2,488 research outputs found
Quantifying the thermal Sunyaev–Zel’dovich effect and excess millimetre emission in quasar environments
In this paper, we probe the hot, post-shock gas component of quasar-driven winds through the thermal Sunyaev–Zel’dovich (tSZ) effect. Combining data sets from the Atacama Cosmology Telescope, the Herschel Space Observatory, and the Very Large Array, we measure average spectral energy distributions of 109 829 optically selected, radio quiet quasars from 1.4 to 3000 GHz in six redshift bins between 0.3 1.91, we measure the tSZ effect at 3.8σ significance with an amplitude corresponding to a total thermal energy of 3.1 × 10⁶⁰ erg. If this energy is due to virialized gas, then our measurement implies quasar host halo masses are ∼6 × 10¹² h⁻¹ M⊙. Alternatively, if the host dark matter halo masses are ∼2 × 10¹² h⁻¹ M⊙ as some measurements suggest, then we measure a >90 per cent excess in the thermal energy over that expected due to virialization. If the measured SZ effect is primarily due to hot bubbles from quasar-driven winds, we find that (5^(+1.2)_(−1.3) per cent of the quasar bolometric luminosity couples to the intergalactic medium over a fiducial quasar lifetime of 100 Myr. An additional source of tSZ may be correlated structure, and further work is required to separate the contributions. At z ≤ 1.91, we detect emission at 95 and 148 GHz that is in excess of thermal dust and optically thin synchrotron emission. We investigate potential sources of this excess emission, finding that CO line emission and an additional optically thick synchrotron component are the most viable candidates
The Fairness of Fair Trade: An Analysis of the Economics of Fair Trade
In 2015, a study done by Cone Communications found that millennials are universally more engaged in corporate social responsibility. In fact, 87% of millennials are willing to purchase a product with social or environmental benefits. Enter, the fair trade label. The fair trade label, which is attached to products which meet the previously mentioned consumer demands, has emerged over the last three decades. Products like organic produce, textiles, and natural commodities have entered into global retailers and supermarkets through these non-traditional distribution channels, supported by increased consumption as well as changing consumer preferences. In order to uncover the underlying economic and social benefits and potential disadvantages, an analysis of the fair trade model has been conducted. Additionally, this paper will examine the future outlook of fair trade labels and how companies are creating niche business strategies within the model to develop sustained competitive advantages
Synthesis and Photophysical Properties of 9,10-Disubstituted Anthracenes
We report the synthesis and photophysical characterization of four 9,10-disubstituted diphenylanthracenes
with specific modifications of the model backbone which involve both the 9,10 para
substituents at the phenyl rings and the substitution with carbon-carbon triple bonds. The effects
of such modifications on the photoluminescence and electroluminescence properties have been
investigated on the basis of the diphenylanthracene molecular characteristics and in view of application
to light-emitting devices. We have found that the substitution with the carbon-carbon
triple bonds at the two 9,10-phenyls noticeably alters the electronic states of the reference molecule,
also introducing a certain degree of sensitivity to the phenyl substituents, which improves
the tunability of the optical emission. Differently, the 9,10 para substituents produce minor changes
in the single-molecule properties, due to the lack of electronic conjugation across the 9,10-phenyls.
However, even a single nitro substituent in the phenyl para position produces the formation of excimers,
which appreciably reduces the optical quantum efficiency. These properties are maintained
in solid-state blends and simple spin-coated bilayer electroluminescent devices have been
fabricated
Indium(111) pentetreotide single photon emission computed tomography (In-111 pentetreotide SPECT): a new technique to evaluate somatostatin receptors in chordomas
Chordomas are rare neoplasms originating along the neuraxis. Although they do not usually show cytological atypia, metastases have been reported in 30 per cent of cases. Survival rates in cases of skull base locations are low, and local recurrence is common after local excision. Radiation therapy is used in post-operative treatment and proton radiation therapy as the primary treatment. In the present paper we present the case of a 50-year-old Caucasian man affected by chordoma of the clivus, with liver and chest metastases, relapsed after several surgical local excisions, to discuss improvements in therapeutic and imaging techniques. Indium(III) (In-III) pentetreotide single photon emission computed tomography (SPECT) was employed to assess the presence of somatostatin receptors and to treat the tumour with radiolabelled Y-90-DOTA-lanreotide. Imaging, performed 2 months afterwards, showed stable disease in the lungs but a local progression in the metastases, in comparison with pre-treatment uptake. These data suggest the usefulness of radiolabelled somatostatin analogues in the diagnosis and therapy of chordomas
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