Archean continental crust formed by magma hybridization and voluminous partial melting

Archean (4.0–2.5 Ga) tonalite–trondhjemite–granodiorite (TTG) terranes represent fragments of Earth’s first continents that formed via high-grade metamorphism and partial melting of hydrated basaltic crust. While a range of geodynamic regimes can explain the production of TTG magmas, the processes by which they separated from their source and acquired distinctive geochemical signatures remain uncertain. This limits our understanding of how the continental crust internally differentiates, which in turn controls its potential for long-term stabilization as cratonic nuclei. Here, we show via petrological modeling that hydrous Archean mafic crust metamorphosed in a non-plate tectonic regime produces individual pulses of magma with major-, minor-, and trace-element signatures resembling—but not always matching—natural Archean TTGs. Critically, magma hybridization due to co-mingling and accumulation of multiple melt fractions during ascent through the overlying crust eliminates geochemical discrepancies identified when assuming that TTGs formed via crystallization of discrete melt pulses. We posit that much Archean continental crust is made of hybrid magmas that represent up to ~ 40 vol% of partial melts produced along thermal gradients of 50–100 °C/kbar, characteristic of overthickened mafic Archean crust at the head of a mantle plume, crustal overturns, or lithospheric peels

Phase equilibrium modelling and implications for P-T determinations of medium-temperature UHP eclogites, North Qaidam terrane, China

In contrast to low-T eclogites (garnet growth zoning preserved) or high-T eclogites (garnet diffusionally homogenized at peak conditions), medium-temperature eclogites pose additional challenges to P-T determinations due to the partial preservation of garnet zoning. The Dulan area, in the southeastern part of North Qaidam ultrahigh-pressure terrane, exposes minor eclogites hosted by ortho- and paragneisses. Four fresh, medium-temperature eclogites contain the paragenesis Grt+Omp+Rt+Qz/Coe+Ph +/- Ky +/- Zo. In all samples, garnet X-Mg shows little zoning, suggesting diffusional modification, and precludes the use of pyrope+almandine+grossular isopleth intersections to determine a P-T path. However, in one sample, sharp zoning in grossular content suggests that grossular growth compositions are preserved. Since garnet pyrope+almandine compositions appear to be modified, we instead use the intersections of grossular and garnet volume isopleths to define a prograde P-T path. This approach yields a path from similar to 17 kbar and similar to 410 degrees C to similar to similar to 35 kbar and similar to 625 degrees C with a gradient of similar to 5-9 degrees C/km through the lawsonite stability field. Peak P-T conditions determined from the intersection between Si pfu in phengite and Zr-in-rutile isopleths are similar to 26-33 kbar and similar to 625-700 degrees C for the four eclogites. These conditions are close to the limit of the lawsonite stability field, suggesting that fluid released from lawsonite breakdown may have promoted re-equilibration at these conditions. These peak conditions are also in good agreement (within 3 kbar and 50 degrees C) with garnet-omphacite-phengite (+/- kyanite) thermobarometry in three of the four samples. We regard the phengite-rutile constraints as more reliable, because they are less sensitive to uncertainties associated with ferric iron compared to conventional thermobarometry. Phase equilibrium modelling predicts that the retrograde assemblage of amphibole+zoisite formed at similar to 60 km. Infiltration of external fluids was likely required for the growth of these hydrous minerals. Based on the comparison of P-T estimation methods applied in this study, we propose that the garnet grossular+volume isopleths can recover the prograde P-T path of medium-temperature eclogites, and that the combination of phengite+rutile isopleths represents a more robust approach to constrain peak P-T conditions

On the occurrence of amphibolite-facies sapphirine, spinel, phlogopite, anorthite, and corundum in the Wet Mountains, Colorado, USA

The Wet Mountains, southern Colorado, expose Mesoproterozoic metamorphic and magmatic rocks that record the early deformational history of the west–central continental USA and growth of Laurentia. Of particular petrological interest are halogen-enriched metamorphic rocks adjacent to the San Isabel A-type granite, situated in the southern Wet Mountains, which contain sapphirine, spinel, phlogopite, anorthite, and corundum. Conventional thermobarometry and phase diagram-based thermodynamic modeling indicates peak pressure–temperature (P–T) conditions of metamorphism within the upper amphibolite facies (∼750–770 °C) at middle-crustal pressures (∼6–7 kbar), and in-situ U-Pb geochronology of monazite constrains peak metamorphism to c. 1340–1320 Ma. These sapphirine-hornfels units are younger than metamorphic lithologies elsewhere in the southern Wet Mountains (c. 1430 Ma), but only slightly post-date the timing of intrusion of the granite itself (1362 ± 7 Ma). These rocks are thus interpreted to be of contact metamorphic origin, with high F contents in mica and amphibole interpreted to record metasomatism in the middle crust by halogen-rich fluids expelled by the San Isabel granite. However, as the temperature of emplacement and crystallization of the granite likely did not greatly exceed 800–850 °C, these rocks document an unusual occurrence of normally granulite-facies and (ultra)high-temperature metamorphic minerals stabilizing at lower grade. Thus, caution must be used when using such parageneses as field indicators of geodynamic settings associated with extreme heat flow, such as continental rifting and/or voluminous emplacement of dry, mafic magma

