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Sample records for atom transferring system

  1. H atom transfer of collinear OH…O system

    Institute of Scientific and Technical Information of China (English)

    WU, Tao(吴韬); CHEN, Xian-Yang(陈先阳); PENG, Jian-Bo(彭建波); JU, Guan-Zhi(居冠之); JU, Guan-Zhi(居冠之)

    2000-01-01

    A quantum mechanical calculation was performed to study the hydrogen atom transfer of collinear OH…O/OD…O system,for which Delves ' coordinates and R-matrix propagation method were applied in a Melius-Blint potential energy surface. The calculation result showed that the state-state H atom transfer probability comported strong oscillation phenomena and collision delay time of the title system was in the fs-ps time scale. The kinetic isotope effect was calculated in this work too.

  2. Population transfer by femtosecond laser pulses in a ladder-type atomic system

    Institute of Scientific and Technical Information of China (English)

    Fan Xi-Jun; Li Ai-Yun; Tong Dian-Min; Liu Cheng-Pu

    2008-01-01

    The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schrodinger equation without including the rotating wave approximation (RWA). It is shown that population transfer is mainly determined by the Rabi frequency (strength) of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.

  3. Efficiency limitation for realizing an atom-molecule adiabatic transfer based on a chainwise system

    CERN Document Server

    Zhai, Jingjing; Zhang, Keye; Qian, Jing; Zhang, Weiping

    2015-01-01

    In a recent work we have developed a robust chainwise atom-molecule adiabatic passage scheme to produce ultracold ground-state molecules via photo-associating free atoms [J. Qian {\\it et.al.} Phys. Rev. A 81 013632 (2010)]. With the help of intermediate auxiliary levels, the pump laser intensity requested in the atomic photo-association process can be greatly reduced. In the present work, we extend the scheme to a more generalized (2$n$+1)-level system and investigate the efficiency limitation for it. As the increase of intermediate levels and auxiliary lasers, the atom-molecule adiabatic passage would be gradually closed, leading to a poor transfer efficiency. For the purpose of enhancing the efficiency, we present various optimization approaches to the laser parameters, involving order number $n$, relative strength ratio and absolute strength. We show there can remain a limit on the population transfer efficiency given by a three-level $\\Lambda$ system. In addition, we illustrate the importance of selecting...

  4. A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL POLYMERIZATION OF STYRENE

    Institute of Scientific and Technical Information of China (English)

    Shu-hui Qin; Dong-qi Qin; Kun-yuan Qiu

    2001-01-01

    A novel photo-induced initiating system, 2,2-dimethoxy-2-phenylacetophenone (DMPA)/ferric tri(N,N-diethyldithiocarbamate) [Fe(DC)3], was developed and used for the atom transfer radical polymerization (ATRP) of styrene in toluene. The polymerization proceeds with DMPA as photo-initiator, Fe(DC)3 as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the polymerization mechanism revealed by end group analysis belongs to a reverse ATRP. Block copolymer was prepared by using thus obtained PSt as macroinitiator and Fe(DC)2 as catalyst under UV light irradiation via a conventional ATRP process.``

  5. Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system.

    Science.gov (United States)

    Bai, Cheng-Hua; Wang, Dong-Yang; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-01-01

    We propose a scheme for the creation of robust entanglement between a movable mirror and atomic ensemble at the macroscopic level in coupled optomechanical system. We numerically simulate the degree of entanglement of the bipartite macroscopic entanglement and show that it depends on the coupling strength between the cavities and is robust with respect to the certain environment temperature. Inspiringly and surprisingly, according to the reported relation between the mechanical damping rate and the mechanical frequency of the movable mirror, the numerical simulation result shows that such bipartite macroscopic entanglement persists for environment temperature up to 170 K, which breaks the liquid nitrogen cooling and liquid helium cooling and largely lowers down the experiment cost. We also investigate the entanglement transfer based on this coupled system. The scheme can be used for the realization of quantum memories for continuous variable quantum information processing and quantum-limited displacement measurements. PMID:27624534

  6. Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system

    Science.gov (United States)

    Bai, Cheng-Hua; Wang, Dong-Yang; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-09-01

    We propose a scheme for the creation of robust entanglement between a movable mirror and atomic ensemble at the macroscopic level in coupled optomechanical system. We numerically simulate the degree of entanglement of the bipartite macroscopic entanglement and show that it depends on the coupling strength between the cavities and is robust with respect to the certain environment temperature. Inspiringly and surprisingly, according to the reported relation between the mechanical damping rate and the mechanical frequency of the movable mirror, the numerical simulation result shows that such bipartite macroscopic entanglement persists for environment temperature up to 170 K, which breaks the liquid nitrogen cooling and liquid helium cooling and largely lowers down the experiment cost. We also investigate the entanglement transfer based on this coupled system. The scheme can be used for the realization of quantum memories for continuous variable quantum information processing and quantum-limited displacement measurements.

  7. Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system.

    Science.gov (United States)

    Bai, Cheng-Hua; Wang, Dong-Yang; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-09-14

    We propose a scheme for the creation of robust entanglement between a movable mirror and atomic ensemble at the macroscopic level in coupled optomechanical system. We numerically simulate the degree of entanglement of the bipartite macroscopic entanglement and show that it depends on the coupling strength between the cavities and is robust with respect to the certain environment temperature. Inspiringly and surprisingly, according to the reported relation between the mechanical damping rate and the mechanical frequency of the movable mirror, the numerical simulation result shows that such bipartite macroscopic entanglement persists for environment temperature up to 170 K, which breaks the liquid nitrogen cooling and liquid helium cooling and largely lowers down the experiment cost. We also investigate the entanglement transfer based on this coupled system. The scheme can be used for the realization of quantum memories for continuous variable quantum information processing and quantum-limited displacement measurements.

  8. Synthesis of End Functional Polymers via Atom Transfer Radical Polymerization in Immobilized Catalytic System

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cross-linked polystyrene with azo-crown ether functional side chain (PSt-1, 10-dicarbonyl-3,6,9-trizaocylcodecane) was prepared under microwave irradiation and the structure was characterized through FT-IR and element analysis. The functionalized cross-linked polystyrene (cross-link degree, 3.5%) combining with immobilized catalyst system (CuBr and ethyl α-bromo-isobutyrate) can catalyze atom transfer radical polymerization of Styrene. Neat polymer products can be obtained then. Complex of La and the polymer end group (EBiB) was synthesized. The third order nonlinear optical property of the polymer-La complex was investigated and the structure was also characterized by FT-IR and XPS.

  9. Efficient transfer of francium atoms

    Science.gov (United States)

    Aubin, Seth; Behr, John; Gorelov, Alexander; Pearson, Matt; Tandecki, Michael; Collister, Robert; Gwinner, Gerald; Shiells, Kyle; Gomez, Eduardo; Orozco, Luis; Zhang, Jiehang; Zhao, Yanting; FrPNC Collaboration

    2016-05-01

    We report on the progress of the FrPNC collaboration towards Parity Non Conservation Measurements (PNC) using francium atoms at the TRIUMF accelerator. We demonstrate efficient transfer (higher than 40%) to the science vacuum chamber where the PNC measurements will be performed. The transfer uses a downward resonant push beam from the high-efficiency capture magneto optical trap (MOT) towards the science chamber where the atoms are recaptured in a second MOT. The transfer is very robust with respect to variations in the parameters (laser power, detuning, alignment, etc.). We accumulate a growing number of atoms at each transfer pulse (limited by the lifetime of the MOT) since the push beam does not eliminate the atoms already trapped in the science MOT. The number of atoms in the science MOT is on track to meet the requirements for competitive PNC measurements when high francium rates (previously demonstrated) are delivered to our apparatus. The catcher/neutralizer for the ion beam has been tested reliably to 100,000 heating/motion cycles. We present initial tests on the direct microwave excitation of the ground hyperfine transition at 45 GHz. Support from NSERC and NRC from Canada, NSF and Fulbright from USA, and CONACYT from Mexico.

  10. Diffusion-regulated phase-transfer catalysis for atom transfer radical polymerization of methyl methacrylate in an aqueous/organic biphasic system.

    Science.gov (United States)

    Ding, Mingqiang; Jiang, Xiaowu; Peng, Jinying; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2015-03-01

    A concept based on diffusion-regulated phase-transfer catalysis (DRPTC) in an aqueous-organic biphasic system with copper-mediated initiators for continuous activator regeneration is successfully developed for atom transfer radical polymerization (ICAR ATRP) (termed DRPTC-based ICAR ATRP here), using methyl methacrylate (MMA) as a model monomer, ethyl α-bromophenylacetate (EBrPA) as an initiator, and tris(2-pyridylmethyl)amine (TPMA) as a ligand. In this system, the monomer and initiating species in toluene (organic phase) and the catalyst complexes in water (aqueous phase) are simply mixed under stirring at room temperature. The trace catalyst complexes transfer into the organic phase via diffusion to trigger ICAR ATRP of MMA with ppm level catalyst content once the system is heated to the polymerization temperature (75 °C). It is found that well-defined PMMA with controlled molecular weights and narrow molecular weight distributions can be obtained easily. Furthermore, the polymerization can be conducted in the presence of limited amounts of air without using tedious degassed procedures. After cooling to room temperature, the upper organic phase is decanted and the lower aqueous phase is reused for another 10 recycling turnovers with ultra low loss of catalyst and ligand loading. At the same time, all the recycled catalyst complexes retain nearly perfect catalytic activity and controllability, indicating a facile and economical strategy for catalyst removal and recycling.

  11. Hydrogen-Atom Transfer Reactions.

    Science.gov (United States)

    Wang, Liang; Xiao, Jian

    2016-04-01

    The cascade [1,n]-hydrogen transfer/cyclization, recognized as the tert-amino effect one century ago, has received considerable interest in recent decades, and great achievements have been made. With the aid of this strategy, the inert C(sp(3))-H bonds can be directly functionalized into C-C, C-N, C-O bonds under catalysis of Lewis acids, Brønsted acids, as well as organocatalysts, and even merely under thermal conditions. Hydrogen can be transferred intramolecularly from hydrogen donor to acceptor in the form of hydride, or proton, followed by cyclization to furnish the cyclic products in processes featuring high atom economy. Methylene/methine adjacent to heteroatoms, e.g., nitrogen, oxygen, sulfur, can be exploited as hydride donor as well as methylene/methine without heteroatom assistance. Miscellaneous electrophilic subunits or intermediates, e.g., alkylidene malonate, carbophilic metal activated alkyne or allene, α,β-unsaturated aldehydes/ketone, saturated aldehydes/iminium, ketenimine/carbodiimide, metal carbenoid, electron-withdrawing groups activated allene/alkyne, in situ generated carbocation, can serve as hydride acceptors. This methodology has shown preeminent power to construct 5-, 6-, or 7-membered heterocyclic as well as carbon rings. In this chapter, various hydrogen donors and acceptors are adequately discussed. PMID:27573142

  12. Transferable basis sets of numerical atomic orbitals

    NARCIS (Netherlands)

    M.J. Louwerse; G. Rothenberg

    2012-01-01

    We show that numerical atomic orbital basis sets that are variationally optimized for specific compounds are biased and not fully transferable to other compounds. The situation improves when the basis sets are optimized for several compounds and a compromise is made. We demonstrate this for basis se

  13. [Electron transfer, ionization, and excitation in atomic collisions]: Progress report

    International Nuclear Information System (INIS)

    The fundamental processes of electron transfer, ionization, and excitation in ion-atom collisions are being studied. These collision processes are treated in the context of simple one- or two-electron systems in order to provide unambiguous results and reveal more clearly the collisional mechanisms. As outlined in the original proposal, three coupled-state calculations are being carried out over the present three-year period: a Sturmian-pseudostate study of ionization in collisions between protons and the hydrogenic ions He+, Li2+, Be3+, ...; a triple-center, atomic-state study of ionization in collisions between α particles and H(ls) atoms and between protons and He+(ls) ions; and an atomic-state study of electron transfer and excitation in collisions between protons and neutral He atoms. 12 refs

  14. Correlated energy transfer between two ultracold atomic species

    Science.gov (United States)

    Krönke, Sven; Knörzer, Johannes; Schmelcher, Peter

    2015-05-01

    We study a single atom as an open quantum system, which is initially prepared in a coherent state of low energy and oscillates in a one-dimensional harmonic trap through an interacting ensemble of NA bosons, held in a displaced trap [arXiv:1410.8676]. The non-equilibrium quantum dynamics of the total system is simulated by means of an ab-initio method, giving us access to all properties of the open system and its finite environment. In this talk, we focus on unraveling the interplay of energy exchange and correlations between the subsystems, which are coupled in such a spatio-temporally localized manner. We show that an inter-species interaction-induced level splitting accelerates the energy transfer between the atomic species for larger NA, which becomes less complete at the same time. System-environment correlations prove to be significant except for times when the excess energy distribution among the subsystems is highly imbalanced. These correlations result in incoherent energy transfer processes, which accelerate the early energy donation of the single atom. By analyzing correlations between intra-subsystem excitations, certain energy transfer channels are shown to be (dis-)favored depending on the instantaneous direction of transfer.

  15. Gas transfer system

    International Nuclear Information System (INIS)

    The state of work on the Vivitron gas transfer system and the system functions are summarized. The system has to: evacuate the Vivitron reservoir; transfer gas from storage tanks to the Vivitron; recirculate gas during operation; transfer gas from the Vivitron to storage tanks; and assure air input. The system is now being installed. Leak alarms are given by SF6 detectors, which set off a system of forced ventilation. Another system continuously monitors the amount of SF6 in the tanks

  16. Soliton Atom Laser with Quantum State Transfer Property

    Institute of Scientific and Technical Information of China (English)

    LIU Xiong-Jun; JING Hui; GE Mo-Lin

    2006-01-01

    @@ We study the nonlinear effects in the quantum states transfer technique from photons to matter waves in the three-level case, which may provide the formation of a soliton atom laser with nonclassical atoms. The validity of quantum transfer mechanism is confirmed in the presence of the intrinsic nonlinear atomic interactions. The accompanied frequency chirp effect is shown to have no influence on the grey solitons formed by the output atom laser and the possible quantum depletion effect is also briefly discussed.

  17. Imaging population transfer in atoms with ultrafast electron pulses

    Science.gov (United States)

    Shao, Hua-Chieh; Starace, Anthony F.

    2016-05-01

    Ultrafast electron diffraction and microscopy have made significant progress recently in investigating atomic-scale structural dynamics in gas-phase and condensed materials. With these advances, direct imaging of electronic motions in atoms and molecules by ultrafast electron diffraction is anticipated. We propose imaging a laser-driven coherent population transfer in lithium atoms by femtosecond ultrafast electron pulses. Valuable information and insight can be obtained from studying such a system in order to refine ultrafast electron techniques and to interpret experimental results. Adiabatic passage by level crossing is used to transfer the electron population from the 2 s to the 2 p state. Our simulations demonstrate the ability of ultrafast electron diffraction to image this population transfer, as the time-dependent diffraction images reflect the electronic motion in the scattering intensity and angular distribution. Furthermore, asymmetric diffraction patterns indicate that even the relative phases of the electronic wave function can be resolved, provided there is sufficient temporal resolution. This work has been supported in part by DOE Award No. DE-SC0012193 [H.-C.S.] and by NSF Grant No. PHYS-1505492 [A.F.S.].

  18. Large-momentum-transfer Bragg interferometer with strontium atoms

    CERN Document Server

    Mazzoni, T; Del Aguila, R; Salvi, L; Poli, N; Tino, G M

    2015-01-01

    We report on the first atom interferometer based on Bragg diffraction in a fountain of alkaline-earth atoms, namely $^{88}$Sr. We demonstrate large momentum transfer to the atoms up to eight photon recoils and the use of the interferometer as a gravimeter with a sensitivity $\\delta g/g=4\\times 10^{-8}$. Thanks to the special characteristics of strontium atoms for precision measurements, this result opens a new way for experiments in fundamental and applied physics.

  19. Modulation transfer spectroscopy in a lithium atomic vapor cell.

    Science.gov (United States)

    Sun, Dali; Zhou, Chao; Zhou, Lin; Wang, Jin; Zhan, Mingsheng

    2016-05-16

    We have investigated modulation transfer spectroscopy of D2 transitions of 7Li atoms in a vapor cell. The role of the intensity of the probe beam in the spectrum is important, we have seen unique characteristics of the signal in the crossover peak. In order to find the best signal for laser locking, the slope and frequency offset of the zero-crossing signal are determined. The dependence of the modulation transfer spectra on polarizations of pump and probe beam is demonstrated. The residual amplitude modulation in the system is also considered, and the distortion of the spectra due to the modulation is analyzed. It was found that the crossover peak is more suitable for frequency stabilization due to its better residual amplitude modulation compensation. PMID:27409886

  20. Transferences of Purkinje systems

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2011-12-01

    Full Text Available The transferences of heterocentric astigmatic Purkinje systems are special: submatrices B and C, that is, the disjugacy and the divergence of the system, are symmetric and submatrix D (the divarication is the transpose of submatrix A (the dilation.  It is the primary purpose of this paper to provide a proof.  The paper also derives other relationships among the fundamental properties and compact expressions for the transference and optical axis locator of a Purkinje system. (S Afr Optom 2011 70(2 57-60

  1. Electron transfer in ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C D

    1979-01-01

    Recent theoretical development in the understanding of electron transfer processes is reviewed. K-K electron transfer processes are studied for projectiles (nuclear charge Z/sub B/) and targets (nuclear charge Z/sub A/) in which Z/sub A/ and Z/sub B/ range from Z/sub A/ much greater than Z/sub B/ to Z/sub A/ approx. = Z/sub B/, over the energy range 0.1 < v/v/sub e/ < 2. (GHT)

  2. Orbital Fluid Transfer System

    Science.gov (United States)

    Johnston, A. S., (Nick); Ryder, Mel; Tyler, Tony R.

    1998-01-01

    An automated fluid and power interface system needs to be developed for future space missions which require on orbit consumable replenishment. Current method of fluid transfer require manned vehicles and extravehicular activity. Currently the US does not have an automated capability for consumable transfer on-orbit. This technology would benefit both Space Station and long duration satellites. In order to provide this technology the Automated Fluid Interface System (AFIS) was developed. The AFIS project was an advanced development program aimed at developing a prototype satellite servicer for future space operations. This mechanism could transfer propellants, cryogens, fluids, gasses, electrical power, and communications from a tanker unit to the orbiting satellite. The development of this unit was a cooperative effort between Marshall Space Flight Center in Huntsville, Alabama, and Moog, Inc. in East Aurora, New York. An engineering model was built and underwent substantial development testing at Marshall Space Flight Center (MSFC). While the AFIS is not suitable for spaceflight, testing and evaluation of the AFIS provided significant experience which would be beneficial in building a flight unit. The lessons learned from testing the AFIS provided the foundation for the next generation fluid transfer mechanism, the Orbital Fluid Transfer System (OFTS). The OFTS project was a study contract with MSFC and Moog, Inc. The OFTS was designed for the International Space Station (ISS), but its flexible design could used for long duration satellite missions and other applications. The OFTS was designed to be used after docking. The primary function was to transfer bipropellants and high pressure gases. The other items addressed by this task included propellant storage, hardware integration, safety and control system issues. A new concept for high pressure couplings was also developed. The results of the AFIS testing provided an excellent basis for the OFTS design. The OFTS

  3. Muon transfer from hot muonic hydrogen atoms to neon

    International Nuclear Information System (INIS)

    A negative muon beam has been directed on adjacent solid layers of hydrogen and neon. Three targets differing by their deuterium concentration were investigated. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. The time structure of the muonic neon X-rays follows the exponential law with a disappearance rate corresponding to the one of μ-p atoms in each target. The rates λppμ and λpd can be extracted

  4. Modulation transfer spectroscopy of ytterbium atoms in hollow cathode lamp

    International Nuclear Information System (INIS)

    We present the experimental study of modulation transfer spectroscopy of ytterbium atoms in a hollow cathode lamp. The dependences of its linewidth, slope and magnitude on the various experimental parameters are measured and fitted by the well-known theoretical expressions. The experimental results are in good agreement with the theoretical prediction. We have observed the Dicke narrowing effect by increasing the current of the hollow cathode lamp. It is also found that there are the optimal current and laser power to generate the better modulation transfer spectroscopy signal, which can be employed for locking the laser frequency to the atomic transition. (authors)

  5. Living atom transfer radical polymerization of 4-acetoxystyrene

    DEFF Research Database (Denmark)

    Gao, Bo; Chen, Xianyi; Ivan, Bela;

    1997-01-01

    Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine(bpy) as initi......Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine...

  6. Wireless power transfer system

    Science.gov (United States)

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2016-02-23

    A system includes a first stage of an inductive power transfer system with an LCL load resonant converter with a switching section, an LCL tuning circuit, and a primary receiver pad. The IPT system includes a second stage with a secondary receiver pad, a secondary resonant circuit, a secondary rectification circuit, and a secondary decoupling converter. The secondary receiver pad connects to the secondary resonant circuit. The secondary resonant circuit connects to the secondary rectification circuit. The secondary rectification circuit connects to the secondary decoupling converter. The second stage connects to a load. The load includes an energy storage element. The second stage and load are located on a vehicle and the first stage is located at a fixed location. The primary receiver pad wirelessly transfers power to the secondary receiver pad across a gap when the vehicle positions the secondary receiver pad with respect to the primary receiver pad.

  7. Synthesis of Amphiphilic Copolymwers by Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie

    2007-01-01

    atom transfer radikal polymerisation (ATRP) blev anvendt til alle polymerisationerne. De reaktionskinetiske forhold samt de opnåelige materialestrukturer viste, at næsten alle anvendte monomer-kombinationer kan håndteres til fremstilling af fluorholdige polymermaterialer med velkontrolleret struktur...

  8. Coherent Transfer of Electronic Wavepacket Motion Between Atoms

    Science.gov (United States)

    Zhou, Tao; Richards, B. G.; Jones, R. R.

    2016-05-01

    We have shown that electron correlations, induced by controlled dipole-dipole (DD) interactions, can enable the coherent transfer of electronic wavepacket motion from atoms to their neighbors. In the experiment, a 5 ns tunable dye laser excites Rb atoms in a MOT to the 25s state in a weak static electric field for which the tunable 25s 33 s 24p34p DD interaction is resonant. A picosecond THz pulse then further excites each Rydberg atom into a coherent superposition, of 25s and 24p states. The evolution of this mixed-parity wavepacket is characterized by time-dependent oscillations in the electric dipole moment, with a period of 2.9 ps. Approximately 5 ns after the wavepacket creation, a second 5 ns dye-laser promotes a second set of atoms from the 5p level into the 33s state. Because of the DD interaction, the second dye laser actually creates atom pairs whose electronic states are correlated via the resonant DD coupling. A 33 s + 34p wavepacket, oscillating with the same 2.9 ps period as the 25 s + 24p wavepacket, develops on the second set of atoms as a result of the correlation. A second, time-delayed ps THz pulse enables the detection of the coherent wavepacket motion on the two sets of atoms. This research has been supported by the NSF.

  9. Do Spin State and Spin Density Affect Hydrogen Atom Transfer Reactivity?

    OpenAIRE

    Saouma, Caroline T.; Mayer, James M.

    2013-01-01

    The prevalence of hydrogen atom transfer (HAT) reactions in chemical and biological systems has prompted much interest in establishing and understanding the underlying factors that enable this reactivity. Arguments have been advanced that the electronic spin state of the abstractor and/or the spin-density at the abstracting atom are critical for HAT reactivity. This is consistent with the intuition derived from introductory organic chemistry courses. Herein we present an alternative view on t...

  10. Photon exchange and correlation transfer in atom-atom entanglement dynamics

    OpenAIRE

    León García, Juan José; Sabín, Carlos

    2009-01-01

    We analyze the entanglement dynamics of a system composed by a pair of neutral two-level atoms that are initially entangled, and the electromagnetic field, initially in the vacuum state, within the formalism of perturbative quantum field theory up to the second order. We show that entanglement sudden death and revival can occur while the atoms remain spacelike-separated and therefore cannot be related with photon exchange between the atoms. We interpret these phenomena as the consequence of a...

  11. Novel Polymers Based on Atom Transfer Radical Polymerization of 2-Methoxyethyl Acrylate

    DEFF Research Database (Denmark)

    Bednarek, Melania; Jankova Atanasova, Katja; Hvilsted, Søren

    2007-01-01

    Atom transfer radical polymerization (ATRP) has been employed in the polymerization of 2-methoxyethyl acrylate (MEA) initiated by ethyl 2-bromoisobutyrate in bulk or in toluene solution at 90– 95 C with the catalytic systems Cu(I)Br/PMDETA or HMTETA. Kinetics investigations revealed that ATRP of...

  12. Acrylamide Homopolymers and Acrylamide-N-Isopropylacrylamide Block Copolymers by Atomic Transfer Radical Polymerization in Water

    NARCIS (Netherlands)

    Wever, D. A. Z.; Raffa, P.; Picchioni, F.; Broekhuis, A. A.

    2012-01-01

    Atomic transfer radical polymerization (ATRP) of acrylamide has been accomplished in aqueous media at room temperature. By using methyl 2-chloropropionate (MeClPr) as the initiator and tris[2-(dimethylamino)ethyl]-amine (Me6TREN)/copper halogenide (CuX) as the catalyst system, different linear polya

  13. Effect of atomic transfer on the decay of a Bose-Einstein condensate

    CERN Document Server

    Zin, P; Charzynski, S; Herschbach, N; Tol, P; Hogervorst, W; Vassen, W; Zin, Pawel; Dragan, Andrzej; Charzynski, Szymon; Herschbach, Norbert; Tol, Paul; Hogervorst, Wim; Vassen, Wim

    2003-01-01

    We present a model describing the decay of a Bose-Einstein condensate, which assumes the system to remain in thermal equilibrium during the decay. We show that under this assumption transfer of atoms occurs from the condensate to the thermal cloud enhancing the condensate decay rate.

  14. Atomic capture and transfer of negative pions stopped in binary mixtures of hydrogen with polyatomic gases

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyev, V.A.; Levay, B.; Minkova, A.; Petrukhin, V.I.; Horvath, D.

    1985-12-01

    The atomic capture and transfer of stopped negative pions have been studied in binary gas mixtures of H/sub 2/+M, where M is CCl/sub 2/F/sub 2/, CClF/sub 3/, CBrF/sub 3/ or SF/sub 6/. The ..pi../sup 0/ yield, versus relative atomic concentration Csub(A) of M, goes through a maximum at Csub(A)proportional0.1 and levels off at zero at high concentrations. This phenomenon together with other observed characteristics of the atomic capture and transfer of pions in these systems is interpreted in the frame of a phenomenological model. The average transfer coefficients anti ..lambda..sub(Z) exhibit a weak concentration dependence. The estimated average atomic capture ratios anti A(Z/H) are lower than those found for noble gases, probably because of the mutual screening of the constituent atoms in the molecules. The probability of pion capture in an atomic orbit is not proportional to the stopping power of the components of the mixture. (orig.).

  15. Excitation and charge transfer in low-energy hydrogen atom collisions with neutral atoms: Theory, comparisons, and application to Ca

    CERN Document Server

    Barklem, Paul S

    2016-01-01

    A theoretical method for the estimation of cross sections and rates for excitation and charge transfer processes in low-energy hydrogen atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent interactions in the neutral atom-hydrogen atom system, is presented. The calculation of potentials and non-adiabatic radial couplings using the method is demonstrated. The potentials are used together with the multi-channel Landau-Zener model to calculate cross sections and rate coefficients. The main feature of the method is that it employs asymptotically exact atomic wavefunctions, which can be determined from known atomic parameters. The method is applied to Li+H, Na+H, and Mg+H collisions, and the results compare well with existing detailed full-quantum calculations. The method is applied to the astrophysically important problem of Ca+H collisions, and rate coefficients are calculated for temperatures in the range 1000-20000 K.

  16. Heating-Assisted Atom Transfer in the Scanning Tunneling Microscope

    CERN Document Server

    Grigorescu, M

    1998-01-01

    The effects of a voltage pulse on the localization probability for a Xe atom prepared in a pure state localized on the STM surface at 0 temperature is investigated by numerically integrating the time-dependent Schroedinger equation. In these calculations the environmental interactions are neglected, and voltage pulses of 20 and 7 ns with symmetric triangular and trapezoidal shapes are considered. The atom dynamics at an environmental temperature of 4 K is studied in the frame of a stochastic, non-linear Liouville equation for the density operator. It is shown that the irreversible transfer from surface to tip may be explained by thermal decoherence rather than by the driving force acting during the application of the voltage pulse.

  17. Muon transfer from muonic hydrogen to heavier atoms; Transfert de charge muonique

    Energy Technology Data Exchange (ETDEWEB)

    Dupays, A

    2004-06-01

    This work concerns muon transfer from muonic hydrogen to heavier atoms. Recently, a method of measurement of the hyperfine structure of ground-state muonic hydrogen based on the collision energy dependence of the muon transfer rate to oxygen has been proposed. This proposal is based on measurements which where performed at the Paul Scherrer Institute in the early nineties which indicate that the muon transfer from muonic hydrogen to oxygen increases by a factor of 4 going from thermal to 0.12 eV energies. The motivation of our calculations was to confirm this behaviour. To study the collision energy dependence of the muon transfer rate, we have used a time-independent close-coupling method. We have set up an hyperspherical elliptic formalism valid for nonzero total angular momentum which allows accurate computations of state-to-state reactive and charge exchange processes. We have applied this formalism to muon-transfer process to oxygen and neon. The comparison with experimental results is in both cases excellent. Finally, the neon transfer rate dependence with energy suggests to use neon instead of oxygen to perform a measurement of the hyperfine structure of muonic hydrogen. The results of accurate calculations of the muon transfer rates from muonic protium and deuterium atoms to nitrogen, oxygen and neon are also reported. Very good agreement with measured rates is obtained and for the three systems, the isotopic effect is perfectly reproduced. (author)

  18. CANISTER TRANSFER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    B. Gorpani

    2000-06-23

    The Canister Transfer System receives transportation casks containing large and small disposable canisters, unloads the canisters from the casks, stores the canisters as required, loads them into disposal containers (DCs), and prepares the empty casks for re-shipment. Cask unloading begins with cask inspection, sampling, and lid bolt removal operations. The cask lids are removed and the canisters are unloaded. Small canisters are loaded directly into a DC, or are stored until enough canisters are available to fill a DC. Large canisters are loaded directly into a DC. Transportation casks and related components are decontaminated as required, and empty casks are prepared for re-shipment. One independent, remotely operated canister transfer line is provided in the Waste Handling Building System. The canister transfer line consists of a Cask Transport System, Cask Preparation System, Canister Handling System, Disposal Container Transport System, an off-normal canister handling cell with a transfer tunnel connecting the two cells, and Control and Tracking System. The Canister Transfer System operating sequence begins with moving transportation casks to the cask preparation area with the Cask Transport System. The Cask Preparation System prepares the cask for unloading and consists of cask preparation manipulator, cask inspection and sampling equipment, and decontamination equipment. The Canister Handling System unloads the canister(s) and places them into a DC. Handling equipment consists of a bridge crane hoist, DC loading manipulator, lifting fixtures, and small canister staging racks. Once the cask has been unloaded, the Cask Preparation System decontaminates the cask exterior and returns it to the Carrier/Cask Handling System via the Cask Transport System. After the DC is fully loaded, the Disposal Container Transport System moves the DC to the Disposal Container Handling System for welding. To handle off-normal canisters, a separate off-normal canister handling

  19. Atomic transfers between implanted bioceramics and tissues in orthopaedics surgery

    CERN Document Server

    Irigaray, J L; Guibert, G; Jallot, E; democrite-00023281, ccsd

    2004-01-01

    We study transfers of ions and debris from bioceramics implanted in bone sites. A contamination of surrounding tissues may play a major role in aseptic loosening of the implant. For these reasons, bioceramics require studies of biocompatibility and biofunctionality . So, in addition to in vitro studies of bioceramics, it is essential to implant them in vivo to know body reactions. We measured the concentration of mineral elements at different time intervals after implantation over a whole cross-section. We found a discontinuity of the mineral elements (Ca, P, Sr, Zn, Fe) at the interface between the implant and the receiver. The osseous attack is not global but, on the contrary, centripetal. Moreover, the fit of the concentration time course indicates that the kinetics of ossification is different for each atomic element and characterizes a distinct biological phenomenon

  20. Entanglement transfer between atoms in two distant cavities via an optical fibre

    Institute of Scientific and Technical Information of China (English)

    Xiao Xing; Fang Mao-Fa

    2009-01-01

    This paper presents a treatment of the entanglement transfer between atoms in two distant cavities coupled by an optical fibre. If the atoms resonantly and collectively interact with the local single-mode cavity fields and the dipoledipole interaction between the atoms is neglected, then it shows that a complete transfer of entanglement from one pair of atoms to another can be deterministieally realized. Furthermore, it also investigates the effects of dipole-dipole interaction on entanglement transfer on the condition that the interaction between the atoms and the cavity is much weaker than the coupling between the cavity and the fibre.

  1. Construction of the isocopalane skeleton: application of a desulfinylative 1,7-hydrogen atom transfer strategy.

    Science.gov (United States)

    Xiao, Xiong; Xu, ZhongYu; Zeng, Qian-Ding; Chen, Xi-Bo; Ji, Wen-Hao; Han, Ying; Wu, PeiYing; Ren, Jiangmeng; Zeng, Bu-Bing

    2015-06-01

    Two attractive chirons, aldehyde 6 and chloride 7, exhibiting functionalized ent-spongiane-type tricyclic skeletons (ABC ring system), have been constructed and their absolute configurations have been studied by NMR spectroscopy and confirmed by single-crystal X-ray diffraction. Both of these chirons are derived from commercially available andrographolide in good yield. Aldehyde 6 is obtained through a novel K2 S2 O8 -catalyzed aquatic ring-closing reaction of allylic sodium sulfonate and intramolecular 1,7-hydrogen atom transfer process. Further mechanistic investigations demonstrate that the 1,7-hydrogen atom transfer is a free-radical process, whereby hydrogen migrates from C18 to C17, as evidenced by double-18- deuterium-labeled isotope experiments. Prospective applications of these two chiral sources are also discussed. PMID:25907201

  2. Cu(II)-mediated atom transfer radical polymerization of methyl methacrylate via a strategy of thermo-regulated phase-separable catalysis in a liquid/liquid biphasic system: homogeneous catalysis, facile heterogeneous separation, and recycling.

    Science.gov (United States)

    Pan, Jinlong; Zhang, Bingjie; Jiang, Xiaowu; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2014-09-01

    A strategy of thermo-regulated phase-separable catalysis (TPSC) is applied to the Cu(II)-mediated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in a p-xylene/PEG-200 biphasic system. Initiators for continuous activator regeneration ATRP (ICAR ATRP) are used to establish the TPSC-based ICAR ATRP system using water-soluble TPMA as a ligand, EBPA as an initiator, CuBr2 as a catalyst, and AIBN as a reducing agent. By heating to 70 °C, unlimited miscibility of both solvents is achieved and the polymerization can be carried out under homogeneous conditions; then on cooling to 25 °C, the mixture separates into two phases again. As a result, the catalyst complex remains in the PEG-200 phase while the obtained polymers stay in the p-xylene phase. The catalyst can therefore be removed from the resultant polymers by easily separating the two different layers and can be reused again. It is important that well-defined PMMA with a controlled molecular weight and narrow molecular weight distribution could be obtained using this TPSC-based ICAR ATRP system.

  3. ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    B. Gorpani

    2000-06-26

    The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed

  4. Pickering emulsion templated interfacial atom transfer radical polymerization for microencapsulation.

    Science.gov (United States)

    Li, Jian; Hitchcock, Adam P; Stöver, Harald D H

    2010-12-01

    This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styrene sulfonate and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). The resulting PSB-modified CL particles were surface active and could be used to stabilize oil-in-water Pickering emulsions. ATRP of water-soluble cross-linking monomers, confined to the oil-water interface by the surface-bound PSB, then led to nanoparticle/polymer composite shells. This method allowed encapsulation of core solvents (xylene, hexadecane, perfluoroheptane) with different solubility parameters. The microcapsule (MC) wall chemistry could accommodate different monomers, demonstrating the versatility of this method. Double-walled MCs were formed by sequentially carrying out PETI-ATRP and in situ polymerization of encapsulated monomers. The double-walled structure was verified by both transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM).

  5. Momentum Transfer of an Atom Moving in an Optical Cavity

    Institute of Scientific and Technical Information of China (English)

    张敬涛; 徐至展

    2001-01-01

    When an atom moves in an optical cavity, the total momentum of the atom does not remain constant. We study a two-level atom moving slowly in an optical cavity, and give the time dependence of its mean momentum. It is found that when the initial momentum of the atom is larger than that of the photon, the mean momentum oscillates around a value less than the initial value. But, if the initial momentum is less than the momentum of the photon, the mean momentum of the atom is greater than its initial value in most cases.

  6. Nonadiabatic effects on population transfer of two Bose-Einstein condensates induced by atomic interaction

    Institute of Scientific and Technical Information of China (English)

    胡正峰; 杜春光; 李师群

    2003-01-01

    We investigate the stimulated Raman adiabatic passage for Bose-Einstein condensate (BEG) states which are trapped in different potential wells or two ground states of BEG in the same trap. We consider that lasers are nearly resonant with the atomic transitions. The difference of population transfer processes between BEG atoms and usual atoms is that the atomic interaction of the BEG atoms can cause some nonadiabatic effects, which may degrade the process. But with suitable detunings of laser pulses, the effects can be remedied to some extent according to different atomic interactions.

  7. Dimer-atom-atom recombination in the universal four-boson system

    OpenAIRE

    Deltuva, A

    2012-01-01

    The dimer-atom-atom recombination process in the system of four identical bosons with resonant interactions is studied. The description uses the exact Alt, Grassberger and Sandhas equations for the four-particle transition operators that are solved in the momentum-space framework. The dimer-dimer and atom-trimer channel contributions to the ultracold dimer-atom-atom recombination rate are calculated. The dimer-atom-atom recombination rate greatly exceeds the three-atom recombination rate.

  8. A scheme for transferring an unknown atomic entangled state via cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Wu Tao; Ye Liu; Ni Zhi-Xiang

    2006-01-01

    In this paper, we propose a scheme for transferring an unknown atomic entangled state via cavity quantum electrodynamics (QED). This scheme, which has a successful probability of 100 percent, does not require Bell-state measurement and performing any operations to reconstruct an initial state. Meanwhile, the scheme only involves atomfield interaction with a large detuning and does not require the transfer of quantum information between the atoms and cavity. Thus the scheme is insensitive to the cavity field states and cavity decay. This scheme can also be extended to transfer ring an entangled state of n-atom.

  9. Hybrid quantum systems of atoms and ions

    CERN Document Server

    Zipkes, Christoph; Palzer, Stefan; Sias, Carlo; Köhl, Michael

    2010-01-01

    In recent years, ultracold atoms have emerged as an exceptionally controllable experimental system to investigate fundamental physics, ranging from quantum information science to simulations of condensed matter models. Here we go one step further and explore how cold atoms can be combined with other quantum systems to create new quantum hybrids with tailored properties. Coupling atomic quantum many-body states to an independently controllable single-particle gives access to a wealth of novel physics and to completely new detection and manipulation techniques. We report on recent experiments in which we have for the first time deterministically placed a single ion into an atomic Bose Einstein condensate. A trapped ion, which currently constitutes the most pristine single particle quantum system, can be observed and manipulated at the single particle level. In this single-particle/many-body composite quantum system we show sympathetic cooling of the ion and observe chemical reactions of single particles in situ...

  10. Synthesis of triblock and random copolymers of 4- acetoxystyrene and styrene by living atom transfer radical polymerization

    DEFF Research Database (Denmark)

    Gao, Bo; Chen, Xianyi; Ivan, Bela;

    1997-01-01

    Triblock copolymers containing polystyrene (PSt) and poly(4-acetoxystyrene) (PAcOSt) segments have been prepared by atom transfer radical polymerization (ATRP). In the first step one of the two monomers was polymerized in bulk using the initiating system alpha,alpha'-dibromo-p-xylene/CuBr/2...

  11. Synthesis and characterization of poly(2-ethylhexyl acrylate) prepared via atom transfer radical polymerization, reverse atom transfer radical polymerization and radical polymerization

    Indian Academy of Sciences (India)

    Dhruba Jyoti Haloi; Bishnu Prasad Koiry; Prithwiraj Mandal; Nikhil Kumar Singha

    2013-07-01

    This investigation reports a comparative study of poly(2-ethylhexyl acrylate) (PEHA) prepared via atom transfer radical polymerization (ATRP), reverse atom transfer radical polymerization (RATRP) and conventional free radical polymerization (FRP). The molecular weights and the molecular weight distributions of the polymers were measured by gel permeation chromatography (GPC) analysis. Structural characterization of the polymers was carried out by 1H NMR and MALDI-TOF-MS analyses. Thermal properties of the polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The polymerization results and the thermal properties of PEHAs prepared via ATRP, RATRP and FRP were compared.

  12. Implementing quantum electrodynamics with ultracold atomic systems

    CERN Document Server

    Kasper, V; Jendrzejewski, F; Oberthaler, M K; Berges, J

    2016-01-01

    We discuss the experimental engineering of model systems for the description of QED in one spatial dimension via a mixture of bosonic $^{23}$Na and fermionic $^6$Li atoms. The local gauge symmetry is realized in an optical superlattice, using heteronuclear boson-fermion spin-changing interactions which preserve the total spin in every local collision. We consider a large number of bosons residing in the coherent state of a Bose-Einstein condensate on each link between the fermion lattice sites, such that the behavior of lattice QED in the continuum limit can be recovered. The discussion about the range of possible experimental parameters builds, in particular, upon experiences with related setups of fermions interacting with coherent samples of bosonic atoms. We determine the atomic system's parameters required for the description of fundamental QED processes, such as Schwinger pair production and string breaking. This is achieved by benchmark calculations of the atomic system and of QED itself using function...

  13. Large momentum transfer atom interferometry with Coriolis force compensation

    Science.gov (United States)

    Kuan, Pei-Chen; Lan, Shau-Yu; Estey, Brian; Haslinger, Philipp; Mueller, Holger

    2012-06-01

    Light-pulse atom interferometers use atom-photon interactions to coherently split, guide, and recombine freely falling matter-waves. Because of Earth's rotation, however, the matter-waves do not recombine precisely, which causes severe loss of contrast in large space-time atom interferometers. I will present our recent progress in using a tip-tilt mirror to remove the influence of the Coriolis force from Earth's rotation. Therefore, we improve the contrast and suppress systematic effects, also reach what is to our knowledge the largest spacetime area.

  14. Heat transfer analysis of atomized droplets during high velocity arc spraying

    Institute of Scientific and Technical Information of China (English)

    ZHU Zi-xin; LIU Yan; CHEN Yong-xiong; XU Bin-shi; ZHANG Wei

    2004-01-01

    The heat transfer problem of the atomized droplets during high velocity arc spraying (HVAS) was modeled and solved by a numerical method using a Fe-Al alloy, and the influences of several important process parameters on the heat transfer behaviors of the atomized droplets were analyzed. The results show that the initial cooling rates of different size droplets range from 105 to 107 K/s, thus producing the coating microstructure with the features of rapid solidification. The droplet size, atomization gas pressure and droplet superheat have great influences on the heat transfer behavior of the droplet. The droplet temperature and cooling rate are much sensitive to the droplet sizes, but insensitive to the atomization gas pressure and droplet superheat. It can be predicted that the properties of HVAS coatings will be improved by decreasing droplet size as well as increasing atomization gas pressure and droplet superheat in certain extents.

  15. Schwinger variational calculation of ionization of hydrogen atoms for large momentum transfers

    Indian Academy of Sciences (India)

    K Chakrabarti

    2002-03-01

    Schwinger variational principle is used here to study large momentum transfer cases of electron and positron impact ionization of atomic hydrogen from the ground state at intermediate and moderately high energies. The results appear somewhat better compared to other theories.

  16. Optical fiber data transfer system

    Science.gov (United States)

    Mcmillan, S. H.

    1988-01-01

    This Phase 2 effort applies the results of Phase 1 to design and fabricate an optical slip ring system for a helicopter rotor blade/wind tunnel application. In this application, there are two assemblies: one on the rotating portion of the mechanical system, one on the stationary portion. The assembly on the rotating portion digitizes and encodes 128 transducer signals from various parts of the blade, and optically transfers data across the noncontacting coupling. Two complete identical independent channels are provided. On the stationary side, the signals are decoded and one channel is transmitted in digital form to a computer for recording and analysis. The second channel reconstructs the analog transducer signals for real time observation. In the opposite direction, eight signal channels enable control signals to be passed from the stationary to the rotating part of the system. Power to the rotor mounted electronics is supplied via power slip rings. The advantages of the optical over the traditional electro-mechanical slip ring method of data transfer across a rotating joint are long life, low-maintenance, immunity to crosstalk, and wider bandwidth. Successful completion of this effort demonstrated that this method is practical and reliable, and can be implemented under difficult conditions of available space, power, environment, and stringent performance and equipment life requirements.

  17. Modulation Transfer Spectroscopy of Ytterbium Atoms in a Hollow Cathode Lamp

    International Nuclear Information System (INIS)

    We present the experimental study of modulation transfer spectroscopy of ytterbium atoms in a hollow cathode lamp. The dependences of its linewidth, slope and magnitude on the various experimental parameters are measured and fitted by the well-known theoretical expressions. The experimental results are in good agreement with the theoretical prediction. We have observed the Dicke narrowing effect by increasing the current of the hollow cathode lamp. It is also found that there are the optimal current and laser power to generate the better modulation transfer spectroscopy signal, which can be employed for locking the laser frequency to the atomic transition. (atomic and molecular physics)

  18. Waste Feed Delivery Transfer System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    JULYK, L.J.

    2000-05-05

    This document provides a documented basis for the required design pressure rating and pump pressure capacity of the Hanford Site waste-transfer system in support of the waste feed delivery to the privatization contractor for vitrification. The scope of the analysis includes the 200 East Area double-shell tank waste transfer pipeline system and the associated transfer system pumps for a11 Phase 1B and Phase 2 waste transfers from AN, AP, AW, AY, and A2 Tank Farms.

  19. Radical and Atom Transfer Halogenation (RATH): A Facile Route for Chemical and Polymer Functionalization.

    Science.gov (United States)

    Han, Yi-Jen; Lin, Chia-Yu; Liang, Mong; Liu, Ying-Ling

    2016-05-01

    This work demonstrates a new halogenation reaction through sequential radical and halogen transfer reactions, named as "radical and atom transfer halogenation" (RATH). Both benzoxazine compounds and poly(2,6-dimethyl-1,4-phenylene oxide) have been demonstrated as active species for RATH. Consequently, the halogenated compound becomes an active initiator of atom transfer radical polymerization. Combination of RATH and sequential ATRP provides an convenient and effective approach to prepare reactive and crosslinkable polymers. The RATH reaction opens a new window both to chemical synthesis and molecular design and preparation of polymeric materials.

  20. Coherent population transfer in Rydberg potassium atom by a single frequency-chirped laser pulse

    Institute of Scientific and Technical Information of China (English)

    Zhang Xian-Zhou; Ma Qiao-Zhi; Li Xiao-Hong

    2006-01-01

    By using the time-dependent multilevel approach, we have calculated the coherent population transfer among the quantum states of potassium atom by a single frequency-chirped laser pulse. The results show that the population can be efficiently transferred to a target state and be trapped there by using an ‘intuitive’ or a ‘counter-intuitive’ frequency sweep laser pulse in the case of ‘narrowband’ frequency-chirped laser pulse. It is also found that a pair of sequential ‘broadband’ frequency-chirped laser pulses can efficiently transfer population from one ground state of the A atom to the other one.

  1. Entanglement and quantum state transfer between two atoms trapped in two indirectly coupled cavities

    Science.gov (United States)

    Zheng, Bin; Shen, Li-Tuo; Chen, Ming-Feng

    2016-05-01

    We propose a one-step scheme for implementing entanglement generation and the quantum state transfer between two atomic qubits trapped in two different cavities that are not directly coupled to each other. The process is realized through engineering an effective asymmetric X-Y interaction for the two atoms involved in the gate operation and an auxiliary atom trapped in an intermediate cavity, induced by virtually manipulating the atomic excited states and photons. We study the validity of the scheme as well as the influences of the dissipation by numerical simulation and demonstrate that it is robust against decoherence.

  2. Nitrogen Atom Transfer From High Valent Iron Nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michael D. [New Mexico State Univ., Las Cruces, NM (United States); Smith, Jeremy M. [Indiana Univ., Bloomington, IN (United States)

    2015-10-14

    This report describes the synthesis and reactions of high valent iron nitrides. Organonitrogen compounds such as aziridines are useful species for organic synthesis, but there are few efficient methods for their synthesis. Using iron nitrides to catalytically access these species may allow for their synthesis in an energy-and atom-efficient manner. We have developed a new ligand framework to achieve these goals as well as providing a method for inducing previously unknown reactivity.

  3. Two-nucleon transfer reactions uphold supersymmetry in atomic nuclei

    OpenAIRE

    Barea, J.; Bijker, R.; Frank, A.

    2004-01-01

    The spectroscopic strengths of two-nucleon transfer reactions constitute a stringent test for two-nucleon correlations in the nuclear wave functions. A comparison between the recently measured 198Hg(d,alpha)196Au reaction and the predictions from the nuclear quartet supersymmetry lends further support to the validity of supersymmetry in nuclear physics.

  4. Mechanism of Photoinduced Metal-Free Atom Transfer Radical Polymerization: Experimental and Computational Studies.

    Science.gov (United States)

    Pan, Xiangcheng; Fang, Cheng; Fantin, Marco; Malhotra, Nikhil; So, Woong Young; Peteanu, Linda A; Isse, Abdirisak A; Gennaro, Armando; Liu, Peng; Matyjaszewski, Krzysztof

    2016-02-24

    Photoinduced metal-free atom transfer radical polymerization (ATRP) of methyl methacrylate was investigated using several phenothiazine derivatives and other related compounds as photoredox catalysts. The experiments show that all selected catalysts can be involved in the activation step, but not all of them participated efficiently in the deactivation step. The redox properties and the stability of radical cations derived from the catalysts were evaluated by cyclic voltammetry. Laser flash photolysis (LFP) was used to determine the lifetime and activity of photoexcited catalysts. Kinetic analysis of the activation reaction according to dissociative electron-transfer (DET) theory suggests that the activation occurs only with an excited state of catalyst. Density functional theory (DFT) calculations revealed the structures and stabilities of the radical cation intermediates as well as the reaction energy profiles of deactivation pathways with different photoredox catalysts. Both experiments and calculations suggest that the activation process undergoes a DET mechanism, while an associative electron transfer involving a termolecular encounter (the exact reverse of DET pathway) is favored in the deactivation process. This detailed study provides a deeper understanding of the chemical processes of metal-free ATRP that can aid the design of better catalytic systems. Additionally, this work elucidates several important common pathways involved in synthetically useful organic reactions catalyzed by photoredox catalysts. PMID:26820243

  5. Table of hyperfine anomaly in atomic systems

    OpenAIRE

    Persson, Jonas R.

    2011-01-01

    This table is a compilation of experimental values of magnetic hyperfine anomaly in atomic and ionic systems. The last extensive compilation was published in 1984 by Buttgenbach (Hyperfine Interactions 20, (1984) p 1) and the aim here is to make an up to date compilation. The literature search covers the period to January 2011.

  6. Optimal control of complex atomic quantum systems

    Science.gov (United States)

    van Frank, S.; Bonneau, M.; Schmiedmayer, J.; Hild, S.; Gross, C.; Cheneau, M.; Bloch, I.; Pichler, T.; Negretti, A.; Calarco, T.; Montangero, S.

    2016-10-01

    Quantum technologies will ultimately require manipulating many-body quantum systems with high precision. Cold atom experiments represent a stepping stone in that direction: a high degree of control has been achieved on systems of increasing complexity. However, this control is still sub-optimal. In many scenarios, achieving a fast transformation is crucial to fight against decoherence and imperfection effects. Optimal control theory is believed to be the ideal candidate to bridge the gap between early stage proof-of-principle demonstrations and experimental protocols suitable for practical applications. Indeed, it can engineer protocols at the quantum speed limit – the fastest achievable timescale of the transformation. Here, we demonstrate such potential by computing theoretically and verifying experimentally the optimal transformations in two very different interacting systems: the coherent manipulation of motional states of an atomic Bose-Einstein condensate and the crossing of a quantum phase transition in small systems of cold atoms in optical lattices. We also show that such processes are robust with respect to perturbations, including temperature and atom number fluctuations.

