The Properties of Convective Clouds Over the Western Pacific and Their Relationship to the Environment of Tropical Cyclones

DTIC Science & Technology

2011-09-30

assimilating satellite, radar and in-situ observations for improved numerical simulations of major Typhoons (Jiangmi, Sinlaku, Nuri and Hagupit) during T- PARC ...oceans from radar , aircraft and satellite data; 2) Derive an accurate mesoscale environment of convective systems through the assimilation of satellite... radar , lidar and in-situ data; 3) Evaluate the quality of the global forecast system (e.g., Navy Operational Global Atmospheric Prediction System or

The Global Ocean Observing System

NASA Technical Reports Server (NTRS)

Kester, Dana

1992-01-01

A Global Ocean Observing System (GOOS) should be established now with international coordination (1) to address issues of global change, (2) to implement operational ENSO forecasts, (3) to provide the data required to apply global ocean circulation models, and (4) to extract the greatest value from the one billion dollar investment over the next ten years in ocean remote sensing by the world's space agencies. The objectives of GOOS will focus on climatic and oceanic predictions, on assessing coastal pollution, and in determining the sustainability of living marine resources and ecosystems. GOOS will be a complete system including satellite observations, in situ observations, numerical modeling of ocean processes, and data exchange and management. A series of practical and economic benefits will be derived from the information generated by GOOS. In addition to the marine science community, these benefits will be realized by the energy industries of the world, and by the world's fisheries. The basic oceanic variables that are required to meet the oceanic and predictability objectives of GOOS include wind velocity over the ocean, sea surface temperature and salinity, oceanic profiles of temperature and salinity, surface current, sea level, the extent and thickness of sea ice, the partial pressure of CO2 in surface waters, and the chlorophyll concentration of surface waters. Ocean circulation models and coupled ocean-atmosphere models can be used to evaluate observing system design, to assimilate diverse data sets from in situ and remotely sensed observations, and ultimately to predict future states of the system. The volume of ocean data will increase enormously over the next decade as new satellite systems are launched and as complementary in situ measuring systems are deployed. These data must be transmitted, quality controlled, exchanged, analyzed, and archived with the best state-of-the-art computational methods.

In Situ Optical Creep Observation of Joint-Scale Tin-Silver-Copper Solder Shear Samples

NASA Astrophysics Data System (ADS)

Herkommer, Dominik; Reid, Michael; Punch, Jeff

2009-10-01

In this paper the creep behavior of lead-free 96.5Sn-3.0Ag-0.5Cu solder is evaluated. A series of creep tests at different stress/temperature and strain rate/temperature pairs has been conducted. The tests were observed in situ with a high-magnification camera system. Optical observation results are presented from selected tests, showing the occurrence of surface effects such as shear bands, voiding, and rumpling. From these observations the main deformation mechanisms were derived and compiled in terms of their dependence on the test conditions.

The Isinglass Auroral Sounding Rocket Campaign: data synthesis incorporating remote sensing, in situ observations, and modelling

NASA Astrophysics Data System (ADS)

Lynch, K. A.; Clayton, R.; Roberts, T. M.; Hampton, D. L.; Conde, M.; Zettergren, M. D.; Burleigh, M.; Samara, M.; Michell, R.; Grubbs, G. A., II; Lessard, M.; Hysell, D. L.; Varney, R. H.; Reimer, A.

2017-12-01

The NASA auroral sounding rocket mission Isinglass was launched from Poker Flat Alaska in winter 2017. This mission consists of two separate multi-payload sounding rockets, over an array of groundbased observations, including radars and filtered cameras. The science goal is to collect two case studies, in two different auroral events, of the gradient scale sizes of auroral disturbances in the ionosphere. Data from the in situ payloads and the groundbased observations will be synthesized and fed into an ionospheric model, and the results will be studied to learn about which scale sizes of ionospheric structuring have significance for magnetosphere-ionosphere auroral coupling. The in situ instrumentation includes thermal ion sensors (at 5 points on the second flight), thermal electron sensors (at 2 points), DC magnetic fields (2 point), DC electric fields (one point, plus the 4 low-resource thermal ion RPA observations of drift on the second flight), and an auroral precipitation sensor (one point). The groundbased array includes filtered auroral imagers, the PFISR and SuperDarn radars, a coherent scatter radar, and a Fabry-Perot interferometer array. The ionospheric model to be used is a 3d electrostatic model including the effects of ionospheric chemistry. One observational and modelling goal for the mission is to move both observations and models of auroral arc systems into the third (along-arc) dimension. Modern assimilative tools combined with multipoint but low-resource observations allow a new view of the auroral ionosphere, that should allow us to learn more about the auroral zone as a coupled system. Conjugate case studies such as the Isinglass rocket flights allow for a test of the models' intepretation by comparing to in situ data. We aim to develop and improve ionospheric models to the point where they can be used to interpret remote sensing data with confidence without the checkpoint of in situ comparison.

The preparation of Zr-deuteride and phase stability studies of the Zr-D system

NASA Astrophysics Data System (ADS)

Maimaitiyili, T.; Steuwer, A.; Bjerkén, C.; Blomqvist, J.; Hoelzel, M.; Ion, J. C.; Zanellato, O.

2017-03-01

Deuteride phases in the zirconium-deuterium system in the temperature range 25-286 °C have been studied in-situ by high resolution neutron diffraction. The study primarily focused on observations of δ→γ transformation at 180 °C, and the peritectoid reaction α + δ ↔ γ at 255 °C in commercial grade Zr powder that was deuterated to a deuterium/Zr ratio of one to one. A detailed description of the zirconium deuteride preparation route by high temperature gas loading is also described. The lattice parameters of α-Zr, δ-ZrDx and ε-ZrDx were determined by whole pattern crystal structure analysis, using Rietveld and Pawley refinements, and are in good agreement with values reported in the literature. The controversial γ-hydride phase was observed both in-situ and ex-situ in deuterated Zr powder after a heat treatment at 286 °C and slow cooling.

Satellite data relay and platform locating in oceanography. Report of the In Situ Ocean Science Working Group

NASA Technical Reports Server (NTRS)

Chase, R.; Cote, C.; Davis, R. E.; Dugan, J.; Frame, D. D.; Halpern, D.; Kerut, E.; Kirk, R.; Mcgoldrick, L.; Mcwilliams, J. C.

1983-01-01

The present and future use of satellites to locate offshore platforms and relay data from in situ sensors to shore was examined. A system of the ARGOS type will satisfy the increasing demand for oceanographic information through data relay and platform location. The improved ship navigation provided by the Global Positioning System (GPS) will allow direct observation of currents from underway ships. Ocean systems are described and demand estimates on satellite systems are determined. The capabilities of the ARGOS system is assessed, including anticipated demand in the next decade.

In-situ analysis of the slip activity during tensile deformation of cast and extruded Mg-10Gd-3Y-0.5Zr (wt.%) at 250 °C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, H.; The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240; Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824

The slip activity and slip interaction in tensile deformation of peak-aged cast and extruded Mg-10Gd-3Y-0.5Zr (wt.%) at 250 °C was investigated using in-situ scanning electron microscopy. Basal slip was the most likely system to be activated during the tensile deformation, while prismatic < a > and pyramidal < c + a > slip also contributed to the deformation. No twinning was observed. The number of non-basal slip systems accounted for ~ 36% of the total active slip systems for the cast alloy, while non-basal slip accounted for 12–17% of the total deformation observations in the extruded alloy. Multiple-slip was observedmore » within grains, and the basal/prismatic pairing type dominated the multiple-slip observations. Slip transfer occurred across grain boundaries and most of the slip transfer observations showed basal-basal type. The involved slip systems of slip transfer pairs were always associated with the same < a > direction. The slip transfer occurred more easily at low angle boundaries (LABs) and boundaries with misorientations greater than 75°. - Highlights: • Slip deformation of a Mg-RE alloy at 250 °C was investigated using in-situ SEM. • The extruded-T5 GW103 alloy did not exhibit a high anisotropic behavior. • Multiple-slip was observed within grains, and basal/prismatic type dominated. • Slip transfer occurred and most of the observations showed basal-basal type. • Slip transfer occurred more easily at LABs and boundaries with misorientations > 75°.« less

Local fluctuations of ozone from 16 km to 45 km deduced from in situ vertical ozone profile

NASA Technical Reports Server (NTRS)

Moreau, G.; Robert, C.

1994-01-01

A vertical ozone profile obtained by an in situ ozone sonde from 16 km to 45 km, has allowed to observe local ozone concentration variations. These variations can be observed, thanks to a fast measurement system based on a UV absorption KrF excimer laser beam in a multipass cell. Ozone standard deviation versus altitude calculated from the mean is derived. Ozone variations or fluctuations are correlated with the different dynamic zones of the stratosphere.

Is There Any Difference between the In Situ and Systemic IL-10 and IFN-γ Production when Clinical Forms of Cutaneous Sporotrichosis Are Compared?

PubMed

Morgado, Fernanda N; Schubach, Armando O; Pimentel, Maria Inês; Lyra, Marcelo R; Vasconcellos, Érica C F; Valete-Rosalino, Claudia M; Conceição-Silva, Fátima

2016-01-01

Fungus of the Sporothrix schenckii complex can produce skin lesions in humans, commonly lymphocutaneous (LC) and fixed (F) forms of sporotrichosis. Some authors have suggested that clinical forms are influenced by differences in virulence and genetic profile of isolates. But little is known about the role of immune response in determining the clinical outcome of sporotrichosis. To verify the profile of systemic and in situ IFN-γ and IL-10 expression in sporotrichosis patients, and consequently to detect any difference between the two compartments and/or clinical presentation, we quantified the number of IFN-γ and IL-10 producer peripheral blood mononuclear cells stimulated with S. schenckii antigen (Ss-Ag) by Elispot, and quantified cytokines expression by in situ immunohistochemistry in the same patient. Three groups were formed: 1- LC (n = 9); 2- F (n = 10); 3- healthy individuals (n = 14). All sporotrichosis patients produced high amounts of systemic IFN- γ when compared to uninfected individuals. No differences were observed between LC and F groups. Regarding in situ IL-10 expression, a difference between LC and F groups was observed: LC lesions presented higher amounts of IL-10 than F lesions differently from systemic IL-10 which showed similarities. Our data suggests that LC lesions present higher IL-10 expression which could be related to regulatory mechanisms for compensating the tissue injury, however favoring fungal persistence in the lesions. Surprisingly, there were no differences in systemic and in situ IFN- γ expression between CL and F patients, although it was significantly higher expressed in these patients than in healthy individuals.

Is There Any Difference between the In Situ and Systemic IL-10 and IFN-γ Production when Clinical Forms of Cutaneous Sporotrichosis Are Compared?

PubMed Central

Morgado, Fernanda N.; Schubach, Armando O.; Pimentel, Maria Inês; Lyra, Marcelo R.; Vasconcellos, Érica C. F.; Valete-Rosalino, Claudia M.; Conceição-Silva, Fátima

2016-01-01

Fungus of the Sporothrix schenckii complex can produce skin lesions in humans, commonly lymphocutaneous (LC) and fixed (F) forms of sporotrichosis. Some authors have suggested that clinical forms are influenced by differences in virulence and genetic profile of isolates. But little is known about the role of immune response in determining the clinical outcome of sporotrichosis. To verify the profile of systemic and in situ IFN-γ and IL-10 expression in sporotrichosis patients, and consequently to detect any difference between the two compartments and/or clinical presentation, we quantified the number of IFN-γ and IL-10 producer peripheral blood mononuclear cells stimulated with S. schenckii antigen (Ss-Ag) by Elispot, and quantified cytokines expression by in situ immunohistochemistry in the same patient. Three groups were formed: 1- LC (n = 9); 2- F (n = 10); 3- healthy individuals (n = 14). All sporotrichosis patients produced high amounts of systemic IFN- γ when compared to uninfected individuals. No differences were observed between LC and F groups. Regarding in situ IL-10 expression, a difference between LC and F groups was observed: LC lesions presented higher amounts of IL-10 than F lesions differently from systemic IL-10 which showed similarities. Our data suggests that LC lesions present higher IL-10 expression which could be related to regulatory mechanisms for compensating the tissue injury, however favoring fungal persistence in the lesions. Surprisingly, there were no differences in systemic and in situ IFN- γ expression between CL and F patients, although it was significantly higher expressed in these patients than in healthy individuals. PMID:27622513

Airborne In Situ and Ground-based Polarimetric Radar Measurements of Tropical Convection in Support of CRYSTAL-FACE

NASA Technical Reports Server (NTRS)

Poellot, Michael R.; Kucera, Paul A.

2004-01-01

This report describes the work performed by the University of North Dakota (UND) under NASA Grant NAG5-11509, titled Airborne In Situ and Ground-based Polarimetric Radar Measurements of Tropical Convection in Support of CRYSTAL-FACE. This work focused on the collection of data by two key platforms: the UND Citation II research aircraft and the NASA NPOL radar system. The CRYSTAL-FACE (C-F) mission addresses several key issues from the NASA Earth System Enterprise, including the variability of water in the atmosphere, the forcing provided by tropical cirrus and the response of the Earth system to this forcing. In situ measurements and radar observations of tropical convection, cirrus clouds and their environment are core elements of C-F. One of the primary issues that C-F is addressing is the relationship of tropical cirrus anvils to precipitating deep convection. The in situ measurements from C-F are being used to validate remote sensing of Earth-Atmosphere properties, increase our knowledge of upper tropospheric water vapor and its distribution, and increase our knowledge of tropical cirrus cloud morphology and composition. Radar measurements, especially polarimetric diversity observations available fiom the NASA NPOL radar, are providing essential information about the initiation, modulation, and dissipation of convective cores and the generation of associated anvils in tropical convection. Specifically, NPOL radar measurements contain information about convective intensity and its vertical structure for comparison with thermodynamic and kinematic environmental measurements observed from soundings. Because of the polarimetric diversity of MOL, statistics on bulk microphysical properties can be retrieved and compared to the other characteristics of convection and associated cirrus anvils. In summary, the central objectives of this proposal were to deploy the UND Citation research aircraft as an in situ sensing platform for this mission and to provide collaborative analyses of the recorded data and to deploy the NPOL radar to observe the characteristics of cirrus and parent convection.

Downscaling, 2-way Nesting, and Data Assimilative Modeling in Coastal and Shelf Waters of the U.S. Mid-Atlantic Bight and Gulf of Maine

NASA Astrophysics Data System (ADS)

Wilkin, J.; Levin, J.; Lopez, A.; Arango, H.

2016-02-01

Coastal ocean models that downscale output from basin and global scale models are widely used to study regional circulation at enhanced resolution and locally important ecosystem, biogeochemical, and geomorphologic processes. When operated as now-cast or forecast systems, these models offer predictions that assist decision-making for numerous maritime applications. We describe such a system for shelf waters of the Mid-Atlantic Bight (MAB) and Gulf of Maine (GoM) where the MARACOOS and NERACOOS associations of U.S. IOOS operate coastal ocean observing systems that deliver a dense observation set using CODAR HF-radar, autonomous underwater glider vehicles (AUGV), telemetering moorings, and drifting buoys. Other U.S. national and global observing systems deliver further sustained observations from moorings, ships, profiling floats, and a constellation of satellites. Our MAB and GoM re-analysis and forecast system uses the Regional Ocean Modeling System (ROMS; myroms.org) with 4-dimensional Variational (4D-Var) data assimilation to adjust initial conditions, boundary conditions, and surface forcing in each analysis cycle. Data routinely assimilated include CODAR velocities, altimeter satellite sea surface height (with coastal corrections), satellite temperature, in situ CTD data from AUGV and ships (NMFS Ecosystem Monitoring voyages), and all in situ data reported via the WMO GTS network. A climatological data assimilative analysis of hydrographic and long-term mean velocity observations specifies the regional Mean Dynamic Topography that augments altimeter sea level anomaly data and is also used to adjust boundary condition biases that would otherwise be introduced in the process of downscaling from global models. System performance is described with respect to the impact of satellite, CODAR and in situ observations on analysis skill. Results from a 2-way nested modeling system that adds enhanced resolution over the NSF OOI Pioneer Array in the central MAB are also shown.

In-situ electric field in human body model in different postures for wireless power transfer system in an electrical vehicle.

PubMed

Shimamoto, Takuya; Laakso, Ilkka; Hirata, Akimasa

2015-01-07

The in-situ electric field of an adult male model in different postures is evaluated for exposure to the magnetic field leaked from a wireless power transfer system in an electrical vehicle. The transfer system is located below the centre of the vehicle body and the transferred power and frequency are 7 kW and 85 kHz, respectively. The in-situ electric field is evaluated for a human model (i) crouching near the vehicle, (ii) lying on the ground with or without his arm stretched, (iii) sitting in the driver's seat, and (iv) standing on a transmitting coil without a receiving coil. In each scenario, the maximum in-situ electric fields are lower than the allowable limit prescribed by international guidelines, although the local magnetic field strength in regions of the human body is higher than the allowable external magnetic field strength. The highest in-situ electric field is observed when the human body model is placed on the ground with his arm extended toward the coils, because of a higher magnetic field around the arm.

The Global Observing System in the Assimilation Context

NASA Technical Reports Server (NTRS)

Reinecker, Michele M.; Gelaro, R.; Pawson, S.; Reichle, R.; McCarty, W.

2011-01-01

Weather and climate analyses and predictions all rely on the global observing system. However, the observing system, whether atmosphere, ocean, or land surface, yields a diverse set of incomplete observations of the different components of Earth s environment. Data assimilation systems are essential to synthesize the wide diversity of in situ and remotely sensed observations into four-dimensional state estimates by combining the various observations with model-based estimates. Assimilation, or associated tools and products, are also useful in providing guidance for the evolution of the observing system of the future. This paper provides a brief overview of the global observing system and information gleaned through assimilation tools, and presents some evaluations of observing system gaps and issues.

Solutions Network Formulation Report. Integrating Salinity Measurements from Aquarius into the Harmful Algal Blooms Observing System

NASA Technical Reports Server (NTRS)

Anderson, Daniel; Lewis, David; Hilbert, Kent

2007-01-01

This Candidate Solution suggests the use of Aquarius sea surface salinity measurements to improve the NOAA/NCDDC (National Oceanic and Atmospheric Administration s National Coastal Data Development Center) HABSOS (Harmful Algal Blooms Observing System) DST (decision support tool) by enhancing development and movement forecasts of HAB events as well as potential species identification. In the proposed configuration, recurring salinity measurements from the Aquarius mission would augment HABSOS sea surface temperature and in situ ocean current measurements. Thermohaline circulation observations combined with in situ measurements increase the precision of HAB event movement forecasting. These forecasts allow coastal managers and public health officials to make more accurate and timely warnings to the public and to better direct science teams to event sites for collection and further measurements.

Evaluation of tropical Pacific observing systems using NCEP and GFDL ocean data assimilation systems

NASA Astrophysics Data System (ADS)

Xue, Yan; Wen, Caihong; Yang, Xiaosong; Behringer, David; Kumar, Arun; Vecchi, Gabriel; Rosati, Anthony; Gudgel, Rich

2017-08-01

The TAO/TRITON array is the cornerstone of the tropical Pacific and ENSO observing system. Motivated by the recent rapid decline of the TAO/TRITON array, the potential utility of TAO/TRITON was assessed for ENSO monitoring and prediction. The analysis focused on the period when observations from Argo floats were also available. We coordinated observing system experiments (OSEs) using the global ocean data assimilation system (GODAS) from the National Centers for Environmental Prediction and the ensemble coupled data assimilation (ECDA) from the Geophysical Fluid Dynamics Laboratory for the period 2004-2011. Four OSE simulations were conducted with inclusion of different subsets of in situ profiles: all profiles (XBT, moorings, Argo), all except the moorings, all except the Argo and no profiles. For evaluation of the OSE simulations, we examined the mean bias, standard deviation difference, root-mean-square difference (RMSD) and anomaly correlation against observations and objective analyses. Without assimilation of in situ observations, both GODAS and ECDA had large mean biases and RMSD in all variables. Assimilation of all in situ data significantly reduced mean biases and RMSD in all variables except zonal current at the equator. For GODAS, the mooring data is critical in constraining temperature in the eastern and northwestern tropical Pacific, while for ECDA both the mooring and Argo data is needed in constraining temperature in the western tropical Pacific. The Argo data is critical in constraining temperature in off-equatorial regions for both GODAS and ECDA. For constraining salinity, sea surface height and surface current analysis, the influence of Argo data was more pronounced. In addition, the salinity data from the TRITON buoys played an important role in constraining salinity in the western Pacific. GODAS was more sensitive to withholding Argo data in off-equatorial regions than ECDA because it relied on local observations to correct model biases and there were few XBT profiles in those regions. The results suggest that multiple ocean data assimilation systems should be used to assess sensitivity of ocean analyses to changes in the distribution of ocean observations to get more robust results that can guide the design of future tropical Pacific observing systems.

Architectures Toward Reusable Science Data Systems

NASA Technical Reports Server (NTRS)

Moses, John Firor

2014-01-01

Science Data Systems (SDS) comprise an important class of data processing systems that support product generation from remote sensors and in-situ observations. These systems enable research into new science data products, replication of experiments and verification of results. NASA has been building systems for satellite data processing since the first Earth observing satellites launched and is continuing development of systems to support NASA science research and NOAA's Earth observing satellite operations. The basic data processing workflows and scenarios continue to be valid for remote sensor observations research as well as for the complex multi-instrument operational satellite data systems being built today.

Assimilation of spatially sparse in situ soil moisture networks into a continuous model domain

USDA-ARS?s Scientific Manuscript database

Growth in the availability of near-real-time soil moisture observations from ground-based networks has spurred interest in the assimilation of these observations into land surface models via a two-dimensional data assimilation system. However, the design of such systems is currently hampered by our ...

High-Temperature Properties of Mold Flux Observed and Measured In Situ by Single/Double Hot-Thermocouple Technique

NASA Astrophysics Data System (ADS)

Wang, Wanlin; Lyu, Peisheng; Zhou, Lejun; Li, Huan; Zhang, Tongsheng

2018-05-01

Mold flux plays very important roles in the continuous casting process, and its high-temperature properties affect the quality of the final as-cast product greatly. Investigations on the melting, isothermal and nonisothermal crystallization, and phase evolution behaviors under a simulated temperature field for the mold flux system using the single/double hot-thermocouple technique (S/DHTT) were reviewed. Meanwhile, further in situ observations on the wetting behavior and heat transfer ability of the mold flux system were also carried out using the S/DHTT. The results summarized here provide a clear understanding of both the high-temperature properties of mold flux and the detailed application of advanced real-time visual high-temperature S/DHTT to this molten slag system.

In-situ Crystallization of Highly Volatile Commercial Mold Flux Using an Isolated Observation System in the Confocal Laser Scanning Microscope

NASA Astrophysics Data System (ADS)

Park, Jun-Yong; Ryu, Jae Wook; Sohn, Il

2014-08-01

The in situ crystallization behavior of highly volatile commercial mold fluxes for medium carbon steels was investigated using the confocal laser scanning microscope (CLSM) equipped with an optimized isolated observation system. The highly volatile compounds of the mold flux were suppressed during heating allowing direct observation in the CLSM. Cooling rates of 25, 50, 100, 400, and 800 K/min were incorporated and continuous cooling transformation (CCT) diagrams of 4 different commercial mold fluxes for medium carbon steels were developed. Identification of the crystalline phase was conducted with XRD and SEM-EDS analysis. A cuspidine crystalline was observed in all samples at various cooling rates. With higher basicity, CaF2, and NaF, the crystallization of the fluxes was enhanced according to the CCT diagram. As the slag structure becomes depolymerized, the diffusion rate of the cathodic ions seems to increase.

A Smart Sensor Web for Ocean Observation: Integrated Acoustics, Satellite Networking, and Predictive Modeling

NASA Astrophysics Data System (ADS)

Arabshahi, P.; Chao, Y.; Chien, S.; Gray, A.; Howe, B. M.; Roy, S.

2008-12-01

In many areas of Earth science, including climate change research, there is a need for near real-time integration of data from heterogeneous and spatially distributed sensors, in particular in-situ and space- based sensors. The data integration, as provided by a smart sensor web, enables numerous improvements, namely, 1) adaptive sampling for more efficient use of expensive space-based sensing assets, 2) higher fidelity information gathering from data sources through integration of complementary data sets, and 3) improved sensor calibration. The specific purpose of the smart sensor web development presented here is to provide for adaptive sampling and calibration of space-based data via in-situ data. Our ocean-observing smart sensor web presented herein is composed of both mobile and fixed underwater in-situ ocean sensing assets and Earth Observing System (EOS) satellite sensors providing larger-scale sensing. An acoustic communications network forms a critical link in the web between the in-situ and space-based sensors and facilitates adaptive sampling and calibration. After an overview of primary design challenges, we report on the development of various elements of the smart sensor web. These include (a) a cable-connected mooring system with a profiler under real-time control with inductive battery charging; (b) a glider with integrated acoustic communications and broadband receiving capability; (c) satellite sensor elements; (d) an integrated acoustic navigation and communication network; and (e) a predictive model via the Regional Ocean Modeling System (ROMS). Results from field experiments, including an upcoming one in Monterey Bay (October 2008) using live data from NASA's EO-1 mission in a semi closed-loop system, together with ocean models from ROMS, are described. Plans for future adaptive sampling demonstrations using the smart sensor web are also presented.

A Video Game Platform for Exploring Satellite and In-Situ Data Streams

NASA Astrophysics Data System (ADS)

Cai, Y.

2014-12-01

Exploring spatiotemporal patterns of moving objects are essential to Earth Observation missions, such as tracking, modeling and predicting movement of clouds, dust, plumes and harmful algal blooms. Those missions involve high-volume, multi-source, and multi-modal imagery data analysis. Analytical models intend to reveal inner structure, dynamics, and relationship of things. However, they are not necessarily intuitive to humans. Conventional scientific visualization methods are intuitive but limited by manual operations, such as area marking, measurement and alignment of multi-source data, which are expensive and time-consuming. A new development of video analytics platform has been in progress, which integrates the video game engine with satellite and in-situ data streams. The system converts Earth Observation data into articulated objects that are mapped from a high-dimensional space to a 3D space. The object tracking and augmented reality algorithms highlight the objects' features in colors, shapes and trajectories, creating visual cues for observing dynamic patterns. The head and gesture tracker enable users to navigate the data space interactively. To validate our design, we have used NASA SeaWiFS satellite images of oceanographic remote sensing data and NOAA's in-situ cell count data. Our study demonstrates that the video game system can reduce the size and cost of traditional CAVE systems in two to three orders of magnitude. This system can also be used for satellite mission planning and public outreaching.

Heliophysical Explorers (HELEX): Solar Orbiter and Sentinels - Report of the Joint Science and Technology Definition Team (JSTDT)

NASA Technical Reports Server (NTRS)

2008-01-01

Heliophysical Explorers (HELEX) brings together and augments the unique capabilities of ESA's Solar Orbiter mission (near-Sun and out-of-ecliptic in-situ plus remote-sensing observations) with those of NASA's Inner Heliospheric Sentinels (in-situ observations from multiple platforms arrayed at varying radial distances and azimuthal locations in the near-ecliptic plane)to investigate, characterize, and understand how the Sun determines the environment of the inner solar system and, more broadly, generates the heliosphere itself. This joint ESA-NASA science program offers a unique opportunity for coordinated, correlative measurements, resulting in a combined observational capability and science return that far outweighs that of either mission alone. Building on the knowledge gained from missions like Helios and Ulysses, and STEREO, HELEX will bring to bear the power of multipoint, in-situ measurements using previously unavailable instrumental capabilities in combination with remote-sensing observations from a new, inner heliospheric perspective to answer fundamental questions about the Sun-heliosphere linkage.

Observation of an electron band above the Fermi level in FeTe₀.₅₅Se₀.₄₅ from in-situ surface doping

DOE PAGES

Zhang, P.; Richard, P.; Xu, N.; ...

2014-10-27

We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe₀.₅₅Se₀.₄₅. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily-electron-doped KFe₂₋ xSe₂ compound.

Building a federated data infrastructure for integrating the European Supersites

NASA Astrophysics Data System (ADS)

Freda, Carmela; Cocco, Massimo; Puglisi, Giuseppe; Borgstrom, Sven; Vogfjord, Kristin; Sigmundsson, Freysteinn; Ergintav, Semih; Meral Ozel, Nurcan; Consortium, Epos

2017-04-01

The integration of satellite and in-situ Earth observations fostered by the GEO Geohazards Supersites and National Laboratories (GSNL) initiative is aimed at providing access to spaceborne and in-situ geoscience data for selected sites prone to earthquake, volcanic eruptions and/or other environmental hazards. The initiative was launched with the "Frascati declaration" at the conclusion of the 3rd International Geohazards workshop of the Group of Earth Observation (GEO) held in November 2007 in Frascati, Italy. The development of the GSNL and the integration of in-situ and space Earth observations require the implementation of in-situ e-infrastructures and services for scientific users and other stakeholders. The European Commission has funded three projects to support the development of the European supersites: FUTUREVOLC for the Icelandic volcanoes, MED-SUV for Mt. Etna and Campi Flegrei/Vesuvius (Italy), and MARSITE for the Marmara Sea near fault observatory (Turkey). Because the establishment of a network of supersites in Europe will, among other advantages, facilitate the link with the Global Earth Observation System of Systems (GEOSS), EPOS (the European Plate Observing System) has supported these initiatives by integrating the observing systems and infrastructures developed in these three projects in its implementation plan aimed at integrating existing and new research infrastructures for solid Earth sciences. In this contribution we will present the EPOS federated approach and the key actions needed to: i) develop sustainable long-term Earth observation strategies preceding and following earthquakes and volcanic eruptions; ii) develop an innovative integrated e-infrastructure component necessary to create an effective service for users; iii) promote the strategic and outreach actions to meet the specific user needs; iv) develop expertise in the use and interpretation of Supersites data in order to promote capacity building and timely transfer of scientific knowledge. All these will facilitate new scientific discoveries through the availability of unprecedented data sets and it will increase resilience and preparedness in the society. Making straightway available observations of natural processes controlling natural phenomena and promoting their comparison with numerical simulations and their interpretation through theoretical analyses will foster scientific excellence in solid Earth research. The EPOS federated approach might be considered as a proxy for other regions of the world and therefore it could contribute to develop the supersite initiative globally.

A Polymer Visualization System with Accurate Heating and Cooling Control and High-Speed Imaging

PubMed Central

Wong, Anson; Guo, Yanting; Park, Chul B.; Zhou, Nan Q.

2015-01-01

A visualization system to observe crystal and bubble formation in polymers under high temperature and pressure has been developed. Using this system, polymer can be subjected to a programmable thermal treatment to simulate the process in high pressure differential scanning calorimetry (HPDSC). With a high-temperature/high-pressure view-cell unit, this system enables in situ observation of crystal formation in semi-crystalline polymers to complement thermal analyses with HPDSC. The high-speed recording capability of the camera not only allows detailed recording of crystal formation, it also enables in situ capture of plastic foaming processes with a high temporal resolution. To demonstrate the system’s capability, crystal formation and foaming processes of polypropylene/carbon dioxide systems were examined. It was observed that crystals nucleated and grew into spherulites, and they grew at faster rates as temperature decreased. This observation agrees with the crystallinity measurement obtained with the HPDSC. Cell nucleation first occurred at crystals’ boundaries due to CO2 exclusion from crystal growth fronts. Subsequently, cells were nucleated around the existing ones due to tensile stresses generated in the constrained amorphous regions between networks of crystals. PMID:25915031

Digital Earth system based river basin data integration

NASA Astrophysics Data System (ADS)

Zhang, Xin; Li, Wanqing; Lin, Chao

2014-12-01

Digital Earth is an integrated approach to build scientific infrastructure. The Digital Earth systems provide a three-dimensional visualization and integration platform for river basin data which include the management data, in situ observation data, remote sensing observation data and model output data. This paper studies the Digital Earth system based river basin data integration technology. Firstly, the construction of the Digital Earth based three-dimensional river basin data integration environment is discussed. Then the river basin management data integration technology is presented which is realized by general database access interface, web service and ActiveX control. Thirdly, the in situ data stored in database tables as records integration is realized with three-dimensional model of the corresponding observation apparatus display in the Digital Earth system by a same ID code. In the next two parts, the remote sensing data and the model output data integration technologies are discussed in detail. The application in the Digital Zhang River basin System of China shows that the method can effectively improve the using efficiency and visualization effect of the data.

The Roadmap of Marine Observation Development Fostering the Understanding of Weather-Climate Characteristics in the Indonesian Maritime Continent

NASA Astrophysics Data System (ADS)

Sakya, A. E.; Ramdhani, A.; Florida, N.; Nurhayati, N.

2016-12-01

Indonesian Maritime Continent (MC) territory has a unique characteristics of weather-climate variation, due to its geographical position. MC accommodates complex atmosphere-ocean interaction phenomena with huge impacts not only on inter-seasonal, but also on global weather and short-term climate variation like Monsoons, Madden-Julian Oscillation (MJO), El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole Mode (IOD). These phenomena give major contribution to the dynamics of rainfall patterns and climate variability in Indonesian MC. The above complexities are more predictable because observations in the Central and Eastern Pacific (TAO/TRITON) and Indian Ocean (RAMA) are available. Moreover, global remote-sensing observations through satellites have also been developed and its data is easily accessed. At present, maritime weather observation in Indonesia relies on global cooperation, observations carried out using remote sensing equipment, and in-situ observations made by the National Ministries/Institution. However, availability of marine observation data in the MC is very limited, especially inside Indonesian waters. It thus serves a challenge to BMKG to become more active in participating national and international partnership programs to encourage continuous in-situ marine observations. BMKG and National Oceanic and Atmospheric Administration America (NOAA) has a joint cooperation to maintain RAMA array as part of the Global Ocean Observing System (GOOS) and to deliver in-situ oceanic and atmospheric data trhough so-called Indonesian Program Initiative on Maritime Observations and Analysis (Indonesia PRIMA). Within next 5 years, BMKG will focus to foster in-situ marine observation on surface as well as underwater through various observation methods. The development of which is framed within the relevant international programs such as - among others - Year of Maritime Continent (YMC) 2017, JCOMM 5 session 2017, and Tropical Pacific Observation System 2020. These activities are also aligned with Indonesian government program envisions global maritime axis through reinforcement of weather and climate services in sea and pushes connectivity between islands, water transportation safety, natural resources marine exploration activities and other maritime activities.

Impact of membrane-induced particle immobilization on seeded growth monitored by in situ liquid scanning transmission electron microscopy

DOE PAGES

Weiner, Rebecca G.; Chen, Dennis P.; Unocic, Raymond R.; ...

2016-04-01

In situ liquid cell scanning transmission electron microscopy probes seeded growth in real time. The growth of Pd on Au nanocubes is monitored as a model system to compare growth within a liquid cell and traditional colloidal synthesis. Furthermore, different growth patterns are observed due to seed immobilization and the highly reducing environment within the liquid cell.

Probe Science: When It Has to Be In-situ

NASA Technical Reports Server (NTRS)

Colaprete, Anthony

2013-01-01

Sometimes remote sensing just isn't enough. Some critical science questions can only (or at least best) be answered with in-situ observations. Also, in-situ measurements are often necessary to calibrate or verify remote observations. It is in these instances that planetary probes are necessary. There is little doubt that the measurements these probes provide are critical. However, in an age when the duration of most planetary missions is measured in years and the number of terabytes of data returned is seen as a measure of value and success, the relatively short life and low data volumes of a probe missions is sometimes seen as a discriminating disadvantage. This talk will review the scientific value of probe missions and how future probe missions are critical to addressing fundamental questions about our solar system.

Fatique crack growth behavior of a single crystal alloy as observed through an in situ fatigue loading stage

NASA Technical Reports Server (NTRS)

Telesman, Jack; Kantzos, Peter

1988-01-01

An in situ fatigue loading stage inside a scanning electron microscope (SEM) was used to determine the fatigue crack growth behavior of a PWA 1480 single-crystal nickel-based superalloy. The loading stage permits real-time viewing of the fatigue damage processes at high magnification. The PWA 1480 single-crystal, single-edge notch specimens were tested with the load axis parallel to the (100) orientation. Two distinct fatigue failure mechanisms were identified. The crack growth rate differed substantially when the failure occurred on a single slip system in comparison to multislip system failure. Two processes by which crack branching is produced were identified and are discussed. Also discussed are the observed crack closure mechanisms.

Twomey effect observed from collocated microphysical and remote sensing measurements over shallow cumulus

NASA Astrophysics Data System (ADS)

Werner, F.; Ditas, F.; Siebert, H.; Simmel, M.; Wehner, B.; Pilewskie, P.; Schmeissner, T.; Shaw, R. A.; Hartmann, S.; Wex, H.; Roberts, G. C.; Wendisch, M.

2014-02-01

Clear experimental evidence of the Twomey effect for shallow trade wind cumuli near Barbados is presented. Effective droplet radius (reff) and cloud optical thickness (τ), retrieved from helicopter-borne spectral cloud-reflected radiance measurements, and spectral cloud reflectivity (γλ) are correlated with collocated in situ observations of the number concentration of aerosol particles from the subcloud layer (N). N denotes the concentration of particles larger than 80 nm in diameter and represents particles in the activation mode. In situ cloud microphysical and aerosol parameters were sampled by the Airborne Cloud Turbulence Observation System (ACTOS). Spectral cloud-reflected radiance data were collected by the Spectral Modular Airborne Radiation measurement sysTem (SMART-HELIOS). With increasing N a shift in the probability density functions of τ and γλ toward larger values is observed, while the mean values and observed ranges of retrieved reff decrease. The relative susceptibilities (RS) of reff, τ, and γλ to N are derived for bins of constant liquid water path. The resulting values of RS are in the range of 0.35 for reff and τ, and 0.27 for γλ. These results are close to the maximum susceptibility possible from theory. Overall, the shallow cumuli sampled near Barbados show characteristics of homogeneous, plane-parallel clouds. Comparisons of RS derived from in situ measured reff and from a microphysical parcel model are in close agreement.

The application of in situ analytical transmission electron microscopy to the study of preferential intergranular oxidation in Alloy 600.

PubMed

Burke, M G; Bertali, G; Prestat, E; Scenini, F; Haigh, S J

2017-05-01

In situ analytical transmission electron microscopy (TEM) can provide a unique perspective on dynamic reactions in a variety of environments, including liquids and gases. In this study, in situ analytical TEM techniques have been applied to examine the localised oxidation reactions that occur in a Ni-Cr-Fe alloy, Alloy 600, using a gas environmental cell at elevated temperatures. The initial stages of preferential intergranular oxidation, shown to be an important precursor phenomenon for intergranular stress corrosion cracking in pressurized water reactors (PWRs), have been successfully identified using the in situ approach. Furthermore, the detailed observations correspond to the ex situ results obtained from bulk specimens tested in hydrogenated steam and in high temperature PWR primary water. The excellent agreement between the in situ and ex situ oxidation studies demonstrates that this approach can be used to investigate the initial stages of preferential intergranular oxidation relevant to nuclear power systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Towards an integrated EU data system within AtlantOS project

NASA Astrophysics Data System (ADS)

Pouliquen, Sylvie; Harscoat, Valerie; Waldmann, Christoph; Koop-Jakobsen, ketill

2017-04-01

The H2020 AtlantOS project started in June 2015 and aims to optimise and enhance the Integrated Atlantic Ocean Observing Systems (IAOOS). One goal is to ensure that data from different and diverse in-situ observing networks are readily accessible and useable to the wider community, international ocean science community and other stakeholders in this field. To achieve that, the strategy is to move towards an integrated data system within AtlantOS that harmonises work flows, data processing and distribution across the in-situ observing network systems, and integrates in-situ observations in existing European and international data infrastructures (Copernicus marine service, SeaDataNet NODCs, EMODnet, OBIS, GEOSS) so called Integrators. The targeted integrated system will deal with data management challenges for efficient and reliable data service to users: • Quality control commons for heterogeneous and nearly real time data • Standardisation of mandatory metadata for efficient data exchange • Interoperability of network and integrator data management systems Presently the situation is that the data acquired by the different in situ observing networks contributing to the AtlantOS project are processed and distributed using different methodologies and means. Depending on the network data management organization, the data are either processed following recommendations elaborated y the network teams and accessible through a unique portal (FTP or Web), or are processed by individual scientific researchers and made available through National Data Centres or directly at institution level. Some datasets are available through Integrators, such as Copernicus or EMODnet, but connected through ad-hoc links. To facilitate the access to the Atlantic observations and avoid "mixing pears with apples", it has been necessary to agree on (1) the EOVs list and definition across the Networks, (2) a minimum set of common vocabularies for metadata and data description to be used by all the Networks, and (3) a minimum level of Near Real Time Quality Control Procedures for selected EOVs. Then a data exchange backbone has been defined and is being setting up to facilitate discovery, viewing and downloading by the users. Some tools will be recommended to help Network plugging their data on this backbone and facilitate integration in the Integrators. Finally, existing services to the users for data discovery, viewing and downloading will be enhanced to ease access to existing observations. An initial working phase relying on existing international standards and protocols, involving data providers, both Networks and Integrators, and dealing with data harmonisation and integration objectives, has led to agreements and recommendations .The setup phase has started, both on Networks and Integrators sides, to adapt the existing systems in order to move toward this integrated EU data system within AtlantOS as well as collaboration with international partners arpound the ATlantic Ocean.

Error Estimation of Pathfinder Version 5.3 SST Level 3C Using Three-way Error Analysis

NASA Astrophysics Data System (ADS)

Saha, K.; Dash, P.; Zhao, X.; Zhang, H. M.

2017-12-01

One of the essential climate variables for monitoring as well as detecting and attributing climate change, is Sea Surface Temperature (SST). A long-term record of global SSTs are available with observations obtained from ships in the early days to the more modern observation based on in-situ as well as space-based sensors (satellite/aircraft). There are inaccuracies associated with satellite derived SSTs which can be attributed to the errors associated with spacecraft navigation, sensor calibrations, sensor noise, retrieval algorithms, and leakages due to residual clouds. Thus it is important to estimate accurate errors in satellite derived SST products to have desired results in its applications.Generally for validation purposes satellite derived SST products are compared against the in-situ SSTs which have inaccuracies due to spatio/temporal inhomogeneity between in-situ and satellite measurements. A standard deviation in their difference fields usually have contributions from both satellite as well as the in-situ measurements. A real validation of any geophysical variable must require the knowledge of the "true" value of the said variable. Therefore a one-to-one comparison of satellite based SST with in-situ data does not truly provide us the real error in the satellite SST and there will be ambiguity due to errors in the in-situ measurements and their collocation differences. A Triple collocation (TC) or three-way error analysis using 3 mutually independent error-prone measurements, can be used to estimate root-mean square error (RMSE) associated with each of the measurements with high level of accuracy without treating any one system a perfectly-observed "truth". In this study we are estimating the absolute random errors associated with Pathfinder Version 5.3 Level-3C SST product Climate Data record. Along with the in-situ SST data, the third source of dataset used for this analysis is the AATSR reprocessing of climate (ARC) dataset for the corresponding period. All three SST observations are collocated, and statistics of difference between each pair is estimated. Instead of using a traditional TC analysis we have implemented the Extended Triple Collocation (ETC) approach to estimate the correlation coefficient of each measurement system w.r.t. the unknown target variable along with their RMSE.

