317 research outputs found
Continuous-wave cavity ringdown spectroscopy of the 8 nu polyad of water in the 25 195-25 340 cm(-1) range
State-of-the-art experiments and calculations are used to record and assign the data obtained in the weakly absorbing blue energy region of the H2O spectrum. Continuous-wave cavity ringdown absorption spectroscopy with Doppler resolution is used to probe the range from 25 195 to 25 470 cm(-1) with an absorption sensitivity of similar to 1 parts per 10(9) (ppb)/cm. 62 lines of the polyad nu(OH)=8 are reported, of which 43 are assigned using variational nuclear calculations. The study includes absorption line intensities (in the range of 10(-28)-10(-26) cm/molecule) for all lines and self-broadening pressure coefficient for a few lines. The newly obtained energy levels are also reported. (c) 2005 American Institute of Physics
Cavity Enhanced Optical Vernier Spectroscopy, Broad Band, High Resolution, High Sensitivity
A femtosecond frequency comb provides a vast number of equidistantly spaced
narrow band laser modes that can be simultaneously tuned and frequency
calibrated with 15 digits accuracy. Our Vernier spectrometer utilizes all of
theses modes in a massively parallel manner to rapidly record both absorption
and dispersion spectra with a sensitivity that is provided by a high finesse
broad band optical resonator and a resolution that is only limited by the
frequency comb line width while keeping the required setup simple.Comment: 11 pages, 3 figures, submitted to PR
Modeling and Simulating a Novel Biohydrogen Production Technology as an Integrated Part of a Municipal Wastewater Treatment Plant
A series of mathematical models and simulations was developed and performed using BioWin software suit in order to determine the suitability of implementing a biohydrogen production technology in an existing wastewater treatment plant. The evaluation of the performance of these approach was based on biohydrogen yield and effluent quality. The simulations show high biohydrogen production rates, with picks during the summer months, while most of the effluent environmental parameters remain at the same or even lower levels compared with the currently used technology
XUV Frequency Combs via Femtosecond Enhancement Cavities
We review the current state of tabletop extreme ultraviolet (XUV) sources
based on high harmonic generation (HHG) in femtosecond enhancement cavities
(fsEC). Recent developments have enabled generation of high photon flux (1014
photons/sec) in the XUV, at high repetition rates (>50 MHz) and spanning the
spectral region from 40 nm - 120 nm. This level of performance has enabled
precision spectroscopy with XUV frequency combs and promises further
applications in XUV spectroscopic and photoemission studies. We discuss the
theory of operation and experimental details of the fsEC and XUV generation
based on HHG, including current technical challenges to increasing the photon
flux and maximum photon energy produced by this type of system. Current and
future applications for these sources are also discussed.Comment: invited review article, 38 page
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Implementing an integrated standards-based management system to ensure compliance at Los Alamos National Laboratory
Los Alamos National Laboratory (LANL or the Laboratory) is developing and implementing a comprehensive, Integrated Standards-Based Management System (ISBMS) to enhance environmental, safety, and health (ESH) compliance efforts and streamline management of ESH throughout the Laboratory. The Laboratory recognizes that to be competitive in today`s business environment and attractive to potential Partnerships, Laboratory operations must be efficient and cost-effective. The Laboratory also realizes potential growth opportunities for developing ESH as a strength in providing new or improved services to its customers. Overall, the Laboratory desires to establish and build upon an ESH management system which ensures continuous improvement in protecting public health and safety and the environment and which fosters a working relationship with stakeholders. A team of process experts from the LANL Environmental Management (EM) Program Office, worked with management system consultants, and the Department of Energy (DOE) to develop an ESH management systems process to compare current LANL ESH management Systems and programs against leading industry standards. The process enabled the Laboratory to gauge its performance in each of the following areas: Planning and Policy Setting; Systems and Procedures; Implementation and Education; and Monitoring and Reporting. The information gathered on ESH management systems enabled LANL to pinpoint and prioritize opportunities for improvement in the provision of ESH services throughout the Laboratory and ultimately overall ESH compliance
Neuroconductor: an R platform for medical imaging analysis
Neuroconductor (https://neuroconductor.org) is an open-source platform for rapid testing and dissemination of reproducible computational imaging software. The goals of the project are to: (i) provide a centralized repository of R software dedicated to image analysis, (ii) disseminate software updates quickly, (iii) train a large, diverse community of scientists using detailed tutorials and short courses, (iv) increase software quality via automatic and manual quality controls, and (v) promote reproducibility of image data analysis. Based on the programming language R (https://www.r-project.org/), Neuroconductor starts with 51 inter-operable packages that cover multiple areas of imaging including visualization, data processing and storage, and statistical inference. Neuroconductor accepts new R package submissions, which are subject to a formal review and continuous automated testing. We provide a description of the purpose of Neuroconductor and the user and developer experience
Structure functions for the three nucleon system
The spectral functions and light-cone momentum distributions of protons and
neutrons in 3He and 3H are given in terms of the three-nucleon wave function
for realistic nucleon-nucleon interactions. To reduce computational complexity,
separable expansions are employed for the nucleon-nucleon potentials. The
results for the light-cone momentum distributions suggest that they are not
very sensitive to the details of the two-body interaction, as long as it has
reasonable short-range repulsion. The unpolarised and polarised structure
functions are examined for both 3He and 3H in order to test the usefulness of
3He as a neutron target. It is found that the measurement of the spin structure
function of polarised 3H would provide a very clear test of the predicted
change in the polarised parton distributions of a bound proton.Comment: 30 pages, REVTeX, 11 figure
Coendangered hard-ticks: threatened or threatening?
The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans). Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals
Threshold for basophil activation test positivity in neuromuscular blocking agents hypersensitivity reactions
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