Article
Engineering, Electrical & Electronic
Bo Li, Dayuan Zhang, Christian Brackmann, Lei Han, Zhanyu Feng, Qiang Gao, Zhongshan Li
Summary: Nonintrusive temperature measurement is crucial in combustion research. In this study, a thermometric technique based on femtosecond two-photon laser-induced fluorescence of carbon monoxide (CO-fs-TPLIF) was proposed. The technique allows for simultaneous excitation and detection of dual vibrational bands of CO, enabling assessment of temperature-dependent Boltzmann distribution and extraction of temperature from fluorescence spectra. Two temperature calibration methods were developed.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Thermodynamics
Ayush Jain, Yejun Wang, Waruna D. Kulatilaka
Summary: Atomic hydrogen (H) and hydroxyl radical (OH) are key intermediate species in hydrocarbon fuel combustion, with their spatial and temporal distribution providing important insights into ignition/extinction processes and flame structure. Simultaneous measurements using femtosecond-duration laser pulses have shown improved efficiency and reduced absorption losses, offering potential for future advancements in imaging techniques.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Pradeep Parajuli, Yejun Wang, Matthew Hay, Viswanatham R. Katta, Waruna D. Kulatilaka
Summary: This study demonstrates the imaging of H in high-pressure flames using a home-built, high-energy fs laser system. The TPLIF signal of H was found to have a quadratic dependence on laser energy. However, issues such as laser absorption and fluorescence signal trapping remain significant at high pressures.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Instruments & Instrumentation
R. S. Dorst, C. G. Constantin, D. B. Schaeffer, J. J. Pilgram, C. Niemann
Summary: Measurements of ion velocity distribution in an explosive laser produced plasma were conducted using laser induced fluorescence (LIF). The effects of fluorescence power and laser irradiance on the saturation vs non-saturation regime were evaluated. The small size of the LIF beam allowed for high spatial resolution in the measurement.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Chemistry, Applied
Artyom A. Astafiev, Aleksander M. Shakhov, Andreii S. Kritchenkov, Victor N. Khrustalev, Denis Shepel, Victor A. Nadtochenko, Alexander G. Tskhovrebov
Summary: Carbon dots (CDs) are a promising class of nanomaterials being synthesized using various methods, including hydrothermal synthesis and breakdown of larger carbon materials by different techniques. This study introduces a novel bottom-up approach to obtain nitrogen-rich carbonaceous nanoparticles via femtosecond laser irradiation of acetonitrile as a source of doping N atoms. It discusses the photophysical properties of the new material and the mechanism of photoluminescence (PL).
Article
Thermodynamics
Stephen W. Grib, Christopher A. Fugger, Paul S. Hsu, Naibo Jiang, Sukesh Roy, S. Alexander Schumaker
Summary: This work demonstrates single-shot, two-dimensional temperature measurements in a premixed linear detonation channel using two-color OH planar laser-induced fluorescence thermometry. The technique was found suitable for detonation environments based on spectral characteristics, and the precision and accuracy of the method were evaluated under different conditions. The ability to distinguish and quantify detonation burning behavior shows promise for future applications in pressure-gain combustion facilities.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Garrett J. Marshall, Patrick S. Walsh, Carl A. Hall, Sukesh Roy, Robert W. Pitz
Summary: A new method, fs-TALIF, was used to capture spatially resolved atomic oxygen profiles in flames, allowing comparisons of number density and O-atom concentration distributions. As stretch rate increases, the radii of peak O-atom in the cells decrease while O-atom concentrations remain relatively unaffected, unlike non-cellular flame data.
