Formation mechanism and properties of CdS-Ag2S nanorod superlattices

The mechanism of formation of recently fabricated CdS-Ag{sub 2}S nanorod superlattices is considered and their elastic properties are predicted theoretically based on experimental structural data. We consider different possible mechanisms for the spontaneous ordering observed in these 1D nanostructures, such as diffusion-limited growth and ordering due to epitaxial strain. A simplified model suggests that diffusion-limited growth partially contributes to the observed ordering, but cannot account for the full extent of the ordering alone. The elastic properties of bulk Ag{sub 2}S are predicted using a first principles method and are fed into a classical valence force field (VFF) model of the nanostructure. The VFF results show significant repulsion between Ag{sub 2}S segments, strongly suggesting that the interplay between the chemical interface energy and strain due to the lattice mismatch between the two materials drives the spontaneous pattern formation

Why provide music therapy in the community for adults with mental health problems?

This paper describes music therapy within a community mental health setting for adults using a care programme approach in England. It describes the setting, and emphasises the importance of multidisciplinary teamwork in order to enable music therapy to be effective. It provides some statistics and descriptive clinical information which demonstrate the efficacy of music therapy for adults with long-term mental health problems, and argues that music therapy should be apriority for this client group. To support these points of view, the article includes a case study showing a psychoanalytically informed approach in music therapy. This paper was given as a keynote address at the 1994 Australian Conference of Music Therapy

Tautomeric properties and crystal structure of N-[2-hydroxy-1-naphthylidene]2,5-dichloroaniline

Unver, Huseyin/0000-0003-3968-4385WOS: 000238682900012The title compound has been synthesised by the reaction of 2-hydroxy-1-naphthaldehyde with 2,5-dichloroaniline. The compound was characterized by elemental analysis, IR and UV-Visible techniques. The UV-Visible spectra of the Schiff base with OH group in ortho position to the imino group was studied in polar and nonpolar solvents in acidic and basic media. The structure of compound has been examined cyrstallographically. It crystallizes in the or-thorhombic space group P2(1)2(1)2(1) with a = 6.059(1), b = 12.105(2) c = 20.006(2) angstrom, V = 1467.4(3) angstrom(3), D-x = 1.431 g.cm(-3) and Z = 4. The crystal structure was solved by direct methods and refined by full-matrix least squares. Molecule of the title compound N-[2-hydroxy-1-naphthylidene]2,5-dichloroaniline is nearly planar. The molecule contains a strong intramolecular N...H-O hydrogen bond between the imine and hydroxyl group [O1 and N1 = 2.540(4) angstrom]. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Electrochemical Behavior of Electrolytic Manganese Dioxide in Aqueous KOH and LiOH Solutions: A Comparative Study

As an inexpensive and high capacity oxidant, electrolytic manganese dioxide (γ-MnO2) is of interest as a cathode for secondary aqueous batteries. Electrochemical behavior of γ-MnO2 was characterized in aqueous 5.0 M KOH and LiOH solutions, and found to depend strongly upon cation identity. In LiOH and mixed LiOH / KOH solutions, Li-ion intercalation appeared to operate in competition with proton intercalation, being favored at higher [Li+] and, for mixed electrolytes, lower sweep rates. Electrochemical and in situ X-ray diffraction data indicated that γ-MnO2 underwent a chemically irreversible transformation upon the first reduction in LiOH solution, while in KOH solution, structure was largely unchanged after the first cycle. These experiments with γ-MnO2 as well as with a closely-related, ramsdellite-like sample, suggest that depending on sample morphology/rate capability, the irreversible process proceeds either through a solid-solution reaction or a two-phase reaction followed by a solid-solution reaction. While discharge capacity and capacity retention during galvanostatic cycling of γ-MnO2 were worse in LiOH than in KOH solution, some improvement was noted in a mixed LiOH/KOH solution

Spectroscopic study, antimicrobial activity and crystal structures of N-(2-hydroxy-5-nitrobenzalidene)4-aminomorpholine and N-(2-hydroxy-1-naphthylidene)4-aminomorpholine