Controlling effects of mesoscale eddies on thermohaline structure and in situ chlorophyll distribution in the western North Pacific

NASA Astrophysics Data System (ADS)

Gao, Wei; Wang, Zhenyan; Zhang, Kainan

2017-11-01

Based on the conductivity, temperature and depth (CTD) data collected at 93 hydrographic stations during a marine cruise and on contemporary satellite altimeter observations, a series of eddies have been observed passing over the stratified upper water of the Parece Vela Basin. The results from hydrographic measurements and in situ chlorophyll fluorescence measurements have revealed that these eddies exerted significant controlling effects on the thermohaline structure and chlorophyll distribution, especially on the prevalent subsurface chlorophyll maximum layer (SCML). Based on these observations and particulate beam attenuation coefficient (cp) data, the in situ phytoplankton bloom around the pycnocline can be largely attributable to the formation of a well-developed SCML in the studied system. The uplift of the cold subsurface water within the cyclone, shoaling the pycnocline to a shallower layer, resulted in a low-temperature anomaly and different salinity anomalies at different depths. This uplift in the cyclone further caused the SCML to appear at a shallower depth with a higher in situ chlorophyll concentration than that in the normal domain. Conversely, the sinking of the warm surface water to the subsurface layer within the anticyclone depressed the pycnocline to a deeper layer and generated a high-temperature anomaly and opposite salinity anomalies compared with the cyclone. The sinking of the pycnocline within the anticyclone considerably influenced the characteristics of the SCML, which had a deeper depth and a lower in situ chlorophyll concentration than that of the normal sea. This study contributes rare quasi-synchronous CTD observations capturing mesoscale eddies and provides valuable descriptions of the variations in the SCML under the influence of mesoscale eddies based on in situ optical measurements from the seldom-discussed western North Pacific.

Real-Time Optical Monitoring of Pt Catalyst Under the Potentiodynamic Conditions

NASA Astrophysics Data System (ADS)

Song, Hyeon Don; Lee, Minzae; Kim, Gil-Pyo; Choi, Inhee; Yi, Jongheop

2016-12-01

In situ monitoring of electrode materials reveals detailed physicochemical transition in electrochemical device. The key challenge is to explore the localized features of electrode surfaces, since the performance of an electrochemical device is determined by the summation of local architecture of the electrode material. Adaptive in situ techniques have been developed for numerous investigations; however, they require restricted measurement environments and provide limited information, which has impeded their widespread application. In this study, we realised an optics-based electrochemical in situ monitoring system by combining a dark-field micro/spectroscopy with an electrochemical workstation to investigate the physicochemical behaviours of Pt catalyst. We found that the localized plasmonic trait of a Pt-decorated Au nanoparticle as a model system varied in terms of its intensity and wavelength during the iterations of a cyclic voltammetry test. Furthermore, we show that morphological and compositional changes of the Pt catalyst can be traced in real time using changes in quantified plasmonic characteristics, which is a distinct advantage over the conventional electrochemistry-based in situ monitoring systems. These results indicate the substantial promise of online operando observation in a wide range of electrical energy conversion systems and electrochemical sensing areas.

Hyperspectral Remote Sensing of the Coastal Ocean: Adaptive Sampling and Forecasting of In situ Optical Properties

DTIC Science & Technology

2002-09-30

integrated observation system that is being coupled to a data assimilative hydrodynamic bio-optical ecosystem model. The system was used adaptively to develop hyperspectral remote sensing techniques in optically complex nearshore coastal waters.

The Importance of Earth Observations and Data Collaboration within Environmental Intelligence Supporting Arctic Research

NASA Technical Reports Server (NTRS)

Casas, Joseph

2017-01-01

Within the IARPC Collaboration Team activities of 2016, Arctic in-situ and remote earth observations advanced topics such as :1) exploring the role for new and innovative autonomous observing technologies in the Arctic; 2) advancing catalytic national and international community based observing efforts in support of the National Strategy for the Arctic Region; and 3) enhancing the use of discovery tools for observing system collaboration such as the U.S. National Oceanic and Atmospheric Administration (NOAA) Arctic Environmental Response Management Application (ERMA) and the U.S. National Aeronautics and Space Administration (NASA) Arctic Collaborative Environment (ACE) project geo reference visualization decision support and exploitation internet based tools. Critical to the success of these earth observations for both in-situ and remote systems is the emerging of new and innovative data collection technologies and comprehensive modeling as well as enhanced communications and cyber infrastructure capabilities which effectively assimilate and dissemination many environmental intelligence products in a timely manner. The Arctic Collaborative Environment (ACE) project is well positioned to greatly enhance user capabilities for accessing, organizing, visualizing, sharing and producing collaborative knowledge for the Arctic.

Signal processing methods for in-situ creep specimen monitoring

NASA Astrophysics Data System (ADS)

Guers, Manton J.; Tittmann, Bernhard R.

2018-04-01

Previous work investigated using guided waves for monitoring creep deformation during accelerated life testing. The basic objective was to relate observed changes in the time-of-flight to changes in the environmental temperature and specimen gage length. The work presented in this paper investigated several signal processing strategies for possible application in the in-situ monitoring system. Signal processing methods for both group velocity (wave-packet envelope) and phase velocity (peak tracking) time-of-flight were considered. Although the Analytic Envelope found via the Hilbert transform is commonly applied for group velocity measurements, erratic behavior in the indicated time-of-flight was observed when this technique was applied to the in-situ data. The peak tracking strategies tested had generally linear trends, and tracking local minima in the raw waveform ultimately showed the most consistent results.

High pressure rheology of gas hydrate formed from multiphase systems using modified Couette rheometer.

PubMed

Pandey, Gaurav; Linga, Praveen; Sangwai, Jitendra S

2017-02-01

Conventional rheometers with concentric cylinder geometries do not enhance mixing in situ and thus are not suitable for rheological studies of multiphase systems under high pressure such as gas hydrates. In this study, we demonstrate the use of modified Couette concentric cylinder geometries for high pressure rheological studies during the formation and dissociation of methane hydrate formed from pure water and water-decane systems. Conventional concentric cylinder Couette geometry did not produce any hydrates in situ and thus failed to measure rheological properties during hydrate formation. The modified Couette geometries proposed in this work observed to provide enhanced mixing in situ, thus forming gas hydrate from the gas-water-decane system. This study also nullifies the use of separate external high pressure cell for such measurements. The modified geometry was observed to measure gas hydrate viscosity from an initial condition of 0.001 Pa s to about 25 Pa s. The proposed geometries also possess the capability to measure dynamic viscoelastic properties of hydrate slurries at the end of experiments. The modified geometries could also capture and mimic the viscosity profile during the hydrate dissociation as reported in the literature. The present study acts as a precursor for enhancing our understanding on the rheology of gas hydrate formed from various systems containing promoters and inhibitors in the context of flow assurance.

High pressure rheology of gas hydrate formed from multiphase systems using modified Couette rheometer

NASA Astrophysics Data System (ADS)

Pandey, Gaurav; Linga, Praveen; Sangwai, Jitendra S.

2017-02-01

Conventional rheometers with concentric cylinder geometries do not enhance mixing in situ and thus are not suitable for rheological studies of multiphase systems under high pressure such as gas hydrates. In this study, we demonstrate the use of modified Couette concentric cylinder geometries for high pressure rheological studies during the formation and dissociation of methane hydrate formed from pure water and water-decane systems. Conventional concentric cylinder Couette geometry did not produce any hydrates in situ and thus failed to measure rheological properties during hydrate formation. The modified Couette geometries proposed in this work observed to provide enhanced mixing in situ, thus forming gas hydrate from the gas-water-decane system. This study also nullifies the use of separate external high pressure cell for such measurements. The modified geometry was observed to measure gas hydrate viscosity from an initial condition of 0.001 Pa s to about 25 Pa s. The proposed geometries also possess the capability to measure dynamic viscoelastic properties of hydrate slurries at the end of experiments. The modified geometries could also capture and mimic the viscosity profile during the hydrate dissociation as reported in the literature. The present study acts as a precursor for enhancing our understanding on the rheology of gas hydrate formed from various systems containing promoters and inhibitors in the context of flow assurance.

The role of in-situ measurements in scintillation modelling

NASA Astrophysics Data System (ADS)

Basu, S.; Basu, S.; Hanson, W. B.

It is shown that the conflicting equatorial scintillation observations obtained from greatly separated ground stations can be organized in the framework of a longitudinal variation of irregularity occurrence, given satellite-borne, in situ measurements of irregularity amplitude of the global F-region irregularity morphology's general features. High-inclination satellite data are used to delineate the morphological features of the polar cap by means of such a method. The lack of diurnal and magnetic control of the irregularity morphology within the low solar flux, northern winter polar cap distinguishes this region from the auroral oval regime. A polar-orbiting communication system sensitive to phase perturbations may observe large differences in the phase-to-amplitude scintillation ratio, as it traverses the auroral oval and proceeds into the polar cap, with its sun-aligned arc system.

An Optimized Autonomous Space In-situ Sensorweb (OASIS) for Volcano Monitoring

NASA Astrophysics Data System (ADS)

Song, W.; Shirazi, B.; Lahusen, R.; Chien, S.; Kedar, S.; Webb, F.

2006-12-01

In response to NASA's announced requirement for Earth hazard monitoring sensor-web technology, we are developing a prototype real-time Optimized Autonomous Space In-situ Sensorweb. The prototype will be focused on volcano hazard monitoring at Mount St. Helens, which has been in continuous eruption since October 2004. The system is designed to be flexible and easily configurable for many other applications as well. The primary goals of the project are: 1) integrating complementary space (i.e., Earth Observing One (EO- 1) satellite) and in-situ (ground-based) elements into an interactive, autonomous sensor-web; 2) advancing sensor-web power and communication resource management technology; and 3) enabling scalability for seamless infusion of future space and in-situ assets into the sensor-web. To meet these goals, we are developing: 1) a test-bed in-situ array with smart sensor nodes capable of making autonomous data acquisition decisions; 2) efficient self-organization algorithm of sensor-web topology to support efficient data communication and command control; 3) smart bandwidth allocation algorithms in which sensor nodes autonomously determine packet priorities based on mission needs and local bandwidth information in real- time; and 4) remote network management and reprogramming tools. The space and in-situ control components of the system will be integrated such that each element is capable of triggering the other. Sensor-web data acquisition and dissemination will be accomplished through the use of SensorML language standards for geospatial information. The three-year project will demonstrate end-to-end system performance with the in-situ test-bed at Mount St. Helens and NASA's EO-1 platform.

Preparation of ion-activated in situ gel systems of scopolamine hydrobromide and evaluation of its antimotion sickness efficacy.

PubMed

Cao, Shi-lei; Zhang, Qi-zhi; Jiang, Xin-guo

2007-04-01

To develop a novel, in situ gel system for nasal delivery of scopolamine hydrobromide (SCOP) and study its efficacy on motion sickness. SCOP in situ gels at 0.2%, 0.5%, and 1.0% gellan gum concentration (w/v) were prepared, respectively, and characterized in terms of viscosity, in vitro release, and nasal ciliotoxicity. Single photon emission computing tomography technique was used to evaluate the nasal residence time of gel containing (99m)Tc tracer. The antimotion sickness efficacy produced by the in situ gel formulation was investigated in rats and compared with those achieved after subcutaneous and oral administration. The viscosity of the gellan gum formulations either in solution or in gel increased with increasing concentrations of gellan gum. Its release in vitro was moderate in artificial nasal fluid. The micrographic results showed that in situ gels were safe, without nasal ciliotoxicity. In comparison with phosphate buffer saline, a prolonged radioactivity of (99m)Tc in the rabbit nasal cavity was observed after administration of the gellan gum formulation. Intranasal SCOP in situ gel at a dose of 100 microg/kg decreased symptoms of motion sickness significantly in comparison with subcutaneous and oral administration (P<0.01). SCOP nasal in situ gel is a safe and promising therapeutic alternative to existing medications for motion sickness.

Challenges in Interpreting and Validating Satellite Soil Moisture Information

USDA-ARS?s Scientific Manuscript database

Global soil moisture products are now being generated routinely using microwave-based satellite observing systems. These include the NASA Soil Moisture Active Passive (SMAP) mission. In order to fully exploit these observations they must be integrated with both in situ measurements and model-based e...

In-situ and real-time growth observation of high-quality protein crystals under quasi-microgravity on earth.

PubMed

Nakamura, Akira; Ohtsuka, Jun; Kashiwagi, Tatsuki; Numoto, Nobutaka; Hirota, Noriyuki; Ode, Takahiro; Okada, Hidehiko; Nagata, Koji; Kiyohara, Motosuke; Suzuki, Ei-Ichiro; Kita, Akiko; Wada, Hitoshi; Tanokura, Masaru

2016-02-26

Precise protein structure determination provides significant information on life science research, although high-quality crystals are not easily obtained. We developed a system for producing high-quality protein crystals with high throughput. Using this system, gravity-controlled crystallization are made possible by a magnetic microgravity environment. In addition, in-situ and real-time observation and time-lapse imaging of crystal growth are feasible for over 200 solution samples independently. In this paper, we also report results of crystallization experiments for two protein samples. Crystals grown in the system exhibited magnetic orientation and showed higher and more homogeneous quality compared with the control crystals. The structural analysis reveals that making use of the magnetic microgravity during the crystallization process helps us to build a well-refined protein structure model, which has no significant structural differences with a control structure. Therefore, the system contributes to improvement in efficiency of structural analysis for "difficult" proteins, such as membrane proteins and supermolecular complexes.

A Coupled Model System for Southeast Florida: Wave Model Validation Using Radar and In Situ Observations

DTIC Science & Technology

2012-02-24

also included. The “ground truth” for waves validation includes in situ data (ADCP and buoy) and high frequency Wellen Radar (WERA HF) data...which swells are able to pass through islands and shoals to arrive at the in situ data region is highly sensitive to whether currents are included...grid 1: WW3 • ∆x = ∆y = 0.5° ≈ 55 km • Longitude: x = -100° to -0.5° W (260° to 359.5° E), nx =200 • Latitude: y =17° to 59° N, ny =85 • no

A combined scanning tunneling microscope-atomic layer deposition tool.

PubMed

Mack, James F; Van Stockum, Philip B; Iwadate, Hitoshi; Prinz, Fritz B

2011-12-01

We have built a combined scanning tunneling microscope-atomic layer deposition (STM-ALD) tool that performs in situ imaging of deposition. It operates from room temperature up to 200 °C, and at pressures from 1 × 10(-6) Torr to 1 × 10(-2) Torr. The STM-ALD system has a complete passive vibration isolation system that counteracts both seismic and acoustic excitations. The instrument can be used as an observation tool to monitor the initial growth phases of ALD in situ, as well as a nanofabrication tool by applying an electric field with the tip to laterally pattern deposition. In this paper, we describe the design of the tool and demonstrate its capability for atomic resolution STM imaging, atomic layer deposition, and the combination of the two techniques for in situ characterization of deposition.

Modeling observations of solar coronal mass ejections with heliospheric imagers verified with the Heliophysics System Observatory.

PubMed

Möstl, C; Isavnin, A; Boakes, P D; Kilpua, E K J; Davies, J A; Harrison, R A; Barnes, D; Krupar, V; Eastwood, J P; Good, S W; Forsyth, R J; Bothmer, V; Reiss, M A; Amerstorfer, T; Winslow, R M; Anderson, B J; Philpott, L C; Rodriguez, L; Rouillard, A P; Gallagher, P; Nieves-Chinchilla, T; Zhang, T L

2017-07-01

We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self-similar expansion model for CME fronts assuming 60° longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%-35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 ± 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide-angle heliospheric imager observations. These results form a first-order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun-Earth L5 point.

Modeling observations of solar coronal mass ejections with heliospheric imagers verified with the Heliophysics System Observatory

PubMed Central

Isavnin, A.; Boakes, P. D.; Kilpua, E. K. J.; Davies, J. A.; Harrison, R. A.; Barnes, D.; Krupar, V.; Eastwood, J. P.; Good, S. W.; Forsyth, R. J.; Bothmer, V.; Reiss, M. A.; Amerstorfer, T.; Winslow, R. M.; Anderson, B. J.; Philpott, L. C.; Rodriguez, L.; Rouillard, A. P.; Gallagher, P.; Nieves‐Chinchilla, T.; Zhang, T. L.

2017-01-01

Abstract We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self‐similar expansion model for CME fronts assuming 60° longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%–35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 ± 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide‐angle heliospheric imager observations. These results form a first‐order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun‐Earth L5 point. PMID:28983209

Underwater microscopy for in situ studies of benthic ecosystems

NASA Astrophysics Data System (ADS)

Mullen, Andrew D.; Treibitz, Tali; Roberts, Paul L. D.; Kelly, Emily L. A.; Horwitz, Rael; Smith, Jennifer E.; Jaffe, Jules S.

2016-07-01

Microscopic-scale processes significantly influence benthic marine ecosystems such as coral reefs and kelp forests. Due to the ocean's complex and dynamic nature, it is most informative to study these processes in the natural environment yet it is inherently difficult. Here we present a system capable of non-invasively imaging seafloor environments and organisms in situ at nearly micrometre resolution. We overcome the challenges of underwater microscopy through the use of a long working distance microscopic objective, an electrically tunable lens and focused reflectance illumination. The diver-deployed instrument permits studies of both spatial and temporal processes such as the algal colonization and overgrowth of bleaching corals, as well as coral polyp behaviour and interspecific competition. By enabling in situ observations at previously unattainable scales, this instrument can provide important new insights into micro-scale processes in benthic ecosystems that shape observed patterns at much larger scales.

In-Situ atomic force microscopic observation of ion beam bombarded plant cell envelopes

NASA Astrophysics Data System (ADS)

Sangyuenyongpipat, S.; Yu, L. D.; Brown, I. G.; Seprom, C.; Vilaithong, T.

2007-04-01

A program in ion beam bioengineering has been established at Chiang Mai University (CMU), Thailand, and ion beam induced transfer of plasmid DNA molecules into bacterial cells (Escherichia coli) has been demonstrated. However, a good understanding of the fundamental physical processes involved is lacking. In parallel work, onion skin cells have been bombarded with Ar+ ions at energy 25 keV and fluence1-2 × 1015 ions/cm2, revealing the formation of microcrater-like structures on the cell wall that could serve as channels for the transfer of large macromolecules into the cell interior. An in-situ atomic force microscope (AFM) system has been designed and installed in the CMU bio-implantation facility as a tool for the observation of these microcraters during ion beam bombardment. Here we describe some of the features of the in-situ AFM and outline some of the related work.

Freshwater in situ toxicity testing: Daphnia magna, Ceriodaphnia dubia, Pimephales promelas, Hyalella azteca and Chironomus tentans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burton, G.A. Jr.

The use of traditional laboratory toxicity test species in field exposures have proven to be a valuable assessment tool for monitoring effluent, water, sediment and storm water quality. Mimicking fluctuating exposures of stressors with associated interactions with differing physico-chemical variables is difficult. In situ exposures are conducted for similar time periods measuring similar response endpoints as in more traditional laboratory tests. However, organisms are transferred to the field and exposed in various types of test chambers. The author has observed responses which are similar and which are significantly different from simultaneous laboratory exposures. Temperature, dissolved oxygen, suspended solids, natural light,more » flow, and predation may affect in situ responses, but are often removed from laboratory exposures. The strengths and weaknesses observed with these test systems over the past few years will be reviewed.« less

Sample Handling and Instruments for the In-Situ Exploration of Ice-Rich Planets. Chapter 9

NASA Technical Reports Server (NTRS)

Castillo, Julie C.; Bar-Cohen, Yoseph; Vance, Steve; Choukroun, Mathieu; Lee, Hyeong Jae; Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Trainer, Melissa G.; Getty, Stephanie A.

2016-01-01

NASA's key science goals for the exploration of the solar system seek a better understanding of the formation and evolutionary processes that have shaped planetary bodies and emphasize the search for habitable environments. Efforts are also made to detect and quantify resources that could be used for the support of human exploration. These themes call for chemistry and physical property observations that may be best approached by in situ measurements. NASA's planetary missions have progressively evolved from remote reconnaissance to in situ exploration with the ultimate goal to return samples. This chapter focuses on the techniques, available or in development, for advanced geophysical and chemical characterization of icy bodies, especially Mars polar areas, Enceladus, Titan, Europa, and Ceres. These astrobiological targets are the objects of recent or ongoing exploration whose findings are driving the formulation of new missions that involve in situ exploration. After reviewing the overall objectives of icy body exploration (Section 9.1) we describe key techniques used for addressing these objectives from surface platforms via geophysical observations (Section 9.2) and chemical measurements (Section 9.3).

Comparing the Scoring of Human Decomposition from Digital Images to Scoring Using On-site Observations.

PubMed

Dabbs, Gretchen R; Bytheway, Joan A; Connor, Melissa

2017-09-01

When in forensic casework or empirical research in-person assessment of human decomposition is not possible, the sensible substitution is color photographic images. To date, no research has confirmed the utility of color photographic images as a proxy for in situ observation of the level of decomposition. Sixteen observers scored photographs of 13 human cadavers in varying decomposition stages (PMI 2-186 days) using the Total Body Score system (total n = 929 observations). The on-site TBS was compared with recorded observations from digital color images using a paired samples t-test. The average difference between on-site and photographic observations was -0.20 (t = -1.679, df = 928, p = 0.094). Individually, only two observers, both students with <1 year of experience, demonstrated TBS statistically significantly different than the on-site value, suggesting that with experience, observations of human decomposition based on digital images can be substituted for assessments based on observation of the corpse in situ, when necessary. © 2017 American Academy of Forensic Sciences.

Virtual Observation System for Earth System Model: An Application to ACME Land Model Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dali; Yuan, Fengming; Hernandez, Benjamin

Investigating and evaluating physical-chemical-biological processes within an Earth system model (EMS) can be very challenging due to the complexity of both model design and software implementation. A virtual observation system (VOS) is presented to enable interactive observation of these processes during system simulation. Based on advance computing technologies, such as compiler-based software analysis, automatic code instrumentation, and high-performance data transport, the VOS provides run-time observation capability, in-situ data analytics for Earth system model simulation, model behavior adjustment opportunities through simulation steering. A VOS for a terrestrial land model simulation within the Accelerated Climate Modeling for Energy model is also presentedmore » to demonstrate the implementation details and system innovations.« less

Virtual Observation System for Earth System Model: An Application to ACME Land Model Simulations

DOE PAGES

Wang, Dali; Yuan, Fengming; Hernandez, Benjamin; ...

2017-01-01

Investigating and evaluating physical-chemical-biological processes within an Earth system model (EMS) can be very challenging due to the complexity of both model design and software implementation. A virtual observation system (VOS) is presented to enable interactive observation of these processes during system simulation. Based on advance computing technologies, such as compiler-based software analysis, automatic code instrumentation, and high-performance data transport, the VOS provides run-time observation capability, in-situ data analytics for Earth system model simulation, model behavior adjustment opportunities through simulation steering. A VOS for a terrestrial land model simulation within the Accelerated Climate Modeling for Energy model is also presentedmore » to demonstrate the implementation details and system innovations.« less

Impact of Membrane-Induced Particle Immobilization on Seeded Growth Monitored by In Situ Liquid Scanning Transmission Electron Microscopy.

PubMed

Weiner, Rebecca G; Chen, Dennis P; Unocic, Raymond R; Skrabalak, Sara E

2016-05-01

In situ liquid cell scanning transmission electron microscopy probes seeded growth in real time. The growth of Pd on Au nanocubes is monitored as a model system to compare growth within a liquid cell and traditional colloidal synthesis. Different growth patterns are observed due to seed immobilization and the highly reducing environment within the liquid cell. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In situ distributed diagnostics of flowable electrode systems: resolving spatial and temporal limitations.

PubMed

Dennison, C R; Gogotsi, Y; Kumbur, E C

2014-09-14

In this study, we have developed an in situ distributed diagnostics tool to investigate spatial and temporal effects in electrochemical systems based on flowable electrodes. Specifically, an experimental approach was developed that enables spatially-resolved voltage measurements to be obtained in situ, in real-time. To extract additional data from these distributed measurements, an experimentally-parameterized equivalent circuit model with a new 'flow capacitor' circuit element was developed to predict the distributions of various system parameters during operation. As a case study, this approach was applied to investigate the behavior of the suspension electrodes used in an electrochemical flow capacitor under flowing and static conditions. The volumetric capacitance is reduced from 15.6 F ml(-1) to 1.1 F ml(-1) under flowing conditions. Results indicate that the majority of the charging in suspension electrodes occurs within ∼750 μm of the current collectors during flow, which gives rise to significant state-of-charge gradients across the cell, as well as underutilization of the available active material. The underlying cause of this observation is attributed to the relatively high electrical resistance of the slurry coupled with a stratified charging regime and insufficient residence time. The observations highlight the need to develop more conductive slurries and to design cells with reduced charge transport lengths.

Deriving surface soil moisture from reflected GNSS signal observations from a grassland site in southwestern France

NASA Astrophysics Data System (ADS)

Zhang, Sibo; Calvet, Jean-Christophe; Darrozes, José; Roussel, Nicolas; Frappart, Frédéric; Bouhours, Gilles

2018-03-01

This work assesses the estimation of surface volumetric soil moisture (VSM) using the global navigation satellite system interferometric reflectometry (GNSS-IR) technique. Year-round observations were acquired from a grassland site in southwestern France using an antenna consecutively placed at two contrasting heights above the ground surface (3.3 and 29.4 m). The VSM retrievals are compared with two independent reference datasets: in situ observations of soil moisture, and numerical simulations of soil moisture and vegetation biomass from the ISBA (Interactions between Soil, Biosphere and Atmosphere) land surface model. Scaled VSM estimates can be retrieved throughout the year removing vegetation effects by the separation of growth and senescence periods and by the filtering of the GNSS-IR observations that are most affected by vegetation. Antenna height has no significant impact on the quality of VSM estimates. Comparisons between the VSM GNSS-IR retrievals and the in situ VSM observations at a depth of 5 cm show good agreement (R2 = 0.86 and RMSE = 0.04 m3 m-3). It is shown that the signal is sensitive to the grass litter water content and that this effect triggers differences between VSM retrievals and in situ VSM observations at depths of 1 and 5 cm, especially during light rainfall events.

The Hurricane-flood-landslide continuum-forecasting Hurricane effects at landfall

USGS Publications Warehouse

Negri, A.J.; Golden, J.H.; Updike, R.G.

2004-01-01

The integration of remote-sensing and in-situ observations, and assimilation of these observations into high-resolution mesoscale models was described. It was observed that the greatest loss of life and property is the direct result of the storm because of the high winds and heavy rain. The research were conducted to develop a warning system that included satellite observations to track dangerous level of precipitation and hurricane. The focus of the continuum project was to improve the ability to predict the evolution of the Earth system.

First Step Towards a Coastal Modelling System for South Africa: a St. Helena Bay Case Study

NASA Astrophysics Data System (ADS)

Collins, C.; Lamont, T.; Loveday, B. R.; Hermes, J. C.; Veitch, J.; Backeberg, B.

2016-02-01

St. Helena Bay, forming part of the southern Benguela ecosystem, is the largest bay on the west coast of South Africa and is a biologically important region for pelagic fish, hake, and rock lobster. To date, only a few infrequent studies have focussed on variations in the bay scale circulation. A monthly ship-based monitoring line, the St. Helena Bay Monitoring Line (SHBML), was initiated in 2000 to determine the seasonal changes in cross-shelf hydrography and biology. Even though there has been an increase in ocean modelling in and around South Africa in recent years, coastal modelling is still in its infancy. The 12-year observational data set in the St. Helena Bay region, the only long-term, cross-shelf, full water column data-set for South Africa, makes this area the perfect natural laboratory for the development of a coastal modelling system. In this study, the climatological mean temperature and salinity from three different ROMS simulations and a HYCOM simulation are evaluated against the in situ observations from the SHBML with the aim of determining the influence of different forcing products, horizontal and vertical resolution as well as vertical coordinate schemes on the vertical structure of the ocean. The model simulations tend to overestimate the temperature and salinity across the shelf, and particularly within St. Helena Bay. Furthermore, the models misrepresent the vertical salinity and temperature structures. Interestingly, below 800m, there is a better agreement between temperature in the models and the in-situ observations. This is the first detailed comparison of modelled and in-situ data for the greater St. Helena Bay area at this scale and the next phase will examine whether the model that is most congruent with the observations resolves the same interannual signals as observed in the in-situ data.

Priorities and developments of sensors, samplers and methods for key marine biological observations.

NASA Astrophysics Data System (ADS)

Simmons, Samantha; Chavez, Francisco; Pearlman, Jay

2016-04-01

Over the last two decades or more, physical oceanography has seen a significant growth in in-situ sensors and platforms including fixed point and cable observatories, Argo floats, gliders and AUVs to supplement satellites for creating a 3-D view of the time-varying global ocean temperature and salinity structures. There are important developments recently for biogeochemists for monitoring nitrate, chemical contaminants, oxygen and pH that can now be added to these autonomous systems. Biologists are still lagging. Given the importance of biology to ocean health and the future earth, and the present reliance on humans and ships for observing species and abundance, it is paramount that new biological sensor systems be developed. Some promising sensor systems based on, but not limited to acoustic, chemical, genomic or imaging techniques, can sense from microbes to whales, are on the horizon. These techniques can be applied in situ with either real time or recorded data and can be captured and returned to the laboratory using the autonomous systems. The number of samples is limiting, requiring adaptive and smart systems. Two steps are envisioned to meeting the challenges. The first is to identify the priority biological variables to focus observation requirements and planning. The second is to address new sensors that can fill the gaps in current capabilities for biological observations. This abstract will review recent efforts to identify core biological variables for the US Integrated Ocean Observing System and address new sensors and innovations for observing these variables, particularly focused on availability and maturity of sensors.

In situ real-time imaging of self-sorted supramolecular nanofibres

NASA Astrophysics Data System (ADS)

Onogi, Shoji; Shigemitsu, Hajime; Yoshii, Tatsuyuki; Tanida, Tatsuya; Ikeda, Masato; Kubota, Ryou; Hamachi, Itaru

2016-08-01

Self-sorted supramolecular nanofibres—a multicomponent system that consists of several types of fibre, each composed of distinct building units—play a crucial role in complex, well-organized systems with sophisticated functions, such as living cells. Designing and controlling self-sorting events in synthetic materials and understanding their structures and dynamics in detail are important elements in developing functional artificial systems. Here, we describe the in situ real-time imaging of self-sorted supramolecular nanofibre hydrogels consisting of a peptide gelator and an amphiphilic phosphate. The use of appropriate fluorescent probes enabled the visualization of self-sorted fibres entangled in two and three dimensions through confocal laser scanning microscopy and super-resolution imaging, with 80 nm resolution. In situ time-lapse imaging showed that the two types of fibre have different formation rates and that their respective physicochemical properties remain intact in the gel. Moreover, we directly visualized stochastic non-synchronous fibre formation and observed a cooperative mechanism.

Improving the Forecast Accuracy of an Ocean Observation and Prediction System by Adaptive Control of the Sensor Network

NASA Astrophysics Data System (ADS)

Talukder, A.; Panangadan, A. V.; Blumberg, A. F.; Herrington, T.; Georgas, N.

2008-12-01

The New York Harbor Observation and Prediction System (NYHOPS) is a real-time, estuarine and coastal ocean observing and modeling system for the New York Harbor and surrounding waters. Real-time measurements from in-situ mobile and stationary sensors in the NYHOPS networks are assimilated into marine forecasts in order to reduce the discrepancy with ground truth. The forecasts are obtained from the ECOMSED hydrodynamic model, a shallow water derivative of the Princeton Ocean Model. Currently, all sensors in the NYHOPS system are operated in a fixed mode with uniform sampling rates. This technology infusion effort demonstrates the use of Model Predictive Control (MPC) to autonomously adapt the operation of both mobile and stationary sensors in response to changing events that are -automatically detected from the ECOMSED forecasts. The controller focuses sensing resources on those regions that are expected to be impacted by the detected events. The MPC approach involves formulating the problem of calculating the optimal sensor parameters as a constrained multi-objective optimization problem. We have developed an objective function that takes into account the spatiotemporal relationship of the in-situ sensor locations and the locations of events detected by the model. Experiments in simulation were carried out using data collected during a freshwater flooding event. The location of the resulting freshwater plume was calculated from the corresponding model forecasts and was used by the MPC controller to derive control parameters for the sensing assets. The operational parameters that are controlled include the sampling rates of stationary sensors, paths of unmanned underwater vehicles (UUVs), and data transfer routes between sensors and the central modeling computer. The simulation experiments show that MPC-based sensor control reduces the RMS error in the forecast by a factor of 380% as compared to uniform sampling. The paths of multiple UUVs were simultaneously calculated such that measurements from on-board sensors would lead to maximal reduction in the forecast error after data assimilation. The MPC controller also reduces the consumption of system resources such as energy expended in sampling and wireless communication. The MPC-based control approach can be generalized to accept data from remote sensing satellites. This will enable in-situ sensors to be regulated using forecasts generated by assimilating local high resolution in-situ measurements with wide-area observations from remote sensing satellites.

Towards the Operational Ensemble-based Data Assimilation System for the Wave Field at the National Weather Service

NASA Astrophysics Data System (ADS)

Flampouris, Stylianos; Penny, Steve; Alves, Henrique

2017-04-01

The National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration (NOAA) provides the operational wave forecast for the US National Weather Service (NWS). Given the continuous efforts to improve forecast, NCEP is developing an ensemble-based data assimilation system, based on the local ensemble transform Kalman filter (LETKF), the existing operational global wave ensemble system (GWES) and on satellite and in-situ observations. While the LETKF was designed for atmospheric applications (Hunt et al 2007), and has been adapted for several ocean models (e.g. Penny 2016), this is the first time applied for oceanic waves assimilation. This new wave assimilation system provides a global estimation of the surface sea state and its approximate uncertainty. It achieves this by analyzing the 21-member ensemble of the significant wave height provided by GWES every 6h. Observations from four altimeters and all the available in-situ measurements are used in this analysis. The analysis of the significant wave height is used for initializing the next forecasting cycle; the data assimilation system is currently being tested for operational use.

An Inversion Analysis of Recent Variability in CO2 Fluxes Using GOSAT and In Situ Observations

NASA Astrophysics Data System (ADS)

Wang, J. S.; Kawa, S. R.; Baker, D. F.; Collatz, G. J.

2016-12-01

About one-half of the global CO2 emissions from fossil fuel combustion and deforestation accumulates in the atmosphere, where it contributes to global warming. The rest is taken up by vegetation and the ocean. The precise contribution of the two sinks and their location and year-to-year variability are not well understood. We use two different approaches, batch Bayesian synthesis inversion and variational data assimilation, to deduce the global spatiotemporal distributions of CO2 fluxes during 2009-2010. One of our objectives is to assess different sources of uncertainties in inferred fluxes, including uncertainties in prior flux estimates and observations, and differences in inversion techniques. For prior constraints, we utilize fluxes and uncertainties from the CASA-GFED model of the terrestrial biosphere and biomass burning driven by satellite observations. We also use measurement-based ocean flux estimates and fixed fossil CO2 emissions. Our inversions incorporate column CO2 measurements from the GOSAT satellite (ACOS retrieval, bias-corrected) and in situ observations (individual flask and afternoon-average continuous observations) to estimate fluxes in 108 regions over 8-day intervals for the batch inversion and at 3° x 3.75° weekly for the variational system. Relationships between fluxes and atmospheric concentrations are derived consistently for the two inversion systems using the PCTM transport model with MERRA meteorology. We compare the posterior fluxes and uncertainties derived using different data sets and the two inversion approaches, and evaluate the posterior atmospheric concentrations against independent data including aircraft measurements. The optimized fluxes generally resemble each other and those from other studies. For example, a GOSAT-only inversion suggests a shift in the global sink from the tropics/south to the north relative to the prior and to an in-situ-only inversion. The posterior fluxes of the GOSAT inversion are better constrained in most regions than those of the in situ inversion because of the greater spatial coverage of the GOSAT observations. The GOSAT inversion also indicates a significantly smaller terrestrial sink in higher-latitude northern regions in boreal summer of 2010 relative to 2009, consistent with observed drought conditions.

Sol-to-Gel Transition in Fast Evaporating Systems Observed by in Situ Time-Resolved Infrared Spectroscopy.

PubMed

Innocenzi, Plinio; Malfatti, Luca; Carboni, Davide; Takahashi, Masahide

2015-06-22

The in situ observation of a sol-to-gel transition in fast evaporating systems is a challenging task and the lack of a suitable experimental design, which includes the chemistry and the analytical method, has limited the observations. We synthesise an acidic sol, employing only tetraethylorthosilicate, SiCl4 as catalyst and deuterated water; the absence of water added to the sol allows us to follow the absorption from the external environment and the evaporation of deuterated water. The time-resolved data, obtained by attenuated total reflection infrared spectroscopy on an evaporating droplet, enables us to identify four different stages during evaporation. They are linked to specific hydrolysis and condensation rates that affect the uptake of water from external environment. The second stage is characterized by a decrease in hydroxyl content, a fast rise of condensation rate and an almost stationary absorption of water. This stage has been associated with the sol-to-gel transition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Real-Time In-Situ Measurements for Earthquake Early Warning and Space-Borne Deformation Measurement Mission Support

NASA Astrophysics Data System (ADS)

Kedar, S.; Bock, Y.; Webb, F.; Clayton, R. W.; Owen, S. E.; Moore, A. W.; Yu, E.; Dong, D.; Fang, P.; Jamason, P.; Squibb, M. B.; Crowell, B. W.

2010-12-01

In situ geodetic networks for observing crustal motion have proliferated over the last two decades and are now recognized as indispensable tools in geophysical research, along side more traditional seismic networks. The 2007 National Research Council’s Decadal Survey recognizes that space-borne and in situ observations, such as Interferometric Synthetic Aperture Radar (InSAR) and ground-based continuous GPS (CGPS) are complementary in forecasting, in assessing, and in mitigating natural hazards. However, the information content and timeliness of in situ geodetic observations have not been fully exploited, particularly at higher frequencies than traditional daily CGPS position time series. Nor have scientists taken full advantage of the complementary natures of geodetic and seismic data, as well as those of space-based and in situ observations. To address these deficits we are developing real-time CGPS data products for earthquake early warning and for space-borne deformation measurement mission support. Our primary mission objective is in situ verification and validation for DESDynI, but our work is also applicable to other international missions (Sentinel 1a/1b, SAOCOM, ALOS 2). Our project is developing new capabilities to continuously observe and mitigate earthquake-related hazards (direct seismic damage, tsunamis, landslides, volcanoes) in near real-time with high spatial-temporal resolution, to improve the planning and accuracy of space-borne observations. We also are using GPS estimates of tropospheric zenith delay combined with water vapor data from weather models to generate tropospheric calibration maps for mitigating the largest source of error, atmospheric artifacts, in InSAR interferograms. These functions will be fully integrated into a Geophysical Resource Web Services and interactive GPS Explorer data portal environment being developed as part of an ongoing MEaSUREs project and NASA’s contribution to the EarthScope project. GPS Explorer, originally designed for web-based dissemination of long-term Solid Earth Science Data Records (ESDR’s) such as deformation time series, tectonic velocity vectors, and strain maps, provides the framework for seamless inclusion of the high rate data products. Detection and preliminary modeling of interesting signals by dense real-time high-rate ground networks will allow mission planners and decision makers to fully exploit the less-frequent but higher resolution InSAR observations. Fusion of in situ elements into an advanced observation system will significantly improve the scientific value of extensive surface displacement data, provide scientists with improved access to modern software tools to manipulate and model these data, increase the data’s accuracy and timeliness at higher frequencies than available from space-based observations, and increase the accuracy of space-based observations through calibration of atmospheric and other systematic errors.

A multi-model assessment of the impact of currents, waves and wind in modelling surface drifters and oil spill

NASA Astrophysics Data System (ADS)

De Dominicis, M.; Bruciaferri, D.; Gerin, R.; Pinardi, N.; Poulain, P. M.; Garreau, P.; Zodiatis, G.; Perivoliotis, L.; Fazioli, L.; Sorgente, R.; Manganiello, C.

2016-11-01

Validation of oil spill forecasting systems suffers from a lack of data due to the scarcity of oil slick in situ and satellite observations. Drifters (surface drifting buoys) are often considered as proxy for oil spill to overcome this problem. However, they can have different designs and consequently behave in a different way at sea, making it not straightforward to use them for oil spill model validation purposes and to account for surface currents, waves and wind when modelling them. Stemming from the need to validate the MEDESS4MS (Mediterranean Decision Support System for Marine Safety) multi-model oil spill prediction system, which allows access to several ocean, wave and meteorological operational model forecasts, an exercise at sea was carried out to collect a consistent dataset of oil slick satellite observations, in situ data and trajectories of different type of drifters. The exercise, called MEDESS4MS Serious Game 1 (SG1), took place in the Elba Island region (Western Mediterranean Sea) during May 2014. Satellite images covering the MEDESS4MS SG1 exercise area were acquired every day and, in the case an oil spill was observed from satellite, vessels of the Italian Coast Guard (ITCG) were sent in situ to confirm the presence of the pollution. During the exercise one oil slick was found in situ and drifters, with different water-following characteristics, were effectively deployed into the oil slick and then monitored in the following days. Although it was not possible to compare the oil slick and drifter trajectories due to a lack of satellite observations of the same oil slick in the following days, the oil slick observations in situ and drifters trajectories were used to evaluate the quality of MEDESS4MS multi-model currents, waves and winds by using the MEDSLIK-II oil spill model. The response of the drifters to surface ocean currents, different Stokes drift parameterizations and wind drag has been examined. We found that the surface ocean currents mainly drive the transport of completely submerged drifters. The accuracy of the simulations increases with higher resolution currents and with addition of the Stokes drift, which is better estimated when provided by wave models. The wind drag improves the modelling of drifter trajectories only in the case of partially emerged drifters, otherwise it leads to an incorrect reproduction of the drifters' direction, which is particularly evident in high speed wind conditions.

Data catalog for JPL Physical Oceanography Distributed Active Archive Center (PO.DAAC)

NASA Technical Reports Server (NTRS)

Digby, Susan

1995-01-01

The Physical Oceanography Distributed Active Archive Center (PO.DAAC) archive at the Jet Propulsion Laboratory contains satellite data sets and ancillary in-situ data for the ocean sciences and global-change research to facilitate multidisciplinary use of satellite ocean data. Geophysical parameters available from the archive include sea-surface height, surface-wind vector, surface-wind speed, surface-wind stress vector, sea-surface temperature, atmospheric liquid water, integrated water vapor, phytoplankton pigment concentration, heat flux, and in-situ data. PO.DAAC is an element of the Earth Observing System Data and Information System and is the United States distribution site for TOPEX/POSEIDON data and metadata.

