Search results for "Tassi"
showing 10 items of 997 documents
CCDC 125321: Experimental Crystal Structure Determination
1996
Related Article: J.Faus, F.Lloret, M.Julve, J.M.Clemente-Juan, M.C.Munoz, X.Solans, M.Font-Bardia|1996|Angew.Chem.,Int.Ed.|35|1485|doi:10.1002/anie.199614851
Preparation and characterization of new low melting ammonium-based ionic liquids with ether functionality
2009
Abstract Eighteen new and three previously known but insufficiently characterized RR´3N+A− and R2R´2N+A− type (R = 2-ethoxyethyl or 4-methoxybenzyl, R´ = methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, A = Br, BF4 or PF6) quaternary ammonium (QA) salts were synthesized and characterized by using 1H and 13C NMR techniques, mass spectroscopy and elemental analysis. The bromide salts were synthesized either by treating dimethyl formamide with an ether functionalized alkyl bromide in the presence of potassium carbonate or by treating a tertiary amine with an ether functionalized alkyl bromide. The QA tetrafluoroborates and hexafluorophosphates were synthesized by metathesis reaction betw…
Tris(1,10-phenanthroline)zinc(II) dichromate tetrahydrate
2002
The title compound, [Zn(C12H8N2)3][Cr2O7]·4H2O, was obtained by mixing 1,10-phenanthroline (phen), potassium chromate and zinc sulfate solutions. The asymmetric unit is composed of a [Zn(phen)3]2+ cation, a Cr2O72− anion and four water molecules. The ZnII ion is in a distorted octahedral environment, coordinated by six N atoms from three phen molecules. The cations are connected to anions by weak C—H⋯O hydrogen bonds, with shortest H⋯O distances of ca 2.27–2.33 A. The Cr2O72− anion is in a staggered conformation. Two of the four crystallographically independent water molecules are ordered, and two others are disordered, each over two sites.
Surface properties and catalytic performance for ethane combustion of La1−xKxMnO3+δ perovskites
2001
Abstract The influence of K substitution in LaMnO3 perovskite on the surface properties and catalytic oxidation of ethane has been studied. La1−xKxMnO3+δ perovskites (x=0.05, 0.10, 0.15, 0.20 and 0.25) with BET surface area of 20–26 m2 g−1 have been prepared by the freeze-drying method and characterized by X-ray diffraction patterns (XRD), TPR, TPD and XPS. The XRD analyses showed the presence of a single crystalline phase (x≤0.15) with the linear increase of the lattice parameter corroborating the incorporation of potassium in the perovskite structure. The XPS studies revealed an enrichment of the perovskite surface with potassium accompanied by an increase in the surface Mn4+/Mn3+ ratio. …
Modeling of the catalytic effects of potassium and calcium on spruce wood gasification in CO2
2016
Abstract Using previously reported thermogravimetric analysis measurements, the effects of calcium and potassium on the char gasification rate of spruce wood were modeled. Spruce wood was leached of inorganic ash elements and doped with measured amounts of potassium and calcium. The wood was gasified in an isothermal thermogravimetric analysis device in CO 2 where the devolatilization of the wood, char formation and char gasification all occurred inside the preheated reactor. A new method for separating the effects of devolatilization and char gasification is presented. Kinetic models were evaluated for their ability to describe the observed catalytic effects of potassium and calcium on the…
Thermal stability and reactivity in oxygen of potassium ferrites with spinel structure
1990
The potassium content really incorporated in the spinel lattice of the magnetite determined by thermogravimetric analysis in vacuum or in oxygen was about 2.45 wt%. In spite of this low content, the potassium strongly stabilises the defect spinel structure resulted by the potassium-substituted magnetite oxidation and increases the transformation temperature of the defect phases into α-Fe2O3 or KFe11O17.
Influence of sample pan on the thermal behaviour of KSCN measured with TG
2003
Abstract In this study, the influence of the sample pan on the thermal behaviour of potassium thiocyanate (KSCN) was investigated. The measurements were performed with thermogravimetry (TG) and the two sample pans used were a platinum pan and a ceramic crucible. The samples were heated to 400–950 °C and the thermal products were identified by powder diffraction. The thermal behaviour of KSCN was found to be dependent on the sample pan used. With the platinum sample pan KSCN reacted in the first step into a mixture of K 2 SO 4 and potassium tetracyanoplatinate (K 2 Pt(CN) 4 ). In the second step, the mixture reacted further to pure K 2 SO 4 . In the ceramic sample crucible, however, the reac…
Fermentation profiles of Manzanilla-Aloreña cracked green table olives in different chloride salt mixtures.
2010
NaCl plays an important role in table olive processing affecting the flavour and microbiological stability of the final product. However, consumers demand foods low in sodium, which makes necessary to decrease levels of this mineral in fruits. In this work, the effects of diverse mixtures of NaCl, CaCl2 and KCl on the fermentation profiles of cracked directly brined Manzanilla-Aloreña olives, were studied by means of response surface methodology based in a simplex lattice mixture design with constrains. All salt combinations led to lactic acid processes. The growth of Enterobacteriaceae populations was always limited and partially inhibited by the presence of CaCl2. Only time to reach half …
Preparation and characterization of sodium iron titanate ion exchanger and its application in heavy metal removal from waste waters.
2006
Abstract The ion exchange properties of sodium iron titanates, namely, NaFeTiO4, Na2Fe2Ti6O16 and iron-doped sodium nonatitanate were investigated. Conventional solid state and sol–gel methods were used in the synthesis of the sodium iron titanates. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). Based on TG analyses, the novel iron-doped sodium nonatitanate was proven to be a member of the layered titanate family. The different sodium iron titanates were compa…
Evaluation of the Clinical Efficacy of Potassium nitrate Desensitizing Mouthwash and a Toothpaste in the Treatment of Dentinal Hypersensitivity
2012
Potassium Nitrate has been used as a desensitizing agent to treat dentinal hypersensitivity. The effectiveness of a potassium nitrate is evaluated both in the form of a toothpaste and a mouthwash in a clinical study. Thirty patients were assessed using evaporative stimuli and thermal stimuli and response was evaluated using Visual Analogue Scale at baseline, at 2 weeks and 4 weeks. The patients were divided into. group I: fifteen patients who used toothpaste containing 5% potassium nitrate, sodium fluoride, xylitol and triclosan, group II: Fifteen patients who used mouthwash containing 3% potassium nitrate, sodium fluoride, xylitol and triclosan . The results of both the assessment methods …