Temperature-dependent bulk viscosity of nitrogen gas determined from spontaneous Rayleigh-Brillouin scattering

Values for the bulk viscosity of molecular nitrogen gas (N2) were derived from spontaneous Rayleigh-Brillouin (RB) scattering at ultraviolet wavelengths (366.8 nm) and at a 90 degree scattering angle. Analysis of the scattering profiles yield values showing a linear increasing trend in the temperature interval from 255 K to 340 K. The present values, pertaining to hypersound acoustics at frequencies in the GHz domain, are found to be in agreement with results from acoustic attenuation experiments in N2 performed at MHz frequencies

Towards European-wide Quality and Benchmarking of Open Educational Resources

Empowered by a multi-partner Consortium, MORIL will deliver high-quality Open Educational Resources (OER) with pedagogically-rich content, specifically designed and developed for distance learning. MORIL refers to "Multilingual Open Educational Resources for Independent Learning". It constitutes a New Generation of open resources, having a strong focus on development and delivery of quality-assured materials for off-campus target groups. MORIL is value added, as face-to-face didactics are not obligatory, contrary to on-campus education. Besides open offers, formal offers are fronted as well, establishing a transparent prospective learning path into higher education for those that seek recognition and/or certification. MORIL will provide a single European access point for lifelong open and flexible learning: a referatory to participating local repository portals. For courses of interest to domestic markets, universities can utilise multilingual versioning and localisation. Blending MORIL with leading edge quality assurance and benchmarking, truly provides the Consortium with a head start. European-wide quality and benchmarking is enabled by E-xcellence: a web-based instrument to assess the quality of e-learning in higher education. Although many instruments already exist, which cover the organisational and content-related quality assurance of higher education institutions and programmes, only few exist which have developed a focus on the parameters of quality assurance that govern e-learning and even fewer or none, have their focus on OER. E-xcellence as such being supplemented to MORIL, is to cater for open and accessible quality and benchmarking. MORIL is supported by the William and Flora Hewlett Foundation

Cavity Ring-down UV spectroscopy of the C2Σ+^2\Sigma^+-X2Π^2\Pi electronic transition of CH

Rotationally resolved spectra of the C$^2\Sigma^+$-X$^2\Pi$ electronic system of the CH radical were measured using cavity ring-down spectroscopy in supersonically expanding, planar hydrocarbon plasma. The experimental conditions allowed the study of highly excited rotational levels starting from vibrationally excited states. Here we present some 200+ new or more accurately recorded transitions in the 0-0, 1-1 and 2-2 vibronic bands in the ultraviolet between 30900-32400 cm$^{-1}$ (324-309 nm). The resulting data, compared to earlier measurements, allows for the determination of more precise molecular constants for each vibrational state and therefore more precise equilibrium values. From this an equilibrium bond length of 1.115798(17) \r{A} for the C$^2{\Sigma}^+$ state is determined. A comprehensive list with observed transitions for each band has been compiled from all available experimental studies and constraints are placed on the predissociation lifetimes

Rayleigh-Brillouin scattering of carbon dioxide

The spectral lineshape of spontaneous Rayleigh-Brillouin scattering in CO2 is studied in a range of pressures. The spectrum is influenced by the bulk viscosity, which is a relaxation phenomenon involving the internal degrees of freedom of the molecule. The associated relaxation rates can be compared to the frequency shift of the scattered light, which demands precise measurements of the spectral lineshape. We find the value of the bulk viscosity around 5.7 X 10^{-6} kg/(ms) for the range of pressures p= 2-4 bar and for conditions of room temperature

B\,^1\Sigma^{+}_{u} and EF\,^{1}\Sigma^{+}_{g} level energies of D2_{2}

Accurate absolute level energies of the B\,^1\Sigma^{+}_{u}, $v=0-8, N$ and EF\,^{1}\Sigma^{+}_{g}, $v=0-21, N$ rovibrational quantum states of molecular deuterium are derived by combining results from a Doppler-free two-photon laser excitation study on several lines in the $EF\,{}^{1}\Sigma_{g}^{+}-X\,{}^{1}\Sigma_{g}^{+}$ (0,0) band, with results from a Fourier-transform spectroscopic emission study on a low-pressure hydrogen discharge. Level energy uncertainties as low as 0.0005 cm$^{-1}$ are obtained for some low-lying E\,^{1}\Sigma^{+}_{g} inner-well rovibrational levels, while uncertainties for higher-lying rovibrational levels and those of the F\,^{1}\Sigma^{+}_{g} outer-well states are nominally 0.005 cm$^{-1}$. Level energies of B\,^1\Sigma^{+}_{u} rovibrational levels, for $v \leq 8$ and $N \leq 10$ are determined at an accuracy of 0.001 cm$^{-1}$. Computed wavelengths of D$_2$ Lyman transitions in the B\,^1\Sigma^{+}_{u}-X\,^{1}\Sigma^{+}_{g} ($v,0$) bands are also tabulated for future applications.Comment: appears in Journal of Molecular Spectroscopy (2014