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https://www.readbyqxmd.com/read/28723086/formation-of-core-shell-ethane-silver-clusters-in-he-droplets
#1
Evgeny Loginov, Luis F Gomez, Boris G Sartakov, Andrey F Vilesov
Ethane core - silver shell clusters consisting of several thousand particles have been assembled in helium droplets upon capture of first ethane molecules, followed by Ag atoms. The composite clusters were studied via infrared laser spectroscopy in the range of C-H stretching vibrations of ethane molecules. The spectra show the splitting of the vibrational bands, which was assigned to different environment of the molecules, such as in contact or devoid of a contact with Ag atoms. The analysis of the band intensities for different number of trapped ethane molecules and Ag atoms indicates that the composite clusters consist of ethane core covered with small Ag clusters having different degree of submergence on the surface...
July 19, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28715034/surface-chemistry-and-stability-of-metastable-corundum-type-in2o3
#2
Eva-Maria Köck, Michaela Kogler, Chen Zhuo, Lukas Schlicker, Maged F Bekheet, Andrew Doran, Aleksander Gurlo, Simon Penner
To account for the explanation of an eventual sensing and catalytic behavior of rhombohedral In2O3 (rh-In2O3) and the dependence of the metastability of the latter on gas atmospheres, in situ electrochemical impedance spectroscopic (EIS), Fourier-transform infrared spectroscopic (FT-IR), in situ X-ray diffraction and in situ thermogravimetric analyses in inert (helium) and reactive gases (hydrogen, carbon monoxide and carbon dioxide) have been conducted to link the gas-dependent electrical conductivity features and the surface chemical properties to its metastability towards cubic In2O3...
July 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28708331/negative-chemical-ionization-gas-chromatography-mass-spectrometry-of-transfluthrin-in-rat-plasma-and-brain
#3
Shirin Hooshfar, Tanzir B Mortuza, Clinton A Rogers, Michael R Linzey, Darren R Gullick, James V Bruckner, Catherine A White, Michael G Bartlett
RATIONALE: Transfluthrin is a relatively non-toxic rapid-acting synthetic pyrethroid insecticide. It is widely used in household and hygiene products. A sensitive and accurate bioanalytical method is required for quantification of its concentration in plasma and its potential target organ, the brain for studies to assess its health effects and toxicokinetics in mammals. METHODS: The samples were prepared by liquid-liquid extraction. Gas chromatography mass spectrometry (GC/MS) analysis was performed for the determination of transfluthrin in biological samples with an overall method run time of 15 min...
July 14, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28699062/rapid-analysis-of-ingredients-in-cream-using-ultrasonic-mist-direct-analysis-in-real-time-time-of-flight-mass-spectrometry
#4
Haruo Shimada, Katsuyuki Maeno, Kazumasa Kinoshita, Yasuo Shida
A novel method for the simultaneous detection of ingredients in pharmaceutical applications such as creams and lotions was developed. An ultrasonic atomizer has been used to produce a mist containing ingredients. The analyte molecules in the mist can be ionized by using direct analysis in real time (DART) at lower temperature than traditionally used, and we thus solved the problem of normal DART-MS measurement using a high-temperature gas. Thereby, molecular-related ions of heat-unstable components and nonvolatile components became detectable...
July 11, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28698266/spirometry-static-lung-volumes-and-diffusing-capacity
#5
Carlos A Vaz Fragoso, Hilary C Cain, Richard Casaburi, Patty J Lee, Lynne Iannone, Linda S Leo-Summers, Peter H Van Ness
BACKGROUND: Spirometric Z-scores from the Global Lung Initiative (GLI) rigorously account for age-related changes in lung function and are thus age-appropriate when establishing spirometric impairments, including a restrictive pattern and air-flow obstruction. However, GLI-defined spirometric impairments have not yet been evaluated regarding associations with static lung volumes (total lung capacity [TLC], functional residual capacity [FRC], and residual volume [RV]) and gas exchange (diffusing capacity)...
July 11, 2017: Respiratory Care
https://www.readbyqxmd.com/read/28693047/thermal-effect-of-j-plasma%C3%A2-energy-in-a-porcine-tissue-model-implications-for-minimally-invasive-surgery
#6
Jasmine D Pedroso, Melissa M Gutierrez, K Warren Volker, David L Howard
OBJECTIVE: To evaluate tissue effect of J-Plasma® (Bovie Medical Corporation, Clearwater, Florida) in porcine liver, kidney, muscle, ovarian, and uterine tissue blocks. DESIGN: Prospective study utilizing porcine tissue blocks to evaluate the thermal spread of J-Plasma® device on liver, kidney, muscle, ovarian, and uterine tissue at various power settings, gas flow, and exposure times. MATERIALS AND METHODS: J-Plasma® helium was used in porcine liver, kidney, and muscle tissue at 20%, 50%, and 100% power, and 1 L/min, 3 L/min, and 5 L/min gas flow at one, five, and 10-second intervals...
