Search results for "zola"

Characterization of hydraulic mortars by means of simultaneous thermal analysis

2008

The properties of hydraulic mortars were studied by means of simultaneous thermal analysis (STA), according to a procedure proposed in the literature. Hydraulic limes, cement and/or slaked lime were mixed using different proportions of both inert and reactive aggregates, in order to test the effectiveness of such procedure in distinguishing the different degree of hydraulicity of such samples. The use of the normalized coordinates suggested in the literature results in overlapping of the clusters of different kinds of mortars. Modified coordinates are proposed, which give promising results in view of outlining a 'master curve' of hydraulicity.

Pumice powder as filler of self-compacting concrete

2015

Abstract An experimental study on the rheological and mechanical properties of self-compacting concrete with pumice powder used as filler additive is presented. Self-compacting concrete (SCC) shows its peculiar characteristics in the fresh state and many researches have been developed with reference to its rheological characteristics paying attention to the techniques of self-compacting properties assessment. One of the most important aspect in concrete mix-design is the type and the amount of fillers with respect to water and cement: this amount has great influence not only on self-compacting properties (fluidity, segregation, etc.), but also on the mechanical properties of the mixture. Vo…

Retention of alkali ions by hydrated low-pH cements: Mechanism and Na+/K+ selectivity

2013

Low-pH cements, also referred to as low-alkalinity cements, can be designed by replacing significant amounts of Portland cement by pozzolanic materials. Their pore solution is characterized by a pH near 11, and an alkali concentration much lower than that of Portland cement. This work investigates the retention of sodium and potassium by a hydrated low-pH cement comprising 60% Portland cement and 40% silica fume. It is shown that sorption of potassium is higher than that of sodium and mainly results from counterion charge balancing of the C-S-H negative surface charge. To explain the greater retention of potassium compared to sodium, it is postulated that potassium, unlike sodium, may enter…

Infantile Central Sleep Apnea - Improvement With Acetazolamide

1999

A Rational Design for Imidazolate-Bridged Linear Trinuclear Compounds from Mononuclear Copper(II) Complexes with 2-[((Imidazol-2-ylmethylidene)amino)…

2001

Two mononuclear copper(II) complexes with the unsymmetrical tridentate ligand 2-[((imidazol-2-ylmethylidene)amino)ethyl]pyridine (HL), [Cu(HL)(H2O)](ClO4)2.2H2O (1) and [Cu(HL)Cl2] (2), have been prepared and characterized. The X-ray analysis of 2 revealed that the copper(II) ion assumes a pentacoordinated square pyramidal geometry with an N3Cl2 donor set. When 1 and 2 are treated with an equimolecular amount of potassium hydroxide, the deprotonation of the imidazole moiety promotes a self-assembled process, by coordination of the imidazolate nitrogen atom to a Cu(II) center of an adjacent unit, leading to the polynuclear complexes [[Cu(L)(H2O)](ClO4)]n (3) and [[Cu(L)Cl].2H2O]n (4). Variab…

Diffusion Control in Single-Site Zinc Reticular Amination Catalysts.

2020

Zn-containing metal-organic frameworks have been used for the first time as heterogeneous catalysts in the amination of C-Cl bonds. The use of extended bis(pyrazolate) linkers can generate highly porous architectures, which favor the diffusion of amines to the confined spaces with respect to other imidazolate frameworks with narrower pore windows. The N4Zn nodes of the Zn-reticular framework show comparable activity to state-of-the-art homogeneous Zn amination catalysts, avoiding the use of basic conditions, precious metals, or other additives. This is combined with long-term activity and stability upon several reaction cycles, without contamination of the reaction product. ispartof: INORGA…

ChemInform Abstract: Synthesis and Characterization of the Acetazolamide Complexes of Co(II) and Zn(II).

1987

Abstract The preparation and characterization of the complexes of Acetazolamide (Acm) with Co(II) and Zn(II) are described. The complexes are of the type M(Acm) 2 (NH 3 ) 2 . Monodentate or bidentate behaviour of Acm from the electronic properties and the IR spectral data is discussed. The probable structures of the complexes are proposed.

Acetazolamide-M(II) [M(II) = Co(II), Ni(II), Cu(II)] complexes with ethylamine, diethylamine, triethylamine, and potassium hidroxide

1991

Abstract Complexes of Co(II), Ni(II), and Cu(II) with dideprotonated Acm are synthesized and characterized. Acm acts as bidentate ligand through the N-sulfonamido atom and the N-thiadiazole atom except for K6CoAcm4·6H2O in which Acm behaves as monodentate through the N-sulfonamido atom.

A Co(III) complex of carbonic anhydrase inhibitor methazolamide and the amino-imino ‘aib’ ligand formed by reaction of acetone and ammonia

1993

Abstract Reaction of Co(NO 3 ) 2 ·6H 2 O with methazolamide {[ N -(3-methyl-5-sulfamoyl-1,3,4-thiadiazol-2(3 H )-ylidene)acetamide] (Hmacm)} and ammonia in acetone to produce [Co(methazolamidate)(2-methyl-2-amino-4-iminopentane) 2 (NH 3 )](NO 3 ) 2 ·2H 2 O is described. The ligand 2-methyl-2-amino-4-iminopentane (aib) is the product obtained from the condensation of two ammonia and two acetone molecules. The complex crystallizes in the monoclinic space group P 2 1 / c with a =16.713(5), b =9.180(1), c =20.273(1) A, β=97.44(4)° for Z =4. The R value is 0.081 for 2150 significant reflections. The Co(III) ion exhibits a nearly regular octahedral arrangement with the CoN bond distances in the …

CCDC 635011: Experimental Crystal Structure Determination

2008

Related Article: M.Sanz, M.E.G.Mosquera, T.Cuenca, C.R.de Arellano, M.Schormann, M.Bochmann|2007|Polyhedron|26|5339|doi:10.1016/j.poly.2007.08.001