Pseudogap and incommensurate magnetic fluctuations in YBa_2Cu_3O_{6. 6}

Unpolarized inelastic neutron scattering is used to study the temperature and wave vector dependence of the dynamical magnetic susceptibility, $\chi''(q,\omega)$, of a well characterized single crystal $YBa_2Cu_3O_{6.6}$ ($T_c=62.7$ K). We find that a pseudogap opens in the spin fluctuation spectrum at temperatures well above $T_c$. We speculate that the appearance of the low frequency incommensurate fluctuations is associated with the opening of the pseudogap. To within the error of the measurements, a gap in the spin fluctuation spectrum is found in the superconducting state.Comment: 6 pages, 3 ps figs, Proceedings of ICNS, Physica B, to be publishe

Stock Market Return and Volatility: Day-of-the-week Effect

Cataloged from PDF version of article.This paper examines the stock market returns and volatility relationship using US daily returns from May 26, 1952 to September 29, 2006. The empirical evidence reported here does not support the proposition that the return-volatility relationship is present and the same for each day of the week. © 2010 Springer Science+Business Media, LLC

CrowdHiLite: A Peer Review Service to Support Serious Reading on the Screen

The advent of smart devices and consumerisation of IT has produced a significant and permanent shift away from print-based reading to digital reading. This, in turn, has changed people’s reading behaviours and suggests that adapted mechanisms should be considered to support digital reading. It is particularly important for novice readers who need to read in-depth scientific literature in their chosen field. In this paper, we propose CrowdHiLite, a novel service architecture that allows expert readers to provide suggestion on individual readers’ highlights to support their reading on the screen through the use of crowdsourcing technique. A demonstration was also provided to show how it would work in real world. A preliminary experiment comparing novice readers’ reading performance with expert rated highlights and normal highlights on the same document found improved reading efficiency and comprehension with the former

UX Research is Dead. Long live UX Research!

This paper critically discusses the future of User Experience (UX) research across the tech industry and hence the shift from classic usability research towards design-led approaches, quantitative research discipline, A/B testing and telemetry. Likely causes for this shift are addressed to empower the UX research discipline to remain relevant. The areas covered include the identity crisis and democratization of UX research; evolvement and sustainability of the UX discipline; and fusion of UX across heterogeneous fields. The adaptations to this shift are discussed from the Point of View (PoV) of practitioners. This includes offering clarity and meaning based on the organizational context and product positioning; and also leveraging deep understanding human behavior with a focus on data integrity that relates to the technology and environment

Macro- and micro-strain in GaN nanowires on Si(111)

We analyze the strain state of GaN nanowire ensembles by x-ray diffraction. The nanowires are grown by molecular beam epitaxy on a Si(111) substrate in a self-organized manner. On a macroscopic scale, the nanowires are found to be free of strain. However, coalescence of the nanowires results in micro-strain with a magnitude from +-0.015% to +-0.03%.This micro-strain contributes to the linewidth observed in low-temperature photoluminescence spectra

Sea level changes along the Turkish coasts of the Black Sea, the Aegean Sea and the Eastern Mediterranean

Short, tidal, subtidal, seasonal, secular sea-level variations, sea-level differences and interactions between the basins have been studied, based on the data collected at some permanent and temporary tide gauges located along the Turkish coasts, mostly along the Straits connecting the Marmara Sea to outer seas. Even though the deficiency of sufficient information prevented us to reach the desired results, many pre-existed studies have been improved. Short-period oscillations were clearly identified along the Turkish Strait System and related to their natu-ral periods. The tidal amplitudes are low along the Turkish coasts, except northern Aegean and eastern Mediterranean. The stability of harmonic constants of Samsun and Antalya were examined and most of the long period constituents were found to be unstable. Even the Marmara Sea is not affected from the tidal oscillations of Black and Aegean Seas, some interactions in low frequency band have been detected. Subtidal sea level fluctuations (3-14 day) have relations with the large-scale cyclic atmospheric patterns passing over the Turkish Straits System. Short-term effects of wind on sea level are evident.Seasonal sea-level fluctuations along the Turkish Straits System are in accord with Black Sea's hydrological cycle. The differential range of the monthly mean sea levels between the Black Sea and the Marmara Sea is highly variable; high during spring and early summer and low during fall and winter.On the average, there is a pronounced sea-level difference (55 cm) along the Turkish Straits System. However, the slope is nonlinear, being much steeper in the Strait of Istanbul. This barotrophic pressure difference is one of the most important factors causing the two-layer flow through the system. The topography and hydrodynamics of the straits, the dominant wind systems and their seasonal variations make this flow more complicated. For secular sea level changes, a rise of 3.2 mm/a was computed for Karsiyaka (1935-71) and a steady trend (-0.4 mm /a) has been observed for annual sea levels at Antalya (1935-77). The decreasing trend (-6.9 mm/a) at Samsun is contrary to the secular rising trend of the Black Sea probably because of its rather short monitoring period (1963-77)