Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

A new tetragonal structure type for Li2B2C.

Abstract: The ternary dilithium diboron carbide, Li2B2C (tetra­gonal, space group P\overline{4}m2, tP10), crystallizes as a new structure type and consists of structural fragments which are typical for structures of elemental lithium and boron or binary borocarbide B13C2. The symmetries of the occupied sites are .m. and 2mm. for the B and C atoms, and \overline{4}m2 and 2mm. for the Li atoms. The coordination polyhedra around the Li atoms are cubocta­hedra and 15-vertex distorted pseudo-Frank–Kasper polyhedra. The environment of the B atom is a ten-vertex polyhedron. The nearest neighbours of the C atom are two B atoms, and this group is surrounded by a deformed cubocta­hedron with one centred lateral facet. Electronic structure calculations using the TB–LMTO–ASA method reveal strong B⋯C and B⋯B inter­actions.

Hydrogen permeation properties of Pd-coated Pd33Ni52Si15 amorphous alloy membrane

Abstract: Abstract The vast majority of experimental techniques used for the measurements of hydrogen permeability through metallic membranes whose one or both surfaces are covered with a thin Pd film is based on the assumption that a ratio of film-to-membrane thickness is small enough to cause hydrogen flow to be independent of the Pd film thickness. In an attempt to verify this assumption, we have measured the hydrogen flow through the Pd33Ni52Si15 amorphous membrane covered with Pd film of 10, 20, and 30 nm in thickness. Contrary to our expectations, we have found a dramatic decrease in hydrogen flow with the increase in Pd film thickness. Our findings are discussed in terms of potential barrier between the two different phases.

Disperse red 1 end capped oligoesters. Synthesis by noncatalyzed ring opening oligomerization and structural characterization

Abstract: The synthesis of novel azofunctional oligoesters through bulk ring opening of e-caprolactone and D,L-lactide (LA) at 100 and 130 °C, respectively, mediated by N-ethyl-N-(2-hydroxyethyl)-4-(4-nitrophenylazo)aniline (Disperse Red 1) (DR1) is described. The synthetic procedure allows "clean" products because no catalysts were used in the reaction. Moreover, DR1 moiety is showed for the first time to promote the ring opening of cyclic esters. The molecular structure of the obtained oligoesters was established by NMR spectroscopy, MALDI ToF MS and electrospray ionization mass spectrometry (ESI MS). ESI-MS/MS fragmentation experiments were used to demonstrate the nature of the chain end groups (hydroxyl and DR1). Intermolecular transesterification reactions were proved by mass spectrometry studies at least in the case of LA oligomerization.

Heat transfer in fluidized and fixed beds of adsorption chillers

Abstract: An innovative idea, shown in the paper constitutes in the use of the fluidized bed of sorbent, instead of the conventional, fixed-bed, commonly used in the adsorption chillers. Bed–to–wall heat transfer coefficients for fixed and fluidized beds of adsorbent are determined. Sorbent particles diameters and velocities of fluidizing gas are discussed in the study. The calculations confirmed, that the bed–to–wall heat transfer coefficient in the fluidized bed of adsorbent is muchhigher than that in a conventional bed.