Supermolecular-Chromophore-Sensitized Near-Infrared-to-Visible Photon Upconversion

Selective near-IR (NIR) excitation (780 nm) of the conjugated supermolecule ruthenium(II) [15-(4?-ethynyl-(2,2?;6?,2??-terpyridinyl))-bis[(5,5?,-10,20-di(2?,6?-bis(3,3-dimethylbutoxy)phenyl)porphinato)zinc(II)]ethyne][4?-pyrrolidin-1-yl-2,2?;6?,2??-terpyridine] bis(hexafluorophosphate) (Pyr1RuPZn2) in solutions containing N,N-bis(ethylpropyl)perylene-3,4,9,10-tetracarboxylicdiimide (PDI) or tetracene gives rise to a substantial anti-Stokes energy gain (PDI, 0.70 eV; tetracene, 0.86 eV). Experimental data clearly demonstrate that this upconverted fluorescence signal is produced via Pyr1RuPZn2-sensitized triplet?triplet annihilation (TTA) photochemistry. The TTA process was confirmed by the quadratic dependence of the integrated 1PDI* emission centered at 541 nm derived from 780 nm laser excitation. The T1?Tn excited state absorption decay of Pyr1RuPZn2, monitored at 900 nm as a function of PDI concentration, revealed Stern?Volmer and bimolecular quenching constants of 10?048 M?1 and 5.9 ? 108 M?1 s?1, respectively, for the PDI triplet sensitization process. The T1?Tn PDI extinction coefficient at 560 nm (εT = 6.6 ? 104 M?1 cm?1) was determined through the triplet energy transfer method utilizing anthracene as the donor chromophore. 3PDI* transient triplet absorption dynamics observed as a function of 485 nm incident nanosecond pump laser fluence demonstrate a bimolecular 3PDI*?3PDI* TTA rate constant (kTT = 1.0 ± 0.2 ? 109 M?1 s?1). The maximum quantum yield of the supermolecule-sensitized PDI upconverted emission (ΦUC = 0.0075 ± 0.0002) was determined relative to [Os(phen)3][PF6]2 at an incident laser power of 22 mW at 780 nm. This study successfully demonstrates NIR-to-visible photon upconversion and achieves a new record anti-Stokes shift of 0.86 eV for sensitized TTA, using the supermolecular Pyr1RuPZn2sensitizer. The stability of the Pyr1RuPZn2/PDI chromophore combination is readily apparent as continuous irradiation at 780 nm produces 541 nm centered fluorescence with no significant decrease in intensity measured over time domains exceeding several hours. The molecular components of these NIR-to-vis upconverting compositions illustrate that substantial anti-Stokes energy gains via a TTA process can be effortlessly realized

A terminal assessment of stages theory : introducing a dynamic states approach to entrepreneurship

Stages of Growth models were the most frequent theoretical approach to understanding entrepreneurial business growth from 1962 to 2006; they built on the growth imperative and developmental models of that time. An analysis of the universe of such models (N=104) published in the management literature shows no consensus on basic constructs of the approach, nor is there any empirical confirmations of stages theory. However, by changing two propositions of the stages models, a new dynamic states approach is derived. The dynamic states approach has far greater explanatory power than its precursor, and is compatible with leading edge research in entrepreneurship

Calculating the carbon footprint:implications for governing emissions and gender relations

In this article, we use fresh empirical evidence, and draw on feminist and critical accounting and organisational theories to contend that carbon calculators can be interpreted as discriminatory control technologies. They do this by providing a new and flexible vocabulary for governing expenses, costs and investments at a distance, avoiding a sense of direct intervention by the government. Thus, given our stance that the carbon calculator cannot be considered a neutral tool, we argue that it has the potential to control personal responsibilities regarding both environmental and family‐based issues

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data

We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross-section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross-sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables, final version to appear in Physical Review

Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

This paper constructs the reduction of heterotic $M$-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe

Measurement of tau polarization in W->taunu decays with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

In this paper, a measurement of tau polarization in W->taunu decays is presented. It is measured from the energies of the decay products in hadronic tau decays with a single final state charged particle. The data, corresponding to an integrated luminosity of 24 pb^-1, were collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the tau polarization is Ptau = -1.06 +/- 0.04 (stat) + 0.05 (syst) - 0.07 (syst), in agreement with the Standard Model prediction, and is consistent with a physically allowed 95% CL interval [-1,-0.91]. Measurements of tau polarization have not previously been made at hadron colliders.Comment: 10 pages plus author list (25 pages total), 4 figures, 4 tables, revised author list, matches published EPJC versio

Readiness of the ATLAS liquid argon calorimeter for LHC collisions

The ATLAS liquid argon calorimeter has been operating continuously since August 2006. At this time, only part of the calorimeter was readout, but since the beginning of 2008, all calorimeter cells have been connected to the ATLAS readout system in preparation for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance, electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter response along eta (averaged over phi) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative muons have been used to cross-check the Monte Carlo simulation. The performance results obtained using the ATLAS readout, data acquisition, and reconstruction software indicate that the liquid argon calorimeter is well-prepared for collisions at the dawn of the LHC era.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-010-1354-y</p

Associations of autozygosity with a broad range of human phenotypes

In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding