177,570 research outputs found
GAS-LIQUID-CHROMATOGRAPHY, THIN-LAYER CHROMATOGRAPHY AND C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTROMETRY IN THE ANALYSIS OF DIASTEREOMERIC MIXTURES OF R-CH(OH)-CH(CH3)-CH=CH2 ALCOHOLS
No full textGas-liquid chromatography, thin-layer chromatography and 13C NMR spectrometry have been employed to identify and analyse diastereomeric mixtures of the β-methylalcohols RCH(OH)-CH(CH3)-CHCH2 where R = CH3, C2H5, n-C3H7, n-C4H9, n-C5H11, iso-C3H7, sec.-C4H9, tert.-C4H9. The existence of a relationship between the analytical data and diastereomeric configuration of the alcohols is pointed out for all the three methods adopte
Costruire (e decostruire) l’altro: filosofia, intercultura e differenza
No full text“Sideways” gaze or thinking (R. Barthes, F. Jullien) refers to a specific type of intercultural philosophy that, more than others, allows us to disengage from the conditioning and prejudices that we suffer when we try to understand a different culture, civilization or religion. This paper identifies and discusses the characteristics of this intercultural approach and shows which theoretical structures and precautions are the most helpful to avoid an erroneous or stereotyped image of the “other”. These structures are based on a particular idea of ‘difference’ that requires to consider as “interdependent variables” (G. Pasqualotto) not only the different compared cultures, but also the point of view from which the comparison is made
[Recensione a: ] R. Redaelli, Emil Lask, Il soggetto e la forma, Macerata, Quodlibet Studio, 2016
No full textSea caves and coastal karst scenery along the maltese coasts: The case study of blue grotto
No full textTens of sea caves and other coastal karst landforms are to be found along the limestone coast of the Maltese Islands. Most of the sea caves develop around the present-day sea level, such as Blue Grotto, which is one of the widest and most spectacular sea cave on the islands. The Blue Grotto karst system is composed by partially submerged chambers, sea arches, gorges and small-scale landforms, such as coastal notches, and speleothems. Such landforms developed at the northwestern side of Wied Babu, in a half a kilometer wide bay near Żurrieq. This chapter presents the results of a detailed geomorphological survey of these coastal and karst landforms and discusses the origin and development of the studied landforms. The close relation with the sea level suggests that the system is partly related to former enlargement of dissolutionally widened karst voids and partly related to present-day marine processes, such as waves, and subaerial processes, including rock collapse. Although most of the species recorded from the environs of Filfla are common elsewhere around the Maltese Islands, in general, the recorded biotopes exhibit high species richness values, which is indicative of a low degree of anthropogenic pressure being exerted on the site
A new method to study microtopographical changes in the intertidal zone: one year of TMEM measuremets on a limestone removable rock slab (RRS).
No full textA new approach to the problem of measuring microtopographical changes on vertical limestones in the intertidal zone, simple and cost-effective, is discussed. It is based on the positioning of a rock removable slab (RRS) in the intertidal zone. The RRS method allows to use the traversing micro erosion meter (TMEM) on vertical rock surfaces, temporarily removing the slab from the operating position, so that measurements can be collected horizontally. Sources of errors and preliminary results, besides the limits and applicability of the method, are discussed.
We have tested the RRS method in the Gulf of Trieste, on a micro-tidal rock coast, collecting data from 7 stations between -0.75 m and +0.75 m m.s.l. The rock surface of the slab was surveyed between November 2007 and November 2008. During this period, the surface varied between -0.127 mm/yr (rising) and 0.034 mm/yr (lowering), according to the elevation of the stations. In the same period, standard deviation increased downward and varied between 0.003 and 0.045.
Beside the TMEM surveying, we have acquired near-monthly photographic images, in order to observe the biological colonisation of the slab. Monthly photographic comparison of the vertical slab indicates that biological colonisation affected mainly the mid-lower portion of the slab, sometimes preventing the collection of measurements.
Preliminary data suggests that the limestone surface lowered mostly in the upper part, while the lower part is strongly affected by algal growth. Consequently, data indicating surface rising is statistically less significant than data indicating surface lowering. Even the RRS used in the intertidal zone provides new interesting data to study weathering and erosion processes on limestone coasts, the first year of surveying suggests that this technique requires longer periods to address the TMEM data to explain geomorphological questions
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