This document presents experimental and theoretical studies on the elastic properties of molybdenum up to 12 GPa. Compressional and shear wave velocities were measured using ultrasonic interferometry combined with synchrotron x-ray diffraction. Both velocities increased linearly with pressure and agreed well with density functional theory calculations. Elastic moduli were derived from the velocity and density data using finite strain equations of state. The results were consistent with previous studies and provided elastic properties of molybdenum to higher pressures than previously reported.
28 Measurement of η photoproduction on the proton from threshold to 1500-MeV ...Cristian Randieri PhD
Measurement of η photoproduction on the proton from threshold to 1500-MeV - The European Physical Journal A, Hadrons and Nuclei, August 2007, Vol. 33, N. 2, pp. 169-184, ISSN: 1434-6001, doi: 10.1140/epja/i2007-10439-9
di O. Bartalini, V. Bellini, J. P. Bocquet, P. Calvat, M. Capogni, L. Casano, M. Castoldi, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, C. Gaulard, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, R. Kunne, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Perrin, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, T. Russew, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2007).
Abstract
Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.
Optical and Impedance Spectroscopy Study of ZnS NanoparticlesIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
42 Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Jou...Cristian Randieri PhD
Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 965-976, doi: 10.1142/S0218301310015412
di G. Mandaglio, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. M. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
We present the analysis of data performed in order to identify the events of the γ + n → π- + p reaction obtained by bombarding a liquid Deuterium target with a polarised γ beam of 0.55-1.5 GeV at the Graal-experiment. We show the effect of different kinematic and hardware constraints used to reduce the contamination coming from the concurrent reaction channels. By the simulation we estimate the contamination degree due to the other reaction channels so we can test the reliability of our method. We describe a new three-dimensional cut based on the Fermi momentum reconstruction and its effect on the suppression of the concurrent double charged pion photoproduction. We present the preliminary beam asymmetry Σ of the π- fotoproduction off quasi-free neutron up to about θc.m., π- = 165° together with some theoretical multipolar analysis. For a comparison we also report the data present in literature on the same reaction for Eγ =850-1740 MeV and θc.m., π- ≤105°.
28 Measurement of η photoproduction on the proton from threshold to 1500-MeV ...Cristian Randieri PhD
Measurement of η photoproduction on the proton from threshold to 1500-MeV - The European Physical Journal A, Hadrons and Nuclei, August 2007, Vol. 33, N. 2, pp. 169-184, ISSN: 1434-6001, doi: 10.1140/epja/i2007-10439-9
di O. Bartalini, V. Bellini, J. P. Bocquet, P. Calvat, M. Capogni, L. Casano, M. Castoldi, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, C. Gaulard, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, R. Kunne, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Perrin, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, T. Russew, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2007).
Abstract
Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.
Optical and Impedance Spectroscopy Study of ZnS NanoparticlesIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
42 Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Jou...Cristian Randieri PhD
Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 965-976, doi: 10.1142/S0218301310015412
di G. Mandaglio, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. M. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
We present the analysis of data performed in order to identify the events of the γ + n → π- + p reaction obtained by bombarding a liquid Deuterium target with a polarised γ beam of 0.55-1.5 GeV at the Graal-experiment. We show the effect of different kinematic and hardware constraints used to reduce the contamination coming from the concurrent reaction channels. By the simulation we estimate the contamination degree due to the other reaction channels so we can test the reliability of our method. We describe a new three-dimensional cut based on the Fermi momentum reconstruction and its effect on the suppression of the concurrent double charged pion photoproduction. We present the preliminary beam asymmetry Σ of the π- fotoproduction off quasi-free neutron up to about θc.m., π- = 165° together with some theoretical multipolar analysis. For a comparison we also report the data present in literature on the same reaction for Eγ =850-1740 MeV and θc.m., π- ≤105°.
Dielectric Properties in Co-Ti Doped CaSrM Hexaferrites iosrjce
The dependence of dielectric constant ' and dielectric loss tangent tanon frequency and
composition have been investigated at fixed temperatures for polycrystalline Ca0.5Sr0.5CoxTixFe12-2xO19 (where
0.0 ≤ x ≤ 0.8) hexaferrites samples prepared by ceramic method. The measurements reveal that the samples
under investigation have high values of ' reached to 106
at 1 KHz and 600K. The experimental results indicated
that ' and tandecrease as the frequency increases and temperature decreases. The studied samples showed
an abnormal dielectric loss (or relaxation peaks) which were shifted towards higher frequency as the
temperature increases. ' and tan increase as Co and Ti ions substitution increases up to x≤0.4, after that both
parameters decreases. The activation energy for dielectric relaxation, ED, was estimated for the samples. It is
shown that, ED, have low values (~0.08- 0.18 eV) and have inverse proportional with the dielectric constant '.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Greener cum chemical synthesis and characterization of Mg doped ZnS nanoparti...IJERA Editor
In the present investigations, high-quality Mg doped ZnS nanoparticles were synthesized by Greener cum
chemical process with the assistance of polyvinyl pyrrolidone (PVP) with two different Mg concentrations.
