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Showing 1 to 20 of 28 for “"Cavity Ring-Down"”.
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Pulsed cavity ring-down spectroscopy in combustion environments
Contains fulltext : 19193_pulscaris.pdf (Publisher’s version ) (Open Access)
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Continuous-wave cavity ring down spectroscopy sensor for Hall thruster erosion measurement
… its development in future applications requiring a long operational time (several thousands of hours). Sputter erosion of boron nitride (BN) acceleration channel wall is principal lifetime limitation for Hall thrusters. The sputtered particles can redeposit causing a critical contamination …
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Entwicklung eines breitbandigen Cavity-Ring-Down-Spektrometers unter Verwendung nahinfraroter, inkohärenter Strahlung
… ist ein spektral breitbandiges Cavity-Ring-Down-Spektrometer (CRD-Spektrometer). Ausgangspunkt der hier vorgestellten Arbeit ist ein Spektrometer auf Basis klassischer Absorptionsspektroskopie in einer Multireflexionszelle. Für dieses Spektrometer wurde als Strahlquelle ein …
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Indirect Detection of Explosive Vapours by Thermal Dissociation Cavity Ring-Down Spectroscopy
… technique exploited radicals generated during the thermal decomposition of triacetone triperoxide (TATP), a peroxide explosive, for detection. These radicals were amplified via a peroxide radical chemical amplification scheme (PERCA) that required the addition of NO and a radical chain …
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Cavity ring down and thermal lens techniques applied to vibrational spectroscopy of gases and liquids.
… and fast time response. In this dissertation cavity ring down (CRD) absorption of oxygen around the region 760 nm has been used to measure the temperature of flowing air in an open optical cavity. This sensor could be a convenient method for measuring the temperature at the input (cold air) …
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Characterisation of a Cavity Ring-Down Spectrometer for measuring CO2, CH4, delta13CO2, and delta13CH4 in ambient air
… and for identifying their sources and sinks. The Cavity Ring-Down Spectrometer (CRDS) G2201-i measures 12CO2, 13CO2, 12CH4, 13CH4, and H2O continuously and simultaneously in a gas sample. In this thesis, the CRDS G2201-i has been installed in Heidelberg for routine ambient air analysis and for …
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Cavity ring down: Construction, validation and experiments measuring the optical extinction of pure clays and their mixtures with salts and carboxylic acids under a range of atmospherically relevant conditions
… interact directly with solar radiation by scattering and absorbing incident light to affect the Earth's climate system. Models indicate that aerosols cool the Earth counterbalancing greenhouse gases, but contribute the largest uncertainty to anthropogenic effects on climate. To address these …
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Entwicklung und Optimierung absorptionsspektroskopischer Techniken zur Untersuchung von Verbrennungsprozessen
… Parameter ermöglichen. Neben der hochsensitiven Cavity Ring-down Spektroskopie wird auch die direkte Absorptionspektroskopie eingesetzt. Die Erschließung des mittleren infraroten Spektralbereichs für die Flammendiagnostik bietet hierbei Zugang zu Molekülen, welche bisher nicht nachgewiesen werden …
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Spectroscopic investigations of the X and A state dynamics of ¹³C₂H₂
… Fluorescence (LIF), Dispersed Fluorescence (DF), Cavity Ring-Down Spectroscopy (CRDS), Noise Immune Cavity Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS) and Stimulated Emission Pumping (SEP) are employed to study the spectroscopy and dynamics of acetylene. All of these experiments …
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Instrument development for exploring the influence of interfacial chemistry on aerosol growth, aging, and partitioning of gases
… a novel rotating aerosol suspension chamber with cavity ring-down spectroscopy provided key insight into the effect of pollutants and other vapors on the overall atmospheric lifetime of particulate matter. The Atmospheric Cloud Simulation Instrument (ACSI) creates a well-defined and controllable …
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Tunable and broadband loop gap resonator for nitrogen vacancy centers in diamond
