Raman spectroscopic quantification of sulfur species in aqueous fluids: Ratios of relative molar scattering factors of Raman bands of H2S, HS−, SO2, HSO4−, SO42−, S2O32−, S3− and H2O at ambient conditions and information on changes with pressure and temperature

2017 ◽  
Vol 467 ◽  
pp. 64-75 ◽  
Author(s):  
Christian Schmidt ◽  
Terry M. Seward
Keyword(s):  
Ambient Conditions ◽  
Sulfur Species ◽  
Raman Spectroscopic

scholarly journals Estimating the viscosity of volcanic melts from the vibrational properties of their parental glasses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michele Cassetta ◽  
Danilo Di Genova ◽  
Marco Zanatta ◽  
Tiziana Boffa Ballaran ◽  
Alexander Kurnosov ◽  
...  
Keyword(s):  
Volcanic Eruptions ◽  
Peak Position ◽  
Accurate Estimation ◽  
Vibrational Properties ◽  
Ambient Conditions ◽  
Shear Moduli ◽  
Raman Spectroscopic ◽  
Viscosity Measurements ◽  
Fertile Ground ◽  
Melt Composition

AbstractThe numerical modelling of magma transport and volcanic eruptions requires accurate knowledge of the viscosity of magmatic liquids as a function of temperature and melt composition. However, there is growing evidence that volcanic melts can be prone to nanoscale modification and crystallization before and during viscosity measurements. This challenges the possibility of being able to quantify the crystal-free melt phase contribution to the measured viscosity. In an effort to establish an alternative route to derive the viscosity of volcanic melts based on the vibrational properties of their parental glasses, we have subjected volcanologically relevant anhydrous glasses to Brillouin and Raman spectroscopic analyses at ambient conditions. Here, we find that the ratio between bulk and shear moduli and the boson peak position embed the melt fragility. We show that these quantities allow an accurate estimation of volcanic melts at eruptive conditions, without the need for viscosity measurements. An extensive review of the literature data confirms that our result also holds for hydrous systems; this study thus provides fertile ground on which to develop new studies of the nanoscale dynamics of natural melts and its impact on the style of volcanic eruptions.

Phase transitions in hydroxide perovskites: a Raman spectroscopic study of stottite, FeGe(OH)6, to 21 GPa

2012 ◽  
Vol 76 (4) ◽  
pp. 949-962 ◽  
Author(s):  
A. K. Kleppe ◽  
M. D. Welch ◽  
W. A. Crichton ◽  
A. P. Jephcoat
Keyword(s):  
Ambient Conditions ◽  
Oh Groups ◽  
Space Group ◽  
Raman Spectroscopic ◽  
Naturally Occurring ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
Comparable Quality

AbstractThe effect of pressure on the naturally occurring hydroxide-perovskite stottite, FeGe(OH)6, has been studied in situ by micro-Raman spectroscopy to 21 GPa at 300 K. The ambient spectrum contains six OH-stretching bands in the range 3064 3352 cm–1. The presence of six non-equivalent OH groups is inconsistent with space group P42/n. In view of this inconsistency a new ambient structure determination of stottite from Tsumeb was carried out, but this did not allow the clear rejection of P42/n symmetry. However, a successful refinement was also carried out in space group P2/n, a subgroup of P42/n, which allows for six non-equivalent O atoms. The two refinements are of comparable quality and do not allow a choice to be made based purely on the X-ray data. However, taken with the ambient and 150 K Raman spectra, a good case can be made for stottite having P2/n symmetry at ambient conditions. On this basis, the pressure induced spectroscopic changes are interpreted in terms of a reversible phase transition P2/n ↔ P42/n.

Simultaneous neutron powder diffraction and Raman spectroscopy – an approach of combining two complementary techniques

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Raphael Finger ◽  
Thomas C. Hansen ◽  
Holger Kohlmann
Keyword(s):  
Raman Spectroscopy ◽  
Neutron Diffraction ◽  
Amorphous Materials ◽  
Lead Sulfate ◽  
Phase Identification ◽  
Ambient Conditions ◽  
Raman Spectroscopic ◽  
Sapphire Single Crystal ◽  
Complementary Techniques

Abstract Diffraction techniques are well-established methods for crystal structure determination as well as phase identification and quantification. Raman spectroscopy can be a valuable complementary characterization technique, because in contrast to the former it yields also information on amorphous materials and it is a probe for short-range structural effects. The herein presented setup allows for simultaneous neutron diffraction and Raman spectroscopy, shown with a sample of lead sulfate under ambient conditions as a proof of principle. In order to fulfil requirements of both methods, a sapphire single-crystal is used as a sample holder. Practical considerations for successful simultaneous in situ neutron diffraction and Raman spectroscopic measurements are given.

