal disparity. Sequential monocular decamouflage was found to be as precise and accurate as conventional simultaneous stereopsis with equivalent depths and exposure durations.

  12. Sequential shrink photolithography for plastic microlens arrays.

    Science.gov (United States)

    Dyer, David; Shreim, Samir; Jayadev, Shreshta; Lew, Valerie; Botvinick, Elliot; Khine, Michelle

    2011-07-18

    Endeavoring to push the boundaries of microfabrication with shrinkable polymers, we have developed a sequential shrink photolithography process. We demonstrate the utility of this approach by rapidly fabricating plastic microlens arrays. First, we create a mask out of the children's toy Shrinky Dinks by simply printing dots using a standard desktop printer. Upon retraction of this pre-stressed thermoplastic sheet, the dots shrink to a fraction of their original size, which we then lithographically transfer onto photoresist-coated commodity shrink wrap film. This shrink film reduces in area by 95% when briefly heated, creating smooth convex photoresist bumps down to 30 µm. Taken together, this sequential shrink process provides a complete process to create microlenses, with an almost 99% reduction in area from the original pattern size. Finally, with a lithography molding step, we emboss these bumps into optical grade plastics such as cyclic olefin copolymer for functional microlens arrays.

  13. Sequential pivotal mechanisms for public project problems

    CERN Document Server

    Apt, Krzysztof R

    2008-01-01

    It is well-known that for several natural decision problems no budget balanced Groves mechanisms exist. This motivated recent research on designing variants of feasible Groves mechanisms (termed as `redistribution of VCG (Vickrey-Clarke-Groves) payments') that generate reduced deficit. With this in mind, we study sequential Groves mechanisms and consider optimal strategies that can lower the taxes that the players would have to pay under the simultaneous mechanism. We show that in the sequential pivotal mechanism for several variants of public project problems such strategies do exist. These strategies differ from truth-telling. In particular we exhibit an optimal strategy with the property that when each player follows it a maximal social welfare is generated.

  14. A minimax procedure in the context of sequential mastery testing

    NARCIS (Netherlands)

    Vos, Hendrik J.

    1999-01-01

    The purpose of this paper is to derive optimal rules for sequential mastery tests. In a sequential mastery test, the decision is to classify a subject as a master or a nonmaster, or to continue sampling and administering another random test item. The framework of minimax sequential decision theory (

  15. Lung Volume Measured during Sequential Swallowing in Healthy Young Adults

    Science.gov (United States)

    Hegland, Karen Wheeler; Huber, Jessica E.; Pitts, Teresa; Davenport, Paul W.; Sapienza, Christine M.

    2011-01-01

    Purpose: Outcomes from studying the coordinative relationship between respiratory and swallow subsystems are inconsistent for sequential swallows, and the lung volume at the initiation of sequential swallowing remains undefined. The first goal of this study was to quantify the lung volume at initiation of sequential swallowing ingestion cycles and…

  16. A NEW INEXACT SEQUENTIAL QUADRATIC PROGRAMMING ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    倪勤

    2002-01-01

    This paper represents an inexact sequential quadratic programming (SQP ) algorithm which can solve nonlinear programming (NLP ) problems. An inexact solution of the quadratic programming subproblem is determined by a projection and contraction method such that only matrix-vector product is required. Some truncated criteria are chosen such that the algorithm is suitable to large scale NLP problem. The global convergence of the algorithm is proved.

  17. Sequential decision analysis for nonstationary stochastic processes

    Science.gov (United States)

    Schaefer, B.

    1974-01-01

    A formulation of the problem of making decisions concerning the state of nonstationary stochastic processes is given. An optimal decision rule, for the case in which the stochastic process is independent of the decisions made, is derived. It is shown that this rule is a generalization of the Bayesian likelihood ratio test; and an analog to Wald's sequential likelihood ratio test is given, in which the optimal thresholds may vary with time.

  18. Compressive Sequential Learning for Action Similarity Labeling.

    Science.gov (United States)

    Qin, Jie; Liu, Li; Zhang, Zhaoxiang; Wang, Yunhong; Shao, Ling

    2016-02-01

    Human action recognition in videos has been extensively studied in recent years due to its wide range of applications. Instead of classifying video sequences into a number of action categories, in this paper, we focus on a particular problem of action similarity labeling (ASLAN), which aims at verifying whether a pair of videos contain the same type of action or not. To address this challenge, a novel approach called compressive sequential learning (CSL) is proposed by leveraging the compressive sensing theory and sequential learning. We first project data points to a low-dimensional space by effectively exploring an important property in compressive sensing: the restricted isometry property. In particular, a very sparse measurement matrix is adopted to reduce the dimensionality efficiently. We then learn an ensemble classifier for measuring similarities between pairwise videos by iteratively minimizing its empirical risk with the AdaBoost strategy on the training set. Unlike conventional AdaBoost, the weak learner for each iteration is not explicitly defined and its parameters are learned through greedy optimization. Furthermore, an alternative of CSL named compressive sequential encoding is developed as an encoding technique and followed by a linear classifier to address the similarity-labeling problem. Our method has been systematically evaluated on four action data sets: ASLAN, KTH, HMDB51, and Hollywood2, and the results show the effectiveness and superiority of our method for ASLAN.

  19. Ultrafast Charge and Triplet State Formation in Diketopyrrolopyrrole Low Band Gap Polymer/Fullerene Blends: Influence of Nanoscale Morphology of Organic Photovoltaic Materials on Charge Recombination to the Triplet State

    Directory of Open Access Journals (Sweden)

    René M. Williams

    2017-01-01

    Full Text Available Femtosecond transient absorption spectroscopy of thin films of two types of morphologies of diketopyrrolopyrrole low band gap polymer/fullerene-adduct blends is presented and indicates triplet state formation by charge recombination, an important loss channel in organic photovoltaic materials. At low laser fluence (approaching solar intensity charge formation characterized by a 1350 nm band (in ~250 fs dominates in the two PDPP-PCBM blends with different nanoscale morphologies and these charges recombine to form a local polymer-based triplet state on the sub-ns timescale (in ~300 and ~900 ps indicated by an 1100 nm absorption band. The rate of triplet state formation is influenced by the morphology. The slower rate of charge recombination to the triplet state (in ~900 ps belongs to a morphology that results in a higher power conversion efficiency in the corresponding device. Nanoscale morphology not only influences interfacial area and conduction of holes and electrons but also influences the mechanism of intersystem crossing (ISC. We present a model that correlates morphology to the exchange integral and fast and slow mechanisms for ISC (SOCT-ISC and H-HFI-ISC. For the pristine polymer, a flat and unstructured singlet-singlet absorption spectrum (between 900 and 1400 nm and a very minor triplet state formation (5% are observed at low laser fluence.

  20. Sequential monitoring of response-adaptive randomized clinical trials

    CERN Document Server

    Zhu, Hongjian; 10.1214/10-AOS796

    2010-01-01

    Clinical trials are complex and usually involve multiple objectives such as controlling type I error rate, increasing power to detect treatment difference, assigning more patients to better treatment, and more. In literature, both response-adaptive randomization (RAR) procedures (by changing randomization procedure sequentially) and sequential monitoring (by changing analysis procedure sequentially) have been proposed to achieve these objectives to some degree. In this paper, we propose to sequentially monitor response-adaptive randomized clinical trial and study it's properties. We prove that the sequential test statistics of the new procedure converge to a Brownian motion in distribution. Further, we show that the sequential test statistics asymptotically satisfy the canonical joint distribution defined in Jennison and Turnbull (\\citeyearJT00). Therefore, type I error and other objectives can be achieved theoretically by selecting appropriate boundaries. These results open a door to sequentially monitor res...

  1. Sequential nonlinear tracking filter without requirement of measurement decorrelation

    Institute of Scientific and Technical Information of China (English)

    Taifan Quan

    2015-01-01

    Sequential measurement processing is of benefit to both estimation accuracy and computational efficiency. When the noises are correlated across the measurement components, decorrelation based on covariance matrix factorization is required in the previous methods in order to perform sequential updates properly. A new sequential processing method, which carries out the sequential updates directly using the correlated measurement components, is proposed. And a typical sequential processing example is investigated, where the converted position measure-ments are used to estimate target states by standard Kalman filtering equations and the converted Doppler measurements are then incorporated into a minimum mean squared error (MMSE) estimator with the updated cross-covariance involved to account for the correlated errors. Numerical simulations demonstrate the superiority of the proposed new sequential processing in terms of better accuracy and consistency than the conventional sequential filter based on measurement decorrelation.

  2. Detection of large expansions in myotonic dystrophy type 1 using triplet primed PCR

    Directory of Open Access Journals (Sweden)

    Susmita eSingh

    2014-04-01

    Full Text Available Myotonic dystrophy type 1 (DM1 is an autosomal dominant neuromuscular disease caused by expansion of a CTG trinucleotide repeat in the DMPK gene. Methodology for genetic testing of DM1 is currently not optimal, in particular for the early-onset patients in pediatric populations where large expanded (CTGn alleles are usually common. Individuals who are homozygous for a normal allele and individuals who are heterozygous for one normal and one large expanded allele are indistinguishable by conventional PCR, as both generate a single product of the normal allele. Thus, reflex Southern blot has often been needed to distinguish these cases. With the aim to decrease the need for reflex Southern blot tests, a novel, single-tube CTG repeat primed PCR technology was designed to distinguish the true homozygous patients from the individuals whose large alleles are missed by conventional PCR. The method utilizes two gene-specific primers that flank the triplet repeat region and a third primer set complementary to the repeated region to detect the large alleles. Compared to traditional PCR, this novel Triplet-repeat Primed PCR can detect the presence of large expanded alleles with demonstrating a ladder pattern. Using this single-step protocol, 45 specimens were tested. The alleles with sizes ≤ 85 repeats were determined by the gene specific primers. 13 abnormal alleles, which missed by the conventional PCR, were successfully detected by the Triplet-repeat Primed PCR. All the abnormal alleles were confirmed and measured by Southern Blot analysis. In summary, optimized TP-PCR can accurately detect the presence of the large expanded alleles. With the ability to distinguish the true homozygous patients from the false negative homozygous individuals, the application of the optimized TP-PCR can significantly reduce the need of Southern Blot tests.

  3. Experimental comparative study of doublet and triplet impinging atomization of gelled fuel based on PIV

    Science.gov (United States)

    Yang, Jian-lu; Li, Ning; Weng, Chun-sheng

    2016-10-01

    Gelled propellant is promising for future aerospace application because of its combination of the advantages of solid propellants and liquid propellants. An effort was made to reveal the atomization properties of gelled fuel by particle image velocimetry (PIV) system. The gelled fuel which was formed by gasoline and Nano-silica was atomized using a like-doublet impingement injector and an axisymmetric like-triplet impingement injector. The orifice diameter and length of the nozzle used in this work were of 0.8mm, 4.8mm, respectively. In the impinging spray process, the impingement angles were set at 90° and 120°, and the injection pressures were of 0.50MPa and 1.00MPa. The distance from the exit of the orifice to the impingement point was fixed at 9.6mm. In this study, high-speed visualization and temporal resolution particle image velocimetry techniques were employed to investigate the impingement atomization characteristics. The experimental investigation demonstrated that a long narrow high speed droplets belt formed around the axis of symmetry in the like-doublet impinging atomization area. However, there was no obvious high-speed belt with impingement angle 2θ = 90° and two high-speed belts appeared with impingement angle 2θ = 120° in the like-doublet impingement spray field. The high droplet velocity zone of the like-doublet impingement atomization symmetrically distributed around the central axis, and that of the like-triplet impingement spray deflected to the left of the central axis - opposite of injector. Although the droplets velocity distribution was asymmetry of like-triplet impingement atomization, the injectors were arranged like axisymmetric conical shape, and the cross section of spray area was similar to a circle rather than a narrow rectangle like the like-doublet impingement atomization.

  4. Josephson effect in multiterminal superconductor-ferromagnet junctions coupled via triplet components

    Science.gov (United States)

    Moor, Andreas; Volkov, Anatoly F.; Efetov, Konstantin B.

    2016-03-01

    On the basis of the Usadel equation we study a multiterminal Josephson junction. This junction is composed by "magnetic" superconductors Sm, which have singlet pairing and are separated from the normal n wire by spin filters so that the Josephson coupling is caused only by fully polarized triplet components. We show that there is no interaction between triplet Cooper pairs with antiparallel total spin orientations. The presence of an additional singlet superconductor S attached to the n wire leads to a finite Josephson current IQ with an unusual current-phase relation. The density of states in the n wire for different orientations of spins of Cooper pairs is calculated. We derive a general formula for the current IQ in a multiterminal Josephson contact and apply this formula for analysis of two four-terminal Josephson junctions of different structures. It is shown in particular that both the "nematic" and the "magnetic" cases can be realized in these junctions. In a two-terminal structure with parallel filter orientations and in a three-terminal structure with antiparallel filter orientations of the "magnetic" superconductors with attached additional singlet superconductor, we find a nonmonotonic temperature dependence of the critical current. Also, in these structures, the critical current shows a Riedel peak like dependence on the exchange field in the "magnetic" superconductors. Although there is no current through the S/n interface due to orthogonality of the singlet and triplet components, the phase of the order parameter in the superconuctor S is shown to affect the Josephson current in a multiterminal structure.

