Download or read book Development and Characterization of Laser Induced Incandescence Towards Nanoparticle Soot Detection written by and published by . This book was released on 2000 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Validation of an Experimental Apparatus for the Characterization of Soot in a Laminar Co flow Diffusion Flame Using Laser induced Incandescence written by Babak Borshanpour and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Induced Incandescence and Laser Induced Breakdown Spectroscopy Based Sensor Development written by Kemal Efe Eseller and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this doctoral dissertation, two laser-based sensors were evaluated for different applications. Laser Induced Incandescence (LII) is a technique which can provide nonintrusive quantitative measurement of soot and it provides a unique diagnostic tool to characterize engine performance. Since LII is linearly proportional to the soot volume fraction, it can provide in situ, real time measurement of soot volume fraction with high temporal and spatial resolution. LII has the capability to characterize soot formation during combustion. The soot volume fraction from both flames and a soot generator was investigated with LII. The effects of experimental parameters, such as laser fluence, gate delay, gate width and various laser beam focusing, on LII signal was studied. Laser Induced Breakdown Spectroscopy (LIBS), a diagnostic tool for in situ elemental analysis, has been evaluated for on-line, simultaneous, multi-species impurity monitoring in hydrogen. LIBS spectra with different impurity levels of nitrogen, argon, and oxygen were recorded and the intensity of the spectral lines of Ar, O, N, and H observed were used to form calibration plots for impurities in hydrogen measurements. An ungated detection method for LIBS has been developed and applied to equivalence ratio measurements of CH4/air and biofuel/air. LIBS has also been used to quantitatively analyze the composition of a slurry sample. The quenching effect of water in slurry samples causes low LIBS signal quality with poor sensitivity. Univariate and multivariate calibration was performed on LIBS spectra of dried slurry samples for elemental analysis of Mg, Si and Fe. Calibration results show that the dried slurry samples give good correlation between spectral intensity and elemental concentration.

Download or read book Characterization of Soot Particles in Laminar Diffusion by Laser induced Incandescence written by Alexandre Dias Flügel and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lizz Roman Dancers Collection written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection contains clipping and publicity files.

Download or read book An Analytical and Quantitative Analysis of the Laser induced Incandescence of Soot written by Richard Trent Wainner and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantitative Detection and Imaging of Soot Particles by Laser induced Incandescence written by K. R. McManus and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soot Analysis in Combustion Environments by Laser induced Incandescence written by R. Wainner and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developments in Surface Contamination and Cleaning Volume 4 written by Rajiv Kohli and published by William Andrew. This book was released on 2011-09-26 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this series Rajiv Kohli and Kash Mittal have brought together the work of experts from different industry sectors and backgrounds to provide a state-of-the-art survey and best-practice guidance for scientists and engineers engaged in surface cleaning or handling the consequences of surface contamination. The expert contributions in this volume cover important fundamental aspects of surface contamination that are key to understanding the behavior of specific types of contaminants. This understanding is essential to develop preventative and mitigation methods for contamination control. The coverage complements the treatment of surface contamination in vol.1, Fundamental and Applied Aspects. This volume covers: Sources and Generation of Particles; Manipulation Techniques for Particles on Surfaces; Particle Deposition and Rebound; Particle Behavior in Liquid Systems; Biological and Metallic Contamination; and includes a comprehensive list of current standards and resources. Comprehensive coverage of innovations in surface contamination and cleaning Written by established experts in the contamination and cleaning field Each chapter is a comprehensive review of the state of the art Case studies included