  7. Remote atom entanglement in a fiber-connected three-atom system

    OpenAIRE

    Yan-Qing, Guo; JING, Chen; He-Shan, Song

    2008-01-01

    An Ising-type atom-atom interaction is obtained in a fiber-connected three-atom system. The interaction is effective when $\\Delta\\approx \\gamma _{0}\\gg g$. The preparations of remote two-atom and three-atom entanglement governed by this interaction are discussed in specific parameters region. The overall two-atom entanglement is very small because of the existence of the third atom. However, the three-atom entanglement can reach a maximum very close to 1.

  8. Remote atom entanglement in a fibre-connected three-atom system

    Institute of Scientific and Technical Information of China (English)

    Guo Yan-Qing; Chen Jing; Song He-Shan

    2008-01-01

    An Ising-type atom-atom interaction is obtained in a fibre-connected three-atom system. The interaction is effective when △≈γO>>g.The preparations of remote two-atom and three-atom entanglements governed by this interaction are discussed in a specific parameter region.The overall two-atom entanglement is very small because of the existence of the third atom.However,the three-atom entanglement can reach a maximum very close to 1.

  9. Dry Transfer Systems for Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Brett W. Carlsen; Michaele BradyRaap

    2012-05-01

    The potential need for a dry transfer system (DTS) to enable retrieval of used nuclear fuel (UNF) for inspection or repackaging will increase as the duration and quantity of fuel in dry storage increases. This report explores the uses for a DTS, identifies associated general functional requirements, and reviews existing and proposed systems that currently perform dry fuel transfers. The focus of this paper is on the need for a DTS to enable transfer of bare fuel assemblies. Dry transfer systems for UNF canisters are currently available and in use for transferring loaded canisters between the drying station and storage and transportation casks.

  10. Non-exponential decay of atomic systems

    CERN Document Server

    Ishkhanyan, A M

    2014-01-01

    We discuss the possibility of non-exponential decay of various quantum quasi-stationary systems. This effect can occur at the times which are greater than the lifetime of a considered system. The mechanism for non-exponential depletion of an initial quasi-stationary state is the cutting of the energy spectrum of final continuous states at long times. We first consider the known examples of cold emission of electrons from metal, tunneling alpha-decay of atomic nuclei, and spontaneous decay in two-level systems. The new physical situations discussed are the single-photon atomic ionization by a weak electromagnetic field and tunneling ionization of atoms by a strong low-frequency electromagnetic field. In both cases the decay obeys a power-law dependence on the (long) interaction time. We find that the most promising possibility for observing non-exponential decay at long times is the single-photon ionization of negative atomic ions near the threshold.

  11. Novel ionic liquids as reaction medium for atom transfer radical polymerization of methyl methacrylate

    Institute of Scientific and Technical Information of China (English)

    Guo Qiao Lai; Fu Min Ma; Zi Qiang Hu; Hua Yu Qiu; Jian Xiong Jiang; Ji Rong Wu; Li Min Chen; Lian Bin Wu

    2007-01-01

    Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system was investigated at 50 ℃ in the absence of any additional ligand in the three room temperature ionic liquids (RTILs), 1-methyl-imidazolium acetate ([mim][CH3COO]), 1-methylimidazolium propionate ([mim][CH3CH2COO]) and 1-methylimidazolium butyrate ([mim] [CH3CH2CH2COO]), respectively. All the polymerization in the three RTILs proceeded in a well-controlled manner. The sequence of the apparent polymerization rate constants was kapp([mim][CH3COO]) > kapp([mim][CH3CH2COO]) > kapp ([mim][CH3CH2CH2COO]).

  12. Surface-initiated atom transfer radical polymerization of methyl methacrylate from magnetite nanoparticles at ambient temperature.

    Science.gov (United States)

    Raghuraman, G K; Dhamodharan, R

    2006-07-01

    The synthesis of methyl methacrylate (MMA) brush from the surface of magnetite nanoparticles (core-shell structure), from initiator moieties anchored covalently to the nanoparticles, via room temperature atom transfer radical polymerization (ATRP) is described. The surface-initiated polymerization was carried out from a surface-confined initiator containing a 2-bromoisobutyrate moiety with Cu(I)Br/PMDETA catalytic system. The initiator moiety was covalently anchored to the nanoparticles via a two step modification reaction scheme. Controlled polymerization was observed if ethyl-2-bromoisobutyrate (2-EiBrB) was added as a free/sacrificial initiator. A linear increase of molecular weight and a narrow molecular weight distribution of the PMMA formed in solution, provide evidence for a controlled surface-initiated polymerization, leading to surface-attached polymer brushes under mild conditions. The grafted PMMA provides good stability and dispersibility for the nanoparticles in organic solvents.

  13. Correlation Between Energy Transfer Rate and Atomization Energy of Some Trinitro Aromatic Explosive Molecules

    Institute of Scientific and Technical Information of China (English)

    Su-hong Ge; Xin-lu Cheng; Zheng-lai Liu; Xiang-dong Yang; Fang-fang Dong

    2008-01-01

    An assumptive theoretical relationship is suggested to describe the property of molecular atomization energy and energy transfer rate in the initiation of explosions. To investigate the relationship between atomization energy and energy transfer rate, the number of doorway modes of explosives is estimated by the theory of Dlott and Fayer in which the rate is proportional to the number of normal mode vibrations. It was evaluated frequencies of normal mode vibrations of eight molecules by means of density functional theory (DFT) at the b3p86/6-31G(d,p) level. It is found that the number of doorway modes shows a linear correlation to the atomization energies of the molecules, which were also calculated by means of the same method. A mechanism of this correlation is discussed. It is also noted that in those explosives with similar molecular structure and molecular weight, the correlation between the atomization energy and the number of doorway modes is higher.

  14. Transfer Potentials shape and equilibrate Monetary Systems

    OpenAIRE

    Dieter Braun; Robert Fischer

    2002-01-01

    We analyze a monetary system of random money transfer on the basis of double entry bookkeeping. Without boundary conditions, we do not reach a price equilibrium and violate text-book formulas of economists quantity theory (MV=PQ). To match the resulting quantity of money with the model assumption of a constant price, we have to impose boundary conditions. They either restrict specific transfers globally or impose transfers locally. Both connect through a general framework of transfer potentia...

  15. Long range intermolecular forces in triatomic systems: connecting the atom-diatom and atom-atom-atom representations

    OpenAIRE

    Cvitas, Marko T.; Soldan, Pavel; Hutson, Jeremy M.

    2005-01-01

    The long-range forces that act between three atoms are analysed in both atom-diatom and atom-atom-atom representations. Expressions for atom-diatom dispersion coefficients are obtained in terms of 3-body nonadditive coefficients. The anisotropy of atom-diatom C_6 dispersion coefficients arises primarily from nonadditive triple-dipole and quadruple-dipole forces, while pairwise-additive forces and nonadditive triple-dipole and dipole-dipole-quadrupole forces contribute significantly to atom-di...

  16. Modulation Transfer Spectroscopy of Ytterbium Atoms in a Hollow Cathode Lamp

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Li; XU Xin-Ye

    2011-01-01

    We present the experimental study of modulation transfer spectroscopy of ytterbium atoms in a hollow cathode lamp.The dependences of its linewidth, slope and magnitude on the various experimental parameters are measured and fitted by the well-known theoretical expressions. The experimental results are in good agreement with the theoretical prediction. We have observed the Dicke narrowing effect by increasing the current of the hollow cathode lamp. It is also found that there are the optimal current and laser power to generate the better modulation transfer spectroscopy signal, which can be employed for locking the laser frequency to the atomic transition.

  17. Excited atomic bromine energy transfer and quenching mechanisms

    Science.gov (United States)

    Johnson, Ray O.

    1993-08-01

    Pulsed and steady-state photolysis experiments have been conducted to determine the rate coefficients for collisional deactivation of the spin-orbit excited state of atomic bromine, Br((sup 2)P(sub 1/2)). Pulsed lifetime studies for quenching by Br2 and CO2 established absolute rate coefficients at room temperature of k(sub Br2) = 1.2 +/- 0.1 x 10(exp-12) and k(sub CO2) = 1.5 +/0.2 x 10(exp-11) cu cm/molecule-s. Steady-state photolysis methods were used to determine the quenching rates for the rare gases, N2, 02, H2, D2, NO, NO2, N2O, SF6, CF4, CH4, CO, CO2, COS, SO2, H2S, HBr, HC1, and HI relative to that for Br2. Quenching rate temperature dependence was examined for Br2, CO2, N2O, HCl, COS, NO, and NO2 for temperatures from 300 to 420 K. Diffusion and three body effects were examined in order to determine the slowest relative quenching rate measurable by this experimental technique.

  18. Generation of a cold pulsed beam of Rb atoms by transfer from a 3D magneto-optic trap

    CERN Document Server

    Chanu, Sapam Ranjita; Natarajan, Vasant

    2016-01-01

    We demonstrate a technique for producing a cold pulsed beam of atoms by transferring a cloud of atoms trapped in a three dimensional magneto-optic trap (MOT). The MOT is loaded by heating a getter source of Rb atoms. We show that it is advantageous to transfer with two beams (with a small angle between them) compared to a single beam, because the atoms stop interacting with the beams in the two-beam technique, which results in a Gaussian velocity distribution. The atoms are further cooled in optical molasses by turning off the MOT magnetic field before the transfer beams are turned on.

  19. Generation of a cold pulsed beam of Rb atoms by transfer from a 3D magneto-optic trap

    Science.gov (United States)

    Chanu, Sapam Ranjita; Rathod, Ketan D.; Natarajan, Vasant

    2016-08-01

    We demonstrate a technique for producing a cold pulsed beam of atoms by transferring a cloud of atoms trapped in a three dimensional magneto-optic trap (MOT). The MOT is loaded by heating a getter source of Rb atoms. We show that it is advantageous to transfer with two beams (with a small angle between them) compared to a single beam, because the atoms stop interacting with the beams in the two-beam technique, which results in a Gaussian velocity distribution. The atoms are further cooled in optical molasses by turning off the MOT magnetic field before the transfer beams are turned on.

  20. Ultracold magnetically tunable interactions without radiative-charge-transfer losses between Ca+, Sr+, Ba+, and Yb+ ions and Cr atoms

    Science.gov (United States)

    Tomza, Michał

    2015-12-01

    The Ca+, Sr+, Ba+, and Yb+ ions immersed in an ultracold gas of the Cr atoms are proposed as experimentally feasible heteronuclear systems in which ion-atom interactions at ultralow temperatures can be controlled with magnetically tunable Feshbach resonances without charge transfer and radiative losses. Ab initio techniques are applied to investigate electronic-ground-state properties of the (CaCr)+, (SrCr)+, (BaCr)+, and (YbCr)+ molecular ions. The potential energy curves, permanent electric dipole moments, and static electric dipole polarizabilities are computed. The spin-restricted open-shell coupled-cluster method restricted to single, double, and noniterative triple excitations and the multireference configuration-interaction method restricted to single and double excitations are employed. The scalar relativistic effects are included within the small-core energy-consistent pseudopotentials. The leading long-range induction and dispersion interaction coefficients are also reported. Finally, magnetic Feshbach resonances between the Ca+, Sr+, Ba+, and Yb+ ions interacting with the Cr atoms are analyzed. The present proposal opens the way towards robust quantum simulations and computations with ultracold ion-atom systems free of radiative charge-transfer losses.

  1. Orbital Express fluid transfer demonstration system

    Science.gov (United States)

    Rotenberger, Scott; SooHoo, David; Abraham, Gabriel

    2008-04-01

    Propellant resupply of orbiting spacecraft is no longer in the realm of high risk development. The recently concluded Orbital Express (OE) mission included a fluid transfer demonstration that operated the hardware and control logic in space, bringing the Technology Readiness Level to a solid TRL 7 (demonstration of a system prototype in an operational environment). Orbital Express (funded by the Defense Advanced Research Projects Agency, DARPA) was launched aboard an Atlas-V rocket on March 9th, 2007. The mission had the objective of demonstrating technologies needed for routine servicing of spacecraft, namely autonomous rendezvous and docking, propellant resupply, and orbital replacement unit transfer. The demonstration system used two spacecraft. A servicing vehicle (ASTRO) performed multiple dockings with the client (NextSat) spacecraft, and performed a variety of propellant transfers in addition to exchanges of a battery and computer. The fluid transfer and propulsion system onboard ASTRO, in addition to providing the six degree-of-freedom (6 DOF) thruster system for rendezvous and docking, demonstrated autonomous transfer of monopropellant hydrazine to or from the NextSat spacecraft 15 times while on orbit. The fluid transfer system aboard the NextSat vehicle was designed to simulate a variety of client systems, including both blowdown pressurization and pressure regulated propulsion systems. The fluid transfer demonstrations started with a low level of autonomy, where ground controllers were allowed to review the status of the demonstration at numerous points before authorizing the next steps to be performed. The final transfers were performed at a full autonomy level where the ground authorized the start of a transfer sequence and then monitored data as the transfer proceeded. The major steps of a fluid transfer included the following: mate of the coupling, leak check of the coupling, venting of the coupling, priming of the coupling, fluid transfer, gauging

  2. Electron transfer and multi-atom abstraction reactions between atomic metal anions and NO, NO2 and SO2

    Science.gov (United States)

    Butson, J. M.; Curtis, S.; Mayer, P. M.

    2016-05-01

    The atomic metal anions Fe-, Cs-, Cu- and Ag- were reacted with NO, NO2 and SO2 to form intact NO-, NO2- and SO2- with no fragmentation. Yields for the molecular anions ranged from 4 to 97% and were found to correlate to the exothermicity of the electron transfer process. Sequential oxygen atom extraction was found to take place between the metal anions and NO and NO2. Reactions between NO2 and Fe- resulted in FeO-, FeO2- and FeO3- while reactions of Cu- with NO2 resulted in CuO- and CuO2-. Reactions of Cu- and Ag- with NO resulted in CuO- and AgO- respectively.

  3. Bibliography on electron transfer processes in ion-ion/atom/molecule collisions (updated 1993)

    International Nuclear Information System (INIS)

    Following our previous compilations [IPPJ-AM-45 (1986), NIFS-DATA-7 (1990)], bibliographic information on experimental and theoretical studies on electron transfer processes in ion-ion/atom/molecule collisions is up-dated. The references published through 1980-1992 are included. For easy finding references for particular combination of collision partners, a simple list is also provided. (author) 1542 refs

  4. Polymer coating comprising 2-methoxyethyl acrylate units synthesized by surface-initiated atom transfer radical polymerization

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2012184029A The present invention relates to preparation of a polymer coating comprising or consisting of polymer chains comprising or consisting of units of 2-methoxyethyl acrylate synthesized by Surface-Initiated Atom Transfer Radical Polymerization (SI ATRP) such as ARGET SI ATRP or...

  5. Surface-initiated Atom Transfer Radical Polymerization - a Technique to Develop Biofunctional Coatings

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Jankova Atanasova, Katja; Hvilsted, Søren

    2009-01-01

    The initial formation of initiating sites for atom transfer radical polymerization (ATRP) on various polymer surfaces and numerous inorganic and metallic surfaces is elaborated. The subsequent ATRP grafting of a multitude of monomers from such surfaces to generate thin covalently linked polymer...

  6. Surface Modification of Nanoporous 1,2-Polybutadiene by Atom Transfer Radical Polymerization or Click Chemistry

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars;

    2010-01-01

    Surface-initiated atom transfer radical polymerization (ATRP) and click chemistry were used to obtain functional nanoporous polymers based oil nanoporous 1,2-polybutadiene (PB) with gyroid morphology. The ATRP monolith initiator was prepared by immobilizing bromoester initiators onto the pore walls...

  7. Hydrolysis of 4-Acetoxystyrene Polymers Prepared by Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Chen, Xianyi; Jankova, Katja; Kops, Jørgen;

    1999-01-01

    Hydrolysis of 4-acetoxystyrene polymers prepared by atom transfer radical polymerization was carried out under various reaction conditions. It was found that hydrazinolysis of 4-acetoxystyrene homopolymers, random and block copolymers with styrene in 1,4-dioxane, afforded the corresponding narrow...

  8. Anticoagulant surface of 316 L stainless steel modified by surface-initiated atom transfer radical polymerization.

    Science.gov (United States)

    Guo, Weihua; Zhu, Jian; Cheng, Zhenping; Zhang, Zhengbiao; Zhu, Xiulin

    2011-05-01

    Polished 316 L stainless steel (SS) was first treated with air plasma to enhance surface hydrophilicity and was subsequently allowed to react with 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane to introduce an atom transfer radical polymerization (ATRP) initiator. Accordingly, the surface-initiated atom transfer radical polymerization of polyethylene glycol methacrylate (PEGMA) was carried out on the surface of the modified SS. The grafting progress was monitored by water contact angle measurements, X-ray photoelectron spectroscopy and atomic force microscopy. The polymer thickness as a function different polymerization times was characterized using a step profiler. The anticoagulative properties of the PEGMA modified SS surface were investigated. The results showed enhanced anticoagulative to acid-citrate-dextrose (ACD) blood after grafting PEGMA on the SS surface. PMID:21528878

  9. Engineering Floquet Hamiltonians in Cold Atom Systems

    Science.gov (United States)

    Polkovnikov, Anatoli

    2016-05-01

    In this talk I will first give a brief overview of the Floquet theory, describing periodically driven systems. Then I will introduce the concept of the high-frequency expansion and will show how it generalizes the celebrated Schrieffer-Wolff transformation to driven systems. Using these tools I will illustrate how one can engineer non-trivial interacting Hamiltonians mostly in the context of cold atom systems and discuss some experimental examples. In the end I will talk about issues of heating and adiabaticity and show that there are very strong parallels between Floquet systems and disordered systems. In particular, I will argue that the heating transition is closely analogous to the many-body localization transition. AFOSR, ARO, NSF.

  10. Saturn facility oil transfer automation system

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Nathan R.; Thomas, Rayburn Dean; Lewis, Barbara Ann; Malagon, Hector Ricardo.

    2014-02-01

    The Saturn accelerator, owned by Sandia National Laboratories, has been in operation since the early 1980s and still has many of the original systems. A critical legacy system is the oil transfer system which transfers 250,000 gallons of transformer oil from outside storage tanks to the Saturn facility. The oil transfer system was iden- ti ed for upgrade to current technology standards. Using the existing valves, pumps, and relay controls, the system was automated using the National Instruments cRIO FGPA platform. Engineered safety practices, including a failure mode e ects analysis, were used to develop error handling requirements. The uniqueness of the Saturn Oil Automated Transfer System (SOATS) is in the graphical user interface. The SOATS uses an HTML interface to communicate to the cRIO, creating a platform independent control system. The SOATS was commissioned in April 2013.

  11. Kinetic Studies of Atom Transfer Radical Polymerisations of Styrene and Chloromethylstyrene with Poly(3-hexyl thiophene Macroinitiator

    Directory of Open Access Journals (Sweden)

    Nattawoot Rattanathamwat

    2015-01-01

    Full Text Available Poly(3-hexyl thiophene-b-poly(styrene-co-chloromethylstyrene copolymers, to be used as a prepolymer for preparing donor-acceptor block copolymers for organic solar cells, have been synthesised by reacting P3HT macroinitiators with styrene and chloromethylstyrene via three types of atom transfer radical polymerisation (ATRP systems, which are (1 a normal ATRP, (2 activators generated by electron transfer (AGET, and (3 a simultaneous reverse and normal initiation (SR&NI. The kinetics of these ATRP systems were studied as a function of monomers to the macroinitiator molar ratio. It was found that all of the three types of ATRP systems led to first order kinetics with respect to monomers. The highest rate constant (k of 3.4 × 10−3 s−1 was obtained from the SR&NI ATRP system. The molecular weights of the product determined by the GPC were lower than were the theoretical values. The result was discussed in light of the chain transfer reaction to the poly(chloromethylstyrene repeating units. Morphology of the synthesized block copolymers, examined by an atomic force microscopy (AFM, were also compared and discussed.

  12. Three-dimensional atom localization via electromagnetically induced transparency in a three-level atomic system.

    Science.gov (United States)

    Wang, Zhiping; Cao, Dewei; Yu, Benli

    2016-05-01

    We present a new scheme for three-dimensional (3D) atom localization in a three-level atomic system via measuring the absorption of a weak probe field. Owing to the space-dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the probe absorption. It is found that, by properly varying the parameters of the system, the probability of finding the atom in 3D space can be almost 100%. Our scheme opens a promising way to achieve high-precision and high-efficiency 3D atom localization, which provides some potential applications in laser cooling or atom nano-lithography via atom localization. PMID:27140374

  13. Three-dimensional atom localization via electromagnetically induced transparency in a three-level atomic system.

    Science.gov (United States)

    Wang, Zhiping; Cao, Dewei; Yu, Benli

    2016-05-01

    We present a new scheme for three-dimensional (3D) atom localization in a three-level atomic system via measuring the absorption of a weak probe field. Owing to the space-dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the probe absorption. It is found that, by properly varying the parameters of the system, the probability of finding the atom in 3D space can be almost 100%. Our scheme opens a promising way to achieve high-precision and high-efficiency 3D atom localization, which provides some potential applications in laser cooling or atom nano-lithography via atom localization.

  14. System for Multicast File Transfer

    Directory of Open Access Journals (Sweden)

    Dorin Custura

    2012-03-01

    Full Text Available The distribution of big files over the network from a single source to a large number of recipients is not efficient by using standard client-server or even peer-to peer file transfer protocols.  Thus, the transfer of a hierarchy of big files to multiple destinations can be optimized in terms of bandwidth usage and data storage reads by using multicast networking. In order to achieve that, a simple application layer protocol can be imagined. It uses multicast UDP as transport and it provides a mechanism for data ordering and retransmission. Some security problems are also considered in this protocol, because at this time the Internet standards supporting multicast security are still in the development stage.

  15. The diffusion transfer of sputtered atoms in plasma spraying on the internal cylindrical surface

    International Nuclear Information System (INIS)

    The sputtering of the surface of the solid by the glow discharge plasma is used widely in the electronics for the deposition of thin films. The sputtered atoms (SA), leaving the surface, clash with the gas atoms and the granules the energy. It is interesting to examine the effect of the condensation coefficient of the SA on the concentration of the SA in the cylindrical discharge volume and the fluxes of the SA to different areas of the wall. The solution of this problem for the case of the diffusion transfer of the SA is the subject of this work

  16. Three-dimensional atom localization from spatial interference in a double two-level atomic system

    Science.gov (United States)

    Zhu, Zhonghu; Yang, Wen-Xing; Xie, Xiao-Tao; Liu, Shasha; Liu, Shaopeng; Lee, Ray-Kuang

    2016-07-01

    We propose a efficient scheme for high-precision three-dimensional (3D) atom localization via spatial interference in a generic double two-level atomic system driven by a weak probe field and three mutually perpendicular standing-wave fields. Because the spatial interference originates from the position-dependent atom-field interaction, the position information of the atom can be obtained by the measurement of the atom population. We find that the precision of 3D atom localization in volumes depends sensitively on the frequency detuning and the phase shifts associated with the standing-wave fields. Interestingly enough, we show that adjusting the frequency detuning and phase shifts can lead to a redistribution of the atoms and a significant change in the visibility of the interference pattern. As a result, the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength.

  17. Activators generated by electron transfer for atom transfer radical polymerization of styrene in the presence of mesoporous silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Khezri, Khezrollah, E-mail: kh.khezri@ut.ac.ir [School of Chemistry, University College of Science, University of Tehran, PO Box 14155-6455, Tehran (Iran, Islamic Republic of); Roghani-Mamaqani, Hossein [Department of Polymer Engineering, Sahand University of Technology, PO Box 51335-1996, Tabriz (Iran, Islamic Republic of)

    2014-11-15

    Graphical abstract: Effect of mesoporous silica nanoparticles (MCM-41) on the activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP) is investigated. Decrement of conversion and number average molecular weight and also increment of polydispersity index (PDI) values are three main results of addition of MCM-41 nanoparticles. Incorporation of MCM-41 nanoparticles in the polystyrene matrix can clearly increase thermal stability and decrease glass transition temperature of the nanocomposites. - Highlights: • Spherical morphology, hexagonal structure, and high surface area with regular pore diameters of the synthesized MCM-41 nanoparticles are examined. • AGET ATRP of styrene in the presence of MCM-41 nanoparticles is performed. • Effect of MCM-41 nanoparticles addition on the polymerization rate, conversion and molecular weights of the products are discussed. • Improvement in thermal stability of the nanocomposites and decreasing T{sub g} values was also observed by incorporation of MCM-41 nanoparticles. - Abstract: Activator generated by electron transfer for atom transfer radical polymerization was employed to synthesize well-defined mesoporous silica nanoparticles/polystyrene composites. Inherent features of spherical mesoporous silica nanoparticles were evaluated by nitrogen adsorption/desorption isotherm, X-ray diffraction and scanning electron microscopy analysis techniques. Conversion and molecular weight evaluations were carried out using gas and size exclusion chromatography respectively. By the addition of only 3 wt% mesoporous silica nanoparticles, conversion decreases from 81 to 58%. Similarly, number average molecular weight decreases from 17,116 to 12,798 g mol{sup −1}. However, polydispersity index (PDI) values increases from 1.24 to 1.58. A peak around 4.1–4.2 ppm at proton nuclear magnetic resonance spectroscopy results clearly confirms the living nature of the polymerization. Thermogravimetric

  18. HYDROPHILIC MODIFICATION OF PPESK POROUS MEMBRANES VIA AQUEOUS SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhuan Yi; You-yi Xu; Li-ping Zhu; Han-bang Dong; Bao-ku Zhu

    2009-01-01

    Hydrophilic surface modification of poly(phthalazinone ether sulfone ketone)(PPESK)porous membranes was achieved via surface-initiated atom transfer radical polymerization(ATRP)in aqueous medium.Prior to ATRP,chloromethyl groups were introduced onto PPESK main chains by chloromethylation.Chloromethylated PPESK(CMPPESK)was fabricated into porous membrane through phase inversion technique.Hydrophilic poly(poly(ethylene glycol)methyl ether methacrylate)(P(PEGMA))brushes were grafted from CMPPESK membrane under the initiation of benzyl chloride groups on membrane surface.The results of Fourier transform infrared(FT-IR)spectroscopy and X-ray photoelectron spectroscopy (XPS)confirmed the grafting of P(PEGMA)chains.Water contact angle measurements and protein adsorption experiments suggested that the hydrophilicity and anti-fouling ability of PPESK membrane were remarkably improved after the grafting of P(PEGMA)brushes.The addition of small amount of water in the reaction solvent apparently accelerated the progress of the grafting reaction.The use of CuCl2 in the catalyst system promoted the controllability of the ATRP reaction.

  19. Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs

    Directory of Open Access Journals (Sweden)

    Fabrice Chemla

    2013-02-01

    Full Text Available The formation of alkylidenezinc carbenoids by 1,4-addition/carbozincation of dialkylzincs or alkyl iodides based on zinc atom radical transfer, in the presence of dimethylzinc with β-(propargyloxyenoates having pendant iodo- and bromoalkynes, is disclosed. Formation of the carbenoid intermediate is fully stereoselective at −30 °C and arises from a formal anti-selective carbozincation reaction. Upon warming, the zinc carbenoid is stereochemically labile and isomerizes to its more stable form.

  20. Functional Virus-Based Polymer-Protein Nanoparticles by Atom Transfer Radical Polymerization

    OpenAIRE

    Pokorski, Jonathan K.; Breitenkamp, Kurt; Finn, M. G.

    2011-01-01

    Viruses and virus-like particles (VLPs) are useful tools in biomedical research. Their defined structural attributes make them attractive platforms for engineered interactions over large molecular surface areas. In this report, we describe the use of VLPs as multivalent macroinitiators for atom transfer radical polymerization (ATRP). The introduction of chemically reactive monomers during polymerization provides a robust platform for post-synthetic modification via the copper-catalyzed azide-...

  1. On Surface-Initiated Atom Transfer Radical Polymerization Using Diazonium Chemistry To Introduce the Initiator Layer

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Lillethorup, Mie; Ceccato, Marcel;

    2011-01-01

    This work features the controllability of surface-initiated atom transfer radical polymerization (SI-ATRP) of methyl methacrylate, initiated by a multilayered 2-bromoisobutyryl moiety formed via diazonium chemistry. The thickness as a function of polymerization time has been studied by varying...... Cu(II)/Cu(I) complexes (L = Me(6)TREN, PMDETA, and BIPY). It is also observed that the ability of polymer brushes to reinitiate depends on the initial thickness and the solvent used for generating it....

  2. Bibliography on electron transfer processes in ion-ion/atom/molecule collisions. Updated 1997

    International Nuclear Information System (INIS)

    Following our previous compilations (IPPJ-AM-45 (1986), NIFS-DATA-7 (1990), NIFS-DATA-20 (1993)), bibliographic information on experimental and theoretical studies on electron transfer processes in ion-ion/atom/molecule collisions is up-dated. The references published through 1954-1996 are listed in the order of the publication year. For easy finding of the references for a combination of collision partners, a simple list is provided. (author)

  3. Bibliography on electron transfer processes in ion-ion/atom/molecule collisions, updated 1990

    International Nuclear Information System (INIS)

    Following a previous compilation, new bibliographic information on experimental and theoretical studies on electron transfer processes in ion-ion/atom/molecule collisions is up-dated. The references published through 1989 are surveyed. For easy finding references for particular combination of collision partners, a simple list is also provided. Furthermore, for convenience, a copy of the previous compilation (IPPJ-AM-45 (1986)) is included. (author) 1363 refs

  4. Bibliography on electron transfer processes in ion-ion/atom/molecule collisions. Updated 1997

    Energy Technology Data Exchange (ETDEWEB)

    Tawara, H.

    1997-04-01

    Following our previous compilations (IPPJ-AM-45 (1986), NIFS-DATA-7 (1990), NIFS-DATA-20 (1993)), bibliographic information on experimental and theoretical studies on electron transfer processes in ion-ion/atom/molecule collisions is up-dated. The references published through 1954-1996 are listed in the order of the publication year. For easy finding of the references for a combination of collision partners, a simple list is provided. (author)

  5. Coherence preservation of a single neutral atom qubit transferred between magic-intensity optical traps

    CERN Document Server

    Yang, Jiaheng; Guo, Ruijun; Xu, Peng; Wang, Kunpeng; Sheng, Cheng; Liu, Min; Wang, Jin; Derevianko, Andrei; Zhan, Mingsheng

    2016-01-01

    We demonstrate that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs). This is a prerequisite step in realizing a large-scale neutral atom quantum information processing platform. A qubit encoded in the hyperfine manifold of $^{87}$Rb atom is dynamically extracted from the static quantum register by an auxiliary moving ODT and reinserted into the static ODT. Previous experiments were limited by decoherences induced by the differential light shifts of qubit states. Here we apply a magic-intensity trapping technique which mitigates the detrimental effects of light shifts and substantially enhances the coherence time to $225 \\pm 21\\,\\mathrm{ms}$. The experimentally demonstrated magic trapping technique relies on the previously neglected hyperpolarizability contribution to the light shifts, which makes the light shift dependence on the trapping laser intensity to be parabolic. Because of the parabolic dependence, at a certain ...

  6. Single-collision studies of hot atom energy transfer and chemical reaction

    International Nuclear Information System (INIS)

    This report discusses research in the collision dynamics of translationally hot atoms, with funding with DOE for the project ''Single-Collision Studies of Hot Atom Energy Transfer and Chemical Reaction,'' Grant Number DE-FG03-85ER13453. The work reported here was done during the period September 9, 1988 through October 31, 1991. During this period this DOE-funded work has been focused on several different efforts: (1) experimental studies of the state-to-state dynamics of the H + RH → H2 R reactions where RH is CH4, C2H6, or C3H8, (2) theoretical (quasiclassical trajectory) studies of hot hydrogen atom collision dynamics, (3) the development of photochemical sources of translationally hot molecular free radicals and characterization of the high resolution CARS spectroscopy of molecular free radicals, (4) the implementation of stimulated Raman excitation (SRE) techniques for the preparation of vibrationally state-selected molecular reactants

  7. In Situ Catalyst Modification in Atom Transfer Radical Reactions with Ruthenium Benzylidene Complexes.

    Science.gov (United States)

    Lee, Juneyoung; Grandner, Jessica M; Engle, Keary M; Houk, K N; Grubbs, Robert H

    2016-06-01

    Ruthenium benzylidene complexes are well-known as olefin metathesis catalysts. Several reports have demonstrated the ability of these catalysts to also facilitate atom transfer radical (ATR) reactions, such as atom transfer radical addition (ATRA) and atom transfer radical polymerization (ATRP). However, while the mechanism of olefin metathesis with ruthenium benzylidenes has been well-studied, the mechanism by which ruthenium benzylidenes promote ATR reactions remains unknown. To probe this question, we have analyzed seven different ruthenium benzylidene complexes for ATR reactivity. Kinetic studies by (1)H NMR revealed that ruthenium benzylidene complexes are rapidly converted into new ATRA-active, metathesis-inactive species under typical ATRA conditions. When ruthenium benzylidene complexes were activated prior to substrate addition, the resulting activated species exhibited enhanced kinetic reactivity in ATRA with no significant difference in overall product yield compared to the original complexes. Even at low temperature, where the original intact complexes did not catalyze the reaction, preactivated catalysts successfully reacted. Only the ruthenium benzylidene complexes that could be rapidly transformed into ATRA-active species could successfully catalyze ATRP, whereas other complexes preferred redox-initiated free radical polymerization. Kinetic measurements along with additional mechanistic and computational studies show that a metathesis-inactive ruthenium species, generated in situ from the ruthenium benzylidene complexes, is the active catalyst in ATR reactions. Based on data from (1) H, (13)C, and (31)P NMR spectroscopy and X-ray crystallography, we suspect that this ATRA-active species is a RuxCly(PCy3)z complex.

  8. Direct visualization of triplex DNA molecular dynamics by fluorescence resonance energy transfer and atomic force microscopy measurements

    Science.gov (United States)

    Chang, Chia-Ching; Lin, Po-Yen; Chen, Yen-Fu; Chang, Chia-Seng; Kan, Lou-Sing

    2007-11-01

    We have detected the dynamics of 17-mer DNA triplex dissociation mechanism at the molecular level. Fluorescence resonance energy transfer (FRET) was used as an indicator of intermolecular interaction in nanometer range, whereas atomic force microscopy (AFM) was employed to address single molecule with sub-angstrom precision. The maximum rupture force of DNA triplex was found at pH 4.65, consistent with macroscopic observations. These results indicated that the FRET together with an AFM detection system could be used to reveal the DNA triplex interaction in nanometer scale unambiguously.

  9. NADS - Nuclear And Atomic Data System

    Energy Technology Data Exchange (ETDEWEB)

    McKinley, M S; Beck, B; McNabb, D

    2004-09-17

    We have developed NADS (Nuclear and Atomic Data System), a web-based graphical interface for viewing pointwise and grouped cross-sections and distributions. Our implementation is a client / server model. The client is a Java applet that displays the graphical interface, which has interactive 2-D, 3-D, and 4-D plots and tables. The server, which can serve and perform computations the data, has been implemented in Python using the FUDGE package developed by Bret Beck at LLNL. Computational capabilities include algebraic manipulation of nuclear evaluated data in databases such as LLNL's ENDL-99, ENDF/B-V and ENDF/B-VI as well as user data. Processed data used in LLNL's transport codes are accessible as well. NADS is available from http://nuclear.llnl.gov/

  10. NADS — Nuclear and Atomic Data System

    Science.gov (United States)

    McKinley, Michael S.; Beck, Bret; McNabb, Dennis

    2005-05-01

    We have developed NADS (Nuclear and Atomic Data System), a web-based graphical interface for viewing pointwise and grouped cross sections and distributions. Our implementation is a client / server model. The client is a Java applet that displays the graphical interface, which has interactive 2-D, 3-D, and 4-D plots and tables. The server, which can serve and perform computations of the data, has been implemented in Python using the FUDGE package developed by Bret Beck at LLNL. Computational capabilities include algebraic manipulation of nuclear evaluated data in databases such as LLNL's ENDL-99, ENDF/B-V, and ENDF/B-VI, as well as user data. Processed data used in LLNL's transport codes are accessible as well. NADS is available from http://nuclear.llnl.gov/.

  11. Atomic dynamics in the mode-mode competition system

    Institute of Scientific and Technical Information of China (English)

    Wu Qin; Fang Mao-Fa

    2004-01-01

    The atomic dynamical properties in the system with competing k-photon and l-photon transitions are studied fully by means of quantum theory. We discuss the influences of the mode-mode competition, the relative competing strengths of the atom and the two-mode field, and the initial state of the system on the atomic dynamics. We show that the presence of the mode-mode competition can result in quite a periodical collapses-revivals of the atomic inversion and the increase of the initial photons of the system can lead to the collapse-revival phenomenon and prolong the revival time of the atomic inversion.

  12. Microwork transfer system in a nanomanufacturing world

    Science.gov (United States)

    Tsuchiya, Kensuke; Nakao, Masayuki; Okusa, Takenori; Hatamura, Yotaro; Matsumoto, Kiyoshi

    1998-01-01

    Practical micromachines, such as magnetic heads or endoscopic tools, can not be made only by shaping processes; they require post-machining processes such as assembling, wiring, piping, etc. The authors have developed an integrated manufacturing system, 'nano manufacturing world' (NMW). It performs shaping, post-machining or transferring like a factory. In this paper, we introduce a microwork transfer system, which functions a) steady transfer of a workpiece, b) non-release chucking of the workpiece during production and c) individual rotation of the workpiece using a preloaded microslide bearing on the pallet. Developed transfer system could realize the functions: less positioning error due to accurate pallet positioning by taper pins, high transfer yield of the workpieces due to no missing by a micro chuck, sub-micron rotational fluctuation due to a roller pallet by a preloaded micro slide bearing. Through the fabrication demonstrations of a sub-1 mm3 micro-house or micro force sensor block of 125 X 100 X 500 micrometers , it has been confirmed that this transfer system improved the performance of integrated manufacturing in NMW.

  13. Universal four-boson system: dimer-atom-atom Efimov effect and recombination reactions

    CERN Document Server

    Deltuva, A

    2013-01-01

    Recent theoretical developments in the four-boson system with resonant interactions are described. Momentum-space scattering equations for the four-particle transition operators are used. The properties of unstable tetramers with approximate dimer-atom-atom structure are determined. In addition, the three- and four-cluster recombination processes in the four-boson system are studied.

  14. File Transfer Algorithm for Autonomous Decentralized System

    Institute of Scientific and Technical Information of China (English)

    GUI Xun; TAN Yong-dong; Qian Qing-quan

    2008-01-01

    A file transfer algorithm based on ADP (autonomous decentralized protocol) was proposed to solve the problem that the ADS (autonomous decentralized system) middleware (NeXUS/Dlink) lacks of file transfer functions for Windows. The algorithm realizes the peer-to-peer file transfer, one-to-N inquiry/multi-response file transfer and one-to-N file distribution in the same data field based on communication patterns provided by the ADP. The peer-to-peer file transfer is implemented through a peer-to-peer communication path, one-to-N inquiry/multi-response file transfer and one-to-N file distribution are implemented through multicast commtmieation. In this algorithm, a file to be transferred is named with a GUID ( global unique identification), every data packet is marked with a sequence number, and file-receiving in parallel is implemented by caching DPOs (data processing objects) and multithread technologies. The algorithm is applied in a simulation system of the decentralized control platform, and the test results and long time stable mrming prove the feasibility of the algorithm.

  15. Ultracold magnetically tunable interactions without radiative charge transfer losses between Ca$^+$, Sr$^+$, Ba$^+$, and Yb$^+$ ions and Cr atoms

    CERN Document Server

    Tomza, Michał

    2015-01-01

    The Ca$^+$, Sr$^+$, Ba$^+$, and Yb$^+$ ions immersed in an ultracold gas of the Cr atoms are proposed as experimentally feasible heteronuclear systems in which ion-atom interactions at ultralow temperatures can be controlled with magnetically tunable Feshbach resonances without charge transfer and radiative losses. \\textit{Ab initio} techniques are applied to investigate electronic-ground-state properties of the (CaCr)$^+$, (SrCr)$^+$, (BaCr)$^+$, and (YbCr)$^+$ molecular ions. The potential energy curves, permanent electric dipole moments, and static electric dipole polarizabilities are computed. The spin restricted open-shell coupled cluster method restricted to single, double, and noniterative triple excitations, RCCSD(T), and the multireference configuration interaction method restricted to single and double excitations, MRCISD, are employed. The scalar relativistic effects are included within the small-core energy-consistent pseudopotentials. The leading long-range induction and dispersion interaction co...

  16. Design Criteria for Bagless Transfer System (BTS) Packaging System

    International Nuclear Information System (INIS)

    This document provides the criteria for the design and installation of a Bagless Transfer System (BTS); Blend, Sieve and Balance Equipment; and Supercritical Fluid Extraction System (SFE). The project consists of 3 major modules: (1) Bagless Transfer System (BTS) Module; (2) Blend, Sieve and Balance Equipment; and (3) Supercritical Fluid Extraction (SFE) Module

  17. A DFT Study of R-X Bond Dissociation Enthalpies of Relevance to the Initiation Process of Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Gillies, Malcolm Bjørn; Matyjaszewski, Krzysztof; Norrby, Per-Ola;

    2003-01-01

    DFT calculations at the B3P86/6-31G** level have been carried out to derive the bond dissociation energies (BDE) and free energies for a number of R-X systems (X ) Cl, Br, I, N3, and S2-CNMe2) that have been or can potentially be used as initiators for atom transfer radical polymerization (ATRP)....

  18. Exciton transfer dynamics in a trimer system

    Institute of Scientific and Technical Information of China (English)

    Tan Qing-Shou; Xu Lan; Kuang Le-Man

    2013-01-01

    We study exciton transfer dynamics in a trimer system by investigating excitation transfer probability (ETP).We calculate ETP in the zero-temperature limit and theoretically predict the environment-assisted quantum critical effect,in which ETP exhibits a sudden change at the critical point of quantum phase transition for the trimer.In particular,we find that the steady-state ETP can be observed in the presence of the environment interaction.

  19. Design of atomic energy information network system

    International Nuclear Information System (INIS)

    As the 21st century is expected to induce a Knowledge based society, responding to this kind of change on our own initiative could be achieved by establishing networks among atomic energy agencies with the Atomic Energy Portal Site in a pivotal role. Thus, enabling the knowledge information from each agency to be easily shared and utilized. Furthermore, it can contribute to further researches by providing accumulated knowledge in the atomic energy, such as research output and past achievements, and by avoiding the repetition of researches on the same subjects. It could also provide remote educational data to researchers and industrial experts in atomic energy, as well as atomic energy information for general public consistently, so that we can promote our confidence in atomic energy

  20. Faithful entanglement transference from qubits to continuous variable systems

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, P; Mundarain, D [Departamento de Fisica, Seccion de Fenomenos Opticos, Universidad Simon BolIvar, Apartado Postal 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)

    2011-05-28

    In this work, we study the transference of entanglement between atomic qubits and the fields of two separate optical cavities. We show that it is possible to transfer all the entanglement of two maximal entangled qubits to the fields of the cavities without post-selection. Initially, the qubit system is in a maximal entangled state and the cavities are in a pure separable state with each cavity in a coherent state. For high excitation levels in the coherent fields, at some characteristic time T, the state of the qubit system becomes separable and at this time all the entanglement is deposited on the mono-modal fields of the cavities. We also consider retrieval of entanglement and an alternative protocol using post-selection.

  1. Quantum noise property in coherent atomic system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-xiang; WANG Hai-hong; CAI Jin; GAO Jiang-rui

    2006-01-01

    The coherent superposition of atomic states leads to the characteristic change of interacting lights because of the coupling between the lights and atoms.In this paper,the noise spectrum of the quantified light interacting with the atoms is studied under the condition of electromagnetically induced transparency (EIT).It is shown that the noise spectrum displays a double M-shape noise profile resulted from the conversion of phase noise of probe beam.A squeezing of 0.3 dB can be observed at the detuning of probe light at the proper parameters of atoms and coupling beam.

  2. Matter, energy, and heat transfer in a classical ballistic atom pump.

    Science.gov (United States)

    Byrd, Tommy A; Das, Kunal K; Mitchell, Kevin A; Aubin, Seth; Delos, John B

    2014-11-01

    A ballistic atom pump is a system containing two reservoirs of neutral atoms or molecules and a junction connecting them containing a localized time-varying potential. Atoms move through the pump as independent particles. Under certain conditions, these pumps can create net transport of atoms from one reservoir to the other. While such systems are sometimes called "quantum pumps," they are also models of classical chaotic transport, and their quantum behavior cannot be understood without study of the corresponding classical behavior. Here we examine classically such a pump's effect on energy and temperature in the reservoirs, in addition to net particle transport. We show that the changes in particle number, of energy in each reservoir, and of temperature in each reservoir vary in unexpected ways as the incident particle energy is varied.

  3. Atomic energy indemnification system in Japan

    International Nuclear Information System (INIS)

    The Japanese legislation on the indemnification by atomic energy enterprisers for atomic energy damages, published in 1961 and enforced in 1962, includes the law concerning indemnification for atomic energy damages and the law concerning atomic energy damage indemnification contracts (hereafter referred to as ''the law concerning indemnification contracts''). While the Japanese laws are same as the foreign legislation in the provisions of the responsibility of atomic energy damages without the error of atomic energy enterprisers, exemption reasons are more important in this respect. When damages are due to exceptionally grave natural disasters or social disturbances, atomic energy enterprisers are exempted from the responsibility. Indemnification amounts are determined, but the Japanese laws do not limit then, different from the foreign regulations. The periods for demanding indemnification are not defined particularly in the law concerning indemnification contracts, and the general basic rules of the civil law are applied. As a result, the demand right terminates in 3 years after the injured persons find damage and offenders, and in 20 years since the unlawful act (Article 724, Civil law). The indemnification liability for atomic energy damages is focused on atomic energy enterprisers concerned in the same way as the foreign laws. The measures for assuring the execution of indemnification responsibility consist in principle of the firm conbination of the liability insurance contracts with private insurance companies and the indemnification contracts for atomic energy damages with the state. The damages of employes suffered in works are excluded from indemnification, which has been the main issue of discussion since the enactment of atomic energy laws. (Okada, K.)

  4. Handshake electron transfer from hydrogen Rydberg atoms incident at a series of metallic thin films

    CERN Document Server

    Gibbard, Jemma A

    2016-01-01

    Thin metallic films have a 1D quantum well along the surface normal direction, which yields particle-in-a-box style electronic quantum states. However the quantum well is not infinitely deep and the wavefunctions of these states penetrate outside the surface where the electron is bound by its own image-charge attraction. Therefore a series of discrete, vacant states reach out from the thin film into the vacuum increasing the probability of electron transfer from an external atom or molecule to the thin film, especially for the resonant case where the quantum well energy matches that of the Rydberg atom. We show that `handshake' electron transfer from a highly excited Rydberg atom to these thin-film states is experimentally measurable. Thicker films, have a wider 1D box, changing the energetic distribution and image-state contribution to the thin film wavefunctions, resulting in more resonances. Calculations successfully predict the number of resonances and the nature of the thin-film wavefunctions for a given...

  5. Protein microarrays based on polymer brushes prepared via surface-initiated atom transfer radical polymerization.

    Science.gov (United States)

    Barbey, Raphael; Kauffmann, Ekkehard; Ehrat, Markus; Klok, Harm-Anton

    2010-12-13

    Polymer brushes represent an interesting platform for the development of high-capacity protein binding surfaces. Whereas the protein binding properties of polymer brushes have been investigated before, this manuscript evaluates the feasibility of poly(glycidyl methacrylate) (PGMA) and PGMA-co-poly(2-(diethylamino)ethyl methacrylate) (PGMA-co-PDEAEMA) (co)polymer brushes grown via surface-initiated atom transfer radical polymerization (SI-ATRP) as protein reactive substrates in a commercially available microarray system using tantalum-pentoxide-coated optical waveguide-based chips. The performance of the polymer-brush-based protein microarray chips is assessed using commercially available dodecylphosphate (DDP)-modified chips as the benchmark. In contrast to the 2D planar, DDP-coated chips, the polymer-brush-covered chips represent a 3D sampling volume. This was reflected in the results of protein immobilization studies, which indicated that the polymer-brush-based coatings had a higher protein binding capacity as compared to the reference substrates. The protein binding capacity of the polymer-brush-based coatings was found to increase with increasing brush thickness and could also be enhanced by copolymerization of 2-(diethylamino)ethyl methacrylate (DEAEMA), which catalyzes epoxide ring-opening of the glycidyl methacrylate (GMA) units. The performance of the polymer-brush-based microarray chips was evaluated in two proof-of-concept microarray experiments, which involved the detection of biotin-streptavidin binding as well as a model TNFα reverse assay. These experiments revealed that the use of polymer-brush-modified microarray chips resulted not only in the highest absolute fluorescence readouts, reflecting the 3D nature and enhanced sampling volume provided by the brush coating, but also in significantly enhanced signal-to-noise ratios. These characteristics make the proposed polymer brushes an attractive alternative to commercially available, 2D microarray

  6. Control and Transfer of Entanglement between Two Atoms Driven by Classical Fields under Dressed-State Representation

    Science.gov (United States)

    Liao, Qing-Hong; Zhang, Qi; Xu, Juan; Yan, Qiu-Rong; Liu, Ye; Chen, An

    2016-06-01

    We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays. Supported by National Natural Science Foundation of China under Grant Nos. 11247213, 61368002, 11304010, 11264030, 61168001, China Postdoctoral Science Foundation under Grant No. 2013M531558, Jiangxi Postdoctoral Research Project under Grant No. 2013KY33, the Natural Science Foundation of Jiangxi Province under Grant No. 20142BAB217001, the Foundation for Young Scientists of Jiangxi Province (Jinggang Star) under Grant No. 20122BCB23002, the Research Foundation of the Education Department of Jiangxi Province under Grant Nos. GJJ13051, GJJ13057, and the Graduate Innovation Special Fund of Nanchang University under Grant No. cx2015137

  7. In Situ Catalyst Modification in Atom Transfer Radical Reactions with Ruthenium Benzylidene Complexes.

    Science.gov (United States)

    Lee, Juneyoung; Grandner, Jessica M; Engle, Keary M; Houk, K N; Grubbs, Robert H

    2016-06-01

    Ruthenium benzylidene complexes are well-known as olefin metathesis catalysts. Several reports have demonstrated the ability of these catalysts to also facilitate atom transfer radical (ATR) reactions, such as atom transfer radical addition (ATRA) and atom transfer radical polymerization (ATRP). However, while the mechanism of olefin metathesis with ruthenium benzylidenes has been well-studied, the mechanism by which ruthenium benzylidenes promote ATR reactions remains unknown. To probe this question, we have analyzed seven different ruthenium benzylidene complexes for ATR reactivity. Kinetic studies by (1)H NMR revealed that ruthenium benzylidene complexes are rapidly converted into new ATRA-active, metathesis-inactive species under typical ATRA conditions. When ruthenium benzylidene complexes were activated prior to substrate addition, the resulting activated species exhibited enhanced kinetic reactivity in ATRA with no significant difference in overall product yield compared to the original complexes. Even at low temperature, where the original intact complexes did not catalyze the reaction, preactivated catalysts successfully reacted. Only the ruthenium benzylidene complexes that could be rapidly transformed into ATRA-active species could successfully catalyze ATRP, whereas other complexes preferred redox-initiated free radical polymerization. Kinetic measurements along with additional mechanistic and computational studies show that a metathesis-inactive ruthenium species, generated in situ from the ruthenium benzylidene complexes, is the active catalyst in ATR reactions. Based on data from (1) H, (13)C, and (31)P NMR spectroscopy and X-ray crystallography, we suspect that this ATRA-active species is a RuxCly(PCy3)z complex. PMID:27186790

  8. Proton-Conducting Sulfonated Ionomers by Chemical Modification and Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller

    The cornerstone in this dissertation is made up by three individual assessments of the diversity in the macromolecular landscape that can be obtained by applying relatively few efficient chemical tools. The intention is to gain deeper knowledge on the chemical tuning of proton exchange membranes...... of hydrocarbon macromolecular architectures, PSU with postsulfonated polystyrene (PS) grafts are investigated. Here, IEC is controlled through the degree of substitution, the graft length and DS. The grafting is performed with atom transfer radical polymerization (ATRP). The third assessment is dedicated...

  9. Reverse atom transfer radical polymerization of styrene in emulsion initiated by AIBN or V50

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai; ZHANG Hongwen; LI Hongtu; WANG Jingyuan

    2005-01-01

    Reverse atom transfer radical polymerization of styrene was conducted in emulsion by using Cu(II)/2,2′- bipydine or Cu(II)/phen complexes, AIBN or V50 as the initiator, Brij-98 or OP-10 as the surfactant. The results of GPC showed that both polymerization processes exhibit living characters when using AIBN as the initiator. However, when V50 was used, the monomer conversion was fairly low and the whole polymerization was not controlled well. The measurement of particle size and its distribution told us that the latex particles were mean and stable when using Brij-98 as the surfactant.

