Photon emission accompanying deformation and fracture of ice

2003 ◽  
Vol 81 (1-2) ◽  
pp. 71-80 ◽  
Author(s):  
Y Mizuno ◽  
T Mizuno
Keyword(s):  
Emission Intensity ◽  
Strain Energy ◽  
Photon Emission ◽  
The Other ◽  
Intensity Data ◽  
Time Resolved ◽  
Near Ultraviolet ◽  
Deformation And Fracture ◽  
Polycrystalline Ice ◽  
Crack Tips

We observed photon emission during deformation and fracture of axially loaded polycrystalline ice. Emission of visible photons (300–650 nm) was correlated with crack generation and fracture, based on time-resolved photon emission signals taken during load changes. Emission intensity, including the entire spectra ranging from 300 to 650 nm, was roughly correlated with increasing strain energy released by fracturing, while considerable scattering of the intensity data implied that emission intensity also depended on the characteristics of each individual crack. Correlation was taken between simultaneous emissions detected with two photomultiplier tubes with different ranges of spectral sensitivity. Brief, intense emissions were clearly associated with load drops, and these probably included wavelengths shorter than 320 nm, indicating that near ultraviolet light is also emitted. On the other hand, weak but continuous signals with wavelengths longer than 650 nm were emitted the entire time the ice was subjected to a load. Emission intensity and spectra may be attributed to microprocesses during fracturing. Experimental evidence for emission of visible photons indicates that the generated electric charges on crack surfaces and at crack tips have energy ranging from 2 to 6 eV. PACS No.: 46.50

scholarly journals Creep and Fabrics of Polycrystalline Ice Under Shear and Compression

1981 ◽  
Vol 27 (95) ◽  
pp. 129-140 ◽  
Author(s):  
Paul Duval
Keyword(s):  
Driving Force ◽  
Strain Energy ◽  
Principal Direction ◽  
Shear Plane ◽  
The Other ◽  
Shearing Stress ◽  
Creep Tests ◽  
Polycrystalline Ice ◽  
Plastic Strain Energy ◽  
Very High

Abstract Creep tests were performed in torsion and torsion–compression on polycrystalline ice at temperatures near the melting point. Syntectonic recrystallization occurs at strains of the order of 2–3%, leading to a rapid increase in strain-rate. It is shown that the increase of creep-rate during tertiary creep arises from the development of fabrics favouring the glide on basal planes but also from the softening processes associated with recrystallization. The c-axis fabric of recrystallized ice developed in simple shear consists of two-maxima, one at the pole of the permanent shear plane and the other between the normal of the second plane of maximum shearing stress and the principal direction of compression. In torsion–compression, a three- or four-maximum fabric is formed according to the intensity of different components of the stress tensor. The maxima are clustered around the principal direction of compression. Processes of fabric formation are discussed. The experimentally developed fabrics are probably produced by the strain-induced recrystallization, for which the driving force is provided by differences in stored plastic strain energy. However the degree of preferred orientation of ice c-axes must be a function of the total strain when syntectonic recrystallization becomes less important. In this case, fabrics are principally formed by plastic flow and a steady state is obtained for very high strains.

scholarly journals Creep and Fabrics of Polycrystalline Ice Under Shear and Compression

1981 ◽  
Vol 27 (95) ◽  
pp. 129-140 ◽  
Author(s):  
Paul Duval
Keyword(s):  
Driving Force ◽  
Strain Energy ◽  
Principal Direction ◽  
Shear Plane ◽  
The Other ◽  
Shearing Stress ◽  
Creep Tests ◽  
Polycrystalline Ice ◽  
Plastic Strain Energy ◽  
Very High

AbstractCreep tests were performed in torsion and torsion–compression on polycrystalline ice at temperatures near the melting point. Syntectonic recrystallization occurs at strains of the order of 2–3%, leading to a rapid increase in strain-rate. It is shown that the increase of creep-rate during tertiary creep arises from the development of fabrics favouring the glide on basal planes but also from the softening processes associated with recrystallization. The c-axis fabric of recrystallized ice developed in simple shear consists of two-maxima, one at the pole of the permanent shear plane and the other between the normal of the second plane of maximum shearing stress and the principal direction of compression. In torsion–compression, a three- or four-maximum fabric is formed according to the intensity of different components of the stress tensor. The maxima are clustered around the principal direction of compression. Processes of fabric formation are discussed. The experimentally developed fabrics are probably produced by the strain-induced recrystallization, for which the driving force is provided by differences in stored plastic strain energy. However the degree of preferred orientation of ice c-axes must be a function of the total strain when syntectonic recrystallization becomes less important. In this case, fabrics are principally formed by plastic flow and a steady state is obtained for very high strains.

