WorldWideScience

Sample records for trap assisted beta

  1. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  2. Trap-assisted decay spectroscopy with ISOLTRAP

    CERN Document Server

    Kowalska, M; Agramunt, J.; Algora, A.; Beck, D.; Blank, B.; Blaum, K.; Böhm, Ch.; Borgmann, Ch.; Breitenfeldt, M.; Fraile, L.M.; George, S.; Herfurth, F.; Herlert, A.; Kreim, S.; Lunney, D.; Minaya-Ramirez, E.; Neidherr, D.; Rosenbusch, M.; Rubio, B.; Schweikhard, L.; Stanja, J.; Zuber, K.

    Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements.

  3. Plasmon assisted optical trapping: fundamentals and biomedical applications

    Science.gov (United States)

    Serafetinides, Alexandros A.; Makropoulou, Mersini; Tsigaridas, Georgios N.; Gousetis, Anastasios

    2015-01-01

    The field of optical trapping has dramatically grown due to implementation in various arenas including physics, biology, medicine and nanotechnology. Certainly, optical tweezers are an invaluable tool to manipulate a variation of particles, such as small dielectric spheres, cells, bacteria, chromosomes and even genes, by highly focused laser beams through microscope. As the main disadvantage of the conventional optical trapping systems is the diffraction limit of the incident light, plasmon assisted nanotrapping is reported as a suitable technique for trapping sub-wavelength metallic or dielectric particles. In this work, firstly, we report briefly on the basic theory of plasmon excitation, focusing on the interaction of nanoscale metallic structures with laser light. Secondly, experimental and numerical simulation results are also presented, demonstrating enhancement of the trapping efficiency of glass or SiO2 substrates, coated with Au and Ag nanostructures, with or without nanoparticles. The optical forces were calculated by measuring the particle's escape velocity calibration method. Finally, representative applications of plasmon assisted optical trapping are reviewed, from cancer therapeutics to fundamental biology and cell nanosurgery.

  4. Parallel optical trap assisted nanopatterning on rough surfaces

    International Nuclear Information System (INIS)

    Tsai, Y-C; Fardel, R; Arnold, C B; Leitz, K-H; Schmidt, M; Otto, A

    2012-01-01

    There exist many optical lithography techniques for generating nanostructures on hard, flat surfaces over large areas. However, few techniques are able to create such patterns on soft materials or surfaces with pre-existing structure. To address this need, we demonstrate the use of parallel optical trap assisted nanopatterning (OTAN) to provide an efficient and robust direct-write method of producing nanoscale features without the need for focal plane adjustment. Parallel patterning on model surfaces of polyimide with vertical steps greater than 1.5 µm shows a feature size uncertainty better than 4% across the step and lateral positional accuracy of 25 nm. A Brownian motion model is used to describe the positional accuracy enabling one to predict how variation in system parameters will affect the nanopatterning results. These combined results suggest that OTAN is a viable technique for massively parallel direct-write nanolithography on non-traditional surfaces. (paper)

  5. Measurement of the beta-neutrino correlation in laser trapped 21Na

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, Nicholas David [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    Trapped radioactive atoms are an appealing source for precise measurements of the beta-neutrino correlation coefficient, a, since the momentum of the neutrino can be inferred from the detection of the unperturbed low-energy recoil daughter nucleus. Sodium-21 is produced on-line at the 88'' cyclotron at Lawrence Berkeley National Laboratory, and 8e5 atoms have been maintained in a magneto-optical trap. A static electric field draws daughter Neon-21 ions to a microchannel plate detector and betas are detected in coincidence with a plastic scintillator beta detector. The Neon-21 time-of-flight distribution determines the beta neutrino correlation coefficient, a. The resulting charge-state distribution is compared to a simple model based on the sudden approximation which suggests a small but important contribution from nuclear recoil-induced ionization. A larger than expected fraction of the daughters are detected in positive charge-states, but no dependence on either the beta or recoil nucleus energy was observed. We find a = 0.5243 plus or minus 0.0092, which is in 3.6 sigma disagreement with the Standard Model prediction of a = 0.559 plus or minus 0.003. Aside from a deviation from the Standard Model, a possible explanation for the discrepancy is that the branching ratio to the first excited state is in error.

  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. Decoherence Assisted Single Electron Trapping at Room Temperature

    Science.gov (United States)

    Elhalawany, Ahmed; Leuenberger, Michael

    2012-02-01

    In this work, we theoretically investigate electron transport in heterostructure semiconductor nanowire (NW). We develop a new mechanism to trap an electron in a quantum dot (QD) by means of decoherence. There are six QDs in the NW. Bias voltage (Vb) is applied across the NW and gate voltage (Vg) is applied to the auxiliary QD to control single charge tunneling. The single electron dynamics along the NW is calculated by means of the generalized master equation based on the tight binding model taking into account electron LO phonon interaction (ELOPI) and thermal broadening inside the QDs. It is shown that the decoherence, which is in the pico-second (ps) regime, speeds up the trapping of the electron in the central QD with probability of 70% in less than 2 ps. Our results can be used for the implementation of high temperature single photon source (SPS) or single electron transistor (SET). We acknowledge support from NSF (Grant No. ECCS-0725514), DARPA/MTO (Grant No. HR0011-08-1-0059), NSF (Grant No. ECCS-0901784), AFOSR (Grant No. FA9550-09-1-0450), and NSF (Grant No. ECCS-1128597).

  8. Light Assisted Collisional Losses in a ^85/87Rb Optical Trap

    Science.gov (United States)

    Gorges, Anthony; Deangelo, Michael; Bingham, Nicholas; Hamilton, Mathew; Roberts, Jacob

    2008-05-01

    Light-assisted collisional loss, loss due to the excitation of an atom-atom pair to a stronger interatomic potential, poses an interesting problem with respect to loading two isotopes into the same optical trap. By loading both ^85Rb and ^87Rb into a far off resonant trap (FORT), we have studied inter- and intraspecies excited state/ground state collisional losses. Because of the relatively weak confinement of the FORT we expect the hyperfine structure of the different isotopes to play a crucial role in the collisional loss rates. This allows us to directly compare losses associated with long range excited state potentials; from purely attractive to purely repulsive, long range to short range. We observe radically different loss rates for different excited state potentials. Additionally, we observe that some collisional channels' loss rates are heavily saturated at our operating intensities (˜15 mW/cm^2). These losses are important limitations in loading dual isotope optical traps.

  9. Treatment of unruptured vertebral dissecting aneurysms: internal trapping or stent-assisted coiling.

    Science.gov (United States)

    Li, Hui; Li, Xi-Feng; Zhang, Xin; He, Xu-Ying; Duan, Chuan-Zhi; Liu, Yan-Chao

    2016-01-01

    Endovascular treatment is an attractive approach for the treatment of unruptured vertebral dissecting aneurysms, and includes internal trapping and stent-assisted coil embolization. However, the optimal therapy remains debatable. We reviewed our experience with both endovascular treatment modalities and compared the safety, efficacy, and short-term outcomes for each approach. We retrospectively reviewed 65 consecutive patients with unruptured vertebral dissecting aneurysms who underwent endovascular treatment between January 2003 and January 2014. 24 patients underwent endovascular internal trapping (group A) while 41 patients underwent stent-assisted coiling (group B). Thirteen patients underwent single stent with coiling while 28 patients underwent double or three stent-assisted coiling. Short-term outcomes were evaluated using the modified Rankin Scale. A favorable clinical outcome was achieved in 58 of 65 patients. Procedure-related complications included ischemic symptoms (n = 6) and recurrence (n = 4). There was no statistical difference in modified Rankin Scale scoring between groups. Group A patients had more ischemia symptoms compared with group B patients (p = 0.043), Group B patients had higher recurrence rates compared with group A patients, but the difference had no statistical significance (p = 1.00). However, recurrence only occurred in patients who underwent stent-assisted coiling alone (p = 0.046). Stent-assisted coiling for unruptured vertebral dissecting aneurysms may maintain artery patency. Multilayer disposition of stents with coils may decrease complications and facilitate aneurysm occlusion. Larger, prospective studies are necessary to determine the long-term outcomes of reconstructive therapy.

  10. Derivation of the tunnelling exchange time for the model of trap-assisted tunnelling

    International Nuclear Information System (INIS)

    Racko, J.; Ballo, P.; Benko, P.; Harmatha, L.; Grmanova, A.; Breza, J.

    2014-01-01

    We present derivation of the tunnelling exchange times that play the key role in the model of trap assisted tunnelling (TAT) considering the electron and hole exchange processes between the trapping centre lying in the forbidden band of the semiconductor and the conduction band, valence band or a metal. All exchange processes are quantitatively described by respective exchange times. The reciprocal values of these exchange times represent the frequency with which the exchange processes contribute to the probability of occupation of the trap by free charge carriers. The crucial problem in any model of TAT is the calculation of the occupation probability. In our approach this probability is expressed in terms of only thermal and tunnelling exchange times. The concept of tunnelling exchange times presents a dominant contribution to our model of TAT. The new approach allows to simply calculate the probability of occupation of the trapping centre by a free charge carrier and subsequently to get the thermal and tunnelling generation-recombination rates occurring in the continuity equations. This is why the TAT model based on thermal and tunnelling exchange times is suitable for simulating the electrical properties of semiconductor nanostructures in which quantum mechanical phenomena play a key role. (authors)

  11. Engineering Vibrationally Assisted Energy Transfer in a Trapped-Ion Quantum Simulator

    Science.gov (United States)

    Gorman, Dylan J.; Hemmerling, Boerge; Megidish, Eli; Moeller, Soenke A.; Schindler, Philipp; Sarovar, Mohan; Haeffner, Hartmut

    2018-01-01

    Many important chemical and biochemical processes in the condensed phase are notoriously difficult to simulate numerically. Often, this difficulty arises from the complexity of simulating dynamics resulting from coupling to structured, mesoscopic baths, for which no separation of time scales exists and statistical treatments fail. A prime example of such a process is vibrationally assisted charge or energy transfer. A quantum simulator, capable of implementing a realistic model of the system of interest, could provide insight into these processes in regimes where numerical treatments fail. We take a first step towards modeling such transfer processes using an ion-trap quantum simulator. By implementing a minimal model, we observe vibrationally assisted energy transport between the electronic states of a donor and an acceptor ion augmented by coupling the donor ion to its vibration. We tune our simulator into several parameter regimes and, in particular, investigate the transfer dynamics in the nonperturbative regime often found in biochemical situations.

  12. Production and trapping of Na isotopes for beta-decay studies

    NARCIS (Netherlands)

    Rogachevskiy, Andrey Valerievich

    2007-01-01

    TRImP is a new facility at KVI, which is presently being completed. The acronym TRImP stands for Trapped Radioactive Isotopes: micro-laboratories for fundamental physics. The Standard Model (SM) quantitatively describes the electroweak and strong interactions. It is agrees very well with

  13. Investigations of the ground-state hyperfine atomic structure and beta decay measurement prospects of 21Na with improved laser trapping techniques

    International Nuclear Information System (INIS)

    Rowe, Mary A.

    1999-01-01

    This thesis describes an experiment in which a neutral atom laser trap loaded with radioactive 21 Na was improved and then used for measurements. The sodium isotope (half-life=22 sec) is produced on line at the 88in cyclotron at Lawrence Berkeley National Laboratory. The author developed an effective magnesium oxide target system which is crucial to deliver a substantive beam of 21 Na to the experiment. Efficient manipulation of the 21 Na beam with lasers allowed 30,000 atoms to be contained in a magneto-optical trap. Using the cold trapped atoms, the author measured to high precision the hyperfine splitting of the atomic ground state of 21 Na. She measured the 3S 1/2 (F=1,m=0)-3S 1/2 (F=2,m=0) atomic level splitting of 21 Na to be 1,906,471,870±200 Hz. Additionally, she achieved initial detection of beta decay from the trap and evaluated the prospects of precision beta decay correlation studies with trapped atoms

  14. Investigations of the ground-state hyperfine atomic structure and beta decay measurement prospects of 21Na with improved laser trapping techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, Mary Anderson [Univ. of California, Berkeley, CA (United States)

    1999-05-01

    This thesis describes an experiment in which a neutral atom laser trap loaded with radioactive 21Na was improved and then used for measurements. The sodium isotope (half-life=22 sec) is produced on line at the 88 in. cyclotron at Lawrence Berkeley National Laboratory. The author developed an effective magnesium oxide target system which is crucial to deliver a substantive beam of 21Na to the experiment. Efficient manipulation of the 21Na beam with lasers allowed 30,000 atoms to be contained in a magneto-optical trap. Using the cold trapped atoms, the author measured to high precision the hyperfine splitting of the atomic ground state of 21Na. She measured the 3S1/2(F=1,m=0)-3S1/2(F=2,m=0) atomic level splitting of 21Na to be 1,906,471,870±200 Hz. Additionally, she achieved initial detection of beta decay from the trap and evaluated the prospects of precision beta decay correlation studies with trapped atoms.

  15. Study on ECH-assisted start-up using trapped particle configuration in KSTAR and application to ITER

    Science.gov (United States)

    Lee, Jeongwon; Kim, Jayhyun; An, YoungHwa; Yoo, Min-Gu; Hwang, Y. S.; Na, Yong-Su

    2017-12-01

    ECH-assisted start-up using trapped particle configuration (TPC) is firstly studied in a superconducting, conventional tokamak, KSTAR. First, improved and efficient start-up using TPC than conventional field null configuration (FNC) is achieved by enhanced pre-ionization plasma quality. TPC shows the broader operation window in terms of the poloidal field quality and the deuterium prefill pressure than that of FNC. Surprisingly the particle trapping enhances the plasma start-up performance even with much lower particle trapping ratio than that of spherical torus. Reliability of TPC with low trapping ratio is investigated by 0D plasma evolution code, TECHP0D. Second, the characteristics of TPC start-up are explored with experiments and modellings. Two kind of start-up failure conditions are identified by the magnetic pitch and prefill pressure scan experiments: (i) low ionization rate; and (ii) low density condition. These experimental observation has consistency with TECHP0D modeling result. Finally, reliable ITER-relevant low toroidal electric field start-up using TPC is achieved with drastically improved success rate of start-up in KSTAR. In this experiments, validity of the ITER-like toroidally inclined ECH/ECCD injection is also expected. Time dependent ITER start-up scenario using TPC is proposed and the superiority of it than FNC is discussed.

  16. Preliminary work on the measurement of the {beta} - {nu} angular correlation in the {sup 6}He beta decay by means of a Paul's trap; Etudes et tests preliminaires a une mesure de la correlation angulaire {beta} - {nu} dans la desintegration du noyau {sup 6}He a l'aide d'un piege de Paul

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, P

    2002-03-01

    The subject of this thesis is the preparation of a measurement of the {beta} - {nu} angular correlation coefficient, in {sup 6}He nuclear {beta} - decay, using a Paul trap. Its principle consists in studying the decay of radioactive ions trapped in a small volume, practically at rest in the center of a transparent electric trap. The trajectories of the particles emitted in the decay are weakly disturbed. The detection in coincidence of the electron and the recoil ion in each decay allows the measurement of 3 observables: the energies of the particles and their relative angle. The {beta} - {nu} angular correlation parameter deduced from the coincidence spectrum is sensitive to the existence of exotic interactions excluded by the V - A theory of the weak interactions. In the case of {sup 6}He decay a deviation observed on the predicted value would imply the existence of tensor type interactions, which might be due to the exchange of leptoquarks. These are gauge bosons present in many extensions of the Standard Model. The work presented here concerns the tests of a transparent Paul trap. The performance of the trap has been tested with ions created in a laser plasma source (Mo{sup +}, Fe{sup +}, Al{sup +}), and also with ions delivered by an ionization source ({sup 4}He{sup +} ions). These experiments were carried out in parallel with their simulations which required the development of a computer code of the electrical potential in various geometries, and of a code of ions transport in the associated fields. These simulations showed a good agreement with the experiment. A Monte Carlo simulation of the experimental setup, for the {beta} - {nu} angular correlation measurement, was then carried out. The distortions of the spectra associated with the varying electric fields in the vicinity of the trap and with the ion cloud size were estimated for various geometries. The statistical needs for the experiment were evaluated in order to reach the required precision. (author)

  17. Light-assisted collisional loss in a Rb85/87 ultracold optical trap

    Science.gov (United States)

    Gorges, Anthony R.; Bingham, Nicholas S.; Deangelo, Michael K.; Hamilton, Mathew S.; Roberts, Jacob L.

    2008-09-01

    We have studied heteronuclear and homonuclear excited-state-ground-state collisions by loading both Rb85 and Rb87 into a far off resonant trap (FORT). Because of the relatively weak confinement of the FORT, we expect the hyperfine structure of the different isotopes to play a crucial role in the collision rates. This dependence on hyperfine structure allows us to measure collisions associated with long-range interatomic potentials of different structures, such as long and short ranged; or such as purely attractive, purely repulsive, or mixed attractive and repulsive. We observe significantly different loss rates for different excited-state potentials. Additionally, we observe that some collisional channels’ loss rates are saturated at our operating intensities (15mW/cm2) . These losses are important limitations in loading dual isotope optical traps.

  18. Nano-coating of beta-galactosidase onto the surface of lactose by using an ultrasound-assisted technique

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Heinämäki, Jyrki

    2010-01-01

    We nano-coated powdered lactose particles with the enzyme beta-galactosidase using an ultrasound-assisted technique. Atomization of the enzyme solution did not change its activity. The amount of surface-attached beta-galactosidase was measured through its enzymatic reaction product D-galactose us......We nano-coated powdered lactose particles with the enzyme beta-galactosidase using an ultrasound-assisted technique. Atomization of the enzyme solution did not change its activity. The amount of surface-attached beta-galactosidase was measured through its enzymatic reaction product D......-galactose using a standardized method. A near-linear increase was obtained in the thickness of the enzyme coat as the treatment proceeded. Interestingly, lactose, which is a substrate for beta-galactosidase, did not undergo enzymatic degradation during processing and remained unchanged for at least 1 month....... Stability of protein-coated lactose was due to the absence of water within the powder, as it was dry after the treatment procedure. In conclusion, we were able to attach the polypeptide to the core particles and determine precisely the coating efficiency of the surface-treated powder using a simple approach....

  19. Trap assisted charge multiplication enhanced photoresponse of Li-P codoped p-ZnO/n-Si heterojunction ultraviolet photodetectors

    Science.gov (United States)

    Sharma, Pankaj; Bhardwaj, Ritesh; Kumar, Amitesh; Mukherjee, Shaibal

    2018-01-01

    In this work, we report a high-performance p-ZnO/n-Si heterojunction-based ultraviolet (UV) photodetector fabricated by dual ion beam sputter deposition. The lithium-phosphorus (Li-P) codoping route was used to realize low resistive and stable p-type ZnO. The current-voltage characteristics of p-ZnO/n-Si heterojunction photodiode showed good rectifying behavior with a rectification ratio of 170 at  ±3 V. The spectral response measurements of the photodiode showed excellent responsivity with a peak observed around ~325 nm and cutoff wavelength around 370 nm. The maximum responsivity achieved was 2.6 A W-1 at an applied reverse bias of  -6 V. The external quantum efficiency determined was of the order of ~1000% which is attributed to the trap assisted multiplication of charge carriers.

  20. Simulation-assisted design of microfluidic sample traps for optimal trapping and culture of non-adherent single cells, tissues, and spheroids.

    Science.gov (United States)

    Rousset, Nassim; Monet, Frédéric; Gervais, Thomas

    2017-03-21

    This work focuses on modelling design and operation of "microfluidic sample traps" (MSTs). MSTs regroup a widely used class of microdevices that incorporate wells, recesses or chambers adjacent to a channel to individually trap, culture and/or release submicroliter 3D tissue samples ranging from simple cell aggregates and spheroids, to ex vivo tissue samples and other submillimetre-scale tissue models. Numerous MST designs employing various trapping mechanisms have been proposed in the literature, spurring the development of 3D tissue models for drug discovery and personalized medicine. Yet, there lacks a general framework to optimize trapping stability, trapping time, shear stress, and sample metabolism. Herein, the effects of hydrodynamics and diffusion-reaction on tissue viability and device operation are investigated using analytical and finite element methods with systematic parametric sweeps over independent design variables chosen to correspond to the four design degrees of freedom. Combining different results, we show that, for a spherical tissue of diameter d < 500 μm, the simplest, closest to optimal trap shape is a cube of dimensions w equal to twice the tissue diameter: w = 2d. Furthermore, to sustain tissues without perfusion, available medium volume per trap needs to be 100× the tissue volume to ensure optimal metabolism for at least 24 hours.

  1. The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array

    Energy Technology Data Exchange (ETDEWEB)

    Hirsh, T. Y.; Perez Galvan, A.; Burkey, M.; Aprahamian, A.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Gallant, A.; Heckmaier, E.; Levand, A. F.; Savard, G.

    2018-04-01

    This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy.

  2. The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array

    Science.gov (United States)

    Hirsh, T. Y.; Pérez Gálvan, A.; Burkey, M. T.; Aprahamian, A.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Gallant, A. T.; Heckmaier, E.; Levand, A. F.; Marley, S. T.; Morgan, G. E.; Nystrom, A.; Orford, R.; Savard, G.; Scielzo, N. D.; Segel, R.; Sharma, K. S.; Siegl, K.; Wang, B. S.

    2018-04-01

    This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from α sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy.

  3. Beta-lactamase-catalyzed aminolysis of depsipeptides: Proof of the nonexistence of a specific D-phenylalanine/enzyme complex by double-label isotope trapping

    International Nuclear Information System (INIS)

    Pazhanisamy, S.; Pratt, R.F.

    1989-01-01

    The steady-state kinetics of the Enterobacter cloacae P99 beta-lactamase-catalyzed aminolysis of the depsipeptide m-[[(phenylacetyl)glycyl]oxy]benzoic acid by D-phenylalanine were consistent with an ordered sequential mechanism with D-phenylalanine binding first. In terms of this mechanism, the kinetics data required that in 20 mM MOPS buffer, pH 7.5, the dissociation constant of the initially formed enzyme/D-phenylalanine complex be around 1.3 mM; at pH 9.0 in 0.1 M carbonate buffer, the complex should be somewhat more stable. Attempts to detect this complex in a binary mixture by spectroscopic methods (fluorescence, circular dichroic, and nuclear magnetic resonance spectra) failed. Kinetic methods were also unsuccessful--the presence of 20 mM D-phenylalanine did not appear to affect beta-lactamase activity nor inhibition of the enzyme by phenylmethanesulfonyl fluoride, phenylboronic acid, or (3-dansylamidophenyl)boronic acid. Equilibrium dialysis experiments appeared to indicate that the dissociation constant of any binary enzyme/D-phenylalanine complex must be somewhat higher than the kinetics allowed (greater than 2 mM). Since the kinetics also required that, at high depsipeptide concentrations, and again with the assumption of the ordered sequential mechanism, the reaction of the enzyme/D-phenylalanine complex to aminolysis products be faster than its reversion to enzyme and D-phenylalanine, a double-label isotope-trapping experiment was performed

  4. Interaction of beta-amyloid(1-40) peptide with pairs of metal ions: An electrospray ion trap mass spectrometric model study.

    Science.gov (United States)

    Drochioiu, Gabi; Manea, Marilena; Dragusanu, Mihaela; Murariu, Manuela; Dragan, Ecaterina Stela; Petre, Brandusa Alina; Mezo, Gabor; Przybylski, Michael

    2009-09-01

    The stoichiometries and the affinity toward simple and paired metal ions of synthetic amyloid-beta(1-40) peptide (Abeta1-40) were investigated by electrospray ion trap mass spectrometry (ESI-MS), circular dichroism (CD), and atomic force microscopy (AFM). The results lead to the working hypothesis that pH-dependent metal binding to Abeta1-40 may induce conformational changes, which affect the affinity toward other metals. A significant copper and zinc binding to Abeta1-40 peptide at pH 5.5 was found, whereas nickel ions commonly bind to each molecule of beta-amyloid peptide. Some complexes of Abeta1-40 with more than one nickel ion were identified by ESI-MS. In addition, nickel ions proved to enhance Abeta oligomerization. On increasing pH, up to 12 ions of zinc may bind to a single Abeta molecule. Under the same pH and concentration conditions, the binding pattern of the independent copper and silver ions to Abeta1-40 was different from that of the equimolecular mixture of the two metal ions. One might assume that some conformational changes due to water loss altered the capacity of Abeta peptide to bind certain heavy metal ions. As a consequence, copper-silver interaction with the binding process to Abeta1-40 became highly complex. A competition between silver and nickel ions for Abeta1-40 binding sites at high pH was also observed. New strategies were proposed to identify the characteristic signals for some important metal ion-peptide complexes in the spectra recorded at high pH or high concentrations of metal ions. To explain the formation of such a large number of high metal ion-Abeta complexes, we took into consideration the participation of both histidine residues and free amino groups as well as carboxylate ones in the binding process. Finally, CD and AFM studies supported the mass spectrometric data.

  5. strange beta: An assistance system for indoor rock climbing route setting

    Science.gov (United States)

    Phillips, C.; Becker, L.; Bradley, E.

    2012-03-01

    This paper applies the mathematics of chaos to the task of designing indoor rock-climbing routes. Chaotic variation has been used to great advantage on music and dance, but the challenges here are quite different, beginning with the representation. We present a formalized system for transcribing rock climbing problems and then describe a variation generator that is designed to support human route-setters in designing new and interesting climbing problems. This variation generator, termed strange beta, uses chaos to introduce novelty. We validated this approach with a large blinded study in a commercial climbing gym, in cooperation with experienced climbers and expert route setters. The results show that strange beta can help a human setter produce routes that are at least as good as, and in some cases better than, those produced in the traditional manner.

  6. Trap-assisted transition between Schottky emission and Fowler-Nordheim tunneling in the interfacial-memristor based on Bi2S3 nano-networks

    Directory of Open Access Journals (Sweden)

    Ye Tian

    2018-03-01

    Full Text Available For the usage of the memristors in functional circuits, a predictive physical model is of great importance. However, other than the developments of the memristive models accounting bulky effects, the achievements on simulating the interfacial memristance are still insufficient. Here we provide a physical model to describe the electrical switching of the memristive interface. It considers the trap-assisted transition between Schottky emission and Fowler-Nordheim tunneling, and successfully reproduces the memristive behaviors occurring on the interface between Bi2S3 nano-networks and F-doped SnO2. Such success not only allows us uncover several features of the memristive interface including the distribution nature of the traps, barrier height/thickness and so on, but also provides a foundation from which we can quantitatively simulate the real interfacial memristor.

  7. Trap-assisted transition between Schottky emission and Fowler-Nordheim tunneling in the interfacial-memristor based on Bi2S3 nano-networks

    Science.gov (United States)

    Tian, Ye; Jiang, Lianjun; Zhang, Xuejun; Zhang, Guangfu; Zhu, Qiuxiang

    2018-03-01

    For the usage of the memristors in functional circuits, a predictive physical model is of great importance. However, other than the developments of the memristive models accounting bulky effects, the achievements on simulating the interfacial memristance are still insufficient. Here we provide a physical model to describe the electrical switching of the memristive interface. It considers the trap-assisted transition between Schottky emission and Fowler-Nordheim tunneling, and successfully reproduces the memristive behaviors occurring on the interface between Bi2S3 nano-networks and F-doped SnO2. Such success not only allows us uncover several features of the memristive interface including the distribution nature of the traps, barrier height/thickness and so on, but also provides a foundation from which we can quantitatively simulate the real interfacial memristor.

  8. Distinguishing triplet energy transfer and trap-assisted recombination in multi-color organic light-emitting diode with an ultrathin phosphorescent emissive layer

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Qin, E-mail: xueqin19851202@163.com; Liu, Shouyin [Department of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China); Xie, Guohua; Chen, Ping; Zhao, Yi; Liu, Shiyong [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2014-03-21

    An ultrathin layer of deep-red phosphorescent emitter tris(1-phenylisoquinoline) iridium (III) (Ir(piq){sub 3}) is inserted within different positions of the electron blocking layer fac-tris (1-phenylpyrazolato-N,C{sup 2′})-iridium(III) (Ir(ppz){sub 3}) to distinguish the contribution of the emission from the triplet exciton energy transfer/diffusion from the adjacent blue phosphorescent emitter and the trap-assisted recombination from the narrow band-gap emitter itself. The charge trapping effect of the narrow band-gap deep-red emitter which forms a quantum-well-like structure also plays a role in shaping the electroluminescent characteristics of multi-color organic light-emitting diodes. By accurately controlling the position of the ultrathin sensing layer, it is considerably easy to balance the white emission which is quite challenging for full-color devices with multiple emission zones. There is nearly no energy transfer detectable if 7 nm thick Ir(ppz){sub 3} is inserted between the blue phosphorescent emitter and the ultrathin red emitter.

  9. Trap-state-assisted white light emission from a CdSe nanocrystal integrated hybrid light-emitting diode.

    Science.gov (United States)

    Chandramohan, S; Ryu, Beo Deul; Kim, Hyun Kyu; Hong, Chang-Hee; Suh, Eun-Kyung

    2011-03-15

    This Letter reports on the fabrication of hybrid white-light-emitting diodes made of semiconductor nanocrystals (NCs) integrated on InGaN/GaN LEDs. Using core type and core/shell type CdSe NCs, the white light properties are systematically engineered for white light generation with high color rendering index (CRI). Unlike CdSe/ZnS core/shell NCs, which exhibited a unique narrowband edge emission, core type CdSe NCs offered extended broad emission toward orange/red wavelengths associated with deep trap states. Consequently, the light-emitting properties of the devices showed strong dependence on the type of NCs used, and devices with CdSe NCs offered admirable characteristics, such as Commission Internationale d'Eclairage coordinates of (0.356, 0.330) and a CRI as high as 87.4.

  10. Preliminary work on the measurement of the β - ν angular correlation in the 6He beta decay by means of a Paul's trap

    International Nuclear Information System (INIS)

    Delahaye, P.

    2002-03-01

    The subject of this thesis is the preparation of a measurement of the β - ν angular correlation coefficient, in 6 He nuclear β - decay, using a Paul trap. Its principle consists in studying the decay of radioactive ions trapped in a small volume, practically at rest in the center of a transparent electric trap. The trajectories of the particles emitted in the decay are weakly disturbed. The detection in coincidence of the electron and the recoil ion in each decay allows the measurement of 3 observables: the energies of the particles and their relative angle. The β - ν angular correlation parameter deduced from the coincidence spectrum is sensitive to the existence of exotic interactions excluded by the V - A theory of the weak interactions. In the case of 6 He decay a deviation observed on the predicted value would imply the existence of tensor type interactions, which might be due to the exchange of leptoquarks. These are gauge bosons present in many extensions of the Standard Model. The work presented here concerns the tests of a transparent Paul trap. The performance of the trap has been tested with ions created in a laser plasma source (Mo + , Fe + , Al + ), and also with ions delivered by an ionization source ( 4 He + ions). These experiments were carried out in parallel with their simulations which required the development of a computer code of the electrical potential in various geometries, and of a code of ions transport in the associated fields. These simulations showed a good agreement with the experiment. A Monte Carlo simulation of the experimental setup, for the β - ν angular correlation measurement, was then carried out. The distortions of the spectra associated with the varying electric fields in the vicinity of the trap and with the ion cloud size were estimated for various geometries. The statistical needs for the experiment were evaluated in order to reach the required precision. (author)

  11. Measurement of the {beta}-{nu} angular correlation parameter in the decay of {sup 6}He using a Paul trap; Mesure du coefficient de correlation angulaire {beta}-{nu} dans la decroissance de {sup 6}He a l'aide d'un piege de Paul

    Energy Technology Data Exchange (ETDEWEB)

    Mery, A

    2007-07-15

    The central topic of this work is the study of the properties and the implementation of a Paul trap used for the measurement of the beta-neutrino angular correlation parameter in the decay of {sup 6}He. This coefficient provides a signature of the nature of the interactions involved in the weak interaction. The value of this coefficient can be deduced from the kinematical distribution of the decay events. An electromagnetic trap is used for the trapping of {sup 6}He{sup +} ions in a small volume. This trap has an open geometry that enables the detection in coincidence of the electron and the recoil ion emitted in the beta decay. A dedicated detection set up is used for the measurement of the electron energy, the ion time of flight and the position of the two particles for each event. A general description of the LPCTrap facility and of its performances is presented and shows that this set up is able to fulfill the proposed measurement. Especially, a comparison is made between the characteristics of the ion cloud obtained from Monte Carlo simulations and the experimental measurements with a good agreement. More than 100 000 coincident events have been recorded during the first experiment. A preliminary analysis of these results is shown. It includes a description of the different observables as well as a comparison between the experimental time of flight spectrum and the simulated spectrum. These data will allow a measurement of the angular correlation parameter with a statistical error smaller than 2 %. (author)

  12. Reducing Trap-Assisted Recombination in Small Organic Molecule-Based Photovoltaics by the Addition of a Conjugated Block Copolymer.

    Science.gov (United States)

    Cho, Kyuwan; Kim, Jinseck; Yoon, So Yeon; Ryu, Ka Yeon; Jang, Song-Rim; Lim, Bogyu; Kim, Kyungkon

    2018-03-01

    The performance of organic photovoltaics (OPVs) based on the small-molecule organic semiconductor p-DTS(FBTTh 2 ) 2 is greatly improved by the addition of a conjugated block copolymer composed of difluoroquinoxaline and thienopyrrolodione blocks (D130). The power conversion efficiency (PCE) of the p-DTS(FBTTh 2 ) 2 -based OPV is improved from 5.08% to 6.75% by the addition of 5 wt% D130 to the photoactive layer, which is composed of p-DTS(FBTTh 2 ) 2 and a fullerene derivative. Current-voltage and grazing incidence wide-angle X-ray scattering analyses revealed that the addition of D130 significantly reduces the trap density of the device and changes the packing orientation of p-DTS(FBTTh 2 ) 2 from mostly edge-on to partially face-on. These changes greatly improve the charge carrier mobility of the OPV, indicating that D130 is highly compatible with p-DTS(FBTTh 2 ) 2 . Furthermore, the addition of D130 improve the photostability of the OPV by reducing the burn-in loss under a light soaking intensity of 1 sun. The D130-based OPV maintained 34% of its initial PCE after a light soaking test for 858 h. In contrast, the PCE of the OPV without D130 reduced to 14% of its initial efficiency in the same time period. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. On-line capillary electrophoresis enrichment by combining chitosan trapping with surfactant assisted sample stacking for the ultratrace determination of organic acids in Plateau alfalfa roots.

    Science.gov (United States)

    Li, Xi; Ju, Yuyun; Xu, Yinyin; Wang, Weifeng; Dong, Yalei; Ma, Yanhua; Chen, Xingguo

    2013-07-30

    In this paper, four organic acids constituents of Plateau alfalfa roots have been identified and detected by a novel capillary electrophoresis (CE) strategy which combined chitosan (CS) trapping and cetyltrimethyl ammonium bromide (CTAB) assisted sample stacking. Under the optimized condition, organic acids, i.e., aconitic acid, gallic acid, citric acid and l-malic acid were concentrated and separated within 3 min. Validation parameters of this method (such as detection limits, linearity and precision) were also investigated and the limit of detection (LOD) was 2.41-53.9 ng mL(-1). Linearity was obtained over the magnitude range of 5-4000 ng mL(-1) approximately for different organic acids and 3×10(2)-1.5×10(4) folds enrichment was achieved. The method has been applied to the determination of organic acids in roots of normal grown Plateau alfalfa and stressing affected Plateau alfalfa. Satisfactory results and recoveries were obtained in the analysis without costly and complicated sample pretreatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Low-temperature vapor synthesis of 1D {beta}-Ga{sub 2}O{sub 3} nanostructures on Si substrate by inert salt-assisted route

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Yingying [School of Chemistry and Chemical Engineering, Key Laboratory of Applied Organic Chemistry in Higher Institutions, Shangrao Normal University, 334000 Jiangxi (China); Yu, Leshu, E-mail: yuleshu2008@126.com [School of Chemistry and Chemical Engineering, Key Laboratory of Applied Organic Chemistry in Higher Institutions, Shangrao Normal University, 334000 Jiangxi (China); Zheng, Dagui; Xie, Aili; Chen, Xueli [School of Chemistry and Chemical Engineering, Key Laboratory of Applied Organic Chemistry in Higher Institutions, Shangrao Normal University, 334000 Jiangxi (China)

    2012-12-01

    Graphical abstract: In this work inert salt-assisted route has been extended to prepare {beta}-Ga{sub 2}O{sub 3} nanowires and nanobelts on bare Si substrate, and thus the depositing temperature was down to 650 Degree-Sign C, much lower than synthetic temperatures in previous reports via the direct oxidation of metallic Ga. Highlights: Black-Right-Pointing-Pointer Inert salt-assisted route has been extended to synthesize {beta}-Ga{sub 2}O{sub 3} nanostructures. Black-Right-Pointing-Pointer {beta}-Ga{sub 2}O{sub 3} nanowires and nanobelts covered bare Si substrate. Black-Right-Pointing-Pointer The depositing temperature was lower down to 650 Degree-Sign C. Black-Right-Pointing-Pointer Low temperature growth was attributed to the well dispersion of Ga over inert salt. Black-Right-Pointing-Pointer The synthesized products have a stable and broad green emission band. - Abstract: The attractive feature of one-dimensional inorganic nanomaterials grown on substrate at low temperature is the good adhesion between the deposited material and the substrate. In this work inert salt-assisted route has been extended to prepare Ga{sub 2}O{sub 3} product on bare Si substrate. By using CaF{sub 2} powder as a dispersant, the vapor pressure of metallic Ga is increased greatly as compared to its non-dispersed state. This allows for the {beta}-Ga{sub 2}O{sub 3} nanostructures to be formed at a relatively low temperature of 650 Degree-Sign C as a result of direct oxidation of the well-mixed metallic Ga and CaF{sub 2} powder. This temperature is much lower than the synthetic temperature required in the cases of direct oxidation of metallic Ga as reported by others. The as-prepared Ga{sub 2}O{sub 3} nanowires and nanobelts are characterized by XRD, SEM, EDX, TEM and PL. The vapor-solid growth process was also discussed for the as-prepared Ga{sub 2}O{sub 3} product on Si substrate. The interesting results indicate the wide applications of inert salt-assisted route to vapor growth of other

  15. Effect of stent-assisted angioplasty on cognitive status and serum levels of amyloid beta in patients with intracranial and/or extracranial artery stenosis

    Directory of Open Access Journals (Sweden)

    Zhao L

    2015-02-01

    Full Text Available Liandong Zhao,1 Ying Zhao,1 Haijun Zhang2 1Department of Neurology, The Second People’s Hospital of Huai’an and The Affiliated Huai’an Hospital of Xuzhou Medical College, Huai’an, Jiangsu, 2Department of Oncology, Zhongda Hospital, Medical School, Southeast University, Nanjing, People’s Republic of China Aim: The study reported here aimed to examine how stent-assisted angioplasty affects cognitive status and serum levels of amyloid betas (Aβs 1-40 and 1-42 in patients with cerebral arterial stenosis.Methods: Patients with cerebral arterial stenosis were given stent-assisted angioplasty plus conventional treatment (stent-assisted angioplasty group or conventional treatment alone (control group. Cognitive status and Aβ1-40 and Aβ1-42 serum levels were determined before treatment and at 4 and 8 weeks after treatment.Results: At 4 weeks after treatment, cognitive status in patients with stent-assisted angioplasty had clearly improved. Aβ1-42 serum levels changed insignificantly in all patients. However, Aβ1-40 serum levels and Aβ1-40/Aβ1-42 ratio decreased further in patients with stent-assisted angioplasty than in patients who received conventional treatment (controls. Eight weeks after treatment, cognitive status in patients who had undergone stent-assisted angioplasty were continuing to improve, Aβ1-42 serum levels had begun to increase dramatically, and Aβ1-40 serum levels and Aβ1-40/Aβ1-42 ratio had declined further.Conclusion: Stent-assisted angioplasty could improve cognitive status and decrease Aβ1-40 serum levels and Aβ1-40/Aβ1-42 ratio. Keywords: arterial stenosis, Alzheimer’s disease, Aβ1-40, Aβ1-42, Aβ1-40/Aβ1-42 ratio

  16. COLD TRAPS

    Science.gov (United States)

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  17. Structural and Biochemical Evidence That a TEM-1 [beta]-Lactamase N170G Active Site Mutant Acts via Substrate-assisted Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicholas G.; Shanker, Sreejesh; Prasad, B.V. Venkataram; Palzkill, Timothy; (Baylor)

    2010-03-12

    TEM-1 {beta}-lactamase is the most common plasmid-encoded {beta}-lactamase in Gram-negative bacteria and is a model class A enzyme. The active site of class A {beta}-lactamases share several conserved residues including Ser{sup 70}, Glu{sup 166}, and Asn{sub 170} that coordinate a hydrolytic water involved in deacylation. Unlike Ser{sup 70} and Glu{sup 166}, the functional significance of residue Asn{sup 170} is not well understood even though it forms hydrogen bonds with both Glu{sup 166} and the hydrolytic water. The goal of this study was to examine the importance of Asn{sup 170} for catalysis and substrate specificity of {beta}-lactam antibiotic hydrolysis. The codon for position 170 was randomized to create a library containing all 20 possible amino acids. The random library was introduced into Escherichia coli, and functional clones were selected on agar plates containing ampicillin. DNA sequencing of the functional clones revealed that only asparagine (wild type) and glycine at this position are consistent with wild-type function. The determination of kinetic parameters for several substrates revealed that the N170G mutant is very efficient at hydrolyzing substrates that contain a primary amine in the antibiotic R-group that would be close to the Asn{sup 170} side chain in the acyl-intermediate. In addition, the x-ray structure of the N170G enzyme indicated that the position of an active site water important for deacylation is altered compared with the wild-type enzyme. Taken together, the results suggest the N170G TEM-1 enzyme hydrolyzes ampicillin efficiently because of substrate-assisted catalysis where the primary amine of the ampicillin R-group positions the hydrolytic water and allows for efficient deacylation.

  18. Famílias de Coleoptera capturadas com armadilha malaise em oito localidades do Estado do Paraná, Brasil: diversidades alfa e beta Families of Coleoptera captured with malaise trap in eight sites of Paraná State, Brazil: alpha and Beta Diversities

    Directory of Open Access Journals (Sweden)

    Renato C Marinoni

    1997-09-01

    Full Text Available Eight geographical areas, considered as representative of the different natural environments still existing in the state of Paraná, in Southern Brazil, were selected for the collection of insects. This data is part of the "Survey of the Entomological Fauna in Paraná State" (henceforth profaupar. These areas were continually sampled using a Malaise trap (Townes' 1972 model throughout a single year (52 weeks from August, 1986, until July 1987. The Coleoptera obtained has been sorted at family level and analyzed. The highest family variety and abundance were observed at Jundiaí do Sul and Ponta Grossa, and the greatest eveness at Jundiaí do Sul and Telêmaco Borba. A study ou phytophagous/non phytophagous families relations made possible a first approach about the vegetation condition in the sites. The following methods were used to analyse the data: Ecological Indices (Alpha Diversity and Clustering and Ordination Analysis (Beta Diversity.

  19. Neutral atom traps of radioactives

    CERN Document Server

    Behr, J A

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear beta decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left...

  20. Comprehensive on-line two-dimensional liquid chromatography × supercritical fluid chromatography with trapping column-assisted modulation for depolymerised lignin analysis.

    Science.gov (United States)

    Sun, Mingzhe; Sandahl, Margareta; Turner, Charlotta

    2018-03-16

    Lignin depolymerisation produces a large variety of low molecular weight phenolic compounds that can be upgraded to value-added chemicals. Detailed analysis of these complex depolymerisation mixtures is, however, hampered by the lack of resolving power of traditional analysis techniques. In this study, a novel online comprehensive two-dimensional reversed-phase liquid chromatography (RPLC) × supercritical fluid chromatography (SFC) method with trapping column interface was developed for the separation of phenolic compounds in depolymerised lignin samples. The trapping capacities of different trapping columns were evaluated. The influence of large volume water-containing injection on SFC performance was studied. The relation between peak capacity and first dimension flow rate and gradient was investigated. The optimized method was applied for the analysis of a depolymerised lignin sample. The RPLC × SFC system exhibited high degree of orthogonality. Compared with traditional loop based interface, trapping column interface can significantly shorten the analysis time and offer higher detectability, with the disadvantage of more severe undersampling in the first dimension. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Trapped antihydrogen

    CERN Document Server

    Butler, E; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jonsell, S; Jørgensen, L V; Kemp, S L; Kurchaninov, L; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Seif el Nasr, S; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S; Yamazaki,Y

    2012-01-01

    Precision spectroscopic comparison of hydrogen and antihydrogen holds the promise of a sensitive test of the Charge-Parity-Time theorem and matter-antimatter equivalence. The clearest path towards realising this goal is to hold a sample of antihydrogen in an atomic trap for interrogation by electromagnetic radiation. Achieving this poses a huge experimental challenge, as state-of-the-art magnetic-minimum atom traps have well depths of only ∼1 T (∼0.5 K for ground state antihydrogen atoms). The atoms annihilate on contact with matter and must be ‘born’ inside the magnetic trap with low kinetic energies. At the ALPHA experiment, antihydrogen atoms are produced from antiprotons and positrons stored in the form of non-neutral plasmas, where the typical electrostatic potential energy per particle is on the order of electronvolts, more than 104 times the maximum trappable kinetic energy. In November 2010, ALPHA published the observation of 38 antiproton annihilations due to antihydrogen atoms that had been ...

  2. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  3. Neutral atom traps of radioactives

    International Nuclear Information System (INIS)

    Behr, J.A.

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear β decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left up to other presenters

  4. VACUUM TRAP

    Science.gov (United States)

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  5. Globalisation Trapped

    Directory of Open Access Journals (Sweden)

    João Caraça

    2017-05-01

    Full Text Available The promise of making society progress through the direct applications of science was finally fulfilled in the mid-20th century. Science progressed immensely, propelled by the effects of the two world wars. The first science-based technologies saw the daylight during the 1940s and their transformative power was such that neither the military, nor subsequently the markets, allowed science to return intact to its curiosity-driven nest. Technoscience was born then and (being progressively pulled away from curiosity-driven science was able to grow enormously, erecting a formidable structure of networks of institutions that impacted decisively on the economy. It is a paradox, or maybe a trap, that the fulfillment of science’s solemn promise of ‘transforming nature’ means seeing ourselves and our Western societies entangled in crises after crises with no clear outcome in view. A redistribution of geopolitical power is under way, along with the deployment of information and communication technologies, forcing dominant structures to oscillate, as knowledge about organization and methods, marketing, design, and software begins to challenge the role of technoscience as the main vector of economic growth and wealth accumulation. What ought to be done?

  6. Cryogenic surface ion traps

    International Nuclear Information System (INIS)

    Niedermayr, M.

