#refereed publications @article{ pubs_lasue:2011, title = "Remote laser induced breakdown spectroscopy ({LIBS}) for lunar exploration", journal = "J. Geophys. Res.", volume = "in press", author = "Jeremie Albert Francois Lasue and Roger C. Wiens and Samuel M. Clegg and Dave T. Vaniman and Katherine Joy and \textbf{\sffamily Seth Humphries} and Alissa Mezzacappa and Nouredine Melikechi and Rhonda McInroy and Stephen Bender", year = "2011", month = "Oct", doi = "10.1029/2011JE003898", url = "http://www.agu.org/pubs/crossref/pip/2011JE003898.shtml", abstract = "Laser Induced Breakdown Spectroscopy ({LIBS}) is an active analytical technique that makes use of a laser pulse to analyze materials of interest at a distance by creating a plasma, which emits photons at characteristic emission line wavelengths. We validate the technique for planetary exploration under vacuum conditions. We review the capability and advantages of the LIBS technique for lunar regolith analysis at 1.5 m distance from a lunar rover and we characterize its potential for the detection of resources for future exploration, such as the determination of regolith water content. The limits of detection determined for the major elements (typically <1 wt.%) help to determine regolith parent material such as feldspathic highland rocks, rocks from the ancient magmatic High Magnesian Suite (Mg-suite), Fe-rich mare basalts or KREEP-rich samples. Compositional parameters commonly used to classify lunar regolith such as TiO2, Al2O3 and K2O abundances are readily determined by LIBS. Certain elements support regolith analysis; for example, Ba and Zr can be used to confirm KREEP-like composition, while quantifying the Ni and Co content can be used to infer the amount of meteoritic material. Finally it is shown that the ice content of lunar soil produces strong H emission with the LIBS techniques at the 25 wt.% H2O level, while measurements on altered basalts give a limit of detection of about 1 wt.% for H2O content. This demonstrates that the 5.6 wt.% water content detected by the recent LCROSS experiment should be easily detectable and quantifiable by LIBS analysis." } @article{ pubs_Anderson:2011, title = "The influence of multivariate analysis methods and target grain size on the accuracy of remote quantitative chemical analysis of rocks using laser induced breakdown spectroscopy", journal = "Icarus", volume = "215", issue = "2", author = "Ryan B. Anderson and Richard V. Morris and Samuel M. Clegg and James F. Bell III and Roger C. Wiens and \textbf{\sffamily Seth D. Humphries} and Stanley A. Mertzman and Trevor G. Graff and Rhonda McInroy", number = "2", pages = "608--627", year = "2011", month = "Oct", note = "", issn = "0019-1035", doi = "10.1016/j.icarus.2011.07.034", url = "http://www.sciencedirect.com/science/article/pii/S001910351100306X", keywords = "Mars", keywords = "Spectroscopy", keywords = "Data Reduction Techniques", abstract = "Laser-induced breakdown spectroscopy ({LIBS}) was used to quantitatively analyze 195 rock slab samples with known bulk chemical compositions, 90 pressed-powder samples derived from a subset of those rocks, and 31 pressed-powder geostandards under conditions that simulate the ChemCam instrument on the Mars Science Laboratory Rover (MSL), Curiosity. The low-volatile (<2 wt) silicate samples (90 rock slabs, corresponding powders, and 22 geostandards) were split into training, validation, and test sets. The LIBS spectra and chemical compositions of the training set were used with three multivariate methods to predict the chemical compositions of the test set. The methods were partial least squares (PLS), multilayer perceptron artificial neural networks (MLP ANNs) and cascade correlation (CC) ANNs. Both the full LIBS spectrum and the intensity at five pre-selected spectral channels per major element (feature selection) were used as input data for the multivariate calculations. The training spectra were supplied to the algorithms without averaging (i.e. five spectra per target) and with averaging (i.e. all spectra from the same target averaged and treated as one spectrum). In most cases neural networks did not perform better than PLS for our samples. PLS2 without spectral averaging outperformed all other procedures on the basis of lowest quadrature root mean squared error (RMSE) for both the full test set and the igneous rocks test set. The RMSE for PLS2 using the igneous rock slab test set is: 3.07 wt SiO2, 0.87 wt TiO2, 2.36 wt Al2O3, 2.20 wt Fe2O3, 0.08 wt MnO, 1.74 wt MgO, 1.14 wt CaO, 0.85 wt Na2O, 0.81 wt K2O. PLS1 with feature selection and averaging had a higher quadrature RMSE than PLS2, but merits further investigation as a method of reducing data volume and computation time and potentially improving prediction accuracy, particularly for samples that differ significantly from the training set. Precision and accuracy were influenced by the ratio of laser beam diameter (~490 [mu]m) to grain size, with coarse-grained rocks often resulting in lower accuracy and precision than analyses of fine-grained rocks and powders. The number of analysis spots that were normally required to produce a chemical analysis within one standard deviation of the true bulk composition ranged from ~10 for fine-grained rocks to >20 for some coarse-grained rocks." } @article{ pubs_Blonquist:2011, title = "Improved Dielectric and Electrical Conductivity Anisotropy Measurements Using {TDR} in Unsaturated Mica", journal = "Vadose Zone Journal", author ="J . Mark Blonquist Jr. and David A. Robinson and \textbf{\sffamily Seth D. Humphries} and Scott B. Jones", volume = "10", number = "3", pages = "1097--1104", year = "2011", month = "Aug", doi = "10.2136/vzj2010.0148", url = "http://vzj.geoscienceworld.org/cgi/content/abstract/10/3/1097", abstract = "Anisotropy in the vadose zone impacts the flow and transport of water and contaminants. Progress has been made in incorporating anisotropy into flow and transport models; however, obtaining accurate estimation of the extent of anisotropy in porous media remains a technical challenge. Electrical and electromagnetic (EM) measurements can be used to investigate the anisotropy of layered media. We developed a parallel-plate time domain reflectometry (TDR) and electrical conductivity cell for accurately measuring the sample-scale dielectric (AKa) and electrical conductivity (A) anisotropy factors and used a dielectric mixture model to predict the theoretical dielectric anisotropy factor (A). Modeling of the cell EM transmission line sampling area based on electrode geometry facilitated an optimal design based on minimizing the sampling area coefficient of variation. This optimal design consists of thin (1-mm) parallel plates with a spacing/width ratio of 1. Dielectric and electrical conductivity measurements were made in mica, layered parallel to the plates in one cell and layered perpendicular to the plates in another. The resulting water-content-dependent dielectric measurements yielded sample-scale AKa factors with peak values of 2.4 occurring near 50 saturation, while electrical conductivity measurements found A values approaching 10 near 75 saturation. Furthermore, the shape of the water-content-dependent AKa followed a Gaussian distribution, while a three-phase dielectric mixture model predicted peak A near 40 saturation. Discrepancies in magnitude were attributed to model assumptions, packing irregularities, and heterogeneity in the mica packing structure, as noted by others. The occurrence of the peak AKa around 50 saturation corroborates anisotropy predictions for transport related to hydraulic processes." } @Article{ pubs_barr:2011, title = "Laser-based carbon dioxide monitoring instrument testing during a 30-day controlled underground carbon release field experiment", journal = "International Journal of Greenhouse Gas Control", volume = "5", number = "1", pages = "138--145", year = "2011", month = "Jan", note = "", issn = "1750-5836", doi = "10.1016/j.ijggc.2010.03.00", url = "http://www.sciencedirect.com/science/article/B83WP-4YV7R35-1/2/4d57b8f32c162040ad09660c6cf8cda5", author = "Jamie L. Barr and \textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and Laura M. Dobeck and John L. Carlsten and Lee H. Spangler", keywords = "Laser diode", keywords = "Remote sensing", keywords = "Spectroscopy", keywords = "Monitoring", keywords = "Carbon capture" , abstract = "The performance of two laser-based instruments for carbon dioxide (CO2) monitoring was tested during a controlled release experiment performed at the zero emissions research and