Solvent influence on the photophysical properties of 4-methoxy-N-methyl-1,8-naphthalimide

4-Methoxy-N-methyl-1,8-naphthalimide (1) exhibits considerable solvatochromism and its UV-vis spectral properties have been studied in several polar/non-polar and protic/aprotic solvents, as well as in ethanol-water mixtures. The results reveal a strong influence of the solvent's polarity and its hydrogen-bond donor (HBD) capability on the photophysical properties of 1. For binary ethanol/water mixtures, preferential solvation models describe the band shifts in the probe's visible absorption spectrum well, but they fail to describe the corresponding shifts of the emission maxima. Pseudolinear approximations between solvent composition and molecule's transition energies, E(T), can be used to study the composition of ethanol-water mixtures, simplifying the mathematical treatment for eventual analytical applications.     

Search for new physics in lepton+photon+X events with 305 pb(-1) of pp collisions at [square root of s] = 1.96 TeV

We present results of a search for anomalous production of events containing a charged lepton (l, either e or mu) and a photon (gamma), both with high transverse momentum, accompanied by additional signatures X, including missing transverse energy (ET) and additional leptons and photons. We use the same selection criteria as in a previous CDF search but with a substantially larger data set, 305 pb(-1), a pp collision energy of 1.96 TeV, and the CDF II detector. We find 42 lgammaET events versus an expectation of 37.3+/-5.4 events. We observe 31 llgamma+X events versus an expectation of 23.0+/-2.7 events. We find no events similar to the run I eegammagammaET event.     

Measurement of bottom-quark hadron masses in exclusive J/psi decays with the CDF detector

We measure the masses of b hadrons in exclusively reconstructed final states containing a J/psi --> mu-mu+ decay using 220 pb(-1) of data collected by the CDF II experiment. We find: m(B+) = 5279.10 +/- 0.41(stat.) +/- 0.36(sys.) MeV/c2, m(B0) = 5279.63 +/- 0.53(stat.) +/- 0.33(sys.) MeV/c2, m(B(s)0) = 5366.01 +/- 0.73(stat.) +/- 0.33(sys.) MeV/c2, m(lambda(b)0) = 5619.7 +/- 1.2(stat.) +/- 1.2(sys.) MeV/c2. m(B+) - m(B0) = -0.53 +/- 0.67(stat.) +/- 0.14(sys.) MeV/c2, m(B(s)0) - m(B0) = 86.38 +/- 0.90(stat.) +/- 0.06(sys.) MeV/c2, m(lambda(b)0) - m(B0) = 339.2 +/- 1.4(stat.) +/- 0.1(sys.) MeV/c2. The measurements of the B(s)0, lambda(b)0 mass, m(B(s)0) - m(B0) and m(lambda(b)0) - m(B0) mass difference are of better precision than the current world averages.     

Search for Higgs bosons decaying to bb and produced in association with W bosons in pp collisions at square root of s = 1.96 TeV

We present a search for Higgs bosons decaying into bb and produced in association with W bosons in pp collisions at square root of s = 1.96 TeV. This search uses 320 pb(-1) of the data set accumulated by the upgraded Collider Detector at Fermilab. Events are selected that have a high-transverse momentum electron or muon, missing transverse energy, and two jets, at least one of which is consistent with the hadronization of a b quark. Both the number of events and the dijet mass distribution are consistent with standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio for the Higgs boson or any new particle with similar decay kinematics. These upper limits range from 10 pb for mH = 110 GeV/c2 to 3 pb for mH = 150 GeV/c2.     

Characterization of unusual alkenones and alkyl alkenoates by electron ionization gas chromatography/mass spectrometry

Unusual long-chain, diunsaturated alkenones and alkyl alkenoates exhibiting double bonds separated by three methylene units instead of the more usual five were characterized by electron ionization (EI) gas chromatography/mass spectrometry. In a first step, the positions of the double bonds of these compounds (isolated from Holocene Black Sea sediments) were confirmed after OsO4 treatment and silylation. Mass spectra of the resulting tetratrimethylsilyloxy derivatives allowed unambiguous determination of the positions of unsaturations. The EI mass spectra of the non-derivatized compounds were then compared with those of the alkenones and alkyl alkenoates having double bonds separated by five methylene units. Specific fragment ions resulting from gamma-H rearrangements were found to be prominent in EI mass spectra of these unusual 'Black Sea' diunsaturated alkenones and alkyl alkenoates. These fragment ions can be used to characterize these compounds in natural samples without the need for laborious derivatization treatments.     