    2015-01-01

    Microfabricated surface traps are a promising architecture to realize a scalable quantum computer based on trapped ions. In principle, hundreds or thousands of surface traps can be located on a single substrate in order to provide large arrays of interacting ions. To this end, trap designs and fabrication methods are required that provide scalable, stable and reproducible ion traps. This work presents a novel surface-trap design developed for cryogenic applications. Intrinsic silicon is used as the substrate material of the traps. The well-developed microfabrication and structuring methods of silicon are utilized to create simple and reproducible traps. The traps were tested and characterized in a cryogenic setup. Ions could be trapped and their life time and motional heating were investigated. Long ion lifetimes of several hours were observed and the measured heating rates were reproducibly low at around 1 phonon per second at a trap frequency of 1 MHz. (author) [de

  7. Utility of imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) on an ion trap mass spectrometer in the analysis of drugs and metabolites in biological tissues.

    Science.gov (United States)

    Drexler, Dieter M; Garrett, Timothy J; Cantone, Joseph L; Diters, Richard W; Mitroka, James G; Prieto Conaway, Maria C; Adams, Stephen P; Yost, Richard A; Sanders, Mark

    2007-01-01

    The properties and potential liabilities of drug candidate are investigated in detailed ADME assays and in toxicity studies, where findings are placed in context of exposure to dosed drug and metabolites. The complex nature of biological samples may necessitate work-up procedures prior to high performance liquid chromatography-mass spectrometric (HPLC-MS) analysis of endogenous or xenobiotic compounds. This concept can readily be applied to biological fluids such as blood or urine, but in localized samples such as organs and tissues potentially important spatial, thus anatomical, information is lost during sample preparation as the result of homogenization and extraction procedures. However, the localization of test article or spatial identification of metabolites may be critical to the understanding of the mechanism of target-organ toxicity and its relevance to clinical safety. Tissue imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) and ion trap mass spectrometry (MS) with higher order mass spectrometric scanning functions was utilized for localization of dosed drug or metabolite in tissue. Laser capture microscopy (LCM) was used to obtain related samples from tissue for analyses by standard MALDI-MS and HPLC-MS. In a toxicology study, rats were administered with a high dosage of a prodrug for 2 weeks. Birefringent microcrystalline material (10-25 microm) was observed in histopathologic formalin-fixed tissue samples. Direct analysis by IMS provided the identity of material in the microcrystals as circulating active drug while maintaining spatial orientation. Complementary data from visual cross-polarized light microscopy as well as standard MALDI-MS and HPLC-MS experiments on LCM samples validated the qualitative results obtained by IMS. Furthermore, the HPLC-MS analysis on the LCM samples afforded a semi-quantitative assessment of the crystalline material in the tissue samples. IMS by MALDI ion trap MS proved sensitive

  8. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  9. Determination of sulfonamide antibiotics and metabolites in liver, muscle and kidney samples by pressurized liquid extraction or ultrasound-assisted extraction followed by liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry (HPLC-QqLIT-MS/MS).

    Science.gov (United States)

    Hoff, Rodrigo Barcellos; Pizzolato, Tânia Mara; Peralba, Maria do Carmo Ruaro; Díaz-Cruz, M Silvia; Barceló, Damià

    2015-03-01

    Sulfonamides are widely used in human and veterinary medicine. The presence of sulfonamides residues in food is an issue of great concern. Throughout the present work, a method for the targeted analysis of 16 sulfonamides and metabolites residue in liver of several species has been developed and validated. Extraction and clean-up has been statistically optimized using central composite design experiments. Two extraction methods have been developed, validated and compared: i) pressurized liquid extraction, in which samples were defatted with hexane and subsequently extracted with acetonitrile and ii) ultrasound-assisted extraction with acetonitrile and further liquid-liquid extraction with hexane. Extracts have been analyzed by liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry. Validation procedure has been based on the Commission Decision 2002/657/EC and included the assessment of parameters such as decision limit (CCα), detection capability (CCβ), sensitivity, selectivity, accuracy and precision. Method׳s performance has been satisfactory, with CCα values within the range of 111.2-161.4 µg kg(-1), limits of detection of 10 µg kg(-1) and accuracy values around 100% for all compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Weak Interaction Measurements with Optically Trapped Radioactive Atoms

    International Nuclear Information System (INIS)

    Vieira, D.J.; Crane, S.G.; Guckert, R.; Zhao, X.; Brice, S.J.; Goldschmidt, A.; Hime, A.; Tupa, D.

    1999-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project is to apply the latest in magneto-optical and pure magnetic trapping technology to concentrate, cool, confine, and polarize radioactive atoms for precise electroweak interaction measurements. In particular, the authors have concentrated their efforts on the trapping of 82 Rb for a parity-violating, beta-asymmetry measurement. Progress has been made in successfully trapping of up to 6 million 82 Rb(t 1/2 =75s) atoms in a magneto-optical trap coupled to a mass separator. This represents a two order of magnitude improvement in the number trapped radioactive atoms over all previous work. They have also measured the atomic hyperfine structure of 82 Rb and demonstrated the MOT-to-MOT transfer and accumulation of atoms in a second trap. Finally, they have constructed and tested a time-orbiting-potential magnetic trap that will serve as a rotating beacon of spin-polarized nuclei and a beta-telescope detection system. Prototype experiments are now underway with the initial goal of making a 1% measurements of the beta-asymmetry parameter A which would match the world's best measurements

  11. Ultrasound-assisted synthesis of 1-N-{beta}-D-glucopyranosyl-1H-1,2,3-triazole benzoheterocycles and their anti-inflammatory activities

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gilson B. da; Guimaraes, Bruna M.; Oliveira, Ronaldo N. de, E-mail: ronaldonoliveira@dcm.ufrpe.br [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Departamento de Ciencias Moleculares; Assis, Shalom P.O.; Lima, Vera L.M. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Departamento de Bioquimica. Laboratorio de Quimica e Metabolismo de Lipideos e Lipoproteinas

    2013-06-15

    In this work, the preparation of various glucosyl triazoles from a reaction between 2,3,4,6-tetra-O-acetyl-{beta}-D-glucopyranosyl azide and terminal alkynes was developed in moderate to excellent yields (63-99%). Ultrasound energy was applied at each step of the reaction to increase chemical reactivity. In addition, the compounds conjugated with benzoheterocycles moieties revealed potent anti-inflammatory activity. (author)

  12. Optimization of a microwave-assisted extraction large-volume injection and gas chromatography-ion trap mass spectrometry procedure for the determination of polybrominated diphenyl ethers, polybrominated biphenyls and polychlorinated naphthalenes in sediments

    Energy Technology Data Exchange (ETDEWEB)

    Yusa, V. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pardo, O. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pastor, A. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)]. E-mail: Agustin.Pastor@uv.es; Guardia, M. de la [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)

    2006-01-31

    A sensitive and rapid method for the determination of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and polychlorinated naphthalenes (PCNs) in sediment samples is proposed. The method involving microwave-assisted extraction (MAE) and large-volume injection (LVI) gas chromatography (GC)-ion trap mass spectrometry (ITMS), and the experimental conditions were optimized using the statistical design of experiments (DOE). A Plackett-Burman (P-B) design was chosen to estimate the influence of five factors, such as resonance excitation voltage (EV), isolation time (IT), excitation time (ET), ion source temperature (IST) and electron energy (EE) on the analytical response in the ITMS determination. In order to increase the analytical response, 70 {mu}L of the final extract were injected into the GC-tandem mass spectrometry (MS-MS) using a programmable temperature vaporizer (PTV). The factor settings involving injection temperature, vaporization temperature, vaporization time and flow during the evaporation step were previously optimized using a central composite design (CCD). The MAE was carried out using the hexane-acetone (1:1, v/v) mixture and the extraction conditions were optimized with a CCD. The highest response was obtained with a volume of 48 mL, a temperature of 152 deg. C and an extraction time of 24 min. The optimized method gives recoveries between 75 and 95% with relative standard deviations (R.S.D.) that ranged from 4 to 13%. The limit of detection (LOD) ranged between 4 and 20 pg g{sup -1} dry weight (dw) when 5 g of sediment were analyzed. The MAE method was applied to the analyses of polyhalogenated compounds in sediments collected in the harbour of Valencia (Spain). The proposed method may serve as an alternative for GC-negative chemical ionization (NCI)-MS and can be used in government testing programmes.

  13. Shrew trap efficiency

    DEFF Research Database (Denmark)

    Gambalemoke, Mbalitini; Mukinzi, Itoka; Amundala, Drazo

    2008-01-01

    We investigated the efficiency of four trap types (pitfall, Sherman LFA, Victor snap and Museum Special snap traps) to capture shrews. This experiment was conducted in five inter-riverine forest blocks in the region of Kisangani. The total trapping effort was 6,300, 9,240, 5,280 and 5,460 trap......-nights for the pitfall, Sherman, Victor and Museum Special traps, respectively. In total, we captured 366 shrews. The use of pitfall traps yielded the highest trapping success (4.1) with at least 18 shrew species identified. Trapping success and the number of species collected was lower for the Sherman (0.6, at least 11...... species), Victor (0.6, at least 8 species) and Museum Special (0.5, at least 6 species) traps. Although Crocidura olivieri and C. denti were caught using all four trap types, captures with different trap types did not produce a sample with the same taxonomic composition. In agreement with previous studies...

  14. Mechanical performance of rat, mouse and mole spring traps, and possible implications for welfare performance.

    Directory of Open Access Journals (Sweden)

    Sandra E Baker

    Full Text Available Lethal spring traps are widely used for killing small mammals in the UK. Many require government approval, based primarily on humaneness. However, mole traps and break-back traps for rats and mice are exempt; those available vary widely in price and apparent quality. The EU is considering implementing a Trapping Directive that would alter UK legislation, and a recent report advised the EU that trapping legislation should cover all trapped species and encourage improvement of traps. Mechanical trap performance is often used as an indicator of welfare impact. We examined the mechanical evidence for scope to improve the welfare standards of rat, mouse and mole spring traps. We measured mechanical performance among a range of rat, mouse and mole traps. Impact momentum values varied 6-8 fold, and clamping force values 4-5.5 fold, among traps for killing each species. There was considerable overlap in the performance of rat and mouse traps. Trap-opening angle and spring type were related to impact momentum and clamping force in traps for both species. There was no relationship between price and mechanical performance in traps for any species, except talpa mole traps. We are unable to judge the direct welfare impact of the traps tested, but rather the potential welfare threat associated with their exemption from approval. The wide variation in mechanical performance in traps for each species, overlap in performance between rat and mouse traps and increasing availability of weaker plastic rodent traps indicate considerable scope for improving the humaneness of spring traps for rats, mice and moles. We conclude that all such traps should be subject to the UK approval process. New welfare categories might improve trap standards further. Our results could also help improve rodent trap design and assist consumers in selecting more powerful traps. Many thousands of rats, mice and moles might benefit.

  15. Beta Blockers

    Science.gov (United States)

    ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ...

  16. A common polymorphic allele of the LH beta-subunit gene is associated with higher exogenous FSH consumption during controlled ovarian stimulation for assisted reproductive technology

    DEFF Research Database (Denmark)

    Alviggi, Carlo; Pettersson, Kim; Longobardi, Salvatore

    2013-01-01

    -optimal ovarian response to a standard long GnRH-agonist down -regulation protocol when stimulated with pure recombinant FSH (r-hFSH). The aim of this study was to confirm the hypothesis that women with v-betaLH display hypo-sensitivity to exogenous FSH in a larger IVF population and to explore the frequency...... a long GnRH-agonist down-regulation protocol received an individualized dose of r-hFSH (100 IU and 375 IU s.c. daily) according to antral follicle count, baseline FSH, body mass index and age. The LH genotype was assessed in all patients by immunofluorometric assay. RESULTS: V-betaLH was present in 11...... number of oocytes retrieved, fertilization rate and pregnancy rate per cycle were observed between groups. However, Group B received a significantly higher cumulative-dose of r-hFSH than Group A (2435.86 +/- 932.8 IU versus 1959.8 +/- 736.45 p = 0.048). When one-way ANOVA in a within design was applied...

  17. Smart Beta or Smart Alpha

    DEFF Research Database (Denmark)

    Winther, Kenneth Lillelund; Steenstrup, Søren Resen

    2016-01-01

    -documented smart beta risk premiums and still motivate active managers to avoid value traps, too highly priced small caps, defensives, etc. By constructing the equity portfolios of active managers that resemble the most widely used risk premiums, we show that the returns and risk-adjusted returns measures......Smart beta has become the flavor of the decade in the investment world with its low fees, easy access to rewarded risk premiums, and appearance of providing good investment results relative to both traditional passive benchmarks and actively managed funds. Although we consider it well documented...... that smart beta investing probably will do better than passive market capitalization investing over time, we believe many are coming to a conclusion too quickly regarding active managers. Institutional investors are able to guide managers through benchmarks and risk frameworks toward the same well...

  18. Trap style influences wild pig behavior and trapping success

    Science.gov (United States)

    Williams, B.L.; Holtfreter, R.W.; Ditchkoff, S.S.; Grand, J.B.

    2011-01-01

    Despite the efforts of many natural resource professionals, wild pig (Sus scrofa) populations are expanding in many areas of the world. Although many creative techniques for controlling pig populations are being explored, trapping has been and still is themost commonly usedmethod of population control formany public and private land managers. We conducted an observational study to examine the efficiency of 2 frequently used trap styles: a small, portable box-style trap and a larger, semi-permanent, corral-style trap.We used game cameras to examine patterns of trap entry by wild pigs around each style of trap, and we conducted a trapping session to compare trapping success between trap styles. Adult female and juvenile wild pigs entered both styles of trap more readily than did adult males, and adult males seemed particularly averse to entering box traps. Less than 10% of adult male visits to box traps resulted in entries, easily the least percentage of any class at any style of trap. Adult females entered corral traps approximately 2.2 times more often per visit than box traps and re-entered corral traps >2 times more frequently. Juveniles entered and reentered both box and corral traps at similar rates. Overall (all-class) entry-per-visit rates at corral traps (0.71) were nearly double that of box traps (0.37). Subsequent trapping data supported these preliminary entry data; the capture rate for corral traps was >4 times that of box traps. Our data suggest that corral traps are temporally and economically superior to box traps with respect to efficiency; that is, corral traps effectively trap more pigs per trap night at a lower cost per pig than do box traps. ?? 2011 The Wildlife Society.

  19. Neutral atom traps.

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Michael Vern

    2008-12-01

    This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

  20. Progress towards magnetic trapping of ultra-cold neutrons

    CERN Document Server

    Huffman, P R; Butterworth, J S; Coakley, K J; Dewey, M S; Dzhosyuk, S N; Gilliam, D M; Golub, R; Greene, G L; Habicht, K; Lamoreaux, S K; Mattoni, C E H; McKinsey, D N; Wietfeldt, F E; Doyle, J M

    2000-01-01

    We report progress towards magnetic trapping of ultra-cold neutrons (UCN) in preparation for a neutron lifetime measurement. UCN will be produced by inelastic scattering of cold (0.89 nm) neutrons in a reservoir of superfluid sup 4 He and confined in a three-dimensional magnetic trap. As the trapped neutrons decay, recoil electrons will generate scintillations in the liquid He, which should be detectable with nearly 100% efficiency. This direct measure of the number of UCN decays vs. time can be used to determine the neutron beta-decay lifetime.

  1. Progress towards magnetic trapping of ultra-cold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, P.R.; Brome, C.R.; Butterworth, J.S.; Coakley, K.J.; Dewey, M.S.; Dzhosyuk, S.N.; Gilliam, D.M.; Golub, R.; Greene, G.L.; Habicht, K.; Lamoreaux, S.K.; Mattoni, C.E.H.; McKinsey, D.N.; Wietfeldt, F.E.; Doyle, J.M

    2000-02-11

    We report progress towards magnetic trapping of ultra-cold neutrons (UCN) in preparation for a neutron lifetime measurement. UCN will be produced by inelastic scattering of cold (0.89 nm) neutrons in a reservoir of superfluid {sup 4}He and confined in a three-dimensional magnetic trap. As the trapped neutrons decay, recoil electrons will generate scintillations in the liquid He, which should be detectable with nearly 100% efficiency. This direct measure of the number of UCN decays vs. time can be used to determine the neutron beta-decay lifetime.

  2. Torque and optical traps

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... Optical traps are an important tool for research in the field of single molecule biophysics. Recent advances in optical trapping have extended their functionality from simple linear manipulation and measurement of forces, to now the ability to rotate objects and measure torques. This mini review summarizes ...

  3. Versatile electrostatic trap

    NARCIS (Netherlands)

    van Veldhoven, J.; Bethlem, H.L.; Schnell, M.; Meijer, G.

    2006-01-01

    A four electrode electrostatic trap geometry is demonstrated that can be used to combine a dipole, quadrupole, and hexapole field. A cold packet of ND315 molecules is confined in both a purely quadrupolar and hexapolar trapping field and additionally, a dipole field is added to a hexapole field to

  4. Quadrupole Ion Traps

    Indian Academy of Sciences (India)

    electron bound to the gravitational field, the 'geonium atom'. The first atomic hyperfine structure experiment on trapped ions was performed by Dehmelt's group using the stored-ion exchange-collision technique in a Paul trap which paved the way for some of the subsequent experiment for atomic frequency. A single atom at.

  5. Y-Trap Cancer Immunotherapy Drug Targets Two Proteins

    Science.gov (United States)

    Two groups of researchers, working independently, have fused a TGF-beta receptor to a monoclonal antibody that targets a checkpoint protein. The result, this Cancer Currents blog describes, is a single hybrid molecule called a Y-trap that blocks two pathways used by tumors to evade the immune system.

  6. Nematode-Trapping Fungi.

    Science.gov (United States)

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  7. Laser-assisted delivery of vitamin C, vitamin E, and ferulic acid formula serum decreases fractional laser postoperative recovery by increased beta fibroblast growth factor expression.

    Science.gov (United States)

    Waibel, Jill S; Mi, Qing-Sheng; Ozog, David; Qu, Le; Zhou, Li; Rudnick, Ashley; Al-Niaimi, Firas; Woodward, Julie; Campos, Valerie; Mordon, Serge

    2016-03-01

    Laser-assisted drug delivery is an emerging technology to achieve greater penetration by existing topical medications to reach desired targets in the tissue. The objective of this research was to study whether laser-assisted delivery of Vitamin C, E, and Ferulic immediately postoperatively of fractional ablative laser could improve wound healing. Secondary objectives were to evaluate the potential molecular markers involved in this wound-healing process. A double blinded, prospective, single center, randomized split face trial of Vitamin C, E, and Ferulic topical formula #740019 to decrease postoperative recovery time in fractional ablative laser resurfacing for photo damage. Fifteen healthy men and women of ages 30-55 years were treated with the Vitamin C, E, and Ferulic acid serum to one side of face and vehicle to the other side of face, within 2 minutes immediately after fractional ablative CO2 laser surgery and daily during the healing process. Patients were evaluated daily on days 1-7 using photographs, patient questionnaires, and molecular evaluation. Clinically, postoperative Vitamin C, E, and Ferulic delivery resulted in decreased edema versus vehicle on postoperative day 7 and decreased erythema versus vehicle on postoperative days 3 and 5. Molecularly, the expression of basic fibroblast growth factor (bFGF) was significantly increased at day 5 on the lesion treated with Vitamin C, E, and Ferulic acid serum compared to vehicle control on the other side. This is first study to show that Vitamin C, E, and Ferulic acid correlate with more rapid wound healing post-fractional ablative laser. Elevated bFGF could be involved in the Vitamin C, E, and Ferulic acid-induced rapid wound healing. © 2015 Wiley Periodicals, Inc.

  8. Characterization of a beta-N-acetylhexosaminidase and a beta-N-acetylglucosaminidase/beta-glucosidase from Cellulomonas fimi.

    Science.gov (United States)

    Mayer, Christoph; Vocadlo, David J; Mah, Melanie; Rupitz, Karen; Stoll, Dominik; Warren, R A J; Withers, Stephen G

    2006-07-01

    The gram-positive soil bacterium Cellulomonas fimi is shown to produce at least two intracellular beta-N-acetylglucosaminidases, a family 20 beta-N-acetylhexosaminidase (Hex20), and a novel family 3-beta-N-acetylglucosaminidase/beta-glucosidase (Nag3), through screening of a genomic expression library, cloning of genes and analysis of their sequences. Nag3 exhibits broad substrate specificity for substituents at the C2 position of the glycone: kcat/Km values at 25 degrees C were 0.066 s(-1) x mM(-1) and 0.076 s(-1) x mM(-1) for 4'-nitrophenyl beta-N-acetyl-D-glucosaminide and 4'-nitrophenyl beta-D-glucoside, respectively. The first glycosidase with this broad specificity to be described, Nag3, suggests an interesting evolutionary link between beta-N-acetylglucosaminidases and beta-glucosidases of family 3. Reaction by a double-displacement mechanism was confirmed for Nag3 through the identification of a glycosyl-enzyme species trapped with the slow substrate 2',4'-dinitrophenyl 2-deoxy-2-fluoro-beta-D-glucopyranoside. Hex20 requires the acetamido group at C2 of the substrate, being unable to cleave beta-glucosides, since its mechanism involves an oxazolinium ion intermediate. However, it is broad in its specificity for the D-glucosyl/D-galactosyl configuration of the glycone: Km and kcat values were 53 microM and 482.3 s(-1) for 4'-nitrophenyl beta-N-acetyl-D-glucosaminide and 66 microM and 129.1 s(-1) for 4'-nitrophenyl beta-N-acetyl-D-galactosaminide.

  9. Trapping cold ground state argon atoms.

    Science.gov (United States)

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  10. Recombination in Perovskite Solar Cells : Significance of Grain Boundaries, Interface Traps, and Defect Ions

    NARCIS (Netherlands)

    Sherkar, Tejas; Momblona, Cristina; Gil-Escrig, Lidon; Avila, Jorge; Sessolo, Michele; Bolink, Henk J.; Koster, Lambert

    2017-01-01

    Trap-assisted recombination, despite being lower as compared with traditional inorganic solar cells, is still the dominant recombination mechanism in perovskite solar cells (PSCs) and limits their efficiency. We investigate the attributes of the primary trap-assisted recombination channels (grain

  11. Microfabricated Waveguide Atom Traps.

    Energy Technology Data Exchange (ETDEWEB)

    Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    A nanoscale , microfabricated waveguide structure can in - principle be used to trap atoms in well - defined locations and enable strong photon-atom interactions . A neutral - atom platform based on this microfabrication technology will be prealigned , which is especially important for quantum - control applications. At present, there is still no reported demonstration of evanescent - field atom trapping using a microfabricated waveguide structure. We described the capabilities established by our team for future development of the waveguide atom - trapping technology at SNL and report our studies to overcome the technical challenges of loading cold atoms into the waveguide atom traps, efficient and broadband optical coupling to a waveguide, and the waveguide material for high - power optical transmission. From the atomic - physics and the waveguide modeling, w e have shown that a square nano-waveguide can be utilized t o achieve better atomic spin squeezing than using a nanofiber for first time.

  12. A protocol for sonication-assisted Agrobacterium rhizogenes-mediated transformation of haploid and diploid sugar beet (Beta vulgaris L.) explants.

    Science.gov (United States)

    Klimek-Chodacka, Magdalena; Baranski, Rafal

    2014-01-01

    Hairy root cultures obtained after Agrobacterium rhizogenes-mediated genetic transformation can serve as a model system for studying plant metabolism and physiology, or can be utilized for the production of secondary metabolites. So far no efficient protocol of hairy root development in sugar beet has been publically released. In this work, two A. rhizogenes strains (A4T and LBA1334) carrying a binary vector pBIN-m-gfp5-ER or pCAMBIA1301 possessing gfp and uidA reporter genes were used to transform petiole explants of haploid and diploid sugar beet genotypes. Five treatment combinations of sonicated-assisted Agrobacterium-mediated transformation were compared. Hairy roots appeared on 0% to 54% of explants depending on the treatment combination used. The highest frequency was achieved when explants of a diploid genotype were sonicated for 15 s in the inoculum containing A. rhizogenes of OD600=0.5 and then co-cultured for three days. Using the same treatment combinations the explants of haploid genotypes developed hairy roots with the frequency ranging from 10% to 36%. Transformation efficiency was independent on the bacterial strain used. The results indicate that haploid sugar beet explants are amenable to transformation using A. rhizogenes, and that the efficiency of that process can be increased by applying short ultrasound treatment.

  13. Ion Trap Quantum Computing

    Science.gov (United States)

    2011-12-01

    stored ions,” Adv. Atom Mol. Phys., vol. Volume 3, pp. 53–72 1968. [48] P. H. Dawson, Quadrupole Mass Spectometry and Its Applications, Melville, NY... DATE December 2011 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Ion trap Quantum Computing 5. FUNDING NUMBERS 6...researcher [30] that introduced the concept of ion traps in the 1950s. His experiments focused on separating atoms with different masses in order to

  14. Search For Trapped Antihydrogen

    CERN Document Server

    Andresen, Gorm B.; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D.; Bray, Crystal C.; Butler, Eoin; Cesar, Claudio L.; Chapman, Steven; Charlton, Michael; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C.; Gill, David R.; Hangst, Jeffrey S.; Hardy, Walter N.; Hayano, Ryugo S.; Hayden, Michael E.; Humphries, Andrew J.; Hydomako, Richard; Jonsell, Svante; Jorgensen, Lars V.; Kurchaninov, Lenoid; Lambo, Ricardo; Madsen, Niels; Menary, Scott; Nolan, Paul; Olchanski, Konstantin; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Nasr, Sarah Seif El; Silveira, Daniel M.; So, Chukman; Storey, James W.; Thompson, Robert I.; van der Werf, Dirk P.; Wilding, Dean; Wurtele, Jonathan S.; Yamazaki, Yasunori

    2011-01-01

    We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over ~30 ms. After a three-week experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9 positrons to produce 6 10^5 antihydrogen atoms, we have identified six antiproton annihilation events that are consist...

  15. Abattoirs as non-hospital source of extended spectrum beta lactamase producers: confirmed by the double disc synergy test and characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Moses Nkechukwu Ikegbunam

    Full Text Available In this study, the presence of extended spectrum beta lactamase (ESBL producing organisms in abattoirs, a non-hospital community was investigated. The presence of ESBL-producing phenotypes was confirmed by the Double Disc Synergy Test (DDST. Out of the 99 isolates screened for ESBL, 28 (28.3% were confirmed positive. The positive isolates were characterised by using Matrix-Assisted Laser Desorption/Ionization Time of flight Mass Spectrometry. 50% of the isolates were Pseudomonas spp., the rest were different species of Acinetobacter, Stenotrophomonas and Achromobacter. Pseudomonas monteilli and Pseudomonas putida were the most occurring in the intestine. The entire positive ESBL producers were subjected to plasmid curing to ascertain the location of the resistant marker. The result of the plasmid curing indicated that the resistant genes were chromosomally borne. The findings have therefore established the presence of ESBL producing organisms in the gut of animals from abattoirs and the table were the meat are sold, and its rate of occurrence is comparable to hospital ICUs. Abattoir communities could probably be a source of human infection with ESBL expressing pathogens and possible transfer to non-ESBL producers.

  16. Trapping Dust to Form Planets

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Growing a planet from a dust grain is hard work! A new study explores how vortices in protoplanetary disks can assist this process.When Dust Growth FailsTop: ALMA image of the protoplanetary disk of V1247 Orionis, with different emission components labeled. Bottom: Synthetic image constructed from the best-fit model. [Kraus et al. 2017]Gradual accretion onto a seed particle seems like a reasonable way to grow a planet from a grain of dust; after all, planetary embryos orbit within dusty protoplanetary disks, which provides them with plenty of fuel to accrete so they can grow. Theres a challenge to this picture, though: the radial drift problem.The radial drift problem acknowledges that, as growing dust grains orbit within the disk, the drag force on them continues to grow as well. For large enough dust grains perhaps around 1 millimeter the drag force will cause the grains orbits to decay, and the particles drift into the star before they are able to grow into planetesimals and planets.A Close-Up Look with ALMASo how do we overcome the radial drift problem in order to form planets? A commonly proposed mechanism is dust trapping, in which long-lived vortices in the disk trap the dust particles, preventing them from falling inwards. This allows the particles to persist for millions of years long enough to grow beyond the radial drift barrier.Observationally, these dust-trapping vortices should have signatures: we would expect to see, at millimeter wavelengths, specific bright, asymmetric structures where the trapping occurs in protoplanetary disks. Such disk structures have been difficult to spot with past instrumentation, but the Atacama Large Millimeter/submillimeter Array (ALMA) has made some new observations of the disk V1247 Orionis that might be just what were looking for.Schematic of the authors model for the disk of V1247 Orionis. [Kraus et al. 2017]Trapped in a Vortex?ALMAs observations of V1247 Orionis are reported by a team of scientists led by Stefan

  17. Antihydrogen formation and trapping

    CERN Document Server

    Madsen, Niels

    2014-01-01

    Antihydrogen, the bound state of a positron and an antiproton, is the only neutral pure antimatter system available to date, and as such provides an excellent testbed for probing fundamental symmetries between matter and antimatter. In this chapter we will concentrate on the physics issues that were addressed in order to achieve the first trapping of antihydrogen. Antihydrogen can be created by merging antiprotons and positrons in a Penning–Malmberg trap. However, traps for antihydrogen are at best about ∼50 μeV deep and, as no readily available cooling techniques exist, the antihydrogen must be formed trapped. Antiprotons are sourced from an accelerator and arrive with a typical energy of 5.3 MeV. The large numbers of positrons needed means that the self-potential of the positrons are of order 2–5 V. With such energetic ingredients a range of plasma control and diagnostic techniques must be brought to bear on the particles to succeed in making any antihydrogen cold enough to be trapped.

  18. Trapping guidelines for area-wide fruit fly programmes

    International Nuclear Information System (INIS)

    2003-11-01

    Different traps and lures have been developed and used over decades to survey fruit fly populations. The first attractant for male fruit flies was methyl eugenol (ME) (for Bactrocera zonata, Howlett, 1912) followed by kerosene for Mediterranean fruit fly, Ceratitis capitata, (medfly), Severin and Severin, 1913. In 1956, Angelica seed oil was used to trap medfly (Steiner et al, 1957). Beroza et al. (1961) discovered trimedlure (TML) to be effective for the same purpose. Beroza and Green, 1963, demonstrated cuelure to be an effective attractant for Bactrocera cucurbitae. Food baits based on protein solutions, fermenting sugar solutions, fruit juices, and vinegar have been used since 1918 for the capture of females of several species. The McPhail trap was the first device to be used with protein baits (McPhail, 1929). Steiner traps were developed in 1957 (Steiner et al., 1957) and Jackson traps in 1971 for TML (Harris et al., 1971). These traps are currently used in various countries for fruit fly surveys in support of control activities and eradication campaigns. The combination of a McPhail trap with a protein attractant, Jackson trap with TML, and the Steiner trap with ME or cuelure (CUE), has remained unchanged for several decades. Global trends in increasing food quality, revenue sources, and fruit and vegetable trade, has resulted in an increased worldwide movement of fruit fly species and requires refinement of survey systems. After years of validating trapping technology through coordinated research programmes (CRP's) and extensive technical assistance to member countries, the Joint Division FAO/IAEA proposes the use of proven technologies in improving trap sensitivity in area-wide fruit fly control programmes (IAEA 1996 and IAEA 1998). These proven technologies include the use of synthetic food lures such as female attractants that can be used for several species of Anastrepha, Bactrocera and Ceratitis. Other citations of information on these developments are

  19. Thermoelectrically cooled water trap

    Science.gov (United States)

    Micheels, Ronald H [Concord, MA

    2006-02-21

    A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

  20. Origin of traps and charge transport mechanism in hafnia

    Energy Technology Data Exchange (ETDEWEB)

    Islamov, D. R., E-mail: damir@isp.nsc.ru; Gritsenko, V. A., E-mail: grits@isp.nsc.ru [Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Cheng, C. H. [Department of Mechatronic Technology, National Taiwan Normal University, Taipei 106, Taiwan (China); Chin, A., E-mail: albert-achin@hotmail.com [National Chiao Tung University, Hsinchu 300, Taiwan (China)

    2014-12-01

    In this study, we demonstrated experimentally and theoretically that oxygen vacancies are responsible for the charge transport in HfO{sub 2}. Basing on the model of phonon-assisted tunneling between traps, and assuming that the electron traps are oxygen vacancies, good quantitative agreement between the experimental and theoretical data of current-voltage characteristics was achieved. The thermal trap energy of 1.25 eV in HfO{sub 2} was determined based on the charge transport experiments.

  1. Measuring the Neutron Lifetime with Magnetically Trapped Ultracold Neutrons

    Science.gov (United States)

    Mumm, H. P.; Huber, M. G.; Yue, A. T.; Thompson, A. K.; Dewey, M. S.; Huffer, C. R.; Huffman, P. R.; Schelhammer, K. W.; O'Shaughnessy, C.; Coakley, K. J.

    2014-03-01

    We describe an experiment to measure the neutron lifetime using a technique with a set of systematic uncertainties largely different than those of previous measurements. In this approach, ultracold neutrons (UCN) are produced by inelastic scattering of cold (0.89 nm) neutrons in a reservoir of superfluid 4He. These neutrons are then confined using a three-dimensional magnetic trap. As the trapped neutrons beta decay, the energetic electrons produced in the decay generate scintillations in the liquid He; each decay is detectable with nearly 100 % efficiency. The neutron lifetime can be directly determined by measuring the scintillation rate as a function of time.

  2. Redesigning octopus traps

    Directory of Open Access Journals (Sweden)

    Eduarda Gomes

    2014-06-01

    In order to minimise the identified problems in the actual traps, the present work proposes a new design with the aim of reducing the volume and weight during transport, and also during onshore storage. Alternative materials to avoid corrosion and formation of encrustations were also proposed.

  3. Measurement of the beta-neutrino correlation of sodium-21 usingshakeoff electrons

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, Paul A.; Abo-Shaeer, Jamil R.; Freedman, Stuart J.; Maruyama, Reina

    2007-01-16

    The beta-neutrino correlation coefficient, a_beta nu, ismeasured in 21Na by detecting the time-of-flight of the recoil nucleusdetected in coincidence with the atomic electrons shaken off in betadecay. The sample of 21Na is confined in a magneto-optic trap. Highdetection efficiency allows low trap density, which suppresses thephotoassociation of molecular sodium, which can cause a large systematicerror. Suppressing the fraction of trapped atoms in the excited stateusing a dark trap also reduces the photoassociation process, and datataken with this technique are consistent. The main remaining systematicuncertainties come from the measurement of the position and size of theatom trap, and the subtraction of background. We find mbox a_betanu=0.5502(60), in agreement with the Standard Model prediction of mboxa_beta nu=0.553(2), and disagreeing with a previous measurement which wassusceptible to an error introduced by the presence of molecularsodium.

  4. Trapping metastable chromium atoms in a crossed optical dipole trap

    Science.gov (United States)

    Beaufils, Q.; Chicireanu, R.; Pouderous, A.; Laburthe-Tolra, B.; Maréchal, E.; Vernac, L.; Keller, J.-C.; Gorceix, O.

    We report the fast accumulation of up to 1 million 52Cr metastable atoms in a mixed trap formed by the superposition of a quadrupolar magnetic trap and a strongly confining optical trap. The cloud is at a temperature of 100 μK with a peak density of 1018 atoms/m3, which is a promising starting point to reach quantum degeneracy by forced evaporation in an optical trap.

  5. A live-trap and trapping technique for fossorial mammals

    African Journals Online (AJOL)

    injuries, the trauma involved in such capture does not promote acclimatization ... involved in the evolution of trap design for use in various field conditions and live capture of other fossorial mammals are discussed. Materials and Methods. Constructing the .... work of setting traps halved by placing only one trap instead of the ...

  6. Optical trapping of gold aerosols

    DEFF Research Database (Denmark)

    Schmitt, Regina K.; Pedersen, Liselotte Jauffred; Taheri, S. M.

    2015-01-01

    Aerosol trapping has proven challenging and was only recently demonstrated.1 This was accomplished by utilizing an air chamber designed to have a minimum of turbulence and a laser beam with a minimum of aberration. Individual gold nano-particles with diameters between 80 nm and 200 nm were trapped...... in air using a 1064 nm laser. The positions visited by the trapped gold nano-particle were quantified using a quadrant photo diode placed in the back focal plane. The time traces were analyzed and the trapping stiffness characterizing gold aerosol trapping determined and compared to aerosol trapping...... of nanometer sized silica and polystyrene particles. Based on our analysis, we concluded that gold nano-particles trap more strongly in air than similarly sized polystyrene and silica particles. We found that, in a certain power range, the trapping strength of polystyrene particles is linearly decreasing...

  7. Feedback trap using optical force

    Science.gov (United States)

    Jun, Yonggun; Pak, Hyuk Kyu

    Recently, the feedback trap using electrophoretic force (ABEL trap) has been used in the experimental study of non-equilibrium thermodynamics such as Landauer's erasure principle. This trap can trap and manipulate a small particle in solution by canceling the Brownian fluctuations. Here, we propose a simple way to control a bead using optical force with feedback and show the dynamics of a single particle in the virtual potential.

  8. Electromagnetic two-dimensional analysis of trapped-ion eigenmodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.; Rewoldt, G.

    1984-11-01

    A two-dimensional electromagnetic analysis of the trapped-ion instability for the tokamak case with ..beta.. not equal to 0 has been made, based on previous work in the electrostatic limit. The quasineutrality condition and the component of Ampere's law along the equilibrium magnetic field are solved for the perturbed electrostatic potential and the component of the perturbed vector potential along the equilibrium magnetic field. The general integro-differential equations are converted into a matrix eigenvalue-eigenfunction problem by expanding in cubic B-spline finite elements in the minor radius and in Fourier harmonics in the poloidal angle. A model MHD equilibrium with circular, concentric magnetic surfaces and large aspect ratio is used which is consistent with our assemption that B << 1. The effect on the trapped-ion mode of including these electromagnetic extensions to the calculation is considered, and the temperature (and ..beta..) scaling of the mode frequency is shown and discussed.

  9. Escaping the tolerance trap

    International Nuclear Information System (INIS)

    Hammoudeh, S.; Madan, V.

    1994-01-01

    In order to examine the implications of the weakening of OPEC's responsiveness in adjusting its production levels, this paper explicitly incorporates rigidity in the quantity adjustment mechanism, thereby extending previous research which assumed smooth quantity adjustments. The rigidity is manifested in a tolerance range for the discrepancy between the declared target price and that of the market. This environment gives rise to a 'tolerance trap' which impedes the convergence process and inevitably brings the market to a standstill before its reaches the targeted price and revenue objectives. OPEC's reaction to the standstill has important implications for the achievement of the target-based equilibrium and for the potential collapse of the market price. This paper examines OPEC's policy options in the tolerance trap and reveals that the optional policy in order to break this impasse and move closer to the equilibrium point is gradually to reduce output and not to flood the market. (Author)

  10. Trapped Ion Qubits

    Energy Technology Data Exchange (ETDEWEB)

    Maunz, Peter Lukas Wilhelm

    2017-04-01

    Qubits can be encoded in clock states of trapped ions. These states are well isolated from the environment resulting in long coherence times [1] while enabling efficient high-fidelity qubit interactions mediated by the Coulomb coupled motion of the ions in the trap. Quantum states can be prepared with high fidelity and measured efficiently using fluorescence detection. State preparation and detection with 99.93% fidelity have been realized in multiple systems [1,2]. Single qubit gates have been demonstrated below rigorous fault-tolerance thresholds [1,3]. Two qubit gates have been realized with more than 99.9% fidelity [4,5]. Quantum algorithms have been demonstrated on systems of 5 to 15 qubits [6–8].

  11. Measuring the neutron lifetime using magnetically trapped neutrons

    Energy Technology Data Exchange (ETDEWEB)

    O' Shaughnessy, C.M.; Golub, R.; Schelhammer, K.W.; Swank, C.M.; Seo, P.-N. [North Carolina State University, 2401 Stinson Drive, Raleigh, NC (United States); Huffman, P.R., E-mail: Paul_Huffman@ncsu.ed [North Carolina State University, 2401 Stinson Drive, Raleigh, NC (United States); Dzhosyuk, S.N.; Mattoni, C.E.H.; Yang, L.; Doyle, J.M. [Harvard University, 17 Oxford Street, Cambridge, MA (United States); Coakley, K.J.; Thompson, A.K.; Mumm, H.P. [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD (United States); Lamoreaux, S.K.; McKinsey, D.N. [Yale University, 217 Prospect Street, New Haven, CT (United States); Yang, G. [University of Maryland, College Park, MD (United States)

    2009-12-11

    The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of {sup 4}He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid {sup 4}He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.

  12. Sediment Trapping in Estuaries

    Science.gov (United States)

    Burchard, Hans; Schuttelaars, Henk M.; Ralston, David K.

    2018-01-01

    Estuarine turbidity maxima (ETMs) are generated by a large suite of hydrodynamic and sediment dynamic processes, leading to longitudinal convergence of cross-sectionally integrated and tidally averaged transport of cohesive and noncohesive suspended particulate matter (SPM). The relative importance of these processes for SPM trapping varies substantially among estuaries depending on topography, fluvial and tidal forcing, and SPM composition. The high-frequency dynamics of ETMs are constrained by interactions with the low-frequency dynamics of the bottom pool of easily erodible sediments. Here, we use a transport decomposition to present processes that lead to convergent SPM transport, and review trapping mechanisms that lead to ETMs at the landward limit of the salt intrusion, in the freshwater zone, at topographic transitions, and by lateral processes within the cross section. We use model simulations of example estuaries to demonstrate the complex concurrence of ETM formation mechanisms. We also discuss how changes in SPM trapping mechanisms, often caused by direct human interference, can lead to the generation of hyperturbid estuaries.

  13. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... it results in that type of thalassemia. About Beta Thalassemia Beta thalassemia happens when the gene that controls ...

  14. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  15. Single Ion Trapping for the Enriched Xenon Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, Samuel J.; /Stanford U., Phys. Dept. /SLAC

    2006-03-28

    In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of {approx_equal} .010 eV.

  16. Effect of the interaction among traps on the shape of thermoluminescence glow curves

    International Nuclear Information System (INIS)

    Marcazzo, J.; Santiago, M.; Spano, F.; Lester, M.; Ortega, F.; Molina, P.; Caselli, E.

    2007-01-01

    The effect of the interaction among traps on the structure of thermoluminescence glow curves has been investigated by generating numerically simulated glow curves for a wide range of trap parameters. The results reported in this paper provide useful insights which assist in the analysis of experimental glow curves. The most important result shows that it is incorrect to assume beforehand that each peak is related to a specific trapping state. The validity of the quasiequilibrium approximation is briefly discussed

  17. The Honey Trap

    DEFF Research Database (Denmark)

    Wagner, Michael

    Michael F. Wagner: The Honey Trap –The democratization of leisure through automobilism The automobile has achieved a central position in modern everyday life as an essential artefact to mobility. This raises the question how automobiles have been mediated for mass consumption? The central thesis...... demonstrates the manner in which automobilism in Denmark was invented, constructed, represented, and appropriated as a leisure culture after 1900 through a mediation and consumption junction that was initiated and promoted by FDM. This is basically the story of unlimited access to Sunday driving or the daytrip...

  18. Atom trap trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O' Connor, T. P.; Young, L.

    2000-05-25

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

  19. Magnetic traps with a spherical separatrix: Tornado traps

    International Nuclear Information System (INIS)

    Peregood, B.P.; Lehnert, B.

    1981-01-01

    A review is given on the features of magnetic traps with a spherical separatrix, with special emphasis on Tornado spiral coil configurations. The confinement and heating of static plasms in Tornado traps is treated, including the topology of the magnetic field structure, the magneto-mechanical properties of the magnetic coil system, as well as the particle orbits and plasma behaviour in these traps. In addition, the mode of rotating plasma operation by crossed electric and magnetic fields is described. The results of experiments on static and rotating plasmas are summarized, and conclusions are drawn about future possibilities of Tornado traps in the creation and containment of hot plasmas. (orig.)

  20. Characteristics of trapped electrons and electron traps in single crystals

    International Nuclear Information System (INIS)

    Budzinski, E.E.; Potter, W.R.; Potienko, G.; Box, H.C.

    1979-01-01

    Two additional carbohydrates are reported whose crystal structures trap electrons intermolecularly in single crystals x irradiated at low temperature, namely sucrose and rhamnose. Five carbohydrate and polyhydroxy compounds are now known which exhibit this phenomenon. The following characteristics of the phenomenon were investigated: (1) the hyperfine couplings of the electron with protons of the polarized hydroxy groups forming the trap; (2) the distances between these protons and the trapped electron; (3) the spin density of the electron at the protons and (4) the relative stabilities of the electron trapped in various crystal structures

  1. Matrix Assisted and/or Laser Desorption Ionization Quadrupole Ion Trap Time-of-Flight Mass Spectrometry of WO3 Clusters Formation in Gas Phase. Nanodiamonds, Fullerene, and Graphene Oxide Matrices

    Science.gov (United States)

    Ausekar, Mayuri Vilas; Mawale, Ravi Madhukar; Pazdera, Pavel; Havel, Josef

    2018-01-01

    The formation of W x O y +●/-● clusters in the gas phase was studied by laser desorption ionization (LDI) and matrix assisted laser desorption ionization (MALDI) of solid WO3. LDI produced (WO3) n + ●/- ● (n = 1-7) clusters. In MALDI, when using nano-diamonds (NDs), graphene oxide (GO), or fullerene (C60) matrices, higher mass clusters were generated. In addition to (WO3) n -● clusters, oxygen-rich or -deficient species were found in both LDI and MALDI (with the total number of clusters exceeding one hundred ≈ 137). This is the first time that such matrices have been used for the generation of(WO3) n +●/-● clusters in the gas phase, while new high mass clusters (WO3) n -● (n = 12-19) were also detected. [Figure not available: see fulltext.

  2. Matrix Assisted and/or Laser Desorption Ionization Quadrupole Ion Trap Time-of-Flight Mass Spectrometry of WO3 Clusters Formation in Gas Phase. Nanodiamonds, Fullerene, and Graphene Oxide Matrices

    Science.gov (United States)

    Ausekar, Mayuri Vilas; Mawale, Ravi Madhukar; Pazdera, Pavel; Havel, Josef

    2018-03-01

    The formation of W x O y +●/-● clusters in the gas phase was studied by laser desorption ionization (LDI) and matrix assisted laser desorption ionization (MALDI) of solid WO3. LDI produced (WO3) n + ●/- ● ( n = 1-7) clusters. In MALDI, when using nano-diamonds (NDs), graphene oxide (GO), or fullerene (C60) matrices, higher mass clusters were generated. In addition to (WO3) n -● clusters, oxygen-rich or -deficient species were found in both LDI and MALDI (with the total number of clusters exceeding one hundred ≈ 137). This is the first time that such matrices have been used for the generation of(WO3) n + ●/-● clusters in the gas phase, while new high mass clusters (WO3) n -● ( n = 12-19) were also detected. [Figure not available: see fulltext.