technology (ZERT) controlled release facility. The first instrument measures path-integrated CO2 concentrations above ground in two orthogonal directions using a continuous-wave, temperature-tunable, distributed feedback (DFB) diode laser with a center wavelength of 2.003 μm. The second instrument also uses a continuous-wave temperature-tunable DFB laser to deliver light via fiber optics to three underground sensors. Two underground sensors utilize absorption cells of 0.3 and 1 m lengths that are buried 1 m apart approximate 0.75 m above the underground release pipe. The third underground sensor utilizes a photonic bandgap (PBG) fiber as part of a fiber optic sensor. A 0.3 tCO2/day controlled release was conducted from July 9 to August 7, 2008. The two instruments were able to distinguish the elevated CO2 concentration associated with the CO2 injection." } @article {pubs_spangler:2010, author = {Lee H. Spangler and Laura M. Dobeck and Kevin S. Repasky and Amin R. Nehrir and \textbf{\sffamily Seth D. Humphries} and Jamie L. Barr and Charlie Keith and Joseph A. Shaw and Rouse, Joshua and Cunningham, Alfred and Benson, Sally and Oldenburg, Curtis and Lewicki, Jennifer and Wells, Arthur and Diehl, J. and Strazisar, Brian and Fessenden, Julianna and Rahn, Thom and Amonette, James and Barr, Jon and Pickles, William and Jacobson, James and Silver, Eli and Male, Erin and Rauch, Henry and Gullickson, Kadie and Trautz, Robert and Kharaka, Yousif and Birkholzer, Jens and Wielopolski, Lucien}, affiliation = {Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA}, title = {A shallow subsurface controlled release facility in {B}ozeman, {M}ontana, {USA}, for testing near surface {CO}2 detection techniques and transport models}, journal = {Environmental Earth Sciences}, publisher = {Springer Berlin / Heidelberg}, issn = {1866-6280}, pages = {227-239}, volume = {60}, issue = {2}, year = {2010}, url = {http://dx.doi.org/10.1007/s12665-009-0400-2}, doi = {10.1007/s12665-009-0400-2}, abstract = {A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO2 transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO2 release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO2 transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO2 from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U.S. Geological Survey investigated movement of CO2 through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented.} } @Article{ pubs_fessenden:2010, title="Novel {MVA} Tools to track {CO}$_2$ Seepage, tested at the {ZERT} controlled release site in {B}ozeman, {MT}", author="Julianna E. Fessenden and Samuel M. Clegg and Thomas A. Rahn and \textbf{\sffamily Seth D. Humphries} and Scott Baldridge", journal = "Environmental Earth Sciences", year ="2010", month="Mar", volume = "60", number="2", pages="325--334", doi="10.1007/s12665-010-0489-3", url="http://www.springerlink.com/content/b425320425x32835/", abstract="Over the past 4 years, controlled field experiments have taken place in Bozeman, MT, USA where pure CO2 has been released at known rates and depths to quantify the detection limits of various monitoring tools and techniques for the use of CO2 seepage detection. As part of this study, new tools engineered at Los Alamos National Laboratory were deployed to determine the sensitivity of these technologies to detect and measure CO2 seepage. These technologies were engineered for above-ground CO2 detection and include laser-based closed path δ13CO2 measurement systems, an O2/CO2 concentration ratio measurement system, and a chamber-based radon detection system. The sensitivity of these technologies to detect CO2 were measured through spatial transects taken perpendicular to the CO2 source and through temporal changes measured diurnally over the course of a 30 day experiment. Results show that the radon system is most sensitive to CO2 detection at the start of the experiment in locations adjacent to the CO2 source. The closed path or in situ δ13CO2 system detected CO2 seepage as far as 2 m away from the source during non-windy periods. The O2/CO2 system detected the CO2 seepage as far as 2 m above-ground and 1 m away from the source. Descriptions of these technologies and an overview of these results are presented." } @Article{ pubs_lanza:2010, author="Nina L. Lanza and Roger C. Wiens and Samuel M. Clegg and Ann M. Ollila and \textbf{\sffamily Seth D. Humphries} and Horton E. Newsom and James E. Barefield and the {C}hem{C}am {T}eam", title="Calibrating the {C}hem{C}am laser-induced breakdown spectroscopy instrument for carbonate minerals on {M}ars", journal="Applied Optics", year ="2010", volume="49", number="13", pages="C211--C217", month="May", doi="10.1364/AO.49.00C211", url="http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-49-13-C211", abstract="The ChemCam instrument suite onboard the NASA Mars Science Laboratory rover includes the first laser-induced breakdown spectroscopy (LIBS) instrument for extraterrestrial applications. Here we examine carbonate minerals in a simulated martian environment to better understand the LIBS signature of these materials on Mars. Both chemical composition and rock type are determined using multivariate analysis techniques. Composition is confirmed using scanning electron microscopy. Our results show that ChemCam can recognize and differentiate between different types of carbonate materials on Mars." } @PhDThesis{pubs_dissertation:2008, title = "Carbon Dioxide Sequestration Monitoring and Verification Via Laser Based Detection System in the 2~$\mu$\lowercase{m} Band", author = "\textbf{\sffamily Seth D. Humphries}", year = "2008", Month = "Sep", school = "Montana State University", location = "Bozeman, MT", url = "http://etd.lib.montana.edu/etd/view/item.php?id=808", abstract = "Carbon Dioxide (CO$_2$) is a known contributor to the green house gas effect. Emissions of CO$_2$ are rising as the global demand for inexpensive energy is placated through the consumption and combustion of fossil fuels. Carbon capture and sequestration (CCS) may provide a method to prevent CO$_2$ from being exhausted to the atmosphere. The carbon may be captured after fossil fuel combustion in a power plant and then stored in a long term facility such as a deep geologic feature. The ability to verify the integrity of carbon storage at a location is key to the success of all CCS projects. A laser-based instrument has been built and tested at Montana State University (MSU) to measure CO$_2$ concentrations above a carbon storage location. The CO$_2$ Detection by Differential Absorption (CODDA) Instrument uses a temperature-tunable distributed feedback (DFB) laser diode that is capable of accessing a spectral region, 2.0027 to 2.0042~$\mu$m, that contains three CO$_2$ absorption lines and a water vapor absorption line. This instrument laser is aimed over an open-air, two-way path of about 100~m, allowing measurements of CO$_2$ concentrations to be made directly above a carbon dioxide release test site. The performance of the instrument for carbon sequestration site monitoring is studied using a newly developed CO$_2$ controlled release facility. The field and CO$_2$ releases are managed by the Zero Emissions Research Technology (ZERT) group at MSU. Two test injections were carried out through vertical wells simulating seepage up well paths. Three test injections were done as CO$_2$ escaped up through a slotted horizontal pipe simulating seepage up through geologic fault zones. The results from these 5 separate controlled release experiments over the course of three summers show that the CODDA Instrument is clearly capable of verifying the integrity of full-scale CO$_2$ storage operations." } @Article{ pubs_humphries:2008, title = "Testing Carbon Sequestration Site Monitor Instruments Using a Controlled Carbon Dioxide Release Facility", author = "\textbf{\sffamily Seth D. Humphries} and Amin R Nehrir and Charlie J. Keith and Kevin S. Repasky and Laura M. Dobeck and John L. Carlsten and Lee H. Spangler", journal = "Applied Optics", pages = "548--555", volume = "47", number = "4", month = "Feb", year = "2008", doi = "10.1364/AO.47.000548", url="http://www.opticsinfobase.org/abstract.cfm?URI=ao-47-4-548", abstract = "Two laser-based instruments for carbon sequestration site monitoring have been developed and tested at a controlled carbon dioxide CO2 release facility. The first instrument uses a temperature tunable distributed feedback (DFB) diode laser capable of accessing the 2002.7–2004.2 nm spectral region that contains three CO2 absorption lines and is used for aboveground atmospheric CO2 concentration measurements. The second instrument also uses a temperature tunable DFB diode laser capable of accessing the 2003.2–2005.5 nm spectral region that contains five CO2 absorption lines for underground CO2 soil gas concentration measurements. The performance of these instruments for carbon sequestration site monitoring was studied using a newly developed controlled CO2 release facility. A 0.3 ton CO2/day injection experiment was performed from 3–10 August 2007. The aboveground differential absorption instrument measured an average atmospheric CO2 concentration of 618 parts per million (ppm) over the CO2 injection site compared with an average background atmospheric CO2 concentration of 448 ppm demonstrating this instrument’s capability for carbon sequestration site monitoring. The underground differential absorption instrument measured a CO2 soil gas concentration of 100,000 ppm during the CO2 injection, a factor of 25 greater than the measured background CO2 soil gas concentration of 4000 ppm demonstrating this instrument’s capability for carbon sequestration site monitoring." } @Article{ pubs_repasky:2006, title = "Differential absorption measurements of carbon dioxide using a temperature tunable distributed feedback diode laser", author = "Kevin S. Repasky and \textbf{\sffamily Seth D. Humphries} and John L. Carlsten", journal = "Review of Scientific Instruments", pages = "113107", volume = "77", number = "11", month = "Nov", year = "2006", doi = "10.1063/1.2370746", url="http://link.aip.org/link/?RSINAK/77/113107/1", abstract = "The design and performance of an absorption measurement instrument for monitoring carbon dioxide are presented. The instrument is based on a temperature tunable distributed feedback diode laser capable of tuning between 2.001 and 2.005 µm. Within this wavelength range are 12 absorption lines for carbon dioxide and 9 absorption lines for water vapor. Initial measurements of laser transmission as a function of carbon dioxide concentration are made using a 2 m long absorption cell. The measured values compare well with the expected values using the known line strength of the carbon dioxide absorption feature. Carbon dioxide measurements over a 77.5 m path length made outside the laboratory show the potential for carbon dioxide concentration monitoring." } @MastersThesis{pubs_thesis:2005, title = "{C}alibration and Results of the {EQUIS} {II} Plasma Impedance Probe ({PIP})", author = "\textbf{\sffamily Seth D. Humphries}", year = "2005", Month = "Dec", school = "Utah State University", location = "Logan, UT", url="http://www.ece.usu.edu/grad/reports_theses_disseratations/2005/humphries_seth_d/thesis.pdf", abstract = "This thesis presents the calibration process and analysis results for the two Plasma Impedance Probe (PIP) units that were flown as part of the NASA EQUIS II campaign from Kwajalein Atoll. The work of calibration that was presented by Krishna Kurra for the PIP on the Floating Potential Measurement Unit (FPMU) is improved and extended herein. The sweeping impedance probe (SIP), the instrument formerly known as plasma sweeping probe (PSP), is an integral part of the PIP. For the SIP, the calibration presented in the work, calibration error of less than 5\% is acheived. The calibration is applied to the flight data to yield impedance measurements. Balmain's normalized theoretical model is fit to normalized calbrated data to obtain electron density profiles within the range of about 2\e{3} to 5\e{6} [N$_e$/cm$^3$]. Electron density profiles from the plasma frequency probe (PFP), also part of the PIP, are compared with the density profiles from the SIP and there is close correlation, verifying the calibration of the SIP." } @Article{ pubs_heinse:2005, author = "Robert Heinse and \textbf{\sffamily Seth D. Humphries} and Robert W. Mace and Scott B. Jones and Susan L. Steinberg and Marcus Tuller and Rebecca M. Newman and Dani Or", title ="Measurement of Porous Media Hydraulic Properties during Parabolic Flight Induced Microgravity", year = "2005", month = "Jul", journal = "SAE Technical Paper", volume = "2005-01-2950", url="http://soilphysics.usu.edu/SCOTT/2005_ICES_Heinse-etal_ParabolicFlight.pdf", abstract = "Bioregenerative life-support systems proposed for long-duration space missions require an understanding of the physical processes that govern distribution and transport of fluids in particulate porous plant- growth media. Our objectives were to develop hardware and instrumentation to measure porous-medium water retention and hydraulic transport properties during parabolic-flight-induced microgravity. Automated measurements complimented periodic manual operations in three separate experiments using porous ceramic aggregates and glass beads. The water content was adjusted in multiple steps in periods of 1.8g. Continuous hydraulic potential measurements provided information on water retention. The short duration of microgravity limited the occurrence of equilibrium potentials under partially saturated conditions. Measured pressure gradients under fixed flow rates were largely unaffected by gravity force in saturated cylindrical porous- medium-filled flow cells. High resolution video imagery provided details on water imbibition rates into dry and previously wetted porous media. Additional analysis of these data will provide insight into the effects of reduced gravity on porous medium hydraulic properties." } #proceedings @article{Spangler20092143, title = "A controlled field pilot for testing near surface CO2 detection techniques and transport models", journal = "Energy Procedia", volume = "1", number = "1", pages = "2143 - 2150", year = "2009", note = "Greenhouse Gas Control Technologies 9, Proceedings of the 9th International Conference on Greenhouse Gas Control Technologies (GHGT-9), 16-20 November 2008, Washington DC, USA", issn = "1876-6102", doi = "10.1016/j.egypro.2009.01.279", url = "http://www.sciencedirect.com/science/article/B984K-4W0SFYG-9X/2/33e9080d944e4e37bfdf66d0b21f8f60", author = "Lee H. Spangler and Laura M. Dobeck and Kevin S. Repasky and Amin R. Nehrir and \textbf{\sffamily Seth Humphries} and Jamie L. Barr and Charlie Keith and Joe A. Shaw and Josh Rouse and Al Cunningham and Sally Benson and Curtis M. Oldenburg and Jennifer L. Lewicki and Art Wells and Rod Diehl and Brian Strazisar and Julianna Fessenden and Thom Rahn and James Amonette and Jon Barr and William Pickles and James Jacobson and Eli Silver and Erin Male and Henry Rauch and Kadie Gullickson and Robert Trautz and Youssif Kharaka and Jens Birkholzer and Lucian Wielopolski", abstract = "A field facility has been developed to allow controlled studies of near surface CO2 transport and detection technologies. The key component of the facility is a shallow, slotted horizontal well divided into six zones. The scale and fluxes were designed to address large scale CO2 storage projects and desired retention rates for those projects. A wide variety of detection techniques were deployed by collaborators from 6 national labs, 2 universities, EPRI, and the USGS. Additionally, modeling of CO2 transport and concentrations in the saturated soil and in the vadose zone was conducted. An overview of these results will be presented." } @inproceedings{pro_heinse:2005, author = "Robert Heinse and Scott B. Jones and \textbf{\sffamily Seth D. Humphries} and Robert W. Mace and Susan L. Steinberg and Marcus Tuller and Robert Newman and Dani Or", year="2005", month = "Jul", title="Measurement of Porous Media Water Retention during Parabolic Flight Induced Microgravity", booktitle="The 35th International Conference on Environmental Systems (ICES) and the 8th European Symposium on Space Environmental Control Systems (ESSECS)", note="Rome, Italy" } @inproceedings{pro_heinse:2004a, author = "Robert Heinse and Scott B. Jones and \textbf{\sffamily Seth D. Humphries} and Robert W. Mace and Susan L. Steinberg and Marcus Tuller and Robert Newman and Dani Or", year="2004", title="Porous Media Water Retention and Saturated Hydraulic Conductivity During Parabolic Flight Induced Microgravity", booktitle="Agronomy Abstracts", affiliation="ASA", note="Madison, WI" } @inproceedings{pro_heinse:2004b, author = "Robert Heinse and Scott B. Jones and \textbf{\sffamily Seth D. Humphries} and Robert W. Mace and Susan L. Steinberg and Marcus Tuller and Robert Newman and Dani Or", year="2004", month ="Nov", title="Porous Media Water Retention and Saturated Hydraulic Conductivity During Parabolic Flight Induced Microgravity", booktitle="SSSA Annual Meeting Abstracts", note="Seattle, WA" } @inproceedings{pro_jones:2003a, author = "Scott B. Jones and Dani Or and Susan L. Steinberg and \textbf{\sffamily Seth D. Humphries} and Gail E. Bingham and Nihad E. Daidzic and Lakshmi Reddi", year="2003", title="Influence of Variable Gravity on Liquid Configurations in Micromodels", booktitle="Agronomy Abstracts", affiliation="ASA", note="Madison, WI" } @InProceedings{pro_jones:2003b, author = {Scott B. Jones and Dani Or and Marcus Tuller and Susan L. Steinberg and \textbf{\sffamily Seth D. Humphries} and Gail E. Bingham and Nihad E. Daidzic and Lakshmi N. Reddi}, booktitle = {{SSSA} {A}nnual {M}eeting {A}bstracts}, details = {http://infoscience.epfl.ch/record/110465}, affiliation = {EPFL}, note = {Denver, CO}, oai-id = {oai:infoscience.epfl.ch:110465}, oai-set = {conf}, review = {REVIEWED}, status = {PUBLISHED}, title = {Influence of {V}ariable {G}ravity on {L}iquid {C}onfigurations in {M}icromodels}, unit = {LASEP}, year = {2003}, month ="Nov" } #oral presentations @article{pres_agu_humphries:2009, author="Samuel M. Clegg and James E. Barefield and \textbf{\sffamily Seth D. Humphries} and Roger C. Wiens and David T. Vaniman and M. Darby Dyar and Jonathan M. Tucker and Shiv K. Sharma and Anupam K. Misra", title="Remote Laser Induced Breakdown Spectroscopy ({LIBS}) Geochemical Investigation under {V}enus Atmospheric Conditions ", year="2009", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract P31D-07", volume="90", number="52", note="San Francisco, CA", abstract="The extreme Venus surface temperature (740 K) and atmospheric pressure (93 atm) creates a challenging environment for future lander missions. Scientific investigations capable of Venus geochemical observations must be completed within several hours of landing before the lander is overcome by the harsh atmosphere. A combined remote Raman – LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. [1] and Sharma et al. [2] have demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with LIBS and demonstrate the quantitative analysis under Venus surface conditions. The LIBS experiment involves focusing a Nd:YAG laser operating at 1064 nm onto the surface of the sample. The laser ablates material from the surface, generating a plasma containing electronically excited atoms, ions and small molecules. Some of this emission is collected with an 89 mm diameter telescope. The light is directed into a Princeton Instruments f/4 0.25 m dispersive spectrometer and recorded with an ICCD detector. The powdered and pelletized samples are placed in a pressure vessel containing supercritical CO2 at 93 atm and at least 423 K and the vessel is placed at least 1.6 m from the telescope and laser. A range of Venus-analog basaltic rock types [3] was chosen for this study to reproduce compositions identified by Soviet Venera and VEGA landers, including several standards: four basalts (BCR-2, BIR-1, GUWBM, JB-2), granite (GBW 07015), andesite (JA-1), carbonate (SARM-40), and Kauai volcanic (KV04-17, KV04-25). We also added a good Venus analog, TAP 04, which is an alkali-rich rock from an olivine minette in the Ayutla volcanic field (Righter and Rosas-Elguera [4]). Our goal was to study samples with a range of abundances for each element of interest so as to optimize the efficacy of the resultant calibration for predicting a range of compositions. Peaks for all required major, minor, and trace elements were well above the noise floor and readily detected. Peak intensities and areas were then used to quantify elemental chemistry. Data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis demonstrates that the major element compositions of rock powders acquired at 93 atm/423 K can be determined with better than 10% accuracy and precision. [1] Wiens R.C., et al. (2005) Spect. Acta A 61, 2324; [2] Sharma, S. K. et al. (2007) Spect. Acta A, 68 , 1036 (2007); [3] Barsukov VL (1992) Venusian Igneous Rocks. In Venus Geology, Geochemistry, and Geophysics (eds. VL Barsukov, AT Basilevsky, VP Volkov, and VW Zharkov). Univ. Arizona Press, pp. 165-176. [4] Righter K. and Rosas-Elguera J. (2001) J. Petrol. 42, 2333." } @article{pres_humphriesAGU:2008, author = "\textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and John L. Carlsten and Lee H. Spangler and Laura M. Dobeck", title=" Laser-Based Instruments Using Differential Absorption Detection for Above and Below Ground Monitoring of Carbon Dioxide", year="2008", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract U44A-08", volume="89", number="53", note="San Francisco, CA", abstract="Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. A field experiment was conducted at the ZERT field site beginning July 9th, 2008 and ending August 7th, 2008 to test the performance of several CO2 detection instruments. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. A flow rate of 0.3 tons CO2/day was used for the entirety of this experiment. This paper describes the results from two laser based instruments that use differential absorption techniques to determine CO2 concentrations in real time both above and below the ground surface. Both instruments use a continuous wave (cw) temperature tunable distributed feedback (DFB) laser capable of tuning across several CO2 and water vapor absorption features between at 2003 nm and 2006 nm. The first instrument uses the DFB laser to measure path integrated atmospheric concentrations of CO2. The second instrument uses the temperature tunable DFB laser to monitor underground CO2 concentrations using a buried photonic bandgap optical fiber. The above ground instrument operated nearly continuously during the CO2 release experiment and an increase in atmospheric CO2 concentration above the release pipe of approximately 2.5 times higher than the background was observed. The underground instrument also operated continuously during the experiment and saw an increase in underground CO2 concentration of approximately 15 times higher than the background. These results from the 2008 ZERT field experiment demonstrate the potential for these instruments to be used for CO2 monitoring of sequestration sites." } @unpublished{pres_humphries:2008, author = "\textbf{\sffamily Seth D. Humphries} and Kevin S. Repasky and Jamie L. Barr and John L. Carlsten", title="Carbon Dioxide Detection Using a Laser Based Instrument", year="2008", month="Aug", note="Optical Technology \& Engineering Conference, Bozeman, MT (invited)", url = "http://optec.montana.edu/" } @unpublished{pres_humphries:2007, author = "\textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Charlie J. Keith and Kevin S. Repasky and Laura M. Dobeck and John L. Carlsten and Lee H. Spangler", title="Differential laser absorption instrument performance at a controlled carbon dioxide release facility", year="2007", month="Sep", note="Optical Technology \& Engineering Conference, Bozeman, MT (invited)", url="http://optec.montana.edu/" } @inproceedings{pres_humphries:2006a, author="\textbf{\sffamily Seth D. Humphries} and Kevin S. Repasky and Joseph A. Shaw and John L. Carlsten and Lee H. Spangler", title="Laser-Based Differential Absorption Carbon Dioxide Sensor", year="2006", month="May", booktitle="5th Annual conference on Carbon Capture \& Sequestration", note="Washington D.C." } @unpublished{pres_humphries:2006b, author="\textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and John L. Carlsten and Joseph A. Shaw and Lee H. Spangler", title ="Differential Absorption Measurements of Carbon Dioxide and Diatomic Oxygen", year="2006", month="Sep", note="Optical Technology \& Engineering Conference, Bozeman, MT" } @inproceedings{pres_humphries:2004, author="\textbf{\sffamily Seth D. Humphries} and Scott B. Jones and Dani Or", title="Automated Analysis of {TDR} Waveforms for Water Content Determination in Saline Soils", year="2004", month="Jul", booktitle="85th AAAS Pacific Division Annual Meeting", note="Logan, UT" } #presented posters @article{post_LIBS_Lanza:2010, author = "Nina L. Lanza and M. D. Deans and Roger C. Wiens and Samuel M. Clegg and \textbf{\sffamily Seth D. Humphries} and Horton E. Newsom and E. B. Rampe, and Ann O. Ollila", title = "Using {LIBS} to determine composition of natural rock coatings for planetary exploration", journal="6th International Conference on {LIBS}", note="Memphis, TN", year = "2010", month = "Sep", url = "http://www.icet.msstate.edu/libs2010/" } @article{post_LIBS_humphries:2010, author = "\textbf{\sffamily Seth D. Humphries} and Jonathan M. Tucker and Rhonda E. McInroy and Stephen J. Obrey and Roger C. Wiens and M. Darby Dyar and Samuel M. Clegg", title = "A {LIBS} elemental Emission Library for {C}hem{C}am at 7~m", journal="6th International Conference on {LIBS}", note="Memphis, TN", year = "2010", month = "Sep", url = "http://www.icet.msstate.edu/libs2010/" } @article{post_vaniman:2010, author = "Alyssa Mezzacappa and Samuel M. Clegg and \textbf{\sffamily Seth D. Humphries} and Sylvestre Maurice and Rhonda E. McInroy and Liese Marie Nortier and David Vaniman and Roger C. Wiens", title = "Sample Analysis in the Lunar Environment using Laser Induced Breakdown Spectroscopy", journal="3rd Annual NASA Lunar Science Forum", note="NASA Ames", year = "2010", month = "Jul", url = "http://lunarscience2010.arc.nasa.gov/" } @inproceedings{post_CCS_humphries:2010, author="\textbf{\sffamily Seth D. Humphries} and Julianna E. Fessenden and Laura M. Dobeck and Lee H. Spangler and Samuel M. Clegg", title="Stable Carbon Isotope Detection for Geologic Sequestration Monitoring", year = "2010", month = "May", booktitle="9th Annual Conference on Carbon Capture \& Sequestration", note="Pittsburgh, PA", abstract="Monitoring, Verification and Accounting (MVA) is necessary as a means of tracking seepage from subsurface storage of CO2. To be able to monitor and track CO2 emissions instruments must be able to measure concentrations at or below natural CO2 levels. The concentration of the stable carbon isotope, 13CO2, is approximately 100 times smaller than that of 12CO2. Frequency modulated spectroscopy (FMS) is an ultra sensitive means of detecting the stable isotopes of CO2 that is conservatively 100x more sensitive than standard absorption spectroscopy. An FMS instrument, built at Los Alamos National Laboratory, is used to monitor shifts in the carbon stable isotope ratio from air samples. This instrument employs a small pump to pull air into an optical chamber where the FMS measurement is made. The in situ FMS instrument was deployed at the ZERT controlled release facility in Bozeman, MT in July of 2009. Data recorded with the in situ FMS instrument during the test release will be compared against air samples probed by a traditional mass spectrometer instrument (using flask collections). Correlation is demonstrated between the two independent measurements and validation of the FMS technique is achieved." } @article{Humphries_lpsca:2010, author = "\textbf{\sffamily Seth D. Humphries} and Jonathan M. Tucker and Rhonda E. McInroy and Stephen J. Obrey and Roger C. Wiens and M. Darby Dyar and Samuel M. Clegg", title = "A {LIBS} {E}lemental {E}mission {L}ibrary for {C}hem{C}am at 7~m", journal="41st LPSC", volume="2096", howpublished = "On the Web", year = "2010", month = "Mar", note="The Woodlands, TX", url = "http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2096.pdf" } @article{Humphries_lpscb:2010, author = "Ryan B. Anderson and Richard V. Morris and Samuel M. Clegg and \textbf{\sffamily Seth D. Humphries} and Roger C. Wiens and J.F. Bell III and S. A. Mertzman", title = "PARTIAL LEAST SQUARES AND NEURAL NETWORKS FOR QUANTITATIVE CALIBRATION OF LASER-INDUCED BREAKDOWN SPECTROSCOPY ({LIBS}) OF GEOLOGIC SAMPLES", journal="41st LPSC", volume="2013", howpublished = "On the Web", year = "2010", month = "Mar", note="The Woodlands, TX", url = "http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2013.pdf" } @article{Humphries_lpscc:2010, author = "Z. E. Gallegos and Nina L. Lanza and Horton E. Newsom and Ann M. Ollila and Penny L. King and G. R. Osinski and Samuel M. Clegg and Roger C. Wiens and David T. Vaniman and \textbf{\sffamily Seth D. Humphries} and Rhonda E. McInroy and P. Lee", title = "USING LASER INDUCED BREAKDOWN SPECTROSCOPY ({LIBS}) TO ASSESS GEOLOGIC SAMPLES ASSOCIATED WITH A TERRESTRIAL IMPACT STRUCTURE AS AN ANALOGUE FOR FUTURE PLANETARY EXPLORATIONS", journal="41st LPSC", volume="2365", howpublished = "On the Web", year = "2010", month = "Mar", note="The Woodlands, TX", url = {http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2365.pdf} } @article{Humphries_lpscd:2010, author = "Nina L. Lanza and M. C. Deans and Samuel M. Clegg and \textbf{\sffamily Seth D. Humphries} and Rhonda E. McInroy and Roger C. Wiens and Horton E. Newsom and Ann M. Ollila", title = "EVALUATING {LIBS} AS A GEOCHEMICAL RECONNAISSANCE TOOL FOR THE {K}10 LUNAR ROVER", journal="41st LPSC", volume="2613", howpublished = "On the Web", year = "2010", month = "Mar", note="The Woodlands, TX", url = {http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2613.pdf} } @article{post_agu_a_humphries:2009, author="\textbf{\sffamily Seth D. Humphries} and Samuel M. Clegg and Julianna E. Fessenden and Laura M. Dobeck and Lee H. Spangler", title="Remote Detection of Carbon Stable Isotope of {CO}2 for Carbon Sequestration", year="2009", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract H21E-0894", volume="90", number="52", note="San Francisco, CA", abstract="Carbon storage in geologic formations is one method to prevent carbon dioxide (CO2), produced by fossil fuel combustion, from entering the Earth's atmosphere. The monitoring, verification and accounting (MVA) of geologically sequestered CO2 is critical to measure the operation and functioning of a geologic storage site. Surface monitoring techniques need to identify seepage from the sequestration reservoir at or below ambient CO2 concentrations. The Zero Emissions Research & Technology (ZERT) group at Montana State University established a field test site where controlled amounts of CO2 are released to test the performance of CO2 detection instruments and measurement techniques. The field site allows a controlled flow rate of CO2 to be released into the near surface, just below the water table, through a 100 m long horizontal pipe. In July of 2009, a release was conducted, with a uniform flow rate of 0.2 tons per day, and the seepage rate was measured. The carbon stable isotope ratio of CO2 is a sensitive diagnostic signature to distinguish between anthropogenic and natural sources of CO2. However, natural concentrations of 13C16O2 are approximately 100 times smaller than 12C16O2. Frequency-modulated spectroscopy (FMS) is an ultra-sensitive technique developed to detect the CO2 stable carbon isotopes. An instrument has been developed using this FMS technique and an integrated volume over a long, open-air path to detect changes in the carbon isotope ratio. This paper will briefly describe the FMs technique and present results from instrument deployment to the ZERT field site to monitor the 13C16O2/12C16O2 stable isotope ratio. LA-UR 09-05648" } @article{post_agu_b_humphries:2009, author="Julianna E. Fessenden and Samuel M. Clegg and \textbf{\sffamily Seth D. Humphries} and Laura M. Dobeck and Lee H. Spangler", title="Seepage CO2 Detection using ZERT Controlled Release site in Bozeman, MT", year="2009", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract H21E-0891", volume="90", number="52", note="San Francisco, CA", abstract="To mitigate against anthropogenic CO2 rise into the atmosphere, the Department of Energy is investing into a technology that will capture CO2 from power plants and store this anthropogenic CO2 in geologic or terrestrial reservoirs. To safely store this CO2 in geologic systems, research in Monitoring, Verification and Accounting (MVA) technologies have been undertaken for the past 7 years. In July 2009, a suite of seepage detection systems from Los Alamos National Laboratory were deployed to the ZERT Controlled Release Engineered Site in Bozeman, Montana. The ZERT Experiment consisted of releasing tank CO2 from a 87-m long buried pipe (10 feet down) at a rate of 0.2 tons per day for 30 days. The accuracy and resolution of these systems were determined and compared to other technologies deployed by researchers from academic, governmental, and industrial institutions. This paper reports on the use of an in situ (closed path) stable isotope detection system that measured, in real time, the d13CO2 of ambient/canopy CO2 over the course of the “ZERT Experiment”. Samples were collected at specific distances away from the pipe, over the course of many days (day/night), and during variable meteorological events. We compare our in situ isotope results to d13CO2 values taken through standard methods (100 ml flask samples, then IRMS analyses). Other institutions took similar data sets and this paper will recognize the other work conducted at the same time. LA-UR 09-05598" } @inproceedings{post_CCSa_humphries:2009, author="\textbf{\sffamily Seth D. Humphries} and Samuel M. Clegg and Julianna E. Fessenden", title="Remote Stable Isotope Detection of Geologic Sequestration Seepage", year="2009", month="May", booktitle="8th Annual Conference on Carbon Capture \& Sequestration", note="Pittsburgh, PA", abstract="A priority for geological sequestration Monitoring, Verification and Accounting (MVA) is a means of tracking seepage at concentrations at or below natural CO2 emissions. Carbon stable isotope ratios are sensitive diagnostic signatures of anthropogenic and natural sources of CO2. However, the concentration of 13CO2 is approximately 100 times smaller than 12CO2 and sensitive analytical tools are required to measure the ratio. Frequency modulated spectroscopy (FMS) is an ultra sensitive means of detecting the stable isotopes of CO2 that is conservatively 100x more sensitive than standard absorption spectroscopy. FMS involves directing a tunable diode laser (TDL) through an electro-opticalmodulator operating in the radio frequency regime producing the original carrier frequency from the TDL (?c) and evenly spaced sidebands (?c - ?m). The 12CO2 and 13CO2 are detected by tuning the TDL and the modulation frequency such that one of the sidebands interacts with a specific spectral feature. Field tests with the remote FMS instrument are underway at Los Alamos National Laboratory. These experiments involve releasing small amounts of CO2 to determine the sensitivity of the technique as a function of distance from the source. The modulated laser beam is directed towards a retro-reflector located 31.5m from the source providing a 63m total path length. The stable isotope ratio is monitored as the carrier frequency is scanned and the sidebands interact with both CO2 isotopes. The results from these field experiments will be presented." } @inproceedings{post_CCSb_humphries:2009, author="Jamie L. Barr and \textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and John L. Carlsten and Lee H. Spangler and Laura M. Dobeck", title="Laser Based Direct Detection of Carbon Dioxide for Surface and Subsurface Monitoring of Carbon Sequestration Sites", year="2009", month="May", booktitle="8th Annual Conference on Carbon Capture \& Sequestration", note="Pittsburgh, PA", abstract="Direct detection of carbon dioxide (CO2) using tunable laser based differential absorption measurement techniques provides a method of monitoring carbon sequestration sites. Two laser based instruments developed for surface and subsurface direct detection of CO2 were tested during a 30 day, 0.3 ton CO2/day controlled release experiment from July 9, 2008 through August 7, 2008. This experiment was performed at the Zero Emissions Research and Technology (ZERT) controlled release facility at Montana State University that was developed for near surface CO2 detection. Both laser based instruments utilize a continuous wave (cw) temperature tunable distributed feedback (DFB) laser as the transmitter. These lasers have a nominal center wavelength of 2.003 ??m and are capable of tuning over several CO2 absorption lines. The first instrument measures the above ground CO2 concentrations in two orthogonal directions using the temperature tunable DFB laser. The second instrument uses a temperature tunable DFB laser to deliver light through fiber optics to three underground sensors. Two underground sensors utilize absorption cells of 0.3 m and 1 m lengths that are buried 1 m apart approximate 0.75 m above the underground release pipe. The third underground sensor uses a photonic bandgap (PBG) fiber as part of an all fiber optic sensor. Results from the controlled release will be presented indicating the ability of these instruments to be used for carbon sequestration site monitoring." } @inproceedings{post_optec_humphries:2008, author = "Jamie L. Barr and Kevin S. Repasky and John L. Carlsten and \textbf{\sffamily Seth D. Humphries}", title="Fiber Optic Gas Sensor", year="2008", month="Aug", note="Optical Technology \& Engineering Conference, Bozeman, MT", url = "http://optec.montana.edu/" } @inproceedings{post_humphries:2008, author="\textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and John L. Carlsten and Lee H. Spangler and Laura M. Dobeck", title="Differential Absorption Measurements of Carbon Dioxide for Carbon Sequestration Site Monitoring Using a Temperature Tunable Diode Laser", year="2008", month="May", booktitle="7th Annual Conference on Carbon Capture \& Sequestration", note="Pittsburgh, PA", abstract="An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A differential absorption measurement instrument based on a continuous wave (cw) temperature tunable distributed feedback (DFB) laser has been developed for measuring atmospheric concentrations of CO2. The tunable DFB laser is capable of tuning across two CO2 absorption features at 2003.50 nm and 2004.02 nm. The measured normalized transmission through the atmosphere is then related to the atmospheric concentration of CO2 through the line strength and normalized line width associated with each absorption feature. A description of this instrument will be presented including the instrument design, operation, and performance characteristics.\\ A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. Two release experiments were performed this past summer with flow rates of 0.1 and 0.3 tons CO2/day. The first release experiment lasted ten days while the second release lasted seven days. Measurements taken with the differential absorption instrument over the horizontal well during these release experiments showed an increase of greater than 300 parts per million (ppm) over the background CO2 concentration. These results indicate the capabilities of the above ground differential absorption instrument for carbon sequestration site monitoring." } @article{post_humphries:2007, author="\textbf{\sffamily Seth D. Humphries} and Amin R. Nehrir and Kevin S. Repasky and John L. Carlsten and Lee H. Spangler and Laura M. Dobeck and Joseph A. Shaw", title="Differential Absorption Measurements of Carbon Dioxide for Carbon Sequestration Site Monitoring Using a Temperature Tunable Diode Laser", year="2007", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract H13F-1657", volume="88", number="52", note="San Francisco, CA", abstract="Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A differential absorption measurement instrument based on a continuous wave (cw) temperature tunable distributed feedback (DFB) laser has been developed for measuring atmospheric concentrations of CO2. The tunable DFB laser is capable of tuning across two CO2 absorption features at 2003.50 nm and 2004.02 nm. The measured normalized transmission through the atmosphere is then related to the atmospheric concentration of CO2 through the line strength and normalized line width associated with each absorption feature. A description of this instrument will be presented including the instrument design, operation, and performance characteristics. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. Two release experiments were performed this past summer with flow rates of 0.1 and 0.3 tons CO2/day. The first release experiment lasted ten days while the second release lasted seven days. Measurements taken with the differential absorption instrument over the horizontal well during these release experiments showed an increase of greater than 300 parts per million (ppm) over the background CO2 concentration. These results indicate the capabilities of the above ground differential absorption instrument for carbon sequestration site monitoring." } @article{post_nehrir:2007, author="Amin R. Nehrir and \textbf{\sffamily Seth D. Humphries} and Kevin S. Repasky and John L. Carlsten and Lee H. Spangler and Laura M. Dobeck", title="Underground Fiber-Optic Differential Absorption Instrument for Monitoring Carbon Dioxide Soil Gas Concentrations for Carbon Sequestration Site Monitoring", year="2007", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract H13F-1658", volume="88", number="52", note="San Francisco, CA", abstract="The burning of fossil fuels has resulted in higher carbon dioxide (CO2) concentrations in the atmosphere with potential impacts on the Earth's climate. The use of fossil fuels is predicted to grow over the next several decades with the potential for further increasing the atmospheric concentration of CO2. A proposed method of diminishing the impacts of increased CO2 on the Earth's climate is to capture and store the CO2 in geologic storage sites. One issue with underground sequestration of CO2 is the ability to monitor sequestration sites to verify the integrity of the storage of the CO2. An underground fiber optic differential absorption instrument based on a tunable distributed feedback (DFB) diode laser is being developed at Montana State University to detect small changes in CO2 soil gas concentration in an effort to monitor the overall integrity of the sequestration storage site. The fiber optic instrument exploits the 2003-2006 nm region of the spectrum which contains four CO2 absorption lines. Light from the DFB laser is delivered to an underground absorption cell one meter in length via a single mode optical fiber. The normalized transmission is measured by tuning the DFB diode laser across these four absorption lines and the results are used to determine the CO2 soil gas concentration. A description of this instrument will be presented including the instrument design, operation, and performance characteristics. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. Two release experiments were performed this past summer with flow rates of 0.1 and 0.3 tons CO2/day. The first release experiment lasted ten days while the second release lasted seven days. Measurements taken with the underground fiber optic differential absorption instrument 2.5 feet below the surface of the soil during these release experiments showed an absolute CO2 soil gas concentration exceeding 100,000 parts per million, an increase by a factor of greater than ten over the background levels of CO2 soil gas concentrations. These results indicate the capabilities of the below ground differential absorption instrument for carbon sequestration site monitoring." } @inproceedings{post_humphries:2007a, author="\textbf{\sffamily Seth D. Humphries} and Kevin S. Repasky and Paul Nachman and Joseph A. Shaw and John L. Carlsten and Lee H. Spangler", title="Atmospheric Carbon Dioxide Measurements Using a Tunable Laser Based System", year="2007", month="May", booktitle="6th Annual Conference on Carbon Capture \& Sequestration", note="Pittsburgh, PA", abstract="The burning of coal and other fossil fuels releases large amounts of carbon dioxide (CO2) into the atmosphere, which can adversely affect Earth’s climate. A proposed remedy involves the capture and sequestration of CO2 in to geologic storage sites. Several such carbon sequestration pilot projects are underway. One of the requirements for a successful carbon sequestration site is the development of reliable site monitoring and verification techniques. A differential absorption instrument based on a continuous-wave (cw), tunable, distributed feedback (DFB) laser is being developed and tested at Montana State University for such monitoring. Our instrument accesses the 2.002-2.004 μm spectral region, which contains 4 CO2 and 2 H20 absorption lines. The CO2 concentration, in parts per million, is determined by monitoring the atmospheric transmission as the laser is tuned across the molecular absorption lines. Field experiments were performed in which CO2 was released underground using a short, vertical injection well. Measurements using our system showed a background (atmospheric) CO2 concentration of 321.5 +/- 16.7 ppm while measurements taken over the injection well site showed a concentration increased to 352.0 +/- 29.2 ppm" } @article{post_gregory:2005, author="Jessica Gregory and Charles M. Swenson and \textbf{\sffamily Seth D. Humphries} and Chad Fish and Chad Carlson and Aroh Barjatya", title="In-situ observations of intermediate layers in the night time ionosphere", year="2005", month="Dec", journal="EOS Transactions AGU, Fall Meeting Supplement, Abstract SA23A-0306", volume="86", number="52", note="San Francisco, CA", abstract="AB: Night time ionospheric electron density profiles have been obtained using impedance and Langmuir probe techniques showing the presence of intermediate layers. Four sounding rockets were launched in July of 2003 at Wallops Island, VA and two more were launched in August of 2004 from Kwajalein atoll, Marshall Islands. Although these rocket campaigns were conducted at different latitudes they both indicated a patchy spatial structure. All six flights used essentially the same plasma impedance probe but the later campaign included a sweeping Langmuir probe. More emphasis is given to the data from the later campaign, ''Scattering Layer in the Bottomside Equatorial F-region Ionosphere'' investigation, which was a part of the NASA EQUIS II campaign. Electron density from this data set is analyzed using Balmain's theory for a short antenna in a cold magnetoplasma and compared with data from the sweeping Langmuir probe. " } #Acknowledgments @book{ack_sukop:2006, author= "Michael C. Sukop and Thorne, Jr, Daniel T.", title = "{L}attice {B}oltzman {M}odeling: an {I}ntroduction for {G}eoscientists and {E}ngineers", year = "2006", publisher = "Springer", isbn = "3540279814" } @article{ack_blonquist:2005, author = "J. Mark Blonquist and Scott B. Jones and David A. Robinson", year= "2005", title = "A time domain transmission sensor with {TDR} performance characteristics", journal ="Journal of Hydrology", volume = "314", pages = "235--245", month = "Nov", doi = "10.1016.j.jhydrol.2005.04.005" } @article{ack_jones:2005a, author = "Scott B. Jones and J. Mark Blonquist and David A. Robinson", title ="Standardizing characterization of electromagnetic water content sensors: {P}art {II}. Evaluation of Seven Sensing Systems", journal = "Vadose Zone Journal", volume="4", number = "4", pages="1059--1069", year="2005", doi = "10.2136/vzj2004.0141", url = "http://vzj.geoscienceworld.org/cgi/content/abstract/4/4/1059" } @article{ack_jones:2005b, author= "Scott B. Jones and J. Mark Blonquist and David A. Robinson and V.P. Rasmussen and Dani Or", year="2005", title="Standardizing characterization of electromagnetic water content sensors: {P}art {I}. Methodology", journal = "Vadose Zone Journal", volume = "4", number = "4", pages = "1048--1058", url = "http://vzj.geoscienceworld.org/cgi/content/abstract/4/4/1048", doi = "10.2136/vzj2004.0140" } @InProceedings{ack_swenson:2005, author= "Charles M. Swenson and Jeff Ward and Chad Carlson and Aroh Barjatya and Chad Fish", title = "Plasma Impedance Probe Diagnostics: Model and Data", booktitle="9th Spacecraft Charging Technology Conference", year="2005", location="Tsukuba, Japan", details="Best Poster Award" } @article{ack_jones:2005c, author="Scott B. Jones and R. William Mace and Dani Or", title ="A Time Domain Reflectometry Coaxial Cell for Manipulation and Monitoring of Water Content and Electrical Conductivity in Variably Saturated Porous Media", journal ="Vadose Zone Journal", volume ="4", number = "4", pages="977--982", year="2005", doi = "10.2136/vzj2005.0048", url = "http://vzj.geoscienceworld.org/cgi/content/abstract/4/4/977" } @article{ack_reddi:2005, author="Lakshmi N. Reddi and Ming Xiao and Susan L. Steinberg", title="Discontinuous Pore Fluid Distribution under Microgravity--{KC}--135 Flight Investigations", journal="Soil Science Society of America Journal", volume="69", pages="593--598", year="2005" } @article{ack_jones:2004, author="Scott B. Jones and Dani Or", year ="2004", title="Frequency Domain Analysis for Extending Time Domain Reflectometry Water Content Measurement in Highly Saline Soils", journal="Soil Science Society of America Journal", volume="68", number = "5", pages="1568--1577", url = "https://www.soils.org/publications/sssaj/articles/68/5/1568", doi = "10.2136/sssaj2004.1568" } @inproceedings{ack_serbin:2004, author="Guy Serbin and Dani Or", title="{GPR} Measurements of Crop Canopies and Soil Water Dynamics Implications for Radar Remote Sensing", booktitle="Tenth International Conference on Ground Penetrating Radar", year="2004", location="Delft, The Netherlands", month="Jun", doi = "10.1109/ICGPR.2004.179786" } @article{ack_heinse:2007, author="Robert Heinse and Scott B. Jones and Susan L. Steinberg and Markus Tuller and Dani Or", year ="2007", title="Measurements and Modeling of Variable Gravity Effects on Water Distribution and Flow in Unsaturated Porous Media", journal="Vadose Zone J", volume="6", pages="713--724", month="Oct", doi="10.2136/vzj2006.0105", abstract="Liquid behavior under reduced gravity conditions is of considerable interest for various components of life-support systems required for manned space missions. High costs and limited opportunities for spaceflight experiments hinder advances in reliable design and operation of elements involving fluids in unsaturated porous media such as plant growth facilities. We used parabolic flight experiments to characterize hydraulic properties under variable gravity conditions deduced from variations in matric potential over a range of water contents. We designed and tested novel measurement cells that allowed dynamic control of water content. Embedded time domain reflectometry probes and fast-responding tensiometers measured changes in water content and matric potential. For near-saturated conditions, we observed rapid establishment of equilibrium matric potentials during the recurring 20-s periods of microgravity. As media water content decreased, the concurrent decrease in hydraulic diffusivity resulted in limited attainment of equilibrium distributions of water content and matric potential in microgravity, and water content heterogeneity within the sample was influenced by the preceding hypergravity phase. For steady fluxes through saturated columns, we observed linear and constant hydraulic gradients during variable gravity, yielding saturated hydraulic conductivities similar to values measured under terrestrial gravity. Our results suggest that water distribution and retention behavior are sensitive to varied gravitational forces, whereas saturated hydraulic conductivity appears to be unaffected. Comparisons between measurements and simulations based on the Richards equation were in reasonable agreement, suggesting that fundamental laws of fluid flow and distribution for macroscopic transport derived on Earth are also applicable in microgravity." } @MastersThesis{ack_davidthesis:2008, title = "Two wavelength Lidar instrument for atmospheric aerosol study", author = "David S. Hoffman", year = "2008", Month = "May", school = "Montana State University", location = "Bozeman, MT", url = "http://etd.lib.montana.edu/etd/2008/hoffman/HoffmanD0508.pdf", abstract = "A two-color lidar instrument and inversion algorithms have been developed for the study of atmospheric aerosols. The two-color lidar laser transmitter is based on the collinear fundamental 1064 nm and second harmonic 532 nm output of a Nd:YAG laser. Scattered light is collected by the two-color lidar receiver using a Schmidt-Cassegrain telescope with the 532 nm channel monitored using a gated photomultiplier tube (PMT) and the 1064 nm channel monitored using an avalanche photodiode (APD). Data is collected from the PMT and APD using a 14 bit 200 MHz data acquisition card. The lidar inversion algorithm developed to analyze the data collected by the two-color lidar is based on a constant lidar ratio assumption at both the 1064 nm and 532 nm wavelengths with the constrained ratio aerosol model (CRAM) providing the initial lidar ratios at the two wavelengths to complete the lidar inversion. Data from the CALIOP lidar on board the CALIPSO satellite are presented to verify software algorithm performance. Data from the two-color lidar are then presented demonstrating the two-color lidar instrument's capabilities. The analysis of these data identifies smoke and industrial aerosols in the atmosphere above Bozeman. Finally an error analysis of the lidar instrument and accompanying analysis software is presented. The findings of this analysis are that error introduced by the APD and PMT is dominant; the error introduced by the optical detectors is much larger than the error from other sources examined such as quantization error, and the error associated the use of numerical integration in the data analysis algorithm." } @MastersThesis{ack_aminthesis:2008, title = "Water vapor profiling using a compact widely tunable diode laser differential absorption lidar ({DIAL})", author = "Amin R. Nehrir", year = "2008", Month = "Nov", school = "Montana State University", location = "Bozeman, MT", url = "http://etd.lib.montana.edu/etd/2008/nehrir/NehrirA1208.pdf", abstract = "Atmospheric water vapor is an important driver of cloud formation, precipitation, and cloud microphysical structure. Changes in the cloud microphysical structure due to the interaction of aerosols and water vapor can produce more reflective clouds, resulting in more incoming solar radiation being reflected back into space, leading to an overall negative radiative forcing. Water vapor also plays an important role in the atmospheric feedback process that acts to amplify the positive radiative forcing resulting from increasing levels of atmospheric CO2. In the troposphere, where the water vapor greenhouse effect is most important, the situation is harder to quantify. A need exists for tools that allow for high spatial resolution range resolved measurements of water vapor number density up to about 4 km. One approach to obtaining this data within the boundary layer is with the Differential Absorption Lidar (DIAL) that is being developed at Montana State University. A differential absorption lidar (DIAL) instrument for automated profiling of water vapor in the lower troposphere has been designed, tested, and is in routine operation. The laser transmitter for the DIAL instrument uses a widely tunable external cavity diode laser (ECDL) to injection seed two cascaded semiconductor optical amplifiers (SOA) to produce a laser transmitter that accesses the 824-841 nm spectral range. The DIAL receiver utilizes a 28-cm-diameter Schmidt-Cassegrain telescope, an avalanche photodiode (APD) detector, and a narrow band optical filter to collect, discriminate, and measure the scattered light. A technique of correcting for the wavelength-dependent incident angle upon the narrow band optical filter as a function of range has been developed to allow accurate water vapor profiles to be measured down to 225 m above the surface. Data comparisons using the DIAL instrument and co-located radiosonde measurements are presented demonstrating the capabilities of the DIAL instrument." } @PhDThesis{ack_taylordiss:2009, title = "A multistate mark recapture analysis to estimate reproductive rate in the Steller sea lion (Eumetopias jubatus), an endangered species", author = "Rebecca L. Taylor", year = "2009", Month = "May", school = "Montana State University", location = "Bozeman, MT", url = "http://etd.lib.montana.edu/etd/2009/taylor/TaylorR0509.pdf", abstract = "The Steller sea lion is an endangered species whose reproductive rate estimates need to be updated. The species is divided into two populations: the endangered western population has declined over 80% from historical levels, while the threatened eastern population has been increasing at approximately 3% for the past three decades. The statistically most compelling reproductive rate estimates for this species are based on now out of date population dynamics, and hence are not applicable to current concerns. Extensive recent branding and resighting efforts by the Alaska Department of Fish and Game in Southeast Alaska make possible an updated estimation of eastern population Steller sea lion reproductive rates. However, the complexity of these data required a different statistical approach than is typically used to estimate reproduction in marked and resighted animals. I developed a novel statistical analysis, based upon a multistate mark recapture likelihood function, specifically to analyze the Southeast Alaska Steller sea lion data. The likelihood function estimates a reproductive rate when only adult females (not pups) are marked, female sightability is correlated with reproductive status, state classification uncertainty is present and the population is open to births during many of the resighting intervals. I apply this analysis to the Southeast Alaska Steller sea lion data and estimate a reproductive rate of 0.66 (0.55, 0.77). Not only does this provide a reproductive rate estimate for the eastern population, which is important for monitoring its health, but it also provides a basis for comparison to the endangered western population. Furthermore, the Alaska Department of Fish and Game continues to have an active branding and resighting program. The methods developed here can be applied to future data collected in either population." } #nonrefereed publications @article{humphries_curiosity, author = "Seth Humphries", title = "Mars gets a {C}urious new rover", journal = "KSL News", volume = "http://www.ksl.com/?nid=968&sid=18124321", month = "November", year = "2011", url = "http://www.ksl.com/?nid=968&sid=18124321" } @book{ pubs_or:2004, author = "Dani Or and Scott B. Jones and Jeff R. VanShaar and \textbf{\sffamily Seth D. Humphries} and Louis Koberstein", title = "WinTDR v. 6.1: A Windows-based time domain reflectometry program for measurement of soil water content and electrical conductivity", year = "2004", publisher = "Utah State University, Soil Physics Group", city="Logan", state="UT", url="http://www.usu.edu/soilphysics/wintdr/documentation.cfm" }