Doping of Mg metal in nanoparticles were found to be a good technique for tuning the band gap of ZnS
nanoparticles. Simultaneously, Mg doping also inhibited the growth of particle size and it decreased from 33.2
nm to 18.3 nm with the increase in doping concentration from 0% to 5%. Band gap was found to rise from 3.12
eV to 3.38 eV and photoluminescence studies exposed that visible Photoluminescence (PL) emission was
improved with doping concentration. The nanoparticles have been characterized by Field Emission Scanning
Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy,
Ultra Violet visible (UV–vis) spectroscopy, and Energy Dispersive X-ray Analysis (EDAX).
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
STM Observation of the Si(111) - (7×7) Reconstructed Surface Modified by Exce...IJECEIAES
The electronic properties of semiconductor surfaces change readily upon changing the carrier densities by controlling the dopant concentration. Additionally, excess dopant atoms can exert electric field which would affect the molecular adsorption process and could be used to manipulate the dynamic movement of confined molecules. A mechanism can be developed to control the molecular dynamic movement on modified semiconductor surface by dopants thus changing the effect of the electric field on the active molecules. In this study, the Si(111) surface was doped with phosphorus excessively using thermal diffusion process. The surface was then reconstructed to the 7×7 configuration via heating under UHV conditions and then studied through STM and STS techniques. The protrusions due to surface and subsurface P atoms appear brighter due to the lone electron pair. The 7×7 reconstruction would be destabilized after a critical P substitution of Si-adatom concentration due to high surface strain result in P-terminated (6√3×6√3)R30º reconstruction.
Site-specific measurement of the giant magnetoresistance (GMR) of individual ...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Vanadium doped zinc telluride (ZnTe:V) thin films (containing 2.5 to 10wt% V) were deposited onto glass
substrates by e-beam evaporation technique in vacuum at a pressure of 8×10-4
Pa. Thermoelectric power of these
films have been measured from room temperature up to 413 K with reference to pure copper material. The
deposition rate of the films was maintained at 2.05 nms-1
. The composition and temperature dependence
thermopower and its related parameters have been studied in detail for a particular thickness of 150 nm. The
Fermi levels were determined using a non-degenerate semiconducting model. The carrier scattering index,
activation energy and temperature coefficient of activation energy have all been obtained at different ranges of
compositions and temperatures. The results of thermopower of ZnTe:V thin films obey an activated conduction
mechanism and also suggest that the simultaneous bipolar conduction of both (n- and p-types) carriers (mixed
carriers) take place. All these samples are optically transparent and mixed crystalline in structure
Dielectric Properties in Co-Ti Doped CaSrM Hexaferrites iosrjce
The dependence of dielectric constant ' and dielectric loss tangent tanon frequency and
composition have been investigated at fixed temperatures for polycrystalline Ca0.5Sr0.5CoxTixFe12-2xO19 (where
0.0 ≤ x ≤ 0.8) hexaferrites samples prepared by ceramic method. The measurements reveal that the samples
under investigation have high values of ' reached to 106
at 1 KHz and 600K. The experimental results indicated
that ' and tandecrease as the frequency increases and temperature decreases. The studied samples showed
an abnormal dielectric loss (or relaxation peaks) which were shifted towards higher frequency as the
temperature increases. ' and tan increase as Co and Ti ions substitution increases up to x≤0.4, after that both
parameters decreases. The activation energy for dielectric relaxation, ED, was estimated for the samples. It is
shown that, ED, have low values (~0.08- 0.18 eV) and have inverse proportional with the dielectric constant '.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Greener cum chemical synthesis and characterization of Mg doped ZnS nanoparti...IJERA Editor
In the present investigations, high-quality Mg doped ZnS nanoparticles were synthesized by Greener cum
chemical process with the assistance of polyvinyl pyrrolidone (PVP) with two different Mg concentrations.