  10. Synthesis and characterization of carbon fibers functionalized with poly (glycidyl methacrylate) via atom transfer radical polymerization

    Science.gov (United States)

    Wu, Yongwei; Xiong, Lei; Qin, Xiaokang; Wang, Zhengyue; Ding, Bei; Ren, Huan; Pi, Xiaolong

    2015-07-01

    In this work, polyacrylonitrile (PAN)-based carbon fibers (CF) were chemically modified with poly (glycidyl methacrylate) (PGMA) via atom transfer radical polymerization (ATRP) to improve the interaction between the CF and polymer matrix. The FT-IR, TGA, and XPS were used to determine the chemical structure of the resulting products and the quantities of PGMA chains grafted from the CF surface. The experimental results confirm that the CF surface was functionalized and glycidyl methacrylate was graft-polymerized onto the CF, and the grafting content of polymer could reach 10.2%.

  11. Optimization of transfer of laser-cooled atom cloud to a quadrupole magnetic

    Indian Academy of Sciences (India)

    S P Ram; S K Tiwari; S R Mishra; H S Rawat

    2014-02-01

    We present here our experimental results on transfer of laser-cooled atom cloud to a quadrupole magnetic trap. We show that by choosing appropriately the ratio of potential energy in magnetic trap to kinetic energy of cloud in molasses, we can obtain the maximum phase-space density in the magnetic trap. These results guide us to choose the value of current to be switched in the quadrupole coils used for magnetic trapping for a given temperature of the cloud after molasses. This study is also useful to set the initial phase-space density of the cloud before evaporative cooling.

  12. Protein repellent hydrophilic grafts prepared by surface-initiated atom transfer radical polymerization from polypropylene

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Jankova Atanasova, Katja; Eskimergen, Rüya;

    2012-01-01

    Grafting of poly(ethylene glycol)methacrylate (PEGMA) and N,N-dimethylacrylamide (DMAAm) from UV-initiator modified polypropylene (PP) was performed by Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP). The modification and hydrophilization of the PP substrates were confirmed...... with Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FTIR) spectroscopy and Water Contact Angle (WCA) measurements. Confocal fluorescence microscopy of modified and unmodified substrates immersed in labelled insulin aspart showed superior repulsion of this protein for the poly(PEGMA) grafts, due...

  13. Railcar waste transfer system hydrostatic test report

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, S.D.

    1997-04-03

    This Acceptance Test Report (ATR) documents for record purposes the field results, acceptance, and approvals of the completed acceptance test per HNF-SD-W417-ATP-001, ''Rail car Waste Transfer System Hydrostatic Test''. The test was completed and approved without any problems or exceptions.

  14. Railcar waste transfer system hydrostatic test

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, S.D.

    1997-03-31

    Recent modifications have been performed on the T-Plant Railcar Waste Transfer System, This Acceptance Test Procedure (ATP) has been prepared to demonstrate that identified piping welds and mechanical connections incorporated during the modification are of high integrity and are acceptable for service. This will be achieved by implementation of a hydrostatic leak test.

  15. Maximizing energy transfer in vibrofluidized granular systems

    NARCIS (Netherlands)

    Windows-Yule, C.R.K.; Rosato, A.D.; Parker, D.J.; Thornton, A.R.

    2015-01-01

    Using discrete particle simulations validated by experimental data acquired using the positron emission particle tracking technique, we study the efficiency of energy transfer from a vibrating wall to a system of discrete, macroscopic particles. We demonstrate that even for a fixed input energy from

  16. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  17. Stokes identification in an atomic ensemble using a filtering system

    Institute of Scientific and Technical Information of China (English)

    Luo Xiao-Ming; Ning Bo; Chen Li-Qing; Zhou Yue; Zhong Zhi-Ping; Jiang Shuo

    2009-01-01

    Polarization filtering and atomic cell filtering are applied in the identification of Stokes signals in an atomic ensemble, and reduce the noise to a level of 10~(-5) and 10~(-4) respectively. Good Stokes signals are then obtained. In this article the two filtering systems and the final Stokes output are presented, and the optimization of the polarization filtering system is highlighted.

  18. Facilitating electron transfer in bioelectrocatalytic systems

    OpenAIRE

    Sekretaryova, Alina

    2016-01-01

    Bioelectrocatalytic systems are based on biological entities, such as enzymes, whole cells, parts of cells or tissues, which catalyse electrochemical processes that involve the interaction between chemical change and electrical energy. In all cases, biocatalysis is implemented by enzymes, isolated or residing inside cells or part of cells. Electron transfer (ET) phenomena, within the protein molecules and between biological redox systems and electronics, enable the development of various bioe...

  19. A test of two approximate two-state treatments for the dynamics of H-atom transfers between two heavy particles

    OpenAIRE

    Klippenstein, Stephen J.; Babamov, Vasil K.; Marcus, R. A.

    1986-01-01

    Reactive transition probabilities and Boltzmann-averaged reactive transition probabilities for a slightly off-resonant model H-atom transfer system with an appreciable energy barrier are calculated using the approximate methods of Babamov et al. and of Crothers–Stückelberg. Both are compared with the corresponding quantities obtained from a numerical two-state treatment of the same model system. The method of Babamov et al. is seen to give more accurate results for the transition probabilitie...

  20. Functionalized polymer film surfaces via surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    The ability to manipulate and control the surface properties of polymer films, without altering the substrate properties, is crucial to their wide-spread applications. In this work, a simple one-step method for the direct immobilization of benzyl chloride groups (as the effective atom transfer radical polymerization (ATRP) initiators) on the polymer films was developed via benzophenone-induced coupling of 4-vinylbenzyl chloride (VBC). Polyethylene (PE) and nylon films were selected as examples of polymer films to illustrate the functionalization of film surfaces via surface-initiated ATRP. Functional polymer brushes of (2-dimethylamino)ethyl methacrylate, sodium 4-styrenesulfonate, 2-hydroxyethyl methacrylate and glycidyl methacrylate, as well as their block copolymer brushes, have been prepared via surface-initiated ATRP from the VBC-coupled PE or nylon film surfaces. With the development of a simple approach to the covalent immobilization of ATRP initiators on polymer film surfaces and the inherent versatility of surface-initiated ATRP, the surface functionality of polymer films can be precisely tailored. - Highlights: ► Atom transfer radical polymerization initiators were simply immobilized. ► Different functional polymer brushes were readily prepared. ► Their block copolymer brushes were also readily prepared

  1. Hydrophilization of poly(ether ether ketone) films by surface-initiated atom transfer radical polymerization

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Jankova Atanasova, Katja; Hvilsted, Søren

    2010-01-01

    Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP) has been exploited to hydrophilize PEEK. The ketone groups on the PEEK surface were reduced to hydroxyl groups which were converted to bromoisobutyrate initiating sites for SI-ATRP. The modification steps were followed by contact an...... in the surface topography. Two possible applications arose from the hydrophilization of PEEK, metal deposition and protein repellency. The performed modification allowed for successful electroless deposition and good adhesion of nickel as well as copper.......Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP) has been exploited to hydrophilize PEEK. The ketone groups on the PEEK surface were reduced to hydroxyl groups which were converted to bromoisobutyrate initiating sites for SI-ATRP. The modification steps were followed by contact...... angle measurements and XPS. Moreover, ATR FTIR has been used to confirm the formation of initiating groups. Grafting of PEGMA from PEEK was performed in aqueous solution. The presence of the PPEGMA grafts on PEEK was revealed by the thermograms from TGA whereas investigations with AFM rejected changes...

  2. O atom transfer from nitric oxide catalyzed by Fe(TPP).

    Science.gov (United States)

    Lin, R; Farmer, P J

    2001-02-14

    The reaction of NO-Fe(TPP) with low pressures of NO gas proceeds through three distinct transformations, the first of which we suggest is the formation of an N--N-coupled, (NO)(2) adduct intermediate. The subsequent formation of NO(NO(2))Fe(TPP), which under these conditions readily loses NO, suggests that it is formed by addition of free NO(2) to the starting nitrosyl. A mechanism is proposed which implies that the addition of a competitive O atom acceptor would lead to catalytic production of N(2)O. In agreement with the proposed mechanism, the formation of N(2)O is decoupled from the formation of the nitrite by using PPh(3) as the competitive acceptor. The mechanism of O atom transfer was examined by cross-labeling experiments, which show that both O atoms in the intermediate are equivalent, even under catalytic conditions. The formation of an intermediate was confirmed by IR spectroscopy of the heterogeneous reaction of an NO-Fe(TPP) film with gaseous NO, in which transient, isotope-sensitive nu(NO) bands are seen prior to NO(NO(2))Fe(TPP) formation. Mixed (14)N/(15)N label experiments demonstrate coupling between the two bound nitrosyls in the transient species. PMID:11456667

  3. How Large are Nonadiabatic Effects in Atomic and Diatomic Systems?

    CERN Document Server

    Yang, Yubo; Tubman, Norm; Krogel, Jaron; Hammes-Schiffer, Sharon; Ceperley, David

    2015-01-01

    With recent developments in simulating nonadiabatic systems to high accuracy, it has become possible to determine how much energy is attributed to nuclear quantum effects beyond zero-point energy. In this work we calculate the non-relativistic ground-state energies of atomic and molecular systems without the Born-Oppenheimer approximation. For this purpose we utilize the fixed-node diffusion Monte Carlo method, in which the nodes depend on both the electronic and ionic positions. We report ground-state energies for all systems studied, ionization energies for the first-row atoms and atomization energies for the first-row hydrides. We find the ionization energies of the atoms to be nearly independent of the Born-Oppenheimer approximation, within the accuracy of our results. The atomization energies of molecular systems, however, show small effects of the nonadiabatic coupling between electrons and nuclei.

  4. How large are nonadiabatic effects in atomic and diatomic systems?

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yubo, E-mail: yyang173@illinois.edu, E-mail: normantubman2015@u.northwestern.edu; Tubman, Norm M., E-mail: yyang173@illinois.edu, E-mail: normantubman2015@u.northwestern.edu; Ceperley, David M. [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Kylänpää, Ilkka [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland); Krogel, Jaron T. [Oak Ridge National Laboratory, Materials Sciences & Technology Division, Oak Ridge, Tennessee 37831 (United States); Hammes-Schiffer, Sharon [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States)

    2015-09-28

    With recent developments in simulating nonadiabatic systems to high accuracy, it has become possible to determine how much energy is attributed to nuclear quantum effects beyond zero-point energy. In this work, we calculate the non-relativistic ground-state energies of atomic and molecular systems without the Born-Oppenheimer approximation. For this purpose, we utilize the fixed-node diffusion Monte Carlo method, in which the nodes depend on both the electronic and ionic positions. We report ground-state energies for all systems studied, ionization energies for the first-row atoms and atomization energies for the first-row hydrides. We find the ionization energies of the atoms to be nearly independent of the Born-Oppenheimer approximation, within the accuracy of our results. The atomization energies of molecular systems, however, show small effects of the nonadiabatic coupling between electrons and nuclei.

  5. How large are nonadiabatic effects in atomic and diatomic systems?

    Science.gov (United States)

    Yang, Yubo; Kylänpää, Ilkka; Tubman, Norm M.; Krogel, Jaron T.; Hammes-Schiffer, Sharon; Ceperley, David M.

    2015-09-01

    With recent developments in simulating nonadiabatic systems to high accuracy, it has become possible to determine how much energy is attributed to nuclear quantum effects beyond zero-point energy. In this work, we calculate the non-relativistic ground-state energies of atomic and molecular systems without the Born-Oppenheimer approximation. For this purpose, we utilize the fixed-node diffusion Monte Carlo method, in which the nodes depend on both the electronic and ionic positions. We report ground-state energies for all systems studied, ionization energies for the first-row atoms and atomization energies for the first-row hydrides. We find the ionization energies of the atoms to be nearly independent of the Born-Oppenheimer approximation, within the accuracy of our results. The atomization energies of molecular systems, however, show small effects of the nonadiabatic coupling between electrons and nuclei.

  6. Ultracold atoms coupled to micro- and nanomechanical oscillators: towards hybrid quantum systems

    Science.gov (United States)

    Treutlein, Philipp

    2009-05-01

    Micro- and nanomechanical oscillators are presently approaching the quantum regime, driven by the continuous improvement of techniques to read out and cool mechanical motion. For trapped ultracold atoms, a rich toolbox of quantum control techniques already exists. By coupling mechanical oscillators to ultracold atoms, hybrid quantum systems could be formed, in which the atoms are used to cool, read out, and coherently manipulate the oscillators' state. In our work, we investigate different coupling mechanisms between ultracold atoms and mechanical oscillators. In a first experiment, we use atom-surface forces to couple the vibrations of a mechanical cantilever to the motion of a Bose-Einstein condensate in a magnetic microtrap on a chip. The atoms are trapped at sub-micrometer distance from the cantilever surface. We make use of the coupling to read out the cantilever vibrations with the atoms. Coupling via surface forces could be employed to couple atoms to molecular-scale oscillators such as carbon nanotubes. In a second experiment, we investigate coupling via a 1D optical lattice that is formed by a laser beam retroreflected from the cantilever tip. The optical lattice serves as a transfer rod which couples vibrations of the cantilever to the atoms and vice versa. Finally, we investigate magnetic coupling between the spin of ultracold atoms and the vibrations of a nanoscale cantilever with a magnetic tip. Theoretical investigations show that at low temperatures, the backaction of the atoms onto the cantilever is significant and the system represents a mechanical analog of cavity quantum electrodynamics in the strong coupling regime.

  7. NLS cargo transfer vehicle propulsion system

    Science.gov (United States)

    Hearn, Hank C.; Langford, G. K.

    1992-02-01

    The propulsion system of the Cargo Transfer Vehicle is designed to meet a wide range of requirements associated with the National Launch System (NLS) resupply function for Space Station Freedom. It provides both orbit adjustment and precise vehicle control capability, and is compatible with close proximity operation at the space station as well as return on the shuttle for ground refurbishment and reuse. Preliminary trade studies have resulted in designing and sizing an integrated bipropellant system using monomethyl hydrazine and nitrogen tetroxide. Design and analysis activities are continuing, and the design will evolve and mature as part of the NLS program.

  8. Confinement-induced resonances in ultracold atom-ion systems

    Science.gov (United States)

    Melezhik, V. S.; Negretti, A.

    2016-08-01

    We investigate confinement-induced resonances in a system composed of a tightly trapped ion and a moving atom in a waveguide. We determine the conditions for the appearance of such resonances in a broad region—from the "long-wavelength" limit to the opposite case when the typical length scale of the atom-ion polarization potential essentially exceeds the transverse waveguide width. We find considerable dependence of the resonance position on the atomic mass which, however, disappears in the "long-wavelength and zero-energy" limit, where the known result for the confined atom-atom scattering is reproduced. We also derive an analytic and a semianalytic formula for the resonance position in the long-wavelength and zero-energy limit and we investigate numerically the dependence of the resonance condition on the finite atomic colliding energy. Our results, which can be investigated experimentally in the near future, could be used to determine the atom-ion scattering length, to determine the temperature of the atomic ensemble in the presence of an ion impurity, and to control the atom-phonon coupling in a linear ion crystal in interaction with a quasi-one-dimensional atomic quantum gas.

  9. Raman Scattering in Coherently Prepared Atomic System

    Institute of Scientific and Technical Information of China (English)

    LIN Fu-Cheng(林福成); Yongjoo Rhee; Jonghoon Yi; Hyunmin Park

    2001-01-01

    Atoms in the coherent superposition state prepared by a pulse pair are used as a novel optical memory material where a single interrogation pulse will produce a new pulse pair preserving the relative amplitudes and phases of the preparing pulse pair. Such a coherent superposition state can also be specially tailored along the propagation path to generate Raman scattering in a relatively short distance with very high efficiency.

  10. A silver bullet: elemental silver as an efficient reducing agent for atom transfer radical polymerization of acrylates.

    Science.gov (United States)

    Williams, Valerie A; Ribelli, Thomas G; Chmielarz, Pawel; Park, Sangwoo; Matyjaszewski, Krzysztof

    2015-02-01

    Elemental silver was used as a reducing agent in the atom transfer radical polymerization (ATRP) of acrylates. Silver wire, in conjunction with a CuBr(2)/TPMA catalyst, enabled the controlled, rapid preparation of polyacrylates with dispersity values down to Đ = 1.03. The silver wire in these reactions was reused several times in sequential reactions without a decline in performance, and the amount of copper catalyst used was reduced to 10 ppm without a large decrease in control. A poly(n-butyl acrylate)-block-poly(tert-butyl acrylate) diblock copolymer was synthesized with a molecular weight of 91 400 and Đ = 1.04, demonstrating good retention of chain-end functionality and a high degree of livingness in this ATRP system. PMID:25599253

  11. NARROW-DISPERSED CROSSLINKED CORE-SHELL POLYMER MICROSPHERES PREPARED BY SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Yu-zeng Zhao; Xin-lin Yang; Feng Bai; Wen-qiang Huang

    2005-01-01

    Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transfer radical polymerization (ATRP) was investigated. Polydivinylbenzene (PDVB) microspheres were prepared by dispersion polymerization with poly(N-vinyl pyrrolidone) (PVP) as stabilizer. The surfaces of PDVB microspheres were chloromethylated by chloromethyl methyl ether in the presence of zinc chloride as catalyst to form chloromethylbenzene initiating core sites for subsequent ATRP grafting of styrene using CuC1/bpy as catalytic system. Polystyrene was found to be grafted not only from the particle surfaces but also from within a thin shell layer, resulting in the formation of particles size increased from 2.38-2.58 μm, which can further grow to 2.93 μm during secondary grafting polymerization of styrene. This demonstrates that grafting polymerization proceeds through a typical ATRP procedure with living nature. All of the prepared microspheres have narrow particle size distribution with coefficient of variation around 10%.

  12. Nonlocality Sudden Birth and Transfer in System and Environment

    Institute of Scientific and Technical Information of China (English)

    QIU Liang

    2011-01-01

    Dynamics of the nonlocality measured by the violation of Svetlichny's Bell-type inequality is investigated in the non-Markovian model. The phenomenon of nonlocality sudden birth for the atoms and the reservoirs is obtained.The evolution of the nonlocality among the atoms or the reservoirs depends on the choice of the atom detuning from the cavity pseudomode, the cavity pseudomode decay and the rotation angles. For the small pseudomode decay in the near-resonance regime, the initial atomic nonlocality is completely transferred to the reservoirs ultimately.

  13. Synergistic oxygen atom transfer by ruthenium complexes with non-redox metal ions.

    Science.gov (United States)

    Lv, Zhanao; Zheng, Wenrui; Chen, Zhuqi; Tang, Zhiming; Mo, Wanling; Yin, Guochuan

    2016-07-28

    Non-redox metal ions can affect the reactivity of active redox metal ions in versatile biological and heterogeneous oxidation processes; however, the intrinsic roles of these non-redox ions still remain elusive. This work demonstrates the first example of the use of non-redox metal ions as Lewis acids to sharply improve the catalytic oxygen atom transfer efficiency of a ruthenium complex bearing the classic 2,2'-bipyridine ligand. In the absence of Lewis acid, the oxidation of ruthenium(ii) complex by PhI(OAc)2 generates the Ru(iv)[double bond, length as m-dash]O species, which is very sluggish for olefin epoxidation. When Ru(bpy)2Cl2 was tested as a catalyst alone, only 21.2% of cyclooctene was converted, and the yield of 1,2-epoxycyclooctane was only 6.7%. As evidenced by electronic absorption spectra and EPR studies, both the oxidation of Ru(ii) by PhI(OAc)2 and the reduction of Ru(iv)[double bond, length as m-dash]O by olefin are kinetically slow. However, adding non-redox metal ions such as Al(iii) can sharply improve the oxygen transfer efficiency of the catalyst to 100% conversion with 89.9% yield of epoxide under identical conditions. Through various spectroscopic characterizations, an adduct of Ru(iv)[double bond, length as m-dash]O with Al(iii), Ru(iv)[double bond, length as m-dash]O/Al(iii), was proposed to serve as the active species for epoxidation, which in turn generated a Ru(iii)-O-Ru(iii) dimer as the reduced form. In particular, both the oxygen transfer from Ru(iv)[double bond, length as m-dash]O/Al(iii) to olefin and the oxidation of Ru(iii)-O-Ru(iii) back to the active Ru(iv)[double bond, length as m-dash]O/Al(iii) species in the catalytic cycle can be remarkably accelerated by adding a non-redox metal, such as Al(iii). These results have important implications for the role played by non-redox metal ions in catalytic oxidation at redox metal centers as well as for the understanding of the redox mechanism of ruthenium catalysts in the oxygen atom

  14. Preparation and characterization of optical-functional diblock copolymer brushes on hollow sphere surface via atom transfer radical polymerization

    International Nuclear Information System (INIS)

    The optical-functional poly(methyl methacrylate)-block-Tb complex diblock copolymer brushes grafted from hollow sphere surface via atom transfer radical polymerization were investigated in this work. A sufficient amount of azo initiator was introduced onto hollow sphere surface firstly. Then the monomer methyl methacrylate was polymerized via surface-initiated reverse atom transfer radical polymerization using azo group modified hollow sphere as initiator. Following, the poly(methyl methacrylate) modified hollow sphere was used as maroinitiator for surface-initiated atom transfer radical polymerization of Tb complex. The samples were characterized by Fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance, gel permeation chromatographer and transmission electron microscopy, respectively. The results indicated that the poly(methyl methacrylate) had grafted from hollow sphere surface and the average diameter of hollow core was about 1 μm. The optical properties of the poly(methyl methacrylate)-block-Tb copolymer modified hollow sphere were also reported.

  15. Radiative charge transfer in cold and ultracold Sulfur atoms colliding with Protons

    CERN Document Server

    Shen, G; Wang, J G; McCann, J F; McLaughlin, B M

    2015-01-01

    Radiative decay processes at cold and ultra cold temperatures for Sulfur atoms colliding with protons are investigated. The MOLPRO quantum chemistry suite of codes was used to obtain accurate potential energies and transition dipole moments, as a function of internuclear distance, between low-lying states of the SH$^{+}$ molecular cation. A multi-reference configuration-interaction (MRCI) approximation together with the Davidson correction is used to determine the potential energy curves and transition dipole moments, between the states of interest, where the molecular orbitals (MO's) are obtained from state-averaged multi configuration-self-consistent field (MCSCF) calculations. The collision problem is solved approximately using an optical potential method to obtain radiative loss, and a fully two-channel quantum approach for radiative charge transfer. Cross sections and rate coefficients are determined for the first time for temperatures ranging from 10 $\\mu$ K up to 10,000 K. Results are obtained for all ...

  16. Surface modification of nanoporous 1,2-polybutadiene by atom transfer radical polymerization or click chemistry.

    Science.gov (United States)

    Guo, Fengxiao; Jankova, Katja; Schulte, Lars; Vigild, Martin E; Ndoni, Sokol

    2010-02-01

    Surface-initiated atom transfer radical polymerization (ATRP) and click chemistry were used to obtain functional nanoporous polymers based on nanoporous 1,2-polybutadiene (PB) with gyroid morphology. The ATRP monolith initiator was prepared by immobilizing bromoester initiators onto the pore walls through two different methodologies: (1) three-step chemical conversion of double bonds of PB into bromoisobutyrate, and (2) photochemical functionalization of PB with bromoisobutyrate groups. Azide functional groups were attached onto the pore walls before click reaction with alkynated MPEG. Following ATRP-grafting of hydrophilic polyacrylates and click of MPEG, the originally hydrophobic samples transformed into hydrophilic nanoporous materials. The successful modification was confirmed by infrared spectroscopy, contact angle measurements and measurements of spontaneous water uptake, while the morphology was investigated by small-angle X-ray scattering and transmission electron microscopy. PMID:20099923

  17. Modification of Jute Fibers with Polystyrene via Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Plackett, David; Jankova, Katja Atanassova; Egsgaard, Helge;

    2005-01-01

    Atom transfer radical polymerization (ATRP) was investigated as a method of covalently bonding polystyrene to jute (Corchorus capsularis) and as a possible approach to fiber composites with enhanced properties. Jute fibers were modified with a brominated initiator and subsequently ATRP modified...... to attach polystyrene and then examined using SEM, DSC, TGA, FTIR, XPS, elemental analysis, and Py-GC-MS. These techniques confirmed that polystyrene had been covalently bound to the fibers and consequently ATRP-modified jute fiber mats were used to prepare hot-pressed polystyrene composites. Composite...... applications, we conclude that further optimization of the ATRP method is required, possibly targeting higher and more uniform loading of polystyrene on the fibers....

  18. Distinguishing nonlinear processes in atomic media via orbital angular momentum transfer

    CERN Document Server

    Akulshin, Alexander M; Mikhailov, Eugeniy E; Novikova, Irina

    2014-01-01

    We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their appearance. As an illustration, in Rb vapours we analyse transverse intensity and phase profiles of the forward-directed collimated blue and near-IR light using self-interference and astigmatic transformation techniques when either or both of two resonant laser beams carry orbital angular momentum. Our observations unambiguously demonstrate that emission at 1.37 {\\mu}m is the result of a parametric four-wave mixing process involving only one of the two applied laser fields.

  19. Charge transfer in the interactions of partially stripped ions with atoms at intermediate and high energies

    International Nuclear Information System (INIS)

    The Coulomb-Born (CB) approximation has been employed to study charge transfer cross sections in collisions of Cq+, Nq+ and Oq+ (q = 1-5) with atomic hydrogen in ground state in the energy range of 30-200 keV/amu. The interaction of the active electron with the incoming projectile ion has been approximated by a model potential containing both a long-range part and a short-range part. Variations of total capture cross sections with impact energy compare favourable well with the available experimental observations and with other theoretical findings. In addition, sub-shell distributions of total capture cross sections are given in graphical form. However, we are unable to find any oscillation in the charge-state dependence of total capture cross sections. (author)

  20. Preparation of polystyrene-grafted titanate nanotubes by in situ atom transfer radical polymerization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This work successfully prepared nanohybrids by in situ atom transfer radical polymerization (ATRP) of styrene from titanate nanotubes (TNTs). Fourier-transform infrared (FT-IR), pronton nuclear magnetic resonance spectroscopy (1H NMR), and thermal gravimetric analysis (TGA) were used to verify the successful graft of polystyrene (PS) chains from TNTs. Transmission electron microscopy (TEM) dis-played that the obtained PS-g-TNTs nanohybrids had a core-shell structure of TNT core and PS shell. The grafted PS content was well controlled and increased with increasing of the monomer/initiator ratio. Further copolymerization of tert-butyl acrylate (tBA) from the surface of PS-g-TNTs was studied, illus-trating the "living" characteristics of the surface-induced ATRP method used in this work.

  1. Synthesis of Dumbbell-shaped Hyperbranched Amphiphilic Block Copolymer by Controlled Atom Transfer Radical Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Kyoung; An, Sung Guk; Cho, Chang Gi [Center for Advanced Functional Polymers, Department of Fiber and Polymer Science, Hanyang University, Seoul (Korea); Noh, Si Tae [Department of Chemical Engineering, Hanyang University, Ansan (Korea)

    2001-04-01

    Amphiphilic block copolymers containing hydrophilic ethylene glycol core and hyperbranched polystyrene (PS) arm were synthesized by atom transfer radical polymerization using hydrophilic macroinitiator and p-chloromethyl styrene (CMS) as AB type monomer. Hydrophilic poly(ethylene glycol)(PEG) macroinitiators with difuntional groups were synthesized by reacting PEG and 2-bromopropionyl bromide. The chemical structure, molecular weight, and polydispersity index of the amphiphilic block copolymer were characterized by {sup 1}H-NMR spectroscopy and GPC analysis. The molecular weight increased as the reaction time increased. Polydispersity index of the obtained polymer was relatively narrow (below 1.39). To control chain density of the hyperbranched PS, styrene and CMS were copolymerized. It was found that amphiphilic block copolymer molecule underwent conformational change in different solvents based on the result for {sup 1}H-NMR spectroscopic analysis. 29 refs., 8 figs., 2 tabs.

  2. Confinement-Induced Resonances in Ultracold Atom-Ion Systems

    CERN Document Server

    Melezhik, Vladimir S

    2016-01-01

    We investigate confinement-induced resonances in a system composed by a tightly trapped ion and a moving atom in a waveguide. We determine the conditions for the appearance of such resonances in a broad region -- from the "long-wavelength" limit to the opposite case when the typical length scale of the atom-ion interaction essentially exceeds the transverse waveguide width. We find considerable dependence of the resonance position on the atomic mass which, however, disappears in the "long-wavelength" limit, where the result for the confined atom-atom scattering is reproduced. We also derive an analytic formula for the resonance position in the "long-wavelength zero-energy" limit. Our results, which can be investigated in current experiments, indicate a strategy to determine the atom-ion scattering length, the temperature of the atomic ensemble in the presence of an ion impurity, and a pathway to control the atom-phonon coupling in a one dimensional ion crystal in interaction with an atomic quantum gas.

  3. Electron transfer modifies chemical properties of C70 fullerene surface: an ab initio molecular dynamics study of C70O3 molozonides doped with light atoms

    OpenAIRE

    Morrison, Carole; Bil, Andrzej; Hutter, Jurg

    2014-01-01

    Light metal atoms such as Li, K (electronic state 2S 1/2) or Ca (1S0) encapsulated in a C 70 cage considerably modifies the chemical properties of the fullerene surface due to metal-to-cage electron transfer. H-doped and anion ozonide systems were also considered to validate the electron transfer hypothesis. The relative stabilities of the eight isomers of the C 70O3 molozonide series at room temperature depend on the identity of the endohedral guest, as was the preferred channel for thermal ...

  4. Composite systems in magnetic field: from hadrons to hydrogen atom

    OpenAIRE

    Kerbikov, B. O.

    2013-01-01

    We briefly review the recent studies of the behavior of composite systems in magnetic field. The hydrogen atom is chosen to demonstrate the new results which may be experimentally tested. Possible applications to physics of antihydrogen are mentioned.

  5. General model of depolarization and transfer of polarization of singly ionized atoms by collisions with hydrogen atoms

    CERN Document Server

    Derouich, Moncef

    2016-01-01

    Simulations of the generation of the atomic polarization is necessary for interpreting the second solar spectrum. For this purpose, it is important to rigorously determine the effects of the isotropic collisions with neutral hydrogen on the atomic polarization of the neutral atoms, ionized atoms and molecules. Our aim is to treat in generality the problem of depolarizing isotropic collisions between singly ionized atoms and neutral hydrogen in its ground state. Using our numerical code, we computed the collisional depolarization rates of the $p$-levels of ions for large number of values of the effective principal quantum number $n^{*}$ and the Uns\\"old energy $E_p$. Then, genetic programming has been utilized to fit the available depolarization rates. As a result, strongly non-linear relationships between the collisional depolarization rates, $n^{*}$ and $E_p$ are obtained, and are shown to reproduce the original data with accuracy clearly better than 10\\%. These relationships allow quick calculations of the ...

  6. Submersible pumping system with heat transfer mechanism

    Science.gov (United States)

    Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew

    2014-04-15

    A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.

  7. System Transfer, Education, and Development in Mozambique

    Directory of Open Access Journals (Sweden)

    Jose Cossa

    2011-03-01

    Full Text Available In this study the author used conceptual historical method to assess the phenomenon of system transfer and the association between education and development in Mozambique. The assessment was administered through critical analysis of documents pertaining to the Salazar (1924-1966, Machel (1975-1986, and Chissano (1986-2005 administrations. The findings were that (a the colonial government created economic and educational systems for colonizing Mozambique, whereas the Machel and Chissano administrations adapted foreign systems of government and education (i.e., Socialism, Soviet, Democracy, Portuguese, etc., to their particular context without altering the inherent theoretical basis of the systems transferred; (b the Machel and Chissano administrations, implicitly or explicitly, perceived the relationship between education and development as circular causality rather than a unidirectional linear causality, while the Salazar administration perceived it as unidirectional linear causality; and (c while the Machel and Chissano administrations focused on primary education, literacy campaigns, and education of women and girls, they differed in the reasons for such focus.

  8. Hydrophilic modification of microporous polysulfone membrane via surface-initiated atom transfer radical polymerization of acrylamide

    International Nuclear Information System (INIS)

    Polyacrylamide (PAM) brushes were grafted from chloromethylated polysulfone (CMPSF) membrane surface by surface-initiated atom transfer radical polymerization (SI-ATRP) to improve the membrane's hydrophilic property. In order to anchor the initiator onto polysulfone (PSF) membrane surface, CMPSF was used to prepare the microporous membrane by phase-inversion process. Attachment of the PAM chains on membrane surface was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The grafted density of PAM was calculated to be 0.08 chains nm-2. Field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM) were used to characterize the surface morphology of the CMPSF membrane and modified membrane. The number-average molecular weight (Mn) of PAM linearly increased with the polymerization time, while the static water contact angle (θ) of the membrane grafted with PAM linearly decreased. This indicated the hydrophilic property of the membrane was linearly correlated with the chain length of graft polymer. Therefore linear control of PSF membrane's hydrophilic property was realized through adjusting polymerization time.

  9. Effect of current and atomized grain size distribution on the solidification of Plasma Transferred Arc coatings

    Directory of Open Access Journals (Sweden)

    Danielle Bond

    2012-10-01

    Full Text Available Plasma Transferred Arc (PTA is the only thermal spray process that results in a metallurgical bond, being frequently described as a hardfacing process. The superior properties of coatings have been related to the fine microstructures obtained, which are finer than those processed under similar heat input with welding techniques using wire feedstock. This observation suggests that the atomized feedstock plays a role on the solidification of coatings. In this study a model for the role of the powders grains in the solidification of PTA coatings is put forward and discussed. An experiment was setup to discuss the model which involved the deposition of an atomized Co-based alloy with different grain size distributions and deposition currents. X ray diffraction showed that there were no phase changes due to the processing parameters. Microstructure analysis by Laser Confocal Microscopy, dilution with the substrate steel and Vickers microhardness were used the characterized coatings and enriched the discussion confirming the role of the powdered feedstock on the solidification of coatings.

  10. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    NARCIS (Netherlands)

    Fan, Zhaochuan; Koster, Rik S.; Wang, Shuaiwei; Fang, Changming; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.; van Huis, Marijn A.; Vlugt, Thijs J. H.

    2014-01-01

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., "Atomic resolution monitoring of cation exchange in CdSe-PbSe heterona

  11. Narrow linewidth single laser source system for onboard atom interferometry

    OpenAIRE

    Theron, Fabien; Carraz, Olivier; Renon, Geoffrey; Bidel, Yannick; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2014-01-01

    A compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser is presented. Thanks to an original stabilization architecture on a saturated absorption setup, we obtain a frequency-agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using a single laser source. The different laser frequencies used for atom interferometry are generated by changing dynamically the frequency of the laser and by creating sidebands using a phase...

  12. Transfer zones in listric normal fault systems

    Science.gov (United States)

    Bose, Shamik

    Listric normal faults are common in passive margin settings where sedimentary units are detached above weaker lithological units, such as evaporites or are driven by basal structural and stratigraphic discontinuities. The geometries and styles of faulting vary with the types of detachment and form landward and basinward dipping fault systems. Complex transfer zones therefore develop along the terminations of adjacent faults where deformation is accommodated by secondary faults, often below seismic resolution. The rollover geometry and secondary faults within the hanging wall of the major faults also vary with the styles of faulting and contribute to the complexity of the transfer zones. This study tries to understand the controlling factors for the formation of the different styles of listric normal faults and the different transfer zones formed within them, by using analog clay experimental models. Detailed analyses with respect to fault orientation, density and connectivity have been performed on the experiments in order to gather insights on the structural controls and the resulting geometries. A new high resolution 3D laser scanning technology has been introduced to scan the surfaces of the clay experiments for accurate measurements and 3D visualizations. Numerous examples from the Gulf of Mexico have been included to demonstrate and geometrically compare the observations in experiments and real structures. A salt cored convergent transfer zone from the South Timbalier Block 54, offshore Louisiana has been analyzed in detail to understand the evolutionary history of the region, which helps in deciphering the kinematic growth of similar structures in the Gulf of Mexico. The dissertation is divided into three chapters, written in a journal article format, that deal with three different aspects in understanding the listric normal fault systems and the transfer zones so formed. The first chapter involves clay experimental models to understand the fault patterns in

  13. Narrow linewidth single laser source system for onboard atom interferometry

    CERN Document Server

    Theron, Fabien; Renon, Geoffrey; Bidel, Yannick; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2014-01-01

    We present an original compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser. Thanks to an original stabilization architecture on a saturated absorption, we obtain a frequency agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using only a single laser source. The different laser frequencies used for atom interferometry are created by changing dynamically the frequency of the laser and by creating sidebands using a phase modulator. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components, which are intrinsically less stable, and to make the setup compact, much less sensitive to vibrations and thermal fluctuations. This source provides spectral linewidth below 2.5 kHz required for precision atom interferometry, and particularly for an high performance atomic inertial sensor.

  14. Theoretical Study of Electron Transfer in Bimolecular System of NH3 and H2O

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mulliken, NPA, MK and CHelpG population analyses have been accomplished at the level of MP2/6-31G(d,p) for the title system. The variations of four kinds of charges on NH3 with intermolecular distance infer that electron transfers from NH3 to H2O. MK and CHelpG population analyses indicate more electron transfer than Mulliken and NPA ones. The atomic charges resulted from MK and CHelpG schemes infer that electron transfers from N in NH3 to H in H2O, which confirms that this bimolecular complex possesses linear structure as H3N…HOH.

  15. Synthesis of Comblike Poly(methyl methacrylate) by Atom Transfer Radical Polymerization with Poly(ethyl 2-bromoacrylate) as Macroinitiator

    Institute of Scientific and Technical Information of China (English)

    Yan SHI; Zhi Feng FU; Yu Dong ZHANG; Shu Ke JIAO

    2003-01-01

    Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical polymerization of ethyl 2-bromoacrylate. The obtained comblike polymers were characterized by GPC and 1H NMR.

  16. Ion conducting solid polymer electrolytes based on polypentafluorostyrene-b-polyether-b-polypentafluorostyrene prepared by atom transfer radical polymerization

    DEFF Research Database (Denmark)

    Jankova, Katja; Jannasch, P.; Hvilsted, Søren

    2004-01-01

    Novel triblock copolymers based on central poly( ethylene glycol) ( PEG) or poly( ethylene glycol-co-propylene glycol) (PEGPG) blocks with poly( pentafluorostyrene) (PFS) outer blocks were prepared by Atom Transfer Radical Polymerization (ATRP) with polydispersities on the order of 1.2 - 1...

  17. ANISOTROPY EFFECTS IN SINGLE-ELECTRON TRANSFER BETWEEN LASER-EXCITED ATOMS AND HIGHLY-CHARGED IONS

    NARCIS (Netherlands)

    1995-01-01

    Recent collision experiments are reviewed in which one-electron transfer between laser excited target atoms and (highly charged) keV-ions has been studied. Especially results showing a dependence of the charge exchange on the initial target orbital alignment are discussed. The question to what exten

  18. A compact system for single site atom loading of a neutral atom qubit array

    Science.gov (United States)

    Dinardo, Brad; Hughes, Steven; McBride, Sterling; Michalchuk, Joey; Anderson, Dana Z.

    2015-05-01

    We present progress towards single atom loading from a magneto optical trap reservoir to a bottle beam (BoB) array trap site for use in quantum computation. Our procedure involves vertically transporting cesium atoms via a moving molasses MOT from a 3D MOT chamber into a six sided, AR-coated, high optical access UHV science chamber. The cesium atoms are to be horizontally displaced 100 μm to a 7 × 7 array of blue-detuned BoB traps. Displacement of the atoms will be accomplished by means of a moving standing wave dipole trap. The single-site loading experiment will take place in the Atomic Qubit Array Cell (AQuA Cell) which is a compact, high performance UHV system that utilizes new miniature silicon and glass ion pump technology. The entire AQuA Cell is 0.6 liters. The cell, cooling, and transport optomechanics is incorporated in a package occupying about 0.028 cubic meters. Funding provided by IARPA MQCO.

  19. Vessel with system for transferring persons or goods

    NARCIS (Netherlands)

    Keuning, J.A.

    2014-01-01

    The invention concerns a vessel (l) comprising a transfer system for transferring persons or goods from the vessel while subjected to waves and/or swell towards a substantially stationary destination, wherein the transfer system comprises a platform (2) having a first mass for supporting the persons

  20. Fiber laser system for cesium and rubidium atom interferometry

    CERN Document Server

    Diboune, Clément; Bidel, Yannick; Cadoret, Malo; Bresson, Alexandre

    2016-01-01

    We present an innovative fiber laser system for both cesium and rubidium manipulation. The architecture is based on frequency conversion of two lasers at 1560 nm and 1878 nm. By taking advantage of existing fiber components at these wavelengths, we demonstrate an all fiber laser system delivering 350 mW at 780 nm for rubidium and 210 mW at 852 nm for cesium. This result highlights the promising nature of such laser system especially for Cs manipulation for which no fiber laser system has been reported. It offers new perspectives for the development of atomic instruments dedicated to onboard applications and opens the way to a new generation of atom interferometers involving three atomic species $^{85}$Rb, $^{87}$Rb and $^{133}$Cs for which we propose an original laser architecture.

  1. Transferable aspherical atom model refinement of protein and DNA structures against ultrahigh-resolution X-ray data.

    Science.gov (United States)

    Malinska, Maura; Dauter, Zbigniew

    2016-06-01

    In contrast to the independent-atom model (IAM), in which all atoms are assumed to be spherical and neutral, the transferable aspherical atom model (TAAM) takes into account the deformed valence charge density resulting from chemical bond formation and the presence of lone electron pairs. Both models can be used to refine small and large molecules, e.g. proteins and nucleic acids, against ultrahigh-resolution X-ray diffraction data. The University at Buffalo theoretical databank of aspherical pseudo-atoms has been used in the refinement of an oligopeptide, of Z-DNA hexamer and dodecamer duplexes, and of bovine trypsin. The application of the TAAM to these data improves the quality of the electron-density maps and the visibility of H atoms. It also lowers the conventional R factors and improves the atomic displacement parameters and the results of the Hirshfeld rigid-bond test. An additional advantage is that the transferred charge density allows the estimation of Coulombic interaction energy and electrostatic potential.

  2. Miniaturized lab system for future cold atom experiments in microgravity

    CERN Document Server

    Kulas, Sascha; Resch, Andreas; Hartwig, Jonas; Ganske, Sven; Matthias, Jonas; Schlippert, Dennis; Wendrich, Thijs; Ertmer, Wolfgang; Rasel, Ernst Maria; Damjanic, Marcin; Weßels, Peter; Kohfeldt, Anja; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Grzeschik, Christoph; Krutzik, Markus; Wicht, Andreas; Peters, Achim; Herrmann, Sven; Lämmerzahl, Claus

    2016-01-01

    We present the technical realization of a compact system for performing experiments with cold $^{87}{\\text{Rb}}$ and $^{39}{\\text{K}}$ atoms in microgravity in the future. The whole system fits into a capsule to be used in the drop tower Bremen. One of the advantages of a microgravity environment is long time evolution of atomic clouds which yields higher sensitivities in atom interferometer measurements. We give a full description of the system containing an experimental chamber with ultra-high vacuum conditions, miniaturized laser systems, a high-power thulium-doped fiber laser, the electronics and the power management. In a two-stage magneto-optical trap atoms should be cooled to the low $\\mu$K regime. The thulium-doped fiber laser will create an optical dipole trap which will allow further cooling to sub-$\\mu$K temperatures. The presented system fulfills the demanding requirements on size and power management for cold atom experiments on a microgravity platform, especially with respect to the use of an op...

  3. Effective Field Theory for Atom-Molecule Systems II: Stationary Solutions and Bogoliubov Excitations in Atom-Molecule Systems

    CERN Document Server

    Sahlberg, Catarina E

    2011-01-01

    We formulate the basic theoretical methods for Bose-Einstein Condensation of atoms close to a Feshbach resonance, in which the tunable scattering length of the atoms is described using a system of coupled atom and molecule fields. These include the Thomas-Fermi description of the condensate profile, the c-field equations, and the Bogoliubov-de Gennes equations, and the Bogoliubov excitation spectrum for a homogenous condensed system. We apply this formalism to the special case of Bragg scattering from a uniform condensate, and find that for moderate and large scattering lengths, there is a dramatic difference in the shift of the peak of the Bragg spectra, compared to that based on a structureless atom model. The result is compatible with the experimental results of Papp et al. [S. B. Papp et al., Phys. Rev. Lett., 101(13):135301, Sep 2008].

  4. Entanglement transfer from two-mode anti-correlated continuous-variable systems to a pair of localized discrete systems

    Science.gov (United States)

    Ran, Du; Yang, Zhen-Biao

    2016-04-01

    We address the entanglement transfer from a bipartite continuous-variable(CV) system to a pair of localized discrete systems. The dynamics behavior can be implemented by two two-level atoms flying through spatially separated identical cavities where two quantized modes are injected. We assume each CV mode couples to one atom via the resonant Jaynes-Cummings interaction. The CV systems are initially prepared in a two-mode anti-correlated SU(2) coherent state, while with the initial atomic states of the cases: |g⟩1|g⟩2, |e⟩1|e⟩2 and |g⟩1|e⟩2, respectively. We find that the entanglement transfer for single-photon excitation case is more efficient than that for multi-photon excitation case. Under same conditions, we also note that the entanglement transfer is more efficient for SU(2) coherent state than for twin-bean (TWB) and pair-coherent (TMC) state. Besides, we show that, for a given total photon number of the initial SU(2) coherent state, the efficiency of entanglement transfer depends upon the distribution of photons in the two CV modes. We also consider the influences of the dissipation and the white noise on the entanglement transfer.

  5. Resonant charge transfer of hydrogen Rydberg atoms incident at a Cu(100) projected band-gap surface

    CERN Document Server

    Gibbard, J A; Kohlhoff, M; Rennick, C J; So, E; Ford, M; Softley, T P

    2015-01-01

    The charge transfer (ionization) of hydrogen Rydberg atoms (principal quantum number $n=25-34$) incident at a Cu(100) surface is investigated. Unlike fully metallic surfaces, where the Rydberg electron energy is degenerate with the conduction band of the metal, the Cu(100) surface has a projected bandgap at these energies, and only discrete image states are available through which charge transfer can take place. Resonant enhancement of charge transfer is observed at hydrogen principal quantum numbers for which the Rydberg energy matches the energy of one of the image states. The integrated surface ionization signals show clear periodicity as the energies of states with increasing $n$ come in and out of resonance with the image states. The velocity dependence of the surface ionization dynamics is also investigated. Decreased velocity of the incident H atom leads to a greater mean distance of ionization and a lower field required to extract the ion. The surface-ionization profiles (signal versus applied field) ...

  6. Cost-Effective Systems for Atomic Layer Deposition

    Science.gov (United States)

    Lubitz, Michael; Medina, Phillip A., IV; Antic, Aleks; Rosin, Joseph T.; Fahlman, Bradley D.

    2014-01-01

    Herein, we describe the design and testing of two different home-built atomic layer deposition (ALD) systems for the growth of thin films with sub-monolayer control over film thickness. The first reactor is a horizontally aligned hot-walled reactor with a vacuum purging system. The second reactor is a vertically aligned cold-walled reactor with a…

  7. Modification of polysulfone membranes via surface-initiated atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Hydrophilic poly((poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) and poly(glycidylmethacrylate) (PGMA) brushes were grafted from chloromethylated polysulfone (CMPSF) membrane surfaces via surface-initiated atom transfer radical polymerization (ATRP). Prior to ATRP, chloromethylation of PSF was performed beforehand and the obtained CMPSF was prepared into porous membranes by phase inversion process. It was demonstrated that the benzyl chloride groups on the CMPSF membrane surface afforded effective macroinitiators to graft the well-defined polymer brushes. 1H NMR was employed to confirm the structure of CMPSF. The grafting yield of P(PEGMA) and PGMA was determined by weight gain measurement. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the grafting of P(PEGMA) and PGMA chains. Water contact angle measurements indicated that the introduction of P(PEGMA) and PGMA graft chains promoted remarkably the surface hydrophilicity of PSF membranes. The effects of P(PEGMA) and PGMA immobilization on membrane morphology, permeability and fouling resistance were investigated. It was found that P(PEGMA) and PGMA grafts brought higher pure water flux, improved hydrophilic surface and better anti-protein absorption ability to PSF membranes after modification. And evidently, macromonomer P(PEGMA) brought much better properties to the PSF membranes than PGMA macromonomer.

  8. Colorful Polyelectrolytes: An Atom Transfer Radical Polymerization Route to Fluorescent Polystyrene Sulfonate.

    Science.gov (United States)

    Huberty, Wayne; Tong, Xiaowei; Balamurugan, Sreelatha; Deville, Kyle; Russo, Paul S; Zhang, Donghui

    2016-03-01

    A labeled green fluorescent polystyrene sulfonate (LNaPSS) has been synthesized using atom transfer radical polymerization of a styrene sulfonate monomer with a fluorescent co-monomer, fluorescein thiocyanate-vinyl aniline. As a result this 100 % sulfonated polymer contains no hydrophobic patches along the chain backbone besides the fluorescent marker itself. The concentration of the fluorescent monomer was kept low to maintain the characteristic properties of the anionic polyelectrolyte, LNaPSS. ATRP conditions facilitated the production of polymers spanning a range of molecular weights from 35,000 to 175,000 in gram-scale batches with polydispersity indices of 1.01-1.24. Molecular weight increased with the monomer to initiator ratio. Gel permeation chromatography results show a unimodal distribution, and the polymer structure was also confirmed by (1)H NMR and FT-IR spectroscopy. Fluorescence spectroscopy confirmed covalent bonding of fluorescein isothiocyanate to the polymer, indicating that the polymer is suitable as a probe in fluorescence microscopy. To demonstrate this ability, the polymer was used to locate structural features in salt crystals formed during drying, as in the evaporation of sea mist. A second application to probe diffusion studies is also demonstrated. PMID:26745991

  9. Electron transfer modifies chemical properties of C70 fullerene surface: An ab initio molecular dynamics study of C70O3 molozonides doped with light atoms

    Science.gov (United States)

    Bil, Andrzej; Hutter, Jürg; Morrison, Carole A.

    2014-06-01

    Light metal atoms such as Li, K (electronic state 2S1/2) or Ca (1S0) encapsulated in a C70 cage considerably modifies the chemical properties of the fullerene surface due to metal-to-cage electron transfer. H-doped and anion ozonide systems were also considered to validate the electron transfer hypothesis. The relative stabilities of the eight isomers of the C70O3 molozonide series at room temperature depend on the identity of the endohedral guest, as was the preferred channel for thermal decomposition. No electron transfer was observed for the complex N@C70 where the fullerene acts as an inert container for the 4S3/2 radical.

  10. Transfer of technology. Foreign contributions and systems

    International Nuclear Information System (INIS)

    The transfer of technology involved when exporting nuclear plants to countries with less-developed industry requires the provision of specific object-related processing methods, and the transfer of basic technical know-how. Such transfer should be organized so that it is both effective and economical. This paper discusses such transfer requirements in the light of the Federal Republic of Germany's agreement to supply nuclear plant to Brazil. The three main phases of such technology transfer comprise, first, a determination of the framework for joint scientific work between the two contracting countries; second, co-operation based on detailed agreements between universities, scientific institutes, licensing authorities etc., and, third, the transfer of know-how, chiefly characterized by high-level co-operation at the industrial level, as well as special training programmes for key personnel etc. At this stage special attention must be paid to the co-ordination of the different activities. (author)

  11. Space Biosensor Systems: Implications for Technology Transfer

    Science.gov (United States)

    Hines, J. W.; Somps, C. J.; Madou, M.; Imprescia, Clifford C. (Technical Monitor)

    1997-01-01

    To meet the need for continuous, automated monitoring of animal subjects, including; humans, during space flight, NASA is developing advanced physiologic sensor and biotelemetry system technologies. The ability to continuously track basic physiological parameters, such as heart rate, blood pH, and body temperature, in untethered subjects in space is a challenging task. At NASA's Ames Research Center, where a key focus is gravitational biology research, engineers have teamed with life scientists to develop wireless sensor systems for automated physiologic monitoring of animal models as small as the rat. This technology is also being adapted, in collaboration with medical professionals, to meet human clinical monitoring needs both in space and on the ground. Thus, these advanced monitoring technologies have important dual-use functions; they meet space flight data collection requirements and constraints, while concurrently addressing a number of monitoring and data acquisition challenges on the ground in areas of clinical monitoring and biomedical research. Additional applications for these and related technologies are being sought and additional partnerships established that enhance development efforts, reduce costs and facilitate technology infusion between the public and private sectors. This paper describes technology transfer and co-development projects that have evolved out of NASA's miniaturized, implantable chemical sensor development efforts.

