An improved calibration curve of the pressure shift of the ruby R1 emission line was obtained under quasi-hydrostatic conditions in the diamond-window, high-pressure cell to 800 kbar. Argon was the pressure-transmitting medium. Metallic copper, as a standard, was studied in situ by X ray diffraction. The reference pressure was determined by calibration against known equations of state of the copper sample and by previously obtained data on silver.

Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions

The status of experimental tests of general relativity and of theoretical frameworks for analyzing them is reviewed and updated. Einstein’s equivalence principle (EEP) is well supported by experiments such as the Eotvos experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves.

/pdf/the-confrontation-between-general-relativity-and-experiment-5dqdube5p9.pdf

The Confrontation Between General Relativity and Experiment

As the technology for diamond film preparation by plasma-assisted CVD and related procedures has advanced, Raman spectroscopy has emerged as one of the principal characterization tools for diamond materials. Cubic diamond has a single Raman-active first order phonon mode at the center of the Brillouin zone. The presence of sharp Raman lines allows cubic diamond to be recognized against a background of graphitic carbon and also to characterize the graphitic carbon. Small shifts in the band wavenumber have been related to the stress state of deposited films. The effect is most noticeable in diamond films deposited on hard substrates such as alumina or carbides. The Raman line width varies with mode of preparation of the diamond and has been related to degree of structural order. The Raman spectrum of hexagonal diamond (lonsdaleite) is distinct from that of the cubic diamond and allows it to be recognized.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400004441

Characterization of diamond films by Raman spectroscopy

The field of viscous liquid and glassy solid dynamics is reviewed by a process of posing the key questions that need to be answered, and then providing the best answers available to the authors and their advisors at this time. The subject is divided into four parts, three of them dealing with behavior in different domains of temperature with respect to the glass transition temperature, Tg , and a fourth dealing with ‘‘short time processes.’’ The first part tackles the high temperature regime T.Tg ,i n which the system is ergodic and the evolution of the viscous liquid toward the condition at Tg is in focus. The second part deals with the regime T;Tg , where the system is nonergodic except for very long annealing times, hence has time-dependent properties ~aging and annealing!. The third part discusses behavior when the system is completely frozen with respect to the primary relaxation process but in which secondary processes, particularly those responsible for ‘‘superionic’’ conductivity, and dopart mobility in amorphous silicon, remain active. In the fourth part we focus on the behavior of the system at the crossover between the low frequency vibrational components of the molecular motion and its high frequency relaxational components, paying particular attention to very recent developments in the short time dielectric response and the high Q mechanical response. © 2000 American Institute of Physics.@S0021-8979~00!02213-1#

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1065&context=mse_pubs

Relaxation in glassforming liquids and amorphous solids

The authors reported on investigation of the thermal conductivity of graphene suspended across trenches in Si∕SiO2 wafer. The measurements were performed using a noncontact technique based on micro-Raman spectroscopy. The amount of power dissipated in graphene and corresponding temperature rise were determined from the spectral position and integrated intensity of graphene’s G mode. The extremely high thermal conductivity in the range of ∼3080–5150W∕mK and phonon mean free path of ∼775nm near room temperature were extracted for a set of graphene flakes. The obtained results suggest graphene’s applications as thermal management material in future nanoelectronic circuits.

/pdf/extremely-high-thermal-conductivity-of-graphene-prospects-25qgwo9zzw.pdf

Extremely high thermal conductivity of graphene: Prospects for thermal management applications in nanoelectronic circuits

Error Analysis of Parameter‐Fitting in Equations of State for Mantle Minerals

Crystal-field spectra of fassaite from the Angra dos Reis meteorite

Experiments in which a sample of MgO contained crystals of ruby include data for the first calibration of the diamond-window pressure cell to approximately 1 Mbar. In the same experiments, pressures determined from volume measurements of MgO calibrated by shock-wave data and from spectral shift of the ruby R1 fluorescent line are essentially identical.

COMPRESSION EXPERIMENTS ON MgO AND RUBY WITH THE DIAMOND-WINDOW PRESSURE CELL TO 1 MEGABAR

Crystal-Field Spectra of Fassaite from the Angra DOS Reis Meteorite

Apollo 16 samples of all four rock types and from all stations contain evidence for hydration and oxidation - i.e., the presence of hydrated iron oxide, probably goethite. Rock 66095 contains native FeNi grains with a characteristic intergrowth of schreibersite and, to lesser extents, of cohenite. Troilite also contains sphalerite. The goethite contains 1.5-4.6 wt.% chlorine and occurs mainly on the edges of FeNi metal, causing a rust color in the cracks and space around the native metal grains, which also contain abundant chlorine. This observation suggests the presence of lawrencite (FeCl2), a phase that deliquesces and oxidizes very rapidly upon exposure to water or to a moist atmosphere.

Peter M. Bell

Papers

Error Analysis of Parameter‐Fitting in Equations of State for Mantle Minerals

Crystal-field spectra of fassaite from the Angra dos Reis meteorite

COMPRESSION EXPERIMENTS ON MgO AND RUBY WITH THE DIAMOND-WINDOW PRESSURE CELL TO 1 MEGABAR

Crystal-Field Spectra of Fassaite from the Angra DOS Reis Meteorite

Rust in the Apollo 16 rocks