43,543 research outputs found
Cathodic electrosynthesis of ZnMn2O4/Mn3O4 composite nanostructures for high performance supercapacitor applications
No full textZnMn2O4/Mn3O4 composite nanostructures were prepared by cathodic electrodeposition followed by heat treatment. A mixed hydroxide precursor was galvanostatically electrodeposited from aqueous solution containing Mn and Zn (as nitrates) and the obtained precursor was annealed to prepare the composite. This composite exhibited much better electrochemical behaviors than bare Mn3O4. Rietveld analysis of the X-ray diffraction (XRD) data showed that the product was composed of Mn3O4, ZnMn2O4 and minor amounts of λ-MnO2. Furthermore, the obtained composite was characterized by Fourier transform infrared spectrometry (FT-IR) and energy dispersive spectrometry (EDS). Field emission scanning electron micrographs (FE-SEM) and transmission electron micrographs (TEM) revealed co-existence of nanoparticles and high aspect ratio nanorods. Electrochemical performance and ion transport of ZnMn2O4/Mn3O4 composite were studied via galvanostatic charge-discharge (GCD) cycling and electrochemical impedance spectroscopy (EIS). Cyclic voltammetric (CV) measurements showed a maximum specific capacitance of 321.34 F/g at the scan rate of 1 mV/s. 93% of this specific capacitance was retained after 2000 cycles
Iron mediated cathodic electrosynthesis of hausmannite nanoparticles
No full textA novel synthetic route has been proposed to prepare hausmannite nanoparticles. The synthetic route comprises an iron mediated constant current cathodic electrodeposition of manganite and heat treatment of the latter to obtain hausmannite. The obtained nanostructures have been characterized using X-ray Diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and Fourier transform Infrared Spectrometry (FTIR). The role of iron in the formation of manganite precursor has been studied by cyclic voltammetry (CV) and differential thermal analysis (DTA). A formation mechanism based on iron mediated formation of Mn3+ and subsequent cathodic reduction of the disproportionated products has been proposed accordingly. The prepared nanoparticles exhibited specific capacitance of 143 F g-1 in 0.5 M Na2SO4 solution. The retained specific capacity was 87% after 2000 cycles
Evaluation of charge storage ability of chrome doped Mn2O3 nanostructures derived by cathodic electrodeposition
No full textA facile synthetic route has been proposed to prepare cauliflower-like nanostructures of Cr doped Mn2O3. The synthesis was carried out by constant current cathodic electrodeposition from Mn2+ nitrate solutions containing minor amounts of dichromate. It was found that the presence of Cr mediates the formation of cathodic MnO2 which then reacts with the excess Mn2+ species to form Mn2O3 nanostructures. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Differential Thermal Analysis (DTA) were used to characterize the nanostructures. The storage ability of the obtained nanostructures was investigated by cyclic voltammetry (CV) in 0.5 M Na2SO4 solution. The results indicated that the Cr doped manganese oxide material shows better performance than the non-doped one, and the charge capacity (SC) of doped manganese oxide (218 F/g) was higher than pure manganese oxide (208 F/g)
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Review of the book Unbegrenzte moglichkeiten: Amerikanisierung in Deutschland und Frankreich (1900-1933) by Egbert Klautke
No full textDr. Jeff R. Schutts (Douglas College) reviews the book Unbegrenzte Moglichkeiten: Amerikanisierung in Deutschland und Frankreich (1900-1933) by Egbert Klautke (2005).Final article published
Letter from R. H. Ford to Commissioner of Indian Affairs, 1860
No full textR. H. Ford (letter author) is the brother of Henry L. Ford. The letter asks if the recently deceased Henry L. Ford was due anything from the government, which would be left to his father, William Ford
Papers of R H Horne
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/69212R.H. "Orion" Horne: Syllabus of Three Lectures on the Undeveloped Characters in Shakespeare's Plays by R.H. Horne, author of "Orion", "Cosmo de Medici" and "Death of Marlowe", etc. Leaflet showing contents of each of the three lectures. On verso, a note by Horne explaining that these lectures had been given at the Manchester Athenuem, the Literary and Scientific Institute, Marylebone, and at the Mechanics Institute, Liverpool. This leaflet is folded in with handwritten expositions (probably lectures): 1. The Bible, 31 pp. 2. Gems form Auriel (Henri Frederico Auriel, 1821-1881), 5 pp. 3. Some illustrations of Shakespeare's Art, 20 pp.113896
Acquisition: [1989.0151] "Papers of R H Horne
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The IPHAS catalogue of H alpha emission-line sources in the northern Galactic plane
No full textWe present a catalogue of point-source H alpha emission-line objects selected from the INT/WFC Photometric Ha Survey (IPHAS) of the northern Galactic plane. The catalogue covers the magnitude range 13 <= r' <= 19.5 and includes Northern hemisphere sources in the Galactic latitude range -5 degrees < b < 5 degrees. It is derived from similar to 1500 deg(2) worth of imaging data, which represents 80 per cent of the final IPHAS survey area. The electronic version of the catalogue will be updated once the full survey data become available. In total, the present catalogue contains 4853 point sources that exhibit strong photometric evidence for Ha emission. We have so far analysed spectra for similar to 300 of these sources, confirming more than 95 per cent of them as genuine emission-line stars. A wide range of stellar populations are represented in the catalogue, including early-type emission-line stars, active late-type stars, interacting binaries, young stellar objects and compact nebulae.