  5. Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Lavrov, B P; Umrikhin, I S [Faculty of Physics, St Petersburg State University, St Petersburg 198504 (Russian Federation)], E-mail: lavrov@pobox.spbu.ru

    2008-05-28

    An optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of D{sub 2} has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of analysis (Lavrov and Ryazanov 2005 JETP Lett. 81 371-4), which does not need any a priori assumptions concerning the molecular structure, being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the root-mean-square estimates for uncertainties of the experimental wavenumbers independent from those presented in the original papers. A total of 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para-deuterium was found by least-squares analysis of the a{sup 3}{sigma}{sup +}{sub g}, v = 0, N = 0 to 18 rovibronic levels with odd and even values of N. All the energy levels were obtained relative to the lowest vibro-rotational level (v = 0, N = 0) of the a{sup 3}{sigma}{sup +}{sub g} electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy-level values differ significantly from those available in the literature.

  6. Transition from non-sequential to sequential double ionisation in many-electron systems

    CERN Document Server

    Pullen, Michael G; Wang, Xu; Tong, Xiao-Min; Sclafani, Michele; Baudisch, Matthias; Pires, Hugo; Schröter, Claus Dieter; Ullrich, Joachim; Pfeifer, Thomas; Moshammer, Robert; Eberly, J H; Biegert, Jens

    2016-01-01

    Obtaining a detailed understanding of strong-field double ionisation of many-electron systems (heavy atoms and molecules) remains a challenging task. By comparing experimental and theoretical results in the mid-IR regime, we have unambiguously identified the transition from non-sequential (e,2e) to sequential double ionisation in Xe and shown that it occurs at an intensity below $10^{14}$ Wcm$^{-2}$. In addition, our data demonstrate that ionisation from the Xe 5s orbital is decisive at low intensities. Moreover, using the acetylene molecule, we propose how sequential double ionisation in the mid-IR can be used to study molecular dynamics and fragmentation on unprecedented few-femtosecond timescales.

  7. A Three-loop Neutrino Mass Model with a Colored Triplet Scalar

    CERN Document Server

    Cheung, Kingman; Okada, Hiroshi

    2016-01-01

    We study a variation of the Krauss-Nasri-Trodden (KNT) model with a colored triplet scalar field and a colored singlet scalar field, in which we discuss the anomaly coming from $b\\to s\\mu\\bar\\mu$, fitting to the muon anomalous magnetic moment and the relic density of the Majorana-type dark matter candidate, as well as satisfying various constraints such as lepton-flavor violations and flavor-changing neutral currents. Also, we discuss the direct constraints from the collider searches and the possibilities of detecting the new fields at the LHC.

  8. Finite-bias conductance anomalies at a singlet-triplet crossing

    DEFF Research Database (Denmark)

    Stevanato, Chiara; Leijnse, Martin Christian; Flensberg, Karsten;

    2012-01-01

    Quantum dots and single-molecule transistors may exhibit level crossings induced by tuning external parameters such as magnetic eld or gate voltage. For Coulomb blockaded devices, this shows up as an inelastic cotunneling threshold in the dierential conductance, which can be tuned to zero...... at the crossing. Here we show that, in addition, level crossings can give rise to a nearly vertical step-edge, ridge or even a Fano-like ridge-valley feature in the dierential conductance inside the relevant Coulomb diamond. We study a gate-tunable quasidegeneracy between singlet and triplet ground states...

  9. Quenching behaviour of quadrupole model magnets for the LHC inner triplets at Fermilab

    CERN Document Server

    Andreev, N; Bauer, P; Bossert, R; Brandt, J; Chichili, D R; Carson, J; Di Marco, J; Fehér, S; Glass, H; Kerby, J S; Lamm, M J; Makarov, A A; Nobrega, A; Novitski, I; Ogitsu, T; Orris, D; Ozelis, J P; Rabehl, Roger Jon; Robotham, W; Sabbi, G L; Schlabach, P; Sylvester, C D; Strait, J B; Tartaglia, M; Tompkins, J C; Yadav, S; Zlobin, A V; Caspi, S; McInturff, A D; Scanlan, R M; Ghosh, A

    2000-01-01

    The US-LHC Accelerator Project is responsible for the design and production of inner triplet high gradient quadrupoles for installation in the LHC Interaction Region. The quadrupoles are required to deliver a nominal field gradient of 215 T/m in a 70 mm bore, and operate in superfluid helium. As part of the magnet development program, a series of 2 m model magnets have been built and tested at Fermilab, with each magnet being tested over several thermal cycles. This paper summarizes the quench performance and analysis of the model magnets tested, including quench training, and the ramp rate and temperature of the magnet quench current. (7 refs).

  10. Desempenho comunicativo em trigêmeos prematuros Acquisition and development language in premature triplets

    Directory of Open Access Journals (Sweden)

    Amanda Tragueta Ferreira

    2008-03-01

    Full Text Available OBJETIVO: descrever habilidades do desenvolvimento de trigêmeos aos 18 meses e aos 29 meses de vida, enfocando a comunicação. MÉTODOS: irmãos trigêmeos dizigóticos do sexo masculino. Os procedimentos de avaliação englobaram: Anamnese, Observação do Comportamento Comunicativo e Escala de Desenvolvimento de Gesell e Amatruda (2000. As avaliações foram realizadas aos 18 e aos 29 meses. As crianças apresentaram atraso do desenvolvimento neuropsicomotor e eram expostas a multilingüismo. RESULTADOS: foi verificada alteração nos comportamentos comunicativos nas três crianças, tanto na primeira quanto na segunda avaliação, embora tenha sido observada melhora do desempenho, após as orientações recebidas pela família. Na segunda avaliação foi observada criptofasia. Dos comportamentos motor grosseiro, delicado, adaptativo, pessoal-social e de linguagem, o último foi o mais afetado para as três crianças, apesar de todos estarem alterados considerando a idade cronológica dos trigêmeos. CONCLUSÃO: as habilidades do desenvolvimento dos trigêmeos avaliados neste estudo estavam alteradas, acometendo todas as áreas. Ressalta-se maior comprometimento da linguagem tanto aos 18 como aos 29 meses.PURPOSE: to describe abilities of triplets' development by 18 months and the 29 months of life, focusing on communication. METHODS: dizygotic male sibling triplets. The evaluation procedures included history of disease, observing the communicative behavior and Escala de Desenvolvimento de Gesell e Amatruda (2000. The evaluations were accomplished by the 18 months and the 29 months. The children showed delay in the neuropshycomotor development and were exposed to multilingualism. RESULTS: alteration was verified in the communicative behaviors in the three children, both in the first as well as in the second evaluation, although an amelioration was shown in the performance, after the orientations received by the family. Cryptophasia was

  11. Hybrid spin and valley quantum computing with singlet-triplet qubits.

    Science.gov (United States)

    Rohling, Niklas; Russ, Maximilian; Burkard, Guido

    2014-10-24

    The valley degree of freedom in the electronic band structure of silicon, graphene, and other materials is often considered to be an obstacle for quantum computing (QC) based on electron spins in quantum dots. Here we show that control over the valley state opens new possibilities for quantum information processing. Combining qubits encoded in the singlet-triplet subspace of spin and valley states allows for universal QC using a universal two-qubit gate directly provided by the exchange interaction. We show how spin and valley qubits can be separated in order to allow for single-qubit rotations.

  12. ARTICLES: Microwave Assisted Synthesis of a New Triplet Iridium(III) Pyrazine Complex

    Science.gov (United States)

    Wu, Qiu-hua; Wang, Chuan-hong; Song, Xi-ming; Zhang, Guo-lin

    2010-06-01

    A new cyclometalated iridium(III) complex Ir(DPP)3 (DPP = 2,3-diphenylpyrazine) was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confirmed by elemental analysis, 1H NMR, and mass spectroscopy. The UV-Vis absorption and photoluminescent properties of the complex were investigated. The complex shows strong 1MLCT (singlet metal to ligand charge-transfer) and 3MLCT (triplet metal to ligand charge-transfer) absorption at 382 and 504 nm, respectively. The complex also shows strong photoluminescence at 573 nm at room temperature. These results suggest the complex to be a promising phosphorescent material.

  13. Singlet-triplet gaps in substituted carbenes predicted from block-correlated coupled cluster method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The block correlated coupled cluster (BCCC) method, with the complete active-space self-consistent-field (CASSCF) reference function, has been applied to investigating the singlet-triplet gaps in several substituted carbenes including four halocarbenes (CHCl, CF2, CCl2, and CBr2) and two hydroxycar-benes (CHOH and C(OH)2). A comparison of our results with the experimental data and other theoretical estimates shows that the present approach can provide quantitative descriptions for all the studied carbenes. It is demonstrated that the CAS-BCCC method is a promising theoretical tool for calculating the electronic structures of diradicals.

  14. Ordering of PCDTBT revealed by time-resolved electron paramagnetic resonance spectroscopy of its triplet excitons.

    Science.gov (United States)

    Biskup, Till; Sommer, Michael; Rein, Stephan; Meyer, Deborah L; Kohlstädt, Markus; Würfel, Uli; Weber, Stefan

    2015-06-22

    Time-resolved electron paramagnetic resonance (TREPR) spectroscopy is shown to be a powerful tool to characterize triplet excitons of conjugated polymers. The resulting spectra are highly sensitive to the orientation of the molecule. In thin films cast on PET film, the molecules' orientation with respect to the surface plane can be determined, providing access to sample morphology on a microscopic scale. Surprisingly, the conjugated polymer investigated here, a promising material for organic photovoltaics, exhibits ordering even in bulk samples. Orientation effects may significantly influence the efficiency of solar cells, thus rendering proper control of sample morphology highly important.

  15. Successful triplet pregnancy in an African with pure gonadal dysgenesis: A plus for assisted reproduction

    Directory of Open Access Journals (Sweden)

    M Aziken

    2015-06-01

    Full Text Available Gonadal dysgenesis represents a congenital developmental disorder of the reproductive system, with its main gynaecologic manifestations being amenorrhea and infertility. We present a unique case of pure gonadal dysgenesis in an ‘about to be’ married lady resident in a society where high premium and success in marriage is dependent on childbirth. With astute evaluation and counseling, assisted reproductive technology (ART was safely and successfully used in this case with eventual triplet pregnancy and delivery. Our index experience shows that situations with compromised fertility the availability and access to ART aids effective treatment planning and births a re-invigorated hope for family life.

  16. Constraints from muon g-2 and LFV processes in the Higgs Triplet Model

    CERN Document Server

    Fukuyama, Takeshi; Tsumura, Koji

    2009-01-01

    Constraints from the muon anomalous magnetic dipole moment and lepton flavor violating processes are translated into lower bounds on v_Delta*m_H++ in the Higgs Triplet Model by considering correlations through the neutrino mass matrix. The discrepancy of the sign of the contribution to the muon anomalous magnetic dipole moment between the measurement and the prediction in the model is clarified. It is shown that mu to e gamma, tau decays (especially, tau to mu e e), and the muonium conversion can give a more stringent bound on v_Delta*m_H++ than the bound from mu to eee which is expected naively to give the most stringent one.

  17. The slab albedo problem for pure-triplet anisotropic scattering by singular eigenfunction method

    Science.gov (United States)

    Türeci, D.; Türeci, R. G.

    2017-02-01

    One-speed, time independent and homogenous medium neutron transport equation can be solved by using pure-triplet anisotropic scattering. This solution bases on finding the Case's eigenfunctions and the orthogonality relations of these eigenfunctions. The infinite medium Green function can be written by using the jump condition after finding Case's eigenfunctions. The slab albedo problem can be investigated as numerical by using suggested solutions over surfaces with the singular eigenfunction method which bases on the infinite medium Green function. The selected numerical results can be tabulated.

  18. Cold Test Results of the Inner Triplet Orbit Correctors for the LHC

    CERN Document Server

    Venturini-Delsolaro, W

    2006-01-01

    The inner triplet orbit correctors for the LHC, MCBX and MCBXA, underwent acceptance tests at superfluid helium temperature at CERN, before shipping to FNAL for integration in the cold masses. A total of 27 MCBX (Horizontal-Vertical Dipole Correctors), of which 9 MCBXA (with nested Sextupole-Dodecapole insert), are needed for the LHC, including spares. The paper discusses the test protocols for series magnets, and reports the results of quench performance and cold magnetic measurements. The peculiarities of combined training and the hysteresis effects in the nested windings are presented, together with the search of the optimum setting procedure to minimize the persistent current effects on the beam dynamics.

  19. Elastic Scattering of Ultracold 133Cs and 85Rb Atoms in Triplet State

    Institute of Scientific and Technical Information of China (English)

    SUN Jin-Feng; HU Qiu-Bo; ZHU Zun-Lue; WANG Xiao-Fei; ZHANG Ji-Cai

    2007-01-01

    Elastic scattering properties of the ultracold interaction for the triplet state of 133Cs and 85Rb atoms are studied using two kinds of potentials by the same phase Φ. One is the interpolation potential, and another is Lennard-Jones potential (L J12,6). The radial Schr(o)dinger equation is also solved using two computational methods, the semiclassical method (WKB), and the Numerov method. Our results are found to be in an excellent agreement with the more recent theoretical values. It shows that the two potentials and methods are applicable for studying ultracold collisions between the mixing alkali atoms.

  20. Successful triplet pregnancy in an African with pure gonadal dysgenesis:A plus for assisted reproduction

    Institute of Scientific and Technical Information of China (English)

    Aziken M; Osaikhuwuomwan J; Osemwenkha A; Iribhogbe O; Orhue A

    2015-01-01

    Gonadal dysgenesis represents a congenital developmental disorder of the reproductive system, with its main gynaecologic manifestations being amenorrhea and infertility. We present a unique case of pure gonadal dysgenesis in an ‘about to be’ married lady resident in a society where high premium and success in marriage is dependent on childbirth. With astute evaluation and counseling, assisted reproductive technology (ART) was safely and successfully used in this case with eventual triplet pregnancy and delivery. Our index experience shows that situations with compromised fertility the availability and access to ART aids effective treatment planning and births a re-invigorated hope for family life.

