Electronic Transport Properties of Pentacene Single Crystals upon Exposure to Air

We report the effect of air exposure on the electronic properties of pentacene single crystals. Air can diffuse reversibly in and out of the crystals and controls the physical properties. We discern two competing mechanisms that modulate the electronic transport. The presence of oxygen increases the hole conduction, as in dark four O2 molecules introduce one charge carrier. This effect is enhanced by the presence of visible light. Contrarily, water, present in ambient air, is incorporated in the crystal lattice and forms trapping sites for injected charges.Comment: 16 pages, 3 figure

Does haste make waste? The human factors of overtaking land design

The aim of this research was to improve overtaking safety and efficiency through improvements in road signage, markings, geometry and speed control associated with the placement and layout of passing lanes. The approach of the research was to explore the effects of several types of overtaking lane treatments in the safety and controlled environment of a state-of-the-art driving simulator. It was found that under the most benign conditions there were no differential effects of the three treatments. With poorer visibility or more taxing road geometry, the drivers relied more heavily on the road markings and signage and the effects of the treatments become more pronounced. The sensitivity to the more "challenging" situations was borne out by the greater speed differential between merge area sections at these sites

Atomic carbon at redshift ~2.5

Using the IRAM 30m telescope we detected the lower fine structure line of neutral carbon towards three high--redshift sources: IRAS FSC10214 (z=2.3), SMMJ14011+0252 (z=2.5) and H1413+117 (Cloverleaf quasar, z=2.5). SMMJ14011+0252 is the first high--redshift, non--AGN source in which CI has been detected. The CI(1-0) line from FSC10214 is almost an order of magnitude weaker than previously claimed, while our detection in the Cloverleaf is in good agreement with earlier observations. The CI(1-0) linewidths are similar to the CO widths, indicating that both lines trace similar regions of molecular gas on galactic scales. Derived CI masses for all three objects are of order few 10^7 solar masses and the implied CI(1-0)/CO(3-2) line luminosity ratio is about 0.2. This number is similar to values found in local galaxies. We derive a CI abundance of 5x10^{-5} which implies significant metal enrichment of the cold molecular gas at redshifts 2.5 (age of the universe 2.7 Gyr). We conclude that the physical properties of systems at large lookback times are similar to today's starburst/AGN environments.Comment: 4 pages, 2 figures; accepted by A&

The synergistic role of embeddedness and capabilities in industrial symbiosis: illustration based upon 12 years of experiences in the Rotterdam Harbour and Industry Complex

Industrial Ecology (IE) is a known concept worldwide; however, its dissemination is not an easy process. Industrial routines are embedded in unsustainable practices that are difficult to change. The complexity and uncertainties of new concepts are often approached with ignorance and misperception. Nevertheless, the integration of economic, environmental and social dimensions in industrial activities is increasingly perceived as a necessary condition for a sustainable society. The paper reflects on the theories of embeddedness, capabilities and transformation to practical experiences of Industrial Symbiosis (IS) in the Rotterdam Harbour and Industry Complex (HIC)

Operations on integral lifts of K(n)

This very rough sketch is a sequel to arXiv:1808.08587; it presents evidence that operations on lifts of the functors K(n) to cohomology theories with values in modules over valuation rings of local number fields, indexed by Lubin-Tate groups of such fields, are extensions of the groups of automorphisms of the indexing group laws, by the exterior algebras on the normal bundle to the orbits of the group laws in the space of lifts.Comment: \S 2.0 hopefully less cryptic. To appear in the proceedings of the 2015 Nagoya conference honoring T Ohkawa. Comments very welcome

Twin polaritons in semiconductor microcavities

The quantum correlations between the beams generated by polariton pair scattering in a semiconductor microcavity above the parametric oscillation threshold are computed analytically. The influence of various parameters like the cavity-exciton detuning, the intensity mismatch between the signal and idler beams and the amount of spurious noise is analyzed. We show that very strong quantum correlations between the signal and idler polaritons can be achieved. The quantum effects on the outgoing light fields are strongly reduced due to the large mismatch in the coupling of the signal and idler polaritons to the external photons

A mathematical formalism for the Kondo effect in WZW branes

In this paper, we show how to adapt our rigorous mathematical formalism for closed/open conformal field theory so that it captures the known physical theory of branes in the WZW model. This includes a mathematically precise approach to the Kondo effect, which is an example of evolution of one conformally invariant boundary condition into another through boundary conditions which can break conformal invariance, and a proposed mathematical statement of the Kondo effect conjecture. We also review some of the known physical results on WZW boundary conditions from a mathematical perspective.Comment: Added explanations of the settings and main result

Molecular gas temperature and density in spiral galaxies

We combine beam-matched CO-13, CO-12 J = 3 yields 2 and J = 2 yields 1 line data to infer the molecular gas excitation conditions in the central 500 to 1600 pc diameters of a small sample of infrared-bright external galaxies: NGC253, IC342, M 83, Maffei 2, and NGC6946. Additional observations of the J = 1 yields 0 lines of C-18O and CO-13 set limits on the opacity of the CO-13 J = 1 yields 0 line averaged over the central kiloparsec of these spiral galaxies