  12. Entanglement between two atoms in the system of Schr(o)dinger cat state interacting with two entangled atoms

    Institute of Scientific and Technical Information of China (English)

    Liu Tang-Kun

    2007-01-01

    By the negative eigenvalues of partial transposition of density matrix, this paper investigates the time evolution of entanglement of the two entangled atoms in the system of two atoms interacting with Schr(o)dinger cat state. The result shows that the two atoms are always in the entanglement state, and the degree of entanglement between the two atoms exhibits ordinary collapses and revivals at 0.2 degree of entanglement, when the light field is large enough. On the other hand, the reinforcement of three different light fields on the degree of entanglement between two atoms is not evident.

  13. Quantum-Classical Connection for Hydrogen Atom-Like Systems

    Science.gov (United States)

    Syam, Debapriyo; Roy, Arup

    2011-01-01

    The Bohr-Sommerfeld quantum theory specifies the rules of quantization for circular and elliptical orbits for a one-electron hydrogen atom-like system. This article illustrates how a formula connecting the principal quantum number "n" and the length of the major axis of an elliptical orbit may be arrived at starting from the quantum…

  14. Replacement of Cross-Site Transfer System Startup Plan

    Energy Technology Data Exchange (ETDEWEB)

    Gerken, M.D.

    1996-01-01

    This Startup Plan provides a discussion of organizational responsibilities, work planning, quality assurance (QA), personnel qualifications, and testing requirements for the Cross-Site Transfer System.

  15. Semiclassical quantisation for a bosonic atom-molecule conversion system

    OpenAIRE

    Graefe, Eva-Maria; Graney, Maria; Rush, Alexander

    2015-01-01

    We consider a simple quantum model of atom-molecule conversion where bosonic atoms can combine into diatomic molecules and vice versa. The many-particle system can be expressed in terms of the generators a deformed $SU(2)$ algebra, and the mean-field dynamics takes place on a deformed version of the Bloch sphere, a teardrop shaped surface with a cusp singularity. We analyse the mean-field and many-particle correspondence, which shows typical features of quantum-classical correspondence. We de...

  16. Cold atoms as a coolant for levitated optomechanical systems

    CERN Document Server

    Ranjit, Gambhir; Geraci, Andrew A

    2014-01-01

    Optically trapped dielectric objects are well suited for reaching the quantum regime of their center of mass motion in an ultra-high vacuum environment. We show that ground state cooling of an optically trapped nanosphere is achievable when starting at room temperature, by sympathetic cooling of a cold atomic gas optically coupled to the nanoparticle. Unlike cavity cooling in the resolved sideband limit, this system requires only a modest cavity finesse and it allows the cooling to be turned off, permitting subsequent observation of strongly-coupled dynamics between the atoms and sphere. Nanospheres cooled to their quantum ground state could have applications in quantum information science or in precision sensing.

  17. Bohm-Aharonov type effects in dissipative atomic systems

    CERN Document Server

    Solomon, A I; Solomon, Allan I.; Schirmer, Sonia G.

    2005-01-01

    A state in quantum mechanics is defined as a positive operator of norm 1. For finite systems, this may be thought of as a positive matrix of trace 1. This constraint of positivity imposes severe restrictions on the allowed evolution of such a state. From the mathematical viewpoint, we describe the two forms of standard dynamical equations - global (Kraus) and local (Lindblad) - and show how each of these gives rise to a semi-group description of the evolution. We then look at specific examples from atomic systems, involving 3-level systems for simplicity, and show how these mathematical constraints give rise to non-intuitive physical phenomena, reminiscent of Bohm-Aharonov effects. In particular, we show that for a multi-level atomic system it is generally impossible to isolate the levels, and this leads to observable effects on the population relaxation and decoherence.

  18. Protein adsorption resistance of PVP-modified polyurethane film prepared by surface-initiated atom transfer radical polymerization

    Science.gov (United States)

    Yuan, Huihui; Qian, Bin; Zhang, Wei; Lan, Minbo

    2016-02-01

    An anti-fouling surface of polyurethane (PU) film grafted with Poly(N-vinylpyrrolidone) (PVP) was prepared through surface-initiated atom transfer radical polymerization (SI-ATRP). And the polymerization time was investigated to obtain PU films with PVP brushes of different lengths. The surface properties and protein adsorption of modified PU films were evaluated. The results showed that the hydrophilicity of PU-PVP films were improved with the increase of polymerization time, which was not positive correlation with the surface roughness due to the brush structure. Additionally, the protein resistance performance was promoted when prolonging the polymerization time. The best antifouling PU-PVP (6.0 h) film reduced the adsoption level of bovine serum albumin (BSA), lysozyme (LYS), and brovin serum fibrinogen (BFG) by 93.4%, 68.3%, 85.6%, respectively, compared to the unmodified PU film. The competitive adsorption of three proteins indicated that LYS preferentially adsorbed on the modified PU film, while BFG had the lowest adsorption selectivity. And the amount of BFG on PU-PVP (6.0 h) film reduced greatly to 0.08 μg/cm2, which was almost one-tenth of its adsorption from the single-protein system. Presented results suggested that both hydrophilicity and surface roughness might be the important factors in all cases of protein adsorption, and the competitive or selective adsorption might be related to the size of the proteins, especially on the non-charged films.

  19. Conventional and atom transfer radical copolymerization of phenoxycarbonylmethyl methacrylate-styrene and thermal behavior of their copolymers

    Directory of Open Access Journals (Sweden)

    2007-08-01

    Full Text Available The atom transfer radical polymerization (ATRP of phenoxycarbonylmethyl methacrylate (PCMMA with styrene (St were performed in bulk at 110°C in the presence of ethyl 2-bromoacetate, cuprous(Ibromide (CuBr, and N,N,N’,N”,N”-pentamethyldiethyltriamine. Also, a series conventional free-radical polymerization (CFRP of PCMMA and styrene were carried out in the presence of 2,2’-azobisisobutyronitrile in 1,4-dioxane solvent at 60°C. The structure of homo and copolymers was characterized by IR, 1H and 13C-NMR techniques. The composition of the copolymers was calculated by 1H-NMR spectra. The average-molecular weight of the copolymers were investigated by Gel Permeation Chromatography (GPC. For copolymerization system, their monomer reactivity ratios were obtained by using both Kelen-Tüdõs and Fineman-Ross equations. Thermal analysis measurements of homo- and copolymers prepared CFRP and ATRP methods were measured by TGA-50 and DSC-50. Blends of poly(PCMMA and poly(St obtained via ATRP method have been prepared by casting films from dichlorormethane solution. The blends were characterized by differential scanning calorimetry. The initial decomposition temperatures of the resulting copolymers increased with increasing mole fraction of St.

  20. Suppression of angular momentum transfer in cold collisions of transition metal atoms in ground States with nonzero orbital angular momentum.

    Science.gov (United States)

    Hancox, Cindy I; Doret, S Charles; Hummon, Matthew T; Krems, Roman V; Doyle, John M

    2005-01-14

    The Zeeman relaxation rate in cold collisions of Ti(3d(2)4s(2) 3F2) with He is measured. We find that collisional transfer of angular momentum is dramatically suppressed due to the presence of the filled 4s(2) shell. The degree of electronic interaction anisotropy, which is responsible for Zeeman relaxation, is estimated to be about 200 times smaller in the Ti-He complex than in He complexes with typical non-S-state atoms.

  1. CMOS compatible strategy based on selective atomic layer deposition of a hard mask for transferring block copolymer lithography patterns

    International Nuclear Information System (INIS)

    A generic, CMOS compatible strategy for transferring a block copolymer template to a semiconductor substrate is demonstrated. An aluminum oxide (Al2O3) hard mask is selectively deposited by atomic layer deposition in an organized array of holes obtained in a PS matrix via PS-b-PMMA self-assembly. The Al2O3 nanodots act as a highly resistant mask to plasma etching, and are used to pattern high aspect ratio (>10) silicon nanowires and nanopillars.

  2. Synthesis of Highly Branched Poly(ε-caprolactone) by Self-condensing Atom Transfer Radical Polymerization of Macroinimers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Branched poly(ε-caprolactone) was synthesized by self-condensing atom transfer radical polymerization of macroinimer, α-acryloyoxy-ω-2-bromopropionyloxy poly(ε-caprolactone),which was prepared by enzyme-catalyzed ring-opening polymerization of ε-caprolactone with 2-hydroxylethyl acrylate as initiator and esterification of the ω-hydroxyl group of the obtained poly(ε-caprolactone) by 2-bromopropionyl bromide.

  3. Negative Refractive Index in a Four-Level Atomic System

    Institute of Scientific and Technical Information of China (English)

    ZhANG Hong-Jun; GONG Shang-Qing; NIU Yue-Ping; LI Ru Xin; XU Zhi-Zhan

    2006-01-01

    @@ We propose a scheme for realizing negative refractive index in a four-level atomic system. It is shown that such a system can simultaneously exhibit negative permittivity and negative permeability in an optical frequency range.Furthermore, by analysing the dispersion property of the left-handed material, we find that the probe beam can be controlled from superluminal to subluminal or vice versa via choosing appropriate parameters.

  4. Field correlations and effective two level atom-cavity systems

    CERN Document Server

    Rebic, S; Tan, S M

    2004-01-01

    We analyse the properties of the second order correlation functions of the electromagnetic field in atom-cavity systems that approximate two-level systems. It is shown that a recently-developed polariton formalism can be used to account for all the properties of the correlations, if the analysis is extended to include two manifolds - corresponding to the ground state and the states excited by a single photon - rather than just two levels.

  5. Quantum phase transition and entanglement in Li atom system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    By use of the exact diagonalization method, the quantum phase transition and en- tanglement in a 6-Li atom system are studied. It is found that entanglement appears before the quantum phase transition and disappears after it in this exactly solvable quantum system. The present results show that the von Neumann entropy, as a measure of entanglement, may reveal the quantum phase transition in this model.

  6. Environment assisted energy transfer in dimer system

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Salman, E-mail: sksafi@comsats.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Chak Shahzad, Islamabad (Pakistan); Ibrahim, M.; Khan, M.K. [Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)

    2014-02-15

    The influence of collective and multilocal environments on the energy transfer between the levels of a dimer is studied. The dynamics of energy transfer are investigated by considering coupling of collective environment with the levels of the dimer in the presence of both two individuals and mutually correlated multilocal environments. It is shown that every way of coupling we consider assists, though differently, the probability of transition between the levels of dimer. The probability of transition is strongly enhanced when the two local environments are mutually correlated. -- Highlights: • The dynamics of energy transfer between the levels of a dimer are studied. • Coupling of collective as well as individual environments are considered. • The environments are in spin star configurations. • The environment assists the energy transfer between the levels. • For correlated multilocal environments, the transition probability is almost 100%.

  7. Antioxidant Activity/Capacity Measurement. 2. Hydrogen Atom Transfer (HAT)-Based, Mixed-Mode (Electron Transfer (ET)/HAT), and Lipid Peroxidation Assays.

    Science.gov (United States)

    Apak, Reşat; Özyürek, Mustafa; Güçlü, Kubilay; Çapanoğlu, Esra

    2016-02-10

    Measuring the antioxidant activity/capacity levels of food extracts and biological fluids is useful for determining the nutritional value of foodstuffs and for the diagnosis, treatment, and follow-up of numerous oxidative stress-related diseases. Biologically, antioxidants play their health-beneficial roles via transferring a hydrogen (H) atom or an electron (e(-)) to reactive species, thereby deactivating them. Antioxidant activity assays imitate this action; that is, antioxidants are measured by their H atom transfer (HAT) or e(-) transfer (ET) to probe molecules. Antioxidant activity/capacity can be monitored by a wide variety of assays with different mechanisms, including HAT, ET, and mixed-mode (ET/HAT) assays, generally without distinct boundaries between them. Understanding the principal mechanisms, advantages, and disadvantages of the measurement assays is important for proper selection of method for valid evaluation of antioxidant properties in desired applications. This work provides a general and up-to-date overview of HAT-based, mixed-mode (ET/HAT), and lipid peroxidation assays available for measuring antioxidant activity/capacity and the chemistry behind them, including a critical evaluation of their advantages and drawbacks. PMID:26805392

  8. Antioxidant Activity/Capacity Measurement. 2. Hydrogen Atom Transfer (HAT)-Based, Mixed-Mode (Electron Transfer (ET)/HAT), and Lipid Peroxidation Assays.

    Science.gov (United States)

    Apak, Reşat; Özyürek, Mustafa; Güçlü, Kubilay; Çapanoğlu, Esra

    2016-02-10

    Measuring the antioxidant activity/capacity levels of food extracts and biological fluids is useful for determining the nutritional value of foodstuffs and for the diagnosis, treatment, and follow-up of numerous oxidative stress-related diseases. Biologically, antioxidants play their health-beneficial roles via transferring a hydrogen (H) atom or an electron (e(-)) to reactive species, thereby deactivating them. Antioxidant activity assays imitate this action; that is, antioxidants are measured by their H atom transfer (HAT) or e(-) transfer (ET) to probe molecules. Antioxidant activity/capacity can be monitored by a wide variety of assays with different mechanisms, including HAT, ET, and mixed-mode (ET/HAT) assays, generally without distinct boundaries between them. Understanding the principal mechanisms, advantages, and disadvantages of the measurement assays is important for proper selection of method for valid evaluation of antioxidant properties in desired applications. This work provides a general and up-to-date overview of HAT-based, mixed-mode (ET/HAT), and lipid peroxidation assays available for measuring antioxidant activity/capacity and the chemistry behind them, including a critical evaluation of their advantages and drawbacks.

  9. W-314, waste transfer alternative piping system description

    International Nuclear Information System (INIS)

    It is proposed that the reliability, operability, and flexibility of the Retrieval Transfer System be substantially upgraded by replacing the planned single in-farm pipeline from the AN-AY-AZ-(SY) Tank Farm Complex to the AP Farm with three parallel pipelines outside the tank farms. The proposed system provides simplified and redundant routes for the various transfer missions, and prevents the risk of transfer gridlock when the privatization effort swings into full operation

  10. W-314, waste transfer alternative piping system description

    Energy Technology Data Exchange (ETDEWEB)

    Papp, I.G.

    1998-04-30

    It is proposed that the reliability, operability, and flexibility of the Retrieval Transfer System be substantially upgraded by replacing the planned single in-farm pipeline from the AN-AY-AZ-(SY) Tank Farm Complex to the AP Farm with three parallel pipelines outside the tank farms. The proposed system provides simplified and redundant routes for the various transfer missions, and prevents the risk of transfer gridlock when the privatization effort swings into full operation.

  11. Photoinduced Charge Transfer at Metal Oxide/Oxide Interfaces Prepared with Plasma Enhanced Atomic Layer Deposition

    Science.gov (United States)

    Kaur, Manpuneet

    LiNbO3 and ZnO have shown great potential for photochemical surface reactions and specific photocatalytic processes. However, the efficiency of LiNbO3 is limited due to recombination or back reactions and ZnO exhibits a chemical instability in a liquid cell. In this dissertation, both materials were coated with precise thickness of metal oxide layers to passivate the surfaces and to enhance their photocatalytic efficiency. LiNbO 3 was coated with plasma enhanced atomic layer deposited (PEALD) ZnO and Al2O3, and molecular beam deposited TiO2 and VO2. On the other hand, PEALD ZnO and single crystal ZnO were passivated with PEALD SiO2 and Al2O3. Metal oxide/LiNbO3 heterostructures were immersed in aqueous AgNO3 solutions and illuminated with ultraviolet (UV) light to form Ag nanoparticle patterns. Alternatively, Al2O3 and SiO2/ZnO heterostructures were immersed in K3PO 4 buffer solutions and studied for photoelectrochemical reactions. A fundamental aspect of the heterostructures is the band alignment and band bending, which was deduced from in situ photoemission measurements. This research has provided insight to three aspects of the heterostructures. First, the band alignment at the interface of metal oxides/LiNbO 3, and Al2O3 or SiO2/ZnO were used to explain the possible charge transfer processes and the direction of carrier flow in the heterostructures. Second, the effect of metal oxide coatings on the LiNbO3 with different internal carrier concentrations was related to the surface photochemical reactions. Third is the surface passivation and degradation mechanism of Al2O 3 and SiO2 on ZnO was established. The heterostructures were characterized after stability tests using atomic force microscopy (AFM), scanning electron microscopy (SEM), and cross-section transmission electron microscopy (TEM). The results indicate that limited thicknesses of ZnO or TiO2 on polarity patterned LiNbO3 (PPLN) enhances the Ag+ photoinduced reduction process. ZnO seems more efficient

  12. 40 CFR 63.689 - Standards: Transfer systems.

    Science.gov (United States)

    2010-07-01

    ...-permanently sealed (e.g., a welded joint between two sections of metal pipe or a bolted and gasketed flange....689 Standards: Transfer systems. (a) The provisions of this section apply to the control of air... section for such air emission control. (b) For each transfer system that is subject to this section and...

  13. PREFACE: Heavy-Ion Spectroscopy and QED Effects in Atomic Systems

    Science.gov (United States)

    Lindgren, Ingvar; Martinson, Indrek; Schuch, Reinhold

    1993-01-01

    now essentially solved. The experimental accuracy is already so high that also higher-order QED effects become observable, and several groups are now active in trying to evaluate such effects from first principles. Another related field where substantial progress has recently been made involves precision measurements of X-ray transitions. This has created an interest in the study of deep inner holes in heavy atoms, where large relativistic and QED effects appear. These effects are as large as in corresponding highly charged ions, but the interpretation requires that the many-body effects from the surrounding electrons are accurately extracted. This is a big challenge at present. Atomic collision physics with highly charged ions has been dominated in recent years by the search for a possibility to describe electron-electron interaction within the dynamics of collisions. The experiments on multielectron transfer reactions with highly charged ions posed in this respect quite a challenge to the theory. The models developed to meet this were often based on methods and terminologies developed for describing the inter-electronic interactions in atomic structure. This caused many controversial discussions, also during this symposium. A new and fast rising field is the interaction of highly charged ions with solid surfaces. This may become an important link between atomic physics and condensed-matter physics, stimulated by the opportunity to study effects in coupled many-body systems present in the case when a large amount of electrons is transferred from the solid to each single ion. Furtheron, collision experiments with cooled ion beams in ion storage rings open new dimensions also for atomic spectroscopy. It appears possible that transition and binding energies can be measured in recombination of very heavy ions with a better quality than by conventional Auger electron or X-ray spectroscopy. Obviously, it is not possible to cover all the fields mentioned here in a single

  14. Electromagnetically Induced Transparency in a Four-Level Atomic System

    Institute of Scientific and Technical Information of China (English)

    LI Jia-Hua; WANG Wen-Yi

    2004-01-01

    In this paper, we analyze and discuss the absorption properties of the probe beam in a four-level atomic system with a nearly hyper-fine doublet structure of two higher-lying excited levels based on electromagnetically induced transparency (EIT) for the two cases of transient process and steady-state process. The main gain of this work is to investigate theoretically the influence of the nearly hyper-fine levels on the probe absorption. For the transient process,using the numerical calculations by a simple Mathematica code we find that the magnitude of the probe absorption at the line center is small compared to the typical three-level atomic system in the context of electromagnetically induced transparency. For the case of the steady state, our results show that the probe absorption can be completely eliminated at the line center of the probe transition just as the usual three-level EIT scheme.

  15. Electromagnetically Induced Transparency in a Four-Level Atomic System

    Institute of Scientific and Technical Information of China (English)

    LIJia-Hua; WANGWen-Yi

    2004-01-01

    In this paper, we analyze and discuss the absorption properties of the probe beam in a four-level atomic system with a nearly hyper-fine doublet structure of two higher-lying excited levels based on electromagnetieally induced transparency (EIT) for the two cases of transient process and steady-state process. The main gain of this work is to investigate theoretically the influence of the nearly hyper-fine levels on the probe absorption. For the transient process, using the numerical calculations by a simple Mathematica code we find that the magnitude of the probe absorption at the line center is small compared to the typical three-level atomic system in the context of electromagnetieally induced transparency. For the case of the steady state, our results show that the probe absorption can be completely eliminated at the line center of the probe transition just as the usual three-level EIT scheme.

  16. Nonlinear control techniques for an atomic force microscope system

    Institute of Scientific and Technical Information of China (English)

    Yongchun FANG; Matthew FEEMSTER; Darren DAWSON; Nader M.JALILI

    2005-01-01

    Two nonlinear control techniques are proposed for an atomic force microscope system.Initially,a learning-based control algorithm is developed for the microcantilever-sample system that achieves asymptotic cantilever tip tracking for periodic trajectories.Specifically,the control approach utilizes a learning-based feedforward term to compensate for periodic dynamics and high-gain terms to account for non-periodic dynamics.An adaptive control algorithm is then developed to achieve asymptotic cantilever tip tracking for bounded tip trajectories despite uncertainty throughout the system parameters.Simulation results are provided to illustrate the efficacy and performance of the control strategies.

  17. Steric effect for proton, hydrogen-atom, and hydride transfer reactions with geometric isomers of NADH-model ruthenium complexes.

    Science.gov (United States)

    Cohen, Brian W; Polyansky, Dmitry E; Achord, Patrick; Cabelli, Diane; Muckerman, James T; Tanaka, Koji; Thummel, Randolph P; Zong, Ruifa; Fujita, Etsuko

    2012-01-01

    Two isomers, [Ru(1)]2+ (Ru = Ru(bpy)2, bpy = 2,2'-bipyridine, 1 = 2-(pyrid-2'-yl)-1-azaacridine) and [Ru(2)]2+ (2 = 3-(pyrid-2'-yl)-4-azaacridine), are bioinspired model compounds containing the nicotinamide functionality and can serve as precursors for the photogeneration of C-H hydrides for studying reactions pertinent to the photochemical reduction of metal-C1 complexes and/or carbon dioxide. While it has been shown that the structural differences between the azaacridine ligands of [Ru(1)]2+ and [Ru(2)]2+ have a significant effect on the mechanism of formation of the hydride donors, [Ru(1HH)]2+ and [Ru(2HH)]2+, in aqueous solution, we describe the steric implications for proton, net-hydrogen-atom and net-hydride transfer reactions in this work. Protonation of [Ru(2*-)] in aprotic and even protic media is slow compared to that of [Ru(1*-)]+. The net hydrogen-atom transfer between *[Ru(1)]2+ and hydroquinone (H2Q) proceeds by one-step EPT, rather than stepwise electron-proton transfer. Such a reaction was not observed for *[Ru(2)]2+ because the non-coordinated N atom is not easily available for an interaction with H2Q. Finally, the rate of the net hydride ion transfer from [Ru(1HH)]2+ to [Ph3C]+ is significantly slower than that of [Ru (2HH)]2+ owing to steric congestion at the donor site. PMID:22470971

  18. Series of broad resonances in atomic three-body systems

    CERN Document Server

    Diaz, D; Hu, C -Y

    2016-01-01

    We re-examine the series of resonances found earlier in atomic three-body systems by solving the Faddeev-Merkuriev integral equations. These resonances are rather broad and line-up at each threshold with gradually increasing gaps, the same way for all thresholds and irrespective of the spatial symmetry. We relate these resonances to the Gailitis mechanism, which is a consequence of the polarization potential.

  19. General Relativistic Radiative Transfer: Applications to Black-Hole Systems

    Science.gov (United States)

    Wu, Kinwah; Fuerst, Steven V.; Mizuno, Yosuke; Nishikawa, Ken-Ichi; Branduardi-Raymont, Graziella; Lee, Khee-Gan

    2007-01-01

    We present general relativistic radiation transfer formulations which include opacity effects due to absorption, emission and scattering explicitly. We consider a moment expansions for the transfer in the presence of scattering. The formulation is applied to calculation emissions from accretion and outflows in black-hole systems. Cases with thin accretion disks and accretion tori are considered. Effects, such as emission anisotropy, non-stationary flows and geometrical self-occultation are investigated. Polarisation transfer in curved space-time is discussed qualitatively.

  20. Quantum information transfer between topological and spin qubit systems

    OpenAIRE

    Leijnse, Martin; Flensberg, Karsten

    2011-01-01

    We propose a method to coherently transfer quantum information, and to create entanglement, between topological qubits and conventional spin qubits. Our suggestion uses gated control to transfer an electron (spin qubit) between a quantum dot and edge Majorana modes in adjacent topological superconductors. Because of the spin polarization of the Majorana modes, the electron transfer translates spin superposition states into superposition states of the Majorana system, and vice versa. Furthermo...

  1. Optical pumping and population transfer of nuclear-spin states of caesium atoms in high magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Luo Jun; Sun Xian-Ping; Zeng Xi-Zhi; Zhan Ming-Sheng

    2007-01-01

    Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti:sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable diode laser. Furthermore, the state population transfer among the of Cs in the ground state due to stochastic collisions between Cs atoms and buffer-gas molecules, is studied at different of the hyperfine interaction can strongly cause the state population transfer and spin-state interchange among the hyperfine Zeeman sublevels. The calculated results maybe explain the steady-state population in hyperfine Zeeman sublevels in terms of rates of optical-pumping, electron-spin flip, nuclear spin flip, and electron-nuclear spin flip-flop transitions among the hyperfine Zeeman sublevels of the ground state of Cs atoms. This method may be applied to the nuclear-spin-based solid-state quantum computation.

  2. EON: software for long time simulations of atomic scale systems

    International Nuclear Information System (INIS)

    The EON software is designed for simulations of the state-to-state evolution of atomic scale systems over timescales greatly exceeding that of direct classical dynamics. States are defined as collections of atomic configurations from which a minimization of the potential energy gives the same inherent structure. The time evolution is assumed to be governed by rare events, where transitions between states are uncorrelated and infrequent compared with the timescale of atomic vibrations. Several methods for calculating the state-to-state evolution have been implemented in EON, including parallel replica dynamics, hyperdynamics and adaptive kinetic Monte Carlo. Global optimization methods, including simulated annealing, basin hopping and minima hopping are also implemented. The software has a client/server architecture where the computationally intensive evaluations of the interatomic interactions are calculated on the client-side and the state-to-state evolution is managed by the server. The client supports optimization for different computer architectures to maximize computational efficiency. The server is written in Python so that developers have access to the high-level functionality without delving into the computationally intensive components. Communication between the server and clients is abstracted so that calculations can be deployed on a single machine, clusters using a queuing system, large parallel computers using a message passing interface, or within a distributed computing environment. A generic interface to the evaluation of the interatomic interactions is defined so that empirical potentials, such as in LAMMPS, and density functional theory as implemented in VASP and GPAW can be used interchangeably. Examples are given to demonstrate the range of systems that can be modeled, including surface diffusion and island ripening of adsorbed atoms on metal surfaces, molecular diffusion on the surface of ice and global structural optimization of nanoparticles

  3. Resonance flourescence in atomic coherent systems spectral features

    CERN Document Server

    Sandhya, S N

    1999-01-01

    We study resonance flourescence in a four level ladder system and illustrate some novel features due to quantum interference and atomic coherence effects. We find that under three photon resonant conditions, in some region of the parameter space of the rabi frequencies $\\Omega_1,\\Omega_2,\\Omega_3$, emission is dominantly by the level 4 at the line center even though there is an almost equal distribution of populations in all the levels. As one increases 'dynamically collapses' to a two level system. The steady state populations and the the resonance flourescence from all the levels provide adequate evidence to this effect.

  4. Observation of EIA in closed and open caesium atomic system

    Institute of Scientific and Technical Information of China (English)

    Zhao Jian-Ming; Zhao Yan-Ting; Huang Tao; Xiao Lian-Tuan; Jia Suo-Tang

    2005-01-01

    We present an experimental study on electromagnetically induced absorption (EIA) in the closed transition of a degenerate two-level Cs atomic system. The coupling and probe lasers coupled with the transition 6S1/2F=4 →6P3/2F'=5 of caesium atom. The signal of EIA was obtained and the frequency detuning and intensity effect of the pumping laser were experimentally investigated. The EIA signal in 6S1/2 F=4 → 6P3/2 F'=4 and 6S1/2 F=4 → 6P3/2F'=3 open transitions was also obtained. As the repumping laser couples with the transition of 6S1/2 F=3 → 6P3/2F'=4, the EIA signal is increased due to the hyperfine optical pumping.

  5. Autonomous quantum thermal machines in atom-cavity systems

    CERN Document Server

    Mitchison, Mark T; Prior, Javier; Woods, Mischa P; Plenio, Martin B

    2016-01-01

    An autonomous quantum thermal machine comprising a trapped atom or ion placed inside an optical cavity is proposed and analysed. Such a machine can operate as a heat engine whose working medium is the quantised atomic motion, or as an absorption refrigerator which cools without any work input. Focusing on the refrigerator mode, we predict that it is possible with state-of-the-art technology to cool a trapped ion almost to its motional ground state using a thermal light source such as sunlight. We nonetheless find that a laser or similar reference system is necessary to stabilise the cavity frequencies. Furthermore, we establish a direct and heretofore unacknowledged connection between the abstract theory of quantum absorption refrigerators and practical sideband cooling techniques. We also highlight and clarify some assumptions underlying several recent theoretical studies on self-contained quantum engines and refrigerators. Our work indicates that cavity quantum electrodynamics is a promising and versatile e...

  6. Atomic Clocks’ Data Exchange System for Time Keeping%守时原子钟数据交互系统

    Institute of Scientific and Technical Information of China (English)

    王玉琢; 王伟波; 张爱敏

    2016-01-01

    The comparisons and synchronizations of remote atomic clocks’ data are vitally significant for accuracy and stability of atomic time scale. This paper introduces GPS common-view method for calculating the time difference between remote atomic clocks. The design and implementation of remote atomic clocks’ data exchange system by file transfer protocol is detailedly discussed.%异地原子钟数据的比对与同步是原子时标准确性和稳定性的基础保障。介绍了GPS共视法计算异地原子钟钟差数据的基本原理,讨论了基于FTP文件传输协议实现异地原子钟数据交互方案的设计和实现。

  7. Entanglement Transfer in a Four-Qubit Dimerized Heisenberg System

    Institute of Scientific and Technical Information of China (English)

    SHAO Bin; HUANG Min; WANG Zhao-ming; ZOU Jian

    2008-01-01

    Entanglement transfer is investigated in a dimerized Heisenberg system.Coneurrence as the measure of entanglement is calculated by the time-evolved state starting from an initially entangled state of spin pair.It is shown that perfect entanglement transfer can be realized at 80me special time and suitable interacting.

  8. Transfer alignment of shipborne inertial-guided weapon systems

    Institute of Scientific and Technical Information of China (English)

    Sun Changyue; Deng Zhenglong

    2009-01-01

    The transfer alignment problem of the shipborne weapon inertial navigation system (INS) is addressed. Specifically, two transfer alignment algorithms subjected to the ship motions induced by the waves are discussed. To consider the limited maneuver level performed by the ship, a new filter algorithm for transfer alignment methods using velocity and angular rate matching is first derived. And then an improved method using integrated velocity and integrated angular rate matching is introduced to reduce the effect of the ship body flexure. The simulation results show the feasibility and validity of the proposed transfer alignment algorithms.

  9. Atomic physics of strongly correlated systems. Progress report, 1 August 1980-31 July 1981

    International Nuclear Information System (INIS)

    Studies of electron correlations of doubly-excited electrons in hyperspherical coordinates, and differential and total cross sections for charge transfer and ionization in fast ion-atom collisions are reported

  10. Teleportation of a ququart system using hyperentangled photons assisted by atomic-ensemble memories

    Science.gov (United States)

    Luo, Ming-Xing; Li, Hui-Ran; Lai, Hong; Wang, Xiaojun

    2016-01-01

    A single photon encoded in both the spin and the orbital angular momentum has recently been experimentally demonstrated [X.-L. Wang et al., Nature 518, 516 (2015)], 10.1038/nature14246 with linear optics using the hyperentangled state, which can be viewed as a bipartite four-dimensional (ququart) entanglement. Here, we investigate this process from a general point of view. By exploring a controlled phase flip induced by atomic ensembles in one-side optical microcavities, we propose teleportations of general ququart systems including a two-atomic-ensemble system, a two-polarized-photon system, one photon with the polarization and spatial degrees of freedom (DOFs), and a hybrid photon-ensemble system using two hyperentangled photons. The output information may also be encoded by different physical systems up to the special requirements of a receiver. These schemes are also adapted to teleportation of a ququart system with only phases or real probability amplitudes, which is beyond previous superdense teleportation [Nature Commun. 6, 7185 (2015)], 10.1038/ncomms8185. With these restrictions, half of the classical communication cost may be saved and experimental complexities are also reduced. Our theoretical schemes are feasible in modern physics and show the possibilities of transferring complex quantum systems for scalable quantum applications.

  11. An rf communications system for the West Valley transfer cart

    International Nuclear Information System (INIS)

    A prototype radio frequency communications system for digital data was designed and built by Oak Ridge National Laboratory for use in controlling the vitrification facility transfer cart at the West Valley Nuclear Services facility in New York. The communications system provides bidirectional wireless data transfer between the operator control station and the material transfer cart. The system was designed to operate in radiation fields of 104 R/h while withstanding a total integrated dose of 107 R of gamma radiation. Implementation of antenna spatial diversity, automatic gain control, and spectral processing improves operation in the reflective environment of the metal-lined reprocessing cells

  12. A pneumatic transfer system for special form 252Cf

    International Nuclear Information System (INIS)

    A pneumatic transfer system has been developed for use with series 100 Special Form 252Cf. It was developed to reduce the exposure to personnel handling sources of 252Cf with masses up to 150 microg by permitting remotely activated two-way transfer between the storage container and the irradiation position. The pneumatic transfer system also permits transfers for reproducible repetitive irradiation periods. In addition to the storage container equipped with quick-release fittings, the transfer system consists of an irradiation station, a control box with momentary contact switches to activate the air-pressure control valves and indicators to identify the location of the source, and connecting air hose and electrical wire. A source of 20 psig air and 110 volt electrical power are required for operation of the transfer system which can be easily moved and set up by one individual in 5 to 10 minutes. Tests have shown that rarely does a source become lodged in the transfer tubing, but two methods have been developed to handle incomplete transfers of the 252Cf source. The first method consists of closing one air vent to allow a pressure impulse to propel the source to the opposite side. The second method applies to those 252Cf capsules with a threaded or tapped end to which a small ferromagnetic piece can be attached; an incompletely transferred source in the transfer tube can then be guided to a position of safety by surrounding the transfer tubing containing the capsule with a horseshoe magnet attached to the end of a long pole

  13. Excited state intramolecular charge transfer reaction of 4-(morpholenyl) benzonitrile in solution: Effects of hetero atom in the donor moiety

    Indian Academy of Sciences (India)

    Tuhin Pradhan; Harun Al Rasid Gazi; Ranjit Biswas

    2010-07-01

    An intramolecular charge transfer (ICT) molecule with an extra hetero atom in its donor moiety has been synthesized in order to investigate how ICT reaction is affected by hetero atom replacement. Photo-physical and photo-dynamical properties of this molecule, 4-(morpholenyl)benzonitrile (M6C), have been studied in 20 different solvents. The correlation between the reaction driving force (- ) and activation barrier ( #) has been explored in order to understand the solvent effects (static and dynamic) on the photo-excited ICT reaction in this molecule. A Kramer’s model analysis of the experimentally observed reaction rate constants indicates a solvent-averaged activation barrier of ∼ 4 in the absence of solvent dynamical control. The reaction in M6C is therefore not a barrier-less reaction but close to the limit where conventional kinetics might break down.

  14. Heat transfer enhancement using air-atomized spray cooling with water-Al2O3 nano-fluid

    International Nuclear Information System (INIS)

    The study deals with the air-atomized spray cooling using nano-fluid as the cooling media for high heat flux applications. The nano-fluid has been prepared by commercial Al2O3 particles of diameter less than 13 nm and water. Heat transfer study has been carried out on a pre-heated steel specimen of dimensions 100 mm x 100 mm x 6 mm. The initial temperature of the plate which was subjected to air-atomized spray cooling was over 900 deg. C. Various coolants consisting of 0.1% volumetric concentration of water -Al2O3 mixture, with or without a dispersing agent (surfactant) were used for the study. The dispersing agents used are sodium dodecyl sulphate (SDS) and polyoxyethylene (20) sorbitan monolaurate (Tween 20). Inverse heat conduction software INTEMP has been used for estimating the surface heat flux and temperatures taking into account the measured internal temperature histories by the thermocouples during the cooling process. The results obtained using nano-fluid coolants are compared with that of the results where pure water (filtered potable water) is used as a coolant. The analyses reveal that the cooling rate, critical heat flux and heat transfer coefficients are significantly enhanced when nano-fluids are used as coolants in air-atomized spray process. Also, the nano-fluid coolants with dispersing agent shows a better enhancement of heat transfer over that of the nano-fluid without the dispersing media. The nano-fluid with dispersing agent Tween 20 is found more effective than that of its counterpart. Overall, the percentage enhancement in cooling rate of all these nano-fluids compared with pure water (filtered potable water) is 10.2% for water-Al2O3, 18.6% for water-Al2O3-SDS, and up to 32.3% for water-Al2O3 -Tween 20. (authors)

  15. Safety and Mission Assurance (SMA) Automated Task Order Management System (ATOMS) Operation Manual

    Science.gov (United States)

    Wallace, Shawn; Fikes, Lou A.

    2016-01-01

    This document describes operational aspects of the ATOMS system. The information provided is limited to the functionality provided by ATOMS and does not include information provided in the contractor's proprietary financial and task management system.

  16. Role of axial base coordination in isonitrile binding and chalcogen atom transfer to vanadium(III) complexes.

    Science.gov (United States)

    Majumdar, Subhojit; Stauber, Julia M; Palluccio, Taryn D; Cai, Xiaochen; Velian, Alexandra; Rybak-Akimova, Elena V; Temprado, Manuel; Captain, Burjor; Cummins, Christopher C; Hoff, Carl D

    2014-10-20

    The enthalpy of oxygen atom transfer (OAT) to V[(Me3SiNCH2CH2)3N], 1, forming OV[(Me3SiNCH2CH2)3N], 1-O, and the enthalpies of sulfur atom transfer (SAT) to 1 and V(N[t-Bu]Ar)3, 2 (Ar = 3,5-C6H3Me2), forming the corresponding sulfides SV[(Me3SiNCH2CH2)3N], 1-S, and SV(N[t-Bu]Ar)3, 2-S, have been measured by solution calorimetry in toluene solution using dbabhNO (dbabhNO = 7-nitroso-2,3:5,6-dibenzo-7-azabicyclo[2.2.1]hepta-2,5-diene) and Ph3SbS as chalcogen atom transfer reagents. The V-O BDE in 1-O is 6.3 ± 3.2 kcal·mol(-1) lower than the previously reported value for 2-O and the V-S BDE in 1-S is 3.3 ± 3.1 kcal·mol(-1) lower than that in 2-S. These differences are attributed primarily to a weakening of the V-Naxial bond present in complexes of 1 upon oxidation. The rate of reaction of 1 with dbabhNO has been studied by low temperature stopped-flow kinetics. Rate constants for OAT are over 20 times greater than those reported for 2. Adamantyl isonitrile (AdNC) binds rapidly and quantitatively to both 1 and 2 forming high spin adducts of V(III). The enthalpies of ligand addition to 1 and 2 in toluene solution are -19.9 ± 0.6 and -17.1 ± 0.7 kcal·mol(-1), respectively. The more exothermic ligand addition to 1 as compared to 2 is opposite to what was observed for OAT and SAT. This is attributed to less weakening of the V-Naxial bond in ligand binding as opposed to chalcogen atom transfer and is in keeping with structural data and computations. The structures of 1, 1-O, 1-S, 1-CNAd, and 2-CNAd have been determined by X-ray crystallography and are reported. PMID:25280113

  17. CMOS compatible strategy based on selective atomic layer deposition of a hard mask for transferring block copolymer lithography patterns

    Energy Technology Data Exchange (ETDEWEB)

    Gay, G; Grampeix, H; Martin, F; Jalaguier, E; De Salvo, B [CEA LETI MINATEC, 17 rue des Martyrs, 38054 Grenoble (France); Baron, T; Agraffeil, C; Salhi, B; Chevolleau, T; Cunge, G; Tortai, J-H, E-mail: guillaume.gay@cea.fr, E-mail: thierry.baron@cea.fr [CNRS-LTM, 17 rue des Martyrs, 38054 Grenoble (France)

    2010-10-29

    A generic, CMOS compatible strategy for transferring a block copolymer template to a semiconductor substrate is demonstrated. An aluminum oxide (Al{sub 2}O{sub 3}) hard mask is selectively deposited by atomic layer deposition in an organized array of holes obtained in a PS matrix via PS-b-PMMA self-assembly. The Al{sub 2}O{sub 3} nanodots act as a highly resistant mask to plasma etching, and are used to pattern high aspect ratio (>10) silicon nanowires and nanopillars.

  18. Iodinated (Perfluoro)alkyl Quinoxalines by Atom Transfer Radical Addition Using ortho-Diisocyanoarenes as Radical Acceptors.

    Science.gov (United States)

    Leifert, Dirk; Studer, Armido

    2016-09-12

    A simple method for the preparation of functionalized quinoxalines is reported. Starting from readily accessible ortho-diisocyanoarenes and (perfluoro)alkyl iodides, the quinoxaline core is constructed during (perfluoro)alkylation by atom transfer radical addition (ATRA), resulting in 2-iodo-3-(perfluoro)alkylquinoxalines. The radical cascades are readily initiated either with visible light or by using α,α'-azobisisobutyronitrile (AIBN). The heteroarene products are obtained in high yields (up to 94 %), and the method can be readily scaled up. Useful follow-up chemistry documents the value of the novel radical quinoxaline synthesis.

  19. Suppression of angular momentum transfer in cold collisions of transition metal atoms in ground States with nonzero orbital angular momentum.

    Science.gov (United States)

    Hancox, Cindy I; Doret, S Charles; Hummon, Matthew T; Krems, Roman V; Doyle, John M

    2005-01-14

    The Zeeman relaxation rate in cold collisions of Ti(3d(2)4s(2) 3F2) with He is measured. We find that collisional transfer of angular momentum is dramatically suppressed due to the presence of the filled 4s(2) shell. The degree of electronic interaction anisotropy, which is responsible for Zeeman relaxation, is estimated to be about 200 times smaller in the Ti-He complex than in He complexes with typical non-S-state atoms. PMID:15698077

  20. Dramatic Influence of an Anionic Donor on the Oxygen-Atom Transfer Reactivity of a MnV–Oxo Complex

    OpenAIRE

    Neu, Heather M.; Quesne, Matthew G; Yang, Tzuhsiung; Prokop-Prigge, Katharine A; Lancaster, Kyle M.; Donohoe, James; DeBeer, Serena; de Visser, Sam P; Goldberg, David P.

    2014-01-01

    Addition of an anionic donor to an MnV(O) porphyrinoid complex causes a dramatic increase in 2-electron oxygen-atom-transfer (OAT) chemistry. The 6-coordinate [MnV(O)(TBP8Cz)(CN)]− was generated from addition of Bu4N+CN− to the 5-coordinate MnV(O) precursor. The cyanide-ligated complex was characterized for the first time by Mn K-edge X-ray absorption spectroscopy (XAS) and gives Mn–O=1.53 Å, Mn–CN=2.21 Å. In combination with computational studies these distances were shown to correlate with ...

  1. Phonon-assisted excitation energy transfer in photosynthetic systems

    Science.gov (United States)

    Chen, Hao; Wang, Xin; Fang, Ai-Ping; Li, Hong-Rong

    2016-09-01

    The phonon-assisted process of energy transfer aiming at exploring the newly emerging frontier between biology and physics is an issue of central interest. This article shows the important role of the intramolecular vibrational modes for excitation energy transfer in the photosynthetic systems. Based on a dimer system consisting of a donor and an acceptor modeled by two two-level systems, in which one of them is coupled to a high-energy vibrational mode, we derive an effective Hamiltonian describing the vibration-assisted coherent energy transfer process in the polaron frame. The effective Hamiltonian reveals in the case that the vibrational mode dynamically matches the energy detuning between the donor and the acceptor, the original detuned energy transfer becomes resonant energy transfer. In addition, the population dynamics and coherence dynamics of the dimer system with and without vibration-assistance are investigated numerically. It is found that, the energy transfer efficiency and the transfer time depend heavily on the interaction strength of the donor and the high-energy vibrational mode, as well as the vibrational frequency. The numerical results also indicate that the initial state and dissipation rate of the vibrational mode have little influence on the dynamics of the dimer system. Results obtained in this article are not only helpful to understand the natural photosynthesis, but also offer an optimal design principle for artificial photosynthesis. Project supported by the National Natural Science Foundation of China (Grant No. 11174233).

  2. 46 CFR 153.430 - Heat transfer systems; general.

    Science.gov (United States)

    2010-10-01

    ... this part and each cargo heating system must: (a) Meet the standards of Subchapters F (Marine... separated from all other cooling and heating systems; and (c) Allow manual regulation of the system's heat... 46 Shipping 5 2010-10-01 2010-10-01 false Heat transfer systems; general. 153.430 Section...

  3. Nonlocality and purity in atom-field coupling system

    Institute of Scientific and Technical Information of China (English)

    Cai Xin; Huang Guang-Ming; Li Gao-Xiang

    2005-01-01

    The effects of initial field state and thermal environment on quantum nonlocality and linear entropy in an atomfield coupling system are investigated. We found that if the cavity is lossless and the reservoir is in vacuum, the atom-field state can exhibit quantum nonlocality periodically and the linear entropies of the atom and the field also oscillate periodically with a period the same as that of quantum nonlocality. And if the cavity dissipation is very weak and the average photon number of the reservoir is very small, the quantum nonlocality will be lost and the linear entropies of the atom and the field oscillate with a decreasing amplitude. The rapidity of the loss of the quantum nonlocality depends on the amplitude of the initial squeezed coherent state, the cavity damping constant κ and the average photon number N of the thermal reservoir. The stronger the field and the larger the constant κ and the average photon number N could be, the more rapidly the nonlocality decreases.

  4. Transfer Function Model of Multirate Feedback Control Systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the suitably defined multivariable version of Krancoperators and the extended input and output vectors, the multirate sampling plant is transformed to a equivalent time invariant single rate one, then the transfer function model of the multivariable multirate sampling plant is obtained. By combining this plant model with the time invariant description of the multirate controller in terms of extended vectors, the closed-loop transfer function model of the multirate feedback control system can be determinated. This transfer function model has a very simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling feedback control systems in the frequency domain.

  5. Collisional transfer of electrons to the continuum of atomic and molecular ions

    International Nuclear Information System (INIS)

    The aim of this study was the systematic investigation of the differences that appear in the peaks of distribution of doubly differential (in angle an energy) 'convoy' electrons, when comparing spectra obtained by bombarding thin carbon foils with atomic (H+) and molecular (H2+) projectiles of equal velocity. The measurements show that the production yield of such electrons is inversely propotional to the ion dwell time in the solid. For long times, the yield ratio fluctuates around the unity value, and the amplitude of this dispersion decreases for longer times. A higher yield is measured for (H2+), but only near the peak cusp. The double differential cross section (DDCS) for electron capture is calculated in second order Born approximation. A transition from a 1s state to the continuum of two correlated protons as a function of their internuclear distance R is considered. As R decreases from approx. 0.5 atomic units towards zero, the DDCS value increases from that corresponding to the atomic projectil (Z=1) limit to the united atom value (Z=2). It is found that, the higher the projectil velocity, the better is the DDCS value agreement with both limits. The equipment used by the author is described. (M.E.L.)

  6. Wireless embedded control system for atomically precise manufacturing

    KAUST Repository

    Khan, Yasser

    2011-04-01

    This paper will explore the possibilities of implementing a wireless embedded control system for atomically precise manufacturing. The manufacturing process, similar to Scanning Tunneling Microscopy, takes place within an Ultra High Vacuum (UHV) chamber at a pressure of 10-10 torr. In order to create vibration isolation, and to keep internal noise to a minimum, a wireless link inside the UHV chamber becomes essential. We present a MATLAB simulation of the problem, and then demonstrate a hardware scheme between a Gumstix computer and a Linux based laptop for controlling nano-manipulators with three degrees of freedom. © 2011 IEEE.

  7. Optical switching and bistability in four-level atomic systems

    Science.gov (United States)

    Kumar, Pardeep; Dasgupta, Shubhrangshu

    2016-08-01

    We explore the coherent control of nonlinear absorption of intense laser fields in four-level atomic systems. For instance, in a four-level ladder system, a coupling field creates electromagnetically induced transparency (EIT) with an Aulter-Townes doublet for the probe field while the control field is absent. A large absorption peak appears at resonance as the control field is switched on. We show how such a large absorption leads to optical switching. Further, this large absorption diminishes and a transparency window appears due to the saturation effects as the strength of the probe field is increased. We further demonstrate that the threshold of the optical bistability can be modified by suitable choices of the coupling and the control fields. In a four-level Y -type configuration, the effect of the control field on saturable absorption (SA) and reverse saturable absorption (RSA) is highlighted in the context of nonlinear absorption of the probe field. We achieve RSA and SA in a simple atomic system just by applying a control field.

  8. Control of pneumatic transfer system for neutron activation analysis

    International Nuclear Information System (INIS)

    Pneumatic transfer system(PTS) is one of the facilities to be used in irradiation of target materials for neutron activation analysis(NAA) in the research reactor. There are two systems the manual and the automatic system in PTS of HANARO research reactor. The pneumatic transfer system consists of many devices, sends and loads the capsules from NAA laboratory into three holes in the reflector tank of reactor and retrieves irradiated capsules after irradiation. This report describes the part's design, control system and the operation procedures. All the algorithm described in the text will be used for maintenance and upgrading

  9. Control of pneumatic transfer system for neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. S.; Chung, Y. S.; Wu, J. S.; Kim, H. K.; Choi, Y. S.; Kim, S. H.; Moon, J. H.; Baek, S. Y

    2000-06-01

    Pneumatic transfer system(PTS) is one of the facilities to be used in irradiation of target materials for neutron activation analysis(NAA) in the research reactor. There are two systems the manual and the automatic system in PTS of HANARO research reactor. The pneumatic transfer system consists of many devices, sends and loads the capsules from NAA laboratory into three holes in the reflector tank of reactor and retrieves irradiated capsules after irradiation. This report describes the part's design, control system and the operation procedures. All the algorithm described in the text will be used for maintenance and upgrading.

  10. Plasmon excitations in two-dimensional atomic cluster systems

    Science.gov (United States)

    Yu, Yan-Qin; Yu, Ya-Bin; Xue, Hong-Jie; Wang, Ya-Xin; Chen, Jie

    2016-09-01

    Properties of plasmon excitations in two-dimensional (2D) atomic cluster systems are theoretically studied within an extended Hubbard model. The collective oscillation equations of charge, plasmon eigen-equations and the energy-absorption spectrum formula are presented. The calculated results show that different symmetries of plasmons exist in the cluster systems, and the symmetry of charge distribution in the plasmon resonance originate from the intrinsic symmetry of the corresponding eigen-plasmon modes, but not from the symmetry of applied external fields; however, the plasmon excitation with a certain polarization direction should be excited by the field in this direction, the dipole mode of plasmons can be excited by both uniform and non-uniform fields, but multipole ones cannot be excited by an uniform field. In addition, we show that for a given electron density, plasmon spectra are red-shifted with increasing size of the systems.

  11. Ultrafast and efficient coherence creation in {\\Lambda}-like atomic systems driven by nonlinearly chirped few-cycle pulses

    OpenAIRE

    Sarma, Amarendra K.; Kumar, Parvendra

    2011-01-01

    We report an ultrafast and efficient way to create the maximum coherence between the two lower states in a -like atomic systems, driven by two nonlinearly chirped few-cycle pulses. The phenomenon of coherent population trapping and electromagnetically induced population transfer are investigated by solving the appropriate density matrix equations without invoking the rotating wave approximation. The robustness of the scheme for maximum coherence against the variation of the laser parameters a...

  12. Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

    Directory of Open Access Journals (Sweden)

    Yannick Borguet

    2010-12-01

    Full Text Available The tandem catalysis of ring-closing metathesis/atom transfer radical reactions was investigated with the homobimetallic ruthenium–indenylidene complex [(p-cymeneRu(μ-Cl3RuCl(3-phenyl-1-indenylidene(PCy3] (1 to generate active species in situ. The two catalytic processes were first carried out independently in a case study before the whole sequence was optimized and applied to the synthesis of several polyhalogenated bicyclic γ-lactams and lactones from α,ω-diene substrates bearing trihaloacetamide or trichloroacetate functionalities. The individual steps were carefully monitored by 1H and 31P NMR spectroscopies in order to understand the intimate details of the catalytic cycles. Polyhalogenated substrates and the ethylene released upon metathesis induced the clean transformation of catalyst precursor 1 into the Ru(II–Ru(III mixed-valence compound [(p-cymeneRu(μ-Cl3RuCl2(PCy3], which was found to be an efficient promoter for atom transfer radical reactions under the adopted experimental conditions.