  1. Fundamental fermion masses from deformed SU{sub q}(2) triplets

    Energy Technology Data Exchange (ETDEWEB)

    Palladino, B.E.; Ferreira, P.L. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)

    1996-10-01

    A spectrum generating q-algebra, within the framework of SU{sub q}(2), is studied in order to describe the mass spectrum of three generations of quarks and leptons. The SU{sub q}(2) quantum group is a q-deformed extension of SU(2), where q=exp{alpha} (with {alpha} real) is the deformation parameter. In this letter, the essential use of inequivalent representations of SU{sub q}(2) is introduced. A formula for the fermion masses is derived. As an example, a possible scheme which corresponds to two triplets associated to up and down quarks is presented here in some detail. 19 refs., 3 tabs.

  2. Higher-order recoil corrections for triplet states of the helium atom

    CERN Document Server

    Patkos, V; Pachucki, K

    2016-01-01

    Nuclear recoil corrections of order $\\alpha^6\\,m^2/M$ are calculated for the lowest-lying triplet states of the helium atom. It improves the theoretical prediction for the isotope shift of the $2^3S-2^3P$ transition energy and influences the determination of the ${}^3\\textrm{He}-{}^4\\textrm{He}$ nuclear charge radii difference. This calculation is a step forward on the way towards the direct determination of the charge radius of the helium nucleus from spectroscopic measurements.

  3. Inelastic and elastic collision rates for triplet states of ultracold strontium

    CERN Document Server

    Traverso, A; de Escobar, Y N Martinez; Mickelson, P G; Nagel, S B; Yan, M; Killian, T C

    2008-01-01

    We report measurement of the inelastic and elastic collision rates for ^{88}Sr atoms in the (5s5p)^3P_0 state in a crossed-beam optical dipole trap. This is the first measurement of ultracold collision properties of a ^3P_0 level in an alkaline-earth atom or atom with similar electronic structure. Since the (5s5p)^3P_0 state is the lowest level of the triplet manifold, large loss rates indicate the importance of principle-quantum-number-changing collisions at short range. We also provide an estimate of the collisional loss rates for the (5s5p){^3P_2} state.

  4. Inelastic and elastic collision rates for triplet states of ultracold strontium

    Science.gov (United States)

    Traverso, A.; Chakraborty, R.; Martinez de Escobar, Y. N.; Mickelson, P. G.; Nagel, S. B.; Yan, M.; Killian, T. C.

    2009-06-01

    We report measurement of the inelastic and elastic collision rates for S88r atoms in the (5s5p)P30 state in a crossed-beam optical dipole trap. Since the (5s5p)P30 state is the lowest level of the triplet manifold, large loss rates indicate the importance of principle-quantum-number-changing collisions at short range. We also provide an estimate of the collisional loss rates for the (5s5p)P32 state. Large loss-rate coefficients for both states indicate that evaporative cooling toward quantum degeneracy in these systems is unlikely to be successful.

  5. On the Effect of Triplet or Doublet Chemotherapy in Advanced Gastric Cancer: Results From a National Cancer Registry.

    Science.gov (United States)

    Carmona-Bayonas, Alberto; Jiménez-Fonseca, Paula; Lorenzo, Maria Luisa Sánchez; Ramchandani, Avinash; Martínez, Elena Asensio; Custodio, Ana; Garrido, Marcelo; Echavarría, Isabel; Cano, Juana María; Barreto, Jose Enrique Lorenzo; García, Teresa García; Manceñido, Felipe Álvarez; Lacalle, Alejandra; Cardona, Marta Ferrer; Mangas, Monserrat; Visa, Laura; Buxó, Elvira; Azkarate, Aitor; Díaz-Serrano, Asunción; Montes, Ana Fernández; Rivera, Fernando

    2016-11-01

    There is currently no consensus regarding first-line chemotherapy for patients with advanced gastric cancer (AGC) who are ineligible to receive trastuzumab. The objective of this study was to evaluate the efficacy and tolerance of triplets versus doublets by analyzing a national gastric cancer registry. Patients with AGC treated with polychemotherapy without associating trastuzumab were included from 2008 through 2016. The effect of triplets versus doublets was compared using 3 methods: Cox proportional hazards regression, propensity score matching (PSM), and coarsened exact matching (CEM). A total of 970 patients were recruited (doublets: n=569; triplets: n=401). In the multivariate Cox model, the use of triplets was associated with better overall survival (OS), with a hazard ratio (HR) of 0.84 (95% CI, 0.72-0.98; P=.035). After PSM, the sample contained 340 pairs. A significant increase in OS, 11.14 months (95% CI, 9.60-12.68) versus 9.60 months (95% CI, 8.44-10.75), was seen in favor of triplets (HR, 0.77; 95% CI, 0.65-0.92; stratified log-rank test, P=.004). The effect appeared to be comparable for anthracycline-based (HR, 0.78; 95% CI, 0.64-0.94) or docetaxel-based triplets (HR, 0.78; 95% CI, 0.60-1.009). The trend was similar after applying the CEM algorithm, with an HR of 0.78 (95% CI, 0.63-0.97; P=.03). Triplet therapy was viable and relative dose intensities exceeded 85%, except for cisplatin in DCX (docetaxel, cisplatin, capecitabine). Triplets had more severe toxicity overall, especially hematologic, hepatic, and mucosal adverse events. With the limitations of a retrospective study that examines a heterogeneous set of chemotherapy regimens, we found that triplets are feasible in daily practice and are associated with a discreet benefit in efficacy at the expense of a moderate increase in toxicity. Copyright © 2016 by the National Comprehensive Cancer Network.

  6. A blocked diketo form of avobenzone: photostability, photosensitizing properties and triplet quenching by a triazine-derived UVB-filter.

    Science.gov (United States)

    Paris, Cecilia; Lhiaubet-Vallet, Virginie; Jiménez, Oscar; Trullas, Carles; Miranda, Miguel Angel

    2009-01-01

    Novel sunscreens are required providing active protection in the UVA and UVB regions. On the other hand, there is an increasing concern about the photosafety of UV filters, as some of them are not sufficiently photostable. Avobenzone is one of the most frequently employed sunscreen ingredients, but it has been reported to partially decompose after irradiation. In the present work, photophysical and photochemical studies on a methylated avobenzone-derivative have shown that the diketo form is responsible for photodegradation. A transient absorption was observed at 380 nm after laser flash photolysis excitation at 308 nm. It was assigned to the triplet excited state of the diketo form, as inferred from quenching by oxygen and beta-carotene. This transient also interacted with key building blocks of biomolecules by triplet-triplet energy transfer (in the case of thymidine) or electron transfer processes (for 2'-deoxyguanosine, tryptophan and tyrosine). Irradiation of the avobenzone derivative in the presence of a triazine UV-B filter (E-35852) diminished the undesirable effects of the compound by an efficient quenching of the triplet excited state. Thus, sunscreen formulations including triplet quenchers could provide effective protection from the potential phototoxic and photoallergic effects derived from poor photostability of avobenzone.

  7. Colossal Proximity Effect in a Superconducting Triplet Spin Valve Based on the Half-Metallic Ferromagnet CrO_{2}

    Directory of Open Access Journals (Sweden)

    A. Singh

    2015-05-01

    Full Text Available Combining superconductors (S and ferromagnets (F offers the opportunity to create a new class of superconducting spintronic devices. In particular, the S/F interface can be specifically engineered to convert singlet Cooper pairs to spin-polarized triplet Cooper pairs. The efficiency of this process can be studied using a so-called triplet spin valve (TSV, which is composed of two F layers and a S layer. When the magnetizations in the two F layers are not collinear, singlet pairs are drained from the S layer, and triplet generation is signaled by a decrease of the critical temperature T_{c}. Here, we build highly efficient TSVs using a 100% spin-polarized half-metallic ferromagnet, CrO_{2}. The application of out-of-plane magnetic fields results in an extremely strong suppression of T_{c}, by well over a Kelvin. The observed effect is an order of magnitude larger than previous studies on TSVs with standard ferromagnets. Furthermore, we clearly demonstrate that this triplet proximity effect is strongly dependent on the transparency and spin activity of the interface. Our results are particularly important in view of the growing interest in generating long-range triplet supercurrents for dissipationless spintronics.

  8. Field-induced transition from chiral spin-triplet to mixed-parity Fulde-Ferrell-Larkin-Ovchinnikov superconductivity

    Science.gov (United States)

    Romano, Alfonso; Cuoco, Mario; Noce, Canio; Gentile, Paola; Annunziata, Gaetano

    2010-02-01

    We analyze the response to a magnetic field of a two-dimensional spin-triplet superconductor with chiral order parameter when triplet pairing is closely competing with the singlet one. The study is performed via numerical solution of the Bogoliubov-de Gennes equations, assuming that the translational symmetry is broken in one direction by the presence of an interface beyond which superconducting pairing is not effective. We show that as the intensity of the magnetic field is increased above a threshold value, the system undergoes a transition to a spatially inhomogeneous state of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) type where chirality disappears and a singlet-triplet mixing takes place along the direction perpendicular to the interface. Subdominant singlet components are found to accompany the triplet dominant ones in both phases. They develop close to the interface at low fields, then turning continuously into oscillating long-range ones as the field is increased. A similar behavior is found for the magnetization. It nucleates at the interface in the chiral phase, then acquiring in the FFLO phase an oscillatory behavior reaching its maximum amplitude at the sites where the dominant triplet component has a node. At these sites, the local spin-resolved density of states exhibits strong resonances, associated with the formation of Andreev bound states, which tend to broaden and decay in intensity as increasingly high magnetic fields are considered.

  9. Discovery of an extremely gas-rich dwarf triplet near the center of the Lynx-Cancer void

    CERN Document Server

    Chengalur, Jayaram N

    2012-01-01

    Giant Metrewave Radio Telescope (GMRT) HI observations, done as part of an ongoing study of dwarf galaxies in the Lynx-Cancer void, resulted in the discovery of a triplet of extremely gas rich galaxies located near the centre of the void.The triplet members SDSS J0723+3621, J0723+3622 and J0723+3624 have absolute magnitudes M_B of -14.2, -11.9 and -9.7 and M(HI)/L_B of \\sim 2.9, ~10 and ~25, respectively. The gas mass fractions, as derived from the SDSS photometry and the GMRT data are 0.93, 0.997, 0.997 respectively. The faintest member of this triplet SDSS J0723+3624 is one of the most gas rich galaxies known. We find that all three galaxies deviate significantly from the Tully-Fisher relation, but follow the baryonic Tully-Fisher relation. All three galaxies also have a baryon fraction that is significantly smaller than the cosmic baryon fraction. For the largest galaxy in the triplet, this is in contradiction to numerical simulations. The discovery of this very unique dwarf triplet lends support to the id...

  10. A sequential nonparametric pattern classification algorithm based on the Wald SPRT. [Sequential Probability Ratio Test

    Science.gov (United States)

    Poage, J. L.

    1975-01-01

    A sequential nonparametric pattern classification procedure is presented. The method presented is an estimated version of the Wald sequential probability ratio test (SPRT). This method utilizes density function estimates, and the density estimate used is discussed, including a proof of convergence in probability of the estimate to the true density function. The classification procedure proposed makes use of the theory of order statistics, and estimates of the probabilities of misclassification are given. The procedure was tested on discriminating between two classes of Gaussian samples and on discriminating between two kinds of electroencephalogram (EEG) responses.

  11. Robust inference for group sequential trials.

    Science.gov (United States)

    Ganju, Jitendra; Lin, Yunzhi; Zhou, Kefei

    2017-03-01

    For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests. Copyright © 2017 John Wiley & Sons, Ltd.

  12. The Free Energy of dsDNA Basepair Triplets Bound to an ssDNA/RecA Filament May be a Non-Linear Function of the Number of Contiguous Bound Triplets

    CERN Document Server

    Feinstein, Efraim; Prentiss, Mara

    2011-01-01

    The homology search process depends on the free energy of double stranded DNA (dsDNA) triplets bound to pre-synaptic filaments. It has been assumed that the total free energy is a linear function of the number of bound dsDNA triplets. We present an analytical model using a simplified version of the known structure of dsDNA bound to ssDNA/RecA filaments. This model predicts that the mechanical energy stored in dsDNA bound to RecA increases non-linearly with the number of contiguous bound dsDNA triplets. We suggest that the free energy increase for the homology searching state is much more rapid than the increase for the post-strand exchange state and propose that this difference may play a vital role in the homology search/strand exchange process.

  13. The Kinetics of Joined Action of Triplet-Triplet Annihilation and First-Order Decay of Molecules in T1 State in the Case of Nondominant First-Order Process: The Kinetic Model in the Case of Spatially Periodic Excitation

    Directory of Open Access Journals (Sweden)

    Paweł Borowicz

    2013-01-01

    Full Text Available In this paper the model developed for estimation of the diffusion coefficient of the molecules in the triplet state is presented. The model is based on the intuitive modification of the Smoluchowski equation for the time-dependent rate parameter. Since the sample is irradiated with the spatially periodic pattern nonexponential effects can be expected in the areas of the constructive interference of the exciting laser beams. This nonexponential effects introduce changes in the observed kinetics of the diffusion-controlled triplet-triplet annihilation. Due to irradiation with so-called long excitation pulse these non-exponential effects are very weak, so they can be described with introducing very simple correction to the kinetic model described in the first paper of this series. The values of diffusion coefficient of anthracene are used to calculate the annihilation radius from the data for spatially homogeneous excitation.

