scholarly journals Superconductivity found in meteorites

2020 ◽  
Vol 117 (14) ◽  
pp. 7645-7649 ◽  
Author(s):  
James Wampler ◽  
Mark Thiemens ◽  
Shaobo Cheng ◽  
Yimei Zhu ◽  
Ivan K. Schuller
Keyword(s):  
Magnetic Field ◽  
Numerical Methods ◽  
Extreme Environments ◽  
Microwave Spectroscopy ◽  
Iron Meteorite ◽  
Vibrating Sample Magnetometry ◽  
X Ray ◽  
Superconducting Phases ◽  
Wide Range ◽  
Complementary Techniques

Meteorites can contain a wide range of material phases due to the extreme environments found in space and are ideal candidates to search for natural superconductivity. However, meteorites are chemically inhomogeneous, and superconducting phases in them could potentially be minute, rendering detection of these phases difficult. To alleviate this difficulty, we have studied meteorite samples with the ultrasensitive magnetic field modulated microwave spectroscopy (MFMMS) technique [J. G. Ramírez, A. C. Basaran, J. de la Venta, J. Pereiro, I. K. Schuller,Rep. Prog. Phys.77, 093902 (2014)]. Here, we report the identification of superconducting phases in two meteorites, Mundrabilla, a group IAB iron meteorite [R. Wilson, A. Cooney,Nature213, 274–275 (1967)] and GRA 95205, a ureilite [J. N. Grossman,Meteorit. Planet. Sci.33, A221–A239 (1998)]. MFMMS measurements detected superconducting transitions in samples from each, above 5 K. By subdividing and remeasuring individual samples, grains containing the largest superconducting fraction were isolated. The superconducting grains were then characterized with a series of complementary techniques, including vibrating-sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDX), and numerical methods. These measurements and analysis identified the likely phases as alloys of lead, indium, and tin.

scholarly journals Solar activity and solar oscillations

1997 ◽  
Vol 181 ◽  
pp. 277-285
Author(s):  
Y. Elsworth
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Radio Emission ◽  
Surface Temperature ◽  
The Sun ◽  
Solar Oscillations ◽  
Thermal Component ◽  
X Ray ◽  
Convective Flows ◽  
Wide Range

Helioseismology provides us with the tools to probe solar activity. So that we can consider how the solar oscillations are influenced by that activity, we first consider the phenomena that we associate with the active Sun. The surface of the Sun is not quiet but shows evidence of convection on a wide range of scales from a few hundred kilometres through to several tens-of-thousands of kilometres. The surface temperature shows signs of the convection structures with the temperature in the bright granules being some 100 K to 200 K hotter than the surrounding dark lanes. Sunspots, which are regions of high magnetic field that suppress convective flows, are clearly visible to even quite crude observations. They are several tens-of-thousands of kilometres in diameter and about 2000 K cooler than their surroundings. Ultraviolet and X-ray pictures from satellites show that the higher layers of the solar atmosphere are very non-uniform with bright regions of high activity. Contemporaneous magnetograms show that these regions are associated with sunspots. Flares - regions of magnetic reconnections - are seen at all wavelengths from X-ray through the visible to radio. They are the non-thermal component of the radio emission of the Sun. There are many other indicators of activity on the Sun.

scholarly journals One-Pot Access to Diverse Functionalized Pyran Annulated Heterocyclic Systems Using SCMNPs@BPy-SO3H as a Novel Magnetic Nanocatalyst

2020 ◽  
Vol 15 (2) ◽  
pp. 348-366 ◽  
Author(s):  
Ke Chen ◽  
Guangzu He ◽  
Qiong Tang ◽  
Qahtan A.Yousif
Keyword(s):  
Magnetic Field ◽  
Reaction Times ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Magnetic Nanocatalyst ◽  
Permanent Magnetic Field ◽  
One Pot ◽  
X Ray ◽  
The One ◽  
Scanning Electron

The SCMNPs@BPy-SO3H catalyst was prepared and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Vibrating Sample Magnetometry (VSM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Afterwards, its capability was efficiently used to promote the one-pot, three-component synthesis of pyrano[2,3-c]pyrazole and 2-amino-3-cyano-pyrano[3,2-c]chromen-5(4H)-one derivatives. The strategy resulted in the desired products with excellent yields and short reaction times. The SCMNPs@BPy-SO3H catalyst was readily recovered using a permanent magnetic field and it was reused in six runs with a slight decrease in catalytic activity. Copyright © 2020 BCREC Group. All rights reserved 

Influence of Magnetic Field on Magnetic Properties of Electrodeposited Co-Ni-P Nanowires

2014 ◽  
Vol 24 (3S1) ◽  
pp. 90-94 ◽  
Author(s):  
Le Tuan Tu ◽  
Luu Van Thiem ◽  
Pham Duc Thang
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Structure And Morphology ◽  
The Magnetic Field

The magnetic properties in Co-Ni-P nanowires arrays with diameter of 200 nm were investigated. All the samples were prepared by electrodeposition method with pH of 5.5 and at room temperature. During the deposition, a magnetic field in range of 0 - 750 Oe was applied parallel to the wires axis. The crystalline structure and morphology of the samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The hysteresis loops were measured at room temperature using vibrating sample magnetometry (VSM). The mixture of hcp phases of the Co-Ni-P based nanowires has been indicated by the XRD pattern. The obtained results show that with 750 Oe magnetic field applied during deposition we can obtain maximum coercivity value (2180 Oe). The \(M_{r}/M_{s}\) ratio was rapid increased when the magnetic field changed from 0 Oe to 750 Oe.

DISTRIBUTION OF SUPERCONDUCTING PHASES IN THE Bi2Sr2CuO6 – CaCuO2 SYSTEM

1988 ◽  
Vol 02 (05) ◽  
pp. 1313-1319 ◽  
Author(s):  
S. Pekker ◽  
J. Sasvári ◽  
Gy. Hutiray
Keyword(s):  
Electrical Resistivity ◽  
Maximum Intensity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Superconducting Phases ◽  
Wide Range

Bi 2 Sr 2 CuO 6 – CaCuO 2 system is studied in a wide range of compositions by electrical resistivity and X-ray diffraction measurements. The T c = 80 K phase can be observed in all compositions except the Ca free Bi 2 Sr 2 CuO 6, while the T c = 110 K phase is characteristic to the high CaCuO 2 concentration range, with maximum intensity at the nominal composition of Bi 2 Sr 2 Ca 2 Ca 5 Cu 6 O 16. The distribution of 20 K, 80 K and 110 K T c phases is estimated from powder X-ray measurements.

Adjusting Microstructure and Magnetic Properties of Ni-Mn-In Metamagnetic Shape Memory Alloys by Addition of Gd

2012 ◽  
Vol 535-537 ◽  
pp. 959-963
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Jing Xin ◽  
Jian Jun Zhang
Keyword(s):  
Magnetic Field ◽  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Shape Memory ◽  
Room Temperature ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microstructure And Magnetic Properties

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It shows that addition of Gd enhances martensite transition temperature and that X-ray diffraction analysis of experimental alloys is revealed which the mixture is martensite and austenite at room temperature. These alloys show promise as a metamagnetic shape memory alloy with magnetic-field-induced shape memory effect.

scholarly journals A systematic study of soft X-ray pulse profiles of magnetars in quiescence

2019 ◽  
Vol 485 (3) ◽  
pp. 4274-4286 ◽  
Author(s):  
Chin-Ping Hu ◽  
C-Y Ng ◽  
Wynn C G Ho
Keyword(s):  
Magnetic Field ◽  
Systematic Study ◽  
High Surface ◽  
The Other ◽  
Quiescent State ◽  
High Luminosity ◽  
X Ray ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Fourier Harmonics

Abstract Magnetars are neutron stars with extremely high surface magnetic fields. They show diverse X-ray pulse profiles in the quiescent state. We perform a systematic Fourier analysis of their soft X-ray pulse profiles. We find that most magnetars have a single-peaked profile and hence have low amplitudes of the second Fourier harmonics (A2). On the other hand, the pulsed fraction (PF) spreads over a wide range. We compared the results with theoretical profiles assuming various surface hotspot asymmetries, viewing geometries, and beaming functions. We found that a single value of the intensity ratio r between two antipodal hotspots is unable to reproduce the observed distribution of A2 and PF for all magnetars. The inferred r is probably anticorrelated with the thermal luminosity, implying that high-luminosity magnetars tend to have two symmetric hotspots. Our results are consistent with theoretical predictions, for which the existence of an evolving toroidal magnetic field breaks the symmetry of the surface temperature.

Evidence of Dynamical Effects and Critical Field in a Cobalt Spin Crossover Complex

2021 ◽  
Author(s):  
Thilini K Ekanayaka ◽  
Ping Wang ◽  
Saeed Yazdani ◽  
Jared Paul Phillips ◽  
Esha Mishra ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
Critical Field ◽  
Applied Magnetic Field ◽  
Spin Crossover ◽  
Magnetic Circular Dichroism ◽  
Orbital Moment ◽  
X Ray ◽  
Wide Range ◽  
Circular Dichroïsm

The [Co(SQ)2(4-CN-py)2] complex exhibits dynamical effects over a wide range of temperature. The orbital moment, determined by X-ray magnetic circular dichroism (XMCD) with decreasing applied magnetic field, indicates a nonzero...

scholarly journals Magnetospheric radius of an inclined rotator in the magnetically threaded disk model

2018 ◽  
Vol 617 ◽  
pp. A126 ◽  
Author(s):  
E. Bozzo ◽  
S. Ascenzi ◽  
L. Ducci ◽  
A. Papitto ◽  
L. Burderi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Disk Surface ◽  
High Energy ◽  
Disk Model ◽  
X Ray ◽  
Simplified Approach ◽  
Wide Range ◽  
Accretion Rates ◽  
Screening Factor

The estimate of the magnetospheric radius in a disk-fed neutron star X-ray binary is a long standing problem in high energy astrophysics. We have reviewed the magnetospheric radius calculations in the so-called magnetically threaded disk model, comparing the simplified approach originally proposed by Ghosh & Lamb (1979, ApJ, 232, 259) with the revised version proposed by Wang (1987, A&A, 183, 257), Wang (1995, ApJ, 449, L153), and Wang (1997, ApJ, 475, L135). We show that for a given set of fixed parameters (assuming also a comparable screening factor of the neutron star magnetic field by the currents induced on the disk surface) the revised magnetically threaded disk model predicts a magnetospheric radius that is significantly smaller than that derived from the Ghosh & Lamb (1979) treatment. For a fixed value of the neutron star magnetic field and a wide range of mass accretion rates, the inclusion of a large inclination angle between the neutron star rotation and magnetic field axes (χ ≳ 60 deg) leads to a further decrease of the magnetospheric radius. To illustrate the relevance of these calculations, we consider, as an example, the case of the transitional pulsars. During the so-called high mode of their sub-luminous accretion disk state, these sources have shown X-ray pulsations interpreted as due to accretion at an unprecedented low luminosity level compared to other neutron stars in X-ray binaries. In the context of the magnetic threaded disk model, we show that accretion at luminosities of ∼1033 erg s−1 (and thus accretion-driven X-ray pulsations) can be more easily explained when the prescription of the magnetospheric radius provided by Wang (1997) is used. This avoids the need to invoke very strong propeller outflows in the transitional pulsars, as proposed in other literature works.

Monte Carlo calculation of the energy parameters and spatial distribution of the cathodic arc ions while passing through the macro-particles filters

2018 ◽  
Vol 1 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Alexey Chernogor ◽  
Igor Blinkov ◽  
Alexey Volkhonskiy
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Monte Carlo ◽  
Monte Carlo Calculation ◽  
Inhomogeneous Magnetic Field ◽  
Flow Energy ◽  
Wide Range ◽  
Field Concentrator ◽  
Cathodic Arc ◽  
The Magnetic Field

The flow, energy distribution and concentrations profiles of Ti ions in cathodic arc are studied by test particle Monte Carlo simulations with considering the mass transfer through the macro-particles filters with inhomogeneous magnetic field. The loss of ions due to their deposition on filter walls was calculated as a function of electric current and number of turns in the coil. The magnetic field concentrator that arises in the bending region of the filters leads to increase the loss of the ions component of cathodic arc. The ions loss up to 80 % of their energy resulted by the paired elastic collisions which correspond to the experimental results. The ion fluxes arriving at the surface of the substrates during planetary rotating of them opposite the evaporators mounted to each other at an angle of 120° characterized by the wide range of mutual overlapping.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

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