2,845 research outputs found
In situ high-temperature behaviour of fluor-elbaite. Breakdown conditions and products
No full textThe thermal behaviour of a fluor-elbaite from Minas Gerais (Brazil) was investigated at room pressure through in situ high-temperature X-ray powder diffraction (HT-XRPD), until the breakdown conditions were reached. The variations of fluor-elbaite structural parameters (unit-cell parameters and mean bond distances) were monitored together with site occupancies, and two main internal reactions were identified: the thermally-induced Fe oxidation process counterbalanced by (OH)– deprotonation, which starts at 500 °C (773 K), followed by a partial intracrystalline Fe–Al exchange between the octahedrally-coordinated Y and Z sites. The fluor-elbaite breakdown reaction occurs between 850 °C (1123 K) and 900 °C (1173 K). The breakdown products were identified at room temperature by XRPD and the breakdown reaction can be described by the following reaction: tourmaline → B-bearing mullite + hematite + spinel + B-poor (Na, Li, H2O)-bearing glass. Boromullite itself was not observed in the final heating products, and the B-bearing mullite from the breakdown reaction exhibited unit-cell parameters a = 7.5382(2) Å, b = 7.6749(2) Å, c = 2.8385(1) Å, V = 164.22(1) Å3 (space group Pbam) consistent with an approximate Al8.5B1.5Si2O19 composition
Mangani-pargasite, NaCa2(Mg4Mn3+)(Si6Al2)O22(OH)2, a new mineral species of the amphibole supergroup
No full textMangani-pargasite, ideally NaCa2(Mg4Mn3+)(Si6Al2)O22(OH)2, is a new mineral species of the calcium amphibole subgroup of the amphibole supergroup. The type specimen was found on the mine dump of the Långban Fe-Mn-(Ba-As-Pb-Sb) deposit in Värmland, Sweden. Crystal chemical analyses resulted in the empirical chemical formula: A(Na0.90Pb0.07K0.03)Σ1.00B(Ca1.93Mn2+0.07)Σ2.00C(Mg4.25Mn3+0.39Al0.26 Fe3+0.10)Σ5.00T(Si6.35Al1.65)Σ8.00O22W(OH)2. In order to complete the description of this newly approved (IMA 2018-151) mineral we report here additional data to those published in papers by Jonsson and Hålenius (2010) and Hålenius and Bosi (2012). Mangani-pargasite is biaxial positive, with a=1.635(5), b=1.645(5), g=1.660(5) and the measured optic angle 2V is 85(5)°. The dispersion is weak (r>v), and the optic orientation is: Y||b; Z^c=25(3)°. Mangani-pargasite is red to brownish red with weak pleochroism; X=pale reddish brown, Y=pale reddish brown and Z=pale brownish red; X≈Y>Z. The unit-cell parameters are a=9.9448(5), b=18.0171(9), c=5.2829(3) Å, b=105.445(3)°, V=912.39(9) Å3, Z=2, space group C2/m. The ten strongest reflections in the X-ray powder diffraction pattern [d-values in Å, I, (h k l)] are: 8.420, 29, (110); 3.368, 17, (131), 3.279, 49, (240); 3.141, 100, (310); 2.817, 44, (33 0); 2.698, 21, (151); 2.389, 18, (350); 1.904, 29, (510); 1.650, 22, (461) and 1.448, 46, (661)
Carbon dioxide therapy in the treatment of localized adiposities: clinical study and histopathological correlations
No full textAesthetic Plast Surg. 2001 May-Jun;25(3):170-4.
Carbon dioxide therapy in the treatment of localized adiposities: clinical study and histopathological correlations.
Brandi C, D'Aniello C, Grimaldi L, Bosi B, Dei I, Lattarulo P, Alessandrini C.