The spatial distribution of catalogue objects shows overdensities near sites of recent or current star formation, as well as possible evidence for the warp of the Galactic plane. Photometrically, the incidence of Ha emission is bimodally distributed in (r' - i'). The blue peak is made up mostly of early-type emission-line stars, whereas the red peak may signal an increasing contribution from other objects, such as young/active low-mass stars. We have cross-matched our H alpha-excess catalogue against the emission-line star catalogue of Kohoutek & Wehmeyer, as well as against sources in SIMBAD. We find that fewer than 10 per cent of our sources can be matched to known objects of any type. Thus IPHAS is uncovering an order of magnitude more faint (r' > 13) emission-line objects than were previously known in the Milky Way
1, 2-H shift in benzylchlorocarbene: isotope effect and influence of the solvent
No full textLaser flash photolysis of 3-chloro-3-benzyldiazirine and 3-chloro-3-(phenyldideuteriomethyl)diazirine in isooctane over the 60 to -80-degrees-C temperature range gives rise to curved Arrhenius plots for both 1,2-H and 1,2-D migration in benzylchlorcarbene. The k(H)/k(D) values increase smoothly from 0.87 to 2.62 when the temperature increases from -60 to +30-degrees-C. The k(H)/k(D) value is approximately 4 for most of the temperatures studied if a solvent correction is applied. Quantum mechanical tunnelling or the influence of the solvent may be a possible explanation for these observations.PT: J; CR: BONNEAU R, 1989, J AM CHEM SOC, V111, P5973 BONNEAU R, 1992, J PHOTOCH PHOTOBIO A, V68, P97 DIX EJ, 1993, J AM CHEM SOC, V115, P10424 EVANSECK JD, 1990, J PHYS CHEM-US, V94, P5518 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 JACKSON JE, 1994, ADV CARBENE CHEM JONES M, 1980, REACTIVE INTERMEDIAT, V2 KIRMSE W, 1971, CARBENE CHEM LIU MTH, 1984, TETRAHEDRON, V40, P887 LIU MTH, 1990, J AM CHEM SOC, V112, P3915 LIU MTH, 1992, J PHOTOCH PHOTOBIO A, V63, P115 LIU MTH, 1992, J PHYS ORG CHEM, V15, P285 LIU MTH, 1994, RES CHEM INTERMEDIAT, V20, P195 MODARELLI DA, 1992, J AM CHEM SOC, V114, P7034 MOSS RA, 1992, TETRAHEDRON LETT, V33, P4287 MOSS RA, 1994, ADV CARBENE CHEM MUROV SL, 1973, HDB PHOTOCHEMISTRY NICKON A, 1993, ACCOUNTS CHEM RES, V26, P84 SALIS GA, 1968, J PHYS CHEM-US, V72, P752 SANDER W, 1994, UNPUB SCHAEFER HF, 1979, ACCOUNTS CHEM RES, V12, P288 SCHOLLER WW, 1989, HOUBEN WEYL METHODEN, P41 SHIMANOUCHI T, 1972, TABLES MOL VIBRATION, V1 SUGIYAMA MH, 1992, J AM CHEM SOC, V114, P966 WIERLACHER S, 1993, J AM CHEM SOC, V115, P8943; NR: 25; TC: 20; J9: J PHOTOCHEM PHOTOBIOL A-CHEM; PG: 5; GA: PV021Source type: Electronic(1
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