  13. Synthesis of Environmentally Responsive Polymers by Atom Transfer Radical Polymerization: Generation of Reversible Hydrophilic and Hydrophobic Surfaces

    Directory of Open Access Journals (Sweden)

    Vikas Mittal

    2010-05-01

    Full Text Available Environmentally responsive poly(N-isopropylacrylamide brushes were grafted from the surface of polymer particles or flat surfaces in order to generate reversible hydrophilic and hydrophobic surfaces. The use of atom transfer radical polymerization was demonstrated for the grafting of polymer brushes as it allows efficient control on the amount of grafted polymer. The polymer particles were generated with or without surfactant in the emulsion polymerization and their surface could be modified with the atom transfer radical polymerization (ATRP initiator. The uniform functionalization of the surface with ATRP initiator was responsible for the uniform grafting of polymer brushes. The grafted brushes responded reversibly with changes in temperature indicating that the reversible responsive behavior could be translated to the particle surfaces. The particles were observed to adsorb and desorb protein and virus molecules by changing the temperatures below or higher than 32 °C. The initiator functionalized particles could also be adsorbed on the flat surfaces. The adsorption process also required optimization of the heat treatment conditions to form a uniform layer of the particles on the substrate. The grafted polymer brushes also responded to the changes in temperatures similar to the spherical particles studied through water droplets placed on the flat substrates.

  14. Time-delay models of heat transfer systems

    International Nuclear Information System (INIS)

    The paper deals with a new approach to modeling the heat transfer phenomena by means of differential equations with delays. The infinite order dynamics of thermal processes by suitable combinations of capacitance and delay elements is presented. An identification of transfer function of heat exchangers is presented. In the mathematical treatment of heat transfer systems, it is usually quite advantageous to deal in the frequency domain rather than the time. In such cases, the response of the system to sinusoidal inputs over a band of frequencies must be known. Identification is based on the least square method, which is based on minimization of the weighted sum of the squares of the errors between the absolute magnitudes of the frequency characteristic real object and the frequency characteristic of time-delay model of heat transfer system, which is proposed in this paper. (author)

  15. Investigation of Condensation Heat Transfer Correlation of Heat Exchanger Design in Secondary Passive Cooling System

    International Nuclear Information System (INIS)

    Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON

  16. Synthesis, characterisation, and oxygen atom transfer reactions involving the first gold(I)-alkylperoxo complexes.

    Science.gov (United States)

    Collado, Alba; Gómez-Suárez, Adrián; Oonishi, Yoshihiro; Slawin, Alexandra M Z; Nolan, Steven P

    2013-11-25

    The synthesis of a new class of organogold species containing a peroxo moiety is reported. Complexes [Au(IPr)(OO(t)Bu)] and [Au(SIPr)(OO(t)Bu)] have been synthesised via a straightforward methodology using the parent gold(I) hydroxide complexes as synthons. These complexes have been successfully used in oxygen-transfer reactions to triphenylphosphine.

  17. Interatomic Coulombic electron capture in atomic, molecular, and quantum dot systems

    Directory of Open Access Journals (Sweden)

    Bande Annika

    2015-01-01

    Full Text Available The interatomic Coulombic electron capture (ICEC process has recently been predicted theoretically for clusters of atoms and molecules. For an atom A capturing an electron e(ε it competes with the well known photorecombination, because in an environment of neutral or anionic neighboring atoms B, A can transfer its excess energy in the ultrafast ICEC process to B which is then ionized. The cross section for e(ε + A + B → A− + B+ + e(ε′ has been obtained in an asymptotic approximation based on scattering theory for several clusters [1,2]. It was found that ICEC starts dominating the PR for distances among participating species of nanometers and lower. Therefore, we believe that the ICEC process might be of importance in the atmosphere, in biological systems, plasmas, or in nanostructured materials. As an example for the latter, ICEC has been investigated by means of electron dynamics in a model potential for semiconductor double quantum dots (QDs [3]. In the simplest case one QD captures an electron while the outgoing electron is emitted from the other. The reaction probability for this process was found to be relatively large.

  18. Dimensional dependence of phonon transport in freestanding atomic layer systems

    Science.gov (United States)

    Kim, Duckjong; Hwangbo, Yun; Zhu, Lijing; Mag-Isa, Alexander E.; Kim, Kwang-Seop; Kim, Jae-Hyun

    2013-11-01

    Due to the fast development of nanotechnology, we have the capability of manipulating atomic layer systems such as graphene, hexagonal boron nitride and dichalcogenides. The major concern in the 2-dimensional nanostructures is how to preserve their exceptional single-layer properties in 3-dimensional bulk structures. In this study, we report that the extreme phonon transport in graphene is highly affected by the graphitic layer stacking based on experimental investigation of the thermal conduction in few-layer graphene, 1-7 layers thick, suspended over holes of various diameters. We fabricate freestanding axisymmetric graphene structures without any perturbing substrate, and measure the in-plane transport property in terms of thermal conduction by using Raman spectroscopy. From the difference in susceptibility to substrate effect, size effect on hot-spot temperature variation and layer number dependence of thermal conductivity, we show that the graphitic membranes with 2 or more layers have characteristics similar to 3-dimensional graphite, which are very different from those of 2-dimensional graphene membranes. This implies that the scattering of out-of-plane phonons by interlayer atomic coupling could be a key mechanism governing the intrinsic thermal property.Due to the fast development of nanotechnology, we have the capability of manipulating atomic layer systems such as graphene, hexagonal boron nitride and dichalcogenides. The major concern in the 2-dimensional nanostructures is how to preserve their exceptional single-layer properties in 3-dimensional bulk structures. In this study, we report that the extreme phonon transport in graphene is highly affected by the graphitic layer stacking based on experimental investigation of the thermal conduction in few-layer graphene, 1-7 layers thick, suspended over holes of various diameters. We fabricate freestanding axisymmetric graphene structures without any perturbing substrate, and measure the in-plane transport

  19. Pump design for High Temperature Sulfuric acid transfer system

    International Nuclear Information System (INIS)

    In the sulfuric acid concentration / decomposition section, consequent issues handling material corrosion and the coupling with high temperature energy source were generated, as well as the study of catalyst activity and stability. And Onuki et al., mentioned that material resistance issues are also important for the development of the hydriodic acid concentration/decomposition section. Moreover, the transfer of high temperature H2SO4 is a very important factor considering safety in successive reaction process and efficiency. As mentioned above, the pump to carry sulfuric acid is very important in SI process, but this study is insufficient. After forced cooling of high temperature H2SO4, reduction of safety and process efficiency which is caused by transfer, re-heating, and pressurization is one of the weaknesses in H2SO4 transfer system. Therefore, in this study, we proposed the newly designed H2SO4 transfer system for SI thermo-chemical cycle and the proposed H2SO4 transfer system was analyzed using computational fluid dynamics (CFD) analysis in order to investigate thermodynamic /hydrodynamic characteristics. As the results, we identify as follows as: By the thermal analysis result of bellows in developed transfer system, it is verified that continuous operation is possible within the deformation temperature limit of Teflon 430 K. Physical/chemical environment of inside the bellows box and performance of bellows in continuous operation condition were evaluated. It is verified that not only the bellows, but also the end-plate made of STS can provide reliability and durability during continuous operation. The CFD results on thermohydrodynamic characteristics show good performance for the proposed H2SO4 transfer system. It is evaluated that it will be efficient in actual manufacturing process because it can provide quantitative transfer and prevent heat loss

  20. Transferring Strong Boundedness among Laguerre Orthogonal Systems

    Indian Academy of Sciences (India)

    I Abu-Falahah; R A Macías; C Segovia; J L Torrea

    2009-04-01

    Given the family of Laguerre polynomials, it is known that several orthonormal systems of Laguerre functions can be considered. In this paper we prove that an exhaustive knowledge of the boundedness in weighted $L^p$ of the heat and Poisson semigroups, Riesz transforms and -functions associated to a particular Laguerre orthonormal system of functions, implies a complete knowledge of the boundedness of the corresponding operators on the other Laguerre orthonormal system of functions. As a byproduct, new weighted $L^p$ boundedness are obtained. The method also allows us to get new weighted estimates for operators related with Laguerre polynomials.

  1. Double lid ports - a high integrity transfer system

    International Nuclear Information System (INIS)

    The traditional method of transferring radioactive material from one containment to another is by plastic bagging which produces considerable secondary wastes and is both tedious and hazardous to the operator. Double lid ports, which were originally designed for the outward transfer of radioactive objects from a hot cell into waste drums at Kernforschungsentrum Karlsruhe, provide a superior method of achieving the transfer, with high integrity, no additional waste production and optimum activity control. Having been developed and proven on circular openings the double lid system is now being adopted for a variety of containment door shapes. (author)

  2. Successful synchronization of the LHC's clockwise beam transfer system

    CERN Multimedia

    2008-01-01

    LHC synchronization test successful The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.

  3. Back-Influence of Molecular Motion on Energy Transfer in the Landau-Teller Model of Atom Molecule Scattering.

    Science.gov (United States)

    Pollak, Eli

    2016-07-21

    This year we celebrate the 80th anniversary of the Landau-Teller model for energy exchange in a collinear collision of an atom with a harmonic diatomic molecule. Even after 80 years though, the analytic theory to date has not included in it the back-influence of the oscillator's motion on the energy transfer between the approaching particle and the molecule. This is the topic of the present paper. The back-influence can be obtained by employing classical second-order perturbation theory. The second-order theory is used in both a classical and semiclassical context. Classically, analytic expressions are derived for the final phase and action of the diatom, after the collision. The energy loss of the atom is shown to decrease linearly with the increasing energy of the oscillator. The magnitude of this decrease is a direct consequence of the back-reaction of the oscillator on the translational motion. The qualitative result is universal, in the sense that it is not dependent on the details of the interaction of the atom with the oscillator. A numerical application to a model collision of an Ar atom with a Br2 diatom demonstrates the importance and accuracy of the second-order perturbation theory. The same results are then used to derive a second-order perturbation theory semiclassical expression for the quantum transition probability from initial vibrational state ni to final vibrational state nf of the oscillator. A comparison of the theory with exact quantum data is presented for a model collision of Br2 with a hydrogen molecule, where the hydrogen molecule is considered as a single approaching particle.

  4. Back-Influence of Molecular Motion on Energy Transfer in the Landau-Teller Model of Atom Molecule Scattering.

    Science.gov (United States)

    Pollak, Eli

    2016-07-21

    This year we celebrate the 80th anniversary of the Landau-Teller model for energy exchange in a collinear collision of an atom with a harmonic diatomic molecule. Even after 80 years though, the analytic theory to date has not included in it the back-influence of the oscillator's motion on the energy transfer between the approaching particle and the molecule. This is the topic of the present paper. The back-influence can be obtained by employing classical second-order perturbation theory. The second-order theory is used in both a classical and semiclassical context. Classically, analytic expressions are derived for the final phase and action of the diatom, after the collision. The energy loss of the atom is shown to decrease linearly with the increasing energy of the oscillator. The magnitude of this decrease is a direct consequence of the back-reaction of the oscillator on the translational motion. The qualitative result is universal, in the sense that it is not dependent on the details of the interaction of the atom with the oscillator. A numerical application to a model collision of an Ar atom with a Br2 diatom demonstrates the importance and accuracy of the second-order perturbation theory. The same results are then used to derive a second-order perturbation theory semiclassical expression for the quantum transition probability from initial vibrational state ni to final vibrational state nf of the oscillator. A comparison of the theory with exact quantum data is presented for a model collision of Br2 with a hydrogen molecule, where the hydrogen molecule is considered as a single approaching particle. PMID:27309793

  5. Transference and counter-transference in systems psychodynamic group process consultation: The consultant’s experience

    Directory of Open Access Journals (Sweden)

    F. Cilliers

    2004-10-01

    Full Text Available This study explored consultants’ experiences of transference and counter-transference when conducting group relations training from the systems psychodynamic stance. A phenomenological research design was used with semistructured interviews conducted on a purposive sample of 13 organisational development consultants in a financial institution. The data was analysed by means of content analysis. The results showed that consultants have varied receptiveness in terms of receiving projections and managing transference. These differences involve triggers, characteristics and systemic valence. The consultants experienced counter- transference on five different cognitive and emotional levels. Distinguishing between personal and group emotions, receiving projections and managing transference, all contribute to the complexity of organisational consulting. Opsomming Hierdie studie het ondersoek ingestel na konsultante se ervarings van oordrag en teen-oordrag tydens groepverhoudingsopleiding vanuit die sistemiese psigodinamiese posisie. ’n Fenomenologiese navorsingsontwerp is gebruik met semi-gestruktureerde onderhoude gevoer met ’n doelgerigte steekproef van 13 organisasie ontwikkelingskonsultante in ’n finansiële instelling. Die data is ontleed deur middel van inhoudsontleding. Die resultate het aangetoon dat konsultante uiteenlopende ontvanklikheid het wat betref die ontvangs van projeksies en die hantering van oordrag. Hierdie verskille behels snellers, kenmerke en sistemiese valensie. Die konsultante het teen-oordrag ervaar op vyf verskillende kognitiewe and emosionele vlakke. Om onderskeid te tref tussen persoonlike en groep-emosies, die ontvang van projeksies en die hantering van oordrag, dra alles by tot die kompleksiteit van konsultering.

  6. Automatic graphene transfer system for improved material quality and efficiency

    OpenAIRE

    Alberto Boscá; Jorge Pedrós; Javier Martínez; Tomás Palacios; Fernando Calle

    2015-01-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The proce...

  7. 2D momentum distribution of electron in transfer ionization of helium atom by fast proton

    International Nuclear Information System (INIS)

    2D distribution of momentum components of the ejected electron in the reaction H+ +He → H+He2++e at 630 keV proton is studied both theoretically and experimentally. This allows to unambiguously identify contributions from the shake-off and binary encounter mechanisms of transfer ionization. It is shown that the results are highly sensitive to the quality of the initial-state wave function.

  8. Ejecta Transfer in the Pluto System

    OpenAIRE

    Porter, Simon; Grundy, William

    2014-01-01

    The small satellites of the Pluto system (Styx, Nix, Kerberos, and Hydra) have very low surface escape velocities, and impacts should therefore eject a large amount of material from their surfaces. We show that most of this material then escapes from the Pluto system, though a significant fraction collects on the surfaces of Pluto and Charon. The velocity at which the dust is ejected from the surfaces of the small satellites strongly determines which object it is likely to hit, and where on t...

  9. Quantum Collapse and Revival of Atom in Mode-Mode Competing System

    Institute of Scientific and Technical Information of China (English)

    WU Qin; FANG Mao-Fa

    2005-01-01

    The atomic inversion dynamics in the mode-mode competing system is studied by means of fully quantum theory. A general solution to the Schrodinger equation of this system is obtained. The influence of the relative competing strength between the atom and the two-mode field on the atomic inversion is disccussed. We show that the presence of the mode-mode competition can result in periodical collapses-revivals of the atomic inversion.

  10. Ionization and charge transfer in high-energy ion-atom collisions

    International Nuclear Information System (INIS)

    Electron capture and loss by fast highly charged ions in a gas target, and ionization of the target by passage of the fast projectile beam, are fundamental processes in atomic physics. These processes, along with excitation, can be experimentally studied separately (''singles'') or together (''coincidence''). This paper is a review of recent results on singles measurements for electron capture and loss and for target ionization, for velocities which are generally high relative to the active electron, including recent ionization measurements for a nearly relativistic projectile. 11 refs., 6 figs

  11. Qubit transfer between photons at telecom and visible wavelengths in a slow-light atomic medium

    International Nuclear Information System (INIS)

    We propose a method that enables efficient conversion of the quantum information frequency between different regions of a spectrum of light based on recently demonstrated strong parametric coupling between two narrow-band single-photon pulses propagating in a slow-light atomic medium [N. Sisakyan and Yu. Malakyan, Phys. Rev. A, 75, 063831 (2007)]. We show that an input qubit at telecom wavelength is transformed into another at a visible domain in a lossless and shape-conserving manner while keeping the initial quantum coherence and entanglement. These transformations can be realized with a quantum efficiency close to its maximum value.

  12. Atomic force microscopy study of the adsorption of protein molecules on transferred Langmuir monolayer

    International Nuclear Information System (INIS)

    Ordered protein films have been obtained by the adsorption of protein molecules on a Langmuir monolayer, which had previously formed on a silicon substrate, using the Langmuir-Blodgett and molecular self-organization methods. A mixture of cholesterol with dipalmitoylphosphatidylcholine (DPPC) and a polymer-cellulose acetopivalinate-were used as immobilization materials. Protein molecules (catalase and alkaline phosphatase) immobilized on solid substrates have been investigated by atomic force micros-copy. It was shown that the developed combined technique provides a deposition of homogeneous ultrathin protein films with a high degree of filling.

  13. The atomic hydrogen cloud in the saturnian system

    Science.gov (United States)

    Tseng, W.-L.; Johnson, R. E.; Ip, W.-H.

    2013-09-01

    The importance of Titan's H torus shaped by solar radiation pressure and of hydrogen atoms flowing out of Saturn's atmosphere in forming the broad hydrogen cloud in Saturn's magnetosphere is still debated. Since the Saturnian system also contains a water product torus which originates from the Enceladus plumes, the icy ring particles, and the inner icy satellites, as well as Titan's H2 torus, we have carried out a global investigation of the atomic hydrogen cloud taking into account all sources. We show that the velocity and angle distributions of the hot H ejected from Saturn's atmosphere following electron-impact dissociation of H2 are modified by collisions with the ambient atmospheric H2 and H. This in turn affects the morphology of the escaping hydrogen from Saturn, as does the morphology of the ionospheric electron distribution. Although an exact agreement with the Cassini observations is not obtained, our simulations show that H directly escaping from Titan is the dominant contributor in the outer magnetosphere. Of the total number of H observed by Cassini from 1 to 5RS, ∼5.7×1034, our simulations suggest ∼20% is from dissociation in the Enceladus torus, ∼5-10% is from dissociation of H2 in the atmosphere of the main rings, and ∼50% is from Titan's H torus, implying that ∼20% comes from Saturn atmosphere.

  14. Emulating solid-state physics with a hybrid system of ultracold ions and atoms

    OpenAIRE

    Bissbort U.; Cocks D.; Negretti A.; Idziaszek Z.; Calarco T.; Schmidt-Kaler F.; Hofstetter W.; Gerritsma R.

    2013-01-01

    We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of scalability and tunability of ultracold atomic systems with the high fidelity operations and detection offered by trapped ion systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to pho...

  15. The Role of Mass Transfer in Membrane Systems

    Directory of Open Access Journals (Sweden)

    Levent Gürel

    2015-12-01

    Full Text Available Membranes are situated in the foreground among the considerably popular treatment systems in the last years. The use of membranes was become widespread in many fields such as drinking water treatment, wastewater treatment and obtaining drinking water from sea water. The predominance of membranes against the classical systems regarding the wastewater treatment, and the decreasing cost of membrane materials each day provided these systems to enter among the preferable options. There are considerably different types of membranes. Microfiltration (MF, ultrafiltration (UF, nanofiltration (NF and reverse osmosis (RO are the processes drawing most attention. One of the most important considerations in membrane processes is the amount of constituents passing from the membrane and rejecting by the membrane. Mass transfer concept arises in this place. Mass transfer is a critically important case used in the design of treatment systems and the estimation of efficiency. In addition to the points mentioned above, investigation of mass transfer occurring in membranes is important in comparing of different membrane types. In this review article, general information about the membranes, membrane types, uses of membranes and module designs are given, concept of mass transfer is viewed and the mass transfer processes realizing in these treatment systems are assessed.

  16. Integration of micro-fabricated atomic magnetometers on military systems

    Science.gov (United States)

    Schultz, Gregory; Mhaskar, Rahul; Prouty, Mark; Miller, Jonathan

    2016-05-01

    A new generation of ultra-high sensitivity magnetic sensors based on innovative micro-electromechanical systems (MEMS) are being developed and incorporated into military systems. Specifically, we are currently working to fully integrate the latest generation of MicroFabricated Atomic Magnetometers (MFAMs) developed by Geometrics on defense mobility systems such as unmanned systems, military vehicles and handheld units. Recent reductions in size, weight, and power of these sensors has enabled new deployment opportunities for improved sensitivity to targets of interest, but has also introduced new challenges associated with noise mitigation, mission configuration planning, and data processing. Our work is focused on overcoming the practical aspects of integrating these sensors with various military platforms. Implications associated with utilizing these combined sensor systems in working environments are addressed in order to optimize signal-to-noise ratios, detection probabilities, and false alarm mitigation. Specifically, we present collaborative work that bridges the gap between commercial specialists and operation platform integration organizations including magnetic signature characterization and mitigation as well as the development of simulation tools that consider a wide array of sensor, environmental, platform, and mission-level parameters. We discuss unique deployment concepts for explosive hazard target geolocation, and data processing. Applications include configurations for undersea and underground threat detection - particularly those associated with stationary or mobile explosives and compact metallic targets such as munitions, subsea threats, and other hazardous objects. We show the potential of current and future features of miniaturized magnetic sensors including very high magnetic field sensitivities, bandwidth selectivity, and array processing.

  17. Interferometry with atoms

    International Nuclear Information System (INIS)

    Optics and interferometry with matter waves is the art of coherently manipulating the translational motion of particles like neutrons, atoms and molecules. Coherent atom optics is an extension of techniques that were developed for manipulating internal quantum states. Applying these ideas to translational motion required the development of techniques to localize atoms and transfer population coherently between distant localities. In this view position and momentum are (continuous) quantum mechanical degrees of freedom analogous to discrete internal quantum states. In our contribution we start with an introduction into matter wave optics in sect. 1, discuss coherent atom optics and atom interferometry techniques for molecular beams in sect. 2 and for trapped atoms in sect. 3. In sect. 4 we then describe tools and experiments that allow to probe the evolution of quantum states of many-body systems by atom interference.

  18. Photoinduced electron transfer in model systems of photosynthesis.

    NARCIS (Netherlands)

    Hofstra, U.

    1988-01-01

    This Thesis describes Investigations on photoinduced electron transfer (ET) for several compounds, serving as model systems of the natural photosynthesis. In addition, the properties of the systems, e.g. the conformation in solution and the electronic properties of the photoexcited states are treate

  19. Some reflections on a knowledge transfer strategy: a systemic inquiry

    OpenAIRE

    Ison, R. L.

    2002-01-01

    This paper presents a case study of a systemic inquiry into a knowledge transfer strategy (KTS) by a division of a UK Ministry. Two main points are made. Firstly that it is possible to 'build' a generalisable form of practice as a response to experiences of complexity by initiating a systemic inquiry that fosters the emergence of a learning system. Secondly, that exploring how metaphors reveal and conceal offers scope for shifting the 'mental furniture' of participants as part of a systemic i...

  20. Photoinduced energy transfer in ZnO–tetraphenylporphyrin systems

    OpenAIRE

    廣光, 一郎; 池上, 崇久; Karino, Kazuhiro; Ohno, Takatsugu; Tanaka, Senku; 白鳥, 英雄; 森戸, 茂一; 藤田, 恭久; 半田, 真

    2009-01-01

    The optical absorption and photoluminescence measurements were carried out for ZnO nanoparticle–tetraphenylporphyrin (TPP) systems made of four kinds of TPP’s with and without p-aminophenyl groups. The ZnO particles were treated with l-cysteine in order to make a ZnO–(l-cysteine)–TPP binding. However, this binding was not formed because of an absence of the ZnO–(l-cysteine) binding. In the case of metal-free TPP’s, the central hydrogen atoms of the TPP ring were replaced by a Zn atom during a...

  1. Fractional angular momentum in cold-atom systems.

    Science.gov (United States)

    Zhang, Yuhe; Sreejith, G J; Gemelke, N D; Jain, J K

    2014-10-17

    The quantum statistics of bosons or fermions are manifest through the even or odd relative angular momentum of a pair. We show theoretically that, under certain conditions, a pair of certain test particles immersed in a fractional quantum Hall state possesses, effectively, a fractional relative angular momentum, which can be interpreted in terms of fractional braid statistics. We propose that the fractionalization of the angular momentum can be detected directly through the measurement of the pair correlation function in rotating ultracold atomic systems in the fractional quantum Hall regime. Such a measurement will also provide direct evidence for the effective magnetic field resulting from Berry phases arising from attached vortices, and of excitations with a fractional particle number, analogous to the fractional charge of the electron fractional quantum Hall effect.

  2. Pfaffian states in coupled atom-cavity systems

    Science.gov (United States)

    Hayward, Andrew L. C.; Martin, Andrew M.

    2016-05-01

    Coupled atom-cavity arrays, such as those described by the Jaynes-Cummings-Hubbard model, have the potential to emulate a wide range of condensed-matter phenomena. In particular, the strongly correlated states of the fractional quantum Hall effect can be realized. At some filling fractions, the fraction quantum Hall effect has been shown to possess ground states with non-Abelian excitations. The most well studied of these states is the Pfaffian state of Moore and Read G. Moore and N. Read, Nucl. Phys. B 360, 362 (1991), 10.1016/0550-3213(91)90407-O, which is the ground state of a Hall liquid with a three-body interaction. We show how an effective three-body interaction can be generated within the cavity QED framework, and that a Pfaffian-like ground state of these systems exists.

  3. Negative refractive index in a four-level atomic system

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhen-Qing; Liu Zheng-Dong; Zhao Shun-Cai; Zheng Jun; Ji Yan-Fang; Liu Nian

    2011-01-01

    A closed four-level system in atomic vapour is proposed,which is made to possess left handedness by using the technique of quantum coherence.The density matrix method is utilized in view of the rotating-wave approximation and the effect of a local field in dense gas.The numerical simulation result shows that the negative permittivity and the negative permeability of the medium can be achieved simultaneously (i.e.the left handedness) in a wider frequency band under appropriate parameter conditions.Furthermore,when analysing the dispersion property of the left-handed material,we can find that the probe beam propagation can be controlled from superluminal to subluminal,or vice versa via changing the detuning of the probe field.

  4. String order via Floquet interactions in atomic systems

    Science.gov (United States)

    Lee, Tony E.; Joglekar, Yogesh N.; Richerme, Philip

    2016-08-01

    We study the transverse-field Ising model with interactions that are modulated in time. In a rotating frame, the system is described by a time-independent Hamiltonian with many-body interactions, similar to the cluster Hamiltonians of measurement-based quantum computing. In one dimension, there is a three-body interaction, which leads to string order instead of conventional magnetic order. We show that the string order is robust to power-law interactions that decay with the cube of distance. In two and three dimensions, there are five- and seven-body interactions. We discuss adiabatic preparation of the ground state as well as experimental implementation with trapped ions, Rydberg atoms, and polar molecules.

  5. Radiative transfer in atmosphere-sea ice-ocean system

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z.; Stamnes, K.; Weeks, W.F. [Univ. of Alaska, Fairbanks, AK (United States); Tsay, S.C. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    Radiative energy is critical in controlling the heat and mass balance of sea ice, which significantly affects the polar climate. In the polar oceans, light transmission through the atmosphere and sea ice is essential to the growth of plankton and algae and, consequently, to the microbial community both in the ice and in the ocean. Therefore, the study of radiative transfer in the polar atmosphere, sea ice, and ocean system is of particular importance. Lacking a properly coupled radiative transfer model for the atmosphere-sea ice-ocean system, a consistent study of the radiative transfer in the polar atmosphere, snow, sea ice, and ocean system has not been undertaken before. The radiative transfer processes in the atmosphere and in the ice and ocean have been treated separately. Because the radiation processes in the atmosphere, sea ice, and ocean depend on each other, this separate treatment is inconsistent. To study the radiative interaction between the atmosphere, clouds, snow, sea ice, and ocean, a radiative transfer model with consistent treatment of radiation in the coupled system is needed and is under development.

  6. Influence on Atomic Inversion Evolution in Medium System from Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Xiao-fei; HAO Dong-shan

    2008-01-01

    In Jaynes-Cummings model, by using the modulation of the coupling coefficient formed by the atom, medium and scattering optical, atomic inversion evolution of arbitrary forms has been worked out. Its feasibility has been proved, and the curvature of the atomic inversion evolution of the arbitrary forms is obtained. It announces that the atom and coupling medium system are to express the operators of the atom and optical field quantum in Jaynes-Cummings model. These operators can express arbitrary medium system. In these systems, the coupling coefficient can be changed and exactly controlled in the longer coherent times.

  7. A new look at the atomic level virial stress: on continuum-molecular system equivalence

    Science.gov (United States)

    Zhou, Min

    2003-09-01

    The virial stress is the most commonly used definition of stress in discrete particle systems. This quantity includes two parts. The first part depends on the mass and velocity (or, in some versions, the fluctuation part of the velocity) of atomic particles, reflecting an assertion that mass transfer causes mechanical stress to be applied on stationary spatial surfaces external to an atomic-particle system. The second part depends on interatomic forces and atomic positions, providing a continuum measure for the internal mechanical interactions between particles. Historic derivations of the virial stress include generalization from the virial theorem of Clausius (1870) for gas pressure and solution of the spatial equation of balance of momentum. The virial stress is stress-like a measure for momentum change in space. This paper shows that, contrary to the generally accepted view, the virial stress is not a measure for mechanical force between material points and cannot be regarded as a measure for mechanical stress in any sense. The lack of physical significance is both at the individual atom level in a time-resolved sense and at the system level in a statistical sense. It is demonstrated that the interatomic force term alone is a valid stress measure and can be identified with the Cauchy stress. The proof in this paper consists of two parts. First, for the simple conditions of rigid translation, uniform tension and tension with thermal oscillations, the virial stress yields clearly erroneous interpretations of stress. Second, the conceptual flaw in the generalization from the virial theorem for gas pressure to stress and the confusion over spatial and material equations of balance of momentum in theoretical derivations of the virial stress that led to its erroneous acceptance as the Cauchy stress are pointed out. Interpretation of the virial stress as a measure for mechanical force violates balance of momentum and is inconsistent with the basic definition of stress

  8. Optimized transfer trajectories in the earth-moon system

    Institute of Scientific and Technical Information of China (English)

    Xie Wen-Xian; Xu Wei; Cai Li

    2008-01-01

    Investigations of low energy transfer trajectories are important for both celestial mechanics and astronautics.Methodologies using the theories from dynamical systems are developed in recent years.This paper investigates the dynamics of the earth-moon system.Low energy transfer trajectories are solved numerically by employing a hybrid strategy:first,a genetic hide and seek method performs a search in large domain to confine the global minimum f(η)(objective function) region;then,a deterministic Nelder-Mead method is utilized to refine the minimum quickly.Some transfer trajectories of the spacecraft in the earth-moon system are successfully simulated which verify the desired efficiency and robustness of the method of this paper.

  9. Development of atom transfer radical polymer-modified gold nanoparticle-based enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Chen, Feng; Hou, Shike; Li, Qingsheng; Fan, Haojun; Fan, Rong; Xu, Zhongwei; Zhala, Gahu; Mai, Xia; Chen, Xiaoyi; Chen, Xuyi; Liu, Yingfu

    2014-10-21

    In this work, a novel enzyme-linked immunosorbent assay (ELISA) with a low limit of detection and high sensitivity was developed using atom transfer radical polymer (ATRP)-modified gold nanoparticles (AuNPs). Clear signal amplification was achieved by introducing an abundance of horseradish peroxidase (HRP) to the AuNPs, because of the ATRP modification. This result suggested that the new ELISA was able to detect antigens in complex mixtures, and the limit of detection (LOD) was lower than that of conventional ELISA by a factor of 81. The new ELISA strategy greatly decreased the LOD during analysis and exhibited excellent reproducibility, stability, and feasibility. Therefore, it is a promising technique with many potential applications in biochemistry and medical science research.

  10. Synthesis of tri-block copolymers through reverse atom transfer radical polymerization of methyl methacrylate using polyurethane macroiniferter

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Reverse atom transfer radical polymerization was successfully used for the first time to synthesis tri-block copolymers. Poly (methyl methacrylate-block-polyurethane-block-poly (methyl methacrylate tri-block copolymers were synthesized using tetraphenylethane-based polyurethane as a macroiniferter, copper(II halide as a catalyst and N, N, N′, N″, N″-pentamethyldiethylenetriamine as a ligand. Controlled nature of the polymerization was confirmed by the linear increase of number average molecular weight with increasing conversion. Mole contents of poly (methyl methacrylate present in the tri-block copolymers were calculated using proton nuclear magnetic resonance spectroscopy and the results were comparable with the gel permeation chromatography results. Differential scanning calorimetric results confirmed the presence of two different types of blocks in the tri-block copolymers.

  11. Surface-Initiated Atom Transfer Radical Polymerization and Electrografting Technique as a Means For Attaining Tailor-Made Polymer Coatings

    DEFF Research Database (Denmark)

    Chernyy, Sergey

    2012-01-01

    Atom transfer radical polymerization initiated from a surface of various substrates (SI-ATRP) has become a progressively popular technique for obtaining thin polymer films with predetermined properties. The present work addresses the main features of SI-ATRP with respect to the controllability......, rates of polymerization, suitable monomers, reaction mixture compositions etc. An alternative potential-driven polymerization approach is discussed, although to a smaller extent. Chapter 1 provides an overview of controlled/living polymerization techniques with an accent made on ATRP. Different...... strategies for initiator grafting, physicochemical properties of polymer brushes and basic principles of quartz crystal microbalance technique (QCM) are discussed. In Chapter 2 various ATRP conditions are probed. The effects of solvent polarity, monomer concentration, initiator surface density, ligand nature...

  12. Effect of Surface Charge on Surface-Initiated Atom Transfer Radical Polymerization from Cellulose Nanocrystals in Aqueous Media.

    Science.gov (United States)

    Zoppe, Justin O; Xu, Xingyu; Känel, Cindy; Orsolini, Paola; Siqueira, Gilberto; Tingaut, Philippe; Zimmermann, Tanja; Klok, Harm-Anton

    2016-04-11

    Cellulose nanocrystals (CNCs) with different charge densities were utilized to examine the role of electrostatic interactions on surface-initiated atom transfer radical polymerization (SI-ATRP) in aqueous media. To this end, growth of hydrophilic uncharged poly(N,N-dimethylacrylamide) (PDMAM) brushes was monitored by electrophoresis, (1)H NMR spectroscopy, and dynamic light scattering (DLS). Molecular weight and polydispersity of PDMAM brushes was determined by GPC analysis of hydrolytically cleaved polymers. Initiator and polymer brush grafting densities, and thus, initiator efficiencies were derived from elemental analysis. Higher initiator efficiency of polymer brush growth was observed for CNCs with higher anionic surface sulfate half-ester group density, but at the expense of high polydispersity caused by inefficient deactivation. PDMAM grafts with number-average molecular weights up to 530 kDa and polydispersity indices Cu-mediated SI-CRP are analogous to those conducted in solution. PMID:26901869

  13. Atomic layer deposition to prevent metal transfer from implants: An X-ray fluorescence study

    Science.gov (United States)

    Bilo, Fabjola; Borgese, Laura; Prost, Josef; Rauwolf, Mirjam; Turyanskaya, Anna; Wobrauschek, Peter; Kregsamer, Peter; Streli, Christina; Pazzaglia, Ugo; Depero, Laura E.

    2015-12-01

    We show that Atomic Layer Deposition is a suitable coating technique to prevent metal diffusion from medical implants. The metal distribution in animal bone tissue with inserted bare and coated Co-Cr alloys was evaluated by means of micro X-ray fluorescence mapping. In the uncoated implant, the migration of Co and Cr particles from the bare alloy in the biological tissues is observed just after one month and the number of particles significantly increases after two months. In contrast, no metal diffusion was detected in the implant coated with TiO2. Instead, a gradient distribution of the metals was found, from the alloy surface going into the tissue. No significant change was detected after two months of aging. As expected, the thicker is the TiO2 layer, the lower is the metal migration.

  14. Hydrophilization of Poly(ether ether ketone) Films by Surface-initiated Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Fristrup, Charlotte Juel; Eskimergen, Rüya; Burkrinsky, J.T.;

    2008-01-01

    - this is the mechanism leading to good adhesion. From the different types of bonding, the covalent bond at the polymer - metal interface is the strongest. In this work the surface ofPEEK is functionalized by covalently bounding of hydrophilic polymer brushes ofpoly(ethyleneglycol) methacrylate (PEGMA) from initiator...... and confirmed by ATR FTIR, water contact ang;le, and Thermal Gravimetric Analysis (TGA). The surface topography was evaluated by "Atomic Force Microscopy (AFM). X-ray Photoelectron Spectroscopy (XPS) has been used to investigate the degree of functionalization. The performed modification allowed for successful......Poly(ether ether ketone) (PEEK) replaces aluminum and other metals in aerospace, electronics, medical, and automotive applications. Therefore, the demand for metallization of PEEK is continuously increasing. Metals seldom bond to a polymer without undergoing some chemical interaction...

  15. Charge transfer on porous silicon membranes studied by current-sensing atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    Bing Xia; Qiang Miao; Jie Chao; Shou Jun Xiao; Hai Tao Wang; Zhong Dang Xiao

    2008-01-01

    A visible rectification effect on the current-voltage curves of metal/porous silicon/p-silicon has been observed by currentsensing atomic force microscopy.The current-voltage curves of porous silicon membranes with different porosities,prepared through variation of etching current density for a constant time,indicate that a higher porosity results in a higher resistance and thus a lower rectification,until the current reaches a threshold at a porosity>55%.We propose that the conductance mode in the porous silicon membrane with porosities>55% is mainly a hopping mechanism between nano-crystallites and an inverse static electric field between the porous silicon and p-Si interface blocks the electron injection from porous silicon to p-Si,but with porosities <55%,electron flows through a direct continuous channel between nano-crystallites.

  16. SYNTHESIS OF POLY(METHYL METHACRYLATE)-graft-POLYSTYRENE BY ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Sheng-min Gong; Qun-sheng Li; Yan Shi; Zhi-feng Fu; Shu-ke Jiao; Wan-tai Yang

    2003-01-01

    The radical copolymerization of methyl methacrylate and 2-hydroxyethyl methacrylate was carried out via atom complex. This polymerization proceeds in a living fashion with controlled molecular weight and low polydispersity. The obtained copolymer was esterified with 2-bromoisobutylryl bromide yielding a macroinitiator, poly(methyl methacrylate-co-2-hydroxyethyl methacrylate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate), and its structure was characterized by 1HNMR. This macroinitiator was used for ATRP of styrene to synthesize poly(methyl methacrylate)-grafi-polystyrene. The molecular weight of graft copolymer increased with the monomer conversion, and the polydispersity remained relatively low.The individual grafted polystyrene chains were cleaved from the macroinitiator backbone by hydrolysis and the hydrolyzed product was characterized by 1H-NMR and GPC.

  17. Charge transfer and ionization in proton-alkali atoms collisions with and without electric field

    International Nuclear Information System (INIS)

    The classical trajectory Monte Carlo simulation has been used to investigate the collisions of protons with alkali metal atoms in their ground state. Model interaction potential has been used to describe the electron-ionic core interaction. The cross sections for the capture and ionization in the energy range 1-100 keV/amu have been calculated and compared with the available experimental and theoretical results. The effects of the presence of a strong static electric field in different geometrical features on the capture and ionization cross sections have also been investigated. It has been found that the electric field causes the cross section for the capture to decrease while for the ionization enhance dramatically. Many of the null field features are retained. The analyses of the final state n, l-distribution in the electron capture process reveals H(2p) to be the most populated level in both the cases, with and without electric field. (author)

  18. Security on Fingerprint Data Transfer System

    Directory of Open Access Journals (Sweden)

    Hinal Modi

    2014-05-01

    Full Text Available Nowadays, the data can undergo grave modifications (access to the credit cards, the transactions in e-commerce, espionage of the secret information in military doma in, theft bio metrics information especially through transmissions on the insecure network or internet. Where, it is necessary to look a robust method to secure the data. In this work we a re focusing on matching data pattern along with all security assurance, so that we can provide discrete wavelet transform watermarking and en-decryption using confusion and diffusion method. The encryption method is based on XORing the message bytes and, it is the key used for encryption and decryption that makes the process of cryptography secure because key was automatically taken by system.Its performance with bio met ric information (finger print using MATLA B 7.10(R20109.

  19. Security on Fingerprint Data Transfer System

    Directory of Open Access Journals (Sweden)

    Hinal Modi

    2015-11-01

    Full Text Available Nowadays, the data can undergo grave modifications (access to the credit cards, the transactions in e-commerce, espionage of the secret information in military domain, theft biometrics information especially through transmissions on the insecure network or internet. Where, it is necess ary to look a robust method to secure the data. In this work we are focusing on matching data pattern along with all security assurance, so that we can provide discrete wavelet transform watermarking and en-decryption using confusion and diffusion method. The encryption method is based on XORing the message bytes and, it is the key used for encryption and decryption that makes the process of cryptography secure because key was automatically taken by system. Its performance with biomet ric information (fingerprint using MATLAB 7.10(R20109.

  20. Effect of pairwise dipole–dipole interaction among three-atom systems

    Indian Academy of Sciences (India)

    P Anantha Lakshmi; Ashoka Vudayagiri; Shaik Ahmed

    2014-08-01

    We present an analysis of a system of three two-level atoms interacting with one another through dipole–dipole interaction. The interaction manifests between the excited state of one of the atoms and the ground state of its nearest neighbour. Steady-state populations of the density matrix elements are presented and are compared with a situation when only two atoms are present. It can be noticed that the third atom modifies the behaviour of the three atoms. Two configurations are analysed, one in which the three atoms are in a line, with no interaction between atoms at the end points and the other in which the atoms form a closed loop with one atom interacting with both its neighbours.

  1. Evidence for alkali metal induced intermolecular acetylenic hydrogen atom transfer between hydrogen-bonded alkyne complexes in solid argon

    International Nuclear Information System (INIS)

    Condensation of acetylene, propyne, and 2-butyne/acetylene mixtures with heavy alkali metal atoms (Na, K, Cs) in an argon matrix at 15 K has led to the appearance of infrared absorptions due to ethylene, propylene, and trans-2-butene, respectively. These results stand in sharp contrast with the products obtained with lithium. Isotopic studies have shown that ethylene formation involved three different acetylene molecules and evidenced a difference in the product yield with hydrogen vs. deuterium as well as a preference for trans- vs. cis-C2H2D2 formation, which is discussed and rationalized by differences in the zero point energies for the different mixed deuterium isotopes of the intermediate vinyl radical. This trend is amplified by methyl substitution. Spectroscopic evidence was found in these experiments for cesium acetylide (Cs+C2H-) and a cesium-acetylene π complex, which are involved in the intermolecular acetylenic hydrogen atom transfer process. 26 references, 3 figures, 2 tables

  2. Hydrogel brushes grafted from stainless steel via surface-initiated atom transfer radical polymerization for marine antifouling

    Science.gov (United States)

    Wang, Jingjing; Wei, Jun

    2016-09-01

    Crosslinked hydrogel brushes were grafted from stainless steel (SS) surfaces for marine antifouling. The brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) respectively with different fractions of crosslinker in the feed. The grafted layers prepared with different thickness were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ellipsometry and water contact angle measurements. With the increase in the fraction of crosslinker in the feed, the thickness of the grafted layer increased and the surface became smooth. All the brush-coated SS surfaces could effectively reduce the adhesion of bacteria and microalgae and settlement of barnacle cyprids, as compared to the pristine SS surface. The antifouling efficacy of the PEGMA polymer (PPEGMA)-grafted surface was higher than that of the MPC polymer (PMPC)-grafted surfaces. Furthermore, the crosslinked hydrogel brush-grafted surfaces exhibited better fouling resistance than the non-crosslinked polymer brush-grafted surfaces, and the antifouling efficacy increased with the crosslinking density. These hydrogel coatings of low toxicity and excellent anti-adhesive characteristics suggested their useful applications as environmentally friendly antifouling coatings.

  3. Control Decisions for Flammable Gas Hazards in Waste Transfer Systems

    International Nuclear Information System (INIS)

    This report describes the control decisions for flammable gas hazards in waste transfer systems (i.e., waste transfer piping and waste transfer-associated structures) made at control decision meetings on November 30, 1999a and April 19, 2000, and their basis. These control decisions, and the analyses that support them, will be documented in an amendment to the Final Safety Analysis Report (FSAR) (CHG 2000a) and Technical Safety Requirements (TSR) (CHG 2000b) to close the Flammable Gas Unreviewed Safety Question (USQ) (Bacon 1996 and Wagoner 1996). Following the Contractor Tier I review of the FSAR and TSR amendment, it will be submitted to the US. Department of Energy (DOE), Office of River Protection (ORP) for review and approval. The control decision meeting on November 30, 1999 to address flammable gas hazards in waste transfer systems followed the control decision process and the criteria for control decisions described in Section 3.3.1.5 of the FSAR. The control decision meeting agenda, attendance list, and introductory and background presentations are included in Attachments 1 through 4. The control decision discussions on existing and other possible controls for flammable gas hazards in waste transfer systems and the basis for selecting or not selecting specific controls are summarized in this report

  4. Specific Heat Properties of Proton Transfer in Hydrogen Bonded Systems

    Institute of Scientific and Technical Information of China (English)

    庞小峰; 封原平

    2003-01-01

    The thermodynamic properties of proton transport along hydrogen-bonded systems at finite temperatures have been studied by our model. We first derive the dynamic equations of the proton transport and find the solutions and the free energy of the systems. Finally, we obtain the specific heats of the hydrogen bonded systems, resulting from the motion of the soliton, by using transfer integral way. The theoretical value is basically consistent with the experimental data.

  5. Particle-bed heat transfer studies at the Atomic Energy Establishment Winfrith (UKAEA)

    International Nuclear Information System (INIS)

    Experimental studies of boiling heat transfer and dryout in electrically heated beds of liquid-saturated particulate have been in progress at AEE Winfrith for the past four years. Results of experimental work published to date relate to water-saturated beds at a pressure of 1 bar. In recent years PWR interests have widened studies of cooling self-heated particle beds because there are both in-vessel and ex-vessel situations where particulate debris may occur during accidents which cause severe core damage. Dryout during boiling heat transfer is a relevant phenomenon in assessments of whether the debris can be adequately cooled and the damage sequence stopped, although much work is yet required to characterise the particulate core debris which may form during these low-probability accidents. This paper outlines work which has been done, or is in progress at AEE Winfrith. Topics include studies of dryout, pressure drop and vapour fraction for beds of spherical particles. Most of the data relate to water-cooled beds, but some data relate to beds cooled with a low latent-heat organic fluid. Direct electrical resistance heating has been used for most of the work, and this has been shown to be suitable for beds of uniform spheres. Work at AEE Winfrith also includes the development of dielectric heating as a means of heating beds of particles. This appears to be an excellent way of heating beds of irregular particles in a way which closely simulates decay-heating, and our progress in this area is described

  6. Interaction transfer of silicon atoms forming Co silicide for Co/√(3)×√(3)R30°-Ag/Si(111) and related magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng-Hsun-Tony; Fu, Tsu-Yi; Tsay, Jyh-Shen, E-mail: jstsay@phy.ntnu.edu.tw [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China)

    2015-05-07

    Combined scanning tunneling microscopy, Auger electron spectroscopy, and surface magneto-optic Kerr effect studies were employed to study the microscopic structures and magnetic properties for ultrathin Co/√(3)×√(3)R30°-Ag/Si(111). As the annealing temperature increases, the upward diffusion of Si atoms and formation of Co silicides occurs at temperature above 400 K. Below 600 K, the √(3)×√(3)R30°-Ag/Si(111) surface structure persists. We propose an interaction transferring mechanism of Si atoms across the √(3)×√(3)R30°-Ag layer. The upward transferred Si atoms react with Co atoms to form Co silicide. The step height across the edge of the island, a separation of 0.75 nm from the analysis of the 2 × 2 structure, and the calculations of the normalized Auger signal serve as strong evidences for the formation of CoSi{sub 2} at the interface. The interaction transferring mechanism for Si atoms enhances the possibility of interactions between Co and Si atoms. The smoothness of the surface is advantage for that the easy axis of magnetization for Co/√(3)×√(3)R30°-Ag/Si(111) is in the surface plane. This provides a possible way of growing flat magnetic layers on silicon substrate with controllable silicide formation and shows potential applications in spintronics devices.

  7. Transfer Efficiency Analysis of Wireless Power Transfer System under Frequency Drift

    DEFF Research Database (Denmark)

    Huang, Shoudao; Li, Zhongqi; Lu, Kaiyuan

    2015-01-01

    Magnetic resonant wireless power transfer (WPT) is an emerging technology that may create new applications for wireless power charging. However, low efficiency resulting from resonant frequency drift is a main obstructing factor for promoting this technology. In this paper, the system efficiency...... and input impedance are obtained by solving the system equivalent equations and based on that a method of adjusting the operating frequency and load resistor is proposed. When resonant frequency drift occurs, the WPT system can now operate at quasi-resonant state and the efficiency can be improved by...

  8. Transfer

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    Bogen er den første samlede indføring i transfer på dansk. Transfer kan anvendes som praksis-filosofikum. Den giver en systematisk indsigt til den studerende, der spørger: Hvordan kan teoretisk viden bruges til at reflektere over handlinger i situationer, der passer til min fremtidige arbejdsplads?...

  9. Production and transfer of energy and information in Hamiltonian systems.

    Directory of Open Access Journals (Sweden)

    Chris G Antonopoulos

    Full Text Available We present novel results that relate energy and information transfer with sensitivity to initial conditions in chaotic multi-dimensional Hamiltonian systems. We show the relation among Kolmogorov-Sinai entropy, Lyapunov exponents, and upper bounds for the Mutual Information Rate calculated in the Hamiltonian phase space and on bi-dimensional subspaces. Our main result is that the net amount of transfer from kinetic to potential energy per unit of time is a power-law of the upper bound for the Mutual Information Rate between kinetic and potential energies, and also a power-law of the Kolmogorov-Sinai entropy. Therefore, transfer of energy is related with both transfer and production of information. However, the power-law nature of this relation means that a small increment of energy transferred leads to a relatively much larger increase of the information exchanged. Then, we propose an "experimental" implementation of a 1-dimensional communication channel based on a Hamiltonian system, and calculate the actual rate with which information is exchanged between the first and last particle of the channel. Finally, a relation between our results and important quantities of thermodynamics is presented.

  10. Automatic graphene transfer system for improved material quality and efficiency

    Science.gov (United States)

    Boscá, Alberto; Pedrós, Jorge; Martínez, Javier; Palacios, Tomás; Calle, Fernando

    2016-02-01

    In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination, and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications.

  11. Physics of polarized scattering at multi-level atomic systems

    CERN Document Server

    Stenflo, Jan

    2015-01-01

    The symmetric peak observed in linear polarization in the core of the solar sodium D$_1$ line at 5896 \\AA\\ has remained enigmatic since its discovery nearly two decades ago. One reason is that the theory of polarized scattering has not been experimentally tested for multi-level atomic systems in the relevant parameter domains, although the theory is continually being used for the interpretation of astrophysical observations. A laboratory experiment that was set up a decade ago to find out whether the D$_1$ enigma is a problem of solar physics or quantum physics revealed that the D$_1$ system has a rich polarization structure in situations where standard scattering theory predicts zero polarization, even when optical pumping of the $m$ state populations of the hyperfine-split ground state is accounted for. Here we show that the laboratory results can be modeled in great quantitative detail if the theory is extended to include the coherences in both the initial and final states of the scattering process. Radiat...

  12. Relativistic calculations of the K-K charge transfer and K-vacancy production probabilities in low-energy ion-atom collisions

    CERN Document Server

    Tupitsyn, I I; Shabaev, V M; Bondarev, A I; Deyneka, G B; Maltsev, I A; Hagmann, S; Plunien, G; Stoehlker, Th

    2011-01-01

    The previously developed technique for evaluation of charge-transfer and electron-excitation processes in low-energy heavy-ion collisions [I.I. Tupitsyn et al., Phys. Rev. A 82, 042701(2010)] is extended to collisions of ions with neutral atoms. The method employs the active electron approximation, in which only the active electron participates in the charge transfer and excitation processes while the passive electrons provide the screening DFT potential. The time-dependent Dirac wave function of the active electron is represented as a linear combination of atomic-like Dirac-Fock-Sturm orbitals, localized at the ions (atoms). The screening DFT potential is calculated using the overlapping densities of each ions (atoms), derived from the atomic orbitals of the passive electrons. The atomic orbitals are generated by solving numerically the one-center Dirac-Fock and Dirac-Fock-Sturm equations by means of a finite-difference approach with the potential taken as the sum of the exact reference ion (atom) Dirac-Fock...