State of the Art and Trends Review of Smart Metering in Electricity Grids

Climate change, awareness of energy efficiency, new trends in electricity markets, the obsolescence of the actual electricity model, and the gradual conversion of consumers to prosumer profiles are the main agents of progressive change in electricity systems towards the Smart Grid paradigm. The introduction of multiple distributed generation and storage resources, with a strong involvement of renewable energies, exposes the necessity of advanced metering or Smart Metering systems, able to manage and control those distributed resources. Due to the heterogeneity of the Smart Metering systems and the specific features of each grid, it is easy to find in the related literature a wide range of solutions with different features. This work describes the key elements in a Smart Metering system and compiles the most employed technologies and standards as well as their main features. Since Smart Metering systems can perform jointly with other activities, these growing initiatives are also addressed. Finally, a revision of the main trends in Smart Metering uses and deployments worldwide is included.his work has been partially supported by the Spanish Ministry of Economy and Competitiveness (project TEC2015-67868-C3-1-R), the University of the Basque Country (UPV/EHU) within the program for the specialization of the postdoctoral researcher staff, and Microgrids with Renewable Distributed Generation (MIGEDIR) (project 713RT0468), funded by the Science and Technology for Development Iberoamerican Program (CYTED)

Deep Learning for Diagonal Earlobe Crease Detection

An article published on Medical News Today in June 2022 presented a fundamental question in its title: Can an earlobe crease predict heart attacks? The author explained that end arteries supply the heart and ears. In other words, if they lose blood supply, no other arteries can take over, resulting in tissue damage. Consequently, some earlobes have a diagonal crease, line, or deep fold that resembles a wrinkle. In this paper, we take a step toward detecting this specific marker, commonly known as DELC or Frank's Sign. For this reason, we have made the first DELC dataset available to the public. In addition, we have investigated the performance of numerous cutting-edge backbones on annotated photos. Experimentally, we demonstrate that it is possible to solve this challenge by combining pre-trained encoders with a customized classifier to achieve 97.7% accuracy. Moreover, we have analyzed the backbone trade-off between performance and size, estimating MobileNet as the most promising encoder.Comment: Accepted at 12th International Conference on Pattern Recognition Applications (ICPRAM 2023

Nanofotónica de OLEDs monocromáticos flexibles

Fabricación e implementación de una pantalla matriz 8x8 de diodos orgánicos emisores de luz (OLEDs) sobre sustrato flexible transparente de tereptalato de polietileno (PET) con emisión de fotones desde capas electroluminiscentes del orden de los nanómetros.Ingeniero (a) ElectrónicoPregrad

Plan estratégico del área de salud ocupacional y medio ambiente de la Universidad Icesi.

El presente proyecto de grado plantea un plan estratégico para el área de Salud Ocupacional y Medio Ambiente (SOMA) de la Universidad Icesi de Cali, que será la guía de trabajo para la líder del área. El plan estratégico permitirá al área de SOMA posicionarse como un área estratégica para la organización, desde el ámbito de la sostenibilidad, y expandir su impacto a nuevos campos como la formación y la consultoría al interior y al exterior de la Universidad. El resultado de la aplicación de este plan estratégico será el reconocimiento del área de SOMA como un área generadora de valor para la organización, que centraliza los proyectos de sostenibilidad desarrollados en la Universidad y que brinda asesoría y formación a diferentes partes interesadas al interior y al exterior de la organización

Study of unwanted emissions in the CENELEC-A band generated by distributed energy resources and their influence over narrow band power line communications

Producción CientíficaDistributed Energy Resources might have a severe influence on Power Line Communications, as they can generate interfering signals and high frequency emissions or supraharmonics that may cause loss of metering and control data. In this paper, the influence of various energy resources on Narrowband Power Line Communications is described and analyzed through several test measurements performed in a real microgrid. Accordingly, the paper describes the effects on smart metering communications through the Medium Access Control (MAC) layer analysis. Results show that the switching frequency of inverters and the presence of battery chargers are remarkable sources of disturbance in low voltage distribution networks. In this sense, the results presented can contribute to efforts towards standardization and normative of emissions at higher frequencies higher, such as CENELEC EN 50160 and IEC/TS 6274

Estrategias de transformación digital en empresas tradicionales

La transformación digital se ha convertido en un tema central en el mundo empresarial en las últimas décadas. Este fenómeno ha sido impulsado por avances tecnológicos significativos, cambios en las preferencias de los consumidores y una creciente competencia en los mercados globales. El objetivo de esta investigación consiste en identificar las mejores estrategias empresariales para lograr una exitosa transformación digital. La metodología empleada en esta investigación es de naturaleza documental y bibliográfica, centrada en la recopilación y análisis de fuentes secundarias que abordan el tema de las estrategias de transformación digital en empresas. El estudio reveló que la transformación digital exitosa en las empresas requiere una visión estratégica clara y el compromiso de la alta dirección. Las empresas que priorizan la experiencia del cliente, fomentan una cultura de innovación y adoptan tecnologías emergentes tienden a obtener mejores resultados. Se recomienda que las empresas definan una visión y estrategia digital sólidas, involucren a la alta dirección y aborden las barreras de resistencia al cambio y la falta de habilidades digitales. Se sugiere que las empresas se enfoquen en áreas específicas, como la adopción de tecnologías emergentes, la seguridad cibernética, la ética en la recopilación de datos y la colaboración con socios estratégicos