294 research outputs found
The Effect Of 4-halogenobenzoate Ligands On Luminescent And Structural Properties Of Lanthanide Complexes: Experimental And Theoretical Approaches
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The ligands 4-fluorobenzoate (4-fba), 4-chlorobenzoate (4-cba), 4-bromobenzoate (4-bba) and 4-iodobenzoate (4-iba) were chosen in order to synthesize europium(III), gadolinium(III) and terbium(III) complexes and compare the effect of halogens on their physical chemistry and luminescent properties. The homobimetallic complex [Eu(4-iba)(3)(H2O)(dmf)](2) crystallizes in the monoclinic P2(1)/c space group with unit cell parameters a = 8.3987(9) angstrom, b = 25.314(3) angstrom, c = 14.1255(17) angstrom, and beta = 105.347(2)degrees 1. FTIR spectroscopy indicates that the bidentate bridging mode of the carboxylato ligand was present in all complexes while bidentate chelate and a mixture of bidentate bridging and chelate modes were also found. According to emission spectra profiles and the Judd-Ofelt parameters the halogen of ligand molecules modifies the chemical environment symmetry around the europium(III) ion in their respective complexes. The complexes [Eu(4-fba)(3)(H2O)(2)] and [Eu(4-iba)(3)(H2O)(2)] have the highest symmetry around the europium(III) while the complexes [Eu(4-cba)(3)]center dot 2H(2)O, [Eu(4-bba)(3)]center dot 5/2H(2)O and [Eu(4-iba)(3)(H2O)(dmf)](2) have the lowest. The different halogens at the para position do not change the covalence degree of Eu-O bonds significantly, however they play a role in the ligand to metal charge transfer energies. The highest non-radiative energy transfer rates from ligand to europium(III) were found for the complexes [Eu(4-cba)(3)]center dot 2H(2)O and [Eu(4-bba)(3)]center dot 5/2H(2)O.39318831891Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)NSF [CHE 1363325]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2008/53868-0]FAPESP [2009/54066-7
Using Gold Nanoparticles as Passive Sampler for Indoor Monitoring of Gaseous Elemental Mercury
This study reports a functional passive sampler for monitoring gaseous elemental mercury (GEM). The material consists of gold nanoparticles (AuNP) deposited forming a film on thiol-modified glass slides. AuNP colloid was synthesized using sodium citrate, resulting in a size of 24.2 +/- 0.8 nm, as determined by transmission electron microscopy analysis. For the indoor test, AuNP films were placed into Petri plates. One part of the lot was kept exposed to the laboratory's atmosphere and the other part was stored in closed plate (control). The films were removed from both plates along a month and analyzed using a direct mercury analyzer. A linear relationship between Hg retention and exposure time was obtained until the 23(rd) day, which allowed to calculate a GEM retention rate of 2.2 ng g(-1) day(-1)the maximum retention capacity was around 50 ng g(-1). This study provides an efficient method for indoor monitoring of GEM using AuNP films as passive sampler.FAPESPCNPqFAPESPCAPESUniv Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Do Campos, SP, BrazilUniv Estadual Campinas UNICAMP, Inst Quim, POB 6154, BR-13083970 Campinas, SP, BrazilUniv Estadual Campinas UNICAMP, Inst Quim, Lab Mat Funcionais, POB 6154, BR-13083970 Campinas, SP, BrazilUniv Fed Sao Paulo UNIFESP, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Do Campos, SP, BrazilFAPESP: 2012/19485-1CNPqFAPESPCAPESWeb of Scienc
Temperature probing and emission color tuning by morphology and size control of upconverting β-NaYb0.67Gd0.30F4:Tm0.015:Ho0.015 nanoparticles
CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe chemical composition, shape and size of upconverting nanoparticles are known to have a great influence on their spectroscopic properties, such as the emission color and the emission intensity variation as a function of temperature. This work shows the52CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informaçãosem informação2013/22127-
How to detect a possible correlation from the information of a sub-system in quantum mechanical systems
A possibility to detect correlations between two quantum mechanical systems
only from the information of a subsystem is investigated. For generic cases, we
prove that there exist correlations between two quantum systems if the
time-derivative of the reduced purity is not zero. Therefore, an
experimentalist can conclude non-zero correlations between his/her system and
some environment if he/she finds the time-derivative of the reduced purity is
not zero. A quantitative estimation of a time-derivative of the reduced purity