… . The LGR design, based on the anode block of a cavity magnetron, demonstrates an average field amplitude of 5 gauss at 42 dBm of input power, and achieves a peak-to-peak field uniformity of 89.5% over an area of 32 mm2 and 97% over an area of 11 mm2 . The broad bandwidth of the LGR is capable of …
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Development, Validation, and Application of Methods for High Time-Response Measurement of Gaseous Atmospheric Chlorinated Species
… the troposphere. We configured a commercial HCl cavity ring-down spectrometer (CRDS) for sampling HCl in the ambient atmosphere and developed validation techniques to characterize the measurement uncertainties. The HCl analyzer was used to make continuous HCl measurements in the polluted marine …
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Methane Dynamics in St. Louis Bay, Mississippi
… methane analysis was developed utilizing cavity ring-down spectroscopy and headspace equilibration. Samples of 70 mL were collected in 140 mL plastic syringes and equilibrated with a methane free headspace. Reproducibility was high (i.e. 4% typical RSD), and samples were successfully …
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Geographic Classification of Wines Using Their Elemental and Water Isotopic Composition; Special Emphasis on Washington State, USA
… Coupled Plasma Mass Spectrometry (ICP-QQQ) and Cavity Ring-Down Spectroscopy, respectively. Linear discriminant analysis resulted in successful regional and continental classification, with 97.5% and 99.2% correct assignments, respectively. WA and California wines were significantly different …
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Aircraft-based measurements for the identification and quantification of sources and sinks in the carbon cycle
… aircraft platform equipped with a high-precision cavity ring-down spectrometer for CO<sub>2</sub>, CH<sub>4</sub> and H<sub>2</sub>O quantification was used to acquire data from previously un-sampled sources. The aircraft mass-balance technique was used to quantify CH4 emissions from natural gas …
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Laserspektroskopische Bestimmung absoluter Konzentrationen von CN- und NH 2 -Radikalen in NO-dotierten Niederdruck-Wasserstoffflammen während der Verbrennung von Graphit
… Die CN-Konzentrationen wurden mit Hilfe der cavity ring-down spectroscopy (CRDS) und die NH2-Konzentrationen mittels der intracavity laser absorption spectroscopy (ICLAS) gemessen. Die Temperaturen wurden über laserinduzierte Fluoreszenz (LIF)Anregungsspektren von OH-Radikalen ermittelt. Die …
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Elucidating the chemistry of particulate and chlorinated nitrates in the troposphere through method development, and chamber and field studies
… chemical ionization mass spectrometry (CIMS) during the ORCA campaign in July 2015 on the west coast of Vancouver Island. Mean ClNO2 mixing ratios were small (< 10 pptv) with a maximum of 46 pptv, in part due to low precursor concentrations, i.e., of nitrogen dioxide (NO2) and ozone, and large …
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Laser-induced plasmas in air for pulsed broadband cavity-enhanced absorption spectroscopy
… inside a high-finesse near-concentric optical cavity. The broadband optical plasma emission was successfully sustained within the cavity and the light leaking from the cavity was used to measure broadband absorption spectra of gaseous azulene through (i) time-dependent cavity ring-down (CRDS), …
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Supercontinuum radiation for ultra-high sensitivity liquid-phase sensing
… for the first time. Firstly, supercontinuum cavity enhanced absorption spectroscopy (SC-CEAS) was used for the kinetic measurement of chemical species in the liquid phase using a linear optical cavity. This technique is simple to implement, robust and achieves a sensitivity of 9.1 × 10−7 cm−1 …
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Dynamics of Atmospherically Important Triatomics in Collisions with Model Organic Surfaces
… Energy exchange and thermal accommodation during the gas-surface collision, the first step of most interfacial reactions, was probed by time-of-flight techniques. The final energy distribution of the scattered molecules was measured under specular scattering conditions (θi = θf = 30°). …
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