July 11, 2017: Surgical Technology International
https://www.readbyqxmd.com/read/28691486/effects-of-non-hydrostatic-stress-on-structural-and-optoelectronic-properties-of-methylammonium-lead-bromide-perovskite
#7
Rong Zhang, Weizhao Cai, Tiange Bi, Niloofar Zarifi, Tyson Terpstra, Chuang Zhang, Zeev Valy Vardeny, Eva Zurek, Shanti Deemyad
We report synchrotron X-ray diffraction, photoconductivity and photoluminescence investigations of methylammonium-lead-bromide (MAPbBr3) under various stress conditions, supported by density-functional-theory (DFT) calculations. MAPbBr3 shows substantial dependence on the hydrostatic conditions. While non-hydrostatic compression of MAPbBr3 leads to amorphization above 2.4GPa, under quasi-hydrostatic (Ar) and hydrostatic (He) pressure the sample remains in crystalline phases. Sequence of phase transitions between two cubic phases (Pm3 ̅m and Im3 ̅) and orthorhombic Pnma phase is observed when using Ar, or no pressure-transmitting-medium (PTM)...
July 10, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28688400/strongly-aligned-molecules-inside-helium-droplets-in-the-near-adiabatic-regime
#8
Benjamin Shepperson, Adam S Chatterley, Anders A Søndergaard, Lars Christiansen, Mikhail Lemeshko, Henrik Stapelfeldt
Iodine (I2) molecules embedded in He nanodroplets are aligned by a 160 ps long laser pulse. The highest degree of alignment, occurring at the peak of the pulse and quantified by ⟨cos(2)
July 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28687797/operating-nanobeams-in-a-quantum-fluid
#9
D I Bradley, R George, A M Guénault, R P Haley, S Kafanov, M T Noble, Yu A Pashkin, G R Pickett, M Poole, J R Prance, M Sarsby, R Schanen, V Tsepelin, T Wilcox, D E Zmeev
Microelectromechanical (MEMS) and nanoelectromechanical systems (NEMS) are ideal candidates for exploring quantum fluids, since they can be manufactured reproducibly, cover the frequency range from hundreds of kilohertz up to gigahertz and usually have very low power dissipation. Their small size offers the possibility of probing the superfluid on scales comparable to, and below, the coherence length. That said, there have been hitherto no successful measurements of NEMS resonators in the liquid phases of helium...
July 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28683190/extension-of-high-resolution-optical-absorption-spectroscopy-to-divalent-neodymium-novel-absorption-spectra-of-nd2-ions-in-strontium-chloride-host-srcl2
#10
Miroslaw Karbowiak, Czesław Rudowicz, Jakub Cichos
Given the virtual lack of information on electronic spectra of divalent neodymium we set for synthesis and characterization of Nd2+ systems. Herein, we report stabilization of neodymium in a chloride host, which importantly has been accomplished with Nd ions introduced in a divalent state during synthesis, unlike by gamma-irradiation of Nd3+ system employed previously. This synthesis method yields good quality SrCl2:Nd2+ single crystals. For the first time the novel electronic absorption spectra of Nd2+ doped in SrCl2 have been recorded with high resolution at liquid helium temperature (4...
July 6, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28682350/qatar-blockade-hits-helium-supply
#11
Declan Butler
No abstract text is available yet for this article.
July 4, 2017: Nature
https://www.readbyqxmd.com/read/28682349/helium-should-be-recycled
#12
EDITORIAL
(no author information available yet)
No abstract text is available yet for this article.
July 4, 2017: Nature
https://www.readbyqxmd.com/read/28676723/analysis-of-reactive-oxygen-and-nitrogen-species-generated-in-three-liquid-media-by-low-temperature-helium-plasma-jet
#13
Julie Chauvin, Florian Judée, Mohammed Yousfi, Patricia Vicendo, Nofel Merbahi
In order to identify aqueous species formed in Plasma activated media (PAM), quantitative investigations of reactive oxygen and nitrogen species (ROS, RNS) were performed and compared to Milli-Q water and culture media without and with Fetal Calf Serum. Electron paramagnetic resonance, fluorometric and colorimetric analysis were used to identify and quantify free radicals generated by helium plasma jet in these liquids. Results clearly show the formation of ROS such as hydroxyl radical, superoxide anion radical and singlet oxygen in order of the micromolar range of concentrations...
