objective: zinc oxide eugenol (zoe) under composite restorations should be covered with a suitable material in order to prevent the harmful effect of zoe on the composite. the aim of this in vitro study was to evaluate microleakage of composite restorations in pulpotomized primary molars with different bases for covering the zoe layer and to assess the distance between different layers. materia...

used pet bottles disposal is an unsolved environmental problem, and there are many efforts for finding an applicable solution for it. many researches have showed that the degradation rate of the polymers increase with the smaller size of fibers. this work was carried out to convert used pet bottles into nanofibers by melt-electrospinning method. uncolored, washed and chipped pet bottles and the...

The cation of the title compound, C(6)H(8)NO(2) (+)·Cl(-), is essentially planar (r.m.s. deviation = 0.0104 Å). Intermolecular O-H⋯Cl and N-H⋯Cl hydrogen bonds, as well as C-H⋯O contacts, connect the mol-ecules in the crystal structure. A short C⋯C distance of only 3.3930 (19) Å between C atoms of neighbouring rings is indicative of π-stacking. The corresponding centroid-centroid distance betwe...

At 296 (2) K, both complexed rings in the iron(II) complex cation of the title salt, [Fe(C(5)H(5))(C(16)H(10)O(2))]PF(6), are almost parallel [dihedral angle between planes = 2.4 (3)°]. The quaternary C atoms of the complexed arene ring are located at the longest distance from the Fe atom, with Fe-C distances of 2.112 (4) and 2.105 (3) Å, which are slightly longer than the average Fe-C distance...

fullerenes are closed−cage carbon molecules formed by 12 pentagonal and n/2 – 10hexagonal faces, where n is the number of carbon atoms. patrick fowler in his lecture inmcc 2009 asked about the wiener index of fullerenes in general. in this paper werespond partially to this question for an infinite class of fullerenes with exactly 10ncarbon atoms. our method is general and can be applied to full...

The title compound, [Fe(C(2)H(5)O)(C(36)H(44)N(4))], contains a five-coordinate iron-porphyrin complex with an axial eth-oxy ligand. The iron(III) atom is displaced by 0.504 (2) Å towards the eth-oxy ligand from the 24-atom mean plane of the porphyrin. The average Fe-N(p) distance is 2.078 (2) Å and the Fe-O distance is 1.8232 (18) Å. The eth-oxy C atoms are disordered in a 0.581 (12):0.419 (12...

In the title complex, [Co(CN)(2)(C(18)H(18)N(4))]PF(6), the Co(III) atom together with one of the pyridyl rings and two cyanide anions are located on a mirror plane, while the P atom is located on an inversion centre. The Co(III) atom exhibits an octa-hedral geometry, coordinated by four N atoms from the tris-(2-pyridyl-meth-yl)amine ligand with an average Co-N distance of 1.953 (2) Å, and two ...

Distance-balanced graphs are introduced as graphs in which every edge uv has the following property: the number of vertices closer to u than to v is equal to the number of vertices closer to v than to u. Basic properties of these graphs are obtained. In this paper, we study the conditions under which some graph operations produce a distance-balanced graph.