Room-temperature polariton lasing in semiconductor microcavities

We observe a room-temperature low-threshold transition to a coherent polariton state in bulk GaN microcavities in the strong-coupling regime. Nonresonant pulsed optical pumping produces rapid thermalization and yields a clear emission threshold of 1 mW, corresponding to an absorbed energy density of 29 microJ cm-2, 1 order of magnitude smaller than the best optically pumped (In,Ga)N quantum-well surface-emitting lasers (VCSELs). Angular and spectrally resolved luminescence show that the polariton emission is beamed in the normal direction with an angular width of +/-5 degrees and spatial size around 5 microm.     

Cost allocation in the establishment of a collaborative transportation agreement—an application in the furniture industry

Transportation is an important part of the Canadian furniture industry supply chain. Even though there are often several manufacturers shipping in the same market region, coordination between two or more manufacturers is rare. Recently, important potential cost savings and delivery time reduction have been identified through transportation collaboration. In this paper we propose and test on a case study involving four furniture companies, a logistics scenario that allows transportation collaboration. Moreover, we address the key issue of cost savings sharing, especially when heterogeneous requirements by each collaborating company impact the cost-savings. To do so, we propose a new cost allocation method that is validated through a case study. Sensibility analysis and details about the actual outcome of the case study complete the discussion.     

A parametric imaging approach for the segmentation of ultrasound data

When an ultrasonic examination is performed, a segmentation tool would often be very useful, either for the detection of pathologies, the early diagnosis of cancer or the follow-up of the lesions. Such a tool must be both reliable and accurate. However, because of the relatively reduced quality of ultrasound images due to the speckled texture, the segmentation of ultrasound data is a difficult task. We have previously proposed to tackle the problem using a multiresolution Bayesian region-based algorithm. For computation time purposes, a multiresolution version has been implemented. In order to improve the quality of the segmentation, we propose to perform the segmentation not only from the envelope image but to combine more information about the properties of the tissues in the segmentation process. Several acoustical parameters have thus been computed, either directly from the images or from the radio-frequency (RF) signal.

In a previous study, two parametric images were involved in the segmentation process. The parameter represented the integrated backscatter (IBS) and the mean central frequency (MCF), which is a measurement related to the attenuation of ultrasound waves in the media. In this study, parameters representative of the scattering conditions in the tissue are evaluated in the multiparametric segmentation process. They are extracted from the K-distribution (,b) and the Nakagami distribution (m,Ω) and are related to the local density of scatterers (,m), the size of the scatterers (b) and the backscattering properties of the medium (Ω).

The acoustical features are calculated locally on a sliding window. This procedure allows to built parametric mapping representing the particular characteristics of the medium. To test the influence of the acoustical parameters in the segmentation process, a set of numerical phantoms has been computed using the Field software developed by J.A. Jensen. Each phantom consists in two regions with two different acoustical properties: the density of scatterers and the scattering amplitude. From both the simulated RF signals and envelope images, the parameters have been computed; their relevance to represent a particular characteristic of the medium is evaluated. The segmentation has been processed for each phantom. The ability of each parameter to improve the segmentation results is validated. A agar–gel phantom has also been created, in order to test the accuracy of the parameters in conditions closer to the in vivo ultrasound imaging. This phantom contains four inclusions with different concentrations of silica. A B&K ultrasound device provides the RF data. The quantification of the segmentation quality is based on the rate of correctly classified pixels and it has been computed for all the parameters either from the field images or the phantom images. The large improvement in the segmentation results obtained reveals that the multiparametric segmentation scheme proposed in this study can be a reliable tool for the processing of noisy ultrasound data.     

Guided quasicontinuous atom laser

We report the first realization of a guided quasicontinuous atom laser by rf outcoupling a Bose-Einstein condensate from a hybrid optomagnetic trap into a horizontal atomic waveguide. This configuration allows us to cancel the acceleration due to gravity and keep the de Broglie wavelength constant at 0.5 microm during 0.1 s of propagation. We also show that our configuration, equivalent to pigtailing an optical fiber to a (photon) semiconductor laser, ensures an intrinsically good transverse mode matching.     

Evidence for B0 s-->phiphi decay and measurements of branching ratio and A(CP) for B+ -->phiK+

We present the first evidence of charmless decays of the B(0)(s) meson, the decay B(0)(s)--> phiphi, and a measurement of the branching ratio BR(B(0)(s)--> phiphi) using 180 pb(-1) of data collected by the CDF II experiment at the Fermilab Tevatron collider. In addition, the BR and direct CP asymmetry for the B+-->phiK+ decay are measured. We obtain BR(B(0)(s)--> phiphi)=[14(+6)(-5)(stat)+/-6(syst)] x 10(-6), BR(B+-->phiK+)=[7.6+/-1.3(stat)+/-0.6(syst)] x 10(-6), and A(CP)(B+-->phiK+)= -0.07+/-0.17(stat)+0.03 / -0.02(syst). Both decays are governed in the standard model by second order (penguin) b-->s(-)ss amplitudes.