Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

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The HITRAN 2008 molecular spectroscopic database

This paper describes the status circa 2001, of the HITRAN compilation that comprises the public edition available through 2001. The HITRAN compilation consists of several components useful for radiative transfer calculation codes: high-resolution spectroscopic parameters of molecules in the gas phase, absorption cross-sections for molecules with very dense spectral features, aerosol refractive indices, ultraviolet line-by-line parameters and absorption cross-sections, and associated database management software. The line-by-line portion of the database contains spectroscopic parameters for 38 molecules and their isotopologues and isotopomers suitable for calculating atmospheric transmission and radiance properties. Many more molecular species are presented in the infrared cross-section data than in the previous edition, especially the chlorofluorocarbons and their replacement gases. There is now sufficient representation so that quasi-quantitative simulations can be obtained with the standard radiance codes. In addition to the description and justification of new or modified data that have been incorporated since the last edition of HITRAN (1996), future modifications are indicated for cases considered to have a significant impact on remote-sensing experiments. (C) 2003 Elsevier Ltd. All rights reserved.

The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001

Graphene’s success has shown not only that it is possible to create stable, single-atom-thick sheets from a crystalline solid but that these materials have fundamentally different properties than the parent material. We have synthesized for the first time, millimeter-scale crystals of a hydrogen-terminated germanium multilayered graphane analogue (germanane, GeH) from the topochemical deintercalation of CaGe2. This layered van der Waals solid is analogous to multilayered graphane (CH). The surface layer of GeH only slowly oxidizes in air over the span of 5 months, while the underlying layers are resilient to oxidation based on X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy measurements. The GeH is thermally stable up to 75 °C; however, above this temperature amorphization and dehydrogenation begin to occur. These sheets can be mechanically exfoliated as single and few layers onto SiO2/Si surfaces. This material represents a new class of covalently terminated graphane analogue...

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Stability and Exfoliation of Germanane: A Germanium Graphane Analogue

Raman scattering measurements on hydrogenated microcrystalline silicon prepared in a hydrogen plasma at deposition temperatures between approximately=65 and 400 degrees C are presented and discussed. The shifts of the crystalline (c) and 'amorphous-like' (a) components of the spectra to lower frequencies with decreasing crystallite size have been correlated with the lattice expansion and the finite dimensions of the crystallites in these films. The roles of hydrogen and of the compressive stress in the samples have been investigated by annealing experiments and a deposition of the samples under negative bias of the substrate, respectively. These results point to a probable mechanism of the crystalline-amorphous transition in silicon. The data presented allow an assignment of the amorphous-like feature in the Raman spectra to surface-like modes at grain boundaries of the crystallites. Strong arguments are given that suggest that the 480 cm-1 peak in the Raman spectra of X-ray amorphous silicon is of the same origin and is hence associated with some shearing modes of Si clusters rather than a broadened density of states. Results on the depolarisation ratio of Raman scattering in the microcrystalline and X-ray amorphous films are also presented and discussed.

https://iopscience.iop.org/article/10.1088/0022-3719/15/2/019/pdf

Raman scattering from hydrogenated microcrystalline and amorphous silicon

The Stokes Raman spectra of pure and hydrogenated amorphous germanium and silicon are discussed. First- and second-order structures due to the vibration of GeGe and SiSi bonds and also first-order structures due to GeH and SiH bonds are observed. The resonance behaviour and the polarization ratio of the observed structures are presented and interpreted in terms of a dielectric constant-bond polarizability model.

Raman scattering in pure and hydrogenated amorphous germanium and silicon

The infrared spectrum of hydrogenated a-Ge produced by sputtering in an ArH2 mixture is reported. Bond stretching, bending, and wagging bands are observed. From the integrated absorption of these bands the concentration of GeH and GeH2 bonds is determined. We also report annealing experiments at temperatures below and above that required for crystallization, the amount of this crystallization being determined by Raman scattering. The GeH2 bands disappear upon annealing faster than GeH and virtually none are left in the crystallized material which nevertheless still contains a significant proportion of GeH bonds. The possible structure of the GeH bonds in the crystalline phase is discussed.

Infrared absorption in hydrogenated amorphous and crystallized germanium

This paper is devoted to the effects of velocity on the shapes of six R(J) lines of the n3 band of water vapor diluted in N2. The experiments have been made at room temperature for total pressures between 0.1 and 1.2atm using a tunable infrared laser frequency difference spectrometer. These measurements, which study broad and narrow lines of low and high J values, are first analyzed using the Voigt and the hard collision (HC) model. It is shown that both lead to unsatisfactory results, the Voigt profile being unable to account for the line narrowing whereas the friction (narrowing) parameter deduced using the HC approach has an unphysical dependence on pressure. Furthermore, at elevated pressure where Dicke narrowing and Doppler effects are negligible, deviations between experimental and fitted profiles are still observed, indicating inhomogeneous effects due to the speed dependence of collisional parameters. In order to go further, an approach based on the kinetic impact equation accounting for both the Dicke narrowing and the speed dependence has been applied. It uses velocity-dependent broadening and shifting coefficients calculated with a semi-classical approach and two parameters. The latter, which govern the memory functions of the modulus and orientation of the H2O velocity are considered as free parameters and determined from experiments. The results show that all profiles, regardless of pressure and of the transition, can be correctly modeled using a single set of memory parameters. This demonstrates the consistency of the approach, which is then used to analyze the different regimes that monitor velocity effects on the line profile. r 2007 Elsevier Ltd. All rights reserved.

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Collisional parameters of H2O lines : Velocity effects on the line-shape

Line-mixing effects have been studied in the ν3 band of CH4 perturbed by N2 at room temperature. New measurements have been made and a model is proposed which is not, for the first time, strictly empirical. Three different experimental set ups have been used in order to measure absorption in the 2800–3200 cm−1 spectral region for total pressures in the 0.25–2 and 25–80 atm ranges. Analysis of the spectra demonstrates the significant influence of line mixing on the shape of the Q branch and of the P and R manifolds. A model is proposed which is based on state-to-state collisional transfer rates calculated from the intermolecular potential surface with a semiclassical approach. The line-coupling relaxation matrix is constructed from these data and two additional parameters which are fitted on measured absorption. Comparisons between measurements and spectra computed accounting for and neglecting line mixing are made. They prove the quality of the approach which satisfactory accounts for the effects of press...

/pdf/experimental-and-theoretical-study-of-line-mixing-in-methane-3g7f2uqsht.pdf

Dionisio Bermejo

Papers

Raman scattering in pure and hydrogenated amorphous germanium and silicon

Infrared absorption in hydrogenated amorphous and crystallized germanium

Collisional parameters of H2O lines : Velocity effects on the line-shape

Experimental and theoretical study of line mixing in methane spectra. I. The N2-broadened ν3 band at room temperature

Absolute Raman intensities of CH4, CH3D, CH2D2, CHD3, and CD4