Prospects of Time-Resolved Photon Emission as a Debug Tool

2002 ◽  
Author(s):  
Jim Vickers ◽  
Nader Pakdaman ◽  
Steven Kasapi
Keyword(s):  
Photon Emission ◽  
Photon Counting ◽  
Signal Propagation ◽  
General Function ◽  
Hot Electron ◽  
Detector Performance ◽  
Time Resolved ◽  
Switching Event ◽  
Emission System

Abstract Dynamic hot-electron emission using time-resolved photon counting can address the long-term failure analysis and debug requirements of the semiconductor industry's advanced devices. This article identifies the detector performance parameters and components that are required to scale and keep pace with the industry's requirements. It addresses the scalability of dynamic emission with the semiconductor advanced device roadmap. It is important to understand the limitations to determining that a switching event has occurred. The article explains the criteria for event detection, which is suitable for tracking signal propagation and looking for logic or other faults in which timing is not critical. It discusses conditions for event timing, whose goal is to determine accurately when a switching event has occurred, usually for speed path analysis. One of the uses of a dynamic emission system is to identify faults by studying the emission as a general function of time.

Analog Circuit Failure Analysis Using Time-Resolved Emission

2005 ◽  
Author(s):  
B.J. Cain ◽  
G.L. Woods ◽  
A. Syed ◽  
R. Herlein ◽  
Toshihiro Nomura
Keyword(s):  
Analog Circuits ◽  
Integrated Circuit ◽  
Analog Circuit ◽  
Photon Emission ◽  
Nonlinear Process ◽  
Time Resolved ◽  
Non Invasive ◽  
Highly Nonlinear ◽  
Excellent Spatial Resolution ◽  
5 Ghz

Abstract Time-Resolved Emission (TRE) is a popular technique for non-invasive acquisition of time-domain waveforms from active nodes through the backside of an integrated circuit. [1] State-of-the art TRE systems offer high bandwidths (> 5 GHz), excellent spatial resolution (0.25um), and complete visibility of all nodes on the chip. TRE waveforms are typically used for detecting incorrect signal levels, race conditions, and/or timing faults with resolution of a few ps. However, extracting the exact voltage behavior from a TRE waveform is usually difficult because dynamic photon emission is a highly nonlinear process. This has limited the perceived utility of TRE in diagnosing analog circuits. In this paper, we demonstrate extraction of voltage waveforms in passing and failing conditions from a small-swing, differential logic circuit. The voltage waveforms obtained were crucial in corroborating a theory for some failures inside an 0.18um ASIC.

scholarly journals Contact interactions in complex fibrous metamaterials

2021 ◽  
Author(s):  
Mario Spagnuolo ◽  
Antonio M. Cazzani
Keyword(s):  
Strain Energy ◽  
Point Of View ◽  
The Other ◽  
Contact Interactions ◽  
Coupling Term ◽  
Dissipation Potential ◽  
Parallel Fibers ◽  
Mathematical Point

AbstractIn this work, an extension of the strain energy for fibrous metamaterials composed of two families of parallel fibers lying on parallel planes and joined by connective elements is proposed. The suggested extension concerns the possibility that the constituent fibers come into contact and eventually scroll one with respect to the other with consequent dissipation due to friction. The fibers interact with each other in at least three different ways: indirectly, through microstructural connections that could allow a relative sliding between the two families of fibers; directly, as the fibers of a family can touch each other and can scroll introducing dissipation. From a mathematical point of view, these effects are modeled first by introducing two placement fields for the two fiber families and adding a coupling term to the strain energy and secondly by adding two other terms that take into account the interdistance between the parallel fibers and the Rayleigh dissipation potential (to account for friction).

SPECT Scan in Somatization Disorder Patients: An Exploratory Study of Eleven Cases

2001 ◽  
Vol 35 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Javier Garcia-Campayo ◽  
Concepcion Sanz-Carrillo ◽  
Teresa Baringo ◽  
Concepción Ceballos
Keyword(s):  
Computed Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Spect Imaging ◽  
The Other ◽  
University Hospital ◽  
Somatization Disorder ◽  
Emission Computed Tomography ◽  
Axis I ◽  
Pain Symptoms

Objective: There are no previous studies using single photon emission computed tomography (SPECT) scans in somatization disorder (SD) patients. The aim of this paper is to assess SPECT imaging abnormalities in SD patients and study any relation to laterality. Method: Eleven SD patients from the Somatization Disorder Unit of Miguel Servet University Hospital, Zaragoza, Spain, not fulfilling criteria for any other psychiatric disorder and showing normal computed tomography (CT) and magnetic resonance imaging (MRI) images were studied with SPECT. Patients with DSM-IV axis I comorbidity were ruled out because it has been demonstrated that SPECT scans can show abnormalities in patients with depression and anxiety disorders. The technique used for SPECT was 99mTc-D,1,hexamethylpropyleneamide- oxime (99mTc-HMPAO) in four patients and 99mTc-bicisate in the other seven. The SPECT scans were evaluated without knowledge of clinical data and entirely by visual inspection. Results: Seven out of 11 (63.6%) SD patients showed hypoperfusion in SPECT imaging. In four cases there was hypoperfusion in the non-dominant hemisphere and the predominance of pain symptoms took place in the contralateral hemibody. In the other three patients hypoperfusion was bilateral. The anatomical regions affected were cerebellum (four cases), frontal and prefrontal areas (three cases), temporoparietal areas (two cases) and the complete hemisphere (one case). Conclusions: A proportion of SD patients may present hypoperfusion in SPECT images, uni- or bilaterally, in different brain areas. Possible aetiological explanations for this finding are discussed. Controlled studies are necessary to confirm or refute this hypothesis.