Doping of Mg metal in nanoparticles were found to be a good technique for tuning the band gap of ZnS
nanoparticles. Simultaneously, Mg doping also inhibited the growth of particle size and it decreased from 33.2
nm to 18.3 nm with the increase in doping concentration from 0% to 5%. Band gap was found to rise from 3.12
eV to 3.38 eV and photoluminescence studies exposed that visible Photoluminescence (PL) emission was
improved with doping concentration. The nanoparticles have been characterized by Field Emission Scanning
Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy,
Ultra Violet visible (UV–vis) spectroscopy, and Energy Dispersive X-ray Analysis (EDAX).
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
STM Observation of the Si(111) - (7×7) Reconstructed Surface Modified by Exce...IJECEIAES
The electronic properties of semiconductor surfaces change readily upon changing the carrier densities by controlling the dopant concentration. Additionally, excess dopant atoms can exert electric field which would affect the molecular adsorption process and could be used to manipulate the dynamic movement of confined molecules. A mechanism can be developed to control the molecular dynamic movement on modified semiconductor surface by dopants thus changing the effect of the electric field on the active molecules. In this study, the Si(111) surface was doped with phosphorus excessively using thermal diffusion process. The surface was then reconstructed to the 7×7 configuration via heating under UHV conditions and then studied through STM and STS techniques. The protrusions due to surface and subsurface P atoms appear brighter due to the lone electron pair. The 7×7 reconstruction would be destabilized after a critical P substitution of Si-adatom concentration due to high surface strain result in P-terminated (6√3×6√3)R30º reconstruction.
Site-specific measurement of the giant magnetoresistance (GMR) of individual ...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Vanadium doped zinc telluride (ZnTe:V) thin films (containing 2.5 to 10wt% V) were deposited onto glass
substrates by e-beam evaporation technique in vacuum at a pressure of 8×10-4
Pa. Thermoelectric power of these
films have been measured from room temperature up to 413 K with reference to pure copper material. The
deposition rate of the films was maintained at 2.05 nms-1
. The composition and temperature dependence
thermopower and its related parameters have been studied in detail for a particular thickness of 150 nm. The
Fermi levels were determined using a non-degenerate semiconducting model. The carrier scattering index,
activation energy and temperature coefficient of activation energy have all been obtained at different ranges of
compositions and temperatures. The results of thermopower of ZnTe:V thin films obey an activated conduction
mechanism and also suggest that the simultaneous bipolar conduction of both (n- and p-types) carriers (mixed
carriers) take place. All these samples are optically transparent and mixed crystalline in structure
STUDY OF ABSORPTION IN CARBON NANOTUBE COMPOSITES FROM 1HZ TO 40GHZjmicro
Absorption performances in High Density Polyethylene (HDPE) and polycarbonate (PC) polymer matrices
containing various loads of carbon nanotubes were analysed. It depends on electrical conductivity,
dielectric constant and thickness of the polymer composites. These parameters can be easily controlled.
Significant absorption, which can reach between 60 and 90%, hence occurs at particular combinations of
these last parameters (in a frequency range from 1Hz to GHz). These new results are really useful in
various applications, and are considered in low scale systems as a major technological solution against
electromagnetic interferences.
STUDY OF ABSORPTION IN CARBON NANOTUBE COMPOSITES FROM 1HZ TO 40GHZjmicro
Absorption performances in High Density Polyethylene (HDPE) and polycarbonate (PC) polymer matrices
containing various loads of carbon nanotubes were analysed. It depends on electrical conductivity,
dielectric constant and thickness of the polymer composites. These parameters can be easily controlled.
Significant absorption, which can reach between 60 and 90%, hence occurs at particular combinations of
these last parameters (in a frequency range from 1Hz to GHz). These new results are really useful in
various applications, and are considered in low scale systems as a major technological solution against
electromagnetic interferences.
The hairpin probe is a well known technique for measuring local electron density in low temperature plasmas. In reactive plasmas, the probe characteristics are affected by surface sputtering, contamination, and secondary electron emission. At higher densities, the plasma absorbs the entire electromagnetic energy of hairpin and hence limits the density measurements. These issues can be resolved by covering the hairpin surface with a thin layer of dielectric. In this letter, the dielectric contribution to the probe characteristics is incorporated in a theory which is experimentally verified. The dielectric covering improves the performance of probe and also allows the hairpin tip to survive in reactive plasma where classical electrical probes are easily damaged.
Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of el...Sérgio Sacani
High-energy cosmic-ray electrons and positrons (CREs), which
lose energy quickly during their propagation, provide a probe of
Galactic high-energy processes1–7 and may enable the observation
of phenomena such as dark-matter particle annihilation or
decay8–10. The CRE spectrum has been measured directly up to
approximately 2 teraelectronvolts in previous balloon- or spaceborne
experiments11–16, and indirectly up to approximately 5
teraelectronvolts using ground-based Cherenkov γ-ray telescope
arrays17,18. Evidence for a spectral break in the teraelectronvolt
energy range has been provided by indirect measurements17,18,
although the results were qualified by sizeable systematic
uncertainties. Here we report a direct measurement of CREs in the
energy range 25 gigaelectronvolts to 4.6 teraelectronvolts by the
Dark Matter Particle Explorer (DAMPE)19 with unprecedentedly
high energy resolution and low background. The largest part of
the spectrum can be well fitted by a ‘smoothly broken power-law’
model rather than a single power-law model. The direct detection of
a spectral break at about 0.9 teraelectronvolts confirms the evidence
found by previous indirect measurements17,18, clarifies the behaviour
of the CRE spectrum at energies above 1 teraelectronvolt and sheds
light on the physical origin of the sub-teraelectronvolt CREs.
Variation of dose distribution with depth and incident energy using EGSnrc Mo...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Polarized blazar X-rays imply particle acceleration in shocksSérgio Sacani
Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization—the only range available until now—probe extended regions of the jet containing particles that left the acceleration site days to years earlier1–3, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree ΠX of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock.
24 Polarization observable measurements for γp → K+Λ and γp → K+Σ for energie...Cristian Randieri PhD
Polarization observable measurements for γp → K+Λ and γp → K+Σ for energies up to 1.5 GeV - The European Physical Journal A, Hadrons and Nuclei, January 2007, Vol. 31, N. 1, pp. 73-93, ISSN: 1434-6001, doi: 10.1140/epja/i2006-10167-8
di A. Lleres, O. Bartalini, V. Bellini, J. P. Bocquet, P. Calvat, M. Capogni, L. Casano, M. Castoldi, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, C. Gaulard, G. Gervino, F. Ghio, B. Girolami, A. Giusa, M. Guidal, E. Hourany, V. Kouznetsov, R. Kunne, A. Lapik, P. Levi Sandri, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Perrin, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, T. Russew, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge (2007)
Abstract
Beam asymmetries and hyperon recoil polarizations for the reactions γ p → K +Λ and γ p → K +Σ0 have been measured from the threshold production to 1500MeV with the GRAAL facility located at the ESRF in Grenoble. These results complement the database for the beam asymmetry, covering for the first time the production threshold region. Recent theoretical analyses are presented for which the beam asymmetry data bring interesting new information and allow to better determine some resonance parameters. Most importantly, these results strengthen the need of a new D13 state around 1900MeV.
STUDY OF ABSORPTION IN CARBON NANOTUBE COMPOSITES FROM 1HZ TO 40GHZjmicro
Absorption performances in High Density Polyethylene (HDPE) and polycarbonate (PC) polymer matrices
containing various loads of carbon nanotubes were analysed. It depends on electrical conductivity,
dielectric constant and thickness of the polymer composites. These parameters can be easily controlled.
Significant absorption, which can reach between 60 and 90%, hence occurs at particular combinations of
these last parameters (in a frequency range from 1Hz to GHz). These new results are really useful in
various applications, and are considered in low scale systems as a major technological solution against
electromagnetic interferences.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
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UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
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In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
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2. 043506-2 Liu et al. J. Appl. Phys. 106, 043506 ͑2009͒
͑1958͒ and Neutron diffraction result of 31.181͑3͒ Å3 from
Zhao et al.10 ͑2000͒, and within mutual uncertainties with the
x-ray diffraction result of 31.150 Å3 ͑3͒ from Zhao et al.
͑2000͒.10 Our DFT calculation at 0 K yields a value of
31.63 Å3 which is in agreement with experimental data
within 1.5%. The unit-cell volumes of Mo as a function of
pressure are compared with previous studies in Fig. 1. The
300 K compression curve from the current experiment is in
excellent agreement with previous results,7,9,10 although
some previous data show minor scattering at the pressure
range from 5 to 9 GPa. The current experimental data also
show an excellent agreement with those from DFT calcula-
tions at ground state ͑Fig. 1͒.
