Search results for "SSB"
showing 10 items of 537 documents
Subphotospheric convection and magnetic activity dependence on metallicity and age: Models and tests
2001
We present an extensive study on the dependence of the convective turnover time (conv) on the stellar metallicity and age for main-sequence stars of masses 0.6{1.6 M. To this aim we have used and compared predictions by stellar models based on the classical Mixing Length Theory and models incorporating a Full Spectrum of Turbulence treatment of subphotospheric convection. We show that the metallicity eect is relevant for dG stars but negligible for dK stars, while stellar age is important when computing the turnover times for red dwarfs younger than logt 8:5 yr. A scatter by up to a factor 3 could be spuriously introduced in the activity vs. Rossby number relationships if such eects are neg…
LU Bibliotēkas SSBA jaunās iespējas lietotāju apkalpošanā
2005
Prezentācijā sniegta informācija par SSBA pakalpojumu, elektronisko dokumentu piegādi (dienesti, apmaksas kārtība, cenas).
Run duration effects on the hydrodynamic properties of a loam soil estimated by steady-state infiltration methods
2020
Steady-state methods for the analysis of single-ring infiltration data are commonly applied. However, the duration of an infiltrometer experiment is often established quite subjectively based on the assumption that in general infiltration stabilizes rather quickly in the field. For a loam soil, the effect of the duration of a beerkan run on sorptivity, S, and saturated hydraulic conductivity, Ks, was tested by using the BEST (Beerkan Estimation of Soil Transfer parameters)-steady method and SSBI (Steady version of the Simplified method based on a Beerkan Infiltration run) method for data analysis. The standard experiment, based on a total of 15 water volumes each establishing an initial pon…
Synthesis and characterization of a new family of bi-, tri-, tetra-, and pentanuclear ferric complexes.
2004
Nine members of a new family of polynuclear ferric complexes have been synthesized and characterized. The reaction of Fe(O(2)CMe)(2) with polydentate Schiff base proligands (H(2)L) derived from salicylidene-2-ethanolamine, followed in some cases by reaction with carboxylic acids, has afforded new complexes of general formulas [Fe(2)(pic)(2)(L)(2)] (where pic(-) is the anion of 2-picolinic acid), [Fe(3)(O(2)CMe)(3)(L)(3)], [Fe(4)(OR)(2)(O(2)CMe)(2)(L)(4)], and [Fe(5)O(OH)(O(2)CR)(4)(L)(4)]. The tri-, tetra-, and pentanuclear complexes all possess unusual structures and novel core topologies. Mössbauer spectroscopy confirms the presence of high-spin ferric centers in the tri- and pentanuclear…
Synthesis and characterization of some diorganotin(IV) complexes of Schiff bases derived from a non-protein amino acid. Crystal structures of {HO2CC6…
2008
Diorganotin(IV) complexes R2Sn(LH)2 (R = Me, nBu) and {[nBu2Sn(LH)]2O}2 (LH = 4-[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)amino]benzoate and 4-[{(E)-1-(2-hydroxyphenyl)methylidene}mino]benzoate) have been reported. The complexes were characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mossbauer spectroscopy. Crystal structures of a ligand {HO2CC6H4[NC(H)}{C(CH3)CH(CH3)-3-OH]-p} and one of its di-n-butyltin(IV) complexes (nBu2Sn{O2CC6H4[NC(H)}{C(CH3)CH(CH3)-3-OH]-p}2) were determined. The spectroscopic data suggest that R2Sn(LH)2 complexes have skew-trapezoidal bipyramidal structure while {[nBu2Sn(LH)]2O}2 complexes adopt a dimeric tetraorganodistannoxane structure in the…
Sintesi e caratterizzazione allo stato solido ed in soluzione di derivati chinolonici di organostagno(IV)
2008
I chinoloni sono antibiotici, recentemente usati anche come chemioterapici. Tra i derivati dell’acido nalidixico, precursore di tutte le classi di chinoloni, sono stati scelti chinoloni di I e II generazione per la sintesi di derivati di diorganostagno(IV). Questi composti sono stati caratterizzati sia allo stato solido che in soluzione con spettroscopia FT-IR, Mössbauer, 1H NMR, e con spettrometria di massa (ES-MS).
Synthesis, Characterization and in vitro antimicrobial activity of dialkyltin(IV)bis(fusidate) complexes.
2008
The complexation of one steroid antibiotic of the fusidane family, sodium fusidate [sodium 2-16-acetyloxy-3,11-dihydroxy-4,8,10,14-tetramethyl-2,3,4,5,6,7,9,11,12, 13,15,16-dodeca hydro-1H-cyclopenta[a]phenanthren-7-ylidene)-6-methyl-hept-5-enoate = (Nafus)], by dialkyltin(IV) has been studied by conventional technique as FT-IR, Mössbauer and NMR spectroscopies. Analytical data supported the general formula Alk2Sn(IV)fus2 (Alk = Me, Bu). Infrared spectral data of the complexes imply the presence of both uni- and bidentate, ester-type and bridging carboxylate group, respectively. On the basis of FT-IR and 119Sn Mössbauer spectroscopy, in both Me2Sn(IV)fus2 and Bu2Sn(IV)fus2, trigonal bipyram…
Organotin(IV)derivatives neurotoxicity and their modulation by Baclofen
2008
Several new diorganotin(IV) and triorganotin(IV) complexes with 4-amino-3- (4-chloro phenyl)]-butanoic acid ( = Baclofen) have been synthesized and their structure investigated both in the solid state and in solution phase through spectroscopic methods (FT-IR, Mössbauer, 1H and 13C NMR). According to experimental analytical data, the stoichiometry of the complexes has been proposed as R2SnBac2 and R3SnBac, respectively for diorganotin(IV) and triorganotin(IV) baclofen complexes. (Baclofen = HBac; R = Me, Bu, Ph).
Innovative Photovoltaic Translucent Components for the Building Envelope
2014
International directives that regulates buildings energy efficiency and environmental sustainability establish strict parameters for the construction of a new generation of “Zero Energy Buildings” indicating transmittance limits for building envelope components and encouraging the use of renewable sources. In this sense, the PV sector aims at the definition of novel efficient solutions for the integration in the building envelope, standing out for their multifunctional features. After an overview on the main PV technologies and building integrated applications, focusing on semi-transparent envelope solutions, the paper shows the results of a research that is being carried out at the Departm…
Integrazione di celle solari di terza generazione nel vetromattone per la realizzazione di involucri edilizi traslucidi fotovoltaici
2013
L’integrazione di celle solari di terza generazione - Dye-sensitised Solar Cells (DSSC) - nel vetromattone consente di ottenere un prodotto edilizio in grado di generare energia pulita, personalizzabile in termini di colore, livelli di trasparenza e fi niture, adatto alla realizzazione di componenti edilizi fotovoltaici, traslucidi e multifunzionali, facilmente integrabili nelle chiusure degli edifi ci per la costruzione di involucri edilizi energeticamente effi cienti ed attivi anche in contesti climatici avversi, quali possono essere quelli del Mediterraneo e delle aree subtropicali. L’articolo illustra 4 differenti ipotesi di integrazione delle DSSC nel vetromattone fornendo, per ciascun…