July 4, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28671184/the-a-b-transition-in-superfluid-helium-3-under-confinement-in-a-thin-slab-geometry
#14
N Zhelev, T S Abhilash, E N Smith, R G Bennett, X Rojas, L Levitin, J Saunders, J M Parpia
The influence of confinement on the phases of superfluid helium-3 is studied using the torsional pendulum method. We focus on the transition between the A and B phases, where the A phase is stabilized by confinement and a spatially modulated stripe phase is predicted at the A-B phase boundary. Here we discuss results from superfluid helium-3 contained in a single 1.08-μm-thick nanofluidic cavity incorporated into a high-precision torsion pendulum, and map the phase diagram between 0.1 and 5.6 bar. We observe only small supercooling of the A phase, in comparison to bulk or when confined in aerogel, with evidence for a non-monotonic pressure dependence...
July 3, 2017: Nature Communications
https://www.readbyqxmd.com/read/28668042/on-the-computations-of-interatomic-coulombic-decay-widths-with-r-matrix-method
#15
Nicolas Sisourat, Selma Engin, Jimena D Gorfinkiel, Sévan Kazandjian, Přemysl Kolorenč, Tsveta Miteva
Interatomic Coulombic Decay (ICD) is a general mechanism in which an excited atom can transfer its excess energy to a neighbor which is thus ionized. ICD belongs to the family of Feshbach resonance processes, and, as such, states undergoing ICD are characterized by their energy width. In this work, we investigate the computations of ICD widths using the R-matrix method as implemented in the UKRmol package. Helium dimer is used here as a benchmark system. The results are compared with those obtained with the well established Fano-Algebraic Diagrammatic Construction method...
June 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28668001/spins-ind-pellet-injector-for-fuelling-of-magnetically-confined-fusion-systems
#16
R Gangradey, J Mishra, S Mukherjee, P Panchal, P Nayak, J Agarwal, Y C Saxena
Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law...
June 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28667967/experimental-helium-liquefier-with-a-gm-cryocooler
#17
Anup Choudhury, Santosh Sahu
A helium liquefier has been developed with a Gifford-McMahon cryocooler using the cold enthalpy available at the first stage, the inter-stage, and the second stage of the cryocooler. Most of the enthalpy of the helium gas at 300 K is absorbed in the first stage by a coaxial heat exchanger and inter-stage region of the cryocooler. Pre-cooled helium gas is liquefied at the second stage heat exchanger where the final cooldown and condensation happens. The measured production capacity of the liquefier is 17.4 l/day at atmospheric pressure...
June 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28665660/solving-the-quantum-many-body-problem-via-correlations-measured-with-a-momentum-microscope
#18
S S Hodgman, R I Khakimov, R J Lewis-Swan, A G Truscott, K V Kheruntsyan
In quantum many-body theory, all physical observables are described in terms of correlation functions between particle creation or annihilation operators. Measurement of such correlation functions can therefore be regarded as an operational solution to the quantum many-body problem. Here, we demonstrate this paradigm by measuring multiparticle momentum correlations up to third order between ultracold helium atoms in an s-wave scattering halo of colliding Bose-Einstein condensates, using a quantum many-body momentum microscope...
June 16, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28664884/protective-radiolucent-aluminium-oxide-coatings-for%C3%A2-beryllium-x-ray-optics
#19
Oksana Yurkevich, Ksenia Maksimova, Alexander Goikhman, Alexey Grunin, Pavel Prokopovich, Alexander Tyurin, Polina Medvedskaya, Ivan Lyatun, Irina Snigireva, Anatoly Snigirev
Beryllium, being one of the most transparent materials to X-ray radiation, has become the material of choice for X-ray optics instrumentation at synchrotron radiation sources and free-electron laser facilities. However, there are concerns due to its high toxicity and, consequently, there is a need for special safety regulations. The authors propose to apply protective coatings in order to seal off beryllium from the ambient atmosphere, thus preventing degradation processes providing additional protection for users and prolonging the service time of the optical elements...
July 1, 2017: Journal of Synchrotron Radiation
https://www.readbyqxmd.com/read/28661266/argon-and-helium-plasma-coagulation-of-porcine-liver-tissue
#20
Tim R Glowka, Jens Standop, Pascal Paschenda, Michael Czaplik, Jörg C Kalff, René H Tolba
Objective Argon plasma coagulation (APC) and helium plasma coagulation (HPC) are electrosurgical techniques that provide noncontact monopolar electrothermal haemostasis. Although these techniques have been widely used clinically during the last three decades, their in vivo effects on liver tissue remain unclear. Methods We investigated the effects of different power levels (10-100 W) of APC and HPC on liver coagulation in 11 Landrace pigs. Capillary blood flow and capillary blood flow velocity were recorded with a combined laser Doppler flowmeter and spectrophotometer...
January 1, 2017: Journal of International Medical Research
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