COMBUSTION AND FLAME
(2021)
Article
Nanoscience & Nanotechnology
Aleksei V. Emelianov, Nikita P. Nekrasov, Maksim V. Moskotin, Georgy E. Fedorov, Nerea Otero, Pablo M. Romero, Vladimir K. Nevolin, Boris I. Afinogenov, Albert G. Nasibulin, Ivan I. Bobrinetskiy
Summary: The fabrication of planar junctions in carbon nanomaterials using femtosecond laser processing technique leads to a significant enhancement in the photoresponse of optoelectronic devices based on single-walled carbon nanotubes. The induced metal/semiconductor planar junction shows a high broadband photoresponsivity, making it suitable for detecting extremely small light intensities with high spatial resolution.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Multidisciplinary Sciences
Chen Xin, Zhongguo Ren, Leran Zhang, Liang Yang, Dawei Wang, Yanlei Hu, Jiawen Li, Jiaru Chu, Li Zhang, Dong Wu
Summary: The authors developed micrometer scale soft robots with multiple microjoints that can achieve different deformation modes, utilizing a two-in-one femtosecond laser strategy to create microactuators composed of hydrogel and metal nanoparticles. These microactuators have short response times and require low actuation power. The ability to integrate multiple microjoints into soft robots at the micrometer scale represents a significant challenge.
NATURE COMMUNICATIONS
(2023)
Article
Thermodynamics
Jinhoon Choe, Wenting Sun
Summary: This study examines the impact of nano-second pulsed non-equilibrium plasma on ammonia combustion in a gas turbine combustor. The results show that plasma can enhance flame stabilization and extend the attached flame regime at lower equivalence ratios. The coupling effects between plasma kinetics and flame dynamics are investigated through NH2 * chemiluminescence and OH PLIF measurements. The findings suggest that NH2 * production in plasma-assisted ammonia oxidation is possibly linked to the production of OH or oxygen-related species.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Guoqing Wang, Shixing Wang, Thibault F. Guiberti
Summary: A novel PLIF technique using a single dye laser is proposed for simultaneous, single-shot imaging of NH3, NH, and NO in NH3-H2 flames. Three wavelength couples are used to image the three species simultaneously. The technique is then used to visualize the structure of premixed and non-premixed flames in a fuel blend of NH3 and H2.
COMBUSTION AND FLAME
(2023)
Article
Biochemical Research Methods
Zhenzhou Cheng, Nan Zhang, Le Chang, Pengfei Qi, Lin Zhang, Lie Lin, Yan Wang, Weiwei Liu
Summary: Myopia and keratoconus are common corneal diseases that affect human vision. Collagen crosslinking (CXL) using riboflavin and ultraviolet A (UVA) light is an effective treatment, but it has risks. This study introduces a new method using near-infrared femtosecond laser to perform two-photon CXL, which enhances corneal stiffness without affecting transparency.
JOURNAL OF BIOPHOTONICS
(2023)
Article
Optics
Maria Ruchkina, Meena Raveesh, Armand Dominguez, Joakim Bood, Christian Brackmann
Summary: A method based on femtosecond two-photon excitation has been developed for simultaneous visualization of interference-free fluorescence of H and O atoms in turbulent flames. This work shows pioneering results on single-shot simultaneous imaging of these radicals under non-stationary flame conditions. The fluorescence signal, showing the distribution of H and O radicals in premixed CH4/O2 flames was investigated for equivalence ratios ranging from 0 = 0.8 to 0 = 1.3. The images have been quantified through calibration measurements and indicate single-shot detection limits on the order of a few percent. Experimental profiles have also been compared with profiles from flame simulations, showing similar trends.
Article
Optics
Maria Ruchkina, Meena Raveesh, Armand Dominguez, Joakim Bood, Christian Rackmann
Summary: A method based on femtosecond two-photon excitation has been developed for simultaneous visualization of interference-free fluorescence of H and O atoms in turbulent flames. This work shows pioneering results on single-shot simultaneous imaging of these radicals under non-stationary flame conditions. The fluorescence signal, showing the distribution of H and O radicals in premixed CH4/O2 flames was investigated for equivalence ratios ranging from 0 = 0.8 to 0 = 1.3. The images have been quantified through calibration measurements and indicate single-shot detection limits on the order of a few percent. Experimental profiles have also been compared with profiles from flame simulations, showing similar trends.
Article
Chemistry, Analytical
Xi Yu, Fumihiro Itoigawa, Shingo Ono
Summary: The induction of surface cleavage on a zinc oxide substrate by femtosecond laser pulses with a specific wavelength has been discussed, showing distinct marks of broken hexagons. The phenomenon is different from the general laser-induced melt process observed on other materials. Additionally, it was found that under multi-pulse irradiation, the dominant process shifts to laser-induced melt instead of cleavage.
Article
Thermodynamics
Daniel R. Richardson, Naibo Jiang, David L. Blunck, James R. Gord, Sukesh Roy
COMBUSTION AND FLAME
(2016)
Article
Optics
Daniel R. Richardson, Naibo Jiang, Hans U. Stauffer, Sean P. Kearney, Sukesh Roy, James R. Gord
Article
Optics
Daniel R. Guildenbecher, Kathryn N. Gabet Hoffmeister, W. Marley Kunzler, Daniel R. Richardson, Sean P. Kearney
Article
Engineering, Mechanical
David L. Blunck, Dale T. Shouse, Craig Neuroth, Amy Lynch, Timothy J. Erdmann, David L. Burrus, Joseph Zelina, Daniel Richardson, Andrew Caswell
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2014)
Article
Optics
Yi Chen, Emre Cenker, Daniel R. Richardson, Sean P. Kearney, Benjamin R. Halls, Scott A. Skeen, Christopher R. Shaddix, Daniel R. Guildenbecher
Article
Engineering, Aerospace
Daniel Reese, Paul Danehy, Naibo Jiang, Josef Felver, Daniel Richardson, James Gord
Article
Optics
Daniel R. Richardson, Sean P. Kearney, Daniel R. Guildenbecher
Article
Optics
Yibin Zhang, Garrett Marshall, Steven J. Beresh, Daniel Richardson, Katya M. Casper
Article
Thermodynamics
Daniel R. Richardson, Sean P. Kearney, Daniel R. Guildenbecher
Summary: Accurate measurement of post-detonation fireball temperatures is crucial for understanding device performance. In this study, a hybrid fs-ps CARS instrument was used to measure temperatures in the fireball of a commercial detonator. Challenges such as light scattering from particulate matter and solid fragments were addressed using a new polarization scheme.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Physics, Applied
Daniel R. R. Richardson
Summary: Coded aperture technology allows for obtaining more spatially and spectrally resolved emission data using a single emission spectrometer and camera, at the expense of some spatial resolution. This technique is particularly useful for studying transient, non-repeating events.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Yibin Zhang, Daniel Richardson, Garrett Marshall, Steven J. Beresh, Katya M. Casper
Summary: The article introduces a dotted-line FLEET technique that combines the dense profile capability of a line with the ability to perform two-component velocimetry with a single camera on a dot. This technique was used downstream of a highly turbulent, supersonic nitrogen free jet, enabling the simultaneous computation and presentation of stream-wise and radial velocities.
Article
Chemistry, Physical
Jonathan E. Retter, Matthew Koll, Daniel R. Richardson, Sean P. Kearney
Summary: In this study, we measured the S-branch linewidths of pure rotational nitrogen and oxygen at temperatures of 80-200 K using an isentropic free-jet expansion method, and obtained the data by monitoring the decay of pure rotational Raman coherences. By fitting and correcting for local pressure, we obtained the linewidth data for rotational transitions of nitrogen and oxygen, and found that nitrogen transitions have larger linewidths at all temperatures. Moreover, the measured linewidth data deviate significantly from the predicted model.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Optics
Jonathan E. Retter, Matthew Koll, Chloe E. Dedic, Paul M. Danehy, Daniel R. Richardson, Sean P. Kearney
Summary: We present a hybrid time-frequency spectroscopic method for simultaneous temperature/pressure measurements in nonreacting compressible flows with known gas composition. The method utilizes a dual-probe femtosecond-picosecond coherent anti-Stokes Raman scattering (CARS) technique to acquire spectra for temperature and pressure calculations. The system is demonstrated through measurements along a 5-mm line in an underexpanded jet. The results show precise thermometry approaching 1%-2% and pressure measurements optimized at probe time delays where the ratio of late probe delay to Raman lifetime exceeds four.
Article
Thermodynamics
Brent A. Rankin, Daniel R. Richardson, Andrew W. Caswell, Andrew G. Naples, John L. Hoke, Frederick R. Schauer
COMBUSTION AND FLAME
(2017)