Source
Unità Operativa di Chirurgia Plastica, Università digli Studi di Siena, Policlinico Le Scotte, Italy. [email protected]
Abstract
The authors report their experience using carbon dioxide (CO2) therapy for the treatment of 48 female patients presenting adipose accumulations, located on the thighs, knees, and/or abdomen; a Carbomed Programmable Automatic Carbon Dioxide Therapy apparatus was used. In light of the effects of CO2 on the microcirculation recently described in the literature, we expected this gas, which we administered subcutaneously, to positively affect the physiological oxidative lipolytic process. The aim of our study was to evaluate the effect of this therapy on localized adiposities. As such, we describe the method we used and report the results observed in the areas treated (in terms of reduction in maximum circumference) as well as side effects. Furthermore, we assessed the effect of subcutaneous administration of CO2 on the microcirculation by showing changes in the Laser Doppler signal and in the concentration of transcutaneous oxygen tension (tcPO2). Pre- and posttreatment biopsies of tissues were performed in seven patients in order to study the changes induced by the use of CO2 on both adipose and connective tissues. All data obtained were statistically analyzed; values of P < 0.05 were considered significan
La Sacca di Goro in un'ottica di sviluppo sostenibile: La fitodepurazione come elemento di riqualificazione bioarchitettonica
No full textRicerca sull'utilizzo di materiali naturali e di strategie non invasive per il recupero di percorsi e manufatti destinati alla fruizione turistica di un'oasi naturalistica nel Delta del Po
Shoulder Reconstruction by Latissimus Dorsi Myocutaneous Flap Based on the Serratus Branch after Advanced Soft-Tissue Sarcoma Excision: Case Report.
No full textExistence of a semicontinuous or continuous utility function: a unified approach and an elementary proof
No full textIn this paper, we present a new unified approach and an elementary proof of a very general theorem on the existence of a semicontinuous or continuous utility function representing a preference relation. A simple and interesting new proof of the famous Debreu Gap Lemma is given. In addition, we prove a new Gap Lemma for the rational numbers and derive some consequences. We also prove a theorem which characterizes the existence of upper semicontinuous utility functions on a preordered topological space which need not be second countable. This is a generalization of the classical theorem of Rader which only gives sufficient conditions for the existence of an upper semicontinuous utility function for second countable topological spaces. (C) 2002 Elsevier Science B.V. All rights reserved
Mean bond-length variation in crystal structures: A bond-valence approach
No full textThe distortion theorem of the bond-valence theory predicts that the mean bond length D increases with increasing deviation of the individual bond lengths from their mean value according to the equation D = (D′ + ΔD), where D′ is the length found in a polyhedron having equivalent bonds and ΔD is the bond distortion. For a given atom, D′ is expected to be similar from one structure to another, whereas D should vary as a function of ΔD. However, in several crystal structures D significantly varies without any relevant contribution from ΔD. In accordance with bond-valence theory, D variation is described here by a new equation: D = (D RU + ΔD top + ΔD iso + ΔD aniso + ΔD elec), where D RU is a constant related to the type of cation and coordination environment, ΔD top is the topological distortion related to the way the atoms are linked, ΔD iso is an isotropic effect of compression (or stretching) in the bonds produced by steric strain and represents the same increase (or decrease) in all the bond lengths in the coordination sphere, ΔD aniso is the distortion produced by compression and stretching of bonds in the same coordination sphere, ΔD elec is the distortion produced by electronic effects. If present, ΔD elec can be combined with ΔD aniso because they lead to the same kind of distortions in line with the distortion theorem. Each D-index, in the new equation, corresponds to an algebraic expression containing experimental and theoretical bond valences. On the basis of this study, the ΔD index defined in bond valence theory is a result of both the bond topology and the distortion theorem (ΔD = ΔD top + ΔD aniso + ΔD elec), and D′ is a result of the compression, or stretching, of bonds (D′ = D RU + ΔD iso). The deficiencies present in the bond-valence theory in explaining mean bond-length variations can therefore be overcome, and the observed variations of D in crystal structures can be described by a self-consistent model. © 2014 International Union of Crystallography
La ricostruzione della spesa socio-sanitaria integrata nei distretti della Regione Emilia-Romagna nel 2010
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