  3. Measuring the Neutron Lifetime using Magnetically Trapped Ultracold Neutrons

    Science.gov (United States)

    Mumm, H. P.; Coakley, K. J.; Dewey, M. S.; Huber, M. G.; Hughes, P. P.; Thompson, A. K.; Golub, R.; Huffer, C. R.; Huffman, P. R.; O'Shaughnessy, C. M.; Schelhammer, K. W.

    2010-11-01

    The neutron beta-decay lifetime is important in both theoretical predictions of the primordial abundance of ^4He and providing a strong unitarity test of the CKM mixing matrix. We have previously demonstrated trapping of Ultracold Neutrons (UCN) in a magnetic trap, and, though statistically limited, measured a lifetime consistent with the world average. A major upgrade of the apparatus has now been completed at NIST. In our unique approach, a 0.89 nm neutron beam is incident on a superfluid ^4He target within the minimum field region of an Ioffe-type magnetic trap. Neutrons are downscattered by single phonon scattering in liquid helium to near rest and trapped; at sufficiently low temperatures, the low phonon density in the helium suppresses upscatter. The electron accompanying neutron decay produces scintillation in the superfluid helium and can be detected in real time. Previous statistical limitations as well as systematics related to neutron material bottling will be reduced by significant increases in field strength and trap volume. Details of analyses of the systematics as well as the initial performance benchmarks of the new apparatus will be presented.

  4. Segmented trapped vortex cavity

    Science.gov (United States)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  5. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward-...

  6. Injection into electron plasma traps

    International Nuclear Information System (INIS)

    Gorgadze, Vladimir; Pasquini, Thomas A.; Fajans, Joel; Wurtele, Jonathan S.

    2003-01-01

    Computational studies and experimental measurements of plasma injection into a Malmberg-Penning trap reveal that the number of trapped particles can be an order of magnitude higher than predicted by a simple estimates based on a ballistic trapping model. Enhanced trapping is associated with a rich nonlinear dynamics generated by the space-charge forces of the evolving trapped electron density. A particle-in-cell simulation is used to identify the physical mechanisms that lead to the increase in trapped electrons. The simulations initially show strong two-stream interactions between the electrons emitted from the cathode and those reflected off the end plug of the trap. This is followed by virtual cathode oscillations near the injection region. As electrons are trapped, the initially hollow longitudinal phase-space is filled, and the transverse radial density profile evolves so that the plasma potential matches that of the cathode. Simple theoretical arguments are given that describe the different dynamical regimes. Good agreement is found between simulation and theory

  7. Electromagnetic trapping of neutral atoms

    International Nuclear Information System (INIS)

    Metcalf, H.J.

    1986-01-01

    Cooling and trapping of neutral atoms is a new branch of applied physics that has potential for application in many areas. The authors present an introduction to laser cooling and magnetic trapping. Some basic ideas and fundamental limitations are discussed, and the first successful experiments are reviewed. Trapping a neutral object depends on the interaction between an inhomogeneous electromagnetic field and a multiple moment that results in the exchange of kinetic for potential energy. In neutral atom traps, the potential energy must be stored as internal atomic energy, resulting in two immediate and extremely important consequences. First, the atomic energy levels will necessarily shift as the atoms move in the trap, and, second, practical traps for ground state neutral atoms atr necessarily very shallow compared to thermal energy. This small depth also dictates stringent vacuum requirements because a trapped atom cannot survive a single collision with a thermal energy background gas molecule. Neutral trapping, therefore, depends on substantial cooling of a thermal atomic sample and is inextricably connected with the cooling process

  8. Quantum computing with trapped ions

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R.J.

    1998-01-01

    The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

  9. Electromagnetic trapping of cold atoms

    International Nuclear Information System (INIS)

    Balykin, V.I.; Minogin, V.G.; Letokhov, V.S.

    2000-01-01

    This review describes the methods of trapping cold atoms in electromagnetic fields and in the combined electromagnetic and gravity fields. We discuss first the basic types of the dipole radiation forces used for cooling and trapping atoms in the laser fields. We outline next the fundamentals of the laser cooling of atoms and classify the temperature limits for basic laser cooling processes. The main body of the review is devoted to discussion of atom traps based on the dipole radiation forces, dipole magnetic forces, combined dipole radiation-magnetic forces, and the forces combined of the dipole radiation-magnetic and gravity forces. Physical fundamentals of atom traps operating as waveguides and cavities for cold atoms are also considered. The review ends with the applications of cold and trapped atoms in atomic, molecular and optical physics. (author)

  10. Fast analysis of phthalates in freeze-dried baby foods by ultrasound-vortex-assisted liquid-liquid microextraction coupled with gas chromatography-ion trap/mass spectrometry.

    Science.gov (United States)

    Russo, Mario Vincenzo; Avino, Pasquale; Notardonato, Ivan

    2016-11-25

    This paper is focused on the determination of phthalates (PAEs), compounds "plausibly" endocrine disruptors, in baby food products by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with GC-IT/MS (UVALLME-GC-IT/MS). Particularly, the whole procedure allows the determination of six phthalates such as DMP, DEP, DBP, iBcEP, BBP and DEHP. After dissolution of 0.1g product sample and addition of anthracene as Internal Standard, 250μL of n-heptane are used as extraction solvent. The solution, held for 5min on the vortex mixer and for 6min in an ultrasonic bath at 100W for favoring the solvent dispersion and consequently the analyte extraction, is centrifuged at 4000rpm for 30min. About 100μL of heptane are recovered and 1μL is injected into the GC-IT/MS. All the analytical parameters investigated are deeply discussed: under the best conditions, the percentage recoveries range between 96.2 and 109.2% with an RSD ≤10.5% whereas the Limit of Detections (LODs) and the Limit of Quantifications (LOQs) are below 11 and 20ngg -1 , respectively, for all the PAEs except for iBcEP (23 and 43ngg -1 , respectively). The linear dynamic range of this procedure is between 10 and 5000ngg -1 with R 2 ≥0.92. The method has been applied to real commercial freeze-dried samples (chicken and turkey meats) available on the Italian pharmaceutical market: three PAEs were preliminary identified, i.e. DEP (14ngg -1 ), DBP (11ngg -1 ) and DEHP (64ngg -1 ). Copyright © 2016. Published by Elsevier B.V.

  11. Trapped quintessential inflation

    International Nuclear Information System (INIS)

    Bueno Sanchez, J.C.; Dimopoulos, K.

    2006-01-01

    Quintessential inflation is studied using a string modulus as the inflaton-quintessence field. The modulus begins its evolution at the steep part of its scalar potential, which is due to non-perturbative effects (e.g. gaugino condensation). It is assumed that the modulus crosses an enhanced symmetry point (ESP) in field space. Particle production at the ESP temporarily traps the modulus resulting in a brief period of inflation. More inflation follows, due to the flatness of the potential, since the ESP generates either an extremum (maximum or minimum) or a flat inflection point in the scalar potential. Eventually, the potential becomes steep again and inflation is terminated. After reheating the modulus freezes due to cosmological friction at a large value, such that its scalar potential is dominated by contributions due to fluxes in the extra dimensions or other effects. The modulus remains frozen until the present, when it can become quintessence and account for the dark energy necessary to explain the observed accelerated expansion

  12. Trap-mulching Argentine ants.

    Science.gov (United States)

    Silverman, Jules; Sorenson, Clyde E; Waldvogel, Michael G

    2006-10-01

    Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies.

  13. A reservoir trap for antiprotons

    CERN Document Server

    Smorra, Christian; Franke, Kurt; Nagahama, Hiroki; Schneider, Georg; Higuchi, Takashi; Van Gorp, Simon; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Yamazaki, Yasunori; Ulmer, Stefan

    2015-01-01

    We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times > 1.08 years are estimated. The device is fail-safe against power-cuts of up to 10 hours. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.

  14. Resistance in bacteria and indirect beta-lactamase detection in E. coli isolated from Culex pipiens detected by matrix-assisted laser desorption ionization time of flight mass spectrometry.

    Science.gov (United States)

    Hleba, Lukáš; Kmeť, Vladimír; Tóth, Tomáš; Kačániová, Miroslava

    2017-01-02

    The aim of this study was detections of antibiotic resistance and resistance mechanism in bacteria isolated from mosquitos (Culex pipiens) living near humans. Therefore, antibiotic resistance in bacteria isolated from Culex pipiens was investigated by disk diffusion test and MIC E-test in this study. MALDI-TOF mass spectrometry was used for detection of resistant mechanism. In this study, hydrolytic breakdown products after a few hours of incubation of the bacteria isolated from Culex pipiens were detected. Results show that enzymatic destruction of ampicillin by beta-lactamases is able to be detected by MALDI-TOF mass spectrometry from wild strains of potential pathogens. The MALDI-TOF mass spectrometry is useful method for routine detection of beta-lactamases resistant mechanism, but overnight incubation of pure culture is necessary. The results are important for proper and fast intervention to limit the spread of beta-lactamase-producing wild bacteria and provide information for appropriate initial therapy of the infections caused by these microbes.

  15. Beta decay of highly charged ions

    International Nuclear Information System (INIS)

    Litvinov, Yuri A; Bosch, Fritz

    2011-01-01

    Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.

  16. Urban fall traps

    Directory of Open Access Journals (Sweden)

    Vera Lucia de Almeida Valsecchi

    2007-06-01

    Full Text Available Objectives: To evaluate the repercussion of falls in the elderly peoplewho live in the city of São Paulo and address - though synthetically- some questions regarding the city and its relation to aging and thequality of life of the elderly. Methods: This is a qualitative study. As fordata collection, “in-depth individual interviews” were applied. Selectionof subjects was guided by a procedure named as “network”. Results:Ten interviews were performed, nine with elderly individuals who werevictims of falls and one with a public authority representative. Dataresulting from interviews confirmed that significant changes occurin live of the elderly, who are victims of what has been called “urbantraps”, and that, by extrapolating mobility and dependence contexts,invade feelings, emotions and desires. The inappropriate environmentprovided by the city of São Paulo is confirmed by absence of adequateurban planning and lack of commitment of public authorities. It alsorevealed that the particular way of being old and living an elderlylife, in addition to right to citizenship, is reflected by major or lesserdifficulties imposed to the elderly to fight for their rights and have theirpublic space respected. Conclusion: The city of São Paulo is not anideal locus for an older person to live in. To the traps that are found inpublic places one can add those that are found in private places andthat contribute to the hard experience of falls among the elderly, anexperience that is sometimes fatal. In Brazil, the attention is basicallyfocused on the consequences of falls and not on prevention, by meansof urban planning that should meet the needs of the most vulnerablegroups - the physically disabled and the elderly.

  17. Innovation: the classic traps.

    Science.gov (United States)

    Kanter, Rosabeth Moss

    2006-11-01

    these traps.

  18. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    .S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return......We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets....

  19. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross...

  20. Laser tweezers: spectroscopy of optically trapped micron-sized particles

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, K.M.; Livett, M.K.; Nugent, K.W. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Information is often obtained about biological systems by analysis of single cells in the system. The optimum conditions for this analysis are when the cells are living and in their natural surroundings as they will be performing their normal functions and interactions. Analysis of cells can be difficult due to their mobility. Laser tweezing is a non contact method that can be employed to overcome this problem and provides a powerful tool in the analysis of functions and interactions at single cell level. In this investigation Raman spectra of a molecule of {beta} - carotene, dissolved in microdroplets of oil was obtained. The droplets were trapped using Nd-YAG beam and a low intensity Ar{sup +} beam was used to analyse the trapped particles. 2 refs., 5 figs.

  1. Funnel traps capture a higher proportion of juvenile Great Tits Parus major than automatic traps

    Science.gov (United States)

    Senar, J.C.; Domenech, J.; Conroy, M.J.

    1999-01-01

    We compared capture rates of Great Tits at funnel traps, where several birds can be captured at once so that some decoy effect may appear, to those obtained at automatic traps, where only one bird can be trapped at a time, at trapping stations in northeastern Spain. Juvenile birds were mainly captured at funnel traps (79% of juvenile captures), whereas adult plumaged birds were captured at both types of traps (51% of captures were at the funnel traps) (test between ages, Pfunnel traps, which may be acting as decoy traps, and thus are vulnerable to the same kinds of biases (eg age or body condition) that have been previously documented for decoy traps.

  2. Trapping Triatominae in Silvatic Habitats

    Directory of Open Access Journals (Sweden)

    Noireau François

    2002-01-01

    Full Text Available Large-scale trials of a trapping system designed to collect silvatic Triatominae are reported. Live-baited adhesive traps were tested in various ecosystems and different triatomine habitats (arboreal and terrestrial. The trials were always successful, with a rate of positive habitats generally over 20% and reaching 48.4% for palm trees of the Amazon basin. Eleven species of Triatominae belonging to the three genera of public health importance (Triatoma, Rhodnius and Panstrongylus were captured. This trapping system provides an effective way to detect the presence of triatomines in terrestrial and arboreal silvatic habitats and represents a promising tool for ecological studies. Various lines of research are contemplated to improve the performance of this trapping system.

  3. Evaporative cooling of trapped atoms

    International Nuclear Information System (INIS)

    Ketterle, W.; Van Druten, N.J.

    1996-01-01

    This report discusses the following topics on evaporative cooling of trapped atoms: Theoretical models for evaporative cooling; the role of collisions for real atoms; experimental techniques and summary of evaporative cooling experiments. 166 refs., 6 figs., 3 tabs

  4. The dynamic air bubble trap reduces cerebral microembolism during cardiopulmonary bypass.

    Science.gov (United States)

    Schoenburg, M; Kraus, B; Muehling, A; Taborski, U; Hofmann, H; Erhardt, G; Hein, S; Roth, M; Vogt, P R; Karliczek, G F; Kloevekorn, W-P

    2003-11-01

    Neuropsychologic disorders are common after coronary artery bypass operations. Air microbubbles are identified as a contributing factor. A dynamic bubble trap might reduce the number of gaseous microemboli. A total of 50 patients undergoing coronary artery bypass operation were recruited for this study. In 26 patients a dynamic bubble trap was placed between the arterial filter and the aortic cannula (group 1), and in 24 patients a placebo dynamic bubble trap was used (group 2). The number of high-intensity transient signals within the proximal middle cerebral artery was continuously measured on both sides during bypass, which was separated into 4 periods: phase 1, start of bypass until aortic clamping; phase 2, aortic clamping until rewarming; phase 3, rewarming until clamp removal; and phase 4, clamp removal until end of bypass. S100 beta values were measured before, immediately after, and 6 and 48 hours after the operation and before hospital discharge. The bubble elimination rate during bypass was 77% in group 1 and 28% in group 2 (P <.0001). The number of high-intensity signals was lower in group 1 during phase 1 (5.8 +/- 7.3 vs 16 +/- 15.4, P <.05 vs group 2) and phase 2 (6.9 +/- 7.3 vs 24.2 +/- 27.3, P <.05 vs group 2) but not during phases 3 and 4. Serum S100 beta values were equally increased in both groups immediately after the operation. Group 2 patients had higher S100 beta values 6 hours after the operation and significantly higher S100 beta values 48 hours after the operation (0.06 +/- 0.14 vs 0.18 +/- 0.24, P =.0133 vs group 2). Age and S100 beta values were correlated in group 2 but not in group 1. Gaseous microemboli can be removed with a dynamic bubble trap. Subclinical cerebral injury detectable by increases of S100 beta disappears earlier after surgical intervention.

  5. Recombination in Perovskite Solar Cells: Significance of Grain Boundaries, Interface Traps, and Defect Ions.

    Science.gov (United States)

    Sherkar, Tejas S; Momblona, Cristina; Gil-Escrig, Lidón; Ávila, Jorge; Sessolo, Michele; Bolink, Henk J; Koster, L Jan Anton

    2017-05-12

    Trap-assisted recombination, despite being lower as compared with traditional inorganic solar cells, is still the dominant recombination mechanism in perovskite solar cells (PSCs) and limits their efficiency. We investigate the attributes of the primary trap-assisted recombination channels (grain boundaries and interfaces) and their correlation to defect ions in PSCs. We achieve this by using a validated device model to fit the simulations to the experimental data of efficient vacuum-deposited p-i-n and n-i-p CH 3 NH 3 PbI 3 solar cells, including the light intensity dependence of the open-circuit voltage and fill factor. We find that, despite the presence of traps at interfaces and grain boundaries (GBs), their neutral (when filled with photogenerated charges) disposition along with the long-lived nature of holes leads to the high performance of PSCs. The sign of the traps (when filled) is of little importance in efficient solar cells with compact morphologies (fused GBs, low trap density). On the other hand, solar cells with noncompact morphologies (open GBs, high trap density) are sensitive to the sign of the traps and hence to the cell preparation methods. Even in the presence of traps at GBs, trap-assisted recombination at interfaces (between the transport layers and the perovskite) is the dominant loss mechanism. We find a direct correlation between the density of traps, the density of mobile ionic defects, and the degree of hysteresis observed in the current-voltage ( J - V ) characteristics. The presence of defect states or mobile ions not only limits the device performance but also plays a role in the J - V hysteresis.

  6. Science, conservation, and camera traps

    Science.gov (United States)

    Nichols, James D.; Karanth, K. Ullas; O'Connel, Allan F.; O'Connell, Allan F.; Nichols, James D.; Karanth, K. Ullas

    2011-01-01

    Biologists commonly perceive camera traps as a new tool that enables them to enter the hitherto secret world of wild animals. Camera traps are being used in a wide range of studies dealing with animal ecology, behavior, and conservation. Our intention in this volume is not to simply present the various uses of camera traps, but to focus on their use in the conduct of science and conservation. In this chapter, we provide an overview of these two broad classes of endeavor and sketch the manner in which camera traps are likely to be able to contribute to them. Our main point here is that neither photographs of individual animals, nor detection history data, nor parameter estimates generated from detection histories are the ultimate objective of a camera trap study directed at either science or management. Instead, the ultimate objectives are best viewed as either gaining an understanding of how ecological systems work (science) or trying to make wise decisions that move systems from less desirable to more desirable states (conservation, management). Therefore, we briefly describe here basic approaches to science and management, emphasizing the role of field data and associated analyses in these processes. We provide examples of ways in which camera trap data can inform science and management.

  7. Progress on the Magnetic Trapping of Ultra-cold Neutrons

    Science.gov (United States)

    Doyle, John M.

    1998-04-01

    Ultra-cold neutrons (UCN) have been instrumental in making improved measurements of the neutron beta-decay lifetime and in searches for a permanent electric dipole moment.(R. Golub, D. Richardson and S.K. Lamoreaux, Ultra-cold Neutrons), Adam Hilger, 1991 The most accurate experiments have taken place using in-core devices at ILL (Grenoble, France) and PNPI (St. Petersburg, Russia). Superthermal techniques offer the promise of high-density sources of UCN via scattering of cold neutrons. Cold neutron beams are available at many neutron facilities. We are currently working on the development of a superfluid helium UCN source using the Cold Neutron Research Facility at the NIST Research Reactor (Gaithersburg) . Our first experiment plans to use superthermal scattering of neutrons in superfluid helium to produce UCN within a magnetic trapping volume. A magnetic trap 30 cm long and 4 cm diameter will be filled with helium at about 100 mK. Cold neutrons (around 11 K) will be introduced into the trapping region where some of them scatter to low enough energies (around 1 mK) so that they are magnetically trapped. Once trapped the UCN travel undisturbed; they have a very small probability of upscattering. Detection will be accomplished as the UCN beta-decay. The resultant high-energy electron creates excited molecular helium dimers, a portion which decay in less than 10 ns and emit radiation in the XUV (50-100 nm). We have developed techniques to measure these scintillations. Analysis indicates that a high accuracy measurement of the neutron beta decay lifetime should be possible using our techniques. An apparatus has been constructed and initial runs are underway. An overview of the experiment, discussion of systematic errors and recent experimental progress will be presented. This work is done in collaboration with C. Brome, J. Butterworth, S. Dzhosyuk, P. Huffman, C. Mattoni, D. McKinsey, M. Cooper, G. Greene, S. Lamoreaux, R. Golub, K. Habicht, K. Coakley, S. Dewey, D

  8. A First Insight into Escherichia coli ST131 High-Risk Clone Among Extended-Spectrum Beta-Lactamase-Producing Urine Isolates in Istanbul with the Use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass-Spectrometry and Real-Time PCR.

    Science.gov (United States)

    Aktaş, Elif; Otlu, Barış; Erdemir, Duygu; Ekici, Hatice; Bulut, Emin

    2017-12-01

    We aim to investigate, as a first insight, the presence and rates of high-risk Escherichia coli ST131 clone in Istanbul and evaluate antimicrobial resistance and CTX-M-15 production of ST131 and non-ST131 isolates. The use of MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry) to detect E. coli ST131 clone is also evaluated. A total of 203 extended-spectrum beta-lactamase (ESBL)-producing urinary isolates from a training hospital in Istanbul were investigated. Detection of E. coli ST131 was done by MALDI-TOF MS and real-time PCR melting curve analysis. The presence of CTX-M and CTX-M-15 beta-lactamases was investigated by PCR and sequence analysis. Of the 203 isolates, 81 (39.9%) and 75 (36.9%) isolates were identified as ST131 clone by PCR and MALDI-TOF MS, respectively. Resistance to ciprofloxacin was significantly higher among ST131 isolates. A total of 169 (83.5%) isolates produced CTX-M beta-lactamase, of which 72 (43%) were CTX-M-15. The production of CTX-M and CTX-M-15 were significantly higher among ST131 isolates. We have demonstrated, for the first time, high rates of ST131 clone among ESBL-producing E. coli isolates in Istanbul, a region with high rates of resistance to third-generation cephalosporins and fluoroquinolones. Further investigation of this high-risk clone and its contribution to high antimicrobial resistance in Turkey is essential. MALDI-TOF MS is a useful tool for detection of high-risk clones and associated resistance patterns, simultaneous to bacterial identification.

  9. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for...

  10. Sorting out Downside Beta

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

    2009-01-01

    textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

  11. A magnetic particle micro-trap for large trapping surfaces

    KAUST Repository

    Gooneratne, Chinthaka P.

    2012-01-08

    Manipulation of micron-size magnetic particles of the superparamagnetic type contributes significantly in many applications like controlling the antibody/antigen binding process in immunoassays. Specifically, more target biomolecules can be attached/tagged and analyzed since the three dimensional structure of the magnetic particles increases the surface to volume ratio. Additionally, such biomolecular-tagged magnetic particles can be easily manipulated by an external magnetic field due to their superparamagnetic behavior. Therefore, magnetic particle- based immunoassays are extensively applied in micro-flow cytometry. The design of a square-loop micro-trap as a magnetic particle manipulator as well as numerical and experimental analysis is presented. Experimental results showed that the micro-trap could successfully trap and concentrate magnetic particles from a large to a small area with a high spatial range.

  12. Beta2-microglobulin.

    Science.gov (United States)

    Drüeke, Tilman B; Massy, Ziad A

    2009-01-01

    Among the uremic toxins in the "middle molecule" range, beta2-microglobulin (beta2-M) is certainly one of the most frequently studied compounds. Its serum level increases with the progression of chronic kidney disease, to reach very high concentrations in patients with end-stage kidney disease. It is the major protein component of dialysis-related amyloidosis, a dramatic complication which results from high extracellular concentration and posttranslational modification of beta2-M and a number of other promoters of amyloid fibril formation and deposition in osteo-articular tissues. Effective removal of beta2-M can be achieved with highly effective hemodialysis and hemodiafiltration techniques but predialysis session serum levels cannot be normalized. The prevalence and severity of beta2-M amyloidosis appear to have decreased in the last 20 years, although its occurrence may simply be delayed.

  13. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... Email Facebook Twitter Home Health Conditions Beta thalassemia Beta thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Beta thalassemia is a blood disorder that reduces the production ...

  14. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  15. The Beta-Neutrino Correlation in Sodium-21 and Other Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, Paul A.; Abo-Shaeer, Jamil; Freedman, Stuart J.; Maruyama, Reina

    2008-01-16

    We have measured the mbox beta - nu correlation coefficient,a_beta nu, in 21Na using a laser-trapped sample. We measure the energyspectrum of the recoil nuclei by measuring their time-of-flight incoincidence with the atomic electrons shaken off in beta decay. Highdetectionefficiency of these low-energy electrons allows good countingstatistics, even with low trap density, which suppresses thephotoassociation of molecular sodium, which can cause a large systematicerror. Our measurement, with a 1 percent fractional uncertainty, agreeswith the Standard Model prediction but disagrees with our previousmeasurement which was susceptible to error introduced by molecularsodium. We summarize precise measurements of a_ beta nu and theirconsequences for searches for Beyond Standard Model scalar and tensorcurrent couplings.

  16. Beta dosimetry using pulsed laser heating of TLD materials

    International Nuclear Information System (INIS)

    Quam, W.

    1983-01-01

    Use of a pulsed CO 2 laser to heat the surface of hot-pressed LiF chips has been investigated. The thermoluminescent traps in the first 10 to 20 μm of depth may be read out with good efficiency, which will allow entrance dose and exit dose to be determined using a standard chip. These dose data can be used to calculate beta dose and gamma dose separately. Readout speed is estimated to be a few milliseconds per chip

  17. How Should Beta-Diversity Inform Biodiversity Conservation?

    Science.gov (United States)

    Socolar, Jacob B; Gilroy, James J; Kunin, William E; Edwards, David P

    2016-01-01

    To design robust protected area networks, accurately measure species losses, or understand the processes that maintain species diversity, conservation science must consider the organization of biodiversity in space. Central is beta-diversity--the component of regional diversity that accumulates from compositional differences between local species assemblages. We review how beta-diversity is impacted by human activities, including farming, selective logging, urbanization, species invasions, overhunting, and climate change. Beta-diversity increases, decreases, or remains unchanged by these impacts, depending on the balance of processes that cause species composition to become more different (biotic heterogenization) or more similar (biotic homogenization) between sites. While maintaining high beta-diversity is not always a desirable conservation outcome, understanding beta-diversity is essential for protecting regional diversity and can directly assist conservation planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Behavior of many ions in a Penning trap and results of the WITCH experiment

    CERN Document Server

    Porobic, Tomica

    Precision measurements of the beta−neutrino angular correlation in nuclear beta-decay provide a unique window into the physics beyond the Standard model. The WITCH (Weak Interaction Trap for CHarged particles) experiment aims to measure this correlation, a(beta-nu), in order to impose a more stringent constraint on the exotic scalar current admixture in the beta-decay Hamiltonian. The apparatus is situated at CERN/ISOLDE laboratory and consists of a unique combination of a retardation spectrometer and two Penning traps, with one of them serving as a scattering-free source. This configuration is suited for a precise measurement of the energy spectrum of 35Ar recoiled daughter ions. The shape of the spectrum then allows a determination of a(beta-nu) and consequently of the presence or absence of a scalar current. Radioactive 35Ar ions are created at ISOLDE by impinging 1.2 GeV protons on the target material. After being separated by a magnetic separator and bunched by REXTRAP, a high-capacity Penning trap, th...

  19. High-spin nuclear traps

    International Nuclear Information System (INIS)

    Walker, P.; Dracoulis, G.

    1994-01-01

    The reaction pathways in stars, where all the heavy elements in the Universe were formed, are inextricably linked with isomers that live long enough to capture a neutron or proton before they decay. These isomers usually have excitation energies below 0.1 MeV. It is also possible to find highly excited isomers, with several MeV of excitation energy, that are trapped because of their large angular momentum (or spin). But attempts to understand the long-lived highly excited isomers, sometimes known as ''spin traps'', have been hampered by the difficulty of producing this exotic form of nuclear matter. Now, a new generation of radioactive ion beams promises a revolution in the study of high-spin nuclear traps. (author)

  20. Laser traps for radioactive isotopes

    International Nuclear Information System (INIS)

    Voytas, P.A.; Behr, J.A.; Ghosh, A.; Gwinner, G.; Orozco, L.A.; Simsarian, J.E.; Sprouse, G.D.; Xu, F.

    1996-01-01

    The techniques of laser cooling and trapping now make it possible to observe large samples of stable atoms in a small volume at low temperature. This capability was recently extended to radioactive isotopes. This opens up new opportunities for the investigation of fundamental symmetries through measurements using radioactive atoms. In this paper we will discuss several fundamental measurements in atomic systems and how the ability to trap radioactive atoms will play an important role in improving the precision of such measurements. Measurements of the effects of the weak interaction are of particular note since they are becoming quite precise. In particular, we will describe in detail the system developed at Stony Brook to trap radioactive alkali atoms and measure weak interaction effects in francium isotopes. (orig.)

  1. Sound trapping and dredging barriers.

    Science.gov (United States)

    Wang, Xu; Wang, Xiaonan; Yu, Wuzhou; Jiang, Zaixiu; Mao, Dongxing

    2017-06-01

    When sound barriers are installed on both sides of a noise source, degradation in performance is observed. Barriers having negative-phase-gradient surfaces successfully eliminate this drawback by trapping sound energy in between the barriers. In contrast, barriers can also be designed to "dredge" the energy flux out. An extended model considering higher-order diffractions, which resulted from the interplay of the induced surface wave and barrier surface periodicity, is presented. It is found that the sound dredging barriers provide a remarkable enhancement over the trapping ones, and hence have the potential to be widely used in noise control engineering.

  2. A live-trap and trapping technique for fossorial mammals

    African Journals Online (AJOL)

    comer of the door and prevents reopening by sliding into the slit at the top of the door. A hole is drilled through the back of the door housing unit and the door to accommodate an L-shaped wire (bent bicycle spoke) measuring 185 mm along the top of the trap, and a 60 mm portion which extends down into the interior.

  3. PEG 400/Cerium Ammonium Nitrate Combined with Microwave-Assisted Synthesis for Rapid Access to Beta-Amino Ketones. An Easy-to-Use Protocol for Discovering New Hit Compounds

    Directory of Open Access Journals (Sweden)

    Giacomo Rossino

    2018-03-01

    Full Text Available Compound libraries are important requirement in target-based drug discovery. In the present work, a small focused compound library based on β-aminoketone scaffold has been prepared combining microwave-assisted organic synthesis (MAOS with polymer-assisted solution phase synthesis (PASPS and replacing reaction workup standard purification procedures with solid phase extraction (SPE. Specifically, the effects of solvent, such as dioxane, dimethylformamide (DMF, polyethylene glycol 400 (PEG 400, temperature, irradiation time, stoichiometric ratio of reagents, and catalysts (HCl, acetic acid, cerium ammonium nitrate (CAN were investigated to maximize both conversion and yield. The optimized protocol generally afforded the desired products in satisfying yields and purities. The designed library is a part of our current research on sigma 1 receptor modulators, a valuable tool for the identification of novel potential hit compounds.

  4. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    is particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known...... as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling-window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross-sectional as well as the time variation...... of the conditional beta series during the financial crises....

  5. High beta tokamak instabilities

    International Nuclear Information System (INIS)

    Bateman, G.

    1977-01-01

    Theoretical predictions using the ideal MHD model indicable that large-scale ballooning modes should appear when the average beta is raised about 1 to 2% in present-day tokamak geometries or 5 to 10% in more optimized geometries. The onset of instability is predicted to be sudden and the behavior of ballooning modes to be strikingly different from the saw-tooth and Mirnov oscillations experimentally observed at low beta. Conditions close to the predicted onset were achieved in ORMAK with no noticeable change in plasma behavior. Experiments are planned for the ISX tokamak to test the beta limit. 15 references, 3 figures

  6. Ion trap architectures and new directions

    Science.gov (United States)

    Siverns, James D.; Quraishi, Qudsia

    2017-12-01

    Trapped ion technology has seen advances in performance, robustness and versatility over the last decade. With increasing numbers of trapped ion groups worldwide, a myriad of trap architectures are currently in use. Applications of trapped ions include: quantum simulation, computing and networking, time standards and fundamental studies in quantum dynamics. Design of such traps is driven by these various research aims, but some universally desirable properties have lead to the development of ion trap foundries. Additionally, the excellent control achievable with trapped ions and the ability to do photonic readout has allowed progress on quantum networking using entanglement between remotely situated ion-based nodes. Here, we present a selection of trap architectures currently in use by the community and present their most salient characteristics, identifying features particularly suited for quantum networking. We also discuss our own in-house research efforts aimed at long-distance trapped ion networking.

  7. Design and performance of a cryogenic apparatus for magnetically trapping ultracold neutrons

    Science.gov (United States)

    Huffman, P. R.; Coakley, K. J.; Doyle, J. M.; Huffer, C. R.; Mumm, H. P.; O'Shaughnessy, C. M.; Schelhammer, K. W.; Seo, P.-N.; Yang, L.

    2014-11-01

    The cryogenic design and performance of an apparatus used to magnetically confine ultracold neutrons (UCN) is presented. The apparatus is part of an effort to measure the beta-decay lifetime of the free neutron and is comprised of a high-current superconducting magnetic trap that surrounds ∼21 l of isotopically pure 4He cooled to approximately 250 mK. A 0.89 nm neutron beam can enter the apparatus from one end of the magnetic trap and a light collection system allows visible light generated within the helium by decays to be transported to detectors at room temperature. Two cryocoolers are incorporated to reduce liquid helium consumption.

  8. Microfabricated linear Paul-Straubel ion trap

    Science.gov (United States)

    Mangan, Michael A [Albuquerque, NM; Blain, Matthew G [Albuquerque, NM; Tigges, Chris P [Albuquerque, NM; Linker, Kevin L [Albuquerque, NM

    2011-04-19

    An array of microfabricated linear Paul-Straubel ion traps can be used for mass spectrometric applications. Each ion trap comprises two parallel inner RF electrodes and two parallel outer DC control electrodes symmetric about a central trap axis and suspended over an opening in a substrate. Neighboring ion traps in the array can share a common outer DC control electrode. The ions confined transversely by an RF quadrupole electric field potential well on the ion trap axis. The array can trap a wide array of ions.

  9. Beta-blockers overdose

    Science.gov (United States)

    ... on how much and what type of this medicine the person took and how quickly they receive treatment. ... Aronson JK. Beta-adrenoceptor antagonists. In: Aronson JK, ed. ... Practice . 9th ed. Philadelphia, PA: Elsevier; 2018:chap 147.

  10. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Abstract. The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  11. Indeterminacy, sunspots, and development traps

    Czech Academy of Sciences Publication Activity Database

    Slobodyan, Sergey

    2005-01-01

    Roč. 29, 1-2 (2005), s. 159-185 ISSN 0165-1889 Institutional research plan: CEZ:AV0Z70850503 Keywords : indeterminacy * development trap * stochastic stability Subject RIV: AH - Economics Impact factor: 0.691, year: 2005 http://dx.doi.org/10.1016/j.jedc.2003.04.011

  12. Efficiency of antlion trap construction.

    Science.gov (United States)

    Fertin, Arnold; Casas, Jérôme

    2006-09-01

    Assessing the architectural optimality of animal constructions is in most cases extremely difficult, but is feasible for antlion larvae, which dig simple pits in sand to catch ants. Slope angle, conicity and the distance between the head and the trap bottom, known as off-centring, were measured using a precise scanning device. Complete attack sequences in the same pits were then quantified, with predation cost related to the number of behavioural items before capture. Off-centring leads to a loss of architectural efficiency that is compensated by complex attack behaviour. Off-centring happened in half of the cases and corresponded to post-construction movements. In the absence of off-centring, the trap is perfectly conical and the angle is significantly smaller than the crater angle, a physical constant of sand that defines the steepest possible slope. Antlions produce efficient traps, with slopes steep enough to guide preys to their mouths without any attack, and shallow enough to avoid the likelihood of avalanches typical of crater angles. The reasons for the paucity of simplest and most efficient traps such as theses in the animal kingdom are discussed.

  13. Quantum computing with trapped ions

    International Nuclear Information System (INIS)

    Haeffner, H.; Roos, C.F.; Blatt, R.

    2008-01-01

    Quantum computers hold the promise of solving certain computational tasks much more efficiently than classical computers. We review recent experimental advances towards a quantum computer with trapped ions. In particular, various implementations of qubits, quantum gates and some key experiments are discussed. Furthermore, we review some implementations of quantum algorithms such as a deterministic teleportation of quantum information and an error correction scheme

  14. Efficiency of subaquatic light traps

    Czech Academy of Sciences Publication Activity Database

    Ditrich, Tomáš; Čihák, P.

    2017-01-01

    Roč. 38, č. 3 (2017), s. 171-184 ISSN 0165-0424 R&D Projects: GA ČR(CZ) GA14-29857S Institutional support: RVO:60077344 Keywords : Heteroptera * Diptera * light trap Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 0.524, year: 2016

  15. Quantum Games in ion traps

    International Nuclear Information System (INIS)

    Buluta, Iulia Maria; Fujiwara, Shingo; Hasegawa, Shuichi

    2006-01-01

    We propose a general, scalable framework for implementing two-choices-multiplayer Quantum Games in ion traps. In particular, we discuss two famous examples: the Quantum Prisoners' Dilemma and the Quantum Minority Game. An analysis of decoherence due to intensity fluctuations in the applied laser fields is also provided

  16. The rise of trapped populations

    Directory of Open Access Journals (Sweden)

    April T Humble

    2014-02-01

    Full Text Available As border security increases and borders become less permeable, cross-border migration is becoming increasingly difficult, selective and dangerous. Growing numbers of people are becoming trapped in their own countries or in transit countries, or being forced to roam border areas, unable to access legal protection or basic social necessities.

  17. Quantum Games in ion traps

    Energy Technology Data Exchange (ETDEWEB)

    Buluta, Iulia Maria [Department of Quantum Engineering and Systems Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)]. E-mail: noa@lyman.q.t.u-tokyo.ac.jp; Fujiwara, Shingo [Department of Quantum Engineering and Systems Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)]. E-mail: fujiwara@lyman.q.t.u-tokyo.ac.jp; Hasegawa, Shuichi [Department of Quantum Engineering and Systems Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)]. E-mail: hasegawa@q.t.u-tokyo.ac.jp

    2006-10-09

    We propose a general, scalable framework for implementing two-choices-multiplayer Quantum Games in ion traps. In particular, we discuss two famous examples: the Quantum Prisoners' Dilemma and the Quantum Minority Game. An analysis of decoherence due to intensity fluctuations in the applied laser fields is also provided.

  18. Cluster observations of trapped ions interacting with magnetosheath mirror modes

    Directory of Open Access Journals (Sweden)

    J. Soucek

    2011-06-01

    Full Text Available Mirror modes are among the most intense low frequency plasma wave phenomena observed in the magnetosheaths of magnetized planets. They appear as large amplitude non-propagating fluctuations in the magnetic field magnitude and plasma density. These structures are widely accepted to represent a non-linear stage of the mirror instability, dominant in plasmas with large ion beta and a significant ion temperature anisotropy T⊥/T∥>1. It has long been recognized that the mirror instability both in the linear and non-linear stage is a kinetic process and that the behavior of resonant particles at small parallel velocities is crucial for its development and saturation. While the dynamics of the instability and the effect of trapped particles have been studied extensively in theoretical models and numerical simulations, only spurious observations of the trapped ions were published to date. In this work we used data from the Cluster spacecraft to perform the first detailed experimental study of ion velocity distribution associated with mirror mode oscillations. We show a conclusive evidence for the predicted cooling of resonant ions at small parallel velocities and heating of trapped ions at intermediate pitch angles.

  19. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  20. Photo-reactive charge trapping memory based on lanthanide complex

    Science.gov (United States)

    Zhuang, Jiaqing; Lo, Wai-Sum; Zhou, Li; Sun, Qi-Jun; Chan, Chi-Fai; Zhou, Ye; Han, Su-Ting; Yan, Yan; Wong, Wing-Tak; Wong, Ka-Leung; Roy, V. A. L.

    2015-10-01

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 104 s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices.

  1. Low Temperature Trapping: from Reactions to Spectroscopy

    Science.gov (United States)

    Schlemmer, S.; Asvany, O.; Brunken, S.

    2013-06-01

    The kinetics of ion - molecule reactions are investigated in higher-order multipole traps by observation of the temporal evolution of mass selected parent ions in the presence of a neutral reaction partner. Rate coeffients for fast reactions (proceeding at collision rate) and very slow reactions (taking millions of collisions) are determined over a wide range of temperatures. Endothermic or hindered reactions can be promoted by excitation of the ion via absorption of a photon. Scanning the photon energy while detecting the number of product ions establishes an action spectroscopy method which we developed over the last 10-15 years and termed LIR: laser or light induced reactions. The main advantages of LIR are mass selection of the parent ion and low temperature conditions in the trap. Long storage times in combination with a near unity detection efficiency make LIR one of the most sensitive spectroscopy methods. The status quo of LIR will be discussed on selected examples. Recent measurements are concerned with ro-vibrational spectra of CH_2D^+ and CH_5^+ at highest resolution using cw OPO radiation. In the particular case of CH_5^+, the lines in the mid IR have been measured at a nominal temperature of 10 K and a frequency comb has been used for absolute calibration. Line positions can be determined to an accuracy which shall enable us in the future to obtain rotational spectra in a THz-IR double resonance approach. We tested the feasibility of this two photon method recently on H_2D^+. S. Schlemmer, T. Kuhn, E. Lescop, and D. Gerlich, Laser excited N_2^+ in a 22-Pole Trap: Experimental Studies of Rotational Relaxation Processes, Int. J. Mass Spectrometry and Ion Processes, 185-187, 589-602, (1999), S.D. Ivanov, O. Asvany, A. Witt, E. Hugo, G. Mathias, B. Redlich, D. Marx and S. Schlemmer, Quantum-induced symmetry breaking explains infrared spectra of CH_5^+ isotopologues, Nature Chemistry, 2, 298-302 (2010) S. Gaertner, J. Krieg, A. Klemann, O. Asvany and S

  2. Scaling ion traps for quantum computing

    CSIR Research Space (South Africa)

    Uys, H

    2010-09-01

    Full Text Available The design, fabrication and preliminary testing of a chipscale, multi-zone, surface electrode ion trap is reported. The modular design and fabrication techniques used are anticipated to advance scalability of ion trap quantum computing architectures...

  3. Stokes Trap: Multiplexed particle trapping and manipulation using fluidics

    Science.gov (United States)

    Shenoy, Anish; Schroeder, Charles

    We report the development of the Stokes Trap, which is a multiplexed microfluidic trap for control over an arbitrary number of small particles in a microfluidic device. Our work involves the design and implementation of ``smart'' flow-based devices by coupling feedback control with microfluidics, thereby enabling new routes for the fluidic-directed assembly of particles. Here, we discuss the development of a new method to achieve multiplexed microfluidic trapping of an arbitrary number of particles using the sole action of fluid flow. In particular, we use a Hele-Shaw microfluidic cell to generate hydrodynamic forces on particles in a viscous-dominated flow defined by the microdevice geometry and imposed peripheral flow rates. This platform allows for a high degree of flow control over individual particles and can be used for manufacturing novel particles for fundamental studies, using fluidic-directed assembly. From a broader perspective, our work provides a solid framework for guiding the design of next-generation, automated on-chip assays.

  4. The Use of Camera Traps in Wildlife

    OpenAIRE

    Yasin Uçarlı; Bülent Sağlam

    2013-01-01

    Camera traps are increasingly used in the abundance and density estimates of wildlife species. Camera traps are very good alternative for direct observation in case, particularly, steep terrain, dense vegetation covered areas or nocturnal species. The main reason for the use of camera traps is eliminated that the economic, personnel and time loss in a continuous manner at the same time in different points. Camera traps, motion and heat sensitive, can take a photo or video according to the mod...

  5. Sympathetic Cooling of Trapped Cd+ Isotopes

    OpenAIRE

    Blinov, B. B.; Deslauriers, L.; Lee, P.; Madsen, M. J.; Miller, R.; Monroe, C.

    2001-01-01

    We sympathetically cool a trapped 112Cd+ ion by directly Doppler-cooling a 114Cd+ ion in the same trap. This is the first demonstration of optically addressing a single trapped ion being sympathetically cooled by a different species ion. Notably, the experiment uses a single laser source, and does not require strong focusing. This paves the way toward reducing decoherence in an ion trap quantum computer based on Cd+ isotopes.

  6. Dynamic array of dark optical traps

    DEFF Research Database (Denmark)

    Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

    2004-01-01

    A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase-encode...

  7. 50 CFR 31.16 - Trapping program.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Trapping program. 31.16 Section 31.16 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE... Disposal § 31.16 Trapping program. Except as hereafter noted, persons trapping animals on wildlife refuge...

  8. An Open Standard for Camera Trap Data

    NARCIS (Netherlands)

    Forrester, Tavis; O'Brien, Tim; Fegraus, Eric; Jansen, P.A.; Palmer, Jonathan; Kays, Roland; Ahumada, Jorge; Stern, Beth; McShea, William

    2016-01-01

    Camera traps that capture photos of animals are a valuable tool for monitoring biodiversity. The use of camera traps is rapidly increasing and there is an urgent need for standardization to facilitate data management, reporting and data sharing. Here we offer the Camera Trap Metadata Standard as an

  9. The Aarhus Ion Micro-Trap Project

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; Nielsen, Otto; Poulsen, Gregers

    and installed in an ultra high vacuum chamber, which includes an ablation oven for all-optical loading of the trap [2]. The next steps on the project are to demonstrate the operation of the micro-trap and the cooling of ions using fiber delivered light. [1] D. Grant, Development of Micro-Scale Ion traps, Master...

  10. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    Using a method based on generating functions, we determine explicitly the mean first-passage time (MFPT) for the trapping issue. Let parameter (0 < < 1) be the weight factor. We show that the efficiency of the trapping process depends on the parameter a; the smaller the value of a, the more efficient is the trapping ...

  11. Revealing trap depth distributions in persistent phosphors

    NARCIS (Netherlands)

    Van den Eeckhout, K.; Bos, A.J.J.; Poelman, D.; Smet, P.F.

    2013-01-01

    Persistent luminescence or afterglow is caused by a gradual release of charge carriers from trapping centers. The energy needed to release these charge carriers is determined by the trap depths. Knowledge of these trap depths is therefore crucial in the understanding of the persistent luminescence

  12. Microscale ion trap mass spectrometer

    Science.gov (United States)

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  13. Rotation sensing with trapped ions

    Science.gov (United States)

    Campbell, W. C.; Hamilton, P.

    2017-03-01

    We present a protocol for rotation measurement via matter-wave Sagnac interferometry using trapped ions. The ion trap based interferometer encloses a large area in a compact apparatus through repeated round-trips in a Sagnac geometry. We show how a uniform magnetic field can be used to close the interferometer over a large dynamic range in rotation speed and measurement bandwidth without contrast loss. Since this technique does not require the ions to be confined in the Lamb-Dicke regime, Doppler laser cooling should be sufficient to reach a sensitivity of { S }=1.4× {10}-6 {{rad}} {{{s}}}-1 {{{H}}{{z}}}-1/2. , which features invited work from the best early-career researchers working within the scope of J. Phys. B. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Wes Campbell was selected by the Editorial Board of J. Phys. B as an Emerging Leader.