Dulger, Basaran/0000-0002-3184-2652; Unver, Huseyin/0000-0003-3968-4385; Dulger, Basaran/0000-0002-3184-2652WOS: 000227744500037Schiff bases N-(2-hydroxy-3-nitrobenzalidene)4-aminomorpholine (1) and N-(2-hydroxy- I -naphthylidene)4-aminomorpholine (2) were synthesized from the reaction of 4-aminomorpholine with 2-hydroxy-5-nitrobenzaldehyde and 2-hydroxy- 1 -naphthaldehyde. Compounds 1 and 2 were characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and UV-Visible techniques. The UV-Visible spectra of the Schiff bases with OH group in ortho position to the imino group were studied in polar and nonpolar solvents in acidic and basic media. The structures of compounds 1 and 2 have been examined cyrstallographically, for two compounds exist as dominant form of enol-imines in both the solutions and solid state. The title compounds 1 and 2 crystallize in the monoclinic space group P2(1)/c and P2(1)/n with unit cell parameters: a=8.410(1) and 11.911(3), b=6.350(9) and 4.860(9), c=21.728(3) and 22.381(6) angstrom, beta=90.190(1) and 95.6(2)degrees, V=1160.6(3) and 1289.5(5) angstrom(3), D-x = 1.438 and 1.320 g cm(-3), respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares. The antimicrobial activities of compounds 1 and 2 have also been studied. The antimicrobial activities of the ligands have been screened in vitro against the organisms Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae UC57, Micrococcus luteus La 297 1, Proteus vulgaris ATCC 8427, Pseudomonas aeruginosa ATCC 27853, Mycobacterium smegmatis CCM 2067, Bacillus cereus ATCC 7064, Listeria monocytogenes ATCC 15313, Candida albicans ATCC 1023 1, Kluyveromyces fragilis NRRL 2415, Rhodotorula rubra DSM 70403, Debaryomyces hansenii DSM 70238 and Hanseniaspora guilliennondii DSM 3432. 0 2004 Elsevier B.V. All rights reserved

Spontaneous Superlattice Formation in Nanorods through Partial Cation Exchange

Lattice mismatch strains are widely known to control nanoscale pattern formation in heteroepitaxy, but such effects have not been exploited in colloidal nanocrystal growth. We demonstrate a colloidal route to synthesizing CdS-Ag2S nanorod superlattices through partial cation exchange. Strain induces the spontaneous formation of periodic structures. Ab initio calculations of the interfacial energy and modeling of strain energies show that these forces drive the self-organization. The nanorod superlattices exhibit high stability against ripening and phase mixing. These materials are tunable near-infrared emitters with potential applications as nanometer-scale optoelectronic devices

Size dependence of the pressure-induced gamma to alpha structuraltransition in iron oxide nanocrystals

The size trend for the pressure-induced gamma-Fe2O3(maghemite) to alpha-Fe2O3 (hematite) structural phase transition in nanocrystals has been observed. The transition pressure was found to increase with decreasing nanocrystal size: 7 nm nanocrystals transformed at 272GPa, 5 nm at 343GPa and 3 nm at 372GPa. Annealing of a bulk sample of gamma-Fe2O3 was found to reduce the transition pressure from 352 to242GPa. The bulk modulus was determined to be 2626GPa for 7 nm nanocrystals of gamma-Fe2O3, which is significantly higher than for the value of 1906 GPa that we measured for bulk samples. For alpha-Fe2O3, the bulk moduli for 7 nm nanocrystals (3365) and bulk (30030) were found to be almost the same within error. The bulk modulus for the gamma phase was found to decrease with decreasing particle size between 10 and 3.2 nm particle size. Values for the ambient pressure molar volume were found within 1 percent to be: 33.0 cm3/mol for bulk gamma-Fe2O3, 32.8 cm3/mol for 7 nm diameter gamma-Fe2O3 nanocrystals, 30.7 cm3/mol for bulk alpha-Fe2O3 and 30.6 cm3/mol for alpha-Fe2O3 nanocrystals