Search results for "melting"
showing 10 items of 238 documents
Relationships between societies and their environment in the Sahel in southwestern Niger over the past four thousand years : a geoarchaeological appr…
2013
The Sahel, a zone between the Sahara Desert and the Sudan forests, is currently experiencing major environmental changes. Since the droughts in 1970s and 1980s, and with the high population growth rate, vegetation cover has deteriorated considerably, contributing to increased runoff and soil erosion. Starting from this observation, we undertook the study of past societies in the Niamey region, to assess their impact on the environment. The lack of archaeological data meant that it was necessary to identify key indicators of occupation during the Neolithic and the Iron Age. In addition to providing new evidence to date the Neolithic site of Kirkissoy, a sedimentary study was conducted on a p…
Geochemistry, Sr–Nd–Pb isotopes and geochronology of amphibole- and mica-bearing lamprophyres in northwestern Iran: Implications for mantle wedge het…
2015
Highlights • Northwestern Iranian lamprophyres have alkaline and calc-alkaline nature. • Studied lamprophyres are emplaced during Late Cretaceous to Late Miocene time. • Lamprophyres originated from different metasomatised lithospheric mantle. Abstract Lamprophyres of different age showing distinctive mineralogy, geochemistry and isotopic ratios are exposed in northwestern Iran. They can be divided into Late Cretaceous sannaite, Late Oligocene-Early Miocene camptonite (amphibole-bearing) and Late Miocene minette (mica-bearing) and spessartite (amphibole-bearing) lamprophyres. Sannaites have high-Ti amphibole along with high-Ti and Al clinopyroxene, and they are characterised by homogeneous …
Exploring evolutionary responses to increasing temperature in an environmental opportunistic pathogen
2017
Variability of sensory profile and quality characteristics for ‘Pesca di Bivona’ and ‘Pesca di Leonforte’ peach (Prunus persica Batsch) fresh-cut sli…
2015
Abstract Peach genotypes in Southern Italy include the white-flesh ‘Pesca di Bivona’ (‘Murtiddara’, ‘Bianca’, ‘Agostina’ and ‘Settembrina’) and the yellow-flesh ‘Pesca di Leonforte’ (‘Settembrina’, ‘Giallone’ and ‘Ottobrina’ ) landraces, with non-melting clingstone fruit, characterized by a persistent aroma and an excellent flavor that is highly appreciated by consumers. The aim of this work was to assess the suitability of these white- and yellow-flesh landraces to be processed as fresh-cut product with regard to the persistence of their quality and sensory profiles. Fruit of ‘Pesca di Bivona’ and ‘Pesca di Leonforte’ landraces were cut into slices and stored at 5 °C for 3, 5, 7, 12 d. Fre…
Record of 1.82 Ga Andean-type continental arc magmatism in NE Rajasthan, India: Insights from zircon and Sm–Nd ages, combined with Nd–Sr isotope geoc…
2009
Abstract We document a Palaeoproterozoic Andean-type continental arc granitoid emplacement event in the northwestern segment of the Aravalli mountain range, NW India. Our study is focused on the Jasrapur pluton which is dominated by monzogranites with a subordinate amount of granodiorite and quartz monzodiorite. These rocks carry typical continental arc geochemical signatures, such as high-K calc-alkaline, mildly peraluminous, I-type and magnesian features, as well as high Rb and low Nb, Y and Rb/Zr ratios, decoupling between LILE and HFSE, and negative Nb–Ta and Ti anomalies. Conventional geothermobarometric estimates suggest high temperature (~ 800 °C) and pressure (≥ 600 MPa) conditions …
Characterization of a fiber-reinforced new fully aromatic liquid crystalline polymer
1998
A new rigid liquid crystalline polymer that demonstrates good mechanical and thermomechanical properties and acceptable processing temperature has been recently synthesized and characterized. The melting temperature and some thermomechanical properties do not seem, however, suitable for use in some applications at high temperature or in the presence of aggressive fluids. The use of appropriate inorganic fillers can overcome these shortcomings. In this work the new LCP, polymerized in a bench-scale apparatus, and the same sample filled with carbon fibers are characterized. The properties of the carbon fiber filled LCP are compared with those of another filled wholly aromatic commercial LCP,…
Properties and interactions – melting point of tribromobenzene isomers
2021
The melting points of tribromobenzene isomers are correlated with the number, nature and distribution of intermolecular interactions in their structures.
Synthesis, characterization and thermal properties of small R2R′2N+X−-type quaternary ammonium halides
2005
Twenty-one R {sub 2} R {sup '} {sub 2}N{sup +} X {sup -} -type (R=methyl or ethyl, R {sup '}=alkyl, X=Br or I) quaternary ammonium (QA) halides have been prepared by using a novel one-pot synthetic route in which a formamide (dimethyl-, diethylformamide, etc.) is treated with alkyl halide in the presence of sodium or potassium carbonate. The formation of QA halides was verified with {sup 1}H-NMR, {sup 13}C-NMR, MS and elemental analysis. The crystal structures of four QA halides (two bromide and two iodide) were determined using X-ray single crystal diffraction, and the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bu…
Novel one-pot synthesis of quaternary ammonium halides: new route to ionic liquids
2004
Treatment of an amide with an alkyl or substituted alkyl halide in the presence of a weak base in a one-pot reaction leads to crystalline quaternary ammonium halides with reasonable chemical yields; some of the compounds show low melting points and a liquid range of over 50–100 °C before decomposition.
Isoniazid cocrystallisation with dicarboxylic acids: vapochemical, mechanochemical and thermal methods
2016
Cocrystallisation with a series of related compounds allows for the exploration of trends and limitations set by structural differences between these compounds. In this work, we investigate how the length of a dicarboxylic acid influences the outcome of cocrystallisation with isoniazid. We have performed a systematic study on the mechanochemical, thermal and solvent vapour-assisted cocrystallisation of aliphatic dicarboxylic acids (C3–C10) with isoniazid. Our results demonstrate that the rate of mechanochemical and vapour-assisted cocrystallisation depends on the acid chain length and shows alternation between odd- and even-chain acids. The results of thermal cocrystallisation showed that t…