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https://www.readbyqxmd.com/read/29341742/measurement-of-the-electron-antineutrino-angular-correlation-in-neutron-%C3%AE-decay
#1
G Darius, W A Byron, C R DeAngelis, M T Hassan, F E Wietfeldt, B Collett, G L Jones, M S Dewey, M P Mendenhall, J S Nico, H Park, A Komives, E J Stephenson
We report the first result for the electron-antineutrino angular correlation (a coefficient) in free neutron β decay from the aCORN experiment. aCORN uses a novel method in which the a coefficient is proportional to an asymmetry in proton time of flight for events where the β electron and recoil proton are detected in delayed coincidence. Data are presented from a 15 month run at the NIST Center for Neutron Research. We obtained a=-0.1090±0.0030(stat)±0.0028(sys), the most precise measurement of the neutron a coefficient reported to date...
July 28, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29341737/superradiant-instability-and-backreaction-of-massive-vector-fields-around-kerr-black-holes
#2
William E East, Frans Pretorius
We study the growth and saturation of the superradiant instability of a complex, massive vector (Proca) field as it extracts energy and angular momentum from a spinning black hole, using numerical solutions of the full Einstein-Proca equations. We concentrate on a rapidly spinning black hole (a=0.99) and the dominant m=1 azimuthal mode of the Proca field, with real and imaginary components of the field chosen to yield an axisymmetric stress-energy tensor and, hence, spacetime. We find that in excess of 9% of the black hole's mass can be transferred into the field...
July 28, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29341684/first-simultaneous-extraction-of-spin-dependent-parton-distributions-and-fragmentation-functions-from-a-global-qcd-analysis
#3
J J Ethier, N Sato, W Melnitchouk
We perform the first global QCD analysis of polarized inclusive and semi-inclusive deep-inelastic scattering and single-inclusive e^{+}e^{-} annihilation data, simultaneously fitting the parton distribution and fragmentation functions using the iterative Monte Carlo method. Without imposing SU(3) symmetry relations, we find the strange polarization to be very small, consistent with zero for both inclusive and semi-inclusive data, which provides a resolution to the strange quark polarization puzzle. The combined analysis also allows the direct extraction from data of the isovector and octet axial charges, and is consistent with a small SU(2) flavor asymmetry in the polarized sea...
September 29, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29341647/attosecond-electron-correlation-dynamics-in-double-ionization-of-benzene-probed-with-two-electron-angular-streaking
#4
Alexander H Winney, Suk Kyoung Lee, Yun Fei Lin, Qing Liao, Pradip Adhikari, Gihan Basnayake, H Bernhard Schlegel, Wen Li
With a novel three-dimensional electron-electron coincidence imaging technique and two-electron angular streaking method, we show that the emission time delay between two electrons can be measured from tens of attoseconds to more than 1 fs. Surprisingly, in benzene, the double ionization rate decays as the time delay between the first and second electron emission increases during the first 500 as. This is further supported by the decay of the Coulomb repulsion in the direction perpendicular to the laser polarization...
September 22, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29339983/analysis-of-the-hamstring-muscle-activation-during-two-injury-prevention-exercises
#5
Alireza Monajati, Eneko Larumbe-Zabala, Mark Goss-Sampson, Fernando Naclerio
The aim of this study was to perform an electromyographic and kinetic comparison of two commonly used hamstring eccentric strengthening exercises: Nordic Curl and Ball Leg Curl. After determining the maximum isometric voluntary contraction of the knee flexors, ten female athletes performed 3 repetitions of both the Nordic Curl and Ball Leg Curl, while knee angular displacement and electromyografic activity of the biceps femoris and semitendinosus were monitored. No significant differences were found between biceps femoris and semitendinosus activation in both the Nordic Curl and Ball Leg Curl...
December 2017: Journal of Human Kinetics
https://www.readbyqxmd.com/read/29339784/anisotropic-sensor-and-memory-device-with-a-ferromagnetic-tunnel-barrier-as-the-only-magnetic-element
#6
L Lόpez-Mir, C Frontera, H Aramberri, K Bouzehouane, J Cisneros-Fernández, B Bozzo, L Balcells, B Martínez
Multiple spin functionalities are probed on Pt/La2Co0.8Mn1.2O6/Nb:SrTiO3, a device composed by a ferromagnetic insulating barrier sandwiched between non-magnetic electrodes. Uniquely, La2Co0.8Mn1.2O6 thin films present strong perpendicular magnetic anisotropy of magnetocrystalline origin, property of major interest for spintronics. The junction has an estimated spin-filtering efficiency of 99.7% and tunneling anisotropic magnetoresistance (TAMR) values up to 30% at low temperatures. This remarkable angular dependence of the magnetoresistance is associated with the magnetic anisotropy whose origin lies in the large spin-orbit interaction of Co2+ which is additionally tuned by the strain of the crystal lattice...
January 16, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29339310/distant-from-input-evidence-of-regions-within-the-default-mode-network-supporting-perceptually-decoupled-and-conceptually-guided-cognition
#7
Charlotte Murphy, Elizabeth Jefferies, Shirley-Ann Rueschemeyer, Mladen Sormaz, Hao-Ting Wang, Daniel S Margulies, Jonathan Smallwood
The default mode network supports a variety of mental operations such as semantic processing, episodic memory retrieval, mental time travel and mind-wandering, yet the commonalities between these functions remains unclear. One possibility is that this system supports cognition that is independent of the immediate environment; alternatively or additionally, it might support higher-order conceptual representations that draw together multiple features. We tested these accounts using a novel paradigm that separately manipulated the availability of perceptual information to guide decision-making and the representational complexity of this information...
January 12, 2018: NeuroImage
https://www.readbyqxmd.com/read/29339001/does-the-surgical-approach-for-treating-mandibular-condylar-fractures-affect-the-rate-of-seventh-cranial-nerve-injuries-a-systematic-review-and-meta-analysis-based-on-a-new-classification-for-surgical-approaches
#8
Essam Ahmed Al-Moraissi, Aurélien Louvrier, Giacomo Colletti, Larry M Wolford, Federico Biglioli, Marwa Ragaey, Christophe Meyer, Edward Ellis
PURPOSE: The purpose of this study was to determine the rate of facial nerve injury (FNI) when performing (ORIF) of mandibular condylar fractures by different surgical approaches. MATERIALS AND METHODS: A systematic review and meta-analysis were performed that included several databases with specific keywords, a reference search, and a manual search for suitable articles. The inclusion criteria were all clinical trials, with the aim of assessing the rate of facial nerve injuries when (ORIF) of mandibular condylar fractures was performed using different surgical approaches...
November 14, 2017: Journal of Cranio-maxillo-facial Surgery
https://www.readbyqxmd.com/read/29337874/angular-molecular-electronic-sensor-with-negative-magnetohydrodynamic-feedback
#9
Egor Egorov, Vadim Agafonov, Svetlana Avdyukhina, Sergey Borisov
A high-precision angular accelerometer based on molecular-electronic transfer (MET) technology with a high dynamic range and a low level of self-noise has been developed. Its difference from the analogues is in the use of liquid (electrolyte) as the inertial mass and the use of negative feedback based on the magnetohydrodynamic effect. This article reports on the development of the angular molecular-electronic accelerometer with a magnetohydrodynamic cell for the creation of negative feedback, and the optimization of electronics for the creation of a feedback signal...
January 16, 2018: Sensors
https://www.readbyqxmd.com/read/29336791/robust-inertia-free-attitude-takeover-control-of-postcapture-combined-spacecraft-with-guaranteed-prescribed-performance
#10
Jianjun Luo, Caisheng Wei, Honghua Dai, Zeyang Yin, Xing Wei, Jianping Yuan
In this paper, a robust inertia-free attitude takeover control scheme with guaranteed prescribed performance is investigated for postcapture combined spacecraft with consideration of unmeasurable states, unknown inertial property and external disturbance torque. Firstly, to estimate the unavailable angular velocity of combination accurately, a novel finite-time-convergent tracking differentiator is developed with a quite computationally achievable structure free from the unknown nonlinear dynamics of combined spacecraft...
January 11, 2018: ISA Transactions
https://www.readbyqxmd.com/read/29336102/behavioural-responses-of-the-yellow-emitting-annelid-tomopteris-helgolandica-to-photic-stimuli
#11
Anaïd Gouveneaux, Marie-Charlotte Gielen, Jérôme Mallefet
In contrast to most mesopelagic bioluminescent organisms specialised in the emission and reception of blue light, the planktonic annelid Tomopteris helgolandica produces yellow light. This unusual feature has long been suggested to serve for intraspecific communication. Yet, this virtually admitted hypothesis has never been tested. In this behavioural study of spectral colour sensitivity, we first present an illustrated repertoire of the postures and action patterns described by captive specimens. Then video tracking and motion analysis are used to quantify the behavioural responses of singled out worms to photic stimuli imitating intraspecific (yellow) or interspecific (blue) bioluminescent signals...
January 16, 2018: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/29335697/photodissociation-dynamics-of-bromoiodomethane-from-the-first-and-second-absorption-bands-a-combined-velocity-map-and-slice-imaging-study
#12
Sonia Marggi Poullain, David V Chicharro, Eduardo Navarro, Luis Rubio-Lago, Jesús González-Vázquez, Luis Bañares
The photodissociation dynamics of bromoiodomethane (CH2BrI) have been investigated at the maximum of the first A and second A' absorption bands, at 266 and 210 nm excitation wavelengths, respectively, using velocity map and slice imaging techniques in combination with a probe detection of both iodine and bromine fragments, I(2P3/2), I*(2P1/2), Br(2P3/2) and Br*(2P1/2) via (2 + 1) resonance enhanced multiphoton ionization. Experimental results, i.e. translational energy and angular distributions, are reported and discussed in conjunction with high level ab initio calculations of potential energy curves and absorption spectra...
January 16, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29335654/microwave-squid-multiplexer-demonstration-for-cosmic-microwave-background-imagers
#13
B Dober, D T Becker, D A Bennett, S A Bryan, S M Duff, J D Gard, J P Hays-Wehle, G C Hilton, J Hubmayr, J A B Mates, C D Reintsema, L R Vale, J N Ullom
Key performance characteristics are demonstrated for the microwave SQUID multiplexer (µmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the µmux produces a white, input referred current noise level of [Formula: see text] at -77 dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure [Formula: see text] in the TES-coupled channels biased at 65% of the sensor normal resistance...
December 2017: Applied Physics Letters
https://www.readbyqxmd.com/read/29335223/electron-channeling-orientation-determination-echord-an-original-approach-to-crystalline-orientation-mapping
#14
C Lafond, T Douillard, S Cazottes, P Steyer, C Langlois
We present a proof-of-concept attesting the feasability to obtain orientation maps of polycrystalline materials within a conventional Scanning Electron Microscope (SEM) using a standard goniometer and Back Scattered Electron (BSE) detector. The described method is based on the analysis of the contrast variation of grains due to the channeling of incident electrons on a rotating sample. On each pixel of the map, experimental intensity profiles as a function of the rotation angle are obtained and compared with simulated ones to retrieve the orientation...
December 28, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/29334868/biomechanical-analyses-of-synchronised-swimming-standard-and-contra-standard-sculling
#15
Lara Elena Gomes, Vera Diogo, Flávio Antônio de Souza Castro, João Paulo Vilas-Boas, Ricardo J Fernandes, Pedro Figueiredo
Synchronised swimming involves a variety of sculling movements essential for body support and propulsion but its study is scarce. We aimed to biomechanically compare standard and contra-standard sculling techniques, and to observe the relationship between measures. Six synchronised swimmers performed two, 30 s maximal intensity, fully tethered standard and contra-standard sculling motions. Kinetic and kinematic data were obtained using a load-cell and underwater cameras, respectively. Force decreased along both techniques' bouts, but no differences in-between techniques were noted for any kinetic variables...
