Poly[[diaquabis(2,2′-bipyridine-κ2 N,N′)(μ3-5-hydroxyisophthalato-κ5 O 1,O 1′:O 3,O 3′:O 3′)(μ3-5-hydroxy­isophthalato-κ4 O 1,O 1′:O 3:O 3′)(μ2-5-hydroxyisophthalato-κ3 O 1,O 1′:O 3)didysprosium(III)] dihydrate]

The polymeric title compound, {[Dy2(C8H4O5)3(C10H8N2)2(H2O)2]·2H2O}n, contains two independent DyIII ions, both of which are nine-coordinated in a distorted tricapped trigonal–prismatic geometry. One DyIII ion is coordinated by five 5-hy­droxy­isophthalate (hip) ligands and one 2,2′-bipyridine (bpy) ligand and the other by three hip ligands, one bpy ligand and two water mol­ecules. The DyIII ions are bridged by the carboxyl­ate groups of the hip ligands, forming a three-dimensional framework. O—H⋯O hydrogen bonds are present in the crystal structure

Efficiency Benchmarking of North American Airports: Comparative Results of Productivity Index, Data Envelopment Analysis and Stochastic Frontier Analysis

Using three common methodologies for measuring airport efficiency, namely the productivity index method, Data Envelopment Analysis (DEA) method, and stochastic frontier analysis (SFA) method, this study examines the efficiency performances of 62 Canadian and U.S. airports. Unlike most previous studies, this study includes aeronautical and non-aeronautical outputs of airports as they are inexplicably tied to each other in airport production. The empirical results reveal that the efficiency scores and rankings measured by these alternative methods are quite similar to each other in the top 15 and bottom 15 ranked airports, whereas considerable differences exist among the airports in the middle range. We also found that the percentage of non-aeronautical revenue, passenger volume, average aircraft size, percentages of international and connecting traffic significantly affect our airport efficiency estimates in all of the three alternative approaches used

Effect of Samarium doping on the nucleation of fcc-Aluminum in undercooled liquids

The effect of Sm doping on the fcc-Al nucleation was investigated in Al-Sm liquids with low Sm concentrations (xSm) with molecular dynamics simulations. The nucleation in the moderately undercooled liquid is achieved by the recently developed persistent-embryo method. Systematically computing the nucleation rate with different xSm (xSm=0%, 1%, 2%, 3%, 5%) at 700 K, we found Sm dopant reduces the nucleation rate by up to 25 orders of magnitudes with only 5% doping concentration. This effect is mostly associated with the increase in the free energy barrier with a minor contribution from suppression of the attachment to the nucleus caused by Sm doping.Comment: 4 figure