2,256 research outputs found
Characterization and analysis of azimuthally sensitive correlations
A unified framework for describing the azimuthal dependence of two-particle
correlations in heavy-ion collisions is introduced, together with the methods
for measuring the corresponding observables. The generalization to azimuthal
correlations between more than two particles is presented.Comment: 7 pages; talk given at Hot Quarks 2004, Taos (NM), July 18-24,200
N-Methyl-4,4-bipyridinium and N-Methyl-N -oxide-4,4 -bipyridinium Bismuth Complexes - Photochromism and Photoluminescence in the Solid State
Three bismuth complexes based on N-methyl-4,4-bipyridinium (hMV(+)), (hMV)[Bi(hMV)Cl-5] (1), and N-methyl-N-oxide-4,4-bipyridinium (MVO+), [Bi(MVO)X-4(dmso)]center dot dmso [X = Cl (2), Br (3)], are reported. All three compounds show luminescence in the solid state with maxima at 545 nm (yellow for 1) and 560 nm (orange for 2 and 3) with quantum yields up to 10 %. Upon UV irradiation, 1 undergoes a color change from white to blue accompanied by a reduction of the photoluminescence intensity. The analysis of the crystal structure of the three complexes points to a photoinduced charge-transfer (PICT) process at the origin of the photochromism in 1
Photochromism and Solid State Photoluminescence of Bi and Pb Complexes and Coordination Polymers based on N-R-4,4’-bipyridinium entities (R= O-, CH3, CH2CN)
Date du colloque : 05/2013</p
Ecological implications of bulliform cells on halophytes, in salt and water stress natural conditions
[EN] Seven Romanian salt-tolerant species were histo-anatomical investigated. These species
have been classified by the authors of the present study as ¿amphibious¿ halophytes, related to the field
observations and anatomical considerations. All the analyzed taxa present bulliform cells at the foliar
epidermis level. Despite the fact that there are different interpretations regarding the bulliform cells role
and functional significance, we correlate these structures with the ecological factors, salinity and,
respectively, drought conditions.This paper was published with support provided by the POSDRU project “Developing the innovation capacity and improving the impact of research through postdoctoral programmes”.Grigore, MN.; Toma, C.; Boscaiu, M. (2010). Ecological implications of bulliform cells on halophytes, in salt and water stress natural conditions. Analele Stiintifice ale Universitatii "Alexandru Ioan Cuza" din Iasi. Biologie Vegetala. 56(2):5-15. http://hdl.handle.net/10251/101713S51556
Isolation, Identification and Seasonal Distribution of Soilborne Fungi in Different Areas of Erbil Governorate
A survey study was undertaken for the isolation and identification of soilborne fungi inhabiting different areas in Erbil, Iraq. A total of 15 soil samples collected seasonally during August 2008-July 2009.
Fungi were isolated from soil during this study\u27s period, by soil dilution plate method on selective medium: Potato Dextrose Agar (PDA), eighty-one different genera of fungi were isolated during the four seasons; (30, 33, 70, and 53) genera isolated in (summer, autumn, winter and spring) respectively, the most frequently isolated fungi during four seasons were Aspergillus sp. (539x103) colony forming units /g.soil, followed by Penicillium sp. (215x103) cfu/g.soil, Rhizopus spp. (115x103) cfu/g.soil, Emericella spp. (109x103) cfu/g.soil, Fusarium spp. (47x103) cfu/g.soil, and Ulocladium botrytis (47x103) cfu/g.soil, while the least frequently isolated fungal genera were Blakeslea tuningtam, Clasterosporium cyperi, Idriella sp., Naranus cryptomeriae and Torula alternata, (1x103) cfu/g.soil, for each one.
Fungi isolated from soil by washing method counted for ninety three species belonging to fifty six genera, among them: Aspergillus sp., Circinella sp., Cunninghamella sp., Mucor spp., Mycelia sterilia, Rhizopus sp
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Si photocathode with Ag-supported dendritic Cu catalyst for CO2 reduction
Si photocathodes integrated with Ag-supported dendritic Cu catalysts are used to perform light-driven reduction of CO2 to C2 and C3 products in aqueous solution. A back illumination geometry with an n-type Si absorber was used to permit the use of absorbing metallic catalysts. Selective carrier collection was accomplished by a p+ implantation on the illumination side and an n+ implantation followed by atomic layer deposition of TiO2 on the electrolyte site. The Ag-supported dendritic Cu CO2 reduction catalyst was formed by evaporation of Ag followed by high-rate electrodeposition of Cu to form a high surface area structure. Under simulated 1 sun illumination in 0.1 M CsHCO3 saturated with CO2, the photovoltage generated by the Si (∼600 mV) enables C2 and C3 products to be produced at -0.4 vs. RHE. Texturing of both sides of the Si increases the light-limited current density, due to reduced reflection on the illumination side, and also deceases the onset potential. Under simulated diurnal illumination conditions photocathodes maintain over 60% faradaic efficiency to hydrocarbon and oxygenate products (mainly ethylene, ethanol, propanol) for several days. After 10 days of testing, contamination from the counter electrode is observed, which causes an increase in hydrogen production. This effect is mitigated by a regeneration procedure which restores the original catalyst selectivity. A tandem, self-powered CO2 reduction device was formed by coupling a Si photocathode with two series-connected semitransparent CH3NH3PbI3 perovskite solar cells, achieving an efficiency for the conversion of sunlight to hydrocarbons and oxygenates of 1.5% (3.5% for all products)
A multi-wavelength view on the dusty Wolf-Rayet star WR 48a
We present results from the first attempts to derive various physical
characteristics of the dusty Wolf-Rayet star WR 48a based on a multi-wavelength
view of its observational properties. This is done on the basis of new optical
and near-infrared spectral observations and on data from various archives in
the optical, radio and X-rays. The optical spectrum of WR 48a is acceptably
well represented by a sum of two spectra: of a WR star of the WC8 type and of a
WR star of the WN8h type. The strength of the interstellar absorption features
in the optical spectra of WR 48a and the near-by stars D2-3 and D2-7 (both
members of the open cluster Danks 2) indicates that WR 48a is located at a
distance of ~4 kpc from us. WR 48a is very likely a thermal radio source and
for such a case and smooth (no clumps) wind its radio emission suggests a
relatively high mass-loss rate of this dusty WR star (dM/dt = a few x 10^(-4)
solar masses per year). Long timescale (years) variability of WR 48a is
established in the optical, radio and X-rays. Colliding stellar winds likely
play a very important role in the physics of this object. However, some
LBV-like (luminous blue variable) activity could not be excluded as well.Comment: Accepted for publication in MNRAS; 16 pages, 16 figures, 6 table
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