Northern Illinois University

About: Northern Illinois University is a education organization based out in DeKalb, Illinois, United States. It is known for research contribution in the topics: Large Hadron Collider & Population. The organization has 8818 authors who have published 20008 publications receiving 632341 citations. The organization is also known as: NIU.

A systematic study of fluorescence-based detection of nitroexplosives and other aromatics in the vapor phase by microporous metal-organic frameworks.

Abstract: A systematic study is conducted on four microporous metal-organic framework compounds built on similar ligands but different structures, namely [Zn3(bpdc)3(bpy)]·4DMF·H2O (1), [Zn3(bpdc)3(2,2'dmbpy)]·4DMF·H2O (2), [Zn2(bpdc)2(bpe)]·2DMF (3), and [Zn(bpdc)(bpe)]·DMF (4) (bpdc=4,4'-biphenyldicarboxylate; bpy=4,4'-bipyridine; 2,2'dmbpy=2,2'-dimethyl-4,4'bipyridine; bpe=1,2-bis(4-pyridyl)ethane; DMF=N,N'-dimethylformamide) to investigate their photoluminescence properties and sensing/detection behavior upon exposure to vapors of various aromatic molecules (analytes) including nitroaromatic explosives. The results show that all four compounds are capable of detecting these molecules in the vapor phase through fluorescence quenching or enhancement. Both electrochemical measurements and theoretical calculations are performed to analyze the analyte-MOF interactions, to explain the difference in signal response by different analytes, and to understand the mechanism of fluorescence quenching or enhancement observed in these systems. Interestingly, compound 3 also shows an emission frequency shift when exposed to benzene (BZ), chlorobenzene (ClBZ), and toluene (TO), which provides an additional variable for the identification of different analytes in the same category.

Crystal and magnetic structure of ferromagnetic superconducting RuSr 2 GdCu 2 O 8

Abstract: The crystal and magnetic structure of a sample of ${\mathrm{RuSr}}_{2}^{160}{\mathrm{GdCu}}_{2}{\mathrm{O}}_{8}$ which orders magnetically at 133 K and exhibits a superconducting transition at 35 K has been investigated by neutron powder diffraction. ${\mathrm{RuO}}_{6}$ octahedra, which substitute at the chain copper site in a ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$-type structure, are rotated by about 14\ifmmode^\circ\else\textdegree\fi{} around the c axis to accommodate physically reasonable Ru-O bond lengths in the plane. This results in a $\sqrt{2}{a}_{p}\ifmmode\times\else\texttimes\fi{}\sqrt{2}{a}_{p}\ifmmode\times\else\texttimes\fi{}c$ supercell. The ${\mathrm{RuO}}_{6}$ rotations are partially ordered to form competing domains that differ in the sense of rotation. We speculate that the degree of ordering depends on annealing conditions. Surprisingly, the only structural parameters that respond to the magnetic ordering at 133 K are the Cu-Cu distance, which defines the thickness of the ${\mathrm{CuO}}_{2}$ double layer, and the buckling angle of the ${\mathrm{CuO}}_{2}$ planes. Magnetic scattering consistent with the previously proposed ferromagnetic ordering of Ru moments perpendicular to the c axis is not observed. We do not rule out ordering of Ru moments parallel to the c axis or itinerant ferromagnetism.

Phonological Awareness Instructional and Assessment Guidelines

Abstract: This article defines phonological awareness and discusses historic and contemporary research findings regarding its relation to early reading. Common misconceptions about phonological awareness are...

Generationally Based Differences in the Workplace: Is There a There There?

Abstract: Stereotypes about generational differences in the workplace abound, and interventions for helping organizations and managers to deal with these supposed differences are increasing. In addition to popular press articles describing the differences and extolling the practices and strategies to deal with them, there are a growing number of researchers who are attempting to establish that there are such differences. Overall, however, there is little solid empirical evidence supporting generationally based differences and almost no theory behind why such differences should even exist. The purposes of this focal article are to explore the myths surrounding generations, to review the risks in using generations in organizational decisions, and to make recommendations for practitioners and researchers on how to proceed in this area.