A5017828071- Spectroscopy and Laser Applications
- Geology and Paleoclimatology Research
- Advanced Fiber Laser Technologies
- Geological formations and processes
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Methane Hydrates and Related Phenomena
- Mechanical and Optical Resonators
- Photonic and Optical Devices
- earthquake and tectonic studies
- Atomic and Subatomic Physics Research
- Landslides and related hazards
- Analytical Chemistry and Sensors
- Coral and Marine Ecosystems Studies
- Quantum optics and atomic interactions
- Marine and fisheries research
- Advanced Fiber Optic Sensors
- Laser Design and Applications
- Advanced MEMS and NEMS Technologies
- Gas Sensing Nanomaterials and Sensors
- Laser-Matter Interactions and Applications
- Advanced Frequency and Time Standards
- Cryospheric studies and observations
- CO2 Sequestration and Geologic Interactions
- Spectroscopy Techniques in Biomedical and Chemical Research
National Institute of Standards and Technology
2016-2025
National Institute of Standards
2014-2024
Material Measurement Laboratory
2012-2023
British Geological Survey
2012-2021
Umeå University
2021
California Institute of Technology
2007-2017
Stanford University
2006-2017
University of Colorado Boulder
2017
Physical Sciences (United States)
2017
Cameron University
2017
The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and used by various computer codes to predict simulate transmission emission light gaseous media (with an emphasis on terrestrial planetary atmospheres). composed five major components: line-by-line parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it not yet feasible representation form),...
1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD), N-methyl-TBD (MTBD), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) are effective organocatalysts for the ring-opening polymerization (ROP) of cyclic esters such as lactide (LA), δ-valerolactone (VL), ε-caprolactone (CL). TBD is shown to polymerize LA, VL, CL in a fast controlled manner, whereas MTBD DBU polymerized LA addition thiourea cocatalyst led ROP VL being achieved. Each catalysts produced polymers displaying high end group fidelity, good...
1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) is an effective organocatalyst for acyl transfer as well the ring-opening polymerization of cyclic esters. Its high activity attributed to its ability simultaneously activate both esters and alcohols, demonstrated in a model reaction. This unique mechanism makes TBD remarkably simple example bifunctional catalyst. The simplicity reaction conditions, ready commercial availability catalyst, provide accessible methodology allow future studies...
The structural flexibility and efficacy of thiourea−amine catalysts for the supramolecular activation ring-opening polymerization (ROP) lactide are described. nature hydrogen bonding group its strength as well steric congestion have been altered, leading to shorter times, better control, pathways influence stereochemistry resulting polymer. tolerance functionality mild conditions ROP mechanism allow block copolymer synthesis by combination nitroxide-mediated reversible addition fragmentation...
Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes RNFL relate to loss. also examined patterns thinning over time MS eyes without a prior history acute optic neuritis (ON).Patients underwent OCT measurement at baseline 6-month intervals during mean follow-up 18 months 3 centers. Low-contrast letter acuity (2.5%,...
Research Article| January 01, 2004 Linking continental-slope failures and climate change: Testing the clathrate gun hypothesis Mark Maslin; Maslin 1Environmental Change Centre, Department of Geography, University College London, 26, Bedford Way, London WC1H 0AP, UK Search for other works by this author on: GSW Google Scholar Matthew Owen; Owen Simon Day; Day David Long 2British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, Geology (2004) 32 (1): 53–56....
Based on new data from the Fladen, Sleipner and Troll areas, combined with earlier published results, a glaciation curve for Late Weichselian in northern North Sea is constructed. The youngest date marine sedimentation prior to late maximum ice extent 29.4 ka BP. At this time probably large parts of southern Norway were deglaciated (corresponding Alesund interstadial western Norway). In period between c. 22 BP, experienced its coalescing British Scandinavian sheet. first recorded inundation...
Reconnaissance seismic and sampling surveys have shown that up to 500 m of Lower early Middle Pleistocene deltaic sediments are preserved in the UK sector North Sea. The distributions delta-related facies record progressive expansion peripheral delta systems northwards across southern Sea during Pleistocene. A late unconformity is present throughout sector, sedimentation above was dominated by glacial erosional depositional processes. complex system deeply incised valleys eroded each three...
Dual-drive Mach-Zehnder modulators were utilized to produce power-leveled optical frequency combs (OFCs) from a continuous-wave laser. The resulting OFCs contained up 50 unique components and spanned more than 200 GHz. Simple changes the modulation allowed for agile control of comb spacing. These then broadband, multiheterodyne measurements CO2 using both multipass cell an cavity. This technique allows robust trace gas species alleviates much cost complexity associated with use femtosecond...
The accuracy of atmospheric trace gas retrievals depends directly on the molecular absorption model used within retrieval algorithm. For remote sensing well-mixed gases, such as carbon dioxide (CO2), where variability is small compared to background, quality key. Recent updates oxygen (O2) coefficients (ABSCO) for 0.76 µm A-band and water vapor (H2O) continuum 1.6 2.06 CO2 bands Orbiting Carbon Observatory (OCO-2 OCO-3) algorithm are described here. Updates in O2 involve inclusion new...
Acceleration measurement is widely used in commercial, scientific, and defense applications, but the resolution accuracy achievable for demanding applications limited by current technology to build calibrate accelerometers. We report an optomechanical accelerometer based on a Fabry–Perot microcavity silicon chip that extremely precise, field deployable, can self-calibrate. The measured acceleration highest reported date microfabricated achieved over wide frequency range ( <mml:math...
Abstract A thin, regionally extensive, laterally persistent sand layer identified within the Holocene coastal sequences of eastern Scotland, dated to 7000 years BP, is suggested be a tsunami deposit. The likely source wave earthquake induced second Storegga Slide on Norwegian continental slope at least 750 km northeast
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 397:139-151 (2009) - DOI: https://doi.org/10.3354/meps08112 Mingulay reef complex: an interdisciplinary study of cold-water coral habitat, hydrography and biodiversity J. M. Roberts1,2,9,*, A. Davies1,10, L. Henry1, Dodds1, G. C. Duineveld3, S. Lavaleye3, Maier3,4, R. W. van Soest5, N. Bergman3, V....
Carbon capture and storage (CCS) is a key technology to potentially mitigate global warming by reducing carbon dioxide (CO2) emissions from industrial facilities power generation that escape into the atmosphere. To broaden usage of geological as viable climate mitigation option, it vital understand CO2 behaviour after its injection within reservoir, including potential migration through overlying sediments, well biogeochemical ecological impacts in event leakage. The release were...
High-precision measurements of radiocarbon (14C) near or below a fraction modern 14C 1 (F14C ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting would provide simple robust benchtop alternative off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement in gas-phase samples CO2 with F14C < using cavity ring-down spectroscopy regime. Repeated analysis derived from combustion either biogenic petrogenic sources...
An optical frequency comb generated with an electro-optic phase modulator and a chirped radio-frequency waveform is used to perform pump-probe spectroscopy on the ${D}_{1}$ ${D}_{2}$ transitions of atomic potassium at 770.1 766.7 nm, respectively. With tooth spacing 200 kHz bandwidth 2 GHz hyperfine can be observed simultaneously. Interferograms are recorded in as little 5 \textmu{}s (a timescale corresponding inverse spacing). Importantly, sub-Doppler features measured long laser carrier...