Ma_Miss Experiment: miniaturized imaging spectrometer for subsurface studies

NASA Astrophysics Data System (ADS)

Coradini, A.; Ammannito, E.; Boccaccini, A.; de Sanctis, M. C.; di Iorio, T.; Battistelli, E.; Capanni, A.

2011-10-01

The study of the Martian subsurface will provide important constraints on the nature, timing and duration of alteration and sedimentation processes on Mars, as well as on the complex interactions between the surface and the atmosphere. A Drilling system, coupled with an in situ analysis package, is installed on the Exomars-Pasteur Rover to perform in situ investigations up to 2m in the Mars soil. Ma_Miss (Mars Multispectral Imager for Subsurface Studies) is a spectrometer devoted to observe the lateral wall of the borehole generated by the Drilling system. The instrument is fully integrated with the Drill and shares its structure and electronics.

Activation of Hydrogen Peroxide by Iron-Containing Minerals and Catalysts in Circumneutral pH Solutions: Implications for ex situ and in situ Treatment of Contaminated Water and Soil

NASA Astrophysics Data System (ADS)

Pham, Anh Le Tuan

The decomposition of hydrogen peroxide (H2O2) on iron minerals can generate hydroxyl radical (•OH), a strong oxidant capable of transforming a wide range of contaminants. This reaction is critical to ex situ advanced oxidation processes employed in waste treatment systems, as well as in situ chemical oxidation processes used for soil and groundwater remediation. Unfortunately, the process in the ex situ treatment systems is relatively inefficient at circumneutral pH values. In this research, the development of iron-containing catalysts with improved efficiency was investigated. In addition, little is known about the factors that control the performance of in situ treatment systems. Another aim of this dissertation was to elucidate those factors to provide a basis for improving the efficiency of the remediation method. Two types of silica- and alumina-containing iron (hydr)oxide catalysts were synthesized by sol-gel processing techniques (Chapter 2). Relative to iron oxides, such as hematite and goethite, these catalysts were 10 to 80 times more effective in catalyzing the production of •OH from H2O2 under circumneutral conditions. The higher efficiency makes these catalysts promising candidates for ex situ advanced oxidation processes. Moreover, because alumina and silica alter the reactivity of the iron oxides with H2O2, understanding the activity of iron associated with natural aluminosilicates and silica-containing minerals in the subsurface is crucial to explaining the variability of •OH production observed in in situ treatment systems. In addition to the sol-gel technique used in Chapter 2, silica-containing iron (hydr)oxide catalysts were synthesized by immobilizing iron oxide onto mesoporous silica supports, such as SBA-15 (Chapter 5). The iron-containing SBA-15 was 10 times more effective than iron oxides in catalyzing the production of •OH from H2O2. Moreover, this catalyst could be employed for selective oxidation of small organic contaminants based on size exclusion. However, a major drawback of the mesoporous silica-based catalysts is their instability under circumneutral conditions (Chapter 6). The dissolution of mesoporous silica materials raises questions about their use for water treatment, because silica dissolution might compromise the behavior of the material. To gain insight into factors that control H2O2 persistence and •OH yield in in situ processes, the decomposition of H2O2 and transformation of contaminants were investigated in the presence of iron-containing minerals and aquifer materials (Chapter 3). Consistent with the observation described in Chapter 2, iron-containing aluminosilicates were more effective than iron oxides in converting H2O2 into •OH. In both iron-containing mineral and aquifer material systems, the yield of •OH was inversely correlated with the rate of H 2O2 decomposition. In the aquifer material systems, the yield also inversely correlated with the Mn content, consistent with the fact that the decomposition of H2O2 on manganese oxides does not produce •OH. The inverse correlation between Mn content and H2O2 loss rate and •OH yield suggests that the amount of Mn in aquifer materials could serve as a proxy for predicting H2O2 decomposition rates and contaminant oxidation efficiency. In addition to the surface and structure properties of iron solids, the presence of solutes, such as dissolved silica, also affected the decomposition of H2O2 (Chapter 4). The adsorption of dissolved silica onto mineral surfaces altered the catalytic sites, thereby decreasing the reactivity of iron- and manganese-containing minerals with H2O 2. Therefore, the presence of dissolved SiO2 could lead to greater persistence of H2O2 in groundwater, which should be considered in the design of in situ H2O 2-based treatment systems. In addition to in situ treatment, dissolved silica also can affect the reactivity of iron-containing catalysts used in ex situ processes. Therefore, its presence in contaminated industrial wastewater should be considered when ex situ treatment systems are designed.

Analysis of a Small Vigorous Mesoscale Convective System in a Low-Shear Environment. Pt. 1; Formation, Echo Structure and Lightning Behavior

NASA Technical Reports Server (NTRS)

Knupp, Kevin; Geerts, Bart; Goodman, Steven J.

1997-01-01

The precipitation output was highly variable due to the transient nature of the intense convective elements. This result is attributed to the high Richardson number (175) of the environment, which is much higher than that of the typical MCS environment. The development of the stratiform precipitation was accomplished locally (in situ), and not be advection of from the convective region. In situ charging of the stratiform region is also supported by the observations.

Octave-spanning supercontinuum generation in in situ tapered As₂S₃ fiber pumped by a thulium-doped fiber laser.

PubMed

Rudy, Charles W; Marandi, Alireza; Vodopyanov, Konstantin L; Byer, Robert L

2013-08-01

We report a supercontinuum spanning well over an octave of measurable bandwidth from about 1 to 3.7 μm in a 2.1 mm long As₂S₃ fiber taper using the in situ tapering method. A sub-100-fs mode-locked thulium-doped fiber laser system with ~300 pJ of pulse energy was used as the pump source. Third-harmonic generation was observed and currently limits the pump pulse energy and achievable spectral bandwidth.

Chalk-calcite-microfluidic experiments: construction and flooding of microsystems with reactive fluids

NASA Astrophysics Data System (ADS)

Neuville, Amélie; Thuy Luu, Thi; Dysthe, Dag Kristian; Vinningland, Jan Ludvig; Hiorth, Aksel

2015-04-01

Direct in situ observation of the pore structure changes that occur when chalk is flooded with brines could resolve many of the open questions that remain about the interactions between mineralogical alterations and oil-liberating mechanisms. Experiments on core scale and field tests that have been carried out the last decade have clearly shown that water chemistry affects the final oil recovery. However, there is generally no consensus in the scientific community of why additional oil is released. In this work, our aim is to focus on in-situ observations of single phase flow and interactions at the pore scale. To do so, we create several types of custom-made microsystems with chalk and calcite crystals. We then do experiments with reacting fluids in these microsystems. During these experiments, we realize in-situ observations (geometrical characteristics, reaction rate) using microsopy techniques (white light vertical/phase shift interferometric microscopy, and classical microscopy), and show how they vary as function as the water chemistry. In simple systems made of calcite, we obtain reactive rates that are coherent with the litterature and with numerical simulations based on Lattice-Boltzmann methods.

Unraveling irradiation induced grain growth with in situ transmission electron microscopy and coordinated modeling

DOE PAGES

Bufford, D. C.; Abdeljawad, F. F.; Foiles, S. M.; ...

2015-11-09

Here, nanostructuring has been proposed as a method to enhance radiation tolerance, but many metallic systems are rejected due to significant concerns regarding long term grain boundary and interface stability. This work utilized recent advancements in transmission electron microscopy (TEM) to quantitatively characterize the grain size, texture, and individual grain boundary character in a nanocrystalline gold model system before and after in situ TEM ion irradiation with 10 MeV Si. The initial experimental measurements were fed into a mesoscale phase field model, which incorporates the role of irradiation-induced thermal events on boundary properties, to directly compare the observed and simulatedmore » grain growth with varied parameters. The observed microstructure evolution deviated subtly from previously reported normal grain growth in which some boundaries remained essentially static. In broader terms, the combined experimental and modeling techniques presented herein provide future avenues to enhance quantification and prediction of the thermal, mechanical, or radiation stability of grain boundaries in nanostructured crystalline systems.« less

Superpave in-situ stress/strain investigation--phase II : vol. I, summary report.

DOT National Transportation Integrated Search

2009-05-01

The characterization of materials is an intergral part of the overall effort to validate the Superpave system and to calibrate the performance prdeictionmodels for the environmental conditions observed in the Commonwealth of Pennsylvania.

Superpave in-situ stress/strain investigation--phase II : vol. II, materials characterization.

DOT National Transportation Integrated Search

2009-05-01

The characterization of materials is an intergral part of the overall effort to validate the Superpave system and to calibrate the performance prdeictionmodels for the environmental conditions observed in the Commonwealth of Pennsylvania.

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles

PubMed Central

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L.; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-01-01

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi2Ta2O9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction–relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes. PMID:28194017

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles

NASA Astrophysics Data System (ADS)

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L.; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-02-01

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi2Ta2O9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction-relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes.

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles.

PubMed

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-02-13

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi 2 Ta 2 O 9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction-relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes.

Melting diagrams of Fe-rich alloys determined from synchrotron in situ measurements in the 15-23 GPa pressure range

NASA Astrophysics Data System (ADS)

Andrault, D.; Bolfan-Casanova, N.; Ohtaka, O.; Fukui, H.; Arima, H.; Fialin, M.; Funakoshi, K.

2009-05-01

We report in situ observations of the melting behaviour of iron alloyed with 10-20 at.% C, O, S, or Si at pressures between 15 and 24 GPa, using X-ray diffraction in a multi-anvil press (SPring8). The degree of partial melting of the iron alloys has been quantified from analysis of the intensity of diffuse X-ray scattering of molten iron as a function for decreasing temperature with a 50° step. Coupled with microanalysis of recovered samples, the in situ observations bring direct constraints on shape and positions of liquidus and solidus curves in the melting diagrams. For the Fe-S system, our results are in good agreement with previous works. We observe that the eutectic temperature increases from 1023 K at 15 GPa to 1123 K at 20.6 GPa and that the eutectic composition decreases with increases pressure. Concerning the Fe-C system the eutectic temperature of 1460 K at 20.7 GPa falls slightly below a linear extrapolation of the previous work. In the case of the Fe-Ni-Si system and the Fe-O system, we find eutectic temperatures significantly lower than previously reported. For the two systems, both eutectic temperature and composition increase with increasing pressure in the 15-20 GPa range. Compare to previous work, we observe eutectic compositions (a) richer in light elements in the Fe-O system, with 9.0 and 10.5 wt% O at 16.5 and 20.5 GPa, respectively, and (b) poorer in the Fe-Ni-Si system with 11.5 wt% Si at 16.9 GPa. We confirm very high solubility of Si and C with solid iron, and report a Si partitioning coefficient of 1.3(2) at 16.9 GPa. The S and O solubility in solid iron appears very small. Therefore, both S and/or O could explain density jumps between liquid outer and solid inner parts of planetary cores, at least up to ˜25 GPa.

The Impact of the Assimilation of Aquarius Sea Surface Salinity Data in the GEOS Ocean Data Assimilation System

NASA Technical Reports Server (NTRS)

Vernieres, Guillaume Rene Jean; Kovach, Robin M.; Keppenne, Christian L.; Akella, Santharam; Brucker, Ludovic; Dinnat, Emmanuel Phillippe

2014-01-01

Ocean salinity and temperature differences drive thermohaline circulations. These properties also play a key role in the ocean-atmosphere coupling. With the availability of L-band space-borne observations, it becomes possible to provide global scale sea surface salinity (SSS) distribution. This study analyzes globally the along-track (Level 2) Aquarius SSS retrievals obtained using both passive and active L-band observations. Aquarius alongtrack retrieved SSS are assimilated into the ocean data assimilation component of Version 5 of the Goddard Earth Observing System (GEOS-5) assimilation and forecast model. We present a methodology to correct the large biases and errors apparent in Version 2.0 of the Aquarius SSS retrieval algorithm and map the observed Aquarius SSS retrieval into the ocean models bulk salinity in the topmost layer. The impact of the assimilation of the corrected SSS on the salinity analysis is evaluated by comparisons with insitu salinity observations from Argo. The results show a significant reduction of the global biases and RMS of observations-minus-forecast differences at in-situ locations. The most striking results are found in the tropics and southern latitudes. Our results highlight the complementary role and problems that arise during the assimilation of salinity information from in-situ (Argo) and space-borne surface (SSS) observations

In Situ Optical Observation of High-Temperature Geological Processes With the Moissanite Cell

NASA Astrophysics Data System (ADS)

Walte, N.; Keppler, H.

2005-12-01

A major drawback of existing techniques in experimental earth and material sciences is the inability to observe ongoing high-temperature processes in situ during an experiment. Examples for important time-dependent processes include the textural development of rocks and oxide systems during melting and crystallization, solid-state and melt-present recrystallization and Ostwald ripening, and bubble nucleation and growth during degassing of glasses and melts. The investigation of these processes by post-mortem analysis of a quenched microstructure is time consuming and often unsatisfactory. Here, we introduce the moissanite cell that allows optical in situ observation of long-term experiments at high temperatures. Moissanite is a transparent gem-quality type of SiC that is characterized by its hardness and superior chemical and thermal resistance. Two moissanite windows with a thickness and diameter of several millimeters are placed into sockets of fired pyrophyllite and fixed onto two opposite metal plates. The sockets are wrapped with heating wire and each window is connected to a thermocouple for temperature control. The sample is placed directly between the moissanite windows and the cell is assembled similarly to a large diamond anvil cell. In situ observation of the sample is done with a microscope through observation windows and movies are recorded with an attached digital camera. Our experiments with the new cell show that temperatures above 1200°C can be maintained and observed in a sample for several days without damaging the cell nor the windows. Time-lapse movies of melting and crystallizing natural and synthetic rocks and of degassing glasses and melts will be presented to show the potential of the new technique for experimental earth and material science.

Observations of Stratiform Lightning Flashes and Their Microphysical and Kinematic Environments

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Williams, Earle

2016-01-01

During the Midlatitude Continental Convective Clouds Experiment (MC3E), combined observations of clouds and precipitation were made from airborne and ground-based in situ and remote sensing platforms. These observations were coordinated for multiple mesoscale convective systems (MCSs) that passed over the MC3E domain in northern Oklahoma. Notably, during a storm on 20 May 2011 in situ and remote sensing airborne observations were made near the times and locations of stratiform positive cloud-to-ground (+CG) lightning flashes. These +CGs resulted from extremely large stratiform lightning flashes that were hundreds of km in length and lasted several seconds. This dataset provides an unprecedented look at kinematic and microphysical environments in the vicinity of large, powerful, and long-lived stratiform lightning flashes. We will use this dataset to understand the influence of low liquid water contents (LWCs) in the electrical charging of MCS stratiform regions.

Observations of Stratiform Lightning Flashes and Their Microphysical and Kinematic Environments

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Williams, Earle

2017-01-01

During the Midlatitude Continental Convective Clouds Experiment (MC3E), combined observations of clouds and precipitation were made from airborne and ground-based in situ and remote sensing platforms. These observations were coordinated for multiple mesoscale convective systems (MCSs) that passed over the MC3E domain in northern Oklahoma. Notably, during a storm on 20 May 2011 in situ and remote sensing airborne observations were made near the times and locations of stratiform positive cloud-to-ground (+CG) lightning flashes. These +CGs resulted from extremely large stratiform lightning flashes that were hundreds of km in length and lasted several seconds. This dataset provides an unprecedented look at kinematic and microphysical environments in the vicinity of large, powerful, and long-lived stratiform lightning flashes. We will use this dataset to understand the influence of low liquid water contents (LWCs) in the electrical charging of MCS stratiform regions.

Towards the creation of a European Network of Earth Observation Networks within GEO. The ConnectinGEO project.

NASA Astrophysics Data System (ADS)

Masó, Joan; Serral, Ivette; Menard, Lionel; Wald, Lucien; Nativi, Stefano; Plag, Hans-Peter; Jules-Plag, Shelley; Nüst, Daniel; Jirka, Simon; Pearlman, Jay; De Maziere, Martine

2015-04-01

ConnectinGEO (Coordinating an Observation Network of Networks EnCompassing saTellite and IN-situ to fill the Gaps in European Observations" is a new H2020 Coordination and Support Action with the primary goal of linking existing Earth Observation networks with science and technology (S&T) communities, the industry sector, the Group on Earth Observations (GEO), and Copernicus. ConnectinGEO aims to facilitate a broader and more accessible knowledge base to support the needs of GEO, its Societal Benefit Areas (SBAs) and the users of the Global Earth Observing System of Systems (GEOSS). A broad range of subjects from climate, natural resources and raw materials, to the emerging UN Sustainable Development Goals (SDGs) will be addressed. The project will generate a prioritized list of critical gaps within available observation data and models to translate observations into practice-relevant knowledge, based on stakeholder consultation and systematic analysis. Ultimately, it will increase coherency of European observation networks, increase the use of Earth observations for assessments and forecasts and inform the planning for future observation systems. ConnectinGEO will initiate a European Network of Earth Observation Networks (ENEON) that will encompass space-based, airborne and in-situ observations networks. ENEON will be composed by project partners representing thematic observation networks along with the GEOSS Science and Technology Stakeholder Network, GEO Communities of Practices, Copernicus services, Sentinel missions and in-situ support data representatives, representatives of the space-based, airborne and in-situ observations European networks (e.g. EPOS, EMSO and GROOM, etc), representatives of the industry sector and European and national funding agencies, in particular those participating in the future ERA-PlaNET. At the beginning, the ENEON will be created and managed by the project. Then the management will be transferred to the network itself to ensure its future continuity. ConnectinGEO's main goal in ENEON is to mature a consultation complemented by a systematic analysis of available data and metadata, which will draw for the first time a coherent picture of the variety of used data interfaces, policies and indicators. This way, the project will stimulate a harmonized and coherent coverage of the European EO networks, reemphasizing the political strategic targets, create opportunities for SMEs to develop products based on the current networks, and open avenue for industry to participate in investments addressing the identified high-priority gaps. The project starts in February 2015 and will last two years. We will present the five threads of the project for gap analysis in the Earth observation networks: global requirements and goals, international research programs, consultation process, systematic analysis of existing data platforsm and industry challenges. The presentation will provide both an overview of the network concepts and approaches and discuss participation of the broader scientific community of data providers and users.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

USGS Publications Warehouse

Hatzinger, P.B.; Bohlke, John Karl; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatzinger, Paul B.; Bohlke, J. K.; Sturchio, N. C.

An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br-as a conservative tracer of themore » injectate), perchlorate concentrations decreased by 78 % and nitrate concentrations decreased by 87 %, during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (ε18O/ε37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of approximately 0.8 (ε18O/ε15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (ε18O/ε37Cl, ε18O/ε15N) derived from homogeneous laboratory systems (e.g., pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent  values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graetz J.; Meng, Y.S.; McGilvray, T.

Oxides and their tailored structures are at the heart of electrochemical energy storage technologies and advances in understanding and controlling the dynamic behaviors in the complex oxides, particularly at the interfaces, during electrochemical processes will catalyze creative design concepts for new materials with enhanced and better-understood properties. Such knowledge is not accessible without new analytical tools. New innovative experimental techniques are needed for understanding the chemistry and structure of the bulk and interfaces, more importantly how they change with electrochemical processes in situ. Analytical Transmission Electron Microscopy (TEM) is used extensively to study electrode materials ex situ and is onemore » of the most powerful tools to obtain structural, morphological, and compositional information at nanometer scale by combining imaging, diffraction and spectroscopy, e.g., EDS (energy dispersive X-ray spectrometry) and Electron Energy Loss Spectrometry (EELS). Determining the composition/structure evolution upon electrochemical cycling at the bulk and interfaces can be addressed by new electron microscopy technique with which one can observe, at the nanometer scale and in situ, the dynamic phenomena in the electrode materials. In electrochemical systems, for instance in a lithium ion battery (LIB), materials operate under conditions that are far from equilibrium, so that the materials studied ex situ may not capture the processes that occur in situ in a working battery. In situ electrochemical operation in the ultra-high vacuum column of a TEM has been pursued by two major strategies. In one strategy, a 'nano-battery' can be fabricated from an all-solid-state thin film battery using a focused ion beam (FIB). The electrolyte is either polymer based or ceramic based without any liquid component. As shown in Fig. 1a, the interfaces between the active electrode material/electrolyte can be clearly observed with TEM imaging, in contrast to the composite electrodes/electrolyte interfaces in conventional lithium ion batteries, depicted in Fig.1b, where quantitative interface characterization is extremely difficult if not impossible. A second strategy involves organic electrolyte, though this approach more closely resembles the actual operation conditions of a LIB, the extreme volatility In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry by Ying Shirley Meng, Thomas McGilvray, Ming-Che Yang, Danijel Gostovic, Feng Wang, Dongli Zeng, Yimei Zhu, and Jason Graetz of the organic electrolytes present significant challenges for designing an in situ cell that is suitable for the vacuum environment of the TEM. Significant progress has been made in the past few years on the development of in situ electron microscopy for probing nanoscale electrochemistry. In 2008, Brazier et al. reported the first cross-section observation of an all solid-state lithium ion nano-battery by TEM. In this study the FIB was used to make a 'nano-battery,' from an all solid-state battery prepared by pulsed laser deposition (PLD). In situ TEM observations were not possible at that time due to several key challenges such as the lack of a suitable biasing sample holder and vacuum transfer of sample. In 2010, Yamamoto et al. successfully observed changes of electric potential in an all-solid-state lithium ion battery in situ with electron holography (EH). The 2D potential distribution resulting from movement of lithium ions near the positive-electrode/electrolyte interface was quantified. More recently Huang et al. and Wang et al. reported the in situ observations of the electrochemical lithiation of a single SnO{sub 2} nanowire electrode in two different in situ setups. In their approach, a vacuum compatible ionic liquid is used as the electrolyte, eliminating the need for complicated membrane sealing to prevent the evaporation of carbonate based organic electrolyte into the TEM column. One main limitation of this approach is that EELS spectral imaging is not possible due to the high plasmon signal of the ionic liquid. To this end, we have developed a novel in situ instrumental system combining analytical electron microscopy with advanced spectroscopy to probe the dynamic phenomena in an all solid-state nano-battery. In situ electron microscopy is a versatile technique that yields insights into challenging questions that could not be obtained using other techniques. However, in order to fully exploit the capabilities, a very carefully thought-out plan of action is essential. It is important to recognize that this is not just a simple characterization tool, but a collection of tools that make up a complete experimental set-up: the choice of FIB operation conditions, specimen holder for biasing, grid materials and design as well as microscope environment must be thoroughly considered before performing an experiment.« less

ISERV Pathfinder. The ISS SERVIR Environmental Research and Visualization System

NASA Technical Reports Server (NTRS)

Howell, Burgess

2011-01-01

SERVIR integrates Earth observations (e.g., space imagery), predictive models, and in situ data to provide timely information products to support environmental decision makers. ISERV propoesed development -- ISERV-W: Internal Visible/Near-Infrared (VNIR), attached to ISS via Window Observational Research Facility (WORF), ISERV-E: External Visible/Broad-Infrared (V/IR) and ISERV-PM: External Passive Microwave.

In situ x-ray diffraction observation of multiple texture turnovers in sputtered Cr films

NASA Astrophysics Data System (ADS)

Zhao, Z. B.; Rek, Z. U.; Yalisove, S. M.; Bilello, J. C.

2004-11-01

A series of Cr films were deposited onto native oxides of (100) Si substrates via a confocal deposition geometry in a magnetron sputter chamber. The film growth chamber was incorporated with an in situ x-ray diffraction system, which allowed the collection of x-ray diffraction data on the growing film in a quasi real time fashion without interruption of film deposition. The in situ x-ray diffraction, coupled with other ex situ characterization techniques, was used to study structural evolutions of the Cr films deposited at various Ar pressures. It was observed that the evolution of the crystallographic structures of Cr films was very sensitive to both deposition conditions and film thickness. With the confocal deposition geometry, the Cr films developed various types of out-of-plane textures. In addition to the (110) and (100) types of textures commonly reported for vapor deposited Cr films, the (111) and (112) types of textures were also observed. The film deposited at low Ar pressure (2 mTorr) developed strong (111) type texture. With the increase in either Ar pressure or film thickness, the Cr films tended to develop (112) and (100) types of texture. At high Ar pressures (>10 mTorr), several changes in texture type with increasing film thickness were observed. The sequence can be described as (110)-->(112)-->(100). The strong tendency for these films to ultimately assume the (100) type of texture could be related to significant rises in substrate temperatures during the late stages of film growth with high Ar pressures. The observation of the multiple texture type changes suggests that the evolution of Cr films is controlled by complex growth kinetics. The competitive growth of grains with different orientations can be altered not only by controllable deposition parameters such as Ar pressure, but also by the variations of in situ film attributes (e.g., residual stress and substrate temperature) occurring concurrently with film growth.

Integrating in-situ, Landsat, and MODIS data for mapping in Southern African savannas: experiences of LCCS-based land-cover mapping in the Kalahari in Namibia.

PubMed

Hüttich, Christian; Herold, Martin; Strohbach, Ben J; Dech, Stefan

2011-05-01

Integrated ecosystem assessment initiatives are important steps towards a global biodiversity observing system. Reliable earth observation data are key information for tracking biodiversity change on various scales. Regarding the establishment of standardized environmental observation systems, a key question is: What can be observed on each scale and how can land cover information be transferred? In this study, a land cover map from a dry semi-arid savanna ecosystem in Namibia was obtained based on the UN LCCS, in-situ data, and MODIS and Landsat satellite imagery. In situ botanical relevé samples were used as baseline data for the definition of a standardized LCCS legend. A standard LCCS code for savanna vegetation types is introduced. An object-oriented segmentation of Landsat imagery was used as intermediate stage for downscaling in-situ training data on a coarse MODIS resolution. MODIS time series metrics of the growing season 2004/2005 were used to classify Kalahari vegetation types using a tree-based ensemble classifier (Random Forest). The prevailing Kalahari vegetation types based on LCCS was open broadleaved deciduous shrubland with an herbaceous layer which differs from the class assignments of the global and regional land-cover maps. The separability analysis based on Bhattacharya distance measurements applied on two LCCS levels indicated a relationship of spectral mapping dependencies of annual MODIS time series features due to the thematic detail of the classification scheme. The analysis of LCCS classifiers showed an increased significance of life-form composition and soil conditions to the mapping accuracy. An overall accuracy of 92.48% was achieved. Woody plant associations proved to be most stable due to small omission and commission errors. The case study comprised a first suitability assessment of the LCCS classifier approach for a southern African savanna ecosystem.

Bridging a possible gap of GRACE observations in the Arctic Ocean using existing GRACE data and in situ bottom pressure sensors

NASA Astrophysics Data System (ADS)

Peralta Ferriz, C.; Morison, J.

2014-12-01

Since 2003, the Gravity Recovery and Climate Experiment (GRACE) satellite system has provided the means of investigating month-to-month to inter-annual variability of, among many other things, Arctic Ocean circulation over the entire Arctic Basin. Such a comprehensive picture could not have been achieved with the limited in situ pressure observations available. Results from the first 10 years of ocean bottom pressure measurements from GRACE in the Arctic Ocean reveal distinct patterns of ocean variability that are strongly associated with changes in large-scale atmospheric circulation (Peralta-Ferriz et al., 2014): the leading mode of variability being a wintertime basin-coherent mass change driven by winds in the Nordic Seas; the second mode of variability corresponding to a mass signal coherent along the Siberian shelves, and driven by the Arctic Oscillation; and the third mode being a see-saw between western and eastern Arctic shelves, also driven by the large-scale wind patterns. In order to understand Arctic Ocean changes, it is fundamental to continue to track ocean bottom pressure. Our concern is what to do if the present GRACE system, which is already well beyond its design lifetime, should fail before its follow-on is launched, currently estimated to be in 2017. In this work, we regress time series of pressure from the existing and potential Arctic Ocean bottom pressure recorder locations against the fundamental modes of bottom pressure variation. Our aim is to determine the optimum combination of in situ measurements to represent the broader scale variability now observed by GRACE. With this understanding, we can be better prepared to use in situ observations to at least partially cover a possible gap in GRACE coverage. Reference:Peralta-Ferriz, Cecilia, James H. Morison, John M. Wallace, Jennifer A. Bonin, Jinlun Zhang, 2014: Arctic Ocean Circulation Patterns Revealed by GRACE. J. Climate, 27, 1445-1468. doi: http://dx.doi.org/10.1175/JCLI-D-13-00013.1

Superpave in-situ stress/strain investigation--phase II : vol. IV, mechanistic analysis and implementation.

DOT National Transportation Integrated Search

2009-05-01

The characterization of materials is an intergral part of the overall effort to validate the Superpave system and to calibrate the performance prdeictionmodels for the environmental conditions observed in the Commonwealth of Pennsylvania.

Satellite Remote Sensing is Key to Water Cycle Integrator

NASA Astrophysics Data System (ADS)

Koike, T.

2016-12-01

To promote effective multi-sectoral, interdisciplinary collaboration based on coordinated and integrated efforts, the Global Earth Observation System of Systems (GEOSS) is now developing a "GEOSS Water Cycle Integrator (WCI)", which integrates "Earth observations", "modeling", "data and information", "management systems" and "education systems". GEOSS/WCI sets up "work benches" by which partners can share data, information and applications in an interoperable way, exchange knowledge and experiences, deepen mutual understanding and work together effectively to ultimately respond to issues of both mitigation and adaptation. (A work bench is a virtual geographical or phenomenological space where experts and managers collaborate to use information to address a problem within that space). GEOSS/WCI enhances the coordination of efforts to strengthen individual, institutional and infrastructure capacities, especially for effective interdisciplinary coordination and integration. GEOSS/WCI archives various satellite data to provide various hydrological information such as cloud, rainfall, soil moisture, or land-surface snow. These satellite products were validated using land observation in-situ data. Water cycle models can be developed by coupling in-situ and satellite data. River flows and other hydrological parameters can be simulated and validated by in-situ data. Model outputs from weather-prediction, seasonal-prediction, and climate-prediction models are archived. Some of these model outputs are archived on an online basis, but other models, e.g., climate-prediction models are archived on an offline basis. After models are evaluated and biases corrected, the outputs can be used as inputs into the hydrological models for predicting the hydrological parameters. Additionally, we have already developed a data-assimilation system by combining satellite data and the models. This system can improve our capability to predict hydrological phenomena. The WCI can provide better predictions of the hydrological parameters for integrated water resources management (IWRM) and also assess the impact of climate change and calculate adaptation needs.

LIDAR Developments at Clermont-Ferrand—France for Atmospheric Observation

PubMed Central

Fréville, Patrick; Montoux, Nadège; Baray, Jean-Luc; Chauvigné, Aurélien; Réveret, François; Hervo, Maxime; Dionisi, Davide; Payen, Guillaume; Sellegri, Karine

2015-01-01

We present a Rayleigh-Mie-Raman LIDAR system in operation at Clermont-Ferrand (France) since 2008. The system provides continuous vertical tropospheric profiles of aerosols, cirrus optical properties and water vapour mixing ratio. Located in proximity to the high altitude Puy de Dôme station, labelled as the GAW global station PUY since August 2014, it is a useful tool to describe the boundary layer dynamics and hence interpret in situ measurements. This LIDAR has been upgraded with specific hardware/software developments and laboratory calibrations in order to improve the quality of the profiles, calibrate the depolarization ratio, and increase the automation of operation. As a result, we provide a climatological water vapour profile analysis for the 2009–2013 period, showing an annual cycle with a winter minimum and a summer maximum, consistent with in-situ observations at the PUY station. An overview of a preliminary climatology of cirrus clouds frequency shows that in 2014, more than 30% of days present cirrus events. Finally, the backscatter coefficient profile observed on 27 September 2014 shows the capacity of the system to detect cirrus clouds at 13 km altitude, in presence of aerosols below the 5 km altitude. PMID:25643059

Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System

NASA Technical Reports Server (NTRS)

Rienecker, Michele M.; Balmaseda, Magdalena; Awaji, Toshiyuki; Barnier, Bernard; Behringer, David; Bell, Mike; Bourassa, Mark; Brasseur, Pierre; Breivik, Lars-Anders; Carton, James;

High-Frequency Observation of Water Spectrum and Its Application in Monitoring of Dynamic Variation of Suspended Materials in the Hangzhou Bay.

PubMed

Dai, Qian; Pan, De-lu; He, Xian-qiang; Zhu, Qian-kun; Gong, Fang; Huang, Hai-qing

2015-11-01

In situ measurement of water spectrum is the basis of the validation of the ocean color remote sensing. The traditional method to obtain the water spectrum is based on the shipboard measurement at limited stations, which is difficult to meet the requirement of validation of ocean color remote sensing in the highly dynamic coastal waters. To overcome this shortage, continuously observing systems of water spectrum have been developed in the world. However, so far, there are still few high-frequency observation systems of the water spectrum in coastal waters, especially in the highly turbid and high-dynamic waters. Here, we established a high-frequency water-spectrum observing system based on tower in the Hangzhou Bay. The system measures the water spectrum at a step of 3 minutes, which can fully match the satellite observation. In this paper, we primarily developed a data processing method for the tower-based high-frequency water spectrum data, to realize automatic judgment of clear sky, sun glint, platform shadow, and weak illumination, etc. , and verified the processing results. The results show that the normalized water-leaving radiance spectra obtained through tower observation have relatively high consistency with the shipboard measurement results, with correlation coefficient of more than 0. 99, and average relative error of 9.96%. In addition, the long-term observation capability of the tower-based high-frequency water-spectrum observing system was evaluated, and the results show that although the system has run for one year, the normalized water-leaving radiance obtained by this system have good consistency with the synchronously measurement by Portable spectrometer ASD in respect of spectral shape and value, with correlation coefficient of more than 0.90 and average relative error of 6.48%. Moreover, the water spectra from high-frequency observation by the system can be used to effectively monitor the rapid dynamic variation in concentration of suspended materials with tide. The tower-based high-frequency water-spectrum observing system provided rich in situ spectral data for the validation of ocean color remote sensing in turbid waters, especially for validation of the high temporal-resolution geostationary satellite ocean color remote sensing.

Observations of the Earth's magnetic field from the Space Station: Measurement at high and extremely low altitude using Space Station-controlled free-flyers

NASA Technical Reports Server (NTRS)

Webster, W., Jr.; Frawley, J. J.; Stefanik, M.

1984-01-01

Simulation studies established that the main (core), crustal and electrojet components of the Earth's magnetic field can be observed with greater resolution or over a longer time-base than is presently possible by using the capabilities provided by the space station. Two systems are studied. The first, a large lifetime, magnetic monitor would observe the main field and its time variation. The second, a remotely-piloted, magnetic probe would observe the crustal field at low altitude and the electrojet field in situ. The system design and the scientific performance of these systems is assessed. The advantages of the space station are reviewed.

Ground-Based Network and Supersite Observations to Complement and Enrich EOS Research

NASA Technical Reports Server (NTRS)

Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.

2011-01-01

Since 1997 NASA has been successfully launching a series of satellites - the Earth Observing System (EOS) - to intensively study, and gain a better understanding of, the Earth as an integrated system. Space-borne remote sensing observations, however, are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite datasets. Through numerous participations, particularly but not limited to the EOS remote-sensing/retrieval and validation projects over the years, NASA/GSFC has developed and continuously refined ground-based networks and mobile observatories that proved to be vital in providing high temporal measurements, which complement and enrich the satellite observations. These are: the AERO NET (AErosol RObotic NETwork) a federation of ground-based globally distributed network of spectral sun-sky photometers; the MPLNET (Micro-Pulse Lidar NETwork, a similarly organized network of micro-pulse lidar systems measuring aerosol and cloud vertical structure continuously; and the SMART-COMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere, mobile observatories, a suite of spectral radiometers and in-situ probes acquiring supersite measurements. Most MPLNET sites are collocated with those of AERONET, and both networks always support the deployment of SMART-COMMIT worldwide. These data products follow the data structure of EOS conventions: Level-0, instrument archived raw data; Level-1 (or 1.5), real-time data with no (or limited) quality assurance; Level-2, not real high temporal and spectral resolutions. In this talk, we will present NASA/GSFC groundbased facilities, serving as network or supersite observations, which have been playing key roles in major international research projects over diverse aerosol regimes to complement and enrich the EOS scientific research.

A Quantitative Approach for Collocating NEON's Sensor-Based Ecological Measurements and in-situ Field Sampling and Observations

NASA Astrophysics Data System (ADS)

Zulueta, R. C.; Metzger, S.; Ayres, E.; Luo, H.; Meier, C. L.; Barnett, D.; Sanclements, M.; Elmendorf, S.

2013-12-01

The National Ecological Observatory Network (NEON) is a continental-scale research platform currently in development to assess the causes of ecological change and biological responses to change across a projected 30-year timeframe. A suite of standardized sensor-based measurements (i.e., Terrestrial Instrument System (TIS) measurements) and in-situ field sampling and observations (i.e., Terrestrial Observation System (TOS) activities) will be conducted across 20 ecoclimatic domains in the U.S. where NEON is establishing 60 terrestrial research sites. NEON's TIS measurements and TOS activities are designed to observe the temporal and spatial dynamics of key drivers and ecological processes and responses to change within each of the 60 terrestrial research sites. The TIS measurements are non-destructive and designed to provide in-situ, continuous, and areally integrated observations of the surrounding ecosystem and environment, while TOS sampling and observation activities are designed to encompass a hierarchy of measurable biological states and processes including diversity, abundance, phenology, demography, infectious disease prevalence, ecohydrology, and biogeochemistry. To establish valid relationships between these drivers and site-specific responses, two contradicting requirements must be fulfilled: (i) both types of observations shall be representative of the same ecosystem, and (ii) they shall not significantly influence one another. Here we outline the theoretical background and algorithmic process for determining areas of mutual representativeness and exclusion around NEON's TIS measurements and develop a procedure which quantitatively optimizes this trade-off through: (i) quantifying the source area distributions of TIS measurements, (ii) determining the ratio of user-defined impact threshold to effective impact area for different TOS activities, and (iii) determining the range of feasible distances between TIS locations and TOS activities. This approach provides an evidence-based and repeatable method for combining sensor-based measurements and field sampling and observations at predefined levels of disturbance and spatial representativeness. The developed approach represents a general framework which is applicable to other environmental research sites where similar collocation is desired.

Mapping Isoprene Emissions over North America using Formaldehyde Column Observations from Space

NASA Technical Reports Server (NTRS)

Palmer, Paul I.; Jacob, Daniel J.; Fiore, Arlene M.; Martin, Randall V.; Chance, Kelly; Kurosu, Thomas P.

2004-01-01

I] We present a methodology for deriving emissions of volatile organic compounds (VOC) using space-based column observations of formaldehyde (HCHO) and apply it to data from the Global Ozone Monitoring Experiment (GOME) satellite instrument over North America during July 1996. The HCHO column is related to local VOC emissions, with a spatial smearing that increases with the VOC lifetime. lsoprene is the dominant HCHO precursor over North America in summer, and its lifetime (approx. = 1 hour) is sufficiently short that the smearing can be neglected. We use the Goddard Earth Observing System global 3-D model of tropospheric chemistry (GEOS-CHEM) to derive the relationship between isoprene emissions and HCHO columns over North America and use these relationships to convert the GOME HCHO columns to isoprene emissions. We also use the GEOS-CHEM model as an intermediary to validate the GOME HCHO column measurements by comparison with in situ observations. The GEOS-CHEM model including the Global Emissions Inventory Activity (GEIA) isoprene emission inventory provides a good simulation of both the GOME data (r(sup 2) = 0.69, n = 756, bias = +l1 %) and the in situ summertime HCHO measurements over North America (r(sup 2) = 0.47, n = 10, bias = -3%). The GOME observations show high values over regions of known high isoprene emissions and a day-to-day variability that is consistent with the temperature dependence of isoprene emission. Isoprene emissions inferred from the GOME data are 20% less than GEIA on average over North America and twice those from the U S . EPA Biogenic Emissions Inventory System (BEIS2) inventory. The GOME isoprene inventory when implemented in the GEOS-CHEM model provides a better simulation of the HCHO in situ measurements thaneitherGEIAorBEIS2 (r(sup 2) = 0.71,n= 10, bias = -10 %).

In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope.

PubMed

Hata, S; Miyazaki, S; Gondo, T; Kawamoto, K; Horii, N; Sato, K; Furukawa, H; Kudo, H; Miyazaki, H; Murayama, M

2017-04-01

This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonnell, S.; Dong, H.; Hawkins, J. M.

2012-04-02

The Al{sub 2}O{sub 3}/GaAs and HfO{sub 2}/GaAs interfaces after atomic layer deposition are studied using in situ monochromatic x-ray photoelectron spectroscopy. Samples are deliberately exposed to atmospheric conditions and interfacial oxide re-growth is observed. The extent of this re-growth is found to depend on the dielectric material and the exposure temperature. Comparisons with previous studies show that ex situ characterization can result in misleading conclusions about the interface reactions occurring during the metal oxide deposition process.

Superpave in-situ stress/strain investigation--phase II : vol. III, field data collection and summary.

DOT National Transportation Integrated Search

2009-05-01

The characterization of materials is an intergral part of the overall effort to validate the Superpave system and to calibrate the performance prdeictionmodels for the environmental conditions observed in the Commonwealth of Pennsylvania.

Semantic Data Integration and Ontology Use within the Global Earth Observation System of Systems (GEOSS) Global Water Cycle Data Integration System

NASA Astrophysics Data System (ADS)

Pozzi, W.; Fekete, B.; Piasecki, M.; McGuinness, D.; Fox, P.; Lawford, R.; Vorosmarty, C.; Houser, P.; Imam, B.

2008-12-01

The inadequacies of water cycle observations for monitoring long-term changes in the global water system, as well as their feedback into the climate system, poses a major constraint on sustainable development of water resources and improvement of water management practices. Hence, The Group on Earth Observations (GEO) has established Task WA-08-01, "Integration of in situ and satellite data for water cycle monitoring," an integrative initiative combining different types of satellite and in situ observations related to key variables of the water cycle with model outputs for improved accuracy and global coverage. This presentation proposes development of the Rapid, Integrated Monitoring System for the Water Cycle (Global-RIMS)--already employed by the GEO Global Terrestrial Network for Hydrology (GTN-H)--as either one of the main components or linked with the Asian system to constitute the modeling system of GEOSS for water cycle monitoring. We further propose expanded, augmented capability to run multiple grids to embrace some of the heterogeneous methods and formats of the Earth Science, Hydrology, and Hydraulic Engineering communities. Different methodologies are employed by the Earth Science (land surface modeling), the Hydrological (GIS), and the Hydraulic Engineering Communities; with each community employing models that require different input data. Data will be routed as input variables to the models through web services, allowing satellite and in situ data to be integrated together within the modeling framework. Semantic data integration will provide the automation to enable this system to operate in near-real-time. Multiple data collections for ground water, precipitation, soil moisture satellite data, such as SMAP, and lake data will require multiple low level ontologies, and an upper level ontology will permit user-friendly water management knowledge to be synthesized. These ontologies will have to have overlapping terms mapped and linked together. so that they can cover an even wider net of data sources. The goal is to develop the means to link together the upper level and lower level ontologies and to have these registered within the GEOSS Registry. Actual operational ontologies that would link to models or link to data collections containing input variables required by models would have to be nested underneath this top level ontology, analogous to the mapping that has been carried out among ontologies within GEON.