  14. Centrifugal trapping in the magnetotail

    Directory of Open Access Journals (Sweden)

    D. C. Delcourt

    1995-03-01

    Full Text Available Particles leaving the neutral sheet in the distant magnetotail at times display adiabatic trajectory sequences characterized by an inflection toward the equator and subsequent mirroring in its vicinity. We demonstrate that this low-latitude mirroring results primarily from a centrifugal deceleration due to the fast direction-changing E×B drift. This effect which we refer to as "centrifugal trapping" appears both in guiding centre and full particle treatments. It thus does not directly relate to nonadiabatic motion. However, pitch angle scattering due to nonadiabatic neutral sheet interaction does play a role in reducing the parallel speed of the particles. We show that centrifugal trapping is an important mechanism for the confinement of the slowest (typically below the equatorial E×B drift speed plasma sheet populations to the midplane vicinity.

  15. Poverty Traps and Climate Change

    OpenAIRE

    Tol, Richard S. J.

    2011-01-01

    PUBLISHED We use a demo-economic model to examine the question of whether climate change could widen or deepen poverty traps. The model includes two crucial mechanisms. Parents are risk averse when deciding how many children to have; fertility is high when infant survival is low. High fertility spreads scarce household resources thin, resulting in children being poorly educated. At the macro level, technological progress is slow because of decreasing returns to scale in agriculture. With h...

  16. Positron trapping at dislocations in metals

    International Nuclear Information System (INIS)

    Bergersen, B.; McMullen, T.

    1977-01-01

    The trapping rate of positrons at dislocations in metals, and its temperature dependence, are calculated. Two different trapping processes, with the excess energy absorbed in either electron-hole pair formation or by phonon creation, are considered and the former is found to be the most important. An extension of the theory to include depletion of the positron density around the dislocations in a diffusion approximation is included. The trapping is found to be transition limited if the temperature is low or the trap potential shallow. At room temperature diffusion is important for deep traps. (author)

  17. Nonadiabatic transitions in electrostatically trapped ammonia molecules

    International Nuclear Information System (INIS)

    Kirste, Moritz; Schnell, Melanie; Meijer, Gerard; Sartakov, Boris G.

    2009-01-01

    Nonadiabatic transitions are known to be major loss channels for atoms in magnetic traps but have thus far not been experimentally reported upon for trapped molecules. We have observed and quantified losses due to nonadiabatic transitions for three isotopologues of ammonia in electrostatic traps by comparing the trapping times in traps with a zero and a nonzero electric field at the center. Nonadiabatic transitions are seen to dominate the overall loss rate even for the present samples that are at relatively high temperatures of 30 mK. It is anticipated that losses due to nonadiabatic transitions in electric fields are omnipresent in ongoing experiments on cold molecules.

  18. Assistive Technology

    Science.gov (United States)

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  19. Assisted Living

    Science.gov (United States)

    Assisted living is for adults who need help with everyday tasks. They may need help with dressing, bathing, ... don't need full-time nursing care. Some assisted living facilities are part of retirement communities. Others are ...

  20. Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

    Energy Technology Data Exchange (ETDEWEB)

    Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

    1983-01-01

    5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

  1. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    Amaral, L.B.D.; Pinto, J.C.M.; Linhares, E.; Linhares, Estevao

    1981-01-01

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author) [pt

  2. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  3. Intrinsic electron trapping in amorphous oxide

    Science.gov (United States)

    Strand, Jack; Kaviani, Moloud; Afanas’ev, Valeri V.; Lisoni, Judit G.; Shluger, Alexander L.

    2018-03-01

    We demonstrate that electron trapping at intrinsic precursor sites is endemic in non-glass-forming amorphous oxide films. The energy distributions of trapped electron states in ultra-pure prototype amorphous (a)-HfO2 insulator obtained from exhaustive photo-depopulation experiments demonstrate electron states in the energy range of 2–3 eV below the oxide conduction band. These energy distributions are compared to the results of density functional calculations of a-HfO2 models of realistic density. The experimental results can be explained by the presence of intrinsic charge trapping sites formed by under-coordinated Hf cations and elongated Hf–O bonds in a-HfO2. These charge trapping states can capture up to two electrons, forming polarons and bi-polarons. The corresponding trapping sites are different from the dangling-bond type defects responsible for trapping in glass-forming oxides, such as SiO2, in that the traps are formed without bonds being broken. Furthermore, introduction of hydrogen causes formation of somewhat energetically deeper electron traps when a proton is immobilized next to the trapped electron bi-polaron. The proposed novel mechanism of intrinsic charge trapping in a-HfO2 represents a new paradigm for charge trapping in a broad class of non-glass-forming amorphous insulators.

  4. Algae commensal community in Genlisea traps

    Directory of Open Access Journals (Sweden)

    Konrad Wołowski

    2011-01-01

    Full Text Available The community of algae occurring in Genlisea traps and on the external traps surface in laboratory conditions were studied. A total of 29 taxa were found inside the traps, with abundant diatoms, green algae (Chlamydophyceae and four morphotypes of chrysophytes stomatocysts. One morphotype is described as new for science. There are two ways of algae getting into Genlisea traps. The majority of those recorded inside the traps, are mobile; swimming freely by flagella or moving exuding mucilage like diatoms being ablate to colonize the traps themselves. Another possibility is transport of algae by invertebrates such as mites and crustaceans. In any case algae in the Genlisea traps come from the surrounding environment. Two dominant groups of algae (Chladymonas div. and diatoms in the trap environment, show ability to hydrolyze phosphomonoseters. We suggest that algae in carnivorous plant traps can compete with plant (host for organic phosphate (phosphomonoseters. From the spectrum and ecological requirements of algal species found in the traps, environment inside the traps seems to be acidic. However, further studies are needed to test the relations between algae and carnivorous plants both in laboratory conditions and in the natural environment. All the reported taxa are described briefly and documented with 74 LM and SEM micrographs.

  5. Assisted Living

    Science.gov (United States)

    ... it, too. Back to top What is the Cost for Assisted Living? Although assisted living costs less than nursing home ... Primarily, older persons or their families pay the cost of assisted living. Some health and long-term care insurance policies ...

  6. Accounts Assistant

    Indian Academy of Sciences (India)

    CHITRA

    (Not more than three months old). Annexure 1. Indian Academy of Sciences. C V Raman Avenue, Bengaluru 560 080. Application for the Post of: Accounts Assistant / Administrative Assistant Trainee / Assistant – Official Language. Implementation Policy / Temporary Copy Editor and Proof Reader / Social Media Manager. 1.

  7. Ion traps: some semiclassical observations

    Energy Technology Data Exchange (ETDEWEB)

    Mielnik, B [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 14-740, Mexico DF 07000 (Mexico); RamIrez, A, E-mail: bogdan@fis.cinvestav.m, E-mail: alejandra.palacios@mail.telcel.co [Soporte a Infraestructura de Redes LAN, Direccion de Informatica, Radiomovil DIPSA S.A. de C.V., Lago Alberto 366, Col. Anahuac, Mexico DF 11320 (Mexico)

    2010-11-15

    The unitary evolution operators generated by periodically varying elastic potentials including the Mathieu case V(q,t)= ({beta}{sub 0} + 2{beta}{sub 1} cos t)q{sup 2}/2 are studied. The evolution operations in the stability areas of the Strutt diagram admit effective (Floquet) Hamiltonians generalizing the orthodox oscillators. The points on the separatrices represent two exceptional types of unitary operations, imitating (in a soft way) the results of the sudden {delta}-like kicks of the elastic potential, or the distorted free evolution (in accelerated, slowed down or even negative time). In all domains the dynamical phenomena illustrate a non-trivial relation between the micro- and macroscopic motion scales.

  8. Ca2+-assisted, direct hydride transfer, and rate-determining tautomerization of C5-reduced PQQ to PQQH2, in the oxidation of beta-D-glucose by soluble, quinoprotein glucose dehydrogenase.

    Science.gov (United States)

    Dewanti, A R; Duine, J A

    2000-08-08

    irreversible) from the C1 position of the beta-anomer of glucose to the C5 of PQQ, (3) irreversible, rate-determining tautomerization of the fluorescing, C5-reduced PQQ to PQQH(2) and release (or earlier) of the product, D-glucono-delta-lactone, and (4) oxidation of PQQH(2) by an electron acceptor. The PQQ-activating Ca(2+) greatly facilitates the reactions occurring in step 2. His144 may also play a role in this by acting as a general base catalyst, initiating hydride transfer by abstracting a proton from the anomeric OH group of glucose. The validity of the proposed mechanism is discussed for other PQQ-containing dehydrogenases.

  9. beta nur pratiwi

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. BETA NUR PRATIWI. Articles written in Pramana – Journal of Physics. Volume 88 Issue 2 February 2017 pp 25 Regular. Asymptotic iteration method for the modified Pöschl–Teller potential and trigonometric Scarf II non-central potential in the Dirac equation spin symmetry.

  10. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  11. Beta-Carotene

    Science.gov (United States)

    ... to reduce symptoms of breathing disorders such as asthma and exercise-induced asthma, cystic fibrosis, and chronic obstructive pulmonary ... seem to reduce the risk of esophageal cancer. Asthma attacks triggered by exercise. Taking beta-carotene by mouth seems to prevent ...

  12. Nuclear double beta decay

    International Nuclear Information System (INIS)

    Hubert, P.; Mennrath, P.

    1985-01-01

    The processes of double beta decay with and without emission of neutrinos are briefly reviewed. After the definitions of the processes and implications for the neutrino properties, the present status of the experimental results is discussed. We conclude with a description of the Bordeaux-Zaragoza-Strasbourg experimental which will run in the Frejus tunnel

  13. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  14. Beta thalassemia - a review

    Directory of Open Access Journals (Sweden)

    R Jha

    2014-09-01

    Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

  15. Peginterferon Beta-1a Injection

    Science.gov (United States)

    Peginterferon beta-1a injection is used to treat people who have relapsing-remitting forms (course of disease where symptoms ... problems with vision, speech, and bladder control). Peginterferon beta-1a injection is in a class of medications ...

  16. Interferon Beta-1b Injection

    Science.gov (United States)

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course of disease ... problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications called ...

  17. Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap

    CERN Document Server

    Amole, C; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Hydomako, R; Kurchaninov, L; Jonsell, S; Madsen, N; Menary, S; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Storey, J W; Thompson, R I; van der Werf, D P; Wurtele, J S

    2012-01-01

    Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antipr...

  18. Portable Pbars, traps that travel

    International Nuclear Information System (INIS)

    Howe, S.D.; Hynes, M.V.; Picklesimer, A.

    1987-10-01

    The advent of antiproton research utilizing relatively small scale storage devices for very large numbers of these particles opens the possibility of transporting these devices to a research site removed from the accelerator center that produced the antiprotons. Such a portable source of antiprotons could open many new areas of research and make antiprotons available to a new research community. At present antiprotons are available at energies down to 1 MeV. From a portable source these particles can be made available at energies ranging from several tens of kilovolts down to a few millielectron volts. These low energies are in the domain of interest to the atomic and condensed matter physicist. In addition such a source can be used as an injector for an accelerator which could increase the energy domain even further. Moreover, the availability of such a source at a university will open research with antiprotons to a broader range of students than possible at a centralized research facility. This report focuses on the use of ion traps, in particular cylindrical traps, for the antiproton storage device. These devices store the charged antiprotons in a combination of electric and magnet fields. At high enough density and low enough temperature the charged cloud will be susceptible to plasma instabilities. Present day ion trap work is just starting to explore this domain. Our assessment of feasibility is based on what could be done with present day technology and what future technology could achieve. We conclude our report with a radiation safety study that shows that about 10 11 antiprotons can be transported safely, however the federal guidelines for this transport must be reviewed in detail. More antiprotons than this will require special transportation arrangements. 28 refs., 8 figs

  19. The composite insect trap: an innovative combination trap for biologically diverse sampling.

    Directory of Open Access Journals (Sweden)

    Laura Russo

    Full Text Available Documentation of insect diversity is an important component of the study of biodiversity, community dynamics, and global change. Accurate identification of insects usually requires catching individuals for close inspection. However, because insects are so diverse, most trapping methods are specifically tailored to a particular taxonomic group. For scientists interested in the broadest possible spectrum of insect taxa, whether for long term monitoring of an ecosystem or for a species inventory, the use of several different trapping methods is usually necessary. We describe a novel composite method for capturing a diverse spectrum of insect taxa. The Composite Insect Trap incorporates elements from four different existing trapping methods: the cone trap, malaise trap, pan trap, and flight intercept trap. It is affordable, resistant, easy to assemble and disassemble, and collects a wide variety of insect taxa. Here we describe the design, construction, and effectiveness of the Composite Insect Trap tested during a study of insect diversity. The trap catches a broad array of insects and can eliminate the need to use multiple trap types in biodiversity studies. We propose that the Composite Insect Trap is a useful addition to the trapping methods currently available to ecologists and will be extremely effective for monitoring community level dynamics, biodiversity assessment, and conservation and restoration work. In addition, the Composite Insect Trap will be of use to other insect specialists, such as taxonomists, that are interested in describing the insect taxa in a given area.

  20. Solar Trap for Banana Drying Method

    Directory of Open Access Journals (Sweden)

    Musa S.

    2017-01-01

    Full Text Available Food drying methods nowadays are mostly in high use of electricity and fuel which lead to high operational cost. This has resulted in a waste of energy and money due to the use of modern tools requires significant costs for implementation. Meanwhile, the traditional food drying process only uses sun rays in their process, where the process is far more efficient than the modern drying method. In this study, the test was conducted to determine the trapped solar heat energy requirements for the process of drying foods such as agricultural products, particularly bananas. The solar trap test by using solar trap container was carried out include determining the thermal energy requirement for drying, preparing equipment (solar trap container to trap solar energy, handling and drying tests on samples of bananas. The percentage amount of water removal and energy required for the drying process was found to be 48% and 134 J. The results of this study can determine that solar trap drying method is easier, quicker and more effective than the usual method of drying because it use natural solar energy. Several proposals have been suggested for improvement for future study, such as controlling the solar trap air in the container, replacing the trap solar wall with a darker color, examining the floors slope so that more solar traps collected and installing a small hose on the base of the container so that the water evaporated in the solar trap may exit through the route.

  1. Trapping leidenfrost drops with crenelations.

    Science.gov (United States)

    Dupeux, Guillaume; Le Merrer, Marie; Clanet, Christophe; Quéré, David

    2011-09-09

    Drops placed on very hot solids levitate on a cushion of their own vapor, as discovered by Leidenfrost. This confers to these drops a remarkable mobility, which makes problematic their control and manipulation. Here we show how crenelated surfaces can be used to increase the friction of Leidenfrost drops by a factor on the order of 100, making them decelerate and be trapped on centimetric distances instead of the usual metric ones. We measure and characterize the friction force as a function of the design of the crenelations.

  2. Bose condensation in (random traps

    Directory of Open Access Journals (Sweden)

    V.A. Zagrebnov

    2009-01-01

    Full Text Available We study a non-interacting (perfect Bose-gas in random external potentials (traps. It is shown that a generalized Bose-Einstein condensation in the random eigenstates manifests if and only if the same occurs in the one-particle kinetic-energy eigenstates, which corresponds to the generalized condensation of the free Bose-gas. Moreover, we prove that the amounts of both condensate densities are equal. This statement is relevant for justification of the Bogoliubov approximation} in the theory of disordered boson systems.

  3. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  4. Virtual potentials for feedback traps.

    Science.gov (United States)

    Jun, Yonggun; Bechhoefer, John

    2012-12-01

    The recently developed feedback trap can be used to create arbitrary virtual potentials, to explore the dynamics of small particles or large molecules in complex situations. Experimentally, feedback traps introduce several finite time scales: There is a delay between the measurement of a particle's position and the feedback response, the feedback response is applied for a finite update time, and a finite camera exposure integrates motion. We show how to incorporate such timing effects into the description of particle motion. For the test case of a virtual quadratic potential, we give the first accurate description of particle dynamics, calculating the power spectrum and variance of fluctuations as a function of feedback gain, testing against simulations. We show that for small feedback gains, the motion approximates that of a particle in an ordinary harmonic potential. Moreover, if the potential is varied in time, for example by varying its stiffness, the work that is calculated approximates that done in an ordinary changing potential. The quality of the approximation is set by the ratio of the update time of the feedback loop to the relaxation time of motion in the virtual potential.

  5. Measurements of flux pumping activation of trapped field magnets

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy; Parks, Drew; Sawh, Ravi-Persad [Texas Center for Superconductivity, 202 Houston Science Center, University of Houston, Houston, TX 77204-5002 (United States); Davey, Kent [Physics Department, 617 Science and Research Building I, University of Houston, Houston, TX 77204-5005 (United States)

    2010-11-15

    Large grains of high temperature superconducting (HTS) material can be utilized as trapped field magnets (TFMs). Persistent currents are set up in the HTS when it is cooled in a magnetic field, or exposed to a magnetic field after cooling. TFMs have been improved over the past two decades by the efforts of a large number of worldwide research groups. However, applications using TFMs have lagged, in part due to the problem of high fields needed for activation. We describe herein experiments designed to observe the behaviour of TFM activation using repeated applications of low fields (called 'pumping'). Significant partial activation is obtained using a non-uniform pumping field (e.g., a small permanent magnet) which is higher in the centre of the HTS than at the periphery. Cooling in zero field followed by pumping with such a field results in trapping the full applied field, in comparison to half of the applied field being trapped by cooling in zero field followed by application of a uniform field. We find that for partial activation by cooling in a field and subsequent activation by pumping, the resulting fields are additive. We also conclude that for activation by fluxoid pumping, creep assists the process.

  6. Production and trapping of francium atoms

    International Nuclear Information System (INIS)

    Atutov, S.N.; Biancalana, V.; Burchianti, A.; Calabrese, R.; Corradi, L.; Dainelli, A.; Guidi, V.; Khanbekyan, A.; Mai, B.; Marinelli, C.; Mariotti, E.; Moi, L.; Sanguinetti, S.; Stancari, G.; Tomassetti, L.; Veronesi, S.

    2004-01-01

    A new facility has been constructed at the INFN Legnaro National Laboratory (LNL) for the production of francium isotopes via a fusion-evaporation nuclear reaction and a laser laboratory has been set up for francium trapping. Francium is produced inside a gold target and after diffusion desorbs from its surface as an ion. A secondary beam line delivers the francium ions to the trapping cell where they are neutralized and trapped in a magneto-optical trap (MOT). Details on the production, delivery and neutralization methods are presented. Preliminary results on trapped francium are also shown. Production rate of ≅ 10 6 ions/s and a trap population of about 100 atoms have been achieved

  7. Low-beta investment strategies

    OpenAIRE

    Korn, Olaf; Kuntz, Laura-Chloé

    2015-01-01

    This paper investigates investment strategies that exploit the low-beta anomaly. Although the notion of buying low-beta stocks and selling high-beta stocks is natural, a choice is necessary with respect to the relative weighting of high-beta stocks and low-beta stocks in the investment portfolio. Our empirical results for US large-cap stocks show that this choice is very important for the risk-return characteristics of the resulting portfolios and their sensitivities to common risk factors. W...

  8. Case Study: Trap Crop with Pheromone Traps for Suppressing Euschistus servus (Heteroptera: Pentatomidae in Cotton

    Directory of Open Access Journals (Sweden)

    P. G. Tillman

    2012-01-01

    Full Text Available The brown stink bug, Euschistus servus (Say, can disperse from source habitats, including corn, Zea mays L., and peanut, Arachis hypogaea L., into cotton, Gossypium hirsutum L. Therefore, a 2-year on-farm experiment was conducted to determine the effectiveness of a sorghum (Sorghum bicolor (L. Moench spp. bicolor trap crop, with or without Euschistus spp. pheromone traps, to suppress dispersal of this pest to cotton. In 2004, density of E. servus was lower in cotton fields with sorghum trap crops (with or without pheromone traps compared to control cotton fields. Similarly, in 2006, density of E. servus was lower in cotton fields with sorghum trap crops and pheromone traps compared to control cotton fields. Thus, the combination of the sorghum trap crop and pheromone traps effectively suppressed dispersal of E. servus into cotton. Inclusion of pheromone traps with trap crops potentially offers additional benefits, including: (1 reducing the density of E. servus adults in a trap crop, especially females, to possibly decrease the local population over time and reduce the overwintering population, (2 reducing dispersal of E. servus adults from the trap crop into cotton, and (3 potentially attracting more dispersing E. servus adults into a trap crop during a period of time when preferred food is not prevalent in the landscape.

  9. One-pot functionalisation of N-substituted tetrahydroisoquinolines by photooxidation and tunable organometallic trapping of iminium intermediates.

    Science.gov (United States)

    Barham, Joshua P; John, Matthew P; Murphy, John A

    2014-01-01

    Nucleophilic trapping of iminium salts generated via oxidative functionalisation of tertiary amines is well established with stabilised carbon nucleophiles. The few reports of organometallic additions have limited scope of substrate and organometallic nucleophile. We report a novel, one-pot methodology that functionalises N-substituted tetrahydroisoquinolines by visible light-assisted photooxidation, followed by trapping of the resultant iminium ions with organometallic nucleophiles. This affords 1,2-disubstituted tetrahydroisoquinolines in moderate to excellent yields.

  10. Laser induced fluorescence of trapped molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Grieman, F.J.

    1979-10-01

    An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references.

  11. How to detect trap cluster systems?

    International Nuclear Information System (INIS)

    Mandowski, Arkadiusz

    2008-01-01

    Spatially correlated traps and recombination centres (trap-recombination centre pairs and larger clusters) are responsible for many anomalous phenomena that are difficult to explain in the framework of both classical models, i.e. model of localized transitions (LT) and the simple trap model (STM), even with a number of discrete energy levels. However, these 'anomalous' effects may provide a good platform for identifying trap cluster systems. This paper considers selected cluster-type effects, mainly relating to an anomalous dependence of TL on absorbed dose in the system of isolated clusters (ICs). Some consequences for interacting cluster (IAC) systems, involving both localized and delocalized transitions occurring simultaneously, are also discussed

  12. Laser cooling and trapping of atoms

    International Nuclear Information System (INIS)

    Chu, S.

    1995-01-01

    The basic ideas of laser cooling and atom trapping will be discussed. These techniques have applications in spectroscopy, metrology, nuclear physics, biophysics, geophysics, and polymer science. (author)

  13. Laser induced fluorescence of trapped molecular ions

    International Nuclear Information System (INIS)

    Grieman, F.J.

    1979-10-01

    An experimental apparatus for obtaining the optical spectra of molecular ions is described. The experimental technique includes the use of three dimensional ion trapping, laser induced fluorescence, and gated photon counting methods. The ions, which are produced by electron impact, are confined in a radio-frequency quadrupole ion trap of cylindrical design. Because the quadrupole ion trap allows mass selection of the molecular ion desired for study, the analysis of the spectra obtained is greatly simplified. The ion trap also confines the ions to a region easily probed by a laser beam. 18 references

  14. High Optical Access Trap 2.0.

    Energy Technology Data Exchange (ETDEWEB)

    Maunz, Peter Lukas Wilhelm [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-26

    The High Optical Access (HOA) trap was designed in collaboration with the Modular Universal Scalable Ion-trap Quantum Computer (MUSIQC) team, funded along with Sandia National Laboratories through IARPA's Multi Qubit Coherent Operations (MQCO) program. The design of version 1 of the HOA trap was completed in September 2012 and initial devices were completed and packaged in February 2013. The second version of the High Optical Access Trap (HOA-2) was completed in September 2014 and is available at IARPA's disposal.

  15. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  16. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades......, but the mechanisms involved are still not clarified. In this review the information obtained in previous studies is recapitulated together with some of the current attempts to resolve the controversy in the field: identification of the putative progenitor cells, identification of the factors involved...

  17. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  18. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  19. Neutron lifetime measurement with a double trap for ultra cold neutrons

    International Nuclear Information System (INIS)

    Pichlmaier, A.; Nesvizhevsky, V.; Neumaier, S.; Geltenbort, P.; Schreckenbach, K.; Varlamov, V.

    1997-01-01

    The main troubles met during experiments dealing with free neutrons beta decay lifetime measurement by ultracold neutron storage in a double trap are discussed. The main improvements for the experiment successful realization are considered. These are the following. The neutrons are stored in traps which walls are covered with Fomblin oil. The outer volume serves for preliminary storage and as an ultracold neutrons monochromator by gravity and the absorber plate. The inner volume presents a storage volume of variable size for the neutron lifetime measurement. The neutrons are first filled into the outer trap. Then the storage trap is filled and closed by the shutter against the outer trap. After the storage time the shutter is opened and the remaining ultracold neutrons are counted in the detector. It is shown that while the lifetime in the preliminary storage volume is of the order of 200 sec the lifetime in the main storage volume is typically only 20 % shorter than the lifetime of the free neutron

  20. Experimental and computational analysis of Doppler cooling and the magneto-optic trap.

    Science.gov (United States)

    Cowan, J. A., Jr.; Cline, R. A.

    1997-04-01

    Cold, dense clouds of cesium atoms have been produced in an undergraduate research lab using Doppler cooling and a vapor cell magneto-optic trap (MOT). Measurements of temperature, density, and filling of a MOT will be reported. In conjunction with this experiment, Windows-based software has been developed to simulate laser cooling and trapping. The program graphically depicts the position and velocity of a variable number of atoms in two dimensions as they are cooled and trapped. The algorithm accounts for absorption, spontaneous and stimulated emission, Doppler and Zeeman shifts, and radiation trapping. The user can adjust time step, atom velocity, laser intensity and detuning, and magnetic field gradient. The program can demonstrate optical molasses, a MOT, and a dark MOT. Simulations can be recorded and played back in the same graphical environment, along with movies from the actual experiment. The simulation is a useful educational tool for explaining and investigating Doppler cooling and the magneto-optic trap. The program allows anyone to obtain computational results and compare them with published experimental results. A beta version of Cool Simulation is downloadable off the World Wide Web.

  1. A discursive review of the textual use of 'trapped' in environmental migration studies: The conceptual birth and troubled teenage years of trapped populations.

    Science.gov (United States)

    Ayeb-Karlsson, Sonja; Smith, Christopher D; Kniveton, Dominic

    2018-02-12

    First mooted in 2011, the concept of Trapped Populations referring to people unable to move from environmentally high-risk areas broadened the study of human responses to environmental change. While a seemingly straightforward concept, the underlying discourses around the reasons for being 'trapped', and the language describing the concept have profound influences on the way in which policy and practice approaches the needs of populations at risk from environmental stresses and shocks. In this article, we apply a Critical Discourse Analysis to the academic literature on the subject to reveal some of the assumptions implicit within discussing 'trapped' populations. The analysis reveals a dominant school of thought that assisted migration, relocation, and resettlement in the face of climate change are potentially effective adaptation strategies along a gradient of migrant agency and governance.

  2. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... nuclear decay of neutrinoless double beta decay typically leading to sub-eV values as well. (Z, A) → (Z + 2, A) + 2e .... Here again energy resolution matters, because of the continuous spectrum of the 2νββ- decay mode, its high .... The benefit of using Te is its high natural abundance. This experiment is in ...

  3. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting ...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  4. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  5. Laser-cooling and electromagnetic trapping of neutral atoms

    International Nuclear Information System (INIS)

    Phillips, W.D.; Migdall, A.L.; Metcalf, H.J.

    1986-01-01

    Until recently it has been impossible to confine and trap neutral atoms using electromagnetic fields. While many proposals for such traps exist, the small potential energy depth of the traps and the high kinetic energy of available atoms prevented trapping. We review various schemes for atom trapping, the advances in laser cooling of atomic beams which have now made trapping possible, and the successful magnetic trapping of cold sodium atoms

  6. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  7. Optimizing Trap Design and Trapping Protocols for Drosophila suzukii (Diptera: Drosophilidae).

    Science.gov (United States)

    Renkema, Justin M; Buitenhuis, Rosemarije; Hallett, Rebecca H

    2014-12-01

    Drosophila suzukii Matsumura (Diptera: Drosophilidae) is a recent invasive pest of fruit crops in North America and Europe. Carpophagous larvae render fruit unmarketable and may promote secondary rot-causing organisms. To monitor spread and develop programs to time application of controls, further work is needed to optimize trap design and trapping protocols for adult D. suzukii. We compared commercial traps and developed a new, easy-to-use plastic jar trap that performed well compared with other designs. For some trap types, increasing the entry area led to increased D. suzukii captures and improved selectivity for D. suzukii when populations were low. However, progressive entry area enlargement had diminishing returns, particularly for commercial traps. Unlike previous studies, we found putting holes in trap lids under a close-fitting cover improved captures compared with holes on sides of traps. Also, red and black traps outperformed yellow and clear traps when traps of all colors were positioned 10-15 cm apart above crop foliage. In smaller traps, attractant surface area and entry area, but not other trap features (e.g., headspace volume), appeared to affect D. suzukii captures. In the new, plastic jar trap, tripling attractant volume (360 vs 120 ml) and weekly attractant replacement resulted in the highest D. suzukii captures, but in the larger commercial trap these measures only increased by-catch of large-bodied Diptera. Overall, the plastic jar trap with large entry area is affordable, durable, and can hold high attractant volumes to maximize D. suzukii capture and selectivity. © 2014 Entomological Society of America.

  8. A donor-like trap at the InGaN/GaN interface with net negative polarization and its possible consequence on internal quantum efficiency

    International Nuclear Information System (INIS)

    Schaake, Christopher A; Brown, David F; Swenson, Brian L; Keller, Stacia; Mishra, Umesh K; Speck, James S

    2013-01-01

    Deep-level transient spectroscopy was performed on InGaN HEMTs and revealed a donor-like trap at the InGaN/GaN interface with net negative polarization. The trap was found to have an energy level of 0.071 eV. A photo-assisted capacitance–voltage (CV) measurement was performed on an InGaN diode. CV curves were measured before and after exposure to a broadband ultraviolet (UV) lamp. The UV lamp caused capacitance to increase as a result of traps being ionized. The trap density was found to be at least 4 × 10 11 cm −2 . (paper)

  9. A donor-like trap at the InGaN/GaN interface with net negative polarization and its possible consequence on internal quantum efficiency

    Science.gov (United States)

    Schaake, Christopher A.; Brown, David F.; Swenson, Brian L.; Keller, Stacia; Speck, James S.; Mishra, Umesh K.

    2013-10-01

    Deep-level transient spectroscopy was performed on InGaN HEMTs and revealed a donor-like trap at the InGaN/GaN interface with net negative polarization. The trap was found to have an energy level of 0.071 eV. A photo-assisted capacitance-voltage (CV) measurement was performed on an InGaN diode. CV curves were measured before and after exposure to a broadband ultraviolet (UV) lamp. The UV lamp caused capacitance to increase as a result of traps being ionized. The trap density was found to be at least 4 × 1011 cm-2.

  10. Secretion Trap Tagging of Secreted and Membrane-Spanning Proteins Using Arabidopsis Gene Traps

    Science.gov (United States)

    Andrew T. Groover; Joseph R. Fontana; Juana M. Arroyo; Cristina Yordan; W. Richard McCombie; Robert A. Martienssen

    2003-01-01

    Secreted and membrane-spanning proteins play fundamental roles in plant development but pose challenges for genetic identification and characterization. We describe a "secretion trap" screen for gene trap insertions in genes encoding proteins routed through the secretory pathway. The gene trap transposon encodes a ß-glucuronidase reporter enzyme...

  11. Differentiation of three pairs of Boc-beta,gamma- and gamma,beta-hybrid peptides by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Ramesh, V; Srinivas, R; Sharma, G V M; Jayaprakash, P; Kunwar, A C

    2008-09-01

    A new series of Boc-N-beta(3), gamma(4)-/gamma(4), beta(3)-isomeric hybrid peptides (containing repeats of beta(3)-Caa and gamma(4)-Caa's, Caa = C-linked carbo beta(3)-/gamma(4)-amino acids derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion-trap and high resolution quadrupole time-of-flight/tandem mass spectrometry (Q-TOF MS/MS). MS(n) of protonated isomeric peptides and [M+H-Boc+H](+) produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The positional isomers are differentiated from one another by the presence of y(n)(+), b(n)(+), and other fragment ions of different m/z values. It is observed that the peptides with beta-Caa at the N-terminus produce extensive fragmentation, whereas gamma-Caa gave rise to much less fragmentation. Peptides with gamma-Caa at the N-terminus lose NH(3), whereas this process is absent for the carbopeptides with beta-Caa at the N-terminus. Two pairs of dipeptide diastereomers are clearly differentiated by the collision-induced dissociation (CID) of their protonated molecules. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-(R)-beta-Caa-(R)-gamma-Caa-OCH(3) (6) and Boc-NH-(R)-gamma-Caa-(R)-beta-Caa-OCH(3) (12), whereas it is insignificant or totally absent for its protonated diastereomeric pair Boc-NH-(S)-beta-Caa-(S)-gamma-Caa-OCH(3) (1) and Boc-NH-(S)-gamma-Caa-(S)-beta-Caa-OCH(3) (7). Further, ESI negative ion tandem mass spectrometry has also been found to be useful for differentiating these isomeric peptide acids.

  12. Beta* and beta-waist measurement and control at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Ptitsyn,V.; Della Penna, A.; Litvinenko, V.N.; Malitsky, N.; Satogata, T.

    2009-05-04

    During the course of last RHIC runs the beta-functions at the collision points ({beta}*) have been reduced gradually to 0.7m. In order to maximize the collision luminosity and ensure the agreement of the actual machine optics with the design one, more precise measurements and control of {beta}* value and {beta}-waist location became necessary. The paper presents the results of the implementation of the technique applied in last two RHIC runs. The technique is based on well-known relation between the tune shift and the beta function and involves precise betatron tune measurements using BBQ system as well as specially developed knobs for {beta}-waist location control.

  13. Diffusion and trapping of muons in aluminium: New experiments and comparison with Kondo theory

    International Nuclear Information System (INIS)

    Hartmann, O.; Karlsson, E.; Waeckelgaard, E.; Waeppling, R.; Hempelmann, R.; Niinikoski, T.O.

    1987-03-01

    The diffusion and trapping of positive muons in aluminium has been studied using the method of muon spin rotation. New measurements have been performed on Al-samples doped with Mg, Si, Ga and Ge-impurities (which trap the muons), and for comparison also on an Ag-sample doped with Er. Trapping rates and trapping site information were obtained for temperatures between 0.05 K and 50 K. A global fit to these and earlier published data for trapping by other impurities (Li, Mn, Ag) and vacancies has made it possible to deduce the temperature dependence of the intrinsic diffusion in Al for the range 0.05 - 200 K and to compare it with the recently developed theory by Kondo for light interstitial diffusion in metals. In the low temperature range (0.05 - 2 K) it shows a T -0.7 dependence, followed by an approximately linear T-dependence (2 - 20 K) and an exponential (activated) behaviour at higher temperatures. The theory for the low-T diffusion, which is based on tunneling with energy dissipation through the screening electrons, describes the experimental data with reasonable parameters. For the intermediate range there are strong indications of one phonon assisted diffusion. The trapping sites close to the impurities are discused with reference to the elastic distortions and the electronic density modifications introduced by the different impurities. (with 52 refs.) (author)

  14. Collective excitations of harmonically trapped ideal gases

    NARCIS (Netherlands)

    Van Schaeybroeck, B.; Lazarides, A.

    2009-01-01

    We theoretically study the collective excitations of an ideal gas confined in an isotropic harmonic trap. We give an exact solution to the Boltzmann-Vlasov equation; as expected for a single-component system, the associated mode frequencies are integer multiples of the trapping frequency. We show

  15. Modes of oscillation in radiofrequency Paul traps

    DEFF Research Database (Denmark)

    Landa, H.; Reznik, B.; Drewsen, M.

    2012-01-01

    We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general threedimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We analytically derive the micromotion amplitude of the ions...

  16. An Experimental Analysis of Social Traps

    Science.gov (United States)

    Brechner, Kevin C.

    1977-01-01

    Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. Alaboratory analog was devised to simulate conditions that produce social traps. The intent was to cause an immediate positive…

  17. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    Tunneling of trapped-atom Bose condensates. SUBODH R SHENOY. Abdus Salam International Centre for Theoretical Physics, P.O. Box 586, Trieste 34100, Italy. Abstract. We obtain the dynamics in number and phase difference, for Bose condensates that tun- nel between two wells of a double-well atomic trap, using the ...

  18. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    hierarchical network. Here, we focus on a particular case with the trap located at the node with the highest degree. We derive rigorous solution to the MFPT that characterizes the trapping process. Moreover ..... The weighted networks can mimic some real-world natural and social systems to some extent [20–22]. We focus ...

  19. Lobster trap detection at the Saba Bank

    NARCIS (Netherlands)

    Beek, van I.J.M.

    2012-01-01

    According to previous studies and anecdotal evidence there are a lot of lost lobster traps at the Saba Bank. One study estimated the loss to be between 210 and 795 lobster traps per year. The Saba Bank is an approximately 2,200 km2 submerged area and spiny lobster (Panulirus argus) is one of the

  20. Astroturf seed traps for studying hydrochory

    NARCIS (Netherlands)

    Wolters, M; Geertsema, J; Chang, ER; Veeneklaas, RM; Carey, PD; Bakker, JP

    1. Astroturf mats can effectively trap diaspores dispersed by tidal water. 2. Within four tidal inundations, up to 745 propagules per m(2) and between three and eight different species per astroturf mat were trapped. Overall, 15 different species were collected on the astroturf mats, 10 of which

  1. Measuring oxide trapping parameters in MOS structure

    Science.gov (United States)

    Maserjian, J.

    1978-01-01

    System for controlled injection of electrons or holes into oxide layer of MOS capacitor can be used to measure oxide trapping parameters. Since trapping mechanisms can cause degradation and ultimate failure of MOS elements exposed to ionizing radiation, system can be helpful in predicting device tolerance.

  2. Insects in IBL-4 pine weevil traps

    Science.gov (United States)

    I. Skrzecz

    2003-01-01

    Pipe traps (IBL-4) are used in Polish coniferous plantations to monitor and control the pine weevil (Hylobius abietis L.). This study was conducted in a one-year old pine plantation established on a reforested clear-cut area in order to evaluate the impact of these traps on non-target insects. Evaluation of the catches indicated that species of

  3. Spectral intensity distribution of trapped fermions

    Indian Academy of Sciences (India)

    The temperature being very low, trapped cold atomic gases are in the quantum degener- acy regime. In this regime bosons ... that this ideal Fermi system, in the presence of an isotropic harmonic trapping potential, is very interesting and we consider ... function of the system as an example. The dynamical response function, ...

  4. Inelastic collision rates of trapped metastable hydrogen

    NARCIS (Netherlands)

    Landhuis, D; Matos, L; Moss, SC; Steinberger, JK; Vant, K; Willmann, L; Greytak, TJ; Kleppner, D

    We report the first detailed decay studies of trapped metastable (2S) hydrogen. By two-photon excitation of ultracold H samples, we have produced clouds of at least 5x10(7) magnetically trapped 2S atoms at densities greater than 4x10(10) cm(-3) and temperatures below 100 muK. At these densities and

  5. Optical trapping at low numerical aperture

    NARCIS (Netherlands)

    Stallinga, S.

    2011-01-01

    A theory of optical trapping at low Numerical Aperture (NA) is presented. The theory offers an analytical description of the competition between the stabilizing gradient and destabilizing scattering force. The trade-off can be characterized by a single dimensionless trapping parameter, which

  6. Influence of trap construction on mosquito capture

    Czech Academy of Sciences Publication Activity Database

    Šebesta, Oldřich; Peško, Juraj; Gelbič, Ivan

    2012-01-01

    Roč. 6, č. 2 (2012), s. 209-215 ISSN 1934-7391 R&D Projects: GA MŠk 2B08003 Institutional research plan: CEZ:AV0Z50070508 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : CDC miniature light traps * baited lard-can traps * mosquitoes Subject RIV: EG - Zoology

  7. Depolarization of UCN stored in material traps

    CERN Document Server

    Serebrov, A; Lasakov, M; Rudnev, Y; Krasnoschekova, I A; Geltenbort, P; Butterworth, J; Bowles, T; Morris, C; Seestrom, S; Smith, D; Young, A R

    2000-01-01

    Depolarization of ultra-cold neutrons (UCN) stored in material traps was first observed. The probability of UCN spin flip per reflection depends on the trap material and varies from 7x10 sup - sup 6 (beryllium) to 10 sup - sup 4 (glass).

  8. Depolarization of UCN stored in material traps

    Energy Technology Data Exchange (ETDEWEB)

    Serebrov, A.; Vasiliev, A.; Lasakov, M.; Rudnev, Yu.; Krasnoshekova, I.; Geltenbort, P.; Butterworth, J.; Bowles, T.; Morris, C.; Seestrom, S.; Smith, D.; Young, A.R

    2000-02-11

    Depolarization of ultra-cold neutrons (UCN) stored in material traps was first observed. The probability of UCN spin flip per reflection depends on the trap material and varies from 7x10{sup -6} (beryllium) to 10{sup -4} (glass)

  9. Cold and trapped metastable noble gases

    NARCIS (Netherlands)

    Vassen, W.; Cohen-Tannoudji, C.; Leduc, M.; Boiron, D.; Westbrook, C.I.; Truscott, A.; Baldwin, K.; Birkl, G.; Cancio, P.; Trippenbach, M.

    2012-01-01

    Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general is emphasized. These aspects include detection techniques and collision processes unique to metastable atoms.

  10. Cryptography, quantum computation and trapped ions

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard J.

    1998-03-01

    The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made.

  11. Enhanced trapping of stable flies via olfactory and visual cues

    Science.gov (United States)

    Adult stable flies are highly attracted to the so-called Alsynite cylinder trap; however this trap is expensive. Here we report the development of a cheaper and better white panel trap with options of adding visual and olfactory stimuli for enhanced stable fly trapping. The white panel trap attracte...

  12. Search for non Standard Model physics in nuclear-$\\beta$ decay with the WITCH experiment

    CERN Document Server

    Coeck, Sam

    In this work the WITCH experiment, which primarily aims for precision measurements of the beta-neutrino-angular correlation coefficient, is presented in detail. First a theoretical description of the beta-decay process is presented and it was shown how measurements of correlation coefficients can reveal the exact nature of the weak interaction. Although many experiments have already been conducted in this field, there is still considerable room for additional phenomena that are not included in the Standard Model. At WITCH the beta-neutrino-angular correlation coefficient will be obtained from precision measurements of the energy spectrum of the nuclei that recoil after beta-decay, thus avoiding the need to observe the neutrino. To enable a measurement of the recoiling ions, the setup uses a combination of two electromagnetic Penning traps and a retardation spectrometer. This allows one to construct the scattering free radioactive source that is needed as the recoiling ions have only a very small kinetic energ...

  13. GAMMASPHERE: Correction technique for detector charge trapping

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, F.S.; Landis, D.A.

    1993-11-01

    GAMMASPHERE uses 110 very large germanium detectors. Such detectors exhibit charge trapping effects on energy resolution initially due to a native electron trap that is present in virtually all germanium. Furthermore, radiation damage is a serious problem in GAMMASPHERE experiments, producing hole traps that degrade resolution and eventually require annealing to restore the original performance. The technique discussed here uses the current pulse shape from a detector to develop a parameter related to the radius of the largest interaction in the ``track`` of a gamma ray in the detector. Since the charge trapping loss in a signal can be related to the distance carriers travel, the ``radius`` parameter can be used by software to apply a trap correction to the signal.

  14. Magnetic trapping of cold bromine atoms.

    Science.gov (United States)

    Rennick, C J; Lam, J; Doherty, W G; Softley, T P

    2014-01-17

    Magnetic trapping of bromine atoms at temperatures in the millikelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br2 molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are lost only by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential.

  15. Beta measurement evaluation and upgrade

    International Nuclear Information System (INIS)

    Swinth, K.L.; Rathbun, L.A.; Roberson, P.L.; Endres, G.W.R.

    1986-01-01

    This program focuses on the resolution of problems associated with the field measurement of the beta dose component at Department of Energy (DOE) facilities. The change in DOE programs, including increased efforts in improved waste management and decontamination and decommissioning (D and D) of facilities, coupled with beta measurement problems identified at Three Mile Island has increased the need to improve beta measurements. In FY 1982, work was initiated to provide a continuing effort to identify problems associated with beta dose assessment at DOE facilities. The problems identified resulted in the development of this program. The investigation includes (1) an assessment of measurement systems now in use, (2) development of improved calibration systems and procedures, (3) application of innovative beta dosimetry concepts, (4) investigation of new instruments or concepts for monitoring and spectroscopy, and (5) development of recommendations to assure an adequate beta measurement program within DOE facilities

  16. Mass trapping with MosquiTRAPs does not reduce Aedes aegypti abundance

    Directory of Open Access Journals (Sweden)

    Carolin Marlen Degener

    2015-06-01

    Full Text Available The objective of this study was to evaluate the effectiveness of Aedes aegypti mass trapping using the sticky trap MosquiTRAP (MQT by performing a cluster randomised controlled trial in Manaus, state of Amazonas, Brazil. After an initial questionnaire and baseline monitoring of adult Ae. aegypti abundance with BG-Sentinel (BGS traps in six clusters, three clusters were randomly assigned to the intervention arm where each participating household received three MQTs for mass trapping during 17 months. The remaining three clusters (control arm did not receive traps. The effect of mass trapping on adult Ae. aegypti abundance was monitored fortnightly with BGS traps. During the last two months of the study, a serological survey was conducted. After the study, a second questionnaire was applied in the intervention arm. Entomological monitoring indicated that MQT mass trapping did not reduce adult Ae. aegypti abundance. The serological survey indicated that recent dengue infections were equally frequent in the intervention and the control arm. Most participants responded positively to questions concerning user satisfaction. According to the results, there is no evidence that mass trapping with MQTs can be used as a part of dengue control programs. The use of this sticky trap is only recommendable for dengue vector monitoring.

  17. Conditional Betas and Investor Uncertainty

    OpenAIRE

    Fernando D. Chague

    2013-01-01

    We derive theoretical expressions for market betas from a rational expectation equilibrium model where the representative investor does not observe if the economy is in a recession or an expansion. Market betas in this economy are time-varying and related to investor uncertainty about the state of the economy. The dynamics of betas will also vary across assets according to the assets' cash-flow structure. In a calibration exercise, we show that value and growth firms have cash-flow structures...

  18. TRAP230/ARC240 and TRAP240/ARC250 Mediator subunits are functionally conserved through evolution

    DEFF Research Database (Denmark)

    Samuelsen, Camilla O; Baraznenok, Vera; Khorosjutina, Olga

    2003-01-01

    for Srb8 and Srb9. Here, we identify a TRAP240/ARC250 homologue in Schizosaccharomyces pombe and demonstrate that this protein, spTrap240, is stably associated with a larger form of Mediator, which also contains conserved homologues of Srb8, Srb10, and Srb11. We find that spTrap240 and Sch. pombe Srb8 (sp...... with the polymerase. Our findings provide experimental evidence for recent suggestions that TRAP230/ARC240 and TRAP240/ARC250 may indeed be the Srb8 and Srb9 homologues of mammalian Mediator. Apparently Srb8/TRAP230/ARC240, Srb9/TRAP240/ARC250, Srb10, and Srb11 constitute a conserved Mediator submodule, which...