  13. Transferability of Japanese Management Systems Overseas: A theoretical jungle

    NARCIS (Netherlands)

    Yokozawa, Kodo; Bruijn, de Erik J.; Boer, de Sirp; Steenhuis, Harm-Jan; Trimble, Robert

    2007-01-01

    Since the 1980s, transferability of Japanese management systems (JMSs) abroad has become an increasing focus of research. However, the conclusions emerging from studies in this field have been conflicting. The main reasons for discordance have been the use of vague definitions of terms and varying m

  14. Transfer effects in learning a second language grammatical gender system

    NARCIS (Netherlands)

    Sabourin, L; Stowe, LA; de Haan, GJ

    2006-01-01

    In this article second language (L2) knowledge of Dutch grammatical gender is investigated. Adult speakers of German, English and a Romance language (French, Italian or Spanish) were investigated to explore the role of transfer in learning the Dutch grammatical gender system. In the first language (

  15. Modeling and design of reacting systems with phase transfer catalysis

    DEFF Research Database (Denmark)

    Piccolo, Chiara; Hodges, George; Piccione, Patrick M.;

    2011-01-01

    Issues related to the design of biphasic (liquid) catalytic reaction operations are discussed. A chemical system involving the reaction of an organic-phase soluble reactant (A) with an aqueous-phase soluble reactant (B) in the presence of phase transfer catalyst (PTC) is modeled and based on it, ...

  16. An Introduction to Register Transfer Level Simulation of Digital Systems.

    Science.gov (United States)

    Hemming, Cliff; Smith R. J., II

    Register transfer level (RTL) descriptions of digital systems have certain advantages over other descriptive techniques, especially during early phases of the design effort. There are at least three identifiable major uses for RTL-type descriptions. First, RTL can serve as documentation of digital processor behavior, recording in a concise fashion…

  17. Putting Dreyfus into Action: The European Credit Transfer System

    Science.gov (United States)

    Markowitsch, Jorg; Luomi-Messerer, Karin; Becker, Matthias; Spottl, Georg

    2008-01-01

    Purpose: The purpose of this article is to look closely at the development of a European Credit Transfer System for Vocational Education and Training (ECVET). The European Commission, together with the member States, are working on it and several pilot projects have been initiated within the Leonardo da Vinci Programme of the European Commission.…

  18. West Valley transfer cart control system design description

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, E.C.; Crutcher, R.I.; Halliwell, J.W.; Hileman, M.S.; Moore, M.R.; Nodine, R.N.; Ruppel, F.R.; Vandermolen, R.I.

    1993-01-01

    Detail design of the control system for the West Valley Nuclear Services Vitrification Facility transfer cart has been completed by Oak Ridge National Laboratory. This report documents the requirements and describes the detail design of that equipment and control software. Copies of significant design documents including analysis and testing reports and design drawings are included in the Appendixes.

  19. The Thompson-Lyons transfer lemma for fusion systems

    OpenAIRE

    Lynd, Justin

    2013-01-01

    In this note, a generalization of the Thompson transfer lemma and its various extensions, most recently due to Lyons, is proven in the context of saturated fusion systems. A strengthening of Alperin's fusion theorem is also given in this setting, following Alperin's own "up and down" fusion.

  20. ATOMIC SCREENING AND INTERSITE COULOMB REPULSION IN STRONGLY CORRELATED SYSTEMS

    NARCIS (Netherlands)

    Meinders, M.B J; van den Brink, J.; Lorenzana, J.; Sawatzky, G.A

    1995-01-01

    We consider the influence of a nearest-neighbor Coulomb interaction in an extended Hubbard model and introduce an interaction term which simulates atomic polarizabilities. The inclusion of atomic polarizabilities in the model has the effect of screening the on-site Coulomb interaction for charged ex

  1. Middle range wireless power transfer systems with multiple resonators

    Institute of Scientific and Technical Information of China (English)

    陈新; 张桂香

    2015-01-01

    The equivalent two-port network model of a middle range wireless power transfer (WPT) system was presented based on strongly coupled multiple resonators. The key parameters of the WPT system include self-inductance, resistance, parasitic capacitance, mutual inductance and S-parameters of coils & resonators were analyzed. The impedance matching method was used to optimize load power and transmission efficiency of the multi-resonator WPT system, and the impedance matching method was realized through adjusting the distances between the coils and resonators. Experiments show that the impedance matching method can effectively improve load power and transmission efficiency for middle range wireless power transfer systems with multiple resonators, at distances up to 3 times the coil radius with efficiency more than 70% and load power also close to 3.5 W.

  2. Plasmon-Exciton Resonant Energy Transfer: Across Scales Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Mohamed El Kabbash

    2016-01-01

    Full Text Available The presence of an excitonic element in close proximity of a plasmonic nanostructure, under certain conditions, may lead to a nonradiative resonant energy transfer known as Exciton Plasmon Resonant Energy Transfer (EPRET process. The exciton-plasmon coupling and dynamics have been intensely studied in the last decade; still many relevant aspects need more in-depth studies. Understanding such phenomenon is not only important from fundamental viewpoint, but also essential to unlock many promising applications. In this review we investigate the plasmon-exciton resonant energy transfer in different hybrid systems at the nano- and mesoscales, in order to gain further understanding of such processes across scales and pave the way towards active plasmonic devices.

  3. Information Entropy Squeezing for a Atom in Mode-Mode Competition System

    Institute of Scientific and Technical Information of China (English)

    WU Qin; FANG Mao-Fa; LI Shao-Xin; LI Ying; HU Yao-Hua

    2008-01-01

    The entropy squeezing properties for a two-level atom interacting with a two-mode field via two different competing transitions are investigated from a quantum information point of view. The influences of the initial state of the system and the relative coupling strength between the atom and the field on the atomic information entropy squeezing are discussed. Our results show that the squeezed direction and the frequency of the information entropy squeezing can be controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field, respectively. We find that, under the same condition, no atomic variance squeezing is predicted from the HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information entropy is a remarkable precision measure for the atomic squeezing in the considered system.

  4. Comprehensive online Atomic Database Management System (DBMS) with Highly Qualified Computing Capabilities

    CERN Document Server

    Tahat, Amani

    2011-01-01

    The intensive need of atomic data is expanding continuously in a wide variety of applications (e.g. fusion energy and astrophysics, laser-produced, plasma researches, and plasma processing).This paper will introduce our ongoing research work to build a comprehensive, complete, up-to-date, user friendly and online atomic Database Management System (DBMS) namely called AIMS by using SQLite (http://www.sqlite.org/about.html)(8). Programming language tools and techniques will not be covered here. The system allows the generation of various atomic data based on professional online atomic calculators. The ongoing work is a step forward to bring detailed atomic model accessible to a wide community of laboratory and astrophysical plasma diagnostics. AIMS is a professional worldwide tool for supporting several educational purposes and can be considered as a complementary database of IAEA atomic databases. Moreover, it will be an exceptional strategy of incorporating the output data of several atomic codes to external ...

  5. On coarse projective integration for atomic deposition in amorphous systems

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Claire Y., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov; Sinno, Talid, E-mail: talid@seas.upenn.edu [Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 220 South 33rd Street, 311A Towne Building, Philadelphia, Pennsylvania 19104 (United States); Han, Sang M., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov [Department of Chemical and Biological Engineering, University of New Mexico, 1 University of New Mexico, MSC01 1120, Albuquerque, New Mexico 87131 (United States); Zepeda-Ruiz, Luis A., E-mail: yungc@seas.upenn.edu, E-mail: meister@unm.edu, E-mail: zepedaruiz1@llnl.gov [Lawrence Livermore National Laboratory, P.O. Box 808, L-367, Livermore, California 94550 (United States)

    2015-10-07

    Direct molecular dynamics simulation of atomic deposition under realistic conditions is notoriously challenging because of the wide range of time scales that must be captured. Numerous simulation approaches have been proposed to address the problem, often requiring a compromise between model fidelity, algorithmic complexity, and computational efficiency. Coarse projective integration, an example application of the “equation-free” framework, offers an attractive balance between these constraints. Here, periodically applied, short atomistic simulations are employed to compute time derivatives of slowly evolving coarse variables that are then used to numerically integrate differential equations over relatively large time intervals. A key obstacle to the application of this technique in realistic settings is the “lifting” operation in which a valid atomistic configuration is recreated from knowledge of the coarse variables. Using Ge deposition on amorphous SiO{sub 2} substrates as an example application, we present a scheme for lifting realistic atomistic configurations comprised of collections of Ge islands on amorphous SiO{sub 2} using only a few measures of the island size distribution. The approach is shown to provide accurate initial configurations to restart molecular dynamics simulations at arbitrary points in time, enabling the application of coarse projective integration for this morphologically complex system.

  6. Quantum dot-dye hybrid systems for energy transfer applications

    OpenAIRE

    Ren, Ting

    2010-01-01

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems.rn rnIn the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stöber silica particles with an outer silica shell of thickness 2 - 24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the ...

  7. Entropy evolution properties in a system of two entangled atoms interacting with light field

    Institute of Scientific and Technical Information of China (English)

    Liu Tang-Kun; Wang Ji-Suo; Feng Jian; Zhan Ming-Sheng

    2005-01-01

    In the paper, we use the field entropy as a measurement of the degree of entanglement between the light field and the atoms of the system which is composed of two dipole-dipole interacting two-level atoms initially in an entangled state interacting with the single mode coherent field in a Kerr medium. The influence of the coupling constant of dipole-dipole interaction between atoms and the coupling strength of the kerr medium with the light field and the intensity of the atoms with the light field becomes weaker. The degree of entanglement only changes slightly with the change of the coupling constant of dipole-dipole interaction between atoms.

  8. Quantum dot-dye hybrid systems for energy transfer applications

    International Nuclear Information System (INIS)

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems. In the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stoeber silica particles with an outer silica shell of thickness 2-24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the total sensitized acceptor emission, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of QDs with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with Monte-Carlo simulations, and by control experiments confirming attractive interactions between QDs and Texas Red freely dissolved in solution. New QD-dye hybrid system consisting of multishell QDs and organic perylene dyes have been synthesized. We developed a versatile approach to assemble extraordinarily stable QD-dye hybrids, which uses dicarboxylate anchors to bind rylene dyes to QD. This system yields a good basis to study the energy transfer between QD and dye because of its simple and compact design: there is no third kind of molecule linking QD and dye; no spacer; and the affinity of the functional group to the QD surface is strong. The FRET signal was measured for these complexes as a function of both dye to QD ratio and center-to-center distance between QD and dye by controlling number of covered ZnS layers. Data showed that fluorescence resonance energy transfer (FRET) was the dominant mechanism of the energy transfer in our QD-dye hybrid system. FRET efficiency can be controlled by not only adjusting the number of dyes on the QD surface or the QD to dye distance, but also properly choosing different dye and QD components. Due to the strong stability, our QD

  9. Quantum dot-dye hybrid systems for energy transfer applications

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Ting

    2010-07-01

    In this thesis, we focus on the preparation of energy transfer-based quantum dot (QD)-dye hybrid systems. Two kinds of QD-dye hybrid systems have been successfully synthesized: QD-silica-dye and QD-dye hybrid systems. In the QD-silica-dye hybrid system, multishell CdSe/CdS/ZnS QDs were adsorbed onto monodisperse Stoeber silica particles with an outer silica shell of thickness 2-24 nm containing organic dye molecules (Texas Red). The thickness of this dye layer has a strong effect on the total sensitized acceptor emission, which is explained by the increase in the number of dye molecules homogeneously distributed within the silica shell, in combination with an enhanced surface adsorption of QDs with increasing dye amount. Our conclusions were underlined by comparison of the experimental results with Monte-Carlo simulations, and by control experiments confirming attractive interactions between QDs and Texas Red freely dissolved in solution. New QD-dye hybrid system consisting of multishell QDs and organic perylene dyes have been synthesized. We developed a versatile approach to assemble extraordinarily stable QD-dye hybrids, which uses dicarboxylate anchors to bind rylene dyes to QD. This system yields a good basis to study the energy transfer between QD and dye because of its simple and compact design: there is no third kind of molecule linking QD and dye; no spacer; and the affinity of the functional group to the QD surface is strong. The FRET signal was measured for these complexes as a function of both dye to QD ratio and center-to-center distance between QD and dye by controlling number of covered ZnS layers. Data showed that fluorescence resonance energy transfer (FRET) was the dominant mechanism of the energy transfer in our QD-dye hybrid system. FRET efficiency can be controlled by not only adjusting the number of dyes on the QD surface or the QD to dye distance, but also properly choosing different dye and QD components. Due to the strong stability, our QD

  10. Convective heat and mass transfer in rotating disk systems

    Energy Technology Data Exchange (ETDEWEB)

    Shevchuk, Igor V. [MBtech Powertrain GmbH, Fellbach-Schmiden (Germany)

    2009-07-01

    The book describes results of investigations of a series of convective heat-and-mass transfer problems in rotating-disk systems, namely, over free rotating disks, under conditions of transient heat transfer, solid-body rotation of fluid, orthogonal flow impingement onto a disk, swirl radial flow between parallel co-rotating disks, in cone-disk systems and for Prandtl and Schmidt numbers larger than one. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD. The book is aimed at the professional audience of academic researchers, industrial R and D engineers, university lecturers and graduate/postgraduate students working in the area of rotating-disk systems. (orig.)

  11. Conduction mechanism studies on electron transfer of disordered system

    Institute of Scientific and Technical Information of China (English)

    徐慧; 宋祎璞; 李新梅

    2002-01-01

    Using the negative eigenvalue theory and the infinite order perturbation theory, a new method was developed to solve the eigenvectors of disordered systems. The result shows that eigenvectors change from the extended state to the localized state with the increase of the site points and the disordered degree of the system. When electric field is exerted, the electrons transfer from one localized state to another one. The conductivity is induced by the electron transfer. The authors derive the formula of electron conductivity and find the electron hops between localized states whose energies are close to each other, whereas localized positions differ from each other greatly. At low temperature the disordered system has the character of the negative differential dependence of resistivity and temperature.

  12. Quantum synapse for cold atoms

    CERN Document Server

    Kouzaev, G A

    2007-01-01

    In this paper, the quantum synaptic effect is studied that arisen in the system of two crossed wires excited by the static (DC) and radio-frequency (RF) currents. The potential barrier between the two orthogonal atom streams is controlled electronically and the atoms can be transferred from one wire to another under certain critical values of the RF and DC currents. The results are interesting in the study of quantum interferometry and quantum registering of cold atoms.

  13. A study on the improvement of the legal system concerning Korean Atomic Energy Act

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Il Un; Jung, Jong Hak; Kim, Jae Ho; Moon, Jong Wook; Kim, In Sub [Chungnam National Univ., Taejon (Korea, Republic of)

    1998-03-15

    Cause-effect analysis, adjustment, and generalization of the current atomic energy act are contents of this research. These are to be based on the legal theory. Analysis of the current atomic energy act from the viewpoint of constitutional law and administrative law. Review of the other domestic legal systems which have similar problems as the atomic energy act has. Inquiry about the operation of nuclear legal systems of foreign nations.

  14. A study on the improvement of the legal system concerning Korean Atomic Energy Act

    International Nuclear Information System (INIS)

    Cause-effect analysis, adjustment, and generalization of the current atomic energy act are contents of this research. These are to be based on the legal theory. Analysis of the current atomic energy act from the viewpoint of constitutional law and administrative law. Review of the other domestic legal systems which have similar problems as the atomic energy act has. Inquiry about the operation of nuclear legal systems of foreign nations

  15. Phase-controlled atom-photon entanglement in a three-level ∧-type closed-loop atomic system

    Institute of Scientific and Technical Information of China (English)

    Ali Mortezapour; Zeinab Kordi; Mohammad Mahmoudi

    2013-01-01

    We study the entanglement of dressed atom and its spontaneous emission in a three-level A-type closed-loop atomic system in a multi-photon resonance condition and beyond it.It is shown that the von Neumann entropy in such a system is phase-dependent,and it can be controlled by either the intensity or relative phase of applied fields.It is demonstrated that for the special case of the Rabi frequency of applied fields,the system is disentangled.In addition,we take into account the effect of Doppler broadening on the entanglement and it is found that a suitable choice of laser propagation direction allows us to obtain the steady state degree of entanglement (DEM) even in the presence of the Doppler effect.

  16. Plasmons in nanoscale and atomic-scale systems

    Directory of Open Access Journals (Sweden)

    Tadaaki Nagao, Gui Han, ChungVu Hoang, Jung-Sub Wi, Annemarie Pucci, Daniel Weber, Frank Neubrech, Vyacheslav M Silkin, Dominik Enders, Osamu Saito and Masud Rana

    2010-01-01

    Full Text Available Plasmons in metallic nanomaterials exhibit very strong size and shape effects, and thus have recently gained considerable attention in nanotechnology, information technology, and life science. In this review, we overview the fundamental properties of plasmons in materials with various dimensionalities and discuss the optical functional properties of localized plasmon polaritons in nanometer-scale to atomic-scale objects. First, the pioneering works on plasmons by electron energy loss spectroscopy are briefly surveyed. Then, we discuss the effects of atomistic charge dynamics on the dispersion relation of propagating plasmon modes, such as those for planar crystal surface, atomic sheets and straight atomic wires. Finally, standing-wave plasmons, or antenna resonances of plasmon polariton, of some widely used nanometer-scale structures and atomic-scale wires (the smallest possible plasmonic building blocks are exemplified along with their applications.

  17. Effects of dipole-dipole interaction on entanglement transfer

    Institute of Scientific and Technical Information of China (English)

    Guo Hong; Xiong Heng-Na

    2008-01-01

    A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered.The effects of dipole-dipole (dd) interaction between two atoms on the atom-atom entanglement and mode-mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled.

  18. Saponification reaction system: a detailed mass transfer coefficient determination.

    Science.gov (United States)

    Pečar, Darja; Goršek, Andreja

    2015-01-01

    The saponification of an aromatic ester with an aqueous sodium hydroxide was studied within a heterogeneous reaction medium in order to determine the overall kinetics of the selected system. The extended thermo-kinetic model was developed compared to the previously used simple one. The reaction rate within a heterogeneous liquid-liquid system incorporates a chemical kinetics term as well as mass transfer between both phases. Chemical rate constant was obtained from experiments within a homogeneous medium, whilst the mass-transfer coefficient was determined separately. The measured thermal profiles were then the bases for determining the overall reaction-rate. This study presents the development of an extended kinetic model for considering mass transfer regarding the saponification of ethyl benzoate with sodium hydroxide within a heterogeneous reaction medium. The time-dependences are presented for the mass transfer coefficient and the interfacial areas at different heterogeneous stages and temperatures. The results indicated an important role of reliable kinetic model, as significant difference in k(L)a product was obtained with extended and simple approach.

  19. Hindi to English Transfer Based Machine Translation System

    Directory of Open Access Journals (Sweden)

    Shashi Pal Singh

    2015-06-01

    Full Text Available In large societies like India there is a huge demand to convert one human language into another. Lots of work has been done in this area. Many transfer based MTS have developed for English to other languages, as MANTRA CDAC Pune, MATRA CDAC Pune, SHAKTI IISc Bangalore and IIIT Hyderabad. Still there is a little work done for Hindi to other languages. Currently we are working on it. In this paper we focus on designing a system, that translate the document from Hindi to English by using transfer based approach. This system takes an input text check its structure through parsing. Reordering rules are used to generate the text in target language. It is better than Corpus Based MTS because Corpus Based MTS require large amount of word aligned data for translation that is not available for many languages while Transfer Based MTS requires only knowledge of both the languages (source language and target language to make transfer rules. We get correct translation for simple assertive sentences and almost correct for complex and compound sentences.

  20. An 80 Mbytes/s data transfer and processing system

    International Nuclear Information System (INIS)

    We describe hardware and software aspects of a very fast and versatile, yet conceptually simple, data transfer and processing system for use with future accelerators. It consists of a transputer-based crate controller (CC), which includes an Intel i860 microcomputer, and of a set of readout cards (RC), each containing a digital signal processor (DSP) for fast data parametrisation and compaction. The reduced data is written into a dual port memory (DPM), where it can be accessed concurrently by the transputer and transferred to a common DPM on the CC card. A crateful of data thus assembled at one place can further be processed by the powerful i860 microcomputer. Address generators (simple binary counters) are included on the crate controller and each readout card to enable direct memory access (DMA) operations, resulting in a considerable increase in data transfer speed (maximum 80 Mbytes/s). The use of a transputer as the sole controller processor, in conjunction with DPMs, renders bus arbitration unnecessary leading to very simple interfacing logic and operating software. The four high speed serial links of the transputer greatly facilitate downloading of programs and intercrate communications. An Intel i960CA processor, situated on the CC card, is used for fast data transfer between crates by means of its 32-bit wide DMA channel. The operating software is written in the Occam language, which was specially developed for programming concurrent systems based on transputers. (author)

  1. Emulating solid-state physics with a hybrid system of ultracold ions and atoms.

    Science.gov (United States)

    Bissbort, U; Cocks, D; Negretti, A; Idziaszek, Z; Calarco, T; Schmidt-Kaler, F; Hofstetter, W; Gerritsma, R

    2013-08-23

    We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of high fidelity operations and detection offered by trapped ion systems with ultracold atomic systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to phonons of the ion lattice, thereby emulating a solid-state system. Starting from the microscopic many-body Hamiltonian, we derive the low energy Hamiltonian, including the atomic band structure, and give an expression for the atom-phonon coupling. We discuss possible experimental implementations such as a Peierls-like transition into a period-doubled dimerized state. PMID:24010420

  2. Emulating solid-state physics with a hybrid system of ultracold ions and atoms.

    Science.gov (United States)

    Bissbort, U; Cocks, D; Negretti, A; Idziaszek, Z; Calarco, T; Schmidt-Kaler, F; Hofstetter, W; Gerritsma, R

    2013-08-23

    We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of high fidelity operations and detection offered by trapped ion systems with ultracold atomic systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to phonons of the ion lattice, thereby emulating a solid-state system. Starting from the microscopic many-body Hamiltonian, we derive the low energy Hamiltonian, including the atomic band structure, and give an expression for the atom-phonon coupling. We discuss possible experimental implementations such as a Peierls-like transition into a period-doubled dimerized state.

  3. Positron-Lithium Atom and Electron-Lithium Atom Scattering Systems at Intermediate and High Energies

    Institute of Scientific and Technical Information of China (English)

    K. Ratnavelu; S. Y. Ng

    2006-01-01

    @@ The coupled-channel optical method is used to study positron scattering by atomic lithium at energies ranging from the ionization threshold to 60 eV. The present method simultaneously treats the target channels and the positronium (Ps) channels in the coupled-channel method together with the continuum effects via an ab-initio optical potential. Ionization, elastic and inelastic cross sections in target channels, and the total cross section are also reported and compared with other theoretical and experimental data. A comparative study with the corresponding electron-lithium data is also reported.

  4. Heat transfer and fluid flow in nuclear systems

    CERN Document Server

    Fenech, Henri

    1982-01-01

    Heat Transfer and Fluid in Flow Nuclear Systems discusses topics that bridge the gap between the fundamental principles and the designed practices. The book is comprised of six chapters that cover analysis of the predicting thermal-hydraulics performance of large nuclear reactors and associated heat-exchangers or steam generators of various nuclear systems. Chapter 1 tackles the general considerations on thermal design and performance requirements of nuclear reactor cores. The second chapter deals with pressurized subcooled light water systems, and the third chapter covers boiling water reacto

  5. On identifying transfer functions and state equations for linear systems.

    Science.gov (United States)

    Shieh, L. S.; Chen, C. F.; Huang, C. J.

    1972-01-01

    Two methods are established for identifying constant-coefficient, C to the 2n power type of noise-free linear systems if the time response data of the input-output or of all states are known. 2n response data are required to identify an nth-order transfer function or state equation for an unknown linear system. The order of the unknown system can be identified by checking a sequence of determinants. The Z transform and its inversion are mainly used.

  6. Effect of Trapping Agent and Polystyrene Chain End Functionality on Radical Trap-Assisted Atom Transfer Radical Coupling

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Carnicom

    2014-10-01

    Full Text Available Coupling reactions were performed to gauge the effect of the inclusion of a radical trap on the success of coupling reactions of monohalogenated polystyrene (PSX chains in atom transfer radical coupling (ATRC type reactions. The effect of both the specific radical trap chosen and the structure of the polymer chain end were evaluated by the extent of dimerization observed in a series of analogous coupling reactions. The commonly used radical trap 2-methyl-2-nitrosopropane (MNP showed the highest amounts of dimerization for PSX (X = Br, Cl compared to coupling reactions performed in its absence or with a different radical trap. A dinitroxide coupling agent was also studied with the extent of coupling nearly matching the effectiveness of MNP in RTA (Radical trap-assisted-ATRC reactions, while N-nitroso and electron rich nitroso coupling agents were the least effective. (2,2,6,6-Tetramethyl-piperin-l-yloxyl-capped PS (PS-TEMPO, prepared by NMP, was subjected to a coupling sequence conceptually similar to RTA-ATRC, but dimerization was not observed regardless of the choice of radical trap. Kinetic experiments were performed to observe rate changes on the coupling reaction of PSBr as a result of the inclusion of MNP, with substantial rate enhancements found in the RTA-ATRC coupling sequence compared to traditional ATRC.

  7. Grafting of thermoresponsive polymer from the surface of functionalized multiwalled carbon nanotubes via atom transfer radical polymerization

    Institute of Scientific and Technical Information of China (English)

    XU GuoYong; XIA Ru; WANG Hu; MENG XiangChun; ZHU QingRen

    2008-01-01

    Multiwalled carbon nanotubes were oxidized with concentrated HNOz and H2SO4 to introduce carboxylic groups onto carbon nanotubes surfaces. The oxidized carbon nanotubes were reacted subsequently with thionyl chloride and 2-Hydroxylethyl-2'-bromoisobutyrate, producing MWNT-based macroinitiators, MWNT-Br, for the atom transfer radical polymerization of (N-isopropylacrylamide). FTIR, XPS, 1H NMR, Raman and TGA were used to characterize the resulting products and to determine the content of the water-soluble poly (N-isopropylacrylamide) chains in the product. The MWNTs grafted with PNIPAM chains have good solubility in distilled water; THF and CHCl3. TEM images of the samples provide direct evidence for the formation of a nanostructure that MWNTs coated with polymer layer. The produced MWNT-g-PNIPAM has a PNIPAM shell, which is very sensitive to the change of temperature.This method would open a door for the fabrication of novel functional carbon nanotube-based nanomaterials or nanodevices with designable structure and tailor-made properties.

  8. Reverse atom transfer radical polymerization (RATRP) for anti-clotting PU-LaCl3-g-P(MPC) films

    Science.gov (United States)

    Lu, Chunyan; Zhou, Ninglin; Xiao, Yinghong; Tang, Yida; Jin, Suxing; Wu, Yue; Shen, Jian

    2013-01-01

    Low grafting density is a disadvantage both in reverse atom transfer radical polymerization (RATRP) and ATRP. In this work, the surfaces of polyurethane (PU) were treated by LaCl3·6H2O to obtain modified surfaces with hydrated layers. The reaction of surface-initiated RATRP was carried out easily, which may be attributed to the enriched hydroxyl groups on the hydrated layers. An innovation found in this work is that some free lanthanum ions (La3+) reacted with the silane coupling agent (CPTM) and the product served as mixed ligand complex. The mixed ligand complex instead of conventional 2,2‧-bipyridine was adopted to serve as a ligand in the process of RATRP. As a result, PU surfaces grafted with well-defined polymer brushes (MPC) were obtained. PU substrates before and after modification were characterized by FTIR, XPS, AFM, SEM, SCA, respectively. The results showed that zwitterionic brushes were successfully fabricated on the PU surfaces (P(MPC)), and the content of the grafted layer increased gradually with polymerization time with the grafting density as high as 97.9%. The blood compatibility of the PU substrates was evaluated by plasma recalcification profiles test and platelet adhesion tests in vitro. It was found that all PU functionalized with zwitterionic brush showed improved resistance to nonspecific protein adsorption and platelet adhesion.

  9. Lipase Immobilization onto the Surface of PGMA-b-PDMAEMA-grafted Magnetic Nanoparticles Prepared via Atom Transfer Radical Polymerization☆

    Institute of Scientific and Technical Information of China (English)

    Jingyun Wang; Fangling Ji; Jishuang Xing; Shuang Cui; Yongming Bao; Wenbo Hao

    2014-01-01

    A block copolymer of 2-dimethylaminoethyl methacrylate (DMAEMA) and glycidyl methacrylate (GMA) was grafted onto the surface of magnetic nanoparticles (Fe3O4) via atom transfer radical polymerization. The resultant PGMA-b-PDMAEMA-grafted-Fe3O4 magnetic nanoparticles with amino and epoxy groups were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, thermo-gravimetric analysis, and scanning electron microscopy. Lipase from Burkholderia cepacia was successfully immobilized onto the magnetic nanoparticles by physical adsorption and covalent bonding. The immobilization capacity of the magnetic particles is 0.5 mg lipase per mg support, with an activity recovery of up to 43.1%under the optimum immobilization condition. Biochemical characterization shows that the immobilized lipase exhibits improved thermal stability, good tolerance to organic solvents with high lg P, and higher pH stability than the free lipase at pH 9.0. After six consecutive cycles, the residual activity of the immobilized lipase is still over 55%of its initial activity.

  10. Effect of Surface Charge on Surface-Initiated Atom Transfer Radical Polymerization from Cellulose Nanocrystals in Aqueous Media.

    Science.gov (United States)

    Zoppe, Justin O; Xu, Xingyu; Känel, Cindy; Orsolini, Paola; Siqueira, Gilberto; Tingaut, Philippe; Zimmermann, Tanja; Klok, Harm-Anton

    2016-04-11

    Cellulose nanocrystals (CNCs) with different charge densities were utilized to examine the role of electrostatic interactions on surface-initiated atom transfer radical polymerization (SI-ATRP) in aqueous media. To this end, growth of hydrophilic uncharged poly(N,N-dimethylacrylamide) (PDMAM) brushes was monitored by electrophoresis, (1)H NMR spectroscopy, and dynamic light scattering (DLS). Molecular weight and polydispersity of PDMAM brushes was determined by GPC analysis of hydrolytically cleaved polymers. Initiator and polymer brush grafting densities, and thus, initiator efficiencies were derived from elemental analysis. Higher initiator efficiency of polymer brush growth was observed for CNCs with higher anionic surface sulfate half-ester group density, but at the expense of high polydispersity caused by inefficient deactivation. PDMAM grafts with number-average molecular weights up to 530 kDa and polydispersity indices interfacial region at the onset of polymerization is proposed. The results presented here could have implications for other substrates that present surface charges and for the assumption that the kinetics of Cu-mediated SI-CRP are analogous to those conducted in solution.

  11. Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

    Directory of Open Access Journals (Sweden)

    M. Abbasian

    2012-06-01

    Full Text Available 'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxide-mediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS, poly(p-methylstyrene (PMS and poly(methylmethacrylate (PMMA as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH. The resulting macroinitiator (sPS-TEMPO for 'living' free radical polymerization was then heated in the presence of styrene and p-methylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, ¹H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials.

  12. Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, M. [Department of Basic Science, Payame Noor University, Tehran (Iran, Islamic Republic of); Shoja, S. Esmaeily [Lab. of Materials, Faculty of Engineering, Islamic Azad University, Bonab (Iran, Islamic Republic of)

    2012-04-15

    'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxide mediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS), poly(p-methylstyrene) (PMS) and poly(methylmethacrylate) (PMMA) as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS) was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH). The resulting macroinitiator (sPSTEMPO) for 'living' free radical polymerization was then heated in the presence of styrene and pmethylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, {sup 1}H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials. (author)

  13. Multiparameter Monitoring and Fault Indication Using Inductive Power Transfer System

    OpenAIRE

    Shaji, K. P.; Alsheba, I.; Khadar, Y. A. Syed; Kannan, S.

    2013-01-01

    The paper aims at demonstrating communication capabilities of IPT. For this data communication is performed between two modules using the concept of IPT. IPT was deemed to be the best solution to the system houses a multi parameter acquisition module such as temperature, speed, voltage, current and data transfer from the motor. The receiver side is another microcontroller coupled to an inductive coil that gets the data and displays in the LCD. A brief background to IPT Inductive Power Transfe...

  14. Development of the prototype pneumatic transfer system for ITER neutron activation system.

    Science.gov (United States)

    Cheon, M S; Seon, C R; Pak, S; Lee, H G; Bertalot, L

    2012-10-01

    The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.

  15. Umbrella sampling of proton transfer in a creatine-water system

    Science.gov (United States)

    Ivchenko, Olga; Bachert, Peter; Imhof, Petra

    2014-04-01

    Proton transfer reactions are among the most common processes in chemistry and biology. Proton transfer between creatine and surrounding solvent water is underlying the chemical exchange saturation transfer used as a contrast in magnetic resonance imaging. The free energy barrier, determined by first-principles umbrella sampling simulations (EaDFT 3 kcal/mol) is in the same order of magnitude as the experimentally obtained activation energy. The underlying mechanism is a first proton transfer from the guanidinium group to the water pool, followed by a second transition where a proton is "transferred back" from the nearest water molecule to the deprotonated nitrogen atom of creatine.

  16. New magnet transport system for the LHC beam transfer lines

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system (pictured here in one of the tunnels) is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The lead vehicle is powered by an electric rail set into the roof of the tunnel. The system is backed up by electrical batteries that enable it to operate in the absence of an outside power source or in the event of power failure. Last but not least, for the long-distance transport of magnets, it can be optically guided by a line traced on the tunnel floor. The convoy moves through the particularly narr...

  17. A New Reaction-controlled Phase-transfer Catalyst System

    Institute of Scientific and Technical Information of China (English)

    Ming Qiang LI; Xi Gao JIAN; Gui Mei WANG; Yan YU

    2004-01-01

    A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.

  18. Improved power transfer to wearable systems through stretchable magnetic composites

    Science.gov (United States)

    Lazarus, N.; Bedair, S. S.

    2016-05-01

    The use of wireless power transfer is common in stretchable electronics since physical wiring can be easily destroyed as the system is stretched. This work presents the first demonstration of improved inductive power coupling to a stretchable system through the addition of a thin layer of ferroelastomeric material. A ferroelastomer, an elastomeric polymer loaded with magnetic particulates, has a permeability greater than one while retaining the ability to survive significant mechanical strains. A recently developed ferroelastomer composite based on sendust platelets within a soft silicone elastomer was incorporated into liquid metal stretchable inductors based on the liquid metal galinstan in fluidic channels. For a single-turn inductor, the maximum power transfer efficiency rises from 71 % with no backplane, to 81 % for a rigid ferrite backplane on the transmitter side alone, to 86 % with a ferroelastomer backplane on the receiver side as well. The coupling between a commercial wireless power transmitter coil with ferrite backplane to a five-turn liquid metal inductor was also investigated, finding an improvement in power transfer efficiency from 81 % with only a rigid backplane to 90 % with the addition of the ferroelastomer backplane. Both the single and multi-turn inductors were demonstrated surviving up to 50 % uniaxial applied strain.

  19. Interfacing ultracold atoms and mechanical oscillators on an atom chip

    Science.gov (United States)

    Treutlein, Philipp

    2010-03-01

    Ultracold atoms can be trapped and coherently manipulated close to a chip surface using atom chip technology. This opens the exciting possibility of studying interactions between atoms and on-chip solid-state systems such as micro- and nanostructured mechanical oscillators. One goal is to form hybrid quantum systems, in which atoms are used to read out, cool, and coherently manipulate the oscillators' state. In our work, we investigate different coupling mechanisms between ultracold atoms and mechanical oscillators. In a first experiment, we use atom-surface forces to couple the vibrations of a mechanical cantilever to the motion of a Bose-Einstein condensate in a magnetic microtrap on an atom chip. The atoms are trapped at about one micrometer distance from the cantilever surface. We make use of the coupling to read out the cantilever vibrations with the atoms and observe resonant coupling to several well-resolved mechanical modes of the condensate. In a second experiment, we investigate coupling via a 1D optical lattice that is formed by a laser beam retroreflected from a SiN membrane oscillator. The optical lattice serves as a `transfer rod' that couples vibrations of the membrane to the atoms and vice versa. We point out that the strong coupling regime can be reached in coupled atom-oscillator systems by placing both the atoms and the oscillator in a high-finesse optical cavity.

  20. Modeling coherent excitation energy transfer in photosynthetic light harvesting systems

    Science.gov (United States)

    Huo, Pengfei

    2011-12-01

    Recent non-linear spectroscopy experiments suggest the excitation energy transfer in some biological light harvesting systems initially occurs coherently. Treating such processes brings significant challenge for conventional theoretical tools that usually involve different approximations. In this dissertation, the recently developed Iterative Linearized Density Matrix (ILDM) propagation scheme, which is non-perturbative and non-Markovian is extended to study coherent excitation energy transfer in various light harvesting complexes. It is demonstrated that the ILDM approach can successfully describe the coherent beating of the site populations on model systems and gives quantitative agreement with both experimental results and the results of other theoretical methods have been developed recently to going beyond the usual approximations, thus providing a new reliable theoretical tool to study this phenomenon. This approach is used to investigate the excited energy transfer dynamics in various experimentally studied bacteria light harvesting complexes, such as Fenna-Matthews-Olsen (FMO) complex, Phycocyanin 645 (PC645). In these model calculations, quantitative agreement is found between computed de-coherence times and quantum beating pattens observed in the non-linear spectroscopy. As a result of these studies, it is concluded that the stochastic resonance behavior is important in determining the optimal throughput. To begin addressing possible mechanics for observed long de-coherence time, various models which include correlation between site energy fluctuations as well as correlation between site energy and inter-site coupling are developed. The influence of both types of correlation on the coherence and transfer rate is explored using with a two state system-bath hamiltonian parametrized to model the reaction center of Rhodobacter sphaeroides bacteria. To overcome the disadvantages of a fully reduced approach or a full propagation method, a brownian dynamics

  1. Atom Localization in two and three dimensions via level populations in an M-type atomic system

    CERN Document Server

    Chaudhari, Nilesh

    2014-01-01

    Schemes for two-dimensional (2D) and three-dimensional (3D) atomic states localization in a five level M-type system using standing-wave laser fields are presented. In the upper two levels of the system we see a `coupled' localization for both 2D and 3D case. Here, the state in which majority of population will be found depends on the sign of the detunings between the upper levels and the intermediate level. The experimental implementation of the scheme using the D2 line of Rb is also proposed.

  2. A theoretical study of the atomic and electronic structures of three prospective atomic scale wire systems

    CERN Document Server

    Shevlin, S A

    2001-01-01

    transport properties of the line are also calculated. Finally we find which of the two models of the (4x1)-Si(111)-ln reconstruction is thermodynamically favoured in a supercell geometry. We use ab initio plane wave techniques in the Local-Density-Approximation, and calculate and compare the electronic structure of the two models with respect to the characteristic energies for electron dispersion along and across the chain structures. We also consider the effects of electronic structure on the in-plane transport properties of the indium lines. The structural and electronic properties of several candidate atomic scale wires are analysed. Three candidates are studied: the trans-polyacetylene molecule, the silicon line on the (001) face of cubic silicon carbide (the (nx2) series of reconstructions) and the indium chain on the (111) face of silicon carbide (the (4x1) reconstruction). We use the polyacetylene molecule as a test-bed for the techniques that we use to calculate transport properties in an empirically ...

  3. Atom Chips

    CERN Document Server

    Folman, R; Cassettari, D; Hessmo, B; Maier, T; Schmiedmayer, J; Folman, Ron; Krüger, Peter; Cassettari, Donatella; Hessmo, Björn; Maier, Thomas

    1999-01-01

    Atoms can be trapped and guided using nano-fabricated wires on surfaces, achieving the scales required by quantum information proposals. These Atom Chips form the basis for robust and widespread applications of cold atoms ranging from atom optics to fundamental questions in mesoscopic physics, and possibly quantum information systems.

  4. Heat transfer and flow in solar energy and bioenergy systems

    Science.gov (United States)

    Xu, Ben

    The demand for clean and environmentally benign energy resources has been a great concern in the last two decades. To alleviate the associated environmental problems, reduction of the use of fossil fuels by developing more cost-effective renewable energy technologies becomes more and more significant. Among various types of renewable energy sources, solar energy and bioenergy take a great proportion. This dissertation focuses on the heat transfer and flow in solar energy and bioenergy systems, specifically for Thermal Energy Storage (TES) systems in Concentrated Solar Power (CSP) plants and open-channel algal culture raceways for biofuel production. The first part of this dissertation is the discussion about mathematical modeling, numerical simulation and experimental investigation of solar TES system. First of all, in order to accurately and efficiently simulate the conjugate heat transfer between Heat Transfer Fluid (HTF) and filler material in four different solid-fluid TES configurations, formulas of an e?ective heat transfer coe?cient were theoretically developed and presented by extending the validity of Lumped Capacitance Method (LCM) to large Biot number, as well as verifications/validations to this simplified model. Secondly, to provide design guidelines for TES system in CSP plant using Phase Change Materials (PCM), a general storage tank volume sizing strategy and an energy storage startup strategy were proposed using the enthalpy-based 1D transient model. Then experimental investigations were conducted to explore a novel thermal storage material. The thermal storage performances were also compared between this novel storage material and concrete at a temperature range from 400 °C to 500 °C. It is recommended to apply this novel thermal storage material to replace concrete at high operating temperatures in sensible heat TES systems. The second part of this dissertation mainly focuses on the numerical and experimental study of an open-channel algae

  5. A general theoretical model for electron transfer reactions in complex systems.

    Science.gov (United States)

    Amadei, Andrea; Daidone, Isabella; Aschi, Massimiliano

    2012-01-28

    In this paper we present a general theoretical-computational model for treating electron transfer reactions in complex atomic-molecular systems. The underlying idea of the approach, based on unbiased first-principles calculations at the atomistic level, utilizes the definition and the construction of the Diabatic Perturbed states of the involved reactive partners (i.e. the quantum centres in our perturbation approach) as provided by the interaction with their environment, including their mutual interaction. In this way we reconstruct the true Adiabatic states of the reactive partners characterizing the electron transfer process as the fluctuation of the electronic density due to the fluctuating perturbation. Results obtained by using a combination of Molecular Dynamics simulation and the Perturbed Matrix Method on a prototypical intramolecular electron transfer (from 2-(9,9'-dimethyl)fluorene to the 2-naphthalene group separated by a steroidal 5-α-androstane skeleton) well illustrate the accuracy of the method in reproducing both the thermodynamics and the kinetics of the process. PMID:22158942

  6. Theoretical atomic collision physics

    Energy Technology Data Exchange (ETDEWEB)

    Lane, N.F. (Rice Univ., Houston, TX (USA) Rice Univ., Houston, TX (USA). Quantum Inst.)

    1990-01-01

    The theoretical atomic physics at Rice University focuses on obtaining a better understanding of the mechanisms that control inelastic collisions between excited atoms and atoms, molecules and ions. Particular attention is given to systems and processes that are of potential importance to advanced energy technologies. In the current year, significant progress has been made in quantitative studies of: quenching of low-Rydberg Na atoms in thermal energy collisions with He, Ne and Ar atoms; selective excitation resulting from charge transfer in collisions of highly stripped ions of He, Li, C, and with Li, Na and He atoms and H{sub 2} molecules at keV energies; differential elastic and single, and double electron transfer in He{sup ++} collisions with He at keV energies; inelastic electron-transfer in ultra-low-energy-energy (T=8 to 80K) collisions between {sup 3}He{sup +} and {sup 4}He and {sup 4}He{sup +} and {sup 3}He; a formalism for ionization by electron impact of ions in dense, high temperature plasmas.

  7. Squeezing enhancement by damping in a driven atom-cavity system

    CERN Document Server

    Nha, H; Kim, S W; An, K; Nha, Hyunchul; Chough, Young-Tak; Kim, Sang Wook; An, Kyungwon

    2001-01-01

    In a driven atom-cavity coupled system in which the two-level atom is driven by a classical field, the cavity mode which should be in a coherent state in the absence of its reservoir, can be squeezed by coupling to its reservoir. The squeezing effect is enhanced as the damping rate of the cavity is increased to some extent.

  8. Genome modifications and cloning using a conjugally transferable recombineering system

    Directory of Open Access Journals (Sweden)

    Mohammad J Hossain

    2015-12-01

    Full Text Available The genetic modification of primary bacterial disease isolates is challenging due to the lack of highly efficient genetic tools. Herein we describe the development of a modified PCR-based, λ Red-mediated recombineering system for efficient deletion of genes in Gram-negative bacteria. A series of conjugally transferrable plasmids were constructed by cloning an oriT sequence and different antibiotic resistance genes into recombinogenic plasmid pKD46. Using this system we deleted ten different genes from the genomes of Edwardsiella ictaluri and Aeromonas hydrophila. A temperature sensitive and conjugally transferable flp recombinase plasmid was developed to generate markerless gene deletion mutants. We also developed an efficient cloning system to capture larger bacterial genetic elements and clone them into a conjugally transferrable plasmid for facile transferring to Gram-negative bacteria. This system should be applicable in diverse Gram-negative bacteria to modify and complement genomic elements in bacteria that cannot be manipulated using available genetic tools.

  9. Realization of Toffoli gate operation using four-level atoms in cavity QED system

    Institute of Scientific and Technical Information of China (English)

    Tang Shi-Qing; Zhang Deng-Yu; Xie Li-Jun; Zhan Xiao-Gui; Gao Feng

    2009-01-01

    This paper proposes a scheme for realization of a three-qubit Toffoli gate operation using three four-level atoms by a selective atom-field interaction in a cavity quantum electrodynamics system. In the proposed protocol, the quantum information is encoded on the stable ground states of atoms, and atomic spontaneous emission is negligible as the large atom-cavity detuning effectively suppresses the spontaneous decay of the atoms. The influence of the dissipation on fidelity and success probability of the three-qubit Toffoli gate is also discussed. The scheme can also be applied to realize an N-qubit Toffoli gate and the interaction time required does not rise with increasing the number of qubits.

  10. Relevant effects of localized atomic interactions and surface density of states on charge transfer in ion-surface collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bonetto, F.; Romero, M.A.; Garcia, E.A.; Vidal, R.; Ferron, J.; Goldberg, E.C. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Santa Fe (Argentina); Ferron, J.; Goldberg, E.C. [Universidad Nacional del Litoral, J., Dept. de Ingenieria de Materiales, Facultad de Ingenieria Quimica, Santa Fe (Argentina)

    2007-12-15

    Through a time-dependent quantum-mechanical calculation of the H{sup +} scattering by a highly oriented pyrolytic graphite (HOPG) surface, we are able to satisfactorily reproduce the interesting features we observed in ion scattering experiments in H{sup +}/HOPG system. We found that the combined effects of the semimetal character of HOPG together with the localized nature of the carbon atom states primarily determine the angular dependence and the magnitude of the ion fractions for large outgoing angles. The spin fluctuation effects (not considered in the present calculation) are discussed as one of the the main causes of the disagreement between the spinless theory results and the experiments for small exit angles. (authors)

  11. Reverse atom transfer radical polymerization (RATRP) for anti-clotting PU-LaCl3-g-P(MPC) films

    International Nuclear Information System (INIS)

    Highlights: ► A facile and efficient approach for surface modification of PU was introduced. ► MPC was grafted onto the surface of PU film by RATRP. ► Some free La3+ ions reacted with CPTM and the product served as mixed ligand complex. ► The obtained PUs had good blood compatibility and a possible usage in biomedicine. - Abstract: Low grafting density is a disadvantage both in reverse atom transfer radical polymerization (RATRP) and ATRP. In this work, the surfaces of polyurethane (PU) were treated by LaCl3·6H2O to obtain modified surfaces with hydrated layers. The reaction of surface-initiated RATRP was carried out easily, which may be attributed to the enriched hydroxyl groups on the hydrated layers. An innovation found in this work is that some free lanthanum ions (La3+) reacted with the silane coupling agent (CPTM) and the product served as mixed ligand complex. The mixed ligand complex instead of conventional 2,2′-bipyridine was adopted to serve as a ligand in the process of RATRP. As a result, PU surfaces grafted with well-defined polymer brushes (MPC) were obtained. PU substrates before and after modification were characterized by FTIR, XPS, AFM, SEM, SCA, respectively. The results showed that zwitterionic brushes were successfully fabricated on the PU surfaces (P(MPC)), and the content of the grafted layer increased gradually with polymerization time with the grafting density as high as 97.9%. The blood compatibility of the PU substrates was evaluated by plasma recalcification profiles test and platelet adhesion tests in vitro. It was found that all PU functionalized with zwitterionic brush showed improved resistance to nonspecific protein adsorption and platelet adhesion.

  12. When absorptive capacity meets technology transfer : transferring of an e-learning system to Russia

    OpenAIRE

    2005-01-01

    This master thesis aims at using the theoretical framework of absorptive capacity as suggested by Cohen and Levinthal (1990) to account for the underlying dimensions critical in a technology transfer process. Technology transfer is a complicated and dynamic process in which technology moves between the transferring partners. The nature of the technology and the capacities of the involved organisations appear to be important in accounting for the transfer. The research applies the use of absor...

  13. A compact and robust diode laser system for atom interferometry on a sounding rocket

    OpenAIRE

    Schkolnik, V.; Hellmig, O.; Wenzlawski, A.; Grosse, J.; Kohfeldt, A.; Döringshoff, K.; Wicht, A.; Windpassinger, P.; Sengstock, K.; Braxmaier, C.; Krutzik, M.; Peters, A

    2016-01-01

    We present a diode laser system optimized for laser cooling and atom interferometry with ultra-cold rubidium atoms aboard sounding rockets as an important milestone towards space-borne quantum sensors. Design, assembly and qualification of the system, combing micro-integrated distributed feedback (DFB) diode laser modules and free space optical bench technology is presented in the context of the MAIUS (Matter-wave Interferometry in Microgravity) mission. This laser system, with a volume of 21...

  14. The Electron Transfer System of Syntrophically Grown Desulfovibrio vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    PBD; ENIGMA; GTL; VIMSS; Walker, Christopher B.; He, Zhili; Yang, Zamin K.; Ringbauer Jr., Joseph A.; He, Qiang; Zhou, Jizhong; Voordouw, Gerrit; Wall, Judy D.; Arkin, Adam P.; Hazen, Terry C.; Stolyar, Sergey; Stahl, David A.

    2009-06-22

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  15. The electron transfer system of syntrophically grown Desulfovibrio vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Walker, C.B.; He, Z.; Yang, Z.K.; Ringbauer, Jr., J.A.; He, Q.; Zhou, J.; Voordouw, G.; Wall, J.D.; Arkin, A.P.; Hazen, T.C.; Stolyar, S.; Stahl, D.A.

    2009-05-01

    Interspecies hydrogen transfer between organisms producing and consuming hydrogen promotes the decomposition of organic matter in most anoxic environments. Although syntrophic couplings between hydrogen producers and consumers are a major feature of the carbon cycle, mechanisms for energy recovery at the extremely low free energies of reactions typical of these anaerobic communities have not been established. In this study, comparative transcriptional analysis of a model sulfate-reducing microbe, Desulfovibrio vulgaris Hildenborough, suggested the use of alternative electron transfer systems dependent upon growth modality. During syntrophic growth on lactate with a hydrogenotrophic methanogen, D. vulgaris up-regulated numerous genes involved in electron transfer and energy generation when compared with sulfate-limited monocultures. In particular, genes coding for the putative membrane-bound Coo hydrogenase, two periplasmic hydrogenases (Hyd and Hyn) and the well-characterized high-molecular weight cytochrome (Hmc) were among the most highly expressed and up-regulated. Additionally, a predicted operon coding for genes involved in lactate transport and oxidation exhibited up-regulation, further suggesting an alternative pathway for electrons derived from lactate oxidation during syntrophic growth. Mutations in a subset of genes coding for Coo, Hmc, Hyd and Hyn impaired or severely limited syntrophic growth but had little affect on growth via sulfate-respiration. These results demonstrate that syntrophic growth and sulfate-respiration use largely independent energy generation pathways and imply that understanding of microbial processes sustaining nutrient cycling must consider lifestyles not captured in pure culture.

  16. Hg Vetical Transference in Soil—Water System

    Institute of Scientific and Technical Information of China (English)

    GUOYIJUN; MOUSUSEN; 等

    1998-01-01

    Hg vertial transference in soil-water system was studied by analyzing Hg vertical ditribution in soil column after adding Hg and one of the two leacheates,deionzied water or acid rain,into soil column.The results indicated that Hg was hardly transferable in puple soil.About 86%-88% of the total soil Hg was distributed in the top layer (0-2cm) and to Hg was detected in the leakage when the purple soil column was leached by deionized water and simulated acid rain.But Hg was more movalbe in yellow soil with only about 20%-22% of the total soil Hg distributed in the top layer (0-2cm),and about 17%-25% washed out from the soil column by deionized water and simulted acid rain,Incremant in soil bulk density colud reduce Hg leaching,thus the more the Hg kept in soil,the less the Hg leached into underground water,Deionized water and acid rain almost played the same role in leaching Hg.Bentioint was most effecient in preventing Hg from vertcal transferring in the soil coulumn.