High Ice Water Content at Low Radar Reflectivity near Deep Convection. Part I ; Consistency of In Situ and Remote-Sensing Observations with Stratiform Rain Column Simulations

NASA Technical Reports Server (NTRS)

Fridlind, A. M.; Ackerman, A. S.; Grandin, A.; Dezitter, F.; Weber, M.; Strapp, J. W.; Korolev, A. V.; Williams, C. R.

2015-01-01

Occurrences of jet engine power loss and damage have been associated with flight through fully glaciated deep convection at -10 to -50 degrees Centigrade. Power loss events commonly occur during flight through radar reflectivity (Zeta (sub e)) less than 20-30 decibels relative to Zeta (dBZ - radar returns) and no more than moderate turbulence, often overlying moderate to heavy rain near the surface. During 2010-2012, Airbus carried out flight tests seeking to characterize the highest ice water content (IWC) in such low-radar-reflectivity regions of large, cold-topped storm systems in the vicinity of Cayenne, Darwin, and Santiago. Within the highest IWC regions encountered, at typical sampling elevations (circa 11 kilometers), the measured ice size distributions exhibit a notably narrow concentration of mass over area-equivalent diameters of 100-500 micrometers. Given substantial and poorly quantified measurement uncertainties, here we evaluate the consistency of the Airbus in situ measurements with ground-based profiling radar observations obtained under quasi-steady, heavy stratiform rain conditions in one of the Airbus-sampled locations. We find that profiler-observed radar reflectivities and mean Doppler velocities at Airbus sampling temperatures are generally consistent with those calculated from in situ size-distribution measurements. We also find that column simulations using the in situ size distributions as an upper boundary condition are generally consistent with observed profiles of radar reflectivity (Ze), mean Doppler velocity (MDV), and retrieved rain rate. The results of these consistency checks motivate an examination of the microphysical pathways that could be responsible for the observed size-distribution features in Ackerman et al. (2015).

Extinction coefficients from lidar observations in ice clouds compared to in-situ measurements from the Cloud Integrating Nephelometer during CRYSTAL-FACE

NASA Technical Reports Server (NTRS)

Noel, Vincent; Winker, D. M.; Garrett, T. J.; McGill, M.

2005-01-01

This paper presents a comparison of volume extinction coefficients in tropical ice clouds retrieved from two instruments : the 532-nm Cloud Physics Lidar (CPL), and the in-situ probe Cloud Integrating Nephelometer (CIN). Both instruments were mounted on airborne platforms during the CRYSTAL-FACE campaign and took measurements in ice clouds up to 17km. Coincident observations from three cloud cases are compared : one synoptically-generated cirrus cloud of low optical depth, and two ice clouds located on top of convective systems. Emphasis is put on the vertical variability of the extinction coefficient. Results show small differences on small spatial scales (approx. 100m) in retrievals from both instruments. Lidar retrievals also show higher extinction coefficients in the synoptic cirrus case, while the opposite tendency is observed in convective cloud systems. These differences are generally variations around the average profile given by the CPL though, and general trends on larger spatial scales are usually well reproduced. A good agreement exists between the two instruments, with an average difference of less than 16% on optical depth retrievals.

Theoretical analysis to interpret projected image data from in-situ 3-dimensional equiaxed nucleation and growth

NASA Astrophysics Data System (ADS)

Mooney, Robin P.; McFadden, Shaun

2017-12-01

In-situ observation of crystal growth in transparent media allows us to observe solidification phase change in real-time. These systems are analogous to opaque systems such as metals. The interpretation of transient 2-dimensional area projections from 3-dimensional phase change phenomena occurring in a bulky sample is problematic due to uncertainty of impingement and hidden nucleation events; in stereology this problem is known as over-projection. This manuscript describes and demonstrates a continuous model for nucleation and growth using the well-established Johnson-Mehl-Avrami-Kolmogorov model, and provides a method to relate 3-dimensional volumetric data (nucleation events, volume fraction) to observed data in a 2-dimensional projection (nucleation count, area fraction). A parametric analysis is performed; the projection phenomenon is shown to be significant in cases where nucleation is occurring continuously with a relatively large variance. In general, area fraction on a projection plane will overestimate the volume fraction within the sample and the nuclei count recorded on the projection plane will underestimate the number of real nucleation events. The statistical framework given in this manuscript provides a methodology to deal with the differences between the observed (projected) data and the real (volumetric) measures.

Helicopter-borne observations of the continental background aerosol in combination with remote sensing and ground-based measurements

NASA Astrophysics Data System (ADS)

Düsing, Sebastian; Wehner, Birgit; Seifert, Patric; Ansmann, Albert; Baars, Holger; Ditas, Florian; Henning, Silvia; Ma, Nan; Poulain, Laurent; Siebert, Holger; Wiedensohler, Alfred; Macke, Andreas

2018-01-01

This paper examines the representativeness of ground-based in situ measurements for the planetary boundary layer (PBL) and conducts a closure study between airborne in situ and ground-based lidar measurements up to an altitude of 2300 m. The related measurements were carried out in a field campaign within the framework of the High-Definition Clouds and Precipitation for Advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) in September 2013 in a rural background area of central Europe.The helicopter-borne probe ACTOS (Airborne Cloud and Turbulence Observation System) provided measurements of the aerosol particle number size distribution (PNSD), the aerosol particle number concentration (PNC), the number concentration of cloud condensation nuclei (CCN-NC), and meteorological atmospheric parameters (e.g., temperature and relative humidity). These measurements were supported by the ground-based 3+2 wavelength polarization lidar system PollyXT, which provided profiles of the particle backscatter coefficient (σbsc) for three wavelengths (355, 532, and 1064 nm). Particle extinction coefficient (σext) profiles were obtained by using a fixed backscatter-to-extinction ratio (also lidar ratio, LR). A new approach was used to determine profiles of CCN-NC for continental aerosol. The results of this new approach were consistent with the airborne in situ measurements within the uncertainties.In terms of representativeness, the PNSD measurements on the ground showed a good agreement with the measurements provided with ACTOS for lower altitudes. The ground-based measurements of PNC and CCN-NC are representative of the PBL when the PBL is well mixed. Locally isolated new particle formation events on the ground or at the top of the PBL led to vertical variability in the cases presented here and ground-based measurements are not entirely representative of the PBL. Based on Mie theory (Mie, 1908), optical aerosol properties under ambient conditions for different altitudes were determined using the airborne in situ measurements and were compared with the lidar measurements. The investigation of the optical properties shows that on average the airborne-based particle light backscatter coefficient is 50.1 % smaller for 1064 nm, 27.4 % smaller for 532 nm, and 29.5 % smaller for 355 nm than the measurements of the lidar system. These results are quite promising, since in situ measurement-based Mie calculations of the particle light backscattering are scarce and the modeling is quite challenging. In contrast, for the particle light extinction coefficient we found a good agreement. The airborne-based particle light extinction coefficient was just 8.2 % larger for 532 nm and 3 % smaller for 355 nm, for an assumed LR of 55 sr. The particle light extinction coefficient for 1064 nm was derived with a LR of 30 sr. For this wavelength, the airborne-based particle light extinction coefficient is 5.2 % smaller than the lidar measurements. For the first time, the lidar ratio of 30 sr for 1064 nm was determined on the basis of in situ measurements and the LR of 55 sr for 355 and 532 nm wavelength was reproduced for European continental aerosol on the basis of this comparison. Lidar observations and the in situ based aerosol optical properties agree within the uncertainties. However, our observations indicate that a determination of the PNSD for a large size range is important for a reliable modeling of aerosol particle backscattering.

In situ water vapor and ozone measurements in Lhasa and Kunming during the Asian summer monsoon

NASA Astrophysics Data System (ADS)

Bian, Jianchun; Pan, Laura L.; Paulik, Laura; Vömel, Holger; Chen, Hongbin; Lu, Daren

2012-10-01

The Asian summer monsoon (ASM) anticyclone circulation system is recognized to be a significant transport pathway for water vapor and pollutants to enter the stratosphere. The observational evidence, however, is largely based on satellite retrievals. We report the first coincident in situ measurements of water vapor and ozone within the ASM anticyclone. The combined water vapor and ozonesondes were launched from Kunming, China in August 2009 and Lhasa, China in August 2010. In total, 11 and 12 sondes were launched in Kunming and Lhasa, respectively. We present the key characteristics of these measurements, and provide a comparison to similar measurements from an equatorial tropical location, during the Tropical Composition, Cloud and Climate Coupling (TC4) campaign in July and August of 2007. Results show that the ASM anticyclone region has higher water vapor and lower ozone concentrations in the upper troposphere and lower stratosphere than the TC4 observations. The results also show that the cold point tropopause in the ASM region has a higher average height and potential temperature. The in situ observations therefore support the satellite-based conclusion that the ASM is an effective transport pathway for water vapor to enter stratosphere.

Comparison of Land Skin Temperature from a Land Model, Remote Sensing, and In-situ Measurement

NASA Technical Reports Server (NTRS)

Wang, Aihui; Barlage, Michael; Zeng, Xubin; Draper, Clara Sophie

2014-01-01

Land skin temperature (Ts) is an important parameter in the energy exchange between the land surface and atmosphere. Here hourly Ts from the Community Land Model Version 4.0, MODIS satellite observations, and in-situ observations in 2003 were compared. Compared with the in-situ observations over four semi-arid stations, both MODIS and modeled Ts show negative biases, but MODIS shows an overall better performance. Global distribution of differences between MODIS and modeled Ts shows diurnal, seasonal, and spatial variations. Over sparsely vegetated areas, the model Ts is generally lower than the MODIS observed Ts during the daytime, while the situation is opposite at nighttime. The revision of roughness length for heat and the constraint of minimum friction velocity from Zeng et al. [2012] bring the modeled Ts closer to MODIS during the day, and have little effect on Ts at night. Five factors contributing to the Ts differences between the model and MODIS are identified, including the difficulty in properly accounting for cloud cover information at the appropriate temporal and spatial resolutions, and uncertainties in surface energy balance computation, atmospheric forcing data, surface emissivity, and MODIS Ts data. These findings have implications for the cross-evaluation of modeled and remotely sensed Ts, as well as the data assimilation of Ts observations into Earth system models.

Sensor Webs as Virtual Data Systems for Earth Science

NASA Astrophysics Data System (ADS)

Moe, K. L.; Sherwood, R.

2008-05-01

The NASA Earth Science Technology Office established a 3-year Advanced Information Systems Technology (AIST) development program in late 2006 to explore the technical challenges associated with integrating sensors, sensor networks, data assimilation and modeling components into virtual data systems called "sensor webs". The AIST sensor web program was initiated in response to a renewed emphasis on the sensor web concepts. In 2004, NASA proposed an Earth science vision for a more robust Earth observing system, coupled with remote sensing data analysis tools and advances in Earth system models. The AIST program is conducting the research and developing components to explore the technology infrastructure that will enable the visionary goals. A working statement for a NASA Earth science sensor web vision is the following: On-demand sensing of a broad array of environmental and ecological phenomena across a wide range of spatial and temporal scales, from a heterogeneous suite of sensors both in-situ and in orbit. Sensor webs will be dynamically organized to collect data, extract information from it, accept input from other sensor / forecast / tasking systems, interact with the environment based on what they detect or are tasked to perform, and communicate observations and results in real time. The focus on sensor webs is to develop the technology and prototypes to demonstrate the evolving sensor web capabilities. There are 35 AIST projects ranging from 1 to 3 years in duration addressing various aspects of sensor webs involving space sensors such as Earth Observing-1, in situ sensor networks such as the southern California earthquake network, and various modeling and forecasting systems. Some of these projects build on proof-of-concept demonstrations of sensor web capabilities like the EO-1 rapid fire response initially implemented in 2003. Other projects simulate future sensor web configurations to evaluate the effectiveness of sensor-model interactions for producing improved science predictions. Still other projects are maturing technology to support autonomous operations, communications and system interoperability. This paper will highlight lessons learned by various projects during the first half of the AIST program. Several sensor web demonstrations have been implemented and resulting experience with evolving standards, such as the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) among others, will be featured. The role of sensor webs in support of the intergovernmental Group on Earth Observations' Global Earth Observation System of Systems (GEOSS) will also be discussed. The GEOSS vision is a distributed system of systems that builds on international components to supply observing and processing systems that are, in the whole, comprehensive, coordinated and sustained. Sensor web prototypes are under development to demonstrate how remote sensing satellite data, in situ sensor networks and decision support systems collaborate in applications of interest to GEO, such as flood monitoring. Furthermore, the international Committee on Earth Observation Satellites (CEOS) has stepped up to the challenge to provide the space-based systems component for GEOSS. CEOS has proposed "virtual constellations" to address emerging data gaps in environmental monitoring, avoid overlap among observing systems, and make maximum use of existing space and ground assets. Exploratory applications that support the objectives of virtual constellations will also be discussed as a future role for sensor webs.

In situ quantification of β-carotene partitioning in oil-in-water emulsions by confocal Raman microscopy.

PubMed

Wan Mohamad, W A Fahmi; Buckow, Roman; Augustin, MaryAnn; McNaughton, Don

2017-10-15

Confocal Raman microscopy (CRM) was able to quantify the β-carotene concentration in oil droplets and determine the partitioning characteristics of β-carotene within the emulsion system in situ. The results were validated by a conventional method involving solvent extraction of β-carotene separately from the total emulsion as well as the aqueous phase separated by centrifugation, and quantification by absorption spectrophotometry. CRM also enabled the localization of β-carotene in an emulsion. From the Raman image, the β-carotene partitioning between the aqueous and oil phases of palm olein-in-water emulsions stabilized by whey protein isolate (WPI) was observed. Increasing the concentration of β-carotene in an emulsion (from 0.1 to 0.3g/kg emulsion) with a fixed gross composition (10% palm olein:2% WPI) decreased the concentration of β-carotene in the oil droplet. CRM is a powerful tool for in situ analyses of components in heterogeneous systems such as emulsions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multifrequency acoustic observations of zooplankton in Knight Inlet, B.C

NASA Astrophysics Data System (ADS)

Trevorrow, Mark V.; Mackas, David L.; Benfield, Mark C.

2004-05-01

A collaborative investigation of midwater zooplankton aggregations in a coastal fjord was conducted in November 2002. Midwater aggregations of zooplankton in a coastal fjord were sampled and mapped using a calibrated, three-frequency (38, 120, and 200 kHz) vessel-based echo-sounder system, a multinet towed zooplankton net (BIONESS), and a high-resolution in situ camera system (ZOOVIS). Dense daytime layers of euphausiids and amphipods near 70- to 90-m depth were found in the lower reaches of the inlet, especially concentrated by tidal flows around a sill which rises above the layer. Quantitative euphausiid and amphipod backscattering measurements, combined with in situ species, size, and abundance estimates, were found to agree closely with recent size- and orientation-averaged fluid-cylinder scattering models produced by Stanton et al. Also, in situ scattering measurements of physonect siphonophores were found to have a much stronger low-frequency (38 kHz) scattering strength, in agreement with a simple bubble scattering model. [Work supported by Dr. J. Eckman, ONR code 322BC.

In Situ Observations of Phase Transitions in Metastable Nickel (Carbide)/Carbon Nanocomposites

PubMed Central

2016-01-01

Nanocomposite thin films comprised of metastable metal carbides in a carbon matrix have a wide variety of applications ranging from hard coatings to magnetics and energy storage and conversion. While their deposition using nonequilibrium techniques is established, the understanding of the dynamic evolution of such metastable nanocomposites under thermal equilibrium conditions at elevated temperatures during processing and during device operation remains limited. Here, we investigate sputter-deposited nanocomposites of metastable nickel carbide (Ni3C) nanocrystals in an amorphous carbon (a-C) matrix during thermal postdeposition processing via complementary in situ X-ray diffractometry, in situ Raman spectroscopy, and in situ X-ray photoelectron spectroscopy. At low annealing temperatures (300 °C) we observe isothermal Ni3C decomposition into face-centered-cubic Ni and amorphous carbon, however, without changes to the initial finely structured nanocomposite morphology. Only for higher temperatures (400–800 °C) Ni-catalyzed isothermal graphitization of the amorphous carbon matrix sets in, which we link to bulk-diffusion-mediated phase separation of the nanocomposite into coarser Ni and graphite grains. Upon natural cooling, only minimal precipitation of additional carbon from the Ni is observed, showing that even for highly carbon saturated systems precipitation upon cooling can be kinetically quenched. Our findings demonstrate that phase transformations of the filler and morphology modifications of the nanocomposite can be decoupled, which is advantageous from a manufacturing perspective. Our in situ study also identifies the high carbon content of the Ni filler crystallites at all stages of processing as the key hallmark feature of such metal–carbon nanocomposites that governs their entire thermal evolution. In a wider context, we also discuss our findings with regard to the much debated potential role of metastable Ni3C as a catalyst phase in graphene and carbon nanotube growth. PMID:27746852

Towards a regional coastal ocean observing system: An initial design for the Southeast Coastal Ocean Observing Regional Association

NASA Astrophysics Data System (ADS)

Seim, H. E.; Fletcher, M.; Mooers, C. N. K.; Nelson, J. R.; Weisberg, R. H.

2009-05-01

A conceptual design for a southeast United States regional coastal ocean observing system (RCOOS) is built upon a partnership between institutions of the region and among elements of the academic, government and private sectors. This design envisions support of a broad range of applications (e.g., marine operations, natural hazards, and ecosystem-based management) through the routine operation of predictive models that utilize the system observations to ensure their validity. A distributed information management system enables information flow, and a centralized information hub serves to aggregate information regionally and distribute it as needed. A variety of observing assets are needed to satisfy model requirements. An initial distribution of assets is proposed that recognizes the physical structure and forcing in the southeast U.S. coastal ocean. In-situ data collection includes moorings, profilers and gliders to provide 3D, time-dependent sampling, HF radar and surface drifters for synoptic sampling of surface currents, and satellite remote sensing of surface ocean properties. Nested model systems are required to properly represent ocean conditions from the outer edge of the EEZ to the watersheds. An effective RCOOS will depend upon a vital "National Backbone" (federally supported) system of in situ and satellite observations, model products, and data management. This dependence highlights the needs for a clear definition of the National Backbone components and a Concept of Operations (CONOPS) that defines the roles, functions and interactions of regional and federal components of the integrated system. A preliminary CONOPS is offered for the Southeast (SE) RCOOS. Thorough system testing is advocated using a combination of application-specific and process-oriented experiments. Estimates of costs and personnel required as initial components of the SE RCOOS are included. Initial thoughts on the Research and Development program required to support the RCOOS are also outlined.

When Worlds Collide: Witnessing Planetary-Scale Impacts in the Coming Decades

NASA Astrophysics Data System (ADS)

Masiero, J. R.; Bauer, J. M.; Grav, T.; Mainzer, A. K.

2017-02-01

Asteroid impacts offer a unique opportunity to study the collisional processes that shape planetary systems. In the coming decades, expanded surveys may give us the chance to predict an impact with enough advance warning to observe it in situ.

A comparative study of the mechanical performance of Glass and Glass/Carbon hybrid polymer composites at different temperature environments

NASA Astrophysics Data System (ADS)

Shukla, M. J.; Kumar, D. S.; Mahato, K. K.; Rathore, D. K.; Prusty, R. K.; Ray, B. C.

2015-02-01

Glass Fiber Reinforced Polymer (GFRP) composites have been widely accepted as high strength, low weight structural material as compared to their metallic counterparts. Some specific advanced high performance applications such as aerospace components still require superior specific strength and specific modulus. Carbon Fiber Reinforced Polymer (CFRP) composites exhibit superior specific strength and modulus but have a lower failure strain and high cost. Hence, the combination of both glass and carbon fiber in polymer composite may yield optimized mechanical properties. Further the in-service environment has a significant role on the mechanical performance of this class of materials. Present study aims to investigate the mechanical property of GFRP and Glass/Carbon (G/C hybrid) composites at room temperature, in-situ and ex-situ temperature conditions. In-situ testing at +70°C and +100°C results in significant loss in inter-laminar shear strength (ILSS) for both the composites as compared to room temperature. The ILSS was nearly equal for both the composite systems tested in-situ at +100°C and effect of fiber hybridisation was completely diminished there. At low temperature ex-situ conditioning significant reduction in ILSS was observed for both the systems. Further at -60°C G/C hybrid exhibited 32.4 % higher ILSS than GFRP. Hence this makes G/C hybrid a better choice of material in low temperature environmental applications.

A Mixed Phase Tale: New Ways of using in-situ cloud observations to reduce climate model biases in Southern Ocean

NASA Astrophysics Data System (ADS)

Gettelman, A.; Stith, J. L.

2014-12-01

Southern ocean clouds are a critical part of the earth's energy budget, and significant biases in the climatology of these clouds exist in models used to predict climate change. We compare in situ measurements of cloud microphysical properties of ice and liquid over the S. Ocean with constrained output from the atmospheric component of an Earth System Model. Observations taken during the HIAPER (the NSF/NCAR G-V aircraft) Pole-to-Pole Observations (HIPPO) multi-year field campaign are compared with simulations from the atmospheric component of the Community Earth System Model (CESM). Remarkably, CESM is able to accurately simulate the locations of cloud formation, and even cloud microphysical properties are comparable between the model and observations. Significantly, the simulations do not predict sufficient supercooled liquid. Altering the model cloud and aerosol processes to better reproduce the observations of supercooled liquid acts to reduce long-standing biases in S. Ocean clouds in CESM, which are typical of other models. Furthermore, sensitivity tests show where better observational constraints on aerosols and cloud microphysics can reduce uncertainty and biases in global models. These results are intended to show how we can connect large scale simulations with field observations in the S. Ocean to better understand Southern Ocean cloud processes and reduce biases in global climate simulations.

Volcano Monitoring: A Case Study in Pervasive Computing

NASA Astrophysics Data System (ADS)

Peterson, Nina; Anusuya-Rangappa, Lohith; Shirazi, Behrooz A.; Song, Wenzhan; Huang, Renjie; Tran, Daniel; Chien, Steve; Lahusen, Rick

Recent advances in wireless sensor network technology have provided robust and reliable solutions for sophisticated pervasive computing applications such as inhospitable terrain environmental monitoring. We present a case study for developing a real-time pervasive computing system, called OASIS for optimized autonomous space in situ sensor-web, which combines ground assets (a sensor network) and space assets (NASA’s earth observing (EO-1) satellite) to monitor volcanic activities at Mount St. Helens. OASIS’s primary goals are: to integrate complementary space and in situ ground sensors into an interactive and autonomous sensorweb, to optimize power and communication resource management of the sensorweb and to provide mechanisms for seamless and scalable fusion of future space and in situ components. The OASIS in situ ground sensor network development addresses issues related to power management, bandwidth management, quality of service management, topology and routing management, and test-bed design. The space segment development consists of EO-1 architectural enhancements, feedback of EO-1 data into the in situ component, command and control integration, data ingestion and dissemination and field demonstrations.

Optimized autonomous space in-situ sensor web for volcano monitoring

USGS Publications Warehouse

Song, W.-Z.; Shirazi, B.; Huang, R.; Xu, M.; Peterson, N.; LaHusen, R.; Pallister, J.; Dzurisin, D.; Moran, S.; Lisowski, M.; Kedar, S.; Chien, S.; Webb, F.; Kiely, A.; Doubleday, J.; Davies, A.; Pieri, D.

2010-01-01

In response to NASA's announced requirement for Earth hazard monitoring sensor-web technology, a multidisciplinary team involving sensor-network experts (Washington State University), space scientists (JPL), and Earth scientists (USGS Cascade Volcano Observatory (CVO)), have developed a prototype of dynamic and scalable hazard monitoring sensor-web and applied it to volcano monitoring. The combined Optimized Autonomous Space In-situ Sensor-web (OASIS) has two-way communication capability between ground and space assets, uses both space and ground data for optimal allocation of limited bandwidth resources on the ground, and uses smart management of competing demands for limited space assets. It also enables scalability and seamless infusion of future space and in-situ assets into the sensor-web. The space and in-situ control components of the system are integrated such that each element is capable of autonomously tasking the other. The ground in-situ was deployed into the craters and around the flanks of Mount St. Helens in July 2009, and linked to the command and control of the Earth Observing One (EO-1) satellite. ?? 2010 IEEE.

Use of In-Situ and Remotely Sensed Snow Observations for the National Water Model in Both an Analysis and Calibration Framework.

NASA Astrophysics Data System (ADS)

Karsten, L. R.; Gochis, D.; Dugger, A. L.; McCreight, J. L.; Barlage, M. J.; Fall, G. M.; Olheiser, C.

2017-12-01

Since version 1.0 of the National Water Model (NWM) has gone operational in Summer 2016, several upgrades to the model have occurred to improve hydrologic prediction for the continental United States. Version 1.1 of the NWM (Spring 2017) includes upgrades to parameter datasets impacting land surface hydrologic processes. These parameter datasets were upgraded using an automated calibration workflow that utilizes the Dynamic Data Search (DDS) algorithm to adjust parameter values using observed streamflow. As such, these upgrades to parameter values took advantage of various observations collected for snow analysis. In particular, in-situ SNOTEL observations in the Western US, volunteer in-situ observations across the entire US, gamma-derived snow water equivalent (SWE) observations courtesy of the NWS NOAA Corps program, gridded snow depth and SWE products from the Jet Propulsion Laboratory (JPL) Airborne Snow Observatory (ASO), gridded remotely sensed satellite-based snow products (MODIS,AMSR2,VIIRS,ATMS), and gridded SWE from the NWS Snow Data Assimilation System (SNODAS). This study explores the use of these observations to quantify NWM error and improvements from version 1.0 to version 1.1, along with subsequent work since then. In addition, this study explores the use of snow observations for use within the automated calibration workflow. Gridded parameter fields impacting the accumulation and ablation of snow states in the NWM were adjusted and calibrated using gridded remotely sensed snow states, SNODAS products, and in-situ snow observations. This calibration adjustment took place over various ecological regions in snow-dominated parts of the US for a retrospective period of time to capture a variety of climatological conditions. Specifically, the latest calibrated parameters impacting streamflow were held constant and only parameters impacting snow physics were tuned using snow observations and analysis. The adjusted parameter datasets were then used to force the model over an independent period for analysis against both snow and streamflow observations to see if improvements took place. The goal of this work is to further improve snow physics in the NWM, along with identifying areas where further work will take place in the future, such as data assimilation or further forcing improvements.

Accurate Characterization of Winter Precipitation Using In-Situ Instrumentation, CSU-CHILL Radar, and Advanced Scattering Methods

NASA Astrophysics Data System (ADS)

Newman, A. J.; Notaros, B. M.; Bringi, V. N.; Kleinkort, C.; Huang, G. J.; Kennedy, P.; Thurai, M.

2015-12-01

We present a novel approach to remote sensing and characterization of winter precipitation and modeling of radar observables through a synergistic use of advanced in-situ instrumentation for microphysical and geometrical measurements of ice and snow particles, image processing methodology to reconstruct complex particle three-dimensional (3D) shapes, computational electromagnetics to analyze realistic precipitation scattering, and state-of-the-art polarimetric radar. Our in-situ measurement site at the Easton Valley View Airport, La Salle, Colorado, shown in the figure, consists of two advanced optical imaging disdrometers within a 2/3-scaled double fence intercomparison reference wind shield, and also includes PLUVIO snow measuring gauge, VAISALA weather station, and collocated NCAR GPS advanced upper-air system sounding system. Our primary radar is the CSU-CHILL radar, with a dual-offset Gregorian antenna featuring very high polarization purity and excellent side-lobe performance in any plane, and the in-situ instrumentation site being very conveniently located at a range of 12.92 km from the radar. A multi-angle snowflake camera (MASC) is used to capture multiple different high-resolution views of an ice particle in free-fall, along with its fall speed. We apply a visual hull geometrical method for reconstruction of 3D shapes of particles based on the images collected by the MASC, and convert these shapes into models for computational electromagnetic scattering analysis, using a higher order method of moments. A two-dimensional video disdrometer (2DVD), collocated with the MASC, provides 2D contours of a hydrometeor, along with the fall speed and other important parameters. We use the fall speed from the MASC and the 2DVD, along with state parameters measured at the Easton site, to estimate the particle mass (Böhm's method), and then the dielectric constant of particles, based on a Maxwell-Garnet formula. By calculation of the "particle-by-particle" scattering matrices over large time intervals using the in-situ measured data, we obtain, simultaneously, all polarimetric radar observables, which are then compared and analyzed against measurements by the CHILL Radar. We present and discuss results from several interesting events observed during the 2014/2015 winter campaign.

Hyperspectral and in situ data fusion for the steering of plant production systems

NASA Astrophysics Data System (ADS)

Verstraeten, W. W.; Coppin, P.

2009-04-01

Plant production systems are governed by biotic and a-biotic factors and by management practices. Some of the relevant parameters have already been identified and incorporated as inputs into existing models for production assessment, early-warning, and process management. These parameters originate nowadays primarily from in-situ measurements and observations. Non-invasive remotely sensed data, the diagnostic tools of excellence where it concerns the interaction of solar energy with biomass, have seldom been included and if so, mostly to support yield assessment and harvest monitoring only. The availability of new-generation hyperspectral/hypertemporal signatures will greatly facilitate their integration into full-fledged plant production model either via direct use, forcing, assimilation or re-initialization strategies. The main objective of IS-HS (Integration of In Situ data and HyperSpectral remote sensing for plant production modeling) is to set up a multidisciplinary research platform to deepen our system understanding and to develop production-oriented schemes to steer capital-intensive vegetation scenarios. Real-time steering in a 10-15 year timeframe is envisaged, where current system state is monitored, and steered towards an ideal state in terms of production quantity and quality. IS-HS focuses on hyperspectral sensor design, time series analysis tools for remote sensing data of vegetation systems, on the establishment of two stream communication between satellite and ground sensors, on the development of citrus plant production systems, and on the design of in-situ data sensor networks. The general framework of this system approach will be presented. In time, this integration should allow to cross the bridge from post-harvest assessment to near real-time potential and actual yield monitoring in terms of crop.

From pattern to process: The strategy of the Earth Observing System: Volume 2: EOS Science Steering Committee report

NASA Technical Reports Server (NTRS)

1987-01-01

The Earth Observing System (EOS) represents a new approach to the study of the Earth. It consists of remotely sensed and correlative in situ observations designed to address important, interrelated global-scale processes. There is an urgent need to study the Earth as a complete, integrated system in order to understand and predict changes caused by human activities and natural processes. The EOS approach is based on an information system concept and designed to provide a long-term study of the Earth using a variety of measurement methods from both operational and research satellite payloads and continuing ground-based Earth science studies. The EOS concept builds on the foundation of the earlier, single-discipline space missions designed for relatively short observation periods. Continued progress in our understanding of the Earth as a system will come from EOS observations spanning several decades using a variety of contemporaneous measurements.

An Evaluation of Soil Moisture Retrievals Using Aircraft and Satellite Passive Microwave Observations during SMEX02

NASA Technical Reports Server (NTRS)

Bolten, John D.; Lakshmi, Venkat

2009-01-01

The Soil Moisture Experiments conducted in Iowa in the summer of 2002 (SMEX02) had many remote sensing instruments that were used to study the spatial and temporal variability of soil moisture. The sensors used in this paper (a subset of the suite of sensors) are the AQUA satellite-based AMSR-E (Advanced Microwave Scanning Radiometer- Earth Observing System) and the aircraft-based PSR (Polarimetric Scanning Radiometer). The SMEX02 design focused on the collection of near simultaneous brightness temperature observations from each of these instruments and in situ soil moisture measurements at field- and domain- scale. This methodology provided a basis for a quantitative analysis of the soil moisture remote sensing potential of each instrument using in situ comparisons and retrieved soil moisture estimates through the application of a radiative transfer model. To this end, the two sensors are compared with respect to their estimation of soil moisture.

Optimized Autonomous Space In-situ Sensor-Web for volcano monitoring

USGS Publications Warehouse

Song, W.-Z.; Shirazi, B.; Kedar, S.; Chien, S.; Webb, F.; Tran, D.; Davis, A.; Pieri, D.; LaHusen, R.; Pallister, J.; Dzurisin, D.; Moran, S.; Lisowski, M.

2008-01-01

In response to NASA's announced requirement for Earth hazard monitoring sensor-web technology, a multidisciplinary team involving sensor-network experts (Washington State University), space scientists (JPL), and Earth scientists (USGS Cascade Volcano Observatory (CVO)), is developing a prototype dynamic and scaleable hazard monitoring sensor-web and applying it to volcano monitoring. The combined Optimized Autonomous Space -In-situ Sensor-web (OASIS) will have two-way communication capability between ground and space assets, use both space and ground data for optimal allocation of limited power and bandwidth resources on the ground, and use smart management of competing demands for limited space assets. It will also enable scalability and seamless infusion of future space and in-situ assets into the sensor-web. The prototype will be focused on volcano hazard monitoring at Mount St. Helens, which has been active since October 2004. The system is designed to be flexible and easily configurable for many other applications as well. The primary goals of the project are: 1) integrating complementary space (i.e., Earth Observing One (EO-1) satellite) and in-situ (ground-based) elements into an interactive, autonomous sensor-web; 2) advancing sensor-web power and communication resource management technology; and 3) enabling scalability for seamless infusion of future space and in-situ assets into the sensor-web. To meet these goals, we are developing: 1) a test-bed in-situ array with smart sensor nodes capable of making autonomous data acquisition decisions; 2) efficient self-organization algorithm of sensor-web topology to support efficient data communication and command control; 3) smart bandwidth allocation algorithms in which sensor nodes autonomously determine packet priorities based on mission needs and local bandwidth information in real-time; and 4) remote network management and reprogramming tools. The space and in-situ control components of the system will be integrated such that each element is capable of autonomously tasking the other. Sensor-web data acquisition and dissemination will be accomplished through the use of the Open Geospatial Consortium Sensorweb Enablement protocols. The three-year project will demonstrate end-to-end system performance with the in-situ test-bed at Mount St. Helens and NASA's EO-1 platform. ??2008 IEEE.

Properties of Minor Ions In the Solar Wind and Implications for the Background Solar Wind Plasma

NASA Technical Reports Server (NTRS)

Esser, Ruth; Wagner, William (Technical Monitor)

2002-01-01

Ion charge states measured in situ in interplanetary space carry information on the properties of the solar wind plasma in the inner corona. The goal of the proposal is to determine coronal plasma conditions that produce the in situ observed charge states. This study is carried out using solar wind models, coronal observations, ion fraction calculations and in situ observations.

Progress and recent developments in the GAINS program

NASA Astrophysics Data System (ADS)

Girz, C. M. I. R.:; MacDonald, A. E.; Caracena, F.; Collander, R. S.; Jamison, B. D.; Anderson, R. L.; Latsch, D.; Lachenmeier, T.; Moody, R. A.; Mares, S.; Cooper, J.; Ganoe, G.; Katzberg, S.; Johnson, T.; Russ, B.

2001-08-01

The GAINS (Global Air-ocean IN-situ System) network of long-duration, high-altitude vehicles is proposed as a means to provide critically needed in-situ observations worldwide. This need is increasingly apparent, for example, in the Arctic where there is growing concern around the shrinking of the ice cap and sea ice extent with concomitant decreases in habitat for animal and plant species. In the mid-latitudes, the sustainability of sufficient soil moisture in grain producing regions is questionable under several climate change scenarios. Preparatory steps using smaller balloons and prototype payloads have been taken toward demonstrating the GAINS balloon concept. The balloon envelope recovery system (BERS) has been tested and radio frequency interference, compatibility and distance checks of the prototype command and communication systems were performed. Electronic and mechanical systems have been integrated in preparation for a 48-h flight of an 18-m diameter prototype.

Lightweight Mg-based composites with thermodynamically stable interfaces by in-situ combustion synthesis

NASA Astrophysics Data System (ADS)

Jo, Ilguk

Lightweight Mg-based composites have been produced by in-situ combustion synthesis of the Al-Ti-C reaction system. The characteristics of the in-situ composites were investigated in terms of phase evolution and interfacial stability using various analysis techniques. The structural analysis results showed that full conversion of the Al-Ti-C reactants into spherical TiC reinforcements with sizes around 1mum was achieved by the combustion reaction. In-situ formed TiC had less oxygen and higher Al contents at the interface than ex-situ formed TiC; these clean interfaces with an Al layer on the reinforcements were shown to yield interfacial stability. For these reasons, the in-situ composites exhibited higher theoretical densities and also good mechanical properties compared with ex-situ produced composites. The interfacial characteristics of molten Mg with the Al-Ti-C reactants and the commercial TiC+Al substrates were evaluated using an infiltration technique under an argon atmosphere. Infiltration length increased with time at temperature, yielding activation energies (Ea) for each system. The value of Ea for the Al-Ti-C system (307.31kJ/mol) is lower than that for the other system (350.84kJ/mol); the high Ea value indicates that the infiltration is not a simple viscosity-controlled phenomenon but involves a chemical reaction. Formation of the Al3Ti phase was observed from the crystal structural analysis of the infiltrated area; thus, existence of reaction promoting the wetting of Mg. The phase evolution, reaction mechanism and kinetics of the Al-Ti-C reaction were studied using DSC and HT-XRD. It was confirmed that, along with the melting of Al, there was formation of Al3Ti by reaction between Al and Ti. A detailed structural analysis indicates that, the reaction mechanism involves melting of Al followed by formation and growth of Al 3Ti, which then contacts the graphite powder and initiates the combustion reaction. The effect of important process parameters, such as the Al content and the reactant sizes, on the microstructure of the resulting in-situ composites is discussed. Feasibility and castability of the composites were investigated by high pressure die casting the composite preforms into automotive parts and durability tests were conducted on the cast parts.

Customised search and comparison of in situ, satellite and model data for ocean modellers

NASA Astrophysics Data System (ADS)

Hamre, Torill; Vines, Aleksander; Lygre, Kjetil

2014-05-01

For the ocean modelling community, the amount of available data from historical and upcoming in situ sensor networks and satellite missions, provides an rich opportunity to validate and improve their simulation models. However, the problem of making the different data interoperable and intercomparable remains, due to, among others, differences in terminology and format used by different data providers and the different granularity provided by e.g. in situ data and ocean models. The GreenSeas project (Development of global plankton data base and model system for eco-climate early warning) aims to advance the knowledge and predictive capacities of how marine ecosystems will respond to global change. In the project, one specific objective has been to improve the technology for accessing historical plankton and associated environmental data sets, along with earth observation data and simulation outputs. To this end, we have developed a web portal enabling ocean modellers to easily search for in situ or satellite data overlapping in space and time, and compare the retrieved data with their model results. The in situ data are retrieved from a geo-spatial repository containing both historical and new physical, biological and chemical parameters for the Southern Ocean, Atlantic, Nordic Seas and the Arctic. The satellite-derived quantities of similar parameters from the same areas are retrieved from another geo-spatial repository established in the project. Both repositories are accessed through standard interfaces, using the Open Geospatial Consortium (OGC) Web Map Service (WMS) and Web Feature Service (WFS), and OPeNDAP protocols, respectively. While the developed data repositories use standard terminology to describe the parameters, especially the measured in situ biological parameters are too fine grained to be immediately useful for modelling purposes. Therefore, the plankton parameters were grouped according to category, size and if available by element. This grouping was reflected in the web portal's graphical user interface, where the groups and subgroups were organized in a tree structure, enabling the modeller to quickly get an overview of available data, going into more detail (subgroups) if needed or staying at a higher level of abstraction (merging the parameters below) if this provided a better base for comparison with the model parameters. Once a suitable level of detail, as determined by the modeller, was decided, the system would retrieve available in situ parameters. The modellers could then select among the pre-defined models or upload his own model forecast file (in NetCDF/CF format), for comparison with the retrieved in situ data. The comparison can be shown in different kinds of plots (e.g. scatter plots), through simple statistical measures or near-coincident values of in situ of model points can be exported for further analysis in the modeller's own tools. During data search and presentation, the modeller can determine both query criteria and what associated metadata to include in the display and export of the retrieved data. Satellite-derived parameters can be queried and compared with model results in the same manner. With the developed prototype system, we have demonstrated that a customised tool for searching, presenting, comparing and exporting ocean data from multiple platforms (in situ, satellite, model), makes it easy to compare model results with independent observations. With further enhancement of functionality and inclusion of more data, we believe the resulting system can greatly benefit the wider community of ocean modellers looking for data and tools to validate their models.

Oxidative degradation of phenols in sono-Fenton-like systems upon high-frequency ultrasound irradiation

NASA Astrophysics Data System (ADS)

Aseev, D. G.; Sizykh, M. R.; Batoeva, A. A.

2017-12-01

The kinetics of oxidative degradation of phenol and chlorophenols upon acoustic cavitation in the megahertz range (1.7 MHz) is studied experimentally in model systems, and the involvement of in situ generated reactive oxygen species (ROSs) is demonstrated. The phenols subjected to high frequency ultrasound (HFUS) are ranked in terms of their rate of conversion: 2,4,6-trichlorophenol > 2,4-dichlorophenol 2-chlorophenol > 4-chlorophenol phenol. Oxidative degradation upon HFUS irradiation is most efficient at low concentrations of pollutants, due to the low steady-state concentrations of the in situ generated ROSs. A dramatic increase is observed in the efficiency of oxidation in several sonochemical oxidative systems (HFUS in combination with other chemical oxidative factors). The system with added Fe2+ (a sono-Fenton system) derives its efficiency from hydrogen peroxide generated in situ as a result of the recombination of OH radicals. The S2O8 2-/Fe2+/HFUS system has a synergetic effect on substrate oxidation that is attributed to a radical chain mechanism. In terms of the oxidation rates, degrees of conversion, and specific energy efficiencies of 4-chlorophenol oxidation based on the amount of oxidized substance per unit of expended energy the considered sonochemical oxidative systems form the series HFUS < S2O8 2-/HFUS < S2O8 2-/Fe2+/HFUS.

Human Planetary Landing System (HPLS) Capability Roadmap NRC Progress Review

NASA Technical Reports Server (NTRS)

Manning, Rob; Schmitt, Harrison H.; Graves, Claude

2005-01-01

Capability Roadmap Team. Capability Description, Scope and Capability Breakdown Structure. Benefits of the HPLS. Roadmap Process and Approach. Current State-of-the-Art, Assumptions and Key Requirements. Top Level HPLS Roadmap. Capability Presentations by Leads. Mission Drivers Requirements. "AEDL" System Engineering. Communication & Navigation Systems. Hypersonic Systems. Super to Subsonic Decelerator Systems. Terminal Descent and Landing Systems. A Priori In-Situ Mars Observations. AEDL Analysis, Test and Validation Infrastructure. Capability Technical Challenges. Capability Connection Points to other Roadmaps/Crosswalks. Summary of Top Level Capability. Forward Work.