with respect to correlations is also given. This clarifies the role of
correlations in the mechanism of decoherence in open quantum systems.Comment: 7 pages, 1 figur
Three Gravitationally Lensed Supernovae Behind CLASH Galaxy Clusters
We report observations of three gravitationally lensed supernovae (SNe) in
the Cluster Lensing And Supernova survey with Hubble (CLASH) Multi-Cycle
Treasury program. These objects, SN CLO12Car (z = 1.28), SN CLN12Did (z =
0.85), and SN CLA11Tib (z = 1.14), are located behind three different clusters,
MACSJ1720.2+3536 (z = 0.391), RXJ1532.9+3021 (z = 0.345), and Abell 383 (z =
0.187), respectively. Each SN was detected in Hubble Space Telescope (HST)
optical and infrared images. Based on photometric classification, we find that
SNe CLO12Car and CLN12Did are likely to be Type Ia supernovae (SNe Ia), while
the classification of SN CLA11Tib is inconclusive. Using multi-color
light-curve fits to determine a standardized SN Ia luminosity distance, we
infer that SN CLO12Car was approximately 1.0 +/- 0.2 mag brighter than field
SNe Ia at a similar redshift and ascribe this to gravitational lens
magnification. Similarly, SN CLN12Did is approximately 0.2 +/- 0.2 mag brighter
than field SNe Ia. We derive independent estimates of the predicted
magnification from CLASH strong+weak lensing maps of the clusters: 0.83 +/-
0.16 mag for SN CLO12Car, 0.28 +/- 0.08 mag for SN CLN12Did, and 0.43 +/- 0.11
mag for SN CLA11Tib. The two SNe Ia provide a new test of the cluster lens
model predictions: we find that the magnifications based on the SN Ia
brightness and those predicted by the lens maps are consistent. Our results
herald the promise of future observations of samples of cluster-lensed SNe Ia
(from the ground or space) to help illuminate the dark-matter distribution in
clusters of galaxies, through the direct determination of absolute
magnifications.Comment: ApJ in pres
Trade openness, real exchange rates and job reallocation
This paper investigates the impact of real exchange rate movements on job reallocation at the industry level. The analysis focuses on the manufacturing sector of Belgium, using data for 82 NACE 3-digit industries, over the time span 1996-2002. I find that real exchange rate changes do have a significant impact on job flows, and that this impact is magnified by increasing levels of trade exposure. In particular, a real appreciation is found to lower net employment growth through higher job destruction, while job creation is not significantly affected. These results are in line with previous empirical evidence on the United States, and differ from earlier findings for France and Germany, where the adjustment to real exchange rate shocks has been found to occur mainly through the job creation margin. I suggest that these differences may be explained by the fact that Belgium is a small open economy
Second-opinion stress tele-echocardiography for the Adonhers (Aged donor heart rescue by stress echo) project
<p>Abstract</p> <p>Background</p> <p>To resolve the current shortage of donor hearts, we established the Adonhers protocol. An upward shift of the donor age cut-off limit (from the present 55 to 65 years) is acceptable if a stress echo screening on the candidate donor heart is normal. This study aimed to verify feasibility of a "second opinion" of digitally transferred images of stress echo results to minimize technical variability in selection of aged donor hearts for heart transplant.</p> <p>Methods</p> <p>The informatics infrastructure was created for a core lab reading with a second opinion from the Pisa stress echo lab. To test the system, simulation standard stress echo cineloops were sent digitally from 5 peripheral labs to the central core lab.</p> <p>Starting January 2009, real marginal donor stress echos were sent via internet to the central core echo lab, Pisa, for a second opinion before heart transplant.</p> <p>Results</p> <p>In the simulation protocol, 30 dipyridamole stress echocardiograms were sent from the five peripheral echo labs to the central core lab in Pisa. Both the echo images and reports were correctly uploaded in the web system and sent to the core echo lab; the second opinion evaluation was obtained in all cases (100% feasibility). In the transplant protocol, eight donor cases were sent to the Pisa core lab for the second opinion protocol, and six of them were transplanted in marginal recipients.</p> <p>Conclusions</p> <p>Second-Opinion Stress Tele-Echocardiography can effectively be performed in a network aimed to safely expand the heart donor pool for heart transplant.</p
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