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https://www.readbyqxmd.com/read/28919700/construction-and-test-results-of-coil-2-of-a-three-coil-800-mhz-rebco-insert-for-the-1-3-ghz-high-resolution-nmr-magnet
#1
Juan Bascuñán, Philip Michael, Seungyong Hahn, Thibault Lecrevisse, Yukikazu Iwasa
This paper focuses on the construction and test results of Coil 2 that is part of a trio of nested coils composing the REBCO 800 MHz insert. Upon its completion, the REBCO 800 MHz insert will be placed in the bore of a 500 MHz low temperature superconducting (LTS) NMR magnet (L500) to form the MIT 1.3 GHz high-resolution NMR magnet. Coil 2 is a stack of 32 double pancake (DP) coils wound with 6-mm wide REBCO tape using the no-insulation (NI) technique. Each pancake is wound on a stainless steel inner supporting ring to prevent the collapsing of its crossover due to the external pressure exerted by the winding pack...
June 2017: IEEE Transactions on Applied Superconductivity: a Publication of the IEEE Superconductivity Committee
https://www.readbyqxmd.com/read/28916834/ultrastructural-characterization-of-the-glomerulopathy-in-alport-mice-by-helium-ion-scanning-microscopy-him
#2
Kenji Tsuji, Hani Suleiman, Jeffrey H Miner, James M Daley, Diane E Capen, Teodor G Păunescu, Hua A Jenny Lu
The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases...
September 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28916738/cold-atmospheric-helium-plasma-causes-synergistic-enhancement-in-cell-death-with-hyperthermia-and-an-additive-enhancement-with-radiation
#3
Rohan Moniruzzaman, Mati Ur Rehman, Qing-Li Zhao, Paras Jawaid, Keigo Takeda, Kenji Ishikawa, Masaru Hori, Kei Tomihara, Kyo Noguchi, Takashi Kondo, Makoto Noguchi
Cold atmospheric plasmas (CAPs) have been proposed as a novel therapeutic method for its anti-cancer potential. However, its biological effects in combination with other physical modalities remain elusive. Therefore, this study examined the effects of cold atmospheric helium plasma (He-CAP) in combination with hyperthermia (HT) 42 °C or radiation 5 Gy. Synergistic enhancement in the cell death with HT and an additive enhancement with radiation were observed following He-CAP treatment. The synergistic effects were accompanied by increased intracellular reactive oxygen species (ROS) production...
September 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28914060/nuclear-spin-symmetry-conservation-in-1-h2-16-o-investigated-by-direct-absorption-ftir-spectroscopy-of-water-vapor-cooled-down-in-supersonic-expansion
#4
Robert Georges, Xavier Michaut, Audrey Moudens, Manuel Goubet, Olivier Pirali, Pascale Soulard, Pierre Asselin, Therese R Huet, Pascale Roy, Martin Fournier, Andrey A Vigasin
We report the results of an experimental study related to the relaxation of the nuclear spin isomers of the water molecule in a supersonic expansion. Rovibrational lines of both ortho- and para- spin isomers were recorded in the spectral range of H2O stretching vibrations around 3700 cm(-1) using FTIR direct absorption. Water vapor seeded either in argon, helium, oxygen or in a mixture of oxygen and argon was expanded into vacuum through a slit nozzle. Partial water vapor pressure in the mixture varied in a wide range from 1...
September 15, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28910102/effects-of-charge-state-charge-distribution-and-structure-on-the-ion-mobility-of-protein-ions-in-helium-gas-results-from-trajectory-method-calculations
#5
Kenneth J Laszlo, Matthew F Bush
Collision cross section (Ω) values of gas-phase ions of proteins and protein complexes are used to probe the structures of the corresponding species in solution. Ions of many proteins exhibit increasing Ω values with increasing charge state, but most Ω values calculated for protein ions have used simple collision models that do not explicitly account for charge. Here we use a combination of ion mobility mass spectrometry experiments using helium gas and trajectory method calculations to characterize the extents to which increases in experimental Ω values with increasing charge state may be attributed to increased momentum transfer concomitant with enhanced long-range interactions between the protein ion and helium atoms...
September 14, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28905916/hardware-efficient-variational-quantum-eigensolver-for-small-molecules-and-quantum-magnets
#6
Abhinav Kandala, Antonio Mezzacapo, Kristan Temme, Maika Takita, Markus Brink, Jerry M Chow, Jay M Gambetta
Quantum computers can be used to address electronic-structure problems and problems in materials science and condensed matter physics that can be formulated as interacting fermionic problems, problems which stretch the limits of existing high-performance computers. Finding exact solutions to such problems numerically has a computational cost that scales exponentially with the size of the system, and Monte Carlo methods are unsuitable owing to the fermionic sign problem. These limitations of classical computational methods have made solving even few-atom electronic-structure problems interesting for implementation using medium-sized quantum computers...
September 13, 2017: Nature
https://www.readbyqxmd.com/read/28895552/measurement-of-track-structure-parameters-of-low-and-medium-energy-helium-and-carbon-ions-in-nanometric-volumes
#7
G Hilgers, M U Bug, H Rabus
Ionization cluster size distributions produced in the sensitive volume of an ion-counting wall-less nanodosimeter by monoenergetic carbon ions with energies between 45 MeV and 150 MeV were measured at the TANDEM-ALPI ion accelerator facility complex of the LNL-INFN in Legnaro. Those produced by monoenergetic helium ions with energies between 2 MeV and 20 MeV were measured at the accelerator facilities of PTB and with a (241)Am alpha particle source. C3H8 was used as the target gas. The ionization cluster size distributions were measured in narrow beam geometry with the primary beam passing the target volume at specified distances from its centre, and in broad beam geometry with a fan-like primary beam...
September 12, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28894129/designing-functionality-in-perovskite-thin-films-using-ion-implantation-techniques-assessment-and-insights-from-first-principles-calculations
#8
Vinit Sharma, Andreas Herklotz, Thomas Zac Ward, Fernando A Reboredo
Recent experimental findings have demonstrated that low doses of low energy helium ions can be used to tailor the structural and electronic properties of single crystal films. These initial studies have shown that changes to lattice expansion were proposed to be the direct result of chemical pressure originating predominantly from the implanted He applying chemical pressure at interstitial sites. However, the influence of possible secondary knock-on damage arising from the He atoms transferring energy to the lattice through nuclear-nuclear collision with the crystal lattice remains largely unaddressed...
September 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28892378/synthesis-of-defect-perovskites-he2-x%C3%A2-x-cazr-f6-by-inserting-helium-into-the-negative-thermal-expansion-material-cazrf6
#9
Brett R Hester, António M Dos Santos, Jamie J Molaison, Justin C Hancock, Angus P Wilkinson
Defect perovskites (He2-x□x)(CaZr)F6 can be prepared by inserting helium into CaZrF6 at high pressure. They can be recovered to ambient pressure at low temperature. There are no prior examples of perovskites with noble gases on the A-sites. The insertion of helium gas into CaZrF6 both elastically stiffens the material and reduces the magnitude of its negative thermal expansion. It also suppresses the onset of structural disorder, which is seen on compression in other media. Measurements of the gas released on warming to room temperature and Rietveld analyses of neutron diffraction data at low temperature indicate that exposure to helium gas at 500 MPa leads to a stoichiometry close to (He1□1)(CaZr)F6...
September 13, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28890491/low-temperature-electronic-paramagnetic-resonance-measurements-of-tempo-and-4-hydroxy-tempo-benzoate-for-purity-analyses-by-the-effective-magnetic-moment-method
#10
Nobuhiro Matsumoto, Takuya Shimosaka
The purities of two high-purity organic compounds with a nitroxyl radical moiety were quantified based on their free-radical content using the effective magnetic-moment method. Magnetic moments were measured and X-band electron paramagnetic resonance (EPR) spectra were obtained using a superconducting quantum interference device and X-band EPR spectrometer, respectively, over a wide temperature range of near-room temperature to near-liquid-helium temperature. Concerning measurements of effective g-values using an EPR spectrometer, both the sweep direction and sweep speed were taken into account to obtain accurate g-values...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28887944/a-calculation-of-the-radiation-environment-on-the-martian-surface
#11
Wouter C de Wet, Lawrence W Townsend
In this work, the radiation environment on the Martian surface, as produced by galactic cosmic radiation incident on the atmosphere, is modeled using the Monte Carlo radiation transport code, High Energy Transport Code-Human Exploration and Development in Space (HETC-HEDS). This work is performed in participation of the 2016 Mars Space Radiation Modeling Workshop held in Boulder, CO, and is part of a larger collaborative effort to study the radiation environment on the surface of Mars. Calculated fluxes for neutrons, protons, deuterons, tritons, helions, alpha particles, and heavier ions up to Fe are compared with measurements taken by Radiation Assessment Detector (RAD) instrument aboard the Mars Science Laboratory over a period of 2 months...
August 2017: Life Sciences in Space Research
https://www.readbyqxmd.com/read/28887941/the-charged-particle-radiation-environment-on-mars-measured-by-msl-rad-from-november-15-2015-to-january-15-2016
#12
Bent Ehresmann, Cary J Zeitlin, Donald M Hassler, Daniel Matthiä, Jingnan Guo, Robert F Wimmer-Schweingruber, Jan K Appel, David E Brinza, Scot C R Rafkin, Stephan I Böttcher, Sönke Burmeister, Henning Lohf, Cesar Martin, Eckart Böhm, Günther Reitz
The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory (MSL) Curiosity rover has been measuring the radiation environment in Gale crater on Mars since August, 2012. These first in-situ measurements provide an important data set for assessing the radiation-associated health risks for future manned missions to Mars. Mainly, the radiation field on the Martian surface stems from Galactic Cosmic Rays (GCRs) and secondary particles created by the GCRs' interactions with the Martian atmosphere and soil...
August 2017: Life Sciences in Space Research
https://www.readbyqxmd.com/read/28887513/coherent-diffractive-imaging-of-single-helium-nanodroplets-with-a-high-harmonic-generation-source
#13
Daniela Rupp, Nils Monserud, Bruno Langbehn, Mario Sauppe, Julian Zimmermann, Yevheniy Ovcharenko, Thomas Möller, Fabio Frassetto, Luca Poletto, Andrea Trabattoni, Francesca Calegari, Mauro Nisoli, Katharina Sander, Christian Peltz, Marc J Vrakking, Thomas Fennel, Arnaud Rouzée
Coherent diffractive imaging of individual free nanoparticles has opened routes for the in situ analysis of their transient structural, optical, and electronic properties. So far, single-shot single-particle diffraction was assumed to be feasible only at extreme ultraviolet and X-ray free-electron lasers, restricting this research field to large-scale facilities. Here we demonstrate single-shot imaging of isolated helium nanodroplets using extreme ultraviolet pulses from a femtosecond-laser-driven high harmonic source...
September 8, 2017: Nature Communications
https://www.readbyqxmd.com/read/28880368/optimization-of-monte-carlo-particle-transport-parameters-and-validation-of-a-novel-high-throughput-experimental-setup-to-measure-the-biological-effects-of-particle-beams
#14
Darshana Patel, Lawrence Bronk, Fada Guan, Christopher R Peeler, Stephan Brons, Ivana Dokic, Amir Abdollahi, Claudia Rittmüller, Oliver Jäkel, David Grosshans, Radhe Mohan, Uwe Titt
PURPOSE: Accurate modeling of the relative biological effectiveness (RBE) of particle beams requires increased systematic in vitro studies with human cell lines with care towards minimizing uncertainties in biologic assays as well as physical parameters. In this study we describe a novel high-throughput experimental setup and an optimized parameterization of the Monte Carlo (MC) simulation technique that is universally applicable for accurate determination of RBE of clinical ion beams...
September 7, 2017: Medical Physics
https://www.readbyqxmd.com/read/28877370/on-the-existence-of-he%C3%AF-he-bond-in-the-endohedral-fullerene-%C3%B0-%C3%B0%C2%B52-c60
#15
Tymofii Yu Nikolaienko, Eugene S Kryachko, Grygoriy A Dolgonos
Twenty years have already been passed since the endohedral fullerene's void ceaselessly attracts attention of both, experimentalists and theoreticians, computational chemists and physicists in particular, who direct their efforts on computer simulations of encapsulating atoms and molecules into fullerene void and on unraveling the arising bonding patterns. We review recent developments on the endohedral He2 @C60 fullerene, on its experimental observation and on related computational works. The two latter are the main concerns in the present work: on the one hand, there experimentally exists the He dimer embedded into C60 void...