  17. Atomic Oxygen Durability Evaluation of Protected Polymers Using Thermal Energy Plasma Systems

    Science.gov (United States)

    Banks, Bruce A.; Rutledge, Sharon K.; Degroh, Kim K.; Stidham, Curtis R.; Gebauer, Linda; Lamoreaux, Cynthia M.

    1995-01-01

    The durability evaluation of protected polymers intended for use in low Earth orbit (LEO) has necessitated the use of large-area, high-fluence, atomic oxygen exposure systems. Two thermal energy atomic oxygen exposure systems which are frequently used for such evaluations are radio frequency (RF) plasma ashers and electron cyclotron resonance plasma sources. Plasma source testing practices such as ample preparation, effective fluence prediction, atomic oxygen flux determination, erosion measurement, operational considerations, and erosion yield measurements are presented. Issues which influence the prediction of in-space durability based on ground laboratory thermal energy plasma system testing are also addressed.

  18. Electromagnetically induced transparency and controllable group velocity in a five-level atomic system

    Institute of Scientific and Technical Information of China (English)

    Lihui Jin; Shangqing Gong; Yueping Niu; Shiqi Jin

    2006-01-01

    @@ The optical properties of a five-level atomic system composed of a A-type four-level atomic and a tripod four-level atomic systems are investigated. It is found that the behaviors of electromagnetically induced transparency (EIT) and group velocity can be controlled by choosing appropriate parameters with the interacting dark resonances. In particular, when all the fields are on resonance, the slow light at the symmetric transparency windows with a much broader EIT width is obtained by tuning the intensity of the coupling field in comparison with its sub-system, which provides potential applications in quantum storage and retrieval of light.

  19. Transferred multipolar atom model for 10β,17β-dihydroxy-17α-methylestr-4-en-3-one dihydrate obtained from the biotransformation of methyloestrenolone.

    Science.gov (United States)

    Faroque, Muhammad Umer; Yousuf, Sammer; Zafar, Salman; Choudhary, M Iqbal; Ahmed, Maqsood

    2016-05-01

    Biotransformation is the structural modification of compounds using enzymes as the catalysts and it plays a key role in the synthesis of pharmaceutically important compounds. 10β,17β-Dihydroxy-17α-methylestr-4-en-3-one dihydrate, C19H28O3·2H2O, was obtained from the fungal biotransformation of methyloestrenolone. The structure was refined using the classical independent atom model (IAM) and a transferred multipolar atom model using the ELMAM2 database. The results from the two refinements have been compared. The ELMAM2 refinement has been found to be superior in terms of the refinement statistics. It has been shown that certain electron-density-derived properties can be calculated on the basis of the transferred parameters for crystals which diffract to ordinary resolution.

  20. The Molybdenum Active Site of Formate Dehydrogenase Is Capable of Catalyzing C-H Bond Cleavage and Oxygen Atom Transfer Reactions.

    Science.gov (United States)

    Hartmann, Tobias; Schrapers, Peer; Utesch, Tillmann; Nimtz, Manfred; Rippers, Yvonne; Dau, Holger; Mroginski, Maria Andrea; Haumann, Michael; Leimkühler, Silke

    2016-04-26

    Formate dehydrogenases (FDHs) are capable of performing the reversible oxidation of formate and are enzymes of great interest for fuel cell applications and for the production of reduced carbon compounds as energy sources from CO2. Metal-containing FDHs in general contain a highly conserved active site, comprising a molybdenum (or tungsten) center coordinated by two molybdopterin guanine dinucleotide molecules, a sulfido and a (seleno-)cysteine ligand, in addition to a histidine and arginine residue in the second coordination sphere. So far, the role of these amino acids in catalysis has not been studied in detail, because of the lack of suitable expression systems and the lability or oxygen sensitivity of the enzymes. Here, the roles of these active site residues is revealed using the Mo-containing FDH from Rhodobacter capsulatus. Our results show that the cysteine ligand at the Mo ion is displaced by the formate substrate during the reaction, the arginine has a direct role in substrate binding and stabilization, and the histidine elevates the pKa of the active site cysteine. We further found that in addition to reversible formate oxidation, the enzyme is further capable of reducing nitrate to nitrite. We propose a mechanistic scheme that combines both functionalities and provides important insights into the distinct mechanisms of C-H bond cleavage and oxygen atom transfer catalyzed by formate dehydrogenase. PMID:27054466

  1. Container lid gasket protective strip for double door transfer system

    Science.gov (United States)

    Allen, Jr., Burgess M

    2013-02-19

    An apparatus and a process for forming a protective barrier seal along a "ring of concern" of a transfer container used with double door systems is provided. A protective substrate is supplied between a "ring of concern" and a safety cover in which an adhesive layer of the substrate engages the "ring of concern". A compressive foam strip along an opposite side of the substrate engages a safety cover such that a compressive force is maintained between the "ring of concern" and the adhesive layer of the substrate.

  2. Photoinduced electron transfer of chlorophyll in lipid bilayer system

    Indian Academy of Sciences (India)

    D K Lee; K W Seo; Y S Kang

    2002-12-01

    Photoinduced electron transfer from chlorophyll- through the interface of dipalmitoylphosphatidylcholine (DPPC) headgroup of the lipid bilayers was studied with electron magnetic resonance (EMR). The photoproduced radicals were identified with electron spin resonance (ESR) and radical yields of chlorophyll- were determined by double integration ESR spectra. The formation of vesicles was identified by changes in measured max values from diethyl ether solutions to vesicles solutions indirectly, and observed directly with SEM and TEM images. The efficiency of photosynthesis in model system was determined by measuring the amount of chlorophyll-a radical yields which were obtained from integration of ESR spectra.

  3. Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

    OpenAIRE

    Syed Shahabuddin; Fatem Hamime Ismail; Sharifah Mohamad; Norazilawati Muhamad Sarih

    2015-01-01

    Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydro...

  4. Thermodynamic aspects of information transfer in complex dynamical systems.

    Science.gov (United States)

    Cafaro, Carlo; Ali, Sean Alan; Giffin, Adom

    2016-02-01

    From the Horowitz-Esposito stochastic thermodynamical description of information flows in dynamical systems [J. M. Horowitz and M. Esposito, Phys. Rev. X 4, 031015 (2014)], it is known that while the second law of thermodynamics is satisfied by a joint system, the entropic balance for the subsystems is adjusted by a term related to the mutual information exchange rate between the two subsystems. In this article, we present a quantitative discussion of the conceptual link between the Horowitz-Esposito analysis and the Liang-Kleeman work on information transfer between dynamical system components [X. S. Liang and R. Kleeman, Phys. Rev. Lett. 95, 244101 (2005)]. In particular, the entropic balance arguments employed in the two approaches are compared. Notwithstanding all differences between the two formalisms, our work strengthens the Liang-Kleeman heuristic balance reasoning by showing its formal analogy with the recent Horowitz-Esposito thermodynamic balance arguments. PMID:26986295

  5. Optically promoted bipartite atomic entanglement in hybrid metallic carbon nanotube systems

    Energy Technology Data Exchange (ETDEWEB)

    Gelin, M. F. [Department of Chemistry, Technische Universität München, D-85747 Garching (Germany); Bondarev, I. V.; Meliksetyan, A. V. [Department of Physics, North Carolina Central University, Durham, North Carolina 27707 (United States)

    2014-02-14

    We study theoretically a pair of spatially separated extrinsic atomic type species (extrinsic atoms, ions, molecules, or semiconductor quantum dots) near a metallic carbon nanotube, that are coupled both directly via the inter-atomic dipole-dipole interactions and indirectly by means of the virtual exchange by resonance plasmon excitations on the nanotube surface. We analyze how the optical preparation of the system by using strong laser pulses affects the formation and evolution of the bipartite atomic entanglement. Despite a large number of possible excitation regimes and evolution pathways, we find a few generic scenarios for the bipartite entanglement evolution and formulate practical recommendations on how to optimize and control the robust bipartite atomic entanglement in hybrid carbon nanotube systems.

  6. Three-body entanglement induced by spontaneous emission in a three two-level atoms system

    Institute of Scientific and Technical Information of China (English)

    Liao Xiang-Ping; Fang Mao-Fa; Zheng Xiao-Juan; Cai Jian-Wu

    2006-01-01

    We study three-body entanglement induced by spontaneous emission in a three two-level atoms system by using the entanglement tensor approach. The results show that the amount of entanglement is strongly dependent on the initial state of the system and the species of atoms. The three-body entanglement is the result of the coherent superposition of the two-body entanglements. The larger the two-body entanglement is, the stronger the three-body entanglement is. On the other hand, if there exists a great difference in three two-body entanglement measures, the three-body entanglement is very weak. We also find that the maximum of the two-body entanglement obtained with nonidentical atoms is greater than that obtained with identical atoms via adjusting the difference in atomic frequency.

  7. Optical transfer function analysis of circular-pupil wavefront coding systems with separable phase masks

    Institute of Scientific and Technical Information of China (English)

    Zhao Ting-Yu; Liu Qin-Xiao; Yu Fei-Hong

    2012-01-01

    This paper proposes a simple method to achieve the optical transfer function of a circular pupil wavefront coding system with a separable phase mask in Cartesian coordinates.Based on the stationary phase method,the optical transfer function of the circular pupil system can be easily obtained from the optical transfer function of the rectangular pupil system by modifying the cut-off frequency and the on-axial modulation transfer function.Finally,a system with a cubic phase mask is used as an example to illustrate the way to achieve the optical transfer function of the circular pupil system from the rectangular pupil system.

  8. I.I. Rabi Prize in Atomic, Molecular and Optical Physics Talk: Novel Quantum Physics in Few- and Many-body Atomic Systems

    Science.gov (United States)

    Chin, Cheng

    2011-05-01

    Recent cold atom researches are reaching out far beyond the realm that was conventionally viewed as atomic physics. Many long standing issues in other physics disciplines or in Gedanken-experiments are nowadays common targets of cold atom physicists. Two prominent examples will be discussed in this talk: BEC-BCS crossover and Efimov physics. Here, cold atoms are employed to emulate electrons in superconductors, and nucleons in nuclear reactions, respectively. The ability to emulate exotic or thought systems using cold atoms stems from the precisely determined, simple, and tunable interaction properties of cold atoms. New experimental tools have also been devised toward an ultimate goal: a complete control and a complete characterization of a few- or many-body quantum system. We are tantalizingly close to this major milestone, and will soon open new venues to explore new quantum phenomena that may (or may not!) exist in scientists' dreams.

  9. Atomically crafted spin lattices as model systems for quantum magnetism

    International Nuclear Information System (INIS)

    Low-dimensional quantum magnetism presents a seemingly unlimited source of rich, intriguing physics. Yet, because realistic experimental representations are difficult to come by, the field remains predominantly theoretical. In recent years, artificial spin structures built through manipulation of magnetic atoms in a scanning tunnelling microscope have developed into a promising testing ground for experimental verification of theoretical models. Here, we present an overview of available tools and discuss recent achievements as well as future avenues. Moreover, we show new observations on magnetic switching in a bistable bit that can be used to extrapolate information on the magnetisation of the microscope tip. (topical review)

  10. Atom interferometry

    International Nuclear Information System (INIS)

    We will first present a development of the fundamental principles of atom interferometers. Next we will discuss a few of the various methods now available to split and recombine atomic De Broglie waves, with special emphasis on atom interferometers based on optical pulses. We will also be particularly concerned with high precision interferometers with long measurement times such those made with atomic fountains. The application of atom interferometry to the measurement of the acceleration due to gravity will be detailed. We will also develop the atom interferometry based on adiabatic transfer and we will apply it to the measurement of the photon recoil in the case of the Doppler shift of an atomic resonance caused by the momentum recoil from an absorbed photon. Finally the outlook of future developments will be given. (A.C.)

  11. A technology transfer tracking system for NREL: Overview and results

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, R.L.; Chapman, M.J. [Chapman Research Group, Inc., Littleton, CO (United States)

    1996-07-01

    The purpose of this study has been to assess the National Renewable Energy Laboratory`s (NREL) technology, transfer--both the activities and the system, with the objective of developing a system to track the benefits of NREL-sponsored or conducted research. There were two factors which facilitated this study and which were important in the ability to make a detailed analysis and series of recommendations. First, was the nature of the lab, being one which, from its beginning, has worked closely with industry and, therefore has been directed toward research which would be of value to industry and hopefully commercialized. Second, the size of the laboratory made it relatively more easy to address issues and to become familiar with the organization and with the scientists themselves.

  12. Geometrical effects on energy transfer in disordered open quantum systems

    CERN Document Server

    Mohseni, M; Lloyd, S; Omar, Y; Rabitz, H

    2013-01-01

    We explore various design principles for efficient excitation energy transport in complex quantum systems. We investigate energy transfer efficiency in randomly disordered geometries consisting of up to 20 chromophores to explore spatial and spectral properties of small natural/artificial Light-Harvesting Complexes (LHC). We find significant statistical correlations among highly efficient random structures with respect to ground state properties, excitonic energy gaps, multichromophoric spatial connectivity, and path strengths. These correlations can even exist beyond the optimal regime of environment-assisted quantum transport. For random configurations embedded in spatial dimensions of 30 A and 50 A, we observe that the transport efficiency saturates to its maximum value if the systems contain 7 and 14 chromophores respectively. Remarkably, these optimum values coincide with the number of chlorophylls in (Fenna-Matthews-Olson) FMO protein complex and LHC II monomers, respectively, suggesting a potential nat...

  13. Quantum entanglement in the system of two two-level atoms interacting with a single-mode vacuum field

    Institute of Scientific and Technical Information of China (English)

    Zeng Ke; Fang Mao-Fa

    2005-01-01

    The entanglement properties of the system of two two-level atoms interacting with a single-mode vacuum field are explored. The quantum entanglement between two two-level atoms and a single-mode vacuum field is investigated by using the quantum reduced entropy; the quantum entanglement between two two-level atoms, and that between a single two-level atom and a single-mode vacuum field are studied in terms of the quantum relative entropy. The influences of the atomic dipole-dipole interaction on the quantum entanglement of the system are also discussed. Our results show that three entangled states of two atoms-field, atom-atom, and atom-field can be prepared via two two-level atoms interacting with a single-mode vacuum field.

  14. Lasing and high temperature phase transitions in atomic systems with dressed state polaritons

    CERN Document Server

    Chestnov, I Yu

    2013-01-01

    We consider the fundamental problem of high temperature phase transitions in the system of high density two-level atoms off-resonantly interacting with a pump field in the presence of optical collisions (OCs) and placed in the cavity. OCs are considered in the framework of thermalization of atomic dressed state (DS) population. For the case of a strong atom-field coupling condition we analyze the problem of thermodynamically equilibrium superradiant phase transition for the order parameter representing a real amplitude of cavity mode and taking place as a result of atomic DSs thermalization process. Such transition is also connected with condensed (coherent) properties of low branch (LB) DS-polaritons occurring in the cavity. For describing non-equilibrium phase transitions we derive Maxwell-Bloch like equations which account for cavity decay rate, collisional decay rate and spontaneous emission. Various aspects of transitions to laser field formation by using atomic DS levels for both positive and negative d...

  15. Observation of electromagnetically induced Talbot effect in an atomic system with nonlinearity

    CERN Document Server

    Zhang, Zhaoyang; Zhang, Dan; Sheng, Jiteng; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

    2016-01-01

    We experimentally demonstrate the Talbot effect resulting from the repeatedly self-reconstruction of a spatially intensity-modulated probe field under the Fresnel near-field regime. By launching the probe beam into an optically induced atomic lattice (established by interfering two coupling fields) inside a thermal rubidium vapor cell, we can obtain an electromagnetically induced grating (EIG) on probe beam in a coherent three-level $\\Lambda$-type Doppler-free atomic configuration with the assistance of electromagnetically induced transparency (EIT) window, which can modify and greatly enhance the Kerr nonlinearity near atomic resonance. The EIG patterns out of the cell can repeat the image at the output plane of the cell at integer multiples of Talbot length, which agree well with the theoretical prediction [Appl. Phys. Lett., 98, 081108 (2011)]. Such first demonstrated EIT Talbot effect in a coherent atomic system may pave a lensless and nondestructive way for imaging ultracold atoms or molecules.

  16. Interaction between two SU(1 , 1) quantum systems and a two-level atom

    Science.gov (United States)

    Abdalla, M. Sebawe; Khalil, E. M.; Obada, A. S.-F.

    2016-07-01

    We consider a two-level atom interacting with two coupled quantum systems that can be represented in terms of su(1 , 1) Lie algebra. The wave function that is obtained using the evolution operator for the atom is initially in a superposition state and the coupled su(1 , 1) systems in a pair coherent Barut-Girardello coherent state. We then discuss atomic inversion, where more periods of revivals are observed and compared with a single su(1 , 1) quantum system. For entanglement and squeezing phenomena, the atomic angles coherence and phase as well as the detuning are effective parameters. The second-order correlation function displays Bunching and anti-Bunching behavior.

  17. Phase-Controlled Atom-Photon Entanglement in a Three-Level V-Type Atomic System via Spontaneously Generated Coherence

    Directory of Open Access Journals (Sweden)

    Mostafa Sahrai

    2011-08-01

    Full Text Available We investigate the dynamical behavior of the atom-photon entanglement in a V-type three-level quantum system using the atomic reduced entropy. It is shown that an atom and photons are entangled at the steady-state; however disentanglement can also be achieved in an special condition. It is demonstrated that in the presence of quantum interference induced by spontaneous emission, the reduced entropy and the atom-photon entanglement are phase-dependent. A non-stationary solution is also obtained when the quantum interference due to the spontaneous emission is completely included.

  18. Dressed-state analysis of efficient three-dimensional atom localization in a ladder-type three-level atomic system

    Science.gov (United States)

    Zhu, Zhonghu; Yang, Wen-Xing; Chen, Ai-Xi; Liu, Shaopeng; Lee, Ray-Kuang

    2016-07-01

    We study the control of high-precision three-dimensional (3D) atom localization by measuring the population of the excited state in a ladder-type three-level atomic system driven by a weak probe field and a control field, together with three mutually perpendicular standing-wave fields. We find that the precision of 3D atom localization in volumes depends sensitively on the frequency detuning of the probe field and the intensity of the control field. Most importantly, we show that adjusting the phase shifts associated with the standing-wave fields leads to a redistribution of the atoms and a significant change of the atomic coherence, so that the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength.

  19. The international regulation of Informal Value Transfer Systems

    Directory of Open Access Journals (Sweden)

    Anand Ajay Shah

    2007-12-01

    Full Text Available After the 11th September 2001 attacks on the United States international attention quickly focused on the sources and methods of terrorist financing. Among the methods terrorists and other criminal actors use to transfer funds are Informal Value Transfer Systems (IVTS which operate either outside the formal financial sector, or through use of the formal financial sector, but without leaving a full record of the transaction. Though the vast majority of funds moved through IVTS are the earnings of migrant workers and immigrant communities, the lack of uniform worldwide regulation of IVTS provides ample opportunity for abuse and misuse. The international community primarily responded to IVTS concerns through the Financial Action Task Force on Money Laundering, which issued a series of recommendations and best practices for states in regulating IVTS operations. While these recommendations are a secure beginning to regulation of IVTS operating within ethnic communities, they fail to address the more modern forms of IVTS that have come about in the post-Cold War globalised world. Comprehensive recommendations governing all types of IVTS, as well as concerted international cooperation and coordination are necessary to address this global phenomenon.

  20. Excited State Structural Dynamics of Carotenoids and Charge Transfer Systems

    International Nuclear Information System (INIS)

    This dissertation describes the development and implementation of a visible/near infrared pump/mid-infrared probe apparatus. Chapter 1 describes the background and motivation of investigating optically induced structural dynamics, paying specific attention to solvation and the excitation selection rules of highly symmetric molecules such as carotenoids. Chapter 2 describes the development and construction of the experimental apparatus used throughout the remainder of this dissertation. Chapter 3 will discuss the investigation of DCM, a laser dye with a fluorescence signal resulting from a charge transfer state. By studying the dynamics of DCM and of its methyl deuterated isotopomer (an otherwise identical molecule), we are able to investigate the origins of the charge transfer state and provide evidence that it is of the controversial twisted intramolecular (TICT) type. Chapter 4 introduces the use of two-photon excitation to the S1 state, combined with one-photon excitation to the S2 state of the carotenoid beta-apo-8'-carotenal. These 2 investigations show evidence for the formation of solitons, previously unobserved in molecular systems and found only in conducting polymers Chapter 5 presents an investigation of the excited state dynamics of peridinin, the carotenoid responsible for the light harvesting of dinoflagellates. This investigation allows for a more detailed understanding of the importance of structural dynamics of carotenoids in light harvesting

  1. Heat transfer in minichannels and microchannels CPU cooling systems

    Science.gov (United States)

    Mihai, Ioan C.

    2009-01-01

    A CPU functioning is extremely complex and it was experimentally revealed that a direct dependence between working speed and cooling degree exists. When the contact between two surfaces is imperfect, the specific thermal resistance of interface layer suddenly increases, so it became of frequent use to apply diverse materials between the CPU and radiator. These materials should both fill the gaps occurred due to surfaces roughness, material's fatigue, loading pressure etc. and transfer as much heat as possible during a short period of time. In order to ensure an appropriate cooling, other complementary methods are used, such as coolers, water or other liquids cooling, Peltier effect and even freon micro-refrigerating systems. In either situation, there are micro or nano channels through which fluids flow and thermal exchange takes place. The present paper aims to analyze the heat transfer under the mentioned conditions, considering the micro or nano scale dimensions of the channels. The thermal calculus can differ with respect to Kn number and for this case for thermal modelling diverse mathematical models can be realized. The model used is validated by comparing the results to numerical results obtained by authors from literature.

  2. Steric Effect for Proton, Hydrogen-Atom, andHydride Transfer Reactions with Geometric Isomers of NADH-Model Ruthenium Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Fujita E.; Cohen, B.W.; Polyansky, D.E.; Achord, P.; Cabelli, D.; Muckerman, J.T.; Tanaka, K.; Thummel, R.P.; Zong, R.

    2012-01-01

    Two isomers, [Ru(1)]{sup 2+} (Ru = Ru(bpy){sub 2}, bpy = 2,2{prime}-bipyridine, 1 = 2-(pyrid-2{prime}-yl)-1-azaacridine) and [Ru(2)]{sup 2+} (2 = 3-(pyrid-2{prime}-yl)-4-azaacridine), are bio-inspired model compounds containing the nicotinamide functionality and can serve as precursors for the photogeneration of C-H hydrides for studying reactions pertinent to the photochemical reduction of metal-C{sub 1} complexes and/or carbon dioxide. While it has been shown that the structural differences between the azaacridine ligands of [Ru(1)]{sup 2+} and [Ru(2)]{sup 2+} have a significant effect on the mechanism of formation of the hydride donors, [Ru(1HH)]{sup 2+} and [Ru(2HH)]{sup 2+}, in aqueous solution, we describe the steric implications for proton, net-hydrogen-atom and net-hydride transfer reactions in this work. Protonation of [Ru(2{sup {sm_bullet}-})]{sup +} in aprotic and even protic media is slow compared to that of [Ru(1{sup {sm_bullet}-})]{sup +}. The net hydrogen-atom transfer between *[Ru(1)]{sup 2+} and hydroquinone (H{sub 2}Q) proceeds by one-step EPT, rather than stepwise electron-proton transfer. Such a reaction was not observed for *[Ru(2)]{sup 2+} because the non-coordinated N atom is not easily available for an interaction with H{sub 2}Q. Finally, the rate of the net hydride ion transfer from [Ru(1HH)]{sup 2+} to [Ph{sub 3}C]{sup +} is significantly slower than that of [Ru(2HH)]{sup 2+} owing to steric congestion at the donor site.

  3. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

    International Nuclear Information System (INIS)

    Highlights: ► Both 1,1-diphenyl-2-picrylhydrazyl radical and its product measurement by HPLC. ► Lowest limit of detection by monitoring 1,1-diphenyl-2-picryl-hydrazine. ► Adsorption problem of the radical on HPLC parts have been pointed out. - Abstract: 1,1-Diphenyl-2-picrylhydrazyl (DPPH·) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH· absorbance at 515 nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH· quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH· resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH· and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH· and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile–10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH· onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH· was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH· using standards (0.02 and 14 μM, respectively). The method was applied to three commonly used AOs, i.e. Trolox®, ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of higher selectivity than colorimetry, and (ii) its help to investigate the mechanisms occurring with the free radical.

  4. Electronic Origins of the Variable Efficiency of Room-Temperature Methane Activation by Homo- and Heteronuclear Cluster Oxide Cations [XYO2](+) (X, Y = Al, Si, Mg): Competition between Proton-Coupled Electron Transfer and Hydrogen-Atom Transfer.

    Science.gov (United States)

    Li, Jilai; Zhou, Shaodong; Zhang, Jun; Schlangen, Maria; Weiske, Thomas; Usharani, Dandamudi; Shaik, Sason; Schwarz, Helmut

    2016-06-29

    The reactivity of the homo- and heteronuclear oxide clusters [XYO2](+) (X, Y = Al, Si, Mg) toward methane was studied using Fourier transform ion cyclotron resonance mass spectrometry, in conjunction with high-level quantum mechanical calculations. The most reactive cluster by both experiment and theory is [Al2O2](•+). In its favorable pathway, this cluster abstracts a hydrogen atom by means of proton-coupled electron transfer (PCET) instead of following the conventional hydrogen-atom transfer (HAT) route. This mechanistic choice originates in the strong Lewis acidity of the aluminum site of [Al2O2](•+), which cleaves the C-H bond heterolytically to form an Al-CH3 entity, while the proton is transferred to the bridging oxygen atom of the cluster ion. In addition, a comparison of the reactivity of heteronuclear and homonuclear oxide clusters [XYO2](+) (X, Y = Al, Si, Mg) reveals a striking doping effect by aluminum. Thus, the vacant s-p hybrid orbital on Al acts as an acceptor of the electron pair from methyl anion (CH3(-)) and is therefore eminently important for bringing about thermal methane activation by PCET. For the Al-doped cluster ions, the spin density at an oxygen atom, which is crucial for the HAT mechanism, acts here as a spectator during the course of the PCET mediated C-H bond cleavage. A diagnostic plot of the deformation energy vis-à-vis the barrier shows the different HAT/PCET reactivity map for the entire series. This is a strong connection to the recently discussed mechanism of oxidative coupling of methane on magnesium oxide surfaces proceeding through Grignard-type intermediates.

  5. A compact and robust diode laser system for atom interferometry on a sounding rocket

    CERN Document Server

    Schkolnik, V; Wenzlawski, A; Grosse, J; Kohfeldt, A; Döringshoff, K; Wicht, A; Windpassinger, P; Sengstock, K; Braxmaier, C; Krutzik, M; Peters, A

    2016-01-01

    We present a diode laser system optimized for laser cooling and atom interferometry with ultra-cold rubidium atoms aboard sounding rockets as an important milestone towards space-borne quantum sensors. Design, assembly and qualification of the system, combing micro-integrated distributed feedback (DFB) diode laser modules and free space optical bench technology is presented in the context of the MAIUS (Matter-wave Interferometry in Microgravity) mission. This laser system, with a volume of 21 liters and total mass of 27 kg, passed all qualification tests for operation on sounding rockets and is currently used in the integrated MAIUS flight system producing Bose-Einstein condensates and performing atom interferometry based on Bragg diffraction. The MAIUS payload is being prepared for launch in fall 2016. We further report on a reference laser system, comprising a rubidium stabilized DFB laser, which was operated successfully on the TEXUS 51 mission in April 2015. The system demonstrated a high level of technol...

  6. Dynamics of an all-optical atomic spin gyroscope.

    Science.gov (United States)

    Fang, Jiancheng; Wan, Shuangai; Yuan, Heng

    2013-10-20

    We present the transfer function of an all-optical atomic spin gyroscope through a series of differential equations and validate the transfer function by experimental test. A transfer function is the basis for further control system design. We build the differential equations based on a complete set of Bloch equations describing the all-optical atomic spin gyroscope, and obtain the transfer function through application of the Laplace transformation to these differential equations. Moreover, we experimentally validate the transfer function in an all-optical Cs-Xe129 atomic spin gyroscope through a series of step responses. This transfer function is convenient for analysis of the form of control system required. Furthermore, it is available for the design of the control system specifically to improve the performance of all-optical atomic spin gyroscopes.

  7. Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

    Science.gov (United States)

    Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

    2016-06-01

    We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

  8. Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

    Science.gov (United States)

    Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

    2016-06-01

    We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency. PMID:27155868

  9. Transfer cask system design activities: status and plan

    Energy Technology Data Exchange (ETDEWEB)

    Locke, D., E-mail: darren.locke@f4e.europa.eu [Fusion for Energy Agency (F4E), Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Gutierrez, C. Gonzalez; Damiani, C.; Gracia, V. [Fusion for Energy Agency (F4E), Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Friconneau, J.-P.; Martins, J.-P.; Blight, J. [ITER Organisation, CS 90 046, 13067St. Paul Lez Durance Cedex (France)

    2011-10-15

    The ITER Cask and Plug Remote Handling System (CPRHS), a.k.a. Transfer Cask System, is a critical element of the ITER Remote Maintenance System (IRMS) devoted to transportation of components between the Tokamak building and Hot Cell. Due to the necessary confinement of contaminated components the CPRHS is defined as Safety Importance Class 1 (SIC-1) plus the mobile nature of the CPRHS brings with it a significant number of complex interfaces with other ITER sub-systems. With a total CPRHS fleet in excess of 20 units, including seven typologies, the management of design and procurement needs to be carefully planned and implemented to ensure compliance with ITER's requirements. Fusion for Energy (F4E) and its beneficiaries/contractors are currently working under ITER Task Agreements (ITAs) on the conceptual design of the CPRHS and, following the signing of the Procurement Arrangement (PA) in mid 2012, will take responsibility for the entire CPRHS fleet. F4E must, therefore, develop a robust strategy to meet the needs of both ITER machine assembly (for which a number of CPRHS units will be utilised) and the remote maintenance of ITER. Within this context this paper will present the status of the current CPRHS design activities, highlight some of the significant issues which will be faced during procurement and present the overall strategy which is being implemented by F4E in order to meet these challenging objectives.

  10. Using a quantum dot system to realize perfect state transfer

    Institute of Scientific and Technical Information of China (English)

    Li Ji; Wu Shi-Hai; Zhang Wen-Wen; Xi Xiao-Qiang

    2011-01-01

    There are some disadvantages to Nikolopoulos et al.'s protocol [Nikolopoulos G M,Petrosyan D and Lambropoulos P 2004 Europhys.Lett.65 297] where a quantum dot system is used to realize quantum communication.To overcome these disadvantages,we propose a protocol that uses a quantum dot array to construct a four-qubit spin chain to realize perfect quantum state transfer (PQST).First,we calculate the interaction relation for PQST in the spin chain.Second,we review the interaction between the quantum dots in the Heitler-London approach.Third,we present a detailed program for designing the proper parameters of a quantum dot array to realize PQST.

  11. Evaluation of Geometrical Modulation Transfer Function in Optical Lens System

    Directory of Open Access Journals (Sweden)

    Cheng-Mu Tsai

    2015-01-01

    Full Text Available This paper presents ray tracing algorithms to evaluate the geometrical modulation transfer function (GMTF of optical lens system. There are two kinds of ray tracings methods that can be applied to help simulate the point spread function (PSF in the image plane, for example, paraxial optics and real ray tracings. The paraxial optics ray tracing is used to calculate the first-order properties such as the effective focal length (EFL and the entrance pupil position through less cost of computation. However, the PSF could have a large tolerance by only using paraxial optics ray tracing for simulation. Some formulas for real ray tracing are applied in the sagittal and tangential line spread function (LSF. The algorithms are developed to demonstrate the simulation of LSF. Finally, the GMTF is evaluated after the fast Fourier transform (FFT of the LSF.

  12. Interference control of nonlinear excitation in a multi-atom cavity quantum electrodynamics system.

    Science.gov (United States)

    Yang, Guoqing; Tan, Zheng; Zou, Bichen; Zhu, Yifu

    2014-12-01

    We show that by manipulating quantum interference in a multi-atom cavity quantum electrodynamics (CQED) system, the nonlinear excitation of the cavity-atom polariton can be resonantly enhanced while the linear excitation is suppressed. Under the appropriate conditions, it is possible to selectively enhance or suppress the polariton excitation with two free-pace laser fields. We report on an experiment with cold Rb atoms in an optical cavity and present experimental results that demonstrate such interference control of the CQED excitation and its direct application to studies of all-optical switching and cross-phase modulation of the cavity-transmitted light.

  13. Manipulation of multiple electromagnetically induced two-photon transparency in a six-level atomic system

    Institute of Scientific and Technical Information of China (English)

    Jia Wen-Zhi; Wang Shun-Jin

    2009-01-01

    In the five-level K-type atomic system, by using another control field to couple the excited level of the coupling transition to the sixth higher excited level, a six-level atomic system is constructed. In this system, the multiple electromagnetically induced two-photon transparency has been investigated. What is more, if choosing the parameters of the control fields properly the triple transparency window will reduce to a double one which means that the multiple electromagnetically induced two-photon transparency can be manipulated in this system. The physical interpretation of these phenomena is given in terms of the dressed states and the dark states.

  14. Quantum Process Tomography for Energy Transfer Systems via Ultrafast Spectroscopy

    Science.gov (United States)

    Yuen-Zhou, Joel

    2012-02-01

    The description of excited state dynamics in energy transfer systems constitutes a theoretical and experimental challenge in modern chemical physics. A spectroscopic protocol that systematically characterizes both coherent and dissipative processes of the probed chromophores is desired [1,2]. In this talk, I show that a set of two-color photon-echo experiments performs quantum state tomography (QST) of the one-exciton manifold of a dimer by reconstructing its density matrix in real time. This possibility in turn allows for a complete description of excited state dynamics via quantum process tomography (QPT). Simulations of a noisy QPT experiment for an inhomogeneously broadened ensemble of model excitonic dimers show that the protocol distills rich information about dissipative excitonic dynamics, which appears nontrivially hidden in the signal monitored in single realizations of four-wave mixing experiments Progress on the experimental side will be discussed, as well as new insights that QPT has offered on the understanding of 2D electronic and vibrational spectroscopy. [1] J. Yuen-Zhou, J. J. Krich, A. Aspuru-Guzik, Quantum state and process tomography of energy transfer systems via ultrafast spectroscopy Joel Yuen-Zhou, Jacob J. Krich, Masoud Mohseni and Al'an Aspuru-Guzik Proc. Nat. Acad. Sci. USA, Early Edition (2011). [2] J. Yuen-Zhou, A. Aspuru-Guzik, Quantum process tomography of molecular dimers from two-dimensional electronic spectroscopy I: General theory and application to homodimers Joel Yuen-Zhou and Al'an Aspuru-Guzik . Chem. Phys. 134, 134505 (2011).

  15. Comprehensive online Atomic Database Management System (DBMS with Highly Qualified Computing Capabilities

    Directory of Open Access Journals (Sweden)

    Amani Tahat

    2011-05-01

    Full Text Available The intensive need of atomic data is expanding continuously in a wide variety of applications (e.g, fusionenergy and astrophysics, laser-produced, plasma researches, and plasma processing.This paper willintroduce our ongoing research work to build a comprehensive, complete, up-to-date, user friendly andonline atomic Database Management System (DBMS namely called AIMS by using SQLite(http://www.sqlite.org/about.html(8. Programming language tools and techniques will not be coveredhere. The system allows the generation of various atomic data based on professional online atomiccalculators. The ongoing work is a step forward to bring detailed atomic model accessible to a widecommunity of laboratory and astrophysical plasma diagnostics. AIMS is a professional worldwide tool forsupporting several educational purposes and can be considered as a complementary database of IAEAatomic databases. Moreover, it will be an exceptional strategy of incorporating the output data of severalatomic codes to external spectral models.

  16. Control of light trapping in a large atomic system by a static magnetic field

    CERN Document Server

    Skipetrov, S E; Havey, M D

    2016-01-01

    We propose to control light trapping in a large ensemble of cold atoms by an external, static magnetic field. For an appropriate choice of frequency and polarization of the exciting pulse, the field is expected to speed up the fluorescence of a dilute atomic system but can significantly slow it down in a dense ensemble. The slowing down of fluorescence is due to the excitation of spatially localized collective atomic states that appear only under a strong magnetic field and have exponentially long lifetimes. The control of fluorescence by the magnetic field may be of interest for use in future quantum-information processing devices. It also paves a way towards the experimental observation of the disorder-induced localization of light in cold atomic systems.

  17. Universal Transfer and Stacking of Chemical Vapor Deposition Grown Two-Dimensional Atomic Layers with Water-Soluble Polymer Mediator.

    Science.gov (United States)

    Lu, Zhixing; Sun, Lifei; Xu, Guanchen; Zheng, Jingying; Zhang, Qi; Wang, Jingyi; Jiao, Liying

    2016-05-24

    Chemical vapor deposition (CVD) has shown great potential in synthesizing various high-quality two-dimensional (2D) transition metal dichalcogenides (TMDCs). However, the nondestruction transfer of these CVD-grown 2D TMDCs at a high yield remains a key challenge for applying these emerging materials in various aspects. To address this challenge, we designed a water-soluble transfer mediator consisting of two polymers, polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVA), which can form strong interactions with CVD-grown 2D TMDCs for the nondestruction transfer of these materials. With this mediator, we realized the physical transfer of CVD-grown MoS2 flakes and several other 2D TMDCs, including 2D alloys and heterostructures to a wide range of substrates at a high yield of >90% with well-retained properties as evidenced by various microscopic, spectroscopic, and electrical measurements. Field-effect transistors (FETs) made on thus-transferred CVD-grown MoS2 monolayers exhibited obviously higher mobility than those transferred by chemical method. We also constructed several artificial 2D crystals showing very strong interlayer coupling by the multiple transfer of CVD-grown 2D TMDCs monolayers with this approach. This transfer approach will make versatile CVD-grown 2D materials and their artificial stacks with pristine qualities easily accessible for both fundamental studies and practical applications. PMID:27158832

  18. The BNL fan-atomized burner system prototype

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Brookhaven National Laboratory (BNL) has a continuing interest in the development of advanced oil burners which can provide new capabilities not currently available with pressure atomized, retention head burners. Specifically program goals include: the ability to operate at firing rates as low as 0.25 gph; the ability to operate with very low excess air levels for high steady state efficiency and to minimize formation of sulfuric acid and iron sulfate fouling; low emissions of smoke, CO, and NO{sub x} even at very low excess air levels; and the potential for modulation - either staged firing or continuous modulation. In addition any such advanced burner must have production costs which would be sufficiently attractive to allow commercialization. The primary motivation for all work sponsored by the US DOE is, of course, improved efficiency. With existing boiler and furnace models this can be achieved through down-firing and low excess air operation. Also, with low excess air operation fouling and efficiency degradation due to iron-sulfate scale formation are reduced.

  19. Secure Data Transfer Guidance for Industrial Control and SCADA Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, Robert E.; Fluckiger, Jerry D.; Clements, Samuel L.; Tews, Cody W.; Burnette, John R.; Goranson, Craig A.; Kirkham, Harold

    2011-09-01

    This document was developed to provide guidance for the implementation of secure data transfer in a complex computational infrastructure representative of the electric power and oil and natural gas enterprises and the control systems they implement. For the past 20 years the cyber security community has focused on preventative measures intended to keep systems secure by providing a hard outer shell that is difficult to penetrate. Over time, the hard exterior, soft interior focus changed to focus on defense-in-depth adding multiple layers of protection, introducing intrusion detection systems, more effective incident response and cleanup, and many other security measures. Despite much larger expenditures and more layers of defense, successful attacks have only increased in number and severity. Consequently, it is time to re-focus the conventional approach to cyber security. While it is still important to implement measures to keep intruders out, a new protection paradigm is warranted that is aimed at discovering attempted or real compromises as early as possible. Put simply, organizations should take as fact that they have been, are now, or will be compromised. These compromises may be intended to steal information for financial gain as in the theft of intellectual property or credentials that lead to the theft of financial resources, or to lie silent until instructed to cause physical or electronic damage and/or denial of services. This change in outlook has been recently confirmed by the National Security Agency [19]. The discovery of attempted and actual compromises requires an increased focus on monitoring events by manual and/or automated log monitoring, detecting unauthorized changes to a system's hardware and/or software, detecting intrusions, and/or discovering the exfiltration of sensitive information and/or attempts to send inappropriate commands to ICS/SCADA (Industrial Control System/Supervisory Control And Data Acquisition) systems.

  20. Six-Fold Degenerate Dark States in a Four-Level Atomic System

    Institute of Scientific and Technical Information of China (English)

    WU Jin-Hui; CUI Cui-Li; BA Nuo; MA Qi-Rong; GUO Xiu-Zhen

    2007-01-01

    With all driving fields on Raman resonance, a tripod-type atomic system quickly evolves into a dark state decoupled from the lossy excited level. The dark state depends strongly on field Rabi frequencies, spontaneous decay rates, and the initial atomic population in a complicated way. Analytical results reveal that it is a sixfold degenerate dark state with its three components superposed both coherently and incoherently due to population redistribution from spontaneous emission.

  1. UHF-Band Wireless Power Transfer System for Structural Health Monitoring Sensor Network

    OpenAIRE

    Tansheng Li; Kikuzo Sawada; Harutoshi Ogai; Wa Si

    2013-01-01

    For detecting and measuring health conditions of bridges, wireless sensor networks are used in these days. However, battery life is critically restricting the application and maintenance cost of sensor network systems. To extend life time, a wireless power transfer system at UHF band is introduced to supply the current wireless sensor network. This power transfer system is based on electric wave at 950 MHz. This power transfer system is redesigned for tiny power transmission, including a comb...

  2. Atom Transfer Radical Polymerization Based on Cyclodextrin%基于环糊精的原子转移自由基聚合

    Institute of Scientific and Technical Information of China (English)

    张华承; 刘召娜; 辛飞飞; 李月明; 孔丽; 郝爱友

    2011-01-01

    综述了近年来基于环糊精的原子转移自由基聚合的最新进展.其中,基于环糊精合成化学的原子转移自由基聚合主要表现在:一方面,通过原子转移自由基聚合反应实现环糊精母体的共价键修饰;另一方面,利用该反应参与构筑非共价键的环糊精自组装体系.而通过原子转移自由基聚合反应获得的这些新型环糊精衍生物和自组装体系还可以被进一步应用到有机合成化学、复杂“智能型”超分子自组装体系的构筑、药物输运与控缓释工具、蛋白识别以及手性分离等领域.%The recent progress in atom transfer radical polymerization (ATRP) based on cyclodextrin has been reviewed. In cyclodextrin synthesis chemistry, ATRP can be applied to covalently modifying the native cyclodextrins and can participate in constructing cyclodextrins assemblies by noncovalent interactions. And these novel cyclodextrins and assemblies obtained by ATRP can be further applied to the fields such as organic synthesis, complicated "smart" supramolecular assemblies, drug delivery and release system, protein recognition and enantiometric separation.

  3. Optical Power Transfer System for Powering a Remote Mobility System for Multiple Missions

    Science.gov (United States)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

    2016-01-01

    An optical power transfer system for powering a remote mobility system for multiple missions comprising a high power source and a chilling station connected to a laser source. The laser source transmits a high optical energy to a beam switch assembly via an optical fiber. The beam switch assembly is optically connected to actively cooled fiber spoolers. Docking stations are adapted for securing the fiber spoolers until alternatively ready for use by a remote mobility system. The remote mobility system is optically connected to the fiber spoolers and has a receiving port adapted for securing the fiber spoolers thereon. The fiber spooler transmits the optical energy to a power conversion system which converts the optical energy received to another usable form of energy. More than one power source may be used where the remote mobility system transfers from one source to another while maintaining an operational radius to each source.

  4. Cooperative phenomena in superconducting atom-chips

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Sebastian; Kubala, Bjoern; Ankerhold, Joachim [Institut fuer Theoretische Physik, Universitaet Ulm, Albert-Einstein-Allee 11, 89069 Ulm (Germany)

    2013-07-01

    We theoretically investigate the physics of hybrid quantum systems, where a cloud of cold atoms is coupled to superconducting microstructures, so called superconducting atom-chips. Coherent enhancement, due to the large number of atoms in the cloud, opens a path to the study of strong coupling effects, like superradiance/Dicke-physics in a decohering environment. A structured environment can be designed by embedding a Cooper pair box within the cavity. Moreover, in such a system the transfer of quantum information between the atomic cloud and the superconducting solid state system can be studied.

  5. Cooperative phenomena in superconducting atom-chips

    International Nuclear Information System (INIS)

    We theoretically investigate the physics of hybrid quantum systems, where a cloud of cold atoms is coupled to superconducting microstructures, so called superconducting atom-chips. Coherent enhancement, due to the large number of atoms in the cloud, opens a path to the study of strong coupling effects, like superradiance/Dicke-physics in a decohering environment. A structured environment can be designed by embedding a Cooper pair box within the cavity. Moreover, in such a system the transfer of quantum information between the atomic cloud and the superconducting solid state system can be studied.

  6. Facile Preparation of Crosslinked Polymeric Nanocapsules via Combination of Surface-Initiated Atom Transfer Radical Polymerization and Ultraviolet Irradiated Crosslinking Techniques

    Directory of Open Access Journals (Sweden)

    Mu Bin

    2009-01-01

    Full Text Available Abstract A facile approach for the preparation of crosslinked polymeric nanocapsules was developed by the combination of the surface-initiated atom transfer radical polymerization and ultraviolet irradiation crosslinking techniques. The well-defined polystyrene grafted silica nanoparticles were prepared via the SI-ATRP of styrene from functionalized silica nanoparticles. Then the grafted polystyrene chains were crosslinked with ultraviolet irradiation. The cross-linked polystyrene nanocapsules with diameter of 20–50 nm were achieved after the etching of the silica nanoparticle templates with hydrofluoric acid. The strategy developed was confirmed with Fourier transform infrared, thermogravimetric analysis, and transmission electron microscopy.

  7. Controlled Grafting of Poly(methyl methacrylate) Brushes on Poly(vinylidene fluoride) Powders by Surface-initiated Atom Transfer Radical Polymerization

    Institute of Scientific and Technical Information of China (English)

    TANG Zhaoqi; LI Wei; LIU Lanqin; HUANG Lei; ZHOU Jin; YU Haiyin

    2009-01-01

    Controlled grafting of well-defined polymer brushes of methyl methacrylate (MMA) on the poly(vinylidene fluoride) (PVDF) powders was carded out by the surface-initiated atom transfer radical polymerization (ATRP). The ATRP initiator was anchored on the PVDF surface by alkaline treatment, followed by UV-induced bromination; then methyl methacrylate (MMA) was grafted onto the brominated PVDF by the ATRP technique. The chemical composition changes of PVDF were characterized by Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS results clearly indicated the successful graft of poly(methyl methacrylate) onto the PVDF surface.

  8. A FACILE APPROAC0H FOR THE SURFACE MODIFICATION OF POLY(VINYLIDENE FLUORIDE)MEMBRANE VIA SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel approach for the surface modification of poly(vinylidene fluoride)(PVDF)membrane was successfully realized through alkaline treatment,UV-induced bromine addition,and followed by surface-initiated atom transfer radical polymerization(ATRP)of methyl methacrylate(MMA).Chemical changes on the PVDF membrane before and after modification were analyzed with attenuated total reflectance Fourier transform infrared spectroscopy(AIR/Fr-IR)and X-ray photoelectron spectroscopy(XPS).Primary kinetic study revealed that the chain growth of poly(methyl methacrylate)(PMMA)from the PVDF surface is consistent with a"controlled"process.

  9. Antioxidant activities of [60]fullerene derivatives from chalcone, flavone and flavanone: A ONIOM approach via H-atom and electron transfer mechanism

    Science.gov (United States)

    Thong, Nguyen Minh; Dao, Duy Quang; Ngo, Thi Chinh; Huyen, Trinh Le; Nam, Pham Cam

    2016-05-01

    Antioxidant properties of C60 flavonoid conjugates were computationally examined via their O-H bond dissociation enthalpies (BDEs) and ionization energies (IEs) using two-layer ONIOM and PM6 methods, respectively. Eight ONIOM((RO)B3LYP/6-311++G(2df,2p):PM6) models were evaluated by computing BDE(O-H)s of a series of polyphenol. Synthetic mechanism of C60 flavonoid conjugates was also explored via the potential energy surfaces of reaction between C60 and malonate flavonoid derivatives (chalcone, flavone and flavanone) at the B3LYP/6-31G(d)//PM6. Antioxidant activities of C60 flavonoid conjugates were discussed via hydrogen atom transfer, single electron transfer mechanisms and the effect of C60 on the BDE(O-H)s and IEs of these compounds.

  10. Performance of turbine auxiliaries and service systems at Rajasthan Atomic Power Station

    International Nuclear Information System (INIS)

    Performance of the turbine auxiliaries and service systems at the Rajasthan Atomic Power Station, India are described. Some of the specific problems encountered in connection with the feed water, turbine governing and common services like compressed air, chilled water, water treatment and chlorination systems are outlined. (K.B.)

  11. Entanglement Transfer via Heisenberg Interaction in a Four-Qubit System

    Institute of Scientific and Technical Information of China (English)

    REN Feng-Hua; WANG Zhao-Ming

    2007-01-01

    We investigate the entanglement transfer in a four-qubit system and calculate the concurrence between any two qubits in different initial states.We show that both the pure entangled state and mixed entangled state can be transferred.For some special coupling constants and some evolution time,entanglement can be completely transferred from one pair particles to another.

  12. Development of a pneumatic transport system for bulk transfer of metal grade uranium oxide powder

    International Nuclear Information System (INIS)

    Uranium oxide powder is a commonly handled ceramic powder in nuclear industries. Design of the powder transfer system is an important aspect because of some of its typical characteristics. Pneumatic transport system has been widely used in transferring powder from one place to another. A pneumatic transport system using vacuum has been presented in the paper. This is used for bulk transfer of UO3 powder. The system consists of a cyclone separator and filter cloth at the top of the cyclone separator. The pneumatic transfer system provides high efficiency with sustainable performance and it is a compact, robust, handy and moveable unit. No degradation of the powder quality has been observed during transfer. The system provides highly efficient, easy and safe transfer of radioactive powder, better working environment for the operator. (author)

  13. Study on H atoms diffusion and adsorption properties of MgH2-V systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on experimental results that VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at.%V nanocomposite, H atoms diffusion and adsorption properties of MgH2-V systems have been investigated by using a first-principles plane-wave pseudopotential method based on the density functional theory. The results are as follows. When VH/MgH2 interface is formed due to V alloying MgH2 phase, the vacancy formed by H atoms near VH phase region is more stable than that without V alloying, while vacancy near MgH2 phase region is less stable than that without V alloying. During the process of H atoms diffusion after V alloying, the max migration barrier energy of H atoms in MgH2-V systems is reduced compared with that of MgH2 phase, which means that H atoms diffuse easily. When H diffuses into VH from MgH2 across VH/MgH2 interface, among three substitutions such as the replacement of H for V vacancy, or interstitial site or V atoms, the replacement of H for V vacancy has the strongest diffusion ability, next interstitial site, and finally V atoms site. As far as H adsorbed on different surfaces of VH phase is concerned, physical adsorption is carried out more easily than chemical adsorption, and the behavior of H atoms adsorbed on the surface near VH phase region can be found more easily than that near MgH2 phase region.

  14. Study on H atoms diffusion and adsorption properties of MgH2-V systems

    Institute of Scientific and Technical Information of China (English)

    ZHOU DianWu; LIU JinShui; PENG Ping

    2008-01-01

    Based on experimental results that VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at.%V nanocomposite,H atoms diffusion and adsorption properties of MgH2-V systems have been investigated by using a first-principles plane-wave pseudopotential method based on the density func-tional theory.The results are as follows.When VH/MgH2 interface is formed due to V alloying MgH2 phase,the vacancy formed by H atoms near VH phase region is more stable than that without V alloying,while vacancy near MgH2 phase region is lessstable than that without V alloying.During the process of H atoms diffusion after V alloying,the max migration barrier energy of H atoms in MgH2-V systems is re-duced compared with that of MgH2 phase,which means that H atoms diffuse easily.When H diffuses into VH from MgH2 across VH/MgH2 interface,among three sub-stitutions such as the replacement of H for V vacancy,or interstitial site or V atoms,the replacement of H for V vacancy has the strongest diffusion ability,next inter-stitial site,and finally V atoms site.As far as H adsorbed on different surfaces of VH phase is concerned,physical adsorption is carried out more easily than chemical adsorption,and the behavior of H atoms adsorbed on the surface near VH phase region can be found more easily than that near MgH2 phase region.