Hydrogen bonding in liquid methanol at ambient conditions and at high pressure

2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Ambient Conditions

Raman spectroscopic imaging for investigations of de novo lipogenesis in hepatocellular carcinoma

2014 ◽  
Vol 52 (08) ◽  
Author(s):  
T Tolstik ◽  
C Marquardt ◽  
C Matthäus ◽  
C Beleites ◽  
C Krafft ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
De Novo ◽  
Spectroscopic Imaging ◽  
De Novo Lipogenesis ◽  
Raman Spectroscopic

Hybrid Micro-Optical Sensors via Sol-Gel Soft Lithography

2000 ◽  
Vol 628 ◽  
Author(s):  
Mark A. Clarner ◽  
Michael J. Lochhead
Keyword(s):  
Optical Sensors ◽  
Soft Lithography ◽  
Sol Gel ◽  
Silica Gels ◽  
Ph Sensing ◽  
Ambient Conditions ◽  
Sensor Applications ◽  
Patterned Structures ◽  
Biological Functionality ◽  
Indicator Dyes

ABSTRACTOrganically modified silica gels and dye-doped silica gels have been patterned into micrometer-scale structures on a substrate using micro molding in capillaries (MIMIC). This approach is from a class of elastomeric stamping and molding techniques collectively known as soft lithography. Soft lithography and sol-gel processing share attractive features in that they are relatively benign processes performed at ambient conditions, which makes both techniques compatible with a wide variety of organic molecules, molecular assemblies, and biomolecules. The combination of sol-gel and soft lithography, therefore, holds enormous promise as a tool for microfabrication of materials with optical, chemical, or biological functionality that are not readily patterned with conventional methods. This paper describes our investigation of micro-patterned organic-inorganic hybrid materials containing indicator dyes for microfluidic sensor applications. Reversible colorimetric pH sensing via entrapped reagents is demonstrated in a prototype microfluidic sensor element. Patterned structures range from one to tens of micrometers in cross-section and are up to centimeters in length. Fundamental chemical processing issues associated with mold filling, cracking and sensor stability are discussed.

Fluorescence of BODIPY Dyes in Gas Phase at near Ambient Conditions

2020 ◽  
Author(s):  
Kseniya A. Mariewskaya ◽  
Denis Larkin ◽  
Yuri Samoilichenko ◽  
Vladimir Korshun ◽  
Alex Ustinov
Keyword(s):  
Gas Phase ◽  
Molecular Interactions ◽  
Atmospheric Pressure ◽  
Fluorescence Spectra ◽  
Visible Range ◽  
Intrinsic Properties ◽  
Ambient Conditions ◽  
Ideal Model ◽  
Molecular Fluorescence ◽  
Tesla Coil

Molecular fluorescence is a phenomenon that is usually observed in condensed phase. It is strongly affected by molecular interactions. The study of fluorescence spectra in the gas phase can provide a nearly-ideal model for the evaluation of intrinsic properties of the fluorophores. Unfortunately, most conventional fluorophores are not volatile enough to allow study of their fluorescence in the gas phase. Here we report very bright gas phase fluorescence of simple BODIPY dyes that can be readily observed at atmospheric pressure using conventional fluorescence instrumentation. To our knowledge, this is the first example of visible range gas phase fluorescence at near ambient conditions. Evaporation of the dye in vacuum allowed us to demonstrate organic molecular electroluminescence in gas discharge excited by electric field produced by a Tesla coil.

Yttrium Oxyhydrides for Photochromic Applications: Correlating Composition and Optical Response

2018 ◽  
Author(s):  
Dmitrii Moldarev ◽  
Elbruz M. Baba ◽  
Marcos V. Moro ◽  
Chang C. You ◽  
Smagul Zh. Karazhanov ◽  
...  
Keyword(s):  
Medical Devices ◽  
Ternary Diagram ◽  
Optical And Electrical Properties ◽  
Ambient Conditions ◽  
Elastic Recoil ◽  
Elastic Recoil Detection Analysis ◽  
Photochromic Properties ◽  
Smart Windows ◽  
Elastic Recoil Detection ◽  
Detection Analysis

It has been recently demonstrated that yttrium oxyhydride(YHO) films can exhibit reversible photochromic properties when exposed to illumination at ambient conditions. This switchable optical propertyenables their utilization in many technological applications, such as smart windows, sensors, goggles, medical devices, etc. However, how the composition of the films affects their optical properties is not fully clear and therefore demands a straightforward investigation. In this work, the composition of YHO films manufactured by reactive magnetron sputtering under different conditions is deduced in a ternary diagram from Time-of-Flight Elastic Recoil Detection Analysis (ToF-ERDA). The results suggest that stable compounds are formed with a specificchemical formula – YH<sub>2-δ</sub>O<sub>δ</sub>. In addition, optical and electrical properties of the films are investigated, and a correlation with their compositions is established. The corresponding photochromic response is found in a specific oxygen concentration range (0.45 < δ < 1.5) with maximum and minimum of magnitude on the lower and higher border, respectively.

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