Short-period cyclic loading system for in situ X-ray observation of anelastic properties at high pressure.

PubMed

Yoshino, Takashi; Yamazaki, Daisuke; Tange, Yoshinori; Higo, Yuji

2016-10-01

To determine the anelastic properties of materials of the Earth's interior, a short-period cyclic loading system was installed for in situ X-ray radiographic observation under high pressure to the multi-anvil deformation DIA press at the bending magnet beam line BL04B1 at SPring-8. The hydraulic system equipped with a piston controlled by a solenoid was designed so as to enable producing smooth sinusoidal stress in a wide range of oscillation period from 0.2 to 100 s and generating variable amplitudes. Time resolved X-ray radiography imaging of the sample and reference material provides their strain as a function of time during cyclic loading. A synchrotron X-ray radiation source allows us to resolve their strain variation with time even at the short period (<1 s). The minimum resolved strain is as small as 10 -4 , and the shortest oscillation period to detect small strain is 0.5 s. Preliminary experimental results exhibited that the new system can resolve attenuation factor Q -1 at upper mantle conditions. These results are in quantitative agreement with previously reported data obtained at lower pressures.

Direct Visualization of Aggregate Morphology and Dynamics in a Model Soil Organic–Mineral System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hufschmid, Ryan; Newcomb, Christina J.; Grate, Jay W.

Interactions between mineral surfaces and organic matter are ubiquitous in soils and the environment. Through both physical and chemical mechanisms, organic-mineral assemblages prevent decomposition of soil organic matter by limiting accessibility or reducing efficacy of enzymes and microbes. To understand the mechanisms underlying organic-mineral interactions, researchers have begun to interrogate these systems at smaller length scales. Current techniques that maintain a hydrated state and allow researchers to characterize nanometer length scales are limited. Here we chose a model organic-mineral system and performed complementary imaging techniques that enable direct nanoscale observations in environmentally relevant conditions: cryogenic TEM and in-situ liquid cellmore » TEM. We observed a three-fold increase in aggregate size of goethite nanoparticles upon addition of a model organic phosphate ligand and quantification of nanoparticle orientation reveals a preference for side-to-side interactions independent of the addition of an organic ligand. Additionally, in-situ liquid cell TEM experiments provides a dynamic view of the interactions allowing us to report velocities of mineral assemblages during aggregation and disaggregation, which could potentially provide binding energetics and kinetic parameters about organic-mineral and mineral-mineral systems.« less

CO Signatures in Subtropical Convective Clouds and Anvils During CRYSTAL-FACE: An Analysis of Convective Transport and Entertainment Using Observations and a Cloud-Resolving Model

NASA Technical Reports Server (NTRS)

Lopez, Jimena P.; Fridlind, Ann M.; Jost, Hans-Jurg; Loewenstein, Max; Ackerman, Andrew S.; Campos, Teresa L.; Weinstock, Elliot M.; Sayres, David S.; Smith, Jessica B.; Pittman, Jasna V.;

CO Signatures in Subtropical Convective Clouds and Anvils during CRYSTAL-FACE: An Analysis of Convective Transport and Entrainment using Observations and a Cloud-Resolving Model

NASA Technical Reports Server (NTRS)

Lopez, Jimena P.; Fridlind, Ann M.; Jost, Hans-Juerg; Loewenstein, Max; Ackerman, Andrew S.; Campos, Teresa L.; Weinstock, Elliot M.; Sayres, David S.; Smith, Jessica B.; Pittman, Jasna V.

2006-01-01

Convective systems are an important mechanism in the transport of boundary layer air into the upper troposphere. The Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) campaign, in July 2002, was developed as a comprehensive atmospheric mission to improve knowledge of subtropical cirrus systems and their roles in regional and global climate. In situ measurements of carbon monoxide (CO), water vapor (H2Ov), and total water (H2Ot) aboard NASA's WB-57F aircraft and CO aboard the U.S. Navy's Twin Otter aircraft were obtained to study the role of convective transport. Three flights sampled convective outflow on 11, 16 and 29 July found varying degrees of CO enhancement relative to the free troposphere. A cloud-resolving model used the in situ observations and meteorological fields to study these three systems. Several methods of filtering the observations were devised here using ice water content, relative humidity with respect to ice, and particle number concentration as a means to statistically sample the model results to represent the flight tracks. A weighted histogram based on ice water content observations was then used to sample the simulations for the three flights. In addition, because the observations occurred in the convective outflow cirrus and not in the storm cores, the model was used to estimate the maximum CO within the convective systems. In general, anvil-level air parcels contained an estimated 20-40% boundary layer air in the analyzed storms.

SMAP soil moisture drying more rapid than observed in situ following rainfall events

USDA-ARS?s Scientific Manuscript database

We examine soil drying rates by comparing observations from the NASA Soil Moisture Active Passive (SMAP) mission to surface soil moisture from in situ probes during drydown periods at SMAP validation sites. SMAP and in situ probes record different soil drying dynamics after rainfall. We modeled this...

Nitrogen Dioxide Trend over the United States: the View from the Ground, the View from Space

NASA Technical Reports Server (NTRS)

Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; Krotkov, Nickolay A.

2014-01-01

Emissions of nitrogen oxides (NOx) are decreasing over the US due to environmental policies and technological change. We use observations of tropospheric nitrogen dioxide (NO2) columns from the Ozone Monitoring Instrument (OMI) satellite instrument and surface NO2 in-situ measurements from the air quality system (AQS) to quantify the trends, and to establish the relationship between the trends in tropospheric column and surface concentration. Both observations show substantial downward trends from 2005 to 2013, with an average reduction of 35 percent according to OMI and 38 percent according to AQS. The annual reduction rates are largest in 2005-2009: -6.2 percent per year and -7 percent per year observed by OMI and AQS, respectively. We examine various factors affecting the estimated trend in OMI NO2 columns and in-situ NO2 observations. An improved understanding of trend offers valuable insights about effectiveness of emission reduction regulations on state and federal level.

Open Surface Solar Irradiance Observations - A Challenge

NASA Astrophysics Data System (ADS)

Menard, Lionel; Nüst, Daniel; Jirka, Simon; Maso, Joan; Ranchin, Thierry; Wald, Lucien

2015-04-01

The newly started project ConnectinGEO funded by the European Commission aims at improving the understanding on which environmental observations are currently available in Europe and subsequently providing an informational basis to close gaps in diverse observation networks. The project complements supporting actions and networking activities with practical challenges to test and improve the procedures and methods for identifying observation data gaps, and to ensure viability in real world scenarios. We present a challenge on future concepts for building a data sharing portal for the solar energy industry as well as the state of the art in the domain. Decision makers and project developers of solar power plants have identified the Surface Solar Irradiance (SSI) and its components as an important factor for their business development. SSI observations are crucial in the process of selecting suitable locations for building new plants. Since in-situ pyranometric stations form a sparse network, the search for locations starts with global satellite data and is followed by the deployment of in-situ sensors in selected areas for at least one year. To form a convincing picture, answers must be sought in the conjunction of these EO systems, and although companies collecting SSI observations are willing to share this information, the means to exchange in-situ measurements across companies and between stakeholders in the market are still missing. We present a solution for interoperable exchange of SSI data comprising in-situ time-series observations as well as sensor descriptions based on practical experiences from other domains. More concretely, we will apply concepts and implementations of the Sensor Web Enablement (SWE) framework of the Open Geospatial Consortium (OGC). The work is based on an existing spatial data infrastructure (SDI), which currently comprises metadata, maps and coverage data, but no in-situ observations yet. This catalogue is already registered in the GEOSS Common Infrastructure (GCI). We describe the challenges and approach to introduce a suite of standards and best practices into the GEO Energy Societal Benefit Area for solar radiation measurements. Challenges range from spatio-temporal coverage across different scales and data quality to intellectual property rights and existing terminology. The approach includes means to share observations based on standardized data and metadata models and a user-friendly data exploration/management tool. The possibility to access and share data considerably improves the information base for strategic planning and control of new solar power resources. The platform will be integrated as a new component into the Webservice-Energy.org GEOSS Community Portal dedicated to Energy and Environment. The ability to provide users with visualisation and download features for in-situ measurements is seen as a key aspect to start engaging the energy community to share, release and integrate more in-situ measurements. This will put to the test the capacity of cooperation in the SSI community by introducing an unprecedented level of collaboration and eventually help to detect gaps in European earth observation networks. The presentation will be an opportunity to seek further collaboration partners and feedback by the community.

Laboratory for Atmospheres: Instrument Systems Report

NASA Technical Reports Server (NTRS)

2011-01-01

Studies of the atmospheres of our solar system's planets including our own require a comprehensive set of observations, relying on instruments on spacecraft, aircraft, balloons, and on the surface. Laboratory personnel define requirements, conceive concepts, and develop instrument systems for spaceflight missions, and for balloon, aircraft, and ground-based observations. Laboratory scientists also participate in the design of data processing algorithms, calibration techniques, and data processing systems. The instrument sections of this report are organized by measurement technique: lidar, passive, in situ and microwave. A number of instruments in various stages of development or modification are also described. This report will be updated as instruments evolve.

Earth observing system - Concepts and implementation strategy

NASA Technical Reports Server (NTRS)

Hartle, R. E.

1986-01-01

The concepts of an Earth Observing System (EOS), an information system being developed by the EOS Science and Mission Requirements Working Group for international use and planned to begin in the 1990s, are discussed. The EOS is designed to study the factors that control the earth's hydrologic cycle, biochemical cycles, and climatologic processes by combining the measurements from remote sensing instruments, in situ measurement devices, and a data and information system. Three EOS platforms are planned to be launched into low, polar, sun-synchronous orbits during the Space Station's Initial Operating Configuration, one to be provided by ESA and two by the United States.

A study of the Alboran sea mesoscale system by means of empirical orthogonal function decomposition of satellite data

NASA Astrophysics Data System (ADS)

Baldacci, A.; Corsini, G.; Grasso, R.; Manzella, G.; Allen, J. T.; Cipollini, P.; Guymer, T. H.; Snaith, H. M.

2001-05-01

This paper presents the results of a combined empirical orthogonal function (EOF) analysis of Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature (SST) data and sea-viewing wide field-of-view sensor (SeaWiFS) chlorophyll concentration data over the Alboran Sea (Western Mediterranean), covering a period of 1 year (November 1997-October 1998). The aim of this study is to go beyond the limited temporal extent of available in situ measurements by inferring the temporal and spatial variability of the Alboran Gyre system from long temporal series of satellite observations, in order to gain insight on the interactions between the circulation and the biological activity in the system. In this context, EOF decomposition permits concise and synoptic representation of the effects of physical and biological phenomena traced by SST and chlorophyll concentration. Thus, it is possible to focus the analysis on the most significant phenomena and to understand better the complex interactions between physics and biology at the mesoscale. The results of the EOF analysis of AVHRR-SST and SeaWiFS-chlorophyll concentration data are presented and discussed in detail. These improve and complement the knowledge acquired during the in situ observational campaigns of the MAST-III Observations and Modelling of Eddy scale Geostrophic and Ageostrophic motion (OMEGA) Project.

Atmospheric Mining in the Outer Solar System: Aerial Vehicle Mission and Design Issues

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2015-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. With these two additional gases, the potential for fueling small and large fleets of additional exploration and exploitation vehicles exists. The mining aerospacecraft (ASC) could fly through the outer planet atmospheres, for global weather observations, localized storm or other disturbance investigations, wind speed measurements, polar observations, etc. Analyses of orbital transfer vehicles (OTVs), landers, and in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points.

Enhance the accuracy of radar snowfall estimation with Multi new Z-S relationships in MRMS system

NASA Astrophysics Data System (ADS)

Qi, Y.

2017-12-01

Snow may have negative affects on roadways and human lives, but the result of the melted snow/ice is good for farm, humans, and animals. For example, in the Southwest and West mountainous area of United States, water shortage is a very big concern. However, snowfall in the winter can provide humans, animals and crops an almost unlimited water supply. So, using radar to accurately estimate the snowfall is very important for human life and economic development in the water lacking area. The current study plans to analyze the characteristics of the horizontal and vertical variations of dry/wet snow using dual polarimetric radar observations, relative humidity and in situ snow water equivalent observations from the National Weather Service All Weather Prediction Accumulation Gauges (AWPAG) across the CONUS, and establish the relationships between the reflectivity (Z) and ground snow water equivalent (S). The new Z-S relationships will be evaluated with independent CoCoRaHS (Community Collaborative Rain, Hail & Snow Network) gauge observations and eventually implemented in the Multi-Radar Multi-Sensor system for improved quantitative precipitation estimation for snow. This study will analyze the characteristics of the horizontal and vertical variations of dry/wet snow using dual polarimetric radar observations, relative humidity and in situ snow water equivalent observations from the National Weather Service All Weather Prediction Accumulation Gauges (AWPAG) across the CONUS, and establish the relationships between the reflectivity (Z) and ground snow water equivalent (S). The new Z-S relationships will be used to reduce the error of snowfall estimation in Multi Radar and Multi Sensors (MRMS) system, and tested in MRMS system and evaluated with the COCORaHS observations. Finally, it will be ingested in MRMS sytem, and running in NWS/NCAR operationally

Using Multiple Space Assests with In-Situ Measurements to Track Flooding in Thailand

NASA Technical Reports Server (NTRS)

Chien, Steve; Doubleday, Joshua; Mclaren, David; Tran, Daniel; Khunboa, Chatchai; Leelapatra, Watis; Pergamon, Vichain; Tanpipat, Veerachai; Chitradon, Royal; Boonya-aroonnet, Surajate;

Effect of H2 and redox condition on biotic and abiotic MTBE transformation

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

2006-01-01

Laboratory studies conducted with surface water sediment from a methyl tert-butyl ether (MTBE)-contaminated site in South Carolina demonstrated that, under methanogenic conditions, [U-14C] MTBE was transformed to 14C tert-butyl alcohol (TBA) with no measurable production of 14CO2. Production of TBA was not attributed to the activity of methanogenic microorganisms, however, because comparable transformation of [U-14C] MTBE to 14C-TBA also was observed in heat-sterilized controls with dissolved H2 concentrations > 5 nM. The results suggest that the transformation of MTBE to TBA may be an abiotic process that is driven by biologically produced H2 under in situ conditions. In contrast, mineralization of [U-14C] MTBE to 14CO2 was completely inhibited by heat sterilization and only observed in treatments characterized by dissolved H2 concentrations < 2 nM. These results suggest that the pathway of MTBE transformation is influenced by in situ H2 concentrations and that in situ H2 concentrations may be an useful indicator of MTBE transformation pathways in ground water systems.

In situ Raman spectroscopic investigation of chromium surfaces under hydrothermal conditions

NASA Astrophysics Data System (ADS)

Maslar, J. E.; Hurst, W. S.; Bowers, W. J.; Hendricks, J. H.; Aquino, M. I.; Levin, I.

2001-08-01

Three chromium coupons were exposed to air-saturated water at pressures of ca. 25 MPa and temperatures up to 545°C in an optically accessible flow cell. In situ Raman spectra were collected at different temperatures as the coupons were heated and then cooled. Coupons were also characterized ex situ with Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray diffraction. Coupons heated to either 374 or 505°C exhibited the same corrosion product, tentatively identified as α-CrOOH that originated as corrosion product released from the optical cell and/or flow system. A coupon heated to 545°C exhibited a variety of Cr III, mixed chromium valence Cr III/Cr VI, and/or Cr VI species during heating. During cooling, the same corrosion product was observed at all temperatures on this coupon and was tentatively identified as Cr 2O 3 with Cr VI incorporated into the Cr 2O 3 Cr III-oxygen network. The difference in observed corrosion processes among the three coupons was attributed to a difference in water purity to which they were exposed.

In situ Visualization of State-of-Charge Heterogeneity within a LiCoO 2 Particle that Evolves upon Cycling at Different Rates

DOE PAGES

Xu, Yahong; Hu, Enyuan; Zhang, Kai; ...

2017-05-05

For designing new battery systems with higher energy density and longer cycle life, it is important to understand the degradation mechanism of the electrode material, especially at the individual particle level. Using in situ transmission X-ray microscopy (TXM) coupled to a pouch cell setup, the inhomogeneous Li distribution as well as the formation, population, and evolution of inactive domains in a single LiCoO 2 particle were visualized in this paper as it was cycled for many times. It is found that the percentage of the particle that fully recovered to the pristine state is strongly related to the cycling rate.more » Interestingly, we also observed the evolution of the inactive region within the particle during long-term cycling. The relationship between morphological degradation and chemical inhomogeneity, including the formation of unanticipated Co metal phase, is also observed. Finally, our work highlights the capability of in situ TXM for studying the degradation mechanism of materials in LIBs.« less

Development and Validation of National Phenology Data Products

NASA Astrophysics Data System (ADS)

Weltzin, J. F.; Rosemartin, A.; Crimmins, T. M.; Gerst, K.

2015-12-01

The USA National Phenology Network (USA-NPN; www.usanpn.org) serves science and society by promoting a broad understanding of plant and animal phenology and the relationships among phenological patterns and environmental change. The National Phenology Database (NPDb) maintained by USA-NPN contains almost 6 million in-situ observation records for plants and animals for the period 1954-2015. These data have been used in a number of science, conservation and natural resource management applications, including national assessments of historical and potential future trends in phenology and regional assessments of spatio-temporal variation in organismal activity. Customizable downloads of raw or summarized data, freely available from www.usanpn.org, are accompanied by metadata, data-use and data-attribution policies, published protocols, version/change control, documentation of QA/QC, and links to publications that use historical or contemporary data held in the NPDb. The National Coordinating Office of USA-NPN is developing a suite of standard data products (e.g., quality-controlled raw or summarized status data) and tools (e.g., a new visualization tool released in 2015) to facilitate use and application by a diverse set of data users. This presentation outlines a workflow for the development and validation of spatially gridded phenology products, drawing on recent work related to the Spring Indices now included in two national Indicator systems. In addition, we discuss how we engage observers to collect in-situ data to validate model predictions. Preliminary analyses indicate high fidelity between historical in-situ and modeled observations on a national scale, but with considerable variability at the regional scale. Regions with strong differences between expected and observed data are identified and will be the focus of in-situ data collection campaigns using USA-NPN's Nature's Notebook on-line user interface (www.nn.usanpn.org).

GEONETCastAmericas

Science.gov Websites

satellite-based data dissemination systems designed to distribute space-based, air-borne and in situ data ) satellite to broadcast environmental and other observation data to an area covering most of North, Central up the broadcast using inexpensive satellite receiver stations based on Digital Video Broadcast (DVB

How Well Has Global Ocean Heat Content Variability Been Measured?

NASA Astrophysics Data System (ADS)

Nelson, A.; Weiss, J.; Fox-Kemper, B.; Fabienne, G.

2016-12-01

We introduce a new strategy that uses synthetic observations of an ensemble of model simulations to test the fidelity of an observational strategy, quantifying how well it captures the statistics of variability. We apply this test to the 0-700m global ocean heat content anomaly (OHCA) as observed with in-situ measurements by the Coriolis Dataset for Reanalysis (CORA), using the Community Climate System Model (CCSM) version 3.5. One-year running mean OHCAs for the years 2005 onward are found to faithfully capture the variability. During these years, synthetic observations of the model are strongly correlated at 0.94±0.06 with the actual state of the model. Overall, sub-annual variability and data before 2005 are significantly affected by the variability of the observing system. In contrast, the sometimes-used weighted integral of observations is not a good indicator of OHCA as variability in the observing system contaminates dynamical variability.

A mobile system combining lidar and sunphotometer on-road measurements: description and first results

NASA Astrophysics Data System (ADS)

Popovici, Ioana; Goloub, Philippe; Podvin, Thierry; Blarel, Luc; Loisil, Rodrigue; Mortier, Augustin; Deroo, Christine; Ducos, Fabrice; Victori, Stéphane; Torres, Benjamin

2018-04-01

The mobile system described in this paper integrates a commercial eye-safe lidar (CIMEL), a sunphotometer and in situ instruments. The system is distinguished by other transportable platforms through its capabilities to perform onroad measurements. The potential of a commercial lidar to provide reliable information on aerosol properties is investigated through comparison with a multi-wavelength Raman lidar. First results from observation campaigns in northern France are presented.

Understanding materials challenges for rechargeable ion batteries with in situ transmission electron microscopy

NASA Astrophysics Data System (ADS)

Yuan, Yifei; Amine, Khalil; Lu, Jun; Shahbazian-Yassar, Reza

2017-08-01

An in-depth understanding of material behaviours under complex electrochemical environment is critical for the development of advanced materials for the next-generation rechargeable ion batteries. The dynamic conditions inside a working battery had not been intensively explored until the advent of various in situ characterization techniques. Real-time transmission electron microscopy of electrochemical reactions is one of the most significant breakthroughs poised to enable radical shift in our knowledge on how materials behave in the electrochemical environment. This review, therefore, summarizes the scientific discoveries enabled by in situ transmission electron microscopy, and specifically emphasizes the applicability of this technique to address the critical challenges in the rechargeable ion battery electrodes, electrolyte and their interfaces. New electrochemical systems such as lithium-oxygen, lithium-sulfur and sodium ion batteries are included, considering the rapidly increasing application of in situ transmission electron microscopy in these areas. A systematic comparison between lithium ion-based electrochemistry and sodium ion-based electrochemistry is also given in terms of their thermodynamic and kinetic differences. The effect of the electron beam on the validity of in situ observation is also covered. This review concludes by providing a renewed perspective for the future directions of in situ transmission electron microscopy in rechargeable ion batteries.

In-situ Multimodal Imaging and Spectroscopy of Mg Electrodeposition at Electrode-Electrolyte Interfaces

NASA Astrophysics Data System (ADS)

Wu, Yimin A.; Yin, Zuwei; Farmand, Maryam; Yu, Young-Sang; Shapiro, David A.; Liao, Hong-Gang; Liang, Wen-I.; Chu, Ying-Hao; Zheng, Haimei

2017-02-01

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and utilized as electrolyte, where non-reversible features during in situ charging-discharging cycles were observed. During charging, a uniform Mg film was deposited on the electrode, which is consistent with the intrinsic non-dendritic nature of Mg deposition in Mg ion batteries. The Mg thin film was not dissolvable during the following discharge process. We found that such Mg thin film is hexacoordinated Mg compounds by in-situ STXM and XAS. This study provides insights on the non-reversibility issue and failure mechanism of Mg ion batteries. Also, our method provides a novel generic method to understand the in situ battery chemistry without any further sample processing, which can preserve the original nature of battery materials or electrodeposited materials. This multimodal in situ imaging and spectroscopy provides many opportunities to attack complex problems that span orders of magnitude in length and time scale, which can be applied to a broad range of the energy storage systems.

In-situ Multimodal Imaging and Spectroscopy of Mg Electrodeposition at Electrode-Electrolyte Interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yimin A.; Yin, Zuwei; Farmand, Maryam

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and utilized as electrolyte, where non-reversible features during in situ charging-discharging cycles were observed. During charging, a uniform Mg film was deposited on the electrode, which is consistent with the intrinsic non-dendritic nature of Mg deposition in Mg ion batteries. The Mg thin film was not dissolvable during the following discharge process. Wemore » found that such Mg thin film is hexacoordinated Mg compounds by in-situ STXM and XAS. This study provides insights on the non-reversibility issue and failure mechanism of Mg ion batteries. Also, our method provides a novel generic method to understand the in situ battery chemistry without any further sample processing, which can preserve the original nature of battery materials or electrodeposited materials. This multimodal in situ imaging and spectroscopy provides many opportunities to attack complex problems that span orders of magnitude in length and time scale, which can be applied to a broad range of the energy storage systems.« less

In-situ Multimodal Imaging and Spectroscopy of Mg Electrodeposition at Electrode-Electrolyte Interfaces

DOE PAGES

Wu, Yimin A.; Yin, Zuwei; Farmand, Maryam; ...

2017-02-10

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and utilized as electrolyte, where non-reversible features during in situ charging-discharging cycles were observed. During charging, a uniform Mg film was deposited on the electrode, which is consistent with the intrinsic non-dendritic nature of Mg deposition in Mg ion batteries. The Mg thin film was not dissolvable during the following discharge process. Wemore » found that such Mg thin film is hexacoordinated Mg compounds by in-situ STXM and XAS. This study provides insights on the non-reversibility issue and failure mechanism of Mg ion batteries. Also, our method provides a novel generic method to understand the in situ battery chemistry without any further sample processing, which can preserve the original nature of battery materials or electrodeposited materials. This multimodal in situ imaging and spectroscopy provides many opportunities to attack complex problems that span orders of magnitude in length and time scale, which can be applied to a broad range of the energy storage systems.« less

Understanding materials challenges for rechargeable ion batteries with in situ transmission electron microscopy

PubMed Central

Yuan, Yifei; Amine, Khalil; Lu, Jun; Shahbazian-Yassar, Reza

2017-01-01

An in-depth understanding of material behaviours under complex electrochemical environment is critical for the development of advanced materials for the next-generation rechargeable ion batteries. The dynamic conditions inside a working battery had not been intensively explored until the advent of various in situ characterization techniques. Real-time transmission electron microscopy of electrochemical reactions is one of the most significant breakthroughs poised to enable radical shift in our knowledge on how materials behave in the electrochemical environment. This review, therefore, summarizes the scientific discoveries enabled by in situ transmission electron microscopy, and specifically emphasizes the applicability of this technique to address the critical challenges in the rechargeable ion battery electrodes, electrolyte and their interfaces. New electrochemical systems such as lithium–oxygen, lithium–sulfur and sodium ion batteries are included, considering the rapidly increasing application of in situ transmission electron microscopy in these areas. A systematic comparison between lithium ion-based electrochemistry and sodium ion-based electrochemistry is also given in terms of their thermodynamic and kinetic differences. The effect of the electron beam on the validity of in situ observation is also covered. This review concludes by providing a renewed perspective for the future directions of in situ transmission electron microscopy in rechargeable ion batteries.

In-situ Multimodal Imaging and Spectroscopy of Mg Electrodeposition at Electrode-Electrolyte Interfaces.

PubMed

Wu, Yimin A; Yin, Zuwei; Farmand, Maryam; Yu, Young-Sang; Shapiro, David A; Liao, Hong-Gang; Liang, Wen-I; Chu, Ying-Hao; Zheng, Haimei

2017-02-10

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and utilized as electrolyte, where non-reversible features during in situ charging-discharging cycles were observed. During charging, a uniform Mg film was deposited on the electrode, which is consistent with the intrinsic non-dendritic nature of Mg deposition in Mg ion batteries. The Mg thin film was not dissolvable during the following discharge process. We found that such Mg thin film is hexacoordinated Mg compounds by in-situ STXM and XAS. This study provides insights on the non-reversibility issue and failure mechanism of Mg ion batteries. Also, our method provides a novel generic method to understand the in situ battery chemistry without any further sample processing, which can preserve the original nature of battery materials or electrodeposited materials. This multimodal in situ imaging and spectroscopy provides many opportunities to attack complex problems that span orders of magnitude in length and time scale, which can be applied to a broad range of the energy storage systems.

In-situ Multimodal Imaging and Spectroscopy of Mg Electrodeposition at Electrode-Electrolyte Interfaces

PubMed Central

Wu, Yimin A.; Yin, Zuwei; Farmand, Maryam; Yu, Young-Sang; Shapiro, David A.; Liao, Hong-Gang; Liang, Wen-I; Chu, Ying-Hao; Zheng, Haimei

2017-01-01

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and utilized as electrolyte, where non-reversible features during in situ charging-discharging cycles were observed. During charging, a uniform Mg film was deposited on the electrode, which is consistent with the intrinsic non-dendritic nature of Mg deposition in Mg ion batteries. The Mg thin film was not dissolvable during the following discharge process. We found that such Mg thin film is hexacoordinated Mg compounds by in-situ STXM and XAS. This study provides insights on the non-reversibility issue and failure mechanism of Mg ion batteries. Also, our method provides a novel generic method to understand the in situ battery chemistry without any further sample processing, which can preserve the original nature of battery materials or electrodeposited materials. This multimodal in situ imaging and spectroscopy provides many opportunities to attack complex problems that span orders of magnitude in length and time scale, which can be applied to a broad range of the energy storage systems. PMID:28186175

Applicability of AgMERRA Forcing Dataset to Fill Gaps in Historical in-situ Meteorological Data

NASA Astrophysics Data System (ADS)

Bannayan, M.; Lashkari, A.; Zare, H.; Asadi, S.; Salehnia, N.

2015-12-01

Integrated assessment studies of food production systems use crop models to simulate the effects of climate and socio-economic changes on food security. Climate forcing data is one of those key inputs of crop models. This study evaluated the performance of AgMERRA climate forcing dataset to fill gaps in historical in-situ meteorological data for different climatic regions of Iran. AgMERRA dataset intercompared with in- situ observational dataset for daily maximum and minimum temperature and precipitation during 1980-2010 periods via Root Mean Square error (RMSE), Mean Absolute Error (MAE) and Mean Bias Error (MBE) for 17 stations in four climatic regions included humid and moderate, cold, dry and arid, hot and humid. Moreover, probability distribution function and cumulative distribution function compared between model and observed data. The results of measures of agreement between AgMERRA data and observed data demonstrated that there are small errors in model data for all stations. Except for stations which are located in cold regions, model data in the other stations illustrated under-prediction for daily maximum temperature and precipitation. However, it was not significant. In addition, probability distribution function and cumulative distribution function showed the same trend for all stations between model and observed data. Therefore, the reliability of AgMERRA dataset is high to fill gaps in historical observations in different climatic regions of Iran as well as it could be applied as a basis for future climate scenarios.

Source attribution using FLEXPART and carbon monoxide emission inventories for the IAGOS In-situ Observation database

NASA Astrophysics Data System (ADS)

Fontaine, Alain; Sauvage, Bastien; Pétetin, Hervé; Auby, Antoine; Boulanger, Damien; Thouret, Valerie

2016-04-01

Since 1994, the IAGOS program (In-Service Aircraft for a Global Observing System http://www.iagos.org) and its predecessor MOZAIC has produced in-situ measurements of the atmospheric composition during more than 46000 commercial aircraft flights. In order to help analyzing these observations and further understanding the processes driving their evolution, we developed a modelling tool SOFT-IO quantifying their source/receptor link. We improved the methodology used by Stohl et al. (2003), based on the FLEXPART plume dispersion model, to simulate the contributions of anthropogenic and biomass burning emissions from the ECCAD database (http://eccad.aeris-data.fr) to the measured carbon monoxide mixing ratio along each IAGOS flight. Thanks to automated processes, contributions are simulated for the last 20 days before observation, separating individual contributions from the different source regions. The main goal is to supply add-value products to the IAGOS database showing pollutants geographical origin and emission type. Using this information, it may be possible to link trends in the atmospheric composition to changes in the transport pathways and to the evolution of emissions. This tool could be used for statistical validation as well as for inter-comparisons of emission inventories using large amounts of data, as Lagrangian models are able to bring the global scale emissions down to a smaller scale, where they can be directly compared to the in-situ observations from the IAGOS database.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

USGS Publications Warehouse

Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (18O/37Cl, 18O/15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion. ?? CSIRO 2009.

Unraveling multiple phases of sulfur cycling during the alteration of ancient ultramafic oceanic lithosphere

NASA Astrophysics Data System (ADS)

Schwarzenbach, Esther M.; Gill, Benjamin C.; Johnston, David T.

2018-02-01

Ultramafic-hosted hydrothermal systems - characterized by ongoing serpentinization reactions - exert an important influence on the global sulfur cycle. Extensive water-rock interaction causes elemental exchange between seawater and the oceanic lithosphere, effectively removing sulfate from seawater through both abiogenic and biogenic processes. Here, we use bulk rock multiple sulfur isotope signatures (32S, 33S, 34S) and in situ sulfide analyses together with petrographic observations to track the sulfur cycling processes and the hydrothermal evolution of ancient peridotite-hosted hydrothermal systems. We investigate serpentinized peridotites from the Northern Apennine ophiolite in Italy and the Santa Elena ophiolite in Costa Rica and compare those with the Iberian Margin (Ocean Drilling Program (ODP) Leg 149 and 173) and the 15°20‧N Fracture Zone along the Mid-Atlantic Ridge (ODP Leg 209). In situ measurements of sulfides in the Northern Apennine serpentinites preserve a large range in δ34Ssulfide of -33.8 to +13.3‰ with significant heterogeneities within single sulfide grains and depending on mineralogy. Detailed mineralogical investigation and comparison with bulk rock Δ33Ssulfide and in situ δ34Ssulfide data implies a thermal evolution of the system from high temperatures (∼350 °C) that allowed thermochemical sulfate reduction and input of hydrothermal sulfide to lower temperatures (<120 °C) that permitted microbial activity. The change in temperature regime is locally preserved in individual samples and correlates with the progressive uplift and exposure of mantle rock associated with detachment faulting along a mid-ocean ridge spreading center. The Santa Elena peridotites preserve distinct signatures for fluid circulation at high temperatures with both closed system thermochemical sulfate reduction and input of mafic-derived sulfur. In addition, the peridotites provide strong evidence that low Ca2+ concentrations in peridotite-hosted systems can limit sulfate removal during anhydrite precipitation at temperatures above 150 °C. This may play a central role for the availability of sulfate to microbial communities within these systems. Overall, the combined application of in situ and bulk rock multiple sulfur isotope measurements with petrographic observations allows us to resolve the different episodes of sulfur cycling during alteration of the oceanic lithosphere and the temporal changes between abiogenic and biogenic processes that control the sulfur cycling in these systems.

Deep-sea macrourid fishes scavenge on plant material: Evidence from in situ observations

NASA Astrophysics Data System (ADS)

Jeffreys, Rachel M.; Lavaleye, Marc S. S.; Bergman, Magda J. N.; Duineveld, Gerard C. A.; Witbaard, Rob; Linley, Thom

2010-04-01

Deep-sea benthic communities primarily rely on an allochthonous food source. This may be in the form of phytodetritus or as food falls e.g. sinking carcasses of nekton or debris of marine macrophyte algae. Deep-sea macrourids are the most abundant demersal fish in the deep ocean. Macrourids are generally considered to be the apex predators/scavengers in deep-sea communities. Baited camera experiments and stable isotope analyses have demonstrated that animal carrion derived from the surface waters is an important component in the diets of macrourids; some macrourid stomachs also contained vegetable/plant material e.g. onion peels, oranges, algae. The latter observations led us to the question: is plant material an attractive food source for deep-sea scavenging fish? We simulated a plant food fall using in situ benthic lander systems equipped with a baited time-lapse camera. Abyssal macrourids and cusk-eels were attracted to the bait, both feeding vigorously on the bait, and the majority of the bait was consumed in <30 h. These observations indicate (1) plant material can produce an odour plume similar to that of animal carrion and attracts deep-sea fish, and (2) deep-sea fish readily eat plant material. This represents to our knowledge the first in situ documentation of deep-sea fish ingesting plant material and highlights the variability in the scavenging nature of deep-sea fishes. This may have implications for food webs in areas where macrophyte/seagrass detritus is abundant at the seafloor e.g. canyon systems and continental shelves close to seagrass meadows (Bahamas and Mediterranean).

Geophysical Characterization of in situ Serpentinization Processes at the Coast Range Ophiolite Microbial Observatory (CROMO)

NASA Astrophysics Data System (ADS)

Ortiz, E.; Tominaga, M.; Cardace, D.; Schrenk, M. O.; Hoehler, T. M.; Kubo, M. D.

2016-12-01

Electrical and magnetic remote sensing both on land and at sea have emerged as a powerful approach to characterize in situ serpentinization and carbonation processes in time and space. We conducted 2D Electrical Resistivity Tomography (ERT) surveys to investigate in situ geological and hydrogeological architecture within the rock formation of the Jurassic age tectonic mélange portion of the Coast Range Ophiolite Microbiological Observatory (CROMO) where serpentinization processes are thought to facilitate an active deep biosphere. We acquired ERT imagery during both wet and dry seasons, along 9 survey tracks traversing two previously drilled wells, CSW1.1 and QV1.1, at different lateral and horizontal resolutions, yielding imagery with depth of 6.9 - 41m. Integrating ERT inversion models with wire-line and core data, we successfully documented temporal changes in the in situ hydrological properties at CROMO, i.e. the lateral and vertical water table boundaries (unconfined aquifer), non-permeable zones (confining bed), and possible confined aquifers that are juxtaposed within three dominant lithological units of serpentinite top soil, serpentinite gravel with clay, and serpentinite basement formation. We conducted rock magnetic experiments on core samples from drilled sites, including Magnetic Property Measurement System (MPMS) measurements, to better understand the connection between these hydrogeological properties and in situ serpentinization processes. Based on the observed downhole distribution of magnetite in correlation with ERT results and lithostratigraphy, we proposed that, at CROMO: (i) zones enriched in ferromagnetic minerals, correspond to in situ serpentinite formation with both high and low resistivity, suggesting that resistivity zones represent in situ architecture of consolidated serpentinite confining beds and possible fractured serpentinite aquifers, respectively; and (ii) zones (e.g. 14 - 31m at CSW site) enriched in superparamagnetic size magnetites (i.e. "pepper flake" magnetites that are observed in serpentine veins) are present in permeable serpentinite gravel aquifer formations (i.e. low resistivity, possible fractured serpentinite aquifers) suggesting groundwater available around the drilled sites is driving present-day serpentinization.

Combining Space-Based and In-Situ Measurements to Track Flooding in Thailand

NASA Technical Reports Server (NTRS)

Chien, Steve; Doubleday, Joshua; Mclaren, David; Tran, Daniel; Tanpipat, Veerachai; Chitradon, Royal; Boonya-aaroonnet, Surajate; Thanapakpawin, Porranee; Khunboa, Chatchai; Leelapatra, Watis;

Observing Climate with Satellites - Are We on Thin Ice?

NASA Technical Reports Server (NTRS)

Tucker, Compton

2012-01-01

The Earth s climate is determined by irradiance from the Sun and properties of the atmosphere, oceans, and land that determine the reflection, absorption, and emission of energy within our atmosphere and at the Earth s surface. Since the 1970s, Earth-viewing satellites have complimented non-satellite geophysical observations with consistent, quantitative, and spatially-continuous measurements that have led to an unprecedented understanding of the Earth s climate system. I will describe the Earth s climate system as elaborated by satellite and in situ observations, review arguments against global warming, and show the convergence of evidence for human-caused warming of our planet.

The impact of different background errors in the assimilation of satellite radiances and in-situ observational data using WRFDA for three rainfall events over Iran

NASA Astrophysics Data System (ADS)

Zakeri, Zeinab; Azadi, Majid; Ghader, Sarmad

2018-01-01

Satellite radiances and in-situ observations are assimilated through Weather Research and Forecasting Data Assimilation (WRFDA) system into Advanced Research WRF (ARW) model over Iran and its neighboring area. Domain specific background error based on x and y components of wind speed (UV) control variables is calculated for WRFDA system and some sensitivity experiments are carried out to compare the impact of global background error and the domain specific background errors, both on the precipitation and 2-m temperature forecasts over Iran. Three precipitation events that occurred over the country during January, September and October 2014 are simulated in three different experiments and the results for precipitation and 2-m temperature are verified against the verifying surface observations. Results show that using domain specific background error improves 2-m temperature and 24-h accumulated precipitation forecasts consistently, while global background error may even degrade the forecasts compared to the experiments without data assimilation. The improvement in 2-m temperature is more evident during the first forecast hours and decreases significantly as the forecast length increases.

Comets in UV

NASA Astrophysics Data System (ADS)

Shustov, B.; Sachkov, M.; Gómez de Castro, A. I.; Vallejo, J. C.; Kanev, E.; Dorofeeva, V.

2018-04-01

Comets are important "eyewitnesses" of Solar System formation and evolution. Important tests to determine the chemical composition and to study the physical processes in cometary nuclei and coma need data in the UV range of the electromagnetic spectrum. Comprehensive and complete studies require additional ground-based observations and in situ experiments. We briefly review observations of comets in the ultraviolet (UV) and discuss the prospects of UV observations of comets and exocomets with space-borne instruments. A special reference is made to the World Space Observatory-Ultraviolet (WSO-UV) project.

Interoperable Access to Near Real Time Ocean Observations with the Observing System Monitoring Center

NASA Astrophysics Data System (ADS)

O'Brien, K.; Hankin, S.; Mendelssohn, R.; Simons, R.; Smith, B.; Kern, K. J.

2013-12-01

The Observing System Monitoring Center (OSMC), a project funded by the National Oceanic and Atmospheric Administration's Climate Observations Division (COD), exists to join the discrete 'networks' of In Situ ocean observing platforms -- ships, surface floats, profiling floats, tide gauges, etc. - into a single, integrated system. The OSMC is addressing this goal through capabilities in three areas focusing on the needs of specific user groups: 1) it provides real time monitoring of the integrated observing system assets to assist management in optimizing the cost-effectiveness of the system for the assessment of climate variables; 2) it makes the stream of real time data coming from the observing system available to scientific end users into an easy-to-use form; and 3) in the future, it will unify the delayed-mode data from platform-focused data assembly centers into a standards- based distributed system that is readily accessible to interested users from the science and education communities. In this presentation, we will be focusing on the efforts of the OSMC to provide interoperable access to the near real time data stream that is available via the Global Telecommunications System (GTS). This is a very rich data source, and includes data from nearly all of the oceanographic platforms that are actively observing. We will discuss how the data is being served out using a number of widely used 'web services' (including OPeNDAP and SOS) and downloadable file formats (KML, csv, xls, netCDF), so that it can be accessed in web browsers and popular desktop analysis tools. We will also be discussing our use of the Environmental Research Division's Data Access Program (ERDDAP), available from NOAA/NMFS, which has allowed us to achieve our goals of serving the near real time data. From an interoperability perspective, it's important to note that access to the this stream of data is not just for humans, but also for machine-to-machine requests. We'll also delve into how we configured access to the near real time ocean observations in accordance with the Climate and Forecast (CF) metadata conventions describing the various 'feature types' associated with particular in situ observation types, or discrete sampling geometries (DSG). Wrapping up, we'll discuss some of the ways this data source is already being used.