Compressional and shear wave velocities as well as the
adiabatic bulk ͑KS = L − 4G / 3 = V2 − 4G / 3͒ and shear
P
FIG. 1. Variation of unit-cell volumes of molybdenum as a function of ͑G = V2͒ moduli at high pressures are obtained from the
S
pressure. Symbols are from experimental studies, dotted line represents the measured sample lengths, travel times, and densities ͑Table
results from current DFT calculations. I͒. As shown in Fig. 2, both V P and VS exhibit linear increase
with pressure at room temperature. The pressure dependence
ployed in WIEN2K code.22,23 The unit cell is divided into non- is in excellent agreement with those from DFT calculations,
overlapping atomic spheres ͑muffin-tin, radius RMT͒ and an although the values of the velocities from DFT calculations
interstitial region where Kohn–Sham wave functions,24 ͑at 0 K͒ are slightly higher than the experimental data at
charge density and potential are expanded in different sets of temperature of 300 K ͑Fig. 2͒.
basis functions. The charge density and potential are ex- To obtain the zero-pressure adiabatic bulk and shear
panded into lattice harmonics inside muffin-tin spheres and moduli as well as their respective pressure derivatives, the
as a Fourier series in the remaining space. A maximum quan- velocity and density data can be fitted simultaneously to the
tum number of ten was used for the atomic wave functions finite strain Eqs. ͑1͒ and ͑2͒ without the input of pressure,27
inside the muffin-tin sphere. The generalized gradient ap-
proximation of Perdew et al.25 was used for the exchange- V2 = ͑1 – 2͒5/2͑L1 + L2͒,
P ͑1͒
correlation functionals. A sphere radius of 2.4 a.u. was used
in the current calculation, and the Brillouin zone was V2 = ͑1 – 2͒5/2͑M1 + M2͒, ͑2͒
S
sampled by 10 000 k-points ͑268 in the irreducible wedges͒.
ء
The plane wave cutoff was set by RMTKmax = 8 where Kmax is Ј
in which M1 = G0, M2 = 5G0 − 3KS0G0L1 = KS0 + 4G0 / 3, and
the maximum k vector in the basis set. The largest vector in Ј Ј
L2 = 5L1 − 3KS0͑KS0 + 4G0 / 3͒. The strain is defined as
the charge density Fourier expansion was Gmax = 14 bohr−1. ͓1 − ͑V0 / V͒2/3͔ / 2, The fitted coefficients, L1, L2, M1, and
The criterion for self-consistency energy convergence was M2, are used for the calculation of the zero-pressure adia-
1 Ry. Convergence tests were conducted by using different batic bulk and shear moduli ͑KS0 and G0͒, as well as their
ء
values of RMTKmax and k-points to make sure the self- Ј
pressure derivatives ͑KS0 and G0͒. Ј
consistent force calculations is well converged with those The velocity and density data from our experiments are
used in the current calculations. The elastic constants were fitted to Eqs. ͑1͒ and ͑2͒ by minimizing the difference be-
calculated using the procedures described in Ref. 23, in tween the calculated and the observed compressional and
which a series of energy minimizations were performed after shear wave velocities, yielding KS0 = 260.7͑5͒ GPa, G0
applying small strains to the Mo unit cells and the elastic Ј Ј
= 125.1͑2͒ GPa, KS0 = 4.7͑1͒, and G0 = 1.5͑1͒. These param-
constants were then derived from the second derivatives of eters reproduce the observed compressional and shear wave
the energy with respect to the applied strains. The bulk and velocities remarkably well in the entire pressure range, with
shear moduli corresponding to polycrystalline sample were a RMS ͑root mean squares͒ misfit of 0.006 km s−1 for V P
obtained using a Voigt–Reuss–Hill average method. The and 0.002 km s−1 for VS, respectively. These results, to-
ء
same values of RMTKmax were used for the current calcula- gether with those from the current DFT calculations, are
tions at all pressures. compared with previous results in Table II.
