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We report new detections and limits from a NOEMA and ALMA CO(1-0) search for molecular outflows in 13 local galaxies with high FIR surface brightness, and combine with results from the literature. CO line ratios and outflow structure provide some constraints on the conversion from observables to quantities such as molecular mass outflow rates. Ratios between outflow emission in higher J CO transitions and in CO(1-0) typically are consistent with excitation Ri1<~1. For IRAS 13120-5453, however, R31=2.10 indicates optically thin CO in the outflow. Like much of the outflow literature, we use alpha(CO) = 0.8, and we present arguments for using C=1 in deriving molecular mass outflow rates Mdot = C*M*v/R. We compare the two main methods for molecular outflow detection: CO mm interferometry and Herschel OH spectroscopy. For 26 sources studied with both methods, we find 80% agreement in detecting vout>~150km/s outflows, and non-matches can be plausibly ascribed to outflow geometry and SNR. For 12 bright ULIRGs with detailed OH-based outflow modeling, CO outflows are detected in all but one. Outflow masses, velocities, and sizes for these 11 sources agree well between the two methods, and modest remaining differences may relate to the different but overlapping regions sampled by CO emission and OH absorption. Outflow properties correlate better with AGN luminosity and with bolometric luminosity than with FIR surface brightness. The most massive outflows are found for systems with current AGN activity, but significant outflows in non-AGN systems must relate to star formation or to AGN activity in the recent past. We report scaling relations for the increase of outflow mass, rate, momentum rate, and kinetic power with bolometric luminosity. Short ~10^6yr flow times and some sources with resolved multiple outflow episodes support a role of intermittent driving, likely by AGN. (abridged), Comment: 37 pages. Accepted for publication in Astronomy & Astrophysics

We report new detections and limits from a NOEMA and ALMA CO(1-0) search for molecular outflows in 13 local galaxies with high FIR surface brightness, and combine with results from the literature. CO line ratios and outflow structure provide some constraints on the conversion from observables to quantities such as molecular mass outflow rates. Ratios between outflow emission in higher J CO transitions and in CO(1-0) typically are consistent with excitation Ri1<~1. For IRAS 13120-5453, however, R31=2.10 indicates optically thin CO in the outflow. Like much of the outflow literature, we use alpha(CO) = 0.8, and we present arguments for using C=1 in deriving molecular mass outflow rates Mdot = C*M*v/R. We compare the two main methods for molecular outflow detection: CO mm interferometry and Herschel OH spectroscopy. For 26 sources studied with both methods, we find 80% agreement in detecting vout>~150km/s outflows, and non-matches can be plausibly ascribed to outflow geometry and SNR. For 12 bright ULIRGs with detailed OH-based outflow modeling, CO outflows are detected in all but one. Outflow masses, velocities, and sizes for these 11 sources agree well between the two methods, and modest remaining differences may relate to the different but overlapping regions sampled by CO emission and OH absorption. Outflow properties correlate better with AGN luminosity and with bolometric luminosity than with FIR surface brightness. The most massive outflows are found for systems with current AGN activity, but significant outflows in non-AGN systems must relate to star formation or to AGN activity in the recent past. We report scaling relations for the increase of outflow mass, rate, momentum rate, and kinetic power with bolometric luminosity. Short ~10^6yr flow times and some sources with resolved multiple outflow episodes support a role of intermittent driving, likely by AGN. (abridged), Comment: 37 pages. Accepted for publication in Astronomy & Astrophysics

