Search results for "Planetary Science"

2020

RIGA International Airport development in Baltic Sea region aviation industry context

2021

In the paper the authors examined key Latvian economy indicators, specifically focusing on trends in development of aviation industry development. In particular, also attention was paid to passengers and cargo volume transportation dynamics, as well as to RIGA International Airport Development Plan through the year 2036. The authors compared operations of RIGA International Airport with available data from other leading Baltic Sea Region airports, specifically within 300 kilometres zone. Another requirement was, a competing airport had to be in the TOP 100 airports globally to be considered. KEY WORDS: RIGA International Airport, Baltic sea region, development plan. JEL CODES: M160, R110, R…

Kieli- ja kielitaitokäsitykset tutkivan opettajan kenttäpäiväkirjamerkinnöissä

2018

This article focuses on a young teacher-researcher’s beliefs about language and language skills. The research is motivated by findings of former studies according with which teachers’ beliefs are often relatively permanent and have a strong effect on their teaching and evaluation practices. The data consists of a teacher-researcher’s diary notes from storytelling events (n=19) in which storycrafting has been used with young primary school pupils. The study was carried out by a theory-driven content analysis in order to reveal and to be able to assess teacher-researcher’s beliefs that are only implicitly present in the data: diary markings were analyzed by comparing them to widely used dicho…

Skulls, Tree Bark, Fossils

2021

AbstractStudies of material objects in the field of memory studies have followed diverse epistemological and disciplinary trajectories, but their shared characteristic has been the questioning of philosophical assumptions concerning human relations with inanimate things and lower-level organic objects, such as plants, within the Aristotelian hierarchy of beings. Rather than accept at face value their categorizations as passive or deficient in comparison to the human subject, critical scholarship has reformulated the place and role of nonhuman entities in culture. This essay examines the nexus of materiality and memory in the work of the French philosopher and art historian Georges Didi-Hube…

Crystal structure of BaCa(CO3)2 alstonite carbonate and its phase stability upon compression

2021

Authors thank the financial support from the Spanish Ministerio de Ciencia, Innovación y Universidades (MICINN) and the Agencia Estatal de Investigación under projects MALTA Consolider Ingenio 2010 network (MAT2015-71070- REDC) and PGC2018-097520-A-I00 (cofinanced by EU FEDER funds) and from the Generalitat Valenciana under project PROMETEO/2018/123. D.S.-P. and A.O.R. acknowledge the financial support of the Spanish MINECO for RyC-2014-15643 and RyC-2016-20301 Ramón y Cajal grants, respectively. C.P. acknowledges the financial support from the Spanish Ministerio de Economia y Competitividad (MINECO project FIS2017-83295-P). Authors also thank Dr. Nicolescu and the Mineralogy and Meteoritic…

Isothermal equation of state and phase stability of Fe 5 Si 3 up to 96 GPa and 3000 K

2017

The composition of Earth's core has first-order implications for understanding the thermal and chemical history of the deep Earth. The present work measures the pressure-volume equation of state of Fe5Si3 to 96 GPa in a diamond anvil cell using noble gas pressure media and demonstrates that Fe5Si3 is not stable at high temperature and pressure, but reappears during thermal quench. The isothermal equation of state at ambient temperature of Fe5Si3 is given by the bulk modulus KT,0 = 167 (8) and KT,0' = 5.1 (2)), with V0 = 56.29 cm3mol-1. At high temperatures and pressures we observed the disappearance of hexagonal Fe5Si3 diffraction peaks and the appearance of peaks corresponding to cubic FeS…

X-ray diffraction line-broadening study on two vibrating, dry-milling procedures in kaolinites

2009

Due to the great technological importance of the microstructure of kaolinite, characterizing its evolution during dry milling of kaolin and analyzing the microstructural information obtained from different methods were the main aims of this work. The microstructural alteration of kaolinite is evaluated by X-ray diffraction and electron microscopy methods, comparing the results obtained and analyzing the correlations between them. The Warren-Averbach and Voigt-function methods of X-ray diffraction microstructural analysis have been applied successfully to the study of the effects of two different, vibrating-cup dry-milling configurations in the microstructure of kaolinite from the reflection…

Center-to-limb variation of the area covered by magnetic bright points in the quiet Sun

2011

CONTEXT: The quiet Sun magnetic fields produce ubiquitous bright points (BPs) that cover a significant fraction of the solar surface. Their contribution to the total solar irradiance (TSI) is so-far unknown. AIMS: To measure the center-to-limb variation (CLV) of the fraction of solar surface covered by quiet Sun magnetic bright points. The fraction is referred to as 'fraction of covered surface', or FCS. METHODS: Counting of the area covered by BPs in G-band images obtained at various heliocentric angles with the 1-m Swedish Solar Telescope on La Palma. Through restoration, the images are close to the diffraction limit of the instrument (~0.1 arcsec). RESULTS: The FCS is largest at disk cen…

X-ray diffraction line broadening on vibrating dry-milled Two Crows sepiolite

2006

A reference sample of sepiolite and products of its comminution by vibrating dry-milling have been studied using X-ray diffraction (XRD) line-broadening analysis, complementary field emission scanning electron microscopy (FESEM) images and surface area measurements. The apparent crystallite sizes determined via XRD are in agreement with observations on FESEM images. The sepiolite aggregates consist of lath-shaped agglutinations of prisms and pinacoids elongated along [001], each lath including several crystallites in that direction. The surface area magnitudes are in the range of previous experimental measurements of other sepiolites. The results obtained show the effectiveness of vibro-mil…

Microscopic evidence of a flat melting curve of tantalum

2010

International audience; New data on the high-pressure melting curve of Ta up to 48GPa are reported. Evidence of melting from changes in sample texture was found in five different experiments using scanning electron microscopy. The obtained melting temperatures are in excellent agreement with earlier measurements using x-ray diffraction or the laser-speckled method but are in contrast with several theoretical calculations. The results are also compared with shock-wave data. These findings are of geophysical relevance because they confirm the validity of earlier experimental techniques that resulted in low melting slopes of the transition metals measured in the diamond-anvil cell, including i…