The crystal structure of potassium magnesium niobium oxide phosphate, KMg(1/3)Nb(2/3)OPO(4), which was described in the space group P4(3)22 [McCarron & Calabrese, (1993 ▶). J. Solid State Chem.102, 354-361], has been redetermined in the revised space group P4(1). Accordingly, the assignment of the space group P4(3)22 and, therefore, localization of K at a single half-occupied position, as noted...

a basic alumina-spinel low cement castable (lcc) composed of sintered bauxite, reactive alumina, calcined alumina, calcined magnesia, microsilica, and high alumina refractory cement was prepared (castable a) to which 5% sodium hexa-meta phosphate was later added (castable b) to prepare samples for heat treatment at 110ºc, 900ºc, and 1400ºc. bulk density (bd), apparent porosity (ap), and cold cr...

the nanopowders of sno2, casno3 and ca2sno4 in the size rang of 5-70 nm have been prepared using solid-state reaction technique. the technique is convenient and inexpensive in comparison to the conventional routes of compound prepared and processing where, many steps of mixing and annealing are involved. formation of resultant compounds was explained on the basis of reaction taken place between...

objectives: the aim of this study was to compare the permeability of dentin after using diamond bur and er:yag laser. materials and methods: seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. the samples were randomly divided into three groups of 24 each and class i cavities were prepared as follows. group 1: high speed diamond bur with ...

introduction: male urethral stricture is a complicated urologic disease that could be successfully treated using internal urethrotomy. laser internal urethrotomy has been used in many cases with favorable outcome in many studies. holmium: yag laser with its incisional properties on tissue is one of the laser types applied for internal urethrotomy. methods: we present a 19 year-old male with his...

Knowledge of the RNA three-dimensional structure, either in isolation or as part of RNP complexes, is fundamental to understand the mechanism of numerous cellular processes. Because of its flexibility, RNA represents a challenge for crystallization, while the large size of cellular complexes brings solution-state NMR to its limits. Here, we demonstrate an alternative approach on the basis of so...

Deuterium NMR provides insight into dynamics over a wide range of kinetic rates. Experimental data can be rigorously fit and rates as well as motional mechanisms extracted. Temperatures dependent studies yield activation energies for key dynamic processes. Two model systems with well-characterized motions were studied to demonstrate this. The ammonium group in L-alanine has an activation energy...

Membranes made from three specifically deuterium-labeled ether-linked bolalipids, [1',1',20',20'-2H4]C20BAS-PC, [2',2',19',19'-2H4]C20BAS-PC, or [10',11'-2H2]C20BAS-PC, were analyzed by 2H NMR spectroscopy. Unlike more common monopolar, ester-linked phospholipids, C20BAS-PC exhibits a high degree of orientational order throughout the membrane and the sn-1 chain of the lipid initially penetrates...

Many structures of the proteins and protein assemblies that play central roles in fundamental biological processes and disease pathogenesis are not readily accessible via the conventional techniques of single-crystal X-ray diffraction and solution-state nuclear magnetic resonance (NMR). On the other hand, many of these challenging biological systems are suitable targets for atomic-level structu...

The silicide Sc2RuSi2 was synthesized from the elements by arc-melting. The structure was refined on the basis of single crystal X-ray diffractometer data: Sc2CoSi2 type, * Manuscript Click here to view linked References