Search results for "TVE"

Phase analysis and oxygen strorage capacity of ceria-lanthana-based TWC promoters prepared by sol-gel routes

2002

Ceria–lanthana-based promoters of three-way catalysts are synthesized by two different sol–gel routes, involving nitrate precursors. The oxygen uptake ability of these compounds is measured by O2 chemisorption. The specific surface area is determined by N2 adsorption (BET). X-ray diffraction data are analyzed by Rietveld refinement, demonstrating that lanthanum forms solid solution with CeO2; its total amount in ceria depends on the competitive formation of La–Al mixed oxides and on the synthetic method. The O2 uptake ability is essentially determined by the La content in the ceria–lanthana solid solution, while it is independent on the surface area and on the CeO2 particle size. The O2 upt…

Template induced crystallization of biominerals on self-assembled monolayers of alkylthiols

1998

Abstract We have studied the templated crystallization of the three polymorphs of calcium carbonate on self-assembled monolayers of ω -substituted alkylthiols on gold surfaces. Our interest has been to model biomineralization processes by examining the effect of structured organic templates on heterogeneous nucleation at the inorganic–organic interphase. The crystallization of the three polymorphs was carried out from solution at two different temperatures. The crystals that were formed on the surface were examined using scanning electron microscopy. Phase quantification was achieved through Rietveld analysis of the X-ray diffraction profiles. This study provides significant clues on factor…

Dinamiche insediative nel comprensorio di Cignana. Continuità e discontinuità tra l'età imperiale e l'età bizantina

2013

The aim of this paper is to illustrate the development of rural settlement of Roman age, in the hinterland of Cignana (close to Agrigento, Sicily). In this area were identified an Early Roman age villa and a Late Roman/Byzantine village, partially excavated by the Superintendence of Agrigento. Since 2007 the Dep. of Beni Culturali of University of Palermo has carried out an intensive and systematic archaeological survey around Cignana, where about 200 archaeological sites were identified. Many sites (farms, and perhaps also some villa) were inhabited from late Hellenistic to Late Roman/Byzantine ages, and some have become very large villages; also, many settlements are placed along the prin…

Reglement des kurländischen Creditvereins

1877

Inhalt: Teil I. Das am 18./30/ Mai 1874 Allerhöchst bestätigte Reglement nebst Einschaltungen -- Theil II. Das Taxations-Reglement.

Structural Modifications of Rb<sub>3</sub>RE(PO<sub>4</sub>)<sub>2</sub> Phases (RE = La, Gd, Y)

2001

Cation Distribution in Ferrites with Spinel Structure Measured by Anomalous Powder Diffraction

1998

The Influence of User-Selected Models on the Results of the Rietveld Refinement of the LaOCl Structure

1998

ChemInform Abstract: Crystal Structure and Magnetic Properties of α-Mn(H2PO2)2× H2O.

2010

Abstract The crystal structure of α-Mn(H2PO2)2·H2O has been refined from X-ray powder diffraction data. The cell is monoclinic (space group P21/c, Z − 4) with α = 7.8601(3) A , b = 7.4411(3) A , c = 10.7717(4) A and β = 102.859(2)°. The structure was refined with the Rietveld refinement principles, using as starting model the parameters of the presumably isostructural compound Zn(H2PO2)2·H2O. The structure can be described as being formed by dimeric entities Mn2O2 of edge-sharing manganese octahedra. Each group is linked through Mn-O-P-O-Mn bridges to four other groups, resulting in a three-dimensional network. The thermal variation in the susceptibility shows a sharp peak at T = 6.5 K and …

Powder X-ray diffraction data for potassium silver thiocyanate, AgK(SCN)2 and dipotassium silver thiocyanate, AgK2(SCN)3

2002

Previously unpublished powder X-ray diffraction data for potassium silver thiocyanate, AgK(SCN)2 and dipotassium silver thiocyanate, AgK2(SCN)3 are presented. F30 values for AgK(SCN)2 and AgK2(SCN)3 are 80(0.0075, 50) and 53(0.0089, 63), respectively. The Rietveld refinement of the patterns is also performed. For AgK(SCN)2Rp=6.98, Rwp=11.84, and RBragg=2.9. For AgK2(SCN)3Rp=7.22, Rwp=10.79, and RBragg=5.0.

Dienasgrāmatas metode darba stresa mazināšanai

2019

Šī maģistra darba mērķis bija apkopojot līdz šim izpētīto informāciju par uztverto stresu, stresu darbā, un par dienasgrāmatas metodi, tās dažādību un izmantošanu, kā arī apkopojot informāciju par šo konstruktu saistībām, realizēt kvantitatīvu salīdzinošu pētījumu ar eksperimentālu dizainu, lai noskaidrotu vai dienasgrāmatas metode ir efektīva, lai mazinātu stresu darbā; vai strukturēta dienasgrāmata ir efetkīvāka par nestrukturētu dienasgrāmatas formātu, kā arī kādi ir biežāk identificētie stresori darba vidē. Pētījumā piedalījās 95 respondenti (eksperimentālā grupa, kura pildīja strukturētu dienasgrāmatu n=30, eksperimentālā grupa, kura pildīja brīvas formas dienasgrāmatu n=32, kontroles …