  14. Nonlinear interferometry approach to photonic sequential logic

    CERN Document Server

    Mabuchi, Hideo

    2011-01-01

    Motivated by rapidly advancing capabilities for extensive nanoscale patterning of optical materials, I propose an approach to implementing photonic sequential logic that exploits circuit-scale phase coherence for efficient realizations of fundamental components such as a NAND-gate-with-fanout and a bistable latch. Kerr-nonlinear optical resonators are utilized in combination with interference effects to drive the binary logic. Quantum-optical input-output models are characterized numerically using design parameters that yield attojoule-scale energy separation between the latch states.

  15. Nonlinear sequential laminates reproducing hollow sphere assemblages

    Science.gov (United States)

    Idiart, Martín I.

    2007-07-01

    A special class of nonlinear porous materials with isotropic 'sequentially laminated' microstructures is found to reproduce exactly the hydrostatic behavior of 'hollow sphere assemblages'. It is then argued that this result supports the conjecture that Gurson's approximate criterion for plastic porous materials, and its viscoplastic extension of Leblond et al. (1994), may actually yield rigorous upper bounds for the hydrostatic flow stress of porous materials containing an isotropic, but otherwise arbitrary, distribution of porosity. To cite this article: M.I. Idiart, C. R. Mecanique 335 (2007).

  16. Automatic differentiation for reduced sequential quadratic programming

    Institute of Scientific and Technical Information of China (English)

    Liao Liangcai; Li Jin; Tan Yuejin

    2007-01-01

    In order to slove the large-scale nonlinear programming (NLP) problems efficiently, an efficient optimization algorithm based on reduced sequential quadratic programming (rSQP) and automatic differentiation (AD) is presented in this paper. With the characteristics of sparseness, relatively low degrees of freedom and equality constraints utilized, the nonlinear programming problem is solved by improved rSQP solver. In the solving process, AD technology is used to obtain accurate gradient information. The numerical results show that the combined algorithm, which is suitable for large-scale process optimization problems, can calculate more efficiently than rSQP itself.

  17. A Sequential Algorithm for Training Text Classifiers

    CERN Document Server

    Lewis, D D; Lewis, David D.; Gale, William A.

    1994-01-01

    The ability to cheaply train text classifiers is critical to their use in information retrieval, content analysis, natural language processing, and other tasks involving data which is partly or fully textual. An algorithm for sequential sampling during machine learning of statistical classifiers was developed and tested on a newswire text categorization task. This method, which we call uncertainty sampling, reduced by as much as 500-fold the amount of training data that would have to be manually classified to achieve a given level of effectiveness.

  18. THE DEVELOPMENT OF SPECIAL SEQUENTIALLY-TIMED

    Directory of Open Access Journals (Sweden)

    Stanislav LICHOROBIEC

    2016-06-01

    Full Text Available This article documents the development of the noninvasive use of explosives during the destruction of ice mass in river flows. The system of special sequentially-timed charges utilizes the increase in efficiency of cutting charges by covering them with bags filled with water, while simultaneously increasing the effect of the entire system of timed charges. Timing, spatial combinations during placement, and the linking of these charges results in the loosening of ice barriers on a frozen waterway, while at the same time regulating the size of the ice fragments. The developed charges will increase the operability and safety of IRS units.

  19. Generalised sequential crossover of words and languages

    CERN Document Server

    Jeganathan, L; Sengupta, Ritabrata

    2009-01-01

    In this paper, we propose a new operation, Generalised Sequential Crossover (GSCO) of words, which in some sense an abstract model of crossing over of the chromosomes in the living organisms. We extend GSCO over language $L$ iteratively ($GSCO^*(L)$ as well as iterated GSCO over two languages $GSCO^*(L_1,L_2)$). Our study reveals that $GSCO^*(L)$ is subclass of regular languages for any $L$. We compare the different classes of GSCO languages with the prominent sub-regular classes.

  20. Sequential cooling insert for turbine stator vane

    Science.gov (United States)

    Jones, Russell B; Krueger, Judson J; Plank, William L

    2014-04-01

    A sequential impingement cooling insert for a turbine stator vane that forms a double impingement for the pressure and suction sides of the vane or a triple impingement. The insert is formed from a sheet metal formed in a zigzag shape that forms a series of alternating impingement cooling channels with return air channels, where pressure side and suction side impingement cooling plates are secured over the zigzag shaped main piece. Another embodiment includes the insert formed from one or two blocks of material in which the impingement channels and return air channels are machined into each block.

  1. Triplet generation and upper critical field in superconducting spin valves based on CrO2

    Science.gov (United States)

    Voltan, S.; Singh, A.; Aarts, J.

    2016-08-01

    It has been recently reported that a superconducting triplet spin valve (TSV) based on the half-metallic CrO2 can show "colossal" variations of the critical temperature, up to more than 1 K. This can be achieved when the magnetic noncollinearity between the mixer (F1) and the drainage ferromagnetic layer (F) is maximized. In this work we investigate further such TSV devices looking at two aspects: first, we present the dependence of the TSV effect on the thickness of the mixer layer; second, we look at the perpendicular upper critical field Hc 2 ⊥ as a function of the temperature. The thickness dependence, which is nonmonotonic as expected, represents a further proof that the effect is due to the generation of equal-spin triplet Cooper pairs, while what we observe for the Hc 2 ⊥ versus T curves is an interesting and peculiar behavior: there is a clear deviation from the universal linear dependence and the average slope is suppressed much more than what can be described with the formalism used for conventional proximized structures.

  2. Intermolecular electron transfer from naphthalene derivatives in the higher triplet excited states.

    Science.gov (United States)

    Sakamoto, Masanori; Cai, Xichen; Hara, Michihiro; Fujitsuka, Mamoru; Majima, Tetsuro

    2004-08-11

    Intermolecular electron transfer (ELT) from a series of naphthalene derivatives (NpD) in the higher triplet excited states (T(n)) to carbon tetrachloride (CCl(4)) in Ar-saturated acetonitrile was observed using the two-color two-laser flash photolysis method. The ELT efficiency depended on the driving force of ELT. Since the ELT from the T(n) state occurred competitively with the internal conversion (IC, T(n) --> T(1)) and the triplet energy transfer (ENT), the ELT became apparent only when sufficient free energy change of ELT was attained. On the other hand, ELT from the T(1) state was not observed, although ELT from the T(1) state with sufficiently long lifetime has a slightly exothermic driving force. The fast ELT from the T(n) state and lack of the reactivity of the T(1) state were explained well by the "sticky" dissociative electron-transfer model based on one-electron reductive attachment to CCl(4) leading to the C-Cl bond cleavage.

  3. Filter-filter interactions. Photostabilization, triplet quenching and reactivity with singlet oxygen.

    Science.gov (United States)

    Lhiaubet-Vallet, Virginie; Marin, Mireia; Jimenez, Oscar; Gorchs, Olga; Trullas, Carles; Miranda, Miguel Angel

    2010-04-01

    In most sunscreens, the presence of two UV filters usually leads to synergistic effects regarding both the final performance and photostabilization of the active principles. However, this may also result in an accelerated decomposition if a photoreaction occurs between the single components. Thus, the understanding of photophysics and photochemistry of UV filter combinations is important to improve sunscreen photostability. In this context, photoreactivity of a commonly used UVA filter, namely tert-butylmethoxydibenzoylmethane (BM-DBM, also known as avobenzone, Parsol 1789, etc.), has been studied in the presence of six commercial solar filters: octyl methoxycinnamate, bis-ethylhexyloxyphenol methoxyphenyl triazine, octocrylene, diethylamino hydroxybenzoyl hexyl benzoate, octyl triazone and dioctyl butamido triazone. To achieve this goal, a mechanism-based strategy has been designed in order to investigate the photostability of sunscreens in a more systematic way, taking into account different processes: tautomerization of BM-DBM, formation of triplet excited state of BM-DBM in its diketo form and its quenching in the presence of UV filters, reactivity of UV filters under triplet photosensitization, quenching of singlet oxygen by UV filters and degradation of the latter under singlet oxygenation conditions.

  4. Observation of Mollow Triplets with Tunable Interactions in Double Lambda Systems of Individual Hole Spins

    Science.gov (United States)

    Lagoudakis, K. G.; Fischer, K. A.; Sarmiento, T.; McMahon, P. L.; Radulaski, M.; Zhang, J. L.; Kelaita, Y.; Dory, C.; Müller, K.; Vučković, J.

    2017-01-01

    Although individual spins in quantum dots have been studied extensively as qubits, their investigation under strong resonant driving in the scope of accessing Mollow physics is still an open question. Here, we have grown high quality positively charged quantum dots embedded in a planar microcavity that enable enhanced light-matter interactions. Under a strong magnetic field in the Voigt configuration, individual positively charged quantum dots provide a double lambda level structure. Using a combination of above-band and resonant excitation, we observe the formation of Mollow triplets on all optical transitions. We find that when the strong resonant drive power is used to tune the Mollow-triplet lines through each other, we observe anticrossings. We also demonstrate that the interaction that gives rise to the anticrossings can be controlled in strength by tuning the polarization of the resonant laser drive. Quantum-optical modeling of our system fully captures the experimentally observed spectra and provides insight on the complicated level structure that results from the strong driving of the double lambda system.

  5. Non-conventional halide oxidation pathways : oxidation by imidazole triplet and surface specific oxidation by ozone

    Science.gov (United States)

    Ammann, Markus; Corral-Arroyo, Pablo; Aellig, Raphael; Orlando, Fabrizio; Lee, Ming-Tao; Artiglia, Luca

    2016-04-01

    Oxidation of halide ions (chloride, bromide, iodide) are the starting point of halogen release mechanisms out of sea water, marine aerosol or other halide containing continental aerosols. Slow oxidation of chloride and bromide by ozone in the bulk aqueous phase is of limited relevance. Faster surface specific oxidation has been suggested based on heterogeneous kinetics experiments. We provide first insight into very efficient bromide oxidation by ozone at the aqueous solution - air interface by surface sensitive X-ray photoelectron spectroscopy indicating significant build-up of an oxidized intermediate at the surface within millisecond time scales. The second source of oxidants in the condensed we have considered is the absorption of light by triplet forming photosensitizers at wavelengths longer than needed for direct photolysis and radical formation. We have performed coated wall flow tube experiments with mixtures of citric acid (CA) and imidazole-2-carboxaldehyde (IC) to represent secondary organic material rich marine aerosol. The halide ions bromide and iodide have been observed to act as efficient electron donors leading to their oxidation, HO2 formation and finally release of molecular halogen compounds. The photosensitization of imidazole-2-carboxaldehyde (IC) involves a well-known mechanism where the triplet excited state of IC is reduced by citric acid to a reduced ketyl radical that reacts with halide ions. A competition kinetics approach has been used to evaluate the rate limiting steps and to assess the significance of this source of halogens to the gas phase.

  6. Efficient Hybrid White Organic Light-Emitting Diodes for Application of Triplet Harvesting with Simple Structure

    CERN Document Server

    Hwang, Kyo Min; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Jwajin; Yoon, Seung Soo; Kim, Young Kwan

    2016-01-01

    In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with simple structure. All the hole transporting material and host in emitting layer (EML) of devices were utilized with same material by using N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine (4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated three color with blue fluorescent and green, red phosphorescent materials. We was investigated the effect of triplet harvesting (TH) by exciton generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs were dominant hole mobility, therefore exciton generation zone was expected in EML. Additionally, we was optimization thickness of hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. Simple hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum external quantum efficiency of 11.2%. Commission Internatio...

  7. Expressions of excited states by triplet dimers in heisenberg antiferromagnetic ladders. Analysis of magnetic Raman spectra

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, Yuhei; Tada, Shinichiro; Suzuki, Toshihiko [Chiba Univ., Graduate School of Science and Technology, Chiba (Japan)

    2002-06-01

    Characteristic properties of excited states in antiferromagnetic ladder systems with spin-1/2 are investigated in relation with the theoretical analysis of the quite asymmetric shape of the peak for twice the spin gap {delta}{sub g} in magnetic Raman spectra. Here, the structure of exchange-scattering spectra are reproduced by the numerical calculation for the finite Heisenberg ladder, in which legs with antiferromagnetic bond J{sub c} is connected by rungs with antiferromagnetic bond J{sub r}. The singlet ground state in this system can be expressed as the ordering of singlet dimers on rungs in the ladder for J{sub c}/J{sub r} {yields} +0. In fact, the value of 0.1 is adopted to be the ratio of J{sub c}/J{sub r} in order to discuss the experimental work of the magnetic Raman spectra for the ladder of V{sup 4+} ions in the oxide compound CaV{sub 2}O{sub 5} reported in Konstantinovic et al., Phys. Rev. B61 (2000), 15185. As for this peak of 2{delta}{sub g}, quite an asymmetric observed shape is explained by the present calculation. According to the analysis of spectra, we discuss the expression of excited states by triplet dimers on rungs: The dominant contribution of the pair of triplet dimers on adjacent rungs to the corresponding state for 2{delta}{sub g} peak is pointed out. (author)

  8. Dark matter versus h→γγ and h→γZ with supersymmetric triplets

    Energy Technology Data Exchange (ETDEWEB)

    Arina, Chiara [Institut d' Astrophysique de Paris, 75 - Paris (France); Martin-Lozano, Victor [Univ. Autonoma de Madrid/CSIC (Spain). Inst. de Fisica Teorica; Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Nardini, Germano [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Bielefeld Univ. (Germany). Fakultaet fuer Physik

    2014-03-15

    The Triplet extension of the MSSM (TMSSM) alleviates the little hierarchy problem and provides a significant enhancement of the loop-induced diphoton rate of the lightest CP-even Higgs h. In this paper we pursue the analysis of the TMSSM Higgs phenomenology by computing for the first time the h→Zγ decay. Interestingly we find that the rates of loop-induced decays are correlated and their signal strengths can rise up to 40%-60% depending on the channel. We furthermore study the dark matter phenomenology of the TMSSM. The lightest neutralino is a good dark matter candidate in two regions. The first one is related to the Higgs and Z resonances and the LSP is mostly Bino. The second one is achieved for a mass larger than 90 GeV and the LSP behaves as the well-tempered neutralino. An advantage of the triplet contribution is that the well-tempered neutralino can be a Bino-Triplino mixture, relieving the problem of achieving M{sub 2}∝M{sub 1} in unified scenarios. The dark matter constraints strongly affect the Higgs phenomenology, reducing the potential enhancements of the diphoton and of the Zγ channels by 20% at most. These enhancements are however larger than the MSSM ones. In the near future, complementarity of dark matter direct searches and collider experiments will be crucial to probe most of the parameter space where the neutralino is the dark matter candidate.

