Search results for "rock"

Adhesive root hairs facilitate Posidonia oceanica seedling settlement on rocky substrates

2015

Posidonia oceanica, the dominant Mediterranean seagrass, has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. During more than 10 years of direct observations, we noticed that P. oceanica seedlings were often firmly anchored to rocky reefs, even at exposed sites. Thus, we analysed the ultrastructural features of seedling root systems to identify specific traits that may represent adaptations for early seedling anchorage on rocky bottoms. Subapical sections of adventitious roots were obtained from 2-3 months old specimens collected in the field and were observed at SEM revealing an extensive coverage of adhesive…

Major and trace elements in Boletus aereus and Clitopilus prunulus growing on volcanic and sedimentary soils of Sicily (Italy)

2017

The aim of this study was to determine and compare the content of 28 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, Tl, U, V and Zn) in fruiting bodies of Boletus aereus Bull. and Clitopilus prunulus P. Kumm collected from eleven unpolluted sites of Sicily (Italy) and, also to relate the abundance of chemical elements in soil with their concentration in mushrooms. Median concentrations of the most abundant elements in Boletus aereus ranged from 31,290 μg/g (K) to 107 μg/g (Zn) in caps and from 24,009 μg/g (K) to 57 μg/g (Zn) in stalks with the following abundance order: K > Na > Ca > Mg > Fe > Al > Rb > Zn. The s…

Collimation and asymmetry of the hot blast wave from the recurrent nova V745 Scorpii

2016

The recurrent symbiotic nova V745 Sco exploded on 2014 February 6 and was observed on February 22 and 23 by the Chandra X-ray Observatory Transmission Grating Spectrometers. By that time the supersoft source phase had already ended and Chandra spectra are consistent with emission from a hot, shock-heated circumstellar medium with temperatures exceeding 10^7K. X-ray line profiles are more sharply peaked than expected for a spherically-symmetric blast wave, with a full width at zero intensity of approximately 2400 km/s, a full width at half maximum of 1200 +/- 30 km/s and an average net blueshift of 165 +/- 10 km/s. The red wings of lines are increasingly absorbed toward longer wavelengths by…

¿Mozart era un mutante?: propuestas didácticas sobre la música preexistente en el cine de superhéroes.

2019

Con el inicio del siglo XXI se produjo el comienzo de una edad dorada para el cine de superhéroes; especialmente, en las películas basadas en cómics de la editorial Marvel. Su éxito se debe, sobre todo, a la adaptación al cine del concepto de 'universo compartido', lo que permite mostrar personajes y situaciones interrelacionadas. Ello ofrece la opción de conectar con diversas promociones de alumnos, puesto que se trata de personajes presentes en los cines durante las últimas dos décadas. Como muestra de ello, en esta propuesta se incluirán fragmentos de dos películas distantes en el tiempo: 'X-Men 2' (2003) y 'Thor: Ragnarok' (2017). La popularidad creciente de estos filmes se ve intensifi…

Thermo‐Hydro‐Mechanical Model and Caprock Deformation Explain the Onset of an Ongoing Seismo‐Volcanic Unrest

2021

Acknowledgments The authors are grateful to the Editor, Prof. Ben‐Zion Yehuda, and the reviewers: Prof. Micol Todesco and an anonymous reviewer, whose comments and recommendations have significantly improved the quality of this work. The authors acknowledge the financial support of the Petroleum Technology Development Fund (PTDF) Nigeria for this research. The comparison of our models with monitoring data was made possible by the outstanding efforts of the staff at the INGV‐Osservatorio Vesuviano, who provide weekly information about geophysical parameters at the Campanian volcanoes (http://www.ov.ingv.it/ov/en/bollettini/272-campi-flegrei-bollettini-settimanali.html). The authors are parti…

Memory and Jesus’ Parables

2018

This article interacts with John P. Meier’s view concerning the parables that can be shown to be “authentic,” i.e., shown to have been uttered by the historical Jesus. His highly critical and largely negative result (only four parables remaining parables of Jesus) demonstrates once more that historical Jesus research that is intrinsically tied to questions of authenticity has run its course. Such an approach can only lead to minimalistic results and destroys the sources that we have. By contrast, the so-called memory approach tries to understand the process and result of remembering Jesus as a parable teller. Collective memory requires typification and repetition in order to bring the past …

The N Variscan margin of the Ruhr coal district (Western Germany): structural style of a buried thrust front?

1988

The Ruhr coal district represents part of an external fold and thrust belt of the Variscan orogen in central Europe. Extensive mining exposed molasse-type, coal-bearing clastic sequences of Upper Carboniferous age, deformed by folding and thrusting. Thrusts range in scale from decameters to 40 kilometers along strike but displacements are below 2.5 km. They are distributed in various stratigraphic levels and no regional detachment horizon is exposed. Displacement is mainly towards NW (towards the foreland) but also towards SE. The thrusts are bound to stockwerk-tectonics and die out towards depth frequently antithetic to the exposed strata. Folds vary in wavelength from decameters to more t…

A year in the life of an aluminous metapelite xenolith—The role of heating rates, reaction overstep, H2O retention and melt loss

2011

Abstract Xenoliths of aluminous metapelite within the Platreef magmatic rocks of the Bushveld Complex, South Africa, are mineralogically and texturally zoned, with coarse-grained margins rich in acicular corundum, spinel and feldspar and cores rich in finer-grained aluminosilicate and cordierite. Xenoliths exhibiting remarkably similar features occur within other intrusions, suggesting a common origin. Using a single 3 m wide xenolith as a case study, a model is proposed to explain their petrogenesis. Mineral equilibria calculations in the NCKFMASHTO system show that the thermal stability of the solid phases, in particular corundum, is highly sensitive to the quantity of H 2 O retained in t…

Comments on “Predicting the Effect of Rock Fragments on Saturated Soil Hydraulic Conductivity”

2007

Hydrogen underground storage—Petrographic and petrophysical variations in reservoir sandstones from laboratory experiments under simulated reservoir …

2018

Abstract Fluctuating energy production by renewables is one of the main issues in transition times of energy production from conventional power plants to an energy production by renewables. Using excess produced electricity (windy/sunny periods) to convert water to oxygen and hydrogen and storing the hydrogen in depleted oil-, gas fields or sedimentary aquifer structures would provide the option to recover and convert hydrogen to electricity in periods with an energy demand. Research focus is here the pore space in the geological underground where still few studies exist. In static batch experiments up to six weeks long, under different reservoir-specific conditions; regarding pressure, tem…