January 16, 2018: Sports Biomechanics
https://www.readbyqxmd.com/read/29334768/angular-and-metric-analysis-of-the-neural-structures-in-the-cerebellopontine-angle
#16
Helbert de Oliveira Manduca Palmiero, Marcos Devanir Silva da Costa, Ricardo Lourenço Caramanti, Feres Eduardo Aparecido Chaddad-Neto
INTRODUCTION: The cerebellopontine angle (CPA) is a subarachnoid space in the lateral aspect of the posterior fossa. In this study, we propose a complementary analysis of the CPA from the cerebellopontine fissure. METHODS: We studied 50 hemi-cerebelli in the laboratory of neuroanatomy and included a description of the CPA anatomy from the cerebellopontine fissure and its relationship with the flocculus and the 5th, 6th, 7th, and 8th cranial nerves (CN) origins. RESULTS: The average distance from the 5th CN to the mid-line (ML) was 19...
January 15, 2018: British Journal of Neurosurgery
https://www.readbyqxmd.com/read/29334735/complex-dynamics-of-photo-switchable-guest-molecules-in-all-optical-poling-close-to-glass-transition-kinetic-monte-carlo-modelling
#17
Wojciech Radosz, Grzegorz Pawlik, Antoni Mitus
We study theoretically the kinetics of non-interacting photo-switchable guest molecules (model azo-dye) dispersed at low concentration in host (model polymer matrix) in the all-optical poling process close to the glass transition temperature Tg. We modify kinetic Monte Carlo model used in our previous studies of nonlinear optical processes in host-guest systems. The polymer matrix is simulated using the bond-fluctuation model. The kinetics of multiple trans-cis-trans cycles is formulated in terms of transition probabilities which depend on local free volume in the matrix and its dynamics...
January 15, 2018: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29331926/two-hump-shaped-angular-distributions-of-neutrons-and-soft-x-rays-in-a-small-plasma-focus-device
#18
Morteza Habibi
Angular distributions of soft X-rays (SXRs) and neutrons emitted by a small plasma focus device (PFD) were investigated simultaneously using TLD-100 dosimeters and Geiger-Muller activation counters, respectively. The distributions represented two humps with a small dip at the angular position 0° and reduced from the angles of ± 15° and ± 30° for the neutrons and SXRs, respectively. The maximum yield of 2.98 × 108 neutrons per shot of the device was obtained at 13.5kV and 6.5mbar. A time of flight (TOF) of 75...
December 28, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/29331358/assessing-risk-category-of-breast-cancer-by-ultrasound-imaging-characteristics
#19
Qiang Guo, Lei Zhang, Zhixin Di, Chunping Ning, Zhiwu Dong, Ziyao Li, Dongmo Wang, Chong Liu, Ming Zhao, Jiawei Tian
The purpose of our study was to assess the potential clinical value of ultrasound imaging in predicting risk category in patients with breast cancer. Three hundred thirty-six patients were enrolled and divided into a high-risk group (99, 29.5%) and mid- to low-risk group (237, 70.5%) according to the St. Gallen risk criteria. All data were retrospectively collected to analyze correlations between ultrasound features and risk category. The results revealed that the ultrasound features of irregular shape (p= 0...
January 10, 2018: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/29331229/hominin-raw-material-procurement-in-the-oldowan-acheulean-transition-at-olduvai-gorge
#20
Lindsay J McHenry, Ignacio de la Torre
The lithic assemblages at the Oldowan-Acheulean transition in Bed II of Olduvai Gorge, Tanzania, represent a wide variety of raw materials reflecting both the diversity of volcanic, metamorphic, and sedimentary source materials available in the Olduvai basin and surroundings and the preferences of the tool-makers. A geochemical and petrographic systematic analysis of lava-derived archaeological stone tools, combined with textural and mineralogical characterization of quartzite, chert, and other metamorphic and sedimentary raw materials from two Middle and Upper Bed II sites, has enabled us to produce a comprehensive dataset and characterization of the rocks employed by Olduvai hominins, which is used here to establish a referential framework for future studies on Early Stone Age raw material provenancing...
January 10, 2018: Journal of Human Evolution
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