September 6, 2017: Journal of Computational Chemistry
https://www.readbyqxmd.com/read/28863639/in-situ-flow-cell-for-combined-x-ray-absorption-spectroscopy-x-ray-diffraction-and-mass-spectrometry-at-high-photon-energies-under-solar-thermochemical-looping-conditions
#16
Matthäus Rothensteiner, Joel Jenni, Hermann Emerich, Alexander Bonk, Ulrich F Vogt, Jeroen A van Bokhoven
An in situ/operando flow cell for transmission mode X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and combined XAS/XRD measurements in a single experiment under the extreme conditions of two-step solar thermochemical looping for the dissociation of water and/or carbon dioxide was developed. The apparatus exposes materials to relevant conditions of both the auto-reduction and the oxidation sub-steps of the thermochemical cycle at ambient temperature up to 1773 K and enables determination of the composition of the effluent gases by online quadrupole mass spectrometry...
August 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28863638/note-development-of-a-cryocooler-based-high-efficiency-cryosorption-pump
#17
Ravi Verma, Aritra Chatterjee, Srinivasan Kasthurirengan, N C Shivaprakash, Upendra Behera
In this communication, we report the development of a cryosorption pump, whose pumping speeds are higher at least by a factor of 1.5 compared to the commercial pumps in specific pressure ranges. This uses a material of high adsorbing capacity along with an adhesive of high thermal conductivity. The measured pumping speeds of these pumps for different gases such as nitrogen, argon, hydrogen, and helium are higher than the commercial cryopumps in the pressure range from 5 × 10(-6) mbar to 5 × 10(-5) mbar. The developed pump will be quite useful for fusion applications...
August 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28863540/theoretical-investigation-of-intersystem-crossing-in-the-cyanonitrene-molecule-1-ncn-%C3%A2-3-ncn
#18
Mark Pfeifle, Yuri Georgievskii, Ahren W Jasper, Stephen J Klippenstein
The NCN diradical is an important intermediate of prompt nitric oxide formation in flames. The mechanism of intersystem crossing (ISC) in the NCN molecule formed via pyrolysis or photolysis of NCN3 is of relevance to the interpretation of experiments that utilize NCN3 as a precursor for laboratory studies of NCN kinetics. This mechanism has been investigated by means of multi-reference configuration interaction calculations. From the potential energy surfaces for NCN3 dissociation, it was inferred that both thermal and photo-chemical decomposition initially lead to NCN in its lowest singlet state, ã(1)Δg, with a possible contribution from the b̃(1)Σg(+) state at low photolysis wavelengths...
August 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28862152/tumor-control-in-ion-beam-radiotherapy-with-different-ions-in-presence-of-hypoxia-an-oxygen-enhancement-ratio-model-based-on-the-microdosimetric-kinetic-model
#19
Lidia Strigari, Francesca Torriani, Lorenzo Manganaro, Taku Inaniwa, Federico Dalmasso, Roberto Cirio, Andrea Attili
Few attempts to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy have been made and systematic studies to evaluate the impact of hypoxia in treatments with beam of different ion species are missing. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates and do not explicitly distinguish between ion species and fractionation schemes. In this study a new OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed...
September 1, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28860579/stable-multi-gev-electron-accelerator-driven-by-waveform-controlled-pw-laser-pulses
#20
Hyung Taek Kim, V B Pathak, Ki Hong Pae, A Lifschitz, F Sylla, Jung Hun Shin, C Hojbota, Seong Ku Lee, Jae Hee Sung, Hwang Woon Lee, E Guillaume, C Thaury, Kazuhisa Nakajima, J Vieira, L O Silva, V Malka, Chang Hee Nam
The achievable energy and the stability of accelerated electron beams have been the most critical issues in laser wakefield acceleration. As laser propagation, plasma wave formation and electron acceleration are highly nonlinear processes, the laser wakefield acceleration (LWFA) is extremely sensitive to initial experimental conditions. We propose a simple and elegant waveform control method for the LWFA process to enhance the performance of a laser electron accelerator by applying a fully optical and programmable technique to control the chirp of PW laser pulses...
August 31, 2017: Scientific Reports
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