  9. Dark Matter versus h into gamma gamma and h into gamma Z with supersymmetric triplets

    CERN Document Server

    Arina, Chiara; Nardini, Germano

    2014-01-01

    The Triplet extension of the MSSM (TMSSM) alleviates the little hierarchy problem and provides a significant enhancement of the loop-induced diphoton rate of the lightest CP-even Higgs h. In this paper we pursue the analysis of the TMSSM Higgs phenomenology by computing for the first time the h into Z + gamma decay. Interestingly we find that the rates of loop-induced decays are correlated and their signal strengths can rise up to 40% - 60% depending on the channel. We furthermore study the dark matter phenomenology of the TMSSM. The lightest neutralino is a good dark matter candidate in two regions. The first one is related to the Higgs and Z resonances and the LSP is mostly Bino. The second one is achieved for a mass larger than 90 GeV and the LSP behaves as the well-tempered neutralino. An advantage of the triplet contribution is that the well-tempered neutralino can be a Bino-Triplino mixture, relieving the problem of achieving M_2 ~ M_1 in unified scenarios. The dark matter constraints strongly affect th...

  10. Doublets, triplets, or quadruplets of novel agents in newly diagnosed myeloma?

    Science.gov (United States)

    Rajkumar, S Vincent

    2012-01-01

    The treatment of multiple myeloma is evolving rapidly. A plethora of doublet, triplet, and quadruplet combinations have been studied for the treatment of newly diagnosed myeloma. Although randomized trials have been conducted comparing older regimens such as melphalan-prednisone with newer regimens containing drugs such as thalidomide, lenalidomide, or bortezomib, there are few if any randomized trials that have compared modern combinations with each other. Even in the few trials that have done so, definitive overall survival or patient-reported quality-of-life differences have not been demonstrated. Therefore, there is marked heterogeneity in how newly diagnosed patients with myeloma are treated around the world. The choice of initial therapy is often dictated by availability of drugs, age and comorbidities of the patient, and assessment of prognosis and disease aggressiveness. This chapter reviews the current data on the most commonly used and tested doublet, triplet, and quadruplet combinations for the treatment of newly diagnosed myeloma and provides guidance on choosing the optimal initial treatment regimen.

  11. Impact of Aggregation on the Photochemistry of Fullerene Films: Correlating Stability to Triplet Exciton Kinetics.

    Science.gov (United States)

    Speller, Emily M; McGettrick, James D; Rice, Beth; Telford, Andrew M; Lee, Harrison K H; Tan, Ching-Hong; De Castro, Catherine S; Davies, Matthew L; Watson, Trystan M; Nelson, Jenny; Durrant, James R; Li, Zhe; Tsoi, Wing C

    2017-07-12

    The photochemistry and stability of fullerene films is found to be strongly dependent upon film nanomorphology. In particular, PC61BM blend films, dispersed with polystyrene, are found to be more susceptible to photobleaching in air than the more aggregated neat films. This enhanced photobleaching correlated with increased oxygen quenching of PC61BM triplet states and the appearance of a carbonyl FTIR absorption band indicative of fullerene oxidation, suggesting PC61BM photo-oxidation is primarily due to triplet-mediated singlet oxygen generation. PC61BM films were observed to undergo photo-oxidation in air for even modest (≤40 min) irradiation times, degrading electron mobility substantially, indicative of electron trap formation. This conclusion is supported by observation of red shifts in photo- and electro-luminescence with photo-oxidation, shown to be in agreement with time-dependent density functional theory calculations of defect generation. These results provide important implications on the environmental stability of PC61BM-based films and devices.

  12. A CP-violating phase in a two Higgs triplet scenario : some phenomenological implications

    CERN Document Server

    Chaudhuri, Avinanda

    2016-01-01

    We consider a scenario where, along with the usual Higgs doublet, two scalar triplets are present. The extension of the triplet sector is required for the Type~II mechanism for the generation of neutrino masses, if this mechanism has to generate a neutrino mass matrix with two-zero texture. One CP-violating phase has been retained in the scalar potential of the model, and all parameters have been chosen consistently with the observed neutrino mass and mixing patterns. We find that a large phase ($\\gtrsim 60^{\\circ}$) splits the two doubly-charged scalar mass eigenstates wider apart, so that the decay $H_1^{++} \\rightarrow H_2^{++} h$ is dominant (with h being the $125$ GeV scalar). We identify a set of benchmark points where this decay dominates. This is complementary to the situation, reported in our earlier work, where the heavier doubly-charged scalar decays as $H_1^{++} \\rightarrow H_2^+ W^+$. We point out the rather spectacular signal, ensuing from $H_1^{++} \\rightarrow H_2^{++} h$, in the form of Higgs ...

  13. Randomized Benchmarking of Barrier versus Tilt Control of a Singlet-Triplet Qubit

    Science.gov (United States)

    Zhang, Chengxian; Throckmorton, Robert E.; Yang, Xu-Chen; Wang, Xin; Barnes, Edwin; Das Sarma, S.

    2017-05-01

    Decoherence due to charge noise is one of the central challenges in using spin qubits in semiconductor quantum dots as a platform for quantum information processing. Recently, it has been experimentally demonstrated in both Si and GaAs singlet-triplet qubits that the effects of charge noise can be suppressed if qubit operations are implemented using symmetric barrier control instead of the standard tilt control. Here, we investigate the key issue of whether the benefits of barrier control persist over the entire set of single-qubit gates by performing randomized benchmarking simulations. We find the surprising result that the improvement afforded by barrier control depends sensitively on the amount of spin noise: for the minimal nuclear spin noise levels present in Si, the coherence time improves by more than 2 orders of magnitude whereas in GaAs, by contrast the coherence time is essentially the same for barrier and tilt control. However, we establish that barrier control becomes beneficial if qubit operations are performed using a new family of composite pulses that reduce gate times by up to 90%. With these optimized pulses, barrier control is the best way to achieve high-fidelity quantum gates in singlet-triplet qubits.

  14. Rectification and Robust Matching Using Oriented Image Triplets for Minimally Invasive Surgery

    Science.gov (United States)

    Conen, N.; Jepping, C.; Luhmann, T.; Maas, H.-G.

    2016-06-01

    Stereo endoscopes for minimally invasive surgery have been available on the market for several years and are well established in some areas. In practice, they offer a stereoscopic view to the surgeon but are not yet intended for 3D measurements. However, using current knowledge about the camera system and the difficult conditions in object space, it is possible to reconstruct a highly accurate surface model of the current endoscopic view. In particular for medical interventions, a highly reliable point cloud and real-time computation are required. To obtain good reliability, a miniaturised trinocular camera system is introduced that reduces the amount of outliers. To reduce computation time, an approach for generation of rectified image triplets and their corresponding interior and exterior camera parameters has been developed. With these modified and parameterised images it is possible to directly process 3D measurements in object space. Accordingly, an efficient semi-global optimisation is implemented by the authors. In this paper the special camera system, the rectification approach and the applied methodology of matching in rectified image triplets are explained. Finally, first results are presented. In conclusion, the trinocular camera system provides more reliable point clouds than a binocular one, especially for areas with repetitive or poor texture. Currently, the benefit of the third camera is not as great as desired.

  15. Variety of SO(10) GUTs with Natural Doublet-Triplet Splitting via the Missing Partner Mechanism

    CERN Document Server

    Babu, K S; Nath, Pran; Syed, Raza M

    2011-01-01

    We present a new class of unified SO(10) models where the GUT symmetry breaking down to the standard model gauge group involves just one scale, in contrast to the conventional SO(10) models which require two scales. Further, the models we discuss possess a natural doublet-triplet splitting via the missing partner mechanism without fine tuning. Such models involve $560+\\ov{560}$ pair of heavy Higgs fields along with a set of light fields. The $560+\\ov{560}$ are the simplest representations of SO(10) besides the $126+\\ov{126}$ which contain an excess of color triplets over $SU(2)_L$ doublets. We discuss several possibilities for realizing the missing partner mechanism within these schemes. With the $126+\\ov{126}$ multiplets, three viable models are found with additional fields belonging to ${210 + 2 \\times 10 + 120}$, ${45 + 10 + 120}$, or ${210 + 16 + \\ov{16} + 10 + 120}$. With the $560+\\ov{560}$, a unique possibility arises for the missing partner mechanism, with additional ${2\\times 10+ 320}$ fields. These m...

  16. Preliminary Design of the HiLumi-LHC Triplet Area Beam Screen

    CERN Document Server

    Kersevan, R; Kos, N

    2014-01-01

    The so-called beam screen (BS) is a proven solution for intercepting the thermal loads caused by the circulating beams in the cryogenically-cooled sections of the LHC and minimizing dynamic vacuum effects [1]. The new triplet area foreseen for the HiLumi-LHC (HL-LHC) machine upgrade [2] has the additional feature of needing internal tungsten shields to reduce the amount of collision debris which is deflected by the high-gradient triplet magnets towards the superconducting magnets' cold masses and coils. The very aggressive optics design, based on large beam separations, calls for a maximum of physical space to remain available to the counter rotating beams in the common BS. This places severe constraints to the fabrication and installation tolerances of the BS itself, in addition to affecting the design and routing of the cryogenic lines in the area. The latest version of the BS design will be shown and discussed, together with future plans for testing materials, fabrication procedures, and installation.

  17. The Chemical Enrichment History of the Fornax Dwarf Spheroidal Galaxy from the Infrared Calcium Triplet

    CERN Document Server

    Pont, F; Gallart, C; Hardy, E; Winnick, R A; Pont, Frederic; Zinn, Robert; Gallart, Carme; Hardy, Eduardo; Winnick, Rebeccah

    2004-01-01

    Near infrared spectra were obtained for 117 red giants in the Fornax dwarf spheroidal galaxy with the FORS1 spectrograph on the VLT, in order to study the metallicity distribution of the stars and to lift the age-metallicity degeneracy of the red giant branch (RGB) in the color-magnitude diagram (CMD). Metallicities are derived from the equivalent widths of the infrared Calcium triplet lines at 8498, 8542, and 8662 A, calibrated with data from globular clusters, the open cluster M67 and the LMC. For a substantial portion of the sample, the strength of the Calcium triplet is unexpectedly high, clearly indicating that the main stellar population of Fornax is significantly more metal-rich than could be inferred from the position of its RGB in the CMD. We show that the relative narrowness of the RGB in Fornax is caused by the superposition of stars of very different ages and metallicities. The metallicity distribution in Fornax is centered at [Fe/H]= -0.9, with a metal-poor tail extending to [Fe/H] ~= -2. While t...

  18. Pyridine-2,6-diyl dinitroxides as room-temperature triplet ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hinako; Tonegawa, Asato; Ishida, Takayuki, E-mail: takayuki.ishida@uec.ac.jp [Department of Engineering Science, The University of Electro-Communications, Tokyo (Japan)

    2016-02-01

    We have proposed tert-butyl 2-pyridyl nitroxide radicals as a promising paramagnetic chelating ligand, where the direct radical-metal bond leads to strong magnetic interaction. We successfully synthesized and isolated PyBN derivatives (pyridine-2,6-diyl bis(tert-butyl nitroxides)). The molecular and crystal structures of the target biradicals, MesPyBN, AntPyBN and tBuOPyBN were determined from the X-ray crystal structure analysis, which possess mesityl, 9-anthryl and tert-butoxy groups at the 5-position of the pyridine ring, respectively. The ground triplet state was characterized by means of SQUID susceptometry for each compound. On heating, the χ{sub m}T values of all the PyBN derivatives increased and reached a plateau at ca. 1.0 cm{sup 3} K mol{sup −1} at 300 K. It implies that biradicals behaved as triplet molecules even at room temperature, or 2J/k{sub B} >> 300 K. From the decay monitored in solution electron-spin resonance spectroscopy, MesPyBN was the most persistent, while tBuOPyBN was the most reactive, of the three.

  19. Commissioning and First Operation of the Low-Beta Triplets and Their Electrical Feed Boxes at the Large Hadron Collider

    CERN Document Server

    Darve, C; Casas-Cubillos, J; Claudet, S; Feher, S; Ferlin, G; Kerby, J; Metral, L; Perin, A; Peterson, T; Prin, H; Rabehl, R; Vauthier, N; Wagner, U; van Weelderen, R

    2010-01-01

    The insertion regions located around the four interaction points of the Large Hadron Collider (LHC) are mainly composed of the low-b triplets, the separation dipoles and their respective electrical feed-boxes (DFBX). The low-b triplets are Nb-Ti superconductor quadrupole magnets, which operate at 215 T/m in superfluid helium at a temperature of 1.9 K. The commissioning and the first operation of these components have been performed. The thermo-mechanical behavior of the low-b triplets and DFBX were studied. Cooling and control systems were tuned to optimize the cryogenic operation of the insertion regions. Hardware commissioning also permitted to test the system response. This paper summarizes the performance results and the lessons learned.

  20. Investigating the intersystem crossing rate and triplet quantum yield of Protoporphyrin IX by means of pulse train fluorescence technique

    Science.gov (United States)

    Gotardo, Fernando; Cocca, Leandro H. Z.; Acunha, Thiago V.; Longoni, Ana; Toldo, Josene; Gonçalves, Paulo F. B.; Iglesias, Bernardo A.; De Boni, Leonardo

    2017-04-01

    Photophysical investigations of PPIX were described in order to determine the triplet conversion efficiency. Time resolved fluorescence and pulse train fluorescence were employed to characterize the main mechanism responsible for deactivation of the first singlet excited state (excited singlet and triplet states). Single pulse and Z-Scan analysis were employed to measure the singlet excited state absorption cross-sections. Theoretical calculations were performed in order to get some properties of PPIX in ground state, first singlet and triplet excited state. A TD-DFT result shows a great possibility of ISC associated to out-of-plane distortions in porphyrinic ring. Furthermore, the B and Q bands in the calculated spectrum are assigned to the four frontier molecular orbitals as proposed by Gouterman for free-based porphyrins.

  1. Third-order spontaneous parametric down-conversion in thin optical fibers as a photon-triplet source

    Energy Technology Data Exchange (ETDEWEB)

    Corona, Maria [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, apdo. postal 70-543, DF 04510 Mexico City (Mexico); Departamento de Optica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Apartado Postal 2732, BC 22860 Ensenada (Mexico); Garay-Palmett, Karina; U' Ren, Alfred B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, apdo. postal 70-543, DF 04510 Mexico City (Mexico)

    2011-09-15

    We study the third-order spontaneous parametric down-conversion (TOSPDC) process, as a means to generate entangled photon triplets. Specifically, we consider thin optical fibers as the nonlinear medium to be used as the basis for TOSPDC in configurations where phase matching is attained through the use of more than one fiber transverse modes. Our analysis in this paper, which follows from our earlier paper [Opt. Lett. 36, 190-192 (2011)], aims to supply experimentalists with the details required in order to design a TOSPDC photon-triplet source. Specifically, our analysis focuses on the photon triplet state, on the rate of emission, and on the TOSPDC phase-matching characteristics for the cases of frequency-degenerate and frequency nondegenerate TOSPDC.

  2. The magnetic field configuration of a solar prominence inferred from spectropolarimetric observations in the He I 10830 A triplet

    CERN Document Server

    Suárez, David Orozco; Bueno, Javier Trujillo

    2014-01-01

    Context: The determination of the magnetic field vector in quiescent solar prominences is possible by interpreting the Hanle and Zeeman effects in spectral lines. However, observational measurements are scarce and lack high spatial resolution. Aims: To determine the magnetic field vector configuration along a quiescent solar prominence by interpreting spectropolarimetric measurements in the He I 1083.0 nm triplet obtained with the Tenerife Infrared Polarimeter installed at the German Vacuum Tower Telescope of the Observatorio del Teide. Methods. The He I 1083.0 nm triplet Stokes profiles are analyzed with an inversion code that takes into account the physics responsible of the polarization signals in this triplet. The results are put into a solar context with the help of extreme ultraviolet observations taken with the Solar Dynamic Observatory and the Solar Terrestrial Relations Observatory satellites. Results: For the most probable magnetic field vector configuration, the analysis depicts a mean field streng...

  3. Transport and noise properties of a normal metal-superconductor-normal metal junction with mixed singlet and chiral triplet pairings

    Science.gov (United States)

    Paul, Ganesh C.; Dutta, Paramita; Saha, Arijit

    2017-01-01

    We study transport and zero frequency shot noise properties of a normal metal-superconductor-normal metal (NSN) junction, with the superconductor having mixed singlet and chiral triplet pairings. We show that in the subgapped regime when the chiral triplet pairing amplitude dominates over that of the singlet, a resonance phenomena emerges out at zero energy where all the quantum mechanical scattering probabilities acquire a value of 0.25. At the resonance, crossed Andreev reflection mediating through such junction, acquires a zero energy peak. This reflects as a zero energy peak in the conductance as well depending on the doping concentration. We also investigate shot noise for this system and show that shot noise cross-correlation is negative in the subgapped regime when the triplet pairing dominates over the singlet one. The latter is in sharp contrast to the positive shot noise obtained when the singlet pairing is the dominating one.

  4. Lepton Flavour Violating Decays tau to lll and mu to e gamma in the Higgs Triplet Model

    CERN Document Server

    Akeroyd, A G; Sugiyama, Hiroaki

    2009-01-01

    Singly and doubly charged Higgs bosons in the Higgs Triplet Model mediate the lepton flavour violating (LFV) decays tau to \\bar{l}ll and mu to e gamma. The LFV decay rates are proportional to products of two triplet Yukawa couplings (h_{ij}) which can be expressed in terms of the parameters of the neutrino mass matrix and an unknown triplet vacuum expectation value. We determine the parameter space of the neutrino mass matrix in which a signal for tau to \\bar{l}ll and/or mu to e gamma is possible at ongoing and planned experiments. The conditions for respecting the stringent upper limit for mu to eee are studied in detail, with emphasis given to the possibility of |h_{ee}|\\simeq 0 which can only be realized if Majorana phases are present.

  5. Forbidden Electronic Transitions between the Singlet Ground State and the Triplet Excited State of Pt(II) Complexes.

    Science.gov (United States)

    Zheng, Greg Y.; Rillema, D. Paul; DePriest, Jeff; Woods, Clifton

    1998-07-13

    Direct access to the triplet emitting state from the ground state is observed for Pt(II) complexes containing heterocyclic (CwedgeC', CwedgeN, NwedgeN') and bis(diphenylphosphino)alkane (PwedgeP') ligands. Extinction coefficients for such transitions are in the range 4-25 M(-)(1) cm(-)(1). Emission quantum yields resulting from singlet-to-triplet excitation are as high as 61-77 times the emission quantum yields resulting from singlet-to-singlet excitation at 296 K. The intersystem crossing quantum yield from the singlet excited state to triplet emitting state is lower than 2% at 296 K but is greatly enhanced at 77 K. The forbidden electronic transition observed for Pt(II) complexes is attributed to result from spin-orbit coupling due to the presence of Pt(II) in the skeleton structure. The importance of excitation spectra on the computation of emission quantum yields is discussed.

  6. J-state interference signatures in the Second Solar Spectrum: Modeling the Cr I triplet at 5204-5208 A

    CERN Document Server

    Smitha, H N; Stenflo, J O; Bianda, M; Sampoorna, M; Ramelli, R; Anusha, L S

    2012-01-01

    The scattering polarization in the solar spectrum is traditionally modeled with each spectral line treated separately, but this is generally inadequate for multiplets where J-state interference plays a significant role. Through simultaneous observations of all the 3 lines of a Cr I triplet, combined with realistic radiative transfer modeling of the data, we show that it is necessary to include J-state interference consistently when modeling lines with partially interacting fine structure components. Polarized line formation theory that includes J-state interference effects together with partial frequency redistribution for a two-term atom is used to model the observations. Collisional frequency redistribution is also accounted for. We show that the resonance polarization in the Cr I triplet is strongly affected by the partial frequency redistribution effects in the line core and near wing peaks. The Cr I triplet is quite sensitive to the temperature structure of the photospheric layers. Our complete frequency...

  7. Implications of a electroweak triplet scalar leptoquark on the ultra-high energy neutrino events at IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Mileo, Nicolas [IFLP, CONICET - Departamento de Física, Universidad Nacional de La Plata,C.C. 67, 1900 La Plata (Argentina); Puente, Alejandro de la [Ottawa-Carleton Institute for Physics, Carleton University,1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Szynkman, Alejandro [IFLP, CONICET - Departamento de Física, Universidad Nacional de La Plata,C.C. 67, 1900 La Plata (Argentina)

    2016-11-22

    We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation of quarks and first and second generations of leptons, and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set 95% CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.

  8. Influence of the Paschen-Back effect on the results of polarimetric inversions of the He I 10830 Å triplet

    Science.gov (United States)

    Sasso, C.; Lagg, A.; Solanki, S. K.; Socas-Navarro, H.

    The He I triplet at 10830 Å has a great potential for determining the magnetic field vector in the upper chromosphere. The triplet is Zeeman sensitive (Landé factors 2.0, 1.75 and 1.25) and shows the signature of the Hanle effect under appropriate conditions. Additionally, the Zeeman sublevels are influenced by the Paschen-Back effect leading to changes in strength and in position of the Zeeman components of the transitions forming the triplet. In this work we calculate the influence of the Paschen-Back effect on the Stokes profiles and investigate its relevance to inversions on spectro-polarimetric data obtained with the Tenerife Infrared Polarimeter (TIP) at the German Vacuum Tower Telescope (VTT).

  9. All-electrical measurement of the triplet-singlet spin relaxation time in self-assembled quantum dots

    Science.gov (United States)

    Eltrudis, K.; Al-Ashouri, A.; Beckel, A.; Ludwig, A.; Wieck, A. D.; Geller, M.; Lorke, A.

    2017-08-01

    We have measured the spin relaxation time of an excited two-electron spin-triplet state into its singlet ground state in self-assembled InAs/GaAs quantum dots. We use a time-resolved measurement scheme that combines transconductance spectroscopy with spin-to-charge conversion to address the |s ↑,p ↑ 〉 triplet state, where one electron is in the quantum dot s-shell and a second one in the p-shell. The evaluation of the state-selective tunneling times from the dots into a nearby two-dimensional electron gas allows us to determine the s- and p-shell occupation and extract the relaxation time from a rate equation model. A comparably long triplet-to-singlet spin relaxation time of 25 μs is found.

  10. Implications of a Electroweak Triplet Scalar Leptoquark on the Ultra-High Energy Neutrino Events at IceCube

    CERN Document Server

    Mileo, Nicolas; Szynkman, Alejandro

    2016-01-01

    We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation leptons and quarks and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set $95\\%$ CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.

  11. A practical O(n log2 n) time algorithm for computing the triplet distance on binary trees

    DEFF Research Database (Denmark)

    Sand, Andreas; Pedersen, Christian Nørgaard Storm; Mailund, Thomas

    2013-01-01

    The triplet distance is a distance measure that compares two rooted trees on the same set of leaves by enumerating all sub-sets of three leaves and counting how often the induced topologies of the tree are equal or different. We present an algorithm that computes the triplet distance between two...... rooted binary trees in time O (n log2 n). The algorithm is related to an algorithm for computing the quartet distance between two unrooted binary trees in time O (n log n). While the quartet distance algorithm has a very severe overhead in the asymptotic time complexity that makes it impractical compared...... to O (n2) time algorithms, we show through experiments that the triplet distance algorithm can be implemented to give a competitive wall-time running time....

  12. Sequential algorithm for fast clique percolation.

    Science.gov (United States)

    Kumpula, Jussi M; Kivelä, Mikko; Kaski, Kimmo; Saramäki, Jari

    2008-08-01

    In complex network research clique percolation, introduced by Palla, Derényi, and Vicsek [Nature (London) 435, 814 (2005)], is a deterministic community detection method which allows for overlapping communities and is purely based on local topological properties of a network. Here we present a sequential clique percolation algorithm (SCP) to do fast community detection in weighted and unweighted networks, for cliques of a chosen size. This method is based on sequentially inserting the constituent links to the network and simultaneously keeping track of the emerging community structure. Unlike existing algorithms, the SCP method allows for detecting k -clique communities at multiple weight thresholds in a single run, and can simultaneously produce a dendrogram representation of hierarchical community structure. In sparse weighted networks, the SCP algorithm can also be used for implementing the weighted clique percolation method recently introduced by Farkas [New J. Phys. 9, 180 (2007)]. The computational time of the SCP algorithm scales linearly with the number of k -cliques in the network. As an example, the method is applied to a product association network, revealing its nested community structure.

  13. Sequential evidence accumulation in decision making

    Directory of Open Access Journals (Sweden)

    Daniel Hausmann

    2008-03-01

    Full Text Available Judgments and decisions under uncertainty are frequently linked to a prior sequential search for relevant information. In such cases, the subject has to decide when to stop the search for information. Evidence accumulation models from social and cognitive psychology assume an active and sequential information search until enough evidence has been accumulated to pass a decision threshold. In line with such theories, we conceptualize the evidence threshold as the ``desired level of confidence'' (DLC of a person. This model is tested against a fixed stopping rule (one-reason decision making and against the class of multi-attribute information integrating models. A series of experiments using an information board for horse race betting demonstrates an advantage of the proposed model by measuring the individual DLC of each subject and confirming its correctness in two separate stages. In addition to a better understanding of the stopping rule (within the narrow framework of simple heuristics, the results indicate that individual aspiration levels might be a relevant factor when modelling decision making by task analysis of statistical environments.