  19. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  20. Supersymmetry Inspired QCD Beta Function

    DEFF Research Database (Denmark)

    Ryttov, Thomas; Sannino, Francesco

    2008-01-01

    We propose an all orders beta function for ordinary Yang-Mills theories with or without fermions inspired by the Novikov-Shifman-Vainshtein-Zakharov beta function of N=1 supersymmetric gauge theories. The beta function allows us to bound the conformal window. When restricting to one adjoint Weyl...... fermion we show how the proposed beta function matches the one of supersymmetric Yang-Mills theory. The running of the pure Yang-Mills coupling is computed and the deviation from the two loop result is presented. We then compare the deviation with the one obtained from lattice data also with respect...

  1. Dynamic returns of beta arbitrage

    OpenAIRE

    Nascimento, Mafalda

    2017-01-01

    This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

  2. Nonlinear spectroscopy of trapped ions

    Science.gov (United States)

    Schlawin, Frank; Gessner, Manuel; Mukamel, Shaul; Buchleitner, Andreas

    2014-08-01

    Nonlinear spectroscopy employs a series of laser pulses to interrogate dynamics in large interacting many-body systems, and it has become a highly successful method for experiments in chemical physics. Current quantum optical experiments approach system sizes and levels of complexity that require the development of efficient techniques to assess spectral and dynamical features with scalable experimental overhead. However, established methods from optical spectroscopy of macroscopic ensembles cannot be applied straightforwardly to few-atom systems. Based on the ideas proposed in M. Gessner et al., (arXiv:1312.3365), we develop a diagrammatic approach to construct nonlinear measurement protocols for controlled quantum systems, and we discuss experimental implementations with trapped ion technology in detail. These methods, in combination with distinct features of ultracold-matter systems, allow us to monitor and analyze excitation dynamics in both the electronic and vibrational degrees of freedom. They are independent of system size, and they can therefore reliably probe systems in which, e.g., quantum state tomography becomes prohibitively expensive. We propose signals that can probe steady-state currents, detect the influence of anharmonicities on phonon transport, and identify signatures of chaotic dynamics near a quantum phase transition in an Ising-type spin chain.

  3. Neutrophil extracellular traps go viral

    Directory of Open Access Journals (Sweden)

    Günther Schönrich

    2016-09-01

    Full Text Available Neutrophils are the most numerous immune cells. Their importance as a first line of defense against bacterial and fungal pathogens is well described. In contrast, the role of neutrophils in controlling viral infections is less clear. Bacterial and fungal pathogens can stimulate neutrophils to produce extracellular traps (NETs in a process called NETosis. Although NETosis has previously been described as a special form of programmed cell, there are forms of NET production that do not end with the demise of neutrophils. As an end result of NETosis, genomic DNA complexed with microbicidal proteins is expelled from neutrophils. These structures can kill pathogens or at least prevent their local spread within host tissue. On the other hand disproportionate NET formation can cause local or systemic damage. Only recently was it recognized that viruses can also induce NETosis. In this review, we discuss the mechanisms by which NETs are produced in the context of viral infection and how this may contribute to both antiviral immunity and immunopathology. Finally, we shed light on viral immune evasion mechanisms targeting NETs.

  4. Environmentally Assisted Cracking of High Strength Beta Titanium Alloys

    Science.gov (United States)

    1993-11-01

    vulgaris bacteria were cultivated U I I 1 4 3 in deaerated Postgate Medium C (in g/l of distilled water: 6.0 lactic acid, 4.5 Na2SO4, 1.0 yeast...Postgate Medium C, diluted by 400 ml of distilled I water and fully argon deaerated. This environment was statically maintained during the FCP I...1410eml Aoi percent rem. 7.89 5.ŝ 1.44 0.40 0.629 0.14 0.05 1 J. Eb ow x, Vo. 140, No. 10, OMW 1993 0 The BeckocherIce! Society. hr-c 2771 I77 1L8suFals Sm

  5. Evaluation of hydrogen trapping mechanisms during performance of different hydrogen fugacity in a lean duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Silverstein, R., E-mail: barrav@post.bgu.ac.il [Department of Material Science and Engineering, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Eliezer, D. [Department of Material Science and Engineering, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Glam, B.; Eliezer, S.; Moreno, D. [Soreq Nuclear Research Center, Yavne, 81800 (Israel)

    2015-11-05

    Hydrogen trapping behavior in a lean duplex stainless steel (LDS) is studied by means of thermal desorption spectrometry (TDS). The susceptibility of a metal to hydrogen embrittlement is directly related to the trap characteristics: source or sink (reversible or irreversible, respectively). Since trapping affects the metal's diffusivity, it has a major influence on the hydrogen assisted cracking (HAC) phenomenon. It is known from previously published works that the susceptibility will depend on the competition between reversible and irreversible traps; meaning a direct relation to the hydrogen's initial state in the steel. In this research the trapping mechanism of LDS, exposed to different hydrogen charging environments, is analyzed by means of TDS. The TDS analysis was supported and confirmed by means of X-ray diffraction (XRD), hydrogen quantitative measurements and microstructural observations. It was found that gaseous charging (which produces lower hydrogen fugacity) creates ∼22% higher activation energy for hydrogen trapping compared with cathodic charging (which produces higher hydrogen fugacity). These results are due to the different effects on the hydrogen behavior in LDS which causes a major difference in the hydrogen contents and different hydrogen assisted phase transitions. The highest activation energy value in the cathodic charged sample was ascribed to the dominant phase transformation of γ → γ{sup ∗}, whereas in the gaseous charged sample it was ascribed to the dominant formation of intermetallic compound, sigma (σ). The relation between hydrogen distribution in LDS and hydrogen trapping mechanism is discussed in details. - Highlights: • The relation between hydrogen distribution and trapping in LDS is discussed. • Hydrogen's initial state in LDS causes different microstructural changes. • Gaseous charged LDS creates higher trapping energy compared to cathodic charged LDS. • The dominant phase transformation in

  6. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  7. Taxonomic, spatial and adaptive genetic variation of Beta section Beta.

    Science.gov (United States)

    Andrello, Marco; Henry, Karine; Devaux, Pierre; Desprez, Bruno; Manel, Stéphanie

    2016-02-01

    The genetic variation of Beta section Beta is structured into four taxonomic and spatial clusters. There are significant associations between molecular markers and environmental variables. We investigated the genetic diversity of Beta section Beta, which includes the wild and cultivated relatives of the sugar beet. The taxa included in the study were: Beta vulgaris subsp. maritima, B. vulgaris subsp. adanensis, B. macrocarpa, B. patula and B. vulgaris subsp. vulgaris (garden beet, leaf beet and swiss chards). We collected 1264 accessions originating from the entire distribution area of these taxa and genotyped them for 4436 DArT markers (DArTs). We showed that the genetic variation of these accessions is structured into four taxonomic and spatial clusters: (1) samples of Beta macrocarpa, (2) samples of Beta vulgaris subsp. adanensis, (3) Mediterranean and Asian samples and (4) Atlantic and Northern European samples. These last two clusters were mainly composed of samples of Beta vulgaris subsp. maritima. We investigated in deeper detail the genetic structure of B. vulgaris subsp. maritima, which constituted the majority (80%) of the wild samples. This subspecies exhibited a clinal genetic variation from South-East to North-West. We detected some markers significantly associated to environmental variables in B. vulgaris subsp. maritima. These associations are interpreted as results of natural selection. The variable most often involved in the associations was annual mean temperature. Therefore, these markers can be useful for the development of frost-tolerant winter beets and drought-tolerant rain-fed beets.

  8. Beta2-adrenoceptors: mechanisms of action of beta2-agonists.

    Science.gov (United States)

    Johnson, M

    2001-03-01

    The human beta2-adrenoceptor is a member of the 7 transmembrane family of receptors. It is encoded by a gene on chromosome 5 and is widely distributed in the respiratory tract. Following beta2-adrenoceptor activation, intracellular signalling is mainly produced by inducing cyclic AMP. This produces airway relaxation through phosphorylation of muscle regulatory proteins and modification of cellular Ca2+concentrations. Beta2-agonists have been characterised into those which directly activate the receptor (salbutamol/terbutaline), those which are taken up into a membrane depot (formoterol) and those which interact with a receptor-specific, auxiliary binding site (salmeterol). These differences in mechanism of action are reflected in the kinetics of airway smooth muscle relaxation and bronchodilation in asthmatic patients. Beta-adrenoceptor desensitisation is associated with beta2-agonist activation and differs depending on the cell type. It is reflected in the different profiles of clinical tolerance to chronic beta2-agonist therapy. A number of polymorphisms of the beta2-receptor have been described which appear to alter the behaviour of the receptor, including the degree of downregulation and response to beta2-agonists.

  9. Identification of active anti-inflammatory principles of beta- beta ...

    African Journals Online (AJOL)

    chromatography. Components of the extracts were identified by thin layer chromatography (TLC) scanner and UV-visible spectroscopy, using scopoletin as standard. Results: ... basic coumarin skeleton ring structure reduce ... Figure 2: Thin-layer chromatogram: (1) Ethanol extract; (2) Dichloromethane fraction; (3) Beta-beta.

  10. Consequence of beta 16 and beta 112 replacements on the kinetics of hemoglobin assembly.

    Science.gov (United States)

    Adachi, K; Yang, Y; Joshi, A A; Vasudevan, G; Morris, A; McDonald, M J

    2001-11-23

    The rates of alpha/beta monomer combination of four beta(A) variants (beta 112C --> S, beta 112C --> D, beta 112C --> T, and beta 112C --> V) in the presence and absence of beta 16G --> D (beta(J)) were measured in an attempt to assess the consequences of amino acid substitution at both a surface (beta 16) and an alpha(1)beta(1) interface (beta 112) residue on oxyhemoglobin assembly. Rates of alpha/beta monomer combination determined spectrally in 0.1 M Tris-HCl, 0.1 M NaCl, 1 mM EDTA, pH 7.4, at 21.5 degrees C differed by over 40-fold (22 +/- 2.0 to 0.49 +/- 0.1 x 10(5) M(-1) s(-1)), and were in the order: HbA beta 112S = HbJ beta 16D, beta 112S > HbA beta 112D = HbJ beta 16D, beta 112D > HbA > Hb J > HbA beta 112T = HbJ beta 16D, beta 112T > HbJ beta 16D, beta 112V > HbA beta 112V. This extensive kinetic investigation of single/double amino acid-substituted recombinant hemoglobin molecules, in conjunction with molecular modeling studies, has allowed examination of an array of unique alpha/beta subunit interactions and assembly processes. Copyright 2001 Academic Press.

  11. TGF-Beta and Breast Cancer Induction

    National Research Council Canada - National Science Library

    Dabovic, Branka

    2001-01-01

    .... We study the molecule TGF-beta, which blocks cell growth. TGF-beta is produced as latent complex consisting of the TGF-beta homodimer, the TGF-beta propeptide dimmer, and a second gene product, the latent TGF-beta binding protein (LTBP...

  12. An Open Standard for Camera Trap Data

    Directory of Open Access Journals (Sweden)

    Tavis Forrester

    2016-12-01

    Full Text Available Camera traps that capture photos of animals are a valuable tool for monitoring biodiversity. The use of camera traps is rapidly increasing and there is an urgent need for standardization to facilitate data management, reporting and data sharing. Here we offer the Camera Trap Metadata Standard as an open data standard for storing and sharing camera trap data, developed by experts from a variety of organizations. The standard captures information necessary to share data between projects and offers a foundation for collecting the more detailed data needed for advanced analysis. The data standard captures information about study design, the type of camera used, and the location and species names for all detections in a standardized way. This information is critical for accurately assessing results from individual camera trapping projects and for combining data from multiple studies for meta-analysis. This data standard is an important step in aligning camera trapping surveys with best practices in data-intensive science. Ecology is moving rapidly into the realm of big data, and central data repositories are becoming a critical tool and are emerging for camera trap data. This data standard will help researchers standardize data terms, align past data to new repositories, and provide a framework for utilizing data across repositories and research projects to advance animal ecology and conservation.

  13. Spin trapping in γ-irradiated system

    International Nuclear Information System (INIS)

    Taniguchi, Hitoshi

    1998-01-01

    Spin trapping techniques, allowing one to visualize transient free radical populations by reacting short-lived radicals with a spin trap to produce persistent spin adduct radicals, require that the rate constant for parent radical addition to the spin trap be sufficiently large. The study on the rate of spin trapping reactions, dependent upon steric and electronic (polar) interactions in the complex, has been extended to nitrone spin trapping using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap. We concentrated on the trapping of carboxyalkyl radicals which feature strong hydrogen bonding between the hydroxyl group of the spin addend carboxyl function and the aminosyl oxygen, and a strongly electron withdrawing effect of the spin addend on the DMPO ring. These two features in these radicals, enhancing the polarization of the N 1 -C 2 bond to produce spin adduct fragmentation, were found to be significantly more pronounced than in the case of hydroxylalkyl radical adducts to DMPO. (J.P.N.)

  14. Fluorescent prey traps in carnivorous plants.

    Science.gov (United States)

    Kurup, R; Johnson, A J; Sankar, S; Hussain, A A; Sathish Kumar, C; Sabulal, B

    2013-05-01

    Carnivorous plants acquire most of their nutrients by capturing ants, insects and other arthropods through their leaf-evolved biological traps. So far, the best-known attractants in carnivorous prey traps are nectar, colour and olfactory cues. Here, fresh prey traps of 14 Nepenthes, five Sarracenia, five Drosera, two Pinguicula species/hybrids, Dionaea muscipula and Utricularia stellaris were scanned at UV 366 nm. Fluorescence emissions of major isolates of fresh Nepenthes khasiana pitcher peristomes were recorded at an excitation wavelength of 366 nm. N. khasiana field pitcher peristomes were masked by its slippery zone extract, and prey capture rates were compared with control pitchers. We found the existence of distinct blue fluorescence emissions at the capture spots of Nepenthes, Sarracenia and Dionaea prey traps at UV 366 nm. These alluring blue emissions gradually developed with the growth of the prey traps and diminished towards their death. On excitation at 366 nm, N. khasiana peristome 3:1 CHCl3–MeOH extract and its two major blue bands showed strong fluorescence emissions at 430–480 nm. Masking of blue emissions on peristomes drastically reduced prey capture in N. khasiana pitchers. We propose these molecular emissions as a critical factor attracting arthropods and other visitors to these carnivorous traps. Drosera, Pinguicula and Utricularia prey traps showed only red chlorophyll emissions at 366 nm.

  15. Atom trap loss, elastic collisions, and technology

    Science.gov (United States)

    Booth, James

    2012-10-01

    The study of collisions and scattering has been one of the most productive approaches for modern physics, illuminating the fundamental structure of crystals, surfaces, atoms, and sub-atomic particles. In the field of cold atoms, this is no less true: studies of cold atom collisions were essential to the production of quantum degenerate matter, the formation of cold molecules, and so on. Over the past few years it has been my delight to investigate elastic collisions between cold atoms trapped in either a magneto-optical trap (MOT) or a magnetic trap with hot, background gas in the vacuum environment through the measurement of the loss of atoms from the trap. Motivated by the goal of creating cold atom-based technology, we are deciphering what the trapped atoms are communicating about their environment through the observed loss rate. These measurements have the advantages of being straightforward to implement and they provide information about the underlying, fundamental inter-atomic processes. In this talk I will present some of our recent work, including the observation of the trap depth dependence on loss rate for argon-rubidium collisions. The data follow the computed loss rate curve based on the long-range Van der Waals interaction between the two species. The implications of these findings are exciting: trap depths can be determined from the trap loss measurement under controlled background density conditions; observation of trap loss rate in comparison to models for elastic, inelastic, and chemical processes can lead to improved understanding and characterization of these fundamental interactions; finally the marriage of cold atoms with collision modeling offers the promise of creating a novel pressure sensor and pressure standard for the high and ultra-high vacuum regime.

  16. Global kink and ballooning modes in high-beta systems and stability of toroidal drift modes

    International Nuclear Information System (INIS)

    Galvao, R.M.O.; Goedbloed, J.P.; Rem, J.; Sakanaka, P.H.; Schep, T.J.; Venema, M.

    1983-01-01

    A numerical code (HBT) has been developed which solves for the equilibrium, global stability and high-n stability of plasmas with arbitrary cross-section. Various plasmas are analysed for their stability to these modes in the high-beta limit. Screw-pinch equilibria are stable to high-n ballooning modes up to betas of 18%. The eigenmode equation for drift waves is analysed numerically. The toroidal branch is shown to be destabilized by the non-adiabatic response of trapped and circulating particles. (author)

  17. Passive Baited Sequential Filth Fly Trap.

    Science.gov (United States)

    Aldridge, Robert L; Britch, Seth C; Snelling, Melissa; Gutierez, Arturo; White, Gregory; Linthicum, Kenneth J

    2015-09-01

    Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted-cone design to passively confine flies in 8 modified collection bottles corresponding to 8 intervals. Efficacy trials in a hot-arid desert environment indicate no significant difference (P  =  0.896) between the modified sequential trap and a Rid-Max® fly trap.

  18. Work on open traps in the USSR

    Science.gov (United States)

    Ryutov, D. D.

    1981-10-01

    A general review of the historical development and future plans for open plasma devices is given. The major characteristics of the AMBAL device (which is close to an ambipolar fusion reactor in terms of many dimensionless parameters that characterize the state of the plasma), of the GOL-3 multimirror trap, the OGRA-4 mirror trap, and the PSP-4 rotating plasma traps are presented. Transverse plasma losses due to the asymmetry of the magnet system and losses produced by plasma instabilities are discussed. Plasma control and plasma heating are considered.

  19. Impurity beam-trapping instability in tokamaks

    International Nuclear Information System (INIS)

    Hogan, J.T.; Howe, H.C.

    1976-12-01

    The sensitivity of neutron energy production to the trapping by impurities by injected neutral beams is considered. The beam-trapping process is affected by inherent low-Z contamination of the tritium plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process are compared to these variables and to the variation with wall material. One finds that use of a low-Z, low sputtering material could retard a possible beam trapping instability

  20. Robust Digital Holography For Ultracold Atom Trapping

    Science.gov (United States)

    Gaunt, Alexander; Hadzibabic, Zoran

    2013-05-01

    We have formulated and experimentally demonstrated an improved algorithm for design of arbitrary two-dimensional holographic traps for ultracold atoms. Our method builds on the best previously available algorithm, MRAF, and improves on it in two ways. First, it allows for creation of holographic atom traps with a well defined background potential. Second, we experimentally show that for creating trapping potentials free of fringing artifacts it is important to go beyond the Fourier approximation in modelling light propagation. To this end, we incorporate full Helmholtz propagation into our calculations.

  1. Trapped Antihydrogen in Its Ground State

    CERN Document Server

    Gabrielse, G.; Kolthammer, W.S.; McConnell, R.; Richerme, P.; Grzonka, D.; Oelert, W.; Sefzick, T.; Zielinski, M.; Fitzakerley, D.W.; George, M.C.; Hessels, E.A.; Storry, C.H.; Weel, M.; Müllers, A.; Walz, J.

    2012-03-16

    Antihydrogen atoms are confined in an Ioffe trap for 15 to 1000 seconds -- long enough to ensure that they reach their ground state. Though reproducibility challenges remain in making large numbers of cold antiprotons and positrons interact, 5 +/- 1 simultaneously-confined ground state atoms are produced and observed on average, substantially more than previously reported. Increases in the number of simultaneously trapped antithydrogen atoms H are critical if laser-cooling of trapped antihydrogen is to be demonstrated, and spectroscopic studies at interesting levels of precision are to be carried out.

  2. Medfly female attractant trapping studies in Guatemala

    International Nuclear Information System (INIS)

    Jeronimo, F.; Rendon, P.; Villatoro, C.

    1999-01-01

    Experiments were conducted from 1994 - 1998 to test the attractiveness of combinations of food-based chemicals for C. capitata (medfly) in Guatemala. Most studies were done in coffee. The 1995 studies, using the FA-2 attractants (ammonium acetate and putrescine) showed that this combination was attractive for females and had potential for use in conjunction with a SIT program. The 1996 studies at three elevations demonstrated that, in general, these attractants, when used in either the Open Bottom Dry Trap (OBDT), Closed Bottom Dry Trap (CBDT), or International Pheromone's McPhail Trap (IPMT) performed better than the Jumbo McPhail trap (JMT) baited with NuLure and borax (NU+B) for capture of feral females. At the high elevation (1400 m), the IPMT with FA-2 and OBDT with FA-2 were best; at the middle elevation (1100 m), the ORDT, IPMT, and CBDT with FA-2 were best; and at low elevations (659 m), the IPMT with FA-2, JMT with NU+B and ORDT with FA-2 were equal in performance. At the middle elevation, using sterile flies, the OBDT with FA-2 worked best. When experiments were carried out in pear, the traps using the FA-2 attractants captured more female flies than the JMT, NU+B, but not significantly more. During the 1997 trials, a third component, trimethylamine was added to the two component lure (FA-3). This attractant was tested in a number of locally produced traps using 2 I soft drink bottles with different color bottoms. The dry versions of the traps contained a yellow sticky insert. All study sites were at low elevation 600 - 650 m, in coffee, testing both sterile and feral flies. With the feral flies during the first phase of the study at finca San Carlos, there were no significant differences between treatments, at finca San Luis, the clear local trap with sticky insert and the green local trap with sticky insert were best, and at finca Valapraiso, the green local trap with yellow sticky insert and yellow local trap with sticky insert captured more flies

  3. Review of the beta situation

    International Nuclear Information System (INIS)

    Sheffield, J.

    1982-01-01

    This note lists some of the possible causes of beta limitation in tokamak and discusses what is known and what is involved in investigating them. The motivation for preparing this note is the observed degradation of confinement with increasing beta poloidal β/sub p/ and beam power P/sub b/ in ISX-B

  4. Amyloid Beta Mediates Memory Formation

    Science.gov (United States)

    Garcia-Osta, Ana; Alberini, Cristina M.

    2009-01-01

    The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

  5. Beta-hemolytic Streptococcal Bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Hans Ulrik; Kolmos, Hans Jørn; Frimodt-Møller, Niels

    2002-01-01

    Bacteremia with beta-hemolytic Streptococci groups A, B, C and G has a mortality rate of approximately 20%. In this study we analyzed the association of various patient risk factors with mortality. Records from 241 patients with beta-hemolytic streptococcal bacteremia were reviewed with particula...

  6. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

  7. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalous...

  8. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  9. The best-beta CAPM

    NARCIS (Netherlands)

    Zou, L.

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  10. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...

  11. Qualitative Identification of Fentanyl Analogs and Other Opioids in Postmortem Cases by UHPLC-Ion Trap-MSn.

    Science.gov (United States)

    Shoff, Elisa N; Zaney, M Elizabeth; Kahl, Joseph H; Hime, George W; Boland, Diane M

    2017-07-01

    Since 2013, the Miami-Dade County Medical Examiner Department has experienced an increase in the number of opioid-related deaths. The majority of cases coincided with the introduction of fentanyl into the local heroin supply. From 2014 to 2015, Miami-Dade County experienced a near 600% increase in fentanyl-related deaths, followed by an additional 200% increase in 2016. In 2015, two novel fentanyl analogs were identified in medical examiner cases: beta-hydroxythiofentanyl and acetyl fentanyl. In 2016, four additional fentanyl analogs emerged: para-fluoroisobutyryl fentanyl, butyryl fentanyl, furanyl fentanyl and carfentanil, as well as the synthetic opioid U-47700. In order to address this epidemic, a method was developed and validated to identify 44 opioid-related and analgesic compounds in postmortem samples using ultra high performance liquid chromatography ion trap mass spectrometry with MSn capabilities. The limit of detection for all compounds ranged from 0.1 to 5 ng/mL, with a majority having MS3 spectral fragmentation. Blood, urine, liver or brain specimens from ~500 postmortem cases were submitted for analysis based on case history and/or initial screening results. Of those cases, 375 were positive for illicit fentanyl and/or one or more fentanyl analogs. Due to the potency of these compounds, they were almost always included in the cause of death. Worth emphasizing and extremely alarming is the detection of carfentanil in 134 cases, 104 of which were initially missed by gas chromatography mass spectrometry. By incorporating this sensitive, highly specific, and evolving screening procedure into the workflow, the toxicology laboratory continues to effectively assist the medical examiners in determining the cause and manner of death of decedents in Miami-Dade County. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Can Beta Blockers Cause Weight Gain?

    Science.gov (United States)

    Beta blockers: Do they cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol ( ...

  13. Rearrangements of the beta-globin gene cluster in apparently typical betaS haplotypes.

    Science.gov (United States)

    Zago, M A; Silva, W A; Gualandro, S; Yokomizu, I K; Araujo, A G; Tavela, M H; Gerard, N; Krishnamoorthy, R; Elion, J

    2001-02-01

    The majority of the chromosomes with the betaS gene have one of the five common haplotypes, designated as Benin, Bantu, Senegal, Cameroon, and Arab-Indian haplotypes. However, 5-10% of the chromosomes have less common haplotypes, usually referred to as atypical haplotypes. We have demonstrated that most atypical haplotypes are generated by recombinations. The present study was carried out in order to explore whether recombination also occurs in chromosomes with the common (or typical) haplotypes. We screened the HS-2 region of the beta-globin gene locus control region (LCR) in 244 sickle cell patients who had typical restriction fragment length polymorphism (RFLP)-defined haplotypes of the betaS-gene cluster. For 14 cases in which the expected and the observed LCR repeat-sequence sizes were discrepant, the analysis was extended to other unexplored polymorphic markers of the bS-globin gene cluster, i.e.: pre-Ggamma framework, pre-Ggamma 6-bp deletion, HS-2 LCR (AT)xR(AT)y and pre-beta(AT)xTy repeats, and the intragenic beta-globin gene framework. In all 14 cases (15 chromosomes) in which the LCR repeat-sequence sizes were discrepant, a recombination involving a typical 3' segment of the betaS globin gene cluster was demonstrated. In most of the cases, the recombination site was located between the beta-globin gene and the betaLCR. Nine cases involving recombination were detected among 156 Brazilian HbS homozygotes and five among 88 African patients homozygotes for the Benin haplotype. INTERPRETATION AND CONCLUSIONS. Thus, 3.1% of apparently typical haplotypes linked to the sickle cell gene involve recombinations similar to those that generate the atypical haplotypes, a finding that reinforces the picture of the beta-globin gene cluster as highly dynamic.

  14. RAVEN Beta Release

    International Nuclear Information System (INIS)

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-01-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  15. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  16. 2014 MARFIN trap-video-diver comparison

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objective of the study was to perform paired diver, trap and video-based surveys to assess species-specific reef fish abundance, and to compare gear-specific...

  17. Methods in mooring deep sea sediment traps

    Digital Repository Service at National Institute of Oceanography (India)

    Venkatesan, R.; Fernando, V.; Rajaraman, V.S.; Janakiraman, G.

    The experience gained during the process of deployment and retrieval of nearly 39 sets of deep sea sediment trap moorings on various ships like FS Sonne, ORV Sagarkanya and DSV Nand Rachit are outlined. The various problems encountered...

  18. Development of an antihydrogen trapping apparatus

    CERN Document Server

    Jenkins, Matthew James

    This thesis details the development and commissioning of the ALPHA antihydrogen trapping apparatus. It discusses the history of antimatter physics that led to and enabled the design of the apparatus. It discusses the importance of antihydrogen trapping in testing one of the basic assumptions of the Standard Model of particle physics (that of CPT invariance). It goes on to discuss the design and construction of the apparatus. Finally, it presents results that demonstrate antihydrogen formation in the new magnetic field configurations that together constitute a magnetic minimum trap for neutral antihydrogen. This is an important preliminary result for any antihydrogen trapping apparatus, and confirms that the ALPHA apparatus does present a potential route towards laser spectroscopy of antihydrogen.

  19. Management of insect pests using semiochemical traps

    DEFF Research Database (Denmark)

    Baroffio, C. A.; Guibert, V.; Richoz, P.

    2016-01-01

    In the absence of effective control measures, the strawberry blossom weevil (Anthonomus rubi) (SBW) and the raspberry beetle (Byturus tomentosus) (RB) cause large (10 - >80%) losses in yield and quality in organically grown raspberry. Attractive lures for both pests were combined into a single....... The aim is to develop optimized lures and cost-effective trap designs for mass trapping and to determine the optimum density and spatial and temporal patterns of deployment of the traps for controlling these pests by mass trapping. The combination between an aggregation pheromone that attracts Anthonomus...... multitrap for the economical management of both of these pests at the same time. This is one of the first approaches to pest management of non-lepidopteran insect pests of horticultural crops using semiochemicals in the EU, and probably the first to target multiple species from different insect orders...

  20. Curious behavior of optically trapped neutral atoms

    International Nuclear Information System (INIS)

    Wieman, C.; Walker, T.; Sesko, D.; Monroe, C.

    1991-01-01

    We have studied the behavior of clouds of neutral atoms contained in a spontaneous force optical trap. Because of the low temperatures of the atoms ( 5 atoms. These include the expansion of the cloud as the number is increased and dramatic changes in the distribution of the atoms at higher numbers. We can explain much of the collective behavior using a simple model that includes a 1/r 2 force between the atoms arising from the multiple scattering of photons. Finally, we discuss the optical trapping of atoms directly from a low pressure vapor in a small glass cell. We have used these optically trapped atoms to load a magnetostatic trap in the same cell. This provided a high density sample of atoms with a temperature of less than 2 μK

  1. AEgIS antihydrogen production trap

    CERN Multimedia

    Caraban Gonzalez, Noemi

    2017-01-01

    During technical stop 2017 the AEgIS experiment was open for upgrades and maintenance. We had the opportunity to take some 360 images from inside and see where antiprotons are ¨trapped¨ and anti-Hydrogen produced.

  2. Laser cool and trap trace noble atoms

    Science.gov (United States)

    Wang, Mingdong; Hong, Yanji; Feng, Gaoping

    2016-01-01

    Laser can be used to cool and manipulate neutron atoms via momentum exchange between photons and atoms. Laser cooling and trapping is well established on alkali, alkali earth, and noble gas elements. Noble gases, with stable physical and chemical properties, no reactions with other elements, have great potential uses in cold collision, spectroscopy measurement, photo-association, atom optics, etc. However, trapping noble gas atoms is generally more difficult because of the lack of suitable UV lasers. Some of these problems will be overcome with future advances in UV laser technology. Excited by electron collisions, noble gas can reach the long life metastable state for the use of laser decelerating, focusing and trapping. In this paper some main methods which are used to achieve cooling and trapping metastable noble gas atoms are discussed.

  3. Sodium hydride precipitation in sodium cold traps

    International Nuclear Information System (INIS)

    McPheeters, C.C.; Raue, D.J.

    1980-06-01

    A series of experiments have been performed to test a calculational model for precipitation of NaH in sodium cold traps. The calculational model, called ACTMODEL, is a computer simulation that uses the system geometry and operating conditions as input to calculate a mass-transfer coefficient and the distribution of NaH in a cold trap. The ACTMODEL was tested using an analytical cold trap (ACT) that is simple and essentially one-dimensional. The ACT flow and temperature profile can be controlled at any desired condition. The ACT was analyzed destructively after each test to measure the actual NaH distribution. Excellent agreement was obtained between the ACTMODEL simulations and the experiments. Mass-transfer coefficients ranging upward from 6 x 10 -5 m/s were measured in both packless and packed traps. As much as a fourfold increase in precipitation surface area was observed with increasing amount of NaH deposited. 11 figures, 2 tables

  4. Separation of effects of oxide-trapped charge and interface-trapped charge on mobility in irradiated power MOSFETs

    International Nuclear Information System (INIS)

    Zupac, D.; Galloway, K.F.; Khosropour, P.; Anderson, S.R.; Schrimpf, R.D.

    1993-01-01

    An effective approach to separating the effects of oxide-trapped charge and interface-trapped charge on mobility degradation in irradiated MOSFETs is demonstrated. It is based on analyzing mobility data sets which have different functional relationships between the radiation-induced-oxide-trapped charge and interface-trapped charge. Separation of effects of oxide-trapped charge and interface-trapped charge is possible only if these two trapped charge components are not linearly dependent. A significant contribution of oxide-trapped charge to mobility degradation is demonstrated and quantified

  5. New results on structure of low beta confinement Polywell cusps simulated by comsol multiphysics

    Directory of Open Access Journals (Sweden)

    B. Mahdavipour

    Full Text Available The Inertial electrostatic confinement (IEC is one of the ways for fusion approaches. It is one of the various methods which can be used to confine hot fusion plasma. The advantage of IEC is that the IEC experiments could be done in smaller size facilities than ITER or NIF, costing less money and moving forward faster. In IEC fusion, we need to trap adequate electrons to confine the desired ion density which is needed for a fusion reactor. Polywell is a device which uses the magnetic cusp system and traps the required amount of electrons for fusion reactions. The purpose of this device is to create a virtual cathode in order to achieve nuclear fusion using inertial electrostatic confinement (Miley and Krupakar Murali, 2014. In this paper, we have simulated the low beta Polywell. Then, we examined the effects of coil spacing, coils current, electron injection energy on confinement time. Keywords: Low beta confinement, Polywell, IEC, Comsol multiphysics

  6. Mechanical trapping of particles in granular media

    Science.gov (United States)

    Kerimov, Abdulla; Mavko, Gary; Mukerji, Tapan; Al Ibrahim, Mustafa A.

    2018-02-01

    Mechanical trapping of fine particles in the pores of granular materials is an essential mechanism in a wide variety of natural and industrial filtration processes. The progress of invading particles is primarily limited by the network of pore throats and connected pathways encountered by the particles during their motion through the porous medium. Trapping of invading particles is limited to a depth defined by the size, shape, and distribution of the invading particles with respect to the size, shape, and distribution of the host porous matrix. Therefore, the trapping process, in principle, can be used to obtain information about geometrical properties, such as pore throat and particle size, of the underlying host matrix. A numerical framework is developed to simulate the mechanical trapping of fine particles in porous granular media with prescribed host particle size, shape, and distribution. The trapping of invading particles is systematically modeled in host packings with different host particle distributions: monodisperse, bidisperse, and polydisperse distributions of host particle sizes. Our simulation results show quantitatively and qualitatively to what extent trapping behavior is different in the generated monodisperse, bidisperse, and polydisperse packings of spherical particles. Depending on host particle size and distribution, the information about extreme estimates of minimal pore throat sizes of the connected pathways in the underlying host matrix can be inferred from trapping features, such as the fraction of trapped particles as a function of invading particle size. The presence of connected pathways with minimum and maximum of minimal pore throat diameters can be directly obtained from trapping features. This limited information about the extreme estimates of pore throat sizes of the connected pathways in the host granular media inferred from our numerical simulations is consistent with simple geometrical estimates of extreme value of pore and

  7. Hydrophobic Nanosized All-Silica Beta Zeolite: Efficient Synthesis and Adsorption Application.

    Science.gov (United States)

    Zhu, Zhiguo; Xu, Hao; Jiang, Jingang; Wu, Haihong; Wu, Peng

    2017-08-16

    All-silica beta zeolite, synthesized by conventional hydroxide route, usually possesses small crystal size of a few hundred nanometers but poor hydrophobicity, whereas the fluoride-mediated one exhibits to be highly hydrophobic but microsized. To obtain nanosized all-silica beta zeolite with excellent hydrophobicity, an innovative and efficient hydrothermal route via interzeolite transformation for synthesizing all-silica beta zeolite is proposed in present study. With the assistance of beta seeds and tetraethylammonium hydroxide as the structure-directing agent, siliceous beta zeolite is well-crystallized at a high solid yield via dissolution-recrystallization of all-silica ITQ-1 crystals at an extremely low water content (H 2 O/SiO 2 molar ratio of 1). The obtained all-silica beta crystals are composed of 30-70 nm nanoparticles and highly hydrophobic just next to siliceous beta-F zeolite synthesized by environmentally unfriendly fluoride route, which is derived from relatively small amounts of internal defect sites. Thus, this beta zeolite is superior to other pure silica beta zeolites in the adsorption of large-sized volatile organic compounds (VOCs), which is mainly attributed to its high total pore volume and specific surface area as well as excellent hydrophobicity.

  8. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  9. On biodiversity conservation and poverty traps

    Science.gov (United States)

    Barrett, Christopher B.; Travis, Alexander J.; Dasgupta, Partha

    2011-01-01

    This paper introduces a special feature on biodiversity conservation and poverty traps. We define and explain the core concepts and then identify four distinct classes of mechanisms that define important interlinkages between biodiversity and poverty. The multiplicity of candidate mechanisms underscores a major challenge in designing policy appropriate across settings. This framework is then used to introduce the ensuing set of papers, which empirically explore these various mechanisms linking poverty traps and biodiversity conservation. PMID:21873176

  10. Optical trapping with femtosecond laser pulses

    Science.gov (United States)

    Devi, Anita; Dhamija, Shaina; De, Arijit K.

    2017-08-01

    Laser trapping of 100nm diameter polystyrene bead under high repetition rate ultrafast pulsed excitation is studied theoretically as well as experimentally. In our theoretical analysis, we explore the role of optical Kerr effect at 50mW average power under pulsed excitation. In our experiment, we use a CMOS camera to record two-photon fluorescence signal from the trapped particle which decays with time due to photo-bleaching.

  11. High Atom Number in Microsized Atom Traps

    Science.gov (United States)

    2015-12-14

    Final Performance Report on ONR Grant N00014-12-1-0608 High atom number in microsized atom traps for the period 15 May 2012 through 14 September...TYPE Final Technical Report 3. DATES COVERED (From - To) 05/15/2012-09/14/2012 4. TITLE AND SUBTITLE High atom number in microsized atom traps...forces for implementing a small-footprint, large-number atom -chip instrument. Bichromatic forces rely on absorption and stimulated emission to produce

  12. Argon gas atoms trapping by carbon dendrites

    Science.gov (United States)

    Danilaev, M. P.; Bogoslov, E. A.; Polskii, Y. E.

    2017-11-01

    The conditions of argon gas atoms trapping by carbon dendrites, which growing in atmospheric pressure gas-discharge plasma, are considered in that paper. It’s showing that the argons atoms trapping by the carbon diamond-like cell can occur in arc gas discharge with current density more than j 0 ∼ 45 mA/sm2 and provided that the eximer molecules of noble gas and carbon atoms (e.g., ArC) can be formed.

  13. Bulk oxide traps and border traps in metal endash oxide endash semiconductor capacitors

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Winokur, P.S.; Riewe, L.C.; Reber, R.A. Jr.

    1998-01-01

    Thermally stimulated current (TSC) and capacitance endash voltage measurements are combined via a newly developed analysis technique to estimate positive and negative oxide-trap charge densities for metal endash oxide endash semiconductor (MOS) capacitors exposed to ionizing radiation or subjected to high-field stress. Significantly greater hole trapping than electron trapping is observed in 3% borosilicate glass (BSG) insulators. Two prominent TSC peaks are observed in these BSG films. A high-temperature peak near 250 degree C is attributed to the E γ ' defect, which is a trivalent Si center in SiO 2 associated with an O vacancy. A lower temperature positive charge center near 100 degree C in these films is likely to be impurity related. The higher temperature E γ ' peak is also observed in 10, 17, and 98 nm thermal oxides. A much weaker secondary peak is observed near ∼60 degree C in some devices, which likely is due to metastably trapped holes in the bulk of the SiO 2 . Negative charge densities in these thermal oxides are primarily associated with electrons in border traps, which do not contribute to TSC, as opposed to bulk electron traps, which can contribute to TSC. Ratios of electron to hole trap densities in the thermal oxides range from ∼30% for radiation exposure to greater than 80% for high-field stress. It is suggested that the large densities of border traps associated with trapped holes in these devices may be due to high space-charge induced electric fields near the Si/SiO 2 interface. In some instances, border traps can reduce near-interfacial electric fields by local compensation of trapped positive charge. This may provide a natural explanation for the large densities of border traps often observed in irradiated or electrically stressed MOS capacitors. copyright 1998 American Institute of Physics

  14. Spectroscopy with trapped highly charged ions

    International Nuclear Information System (INIS)

    Beiersdorfer, Peter

    2009-01-01

    We give an overview of atomic spectroscopy performed on electron beam ion traps at various locations throughout the world. Spectroscopy at these facilities contributes to various areas of science and engineering, including but not limited to basic atomic physics, astrophysics, extreme ultraviolet lithography, and the development of density and temperature diagnostics of fusion plasmas. These contributions are accomplished by generating, for example, spectral surveys, making precise radiative lifetime measurements, accounting for radiative power emitted in a given wavelength band, illucidating isotopic effects, and testing collisional-radiative models. While spectroscopy with electron beam ion traps had originally focused on the x-ray emission from highly charged ions interacting with the electron beam, the operating modes of such devices have expanded to study radiation in almost all wavelength bands from the visible to the hard x-ray region; and at several facilities the ions can be studied even in the absence of an electron beam. Photon emission after charge exchange or laser excitation has been observed; and the work is no longer restricted to highly charged ions. Much of the experimental capabilities are unique to electron beam ion traps, and the work performed with these devices cannot be undertaken elsewhere. However, in other areas the work on electron beam ion traps rivals the spectroscopy performed with conventional ion traps or heavy-ion storage rings. The examples we present highlight many of the capabilities of the existing electron beam ion traps and their contributions to physics.

  15. The Electronic McPhail Trap

    Science.gov (United States)

    Potamitis, Ilyas; Rigakis, Iraklis; Fysarakis, Konstantinos

    2014-01-01

    Certain insects affect cultivations in a detrimental way. A notable case is the olive fruit fly (Bactrocera oleae (Rossi)), that in Europe alone causes billions of euros in crop-loss/per year. Pests can be controlled with aerial and ground bait pesticide sprays, the efficiency of which depends on knowing the time and location of insect infestations as early as possible. The inspection of traps is currently carried out manually. Automatic monitoring traps can enhance efficient monitoring of flying pests by identifying and counting targeted pests as they enter the trap. This work deals with the hardware setup of an insect trap with an embedded optoelectronic sensor that automatically records insects as they fly in the trap. The sensor responsible for detecting the insect is an array of phototransistors receiving light from an infrared LED. The wing-beat recording is based on the interruption of the emitted light due to the partial occlusion from insect's wings as they fly in the trap. We show that the recordings are of high quality paving the way for automatic recognition and transmission of insect detections from the field to a smartphone. This work emphasizes the hardware implementation of the sensor and the detection/counting module giving all necessary implementation details needed to construct it. PMID:25429412

  16. The Electronic McPhail Trap

    Directory of Open Access Journals (Sweden)

    Ilyas Potamitis

    2014-11-01

    Full Text Available Certain insects affect cultivations in a detrimental way. A notable case is the olive fruit fly (Bactrocera oleae (Rossi, that in Europe alone causes billions of euros in crop-loss/per year. Pests can be controlled with aerial and ground bait pesticide sprays, the efficiency of which depends on knowing the time and location of insect infestations as early as possible. The inspection of traps is currently carried out manually. Automatic monitoring traps can enhance efficient monitoring of flying pests by identifying and counting targeted pests as they enter the trap. This work deals with the hardware setup of an insect trap with an embedded optoelectronic sensor that automatically records insects as they fly in the trap. The sensor responsible for detecting the insect is an array of phototransistors receiving light from an infrared LED. The wing-beat recording is based on the interruption of the emitted light due to the partial occlusion from insect’s wings as they fly in the trap. We show that the recordings are of high quality paving the way for automatic recognition and transmission of insect detections from the field to a smartphone. This work emphasizes the hardware implementation of the sensor and the detection/counting module giving all necessary implementation details needed to construct it.

  17. Highly charged ions trapping for lifetime measurements

    International Nuclear Information System (INIS)

    Attia, D.

    2007-10-01

    A new experimental setup dedicated to highly charged ion trapping is presented in this work. The final goal is to perform lifetime measurement of metastable states produced by our ECR (Electron Cyclotron Resonance) ion source. Lifetimes to be measured are in the range of a few ms and more. We have measured the lifetimes of the M1 transitions of the metastable states of Ar 9+ , Ar 13+ and Ar 14+ . These measurements are useful to test the N-body problem in the relativistic range. The trap we have built, was designed a few years ago at the Weizman Institute in Israel, it allows ions with an energy of several keV to be trapped for lifetimes of about 1 second. This trap was originally designed to study the dynamics of excited molecules. We have shown for the first time how the trap operates and that it can operate with highly charged ions. We have studied the beam dynamics of highly charged ions and the trap has been tested with various species of ions and different charge states: from O + to O 6+ , from Ar 8+ to Ar 13+ , and from Kr 13+ to Kr 20+

  18. The Use of Camera Traps in Wildlife

    Directory of Open Access Journals (Sweden)

    Yasin Uçarlı

    2013-11-01

    Full Text Available Camera traps are increasingly used in the abundance and density estimates of wildlife species. Camera traps are very good alternative for direct observation in case, particularly, steep terrain, dense vegetation covered areas or nocturnal species. The main reason for the use of camera traps is eliminated that the economic, personnel and time loss in a continuous manner at the same time in different points. Camera traps, motion and heat sensitive, can take a photo or video according to the models. Crossover points and feeding or mating areas of the focal species are addressed as a priority camera trap set locations. The population size can be finding out by the images combined with Capture-Recapture methods. The population density came out the population size divided to effective sampling area size. Mating and breeding season, habitat choice, group structures and survival rates of the focal species can be achieved from the images. Camera traps are very useful to obtain the necessary data about the particularly mysterious species with economically in planning and conservation efforts.

  19. Achieving Translationally Invariant Trapped Ion Rings

    Science.gov (United States)

    Urban, Erik; Li, Hao-Kun; Noel, Crystal; Hemmerling, Boerge; Zhang, Xiang; Haeffner, Hartmut

    2017-04-01

    We present the design and implementation of a novel surface ion trap design in a ring configuration. By eliminating the need for wire bonds through the use of electrical vias and using a rotationally invariant electrode configuration, we have realized a trap that is able to trap up to 20 ions in a ring geometry 45um in diameter, 400um above the trap surface. This large trapping height to ring diameter ratio allows for global addressing of the ring with both lasers and electric fields in the chamber, thereby increasing our ability to control the ring as a whole. Applying compensating electric fields, we measure very low tangential trap frequencies (less than 20kHz) corresponding to rotational barriers down to 4mK. This measurement is currently limited by the temperature of the ions but extrapolation indicates the barrier can be reduced much further with more advanced cooling techniques. Finally, we show that we are able to reduce this energy barrier sufficiently such that the ions are able to overcome it either through thermal motion or rotational motion and delocalize over the full extent of the ring. This work was funded by the Keck Foundation and the NSF.