scholarly journals Copper Complexes of Benzoylacetone Bis-Thiosemicarbazones: Metal and Ligand Based Redox Reactivity

2021 ◽  
Vol 74 (1) ◽  
pp. 34 ◽  
Author(s):  
Jessica K. Bilyj ◽  
Jeffrey R. Harmer ◽  
Paul V. Bernhardt
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Cyclic Voltammetry ◽  
Copper Complexes ◽  
Atmospheric Oxygen ◽  
The Other ◽  
Oxidation Reactions ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Vis Spectroscopy ◽  
Electron Paramagnetic

Bis-thiosemicarbazones derived from the β-diketone benzoylacetone (H3banR, R=Me, Et, Ph) are potentially tetradentate N2S2 ligands whose coordination chemistry with copper is reported. In the absence of oxygen and in the presence of base they form anionic CuII complexes of the fully deprotonated ligands [CuII(banR)]–. Upon exposure to atmospheric oxygen they undergo a complex series of reactions leading to two types of products; one a ligand oxidised ketone complex [CuII(banRO)] and the other an unprecedented dimeric di-CuIII complex [(CuIII(banR))2] depending on the R substituent. Time-resolved UV-vis spectroscopy, cyclic voltammetry, spectroelectrochemistry, and electron paramagnetic resonance (EPR) spectroscopy have been used to identify intermediates on the way to stable products formed under both anaerobic and aerobic conditions. It is found that both ligand-centred and Cu-centred oxidation reactions are occurring in parallel leading to this unusually complicated mixture of products.

scholarly journals Mass loss from the exoplanet WASP-12b inferred from Spitzer phase curves

2019 ◽  
Vol 489 (2) ◽  
pp. 1995-2013 ◽  
Author(s):  
Taylor J Bell ◽  
Michael Zhang ◽  
Patricio E Cubillos ◽  
Lisa Dang ◽  
Luca Fossati ◽  
...  
Keyword(s):  
Mass Loss ◽  
Infrared Radiation ◽  
High Energy ◽  
The Other ◽  
Phase Curve ◽  
Near Ultraviolet ◽  
Energy Irradiation ◽  
Ultraviolet Observations ◽  
Host Stars ◽  
Co Emission

ABSTRACT The exoplanet WASP-12b is the prototype for the emerging class of ultrahot, Jupiter-mass exoplanets. Past models have predicted – and near-ultraviolet observations have shown – that this planet is losing mass. We present an analysis of two sets of 3.6 and 4.5 $\mu \rm{m}$Spitzer phase curve observations of the system which show clear evidence of infrared radiation from gas stripped from the planet, and the gas appears to be flowing directly toward or away from the host star. This accretion signature is only seen at 4.5 $\mu \rm{m}$, not at 3.6 $\mu \rm{m}$, which is indicative either of CO emission at the longer wavelength or blackbody emission from cool, ≲600 K gas. It is unclear why WASP-12b is the only ultrahot Jupiter to exhibit this mass-loss signature, but perhaps WASP-12b’s orbit is decaying as some have claimed, while the orbits of other exoplanets may be more stable; alternatively, the high-energy irradiation from WASP-12A may be stronger than the other host stars. We also find evidence for phase offset variability at the level of 6.4σ (46.2°) at 3.6 $\mu \rm{m}$.

scholarly journals Integration of Single-Photon Emitters in 2D Materials with Plasmonic Waveguides at Room Temperature

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1663
Author(s):  
Kwang-Yong Jeong ◽  
Seong Won Lee ◽  
Jae-Hyuck Choi ◽  
Jae-Pil So ◽  
Hong-Gyu Park
Keyword(s):  
Integrated Circuits ◽  
Room Temperature ◽  
Single Photon ◽  
Hexagonal Boron Nitride ◽  
Photon Emission ◽  
Plasmonic Waveguide ◽  
Practical Implementation ◽  
Plasmonic Waveguides ◽  
Time Resolved ◽  
Ag Nanowire

Efficient integration of a single-photon emitter with an optical waveguide is essential for quantum integrated circuits. In this study, we integrated a single-photon emitter in a hexagonal boron nitride (h-BN) flake with a Ag plasmonic waveguide and measured its optical properties at room temperature. First, we performed numerical simulations to calculate the efficiency of light coupling from the emitter to the Ag plasmonic waveguide, depending on the position and polarization of the emitter. In the experiment, we placed a Ag nanowire, which acted as the plasmonic waveguide, near the defect of the h-BN, which acted as the single-photon emitter. The position and direction of the nanowire were precisely controlled using a stamping method. Our time-resolved photoluminescence measurement showed that the single-photon emission from the h-BN flake was enhanced to almost twice the intensity as a result of the coupling with the Ag nanowire. We expect these results to pave the way for the practical implementation of on-chip nanoscale quantum plasmonic integrated circuits.

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