The ambient pressure adiabatic bulk modulus KS0, 260.7
III. RESULTS AND DISCUSSION
GPa, agrees very well with previous values ͑259.3–263.8
GPa͒ from acoustic measurements on single crystal,3–6
The x-ray powder diffraction patterns show that the Mo within their respective estimates of error ͑ϳ1% – 2%͒. One
sample remains in the bcc phase up to the peak pressure of exception is that the KS0 value of Bolef and de Klerk2 ͑1962͒,
the current study ͑12.0 GPa͒. The refined unit-cell volumes which is only in marginal agreement with the upper bound of
show a smooth decrease with increasing pressure ͑Fig. 1͒. the current data as well as other single crystal acoustic mea-
We obtain a value of 31.175͑25͒ Å3 from our experiment for surements. The zero-pressure adiabatic shear modulus G0
the unit-cell volume at ambient conditions, which is in good from our measurement is in excellent agreement with the
agreement with the value of 31.161 Å3 from Pearson26 Voigt-Reuss-Hill ͑VRH͒ averages of shear moduli from pre-
Downloaded 27 Oct 2009 to 129.49.95.44. Redistribution subject to AIP license or copyright; see http://jap.aip.org/jap/copyright.jsp
3. 043506-3 Liu et al. J. Appl. Phys. 106, 043506 ͑2009͒
TABLE I. Experimental ultrasonic data and unit-cell parameters of molybdenum.
Pa L 2tp 2ts VP VS V KS G
͑GPa͒ ͑mm͒ ͑s͒ ͑s͒ ͑km s−1͒ ͑km s−1͒ ͑Å3͒ ͑g cm−3͒ ͑GPa͒ ͑GPa͒
1.7 0.7631 0.2333 0.4326 6.542 3.528 30.972 10.286 269.5 128.0
2.4 0.7616 0.2323 0.431 6.557 3.534 30.893 10.312 271.4 128.8
3.1 0.7602 0.2309 0.4293 6.585 3.542 30.820 10.337 275.3 129.7
4.1 0.7597 0.2299 0.4276 6.609 3.553 30.708 10.374 278.5 131.0
4.6 0.7587 0.2287 0.426 6.635 3.562 30.656 10.392 281.7 131.9
5.3 0.7587 0.2279 0.425 6.658 3.570 30.577 10.419 284.8 132.8
5.6 0.7582 0.2271 0.4239 6.677 3.577 30.544 10.43 287.1 133.5
6.1 0.7577 0.2263 0.4228 6.696 3.584 30.493 10.448 289.5 134.2
6.7 0.7577 0.2257 0.422 6.714 3.591 30.429 10.47 292.0 135.0
7.1 0.7582 0.2253 0.4212 6.726 3.598 30.387 10.484 293.3 135.7
8.4 0.7592 0.2245 0.4202 6.763 3.614 30.251 10.531 298.3 137.6
9.1 0.7592 0.2239 0.4192 6.782 3.622 30.187 10.553 300.8 138.4
9.6 0.7592 0.2231 0.4182 6.806 3.631 30.137 10.571 303.8 139.4
10.1 0.7587 0.2223 0.4174 6.826 3.635 30.086 10.589 306.8 139.9
10.8 0.7582 0.2215 0.4162 6.846 3.643 30.018 10.613 309.6 140.9
11.1 0.7587 0.2209 0.4156 6.869 3.651 29.985 10.625 312.5 141.6
12.0 0.7582 0.2199 0.4144 6.896 3.659 29.903 10.654 316.5 142.6
a
P = −3KS0͑1 – 2͒5/2͓1 + 3͑4 − KЈ ͒ / 2͔ ͑Ref. 27͒. Values in parentheses are 1 error in the last digits. The uncertainty of the unit-cell volumes are less than
S0
0.15%. Travel times have 1 of ϳ0.4 ns for S wave, and ϳ0.2 ns for P wave. The uncertainties are less than 0.5% in velocities and less than 1.5% in the
derived elastic moduli. The densities at pressures are calculated using the unit-cell volumes and the theoretical density at room temperature ͑ = ءV / V0͒.
0
vious single crystal elastic constant measurements,3–6 except
that of Bolef and de Klerk2 ͑1962͒, with which the agreement
is within ϳ2%.
Our experimental results for the pressure derivatives of
Ј Ј
the bulk and shear moduli, KS0 = 4.7͑1͒ and G0 = 1.5͑1͒, ap-
pear to be slightly higher than the respective value of 4.44
and 1.43 derived using experimental data up to 0.5 GPa from
Katahara et al. ͑1979͒. It should be noted that the current
results are derived from a finite strain fit instead of a linear fit
to pressure. If we fit the current elastic moduli data with a
linear expression of pressure as in Katahara et al. ͑1979͒, we
Ј
obtain KS0 = 261.0 GPa, G0 = 125.3͑2͒ GPa, KS0 = 4.54͑1͒,
Ј
and G0 = 1.45͑1͒ ͑see Table II͒, which is in excellent agree-
FIG. 2. ͑Color online͒ Elastic compressional ͑V P͒ and shear ͑VS͒ wave ment with those from Katahara et al. ͑1979͒. The close
velocities for molybdenum as a function of pressure from the current ultra- Ј Ј
agreement of KS0, G0, KS0, and G0 derived from the current
sonic and x-ray measurements to 12.0 GPa ͑symbols͒ and from DFT calcu- measurements with the results of Katahara et al. ͑1979͒ sug-
lations ͑lines͒.