  20. Effectiveness of different trap design in mass trapping of Bothynoderes punctiventris Germar

    Directory of Open Access Journals (Sweden)

    Sivčev Ivan L.

    2006-01-01

    Full Text Available The discovery of an aggregation attractant for Bothynoderes punctiventris Germ. raised several questions for possible improvements of IPM of Bothynoderes punctiventris in sugar beet. First results on exploration of possibilities for its use for monitoring purposes as well as for mass trapping of adults of the pest are described in this paper. Trap design effectiveness was evaluated in the overwintering fields of sugar beet weevil for two years in localities in Serbia and Hungary. Among trap designs tested it was proved that baited CSALOMON® TAL trap design was optimal.

  1. Two betas or not two betas: regulation of asymmetric division by beta-catenin.

    Science.gov (United States)

    Mizumoto, Kota; Sawa, Hitoshi

    2007-10-01

    In various organisms, cells divide asymmetrically to produce distinct daughter cells. In the nematode Caenorhabditis elegans, asymmetric division is controlled by the asymmetric activity of a Wnt signaling pathway (the Wnt/beta-catenin asymmetry pathway). In this process, two specialized beta-catenin homologs have crucial roles in the transmission of Wnt signals to the asymmetric activity of a T-cell factor (TCF)-type transcription factor, POP-1, in the daughter cells. One beta-catenin homolog regulates the distinct nuclear level of POP-1, and the other functions as a coactivator of POP-1. Both beta-catenins localize asymmetrically in the daughter nuclei using different mechanisms. The recent discovery of reiterative nuclear asymmetries of a highly conserved beta-catenin in an annelid suggests that similar molecular mechanisms might regulate asymmetric cell divisions in other organisms.

  2. BETA (Bitter Electromagnet Testing Apparatus)

    Science.gov (United States)

    Bates, Evan M.; Birmingham, William J.; Rivera, William F.; Romero-Talamas, Carlos A.

    2017-10-01

    The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) prototype of the 10-T Adjustable Long Pulse High-Field Apparatus (ALPHA). These water-cooled resistive magnets use high DC currents to produce strong uniform magnetic fields. Presented here is the successful completion of the BETA project and experimental results validating analytical magnet designing methods developed at the Dusty Plasma Laboratory (DPL). BETA's final design specifications will be highlighted which include electromagnetic, thermal and stress analyses. The magnet core design will be explained which include: Bitter Arcs, helix starters, and clamping annuli. The final version of the magnet's vessel and cooling system are also presented, as well as the electrical system of BETA, which is composed of a unique solid-state breaker circuit. Experimental results presented will show the operation of BETA at 1 T. The results are compared to both analytical design methods and finite element analysis calculations. We also explore the steady state maximums and theoretical limits of BETA's design. The completion of BETA validates the design and manufacturing techniques that will be used in the succeeding magnet, ALPHA.

  3. Neutrophil beta-2 microglobulin: an inflammatory mediator

    DEFF Research Database (Denmark)

    Bjerrum, O W; Nissen, Mogens Holst; Borregaard, N

    1990-01-01

    Beta-2 microglobulin (beta 2m) constitutes the light invariant chain of HLA class I antigen, and is a constituent of mobilizable compartments of neutrophils. Two forms of beta 2m exist: native beta 2m and proteolytically modified beta 2m (Des-Lys58-beta 2m), which shows alpha mobility in crossed...... radioimmuno-electrophoresis. The modification of native beta 2m can be executed by membrane-associated activity of mononuclear cells, and Des-Lys58-beta 2m augments the production of interleukin 2. In this study we present evidence that human neutrophils contain native beta 2m in specific granules, secretory...... vesicles, and plasma membrane. Beta 2m was released in the native form from neutrophils in response to stimulation with chemotactic stimuli and phorbol ester. The results of experiments designed to study the modification of native beta 2m by neutrophils indicated that neutrophils do not participate...

  4. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J. [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  5. Variants of beta-glucosidases

    Science.gov (United States)

    Fidantsef, Ana; Lamsa, Michael; Gorre-Clancy, Brian

    2014-10-07

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  6. Variants of beta-glucosidase

    Science.gov (United States)

    Fidantsef, Ana [Davis, CA; Lamsa, Michael [Davis, CA; Gorre-Clancy, Brian [Elk Grove, CA

    2009-12-29

    The present invention relates to variants of a parent beta-glucosidase, comprising a substitution at one or more positions corresponding to positions 142, 183, 266, and 703 of amino acids 1 to 842 of SEQ ID NO: 2 or corresponding to positions 142, 183, 266, and 705 of amino acids 1 to 844 of SEQ ID NO: 70, wherein the variant has beta-glucosidase activity. The present invention also relates to nucleotide sequences encoding the variant beta-glucosidases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  7. 21 CFR 868.5995 - Tee drain (water trap).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

  8. Description of the IMR Standard Light Trap and the Vertical ...

    African Journals Online (AJOL)

    The construction of different versions of a cheap, robust, and easy to operate light trap for catching various aquatic organisms is shown. The trap can be used to > 300 m depth and meets a number of criteria. Small-scale vertical distribution of decapod larvae was investigated during trap trials. The traps (6-10) were set for 24 ...

  9. Bait preference in basket trap fishing operation and heavy metal ...

    African Journals Online (AJOL)

    The bait preference of basket traps fishing operation and heavy metal contamination in the trap catches from Lagos Lagoon were carried out between January and June 2011. Sixty baskets traps were used for the fishing operation, twenty basket traps were baited each with soap, coconut and maize. Clibanarius africanus ...

  10. Studies on cold atoms trapped in a Quasi-Electrostatic optical dipole trap

    International Nuclear Information System (INIS)

    Roy, Sanjukta; Chaudhuri, Saptarishi; Unnikrishnan, C S

    2007-01-01

    We discuss the results of measurements of the temperature and density distribution of cold Rubidium atoms trapped and cooled in an optical dipole trap formed by focussed CO 2 laser beams at a wavelength of 10.6 μm from a cold, collimated and intense atomic beam of flux 2 x 10 10 atoms/s produced using an elongated 2D + MOT. A large number of rubidium atoms (≥ 10 10 ) were trapped in the MOT and the number density of atoms were further increased by making a temporal dark MOT to prevent density-limiting processes like photon rescattering by atoms at the trap centre. Subsequently, between 10 7 to 10 8 cold atoms at a temperature below 30 μK were transferred into a Quasi-Electrostatic trap (QUEST) formed by focussed CO 2 laser beams at the MOT centre. Both single beam and crossed dual beam dipole traps were studied with a total output power of 50 W from the CO 2 laser with focal spot sizes less than 100 microns. Various measurements were done on the cold atoms trapped in the dipole trap. The total atom number in the dipole trap and the spatial atom number density distribution in the trap was measured by absorption imaging technique. The temperature was determined from time-of-flight (TOF) data as well as from the absorption images after ballistic expansion of the atom cloud released from the dipole trap. The results from measurements are used to maximize the initial phase-space density prior to forced evaporative cooling to produce a Bose-Einstein Condensate

  11. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  12. Precision Tests of the Electroweak Interaction using Trapped Atoms and Ions

    Energy Technology Data Exchange (ETDEWEB)

    Melconian, Daniel George [Texas A & M Univ., College Station, TX (United States)

    2017-06-21

    The objective of the proposed research is to study fundamental aspects of the electroweak interaction via precision measurements in beta decay to test our current understanding of fundamental particles and forces as contained in the so-called "Standard Model" of particle physics. By comparing elegant experiments to rigorous theoretical predictions, we will either confirm the Standard Model to a higher degree and rule out models which seek to extend it, or find evidence of new physics and help guide theorists in developing the New Standard Model. The use of ion and neutral atom traps at radioactive ion beam facilities has opened up a new vista in precision low-energy nuclear physics experiments. Traps provide an ideal source of decaying atoms: they can be extremely cold (~1 mK); they are compact (~1 mm^3); and perhaps most importantly, the daughter particles escape with negligible distortions to their momenta in a scattering-free, open environment. The project is taking advantage of these technologies and applying them to precision beta-decay studies at radioactive beam facilities. The program consists of two complementary efforts: 1) Ion traps are an extremely versatile tool for purifying, cooling and bunching low-energy beams of short-lived nuclei. A large-bore (210~mm) superconducting 7-Tesla solenoid is at the heart of a Penning trap system for which there is a dedicated beamline at T-REX, the upgraded radioactive beam facility at the Cyclotron Institute, Texas A&M University. In addition to providing a general-purpose decay station, the flagship program for this system is measuring the ft-values and beta-neutrino correlation parameters from isospin T=2 superallowed beta-delayed proton decays, complimenting and expanding the already strong program in fundamental interactions at the Institute. 2) A magneto-optical trap is being used at the TRIUMF Neutral Atom Trap facility to observe the (un)polarized angular distribution parameters of isotopes of potassium. We

  13. Experimental apparatus to test air trap valves

    Energy Technology Data Exchange (ETDEWEB)

    Lemos De Lucca, Y de F [CTH-DAEE-USP/FAAP/UNICAMP (Brazil); Aquino, G A de [SABESP/UNICAMP (Brazil); Filho, J G D, E-mail: yvone.lucca@gmail.co [Water Resources Department, University of Campinas-UNICAMP, Av. Albert Einstein, 951, Cidade Universitaria-Barao Geraldo-Campinas, S.P., 13083-852 (Brazil)

    2010-08-15

    It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the water hammer phenomenon, the instability and the loss of pressure in the water distribution networks. As a result, it can overload the pumps, increase the consumption of electricity, and damage the pumping system. In order to avoid its formation, all of the trapped air should be removed through 'air trap valves'. In Brazil, manufacturers frequently have unreliable sizing charts, which cause malfunctioning of the 'air trap valves'. The result of these malfunctions causes accidents of substantial damage. The construction of a test facility will provide a foundation of technical information that will be used to help make decisions when designing a system of pipelines where 'air trap valves' are used. To achieve this, all of the valve characteristics (geometric, mechanic, hydraulic and dynamic) should be determined. This paper aims to describe and analyze the experimental apparatus and test procedure to be used to test 'air trap valves'. The experimental apparatus and test facility will be located at the University of Campinas, Brazil at the College of Civil Engineering, Architecture, and Urbanism in the Hydraulics and Fluid Mechanics laboratory. The experimental apparatus will be comprised of various components (pumps, steel pipes, butterfly valves to control the discharge, flow meter and reservoirs) and instrumentation (pressure transducers, anemometer and proximity sensor). It should be emphasized that all theoretical and experimental procedures should be defined while taking into consideration flow parameters and fluid properties that influence the tests.

  14. Flux trapping and shielding in irreversible superconductors

    International Nuclear Information System (INIS)

    Frankel, D.J.

    1978-05-01

    Flux trappings and shielding experiments were carried out on Pb, Nb, Pb-Bi, Nb-Sn, and Nb-Ti samples of various shapes. Movable Hall probes were used to measure fields near or inside the samples as a function of position and of applied field. The trapping of transverse multipole magnetic fields in tubular samples was accomplished by cooling the samples in an applied field and then smoothly reducing the applied field to zero. Transverse quadrupole and sextupole fields with gradients of over 2000 G/cm were trapped with typical fidelity to the original impressed field of a few percent. Transverse dipole fields of up to 17 kG were also trapped with similar fidelity. Shielding experiments were carried out by cooling the samples in zero field and then gradually applying an external field. Flux trapping and shielding abilities were found to be limited by two factors, the pinning strength of the material, and the susceptibility of a sample to flux jumping. The trapping and shielding behavior of flat disk samples in axial fields and thin-walled tubular samples in transverse fields was modeled. The models, which were based on the concept of the critical state, allowed a connection to be made between the pinning strength and critical current level, and the flux trapping and shielding abilities. Adiabatic and dynamic stability theories are discussed and applied to the materials tested. Good qualitative, but limited quantitative agreement was obtained between the predictions of the theoretical stability criteria and the observed flux jumping behavior

  15. Optimising camera traps for monitoring small mammals.

    Directory of Open Access Journals (Sweden)

    Alistair S Glen

    Full Text Available Practical techniques are required to monitor invasive animals, which are often cryptic and occur at low density. Camera traps have potential for this purpose, but may have problems detecting and identifying small species. A further challenge is how to standardise the size of each camera's field of view so capture rates are comparable between different places and times. We investigated the optimal specifications for a low-cost camera trap for small mammals. The factors tested were 1 trigger speed, 2 passive infrared vs. microwave sensor, 3 white vs. infrared flash, and 4 still photographs vs. video. We also tested a new approach to standardise each camera's field of view. We compared the success rates of four camera trap designs in detecting and taking recognisable photographs of captive stoats (Mustelaerminea, feral cats (Felis catus and hedgehogs (Erinaceuseuropaeus. Trigger speeds of 0.2-2.1 s captured photographs of all three target species unless the animal was running at high speed. The camera with a microwave sensor was prone to false triggers, and often failed to trigger when an animal moved in front of it. A white flash produced photographs that were more readily identified to species than those obtained under infrared light. However, a white flash may be more likely to frighten target animals, potentially affecting detection probabilities. Video footage achieved similar success rates to still cameras but required more processing time and computer memory. Placing two camera traps side by side achieved a higher success rate than using a single camera. Camera traps show considerable promise for monitoring invasive mammal control operations. Further research should address how best to standardise the size of each camera's field of view, maximise the probability that an animal encountering a camera trap will be detected, and eliminate visible or audible cues emitted by camera traps.

  16. Optimising camera traps for monitoring small mammals.

    Science.gov (United States)

    Glen, Alistair S; Cockburn, Stuart; Nichols, Margaret; Ekanayake, Jagath; Warburton, Bruce

    2013-01-01

    Practical techniques are required to monitor invasive animals, which are often cryptic and occur at low density. Camera traps have potential for this purpose, but may have problems detecting and identifying small species. A further challenge is how to standardise the size of each camera's field of view so capture rates are comparable between different places and times. We investigated the optimal specifications for a low-cost camera trap for small mammals. The factors tested were 1) trigger speed, 2) passive infrared vs. microwave sensor, 3) white vs. infrared flash, and 4) still photographs vs. video. We also tested a new approach to standardise each camera's field of view. We compared the success rates of four camera trap designs in detecting and taking recognisable photographs of captive stoats (Mustelaerminea), feral cats (Felis catus) and hedgehogs (Erinaceuseuropaeus). Trigger speeds of 0.2-2.1 s captured photographs of all three target species unless the animal was running at high speed. The camera with a microwave sensor was prone to false triggers, and often failed to trigger when an animal moved in front of it. A white flash produced photographs that were more readily identified to species than those obtained under infrared light. However, a white flash may be more likely to frighten target animals, potentially affecting detection probabilities. Video footage achieved similar success rates to still cameras but required more processing time and computer memory. Placing two camera traps side by side achieved a higher success rate than using a single camera. Camera traps show considerable promise for monitoring invasive mammal control operations. Further research should address how best to standardise the size of each camera's field of view, maximise the probability that an animal encountering a camera trap will be detected, and eliminate visible or audible cues emitted by camera traps.

  17. [Study on TGF beta 1, TGF beta 2, TGF beta 3 expression in the chick basilar papilla following gentamicin toxicity].

    Science.gov (United States)

    Li, H; Wang, J

    1998-10-01

    The beta-type transforming growth factors (TGF beta s) are secreted proteins, which play an important role in regulation of cell proliferation and differentiation in the embryonic inner ear. In order to probe into the effect of TGF beta s on the hair cell regeneration, expression of TGF beta 1, TGF beta 2 and TGF beta 3 proteins were examined by using immunohistochemistry in the chicken basilar papilla during hair cell regeneration following gentamicin ototoxicity. Ten-day-old chickens received daily subcutaneous injection of gentamicin sulfate 50 mg/kg of ten consecutive days. The animals were allowed to survive 1,3,7,14,21 and 28 days before sacrifice and preparation for examination of the expression of TGF beta 1, TGF beta 2 and TGF beta 3 proteins. Immunostaining results demonstrated that TGF beta 2 and TGF beta 3 proteins were observed in the damaged region of basilar papilla. TGF beta 2 and TGF beta 3 proteins positive cells were limited to the lumenal nuclear layer within the damaged region. TGF beta 1 protein positive cell was not found in our study. These results indicated that TGF beta 2 and TGF beta 3 proteins might play a role in regulating proliferation of the supporting cells immigrated into the lumenal nuclear layer during hair cell regeneration.

  18. Subtype-selective modulation of human beta 1- and beta 2-adrenoceptor function by beta-adrenoceptor agonists and antagonists

    NARCIS (Netherlands)

    Brodde, O. E.; Daul, A.; Michel, M. C.

    1990-01-01

    In healthy volunteers a 14-day treatment with the selective beta 1-adrenoceptor agonist xamoterol (2 x 200 mg/day) desensitized beta 1-adrenoceptor-mediated physiological effects, but did not affect beta 2-adrenoceptor-mediated effects; in contrast, a 9-day treatment with the selective beta

  19. Selective regulation of beta 1- and beta 2-adrenoceptors in the human heart by chronic beta-adrenoceptor antagonist treatment

    NARCIS (Netherlands)

    Michel, M. C.; Pingsmann, A.; Beckeringh, J. J.; Zerkowski, H. R.; Doetsch, N.; Brodde, O. E.

    1988-01-01

    1. In 44 patients undergoing coronary artery bypass grafting, the effect of chronic administration of the beta-adrenoceptor antagonists sotalol, propranolol, pindolol, metoprolol and atenolol on beta-adrenoceptor density in right atria (containing 70% beta 1- and 30% beta 2-adrenoceptors) and in

  20. Optimization of multifunnel traps for emerald ash borer (Coleoptera: Buprestidae): influence of size, trap coating, and color.

    Science.gov (United States)

    Francese, Joseph A; Rietz, Michael L; Mastro, Victor C

    2013-12-01

    Field assays were conducted in southeastern and south-central Michigan in 2011 and 2012 to optimize green and purple multifunnel (Lindgren funnel) traps for use as a survey tool for the emerald ash borer, Agrilus planipennis Fairmaire. Larger sized (12- and 16-unit) multifunnel traps caught more beetles than their smaller-sized (4- and 8-unit) counterparts. Green traps coated with untinted (white) fluon caught almost four times as many adult A. planipennis as Rain-X and tinted (green) fluon-coated traps and almost 33 times more beetles than untreated control traps. Purple multifunnel traps generally caught much lower numbers of A. planipennis adults than green traps, and trap catch on them was not affected by differences in the type of coating applied. However, trap coating was necessary as untreated control purple traps caught significantly less beetles than traps treated with Rain-X and untinted or tinted (purple) fluon. Proportions of male beetles captured were generally much higher on green traps than on purple traps, but sex ratios were not affected by trap coating. In 2012, a new shade of purple plastic, based on a better color match to an attractive purple paint than the previously used purple, was used for trapping assays. When multifunnel traps were treated with fluon, green traps caught more A. planipennis adults than both shades of purple and a prism trap that was manufactured based on the same color match. Trap catch was not affected by diluting the fluon concentration applied to traps to 50% (1:1 mixture in water). At 10%, trap catch was significantly lowered.

  1. Spatial mismatch between sea lamprey behaviour and trap location explains low success at trapping for control

    Science.gov (United States)

    Rous, Andrew M.; McLean, Adrienne R.; Barber, Jessica; Bravener, Gale; Castro-Santos, Theodore; Holbrook, Christopher M.; Imre, Istvan; Pratt, Thomas C.; McLaughlin, Robert L.

    2017-01-01

    Crucial to the management of invasive species is understanding space use and the environmental features affecting space use. Improved understanding of space use by invasive sea lamprey (Petromyzon marinus) could help researchers discern why trap success in large rivers is lower than needed for effective control. We tested whether manipulating discharge nightly could increase trap success at a hydroelectric generating station on the St. Marys River. We quantified numbers of acoustically tagged sea lampreys migrating up to, and their space use at, the hydroelectric generating station. In 2011 and 2012, 78% and 68%, respectively, of tagged sea lampreys reached the generating station. Sea lampreys were active along the face, but more likely to occur at the bottom and away from the traps near the surface, especially when discharge was high. Our findings suggest that a low probability of encountering traps was due to spatial (vertical) mismatch between space use by sea lamprey and trap locations and that increasing discharge did not alter space use in ways that increased trap encounter. Understanding space use by invasive species can help managers assess the efficacy of trapping and ways of improving trapping success.

  2. Dispenser and trap design affect the effectiveness of sex pheromone on trap capture of dogwood borer

    Science.gov (United States)

    The capture of dogwood borer (DWB), Synanthedon scitula Harris (Lepidoptera: Sesiidae), was evaluated in field trapping studies using wing-style sticky traps baited with rubber septum or polyethylene vial dispensers containing the most effective sex pheromone ternary blend [86:6:6 v:v:v (Z,Z)-3,13-o...

  3. Controlling trapping potentials and stray electric fields in a microfabricated ion trap through design and compensation

    International Nuclear Information System (INIS)

    Charles Doret, S; Amini, Jason M; Wright, Kenneth; Volin, Curtis; Killian, Tyler; Ozakin, Arkadas; Denison, Douglas; Hayden, Harley; Pai, C-S; Slusher, Richart E; Harter, Alexa W

    2012-01-01

    Recent advances in quantum information processing with trapped ions have demonstrated the need for new ion trap architectures capable of holding and manipulating chains of many (>10) ions. Here we present the design and detailed characterization of a new linear trap, microfabricated with scalable complementary metal-oxide-semiconductor (CMOS) techniques, that is well-suited to this challenge. Forty-four individually controlled dc electrodes provide the many degrees of freedom required to construct anharmonic potential wells, shuttle ions, merge and split ion chains, precisely tune secular mode frequencies, and adjust the orientation of trap axes. Microfabricated capacitors on dc electrodes suppress radio-frequency pickup and excess micromotion, while a top-level ground layer simplifies modeling of electric fields and protects trap structures underneath. A localized aperture in the substrate provides access to the trapping region from an oven below, permitting deterministic loading of particular isotopic/elemental sequences via species-selective photoionization. The shapes of the aperture and radio-frequency electrodes are optimized to minimize perturbation of the trapping pseudopotential. Laboratory experiments verify simulated potentials and characterize trapping lifetimes, stray electric fields, and ion heating rates, while measurement and cancellation of spatially-varying stray electric fields permits the formation of nearly-equally spaced ion chains. (paper)

  4. Beta-glucans and cholesterol

    Czech Academy of Sciences Publication Activity Database

    Šíma, Petr; Vannucci, Luca; Větvička, V.

    2017-01-01

    Roč. 41, č. 4 (2017), s. 1799-1808 ISSN 1107-3756 Institutional support: RVO:61388971 Keywords : cholesterol * beta-glucans * diet Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.341, year: 2016

  5. Radioisotope indicator, type BETA 2

    International Nuclear Information System (INIS)

    Duszanski, M.; Pankow, A.; Skwarczynski, B.

    1975-01-01

    The authors describe a radioisotope indicator, type BETA 2, constructed in the ZKMPW Works to be employed in mines for counting, checking, signalling the presence and positioning of cars, as well as monitoring the state of some other equipment. (author)

  6. Beta-Testing Agreement | FNLCR

    Science.gov (United States)

    Beta-Testing Agreements are appropriate forlimited term evaluation and applications development of new software, technology, or equipment platforms by the Frederick National Laboratory in collaboration with an external commercial partner. It ma

  7. LHC $\\beta^*$ reach in 2012

    CERN Document Server

    Bruce, R

    2012-01-01

    The available aperture in the LHC imposes a lower limit on the achievable $\\beta^*$ . The aperture must be protected by the collimation system, and the collimator families have to be ordered in a strict hierarchy for optimal performance, with large enough margins so that the hierarchy is not violated by machine imperfections such as closed orbit distortions or $\\beta$-beating. The achievable $\\beta^*$ is thus a function of both the aperture and the collimator settings. An overview of the run in 2011 is presented, as well as a review of the necessary margins between collimator families and the aperture. Finally an outlook towards possible scenarios for $\\beta^*$ in 2012 and at higher energies is given.

  8. Beta-carotene blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003571.htm Beta-carotene blood test To use the sharing features on this page, ... skin is broken) Alternative Names Carotene test Images Blood test References Chernecky CC, Berger BJ. Carotene - serum. In: ...

  9. Trapping for invasive crayfish: comparisons of efficacy and selectivity of baited traps versus novel artificial refuge traps

    Directory of Open Access Journals (Sweden)

    Green Nicky

    2018-01-01

    Full Text Available Non-native crayfish can dominate the invertebrate biomass of invaded freshwaters, with their high ecological impacts resulting in their populations being controlled by numerous methods, especially trapping. Although baited funnel traps (BTs are commonly used, they tend to be selective in mainly catching large-bodied males. Here, the efficacy and selectivity of BTs were tested against an alternative trapping method based on artificial refuges (ARTs that comprised of a metal base with several tubes (refuges attached. The target species was signal crayfish Pacifastacus leniusculus in an upland river in southwest England. Trapping was completed in April to October over two consecutive years. In total, 5897 crayfish were captured, with 87% captured in ARTs. Comparison of the catch per unit effort (CPUE between the trapping methods in the same 24 hour periods revealed significantly higher CPUE in ARTs than of BTs. ARTs fished for 6 consecutive days had higher catches than both methods over 24 hours. Whilst catches in BTs were significantly dominated by males (1.49M:1F, the sex ratio of catches in ARTs was 0.99M:1F. The mean carapace length of crayfish was also significantly larger in BTs (43.2 ± 0.6 mm than in ARTs (33.6 ± 0.2 mm. Thus, ARTs had higher CPUE over 24 hour and 6 day periods versus BTs and also captured a greater proportion of smaller and female individuals. These results indicate that when trapping methods are deployed for managing invasions, the use of ARTs removes substantial numbers of crayfish of both sexes and of varying body sizes.

  10. Microfabricated Microwave-Integrated Surface Ion Trap

    Science.gov (United States)

    Revelle, Melissa C.; Blain, Matthew G.; Haltli, Raymond A.; Hollowell, Andrew E.; Nordquist, Christopher D.; Maunz, Peter

    2017-04-01

    Quantum information processing holds the key to solving computational problems that are intractable with classical computers. Trapped ions are a physical realization of a quantum information system in which qubits are encoded in hyperfine energy states. Coupling the qubit states to ion motion, as needed for two-qubit gates, is typically accomplished using Raman laser beams. Alternatively, this coupling can be achieved with strong microwave gradient fields. While microwave radiation is easier to control than a laser, it is challenging to precisely engineer the radiated microwave field. Taking advantage of Sandia's microfabrication techniques, we created a surface ion trap with integrated microwave electrodes with sub-wavelength dimensions. This multi-layered device permits co-location of the microwave antennae and the ion trap electrodes to create localized microwave gradient fields and necessary trapping fields. Here, we characterize the trap design and present simulated microwave performance with progress towards experimental results. This research was funded, in part, by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA).

  11. Exploring strategies for protein trapping in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Quinones-Coello, Ana T.; Petrella, Lisa N.; Ayers, Kathleen; Melillo, Anthony; Mazzalupo, Stacy; Hudson, Andrew M.; Wang, Shu; Castiblanco, Claudia; Buszczak, Michael; Hoskins, Roger A.; Cooley, Lynn

    2006-12-18

    The use of fluorescent protein tags has had a huge impact oncell biological studies in virtually every experimental system.Incorporation of coding sequence for fluorescent proteins such as greenfluorescent protein (GFP) into genes at their endogenous chromosomalposition is especially useful for generating GFP-fusion proteins thatprovide accurate cellular and subcellular expression data. We testedmodifications of a transposon-based protein trap screening procedure inDrosophila to optimize the rate of recovering useful protein traps andtheir analysis. Transposons carrying the GFP-coding sequence flanked bysplice acceptor and donor sequences were mobilized, and new insertionsthat resulted in production of GFP were captured using an automatedembryo sorter. Individual stocks were established, GFP expression wasanalyzed during oogenesis, and insertion sites were determined bysequencing genomic DNA flanking the insertions. The resulting collectionincludes lines with protein traps in which GFP was spliced into mRNAs andembedded within endogenous proteins or enhancer traps in which GFPexpression depended on splicing into transposon-derived RNA. We report atotal of 335 genes associated with protein or enhancer traps and aweb-accessible database for viewing molecular information and expressiondata for these genes.

  12. Progress Towards a Practical Multicell Positron Trap

    Science.gov (United States)

    Danielson, J. R.

    2013-10-01

    The physics and technology of positron confinement is central to a range of applications at the forefront of antimatter science. Progress in this area has been driven by the development of a suite of novel non-neutral plasma techniques whereby up to 4 ×109 positrons have now been trapped and stored. However the next generation of experiments will require orders of magnitude more positrons. This talk describes techniques to increase storage capacity to >=1012 using a novel multi-cell trap architecture. Plasmas will be stored in separate Penning-Malmberg traps (``cells'') arranged in parallel off the magnetic axis to maximize use of the magnetic field volume while minimizing the required confinement voltages. Experiments with electrons in a test structure will be described to explore the basic physics and technology of the multicell concept and to set the design of a 21-cell trap for 1012 positrons. Over 50% of a trapped plasma has been injected into an off-axis cell, and hour-long confinement of 2 ×108 particles has been achieved using rotating electric fields. Experiments are under way to identify the limits of the injection process and demonstrate confinement >1010 particles in a single off-axis cell using kilovolt confinement potentials. In collaboration with N. C. Hurst, C. J. Baker, and C. M. Surko. This work is supported by U.S. DTRA and the U.S. DOE/NSF plasma partnership.

  13. Optimal optical trap for bacterial viability

    Science.gov (United States)

    Mirsaidov, Utkur; Timp, Winston; Timp, Kaethe; Mir, Mustafa; Matsudaira, Paul; Timp, Gregory

    2008-08-01

    Optical trapping is a powerful tool for the micromanipulation of living cells—especially bacteria—but photodamage induced by the laser beam can adversely affect viability. We have explored optical trapping conditions in the near infrared (840-930nm) that preserve the viability of E. coli, as measured by gene expression of green fluorescent protein. We have found that time-sharing the optical traps, i.e., dwelling only 10μs-1ms on the cell, improves viability relative to continuous wave (CW) exposure for the same exposure time. We have also observed that similar to CW traps the photodamage in a time-shared trap depends weakly on wavelength, but linearly on peak power, implying an effect induced by single photon absorption. Taken altogether, integrating the exposure time and peak power, the data indicate that there is a lethal energy dose of about 5J for E. coli. Thus a single parameter—the energy—can be used to describe the limitation on viability.

  14. Experimental pseudo-symmetric trap EPSILON

    International Nuclear Information System (INIS)

    Skovoroda, A.A.; Arsenin, V.V.; Dlougach, E.D.; Kulygin, V.M.; Kuyanov, A.Yu.; Timofeev, A.V.; Zhil'tsov, V.A.; Zvonkov, A.V.

    2001-01-01

    Within the framework of the conceptual project 'Adaptive Plasma EXperiment' a trap with the closed magnetic field lines 'Experimental Pseudo-Symmetric trap' is examined. The project APEX is directed at the theoretical and experimental development of physical foundations for stationary thermonuclear reactor on the basis of an alternative magnetic trap with tokamak-level confinement of high β plasma. The fundamental principle of magnetic field pseudosymmetry that should be satisfied for plasma to have tokamak-like confinement is discussed. The calculated in paraxial approximation examples of pseudosymmetric curvilinear elements with poloidal direction of B isolines are adduced. The EPSILON trap consisting of two straight axisymmetric mirrors linked by two curvilinear pseudosymmetric elements is considered. The plasma currents are short-circuited within the curvilinear element what increases the equilibrium β. The untraditional scheme of MHD stabilization of a trap with the closed field lines by the use of divertor inserted into axisymmetric mirror is analyzed. The experimental installation EPSILON-OME that is under construction for experimental check of divertor stabilization is discussed. The possibility of ECR plasma production in EPSILON-OME under conditions of high density and small magnetic field is examined. (author)

  15. Electron scattering by trapped fermionic atoms

    International Nuclear Information System (INIS)

    Wang Haijun; Jhe, Wonho

    2002-01-01

    Considering the Fermi gases of alkali-metal atoms that are trapped in a harmonic potential, we study theoretically the elastic and inelastic scattering of the electrons by the trapped Fermi atoms and present the corresponding differential cross sections. We also obtain the stopping power for the cases that the electronic state as well as the center-of-mass state are excited both separately and simultaneously. It is shown that the elastic scattering process is no longer coherent in contrast to the electron scattering by the atomic Bose-Einstein condensate (BEC). For the inelastic scattering process, on the other hand, the differential cross section is found to be proportional to the 2/3 power of the number of the trapped atoms. In particular, the trapped fermionic atoms display the effect of ''Fermi surface,'' that is, only the energy levels near the Fermi energy have dominant contributions to the scattering process. Moreover, it is found that the stopping power scales as the 7/6 power of the atomic number. These results are fundamentally different from those of the electron scattering by the atomic BEC, mainly due to the different statistics obeyed by the trapped atomic systems

  16. Foreign assistance

    International Nuclear Information System (INIS)

    1991-07-01

    This paper reports that providing energy assistance to developing countries remains a relatively low priority of the Agency for International Development. AID is helping some developing countries meet their energy needs, but this assistance varies substantially because of the agency's decentralized structure. Most AID energy funding has gone to a handful of countries-primarily Egypt and Pakistan. With limited funding in most other countries, AID concentrates on providing technical expertise and promoting energy policy reforms that will encourage both energy efficiency and leverage investment by the private sector and other donors. Although a 1989 congressional directive to pursue a global warming initiative has had a marginal impact on the agency's energy programming, many AID energy programs, including those directed at energy conservation, help address global warming concerns

  17. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Green fluorescent protein/beta-galactosidase double reporters for visualizing Drosophila gene expression patterns.

    Science.gov (United States)

    Timmons, L; Becker, J; Barthmaier, P; Fyrberg, C; Shearn, A; Fyrberg, E

    1997-01-01

    We characterized 120 novel yeast Ga14-targeted enhancer trap lines in Drosophila using upstream activating sequence (UAS) reporter plasmids incorporating newly constructed fusions of Aequorea victoria green fluorescent protein (GFP) and Escherichia coli beta-galactosidase genes. Direct comparisons of GFP epifluorescence and beta-galactosidase staining revealed that both proteins function comparably to their unconjugated counterparts within a wide variety of Drosophila tissues. Generally, both reporters accumulated in similar patterns within individual lines, but in some tissues, e.g., brain, GFP staining was more reliable than that of beta-galactosidase, whereas in other tissues, most notably tests and ovaries, the converse was true. In cases of weak enhancers, we occasionally could detect beta-galactosidase staining in the absence of discernible GFP fluorescence. This shortcoming of GFP can, in most cases, be alleviated by using the more efficient S65T GFP derivative. The GFP/beta-gal reporter fusion protein facilitated monitoring several aspects of protein accumulation. In particular, the ability to visualize GFP fluorescence enhances recognition of global static and dynamic patterns in live animals, whereas beta-galactosidase histochemistry affords sensitive high resolution protein localization. We present a catalog of Ga 14-expressing strains that will be useful for investigating several aspects of Drosophila melanogaster cell and developmental biology.

  19. Improvements in Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) Trapping Systems.

    Science.gov (United States)

    Navarro-Llopis, Vicente; Primo, Jaime; Vacas, Sandra

    2018-03-20

    Improved trap efficacy is crucial for implementing control methods for red palm weevil, Rhynchophorus ferrugineus (Olivier; Coleoptera: Dryophthoridae), based on trapping systems, such as mass trapping, attract and infect or attract and sterilize techniques. Although new trap designs have been proposed and aggregation pheromone dispensers have been optimized, aspects such as the use of co-attractants (molasses) and trap placement are still not well defined and standardized. The efficacy of three concentrations of molasses and different formulations to reduce water evaporation in traps was studied in different field trials to improve trapping systems and to prolong trap servicing periods. In addition, the performance of installing groups of traps or single traps was also evaluated with the aim of improving the attracted/captured weevils ratio. Our results showed that captures increased when molasses were added at 15% to the water contained in the trap and that a thin layer of oil, created by adding 2-3% of paraffinic oil to water, was able to effectively reduce evaporation and prolong trap servicing periods. Moreover, 3.5-fold more weevils were captured when placing five traps instead of one at the same trapping point. Results obtained allow improved efficacy and may have an impact in the economic viability of trapping systems and, therefore, in integrated pest management programs.

  20. Stable fly (Stomoxys calcitrans: Diptera, Muscidae) trap response to changes in effective trap height caused by growing vegetation.

    Science.gov (United States)

    Beresford, D V; Sutcliffe, J F

    2008-06-01

    Stable flies (Stomoxys calcitrans L.) are blood-feeding pests of cattle, whose populations are often monitored using sticky traps. Trap responses at different heights were compared with: 1) a choice and no-choice test, with sticky cards set at 30 and 121 cm heights (above ground), and 2) tall (120 cm) traps placed in short (3 cm) and tall (40 cm) grass to assess how vegetation height affects trap catches. In the first experiment, the percentage of upper to lower trap catches were similar at choice (16%) and no-choice traps (15%). In the vegetation study, stable fly catch height data were fitted to gamma distributions to determine the most productive trap heights; 20 cm above short grass and 24 cm above tall grass (from lower edge of trap). The results indicate that traps used to monitor stable fly populations should be maintained at a constant distance above surrounding vegetation rather than ground surface, otherwise trap data can be misleading.

  1. $Q$-value and half-lives for the double-$\\beta$-decay nuclide $^{110}$Pd

    CERN Document Server

    Fink, D.; Beck, D.; Blaum, K.; Bohm, Ch.; Borgmann, Ch.; Breitenfeldt, M.; Herfurth, F.; Herlert, A.; Kotila, J.; Kowalska, M.; Kreim, S.; Lunney, D.; Naimi, S.; Rosenbusch, M.; Schwarz, S.; Schweikhard, L.; Simkovic, F.; Stanja, J.; Zuber, K.

    2012-01-01

    The $^{110}$Pd $\\beta\\beta$- decay ${Q}$-value was measured with the Penning-trap mass spectrometer ISOLTRAP to be ${Q}$ = 2017.85(64) keV. This value shifted by 14 keV compared to the literature value and is 17 times more precise, resulting in new phase-space factors for the two-neutrino and neutrinoless decay modes. In addition a new set of the relevant matrix elements has been calculated. The expected half-life of the two-neutrino mode was reevaluated as 1.5(6) $\\times$10$^{20}$ yr. With its high natural abundance, the new results reveal $^{110}$Pd to be an excellent candidate for double-$\\beta$ -decay studies.

  2. Q values of the 76Ge and 100Mo double-beta decays

    International Nuclear Information System (INIS)

    Rahaman, S.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Jokinen, A.; Julin, J.; Kankainen, A.; Saastamoinen, A.; Suhonen, J.; Weber, C.; Aystoe, J.

    2008-01-01

    Penning trap measurements using mixed beams of 76 Ge- 76 Se and 100 Mo- 100 Ru have been utilized to determine the double-beta decay Q-values of 76 Ge and 100 Mo with uncertainties less than 200 eV. The value for 76 Ge, 2039.04(16) keV is in agreement with the published SMILETRAP value, 2039.006(50) keV. The new value for 100 Mo, 3034.40(17) keV is 30 times more precise than the previous literature value, sufficient for the ongoing neutrinoless double-beta decay searches in 100 Mo. Moreover, the precise Q-value is used to calculate the phase-space integrals and the experimental nuclear matrix element of double-beta decay

  3. Neutrophil beta-2 microglobulin: an inflammatory mediator

    DEFF Research Database (Denmark)

    Bjerrum, O W; Nissen, Mogens Holst; Borregaard, N

    1990-01-01

    vesicles, and plasma membrane. Beta 2m was released in the native form from neutrophils in response to stimulation with chemotactic stimuli and phorbol ester. The results of experiments designed to study the modification of native beta 2m by neutrophils indicated that neutrophils do not participate...... in the proteolysis of beta 2m. However, we demonstrated that native beta 2m following degranulation may be transformed to Des-Lys58-beta 2m by lymphocytes. We suggest that neutrophil beta 2m following exocytosis may be transformed to Des-Lys58-beta 2m, acting as an extracellular messenger between granulocytes...

  4. Are calculated betas good for anything?

    OpenAIRE

    Fernandez, Pablo

    2004-01-01

    We calculate betas of 3,813 companies using 60 monthly returns each day of December 2001 and January 2002. The median (average) of the maximum beta divided by the minimum beta was 3.07 (15.7). The median of the percentage daily change (in absolute value) of the betas was 20%. Industry betas are also unstable. On average, the maximum beta of an industry was 2.7 times its minimum beta in December 2001 and January 2002. The median (average) of the percentage daily change (in absolute value) of t...

  5. Merits of Using Tranquilizer Trap Devices on Leg-Hold Traps Used to Capture Gray Wolves (Canis lupus)

    OpenAIRE

    Sahr, Duane P.

    1997-01-01

    Gray wolves (Canis lupus) are frequently captured with leg-hold traps for reintroduction, relocation to reduce depredations on livestock, or as subjects for research projects. Wolves captured with leg-hold traps often sustain injuries to their feet, legs, and teeth during struggles to escape. Other studies have shown that the use of tranquilizer devices on leg-hold traps reduces such injuries to coyotes. This study (1) assessed whether use of tranquilizer trap devices (TTDs) on leg-hold traps...

  6. An electrostatic autoresonant ion trap mass spectrometer

    International Nuclear Information System (INIS)

    Ermakov, A. V.; Hinch, B. J.

    2010-01-01

    A new method for ion extraction from an anharmonic electrostatic trap is introduced. Anharmonicity is a common feature of electrostatic traps which can be used for small scale spatial confinement of ions, and this feature is also necessary for autoresonant ion extraction. With the aid of ion trajectory simulations, novel autoresonant trap mass spectrometers (ART-MSs) have been designed based on these very simple principles. A mass resolution ∼60 is demonstrated for the prototypes discussed here. We report also on the pressure dependencies, and the (mV) rf field strength dependencies of the ART-MS sensitivity. Importantly the new MS designs do not require heavy magnets, tight manufacturing tolerances, introduction of buffer gases, high power rf sources, nor complicated electronics. The designs described here are very inexpensive to implement relative to other instruments, and can be easily miniaturized. Possible applications are discussed.

  7. Ion funnel ion trap and process

    Science.gov (United States)

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  8. Vortices and monopoles in a harmonic trap

    Energy Technology Data Exchange (ETDEWEB)

    Tong, David; Turner, Carl [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 OWA (United Kingdom)

    2015-12-15

    The Ω-deformation is a harmonic trap, penning certain excitations near the origin in a manner consistent with supersymmetry. Here we explore the dynamics of BPS monopoles and vortices in such a trap. We pay particular attention to monopoles in the Higgs phase, when they are confined to a vortex string. Unusually for BPS solitons, the mass of these confined monopoles is quadratic in the topological charges. We compute an index theorem to determine the number of collective coordinates of confined monopoles. Despite being restricted to move on a line, we find that they have a rich dynamics. As the strength of the trap increases, the number of collective coordinates can change, sometimes with constituent monopoles disappearing, sometimes with new ones emerging.

  9. Quasi-conical centrifugal ion trap

    International Nuclear Information System (INIS)

    Golikov, Yu.K.; Solov'ev, K.V.; Grigor'ev, D.V.; Flegontova, E.Yu.

    1999-01-01

    This paper describes a new excellent ion trap that principally differs from the classic hyperbolic one by its action. The action is based on the axisymmetric electrostatic quasi-conical field with the following potential type: F=F 0 [ln r - r 2 /2+z 2 ], where r, z are cylindrical dimensionless coordinates. The radial potential run (f=ln r-r 2 /2), in this case, is exactly presented by the approximation function f a =ar 2 +b/r 2 +c. In addition, there are some ranges of r (for example, 0.6< r<0.35), in which the concurrence accuracy value is above 0.5%. The paper presents the theory of particles dynamics in the centrifugal trap. Basic correlation for resolution ratios and sensitivity values are developed. Recommendations on the centrifugal trap design implementation, including the recording system, are given

  10. Blue-Detuned Magneto-Optical Trap

    Science.gov (United States)

    Jarvis, K. N.; Devlin, J. A.; Wall, T. E.; Sauer, B. E.; Tarbutt, M. R.

    2018-02-01

    We present the properties and advantages of a new magneto-optical trap (MOT) where blue-detuned light drives "type-II" transitions that have dark ground states. Using 87Rb, we reach a radiation-pressure-limited density exceeding 1 011 cm-3 and a temperature below 30 μ K . The phase-space density is higher than in normal atomic MOTs and a million times higher than comparable red-detuned type-II MOTs, making the blue-detuned MOT particularly attractive for molecular MOTs, which rely on type-II transitions. The loss of atoms from the trap is dominated by ultracold collisions between Rb atoms. For typical trapping conditions, we measure a loss rate of 1.8 (4 )×10-10 cm3 s-1 .

  11. Optical trapping of carbon nanotubes and graphene

    Directory of Open Access Journals (Sweden)

    S. Vasi

    2011-09-01

    Full Text Available We study optical trapping of nanotubes and graphene. We extract the distribution of both centre-of-mass and angular fluctuations from three-dimensional tracking of these optically trapped carbon nanostructures. The optical force and torque constants are measured from auto and cross-correlation of the tracking signals. We demonstrate that nanotubes enable nanometer spatial, and femto-Newton force resolution in photonic force microscopy by accurately measuring the radiation pressure in a double frequency optical tweezers. Finally, we integrate optical trapping with Raman and photoluminescence spectroscopy demonstrating the use of a Raman and photoluminescence tweezers by investigating the spectroscopy of nanotubes and graphene flakes in solution. Experimental results are compared with calculations based on electromagnetic scattering theory.

  12. Neutrophil Extracellular Traps in Ulcerative Colitis

    DEFF Research Database (Denmark)

    Bjerg Bennike, Tue; Carlsen, Thomas Gelsing; Ellingsen, Torkell

    2015-01-01

    microscopy and confocal microscopy. RESULTS: We identified and quantified 5711 different proteins with proteomics. The abundance of the proteins calprotectin and lactotransferrin in the tissue correlated with the degree of tissue inflammation as determined by histology. However, fecal calprotectin did...... not correlate. Forty-six proteins were measured with a statistically significant differences in abundances between the UC colon tissue and controls. Eleven of the proteins with increased abundances in the UC biopsies were associated with neutrophils and neutrophil extracellular traps. The findings were...... validated by microscopy, where an increased abundance of neutrophils and the presence of neutrophil extracellular traps by extracellular DNA present in the UC colon tissue were confirmed. CONCLUSIONS: Neutrophils, induced neutrophil extracellular traps, and several proteins that play a part in innate...

  13. Sodium hydride precipitation in sodium cold traps

    International Nuclear Information System (INIS)

    McPheeters, C.C.; Raue, D.J.