  14. Sensitivity validation technique for sequential kriging metamodel

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Seung Kyun; Lee, Jin Min; Lee, Tae Hee [Hanyang Univ., Seoul (Korea, Republic of)

    2012-08-15

    Metamodels have been developed with a variety of design optimization techniques in the field of structural engineering over the last decade because they are efficient, show excellent prediction performance, and provide easy interconnections into design frameworks. To construct a metamodel, a sequential procedure involving steps such as the design of experiments, metamodeling techniques, and validation techniques is performed. Because validation techniques can measure the accuracy of the metamodel, the number of presampled points for an accurate kriging metamodel is decided by the validation technique in the sequential kriging metamodel. Because the interpolation model such as the kriging metamodel based on computer experiments passes through responses at presampled points, additional analyses or reconstructions of the meta models are required to measure the accuracy of the meta model if existing validation techniques are applied. In this study, we suggest a sensitivity validation that does not require additional analyses or reconstructions of the meta models. Fourteen two dimensional mathematical problems and an engineering problem are illustrated to show the feasibility of the suggested method.

  15. Information Geometry and Sequential Monte Carlo

    CERN Document Server

    Sim, Aaron; Stumpf, Michael P H

    2012-01-01

    This paper explores the application of methods from information geometry to the sequential Monte Carlo (SMC) sampler. In particular the Riemannian manifold Metropolis-adjusted Langevin algorithm (mMALA) is adapted for the transition kernels in SMC. Similar to its function in Markov chain Monte Carlo methods, the mMALA is a fully adaptable kernel which allows for efficient sampling of high-dimensional and highly correlated parameter spaces. We set up the theoretical framework for its use in SMC with a focus on the application to the problem of sequential Bayesian inference for dynamical systems as modelled by sets of ordinary differential equations. In addition, we argue that defining the sequence of distributions on geodesics optimises the effective sample sizes in the SMC run. We illustrate the application of the methodology by inferring the parameters of simulated Lotka-Volterra and Fitzhugh-Nagumo models. In particular we demonstrate that compared to employing a standard adaptive random walk kernel, the SM...

  16. Modifications of sequential designs in bioequivalence trials.

    Science.gov (United States)

    Zheng, Cheng; Zhao, Lihui; Wang, Jixian

    2015-01-01

    Bioequivalence (BE) studies are designed to show that two formulations of one drug are equivalent and they play an important role in drug development. When in a design stage, it is possible that there is a high degree of uncertainty on variability of the formulations and the actual performance of the test versus reference formulation. Therefore, an interim look may be desirable to stop the study if there is no chance of claiming BE at the end (futility), or claim BE if evidence is sufficient (efficacy), or adjust the sample size. Sequential design approaches specially for BE studies have been proposed previously in publications. We applied modification to the existing methods focusing on simplified multiplicity adjustment and futility stopping. We name our method modified sequential design for BE studies (MSDBE). Simulation results demonstrate comparable performance between MSDBE and the original published methods while MSDBE offers more transparency and better applicability. The R package MSDBE is available at https://sites.google.com/site/modsdbe/.

  17. Induced spin-triplet pairing in the coexistence state of antiferromagnetism and singlet superconductivity: Collective modes and microscopic properties

    Science.gov (United States)

    Almeida, D. E.; Fernandes, R. M.; Miranda, E.

    2017-07-01

    The close interplay between superconductivity and antiferromagnetism in several quantum materials can lead to the appearance of an unusual thermodynamic state in which both orders coexist microscopically, despite their competing nature. A hallmark of this coexistence state is the emergence of a spin-triplet superconducting gap component, called a π triplet, which is spatially modulated by the antiferromagnetic wave vector, reminiscent of a pair density wave. In this paper, we investigate the impact of these π -triplet degrees of freedom on the phase diagram of a system with competing antiferromagnetic and superconducting orders. Although we focus on a microscopic two-band model that has been widely employed in studies of iron pnictides, most of our results follow from a Ginzburg-Landau analysis, and as such should be applicable to other systems of interest, such as cuprates and heavy fermion materials. The Ginzburg-Landau functional reveals not only that the π -triplet gap amplitude couples trilinearly with the singlet gap amplitude and the staggered magnetization magnitude but also that the π -triplet d -vector couples linearly with the magnetization direction. While in the mean-field level this coupling forces the d -vector to align parallel or antiparallel to the magnetization, in the fluctuation regime it promotes two additional collective modes—a Goldstone mode related to the precession of the d -vector around the magnetization and a massive mode, related to the relative angle between the two vectors, which is nearly degenerate with a Leggett-like mode associated with the phase difference between the singlet and triplet gaps. We also investigate the impact of magnetic fluctuations on the superconducting-antiferromagnetic phase diagram, showing that due to their coupling with the π -triplet order parameter the coexistence region is enhanced. This effect stems from the fact that the π -triplet degrees of freedom promote an effective attraction between

  18. G-sequentially connectedness for topological groups with operations

    Science.gov (United States)

    Mucuk, Osman; Cakalli, Huseyin

    2016-08-01

    It is a well-known fact that for a Hausdorff topological group X, the limits of convergent sequences in X define a function denoted by lim from the set of all convergent sequences in X to X. This notion has been modified by Connor and Grosse-Erdmann for real functions by replacing lim with an arbitrary linear functional G defined on a linear subspace of the vector space of all real sequences. Recently some authors have extended the concept to the topological group setting and introduced the concepts of G-sequential continuity, G-sequential compactness and G-sequential connectedness. In this work, we present some results about G-sequentially closures, G-sequentially connectedness and fundamental system of G-sequentially open neighbourhoods for topological group with operations which include topological groups, topological rings without identity, R-modules, Lie algebras, Jordan algebras, and many others.

  19. Sequential Analysis in High Dimensional Multiple Testing and Sparse Recovery

    CERN Document Server

    Malloy, Matt

    2011-01-01

    This paper studies the problem of high-dimensional multiple testing and sparse recovery from the perspective of sequential analysis. In this setting, the probability of error is a function of the dimension of the problem. A simple sequential testing procedure for this problem is proposed. We derive necessary conditions for reliable recovery in the non-sequential setting and contrast them with sufficient conditions for reliable recovery using the proposed sequential testing procedure. Applications of the main results to several commonly encountered models show that sequential testing can be exponentially more sensitive to the difference between the null and alternative distributions (in terms of the dependence on dimension), implying that subtle cases can be much more reliably determined using sequential methods.

  20. Method of sequential mesh on Koopman-Darmois distributions

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    For costly and/or destructive tests,the sequential method with a proper maximum sample size is needed.Based on Koopman-Darmois distributions,this paper proposes the method of sequential mesh,which has an acceptable maximum sample size.In comparison with the popular truncated sequential probability ratio test,our method has the advantage of a smaller maximum sample size and is especially applicable for costly and/or destructive tests.

  1. STATE OF THE ART - MODERN SEQUENTIAL RULE MINING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Anjali Paliwal

    2015-10-01

    Full Text Available This paper is state of the art of existing sequential rule mining algorithms. Extracting sequential rule is a very popular and computationally expensive task. We also explain the fundamentals of sequential rule mining. We describe today’s approaches for sequential rule mining. From the broad variety of efficient algorithms that have been developed we will compare the most important ones. We will systematize the algorithms and analyze their performance based on both their run t ime performance and theoretical considerations. Their strengths and weaknesses are also investigated.

  2. State of The Art - Modern Sequential Rule Mining Techniques

    Directory of Open Access Journals (Sweden)

    Ms. Anjali Paliwal

    2014-08-01

    Full Text Available This paper is state of the art of existing sequential rule mining algorithms. Extracting sequential rule is a very popular and computationally expensive task. We also explain the fundamentals of sequential rule mining. We describe today’s approaches for sequential rule mining. From the broad variety of efficient algorithms that have been developed we will compare the most important ones. We will systematize the algorithms and analyze their performance based on both their run time performance and theoretical considerations. Their strengths and weaknesses are also investigated.

  3. The fine tuning of carotenoid-chlorophyll interactions in light-harvesting complexes: an important requisite to guarantee efficient photoprotection via triplet-triplet energy transfer in the complex balance of the energy transfer processes

    Science.gov (United States)

    Di Valentin, Marilena; Carbonera, Donatella

    2017-08-01

    Triplet-triplet energy transfer (TTET) from the chlorophyll to the carotenoid triplet state is the process exploited by photosynthetic systems to protect themselves from singlet oxygen formation under light-stress conditions. A deep comprehension of the molecular strategies adopted to guarantee TTET efficiency, while at the same time maintaining minimal energy loss and efficient light-harvesting capability, is still lacking. The paramagnetic nature of the triplet state makes electron paramagnetic resonance (EPR) the method of choice when investigating TTET. In this review, we focus on our extended comparative study of two photosynthetic antenna complexes, the Peridinin-chlorophyll a-protein of dinoflagellates and the light-harvesting complex II of higher plants, in order to point out important aspects of the molecular design adopted in the photoprotection strategy. We have demonstrated that a proper analysis of the EPR data allows one to identify the pigments involved in TTET and, consequently, gain an insight into the structure of the photoprotective sites. The structural information has been complemented by a detailed description of the electronic structure provided by hyperfine spectroscopy. All these elements represent the fundamental building blocks toward a deeper understanding of the requirements for efficient photoprotection, which is fundamental to guarantee the prolonged energy conversion action of photosynthesis.

  4. Sequential cooling insert for turbine stator vane

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Russel B

    2017-04-04

    A sequential flow cooling insert for a turbine stator vane of a small gas turbine engine, where the impingement cooling insert is formed as a single piece from a metal additive manufacturing process such as 3D metal printing, and where the insert includes a plurality of rows of radial extending impingement cooling air holes alternating with rows of radial extending return air holes on a pressure side wall, and where the insert includes a plurality of rows of chordwise extending second impingement cooling air holes on a suction side wall. The insert includes alternating rows of radial extending cooling air supply channels and return air channels that form a series of impingement cooling on the pressure side followed by the suction side of the insert.

  5. Sequential Stereotype Priming: A Meta-Analysis.

    Science.gov (United States)

    Kidder, Ciara K; White, Katherine R; Hinojos, Michelle R; Sandoval, Mayra; Crites, Stephen L

    2017-08-01

    Psychological interest in stereotype measurement has spanned nearly a century, with researchers adopting implicit measures in the 1980s to complement explicit measures. One of the most frequently used implicit measures of stereotypes is the sequential priming paradigm. The current meta-analysis examines stereotype priming, focusing specifically on this paradigm. To contribute to ongoing discussions regarding methodological rigor in social psychology, one primary goal was to identify methodological moderators of the stereotype priming effect-whether priming is due to a relation between the prime and target stimuli, the prime and target response, participant task, stereotype dimension, stimulus onset asynchrony (SOA), and stimuli type. Data from 39 studies yielded 87 individual effect sizes from 5,497 participants. Analyses revealed that stereotype priming is significantly moderated by the presence of prime-response relations, participant task, stereotype dimension, target stimulus type, SOA, and prime repetition. These results carry both practical and theoretical implications for future research on stereotype priming.

  6. Sequential pattern formation governed by signaling gradients

    CERN Document Server

    Jörg, David J; Jülicher, Frank

    2016-01-01

    Rhythmic and sequential segmentation of the embryonic body plan is a vital developmental patterning process in all vertebrate species. However, a theoretical framework capturing the emergence of dynamic patterns of gene expression from the interplay of cell oscillations with tissue elongation and shortening and with signaling gradients, is still missing. Here we show that a set of coupled genetic oscillators in an elongating tissue that is regulated by diffusing and advected signaling molecules can account for segmentation as a self-organized patterning process. This system can form a finite number of segments and the dynamics of segmentation and the total number of segments formed depend strongly on kinetic parameters describing tissue elongation and signaling molecules. The model accounts for existing experimental perturbations to signaling gradients, and makes testable predictions about novel perturbations. The variety of different patterns formed in our model can account for the variability of segmentatio...

  7. Sequential pattern formation governed by signaling gradients

    Science.gov (United States)

    Jörg, David J.; Oates, Andrew C.; Jülicher, Frank

    2016-10-01

    Rhythmic and sequential segmentation of the embryonic body plan is a vital developmental patterning process in all vertebrate species. However, a theoretical framework capturing the emergence of dynamic patterns of gene expression from the interplay of cell oscillations with tissue elongation and shortening and with signaling gradients, is still missing. Here we show that a set of coupled genetic oscillators in an elongating tissue that is regulated by diffusing and advected signaling molecules can account for segmentation as a self-organized patterning process. This system can form a finite number of segments and the dynamics of segmentation and the total number of segments formed depend strongly on kinetic parameters describing tissue elongation and signaling molecules. The model accounts for existing experimental perturbations to signaling gradients, and makes testable predictions about novel perturbations. The variety of different patterns formed in our model can account for the variability of segmentation between different animal species.

  8. Multilevel sequential Monte-Carlo samplers

    KAUST Repository

    Jasra, Ajay

    2016-01-05

    Multilevel Monte-Carlo methods provide a powerful computational technique for reducing the computational cost of estimating expectations for a given computational effort. They are particularly relevant for computational problems when approximate distributions are determined via a resolution parameter h, with h=0 giving the theoretical exact distribution (e.g. SDEs or inverse problems with PDEs). The method provides a benefit by coupling samples from successive resolutions, and estimating differences of successive expectations. We develop a methodology that brings Sequential Monte-Carlo (SMC) algorithms within the framework of the Multilevel idea, as SMC provides a natural set-up for coupling samples over different resolutions. We prove that the new algorithm indeed preserves the benefits of the multilevel principle, even if samples at all resolutions are now correlated.

