Bjorn O. Mysen

Bio: Bjorn O. Mysen is an academic researcher from Carnegie Institution for Science. The author has contributed to research in topics: Silicate & Solubility. The author has an hindex of 62, co-authored 239 publications receiving 12694 citations. Previous affiliations of Bjorn O. Mysen include Centre national de la recherche scientifique & Carnegie Learning.

Silicate glasses and melts : properties and structure

Abstract: 1. The Discovery of Silicate Melts. An Industrial and Geological Perspective. 2. Glass Versus Melt. 3. Glasses and Melts vs. Crystals. 4. Melt and Glass Structure - Basic Concepts. 5. Silica - A Deceitful Simplicity. 6. Binary Metal Oxide-Silica Systems I. Physical Properties. 7. Binary Metal Oxide-Silica Systems II. Structure. 8. Aluminosilicate Systems I. Physical Properties. 9. Aluminosilicate Systems II. Structure. 10. Iron-bearing Melts I. Physical Properties. 11. Iron-bearing Melts II. Structure. 12. The Titanium Anomalies. 13. Phosphorus. 14. Water - An Elusive Component. 15. Volatiles I. The System C-O-H-S. 16. Volatiles II. Noble Gases and Halogens. 17. Natural Melts. References. Subject Index.

Structure and Properties of Silicate Melts

Abstract: 1. Silica. Introduction. Principal building blocks and concepts. Structure of SiO 2 . Summary. 2. Metal Oxide-Silica Systems. Introduction. Bulk properties. Activity-composition relationships. Structural models. Summary. 3. Aluminosilicate Systems. Introduction. Aluminum charge-balance. Properties of aluminosilicate melts. Structure of aluminosilicate glasses and melts. Summary. 4. Iron Oxides. Introduction. Structure positions of ferric and ferrous iron in silicate melts. Determination Fe 3+ /SFe. Redox equilibria and melt structure. Relationships between simple and complex systems. Redox equilibria of iron and melt polymerization. Phase equilibria in iron-bearing systems. Physical properties of iron-bearing silicate melts. Summary. 5. Titanium. Introduction. Properties of titanium-bearing systems. Structural role of titanium in melts and glasses. Summary. 6. Phosphorous. Introduction. Properties of phosphorous-bearing systems. Structural role of phosphorous in silicate melts and glasses. Summary. 7. Volatiles. Introduction. Water. Hydrogen. Sulfur. Carbon. Fluorine. Summary. 8. Multicomponent, Complex Systems. Introduction. Data base. Structure of magmatic liquids. Petrological implications. Summary. References. System Index. Subject Index.

Raman spectroscopy of SiO2 glass at high pressure.

Abstract: A new technique has been developed for optical studies of amorphous solids to very high pressures. Raman spectra of Si${\mathrm{O}}_{2}$ glass measured at 8 GPa indicate a significant reduction in the width of the Si-O-Si angle distribution, which has been associated with a number of anomalous properties of silica glass under ambient conditions. Between 8 and \ensuremath{\sim} 30 GPa irreversible changes in the Raman spectrum occur that are consistent with a shift in ring statistics in densified glass. The spectra suggest a breakdown in intermediate-range order at higher pressure.

Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks

Abstract: Data from experimental runs, coexisting phases in ultramafic rocks and phenocryst-matrix pairs in volcanic rocks have been used to compile a table of mineral-liquid distribution coefficients for Ti, Zr, Y, and Nb for basic, intermediate and acid melt compositions. These values have then been used to interpret variations of these elements, first in basalts and second, during fractional crystallization from basic to acid magmas. For basalts, petrogenetic modelling of Zr/Y, Zr/Ti, and Zr/Nb ratios, when used in conjunction with REE, Cr and isotopic variations, suggests that: (1) the increase in Zr/Y ratio from mid-ocean ridge to within plate basalts and the low Zr/Nb ratios of alkalic basalts are due to (fluid controlled) source heterogeneities; (2) the low Zr and Zr/Y ratio of volcanic arc basalts results from high degree of partial melting of a depleted source; and (3) the high Zr and similar Zr/Y ratio of basalts from fast spreading relative to slow spreading ridges results from open-system fractional crystallization. Modelling of fractionation trends in more evolved rocks using Y-Zr, Ti-Zr and Nb-Zr diagrams highlights in particular the change in crystallizing mafic phases from island arcs (clinopyroxene-dominated) to Andean-type arcs (amphibole±biotite-dominated). These methods can be applied to altered lavas of unknown affinities to provide additional information on their genesis and eruptive environment.

Expert and novice performance in solving physics problems

Abstract: Although a sizable body of knowledge is prerequisite to expert skill, that knowledge must be indexed by large numbers of patterns that, on recognition, guide the expert in a fraction of a second to relevant parts of the knowledge store. The knowledge forms complex schemata that can guide a problem's interpretation and solution and that constitute a large part of what we call physical intuition.

Relaxation in glassforming liquids and amorphous solids

Abstract: 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#

Observation of coherent optical information storage in an atomic medium using halted light pulses

Abstract: Electromagnetically induced transparency1,2,3 is a quantum interference effect that permits the propagation of light through an otherwise opaque atomic medium; a ‘coupling’ laser is used to create the interference necessary to allow the transmission of resonant pulses from a ‘probe’ laser. This technique has been used4,5,6 to slow and spatially compress light pulses by seven orders of magnitude, resulting in their complete localization and containment within an atomic cloud4. Here we use electromagnetically induced transparency to bring laser pulses to a complete stop in a magnetically trapped, cold cloud of sodium atoms. Within the spatially localized pulse region, the atoms are in a superposition state determined by the amplitudes and phases of the coupling and probe laser fields. Upon sudden turn-off of the coupling laser, the compressed probe pulse is effectively stopped; coherent information initially contained in the laser fields is ‘frozen’ in the atomic medium for up to 1 ms. The coupling laser is turned back on at a later time and the probe pulse is regenerated: the stored coherence is read out and transferred back into the radiation field. We present a theoretical model that reveals that the system is self-adjusting to minimize dissipative loss during the ‘read’ and ‘write’ operations. We anticipate applications of this phenomenon for quantum information processing.

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

Abstract: 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.