    1979-10-01

    A series of experiments have been performed to test a calculational model for precipitation of NaH in sodium cold traps. The calculational model, called ACTMODEL, is a computer simulation that uses the system geometry and operating conditions as input to calculate a mass transfer coefficient and the distribution of NaH in a cold trap. The ACTMODEL was tested using an analytical cold trap (ACT) that is simple and essentially one-dimensional. The ACT flow and temperature profile may be controlled at any desired condition. The ACT was analyzed destructively after each test to measure the actual NaH distribution. Excellent agreement was obtained between the ACTMODEL simulations and the experiments

  14. Conception of PIPERADE: A high-capacity Penning-trap mass separator for high isobaric contamination at DESIR

    Energy Technology Data Exchange (ETDEWEB)

    Minaya Ramirez, E., E-mail: minaya@ipno.in2p3.fr [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Alfaurt, P.; Aouadi, M.; Ascher, P.; Blank, B. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Blaum, K. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Cam, J.-F. [Laboratoire de Physique Corpusculaire, Caen (France); Chauveau, P. [Grand Accélérateur National d’Ions Lourds CEA/DSM-CNRS-IN2P3, Caen (France); Daudin, L. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Delahaye, P. [Grand Accélérateur National d’Ions Lourds CEA/DSM-CNRS-IN2P3, Caen (France); Delalee, F. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Dupré, P. [Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay (France); El Abbeir, S.; Gerbaux, M.; Grévy, S.; Guérin, H. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Lunney, D. [Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay (France); Metz, F. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Naimi, S. [Riken, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Perrot, L. [Institut de Physique Nucléaire, Orsay (France); and others

    2016-06-01

    The DESIR (decay, excitation and storage of radioactive ions) facility at GANIL-SPIRAL2 will receive a large variety of exotic nuclei at low energy (up to 60 keV) with high intensities. However, the production methods of radioactive beams are non selective, limiting the purity of the beams of interest. Moreover, the high precision needed for nuclear structure and astrophysics studies using beta decay spectroscopy, laser spectroscopy and trap-based experiments at DESIR requires highly pure samples of exotic nuclei. The aim of the double-Pennig-trap mass separator PIPERADE is to deliver large and very pure samples of exotic nuclei to the different experiments in DESIR. New excitation schemes and a large inner diameter of the first trap will mitigate space charge effects to attempt trapping of up to 10{sup 5} ions per pulse. The purification cycle will be performed in a few milliseconds so that short-lived nuclei can be purified. To extract the nuclides of interest from the large amount of isobaric contaminants, a resolving power of 10{sup 5} is mandatory. Afterwards the ions of interest will be accumulated in the second trap until they constitute a sufficiently pure sample for the measurements. The status of the project is presented.

  15. Decelerating and Trapping Large Polar Molecules.

    Science.gov (United States)

    Patterson, David

    2016-11-18

    Manipulating the motion of large polyatomic molecules, such as benzonitrile (C 6 H 5 CN), presents significant difficulties compared to the manipulation of diatomic molecules. Although recent impressive results have demonstrated manipulation, trapping, and cooling of molecules as large as CH 3 F, no general technique for trapping such molecules has been demonstrated, and cold neutral molecules larger than 5 atoms have not been trapped (M. Zeppenfeld, B. G. U. Englert, R. Glöckner, A. Prehn, M. Mielenz, C. Sommer, L. D. van Buuren, M. Motsch, G. Rempe, Nature 2012, 491, 570-573). In particular, extending Stark deceleration and electrostatic trapping to such species remains challenging. Here, we propose to combine a novel "asymmetric doublet state" Stark decelerator with recently demonstrated slow, cold, buffer-gas-cooled beams of closed-shell volatile molecules to realize a general system for decelerating and trapping samples of a broad range of volatile neutral polar prolate asymmetric top molecules. The technique is applicable to most stable volatile molecules in the 100-500 AMU range, and would be capable of producing trapped samples in a single rotational state and at a motional temperature of hundreds of mK. Such samples would immediately allow for spectroscopy of unprecedented resolution, and extensions would allow for further cooling and direct observation of slow intramolecular processes such as vibrational relaxation and Hertz-level tunneling dynamics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Screening the Hanford tanks for trapped gas

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, P.

    1995-10-01

    The Hanford Site is home to 177 large, underground nuclear waste storage tanks. Hydrogen gas is generated within the waste in these tanks. This document presents the results of a screening of Hanford`s nuclear waste storage tanks for the presence of gas trapped in the waste. The method used for the screening is to look for an inverse correlation between waste level measurements and ambient atmospheric pressure. If the waste level in a tank decreases with an increase in ambient atmospheric pressure, then the compressibility may be attributed to gas trapped within the waste. In this report, this methodology is not used to estimate the volume of gas trapped in the waste. The waste level measurements used in this study were made primarily to monitor the tanks for leaks and intrusions. Four measurement devices are widely used in these tanks. Three of these measure the level of the waste surface. The remaining device measures from within a well embedded in the waste, thereby monitoring the liquid level even if the liquid level is below a dry waste crust. In the past, a steady rise in waste level has been taken as an indicator of trapped gas. This indicator is not part of the screening calculation described in this report; however, a possible explanation for the rise is given by the mathematical relation between atmospheric pressure and waste level used to support the screening calculation. The screening was applied to data from each measurement device in each tank. If any of these data for a single tank indicated trapped gas, that tank was flagged by this screening process. A total of 58 of the 177 Hanford tanks were flagged as containing trapped gas, including 21 of the 25 tanks currently on the flammable gas watch list.

  17. Tables of double beta decay data

    Energy Technology Data Exchange (ETDEWEB)

    Tretyak, V.I. [AN Ukrainskoj SSR, Kiev (Ukraine)]|[Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Zdesenko, Y.G. [AN Ukrainskoj SSR, Kiev (Ukraine)

    1995-12-31

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2{beta} transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2{beta}{sup -}; 2{beta}{sup +}; {epsilon}{beta}{sup +}; 2{epsilon}) and modes (0{nu}; 2{nu}; 0{nu}M) of decay. (authors). 189 refs., 9 figs., 3 tabs.

  18. Beta Instability and Stochastic Market Weights

    OpenAIRE

    David H. Goldenberg

    1985-01-01

    An argument is given for individual firm beta instability based upon the stochastic character of the market weights defining the market portfolio and the constancy of its beta. This argument is generalized to market weighted portfolios and the form of the stochastic process generating betas is linked to that of the market return process. The implications of this analysis for adequacy of models of beta nonstationarity and estimation of betas are considered in light of the available empirical e...

  19. High beta plasmas in the PBX tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bol, K.; Buchenauer, D.; Chance, M.; Couture, P.; Fishman, H.; Fonck, R.; Gammel, G.; Grek, B.; Ida, K.; Itami, K.

    1986-04-01

    Bean-shaped configurations favorable for high ..beta.. discharges have been investigated in the Princeton Beta Experiment (PBX) tokamak. Strongly indented bean-shaped plasmas have been successfully formed, and beta values of over 5% have been obtained with 5 MW of injected neutral beam power. These high beta discharges still lie in the first stability regime for ballooning modes, and MHD stability analysis implicates the external kink as responsible for the present ..beta.. limit.

  20. Mats and LaSpec: High-precision experiments using ion traps and lasers at Fair

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, D.; Lallena, A.M.; Blaum, K.; Bohm, C.; Cakirli, R.B.; Crespo Lopez-Urrutia, J.R.; Eliseev, S.; Ketelaer, J.; Kreim, M.S.; Kowalska, M.; Litvinov, Y.A.; Nagy, S.; Neidherr, D.; Repp, J.; Roux, C.; Schabinger, B.; Ullrich, J.; Nortershauser, W.; Eberhardt, K.; Geppert, C.; Kramer, J.; Krieger, A.; Sanchez, R.; Ahammed, M.; Das, P.; Ray, A.; Algora, A.; Rubio, B.; Tain, J.L.; Audi, G.; Lunney, D.; Naimi, S.; Aysto, J.; Jokinen, A.; Kolhinen, V.; Moore, I.; Beck, D.; Block, M.; Geissel, H.; Heinz, S.; Herfurth, F.; Litvinov, Y.A.; Minaya-Ramirez, E.; Plab, W.R.; Quint, W.; Scheidenberger, C.; Winkler, M.; Bender, M.; Billowes, J.; Campbell, P.; Flanagan, K.T.; Schwarz, S.; Bollen, G.; Ferrer, R.; George, S.; Kester, O.; Brodeur, M.; Brunner, T.; Delheij, P.; Dilling, J.; Ettenauer, S.; Lapierre, A.; Bushaw, B.A.; Cano-Ott, D.; Martinez, T.; Cortes, G.; Gomez-Hornillos, M.B.; Dax, A.; Herlert, A.; Yordanov, D.; De, A.; Dickel, T.; Geissel, H.; Jesch, C.; Kuhl, T.; Petrick, M.; PlaB, W.R.; Scheidenberger, C.; Garcia-Ramos, J.E.; Gartzke, E.; Habs, D.; Szerypo, J.; Thirolf, P.G.; Weber, C.; Gusev, Y.; Nesterenko, D.; Novikov, Y.N.; Popov, A.; Seliverstov, M.; Vasiliev, A.; Vorobjev, G.; Heenen, P.H.; Marx, G.; Schweikhard, L.; Ziegler, F.; Hobein, M.; Schuch, R.; Solders, A.; Suhonen, M.; Huber, G.; Wendt, K.; Huyse, M.; Koudriavtsev, I.; Neyens, G.; Van Duppen, P.; Le Blanc, F.; Matos, M.; Reinhard, P.G.; Schneider, D.

    2010-05-15

    Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10{sup -9} can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. Decay studies in ion traps will become possible with MATS. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The accuracy of laser-spectroscopic-determined nuclear properties is very high while requirements concerning production rates are moderate. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy. Since MATS and LaSpec require high-quality low

  1. The NSSDC trapped radiation model facility

    International Nuclear Information System (INIS)

    Gaffey, J.D. Jr.; Bilitza, D.

    1990-01-01

    The National Space Science Data Center (NSSDC) trapped radiation models calculate the integral and differential electron and proton flux for given values of the particle energy E, drift shell parameter L, and magnetic field strength B for either solar maximum or solar minimum. The most recent versions of the series of models, which have been developed and continuously improved over several decades by Dr. James Vette and coworkers at NSSDC, are AE-8 for electrons and AP-8 for protons. The present status of the NSSDC trapped particle models is discussed. The limits of validity of the models are described. 17 refs

  2. Particle confinement in penning traps an introduction

    CERN Document Server

    Vogel, Manuel

    2018-01-01

    This book provides an introduction to the field of Penning traps and related experimental techniques. It serves both as a primer for those entering the field, and as a quick reference for those working in it. The book is motivated by the observation that often a vast number of different resources have to be explored to gain a good overview of Penning trap principles. This is especially true for students who experience additional difficulty due to the different styles of presentation and notation. This volume provides a broad introductory overview in unified notation.

  3. Beta contamination monitor energy response

    Energy Technology Data Exchange (ETDEWEB)

    Bjork, C.W.; Olsher, R.H.

    1998-12-31

    Beta contamination is monitored at Los Alamos National Laboratory (LANL) with portable handheld probes and their associated counters, smear counters, air-breathing continuous air monitors (CAM), personnel contamination monitors (PCM), and hand and foot monitors (HFM). The response of these monitors was measured using a set of anodized-aluminum beta sources for the five isotopes: Carbon-14, Technetium-99, Cesium-137, Chlorine-36 and Strontium/Yttrium-90. The surface emission rates of the sources are traceable to the National Institute of Standards and Technology (NIST) with a precision of one relative standard deviation equal to 1.7%. All measurements were made in reproducible geometry, mostly using aluminum source holders. All counts, significantly above background, were collected to a precision of 1% or better. The study of the hand-held probes included measurements of six air gaps from 0.76 to 26.2 mm. The energy response of the detectors is well-parameterized as a function of the average beta energy of the isotopes (C14=50 keV, Tc99=85, Cs137=188, C136=246, and Sr/Y90=934). The authors conclude that Chlorine-36 is a suitable beta emitter for routine calibration. They recommend that a pancake Geiger-Mueller (GM) or gas-proportional counter be used for primarily beta contamination surveys with an air gap not to exceed 6 mm. Energy response varies about 30% from Tc99 to Sr/Y90 for the pancake GM detector. Dual alpha/beta probes have poor to negligible efficiency for low-energy betas. The rugged anodized sources represent partially imbedded contamination found in the field and they are provided with precise, NIST-traceable, emission rates for reliable calibration.

  4. Sticky traps saturate with navel orangeworm in a nonlinear fashion

    Directory of Open Access Journals (Sweden)

    L.P.S. Kuenen

    2016-01-01

    Full Text Available Trapping is an essential tool used to decide the need for and/or timing of an insecticide application. The assumption is that the information is accurate, but accuracy is dependent on trap reliability and efficacy. One factor that affects reliability is trap saturation, defined as the measurable decrease in trap capture due to reduced trapping effectiveness caused by the accumulation of insects already in a trap. In this study, we used unmated female navel orangeworm (NOW, Amyelois transitella (Walker as sex pheromone baits in wing traps that varied by color and glue/trapping surface in order to evaluate saturation thresholds and quantify trap effectiveness. Effectiveness decreased in each type of sticky trap as the number of insects caught increased, because of the accumulation of scales and insect bodies on the glue surface. The continued accumulation of insects further reduced trap capture, and this decrease in capture could be described by a regression using a power transformation. The resulting saturation equations that we calculated will help pest control advisers and growers interpret their trap data by better estimating the relationship between the number of males trapped versus those that visited the trap.

  5. Ball-grid array architecture for microfabricated ion traps

    Science.gov (United States)

    Guise, Nicholas D.; Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-05-01

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with 40Ca+ ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with 171Yb+ ions in a second BGA trap.

  6. Ball-grid array architecture for microfabricated ion traps

    International Nuclear Information System (INIS)

    Guise, Nicholas D.; Fallek, Spencer D.; Stevens, Kelly E.; Brown, K. R.; Volin, Curtis; Harter, Alexa W.; Amini, Jason M.; Higashi, Robert E.; Lu, Son Thai; Chanhvongsak, Helen M.; Nguyen, Thi A.; Marcus, Matthew S.; Ohnstein, Thomas R.; Youngner, Daniel W.

    2015-01-01

    State-of-the-art microfabricated ion traps for quantum information research are approaching nearly one hundred control electrodes. We report here on the development and testing of a new architecture for microfabricated ion traps, built around ball-grid array (BGA) connections, that is suitable for increasingly complex trap designs. In the BGA trap, through-substrate vias bring electrical signals from the back side of the trap die to the surface trap structure on the top side. Gold-ball bump bonds connect the back side of the trap die to an interposer for signal routing from the carrier. Trench capacitors fabricated into the trap die replace area-intensive surface or edge capacitors. Wirebonds in the BGA architecture are moved to the interposer. These last two features allow the trap die to be reduced to only the area required to produce trapping fields. The smaller trap dimensions allow tight focusing of an addressing laser beam for fast single-qubit rotations. Performance of the BGA trap as characterized with 40 Ca + ions is comparable to previous surface-electrode traps in terms of ion heating rate, mode frequency stability, and storage lifetime. We demonstrate two-qubit entanglement operations with 171 Yb + ions in a second BGA trap

  7. Direct measurement of beta-agonists in swine hair extract in multiplexed mode by surface-enhanced Raman spectroscopy and microfluidic paper.

    Science.gov (United States)

    Dou, Bin; Luo, Yong; Chen, Xu; Shi, Bo; Du, Yuguang; Gao, Zhigang; Zhao, Weijie; Lin, Bingcheng

    2015-02-01

    Bare gold nanoparticles selectively enhance the Raman signal of beta-agnonists in swine hair extract at 780 nm, which enables analysis of beta-agonists in swine hair extract without chemical labeling, purification, or separation. The analysis is multiplexable and the LOD of beta-agonists is around ng/mL in the assistance of microfluidic paper. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analysis of betaS and betaA genes in a Mexican population with African roots.

    Science.gov (United States)

    Magaña, María Teresa; Ongay, Zoyla; Tagle, Juan; Bentura, Gilberto; Cobián, José G; Perea, F Javier; Casas-Castañeda, Maricela; Sánchez-López, Yoaly J; Ibarra, Bertha

    2002-01-01

    To investigate the origin of the beta(A) and beta(S) genes in a Mexican population with African roots and a high frequency of hemoglobin S, we analyzed 467 individuals (288 unrelated) from different towns in the states of Guerrero and Oaxaca in the Costa Chica region. The frequency of the sickle-cell trait was 12.8%, which may represent a public health problem. The frequencies of the beta-haplotypes were determined from 350 nonrelated chromosomes (313 beta(A) and 37 beta(S)). We observed 15 different beta(A) haplotypes, the most common of which were haplotypes 1 (48.9%), 2 (13.4%), and 3 (13.4%). The calculation of pairwise distributions and Nei's genetic distance analysis using 32 worldwide populations showed that the beta(A) genes are more closely related to those of Mexican Mestizos and North Africans. Bantu and Benin haplotypes and haplotype 9 were related to the beta(S) genes, with frequencies of 78.8, 18.2, and 3.0%, respectively. Comparison of these haplotypes with 17 other populations revealed a high similitude with the population of the Central African Republic. These data suggest distinct origins for the beta(A) and beta(S) genes in Mexican individuals from the Costa Chica region.

  9. Assisted Vaginal Delivery

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Assisted Vaginal Delivery Home For Patients Search FAQs Assisted Vaginal Delivery ... Delivery FAQ192, February 2016 PDF Format Assisted Vaginal Delivery Labor, Delivery, and Postpartum Care What is assisted ...

  10. Investigation of two-frequency Paul traps for antihydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Leefer, Nathan; Krimmel, Kai, E-mail: kkrimmel@students.uni-mainz.de [Helmholtz-Institut Mainz (Germany); Bertsche, William [University of Manchester (United Kingdom); Budker, Dmitry [Helmholtz-Institut Mainz (Germany); Fajans, Joel [University of California at Berkeley, Department of Physics (United States); Folman, Ron [Ben-Gurion University of the Negev, Department of Physics (Israel); Häffner, Hartmut [University of California at Berkeley, Department of Physics (United States); Schmidt-Kaler, Ferdinand [Helmholtz-Institut Mainz (Germany)

    2017-11-15

    Radio-frequency (rf) Paul traps operated with multifrequency rf trapping potentials provide the ability to independently confine charged particle species with widely different charge-to-mass ratios. In particular, these traps may find use in the field of antihydrogen recombination, allowing antiproton and positron clouds to be trapped and confined in the same volume without the use of large superconducting magnets. We explore the stability regions of two-frequency Paul traps and perform numerical simulations of small samples of multispecies charged-particle mixtures of up to twelve particles that indicate the promise of these traps for antihydrogen recombination.

  11. Interaction of a spheromak-like compact toroid with a high beta spherical tokamak plasma

    International Nuclear Information System (INIS)

    Hwang, D.Q.; McLean, H.S.; Baker, K.L.; Evans, R.W.; Horton, R.D.; Terry, S.D.; Howard, S.; Schmidt, G.L.

    2000-01-01

    Recent experiments using accelerated spheromak-like compact toroids (SCTs) to fuel tokamak plasmas have quantified the penetration mechanism in the low beta regime; i.e. external magnetic field pressure dominates plasma thermal pressure. However, fusion reactor designs require high beta plasma and, more importantly, the proper plasma pressure profile. Here, the effect of the plasma pressure profile on SCT penetration, specifically, the effect of diamagnetism, is addressed. It is estimated that magnetic field pressure dominates penetration even up to 50% local beta. The combination of the diamagnetic effect on the toroidal magnetic field and the strong poloidal field at the outer major radius of a spherical tokamak will result in a diamagnetic well in the total magnetic field. Therefore, the spherical tokamak is a good candidate to test the potential trapping of an SCT in a high beta diamagnetic well. The diamagnetic effects of a high beta spherical tokamak discharge (low aspect ratio) are computed. To test the penetration of an SCT into such a diamagnetic well, experiments have been conducted of SCT injection into a vacuum field structure which simulates the diamagnetic field effect of a high beta tokamak. The diamagnetic field gradient length is substantially shorter than that of the toroidal field of the tokamak, and the results show that it can still improve the penetration of the SCT. Finally, analytic results have been used to estimate the effect of plasma pressure on penetration, and the effect of plasma pressure was found to be small in comparison with the magnetic field pressure. The penetration condition for a vacuum field only is reported. To study the diamagnetic effect in a high beta plasma, additional experiments need to be carried out on a high beta spherical tokamak. (author)

  12. Biased trapping issue on weighted hierarchical networks

    Indian Academy of Sciences (India)

    In this paper, we present trapping issues of weight-dependent walks on weighted hierarchical networks which are based on the classic scale-free hierarchical networks. Assuming that edge's weight is used as local information by a random walker, we introduce a biased walk. The biased walk is that a walker, at each step, ...

  13. Collisionless modes of a trapped Bose gas

    NARCIS (Netherlands)

    Bijlsma, M.J.; Stoof, H.T.C.

    1999-01-01

    We calculate the excitation frequencies of low-lying modes of a trapped Bose-condensed gas at nonzero temperatures. In our calculation we include the dynamics of the noncondensed cloud, and find agreement with experimental results if we assume that in the experiment both the in-phase and

  14. Collisionless modes of a trapped Bose gas

    NARCIS (Netherlands)

    Bijlsma, M.J.; Stoof, H.T.C.

    1999-01-01

    We calculate the excitation frequencies of the low-lying modes of a trapped Bose-condensed gas at nonzero temperatures. We include in our calculation the dynamics of the noncondensed cloud, and find agreement with experimental results if we assume that in the experiment both the in-phase and

  15. Condensate growth in trapped Bose gates

    NARCIS (Netherlands)

    Bijlsma, M.J.; Zaremba, E.; Stoof, H.T.C.

    2000-01-01

    We study the dynamics of condensate fromation in an inhomogeneous trapped Bose gas with a positive interatomic scattering length. We take into account both the nonequilibrium kinetics of the thermal cloud and the Hartree-Fock mean-field efects in the condensed and the noncondensed parts of the gas.

  16. Condensate growth in trapped Bose gases

    NARCIS (Netherlands)

    Bijlsma, M.J.; Zaremba, E.; Stoof, H.T.C.

    2000-01-01

    We study the dynamics of condensate formation in an inhomogeneous trapped Bose gas with a positive interatomic scattering length. We take into account both the nonequilibrium kinetics of the thermal cloud and the Hartree-Fock mean-field effects in the condensed and the noncondensed parts of the gas.

  17. Hydrogen and deuterium trapping in iron

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H H; Lin, R W

    1981-02-01

    The research described is directed at present almost exclusively to hydrogen transport, including both chemical and physical trapping, in iron and iron-base alloys. Some attention is directed to isotope effects. Efforts are made to clarify and understand hydrogen-related phenomena which are believed to be of direct importance to practical performance.

  18. 49 CFR 236.728 - Circuit, trap.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, trap. 236.728 Section 236.728 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION...

  19. Electrostatic model of semiconductor nanoparticles trapped

    Indian Academy of Sciences (India)

    A simple electrostatic model is applied to study the solvation energy and localization energy to inorganic semiconductor nanocrystallites trapped in polymer and ion conducting polymer electrolytes. The effective mass approximation has been applied to the system. In the single charge configuration, the dielectric constant of ...

  20. Exciton self-trapping in bulk polyethylene

    International Nuclear Information System (INIS)

    Ceresoli, D; Righi, M C; Tosatti, E; Scandolo, S; Santoro, G; Serra, S

    2005-01-01

    We studied the behaviour of an injected electron-hole pair in crystalline polyethylene theoretically. Time-dependent adiabatic evolution by ab initio molecular dynamics simulations show that the pair will become self-trapped in the perfect crystal, with a trapping energy of about 0.38 eV, with formation of a pair of trans-gauche conformational defects, three C 2 H 4 units apart on the same chain. The electron is confined in the interchain pocket created by a local, 120 0 rotation of the chain between the two defects, while the hole resides on the chain and is much less bound. Despite the large energy stored in the trapped excitation, there does not appear to be a direct non-radiative channel for electron-hole recombination. This suggests that intrinsic self-trapping of electron-hole pairs inside the ideal quasi-crystalline fraction of polyethylene might not be directly relevant for electrical damage in high-voltage cables

  1. A naturally occurring trap for antiprotons

    International Nuclear Information System (INIS)

    Eades, J.; Morita, N.; Ito, T.M.

    1993-05-01

    The phenomenon of delayed annihilation of antiprotons in helium is the first instance of a naturally occurring trap for antimatter in ordinary matter. Recent studies of this effect at CERN are summarized, and plans are described for laser excitation experiments to test its interpretation in terms of metastable exotic helium atom formation. (author)

  2. Photoluminescence, trap states and thermoluminescence decay ...

    Indian Academy of Sciences (India)

    Administrator

    Photoluminescence, trap states and thermoluminescence decay process study of Ca2MgSi2O7 : Eu. 2+. , Dy. 3+ phosphor. RAVI SHRIVASTAVA*, JAGJEET KAUR, VIKAS DUBEY and BEENA JAYKUMAR. Govt. VYT PG Autonomous College, Durg 491 001, (C.G.) India. MS received 9 July 2013; revised 5 December 2013.

  3. Optical system for trapping particles in air.

    Science.gov (United States)

    Kampmann, R; Chall, A K; Kleindienst, R; Sinzinger, S

    2014-02-01

    An innovative optical system for trapping particles in air is presented. We demonstrate an optical system specifically optimized for high precision positioning of objects with a size of several micrometers within a nanopositioning and nanomeasuring machine (NPMM). Based on a specification sheet, an initial system design was calculated and optimized in an iterative design process. By combining optical design software with optical force simulation tools, a highly efficient optical system was developed. Both components of the system, which include a refractive double axicon and a parabolic ring mirror, were fabricated by ultra-precision turning. The characterization of the optical elements and the whole system, especially the force simulations based on caustic measurements, represent an important interim result for the subsequently performed trapping experiments. The caustic of the trapping beam produced by the system was visualized with the help of image processing techniques. Finally, we demonstrated the unique efficiency of the configuration by reproducibly trapping fused silica spheres with a diameter of 10 μm at a distance of 2.05 mm from the final optical surface.

  4. Magneto-optical trapping of barium

    NARCIS (Netherlands)

    De, S.; Dammalapati, U.; Jungmann, K.; Willmann, L.

    Laser cooling and trapping of the heavy alkaline-earth-metal element barium has been achieved based on the strong 6s(2) (1)S(0)-6s6p (1)P(1) transition. The excited state decays to a large fraction into metastable D states. Two schemes were implemented where three additional laser-driven transitions

  5. Aircraft Detectors, Trap Triggers and Combination Locks

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Aircraft Detectors, Trap Triggers and Combination Locks - Functional Diversity of Insect Mechanosensory Hairs. Jürgen Tautz. General Article Volume 5 Issue 2 February 2000 pp 32-38 ...

  6. Laser cooling and trapping of barium

    NARCIS (Netherlands)

    De, Subhadeep

    2008-01-01

    Laser cooling and trapping of heavy alkaline-earth element barium have been demonstrated for the first time ever. For any possible cycling transition in barium that could provide strong cooling forces, the excited state has a very large branching probability to metastable states. Additional lasers

  7. Electrostatic model of semiconductor nanoparticles trapped in ...

    Indian Academy of Sciences (India)

    A simple electrostatic model is applied to study the solvation energy and localization energy to inorganic semiconductor nanocrystallites trapped in polymer and ion conducting polymer electrolytes. The effective mass approximation has been applied to the system. In the single charge configuration, the dielectric constant of ...

  8. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    Abstract. We obtain the dynamics in number and phase difference, for Bose condensates that tun- nel between two wells of a double-well atomic trap, using the (nonlinear) Gross–Pitaevskii equation. The dynamical equations are of the canonical form for the two conjugate variables, and the Hamil- tonian corresponds to that ...

  9. Quantum monodromy in trapped Bose condensates

    NARCIS (Netherlands)

    Waalkens, H.

    2002-01-01

    Bose-Einstein condensation of ultra cold atoms is typically realized in magnetic traps which effectively lead to an axially symmetric harmonic potential. This letter shows that the spectrum of collective vibrational modes of a repulsive condensate in a prolate potential displays a defect known as

  10. Superfluorescence with cold trapped neon atoms

    International Nuclear Information System (INIS)

    Zachorowski, Jerzy

    2003-01-01

    A method for observation of superfluorescence in a cloud of cold metastable Ne atoms is proposed. Means of achieving a cold sample of trapped metastable atoms are discussed. The feasibility of obtaining conditions for a superfluorescence pulse is studied. The paper also discusses the prospects for obtaining intense pulses of extreme ultraviolet radiation

  11. EPR spin trapping of protein radicals

    DEFF Research Database (Denmark)

    Davies, Michael Jonathan; Hawkins, Clare Louise

    2004-01-01

    Electron paramagnetic resonance (EPR) spin trapping was originally developed to aid the detection of low-molecular-mass radicals formed in chemical systems. It has subsequently found widespread use in biology and medicine for the direct detection of radical species formed during oxidative stress ...

  12. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    We obtain the dynamics in number and phase difference, for Bose condensates that tunnel between two wells of a double-well atomic trap, using the (nonlinear) Gross–Pitaevskii equation. The dynamical equations are of the canonical form for the two conjugate variables, and the Hamiltonian corresponds to that of a ...

  13. Low temperature delayed recombinationand trap tunneling

    Czech Academy of Sciences Publication Activity Database

    Mihóková, Eva; Schulman, L. S.

    2015-01-01

    Roč. 27, č. 7 (2015), 1-8 ISSN 0953-8984 Grant - others:AVČR(CZ) M100101212 Institutional support: RVO:68378271 Keywords : scintillator * tunneling * traps Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.209, year: 2015

  14. Magmatic underplating beneath the Rajmahal Traps: Gravity ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Rajmahal Traps is characterized by N-S trend- ing fault controlled basement depression that con- nects the ... deformed in a cold, brittle fashion separated by down-dropped valleys/grabens. The grabens may fill with up to .... Keeping all other parameters constant, the boundary of the transitional layer together with its density ...

  15. Dissipative Solitons that Cannot be Trapped

    International Nuclear Information System (INIS)

    Pardo, Rosa; Perez-Garcia, Victor M.

    2006-01-01

    We show that dissipative solitons in systems with high-order nonlinear dissipation cannot survive in the presence of trapping potentials of the rigid wall or asymptotically increasing type. Solitons in such systems can survive in the presence of a weak potential but only with energies out of the interval of existence of linear quantum mechanical stationary states

  16. Soil conservation through sediment trapping: a review

    NARCIS (Netherlands)

    Getahun, M.M.; Keesstra, S.D.; Stroosnijder, L.; Baartman, J.E.M.; Maroulis, J.

    2015-01-01

    Preventing the off-site effects of soil erosion is an essential part of good catchment management. Most efforts are in the form of on-site soil and water conservation measures. However, sediment trapping can be an alternative (additional) measure to prevent the negative off-site effects of soil

  17. Efficacy of multifunnel traps for capturing emerald ash borer (Coleoptera: Buprestidae): effect of color, glue, and other trap coatings.

    Science.gov (United States)

    Francese, Joseph A; Fraser, Ivich; Lance, David R; Mastro, Victor C

    2011-06-01

    Tens of thousands of adhesive-coated purple prism traps are deployed annually in the United States to survey for the invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). A reusable, more user-friendly trap is desired by program managers, surveyors, and researchers. Field assays were conducted in southeastern Michigan to ascertain the feasibility of using nonsticky traps as survey and detection tools for emerald ash borer. Three nonsticky trap designs, including multifunnel (Lindgren), modified intercept panel, and drainpipe (all painted purple) were compared with the standard purple prism trap; no statistical differences in capture of emerald ash borer adults were detected between the multifunnel design and the prism. In subsequent color comparison assays, both green- and purple-painted multifunnel traps (and later, plastic versions of these colors) performed as well or better than the prism traps. Multifunnel traps coated with spray-on adhesive caught more beetles than untreated traps. The increased catch, however, occurred in the traps' collection cups and not on the trap surface. In a separate assay, there was no significant difference detected between glue-coated traps and Rain-X (normally a glass treatment)-coated traps, but both caught significantly more A. planipennis adults than untreated traps.

  18. A=225 implantation for $^{221}$Fr source for TRIUMF atom trap

    CERN Multimedia

    The FrPNC Collaboration is mounting an atom trap for parity violation experiments and precision spectroscopy on francium atoms at TRIUMF's ISAC facility. We would like to use ISOLDE's capability of simultaneously implanting A=225 (while another experiment runs online) to make a long-lived source feeding $^{221}$Fr for tests of the trap. $^{225}$Ra $\\beta$-decays to $^{225}$Ac, which then $\\alpha$-decays, producing 100 keV $^{221}$Fr t$_{1/2}$= 4.8 minute recoils. The implanted A=225 source would be shipped to TRIUMF, where it would be held for several minutes at a time a few mm from the same yttrium foil that normally receives the ISAC beam. SRIM calculations imply that 20% of the $^{221}$Fr will be implanted in a 1 cm diameter spot on the yttrium. Then the yttrium foil is moved to the trap and heated to release the Fr atoms, just as in normal ISAC online operation. A test implantation will be done at 10$^{7}$/sec production for 1 day, testing whether carbon cracking on the implantation foil in the mass separ...

  19. Recent Progress Towards a Measurement of the Neutron Lifetime Using Magnetically Trapped Ultracold Neutrons

    Science.gov (United States)

    Schelhammer, K. W.; Huffer, C. R.; Huffman, P. R.; Marley, D. E.; Coakley, K. J.; Huber, Michael; Hughes, P. P.; Mumm, H. P.; Thompson, A. K.; Yue, A. T.; Abrams, N. C.

    2012-03-01

    Free neutron beta decay is a fundamental process in the Standard Model that can be used to test the weak interaction as well as provide information about primordial ^4He abundance. Recent precision measurements of the neutron lifetime have led to reduced confidence in the absolute value of this parameter; due presumably to unknown systematic effects. This work seeks to measure the neutron lifetime using a different technique that employs a superconducting magnetic trap to confine ultracold neutrons. Neutrons are loaded into the trap through the superthermal technique where 1 mEv neutrons down scatter from phonons in liquid helium losing the majority of their energy. Neutrons in the appropriate spin state are then confined by the static magnetic field. During the past year, over 400 run cycles of data were collected using the upgraded apparatus. Analysis of previous data sets was limited due to large numbers of background events relative to the neutron decay signal. An increased number of trapped neutrons as well as a analysis using pulse shape discrimination allows one to significantly increase the overall precision of the measurement. Details of this ongoing analysis will be presented with preliminary results.

  20. The mass of $^{22}$Mg and a concept for a novel laser ion source trap

    CERN Document Server

    Mukherjee, Manas

    Clean and high-quality radioactive ion beams can be prepared by combining ion trap and resonance laser ionization techniques. A feasibility study for such a laser ion source trap has been carried out which shows enormous improvement in the beam emittance, purity, and in addition allows for a variation of the ion beam time structure. Direct high-precision mass measurements around mass number A=22 are of utmost importance. First, the masses of the superallowed $\\beta$-emitter $^{22}$Mg and its daughter $^{22}$Na are needed to test the conserved-vector-current(CVC) hypothesis and the Cabibbo-Kobayashi-Maskawa(CKM) matrix unitarity, both being predictions of the Standard Model. Second, to calculate the reaction rate of $^{21}$Na($p,\\gamma$)$^{22}$Mg the involved masses are required very accurately. This rate is needed in order to extract an upper limit on the amount of a characteristic $\\gamma$-radiation emitted from classical nova bursts which has been searched for but not yet detected. At the triple trap mass s...

  1. Retrospective accident dosimetry using trapped charges

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. I.; Kim, J. L.; Chang, I.; Kim, B. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Dicentric chromosome aberrations technique scoring of aberrations in metaphases prepared from human lymphocytes is most commonly used. This is considered as a reliable technique because the sample is extracted from the individual human body itself. There are other techniques in biological dosimetry such as Fluorescence In Situ Hybridization (FISH) using translocations, premature chromosome condensation (PCC) and micronucleus assay. However the minimum detectable doses (MDD) are relatively high and sample preparation time is also relatively longer. Therefore, there is limitation in use of these techniques for the purpose of triage in a short time in case of emergency situation relating large number of persons. Electronic paramagnetic resonance (EPR) technique is based on the signal from unpaired electrons such as free radicals in irradiated materials especially tooth enamel, however it has also limitation for the purpose of triage because of difficulty of sample taking and its high MDD. Recently as physical methods, thermoluminescence (TL) and optically stimulated luminescence (OSL) technique have been attracted due to its lower MDD and simplicity of sample preparation. Density of the trapped charges is generally proportional to the radiation dose absorbed and the intensity of emitting light is also proportional to the density of trapped charges, thus it can be applied to measure radiation dose retrospectively. In this presentation, TL and OSL techniques are going to introduced and discussed as physical methods for retrospective accident dosimetry using trapped charges especially in electronic component materials. As a tool for dose reconstruction for emergency situation, thermoluminescece and optically stimulated luminescence techniques which are based on trapped charges during exposure of material are introduced. These techniques have several advantages such as high sensitivity, fast evaluation and ease to sample collection over common biological dosimetry and EPR

  2. Resonant quantum transitions in trapped antihydrogen atoms.

    Science.gov (United States)

    Amole, C; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Donnan, P H; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Shields, C R; Silveira, D M; Stracka, S; So, C; Thompson, R I; van der Werf, D P; Wurtele, J S

    2012-03-07

    The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and--by comparison with measurements on its antimatter counterpart, antihydrogen--the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave radiation to flip the spin of the positron in antihydrogen atoms that were magnetically trapped in the ALPHA apparatus. The spin flip causes trapped anti-atoms to be ejected from the trap. We look for evidence of resonant interaction by comparing the survival rate of trapped atoms irradiated with microwaves on-resonance to that of atoms subjected to microwaves that are off-resonance. In one variant of the experiment, we detect 23 atoms that survive in 110 trapping attempts with microwaves off-resonance (0.21 per attempt), and only two atoms that survive in 103 attempts with microwaves on-resonance (0.02 per attempt). We also describe the direct detection of the annihilation of antihydrogen atoms ejected by the microwaves.

  3. Trapping technology for gaseous fission products from voloxidation process

    International Nuclear Information System (INIS)

    Shin, Jin Myeong; Park, J. J.; Park, G. I.; Jung, I. H.; Lee, H. H.; Kim, G. H.; Yang, M. S.

    2005-05-01

    The objective of this report is to review the different technologies for trapping the gaseous wastes containing Cs, Ru, Tc, 14 C, Kr, Xe, I and 3 H from a voloxidation process. Based on literature reviews and KAERI's experimental results on the gaseous fission products trapping, appropriate trapping method for each fission product has been selected considering process reliability, simplicity, decontamination factor, availability, and disposal. Specifically, the most promising trapping method for each fission product has been proposed for the development of the INL off-gas trapping system. A fly ash filter is proposed as a trapping media for a cesium trapping unit. In addition, a calcium filter is proposed as a trapping media for ruthenium, technetium, and 14 C trapping unit. In case of I trapping unit, AgX is proposed. For Kr and Xe, adsorption on solid is proposed. SDBC (Styrene Divinyl Benzene Copolymer) is also proposed as a conversion media to HTO for 3 H. This report will be used as a useful means for analyzing the known trapping technologies and help selecting the appropriate trapping methods for trapping volatile and semi-volatile fission products, long-lived fission products, and major heat sources generated from a voloxidation process. It can also be used to design an off-gas treatment system

  4. LGR adult trap data - Operation of the adult trap at Lower Granite Dam

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Bonneville Power Administration (BPA) - funded project pays for NOAA staff to operate the adult salmon trap located in the fish ladder at Lower Granite Dam. The...

  5. Beta-hemolytic streptococcal bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Hans Ulrik; Kolmos, Hans Jørn; Frimodt-Møller, Niels

    2002-01-01

    Bacteremia with beta-hemolytic Streptococci groups A, B, C and G has a mortality rate of approximately 20%. In this study we analyzed the association of various patient risk factors with mortality. Records from 241 patients with beta-hemolytic streptococcal bacteremia were reviewed with particular...... attention to which predisposing factors were predictors of death. A logistic regression model found age, burns, immunosuppressive treatment and iatrogenic procedures prior to the infection to be significant predictors of death, with odds ratios of 1.7 (per decade), 19.7, 3.6 and 6.8, respectively...

  6. Modelling and comparison of trapped fields in (RE)BCO bulk superconductors for activation using pulsed field magnetization

    Science.gov (United States)

    Ainslie, M. D.; Fujishiro, H.; Ujiie, T.; Zou, J.; Dennis, A. R.; Shi, Y.-H.; Cardwell, D. A.

    2014-06-01

    The ability to generate a permanent, stable magnetic field unsupported by an electromotive force is fundamental to a variety of engineering applications. Bulk high temperature superconducting (HTS) materials can trap magnetic fields of magnitude over ten times higher than the maximum field produced by conventional magnets, which is limited practically to rather less than 2 T. In this paper, two large c-axis oriented, single-grain YBCO and GdBCO bulk superconductors are magnetized by the pulsed field magnetization (PFM) technique at temperatures of 40 and 65 K and the characteristics of the resulting trapped field profile are investigated with a view of magnetizing such samples as trapped field magnets (TFMs) in situ inside a trapped flux-type superconducting electric machine. A comparison is made between the temperatures at which the pulsed magnetic field is applied and the results have strong implications for the optimum operating temperature for TFMs in trapped flux-type superconducting electric machines. The effects of inhomogeneities, which occur during the growth process of single-grain bulk superconductors, on the trapped field and maximum temperature rise in the sample are modelled numerically using a 3D finite-element model based on the H-formulation and implemented in Comsol Multiphysics 4.3a. The results agree qualitatively with the observed experimental results, in that inhomogeneities act to distort the trapped field profile and reduce the magnitude of the trapped field due to localized heating within the sample and preferential movement and pinning of flux lines around the growth section regions (GSRs) and growth sector boundaries (GSBs), respectively. The modelling framework will allow further investigation of various inhomogeneities that arise during the processing of (RE)BCO bulk superconductors, including inhomogeneous Jc distributions and the presence of current-limiting grain boundaries and cracks, and it can be used to assist optimization of

  7. A {beta} - {gamma} coincidence; Metodo de coincidencias {beta} - {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Agullo, F.

    1960-07-01

    A {beta} - {gamma} coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from {sup 1}98 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs.

  8. Efficacy of trap modifications for increasing capture rates of aquatic snakes in floating aquatic funnel traps

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2013-01-01

    Increasing detection and capture probabilities of rare or elusive herpetofauna of conservation concern is important to inform the scientific basis for their management and recovery. The Giant Gartersnake (Thamnophis gigas) is an example of a secretive, wary, and generally difficult-to-sample species about which little is known regarding its patterns of occurrence and demography. We therefore evaluated modifications to existing traps to increase the detection and capture probabilities of the Giant Gartersnake to improve the precision with which occurrence, abundance, survival, and other demographic parameters are estimated. We found that adding a one-way valve constructed of cable ties to the small funnel opening of traps and adding hardware cloth extensions to the wide end of funnels increased capture rates of the Giant Gartersnake by 5.55 times (95% credible interval = 2.45–10.51) relative to unmodified traps. The effectiveness of these modifications was insensitive to the aquatic habitat type in which they were deployed. The snout-vent length of the smallest and largest captured snakes did not vary among trap modifications. These trap modifications are expected to increase detection and capture probabilities of the Giant Gartersnake, and show promise for increasing the precision with which demographic parameters can be estimated for this species. We anticipate that the trap modifications found effective in this study will be applicable to a variety of aquatic and semi-aquatic reptiles and amphibians and improve conservation efforts for these species.

  9. Continuous Arsine Detection Using a Peltier-Effect Cryogenic Trap To Selectively Trap Methylated Arsines.

    Science.gov (United States)

    Chen, Guoying; Lai, Bunhong; Mao, Xuefei; Chen, Tuanwei; Chen, Miaomiao

    2017-09-05

    Hydride generation (HG) is an effective technique that eliminates interfering matrix species and enables hydride separation. Arsenic speciation analysis can be fulfilled by cryogenic trapping (CT) based on boiling points of resulting arsines using liquid nitrogen (LN 2 ) as a coolant. In this work, LN 2 was replaced by the thermoelectric effect using a cryogenic trap that consisted of a polytetrafluoroethylene (PTFE) body sandwiched by two Peltier modules. After the trap was precooled, the arsines flew along a zigzag channel in the body and reached a sorbent bed of 0.2 g of 15% OV-3 on Chromosorb W-AW-DMCS imbedded near the exit of the trap. CH 3 AsH 2 and (CH 3 ) 2 AsH were trapped, while AsH 3 , that passed the trap unaffected, was detected by atomic fluorescence spectrometry. Continuous operation led to enhanced throughput. For inorganic As, the limit of detection (LOD) was 1.1 ng/g and recovery was 101.0 ± 1.1%. Monomethylarsonic acid and dimethylarsinic acid did not interfere with 0.2 ± 1.2% and -0.3 ± 0.5% recoveries, respectively.

  10. Design of a marine sediment trap and accessories

    Digital Repository Service at National Institute of Oceanography (India)

    Janakiraman, G.; Fernando, V.; Venkatesan, R.; Rajaraman, V.S.

    The marine sediment trap and the mooring accessories were developed indigenously and were used successfully for the collection of settling sediments in the Arabian Sea The experience gained in using sediment trap and further improvements...

  11. Kairomone trapping system for delivery of Beauveria bassiana to ...

    African Journals Online (AJOL)

    Mo

    /trap, with no significant differences ... integration with other weevil trapping strategies (e.g. use of pheromones) should focus on placement of the tissues at the soil surface .... growing susceptible and resistant cultivars, which concurs with the ...

  12. Malaysian skills development and the middle-income trap

    DEFF Research Database (Denmark)

    Søborg, Henrik

    Education, human resource training, middle-income trap and the way towards a more knowledge-based economy......Education, human resource training, middle-income trap and the way towards a more knowledge-based economy...

  13. A radio-frequency ion trap with string electrodes

    Science.gov (United States)

    Kanai, Daisuke; Hasegawa, Taro

    2018-02-01

    A radio-frequency (rf) ion trap with string electrodes is introduced. In this trap configuration, the rf electrodes are made of narrow metal strings, by which a negligibly small portion of light-induced fluorescence (LIF) is blocked. Then the LIF collection solid angle can be maximized. In the demonstration, barium ions are trapped and laser-cooled in the rf trap with string electrodes successfully, and the crystallization is confirmed by the LIF spectrum.