Reactions of SO 2 on hydrated cement particle system for atmospheric pollution reduction: A DRIFTS and XANES study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramakrishnan, Girish; Wu, Qiyuan; Moon, Juhyuk

An investigation of the adsorptive property of hydrated cement particle system for sulfur dioxide (SO2) removal was conducted. In situ and ex situ experiments using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and X-ray Absorption Near Edge Spectroscopy (XANES) characterization techniques were employed to identify surface species formed during the exposure to SO2. Oxidation of SO2 to sulfate and sulfite species observed during these experiments indicated dominant reaction pathways for SO2 reaction with concrete constituents, such as calcium hydroxide, which were also moderated by adsorption on porous surfaces of crushed aggregates. The impact of variable composition of concrete on itsmore » adsorption capacity and reaction mechanisms was also proposed in this work.« less

AQUA-USERS: AQUAculture USEr Driven Operational Remote Sensing Information Services

NASA Astrophysics Data System (ADS)

Laanen, Marnix; Poser, Kathrin; Peters, Steef; de Reus, Nils; Ghebrehiwot, Semhar; Eleveld, Marieke; Miller, Peter; Groom, Steve; Clements, Oliver; Kurekin, Andrey; Martinez Vicente, Victor; Brotas, Vanda; Sa, Carolina; Couto, Andre; Brito, Ana; Amorim, Ana; Dale, Trine; Sorensen, Kai; Boye Hansen, Lars; Huber, Silvia; Kaas, Hanne; Andersson, Henrik; Icely, John; Fragoso, Bruno

2015-12-01

The FP7 project AQUA-USERS provides the aquaculture industry with user-relevant and timely information based on the most up-to-date satellite data and innovative optical in-situ measurements. Its key purpose is to develop an application that brings together satellite information on water quality and temperature with in-situ observations as well as relevant weather prediction and met-ocean data. The application and its underlying database are linked to a decision support system that includes a set of (user-determined) management options. Specific focus is on the development of indicators for aquaculture management including indicators for harmful algae bloom (HAB) events. The methods and services developed within AQUA-USERS are tested by the members of the user board, who represent different geographic areas and aquaculture production systems.

In situ measurement of magnesium carbonate formation from CO2 using static high-pressure and -temperature 13C NMR.

PubMed

Surface, J Andrew; Skemer, Philip; Hayes, Sophia E; Conradi, Mark S

2013-01-02

We explore a new in situ NMR spectroscopy method that possesses the ability to monitor the chemical evolution of supercritical CO(2) in relevant conditions for geological CO(2) sequestration. As a model, we use the fast reaction of the mineral brucite, Mg(OH)(2), with supercritical CO(2) (88 bar) in aqueous conditions at 80 °C. The in situ conversion of CO(2) into metastable and stable carbonates is observed throughout the reaction. After more than 58 h of reaction, the sample was depressurized and analyzed using in situ Raman spectroscopy, where the laser was focused on the undisturbed products through the glass reaction tube. Postreaction, ex situ analysis was performed on the extracted and dried products using Raman spectroscopy, powder X-ray diffraction, and magic-angle spinning (1)H-decoupled (13)C NMR. These separate methods of analysis confirmed a spatial dependence of products, possibly caused by a gradient of reactant availability, pH, and/or a reaction mechanism that involves first forming hydroxy-hydrated (basic, hydrated) carbonates that convert to the end-product, anhydrous magnesite. This carbonation reaction illustrates the importance of static (unmixed) reaction systems at sequestration-like conditions.

The Response of the Ionospheric Cusp to the Solar Through Two Perspectives: Low Energy Changed Particle In-Situ Measurements and Low- Energy Neutral Atom Imaging

NASA Technical Reports Server (NTRS)

Coffey, V. N.; Moore, T. E.; Chandler, M. O.; Craven, P. D.

2000-01-01

The IMAGE mission provides a new perspective on the study of the response of the magnetosphere/ionosphere system to changing solar wind conditions, particularly the variability of ion outflow. Learning to interpret this new type of data becomes an essential step in the process of melding these results with the wealth of in-situ charged particle observations obtained over the past 25 years. In order to understand how the in-situ data correspond to and contrast with IMAGE results we will perform a conjunctive study of event data from two instruments to shed light on the coupling of the solar wind and ionosphere from these different perspectives. We will use the Low Energy Neutral Atom instrument (LENA) which images energetic neutral atom emissions from upward flowing ionospheric ions and the Thermal Ion Dynamics Instrument (TIDE) on the Polar satellite which measures in-situ ion outflow from 0.3-300 eV. Our primary goal will be to understand how comparing the imaging and in-situ perspectives can aid in the analysis of both data sets.

The Response of the Ionospheric Cusp to the Solar Wind Through Two Perspectives: Low Energy Charged Particle In-Situ Measurements and Low-Energy Neutral Atom Imaging

NASA Technical Reports Server (NTRS)

Coffey, V. N.; Moore, T. E.; Chandler, M. O.; Giles, B. L.; Craven, P. D.; Rose, M. Franklin (Technical Monitor)

2000-01-01

The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission provides a new perspective on the study of the response of the magnetosphere/ionosphere system to changing solar wind conditions, particularly the variability of ion outflow. Learning to interpret this new type of data becomes an essential step in the process of melding these results with the wealth of in-situ charged particle observations obtained over the past 25 years. In order to understand how the in-situ data correspond to and contrast with IMAGE results we will perform a conjunctive study of event data from two instruments to shed light on the coupling of the solar wind and ionosphere from these different perspectives. We will use the Low Energy Neutral Atom instrument (LENA) which images energetic neutral atom emissions from upward flowing ionospheric ions and the Thermal Ion Dynamics Instrument (TIDE) on the Polar satellite which measures in-situ ion outflow from 0.3-300 eV. Our primary goal will be to understand how comparing the imaging and in-situ perspectives can aid in the analysis of both data sets.

Future Exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Matson, D. L.; Coustenis, A.; Lunine, J.; Lebreton, J.; Reh, K.; Beauchamp, P.

2009-05-01

The future exploration of Titan and Enceladus has become very important for the planetary community. The study conducted last year of the Titan Saturn System Mission (TSSM) led to an announcement in which ESA and NASA prioritized future OPF missions, stating that TSSM is planned after EJSM (for details see http://www.lpi.usra.edu/opag/). TSSM consists of a TSSM Orbiter that would carry two in situ elements: the Titan Montgolfiere hot air balloon and the Titan Lake Lander. The mission could launch in the 2023-2025 timeframe on a trajectory to arrive ~9 years later for a 4-year mission in the Saturn system. Soon after arrival at Saturn, the montgolfiere would be delivered to Titan to begin its mission of airborne, scientific observations of Titan from an altitude of about 10 km. The montgolfiere would have a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) power system and would be designed to last at least 6-12 months in Titan's atmosphere. With the predicted winds and weather, that would be sufficient to circumnavigate the globe! On a subsequent fly-by, the TSSM orbiter would release the Lake Lander on a trajectory toward Titan for a targeted entry. It would descend through the atmosphere making scientific measurements, much like Huygens did, and then land and float on one of Titan's seas. This would be its oceanographic phase, making a physical and chemical assessment of the sea. The Lake Lander would operate 8-10 hours until its batteries become depleted. Following the delivery of the in situ elements, the TSSM orbiter would explore the Saturn system via a 2-year tour that includes in situ sampling of Enceladus' plumes as well as Titan flybys. After the Saturn system tour, the TSSM orbiter would enter orbit around Titan for a global survey phase. Synergistic and coordinated observations would be carried out between the TSSM orbiter and the in situ elements. The scientific requirements were developed by the international TSSM Joint Science Definition Team (JSDT). The orbiter was NASA's responsibility while the in situ elements were designed by ESA. The engineering and flight operations aspects of TSSM were developed in a collaborative study, conducted by NASA and ESA engineering teams working on both sides of the Atlantic. This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The European part was conducted in ESA within the Cosmic Vision 1 plan. Copyright 2008 California Institute of Technology. Government sponsorship acknowledged.

System for enhanced longevity of in situ microbial filter used for bioremediation

DOEpatents

Carman, M. Leslie; Taylor, Robert T.

2000-01-01

An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

Trends in Planetary Data Analysis. Executive summary of the Planetary Data Workshop

NASA Technical Reports Server (NTRS)

Evans, N.

1984-01-01

Planetary data include non-imaging remote sensing data, which includes spectrometric, radiometric, and polarimetric remote sensing observations. Also included are in-situ, radio/radar data, and Earth based observation. Also discussed is development of a planetary data system. A catalog to identify observations will be the initial entry point for all levels of users into the data system. There are seven distinct data support services: encyclopedia, data index, data inventory, browse, search, sample, and acquire. Data systems for planetary science users must provide access to data, process, store, and display data. Two standards will be incorporated into the planetary data system: Standard communications protocol and Standard format data unit. The data system configuration must combine a distributed system with those of a centralized system. Fiscal constraints have made prioritization important. Activities include saving previous mission data, planning/cost analysis, and publishing of proceedings.

Spacer geometry and particle deposition in spiral wound membrane feed channels.

PubMed

Radu, A I; van Steen, M S H; Vrouwenvelder, J S; van Loosdrecht, M C M; Picioreanu, C

2014-11-01

Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Review of Molecular-Level Mechanism of Membrane Degradation in the Polymer Electrolyte Fuel Cell

PubMed Central

Ishimoto, Takayoshi; Koyama, Michihisa

2012-01-01

Chemical degradation of perfluorosulfonic acid (PFSA) membrane is one of the most serious problems for stable and long-term operations of the polymer electrolyte fuel cell (PEFC). The chemical degradation is caused by the chemical reaction between the PFSA membrane and chemical species such as free radicals. Although chemical degradation of the PFSA membrane has been studied by various experimental techniques, the mechanism of chemical degradation relies much on speculations from ex-situ observations. Recent activities applying theoretical methods such as density functional theory, in situ experimental observation, and mechanistic study by using simplified model compound systems have led to gradual clarification of the atomistic details of the chemical degradation mechanism. In this review paper, we summarize recent reports on the chemical degradation mechanism of the PFSA membrane from an atomistic point of view. PMID:24958288

New Insights in the Long-Term Atmospheric Corrosion Mechanisms of Low Alloy Steel Reinforcements of Cultural Heritage Buildings

PubMed Central

Bouchar, Marie; Dillmann, Philippe; Neff, Delphine

2017-01-01

Reinforcing clamps made of low alloy steel from the Metz cathedral and corroded outdoors during 500 years were studied by OM, FESEM/EDS, and micro-Raman spectroscopy. The corrosion product layer is constituted of a dual structure. The outer layer is mainly constituted of goethite and lepidocrocite embedding exogenous elements such as Ca and P. The inner layer is mainly constituted of ferrihydrite. The behaviour of the inner layer under conditions simulating the wetting stage of the RH wet/dry atmospheric corrosion cycle was observed by in situ micro-Raman spectroscopy. The disappearance of ferrihydrite near the metal/oxide interface strongly suggests a mechanism of reductive dissolution caused by the oxidation of the metallic substrate and was observed for the first time in situ on an archaeological system. PMID:28773030

TESTING IN SITU ASSEMBLY WITH THE KEPLER PLANET CANDIDATE SAMPLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, Brad M. S.; Murray, Norm, E-mail: hansen@astro.ucla.edu, E-mail: murray@cita.utoronto.ca

2013-09-20

We present a Monte Carlo model for the structure of low-mass (total mass <25 M{sub ⊕}) planetary systems that form by the in situ gravitational assembly of planetary embryos into final planets. Our model includes distributions of mass, eccentricity, inclination, and period spacing that are based on the simulation of a disk of 20 M{sub ⊕}, forming planets around a solar-mass star, and assuming a power-law surface density distribution that drops with distance a as ∝ a {sup –1.5}. The output of the Monte Carlo model is then subjected to the selection effects that mimic the observations of a transitingmore » planet search such as that performed by the Kepler satellite. The resulting comparison of the output to the properties of the observed sample yields an encouraging agreement in terms of the relative frequencies of multiple-planet systems and the distribution of the mutual inclinations when moderate tidal circularization is taken into account. The broad features of the period distribution and radius distribution can also be matched within this framework, although the model underpredicts the distribution of small period ratios. This likely indicates that some dissipation is still required in the formation process. The most striking deviation between the model and observations is in the ratio of single to multiple systems in that there are roughly 50% more single-planet candidates observed than are produced in any model population. This suggests that some systems must suffer additional attrition to reduce the number of planets or increase the range of inclinations.« less

Ice lollies: An ice particle generated in supercooled conveyor belts

NASA Astrophysics Data System (ADS)

Keppas, S. Ch.; Crosier, J.; Choularton, T. W.; Bower, K. N.

2017-05-01

On 21 January 2009, a maturing low-pressure weather system approached the UK along with several associated frontal systems. As a part of the Aerosol Properties, PRocesses And InfluenceS on the Earth's climate-Clouds project, an observational research flight took place in southern England, sampling the leading warm front of this system. During the flight, a distinctive hydrometeor type was repeatedly observed which has not been widely reported in previous studies. We refer to the hydrometeors as "drizzle-rimed columnar ice" or "ice lollies" for short due to their characteristic shape. We discuss the processes that led to their formation using in situ and remote sensing data.

Towards Improved Satellite-In Situ Oceanographic Data Interoperability and Associated Value Added Services at the Podaac

NASA Astrophysics Data System (ADS)

Tsontos, V. M.; Huang, T.; Holt, B.

2015-12-01

The earth science enterprise increasingly relies on the integration and synthesis of multivariate datasets from diverse observational platforms. NASA's ocean salinity missions, that include Aquarius/SAC-D and the SPURS (Salinity Processes in the Upper Ocean Regional Study) field campaign, illustrate the value of integrated observations in support of studies on ocean circulation, the water cycle, and climate. However, the inherent heterogeneity of resulting data and the disparate, distributed systems that serve them complicates their effective utilization for both earth science research and applications. Key technical interoperability challenges include adherence to metadata and data format standards that are particularly acute for in-situ data and the lack of a unified metadata model facilitating archival and integration of both satellite and oceanographic field datasets. Here we report on efforts at the PO.DAAC, NASA's physical oceanographic data center, to extend our data management and distribution support capabilities for field campaign datasets such as those from SPURS. We also discuss value-added services, based on the integration of satellite and in-situ datasets, which are under development with a particular focus on DOMS. The distributed oceanographic matchup service (DOMS) implements a portable technical infrastructure and associated web services that will be broadly accessible via the PO.DAAC for the dynamic collocation of satellite and in-situ data, hosted by distributed data providers, in support of mission cal/val, science and operational applications.

In Situ Observations of PSCs Generated by Gravity Waves

NASA Technical Reports Server (NTRS)

Pfister, Leonhard; Bui, Paul; Mahoney, M. J.; Gandrud, Bruce; Hipskind, K. Stephen (Technical Monitor)

2000-01-01

During SOLVE, the bulk of the in-situ observations of PSCs are of large scale extended structures associated with synoptic scale cooling. The nature of these structures is also determined by layers of high relative NOy that have been stretched into thin layers by advective processes. Some of the in situ observations, however, are clearly correlated with gravity wave signatures. The first goal of this work is to examine these cases and evaluate gravity wave parameters. In particular, we are interested in the intrinsic periods of the waves and their temperature amplitude, which are key ingredients in the nucleation process. Secondly, we will examine some rudimentary properties of the particle size distributions and composition, comparing these with in situ observations of the more extended PSC features. Finally, we will attempt to ascertain the mechanism which generates the gravity waves.

The CONCEPTS Global Ice-Ocean Prediction System: Establishing an Environmental Prediction Capability in Canada

NASA Astrophysics Data System (ADS)

Pellerin, Pierre; Smith, Gregory; Testut, Charles-Emmanuel; Surcel Colan, Dorina; Roy, Francois; Reszka, Mateusz; Dupont, Frederic; Lemieux, Jean-Francois; Beaudoin, Christiane; He, Zhongjie; Belanger, Jean-Marc; Deacu, Daniel; Lu, Yimin; Buehner, Mark; Davidson, Fraser; Ritchie, Harold; Lu, Youyu; Drevillon, Marie; Tranchant, Benoit; Garric, Gilles

2015-04-01

Here we describe a new system implemented recently at the Canadian Meteorological Centre (CMC) entitled the Global Ice Ocean Prediction System (GIOPS). GIOPS provides ice and ocean analyses and 10 day forecasts daily at 00GMT on a global 1/4° resolution grid. GIOPS includes a full multivariate ocean data assimilation system that combines satellite observations of sea level anomaly and sea surface temperature (SST) together with in situ observations of temperature and salinity. In situ observations are obtained from a variety of sources including: the Argo network of autonomous profiling floats, moorings, ships of opportunity, marine mammals and research cruises. Ocean analyses are blended with sea ice analyses produced by the Global Ice Analysis System.. GIOPS has been developed as part of the Canadian Operational Network of Coupled Environmental PredicTion Systems (CONCEPTS) tri-departmental initiative between Environment Canada, Fisheries and Oceans Canada and National Defense. The development of GIOPS was made through a partnership with Mercator-Océan, a French operational oceanography group. Mercator-Océan provided the ocean data assimilation code and assistance with the system implementation. GIOPS has undergone a rigorous evaluation of the analysis, trial and forecast fields demonstrating its capacity to provide high-quality products in a robust and reliable framework. In particular, SST and ice concentration forecasts demonstrate a clear benefit with respect to persistence. These results support the use of GIOPS products within other CMC operational systems, and more generally, as part of a Government of Canada marine core service. Impact of a two-way coupling between the GEM atmospheric model and NEMO-CICE ocean-ice model will also be presented.

Can we get a better knowledge on dissolution processes in chalk by using microfluidic chips?

NASA Astrophysics Data System (ADS)

Neuville, Amélie; Minde, Mona; Renaud, Louis; Vinningland, Jan Ludvig; Dysthe, Dag Kristian; Hiorth, Aksel

2017-04-01

This work has been initiated in the context of research on improving the oil recovery in chalk bedrocks. One of the methods to improve the oil recovery is to inject "smart water" (acidic water/brines). Experiments on core scale and field tests that have been carried out the last decade have clearly shown that water chemistry affects the final oil recovery. However, there is generally no consensus in the scientific community of why additional oil is released, and it is also still not understood what are the mineralogical and structural changes. Direct in situ observation of the structural changes that occur when chalk is flooded with brines could resolve many of the open questions that remain. One of the highlights of this work is thus the development of an innovative methodology where fluid/rock interactions are observed in-situ by microscopy. To do so, we create several types of custom-made microfluidic systems that embeds reactive materials like chalk and calcite. The methodology we develop can be applied to other reactive materials. We will present an experiment where a calcite window dissolves with a fluid, where we observe in-situ the topography features of the calcite window, as well as the dissolution rate [1]. The injected fluid circulates at controlled flowrates in a channel which is obtained by xurography: double sided tape is cut out with a cutter plotter and placed between the reactive window and a non-reactive support. While the calcite window reacts, its topography is measured in situ every 10 s using an interference microscope, with a pixel resolution of 4.9 μm and a vertical resolution of 50 nm. These experiments are also compared with reactive flow simulations done with Lattice Boltzmann methods. Then, we will present a dissolution experiment done with a microfluidic system that embeds chalk. In this experiment, the main flow takes place at the chalk surface, in contact with fluid flowing in a channel above the chalk sample. Thus the reaction mostly occurs at the surface of the sample. The reacting chalk surface is observed in situ by stereomicroscopy and by interferometry. The dissolution velocities are highly heterogeneous. To identify the mineral change of the surface, a posteriori measurements using field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDS). [1] Neuville et al, 2016, Xurography for microfluidics on a reactive solid, Lab on Chip, DOI: 10.1039/c6lc01253a

DHS Internship Summary-Crystal Assembly at Different Length Scales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishchenko, L

2009-08-06

I was part of a project in which in situ atomic force microscopy (AFM) was used to monitor growth and dissolution of atomic and colloidal crystals. At both length scales, the chemical environment of the system greatly altered crystal growth and dissolution. Calcium phosphate was used as a model system for atomic crystals. A dissolution-reprecipitation reaction was observed in this first system, involving the conversion of brushite (DCPD) to octacalcium phosphate (OCP). In the second system, polymeric colloidal crystals were dissolved in an ionic solvent, revealing the underlying structure of the crystal. The dissolved crystal was then regrown through anmore » evaporative step method. Recently, we have also found that colloids can be reversibly deposited in situ onto an ITO (indium tin oxide) substrate via an electrochemistry setup. The overall goal of this project was to develop an understanding of the mechanisms that control crystallization and order, so that these might be controlled during material synthesis. Controlled assembly of materials over a range of length scales from molecules to nanoparticles to colloids is critical for designing new materials. In particular, developing materials for sensor applications with tailorable properties and long range order is important. In this work, we examine two of these length scales: small molecule crystallization of calcium phosphate (whose crystal phases include DCPD, OCP, and HAP) and colloidal crystallization of Poly(methyl methacrylate) beads. Atomic Force Microscopy is ideal for this line of work because it allows for the possibility of observing non-conducting samples in fluid during growth with high resolution ({approx} 10 nm). In fact, during atomic crystal growth one can observe changes in atomic steps, and with colloidal crystals, one can monitor the individual building blocks of the crystal. Colloids and atoms crystallize under the influence of different forces acting at different length scales as seen in Table 1. In particular, molecular crystals, which are typically dominated by ionic and covalent bonding, are an order of magnitude more strongly bonded than colloidal crystals. In molecular crystals, ordering is driven by the interaction potentials between molecules. By contrast, colloidal assembly is a competition between the repulsive electrostatic forces that prevent aggregation in solution (due to surface charge), and short-range van der Waals and entropic forces that leads to ordering. Understanding atomic crystallization is fundamentally important for fabrication of tailorable crystalline materials, for example for biological or chemical sensors. The transformation of brushite to OCP not only serves as a model system for atomic crystal growth (applicable to many other crystal growth processes), but is also important in bone cements. Colloidal crystals have unique optical properties which respond to chemical and mechanical stimuli, making them very important for sensing applications. The mechanism of colloidal crystal assembly is thus fundamentally important. Our in situ dissolution and regrowth experiments are one good method of analyzing how these crystals pack under different conditions and how defect sites are formed and filled. In these experiments, a silica additive was used to strengthen the colloidal crystal during initial assembly (ex situ) and to increase domain size and long range order. Reversible electrodeposition of colloids onto a conductive substrate (ITO in our case) is another system which can further our knowledge of colloidal assembly. This experiment holds promise of allowing in situ observation of colloidal crystal growth and the influence of certain additives on crystal order. The ultimate goal would be to achieve long range order in these crystals by changing the surface charge or the growth environment.« less

North-South America Network of Magnetically Conjugate All-Sky Imagers

DTIC Science & Technology

2015-01-02

based (radio and optical) systems and via in‐situ instruments onboard rockets and satellites. The ionosphere can be observed by a variety...to study the full system in a comprehensive way. The two locations at the base of a given terrestrial B‐line (one in the northern hemisphere and one...imagers to be established. This was based on the need to study ionospheric disturbances ordered by their geomagnetic

HDPE-HA composites synthetized by in situ polymerization with different filler content

NASA Astrophysics Data System (ADS)

Hermán, V.; Karam, A.; Albano, C.; Romero, K.; González, G.

2012-07-01

In Situ ethylene polymerization was used to synthesize high density polyethylene - hydroxyapatite (HDPE-HA) composites, employing Cp2ZrCl2/MAO as catalytic system. A good dispersion of HA into the HDPE matrix was obtained when the following synthesis conditions were combined: high stirring velocities (2000 rpm), low quantities of solvent (100 mL), and 10 °C. Under these conditions different filler content was used to synthetized HDPE-HA composites. An interaction between HA and HDPE was obtained by FTIR. On the other hand, thermal analysis indicated that no significant differences were observed between HDPE and the composites.

In situ SAXS study on cationic and non-ionic surfactant liquid crystals using synchrotron radiation.

PubMed

Fritscher, C; Hüsing, N; Bernstorff, S; Brandhuber, D; Koch, T; Seidler, S; Lichtenegger, H C

2005-11-01

In situ synchrotron small-angle X-ray scattering was used to investigate various surfactant/water systems with hexagonal and lamellar structures regarding their structural behaviour upon heating and cooling. Measurements of the non-ionic surfactant Triton X-45 (polyethylene glycol 4-tert-octylphenyl ether) at different surfactant concentrations show an alignment of the lamellar liquid-crystalline structure close to the wall of the glass capillaries and also a decrease in d-spacing following subsequent heating/cooling cycles. Additionally, samples were subjected to a weak magnetic field (0.3-0.7 T) during heating and cooling, but no influence of the magnetic field was observed.

Evaluation of MODIS Land Surface Temperature with In Situ Snow Surface Temperature from CREST-SAFE

NASA Astrophysics Data System (ADS)

Perez Diaz, C. L.; Lakhankar, T.; Romanov, P.; Munoz, J.; Khanbilvardi, R.; Yu, Y.

2016-12-01

This paper presents the procedure and results of a temperature-based validation approach for the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) product provided by the National Aeronautics and Space Administration (NASA) Terra and Aqua Earth Observing System satellites using in situ LST observations recorded at the Cooperative Remote Sensing Science and Technology Center - Snow Analysis and Field Experiment (CREST-SAFE) during the years of 2013 (January-April) and 2014 (February-April). A total of 314 day and night clear-sky thermal images, acquired by the Terra and Aqua satellites, were processed and compared to ground-truth data from CREST-SAFE with a frequency of one measurement every 3 min. Additionally, this investigation incorporated supplementary analyses using meteorological CREST-SAFE in situ variables (i.e. wind speed, cloud cover, incoming solar radiation) to study their effects on in situ snow surface temperature (T-skin) and T-air. Furthermore, a single pixel (1km2) and several spatially averaged pixels were used for satellite LST validation by increasing the MODIS window size to 5x5, 9x9, and 25x25 windows for comparison. Several trends in the MODIS LST data were observed, including the underestimation of daytime values and nighttime values. Results indicate that, although all the data sets (Terra and Aqua, diurnal and nocturnal) showed high correlation with ground measurements, day values yielded slightly higher accuracy ( 1°C), both suggesting that MODIS LST retrievals are reliable for similar land cover classes and atmospheric conditions. Results from the CREST-SAFE in situ variables' analyses indicate that T-air is commonly higher than T-skin, and that a lack of cloud cover results in: lower T-skin and higher T-air minus T-skin difference (T-diff). Additionally, the study revealed that T-diff is inversely proportional to cloud cover, wind speed, and incoming solar radiation. Increasing the MODIS window size showed an overestimation of in situ LST and some improvement in the daytime Terra and nighttime Aqua biases, with the highest accuracy achieved with the 5x5 window. A comparison between MODIS emmisivity from bands 31, 32, and in situ emissivity showed that emissivity errors (Relative error = -.003) were insignificant.

In situ reworking /gardening/ of the lunar surface - Evidence from the Apollo cores

NASA Technical Reports Server (NTRS)

Morris, R. V.

1978-01-01

The in situ reworking (gardening) of the lunar surface by impacting projectiles creates an in situ reworking zone extending horizontally over the entire regolith surface and extending vertically from the surface to a depth which varies from place-to-place on the moon. On the basis of available evidence, the 'high-maturity' zones observed at the top of the lunar cores have resulted from the in situ reworking of the present-day lunar surface. The temporal variation of the in situ reworking depth was investigated using depths inferred from maturity I sub s/FeO and Al-26 profiles of Apollo cores. The observed temporal variation of the in situ reworking depth in units of centimeters is equal to 2.2 times the time (in units of million years) to the 0.45th power.

DEMONSTRATION BULLETIN: NEW YORK STATE MULTI-VENDOR BIOREMEDIATION - R.E. WRIGHT ENVIRONMENTAL, INC.'S IN-SITU BIOREMEDIATION TREATMENT SYSTEM

EPA Science Inventory

The R.E. Wright Environmental, Inc.‘s (REWEI) In-situ Bioremediation Treatment System is an in-situ bioremediation technology for the treatment of soils contaminated with organic compounds. According to the Developer, contaminated soils are remediated in-situ by stimulating the a...

LWS Proposal to Provide Scientific Guidance and Modeling Support for the Ionospheric Mapping Mission. Part 1

NASA Technical Reports Server (NTRS)

Richmond, Arthur D.

2005-01-01

A data assimilation system for specifying the thermospheric density has been developed over the last several years. This system ingests GRACE/CHAMP-type in situ as well as SSULI/SSUSI remote sensing observations while making use of a physical model, the Coupled Thermosphere-Ionosphere Model (CTIM) (Fuller-Rowel1 et al., 1996). The Kalman filter was implemented as the backbone to the data assimilation system, which provides a statistically 'best' estimate as well as an estimate of the error in its state. The system was tested using a simulated thermosphere and observations. CHAMP data were then used to provide the system with a real data source. The results of this study are herein.

Correlation of In Situ Measurements of Plasma Irregularities with Ground-Based Scintillation Observations

DTIC Science & Technology

2010-06-01

extensive case study of the relationships between the observation of in situ irregularities, UHF scintillation observed by the Scin - tillation Decision...use these space-based measurements, however, the correlation between the structures and the resulting scin - tillation must be quantified. [10] As a

Precipitation characteristics in tropical Africa using satellite and in situ observations

NASA Astrophysics Data System (ADS)

Dezfuli, A. K.; Ichoku, I.; Huffman, G. J.; Mohr, K. I.

2017-12-01

Tropical Africa receives nearly all its precipitation as a result of convection. The characteristics of rain-producing systems in this region have not been well-understood, despite their crucial role in regional and global circulation. This is mainly due to the lack of in situ observations. Here, we have used precipitation records from the Trans-African Hydro-Meteorological Observatory (TAHMO) ground-based gauge network to improve our knowledge about the rainfall systems in the region, and to validate the recently-released IMERG precipitation product based on satellite observations from the Global Precipitation Measurement (GPM) constellation. The high temporal resolution of the gauge data has allowed us to identify three classes of rain events based on their duration and intensity. The contribution of each class to the total rainfall and the favorable surface atmospheric conditions for each class have been examined. As IMERG aims to continue the legacy of its predecessor, TRMM Multi-Satellite Precipitation Analysis (TMPA), and provide higher resolution data, continent-wide comparisons are made between these two products. Due to its improved temporal resolution, IMERG shows some advantages over TMPA in capturing the diurnal cycle and propagation of the meso-scale convective systems. However, the performance of the two satellite-based products varies by season, region and the evaluation statistics. The results of this study serve as a basis for our ongoing work on the impacts of biomass burning on precipitation processes in Africa.

Preliminary analysis of University of North Dakota aircraft data from the FIRE Cirrus IFO-2

NASA Technical Reports Server (NTRS)

Poellot, Michael R.

1995-01-01

The stated goals of the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) are 'to promote the development of improved cloud and radiation parameterization for use in climate models, and to provide for assessment and improvement of ISCCP projects'. FIRE Phase 2 has focused on the formation, maintenance and dissipation of cirrus and marine stratocumulus cloud systems. These objectives have been approached through a combination of modeling, extended-time observations and intensive field observation (IFO) periods. The work under this grant was associated with the FIRE Cirrus IFO 2. This field measurement program was conducted to obtain observations of cirrus cloud systems on a range of scales from the synoptic to the microscale, utilizing simultaneous measurements from a variety of ground-based, satellite and airborne platforms. By combining these remote and in situ measurements a more complete picture of cirrus systems can be obtained. The role of the University of North Dakota in Phase 2 was three-fold: to collect in situ microphysical data during the Cirrus IFO 2; to process and archive these data; and to collaborate in analyses of IFO data. This report will summarize the activities and findings of the work performed under this grant; detailed description of the data sets available and of the analyses are contained in the Semi-annual Status Reports submitted to NASA.

In-situ observation of recrystallization in an AlMgScZr alloy using confocal laser scanning microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taendl, J., E-mail: johannes.taendl@tugraz.atl; Nambu, S.; Orthacker, A.

2015-10-15

In this work we present a novel in-situ approach to study the recrystallization behavior of age hardening alloys. We use confocal laser scanning microscopy (CLSM) at 400 °C to investigate the static recrystallization of an AlMg4Sc0.4Zr0.12 alloy in-situ. The results are combined with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses. It was found that CLSM is a powerful tool to visualize both the local initiation and temporal sequence of recrystallization. After fast nucleation and initial growth, the grain growth rate decreases and the grain boundary migration stops after some minutes due to Zener pinning from Al{sub 3}(Sc,Zr)more » precipitates produced during the heat treatment. EBSD and TEM analyses confirm both the boundary movements and the particle-boundary interactions. - Highlights: • First time that CLSM is used to study recrystallization in-situ. • The start and end of recrystallization can be directly observed. • The procedure is easy to apply and requires only simple data interpretation. • In-situ observations on the surface correlate to modifications inside the bulk. • In-situ observations correlate to EBSD and EFTEM analyses.« less

Survey of in-situ and remote sensing methods for soil moisture determination

NASA Technical Reports Server (NTRS)

Schmugge, T. J.; Jackson, T. J.; Mckim, H. L.

1981-01-01

General methods for determining the moisture content in the surface layers of the soil based on in situ or point measurements, soil water models and remote sensing observations are surveyed. In situ methods described include gravimetric techniques, nuclear techniques based on neutron scattering or gamma-ray attenuation, electromagnetic techniques, tensiometric techniques and hygrometric techniques. Soil water models based on column mass balance treat soil moisture contents as a result of meteorological inputs (precipitation, runoff, subsurface flow) and demands (evaporation, transpiration, percolation). The remote sensing approaches are based on measurements of the diurnal range of surface temperature and the crop canopy temperature in the thermal infrared, measurements of the radar backscattering coefficient in the microwave region, and measurements of microwave emission or brightness temperature. Advantages and disadvantages of the various methods are pointed out, and it is concluded that a successful monitoring system must incorporate all of the approaches considered.

A unified metabolism for Mars: A new approach developed from research on extraterrestrial life detection by enzymatically induced exchange of O 18

NASA Technical Reports Server (NTRS)

1972-01-01

A general graded life detection approach ranging from environmental and in situ observations to specific metabolic experiments on Mars is reported. A zero dead volume leak and computer mediated data acquisition system is also discussed. Soil analyses were also conducted.

Mapping sub-surface geostrophic currents from altimetry and a fleet of gliders

NASA Astrophysics Data System (ADS)

Alvarez, A.; Chiggiato, J.; Schroeder, K.

2013-04-01

Integrating the observations gathered by different platforms into a unique physical picture of the environment is a fundamental aspect of networked ocean observing systems. These are constituted by a spatially distributed set of sensors and platforms that simultaneously monitor a given ocean region. Remote sensing from satellites is an integral part of present ocean observing systems. Due to their autonomy, mobility and controllability, underwater gliders are envisioned to play a significant role in the development of networked ocean observatories. Exploiting synergism between remote sensing and underwater gliders is expected to result on a better characterization of the marine environment than using these observational sources individually. This study investigates a methodology to estimate the three dimensional distribution of geostrophic currents resulting from merging satellite altimetry and in situ samples gathered by a fleet of Slocum gliders. Specifically, the approach computes the volumetric or three dimensional distribution of absolute dynamic height (ADH) that minimizes the total energy of the system while being close to in situ observations and matching the absolute dynamic topography (ADT) observed from satellite at the sea surface. A three dimensional finite element technique is employed to solve the minimization problem. The methodology is validated making use of the dataset collected during the field experiment called Rapid Environmental Picture-2010 (REP-10) carried out by the NATO Undersea Research Center-NURC during August 2010. A marine region off-shore La Spezia (northwest coast of Italy) was sampled by a fleet of three coastal Slocum gliders. Results indicate that the geostrophic current field estimated from gliders and altimetry significantly improves the estimates obtained using only the data gathered by the glider fleet.

Behavior of Sn atoms in GeSn thin films during thermal annealing: Ex-situ and in-situ observations

NASA Astrophysics Data System (ADS)

Takase, Ryohei; Ishimaru, Manabu; Uchida, Noriyuki; Maeda, Tatsuro; Sato, Kazuhisa; Lieten, Ruben R.; Locquet, Jean-Pierre

2016-12-01

Thermally induced crystallization processes for amorphous GeSn thin films with Sn concentrations beyond the solubility limit of the bulk crystal Ge-Sn binary system have been examined by X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, and (scanning) transmission electron microscopy. We paid special attention to the behavior of Sn before and after recrystallization. In the as-deposited specimens, Sn atoms were homogeneously distributed in an amorphous matrix. Prior to crystallization, an amorphous-to-amorphous phase transformation associated with the rearrangement of Sn atoms was observed during heat treatment; this transformation is reversible with respect to temperature. Remarkable recrystallization occurred at temperatures above 400 °C, and Sn atoms were ejected from the crystallized GeSn matrix. The segregation of Sn became more pronounced with increasing annealing temperature, and the ejected Sn existed as a liquid phase. It was found that the molten Sn remains as a supercooled liquid below the eutectic temperature of the Ge-Sn binary system during the cooling process, and finally, β-Sn precipitates were formed at ambient temperature.

BOREAS HYD-2 Estimated Snow Water Equivalent (SWE) from Microwave Measurements

NASA Technical Reports Server (NTRS)

Powell, Hugh; Chang, Alfred T. C.; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Smith, David E. (Technical Monitor)

2000-01-01

The surface meteorological data collected at the Boreal Ecosystem-Atmosphere Study (BOREAS) tower and ancillary sites are being used as inputs to an energy balance model to monitor the amount of snow storage in the boreal forest region. The BOREAS Hydrology (HYD)-2 team used Snow Water Equivalent (SWE) derived from an energy balance model and in situ observed SWE to compare the SWE inferred from airborne and spaceborne microwave data, and to assess the accuracy of microwave retrieval algorithms. The major external measurements that are needed are snowpack temperature profiles, in situ snow areal extent, and SWE data. The data in this data set were collected during February 1994 and cover portions of the Southern Study Area (SSA), Northern Study Area (NSA), and the transect areas. The data are available from BORIS as comma-delimited tabular ASCII files. The SWE data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

In-situ study of discontinuous precipitation in Al-15 at.% Zn

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdou, S.; El-Boragy, M.; Solorzano, G.

1996-05-01

In the present study, attention was focused on in-situ work on discontinuous precipitation in Al-15.0 at.% Zn in a high voltage electron microscope using a hot stage and a video system. The microscope was an AEI instrument with a maximum voltage of 1.25 MV. The voltage used was 500 kV. The scope of the present study was to check if the grain boundary migration in the discontinuous precipitation reaction proceeds in a stop-and-go fashion. From all the observations reported here it can be concluded that the stop-and-go type of grain boundary migration seems to be a very general one. Butmore » in many cases it cannot easily experimentally be proved. In case of discontinuous precipitation in Al-15.0 at.% Zn it has been clearly demonstrated by in-situ observations in a high-voltage electron microscope that the reaction front migration occurs in a stop-and-go fashion. Consequently, there is a drastic difference between the average velocity and the instantaneous velocity. The only quantity, which can be determined in traditional experiments, is the average velocity to which the Petermann-Hornbogen equation is adequate.« less

Hyperspectral Remote Sensing of the Coastal Ocean: Adaptive Sampling and Forecasting of In situ Optical Properties

DTIC Science & Technology

2003-09-30

We are developing an integrated rapid environmental assessment capability that will be used to feed an ocean nowcast/forecast system. The goal is to develop a capacity for predicting the dynamics in inherent optical properties in coastal waters. This is being accomplished by developing an integrated observation system that is being coupled to a data assimilative hydrodynamic bio-optical ecosystem model. The system was used adaptively to calibrate hyperspectral remote sensing sensors in optically complex nearshore coastal waters.

In situ observations of Pc1 pearl pulsations by the Van Allen Probes

NASA Astrophysics Data System (ADS)

Paulson, K. W.; Smith, C. W.; Lessard, M. R.; Engebretson, M. J.; Torbert, R. B.; Kletzing, C. A.

2014-03-01

We present in situ observations of Pc1 pearl pulsations using the Van Allen Probes. These waves are often observed using ground-based magnetometers, but are rarely observed by orbiting satellites. With the Van Allen Probes, we have seen at least 14 different pearl pulsation events during the first year of operations. These new in situ measurements allow us to identify the wave classification based on local magnetic field conditions. Additionally, by using two spacecraft, we are able to observe temporal changes in the region of observation. The waves appear to be generated at an overall central frequency, as often observed on the ground, and change polarization from left- to right-handedness as they propagate into a region where they are resonant with the crossover frequency (where R- and L-mode waves have the same phase velocity). By combining both in situ and ground-based data, we have found that the region satisfying electromagnetic ion cyclotron wave generation conditions is azimuthally large while radially narrow. The observation of a similar modulation period on the ground as in the magnetosphere contradicts the bouncing wave packet mechanism of generation.

Modeling slip system strength evolution in Ti-7Al informed by in-situ grain stress measurements

DOE PAGES

Pagan, Darren C.; Shade, Paul A; Barton, Nathan R.; ...

2017-02-17

Far-field high-energy X-ray diffraction microscopy is used to asses the evolution of slip system strengths in hexagonal close-packed (HCP) Ti-7A1 during tensile deformation in-situ. The following HCP slip system families are considered: basal < a >, prismatic < a >, pyramidal < a >, and first-order pyramidal < c + a >. A 1 mm length of the specimen's gauge section, marked with fiducials and comprised of an aggregate of over 500 grains, is tracked during continuous deformation. The response of each slip system family is quantified using 'slip system strength curves' that are calculated from the average stress tensorsmore » of each grain over the applied deformation history. These curves, which plot the average resolved shear stress for each slip system family versus macroscopic strain, represent a mesoscopic characterization of the aggregate response. A short time-scale transient softening is observed in the basal < a >, prismatic < a >, and pyramidal < a > slip systems, while a long time-scale transient hardening is observed in the pyramidal < c + a > slip systems. These results are used to develop a slip system strength model as part of an elasto-viscoplastic constitutive model for the single crystal behavior. A suite of finite element simulations is performed on a virtual polycrystal to demonstrate the relative effects of the different parameters in the slip system strength model. Finally, the model is shown to accurately capture the macroscopic stress-strain response using parameters that are chosen to capture the mesoscopic slip system responses.« less

An oceanographic survey for oil spill monitoring and model forecasting validation using remote sensing and in situ data in the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Pisano, A.; De Dominicis, M.; Biamino, W.; Bignami, F.; Gherardi, S.; Colao, F.; Coppini, G.; Marullo, S.; Sprovieri, M.; Trivero, P.; Zambianchi, E.; Santoleri, R.

2016-11-01

A research cruise was organized on board the Italian National Research Council (CNR) R/V Urania to test the oil spill monitoring system developed during the PRogetto pilota Inquinamento Marino da Idrocarburi project (PRIMI, pilot project for marine oil pollution). For the first time, this system integrated in a modular way satellite oil spill detection (Observation Module) and oil spill displacement forecasting (Forecast Module) after detection. The Observation Module was based on both Synthetic Aperture RADAR (SAR) and optical satellite detection, namely SAR and Optical Modules, while the Forecast Module on Lagrangian numerical circulation models. The cruise (Aug. 6-Sep. 7, 2009) took place in the Mediterranean Sea, around Sicily, an area affected by heavy oil tanker traffic with frequent occurrence of oil spills resulting from illegal tank washing. The cruise plan was organized in order to have the ship within the SAR image frames selected for the cruise, at acquisition time. In this way, the ship could rapidly reach oil slicks detected in the images by the SAR Module, and/or eventually by the Optical Module, in order to carry out visual and instrumental inspection of the slicks. During the cruise, several oil spills were detected by the two Observation Modules and verified in situ, with the essential aid of the Forecasting Module which provided the slick position by the time the ship reached the area after the alert given by the SAR and/or optical imagery. Results confirm the good capability of oil spill SAR detection and indicate that also optical sensors are able to detect oil spills, ranging from thin films to slicks containing heavily polluted water. Also, results confirm the useful potential of oil spill forecasting models, but, on the other hand, that further work combining satellite, model and in situ data is necessary to refine the PRIMI system.