Download or read book Laser induced Incandescence for Soot Diagnostics written by and published by . This book was released on 2012 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Microscopic and Spectroscopic Characterization for Soot Source Differentiation by Laser Derivatization written by Chethan Gaddam and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion produced soot is highly variable with nanostructure and chemistry dependent upon combustion conditions and fuel. Previous studies have shown soot nanostructure to be dependent upon the source via quantification of high-resolution transmission electron microscopy (HRTEM) images for nanostructural parameters. In principle this permits identification of the soot source and its contribution to any particular receptor site. Yet many structural aspects are subtle, and the chemistry of lamellae is unaddressed for reasons of poorly resolved or differentiated nanostructure and insufficient sample quantity for traditional analytical methods. This characterization gap then leads to the formative question prompting this study: how best to bring out small differences in nanostructure and other seemingly subtle differences in chemistry? A process of pulsed laser annealing is proposed to highlight compositional and structural differences thereby distinctively and uniquely identifying the source of the soot. The operative premise being that small variations in nanostructure and unresolved differences in chemistry exist and are specific to the particular combustion process. The overall goal is then to develop the laser-based heating as an analytical tool by identifying the process conditions and operational parameters for optimal derivatization. Specific objectives directed towards achieving this goal include: 1)Identifying optimal laser operational parameters for derivatization. 2)Defining the dependence upon nanostructure and molecular composition using model soots while also identifying variability and range of outcomes. 3)Demonstrating differentiation upon combustion derived soots from real engines, e.g. diesel, gasoline, gas-turbines, combustors, etc.4)Applying image processing algorithms to the laser heated soots to quantify and differentiate the transformed carbon nanostructures.For laser derivatization, a sample-housing chamber was custom built using a commercial optical grade quartz tube. Depending on the sample quantity, two different sample support systems were designed. Soot was laser-heated while in an inert (Ar) atmosphere using a pulsed Nd:YAG laser operating at 1064 nm. A laser beam dimension of ca 9 mm in diameter ensured that the entire sample area received uniform irradiation. To identify the optimal laser fluence, pulsed laser heating was applied at three different laser fluences to three carbon samples. Laser heating at these short timescales produced partially graphitized structures comprised of extended graphitic layers (>1 nm), and voids as material is rearranged. While laser heating the material with additional pulses did further graphitize the material, multiple pulses were not particularly beneficial for laser derivatization as this repetitive exposure decreased the degree of differentiation between the test samples. Based on visual HRTEM observations and quantified fringe analysis, a single pulse laser fluence of 250 mJ/cm2 (~2800 K, determined from multi-wavelength pyrommetry) produced the best derivatization without causing fragmentation or material ablation. For demonstrating the uniqueness of the laser-derivatized (nano)structure as dependent upon source and combustion conditions, the laser derivatization technique was validated by comparing different synthetic carbons, selected soots from transportation and residential combustion sources, and laboratory flames, each with recognizable nanostructure. After laser heating, the direction of nanostructure evolution of the synthetic carbons (possessing C:H > 10:1) appeared to be governed by their initial nanostructure as shown by HRTEM images. As illustration of chemistry's role, though nascent R250 carbon black showed structural similarity across multiple particles, laser heating led to either hollow shells or particles with internal structures. These differences were attributed to the chemistry of construction, i.e., the sp2/sp3 bonding as quantified by electron energy loss spectroscopy (EELS), showing significant differences between particles as large as 60%. The nanostructure of soots from different transportation sources (such as diesel, jet and gasoline engines) evolved distinctively upon laser annealing. Laser derivatization of soot collected from same platform (engine-type) revealed that fuel commonality leads to similar nanostructure for the same class of combustion source, whereas, fuel dependence and ensuing chemistry differences were prominently illustrated by comparison of laser-annealed soots originating from ultra-low sulfur diesel (ULSD) and an oxygenated fuel blend. The origin for this dependence was identified by X-ray photoelectron spectroscopy (XPS), revealing a significantly lower sp2/sp3 carbon bonding for the oxygenated fuels compared to their pure hydrocarbon fuels. As another example, laser annealing of residential boiler soot produced highly intertwined lamellae; this was attributed to inherent chemistry differences relative to the biodiesel (B100) soot that similarly lacked recognizable nanostructure. These observations suggest that the initial soot nanostructure in conjunction with the chemistry of construction governs the material transformation under pulsed laser annealing. Image processing algorithms were applied to quantify and differentiate the carbon nanostructural changes after laser annealing. A "recognition key" approach using a combination of present quantification algorithms: 1) fringe analysis, 2) stacking distribution, and 3) void dimension was reported for two laser-heated carbons, as examples. A second, method, using the radial intensity profile generated from the Fourier-Transformed bright field image was implemented to identify soot source upon laser derivatization against a reference set of values in a database. This semi-automated analytical method involves conversion of HRTEM images into the frequency domain, band-pass filtering, radial intensity profiling, and identification by least squares comparison with an empirically set limit for the sum of residuals. To illustrate the analytical methodology for source identification, a mixture of three soots was analyzed by laser derivatization. Laser heating led to visual differences; further quantification and comparison to the database identified the respective sources.