TABLE II. Elastic moduli and their pressure derivatives of Mo.
References KS0 GV GR GVRH KЈ
S0 GЈ KT Ј
KT Notes
2 268.3 124.5 121.0 122.7 Single crystal, ultrasonic, 77–500 K
3 261.9 126.7 126.4 126.6 Single crystal, ultrasonic, 4.2–300 K
4 259.3 126.2 122.9 124.5 Single crystal, pulse echo, Ϫ198–650 C
4 261.6 125.8 122.6 124.2 Single crystal, thin rod resonance, Ϫ198–650 C
5 263.8 126.4 123.2 124.8 Single crystal, ultrasonic, Ϫ190–100 C
6 262.6 126.0 122.7 124.4 4.44 1.43 single crystal, ultrasonic, to 0.5 GPa
7 267͑11͒ ͓4.46͔ DAC, to 10 GPa
13 267 3.9 Shock wave experiment
8 262.8 3.95 DAC, to 272 GPa
10 268 ͑1͒ 3.81 ͑6͒ EoS, x-ray, to 10 GPa and 1475 K, combine shock data
10 264 ͑1͒ 4.05 ͑2͒ EoS, x-ray, to 10 GPa and 1475 K, combine shock data
10 266͑9͒ 4.1͑9͒ EoS, x-ray, to 10 GPa and 1475 K
This study 260.7͑5͒ 125.1͑2͒ 4.7͑1͒ 1.5͑1͒ Ultrasonic, 3rd FS, to 12 GPa
This study 261.0͑5͒ 125.3͑2͒ 4.54͑1͒ 1.45͑1͒ Ultrasonic, linear fit to 12 GPa
This study 261.9 4.5 DFT
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4. 043506-4 Liu et al. J. Appl. Phys. 106, 043506 ͑2009͒
ACKNOWLEDGMENTS
This research is supported by DoE/NNSA ͑Contract No.
DEFG5206NA2621 to B.L.͒. We thank Michael Vaughan
and Liping Wang for technical support at the X17B2 beam-
line. These experiments were carried out at the National Syn-
chrotron Light Source ͑NSLS͒, which is supported by the
U.S. Department of Energy, Division of Materials Sciences
and Division of Chemical Sciences under Contract No. DE-
AC02-76CH00016. X-17B2 is supported by COMPRES.
Mineral Physics Institute Publication No. 478.
1
H. K. Mao, P. M. Bell, J. W. Shaner, and D. J. Steinberg, J. Appl. Phys. 49,
3276 ͑1978͒.
2
D. I. Bolef and J. de Klerk, J. Appl. Phys. 33, 2311 ͑1962͒.
3
F. H. Featherston and J. R. Neighbours, Phys. Rev. 130, 1324 ͑1963͒.
4
J. M. Dickinson and P. E. Armstrong, J. Appl. Phys. 38, 602 ͑1967͒.
5
D. L. Davidson and F. R. Brotzen, J. Appl. Phys. 39, 5768 ͑1968͒.
6
K. W. Katahara, M. H. Manghnani, and E. S. Fisher, J. Phys. F: Met. Phys.
FIG. 3. ͑Color online͒ Variation of bulk ͑KS͒ and shear ͑G͒ modulus for
9, 773 ͑1979͒.
molybdenum as a function of pressure. Symbols are from experimental stud- 7
L. C. Ming and M. H. Manghnani, J. Appl. Phys. 49, 208 ͑1978͒.
ies, solid line represents the results from current DFT calculations, and 8
Y. K. Vohra and A. L. Ruoff, Phys. Rev. B 42, 8651 ͑1990͒.
dashed lines are the extrapolations of results from Katahara et al. ͑1979͒. 9
T. S. Duffy, G. Shen, J. Shu, H. K. Mao, R. J. Hemley, and A. K. Singh,
J. Appl. Phys. 86, 6729 ͑1999͒.
10
gests that bulk and shear moduli of the current measurements Y. Zhao, A. C. Lawson, J. Zhang, B. I. Bennett, and R. B. Von Dreele,
Phys. Rev. B 62, 8766 ͑2000͒.
are in excellent agreement with those extrapolated values 11
D. L. Farber, M. Krisch, D. Antonangeli, A. Beraud, J. Badro, F. Occelli,
using the results of Katahara et al. ͑1979͒ and the effect of and D. Orlikowski, Phys. Rev. Lett. 96, 115502 ͑2006͒.
the second pressure derivatives ͑KЉ and GЉ͒ in the current
12
R. Selva Vennila, S. R. Kulkarni, S. K. Saxena, H.-P. Liermann, and S. V.
Sinogeikin, Appl. Phys. Lett. 89, 261901 ͑2006͒.
pressure range ͑12.0 GPa͒ is negligible ͑Fig. 3͒. 13
W. J. Carter, S. P. Marsh, J. N. Fritz, and R. G. McQueen, NBS Spec.
As seen in Fig. 3, the current experimental observation Publ. 36, 147 ͑1971͒.
14
of the pressure dependence for the bulk and shear moduli is G. H. Miller, T. J. Ahrens, and E. M. Stopler, J. Appl. Phys. 63, 4469
also supported by our DFT calculations. Quantitatively, with ͑1988͒.
15
R. S. Hixson, D. A. Boness, and J. W. Shaner, Phys. Rev. Lett. 62, 637
the density and elastic moduli data from DFT calculations, ͑1989͒.
we can perform finite strain fit to determine the bulk and 16
B. K. Godwal and R. Jeanloz, Phys. Rev. B 41, 7440 ͑1990͒.
17
shear moduli and their pressure derivatives following the J. A. Moriarty, Phys. Rev. B 45, 2004 ͑1992͒.
18
procedures described above for the analysis of experimental B. Belonoshko, S. I. Simak, A. E. Kochetov, B. Johansson, L. Burak-
ovsky, and D. L. Preston, Phys. Rev. Lett. 92, 195701 ͑2004͒.
data. The fitting results KS0 = 259͑5͒ GPa, G0 = 130͑2͒ GPa, 19
B.-S. Li, J. Kung, and R. C. Liebermann, Phys. Earth Planet. Inter. 143–
Ј Ј
KS0 = 4.4͑7͒, and G0 = 1.7͑3͒, compare very well with the ex- 144, 559 ͑2004͒.
20
perimental data on the pressure derivative of the bulk and R. C. Liebermann and B. Li, in Ultrahigh Pressure Mineralogy: Physics
shear moduli. By comparison, the x-ray diffraction studies and Chemistry of the Earth’s Deep Interior, Reviews in Mineralogy Vol.
37 edited by R. J. Hemley ͑Mineralogical Society of America, Washing-
Ј
͑Refs. 8, 10, and 13͒ appear to have a lower K0 of 3.8–4.1 ton, D. C., 1998͒.
Ј Ј
͑we ignored the small difference between KS0 and KT0͒ but 21
W. Liu and B. Li, Appl. Phys. Lett. 93, 191904 ͑2008͒.
with a slightly higher K0 ͑263–268 GPa͒, this could be due to
22
K. Schwarz, J. Solid State Chem. 176, 319 ͑2003͒.
23
Ј
the tradeoff between K0 and K0 in EOS analysis. If the value P. Blaha, K. Schwarz, P. Sorantin, and S. B. Trickey, Comput. Phys. Com-
mun. 59, 399 ͑1990͒.
Ј
of K0 ϳ 3.9 with K0 = 262.5 GPa obtained from diamond an- 24
W. Kohn and L. J. Sham, Phys. Rev. 140, A1133 ͑1965͒.
vil cell ͑DAC͒ measurements up to 272 GPa is as accurate as 25
J. P. Perdew, K. Burke, and M. Ernzerhof, Phys. Rev. Lett. 77, 3865
that from the current acoustic study, the apparent discrepancy ͑1996͒.
26
Ј
in K0 may be attributed to the increased effect of the second W. B. Pearson, Handbook of Lattice Spacings and Structures of Metals
and Alloys ͑Pergamon, New York, 1958͒, Vol. 1.
order pressure derivatives ͑KЉ and GЉ͒ at these extreme pres- 27
G. F. Davies and A. M. Dziewonski, Phys. Earth Planet. Inter. 10, 336
sures. ͑1975͒.
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