Search results for "HORIZON"
showing 10 items of 600 documents
Anthropogenic soils are the golden spikes for the Anthropocene
2011
We propose that the Anthropocene be defined as the last c. 2000 years of the late Holocene and characterized on the basis of anthropogenic soils. This contrasts with the original definition of the Anthropocene as the last c. 250 years (since the Industrial Revolution) and more recent proposals that the Anthropocene began some 5000 to 8000 years ago in the early to mid Holocene (the early-Anthropocene hypothesis). Anthropogenic soil horizons, of which several types are recognized, provide extensive terrestrial stratigraphic markers for defining the start of the Anthropocene. The pedosphere is regarded as the best indicator of the rise to dominance of human impacts on the total environment b…
Áreas y suelos: El tamaño de los yacimientos de superficie. Una propuesta metodológica
2011
En los estudios sobre el patrón de asentamiento y en los análisis del territorio, la variable"tamaño" del asentamiento juega un papel importante. Considerada como"proxy" de la población, no siempre resulta fácil de calcular en ausencia de estructuras arqueológicas construidas: aterrazamientos o fortificaciones. En este trabajo se presenta una aproximación al cálculo de dicha variable en los asentamientos de superficie caracterizados simplemente por la dispersión de materiales, que toma como punto de partida la correlación entre aquélla y la presencia de los horizontes edáficos ah. La reciprocidad positiva de ambos factores permite sugerir diversas hipótesis sobre la relación entre la formac…
First evidence of Pleistocene ochre production from bacteriogenic iron oxides. A case study of the Upper Palaeolithic site at the San Teodoro Cave (S…
2020
Abstract The use of iron pigments is well documented in the archaeological horizons of the different parts of the world since the Middle Pleistocene. The mineralogical and chemical composition of the pigments allowed defining, in most cases, their inorganic origin, which were then used after a limited transformation and manipulation. The use of a biogenic ochraceous pigment and its manipulation has recently been described in a late Holocene archaeological horizon of the American continent. Here we describe the earliest case of archaeological use of ferrous pigment produced by iron-oxidising bacteria (FeOB), the first identified in a European Epigravettian (late Upper Palaeolithic) layer, at…
From sepulchre to butchery-cooking: Facies analysis, taphonomy and stratigraphy of the Upper Palaeolithic post burial layer from the San Teodoro Cave…
2020
Abstract The San Teodoro Cave is considered the most significant witness of the first, Epigravettian, human colonization of Sicily from the Italian continent. Furthermore the site is a paradigmatic horizon in the Pleistocene faunal record, demonstrating a progressive transition from mega faunas to smaller-sized, Boreal, faunas. The site has been repeatedly studied and excavated, with different aims and approaches, leading to an interpretation of Epigravettian burial site and daily attendance. Here we propose a reappraisal of the study of the stratigraphy of the site, and in particular of the bone-rich layer (PAL) accumulated over the red ochre layer that apparently sealed all the different …
Perspectives of a possible horizon
2018
The contemporary landscape expresses in itself all the contradictions of present time, marked by the lack of a coherent thought on the transformation of places and of a clear aesthetic elaboration. So, the project must reflect not only on the relationship between man and the landscape but above all on the importance of taking care of the physical present, on the need to return to a way of dwelling that respects the places. Architecture, looking for the complete sense of the landscape, plays a fundamental role in the reconstruction of coherence of places and reveals their latent beauty.
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
2021
Full list of authors: Janssen, Michael; Falcke, Heino; Kadler, Matthias; Ros, Eduardo; Wielgus, Maciek; Akiyama, Kazunori; Baloković, Mislav; Blackburn, Lindy; Bouman, Katherine L.; Chael, Andrew; Chan, Chi-kwan; Chatterjee, Koushik; Davelaar, Jordy; Edwards, Philip G.; Fromm, Christian M.; Gómez, José L.; Goddi, Ciriaco; Issaoun, Sara; Johnson, Michael D.; Kim, Junhan; Koay, Jun Yi; Krichbaum, Thomas P.; Liu, Jun; Liuzzo, Elisabetta; Markoff, Sera; Markowitz, Alex; Marrone, Daniel P.; Mizuno, Yosuke; Müller, Cornelia; Ni, Chunchong; Pesce, Dominic W.; Ramakrishnan, Venkatessh; Roelofs, Freek; Rygl, Kazi L. J.; van Bemmel, Ilse; Event Horizon Telescope Collaboration.--This Open Access artic…
Polarization calibration techniques for the new-generation VLBI
2020
The calibration and analysis of polarization observations in Very Long Baseline Interferometry (VLBI) requires the use of specific algorithms that suffer from several limitations, closely related to assumptions in the data properties that may not hold in observations taken with new-generation VLBI equipment. Nowadays, the instantaneous bandwidth achievable with VLBI backends can be as high as several GHz, covering several radio bands simultaneously. In addition, the sensitivity of VLBI observations with state-of-the-art equipment may reach dynamic ranges of tens of thousands, both in total intensity and in polarization. In this paper, we discuss the impact of the limitations of common VLBI …
The Polarized Image of a Synchrotron-emitting Ring of Gas Orbiting a Black Hole
2021
Full list of authors: Narayan, Ramesh; Palumbo, Daniel C. M.; Johnson, Michael D.; Gelles, Zachary; Himwich, Elizabeth; Chang, Dominic O.; Ricarte, Angelo; Dexter, Jason; Gammie, Charles F.; Chael, Andrew A.; Event Horizon Telescope Collaboration; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Algaba, Juan Carlos; Anantua, Richard; Asada, Keiichi; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David Baloković, Mislav; Barrett, John; Benson, Bradford A.; Bintley, Dan; Blackburn, Lindy; Blundell, Raymond; Boland, Wilfred; Bouman, Katherine L.; Bower, Geoffrey C.; Boyce, Hope; Bremer, Michael; Brinkerink, Christiaan D.; Brissenden, Roger; Britzen, Silke; Broderick, Avery E.; Broguiere, Domini…
Evaporation of Near-Extremal Reissner-Nordström Black Holes
2000
The formation of near-extremal Reissner-Nordstrom black holes in the S-wave approximation can be described, near the event horizon, by an effective solvable model. The corresponding one-loop quantum theory remains solvable and allows to follow analytically the evaporation process which is shown to require an infinite amount of time.
New horizons for fundamental physics with LISA
2022
K. G. Arun et al.