  9. Isoscaling in Statistical Sequential Decay Model

    Institute of Scientific and Technical Information of China (English)

    TIAN Wen-Dong; SU Qian-Min; WANG Hong-Wei; WANG Kun; YAN Ting-ZHi; MA Yu-Gang; CAI Xiang-Zhou; FANG De-Qing; GUO Wei; MA Chun-Wang; LIU Gui-Hua; SHEN Wen-Qing; SHI Yu

    2007-01-01

    A sequential decay model is used to study isoscaling, I.e. The factorization of the isotope ratios from sources of different isospins and sizes over a broad range of excitation energies, into fugacity terms of proton and neutron number, R21(N, Z) = Y2(N, Z)/Y1(N, Z) = Cexp(αN +βZ). It is found that the isoscaling parameters α and β have a strong dependence on the isospin difference of equilibrated source and excitation energy, no significant influence of the source size on α andβ has been observed. It is found that α and β decrease with the excitation energy and are linear functions of 1/T and △(Z/A)2 or △(N/A)2 of the sources. Symmetry energy coefficient Csym is constrained from the relationship of α and source △(Z/A)2, β and source △(N/A)2.

  10. Steganography Based on Baseline Sequential JPEG Compression

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Information hiding in Joint Photographic Experts Group (JPEG) compressed images are investigated in this paper. Quantization is the source of information loss in JPEG compression process. Therefore, information hidden in images is probably destroyed by JPEG compression. This paper presents an algorithm to reliably embed information into the JPEG bit streams in the process of JPEG encoding. Information extraction is performed in the process of JPEG decoding. The basic idea of our algorithm is to modify the quantized direct current (DC) coefficients and non-zero alternating current (AC) coefficients to represent one bit information (0 or 1). Experimental results on gray images using baseline sequential JPEG encoding show that the cover images (images without secret information) and the stego-images (images with secret information) are perceptually indiscernible.

  11. Mechanistic studies on a sequential PDT protocol

    Science.gov (United States)

    Kessel, David

    2016-03-01

    A low (~LD15) PDT dose resulting in selective lysosomal photodamage can markedly promote photokilling by subsequent photodamage targeted to mitochondria. Experimental data are consistent with the proposal that cleavage of the autophagyassociated protein ATG5 to a pro-apoptotic fragment is responsible for this effect. This process is known to be dependent on the proteolytic activity of calpain. We have proposed that Ca2+ released from photodamaged lysosomes is the trigger for ATG5 cleavage. We can now document the conversion of ATG5 to the truncated form after lysosomal photodamage. Photofrin, a photosensitizer that targets both mitochondria and lysosomes, can be used for either phase of the sequential PDT process. The ability of Photofrin to target both loci may explain the well-documented efficacy of this agent.

  12. Sequential infiltration synthesis for advanced lithography

    Science.gov (United States)

    Darling, Seth B.; Elam, Jeffrey W.; Tseng, Yu-Chih; Peng, Qing

    2015-03-17

    A plasma etch resist material modified by an inorganic protective component via sequential infiltration synthesis (SIS) and methods of preparing the modified resist material. The modified resist material is characterized by an improved resistance to a plasma etching or related process relative to the unmodified resist material, thereby allowing formation of patterned features into a substrate material, which may be high-aspect ratio features. The SIS process forms the protective component within the bulk resist material through a plurality of alternating exposures to gas phase precursors which infiltrate the resist material. The plasma etch resist material may be initially patterned using photolithography, electron-beam lithography or a block copolymer self-assembly process.

  13. Compound imaging using Synthetic Aperture Sequential Beamformation

    DEFF Research Database (Denmark)

    Jensen, Casper Bo; Jensen, Jonas; Hemmsen, Martin Christian

    2011-01-01

    Synthetic Aperture Sequential Beamforming (SASB) is a technique with low complexity and the ability to yield a more uniform lateral resolution with range. However, the presence of speckle artifacts in ultrasound images degrades the contrast. In conventional imaging speckle is reduced by using...... spatial compounding at the cost of a reduced frame rate. The objective is to apply spatial compounding to SASB and evaluate if the images have a reduced speckle appearance and thereby an improved image quality in terms of contrast compared to ordinary SASB. Using the simulation software Field II, RF data...... detection the five second stage images are added to form the compounded image. Using a ProFocus scanner and the 8804 linear array transducer (BK Medical, Herlev, Denmark) measurements of a phantom containing water filled cysts are obtained to validate the simulation results. The setup is the same...

  14. Composite SAR imaging using sequential joint sparsity

    Science.gov (United States)

    Sanders, Toby; Gelb, Anne; Platte, Rodrigo B.

    2017-06-01

    This paper investigates accurate and efficient ℓ1 regularization methods for generating synthetic aperture radar (SAR) images. Although ℓ1 regularization algorithms are already employed in SAR imaging, practical and efficient implementation in terms of real time imaging remain a challenge. Here we demonstrate that fast numerical operators can be used to robustly implement ℓ1 regularization methods that are as or more efficient than traditional approaches such as back projection, while providing superior image quality. In particular, we develop a sequential joint sparsity model for composite SAR imaging which naturally combines the joint sparsity methodology with composite SAR. Our technique, which can be implemented using standard, fractional, or higher order total variation regularization, is able to reduce the effects of speckle and other noisy artifacts with little additional computational cost. Finally we show that generalizing total variation regularization to non-integer and higher orders provides improved flexibility and robustness for SAR imaging.

  15. Sequential hadronization and the opportunities it presents

    Science.gov (United States)

    Bellwied, R.

    2016-08-01

    Continuum extrapolated lattice QCD calculations of quantum number specific susceptibilities and the most recent RHIC and LHC data on produced particle yields, as well as their higher moment fluctuations, can be interpreted using a scenario of sequential flavor dependent hadronization during the QCD crossover transition. I will present the latest data from lattice QCD and experiment and confront the question whether the separation of strangeness and light quark chemical freeze-out could have consequences beyond a simple strangeness enhancement, firstly in the production of exotic strange states and secondly in the flavor dependent evolution of dynamic quantities such as in-medium energy loss and anisotropic flow, which are generated predominantly during the collective partonic phase.

  16. Lipid peroxidation in experimental uveitis: sequential studies.

    Science.gov (United States)

    Goto, H; Wu, G S; Chen, F; Kristeva, M; Sevanian, A; Rao, N A

    1992-06-01

    Previously we have detected the occurrence of retinal lipid peroxidation initiated by phagocyte-derived oxygen radicals in experimental autoimmune uveitis (EAU). In the current studies, the confirmation of inflammation-mediated lipid peroxidation was proceeded further to include measurement of multiple parameters, including conjugated dienes, ketodienes, thiobarbituric acid reactive substances and fluorescent chromolipids. The assay for myeloperoxidase, a measure for the number of polymorphonuclear leukocytes in the inflammatory sites was also carried out. The levels of all these parameters were followed through the course of EAU development. The sequential evaluation of histologic changes using both light and electron microscopy was also carried out and the results were correlated with lipid peroxidation indices. These data suggest that the retinal lipid peroxidation plays a causative role in the subsequent retinal degeneration.

  17. [Triplet pregnancy complicated by intrauterine death of two fetuses--case report].

    Science.gov (United States)

    Teliga-Czajkowska, Justyna; Dadalska, Ewa; Sopliński, Aleksander

    2003-10-01

    Multiple pregnancy still constitutes a difficult therapeutic problem in perinatology. The incidence of this phenomenon describes Hellin's formula: the number of twin pregnancy is 1/n, triplet--1/n 2 etc. Among complications observed in multiple pregnancy intrauterine death of one or more foetuses is not rare. Due to progressive disturbances in haemostasis the risk for a mother and remaining live foetus increases with gestation. The aim of this paper was to present a case report of triplet pregnancy complicated by an intrauterine death of two foetuses. 33 years old patient was diagnosed by ultrasound in the 19th week of her second gestation (1 child) a triplet pregnancy. Three live foetuses were seen then with biometry of about 14/15 gestational week There was one joint placenta on the back uterine wall and two children were sharing an amniotic sac. On the consecutive ultrasound examination the three foetuses were alive, but only one had a biometry for 21st week, two--were slowing down having measurements adequate for 19/20th week. After four weeks on usg the death of two siblings was confirmed (age 19/20 gestational week). One remaining live foetus was according to usg 24 weeks old. The patient was transferred to the II Dept. Even though no disturbances in coagulation were observed, low molecule heparin prophylaxis was introduced. During hospital stay a gestational diabetes was diagnosed well corrected by diet only. Coagulation parameters as well as infection indexes were regularly monitored. The foetal well-being was established by non-stress test, biophysical profile and Doppler vascular flows. After 39 days of hospitalisation an elevation of fibrin degradation products (FDP) was noted so the dosage of low molecule heparin was immediately increased to the therapeutic values. In spite of that FDP still were growing. It was decided to introduce a steroids treatment to accelerate the maturity of foetal lungs. In the 31st week according to usg, after PROM, the

  18. Synthesis, measurements, and theoretical analysis of carbazole derivatives with high-triplet-energy

    Energy Technology Data Exchange (ETDEWEB)

    Li Jianli; Mi Xiaoyun; Wan Yuchun [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Si Zhenjun, E-mail: szj@cust.edu.cn [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6 16610 (Czech Republic); Sun Haiying; Duan Qian [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); He Xingquan [School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Yan Dong; Wan Sha [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China)

    2012-05-15

    In order to obtain the blue light-emitting organic materials with high triplet state energy, two 3,5-diphenyl-4H-1,2,4-triazole (Tz) containing carbazole (Cz) derivatives of 9-(4-(3,5-diphenyl-4H-1,2,4-triazol-4-yl)phenyl)-9H-carbazole (TzCz1) and 3,6-di-tert-butyl-9-(4-(3,5-diphenyl-4H-1,2,4-triazol-4-yl)phenyl) -9H-carbazole (TzCz2) are synthesized using Cz acting as the starting material, as well as characterized by the {sup 1}H NMR spectra, ultraviolet-visible (UV-vis) absorption spectra, and the IR absorption spectra. The luminescence quantum yields (LQYs) of TzCz1 and TzCz2 are measured in CH{sub 2}Cl{sub 2} solution to be 32.1% and 47.5%, respectively. The electrochemical analysis and the photophysical measurements suggest that the triplet energy levels and the energy gaps of the highest-occupied orbital and the lowest-unoccupied orbital are 2.83 eV and 3.59 eV for TzCz1, and 2.80 eV and 3.43 eV for TzCz2. At last, the theoretical analyses of their ground state geometries and the simulated UV-vis absorption spectra are carried out at B3LYP1/6-31G Low-Asterisk level. The studies mentioned above indicate that both TzCz1 and TzCz2 are suitable for the host materials of blue light-emitting diodes. - Highlights: Black-Right-Pointing-Pointer Synthesis of two blue light-emitting Carbazole derivatives. Black-Right-Pointing-Pointer Photophysical and electrochemical properties are systematically studied. Black-Right-Pointing-Pointer Theoretical analysis of geometry of the ground states and the UV-vis absorption are performed with Firefly package. Black-Right-Pointing-Pointer The triplet energy levels are measured to be ca. 2.83 eV.

  19. Discriminative predation: Simultaneous and sequential encounter experiments

    Institute of Scientific and Technical Information of China (English)

    C.D.BEATTY; D.W.FRANKS

    2012-01-01

    There are many situations in which the ability of animals to distinguish between two similar looking objects can have significant selective consequences.For example,the objects that require discrimination may be edible versus defended prey,predators versus non-predators,or mates of varying quality.Working from the premise that there are situations in which discrimination may be more or less successful,we hypothesized that individuals find it more difficult to distinguish between stimuli when they encounter them sequentially rather than simultaneously.Our study has wide biological and psychological implications from the perspective of signal perception,signal evolution,and discrimination,and could apply to any system where individuals are making relative judgments or choices between two or more stimuli or signals.While this is a general principle that might seem intuitive,it has not been experimentally tested in this context,and is often not considered in the design of models or experiments,or in the interpretation of a wide range of studies.Our study is different from previous studies in psychology in that a) the level of similarity of stimuli are gradually varied to obtain selection gradients,and b) we discuss the implications of our study for specific areas in ecology,such as the level of perfection of mimicry in predator-prey systems.Our experiments provide evidence that it is indeed more difficult to distinguish between stimuli - and to learn to distinguish between stimuli - when they are encountered sequentially rather than simultaneously,even if the intervening time interval is short.

  20. The sequential propensity household projection model

    Directory of Open Access Journals (Sweden)

    Tom Wilson

    2013-04-01

    Full Text Available BACKGROUND The standard method of projecting living arrangements and households in Australia and New Zealand is the 'propensity model', a type of extended headship rate model. Unfortunately it possesses a number of serious shortcomings, including internal inconsistencies, difficulties in setting living arrangement assumptions, and very limited scenario creation capabilities. Data allowing the application of more sophisticated dynamic household projection models are unavailable in Australia. OBJECTIVE The aim was create a projection model to overcome these shortcomings whilst minimising input data requirements and costs, and retaining the projection outputs users are familiar with. METHODS The sequential propensity household projection model is proposed. Living arrangement projections take place in a sequence of calculations, with progressively more detailed living arrangement categories calculated in each step. In doing so the model largely overcomes the three serious deficiencies of the standard propensity model noted above. RESULTS The model is illustrated by three scenarios produced for one case study State, Queensland. They are: a baseline scenario in which all propensities are held constant to demonstrate the effects of population growth and ageing, a housing crisis scenario where housing affordability declines, and a prosperity scenario where families and individuals enjoy greater real incomes. A sensitivity analysis in which assumptions are varied one by one is also presented. CONCLUSIONS The sequential propensity model offers a more effective method of producing household and living arrangement projections than the standard propensity model, and is a practical alternative to dynamic projection models for countries and regions where the data and resources to apply such models are unavailable.