With the integration of metallurgical as well as mining variables into the modelling of economic concepts such as ultimate pit limits and extraction grades, decision-making has become extremely complicated for companies that own several deposits with alternative processes, different mineral types, a range of haulage options and a number of low-grade stocks.The paper focuses on the managerial aspects behind the use of operational research models that can handle such variables inter-temporally and simultaneously, in a case study of Codelco Chile's Codelco Norte division that was formed by merging the Chuquicamata and Radomiro Tomic divisions and whose deposits include both sulphide and oxide ores. The integrated planning of Chuquicamata mine with MM mine is analysed, both involving open-pit exploitation followed by underground mining but the MM deposit having very high Cu and As contents in the upper part of the orebody., With the integration of metallurgical as well as mining variables into the modelling of economic concepts such as ultimate pit limits and extraction grades, decision-making has become extremely complicated for companies that own several deposits with alternative processes, different mineral types, a range of haulage options and a number of low-grade stocks.The paper focuses on the managerial aspects behind the use of operational research models that can handle such variables inter-temporally and simultaneously, in a case study of Codelco Chile's Codelco Norte division that was formed by merging the Chuquicamata and Radomiro Tomic divisions and whose deposits include both sulphide and oxide ores. The integrated planning of Chuquicamata mine with MM mine is analysed, both involving open-pit exploitation followed by underground mining but the MM deposit having very high Cu and As contents in the upper part of the orebody.

Two methods of producing high velocity liquid impact on solid targets are described. The jet method is described in full detail and the work aimed at relating jet impact damage to that produced by drop impact is fully discussed. High speed photography has been used extensively to study impact phenomena, and pressure measurements have been made using 250 micrometers diameter transducers. A hydrostatic test apparatus has been developed for measuring the residual strength of brittle specimens following impact. With glasses, large strength losses can occur before the damage reaches visible dimensions. The factors affecting the residual strength curves are discussed. (Author)

SCOPUS: ar.j, info:eu-repo/semantics/published

SCOPUS: ar.j, info:eu-repo/semantics/published

Appartient à l’ensemble documentaire : MethMusiq, Contient une table des matières, Avec mode texte, Chant (musique)

The value chain framework model proposed by Porter (1985) was used to assess the activities which have the greatest effect in driving mining business value. The model groups business activities under two main headings, upstream primary activities which are directly concerned with company outputs and make up the value chain, and downstream support activities which provide the common services and shared resources for the business to operate and which overarch the value train. In the case of mining resource-related activities are upstream and are generally known as mineral resource management. This function covers exploration and planning and development with the respective goals of discovering mineral resources and transforming them into mineral reserves in the most effective and efficient way. The outcome is a business plan which defines the methods and rate that the orebody is mined, together with the onsite and offsite infrastructure needed to deliver the mineral products to market. Downstream are the industrial activities needed to execute the business plan. It is suggested that mining companies that excel in total shareholder return (TSR) over an entire economic cycle also excel in increasing their reserves and production, or total reserve increment (TRI). An analysis is presented of the TSR and TRI figures for 13 mining companies which shows that the most effective levers of value creation are often in the upper part of the value chain, with typical drivers to increase reserves being exploration or acquisitions., The value chain framework model proposed by Porter (1985) was used to assess the activities which have the greatest effect in driving mining business value. The model groups business activities under two main headings, upstream primary activities which are directly concerned with company outputs and make up the value chain, and downstream support activities which provide the common services and shared resources for the business to operate and which overarch the value train. In the case of mining resource-related activities are upstream and are generally known as mineral resource management. This function covers exploration and planning and development with the respective goals of discovering mineral resources and transforming them into mineral reserves in the most effective and efficient way. The outcome is a business plan which defines the methods and rate that the orebody is mined, together with the onsite and offsite infrastructure needed to deliver the mineral products to market. Downstream are the industrial activities needed to execute the business plan. It is suggested that mining companies that excel in total shareholder return (TSR) over an entire economic cycle also excel in increasing their reserves and production, or total reserve increment (TRI). An analysis is presented of the TSR and TRI figures for 13 mining companies which shows that the most effective levers of value creation are often in the upper part of the value chain, with typical drivers to increase reserves being exploration or acquisitions.

The paper discusses the behaviour of a metal market through the use of supply and demand curves. It is followed by an analysis of the metal supply from individual companies as a reaction to changes in the economic variables., The paper discusses the behaviour of a metal market through the use of supply and demand curves. It is followed by an analysis of the metal supply from individual companies as a reaction to changes in the economic variables.

Concours pour l'agrégation en chirurgie

Concours pour l'agrégation en chirurgie