  14. Modular Universal Scalable Ion-trap Quantum Computer

    Science.gov (United States)

    2016-06-02

    trap quantum computer . This architecture has two separate layers of scalability: the first is to increase the number of ion qubits in a single trap...Distribution Unlimited UU UU UU UU 02-06-2016 1-Aug-2010 31-Jan-2016 Final Report: Modular Universal Scalable Ion-trap Quantum Computer The views...P.O. Box 12211 Research Triangle Park, NC 27709-2211 Ion trap quantum computation , scalable modular architectures REPORT DOCUMENTATION PAGE 11

  15. Large-Volume Gravid Traps Enhance Collection of Culex Vectors.

    Science.gov (United States)

    Popko, David A; Walton, William E

    2016-06-01

    Gravid mosquito collections were compared among several large-volume (infusion volume ≥35 liters) gravid trap designs and the small-volume (infusion volume  =  6 liters) Centers for Disease Control and Prevention (CDC) gravid trap used routinely by vector control districts for vector and pathogen surveillance. The numbers of gravid Culex quinquefasciatus, Cx. tarsalis, and Cx. stigmatosoma collected by large gravid traps were greater than by the CDC gravid trap during nearly all overnight trials. Large-volume gravid traps collected on average 6.6-fold more adult female Culex mosquitoes compared to small-volume CDC gravid traps across 3 seasons during the 3 years of the studies. The differences in gravid mosquito collections between large-versus small-volume gravid traps were greatest during spring, when 8- to 56-fold more Culex individuals were collected using large-volume gravid traps. The proportion of gravid females in collections did not differ appreciably among the more effective trap designs tested. Important determinants of gravid trap performance were infusion container size and type as well as infusion volume, which determined the distance between the suction trap and the infusion surface. Of lesser importance for gravid trap performance were the number of suction traps, method of suction trap mounting, and infusion concentration. Fermentation of infusions between 1 and 4 wk weakly affected total mosquito collections, with Cx. stigmatosoma collections moderately enhanced by comparatively young and organically enriched infusions. A suction trap mounted above 100 liters of organic infusion housed in a 121-liter black plastic container collected the most gravid mosquitoes over the greatest range of experimental conditions, and a 35-liter infusion with side-mounted suction traps was a promising lesser-volume alternative design.

  16. A Trap For Capturing Arthropods Crawling up Tree Boles

    Science.gov (United States)

    James L. Hanula; Kirsten C.P. New

    1996-01-01

    A simple trap is described that captures arthropods as they crawl up tree boles. Constructed from metal funnels, plastic sandwich containers, and specimen cups, the traps can be assembled by one person at a rate of 5 to 6 per hour and installed in 2 to 3 minutes. Specimen collection required 15 to 20 seconds per trap. In 1993, three traps were placed on each tree. In...

  17. Evaluation of efficiency and trapping capacity of restricted access media trap columns for the online trapping of small molecules.

    Science.gov (United States)

    Baghdady, Yehia Z; Schug, Kevin A

    2016-11-01

    Restricted access media are generally composed from multi-modal particles that combine a size excluding outer surface and an inner-pore retention mechanism for small molecules. Such materials can be used for either online isolation and pre-concentration of target small molecules or removal of small molecule interferences from large macromolecules, such as proteins in complex biological matrices. Thus, they are considered as enhanced online solid-phase extraction materials. We evaluated the efficiency and trapping capacity of different semi-permeable surface restricted access media columns (C 18 , C 8 , and C 4 inner pores) for four model small molecule compounds (dopamine hydrochloride, acetaminophen, 4-hydroxybenzoic acid, and diethyl phthalate) having variable physicochemical properties. We further studied the effect of mobile phase flow rate (0.25, 0.5, 1, and 2 mL/min) and pH, using 98:2 0.5% acetic acid in water/ methanol (pH 2.88) and 5 mM ammonium acetate in 98:2 water/methanol (pH 6.61) as mobile phases. Breakthrough curves generated using frontal analysis were analyzed to determine important chromatographic parameters specific for each of the studied compounds. Experimental determination of these parameters allowed selection of the most efficient trap column and the best loading mobile phase conditions for maximal solute enrichment and pre-concentration on restricted access media trap columns. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Synthesis of multi-walled carbon nanotubes/{beta}-FeOOH nanocomposites with high adsorption capacity

    Energy Technology Data Exchange (ETDEWEB)

    Song Haojie, E-mail: shj6922@163.com [School of Materials Science and Engineering, Jiangsu University (China); Liu Lei [Pharmaceutic College of Henan University (China); Jia Xiaohua; Min Chunying [School of Materials Science and Engineering, Jiangsu University (China)

    2012-12-15

    A hybrid nanostructure of multi-walled carbon nanotubes (CNTs) and {beta}-ferric oxyhydroxide ({beta}-FeOOH) nanoparticles is synthesized by ultrasonic-assisted in situ hydrolysis of the precursor ferric chloride and CNTs. Characterization by X-ray diffraction, scanning electron microscopy , and transmission electron microscopy establishes the nanohybrid structure of the synthesized sample. The results revealed that the surface of CNTs was uniformly assembled by numerous {beta}-FeOOH nanoparticles and had an average diameter of 3 nm. The formation route of anchoring {beta}-FeOOH nanoparticles onto CNTs was proposed as the intercalation and adsorption of iron ions onto the wall of CNTs, followed by the nucleation and growth of {beta}-FeOOH nanoparticles. The values of remanent magnetization (M{sub r}) and coercivity (H{sub c}) of the as-synthesized CNTs/{beta}-FeOOH nanocomposites were 0.1131 emu g, and 490.824 Oe, respectively. Furthermore, CNTs/{beta}-FeOOH nanocomposites showed a very high adsorption capacity of Congo red and thus these nanocomposites can be used as good adsorbents and can be used for the removal of the dye of Congo red from the waste water system.

  19. Novel anthracycline-spacer-beta-glucuronide, -beta-glucoside, and -beta-galactoside prodrugs for application in selective chemotherapy

    NARCIS (Netherlands)

    Leenders, RGG; Damen, EWP; Bijsterveld, EJA; Scheeren, HW; Houba, PHJ; van der Meulen-Muileman, IH; Boven, E; Haisma, HJ

    A series of anthracycline prodrugs containing an immolative spacer was synthesized for application in selective chemotherapy. The prodrugs having the general structure anthracycline-spacer-beta-glycoside were designed to be activated by beta-glucuronidase or beta-galactosidase. Prodrugs with

  20. Trap Fishery and Reproductive Biology of the Whitespotted ...

    African Journals Online (AJOL)

    Abstract—Fish samples and catch data were collected monthly from traditional basket fish traps set on reefs within the Dar es Salaam Marine Reserves (DMRs) to evaluate trap catch dynamics and reproductive biology of the rabbit fish Siganus sutor (Valenciennes 1835). Trap catch composition was 85% rabbitfishes by ...

  1. Optical trapping of spermatozoa using Laguerre-Gaussian laser modes

    Science.gov (United States)

    Dasgupta, Raktim; Ahlawat, Sunita; Verma, Ravi Shanker; Shukla, Sunita; Gupta, Pradeep Kumar

    2010-11-01

    We report results of a study on the use of Laguerre-Gaussian (LG) modes for optical trapping of spermatozoa. The results show that for a given trap beam power the first-order LG mode (LG01) leads to lower photodamage to the cells without compromising the trapping efficiency.

  2. Cold highly charged ions in a cryogenic Paul trap

    DEFF Research Database (Denmark)

    Versolato, O.O.; Schwarz, M.; Windberger, A.

    2013-01-01

    linear Paul trap in which HCIs will be sympathetically cooled by 9Be +  ions. Optimized optical access for laser light is provided while maintaining excellent UHV conditions. The Paul trap will be connected to an electron beam ion trap (EBIT) which is able to produce a wide range of HCIs. This EBIT...

  3. Using Malaise traps to sample ground beetles (Coleoptera: Carabidae)

    Science.gov (United States)

    Michael D. Ulyshen; James L. Hanula; Scott Horn

    2005-01-01

    Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages...

  4. Cape Vulture Gyps coprotheres caught in gin trap

    African Journals Online (AJOL)

    campbell

    one investigation reported 24% of traded birds as having been trapped. (Beilis & Esterhuizen 2005,. Mander et al. 2007). It would seem likely that gin traps are implicated in at least some of these instances. We can trace only a single record of a Cape Vulture G. coprotheres being caught in a gin trap, a bird killed in Lesotho.

  5. Characterization of a magnetic trap by polarization dependent Zeeman spectroscopy

    DEFF Research Database (Denmark)

    Nielsen, Carsten Vandel; Lyngsøe, Jens Kristian; Thorseth, Anders

    2008-01-01

    This paper demonstrates a detailed experimental study of our cloverleaf magnetic trap for sodium atoms. By using polarization dependent Zeeman spectroscopy of our atomic beam, passing the magnetic trap region, we have determined important trap parameters such as gradients, their curvatures...

  6. Contra omega\\ beta-continuity

    Directory of Open Access Journals (Sweden)

    Hiam H. Aljarrah

    2014-09-01

    sets in topological spaces to present and study a new class of functions called contra omega\\beta-continuous functions. This notion is a weak form of contra-continuity. We also discuss the relationships between this new class and other classes of functions and some examples of applications are shown.

  7. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    Dorame, L.; Meloni, D.; Morisi, S.; Peinado, E.; Valle, J.W.F.

    2012-01-01

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  8. Beta Cell Workshop 2013 Kyoto

    DEFF Research Database (Denmark)

    Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

    2013-01-01

    The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

  9. Caliber Schools. Caliber: Beta Academy

    Science.gov (United States)

    EDUCAUSE, 2015

    2015-01-01

    Caliber: Beta Academy is reimagining education as we know it, with the belief that the innovations in its model will allow 100% of its students to graduate ready to attend and succeed in a competitive four-year college and beyond. The academic model of the school features personalized learning plans, blended learning for English and math,…

  10. Electret dosemeter for beta radiation

    International Nuclear Information System (INIS)

    Campos, L.L.; Caldas, L.V.E.; Mascarenhas, S.

    The response characteristics of an electret dosemeter for beta radiation are studied. Experiments were performed using different geometries and walls, and it was verified for which geometry the dosemeter sensitivity is greater. Sources of 90 Sr - 90 Y, 204 Tl and 85 Kr were used in the experiments. (I.C.R.) [pt

  11. An ion trap time-of-flight mass spectrometer with high mass resolution for cold trapped ion experiments

    Science.gov (United States)

    Schmid, P. C.; Greenberg, J.; Miller, M. I.; Loeffler, K.; Lewandowski, H. J.

    2017-12-01

    Trapping molecular ions that have been sympathetically cooled with laser-cooled atomic ions is a useful platform for exploring cold ion chemistry. We designed and characterized a new experimental apparatus for probing chemical reaction dynamics between molecular cations and neutral radicals at temperatures below 1 K. The ions are trapped in a linear quadrupole radio-frequency trap and sympathetically cooled by co-trapped, laser-cooled, atomic ions. The ion trap is coupled to a time-of-flight mass spectrometer to readily identify product ion species and to accurately determine trapped ion numbers. We discuss, and present in detail, the design of this ion trap time-of-flight mass spectrometer and the electronics required for driving the trap and mass spectrometer. Furthermore, we measure the performance of this system, which yields mass resolutions of m/Δm ≥ 1100 over a wide mass range, and discuss its relevance for future measurements in chemical reaction kinetics and dynamics.

  12. Beta limits of a completely bootstrapped tokamak

    International Nuclear Information System (INIS)

    Weening, R.H.; Bondeson, A.

    1992-03-01

    A beta limit is given for a completely bootstrapped tokamak. The beta limit is sensitive to the achievable Troyon factor and depends directly upon the strength of the tokamak bootstrap effect. (author) 16 refs

  13. How Do Beta Blocker Drugs Affect Exercise?

    Science.gov (United States)

    ... Aneurysm More How do beta blocker drugs affect exercise? Updated:Aug 22,2017 Beta blockers are a ... about them: Do they affect your ability to exercise? The answer can vary a great deal, depending ...

  14. Interferon Beta-1a Subcutaneous Injection

    Science.gov (United States)

    Interferon beta-1a subcutaneous injection is used to reduce episodes of symptoms and slow the development of disability in ... problems with vision, speech, and bladder control). Interferon beta-1a is in a class of medications called ...

  15. Interferon Beta-1a Intramuscular Injection

    Science.gov (United States)

    Interferon beta-1a intramuscular injection is used to reduce the number of episodes of symptoms and slow the development ... problems with vision, speech, and bladder control). Interferon beta-1a is in a class of medications called ...

  16. Estimation of oxide related electron trap energy of porous silicon nanostructures

    International Nuclear Information System (INIS)

    Das, Mainak Mohan; Ray, Mallar; Bandyopadhyay, Nil Ratan; Hossain, Syed Minhaz

    2010-01-01

    Estimation of electron trap energy (E t ), with respect to bulk Si valence band, of oxidized porous silicon (PS) nanostructures is reported. Photoluminescence (PL) spectra of oxidized PS prepared with different formation parameters have been investigated and the room temperature PL characteristics have been successfully explained on the basis of oxide related trap assisted transitions. PL peak energy for the oxidized samples with low porosity exhibited a blue shift with increasing formation current density (J). For the high porosity samples double peaks appeared in the PL spectra. One of these peaks remained constant at ∼730 nm while the other was blue shifted with increase in J. Evolution of PS nanostructure was correlated to the formation parameters using a simple growth mechanism. PS nanostructure was modelled as an array of regular hexagonal pores and the average value of E t was estimated to be 1.67 eV.

  17. Electronic properties of hafnium oxide: A contribution from defects and traps

    Science.gov (United States)

    Gritsenko, Vladimir A.; Perevalov, Timofey V.; Islamov, Damir R.

    2016-02-01

    In the present article, we give a review of modern data and latest achievements pertaining to the study of electronic properties of oxygen vacancies in hafnium oxide. Hafnium oxide is a key dielectric for use in many advanced silicon devices. Oxygen vacancies in hafnium oxide largely determine the electronic properties of the material. We show that the electronic transitions between the states due to oxygen vacancies largely determine the optical absorption and luminescent properties of hafnium oxide. We discuss the role of oxygen vacancies as traps that facilitate charge transport in hafnium oxide films. Also, we demonstrate the fact that the electrical conductivity in hafnium oxide is controlled by the phonon-assisted tunnelling of charge carriers between traps that were identified as oxygen vacancies.

  18. First trimester biochemistry in pregnancies conceived using assisted reproduction techniques

    DEFF Research Database (Denmark)

    Tabor, Ann; Ekelund, Charlotte; Nørgaard, Pernille

    Objective: To examine the effects of method of conception on first trimester PAPP-A and free beta-hCG and the dependency of gestational age at the time of sampling on these effects Methods: Data on more than 100 000 spontaneously conceived and on 6 859 pregnancies conceived by assisted reproducti...

  19. Quantum Rabi Model with Trapped Ions.

    Science.gov (United States)

    Pedernales, J S; Lizuain, I; Felicetti, S; Romero, G; Lamata, L; Solano, E

    2015-10-20

    We propose the quantum simulation of the quantum Rabi model in all parameter regimes by means of detuned bichromatic sideband excitations of a single trapped ion. We show that current setups can reproduce, in particular, the ultrastrong and deep strong coupling regimes of such a paradigmatic light-matter interaction. Furthermore, associated with these extreme dipolar regimes, we study the controlled generation and detection of their entangled ground states by means of adiabatic methods. Ion traps have arguably performed the first quantum simulation of the Jaynes-Cummings model, a restricted regime of the quantum Rabi model where the rotating-wave approximation holds. We show that one can go beyond and experimentally investigate the quantum simulation of coupling regimes of the quantum Rabi model that are difficult to achieve with natural dipolar interactions.

  20. Trapped Ion Quantum Computation by Adiabatic Passage

    International Nuclear Information System (INIS)

    Feng Xuni; Wu Chunfeng; Lai, C. H.; Oh, C. H.

    2008-01-01

    We propose a new universal quantum computation scheme for trapped ions in thermal motion via the technique of adiabatic passage, which incorporates the advantages of both the adiabatic passage and the model of trapped ions in thermal motion. Our scheme is immune from the decoherence due to spontaneous emission from excited states as the system in our scheme evolves along a dark state. In our scheme the vibrational degrees of freedom are not required to be cooled to their ground states because they are only virtually excited. It is shown that the fidelity of the resultant gate operation is still high even when the magnitude of the effective Rabi frequency moderately deviates from the desired value.

  1. Scalable quantum search using trapped ions

    International Nuclear Information System (INIS)

    Ivanov, S. S.; Ivanov, P. A.; Linington, I. E.; Vitanov, N. V.

    2010-01-01

    We propose a scalable implementation of Grover's quantum search algorithm in a trapped-ion quantum information processor. The system is initialized in an entangled Dicke state by using adiabatic techniques. The inversion-about-average and oracle operators take the form of single off-resonant laser pulses. This is made possible by utilizing the physical symmetries of the trapped-ion linear crystal. The physical realization of the algorithm represents a dramatic simplification: each logical iteration (oracle and inversion about average) requires only two physical interaction steps, in contrast to the large number of concatenated gates required by previous approaches. This not only facilitates the implementation but also increases the overall fidelity of the algorithm.

  2. Progress towards a practical multicell positron trap

    Energy Technology Data Exchange (ETDEWEB)

    Danielson, J. R. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States); Hurst, N. C.; Surko, C. M. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States)

    2013-03-19

    Described here is progress in an experimental program to develop a 21 cell multicell trap for the accumulation and storage of {approx} 10{sup 12} positrons. The basic architecture is an arrangement of multiple Penning-Malmberg (PM) trapped plasmas (i.e., cells) arranged in parallel in a common vacuum system and magnetic field. Experiments are described that are intended to address several key issues, including the effects of large space charge potentials and high plasma densities on: plasma heating, deterioration of confinement, and decreased efficiency of rotating electric fields in producing plasma compression. The confinement of PM plasmas displaced both radially and toward the ends of the uniform magnetic field region will also be investigated.

  3. Single-molecule studies using magnetic traps.

    Science.gov (United States)

    Lionnet, Timothée; Allemand, Jean-François; Revyakin, Andrey; Strick, Terence R; Saleh, Omar A; Bensimon, David; Croquette, Vincent

    2012-01-01

    In recent years, techniques have been developed to study and manipulate single molecules of DNA and other biopolymers. In one such technique, the magnetic trap, a single DNA molecule is bound at one end to a glass surface and at the other to a magnetic microbead. Small magnets, whose position and rotation can be controlled, pull on and rotate the microbead. This provides a simple method to stretch and twist the molecule. The system allows one to apply and measure forces ranging from 10(-3) to >100 pN. In contrast to other techniques, the force measurement is absolute and does not require calibration of the sensor. In this article, we describe the principle of the magnetic trap, as well as its use in the measurement of the elastic properties of DNA and the study of DNA-protein interactions.

  4. Single photon from a single trapped atom

    International Nuclear Information System (INIS)

    Dingjan, J.; Jones, M.P.A.; Beugnon, J.; Darquiee, B.; Bergamini, S.; Browaeys, A.; Messin, G.; Grangier, P.

    2005-01-01

    Full text: A quantum treatment of the interaction between atoms and light usually begins with the simplest model system: a two-level atom interacting with a monochromatic light wave. Here we demonstrate an elegant experimental realization of this system using an optically trapped single rubidium atom illuminated by resonant light pulses. We observe Rabi oscillations, and show that this system can be used as a highly efficient triggered source of single photons with a well-defined polarisation. In contrast to other sources based on neutral atoms and trapped ions, no optical cavity is required. We achieved a flux of single photons of about 10 4 s -1 at the detector, and observe complete antibunching. This source has potential applications for distributed atom-atom entanglement using single photons. (author)

  5. Acoustic mirrors as sensory traps for bats.

    Science.gov (United States)

    Greif, Stefan; Zsebők, Sándor; Schmieder, Daniela; Siemers, Björn M

    2017-09-08

    Sensory traps pose a considerable and often fatal risk for animals, leading them to misinterpret their environment. Bats predominantly rely on their echolocation system to forage, orientate, and navigate. We found that bats can mistake smooth, vertical surfaces as clear flight paths, repeatedly colliding with them, likely as a result of their acoustic mirror properties. The probability of collision is influenced by the number of echolocation calls and by the amount of time spent in front of the surface. The echolocation call analysis corroborates that bats perceive smooth, vertical surfaces as open flyways. Reporting on occurrences with different species in the wild, we argue that it is necessary to more closely monitor potentially dangerous locations with acoustic mirror properties (such as glass fronts) to assess the true frequency of fatalities around these sensory traps. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  6. Trapped ghosts: a new class of wormholes

    Energy Technology Data Exchange (ETDEWEB)

    Bronnikov, Kirill A [Center of Gravitation and Fundamental Metrology, VNIIMS, Ozyornaya St. 46, Moscow 119361 (Russian Federation); Sushkov, Sergey V, E-mail: kb20@yandex.r, E-mail: sergey_sushkov@mail.r [Department of General Relativity and Gravitation, Kazan State University, Kremlyovskaya St. 18, Kazan 420008 (Russian Federation)

    2010-05-07

    We construct examples of static, spherically symmetric wormhole solutions in general relativity with a minimally coupled scalar field phi whose kinetic energy is negative in a restricted region of space near the throat (of arbitrary size) and positive far away from it. Thus in such configurations a 'ghost' is trapped in the strong-field region, which may in principle explain why no ghosts are observed under usual conditions. Some properties of general wormhole models with the phi field are revealed: it is shown that (i) trapped-ghost wormholes are only possible with nonzero potentials V(phi); (ii) in wormholes with two asymptotically flat regions, a nontrivial potential V(phi) has an alternate sign and (iii) a wormhole with two asymptotically flat regions which is mirror symmetric with respect to its throat has necessarily a zero Schwarzschild mass at both asymptotics.

  7. Airfoil Pitch Control Using Trapped Vorticity Concentrations

    Science.gov (United States)

    Brzozowski, Daniel; Culp, John; Glezer, Ari

    2007-11-01

    Closed-loop feedback control of the attitude of a free pitching airfoil is effected without moving control surfaces by alternate actuation of nominally-symmetric trapped vorticity concentrations on the suction and pressure surfaces near the trailing edge. The pitching moment is varied with minimal lift and drag penalties over a broad range of angles of attack when the baseline flow is fully attached. Accumulation (trapping) and regulation of vorticity is managed by integrated hybrid actuators (each comprised of a miniature [O(0.01c)] obstruction and a synthetic jet actuator). In the present work, the model is trimmed using a position feedback loop and a servo motor actuator. Once the model is trimmed, the position feedback loop is opened and the servo motor acts like an inner loop control to alter the model's dynamic characteristics. Position control of the model is achieved using a reference model-based outer loop controller.

  8. Towards antihydrogen trapping and spectroscopy at ALPHA

    International Nuclear Information System (INIS)

    Butler, E.; Andresen, G. B.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Bowe, P. D.; Bray, C. C.; Cesar, C. L.; Chapman, S.; Charlton, M.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayano, R. S.; Hayden, M. E.; Humphries, A. J.; Hydomako, R.

    2011-01-01

    Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN’s Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background.

  9. Acoustic rainbow trapping by coiling up space

    KAUST Repository

    Ni, Xu

    2014-11-13

    We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

  10. Trapped individual ion at absolute zero temperature

    Science.gov (United States)

    Yu, Nan; Dehmelt, Hans; Nagourney, Warren

    1989-01-01

    Laser cooling and ion trapping have progressed to such an extent that one can now speak of realizing a confined atom at absolute zero temperature. In this short publication, we analyze an experiment toward such realization using a single Ba+ ion in a miniature rf trap. The Ba+ ion is first laser-cooled to the limit where the ion spends most of its time in the zero-point energy state. Then a test sequence allows one to verify whether or not the ion is actually in its zero-point state. The test sequence may also serve as a device for state selection of an atom at absolute zero temperature. PMID:16594054

  11. Ultrasonic trap for light scattering measurement

    Science.gov (United States)

    Barton, Petr; Pavlu, Jiri

    2017-04-01

    Light scattering is complex phenomenon occurring widely in space environments, including the dense dusty clouds, nebulas or even the upper atmosphere of the Earth. However, when the size of the dust (or of other scattering center) is close to the incident light wavelength, theoretical determination is difficult. In such case, Mie theory is to be used but there is a lack of the material constants for most space-related materials. For experimental measurement of light scattering, we designed unique apparatus, based on ultrasonic trap. Using acoustic levitation we are able to capture the dust grain in midair, irradiate it with laser, and observe scattering directly with goniometer-mounted photodiode. Advantage of this approach is ability to measure directly in the air (thus, no need for the carrier medium) and possibility to study non-spherical particles. Since the trap development is nearly finished and initial experiments are carried out, the paper presents first tests on water droplets.

  12. The beta subunit of casein kinase II

    DEFF Research Database (Denmark)

    Boldyreff, B; Piontek, K; Schmidt-Spaniol, I

    1991-01-01

    cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies.......cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies....

  13. Near ground state Raman sideband cooling of an ion in a hybrid radiofrequency-optical lattice trap

    Science.gov (United States)

    Bylinskii, Alexei; Karpa, Leon; Gangloff, Dorian; Cetina, Marko; Vuletic, Vladan

    2013-05-01

    We achieve near ground state cooling of an ion in a hybrid trap formed by a two-dimensional radio-frequency Paul trap and an optical lattice produced by a cavity in the axial dimension. We drive far-detuned lattice-assisted Raman transitions on the red vibrational sideband between the Zeeman sublevels of the 2S1/2 ground level of 174Yb+. The cooling cycle is completed by a close-detuned spontaneous Raman transition. Efficient Cooling in all three dimensions is achieved this way. Furthermore, spatially dependent AC Stark shifts induced by the lattice allow us to measure axial temperature via ion fluorescence, and we estimate the population of the lattice vibrational ground state to be above 50%. This work is an important step towards quantum information and quantum simulations with ions in hybrid traps and optical lattices. Army Research Office, National Science Foundation, National Science and Engineering Research Council of Canada, Alexander von Humboldt Foundation.

  14. Discrepancies between Aedes aegypti identification in the field and in the laboratory after collection with a sticky trap

    Directory of Open Access Journals (Sweden)

    Rafael Maciel-de-Freitas

    2014-09-01

    Full Text Available Currently, sticky traps are regularly employed to assist in the surveillance of Aedes aegypti infestation. We tested two alternative procedures for specimen identification performed by local health agents: directly in the field, as recommended by certain manufacturers, or after transportation to the laboratory. A total of 384 sticky traps (MosquiTRAP were monitored monthly during one year in four geographically representative Brazilian municipalities. When the same samples were inspected in the field and in the laboratory, large differences were noted in the total number of mosquitoes recorded and in the number of specimens identified as Ae. aegypti by both procedures. Although field identification has the potential to speed vector surveillance, these results point to uncertainties in the evaluated protocol.

  15. Fast Quantum Rabi Model with Trapped Ions.

    Science.gov (United States)

    Moya-Cessa, Héctor M

    2016-12-12

    We show how to produce a fast quantum Rabi model with trapped ions. Its importance resides not only in the acceleration of the phenomena that may be achieved with these systems, from quantum gates to the generation of nonclassical states of the vibrational motion of the ion, but also in reducing unwanted effects such as the decay of coherences that may appear in such systems.

  16. Quantum interference from remotely trapped ions

    International Nuclear Information System (INIS)

    Gerber, S; Rotter, D; Hennrich, M; Blatt, R; Rohde, F; Schuck, C; Almendros, M; Gehr, R; Dubin, F; Eschner, J

    2009-01-01

    We observe quantum interference of photons emitted by two continuously laser-excited single ions, independently trapped in distinct vacuum vessels. High contrast two-photon interference is observed in two experiments with different ion species, Ca + and Ba + . Our experimental findings are quantitatively reproduced by Bloch equation calculations. In particular, we show that the coherence of the individual resonance fluorescence light field is determined from the observed interference.

  17. Quantum interference from remotely trapped ions

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, S; Rotter, D; Hennrich, M; Blatt, R [Institute for Experimental Physics, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck (Austria); Rohde, F; Schuck, C; Almendros, M; Gehr, R; Dubin, F; Eschner, J [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Av del Canal OlImpic, E-08860 Castelldefels (Spain)], E-mail: francois.dubin@icfo.es

    2009-01-15

    We observe quantum interference of photons emitted by two continuously laser-excited single ions, independently trapped in distinct vacuum vessels. High contrast two-photon interference is observed in two experiments with different ion species, Ca{sup +} and Ba{sup +}. Our experimental findings are quantitatively reproduced by Bloch equation calculations. In particular, we show that the coherence of the individual resonance fluorescence light field is determined from the observed interference.

  18. Spin-polarized deuterium in magnetic traps

    International Nuclear Information System (INIS)

    Koelman, J.M.V.A.; Stoof, H.T.C.; Verhaar, B.J.; Walraven, J.T.M.

    1987-01-01

    We have calculated the spin-exchange two-body rate constants associated with the population dynamics of the hyperfine levels of atomic deuterium as a function of magnetic field in the Boltzmann zero-temperature limit. Results indicate that a gas of low-field--seeking deuterium atoms trapped in a static magnetic field minimum decays rapidly into an ultrastable gas of doubly spin-polarized deuterium. We also discuss the temperature dependence of various effects

  19. Progress towards microwave spectroscopy of trapped antihydrogen

    International Nuclear Information System (INIS)

    Ashkezari, Mohammad D.; Andresen, Gorm B.; Baquero-Ruiz, Marcelo; Bertsche, Wil; Bowe, Paul D.; Butler, Eoin; Cesar, Claudio L.; Chapman, Steve; Charlton, Michael; Deller, Adam; Eriksson, Stefan; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C.; Gill, Dave R.; Gutierrez, Andrea; Hangst, Jeffrey S.; Hardy, Walter N.; Hayano, Ryugo S.; Hayden, Michael E.

    2012-01-01

    Precision comparisons of hyperfine intervals in atomic hydrogen and antihydrogen are expected to yield experimental tests of the CPT theorem. The CERN-based ALPHA collaboration has initiated a program of study focused on microwave spectroscopy of trapped ground-state antihydrogen atoms. This paper outlines some of the proposed experiments, and summarizes measurements that characterize microwave fields that have been injected into the ALPHA apparatus.

  20. On Fuzzy {beta}-I-open sets and Fuzzy {beta}-I-continuous functions

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Aynur [Department of Mathematics, Faculty of Science and Arts, Selcuk University, Campus, 42075 Konya (Turkey)], E-mail: akeskin@selcuk.edu.tr

    2009-11-15

    In this paper, first of all we obtain some properties and characterizations of fuzzy {beta}-I-open sets. After that, we also define the notion of {beta}-I-closed sets and obtain some properties. Lastly, we introduce the notions of fuzzy {beta}-I-continuity with the help of fuzzy {beta}-I-open sets to obtain decomposition of fuzzy continuity.

  1. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Drug- and disease-induced changes of human cardiac beta 1- and beta 2-adrenoceptors

    NARCIS (Netherlands)

    Brodde, O. E.; Zerkowski, H. R.; Borst, H. G.; Maier, W.; Michel, M. C.

    1989-01-01

    Cardiac beta-adrenoceptor density and subtype distribution has been determined in different kinds of heart failure. A decrease in cardiac beta-adrenoceptor function appears to be a general phenomenon in all kinds of heart failure. However, cardiac beta 1- and beta 2-adrenoceptors seem to be

  4. Cryogenic setup for trapped ion quantum computing.

    Science.gov (United States)

    Brandl, M F; van Mourik, M W; Postler, L; Nolf, A; Lakhmanskiy, K; Paiva, R R; Möller, S; Daniilidis, N; Häffner, H; Kaushal, V; Ruster, T; Warschburger, C; Kaufmann, H; Poschinger, U G; Schmidt-Kaler, F; Schindler, P; Monz, T; Blatt, R

    2016-11-01

    We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternating magnetic field noise, resulting in 120 dB reduction of 50 Hz noise along the magnetic field axis. We combine this efficient magnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of optical qubits due to the motion of the cryostat. We measure vibrations of the cryostat of less than ±20 nm over 2 s. In addition to the cryogenic apparatus, we describe the setup required for an operation with 40 Ca + and 88 Sr + ions. The instability of the laser manipulating the optical qubits in 40 Ca + is characterized by yielding a minimum of its Allan deviation of 2.4 ⋅ 10 -15 at 0.33 s. To evaluate the performance of the apparatus, we trapped 40 Ca + ions, obtaining a heating rate of 2.14(16) phonons/s and a Gaussian decay of the Ramsey contrast with a 1/e-time of 18.2(8) ms.

  5. Iodine Gas Trapping using Granular Porous Bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Hwan; Shin, Jin Myeong; Park, Jang Jin; Park, Geun Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yim, Mansung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    {sup 129}I is a radionuclide with a very long half-life of 1.57 Χ 10{sup 7} years and has negative health effects to the human body. Therefore, the emission of {sup 129}I into the air is closely regulated by the Environmental Protection Agency (EPA). Many methods for trapping gaseous {sup 129}I have been developed thus far, including wet scrubbing and adsorption using silver loaded zeolites. Although wet scrubbing can effectively remove iodine, it suffers from corrosion of the vessel due to high concentration of the scrubbing solution. Silver loaded zeolites also show effectiveness in capturing {sup 129}I gas, yet weak thermal stability of physisorbed iodine remains a challenge. We studied a novel and facile method to trap iodine gas using bismuth. Granular bismuth having many pores was synthesized using bismuth nitrate and polyvinyl alcohol as a bismuth precursor and pore forming agent, respectively. Reaction of iodine and our samples resulted in an iodine capturing capacity of more than 2 times that of the commercial grade silver exchanged zeolite (AgX). Granular porous bismuths synthesized using bismuth nitrate and PVA show a promising performance in capturing iodine gas. The use of bismuth in trapping {sup 129}I gas can reduce the process cost as bismuth is cheap. Further study is going on to improve the mechanical property of granular porous bismuths for their easy handling.

  6. SURVEY OF THE ENTOMOFAUNA THROUGH LUMINOUS TRAP

    Directory of Open Access Journals (Sweden)

    V. R. Andrade Neto

    2014-09-01

    Full Text Available The demand for forest-based raw materials for energy, construction, paper pulp and the pressure to comply with legal requirements concerning environmental legislation, for example, the replacement of the permanent preservation area, legal reserve and recovery of degraded area, leads to encourage the production of healthy seedlings in a health status to do not compromise their future production. The present study aimed to survey the entomofauna population using the “Luiz de Queiroz” model of luminous trap, with white and red fluorescent lamps. The experiment was conducted at the nursery “Flora Sinop” in Sinop – MT. The survey was conducted weekly between the months of April to July 2010, totaling 4 months sand, 32 samples collected. The orders Hemiptera and Coleoptera showed the highest number of individuals captured, either in attraction with white or red light. It was captured 10.089 individuals, 9.339 collected under the influence of white light, representing 92,56%, and 750 with red light, only 7,44% of the total. The white light luminous trap possessed greater efficiency in the attraction of insects when compared with the red light trap.

  7. Impurity Trapping of Positive Muons in Metals

    CERN Multimedia

    2002-01-01

    Polarized positive muons are implanted into metal samples. In an applied magnetic field the muon spin precession is studied. The line width in the precession frequency spectrum gives information about the static and dynamic properties of muons in a metal lattice. At temperatures where the muon is immobile within its lifetime the line width gives information about the site of location. At temperatures where the muon is mobile, the line width gives information on the diffusion process. It is known from experiments on quasi-elastic neutron scattering on hydrogen in niobium that interstitial impurities like nitrogen tend to act as traps for hydrogen. These trapping effects have now been studied systematically for muons in both f.c.c. metals (aluminium and copper) and b.c.c. metals (mainly niobium). Direct information on the trapping rates and the nature of the diffusion processes can be obtained since the muonic lifetime covers a time range where many of these processes occur.\\\\ \\\\ Mathematical models are set up ...

  8. Trapping and manipulating single molecules of DNA

    Science.gov (United States)

    Shon, Min Ju

    This thesis presents the development and application of nanoscale techniques to trap and manipulate biomolecules, with a focus on DNA. These methods combine single-molecule microscopy and nano- and micro-fabrication to study biophysical properties of DNA and proteins. The Dimple Machine is a lab-on-a-chip device that can isolate and confine a small number of molecules from a bulk solution. It traps molecules in nanofabricated chambers, or "dimples", and the trapped molecules are then studied on a fluorescence microscope at the single-molecule level. The sampling of bulk solution by dimples is representative, reproducible, and automated, enabling highthroughput single-molecule experiments. The device was applied to study hybridization of oligonucleotides, particularly in the context of reaction thermodynamics and kinetics in nanoconfinement. The DNA Pulley is a system to study protein binding and the local mechanical properties of DNA. A molecule of DNA is tethered to a surface on one end, and a superparamagnetic bead is attached to the other. A magnet pulls the DNA taut, and a silicon nitride knife with a nanoscale blade scans the DNA along its contour. Information on the local properties of the DNA is extracted by tracking the bead with nanometer precision in a white-light microscope. The system can detect proteins bound to DNA and localize their recognition sites, as shown with a model protein, EcoRI restriction enzyme. Progress on the measurements of nano-mechanical properties of DNA is included.

  9. Sequence of PSE-2 beta-lactamase.

    OpenAIRE

    Huovinen, P; Huovinen, S; Jacoby, G A

    1988-01-01

    The nucleotide sequence of PSE-2 beta-lactamase, an enzyme that readily hydrolyzes both carbenicillin and oxacillin, has been determined. The deduced sequence of 266 amino acids contained 93 residues identical to those of OXA-2 beta-lactamase and the Ser-Thr-Phe-Lys tetrad also found in the active site of TEM-1 beta-lactamase.

  10. THE ALPHA/BETA-HYDROLASE FOLD

    NARCIS (Netherlands)

    OLLIS, DL; CHEAH, E; CYGLER, M; FROLOW, F; FRANKEN, SM; HAREL, M; REMINGTON, SJ; SILMAN, [No Value; SCHRAG, J; SUSSMAN, JL; VERSCHUEREN, KHG; GOLDMAN, A

    We have identified a new protein fold-the alpha/beta-hydrolase fold-that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an alpha/beta-sheet, not barrel, of eight beta-sheets connected by alpha-helices. These

  11. Beta-lactamases in Enterobacteriaceae in broilers

    NARCIS (Netherlands)

    Dierikx, C.M.

    2013-01-01

    Resistance to cephalosprins due to the production of extended spectrum beta-lactamases (ESBLs) or plasmid mediated AmpC beta-lactamases is increasingly found in infections in humans outside the hospital. The genes encoding for these beta-lactamases are located on mobile DNA (plasmids), which can be

  12. Progress Report on the Improved Linear Ion Trap Physics Package

    Science.gov (United States)

    Prestage, John D.

    1995-01-01

    This article describes the first operational results from the extended linear ion trap frequency standard now being developed at JPL. This new design separates the state selection/interrogation region from the more critical microwave resonance region where the multiplied local oscillator (LO) signal is compared to the stable atomic transition. Hg+ ions have been trapped, shuttled back and forth between the resonance and state selection traps. In addition, microwave transitions between the Hg+ clock levels have been driven in the resonance trap and detected in the state selection trap.

  13. Single qubit manipulation in a microfabricated surface electrode ion trap

    Science.gov (United States)

    Mount, Emily; Baek, So-Young; Blain, Matthew; Stick, Daniel; Gaultney, Daniel; Crain, Stephen; Noek, Rachel; Kim, Taehyun; Maunz, Peter; Kim, Jungsang

    2013-09-01

    We trap individual 171Yb+ ions in a surface trap microfabricated on a silicon substrate, and demonstrate a complete set of high fidelity single qubit operations for the hyperfine qubit. Trapping times exceeding 20 min without laser cooling, and heating rates as low as 0.8 quanta ms-1, indicate stable trapping conditions in these microtraps. A coherence time of more than 1 s, high fidelity qubit state detection and single qubit rotations are demonstrated. The observation of low heating rates and demonstration of high quality single qubit gates at room temperature are critical steps toward scalable quantum information processing in microfabricated surface traps.

  14. Single qubit manipulation in a microfabricated surface electrode ion trap

    International Nuclear Information System (INIS)

    Mount, Emily; Baek, So-Young; Gaultney, Daniel; Crain, Stephen; Noek, Rachel; Kim, Taehyun; Maunz, Peter; Kim, Jungsang; Blain, Matthew; Stick, Daniel

    2013-01-01

    We trap individual 171 Yb + ions in a surface trap microfabricated on a silicon substrate, and demonstrate a complete set of high fidelity single qubit operations for the hyperfine qubit. Trapping times exceeding 20 min without laser cooling, and heating rates as low as 0.8 quanta ms −1 , indicate stable trapping conditions in these microtraps. A coherence time of more than 1 s, high fidelity qubit state detection and single qubit rotations are demonstrated. The observation of low heating rates and demonstration of high quality single qubit gates at room temperature are critical steps toward scalable quantum information processing in microfabricated surface traps. (paper)

  15. A Rotating-Bears Optical Dipole Trap for Cold Aatoms

    International Nuclear Information System (INIS)

    Friedman, N.; Ozeri, R.; Khaykovich, L.; Davidson, N.

    1999-01-01

    In the last few years, several optical dipole traps for cold atoms were demonstrated and used to study cold atomic collisions, long atomic coherence times and quantum collective effects. Blue-detuned dipole traps, where repulsive light forces confines atoms mostly in dark, offer long storage, and photon-scattering times, combined with strong confinement forces. Unfortunately, such blue-detuned dipole traps involve complicated light intensity distributions that require either multiple laser beams or complicated phase elements. Here, we propose and demonstrate a novel configuration for a single-beam blue-detuned dipole trap, which enables larger trapping volume, and fast temporal changes in the trap size and shape. Our trap consists of a tightly-focused laser beam which is rapidly rotated (with rotation frequency up to 400 khz) with two orthogonal acousto optical scanners. For very high rotation frequencies the atoms feel a time-averaged static dipole potential. Therefore, when the radius of rotation is larger than the beam size, a dark volume which is completely surrounded by light is obtained around the focal region. By changing the rotation radius and the trapping laser intensity and detuning, the trap dimensions and oscillation frequency could be changed over a large parameter range. In particular trap diameters were changed between 50 to 220 microns and trap length was changed between 3.5 to 16 mm. ∼10 6 atoms were loaded into the rotating-beam dipole trap from a magneto optical trap. The density of the trapped atoms was 4x10 10 atoms/cm 3 ,their temperature was -6 pK. and the trap (1/e) lifetime was 0.65 sec, limited by collisions with background atoms. When the rotation frequency was decreased below the oscillation frequency of the atoms in the trap, the trap became unstable, and a sharp reduction of the trap lifetime was observed, in agreement with our theoretical analysis. Finally, we demonstrated adiabatic compression of atoms in the trap by decreasing

  16. Beta* and beta-waist measurement and control at RHIC

    International Nuclear Information System (INIS)

    Ptitsyn, V.; Della Penna, A.; Litvinenko, V.N.; Malitsky, N.; Satogata, T.

    2009-01-01

    During the course of last RHIC runs the beta-functions at the collision points (β*) have been reduced gradually to 0.7m. In order to maximize the collision luminosity and ensure the agreement of the actual machine optics with the design one, more precise measurements and control of β* value and β-waist location became necessary. The paper presents the results of the implementation of the technique applied in last two RHIC runs. The technique is based on well-known relation between the tune shift and the beta function and involves precise betatron tune measurements using BBQ system as well as specially developed knobs for β-waist location control

  17. Self-assembly of a novel beta-In2S3 nanostructure exhibiting strong quantum confinement effects.

    Science.gov (United States)

    Zhang, Wu; Ma, Dekun; Huang, Zhen; Tang, Qun; Xie, Qin; Qian, Yitai

    2005-05-01

    The 3D beta-In2S3 flowerlike architecture assembled from nanoflakes was prepared via a novel complex-precursor assisted (CPA) solvothermal route. The as-prepared beta-In2S3 powder was characterized by X-ray diffraction pattern (XRD), X-ray photoelectron spectra (XPS), transition electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), ultraviolet-visible light (UV-vis) spectra, and photoluminescence spectrum. The novel 3D beta-In2S3 nanostructure exhibit a strong quantum confinement effect. FT-IR spectra were used to investigate the coordinative chemical effect in the complex. A possible mechanism was discussed.

  18. Gene encoding the human. beta. -hexosaminidase. beta. chain: Extensive homology of intron placement in the. alpha. - and. beta. -chain genes

    Energy Technology Data Exchange (ETDEWEB)

    Proia, R.L. (National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, MD (USA))

    1988-03-01

    Lysosomal {beta}-hexosaminidase is composed of two structurally similar chains, {alpha} and {beta}, that are the products of different genes. Mutations in either gene causing {beta}-hexosaminidase deficiency result in the lysosomal storage disease GM2-gangliosidosis. To enable the investigation of the molecular lesions in this disorder and to study the evolutionary relationship between the {alpha} and {beta} chains, the {beta}-chain gene was isolated, and its organization was characterized. The {beta}-chain coding region is divided into 14 exons distributed over {approx}40 kilobases of DNA. Comparison with the {alpha}-chain gene revealed that 12 of the 13 introns interrupt the coding regions at homologous positions. This extensive sharing of intron placement demonstrates that the {alpha} and {beta} chains evolved by way of the duplication of a common ancestor.

  19. DNA damage: beta zero versus beta plus thalassemia.

    Science.gov (United States)

    Sagar, Chandan S; Kumar, Rakesh; Sharma, Dharmesh C; Kishor, Purnima

    2015-01-01

    β thalassemia results in an increase in the α to non-α chain ratio. Iron released from unpaired α chains in RBCs and that ensuing from regular transfusions is the major cause of cellular damage. The use of iron chelators to counter the iron overload is accompanied by side-effects. The extent of iron toxicity could vary from one patient to another and could help in determining the optimal chelator dose for each patient. To observe the pro-oxidant/antioxidant disturbance and the extent of DNA damage in β thalassemia patients with different β globin gene anomalies. The formation of Reactive Oxygen Species (ROS ) was observed by incubation of cell suspensions with 2',7', dichlorofluorescin-diacetate (DCFH DA) and DNA damage was demonstrated by single cell gel electrophoresis. Heinz bodies were observed by staining blood smears. The study group comprised 50 regularly transfused beta thalassemia patients and 40 non thalassemic controls. While Heinz bodies and nucleated RBCs were seen in all the patients, oxidation of DCFH and DNA damage were seen to be associated with the β globin gene defect. DNA damage was found to be greater in β(0) homozygotes as compared to the β(+) homozygotes, and was maximum in patients presenting with the 619 base pair deletion. In the present study, iron toxicity, as indicated by DNA damage, has been seen to vary in the patients. Thus, monitoring of the dose of iron chelators, according to the type of mutation in the beta globin gene, may help improve the compliance of beta thalassemics to chelation therapy and prevent side-effects in patients with beta plus mutations.

  20. A Beta-Beta Achievability Bound with Applications

    OpenAIRE

    Yang, Wei; Collins, Austin; Durisi, Giuseppe; Polyanskiy, Yury; Poor, H. Vincent

    2016-01-01

    A channel coding achievability bound expressed in terms of the ratio between two Neyman-Pearson $\\beta$ functions is proposed. This bound is the dual of a converse bound established earlier by Polyanskiy and Verd\\'{u} (2014). The new bound turns out to simplify considerably the analysis in situations where the channel output distribution is not a product distribution, for example due to a cost constraint or a structural constraint (such as orthogonality or constant composition) on the channel...