  15. Analogies between dark solitons in atomic Bose-Einstein condensates and optical systems

    International Nuclear Information System (INIS)

    Dark solitons have been observed in optical systems (optical fibres, dielectric guides and bulk media), and, more recently, in harmonically confined atomic Bose-Einstein condensates. This paper presents an overview of some of the common features and analogies experienced by these two intrinsically nonlinear systems, with emphasis on the stability of dark solitons in such systems and their decay via emission of radiation. The closely related issue of vortex dynamics in such systems is also briefly discussed

  16. Non-additivity in laser-illuminated many-atom systems

    CERN Document Server

    Shahmoon, Ephraim; Kurizki, Gershon

    2013-01-01

    We show that atoms subject to laser radiation may form a non-additive many-body system on account of their long-range interactions, when the atoms are trapped in the vicinity of a fiber with Bragg grating. When the laser frequency is inside the grating's bandgap but very close to its edge, we find that the range and strength of the laser-induced interaction becomes substantially enhanced, due to the large density of states near the edge, while the competing process of scattering to the fiber is inhibited. The dynamics of this system conforms to a prominent model of statistical physics which exhibits slow relaxation. This suggests the possibility of using laser-illuminated atoms to study the characteristics of non-additive systems.

  17. Simulations of quantum transport in nanoscale systems: application to atomic gold and silver wires

    DEFF Research Database (Denmark)

    Mozos, J.L.; Ordejon, P.; Brandbyge, Mads;

    2002-01-01

    We present a first-principles method for studying the electronic transport through nanoscale atomic systems under non-equilibrium conditions. The method is based on density functional theory, and allows the calculation of the response of the system to an applied finite potential difference....... The potential drop profile and induced electronic current (and therefore the conductance) are obtained from first principles. The method takes into account the atomic structure of both the nanoscale structure and the semi-infinite electrodes through which the potential is applied. Non-equilibrium Green......'s function techniques are used to calculate the quantum conductance. Here we apply the method to the study of the electronic transport in wires of gold and silver with atomic thickness. We show the results of our calculations, and compare with some of the abundant experimental data on these systems....

  18. Review On Heat Transfer Enhancement Techniques in Thermal Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    B. Kanimozhi

    2014-02-01

    Full Text Available Heat transfer enhancements of both experimental and analytical studies have been reported in view of their industrial and domestic significances. This review is confined to the enhancement of heat transfer in solidification processes and latent heat thermal storage system due to low heat thermal conductivity of the PCM. The review covers different methods of heat transfer enhancement techniques, encapsulation of phase change materials in Thermal Energy Storage System and solar system.

  19. INTRAMOLECULAR CHARGE AND ENERGY TRANSFER IN MULTICHROMOPHORIC AROMATIC SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Edward C. Lim

    2008-09-09

    A concerted experimental and computational study of energy transfer in nucleic acid bases and charge transfer in dialkylaminobenzonitriles, and related electron donor-acceptor molecules, indicate that the ultrafast photoprocesses occur through three-state conical interactions involving an intermediate state of biradical character.

  20. Radiological safety observations in the gas-jet transport system for transporting radioactive atoms of RIB facility

    International Nuclear Information System (INIS)

    RIB facility of VECC with its significant progress leading to the ultimate project 'ANURIB' unfastens a wide spectrum of radiological safety issues which need to be systematically attended. The issues range from, limiting of external exposure, containment of both fixed and transferable type of radioactive contamination of short and long lived radioisotopes and controlling any probable internal exposure to complex ones like estimation of various limiting values of radiation protection and operational quantities. The present work is mainly focussed on the radiological safety issues of transporting the radioactive atoms generated inside the He-Jet multi target chamber (from RTC vault) to the RIB facility (Radioactive Ion Beam facility) at HR Cave using the gas-jet transport system. The radiological safety issues are discussed for both ISOL and PFS method of RIB production

  1. Generation of molecular diffuse-band stimulated radiation through multiple excitation mechanism in potassium molecule-atom system

    Institute of Scientific and Technical Information of China (English)

    贾锁堂; 秦莉娟; 钱祖良; 王祖赓; 王钢; 周国生

    1997-01-01

    Population reduction effect generated in two-photon resonant excitation process of potassium atoms in a potassium molecule-atom system is theoretically investigated The obtained result is compared with the relevant experimental ones in the process of two-photon resonant excitation of potassium molecules and in the process of two-photon mixed excitation of potassium molecule-atoms.

  2. Experimental system for the storage of light in atomic vapor

    Science.gov (United States)

    Mair, A.; Fleischhauer, A.; Lukin, M. D.; Phillips, D. F.; Walsworth, R. L.

    2001-05-01

    In a recently reported experiment (D. F. Phillips, A. Fleischhauer, A. Mair, R. L. Walsworth, and M. D. Lukin, Phys. Rev. Lett. 86), 4783 (2001)., we reversibly stored a light pulse in a Zeeman (spin) coherence of Rb vapor for times ~ 0.5 ms. In this experiment, the Rb is warmed slightly above room temperature ( ~ 80^circC) and constrained by a buffer gas of a few torr of He. Experimental details of this light storage system will be presented.

  3. Upper Secondary Students' Understanding of the Basic Physical Interactions in Analogous Atomic and Solar Systems

    Science.gov (United States)

    Taber, Keith S.

    2013-01-01

    Comparing the atom to a "tiny solar system" is a common teaching analogy, and the extent to which learners saw the systems as analogous was investigated. English upper secondary students were asked parallel questions about the physical interactions between the components of a simple atomic system and a simple solar system to investigate…

  4. Atomic scattering in the diffraction limit: electron transfer in keV Li+-Na(3s, 3p) collisions

    DEFF Research Database (Denmark)

    Poel, Mike van der; Nielsen, C.V.; Rybaltover, M.;

    2002-01-01

    of the de Broglie wavelength lambda(dB) = 150 fm at a velocity v = 0.20 au and the effective atomic diameter for electron capture 2R = 20 au. Parallel AO and MO semiclassical coupled-channel calculations of the Na(3s, 3p) --> Li(2s, 2p) state-to-state collision amplitudes have been performed, and quantum...

  5. New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Montaser, A.

    1992-01-01

    New high temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. Emphasis was placed on atmospheric pressure He inductively coupled plasmas (ICP) suitable for atomization, excitation, and ionization of elements; simulation and computer modeling of plasma sources with potential for use in spectrochemical analysis; spectroscopic imaging and diagnostic studies of high temperature plasmas, particularly He ICP discharges; and development of new, low-cost sample introduction systems, and examination of techniques for probing the aerosols over a wide range. Refs., 14 figs. (DLC)

  6. Applications of quantum and classical connections in modeling atomic, molecular and electrodynamic systems

    CERN Document Server

    Popa, Alexandru

    2013-01-01

    Applications of Quantum and Classical Connections in Modeling Atomic, Molecular and Electrodynamical Systems is a reference on the new field of relativistic optics, examining topics related to relativistic interactions between very intense laser beams and particles. Based on 30 years of research, this unique book connects the properties of quantum equations to corresponding classical equations used to calculate the energetic values and the symmetry properties of atomic, molecular and electrodynamical systems. In addition, it examines applications for these methods, and for the calculation of

  7. Two-photon phase gate with linear optical elements and atom-cavity system

    Science.gov (United States)

    Kang, Yi-Hao; Xia, Yan; Lu, Pei-Min

    2016-09-01

    We propose a protocol for implementing π phase gate of two photons with linear optical elements and an atom-cavity system. The evolution of the atom-cavity system is based on the quantum Zeno dynamics. The devices in the present protocol are simple and feasible with current experimental technology. Moreover, the method we proposed here is deterministic with a high fidelity. Numerical simulation shows that the evolution in cavity is efficient and robust. Therefore, the protocol may be helpful for quantum computation field.

  8. Simulating narrow nonlinear resonance features for magnetometry in compact cold atom systems

    Science.gov (United States)

    Meyer, David; Robinson, Jenn; Kunz, Paul; Quraishi, Qudsia

    2015-05-01

    We are investigating cold atom magnetometry applications and have developed a numeric model of Electromagnetically Induced Absorption (EIA) and Nonlinear Magneto-Optical Rotation (NMOR) for degenerate two-level systems. While most EIA and NMOR research is done in warm vapors, cold atoms avoid Doppler broadening and better isolate the various optical pumping mechanisms involved. Our model focuses on the effect of transverse magnetic fields on both EIA and NMOR features and shows that critical points of both yield quantitative measures of the magnitude and direction of the transverse field. This dependence reveals the underlying optical pumping mechanisms and makes possible a single, in-situ measurement of the background magnetic field zero to the sub-milligauss level, reducing background fields to enhance sub-Doppler cooling and collectively-enhanced neutral-atom quantum memory lifetimes. Separately, we are pursuing experimental measurements on the relationship between EIA and NMOR in a compact cold atom apparatus. To improve the system's capabilities we are designing our next-generation atom chip to reduce system size and employ versatile geometries enabling multi-site trapping.

  9. Universal quantum gates for photon-atom hybrid systems assisted by bad cavities.

    Science.gov (United States)

    Wang, Guan-Yu; Liu, Qian; Wei, Hai-Rui; Li, Tao; Ai, Qing; Deng, Fu-Guo

    2016-01-01

    We present two deterministic schemes for constructing a CNOT gate and a Toffoli gate on photon-atom and photon-atom-atom hybrid quantum systems assisted by bad cavities, respectively. They are achieved by cavity-assisted photon scattering and work in the intermediate coupling region with bad cavities, which relaxes the difficulty of their implementation in experiment. Also, bad cavities are feasible for fast quantum operations and reading out information. Compared with previous works, our schemes do not need any auxiliary qubits and measurements. Moreover, the schematic setups for these gates are simple, especially that for our Toffoli gate as only a quarter wave packet is used to interact the photon with each of the atoms every time. These atom-cavity systems can be used as the quantum nodes in long-distance quantum communication as their relatively long coherence time is suitable for multi-time operations between the photon and the system. Our calculations show that the average fidelities and efficiencies of our two universal hybrid quantum gates are high with current experimental technology.

  10. Universal quantum gates for photon-atom hybrid systems assisted by bad cavities

    Science.gov (United States)

    Wang, Guan-Yu; Liu, Qian; Wei, Hai-Rui; Li, Tao; Ai, Qing; Deng, Fu-Guo

    2016-04-01

    We present two deterministic schemes for constructing a CNOT gate and a Toffoli gate on photon-atom and photon-atom-atom hybrid quantum systems assisted by bad cavities, respectively. They are achieved by cavity-assisted photon scattering and work in the intermediate coupling region with bad cavities, which relaxes the difficulty of their implementation in experiment. Also, bad cavities are feasible for fast quantum operations and reading out information. Compared with previous works, our schemes do not need any auxiliary qubits and measurements. Moreover, the schematic setups for these gates are simple, especially that for our Toffoli gate as only a quarter wave packet is used to interact the photon with each of the atoms every time. These atom-cavity systems can be used as the quantum nodes in long-distance quantum communication as their relatively long coherence time is suitable for multi-time operations between the photon and the system. Our calculations show that the average fidelities and efficiencies of our two universal hybrid quantum gates are high with current experimental technology.

  11. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    Science.gov (United States)

    Ambrosek, James Wallace

    2011-12-01

    A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

  12. Theoretical analysis of the spectroscopy of atomic Bose-Hubbard systems

    Science.gov (United States)

    Inaba, Kensuke; Yamashita, Makoto

    2016-04-01

    We provide a numerical method to calculate comprehensively the microwave and the laser spectra of ultracold bosonic atoms in optical lattices at finite temperatures. Our formulation is built up with the sum rules, up to the second order, derived from the general principle of spectroscopy. The sum rule approach allows us to discuss the physical origins of a spectral peak shift and also a peak broadening. We find that a spectral broadening of superfluid atoms can be determined from number fluctuations of atoms, while that of normal-state atoms is mainly attributed to quantum fluctuations resulting from hopping of atoms. To calculate spectra at finite temperatures, based on the sum rule approach, we provide a two-mode approximation assuming that spectra of the superfluid and normal state atoms can be calculated separately. Our method can properly deal with multipeak structures of spectra resulting from thermal fluctuations and also coexisting of the superfluid and the normal states. By combining the two-mode approximation with a finite temperature Gutzwiller approximation, we calculate spectra at finite temperatures by considering realistic systems, and the calculated spectra show nice agreements with those in experiments.

  13. Electron transfer and atom exchange between aqueous Fe(II) and structural Fe(III) in clays. Role in U and Hg(II) transformations

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Michelle [Univ. of Iowa, Iowa City, IA (United States)

    2016-08-31

    During this project, we investigated Fe electron transfer and atom exchange between aqueous Fe(II) and structural Fe(III) in clay minerals. We used selective chemical extractions, enriched Fe isotope tracer experiments, computational molecular modeling, and Mössbauer spectroscopy. Our findings indicate that structural Fe(III) in clay minerals is reduced by aqueous Fe(II) and that electron transfer occurs when Fe(II) is sorbed to either basal planes and edge OH-groups of clay mineral. Findings from highly enriched isotope experiments suggest that up to 30 % of the Fe atoms in the structure of some clay minerals exhanges with aqueous Fe(II). First principles calculations using a small polaron hopping approach suggest surprisingly fast electron mobility at room temperature in a nontronite clay mineral and are consistent with temperature dependent Mössbauer data Fast electron mobility suggests that electrons may be able to conduct through the mineral fast enough to enable exchange of Fe between the aqueous phase and clay mineral structure. over the time periods we observed. Our findings suggest that Fe in clay minerals is not as stable as previously thought.

  14. Non-atomic Games for Multi-User Systems

    CERN Document Server

    Bonneau, Nicolas; Altman, Eitan; Hjørungnes, Are

    2007-01-01

    In this contribution, the performance of a multi-user system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while perfect channel state information is assumed at the base station). We consider the realistic case of frequency selective channels for uplink CDMA. This scenario illustrates the case of decentralized schemes, where limited information on the network is available at the terminal. Various receivers are considered, namely the Matched filter, the MMSE filter and the optimum filter. The goal of this paper is to derive simple expressions for the non-cooperative Nash equilibrium as the number of mobiles becomes large and the spreading length increases. To that end two asymptotic methodologies are combined. The first is asymptotic random matrix theory which allows us to obtain explicit expressions of the impact of all other mobiles on any ...

  15. High-performance laser power feedback control system for cold atom physics

    Institute of Scientific and Technical Information of China (English)

    Bo Lu; Thibault Vogt; Xinxing Liu; Xiaoji Zhou; Xuzong Chen

    2011-01-01

    @@ A laser power feedback control system that features fast response,large-scale performance,low noise,and excellent stability is presented.Some essential points used for optimization are described.Primary optical lattice experiments are given as examples to show the performance of this system.With these performance characteristics,the power control system is useful for applications in cold atom physics and precision measurements.%A laser power feedback control system that features fast response, large-scale performance, low noise, and excellent stability is presented. Some essential points used for optimization are described. Primary optical lattice experiments are given as examples to show the performance of this system. With these performance characteristics, the power control system is useful for applications in cold atom physics and precision measurements.

  16. Upper Secondary Students' Understanding of the Basic Physical Interactions in Analogous Atomic and Solar Systems

    Science.gov (United States)

    Taber, Keith S.

    2013-08-01

    Comparing the atom to a `tiny solar system' is a common teaching analogy, and the extent to which learners saw the systems as analogous was investigated. English upper secondary students were asked parallel questions about the physical interactions between the components of a simple atomic system and a simple solar system to investigate how they understood the forces acting within the two systems. A sample of just over 100 across the 15-18 age range responded to a pencil-and-paper instrument that asked about four aspects of the two systems. It was found that for both systems, about four fifths of students expected forces to decrease with increasing distance; but that only a little over half expected there to be interactions between the minor constituents (electrons and planets). Most students failed to apply Newton's third law to either system. There was a considerable difference in the extent to which respondents were able to identify the type of force acting in the systems (nearly all for the solar system, but only a small proportion in the case of the atom). The findings are considered in terms of both the limitations of students' understanding of the basic physics and possible implications for the use of the teaching analogy.

  17. INTRODUCTION: Many-Body Theory of Atomic Systems: Proceedings of the Nobel Symposium 46

    Science.gov (United States)

    Lindgren, Ingvar; Lundqvist, Stig

    1980-01-01

    A Nobel Symposium provides an excellent opportunity to bring together a group of prominent scientists for a stimulating meeting. The Nobel Symposia are very small meetings by invitation only and the number of key participants is usually in the range 20-40. These symposia are organized through a special Nobel Symposium Committee after proposals from individuals. They have been made possible through a major grant from the Tri-Centennial Fund of the Bank of Sweden. Our first ideas to arrange a Nobel Symposium on many-body theory of atomic systems came up more than two years ago. It was quite obvious to us that a major break-through was happening in this field. Very accurate schemes have been available for some time for studying the static properties of small closed-shell atomic systems. By "atomic" systems we understand here atoms as well as free molecules, which can be treated by the same formalism, although the technical approaches might be quite different. The conceptual and computational developments in recent years, however, have made it possible to apply the many-body formalism also to heavier systems. Although no rigorous relativistic many-body theory yet exists, there seems to be a general agreement about the way relativistic calculations should be performed on normal atoms and molecules. Schemes based on relativistic perturbation theory as well as on relativistic multi- configurational Hartree-Fock are now in operation and a rapid development is expected in this area. Another field of atomic theory, where significant progress has been made recently, is in the application of many-body formalism to open-shell systems. General schemes, applicable to systems with one or several open shells, are now available, which will make it possible to apply many-body formalism to a much larger group of atomic systems and, in particular, to systems of more physical interest, A number of atomic properties - not only the correlation energy - can then be compared with the

  18. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Boudier, Ariane; Tournebize, Juliana [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Bartosz, Grzegorz [Department of Molecular Biophysics, University of Lodz, Lodz (Poland); El Hani, Safae; Bengueddour, Rachid [Laboratoire de Nutrition et Sante, Biology Department, Faculty of Sciences, Ibn Tofail University, Kenitra (Morocco); Sapin-Minet, Anne [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Leroy, Pierre, E-mail: pierre.leroy@pharma.uhp-nancy.fr [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Both 1,1-diphenyl-2-picrylhydrazyl radical and its product measurement by HPLC. Black-Right-Pointing-Pointer Lowest limit of detection by monitoring 1,1-diphenyl-2-picryl-hydrazine. Black-Right-Pointing-Pointer Adsorption problem of the radical on HPLC parts have been pointed out. - Abstract: 1,1-Diphenyl-2-picrylhydrazyl (DPPH{center_dot}) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH{center_dot} absorbance at 515 nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH{center_dot} quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH{center_dot} resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH{center_dot} and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH{center_dot} and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile-10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH{center_dot} onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH{center_dot} was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH{center_dot} using standards (0.02 and 14 {mu}M, respectively). The method was applied to three commonly used AOs, i.e. Trolox{sup Registered-Sign }, ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of

  19. Configurable memory system and method for providing atomic counting operations in a memory device

    Science.gov (United States)

    Bellofatto, Ralph E.; Gara, Alan G.; Giampapa, Mark E.; Ohmacht, Martin

    2010-09-14

    A memory system and method for providing atomic memory-based counter operations to operating systems and applications that make most efficient use of counter-backing memory and virtual and physical address space, while simplifying operating system memory management, and enabling the counter-backing memory to be used for purposes other than counter-backing storage when desired. The encoding and address decoding enabled by the invention provides all this functionality through a combination of software and hardware.

  20. Quantum dynamics of hydrogen atoms on graphene. I. System-bath modeling

    International Nuclear Information System (INIS)

    An accurate system-bath model to investigate the quantum dynamics of hydrogen atoms chemisorbed on graphene is presented. The system comprises a hydrogen atom and the carbon atom from graphene that forms the covalent bond, and it is described by a previously developed 4D potential energy surface based on density functional theory ab initio data. The bath describes the rest of the carbon lattice and is obtained from an empirical force field through inversion of a classical equilibrium correlation function describing the hydrogen motion. By construction, model building easily accommodates improvements coming from the use of higher level electronic structure theory for the system. Further, it is well suited to a determination of the system-environment coupling by means of ab initio molecular dynamics. This paper details the system-bath modeling and shows its application to the quantum dynamics of vibrational relaxation of a chemisorbed hydrogen atom, which is here investigated at T = 0 K with the help of the multi-configuration time-dependent Hartree method. Paper II deals with the sticking dynamics

  1. Quantum dynamics of hydrogen atoms on graphene. I. System-bath modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bonfanti, Matteo, E-mail: matteo.bonfanti@unimi.it [Dipartimento di Chimica, Università degli Studi di Milano, v. Golgi 19, 20133 Milano (Italy); Jackson, Bret [Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Hughes, Keith H. [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom); Burghardt, Irene [Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main (Germany); Martinazzo, Rocco, E-mail: rocco.martinazzo@unimi.it [Dipartimento di Chimica, Università degli Studi di Milano, v. Golgi 19, 20133 Milano (Italy); Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Richerche, v. Golgi 19, 20133 Milano (Italy)

    2015-09-28

    An accurate system-bath model to investigate the quantum dynamics of hydrogen atoms chemisorbed on graphene is presented. The system comprises a hydrogen atom and the carbon atom from graphene that forms the covalent bond, and it is described by a previously developed 4D potential energy surface based on density functional theory ab initio data. The bath describes the rest of the carbon lattice and is obtained from an empirical force field through inversion of a classical equilibrium correlation function describing the hydrogen motion. By construction, model building easily accommodates improvements coming from the use of higher level electronic structure theory for the system. Further, it is well suited to a determination of the system-environment coupling by means of ab initio molecular dynamics. This paper details the system-bath modeling and shows its application to the quantum dynamics of vibrational relaxation of a chemisorbed hydrogen atom, which is here investigated at T = 0 K with the help of the multi-configuration time-dependent Hartree method. Paper II deals with the sticking dynamics.

  2. Geometry-Induced Memory Effects in Isolated Quantum Systems: Cold-Atom Applications

    Science.gov (United States)

    Lai, Chen-Yen; Chien, Chih-Chun

    2016-03-01

    Memory effects result from the history-dependent behavior of a system, are abundant in our daily life, and have broad applications. Here, we explore the possibilities of generating memory effects in simple isolated quantum systems. By utilizing geometrical effects from a class of lattices supporting flatbands consisting of localized states, memory effects could be observed in ultracold atoms in optical lattices. As the optical lattice continuously transforms from a triangular lattice into a kagome lattice with a flatband, history-dependent density distributions manifest quantum memory effects even in noninteracting systems, including fermionic as well as bosonic systems, in the proper ranges of temperatures. Rapid growth of ultracold technology predicts a bright future for quantum memory-effect systems, and here two prototypical applications of geometry-induced quantum memory effects are proposed: A cold-atom-based accelerometer using an atomic differentiator to record the mechanical change rate of a coupled probe, and an atomic quantum memory cell for storing information with write-in and readout schemes.

  3. New rapid transfer alignment method for SINS of airborne weapon systems

    Institute of Scientific and Technical Information of China (English)

    Yu Chen; Yan Zhao

    2014-01-01

    Transfer alignment is an effective alignment method for the strapdown inertial navigation system (SINS) of airborne weapon systems. The traditional transfer alignment methods for large misalignment angles alignment use nonlinear transfer align-ment models and incorporate nonlinear filtering. A rapid transfer alignment method with linear models and linear filtering for ar-bitrary misalignment angles is presented. Through the attitude quaternion decomposition, the purpose of transfer alignment is converted to estimate a constant quaternion. Employing special manipulations on measurement equation, velocity and attitude linear measurement equations are derived. Then the linear trans-fer alignment model for arbitrary misalignment angles is built. An adaptive Kalman filter is developed to handle modeling errors of the measurement noise statistics. Simulation results show feasibili-ty and effectiveness of the proposed method, which provides an alternative rapid transfer alignment method for airborne weapons.

  4. Charge transfer across the water/nitrobenzene interface bythree-electrode system

    Institute of Scientific and Technical Information of China (English)

    YUAN; Yi; (袁艺); GAO; Zhao; (高(目目空); ); ZHANG; Meiqin; (张美芹); ZHANG; Zhiquan; (张志权); SHAO; Yuanhua; (邵元华)

    2002-01-01

    A droplet of aqueous solution containing a certain molar ratio of redox couple is first attached onto a platinum electrode surface, then the resulting drop electrode is immersed into the organic solution containing very hydrophobic electrolyte. Combined with reference and counter electrodes, a classical three-electrode system has been constructed. Ion transfer (IT) and electron transfer (ET) are investigated systematically using three-electrode voltammetry. Potassium ion transfer and electron transfer between potassium ferricyanide in the aqueous phase and ferrocene in nitrobenzene are observed with potassium ferricyanide/potassium ferrocyanide as the redox couple. Meanwhile, the transfer reactions of lithium, sodium, potassium, proton and ammonium ions are obtained with ferric sulfate/ferrous sulfate as the redox couple. The formal transfer potentials and the standard Gibbs transfer energy of these ions are evaluated and consistent with the results obtained by a four-electrode system and other methods.

  5. Long-range radionuclide transfer in air and water systems

    International Nuclear Information System (INIS)

    Long-range radionuclide air transfer of radionuclide after the first nuclear explosions and after accidents at nuclear installations is observed. Data on transport of radionuclides by the Yenisej river, Pripyat' river, Sozh river, Iput' river, Besed' river are given. The time of radionuclide transfer from Irish sea to Baltic and Barents sea has been defined using change of a relationship of isotopes Cs 134/Cs 137. (authors)

  6. A mass transfer in heterogeneous systems by the adsorption method (

    Directory of Open Access Journals (Sweden)

    N. Bošković-Vragolović

    2009-01-01

    Full Text Available A mass transfer coefficient between: a liquid and single sphere and a liquid and column wall in packed and fluidized beds of a spherical inert particle have been studied experimentally using the adsorption method. The experiments were conducted in a column 40 mm in diameter for packed and fluidized beds, and in a two-dimensional column 140 mm×10 mm for the flow past single sphere. In all runs, the mass transfer rates were determined in the presence of spherical glass particles, 3 mm in diameter, for packed and fluidized beds. The mass transfer data were obtained by studying transfer for flow past single sphere, 20 mm in diameter. This paper discusses the possibilities of application of the adsorption method for fluid flow visualization. Local and average mass transfer coefficients were determined from the color intensity of the surface of the foils of silica gel. Correlations, Sh = f(Re and jD = f(Re, were derived using the mass transfer coefficient data.

  7. Instability of mass transfer in a planet-star system

    CERN Document Server

    Jia, Shi

    2016-01-01

    We show that the angular momentum exchange mechanism governing the evolution of mass transferring binary stars does not apply to Roche-lobe filling planets, because most of the angular momentum of the mass transferring stream is absorbed by the host star. Apart from a correction for the difference in specific angular momentum of the stream and the centre of mass of the planet, the orbit does not expand much on Roche-lobe overflow. We explore the conditions for dynamically unstable Roche-lobe overflow as a function of planet mass and mass and radius (age) of host star and equation of state of planet. For a Sun-like host, gas giant planets in a range of mass and entropy can undergo dynamical mass transfer. Examples of the evolution of the mass transfer process are given. Dynamic mass transfer of rocky planets depend somewhat sensitively on equation of state used. Silicate planets in the range $1 M_{\\oplus} transfer before set...

  8. Sustainable management after irrigation system transfer: experiences in Colombia: the RUT irrigation district

    OpenAIRE

    Cobo, N.U.

    2006-01-01

    This book is focused in the formulation of a framework for the sustainable management of the irrigation systems transferred to the users organizations by the government. It describes the experience of the irrigation management transfer in Colombia, the impacts from a technical, social, environment and economic point of view, the current status of some transferred systems and proposes management alternatives in view of sustainability based on an integrated and participatory approach.

  9. Review On Heat Transfer Enhancement Techniques in Thermal Energy Storage Systems

    OpenAIRE

    B. Kanimozhi; Prabhu, A

    2014-01-01

    Heat transfer enhancements of both experimental and analytical studies have been reported in view of their industrial and domestic significances. This review is confined to the enhancement of heat transfer in solidification processes and latent heat thermal storage system due to low heat thermal conductivity of the PCM. The review covers different methods of heat transfer enhancement techniques, encapsulation of phase change materials in Thermal Energy Storage System and solar...

  10. Preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization for the selective recognition of tetracycline from aqueous medium

    International Nuclear Information System (INIS)

    Highlights: ► Atom transfer radical emulsion polymerization is a “living” and green technique. ► Nanoparticles can overcome mass transfer limitations and improve accessibility. ► Molecular imprinted nanoparticles with magnetic property for fast separation. ► The performance of imprinted nanoparticles was investigated in detail. ► Nanoparticles were used to selective recognize Tetracycline from water medium. - Abstract: In the work, we reported an effective method for the preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization (ATREP), and then as-prepared magnetic molecularly imprinted nanoparticles (MMINs) were evaluated as adsorbents for selective recognition of tetracycline (TC) molecules from aqueous medium. The resulting nanoparticles were characterized by FT-IR, TGA, VSM, SEM and TEM. The results demonstrated MMINs with a narrow diameter distribution were cross-linked with modified Fe3O4 particles, composed of imprinted layer and exhibited good magnetic sensitivity, magnetic and thermal stability. Batch rebinding studies were carried out to determine the specific adsorption equilibrium, kinetics, and selective recognition. The estimated adsorption capacity of MMINs towards TC by the Langmuir isotherm model was 12.10 mg g−1 at 298 K, which was 6.33 times higher than that of magnetic non-molecularly imprinted nanoparticles (MNINs). The kinetic property of MMINs was well-described by the pseudo-second-order rate equation. The results of selective recognition experiments demonstrated outstanding affinity and selectivity towards TC over competitive antibiotics. The reusability of MMINs showed no obviously deterioration at least five repeated cycles in performance. In addition, the MMINs prepared were successfully applied to the extraction of TC from the spiked pork sample.

  11. Preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization for the selective recognition of tetracycline from aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jiangdong; Pan, Jianming; Xu, Longcheng; Li, Xiuxiu [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhou, Zhiping [School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhang, Rongxian [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yan, Yongsheng, E-mail: djdxxx123@163.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100191 (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer Atom transfer radical emulsion polymerization is a 'living' and green technique. Black-Right-Pointing-Pointer Nanoparticles can overcome mass transfer limitations and improve accessibility. Black-Right-Pointing-Pointer Molecular imprinted nanoparticles with magnetic property for fast separation. Black-Right-Pointing-Pointer The performance of imprinted nanoparticles was investigated in detail. Black-Right-Pointing-Pointer Nanoparticles were used to selective recognize Tetracycline from water medium. - Abstract: In the work, we reported an effective method for the preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization (ATREP), and then as-prepared magnetic molecularly imprinted nanoparticles (MMINs) were evaluated as adsorbents for selective recognition of tetracycline (TC) molecules from aqueous medium. The resulting nanoparticles were characterized by FT-IR, TGA, VSM, SEM and TEM. The results demonstrated MMINs with a narrow diameter distribution were cross-linked with modified Fe{sub 3}O{sub 4} particles, composed of imprinted layer and exhibited good magnetic sensitivity, magnetic and thermal stability. Batch rebinding studies were carried out to determine the specific adsorption equilibrium, kinetics, and selective recognition. The estimated adsorption capacity of MMINs towards TC by the Langmuir isotherm model was 12.10 mg g{sup -1} at 298 K, which was 6.33 times higher than that of magnetic non-molecularly imprinted nanoparticles (MNINs). The kinetic property of MMINs was well-described by the pseudo-second-order rate equation. The results of selective recognition experiments demonstrated outstanding affinity and selectivity towards TC over competitive antibiotics. The reusability of MMINs showed no obviously deterioration at least five repeated cycles in performance. In addition, the MMINs prepared were successfully

  12. Anti-oxidant activity of 6-gingerol as a hydroxyl radical scavenger by hydrogen atom transfer, radical addition and electron transfer mechanisms

    Indian Academy of Sciences (India)

    MANISH K TIWARI; P C MISHRA

    2016-08-01

    Mechanisms of anti-oxidant action of 6-gingerol as a hydroxyl radical scavenger have been investigated using the transition state theory within the framework of density functional theory. Hydrogen abstraction by a hydroxyl radical from the different sites of 6-gingerol and addition of the former to the different sites ofthe latter were studied. Electron transfer from 6-gingerol to a hydroxyl radical was also studied. Solvent effect in aqueous media was treated using the integral equation formalism of the polarizable continuum model (IEFPCM). Reaction rate constants in aqueous media were generally found to be larger than those in gas phase. The tunneling contributions to rate constants were found to be appreciable. Our results show that 6-gingerol is an excellent anti-oxidant and would scavenge hydroxyl radicals efficiently.

  13. The Langevin and generalised Langevin approach to the dynamics of atomic, polymeric and colloidal systems

    CERN Document Server

    Snook, Ian

    2007-01-01

    The Langevin and Generalised Langevin Approach To The Dynamics Of Atomic, Polymeric And Colloidal Systems is concerned with the description of aspects of the theory and use of so-called random processes to describe the properties of atomic, polymeric and colloidal systems in terms of the dynamics of the particles in the system. It provides derivations of the basic equations, the development of numerical schemes to solve them on computers and gives illustrations of application to typical systems.Extensive appendices are given to enable the reader to carry out computations to illustrate many of the points made in the main body of the book.* Starts from fundamental equations* Gives up-to-date illustration of the application of these techniques to typical systems of interest* Contains extensive appendices including derivations, equations to be used in practice and elementary computer codes

  14. Miniature Bose–Einstein condensate system design based on a transparent atom chip

    Science.gov (United States)

    Cheng, Jun; Li, Xiaolin; Zhang, Jingfang; Xu, Xinping; Jiang, Xiaojun; Zhang, Haichao; Wang, Yuzhu

    2016-08-01

    We propose a new miniature Bose–Einstein condensate (BEC) system based on a transparent atom chip with a compact external coil structure. A standard six-beam macroscopic magneto-optical trap (MOT) is able to be created near the chip surface due to the chip’s transparency. A novel wire pattern consisting of a double-z wire and a z-shaped wire is designed on the transparent atom chip. With a vertical bias magnetic field, the double-z wire can create the quadrupole magnetic field of an intermediate chip MOT, which is suitable for transporting atoms from the macroscopic MOT to the chip z-wire trap efficiently. The compact external coil structure is designed with a rectangular frameless geometry consisting of only four coil pairs and its volume is less than 0.3 liters. The maximum system power consumption during the BEC generation procedure is about 45 W. The miniature system is evaluated, and about 3 × 106 atoms can be loaded into the chip z-wire trap. The miniature chip BEC system has the advantages of small volume and low power consumption, and it has great potential for practical applications of BEC.

  15. Observation of Electromagnetically Induced Transparency in a Zeeman-Sublevel System in Rubidium Atomic Vapour

    Institute of Scientific and Technical Information of China (English)

    肖峰; 郭瑞民; 陈帅; 张宇; 李路明; 陈徐宗

    2003-01-01

    We observed electromagnetically induced transparency (EIT) in a Zeeman-sublevel system using rubidium atomic vapour at the temperature of 75℃, in which the width of the EIT signal is only 0.6 MHz. Two different methods were performed to observe the EIT signal in our experiment.

  16. Electromagnetically-induced transparency in a multi-V-type system in cesium atomic vapour

    Institute of Scientific and Technical Information of China (English)

    赵建明; 尹王保; 汪丽蓉; 肖连团; 贾锁堂

    2002-01-01

    Electromagnetically-induced transparency is observed in a three-level multi-V-type system in cesium vapour atroom temperature. The absorption property is measured and the hyperfine structures of atomic states can be determined.The results of the experiment agree with the theoretical analysis.

  17. Numerical Studies of Collective Phenomena in Two-Dimensional Electron and Cold Atom Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rezayi, Edward

    2013-07-25

    Numerical calculations were carried out to investigate a number of outstanding questions in both two-dimensional electron and cold atom systems. These projects aimed to increase our understanding of the properties of and prospects for non-Abelian states in quantum Hall matter.

  18. Study of thermal energies of the excitation transfer of potassium atoms in the (4Psub(1/2)) state in collision with helium atoms

    International Nuclear Information System (INIS)

    The collision theory is established for fine structure changes in the first doublet of the alkali metal - rare gas couple: the adiabatic potential curves are calculated, the semi-classical and quantum treatments of collision are given and the influence of the interaction potential on the total cross-section is analyzed. The experimental device built to measure the total cross-sections of fine structure transition for the K*-He couple is described: rare gas jet system, alkali jet system, laser, optics, detection. The results obtained on the cross-section sigma(4Psub(1/2)→4Psub(3/2)) are given for the couple K*-He from 0.07 to 0.4 eV

  19. Ultracold atoms in optical lattices simulating quantum many-body systems

    CERN Document Server

    Lewenstein, Maciej; Ahufinger, Verònica

    2012-01-01

    Quantum computers, though not yet available on the market, will revolutionize the future of information processing. Quantum computers for special purposes like quantum simulators are already within reach. The physics of ultracold atoms, ions and molecules offer unprecedented possibilities of control of quantum many body systems and novel possibilities of applications to quantum information processing and quantum metrology. Particularly fascinating is the possibility of usingultracold atoms in lattices to simulate condensed matter or even high energy physics.This book provides a complete and co

  20. Resonatorkühlung und Spektroskopie des gebundenen Atom-Resonator-Systems

    OpenAIRE

    Maunz, Peter L. W.

    2007-01-01

    Das Kühlen einzelner Atome ist die Voraussetzung dafür, sie in einer Lichtfalle einfangen und beobachten zu können. Mit der Laserkühlung steht der Atomphysik eine effiziente Methode dafür zur Verfügung. Deren Nachteil besteht jedoch darin, daß sie auf der wiederholten Absorption und spontanen Emission von Photonen beruht. Daher ist diese Methode nur für wenige Atomsorten, die einen geschlossenen Übergang aufweisen, anwendbar. Im stark gekoppelten Atom-Resonator-System kann die spontane Emissi...

  1. Initial tests of atomic layer deposition (ALD) coatings for superconducting RF systems

    International Nuclear Information System (INIS)

    Atomic Layer Deposition (ALD) is a method of synthesizing materials in single atomic layers. We are studying this technique as a method of producing highly controlled surfaces for superconducting RF systems. We have begun tests of ALD coatings of single cells that will involve RF measurements of a cell before and after coating at Argonne. In addition to the tests on complete cells, we are also beginning a program of point contact tunneling measurements to determine the properties of the superconductors at the interface between the bulk niobium and the oxide layer. We describe the method, and tests we are beginning with single cell resonators and small samples.

  2. Three-Photon Resonant Nondegenerate Six-Wave Mixing in a Dressed Atomic System

    Institute of Scientific and Technical Information of China (English)

    SUN Jiang; FU Guang-Sheng; SU Hong-Xin; ZUO Zhan-Chun; WU Ling-An; FU Pan-Ming

    2008-01-01

    We report a three-photon resonant nondegenerate six-wave mixing (NSWM) in a dressed cascade five-level system.It has advantages that phase match condition is not stringent and NSWM signal is enhanced tremendously due to the multiple resonance with the atomic transition frequencies. In the presence of a strong coupling field,the threephoton resonant NSWM spectrum exhibits Autler-Townes splitting. This technique provides a spectroscopic tool for measuring not only the resonant frequency and dephasing rate but also the transition dipole moment between two highly excited atomic states.

  3. Theory of quantum and classical connections in modeling atomic, molecular and electrodynamical systems

    CERN Document Server

    Popa, Alexandru

    2013-01-01

    Quantum and Classical Connections in Modeling Atomic, Molecular and Electrodynamic Systems is intended for scientists and graduate students interested in the foundations of quantum mechanics and applied scientists interested in accurate atomic and molecular models. This is a reference to those working in the new field of relativistic optics, in topics related to relativistic interactions between very intense laser beams and particles, and is based on 30 years of research. The novelty of this work consists of accurate connections between the properties of quantum equations and correspon

  4. Absorption-Dispersion Properties in a Four-Level Atomic System with Vacuum-Induced Coherence

    Institute of Scientific and Technical Information of China (English)

    WEI Hua; LI Jia-Hua; ZHAN Zhi-Ming; PENG Ju-Cun

    2005-01-01

    We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.

  5. Absorption-Dispersion Properties in a Four-Level Atomic System with Vacuum-Induced Coherence

    Institute of Scientific and Technical Information of China (English)

    WEIHua; LIJia-Hua; ZHANZhi-Ming; PENGJu-Cun

    2005-01-01

    We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (FIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.

  6. Coupled-cluster calculations of properties of Boron atom as a monovalent system

    CERN Document Server

    Gharibnejad, H

    2015-01-01

    We present relativistic coupled-cluster (CC) calculations of energies, magnetic-dipole hyperfine constants, and electric-dipole transition amplitudes for low-lying states of atomic boron. The trivalent boron atom is computationally treated as a monovalent system. We explore performance of the CC method at various approximations. Our most complete treatment involves singles, doubles and the leading valence triples. The calculations are done using several approximations in the coupled-cluster (CC) method. The results are within 0.2-0.4% of the energy benchmarks. The hyperfine constants are reproduced with 1-2% accuracy.

  7. Magnetic-field-mediated coupling and control in hybrid atomic-nanomechanical systems

    CERN Document Server

    Tretiakov, A

    2016-01-01

    Magnetically coupled hybrid quantum systems enable robust quantum state control through Landau-Zener transitions. Here, we show that an ultracold atomic sample coupled to a nanomechanical resonator via oscillating magnetic fields can be used to cool the resonator's mechanical motion, to measure the mechanical temperature, and to enable entanglement of these mesoscopic objects. We calculate the expected coupling for both permanent-magnet and current-conducting nanostring resonators and describe how this hybridization is attainable using recently developed fabrication techniques, including SiN nanostrings and atom chips.

  8. Atom-photon entanglement in the system with competing k-photon and l-photon transitions

    Institute of Scientific and Technical Information of China (English)

    Wu Qin; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    We have investigated the evolution of the atomic quantum entropy and the entanglement of atom-photon in the system with competing k-photon and l-photon transitions by means of fully quantum theory, and examined the effects of competing photon numbers (k and l), the relative coupling strength between the atom and the two-mode field(λ/g),and the initial photon number of the field on the atomic quantum entropy and the entanglement of atom-photon.The results show that the multiphoton competing transitions or the large relative coupling strength can lead to the strong entanglement between atoms and photons. The maximal atom-photon entanglement can be prepared via the appropriate selection of system parameters and interaction time.

  9. Entanglement in a system of two two-level atoms interacting with a single-mode field

    Institute of Scientific and Technical Information of China (English)

    Jin Li-Juan; Fang Mao-Fa

    2006-01-01

    We investigate the entanglement in a system of two coupling atoms interacting with a single-mode field by means of quantum information entropy theory. The quantum entanglement between the two atoms and the coherent field is discussed by using the quantum reduced entropy, and the entanglement between the two coupling atoms is also investigated by using the quantum relative entropy. In addition, the influences of the atomic dipole-dipole interaction intensity and the average photon number of the coherent field on the degree of the entanglement is examined. The results show that the evolution of the degree of entanglement between the two atoms and the field is just opposite to that of the degree of entanglement between the two atoms. And the properties of the quantum entanglement in the system rely on the atomic dipole-dipole interaction and the average photon number of the coherent field.

  10. Changes to the Transfer Line Collimation System for the High-Luminosity LHC Beams

    CERN Document Server

    Kain, V; Bracco, C; Fraser, M; Galleazzi, F; Gianfelice-Wendt, E; Kosmicki, A; Maciariello, F; Meddahi, M; Nuiry, F X; Steele, G; Velotti, F

    2015-01-01

    The current LHC transfer line collimation system will not be able to provide enough protection for the high brightness beams in the high-luminosity LHC era. The new collimation system will have to attenuate more and be more robust than its predecessor. The active jaw length of the new transfer line collimators will therefore be 2.1 m instead of currently 1.2 m. The transfer line optics will have to be adjusted for the new collimator locations and larger beta functions at the collimators for absorber robustness reasons. In this paper the new design of the transfer line collimation system will be presented with its implications on transfer line optics and powering, maintainability, protection of transfer line magnets in case of beam loss on a collimator and protection of the LHC aperture.

  11. Interfacility transfers in a non-trauma system setting: an assessment of the Greek reality

    Directory of Open Access Journals (Sweden)

    Larentzakis Andreas

    2010-03-01

    Full Text Available Abstract Background Quality assessment of any trauma system involves the evaluation of the transferring patterns. This study aims to assess interfacility transfers in the absence of a formal trauma system setting and to estimate the benefits from implementing a more organized structure. Methods The 'Report of the Epidemiology and Management of Trauma in Greece' is a one year project of trauma patient reporting throughout the country. It provided data concerning the patterns of interfacility transfers. We compared the transferred patient group to the non transferred patient group. Information reviewed included patient and injury characteristics, need for an operation, Intensive Care Unit (ICU admittance and mortality. Analysis employed descriptive statistics and Chi-square test. Interfacility transfers were then assessed according to each health care facility's availability of five requirements; Computed Tomography scanner, ICU, neurosurgeon, orthopedic and vascular surgeon. Results Data on 8,524 patients were analyzed; 86.3% were treated at the same facility, whereas 13.7% were transferred. Transferred patients tended to be younger, male, and more severely injured than non transferred patients. Moreover, they were admitted to ICU more often, had a higher mortality rate but were less operated on compared to non transferred patients. The 34.3% of transfers was from facilities with none of the five requirements, whereas the 12.4% was from those with one requirement. Low level facilities, with up to three requirements transferred 43.2% of their transfer volume to units of equal resources. Conclusion Trauma management in Greece results in a high number of transfers. Patients are frequently transferred between low level facilities. Better coordination could lead to improved outcomes and less cost.

  12. Coherent internal state transfer by three-photon STIRAP-like scheme for many-atom samples

    CERN Document Server

    Kamsap, Marius Romuald; Pedregosa-Gutierrez, Jofre; Hagel, Gaetan; Houssin, Marie; Morizot, Olivier; Knoop, Martina; Champenois, Caroline

    2013-01-01

    A STIRAP-like scheme is proposed to exploit a three-photon resonance taking place in alkaline-earth-metal ions. This scheme is designed for state transfer between the two fine structure components of the metastable D-state which are two excited states that can serve as optical or THz qu-bit. The advantage of a coherent three-photon process compared to two-photon STIRAP lies in the possibility of exact cancellation of the first order Doppler shift which opens the way for an application to a sample composed of many ions. The transfer efficiency and its dependence with experimental parameters are analyzed by numerical simulations. This efficiency is shown to reach a fidelity as high as $(1-8.10^{-5})$ with realistic parameters. The scheme is also extended to the synthesis of a linear combination of three stable or metastable states.

  13. Realization of Three-Qubit Controlled-Phase Gate Operation with Atoms in Cavity QED System

    Institute of Scientific and Technical Information of China (English)

    TANG Shi-Qing; ZHANG Deng-Yu; XIE Li-Jun; ZHAN Xiao-Gui; GAO Feng

    2009-01-01

    We propose a scheme for realization of three-qubit controlled-phase gate via passing two three-level atoms through a high-Q optical cavity in a cavity QED system. In the presented protocol, the two stable ground states of the atoms act as the two controlling qubits and the zero- and one-photon Fock states of the cavity-field form the target qubit, and no auxiliary state or any measurement is required. The numerical simulation shows that the gate fidelities remain at a high level under the influence of the atomic spontaneous emission, the decay of the cavity mode and deviation of the coupling strength. The experimental feasibility of our proposal is also discussed.

  14. Ab-initio atomic level stresses in Cu-Zr systems

    Science.gov (United States)

    Ojha, Madhusudan; Nicholson, Don M.; Egami, Takeshi

    2014-03-01

    In our recent studies [D. M. Nicholson, Madhusudan Ojha and Takeshi Egami, J. Phys.: Condens. Matter 25 435505 (2013)] we have calculated ab-initio atomic level stresses in the simple B2 Cu-Zr system, Cu50Zr50 liquid and glass and have found tremendous atomic level stress in the B2 structure due to strong bonding between Cu and Zr and significantly smaller atomic level stresses in liquid and glass due to reduced chemical order. We have extended our studies to additional structures and stoichiometries. On the basis of these results we discuss the relationship between short-range order, bonding, electronic density of states and atomic level stress. We are searching for an explanation of the unique position of Zr as a promotor of glass forming ability. We report the differences in atomic level stress, bonding, and density of states when Ti, Y, and Nb replace Zr on fixed structures. The work at the University of Tennessee and Oak Ridge National Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division.

  15. Temperature-controlled electrothermal atomization-atomic absorption spectrometry using a pyrometric feedback system in conjunction with a background monitoring device

    Science.gov (United States)

    Van Deijck, W.; Roelofsen, A. M.; Pieters, H. J.; Herber, R. F. M.

    The construction of a temperature-controlled feedback system for electrothermal atomization-atomic absorption spectrometry (ETA-AAS) using an optical pyrometer applied to the atomization stage is described. The system was used in conjunction with a fast-response background monitoring device. The heating rate of the furnace amounted to 1400° s -1 with a reproducibility better than 1%. The precision of the temperature control at a steady state temperature of 2000°C was 0.1%. The analytical improvements offered by the present system have been demonstrated by the determination of cadmium and lead in blood and finally by the determination of lead in serum. Both the sensitivity and the precision of the method have been improved. The accuracy of the method was checked by determining the lead content for a number of scrum samples both by ETA-AAS and differential pulse anodic stripping voltametry (DPASV) and proved to be satisfactory.

  16. Performance improvement of complementary feeders using static transfer switch system

    Institute of Scientific and Technical Information of China (English)

    Tahir MAHMOOD; Mohammad Ahmad CHOUDHRY

    2009-01-01

    The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches (STSs) at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders' thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently pro-posed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector I-10/2, the alternate feeder of Islamabad Electric Supply COmpany (IESCO), Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.

  17. Role of Bhabha Atomic Research Center (BARC) parallel processing system in structural analysis of nuclear components

    International Nuclear Information System (INIS)

    Computational structural analysis of nuclear reactor components requires high speed computing systems. Parallel processing systems, such as ANUPAM developed at Bhabha Atomic Research Centre, have helped immensely in meeting this requirement. The implementation of structural integrity analysis code on ANUPAM is illustrated here by commissioning two in house codes TABS and FAIR. The parallelization strategies and the efficiency of ANUPAM are highlighted. (author). 6 refs., 3 figs

  18. Interaction of Triply-Dressing Electromagnetically Induced Transparency in Five-level Folding Atomic System

    Institute of Scientific and Technical Information of China (English)

    LI Chang-Biao; NIE Zhi-Qiang; ZHANG Wei-Feng; ZHANG Yan-Peng; SONG Jian-Ping; LI Yuan-Yuan; LU Ke-Qing

    2008-01-01

    @@ We consider a five-level atomic folding system, which involve two kinds of dressing mechanisms (the nested-cascade and the sequential-cascade) in interaction of three-dressing fields, the numerical results show that three-dressing fields are interchangeable under certain conditions, which can be considered as two four-level sub-system configurations (a nested-cascade N configuration and a sequential-cascade inverted-Y configuration).

  19. Enhanced two phase flow in heat transfer systems

    Energy Technology Data Exchange (ETDEWEB)

    Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

    2013-12-03

    A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

  20. A compact and robust diode laser system for atom interferometry on a sounding rocket

    Science.gov (United States)

    Schkolnik, V.; Hellmig, O.; Wenzlawski, A.; Grosse, J.; Kohfeldt, A.; Döringshoff, K.; Wicht, A.; Windpassinger, P.; Sengstock, K.; Braxmaier, C.; Krutzik, M.; Peters, A.

    2016-08-01

    We present a diode laser system optimized for laser cooling and atom interferometry with ultra-cold rubidium atoms aboard sounding rockets as an important milestone toward space-borne quantum sensors. Design, assembly and qualification of the system, combing micro-integrated distributed feedback (DFB) diode laser modules and free space optical bench technology, is presented in the context of the MAIUS (Matter-wave Interferometry in Microgravity) mission. This laser system, with a volume of 21 l and total mass of 27 kg, passed all qualification tests for operation on sounding rockets and is currently used in the integrated MAIUS flight system producing Bose-Einstein condensates and performing atom interferometry based on Bragg diffraction. The MAIUS payload is being prepared for launch in fall 2016. We further report on a reference laser system, comprising a rubidium stabilized DFB laser, which was operated successfully on the TEXUS 51 mission in April 2015. The system demonstrated a high level of technological maturity by remaining frequency stabilized throughout the mission including the rocket's boost phase.