Download or read book Analysis of Laser induced Incandescence and Novel Soot Measurement Approaches written by B. Mewes and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser induced Incandescence for Soot Diagnostics written by Jonathan Johnsson and published by . This book was released on 2009 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics of Nanoparticles in Stagnation Flames written by Yiyang Zhang and published by Springer. This book was released on 2017-03-20 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies the collision, coalescence and deposition of nanoparticles in stagnation flames. With the help of synthesis experiments, in-situ laser diagnostics and molecular dynamics simulations, it investigates the growth of nanoparticles in flames and their deposition in boundary layers at a macroscopic flow field scale, as well as particle and molecular scale issues such as the interaction force between particles, how the collision rate is enhanced by attractive forces, and how the nano-scale coalescence process is influenced by the high surface curvature – all of which are crucial to understanding nanoparticle transport phenomena at high temperatures. The book also reports on a novel in-situ laser diagnostics phenomenon called phase-selective laser-induced breakdown spectroscopy and related applications for tracing gas-to-particle transitions and measuring local particle volume fractions in nano-aerosols.

Download or read book Investigation of Transient Gas Dynamics from Laser energized Nanoparticles written by Farzan Memarian and published by . This book was released on 2013 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot is formed whenever the combustion of hydrocarbon fuels is incomplete. Since soot particles are very small, they can be inhaled and cause severe health problems, such as pulmonary diseases. They can also cause environmental pollution, and have a significant effect on global warming and melting of polar ice sheets. The environmental and health impact of soot depends strongly on soot particle size and morphology, so there is a pressing need for measuring techniques that characterize aerosolized soot. Laser-Induced incandescence (LII) has proved to be a reliable technique for making spatial and temporal measurements of soot primary particle sizes and soot volume fractions. Nevertheless, there are some unresolved issues in LII, which may cause large errors in soot primary particle size inferred from LII data. One of these issues is anomalous cooling, which is the unexpectedly high initial rate of soot particle cooling observed in experiments, which can not be predicted by LII models. Among the speculations about the possible causes of this phenomenon is the transient gas dynamics effects which have been ignored in LII models. Another phenomena that has been speculated to affect LII predictions in high fluence LII, is how the gas dynamics of sublimed carbon clusters impact the local gas dynamics surrounding the particle during the cooling phase. The focus of this thesis is to investigate transient effects on heat conduction in low fluence LII, and the gas dynamics of sublimed species in high fluence LII using Direct Simulation Monte Carlo (DSMC) method. DSMC is a statistical/numerical method which works based on the physics of Boltzmann equation. In this method a large number of real molecules are represented by the so called simulated molecules and the state of these molecules is tracked during the simulation as they undergo collisions with each other and with the boundaries. The results show that transient effects contribute to anomalous cooling but are not the only cause of this phenomenon. The time scale over which transient effects are significant is also found to be very close to that of anomalous cooling which implies the real cause of anomalous cooling has some similarities to transient effects. Also regarding gas dynamics of sublimation, two effects in particular have been investigated using DSMC, namely, back flux of sublimed species and formation of shock waves. DSMC results confirm the back flux of sublimed species but no shock wave was observed for the boundary conditions considered in this study.

Download or read book Laser induced Incandescence written by and published by . This book was released on 2015 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The understanding of soot formation in combustion processes and the optimization of practical combustion systems require in situ measurement techniques that can provide important characteristics, such as particle concentrations and sizes, under a variety of conditions. Of equal importance are techniques suitable for characterizing soot particles produced from incomplete combustion and emitted into the environment. Also, the production of engineered nanoparticles, such as carbon blacks, may benefit from techniques that allow for online monitoring of these processes.

Download or read book Characterization of Laser heated Soot Particles Using Optical Pyrometry written by K. R. McManus and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: