Liquid Desiccant in Air Conditioners (open access)

Liquid Desiccant in Air Conditioners

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses air conditioning that would reduce system corrosion and be more efficient as part of the "Nano-Engineered Porous Hollow Fiber Membrane-Based Air Conditioning System" project.
Date: February 15, 2012
Creator: United Technologies Research Center
Object Type: Text
System: The UNT Digital Library
Measurement of Moisture Outgassing of the Plastic-Bonded TATB Explosive LX-17 (open access)

Measurement of Moisture Outgassing of the Plastic-Bonded TATB Explosive LX-17

None
Date: February 15, 2012
Creator: Small, W; Glascoe, E A & Overturf, G E
Object Type: Article
System: The UNT Digital Library
Membrane-Based Absorption Refrigeration Systems (open access)

Membrane-Based Absorption Refrigeration Systems

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses air conditioning that uses a heat-powered refrigeration system as part of the "Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat" project.
Date: February 15, 2012
Creator: University of Florida
Object Type: Text
System: The UNT Digital Library
Membrane Dehumidifier (open access)

Membrane Dehumidifier

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses air conditioning with more energy efficient dehumidifying as part of the "High-Efficiency, On-Line Membrane Air Dehumidifier Enabling Sensible Cooling for Warm and Humid Climates" project.
Date: February 15, 2012
Creator: ADMA Products
Object Type: Text
System: The UNT Digital Library
New Sources of Gravitational Waves During Inflation (open access)

New Sources of Gravitational Waves During Inflation

We point out that detectable inflationary tensor modes can be generated by particle or string sources produced during inflation, consistently with the requirements for inflation and constraints from scalar fluctuations. We show via examples that this effect can dominate over the contribution from quantum fluctuations of the metric, occurring even when the inflationary potential energy is too low to produce a comparable signal. Thus a detection of tensor modes from inflation does not automatically constitute a determination of the inflationary Hubble scale.
Date: February 15, 2012
Creator: Senatore, Leonardo; Silverstein, Eva; /Stanford U., Phys. Dept. /SLAC; Zaldarriaga, Matias & /Princeton, Inst. Advanced Study
Object Type: Report
System: The UNT Digital Library
NLO Vector Boson Production With Light Jets (open access)

NLO Vector Boson Production With Light Jets

In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to …
Date: February 15, 2012
Creator: Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T. et al.
Object Type: Article
System: The UNT Digital Library
Observation and Study of the Baryonic B-meson Decays B to D(*) p pbar (pi) (pi) (open access)

Observation and Study of the Baryonic B-meson Decays B to D(*) p pbar (pi) (pi)

We present results for B-meson decay modes involving a charm meson, protons, and pions using 455 x 10{sup 6} B{bar B} pairs recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider. The branching fractions are measured for the following ten decays: {bar B}{sup 0} {yields} D{sup 0}p{bar p}, {bar B}{sup 0} {yields} D*{sup 0}p{bar p}, {bar B}{sup 0} {yields} D{sup +}p{bar p}{pi}{sup -}, {bar B}{sup 0} {yields} D*{sup +}p{bar p}{pi}{sup -}, B{sup -} {yields} D{sup 0}p{bar p}{pi}{sup -}, B{sup -} {yields} D*{sup 0}pp{pi}{sup -}, {bar B}{sup 0} {yields} D{sup 0}p{bar p}{pi}{sup -}{pi}{sup +}, {bar B}{sup 0} {yields} D*{sup 0}p{bar p}{pi}{sup -}{pi}{sup +}, B{sup -} {yields} D{sup +}p{bar p}{pi}{sup -}{pi}{sup -}, and B{sup -} {yields} D*{sup +}p{bar p}{pi}{sup -}{pi}{sup -}. The four B{sup -} and the two five-body B{sup 0} modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(p{bar p}) and M(D{sup (*)0}p) invariant mass distributions show enhancements near threshold values. In the four-body mode {bar B}{sup 0} {yields} D{sup +}p{bar p}{pi}{sup -}, the M(p{pi}{sup -}) distribution shows a narrow structure of unknown origin near 1.5GeV/c{sup 2}. The distributions …
Date: February 15, 2012
Creator: del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J. et al.
Object Type: Article
System: The UNT Digital Library
OPERATIONAL AND COMPOSITIONAL FACTORS THAT AFFECT THE PERFORMANCE PROPERTIES OF ARP/MCU SALTSTONE GROUT (open access)

OPERATIONAL AND COMPOSITIONAL FACTORS THAT AFFECT THE PERFORMANCE PROPERTIES OF ARP/MCU SALTSTONE GROUT

The Saltstone Production Facility (SPF) receives low level waste (LLW) salt solution from Tank 50H for treatment and disposal. Tank 50H receives transfers from the Effluent Treatment Project (ETP), the H-Canyon General Purpose Evaporator, and the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT). At the SPF, the LLW is mixed with premix (a cementitious mixture of portland cement (PC), blast furnace slag (BFS) and Class F fly ash (FA)) in a Readco mixer to produce fresh (uncured) saltstone that is transferred to the Saltstone Disposal Facility (SDF) vaults. The saltstone formulation (mix design) must produce a grout waste form that meets both placement and performance properties. In previous simulated saltstone studies, multiple compositional factors were identified that drive the performance properties of saltstone made from the projected ARP/MCU salt solution. This composition was selected as salt solution simulant since ARP/MCU is the primary influent into Tank 50H. The primary performance property investigated was hydraulic conductivity since it is a variable input property to the saltstone Performance Assessment (PA) transport model. In addition, the porosity, also referred to as void structure, is another variable that impacts the PA response. In addition, Young's modulus …
Date: February 15, 2012
Creator: Reigel, M.; Edwards, T. & Pickenheim, B.
Object Type: Report
System: The UNT Digital Library
RADIUM AND THORIUM SORPTION BY MONOSODIUM TITANATE (MST) AND MODIFIED MST (mMST) (open access)

RADIUM AND THORIUM SORPTION BY MONOSODIUM TITANATE (MST) AND MODIFIED MST (mMST)

A series of tests were planned to examine the removal of Ra and Th by monosodium titanate (MST) and modified monosodium titanate (mMST). Simulated waste solutions were prepared containing Ra and Th, along with Sr, Np, Pu, and U. Following simulant preparation the simulants were filtered through 0.45-m filters. Analysis of the simulants indicated no Th in the filtered solution. This is due to the very low solubility of Th in alkaline solutions. Based on the reported detection limits for {sup 228}Th by gamma analyses, the solubility of Th in the simulant solutions is < 3.0E-10 g/L or < 1.3E-12 M. Therefore, data could not be obtained regarding the removal of Th by MST and mMST; however, testing proceeded to examine the removal of Ra. Sorption testing indicated that Ra, like Sr, is very rapidly removed from solution by both MST and mMST. The Ra concentration in solution fell below the method detection limit (MDL) within 30 minutes of contact with MST, and within 2 hours of contact with mMST, when tested at 25 C using a 5.6 M Na simulant. Additional testing examined the effects of ionic strength and temperature on the MST and mMST performance. Results from these …
Date: February 15, 2012
Creator: Taylor-Pashow, K. & Hobbs, D.
Object Type: Report
System: The UNT Digital Library
Real-structure effects: Band gaps of Mg_xZn_{1-x}O, Cd_xZn_{1-x}O, and n-type ZnO from ab-initio calculations (open access)

Real-structure effects: Band gaps of Mg_xZn_{1-x}O, Cd_xZn_{1-x}O, and n-type ZnO from ab-initio calculations

Many-body perturbation theory is applied to compute the quasiparticle electronic structures and the optical-absorption spectra (including excitonic effects) for several transparent conducting oxides. We discuss HSE+G{sub 0}W{sub 0} results for band structures, fundamental band gaps, and effective electron masses of MgO, ZnO, CdO, SnO{sub 2}, SnO, In{sub 2}O{sub 3}, and SiO{sub 2}. The Bethe-Salpeter equation is solved to account for excitonic effects in the calculation of the frequency-dependent absorption coefficients. We show that the HSE+G{sub 0}W{sub 0} approach and the solution of the Bethe-Salpeter equation are very well-suited to describe the electronic structure and the optical properties of various transparent conducting oxides in good agreement with experiment.
Date: February 15, 2012
Creator: Schleife, A & Bechstedt, F
Object Type: Article
System: The UNT Digital Library
Science and Technology Review March 2012 (open access)

Science and Technology Review March 2012

This month's issue has the following articles: (1) Honoring a Legacy of Service to the Nation - The nation pays tribute to George Miller, who retired in December 2011 as the Laboratory's tenth director; (2) Life-Extension Programs Encompass All Our Expertise - Commentary by Bruce T. Goodwin; (3) Extending the Life of an Aging Weapon - Stockpile stewards have begun work on a multiyear effort to extend the service life of the aging W78 warhead by 30 years; (4) Materials by Design - Material microstructures go three-dimensional with improved additive manufacturing techniques developed at Livermore; (5) Friendly Microbes Power Energy-Producing Devices - Livermore researchers are demonstrating how electrogenic bacteria and microbial fuel cell technologies can produce clean, renewable energy and purify water; and (6) Chemical Sensor Is All Wires, No Batteries - Livermore's 'batteryless' nanowire sensor could benefit applications in diverse fields such as homeland security and medicine.
Date: February 15, 2012
Creator: Nikolic, R J
Object Type: Report
System: The UNT Digital Library
Simplifying Multi-loop Integrands of Gauge Theory and Gravity Amplitudes (open access)

Simplifying Multi-loop Integrands of Gauge Theory and Gravity Amplitudes

We use the duality between color and kinematics to simplify the construction of the complete four-loop four-point amplitude of N = 4 super-Yang-Mills theory, including the nonplanar contributions. The duality completely determines the amplitude's integrand in terms of just two planar graphs. The existence of a manifestly dual gauge-theory amplitude trivializes the construction of the corresponding N = 8 supergravity integrand, whose graph numerators are double copies (squares) of the N = 4 super-Yang-Mills numerators. The success of this procedure provides further nontrivial evidence that the duality and double-copy properties hold at loop level. The new form of the four-loop four-point supergravity amplitude makes manifest the same ultraviolet power counting as the corresponding N = 4 super-Yang-Mills amplitude. We determine the amplitude's ultraviolet pole in the critical dimension of D = 11/2, the same dimension as for N = 4 super-Yang-Mills theory. Strikingly, exactly the same combination of vacuum integrals (after simplification) describes the ultraviolet divergence of N = 8 supergravity as the subleading-in-1/N{sub c}{sup 2} single-trace divergence in N = 4 super-Yang-Mills theory.
Date: February 15, 2012
Creator: Bern, Z.; Carrasco, J.J.M.; Dixon, L.J.; Johansson, H. & Roiban, R.
Object Type: Article
System: The UNT Digital Library
Single-cycle Terahertz Pulses with >0.2 V/A Field Amplitudes via Coherent Transition Radiation (open access)

Single-cycle Terahertz Pulses with >0.2 V/A Field Amplitudes via Coherent Transition Radiation

We demonstrate terahertz pulses with field amplitudes exceeding 0.2 V/{angstrom} generated by coherent transition radiation. Femtosecond, relativistic electron bunches generated at the Linac Coherent Light Source are passed through a beryllium foil, and the emitted radiation is characterized as a function of the bunch duration and charge. Broadband pulses centered at a frequency of 10 THz with energies of 140 {mu}J are measured. These far-below-bandgap pulses drive a nonlinear optical response in a silicon photodiode, with which we perform nonlinear autocorrelations that yield information regarding the terahertz temporal profile. Simulations of the spatiotemporal profile agree well with experimental results.
Date: February 15, 2012
Creator: Daranciang, Dan; Goodfellow, John; Fuchs, Matthias; Wen, Haidan; Ghimire, Shambhu; Reis, David A. et al.
Object Type: Article
System: The UNT Digital Library
Singlet-Doublet Dark Matter (open access)

Singlet-Doublet Dark Matter

In light of recent data from direct detection experiments and the Large Hadron Collider, we explore models of dark matter in which an SU(2){sub L} doublet is mixed with a Standard Model singlet. We impose a thermal history. If the new particles are fermions, this model is already constrained due to null results from XENON100. We comment on remaining regions of parameter space and assess prospects for future discovery. We do the same for the model where the new particles are scalars, which at present is less constrained. Much of the remaining parameter space for both models will be probed by the next generation of direct detection experiments. For the fermion model, DeepCore may also play an important role.
Date: February 15, 2012
Creator: Cohen, Timothy; /SLAC /Michigan U., MCTP; Kearney, John; Pierce, Aaron; /Michigan U., MCTP; Tucker-Smith, David et al.
Object Type: Report
System: The UNT Digital Library
Small Body Exploration Technologies as Precursors for Interstellar Robotics (open access)

Small Body Exploration Technologies as Precursors for Interstellar Robotics

The scientific activities undertaken to explore our Solar System will be the same as required someday at other stars. The systematic exploration of primitive small bodies throughout our Solar System requires new technologies for autonomous robotic spacecraft. These diverse celestial bodies contain clues to the early stages of the Solar System's evolution as well as information about the origin and transport of water-rich and organic material, the essential building blocks for life. They will be among the first objects studied at distant star systems. The technologies developed to address small body and outer planet exploration will form much of the technical basis for designing interstellar robotic explorers. The Small Bodies Assessment Group, which reports to NASA, initiated a Technology Forum in 2011 that brought together scientists and technologists to discuss the needs and opportunities for small body robotic exploration in the Solar System. Presentations and discussions occurred in the areas of mission and spacecraft design, electric power, propulsion, avionics, communications, autonomous navigation, remote sensing and surface instruments, sampling, intelligent event recognition, and command and sequencing software. In this paper, the major technology themes from the Technology Forum are reviewed, and suggestions are made for developments that will have the largest …
Date: February 15, 2012
Creator: Noble, Robert & Sykes, Mark V.
Object Type: Article
System: The UNT Digital Library
Statistical line-by-line model for atomic spectra in intermediate coupling (open access)

Statistical line-by-line model for atomic spectra in intermediate coupling

None
Date: February 15, 2012
Creator: Iglesias, C
Object Type: Article
System: The UNT Digital Library
Study of CP Violation in Dalitz-Plot Analyses of B-Meson Decays to Three Kaons (open access)

Study of CP Violation in Dalitz-Plot Analyses of B-Meson Decays to Three Kaons

The Standard Model (SM) explains CP violation in terms of the CKM matrix. The BABAR experiment was designed mainly to test the CKM model in B decays. B decays that proceed through b {yields} s loop diagrams, of which B {yields} KKK decays are an example, are sensitive to new physics effects that could lead to deviations from the CKM predictions for CP violation. We present studies of CP violation in the decays B{sup +} {yields} K{sup +}K{sup -}K{sup +}, B{sup +} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sup +}, and B{sup 0} {yields} K{sup +}K{sup -}K{sub S}{sup 0}, using a Dalitz plot amplitude analysis. These studies are based on approximately 470 million B{bar B} decays collected by BABAR at the PEP-II collider at SLAC. We perform measurements of time-dependent CP violation in B{sup 0} {yields} K{sup +}K{sup -}K{sub S}{sup 0}, including B{sup 0} {yields} {phi}K{sub S}{sup 0}. We measure a CP-violating phase {beta}{sub eff} ({phi}K{sub S}{sup 0}) = 0.36 {+-} 0.11 {+-} 0.04 rad., in agreement with the SM. This is the world's most precise measurement of this quantity. We also measure direct CP asymmetries in all three decay modes, including the direct CP asymmetry A{sub CP} ({phi}K{sup +}) = …
Date: February 15, 2012
Creator: Lindquist, Brian
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Summary Report on CO{sub 2} Geologic Sequestration & Water Resources Workshop (open access)

