Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 24 for “"Tunable Diode Laser"”.
-
Advances in tunable diode laser spectroscopy for aero engine research
Tunable diode laser spectroscopy (TDLS) is a widely used technique for the measurement of gas species and offers in-situ operation, accuracy and faster response time compared to other optical and non-optical gas sensing techniques.The work in this thesis focusses on the measurement of CO2 in the …
-
Near-infrared tunable diode laser absorption spectrometer for trace gas detection
A ground based near-infrared tunable diode laser absorption spectrometer (TDLAS), capable of measuring methane (CH₄) and nitrous oxide (N₂0) in their natural abundance's within the atmosphere, has been designed and constructed. The spectrometer has high resolution (0.0003 cm⁻¹), high precision …
-
Near infrared tunable diode laser spectroscopy for aero engine related applications
Tunable diode laser spectroscopy is a widely used technique for recovering quantitative gas information in a range of industrial applications. Established methods often use readily available, robust and low cost optoelectronic hardware in the near-infrared, with output wavelengths that coincide …
-
Development and testing of real-time tunable diode laser based water vapor measurement system
The water vapor sensor based on tunable laser diode absorption spectroscopy, capable of measuring concentration of water vapor in real time at multiple locations in fire environment under extreme obscuration was designed. A three-tier detection sensitivity scheme was implemented using various …
-
Determination of Flame Dynamics for Unsteady Combustion Systems using Tunable Diode Laser Absorption Spectroscopy
… the response in chemical reaction rate. Tunable Diode Laser Absorption Spectroscopy (TDLAS), centered over two water absorption features, allows a dynamic measurement of the product gas temperature. The response in product gas temperature directly relates to the enthalpy fluctuations that …
-
Determining Emission Factors from Marine Vessels Employing Differential Optical Absorption Spectroscopy (DOAS) and Tunable Diode Laser Absorption Spectroscopy (TDLAS)
High SO2 concentrations are harmful to human health and impact climate by affecting cloud formation. Ship contrails are the major source of SO2 in the open-ocean and impact coastal region air quality. The International Maritime Organization (IMO) regulates SO2 emissions by requiring ships to use …
-
Diode laser gas sensing for high-speed temperature and speciation measurements inside explosive fireballs
… enables the fielding of a wide variety of proven tunable diode laser absorption techniques in explosive applications. In addition, details of the theory, application, and data analytics for the relevant spectroscopic measurements are also addressed. The developed hardware and technique were used …
-
Effects of Water Vapor on the Kinetics of the Methylperoxy Radical Self-reaction and Reaction with Hydroperoxy
… at temperatures between 263 and 303 K using laser flash photolysis coupled with UV time-resolved absorption detection at 220 nm and 260 nm. Water vapor concentration was quantified using tunable diode laser spectroscopy operating in the mid-IR. The HO2 self-reaction rate constant is …
-
Entwicklung eines miniaturisierten ballongetragenen Diodenlaser-Spektrometers zur Messung von stratosphärischen Methan- und Wasserdampfkonzentrationen
… dieser Arbeit wurde ein NIR-TDL (Near Infra-Red Tunable Diode Laser) Spektrometer entwickelt, das eine simultane Messung von CH4 und H2O mit hoher Zeitauflösung (1 - 10 s) erlaubt. Das Gerät ist speziell für Mitflüge auf vorhandenen Ballon-Nutzlasten konzipiert und wurde auf geringe Masse (ca. 25 …
-
Laser absorption spectroscopy for investigation of hypersonic propulsion
… the inflow gas in the ACT-II facility, using tunable diode laser absorption spectroscopy (TDLAS) to measure temperature and nitric oxide (NO) concentration. Another fundamental challenge associated with scramjet operation is achieving efficient fuel-air mixing and ignition within the short …
-
Indium phosphide based integrated photonic devices for telecommunications and sensing applications
… fiber-optic telecommunications and an integrated tunable laser for trace-gas sensing are investigated in this thesis. These devices are fabricated in the indium phosphide (InP) material system, which includes InP and the ternary/quaternary III-V semiconductors that can be grown closely …
-
An Optical Analysis of the Blowoff Behavior for Bluff Body-Stabilized Flames in Vitiated Flow
… application to the turbulent combustion rig, a tunable diode laser absorption spectroscopy (TDLAS) system was developed. A TDL with a center wavelength in the near infrared region was simultaneously scanned across absorption lines of H<sub>2</sub>O and CO<sub>2</sub> to obtain temperature and …
-
Hydrogen purity assessment using laser absorption Spectroscopy
… spectrometer (𝐻2-Spectrometer) based on direct Tunable Diode Laser Absorption Spectroscopy (d-TDLAS). The goal is to establish a traceable and accurate methodology for hydrogen purity and concentration measurement without relying on calibration gases. The main objective of this research is to …
-
Design of an Optical Fiber-Coupled Sensor for Ambient Methane Measurement
A tunable diode laser system was developed for remote monitoring of ambient methane using fiber optically connected all-optical sensor heads. Experiments were performed to quantitatively evaluate the influence of selected system hardware and software configurations, with the further goal of …
-
Developing in situ instrumentation to monitor anthropogenic change
… the development process of CSPEC, a deep-sea laser spectrometer designed to measure the ocean carbon system through alternating measurements of the partial pressure of carbon dioxide (pCO2) and dissolved inorganic carbon (DIC). CSPEC uses tunable diode laser absorption spectroscopy (TDLAS) to …
-
Developing In Situ Instrumentation to Monitor Anthropogenic Change
… the development process of CSPEC, a deep-sea laser spectrometer designed to measure the ocean carbon system through alternating measurements of the partial pressure of carbon dioxide (pCO₂) and dissolved inorganic carbon (DIC) . CSPEC uses tunable diode laser absorption spectroscopy (TDLAS) to …
-
Laser Remote Sensing for Environmental Monitoring
This thesis studies the techniques of laser remote sensing and their applications in environmental monitoring, as documented in several published papers. The environment where the human being live is degrading with an accelerating speed. Quantitative monitoring characterizes the quality of the …
Page 1 of 2