Summary Report on CO{sub 2} Geologic Sequestration & Water Resources Workshop

The United States Environmental Protection Agency (EPA) and Lawrence Berkeley National Laboratory (LBNL) jointly hosted a workshop on “CO{sub 2} Geologic Sequestration and Water Resources” in Berkeley, June 1–2, 2011. The focus of the workshop was to evaluate R&D needs related to geological storage of CO{sub 2} and potential impacts on water resources. The objectives were to assess the current status of R&D, to identify key knowledge gaps, and to define specific research areas with relevance to EPA’s mission. About 70 experts from EPA, the DOE National Laboratories, industry, and academia came to Berkeley for two days of intensive discussions. Participants were split into four breakout session groups organized around the following themes: Water Quality and Impact Assessment/Risk Prediction; Modeling and Mapping of Area of Potential Impact; Monitoring and Mitigation; Wells as Leakage Pathways. In each breakout group, participants identified and addressed several key science issues. All groups developed lists of specific research needs; some groups prioritized them, others developed short-term vs. long-term recommendations for research directions. Several crosscutting issues came up. Most participants agreed that the risk of CO{sub 2} leakage from sequestration sites that are properly selected and monitored is expected to be low. However, it also became …
Date: February 15, 2012
Creator: Varadharajan, C.; Birkholzer, J.; Kraemer, S.; Porse, S.; Carroll, S.; Wilkin, R. et al.
Object Type: Report
System: The UNT Digital Library
Ultrafast Photovoltaic Response in Ferroelectric Nanolayers (open access)

Ultrafast Photovoltaic Response in Ferroelectric Nanolayers

We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric PbTiO3 via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering to visualize atomic displacements on femtosecond timescales, photoinduced changes in the unit-cell tetragonality are observed. These are driven by the motion of photogenerated free charges within the ferroelectric and can be simply explained by a model including both shift and screening currents, associated with the displacement of electrons first antiparallel to and then parallel to the ferroelectric polarization direction.
Date: February 15, 2012
Creator: Daranciang, Dan
Object Type: Article
System: The UNT Digital Library
Using SciDB to Support Photon Science Data Analysis (open access)

Using SciDB to Support Photon Science Data Analysis

Array data analytic systems like SciDB hold great potential to accelerate processing data from SLAC's Linac Coherent Light Source and other experiments. SciDB is unique in its ability to integrate storage and processing of array data efficiently, providing both space-efficient storage and out-of-memory efficient parallel array processing. We describe a recent effort to leverage SciDB to store and process LCLS data. The work includes development of software to import data into SciDB, subsequent benchmarks, and interactive manipulation of data in SciDB.
Date: February 15, 2012
Creator: Becla, Jack; Wang, Daniel & lim, Kian-Tat
Object Type: Report
System: The UNT Digital Library
X-Ray Diffraction on NIF (open access)

X-Ray Diffraction on NIF

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.
Date: February 15, 2012
Creator: Eggert, J H & Wark, J
Object Type: Article
System: The UNT Digital Library
Zeroing in on Supersymmetric Radiation Amplitude Zeros (open access)

Zeroing in on Supersymmetric Radiation Amplitude Zeros

Radiation amplitude zeros have long been used to test the Standard Model. Here, we consider the supersymmetric radiation amplitude zero in chargino-neutralino associated production, which can be observed at the luminosity upgraded LHC. Such an amplitude zero only occurs if the neutralino has a large wino fraction and hence this observable can be used to determine the neutralino eigenstate content. We find that this observable can be measured by comparing the p{sub T} spectrum of the softest lepton in the trilepton {tilde {chi}}{sub 1}{sup {+-}} {tilde {chi}}{sub 2}{sup 0} decay channel to that of a control process such as {tilde {chi}}{sub 1}{sup +} {tilde {chi}}{sub 1}{sup -} or {tilde {chi}}{sub 2}{sup 0} {tilde {chi}}{sub 2}{sup 0}. We test this technique on a previously generated model sample of the 19 dimensional parameter space of the phenomenological MSSM, and find that it is effective in determining the wino content of the neutralino.
Date: February 15, 2012
Creator: Hewett, JoAnne L.; Ismail, Ahmed & Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies (open access)

Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies

We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of {approx}71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (mLSP < 50 GeV) annihilating into {tau}-pairs and heavier LSPs annihilating into b{bar b}. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.
Date: March 15, 2012
Creator: Cotta, R. C.; Drlica-Wagner, A.; Murgia, S.; Bloom, E. D.; Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS) (open access)

Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficient soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as …
Date: March 15, 2012
Creator: Spangler, Lee; Bricklemyer, Ross & Brown, David
Object Type: Report
System: The UNT Digital Library