The advanced qualtiy control techniques planned for the Internation Soil Moisture Network

NASA Astrophysics Data System (ADS)

Xaver, A.; Gruber, A.; Hegiova, A.; Sanchis-Dufau, A. D.; Dorigo, W. A.

2012-04-01

In situ soil moisture observations are essential to evaluate and calibrate modeled and remotely sensed soil moisture products. Although a number of meteorological networks and field campaigns measuring soil moisture exist on a global and long-term scale, their observations are not easily accessible and lack standardization of both technique and protocol. Thus, handling and especially comparing these datasets with satellite products or land surface models is a demanding issue. To overcome these limitations the International Soil Moisture Network (ISMN; http://www.ipf.tuwien.ac.at/insitu/) has been initiated to act as a centralized data hosting facility. One advantage of the ISMN is that users are able to access the harmonized datasets easily through a web portal. Another advantage is the fully automated processing chain including the data harmonization in terms of units and sampling interval, but even more important is the advanced quality control system each measurement has to run through. The quality of in situ soil moisture measurements is crucial for the validation of satellite- and model-based soil moisture retrievals; therefore a sophisticated quality control system was developed. After a check for plausibility and geophysical limits a quality flag is added to each measurement. An enhanced flagging mechanism was recently defined using a spectrum based approach to detect spurious spikes, jumps and plateaus. The International Soil Moisture Network has already evolved to one of the most important distribution platforms for in situ soil moisture observations and is still growing. Currently, data from 27 networks in total covering more than 800 stations in Europe, North America, Australia, Asia and Africa is hosted by the ISMN. Available datasets also include historical datasets as well as near real-time measurements. The improved quality control system will provide important information for satellite-based as well as land surface model-based validation studies.

In Situ Biomineralization and Particle Deposition Distinctively Mediate Biofilm Susceptibility to Chlorine

PubMed Central

Li, Xiaobao; Chopp, David L.; Russin, William A.; Brannon, Paul T.; Parsek, Matthew R.

2016-01-01

Microbial biofilms and mineral precipitation commonly co-occur in engineered water systems, such as cooling towers and water purification systems, and both decrease process performance. Microbial biofilms are extremely challenging to control and eradicate. We previously showed that in situ biomineralization and the precipitation and deposition of abiotic particles occur simultaneously in biofilms under oversaturated conditions. Both processes could potentially alter the essential properties of biofilms, including susceptibility to biocides. However, the specific interactions between mineral formation and biofilm processes remain poorly understood. Here we show that the susceptibility of biofilms to chlorination depends specifically on internal transport processes mediated by biomineralization and the accumulation of abiotic mineral deposits. Using injections of the fluorescent tracer Cy5, we show that Pseudomonas aeruginosa biofilms are more permeable to solutes after in situ calcite biomineralization and are less permeable after the deposition of abiotically precipitated calcite particles. We further show that biofilms are more susceptible to chlorine killing after biomineralization and less susceptible after particle deposition. Based on these observations, we found a strong correlation between enhanced solute transport and chlorine killing in biofilms, indicating that biomineralization and particle deposition regulate biofilm susceptibility by altering biocide penetration into the biofilm. The distinct effects of in situ biomineralization and particle deposition on biocide killing highlight the importance of understanding the mechanisms and patterns of biomineralization and scale formation to achieve successful biofilm control. PMID:26944848

Interface test series: An in situ study of factors affecting the containment of hydraulic fractures

NASA Astrophysics Data System (ADS)

Warpinski, N. R.; Finley, S. J.; Vollendorf, W. C.; Obrien, M.; Eshom, E.

1982-02-01

In situ experiments, which are accessible for direct observation by mineback, were conducted to determine the effect that material-property interfaces and in situ stress differences have on hydraulic fracture propagation and the resultant overall geometry. These experiments show conclusively that a difference in elastic modulus at a geologic interface has little or no effect on crack growth and, therefore, is not a feature which would promote containment of fractures within a specified reservoir zone. However, differences in the in situ stress between adjacent layers is shown to have a considerable influence on fracture propagation. Experiments were conducted in a low modulus ash-fall tuff which contained two layers of high minimum principal in situ stress and which was overlain by a formation with at least a factor of 5 increase in elastic modulus. Fractures were observed to terminate in regions of high minimum principal in situ stress in nearly every case.

Direct measurement of CO2 solubility and pH in NaCl hydrothermal solutions by combining in-situ potentiometry and Raman spectroscopy up to 280 °C and 150 bar

NASA Astrophysics Data System (ADS)

Truche, Laurent; Bazarkina, Elena F.; Berger, Gilles; Caumon, Marie-Camille; Bessaque, Gilles; Dubessy, Jean

2016-03-01

The in-situ monitoring of aqueous solution chemistry at elevated temperatures and pressures is a major challenge in geochemistry. Here, we combined for the first time in-situ Raman spectroscopy for concentration measurements and potentiometry for pH measurement in a single hydrothermal cell equipped with sampling systems and operating under controlled conditions of temperature and pressure. Dissolved CO2 concentration and pH were measured at temperatures up to 280 °C and pressures up to 150 bar in the H2O-CO2 and H2O-CO2-NaCl systems. A Pitzer specific-ion-interaction aqueous model was developed and confirmed the accuracy and consistency of the measurements, at least up to 250 °C. The revised Pitzer parameters for the H2O-CO2-NaCl system were formatted for the Phreeqc geochemical software. Significant changes with respect to the Pitzer.dat database currently associated with Phreeqc were observed. The new model parameters are now available for further applications. The Raman and pH probes tested here may also be applied to field monitoring of hydrothermal springs, geothermal wells, and oil and gas boreholes.

Transparent metal model study of the use of a cellular growth front to form aligned monotectic composite materials

NASA Technical Reports Server (NTRS)

Kaukler, William F.

1988-01-01

The purpose of this work was to resolve a scientific controversy in the understanding of how second phase particles become aligned during unidirectional growth of a monotectic alloy. A second aspect was to make the first systematic observations of the solidification behavior of a monotectic alloy during cellular growth in-situ. This research provides the first systematic transparent model study of cellular solidification. An interface stability diagram was developed for the planar to cellular transition of the succinonitrile glycerol (SNG) system. A method was developed utilizing Fourier Transform Infrared Spectroscopy which allows quantitative compositional analysis of directionally solidified SNG along the growth axis. To determine the influence of cellular growth front on alignment for directionally solidified monotectic alloys, the planar and cellular growth morphology was observed in-situ for SNG between 8 and 17 percent glycerol and for a range of over two orders of magnitude G/R.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parkin, William M.; Balan, Adrian; Liang, Liangbo

Here, we report how the presence of electron-beam-induced sulfur vacancies affects first-order Raman modes and correlate the effects with the evolution of the in situ transmission-electron microscopy (TEM) two-terminal conductivity of monolayer MoS 2 under electron irradiation. We observe a redshift in the E Raman peak and a less pronounced blueshift in the A' 1 peak with increasing electron dose. Using energy-dispersive X-ray spectroscopy (EDS), we show that irradiation causes partial removal of sulfur and correlate the dependence of the Raman peak shifts with S vacancy density (a few %), which is confirmed by first-principles density functional theory calculations. Inmore » situ device current measurements show exponential decrease in channel current upon irradiation. Our analysis demonstrates that the observed frequency shifts are intrinsic properties of the defective systems and that Raman spectroscopy can be used as a quantitative diagnostic tool to characterize MoS 2-based transport channels.« less

Data sets for snow cover monitoring and modelling from the National Snow and Ice Data Center

NASA Astrophysics Data System (ADS)

Holm, M.; Daniels, K.; Scott, D.; McLean, B.; Weaver, R.

2003-04-01

A wide range of snow cover monitoring and modelling data sets are pending or are currently available from the National Snow and Ice Data Center (NSIDC). In-situ observations support validation experiments that enhance the accuracy of remote sensing data. In addition, remote sensing data are available in near-real time, providing coarse-resolution snow monitoring capability. Time series data beginning in 1966 are valuable for modelling efforts. NSIDC holdings include SMMR and SSM/I snow cover data, MODIS snow cover extent products, in-situ and satellite data collected for NASA's recent Cold Land Processes Experiment, and soon-to-be-released ASMR-E passive microwave products. The AMSR-E and MODIS sensors are part of NASA's Earth Observing System flying on the Terra and Aqua satellites Characteristics of these NSIDC-held data sets, appropriateness of products for specific applications, and data set access and availability will be presented.

Direct observation of spherulitic growth stages of CaCO 3 in a poly(acrylic acid)-chitosan system: In situ SPM study

NASA Astrophysics Data System (ADS)

Ulčinas, A.; Butler, M. F.; Heppenstall-Butler, M.; Singleton, S.; Miles, M. J.

2007-09-01

Crystallization of a CaCO 3 thin film from supersaturated solution on chitosan in the presence of poly-acrylic acid was investigated by in situ AFM and SNOM. It was directly observed that crystallization proceeds through characteristic stages consistent with the theory of spherulitic growth: development of individual branches, build-up of larger scale "lobe" features, followed by overgrowth and ripening. We propose that crystallization of CaCO 3 on chitosan in the presence of poly(acrylic acid) (PAA) proceeds in a gelatinous matrix formed by PAA stabilized amorphous CaCO 3; the spherulitic character of crystallization is initiated by the high viscosity of gel and presence of PAA impurities. Characteristic sizes of spherulite features deviate significantly from the prediction based on diffusivity of PAA in water due to low diffusivity of PAA in gel.

Ab initio structure search and in situ 7Li NMR studies of discharge products in the Li–S battery system

DOE PAGES

See, Kimberly A.; Leskes, Michal; Griffin, John M.; ...

2014-11-10

The high theoretical gravimetric capacity of the Li–S battery system makes it an attractive candidate for numerous energy storage applications. In practice, cell performance is plagued by low practical capacity and poor cycling. In an effort to explore the mechanism of the discharge with the goal of better understanding performance, we examine the Li–S phase diagram using computational techniques and complement this with an in situ 7Li NMR study of the cell during discharge. Both the computational and experimental studies are consistent with the suggestion that the only solid product formed in the cell is Li 2S, formed soon aftermore » cell discharge is initiated. In situ NMR spectroscopy also allows the direct observation of soluble Li +-species during cell discharge; species that are known to be highly detrimental to capacity retention. We suggest that during the first discharge plateau, S is reduced to soluble polysulfide species concurrently with the formation of a solid component (Li 2S) which forms near the beginning of the first plateau, in the cell configuration studied here. The NMR data suggest that the second plateau is defined by the reduction of the residual soluble species to solid product (Li 2S). Lastly, a ternary diagram is presented to rationalize the phases observed with NMR during the discharge pathway and provide thermodynamic underpinnings for the shape of the discharge profile as a function of cell composition.« less

Bioturbation in a Declining Oxygen Environment, in situ Observations from Wormcam

PubMed Central

Sturdivant, S. Kersey; Díaz, Robert J.; Cutter, George R.

2012-01-01

Bioturbation, the displacement and mixing of sediment particles by fauna or flora, facilitates life supporting processes by increasing the quality of marine sediments. In the marine environment bioturbation is primarily mediated by infaunal organisms, which are susceptible to perturbations in their surrounding environment due to their sedentary life history traits. Of particular concern is hypoxia, dissolved oxygen (DO) concentrations ≤2.8 mg l−1, a prevalent and persistent problem that affects both pelagic and benthic fauna. A benthic observing system (Wormcam) consisting of a buoy, telemetering electronics, sediment profile camera, and water quality datasonde was developed and deployed in the Rappahannock River, VA, USA, in an area known to experience seasonal hypoxia from early spring to late fall. Wormcam transmitted a time series of in situ images and water quality data, to a website via wireless internet modem, for 5 months spanning normoxic and hypoxic periods. Hypoxia was found to significantly reduce bioturbation through reductions in burrow lengths, burrow production, and burrowing depth. Although infaunal activity was greatly reduced during hypoxic and near anoxic conditions, some individuals remained active. Low concentrations of DO in the water column limited bioturbation by infaunal burrowers and likely reduced redox cycling between aerobic and anaerobic states. This study emphasizes the importance of in situ observations for understanding how components of an ecosystem respond to hypoxia. PMID:22493701

A novel platform for in situ investigation of cells and tissues under mechanical strain

PubMed Central

Ahmed, Wylie W.; Kural, Mehmet H.; Saif, Taher A.

2010-01-01

The mechanical micro-environment influences cellular responses such as migration, proliferation, differentiation, and apoptosis. Cells are subjected to mechanical stretching in vivo, e.g., epithelial cells during embryogenesis. Current methodologies do not allow high resolution in situ observation of cells and tissues under applied strain, which may reveal intracellular dynamics and the origin of cell mechanosensitivity. We have developed a novel polydimethylsiloxane (PDMS) substrate capable of applying tensile and compressive strain (up to 45%) to cells and tissues while allowing in situ observation with high resolution optics. The strain field of the substrate was characterized experimentally using digital image correlation (DIC) and the deformation was modeled with finite element method (FEM) using a Mooney-Rivlin hyperelastic constitutive relation. The substrate strain was found to be uniform for greater than 95% of the substrate area. As a demonstration of our system, we applied mechanical strain to single fibroblasts transfected with GFP-Actin and whole transgenic Drosophila embryos expressing GFP in all neurons during live imaging. We report three observations of biological responses due to applied strain: (1) dynamic rotation of intact actin stress fibers in fibroblasts; (2) lamellipodia activity and actin polymerization in fibroblasts; (3) active axonal contraction in Drosophila embryo motor neurons. Our novel platform may serve as an important tool in studying the mechanoresponse of cells and tissues including whole embryos. PMID:20188869

First In-Situ Observations of Exospheric Response to CME Impact at Mercury

NASA Astrophysics Data System (ADS)

Raines, J. M.; Wallace, K. L.; Sarantos, M.; Jasinksi, J. M.; Tracy, P. J.; Dewey, R. M.; Weberg, M. J.; Slavin, J. A.

2018-05-01

We present the first in-situ observations of enhancements to Mercury's He exosphere generated by CME impact. These results have implications for understanding exosphere generation and loss processes, as well space weathering of the planet's surface.

Interactions between Coronal Mass Ejections Viewed in Coordinated Imaging and In Situ Observations

NASA Technical Reports Server (NTRS)

Liu, Ying D.; Luhmann, Janet G.; Moestl, Christian; Martinez-Oliveros, Juan C.; Bale, Stewart D.; Lin, Robert P.; Harrison, Richard A.; Temmer, Manuela; Webb, David F.; Odstrcil, Dusan

2013-01-01

The successive coronal mass ejections (CMEs) from 2010 July 30 - August 1 present us the first opportunity to study CME-CME interactions with unprecedented heliospheric imaging and in situ observations from multiple vantage points. We describe two cases of CME interactions: merging of two CMEs launched close in time and overtaking of a preceding CME by a shock wave. The first two CMEs on August 1 interact close to the Sun and form a merged front, which then overtakes the July 30 CME near 1 AU, as revealed by wide-angle imaging observations. Connections between imaging observations and in situ signatures at 1 AU suggest that the merged front is a shock wave, followed by two ejecta observed at Wind which seem to have already merged. In situ measurements show that the CME from July 30 is being overtaken by the shock at 1 AU and is significantly compressed, accelerated and heated. The interaction between the preceding ejecta and shock also results in variations in the shock strength and structure on a global scale, as shown by widely separated in situ measurements from Wind and STEREO B. These results indicate important implications of CME-CME interactions for shock propagation, particle acceleration and space weather forecasting.

Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

DOE PAGES

Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; ...

2015-05-14

In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation andmore » streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.« less

The Grand Challenges of WCRP and the Climate Observing System of the Future

NASA Astrophysics Data System (ADS)

Brasseur, G. P.

2017-12-01

The successful implementation the Paris agreement on climate change (COP21) calls for a well-designed global monitoring system of essential climate variables, climate processes and Earth system budgets. The Grand Challenges implemented by the World Climate Research Programme (WCRP) provide an opportunity to investigate issues of high societal relevance, directly related to sea level rise, droughts, floods, extreme heat events, food security, and fresh water availability. These challenges would directly benefit from a well-designed suite of systematic climate observations. Quantification of the evolution of the global energy, water and carbon budgets as well as the development and the production of near-term and regional climate predictions require that a comprehensive, focused, multi-platform observing system (satellites, ground-based and in situ observations) be established in an international context. This system must be accompanied by the development of climate services that should translate and disseminate scientific outcomes as actionable information for users and stakeholders.

Unravel the submesoscale dynamics of the phytoplanktonic community in the NW Mediterranean Sea by in situ observations: the 2015 OSCAHR cruise

NASA Astrophysics Data System (ADS)

Marrec, Pierre; Doglioli, Andrea M.; Grégori, Gérald; Della Penna, Alice; Wagener, Thibaut; Rougier, Gille; Bhairy, Nagib; Dugenne, Mathilde; Lahbib, Soumaya; Thyssen, Melilotus

2017-04-01

Submesoscale phenomena have been recently recognized as a key factor in physical-biological-biogeochemical interactions, even if it remains unclear how these processes affect the global state of the ocean. Significant large-scale impacts of submesoscale structures on primary production and influence on the phytoplankton community structure and diversity have also been reported. In the past decade submesoscale dynamics have been predominately studied through the analysis of numerical simulations. Observing the coupled physical and biogeochemical variability at this scale remains challenging due to the ephemeral nature of submesoscale structures. The in-situ study of such structures necessitates multidisciplinary approaches involving in situ observations, remote sensing and modeling. Last progresses in biogeochemical sensor development and advanced methodology including Lagrangian real-time adaptative strategies represent outstanding opportunities. The OSCAHR (Observing Submesoscale Coupling At High Resolution) campaign has been conducted thanks to a multidisciplinary approach in order to improve the understanding of submesoscale processes. An ephemeral submesoscale structure was first identified in the Ligurian Sea in fall 2015 using both satellite and numerical modeling data before the campaign. Afterwards, advanced observing systems for the physical, biological and biogeochemical characterization of the sea surface layer at a high spatial and temporal frequency were deployed during a 10-days cruise. A MVP (Moving Vessel Profiler) was used to obtain high resolution CTD profiles associated to a new pumping system with 1-m vertical resolution. Moreover, along the ship track, in addition to the standard measurements of seawater surface samples (Chl-a, nutrients, O2, SST, SSS …), we deployed an automated flow cytometer for near real-time characterization of phytoplankton functional groups (from micro-phytoplankton down to cyanobacteria). The observed submesoscale feature presented a cyclonic structure with a relatively cold core surrounded by warmer waters. Six phytoplankton groups were identified across the structure with an unprecedented spatial and temporal resolution. According to our observations, we could quantify the influence of the fast established physical structure on the spatial distribution of the phytoplankton functional groups, giving coherence to the observed community structuration. Moreover, the high resolution of our observations allows us to estimate the growth rate of the main phytoplankton groups. Our innovative adaptative strategy with a multidisciplinary and transversal approach provides a deeper understanding of the marine biogeochemical dynamics through the first trophic levels.

A Review of In Situ Observations of Crystallization and Growth in High Temperature Oxide Melts

NASA Astrophysics Data System (ADS)

Wang, Zhanjun; Sohn, Il

2018-05-01

This review summarizes the significant results of high-temperature confocal laser scanning microscopy (CLSM) and single hot thermocouple technology (SHTT) and its application in observing the crystallization and growth in high-temperature oxide melts from iron- and steel-making slags to continuous casting mold fluxes. Using in situ observations of CLSM and SHTT images of high-temperature molten oxides with time, temperature, and composition, the crystallization behavior, including crystal morphology, crystallization temperature, initial nucleation and growth rate, could be obtained. The broad range of applications using in situ observations during crystallization have provided a wealth of opportunities in pyrometallurgy and is provided in this review.

Studying Weather and Climate Using Atmospheric Retrospective Analyses

NASA Astrophysics Data System (ADS)

Bosilovich, M. G.

2014-12-01

Over the last 35 years, tremendous amounts of satellite observations of the Earth's atmosphere have been collected along side the much longer and diverse record of in situ measurements. The satellite data records have disparate qualities, structure and uncertainty which make comparing weather from the 80s and 2000s a challenging prospect. Likewise, in-situ data records lack complete coverage of the earth in both space and time. Atmospheric reanalyses use the observations with numerical models and data assimilation to produce continuous and consistent weather data records for periods longer than decades. The result is a simplified data format with a relatively straightforward learning curve that includes many more variables available (through the modeling component of the system), but driven by a full suite of observational data. The simplified data format allows introduction into weather and climate data analysis. Some examples are provided from undergraduate meteorology program internship projects. We will present the students progression through the projects from their initial understanding and competencies to some final results and the skills learned along the way. Reanalyses are a leading research tool in weather and climate, but can also provide an introductory experience as well, allowing students to develop an understanding of the physical system while learning basic programming and analysis skills.

Copernicus Earth observation programme

NASA Astrophysics Data System (ADS)

Žlebir, Silvo

European Earth observation program Copernicus is an EU-wide programme that integrates satellite data, in-situ data and modeling to provide user-focused information services to support policymakers, researchers, businesses and citizens. Land monitoring service and Emergency service are fully operational already, Atmosphere monitoring service and Marine environment monitoring service are preoperational and will become fully operational in the following year, while Climate change service and Security service are in an earlier development phase. New series of a number of dedicated satellite missions will be launched in the following years, operated by the European Space Agency and EUMETSAT, starting with Sentinel 1A satellite early this year. Ground based, air-borne and sea-borne in-situ data are provided by different international networks and organizations, EU member states networks etc. European Union is devoting a particular attention to secure a sustainable long-term operational provision of the services. Copernicus is also stated as a European Union’s most important contribution to Global Earth Observation System of Systems (GEOSS). The status and the recent development of the Copernicus programme will be presented, together with its future perspective. As Copernicus services have already demonstrated their usability and effectiveness, some interesting cases of their deployment will be presented. Copernicus free and open data policy, supported by a recently adopted EU legislative act, will also be presented.

First observations of tropospheric δD data observed by ground- and space-based remote sensing and surface in-situ measurement techniques at MUSICA's principle reference station (Izaña Observatory, Spain)

NASA Astrophysics Data System (ADS)

González, Yenny; Schneider, Matthias; Christner, Emanuel; Rodríguez, Omaira E.; Sepúlveda, Eliezer; Dyroff, Christoph; Wiegele, Andreas

2013-04-01

The main goal of the project MUSICA (Multiplatform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) is the generation of a quasi global tropospheric water vapor isototopologue dataset of a good and well-documented quality. Therefore, new ground- and space-based remote sensing observations (NDACC-FTIR and IASI/METOP) are combined with in-situ measurements. This work presents the first comparison between in-situ and remote sensing observations made at the Izaña Atmospheric Research Centre (Tenerife, Canary Islands, Spain). The in-situ measurements are made by a Picarro L2120-i water vapor isotopologue analyzer. At Izaña the in-situ data are affected by local small-scale mixing processes: during daylight, the thermally buoyant upslope flow prompts the mixing between the Marine Boundary Layer (MBL) and the low Free Troposphere (FT). However, the remote sensors detect δD values averaged over altitudes that are more representative for the free troposphere. This difference has to be considered for the comparison. In general, a good agreement between the MUSICA remote sensing and the in situ H2O-versus-δD plots is found, which demonstrates that the MUSICA δD remote sensing products add scientifically valuable information to the H2O data.

DEMONSTRATION BULLETIN: IN SITU ELECTROKINETIC EXTRACTION SYSTEM - SANDIA NATIONAL LABORATORIES

EPA Science Inventory

Sandia National Laboratories (SNL) has developed an in situ soil remediation system that uses electrokinetic principles to remediate hexavalent chromium-contaminated unsaturated or partially saturated soils. The technology involves the in situ application of direct current to the...

Impact of Targeted Ocean Observations for Improving Ocean Model Initialization for Coupled Hurricane Forecasting

NASA Astrophysics Data System (ADS)

Halliwell, G. R.; Srinivasan, A.; Kourafalou, V. H.; Yang, H.; Le Henaff, M.; Atlas, R. M.

2012-12-01

The accuracy of hurricane intensity forecasts produced by coupled forecast models is influenced by errors and biases in SST forecasts produced by the ocean model component and the resulting impact on the enthalpy flux from ocean to atmosphere that powers the storm. Errors and biases in fields used to initialize the ocean model seriously degrade SST forecast accuracy. One strategy for improving ocean model initialization is to design a targeted observing program using airplanes and in-situ devices such as floats and drifters so that assimilation of the additional data substantially reduces errors in the ocean analysis system that provides the initial fields. Given the complexity and expense of obtaining these additional observations, observing system design methods such as OSSEs are attractive for designing efficient observing strategies. A new fraternal-twin ocean OSSE system based on the HYbrid Coordinate Ocean Model (HYCOM) is used to assess the impact of targeted ocean profiles observed by hurricane research aircraft, and also by in-situ float and drifter deployments, on reducing errors in initial ocean fields. A 0.04-degree HYCOM simulation of the Gulf of Mexico is evaluated as the nature run by determining that important ocean circulation features such as the Loop Current and synoptic cyclones and anticyclones are realistically simulated. The data-assimilation system is run on a 0.08-degree HYCOM mesh with substantially different model configuration than the nature run, and it uses a new ENsemble Kalman Filter (ENKF) algorithm optimized for the ocean model's hybrid vertical coordinates. The OSSE system is evaluated and calibrated by first running Observing System Experiments (OSEs) to evaluate existing observing systems, specifically quantifying the impact of assimilating more than one satellite altimeter, and also the impact of assimilating targeted ocean profiles taken by the NOAA WP-3D hurricane research aircraft in the Gulf of Mexico during the Deepwater Horizon oil spill. OSSE evaluation and calibration is then performed by repeating these two OSEs with synthetic observations and comparing the resulting observing system impact to determine if it differs from the OSE results. OSSEs are first run to evaluate different airborne sampling strategies with respect to temporal frequency of flights and the horizontal separation of upper-ocean profiles during each flight. They are then run to assess the impact of releasing multiple floats and gliders. Evaluation strategy focuses on error reduction in fields important for hurricane forecasting such as the structure of ocean currents and eddies, upper ocean heat content distribution, and upper-ocean stratification.

AN INTEGRATED APPROACH TO AIR QUALITY USING IN SITU, SATELLITE, AND MODELED DATA - FOCUSED ON THE FUTURE OF EARTH OBSERVATIONS SYSTEM (EOS)

EPA Science Inventory

EPA through statutory mandates has monitored air, water, land and human health for the past several decades. The design of the ambient air monitoring networks, for the most part, has been loosely tied single-pollutant networks focused on large urban areas. These networks supply t...

Estimating Surface NO2 and SO2 Mixing Ratios from Fast-Response Total Column Observations and Potential Application to Geostationary Missions

EPA Science Inventory

Total-column nitrogen dioxide (NO2) data collected by a ground-based sun-tracking spectrometer system 21 (Pandora) and an photolytic-converter-based in-situ instrument collocated at NASA’s Langley Research Center in 22 Hampton, Virginia were analyzed to study the relationship bet...

Current systematic carbon-cycle observations and the need for implementing a policy-relevant carbon observing system

NASA Astrophysics Data System (ADS)

Ciais, P.; Dolman, A. J.; Bombelli, A.; Duren, R.; Peregon, A.; Rayner, P. J.; Miller, C.; Gobron, N.; Kinderman, G.; Marland, G.; Gruber, N.; Chevallier, F.; Andres, R. J.; Balsamo, G.; Bopp, L.; Bréon, F.-M.; Broquet, G.; Dargaville, R.; Battin, T. J.; Borges, A.; Bovensmann, H.; Buchwitz, M.; Butler, J.; Canadell, J. G.; Cook, R. B.; DeFries, R.; Engelen, R.; Gurney, K. R.; Heinze, C.; Heimann, M.; Held, A.; Henry, M.; Law, B.; Luyssaert, S.; Miller, J.; Moriyama, T.; Moulin, C.; Myneni, R. B.; Nussli, C.; Obersteiner, M.; Ojima, D.; Pan, Y.; Paris, J.-D.; Piao, S. L.; Poulter, B.; Plummer, S.; Quegan, S.; Raymond, P.; Reichstein, M.; Rivier, L.; Sabine, C.; Schimel, D.; Tarasova, O.; Valentini, R.; Wang, R.; van der Werf, G.; Wickland, D.; Williams, M.; Zehner, C.

2014-07-01

A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy-relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. In addition, uncertainties for each observation data-stream should be assessed. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases interoperable, and on the calibration of each component of the system to agreed-upon international scales.

Analysis of meteorological variables in the Australasian region using ground- and space-based GPS techniques

NASA Astrophysics Data System (ADS)

Kuleshov, Yuriy; Choy, Suelynn; Fu, Erjiang Frank; Chane-Ming, Fabrice; Liou, Yuei-An; Pavelyev, Alexander G.

2016-07-01

Results of analysis of meteorological variables (temperature and moisture) in the Australasian region using the global positioning system (GPS) radio occultation (RO) and GPS ground-based observations verified with in situ radiosonde (RS) data are presented. The potential of using ground-based GPS observations for retrieving column integrated precipitable water vapour (PWV) over the Australian continent has been demonstrated using the Australian ground-based GPS reference stations network. Using data from the 15 ground-based GPS stations, the state of the atmosphere over Victoria during a significant weather event, the March 2010 Melbourne storm, has been investigated, and it has been shown that the GPS observations has potential for monitoring the movement of a weather front that has sharp moisture contrast. Temperature and moisture variability in the atmosphere over various climatic regions (the Indian and the Pacific Oceans, the Antarctic and Australia) has been examined using satellite-based GPS RO and in situ RS observations. Investigating recent atmospheric temperature trends over Antarctica, the time series of the collocated GPS RO and RS data were examined, and strong cooling in the lower stratosphere and warming through the troposphere over Antarctica has been identified, in agreement with outputs of climate models. With further expansion of the Global Navigation Satellite Systems (GNSS) system, it is expected that GNSS satellite- and ground-based measurements would be able to provide an order of magnitude larger amount of data which in turn could significantly advance weather forecasting services, climate monitoring and analysis in the Australasian region.

A Structural Study of Escherichia coli Cells Using an In Situ Liquid Chamber TEM Technology.

PubMed

Wang, Yibing; Chen, Xin; Cao, Hongliang; Deng, Chao; Cao, Xiaodan; Wang, Ping

2015-01-01

Studying cell microstructures and their behaviors under living conditions has been a challenging subject in microbiology. In this work, in situ liquid chamber TEM was used to study structures of Escherichia coli cells in aqueous solutions at a nanometer-scale resolution. Most of the cells remained intact under electron beam irradiation, and nanoscale structures were observed during the TEM imaging. The analysis revealed structures of pili surrounding the E. coli cells; the movements of the pili in the liquid were also observed during the in situ tests. This technology also allowed the observation of features of the nucleoid in the E. coli cells. Overall, in situ TEM can be applied as a valuable tool to study real-time microscopic structures and processes in microbial cells residing in native aqueous solutions.

Long open-path TDL based system for monitoring the background concentration for deployment at Jungfraujoch High Altitude Research Station- Switzerland

NASA Astrophysics Data System (ADS)

Simeonov, V.; van den Bergh, H.; Parlange, M. B.

2009-12-01

A new long-open-path instrument developed at EPFL for methane and water vapor observation will be presented. The instrument is developed and will be used within the GAW+ CH program and aims at long-term monitoring of background methane concentration at the High Altitude Research Station Jungfraujoch (3580 mASL). The instrument is built on the monostatic scheme (transceiver -distant retroreflector) using a 1.65 nm tunable diode laser (TDL) and a retroreflector at 1200 m from the transceiver. The data will be compared with in-situ measurements to evaluate the effect of the station on the in-situ data.

A remote sensing data assimilation system for cold land processes hydrologic estimation

NASA Astrophysics Data System (ADS)

Andreadis, Konstantinos M.

2009-12-01

Accurate forecasting of snow properties is important for effective water resources management, especially in mountainous areas. Model-based approaches are limited by biases and uncertainties. Remote sensing offers an opportunity for observation of snow properties over larger areas. Traditional approaches to direct estimation of snow properties from passive microwave remote sensing have been plagued by limitations such as the tendency of estimates to saturate for moderately deep snowpacks and the effects of mixed land cover. To address these complications, a data assimilation system is developed and evaluated in a three-part research. The data assimilation system requires the embedding of a microwave emissions model which uses modeled snowpack properties. In the first part of this study, such a model is evaluated using multi-scale TB measurements from the Cold Land Processes Experiment. The model's ability to reproduce snowpack microphysical properties is evaluated through comparison with snowpit measurements, while TB predictions are evaluated through comparison with in-situ, aircraft and satellite measurements. Point comparisons showed limitations in the model, while the spatial averaging and the effects of forest cover suppressed errors in comparisons with aircraft measurements. The layered character of snowpacks increases the complexity of algorithms intended to retrieve snow properties from the snowpack microwave return signal. Implementation of a retrieval strategy requires knowledge of stratigraphy, which practically can only be produced by models. In the second part of this study, we describe a multi-layer model designed for such applications. The model coupled with a radiative transfer scheme improved the estimation of TB, while potential impacts when assimilating radiances are explored. A system that merges SWE model predictions and observations of SCE and TB, is evaluated in the third part of this study over one winter season in the Upper Snake River basin. Two data assimilation techniques, the Ensemble Kalman filter and the Ensemble Multiscale Kalman filter are tested with the multilayer snow model forced by downscaled re-analysis meteorological observations. Both the EnKF and EnMKF showed modest improvements when compared with the open-loop simulation, relative to a baseline simulation which used in-situ meteorological data, while comparisons with in-situ SWE measurements showed an overall improvement.

In-column bonded phase polymerization for improved packing uniformity

PubMed Central

Huckabee, Alexis G.; Yerneni, Charu; Jacobson, Rachel E.; Alzate, Edwin J.; Chen, Tse-Hong; Wirth, Mary J.

2017-01-01

It is difficult to pack chromatographic particles having polymeric-bonded phases because solvents used for making a stable slurry cause the polymer layer to swell. Growth of the polymer inside the column (in situ) after packing was investigated and compared with conventional, ex situ polymer growth. The method of activators generated by electron transfer, along with atom-transfer radical polymerization, enabled polymerization under ambient conditions. Nonporous, 0.62 µm silica particles with silane initiators were used. Polyacrylamide films with a hydrated thickness of 23 nm in 75:25 water/isopropanol grew in 55 min for both in situ and ex situ preparations, and the same carbon coverage was observed. Higher chromatographic resolution and better column-to-column reproducibility were observed for in situ polymer growth, as evaluated by hydrophilic interaction liquid chromatography for the model glycoprotein, ribonuclease B. In situ polymer growth was also found to give lower eddy diffusion, as shown by a narrower peak width for injected acetonitrile in 50:50 acetonitrile/water. When columns were packed more loosely, bed collapse occurred quickly for ex situ, but not for in situ, polymer growth. The higher resolution and stability for in situ polymer growth is explained by packing with hard, rather than soft, contacts between particles. PMID:28387037

A new multispectral imaging instrument for in-situ characterization of flocs and colloidal aggregates in natural waters

NASA Astrophysics Data System (ADS)

Bostater, Charles R.

2016-05-01

In-situ sampling, characterization and quantification of colloidal aggregates and flocs in ambient water is complex but needed in order to understand their role in development and maintenance of moving fluid muds, muck, bottom boundary lutocline layers and nephelometric interfaces in aquatic systems. These bottom boundary interfaces and associated processes contribute to sedimentation, particle deposition and resuspension of total particulate matter and associated nutrients. Increasing the scientific understanding of the above requires advances in environmental sensing instrumentation (passive and active) to successfully understand these aquatic interfaces. Standalone in-situ sensors that automatically perform multiple steps including sampling, separation, and detection have the potential to greatly advance analytical science. A new in-situ multispectral optical camera system for environmental monitoring and surveillance of delicate flocs and related aggregate structures is described. Results of the system show that flocs - 0.1 mm -10.2 mm diameter (mean diameter of 2.77 mm), with a variance of 5.952 mm and a median effective cross-section area of 30 mm2 can be measured using the passive multispectral optical imaging system. The system is lightweight, compact and suitable for shallow or deep water deployment. When combined with fixed station acoustic echogram instruments, nephelometric (turbidity) waves can be easily observed. Time sequential analysis of imagery allows the system to be used as an optical particle velocimetry system (OPVS). Initial shallow water testing resulted in Lagrangian particle velocities of 0.3 to 3 cm sec-1 to be measured. Similar results were obtained from an acoustic velocity current meter (MAVS3) and a Marsh McBirney 201D electromagnetic current meters. When combined with results from direct methods using sondes for estimating sediment mass fluxes, the combined systems provide data necessary for sediment and water quality modeling. The new optical sensor system will help address analytical needs reported in past studies and provides a new standard method and protocol for measuring the movement of sediment and particulates in the aquatic bottom boundary layers.

Fe-FeO and Fe-Fe3C melting relations at Earth's core-mantle boundary conditions: Implications for a volatile-rich or oxygen-rich core

NASA Astrophysics Data System (ADS)

Morard, G.; Andrault, D.; Antonangeli, D.; Nakajima, Y.; Auzende, A. L.; Boulard, E.; Cervera, S.; Clark, A.; Lord, O. T.; Siebert, J.; Svitlyk, V.; Garbarino, G.; Mezouar, M.

2017-09-01

Eutectic melting temperatures in the Fe-FeO and Fe-Fe3C systems have been determined up to 150 GPa. Melting criteria include observation of a diffuse scattering signal by in situ X-Ray diffraction, and textural characterisation of recovered samples. In addition, compositions of eutectic liquids have been established by combining in situ Rietveld analyses with ex situ chemical analyses. Gathering these new results together with previous reports on Fe-S and Fe-Si systems allow us to discuss the specific effect of each light element (Si, S, O, C) on the melting properties of the outer core. Crystallization temperatures of Si-rich core compositional models are too high to be compatible with the absence of extensive mantle melting at the core-mantle boundary (CMB) and significant amounts of volatile elements such as S and/or C (>5 at%, corresponding to >2 wt%), or a large amount of O (>15 at% corresponding to ∼5 wt%) are required to reduce the crystallisation temperature of the core material below that of a peridotitic lower mantle.

Small Body Landing Accuracy Using In-Situ Navigation

NASA Technical Reports Server (NTRS)

Bhaskaran, Shyam; Nandi, Sumita; Broschart, Stephen; Wallace, Mark; Olson, Corwin; Cangahuala, L. Alberto

2011-01-01

Spacecraft landings on small bodies (asteroids and comets) can require target accuracies too stringent to be met using ground-based navigation alone, especially if specific landing site requirements must be met for safety or to meet science goals. In-situ optical observations coupled with onboard navigation processing can meet the tighter accuracy requirements to enable such missions. Recent developments in deep space navigation capability include a self-contained autonomous navigation system (used in flight on three missions) and a landmark tracking system (used experimentally on the Japanese Hayabusa mission). The merging of these two technologies forms a methodology to perform autonomous onboard navigation around small bodies. This paper presents an overview of these systems, as well as the results from Monte Carlo studies to quantify the achievable landing accuracies by using these methods. Sensitivity of the results to variations in spacecraft maneuver execution error, attitude control accuracy and unmodeled forces are examined. Cases for two bodies, a small asteroid and on a mid-size comet, are presented.

Precipitation Characteristics in Tropical Africa Using Satellite and In-Situ Observations

NASA Technical Reports Server (NTRS)

Dezfuli, Amin; Ichoku, Charles; Huffman, George; Mohr, Karen

2017-01-01

Tropical Africa receives nearly all its precipitation as a result of convection. The characteristics of rain-producing systems in this region, despite their crucial role in regional and global circulation, have not been well-understood. This is mainly due to the lack of in situ observations. Here, we have used precipitation records from the Trans-African Hydro-Meteorological Observatory (TAHMO) to improve our knowledge about the rainfall systems in the region, and to validate the recently-released IMERG precipitation product. The high temporal resolution of the gauge data has allowed us to identify three classes of rain events based on their duration and intensity. The contribution of each class to the total rainfall and the favorable surface atmospheric conditions for each class have been examined. As IMERG aims to continue the legacy of its predecessor, TMPA, and provide higher resolution data, continent-wide comparisons are made between these two products. IMERG, due to its improved temporal resolution, shows some advantages over TMPA in capturing the diurnal cycle and propagation of the meso-scale convective systems. However, the performance of the two satellite-based products varies by season, region and the evaluation statistics. The results of this study serve as a basis for our ongoing work on the impacts of biomass burning on precipitation processes in Africa.

Remote and In Situ Observations of an Unusual Earth-Directed Coronal Mass Ejection from Multiple Viewpoints

NASA Technical Reports Server (NTRS)

Nieves-Chinchilla, T.; Colaninno, R.; Vourlidas, A.; Szabo, A.; Lepping, R. P.; Boardsen, S. A.; Anderson, B. J.; Korth, H.

2012-01-01

During June 16-21, 2010, an Earth-directed Coronal Mass Ejection (CME) event was observed by instruments onboard STEREO, SOHO, MESSENGER and Wind. This event was the first direct detection of a rotating CME in the middle and outer corona. Here, we carry out a comprehensive analysis of the evolution of the CME in the interplanetary medium comparing in-situ and remote observations, with analytical models and three-dimensional reconstructions. In particular, we investigate the parallel and perpendicular cross section expansion of the CME from the corona through the heliosphere up to 1 AU. We use height-time measurements and the Gradual Cylindrical Shell (GCS) technique to model the imaging observations, remove the projection effects, and derive the 3-dimensional extent of the event. Then, we compare the results with in-situ analytical Magnetic Cloud (MC) models, and with geometrical predictions from past works. We nd that the parallel (along the propagation plane) cross section expansion agrees well with the in-situ model and with the Bothmer & Schwenn [1998] empirical relationship based on in-situ observations between 0.3 and 1 AU. Our results effectively extend this empirical relationship to about 5 solar radii. The expansion of the perpendicular diameter agrees very well with the in-situ results at MESSENGER ( 0:5 AU) but not at 1 AU. We also find a slightly different, from Bothmer & Schwenn [1998], empirical relationship for the perpendicular expansion. More importantly, we find no evidence that the CME undergoes a significant latitudinal over-expansion as it is commonly assumed

Automated in situ observations of upper ocean biogeochemistry, bio-optics, and physics and their potential use for global studies

NASA Technical Reports Server (NTRS)

Dickey, Tommy D.; Granata, Timothy C.; Taupier-Letage, Isabelle

1992-01-01

The processes controlling the flux of carbon in the upper ocean have dynamic ranges in space and time of at least nine orders of magnitude. These processes depend on a broad suite of inter-related biogeochemical, bio-optical, and physical variables. These variables should be sampled on scales matching the relevant phenomena. Traditional ship-based sampling, while critical for detailed and more comprehensive observations, can span only limited portions of these ranges because of logistical and financial constraints. Further, remote observations from satellite platforms enable broad horizontal coverage which is restricted to the upper few meters of the ocean. For these main reasons, automated subsurface measurement systems are important for the fulfillment of research goals related to the regional and global estimation and modeling of time varying biogeochemical fluxes. Within the past few years, new sensors and systems capable of autonomously measuring several of the critical variables have been developed. The platforms for deploying these systems now include moorings and drifters and it is likely that autonomous underwater vehicles (AUV's) will become available for use in the future. Each of these platforms satisfies particular sampling needs and can be used to complement both shipboard and satellite observations. In the present review, (1) sampling considerations will be summarized, (2) examples of data obtained from some of the existing automated in situ sampling systems will be highlighted, (3) future sensors and systems will be discussed, (4) data management issues for present and future automated systems will be considered, and (5) the status of near real-time data telemetry will be outlined. Finally, we wish to make it clear at the outset that the perspectives presented here are those of the authors and are not intended to represent those of the United States JGOFS program, the International JGOFS program, NOAA's C&GC program, or other global ocean programs.

Free radicals in the stratosphere - A new observational technique

NASA Technical Reports Server (NTRS)

Anderson, J. G.; Hazen, N. L.; Mclaren, B. E.; Rowe, S. P.; Schiller, C. M.; Schwab, M. J.; Solomon, L.; Thompson, E. E.; Weinstock, E. M.

1985-01-01

A new approach to in situ observations of trace reactive species in the stratosphere is described. A balloon-borne system, floating 40 kilometers above the earth's surface, successfully lowered and then retracted a cluster of instruments a distance of 12 kilometers on a filament of Kevlar. This instrument cluster is capable of detecting gas-phase free radicals at the part-per-trillion level. The suspended instrument array has excellent stability and has been used to measured atomic oxygen concentrations in the stratosphere.

Understanding Apex Predator and Pelagic Fish Habitat Utilization in the California Current System by Integrating Animal Tracking With in Situ Oceanographic Observations

DTIC Science & Technology

2007-01-01

Fish To date 1,000 archival tags have been deployed on 3 species of tunas ( bluefin , yellowfin and albacore) and over 400 tags have been...observations. Analyses of seasonal movements off California indicated four distinct regions that are occupied primarily by tunas . For example, bluefin ...when in areas of high productivity and more dispersed when in regions of low productivity. In the spring through fall, bluefin tuna were located in

SCHeMA web-based observation data information system

NASA Astrophysics Data System (ADS)

Novellino, Antonio; Benedetti, Giacomo; D'Angelo, Paolo; Confalonieri, Fabio; Massa, Francesco; Povero, Paolo; Tercier-Waeber, Marie-Louise

2016-04-01

It is well recognized that the need of sharing ocean data among non-specialized users is constantly increasing. Initiatives that are built upon international standards will contribute to simplify data processing and dissemination, improve user-accessibility also through web browsers, facilitate the sharing of information across the integrated network of ocean observing systems; and ultimately provide a better understanding of the ocean functioning. The SCHeMA (Integrated in Situ Chemical MApping probe) Project is developing an open and modular sensing solution for autonomous in situ high resolution mapping of a wide range of anthropogenic and natural chemical compounds coupled to master bio-physicochemical parameters (www.schema-ocean.eu). The SCHeMA web system is designed to ensure user-friendly data discovery, access and download as well as interoperability with other projects through a dedicated interface that implements the Global Earth Observation System of Systems - Common Infrastructure (GCI) recommendations and the international Open Geospatial Consortium - Sensor Web Enablement (OGC-SWE) standards. This approach will insure data accessibility in compliance with major European Directives and recommendations. Being modular, the system allows the plug-and-play of commercially available probes as well as new sensor probess under development within the project. The access to the network of monitoring probes is provided via a web-based system interface that, being implemented as a SOS (Sensor Observation Service), is providing standard interoperability and access tosensor observations systems through O&M standard - as well as sensor descriptions - encoded in Sensor Model Language (SensorML). The use of common vocabularies in all metadatabases and data formats, to describe data in an already harmonized and common standard is a prerequisite towards consistency and interoperability. Therefore, the SCHeMA SOS has adopted the SeaVox common vocabularies populated by SeaDataNet network of National Oceanographic Data Centres. The SCHeMA presentation layer, a fundamental part of the software architecture, offers to the user a bidirectional interaction with the integrated system allowing to manage and configure the sensor probes; view the stored observations and metadata, and handle alarms. The overall structure of the web portal developed within the SCHeMA initiative (Sensor Configuration, development of Core Profile interface for data access via OGC standard, external services such as web services, WMS, WFS; and Data download and query manager) will be presented and illustrated with examples of ongoing tests in costal and open sea.

Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA)

USGS Publications Warehouse

Spencer, R.G.M.; Pellerin, B.A.; Bergamaschi, B.A.; Downing, B.D.; Kraus, T.E.C.; Smart, D.R.; Dahlgren, R.A.; Hernes, P.J.

2007-01-01

Dissolved organic matter (DOM) concentration and composition in riverine and stream systems are known to vary with hydrological and productivity cycles over the annual and interannual time scales. Rivers are commonly perceived as homogeneous with respect to DOM concentration and composition, particularly under steady flow conditions over short time periods. However, few studies have evaluated the impact of short term variability ( < 1 day) on DOM dynamics. This study examined whether diurnal processes measurably altered DOM concentration and composition in the hypereutrophic San Joaquin River (California) during a relatively quiescent period. We evaluated the efficacy of using optical in situ measurements to reveal changes in DOM which may not be evident from bulk dissolved organic carbon (DOC) measurement alone. The in situ optical measurements described in this study clearly showed for the first time diurnal variations in DOM measurements, which have previously been related to both composition and concentration, even though diurnal changes were not well reflected in bulk DOC concentrations. An apparent asynchronous trend of DOM absorbance and chlorophyll-a in comparison to chromophoric dissolved organic matter (CDOM) fluorescence and spectral slope S290-350 suggests that no one specific CDOM spectrophotometric measurement explains absolutely DOM diurnal variation in this system; the measurement of multiple optical parameters is therefore recommended. The observed diurnal changes in DOM composition, measured by in situ optical instrumentation likely reflect both photochemical and biologically-mediated processes. The results of this study highlight that short-term variability in DOM composition may complicate trends for studies aiming to distinguish different DOM sources in riverine systems and emphasizes the importance of sampling specific study sites to be compared at the same time of day. The utilization of in situ optical technology allows short-term variability in DOM dynamics to be monitored and serves to increase our understanding of its processing and fundamental role in the aquatic environment. Copyright ?? 2007 John Wiley & Sons, Ltd.

Observations and modeling of the ionospheric gravity and diamagnetic current systems from CHAMP and Swarm measurements

NASA Astrophysics Data System (ADS)

Alken, P.

2016-01-01

The CHAMP and Swarm satellites, which provide high-quality magnetic field measurements in low-altitude polar orbits, are ideally suited for investigating ionospheric current systems. In this study, we focus on the F region low-latitude gravity and diamagnetic currents which are prominent in the equatorial ionization anomaly (EIA) region in the North and South Hemisphere. During its 10 year mission, CHAMP has sampled nearly the entire altitude range of the EIA, offering the opportunity to study these currents from above, inside, and below their source region. The Swarm constellation offers the unique opportunity to study near-simultaneous measurements of the current systems at different longitudinal separations. In this study, we present new observations of these current systems, investigate their seasonal and local time dependence, investigate the use of in situ electron density measurements as a proxy for the magnetic perturbations, and compute the longitudinal self correlation of these currents. We find that these currents are strongest during spring and fall, produce nighttime magnetic fields at satellite altitude of up to 5-7 nT during solar maximum, 2-3 nT during solar minimum, and are highly correlated with in situ electron density measurements. We also find these currents are self-correlated above 70% up to 15° longitude in both hemispheres during the evening.

Utilizing Free and Open Source Software to access, view and compare in situ observations, EO products and model output data

NASA Astrophysics Data System (ADS)

Vines, Aleksander; Hamre, Torill; Lygre, Kjetil

2014-05-01

The GreenSeas project (Development of global plankton data base and model system for eco-climate early warning) aims to advance the knowledge and predictive capacities of how marine ecosystems will respond to global change. A main task has been to set up a data delivery and monitoring core service following the open and free data access policy implemented in the Global Monitoring for the Environment and Security (GMES) programme. The aim is to ensure open and free access to historical plankton data, new data (EO products and in situ measurements), model data (including estimates of simulation error) and biological, environmental and climatic indicators to a range of stakeholders, such as scientists, policy makers and environmental managers. To this end, we have developed a geo-spatial database of both historical and new in situ physical, biological and chemical parameters for the Southern Ocean, Atlantic, Nordic Seas and the Arctic, and organized related satellite-derived quantities and model forecasts in a joint geo-spatial repository. For easy access to these data, we have implemented a web-based GIS (Geographical Information Systems) where observed, derived and forcasted parameters can be searched, displayed, compared and exported. Model forecasts can also be uploaded dynamically to the system, to allow modelers to quickly compare their results with available in situ and satellite observations. We have implemented the web-based GIS(Geographical Information Systems) system based on free and open source technologies: Thredds Data Server, ncWMS, GeoServer, OpenLayers, PostGIS, Liferay, Apache Tomcat, PRTree, NetCDF-Java, json-simple, Geotoolkit, Highcharts, GeoExt, MapFish, FileSaver, jQuery, jstree and qUnit. We also wanted to used open standards to communicate between the different services and we use WMS, WFS, netCDF, GML, OPeNDAP, JSON, and SLD. The main advantage we got from using FOSS was that we did not have to invent the wheel all over again, but could use already existing code and functionalities on our software for free: Of course most the software did not have to be open source for this, but in some cases we had to do minor modifications to make the different technologies work together. We could extract the parts of the code that we needed for a specific task. One example of this was to use part of the code from ncWMS and Thredds to help our main application to both read netCDF files and present them in the browser. This presentation will focus on both difficulties we had with and advantages we got from developing this tool with FOSS.

Climate Observing Systems: Where are we and where do we need to be in the future

NASA Astrophysics Data System (ADS)

Baker, B.; Diamond, H. J.

2017-12-01

Climate research and monitoring requires an observational strategy that blends long-term, carefully calibrated measurements as well as short-term, focused process studies. The operation and implementation of operational climate observing networks and the provision of related climate services, both have a significant role to play in assisting the development of national climate adaptation policies and in facilitating national economic development. Climate observing systems will require a strong research element for a long time to come. This requires improved observations of the state variables and the ability to set them in a coherent physical (as well as a chemical and biological) framework with models. Climate research and monitoring requires an integrated strategy of land/ocean/atmosphere observations, including both in situ and remote sensing platforms, and modeling and analysis. It is clear that we still need more research and analysis on climate processes, sampling strategies, and processing algorithms.

ARMOR3D: A 3D multi-observations T,S,U,V product of the ocean

NASA Astrophysics Data System (ADS)

Verbrugge, Nathalie; Mulet, Sandrine; Guinehut, Stéphanie; Buongiorno-Nardelli, Bruno

2017-04-01

To have a synoptic view of the 3D ocean to pursue oceanic studies, an observed gridded product can be often useful instead of using raw observations which can be irregularly distributed in space and time as the in situ profiles for instance or which offer only a surface view of the ocean as satellite data. The originality of the ARMOR3D observation based product is to take advantage of the strengths of these 2 types of data by combining satellite SLA, SST, SSS datasets with in situ T, S vertical profiles in order to build a global 3D weekly temperature, salinity and geostrophic velocities fields at a spatial 1/4° resolution. The mesoscale content of the satellite data and the vertical sampling of the in situ profiles are complementary in this statistical approach. ARMOR3D is part of the CMEMS project through the GLO-OBS component. A full reprocessing from 1993 to 2016 and near-real-time fields from 1/1/2014 to present are available through the CMEMS web portal. The range of applications of this product is wide: OSE studies have been already conducted to evaluate the ARGO network and in 2017, OSE and OSSE will be performed in the western Tropical Pacific as part of the TPOS2020 project (Tropical Pacific Observing System for 2020 Pacific). The product is useful also to study mesoscale eddies characteristics as well as links with the biogeochemical processes. For example, in 2015, ARMOR3D fields have been used as inputs of a micronekton model within the framework of the ESA OSMOSIS Project. Furthermore, ARMOR3D also contributes to the annual CMEMS Ocean State Report.

Rocky 7 prototype Mars rover field geology experiments 1. Lavic Lake and sunshine volcanic field, California

USGS Publications Warehouse

Arvidson, R. E.; Acton, C.; Blaney, D.; Bowman, J.; Kim, S.; Klingelhofer, G.; Marshall, J.; Niebur, C.; Plescia, J.; Saunders, R.S.; Ulmer, C.T.

1998-01-01

Experiments with the Rocky 7 rover were performed in the Mojave Desert to better understand how to conduct rover-based, long-distance (kilometers) geological traverses on Mars. The rover was equipped with stereo imaging systems for remote sensing science and hazard avoidance and 57Fe Mo??ssbauer and nuclear magnetic resonance spectrometers for in situ determination of mineralogy of unprepared rock and soil surfaces. Laboratory data were also obtained using the spectrometers and an X ray diffraction (XRD)/XRF instrument for unprepared samples collected from the rover sites. Simulated orbital and descent image data assembled for the test sites were found to be critical for assessing the geologic setting, formulating hypotheses to be tested with rover observations, planning traverses, locating the rover, and providing a regional context for interpretation of rover-based observations. Analyses of remote sensing and in situ observations acquired by the rover confirmed inferences made from orbital and simulated descent images that the Sunshine Volcanic Field is composed of basalt flows. Rover data confirmed the idea that Lavic Lake is a recharge playa and that an alluvial fan composed of sediments with felsic compositions has prograded onto the playa. Rover-based discoveries include the inference that the basalt flows are mantled with aeolian sediment and covered with a dense pavement of varnished basalt cobbles. Results demonstrate that the combination of rover remote sensing and in situ analytical observations will significantly increase our understanding of Mars and provide key connecting links between orbital and descent data and analyses of returned samples. Copyright 1998 by the American Geophysical Union.

Ground-based SMART-COMMIT Measurements for Studying Aerosol and Cloud Properties

NASA Technical Reports Server (NTRS)

Tsay, Si-Chee

2008-01-01

From radiometric principles, it is expected that the retrieved properties of extensive aerosols and clouds from reflected/emitted measurements by satellite (and/or aircraft) should be consistent with those retrieved from transmitted/emitted radiance observed at the surface. Although space-borne remote sensing observations cover large spatial domain, they are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite data sets. The development and deployment of SMARTCOMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile facilities are aimed for the optimal utilization of collocated ground-based observations as constraints to yield higher fidelity satellite retrievals and to determine any sampling bias due to target conditions. To quantify the energetics of the surface-atmosphere system and the atmospheric processes, SMART-COMMIT instruments fall into three categories: flux radiometer, radiance sensor and in-situ probe. In this paper, we will demonstrate the capability of SMART-COMMIT in recent field campaigns (e.g., CRYSTAL-FACE, UAE 2, BASEASIA, NAMMA) that were designed and executed to study the compelling variability in temporal scale of both anthropogenic and natural aerosols (e.g., biomass-burning smoke, airborne dust) and cirrus clouds. We envision robust approaches in which well-collocated ground-based measurements and space-borne observations will greatly advance our knowledge of extensive aerosols and clouds.

Seeing through Musculoskeletal Tissues: Improving In Situ Imaging of Bone and the Lacunar Canalicular System through Optical Clearing

PubMed Central

Berke, Ian M.; Miola, Joseph P.; David, Michael A.; Smith, Melanie K.; Price, Christopher

2016-01-01

In situ, cells of the musculoskeletal system reside within complex and often interconnected 3-D environments. Key to better understanding how 3-D tissue and cellular environments regulate musculoskeletal physiology, homeostasis, and health is the use of robust methodologies for directly visualizing cell-cell and cell-matrix architecture in situ. However, the use of standard optical imaging techniques is often of limited utility in deep imaging of intact musculoskeletal tissues due to the highly scattering nature of biological tissues. Drawing inspiration from recent developments in the deep-tissue imaging field, we describe the application of immersion based optical clearing techniques, which utilize the principle of refractive index (RI) matching between the clearing/mounting media and tissue under observation, to improve the deep, in situ imaging of musculoskeletal tissues. To date, few optical clearing techniques have been applied specifically to musculoskeletal tissues, and a systematic comparison of the clearing ability of optical clearing agents in musculoskeletal tissues has yet to be fully demonstrated. In this study we tested the ability of eight different aqueous and non-aqueous clearing agents, with RIs ranging from 1.45 to 1.56, to optically clear murine knee joints and cortical bone. We demonstrated and quantified the ability of these optical clearing agents to clear musculoskeletal tissues and improve both macro- and micro-scale imaging of musculoskeletal tissue across several imaging modalities (stereomicroscopy, spectroscopy, and one-, and two-photon confocal microscopy) and investigational techniques (dynamic bone labeling and en bloc tissue staining). Based upon these findings we believe that optical clearing, in combination with advanced imaging techniques, has the potential to complement classical musculoskeletal analysis techniques; opening the door for improved in situ investigation and quantification of musculoskeletal tissues. PMID:26930293

Seeing through Musculoskeletal Tissues: Improving In Situ Imaging of Bone and the Lacunar Canalicular System through Optical Clearing.

PubMed

Berke, Ian M; Miola, Joseph P; David, Michael A; Smith, Melanie K; Price, Christopher

2016-01-01

In situ, cells of the musculoskeletal system reside within complex and often interconnected 3-D environments. Key to better understanding how 3-D tissue and cellular environments regulate musculoskeletal physiology, homeostasis, and health is the use of robust methodologies for directly visualizing cell-cell and cell-matrix architecture in situ. However, the use of standard optical imaging techniques is often of limited utility in deep imaging of intact musculoskeletal tissues due to the highly scattering nature of biological tissues. Drawing inspiration from recent developments in the deep-tissue imaging field, we describe the application of immersion based optical clearing techniques, which utilize the principle of refractive index (RI) matching between the clearing/mounting media and tissue under observation, to improve the deep, in situ imaging of musculoskeletal tissues. To date, few optical clearing techniques have been applied specifically to musculoskeletal tissues, and a systematic comparison of the clearing ability of optical clearing agents in musculoskeletal tissues has yet to be fully demonstrated. In this study we tested the ability of eight different aqueous and non-aqueous clearing agents, with RIs ranging from 1.45 to 1.56, to optically clear murine knee joints and cortical bone. We demonstrated and quantified the ability of these optical clearing agents to clear musculoskeletal tissues and improve both macro- and micro-scale imaging of musculoskeletal tissue across several imaging modalities (stereomicroscopy, spectroscopy, and one-, and two-photon confocal microscopy) and investigational techniques (dynamic bone labeling and en bloc tissue staining). Based upon these findings we believe that optical clearing, in combination with advanced imaging techniques, has the potential to complement classical musculoskeletal analysis techniques; opening the door for improved in situ investigation and quantification of musculoskeletal tissues.

Evaluation of multi-mode CryoSat-2 altimetry data over the Po River against in situ data and a hydrodynamic model

NASA Astrophysics Data System (ADS)

Schneider, Raphael; Tarpanelli, Angelica; Nielsen, Karina; Madsen, Henrik; Bauer-Gottwein, Peter

2018-02-01

Coverage of in situ observations to monitor surface waters is insufficient on the global scale, and decreasing across the globe. Satellite altimetry has become an increasingly important monitoring technology for continental surface waters. The ESA CryoSat-2 altimetry mission, launched in 2010, has two novel features. (i) The radar altimeter instrument on board of CryoSat-2 is operated in three modes; two of them reduce the altimeter footprint by using Delay-Doppler processing. (ii) CryoSat-2 is placed on a distinct orbit with a repeat cycle of 369 days, leading to a drifting ground track pattern. The drifting ground track pattern challenges many common methods of processing satellite altimetry data over rivers. This study evaluates the observation error of CryoSat-2 water level observations over the Po River, Italy, against in situ observations. The average RMSE between CryoSat-2 and in situ observations was found to be 0.38 meters. CryoSat-2 was also shown to be useful for channel roughness calibration in a hydrodynamic model of the Po River. The small across-track distance of CryoSat-2 means that observations are distributed almost continuously along the river. This allowed resolving channel roughness with higher spatial resolution than possible with in situ or virtual station altimetry data. Despite the Po River being extensively monitored, CryoSat-2 still provides added value thanks to its unique spatio-temporal sampling pattern.

Simultaneous observations of structure function parameter of refractive index using a high-resolution radar and the DataHawk small airborne measurement system

NASA Astrophysics Data System (ADS)

Scipión, Danny E.; Lawrence, Dale A.; Milla, Marco A.; Woodman, Ronald F.; Lume, Diego A.; Balsley, Ben B.

2016-09-01

The SOUSY (SOUnding SYstem) radar was relocated to the Jicamarca Radio Observatory (JRO) near Lima, Peru, in 2000, where the radar controller and acquisition system were upgraded with state-of-the-art parts to take full advantage of its potential for high-resolution atmospheric sounding. Due to its broad bandwidth (4 MHz), it is able to characterize clear-air backscattering with high range resolution (37.5 m). A campaign conducted at JRO in July 2014 aimed to characterize the lower troposphere with a high temporal resolution (8.1 Hz) using the DataHawk (DH) small unmanned aircraft system, which provides in situ atmospheric measurements at scales as small as 1 m in the lower troposphere and can be GPS-guided to obtain measurements within the beam of the radar. This was a unique opportunity to make coincident observations by both systems and to directly compare their in situ and remotely sensed parameters. Because SOUSY only points vertically, it is only possible to retrieve vertical radar profiles caused by changes in the refractive index within the resolution volume. Turbulent variations due to scattering are described by the structure function parameter of refractive index Cn2. Profiles of Cn2 from the DH are obtained by combining pressure, temperature, and relative humidity measurements along the helical trajectory and integrated at the same scale as the radar range resolution. Excellent agreement is observed between the Cn2 estimates obtained from the DH and SOUSY in the overlapping measurement regime from 1200 m up to 4200 m above sea level, and this correspondence provides the first accurate calibration of the SOUSY radar for measuring Cn2.

Characterization of the Aerosol Instrument Package for the In-service Aircraft Global Observing System IAGOS

NASA Astrophysics Data System (ADS)

Bundke, Ulrich; Berg, Marcel; Tettig, Frank; Franke, Harald; Petzold, Andreas

2015-04-01

The atmospheric aerosol influences the climate twofold via the direct interaction with solar radiation and indirectly effecting microphysical properties of clouds. The latter has the largest uncertainty according to the last IPPC Report. A measured in situ climatology of the aerosol microphysical properties is needed to reduce the reported uncertainty of the aerosol climate impact. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. The IAGOS Aerosol Package (IAGOS-P2C) consists of two modified Butanol based CPCs (Model Grimm 5.410) and one optical particle counter (Model Grimm Sky OPC 1.129). A thermodenuder at 250°C is placed upstream the second CPC, thus the number concentrations of the total aerosol and the non-volatile aerosol fraction is measured. The Sky OPC measures the size distribution in the rage theoretically up to 32 μ m. Because of the inlet cut off diameter of D50=3 μ m we are using the 16 channel mode in the range of 250 nm - 2.5 μ m at 1 Hz resolution. In this presentation the IAGOS Aerosol package is characterized for pressure levels relevant for the planned application, down to cruising level of 150 hPa including the inlet system. In our aerosol lab we have tested the system against standard instrumentation with different aerosol test substances in a long duration test. Particle losses are characterized for the inlet system. In addition first results for airborne measurements are shown from a first field campaign.

Application of Fiber Optic ATR-FTIR Methods for In Situ Characterization of Protein Delivery Systems in Real Time

PubMed Central

McFearin, Cathryn L.; Sankaranarayanan, Jagadis; Almutairi, Adah

2011-01-01

Real Time Characterization of Protein Delivery Systems A fiber optic coupled ATR-FTIR spectroscopy technique was applied to the study of two different therapeutic delivery systems, acid degradable hydrogels and nanoparticles. Real time exponential release of a model protein, human serum albumin (HSA), was observed from two different polymeric hydrogels formulated with a pH sensitive crosslinker. Spectroscopic examination of nanoparticles formulated with an acid degradable polymer shell and encapsulated HSA exhibited vibrational signatures characteristic of both particle and payload when exposed to lowered pH conditions demonstrating the ability of this methodology to simultaneously measure phenomena arising from a system with a mixture of components. In addition, thorough characterization of these pH sensitive delivery vehicles without encapsulated protein was also accomplished in order to separate the effects of the payload during degradation. By providing in situ, real time detection in combination with the ability to specifically identify different components in a mixture without involved sample preparation and minimal sample disturbance, the versatility and suitability of this type of experiment for research in the pharmaceutical field is demonstrated. PMID:21476582

[Observation in situ of differentiation from PGC to hematopoietic system cells in chicken embryo].

PubMed

Zhou, Dong-Yu; Liu, Rong-Xiu; Pei, Yue-Hu

2009-02-01

To study the relationship between hematopoiesis and primordial germ cells, chick embryos at different developing stages were flatbed and located. After fixed by glutaral, the embryos were PAS and HE stained respectively, dehydrated serially, transparent, mounted, and were observed in situ or in cut sheet condition. The results showed: (1) the cellule amorphous and the disposition in chick embryo of PGCs were coincident no matter stained by PAS or HE staining, and HE staining could disclose the morphologic characteristics more clearly, exactly and completely; (2) genesis of blood island could be observed at the boundary of light and dark region of the extraembryonic blastoderm at about 26 hours; (3) both the blood vessel endothelium cells and free cells of the blood island were differentiated from PGCs. The generating of genuine yolk sac was at about 44 - 48 hours. It is concluded that the initial anatomic site of blood island genesis may be is mesoblast of extraembryonic blastoderm rather than the yolk sac; the blood vessel endothelium cells and the blood cells are generated parallel; the PGCs are the common ancestry of angioblast and HSC.

Time-Lapse, in Situ Imaging of Ice Crystal Growth Using Confocal Microscopy

PubMed Central

2016-01-01

Ice crystals nucleate and grow when a water solution is cooled below its freezing point. The growth velocities and morphologies of the ice crystals depend on many parameters, such as the temperature of ice growth, the melting temperature, and the interactions of solutes with the growing crystals. Three types of morphologies may appear: dendritic, cellular (or fingerlike), or the faceted equilibrium form. Understanding and controlling which type of morphology is formed is essential in several domains, from biology to geophysics and materials science. Obtaining, in situ, three dimensional observations without introducing artifacts due to the experimental technique is nevertheless challenging. Here we show how we can use laser scanning confocal microscopy to follow in real-time the growth of smoothed and faceted ice crystals in zirconium acetate solutions. Both qualitative and quantitative observations can be made. In particular, we can precisely measure the lateral growth velocity of the crystals, a measure otherwise difficult to obtain. Such observations should help us understand the influence of the parameters that control the growth of ice crystals in various systems. PMID:27917410

Time-Lapse, in Situ Imaging of Ice Crystal Growth Using Confocal Microscopy.

PubMed

Marcellini, Moreno; Noirjean, Cecile; Dedovets, Dmytro; Maria, Juliette; Deville, Sylvain

2016-11-30

Ice crystals nucleate and grow when a water solution is cooled below its freezing point. The growth velocities and morphologies of the ice crystals depend on many parameters, such as the temperature of ice growth, the melting temperature, and the interactions of solutes with the growing crystals. Three types of morphologies may appear: dendritic, cellular (or fingerlike), or the faceted equilibrium form. Understanding and controlling which type of morphology is formed is essential in several domains, from biology to geophysics and materials science. Obtaining, in situ, three dimensional observations without introducing artifacts due to the experimental technique is nevertheless challenging. Here we show how we can use laser scanning confocal microscopy to follow in real-time the growth of smoothed and faceted ice crystals in zirconium acetate solutions. Both qualitative and quantitative observations can be made. In particular, we can precisely measure the lateral growth velocity of the crystals, a measure otherwise difficult to obtain. Such observations should help us understand the influence of the parameters that control the growth of ice crystals in various systems.

Application of in situ polymerization for design and development of oral drug delivery systems.

PubMed

Ngwuluka, Ndidi

2010-12-01

Although preformed polymers are commercially available for use in the design and development of drug delivery systems, in situ polymerization has also been employed. In situ polymerization affords the platform to tailor and optimize the drug delivery properties of polymers. This review brings to light the benefits of in situ polymerization for oral drug delivery and the possibilities it provides to overcome the challenges of oral route of administration.

In situ measurement on TSV-Cu deformation with hotplate system based on sheet resistance

NASA Astrophysics Data System (ADS)

Sun, Yunna; Wang, Bo; Wang, Huiying; Wu, Kaifeng; Yang, Shengyong; Wang, Yan; Ding, Guifu

2017-12-01

The in situ measurement of TSVs deformation at different temperature is meaningful for learning more about the thermal deformation schemes of 3D TSVs in the microelectronic devices. An efficient and smart hotplate based on sheet resistance is designed for offering more heat, producing a uniform temperature distribution, relieving thermal stress and heat concentration issues, and reducing room space, which was optimized by the finite element method (FEM). The fabricated hotplate is efficient and smart (2.5 cm  ×  2.0 cm  ×  0.5 cm) enough to be located in the limited space during measuring. The thermal infrared imager was employed as the temperature sensor for monitoring the temperature distribution of TSVs sample. The 3D profilometry was adopted as the observer for TSVs profiles survey. The in situ 2D top surface profiles and 3D displacement profiles of TSVs sample at the different temperature were measured by 3D profilometer. The in situ average relative deformation and effective plastic deformation of the TSV sample were measured. With optical measurement method, 3D profilometry, the TSV sample can be tested repeatedly.

High-Resolution in Situ Measurement of Nitrate in Runoff from the Greenland Ice Sheet.

PubMed

Beaton, Alexander D; Wadham, Jemma L; Hawkings, Jon; Bagshaw, Elizabeth A; Lamarche-Gagnon, Guillaume; Mowlem, Matthew C; Tranter, Martyn

2017-11-07

We report the first in situ high-resolution nitrate time series from two proglacial meltwater rivers draining the Greenland Ice Sheet, using a recently developed submersible analyzer based on lab-on-chip (LOC) technology. The low sample volume (320 μL) required by the LOC analyzer meant that low concentration (few micromolar to submicromolar), highly turbid subglacial meltwater could be filtered and colorimetrically analyzed in situ. Nitrate concentrations in rivers draining Leverett Glacier in southwest Greenland and Kiattuut Sermiat in southern Greenland exhibited a clear diurnal signal and a gradual decline at the commencement of the melt season, displaying trends that would not be discernible using traditional daily manual sampling. Nitrate concentrations varied by 4.4 μM (±0.2 μM) over a 10 day period at Kiattuut Sermiat and 3.0 μM (±0.2 μM) over a 14 day period at Leverett Glacier. Marked changes in nitrate concentrations were observed when discharge began to increase. High-resolution in situ measurements such as these have the potential to significantly advance the understanding of nutrient cycling in remote systems, where the dynamics of nutrient release are complex but are important for downstream biogeochemical cycles.

Growth and Properties of Lattice Matched GaAsSbN Epilayer on GaAs for Solar Cell Applications

NASA Technical Reports Server (NTRS)

Bharatan, Sudhakar; Iyer, Shanthi; Matney, Kevin; Collis, Ward J.; Nunna Kalyan; Li, Jia; Wu, Liangjin; McGuire, Kristopher; McNeil, Laurie E.

2006-01-01

The growth and properties of GaAsSbN single quantum wells (SQWs) are investigated in this work. The heterostructures were grown on GaAs substrates in an elemental solid source molecular beam epitaxy (MBE) system assisted with a RF plasma nitrogen source. A systematic study has been carried out to determine the influence of various growth conditions, such as the growth temperature and the source shutter-opening sequence, on the quality of the grown layers and the incorporation of N and Sb. The effects of ex situ and in situ annealing under As overpressure on the optical properties of the layers have also been investigated. Substrate temperature in the range of 450-470 C was found to be optimum. Simultaneous opening of the source shutters was found to yield sharper QW interfaces. N and Sb incorporations were found to depend strongly upon substrate temperatures and source shutter opening sequences. A significant increase in PL intensity with a narrowing of PL line shape and blue shift in emission energy were observed on annealing the GaAsSbN/GaAs SQW, with in situ annealing under As overpressure providing better results, compared to ex situ annealing.

How well do satellite observations and models capture diurnal variation in aerosols over the Korean Peninsula?

NASA Astrophysics Data System (ADS)

Hyer, E. J.; Xian, P.; Campbell, J. R.

2016-12-01

Aerosol sources, sinks, and transport processes have important variations over the diurnal cycle. Advances in geostationary satellite observation have made it possible to retrieve aerosol properties over a larger fraction of the diurnal cycle in many areas. However, the conditions for retrieval of aerosol from space also have systematic diurnal variation, which must be considered when interpreting satellite data. We used surface PM2.5 observations from the Korean National Institute for Environmental Research, together with the dense network of AERONET sun photometers deployed in Korea for the KORUS-AQ mission in spring 2016, to examine diurnal variations in aerosol conditions and quantify the effect of systematic diurnal processes on daily integrated aerosol quantities of forcing and PM2.5 24-hour exposure. Time-resolved observations of aerosols from in situ data were compared to polar and geostationary satellite observations to evaluate these questions: 1) How well is diurnal variation observed in situ captured by satellite products? 2) Do the satellite products show evidence of systematic biases related to diurnally varying observing conditions? 3) What is the implication of diurnal variation for aerosol forcing estimates based on observations near solar noon? The diurnal variation diagnosed from observations was also compared to the output of the Navy Aerosol Analysis and Prediction System (NAAPS), to examine the ability of this model to capture aerosol diurnal variation. Finally, we discuss the implications of the observed diurnal variation for assimilation of aerosol observations into forecast models.

In situ laser-induced breakdown spectroscopy measurements of chemical compositions in stainless steels during tungsten inert gas welding

NASA Astrophysics Data System (ADS)

Taparli, Ugur Alp; Jacobsen, Lars; Griesche, Axel; Michalik, Katarzyna; Mory, David; Kannengiesser, Thomas

2018-01-01

A laser-induced breakdown spectroscopy (LIBS) system was combined with a bead-on-plate Tungsten Inert Gas (TIG) welding process for the in situ measurement of chemical compositions in austenitic stainless steels during welding. Monitoring the weld pool's chemical composition allows governing the weld pool solidification behavior, and thus enables the reduction of susceptibility to weld defects. Conventional inspection methods for weld seams (e.g. ultrasonic inspection) cannot be performed during the welding process. The analysis system also allows in situ study of the correlation between the occurrence of weld defects and changes in the chemical composition in the weld pool or in the two-phase region where solid and liquid phase coexist. First experiments showed that both the shielding Ar gas and the welding arc plasma have a significant effect on the selected Cr II, Ni II and Mn II characteristic emissions, namely an artificial increase of intensity values via unspecific emission in the spectra. In situ investigations showed that this artificial intensity increase reached a maximum in presence of weld plume. Moreover, an explicit decay has been observed with the termination of the welding plume due to infrared radiation during sample cooling. Furthermore, LIBS can be used after welding to map element distribution. For austenitic stainless steels, Mn accumulations on both sides of the weld could be detected between the heat affected zone (HAZ) and the base material.

Quantifying Spatial and Seasonal Variability in Atmospheric Ammonia with In Situ and Space-Based Observations

EPA Science Inventory

Ammonia plays an important role in many biogeochemical processes, yet atmospheric mixing ratios arc not well known. Recently, methods have been developed for retrieving NH₃ from space-based observations, but they have not been compared to in situ measurements. We have ...

An Inversion Analysis of Recent Variability in Natural CO2 Fluxes Using GOSAT and In Situ Observations

NASA Astrophysics Data System (ADS)

Wang, J. S.; Kawa, S. R.; Baker, D. F.; Collatz, G. J.; Ott, L. E.

2015-12-01

About one-half of the global CO2 emissions from fossil fuel combustion and deforestation accumulates in the atmosphere, where it contributes to global warming. The rest is taken up by vegetation and the ocean. The precise contribution of the two sinks, and their location and year-to-year variability are, however, not well understood. We use two different approaches, batch Bayesian synthesis inversion and variational data assimilation, to deduce the global spatiotemporal distributions of CO2 fluxes during 2009-2010. One of our objectives is to assess different sources of uncertainties in inferred fluxes, including uncertainties in prior flux estimates and observations, and differences in inversion techniques. For prior constraints, we utilize fluxes and uncertainties from the CASA-GFED model of the terrestrial biosphere and biomass burning driven by satellite observations and interannually varying meteorology. We also use measurement-based ocean flux estimates and two sets of fixed fossil CO2 emissions. Here, our inversions incorporate column CO2 measurements from the GOSAT satellite (ACOS retrieval, filtered and bias-corrected) and in situ observations (individual flask and afternoon-average continuous observations) to estimate fluxes in 108 regions over 8-day intervals for the batch inversion and at 3° x 3.75° weekly for the variational system. Relationships between fluxes and atmospheric concentrations are derived consistently for the two inversion systems using the PCTM atmospheric transport model driven by meteorology from the MERRA reanalysis. We compare the posterior fluxes and uncertainties derived using different data sets and the two inversion approaches, and evaluate the posterior atmospheric concentrations against independent data including aircraft measurements. The optimized fluxes generally resemble those from other studies. For example, the results indicate that the terrestrial biosphere is a net CO2 sink, and a GOSAT-only inversion suggests a shift in the global sink from the tropics/south to the north relative to the prior and to an in-situ-only inversion. We also find a smaller terrestrial sink in higher-latitude northern regions in boreal summer of 2010 relative to 2009.

An Inversion Analysis of Recent Variability in Natural CO2 Fluxes Using GOSAT and In Situ Observations

NASA Technical Reports Server (NTRS)

Wang, James S.; Kawa, S. Randolph; Collatz, G. James; Baker, David F.; Ott, Lesley

2015-01-01

About one-half of the global CO2 emissions from fossil fuel combustion and deforestation accumulates in the atmosphere, where it contributes to global warming. The rest is taken up by vegetation and the ocean. The precise contribution of the two sinks, and their location and year-to-year variability are, however, not well understood. We use two different approaches, batch Bayesian synthesis inversion and variational data assimilation, to deduce the global spatiotemporal distributions of CO2 fluxes during 2009-2010. One of our objectives is to assess different sources of uncertainties in inferred fluxes, including uncertainties in prior flux estimates and observations, and differences in inversion techniques. For prior constraints, we utilize fluxes and uncertainties from the CASA-GFED model of the terrestrial biosphere and biomass burning driven by satellite observations and interannually varying meteorology. We also use measurement-based ocean flux estimates and two sets of fixed fossil CO2 emissions. Here, our inversions incorporate column CO2 measurements from the GOSAT satellite (ACOS retrieval, filtered and bias-corrected) and in situ observations (individual flask and afternoon-average continuous observations) to estimate fluxes in 108 regions over 8-day intervals for the batch inversion and at 3 x 3.75 weekly for the variational system. Relationships between fluxes and atmospheric concentrations are derived consistently for the two inversion systems using the PCTM atmospheric transport model driven by meteorology from the MERRA reanalysis. We compare the posterior fluxes and uncertainties derived using different data sets and the two inversion approaches, and evaluate the posterior atmospheric concentrations against independent data including aircraft measurements. The optimized fluxes generally resemble those from other studies. For example, the results indicate that the terrestrial biosphere is a net CO2 sink, and a GOSAT-only inversion suggests a shift in the global sink from the tropics south to the north relative to the prior and to an in-situ-only inversion. We also find a smaller terrestrial sink in higher-latitude northern regions in boreal summer of 2010 relative to 2009.

Carbon contamination analysis and its effect on extreme ultra violet mask imaging performance using coherent scattering microscopy/in-situ accelerated contamination system.

PubMed

Jeong, Chang Young; Lee, Sangsul; Doh, Jong Gul; Lee, Jae Uk; Cha, Han-sun; Nichols, William T; Lee, Dong Gun; Kim, Seong Sue; Cho, Han Ku; Rah, Seung-yu; Ahn, Jinho

2011-07-01

The coherent scattering microscopy/in-situ accelerated contamination system (CSM/ICS) is a developmental metrology tool designed to analyze the impact of carbon contamination on the imaging performance. It was installed at 11B EUVL beam-line of the Pohang Accelerator Laboratory (PAL). Monochromatized 13.5 nm wavelength beam with Mo/Si multilayer mirrors and zirconium filters was used. The CSM/ICS is composed of the CSM for measuring imaging properties and the ICS for implementing acceleration of carbon contamination. The CSM has been proposed as an actinic inspection technique that records the coherent diffraction pattern from the EUV mask and reconstructs its aerial image using a phase retrieval algorithm. To improve the CSM measurement accuracy, optical and electrical noises of main chamber were minimized. The background noise level measured by CCD camera was approximately 8.5 counts (3 sigma) when the EUV beam was off. Actinic CD measurement repeatability was <1 A (3 sigma) at 17.5 nm line and space pattern. The influence of carbon contamination on the imaging properties can be analyzed by transferring EUV mask to CSM imaging center position after executing carbon contamination without a fine alignment system. We also installed photodiode and ellipsometry for in-situ reflectivity and thickness measurement. This paper describes optical design and system performance observed during the first phase of integration, including CSM imaging performance and carbon contamination analysis results.

In situ observation of the water-sediment interface in combined sewers, using endoscopy.

PubMed

Oms, C; Gromaire, M C; Chebbo, G

2003-01-01

A new method for water-sediment interface observation has been designed. This system is based on a small diameter endoscope protected by a graduated plastic tube. It makes it possible to visualise in a non-destructive manner the sediments and the water-sediment interface. The endoscope was used to investigate Le Marais catchment (Paris): an immobile organic layer was observed at the water-sediment interface. This layer appears in pools of gross bed sediment, at the upstream of collectors, in zones where velocity is slow and where bed shear stress is less than 0.03 N/m2.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Juan; Zhou, Yufan; Sui, Xiao

Switchable ionic liquids (SWIL) play an important role in green chemistry. Due to the nature of SWIL chemistry, such as air sensitivity and pressure and temperature dependence, it is difficult to characterize SWIL using vacuum-based surface techniques. The fully CO2 loaded and none-loaded DBU and hexanol mixtures, a SWIL system, were analyzed in situ by time-of-flight secondary ion mass spectrometry (ToF-SIMS) coupled with the System for Analysis at the Liquid Vacuum Interface (SALVI), respectively. The DBU/Hexanol/CO2 SWIL was injected into the microchannel before liquid SIMS analysis. Bi3+ primary ion beam was used. The positive and negative spectra of the SWILmore » chemical components are presented. The characteristic peaks m/z 153 (reduced DBU) in the positive mode and m/z 101 (oxidized hexanol) in negative mode were observed. In addition, ion pair peaks including m/z 253, 319, 305, 451 in the positive mode and m/z 145, 223, 257 in the negative mode are first observed using this approach. These results demonstrate that the SALVI microfluidic reactor enables the vacuum-based surface technique (i.e., ToF-SIMS) for in situ characterization of challenging liquid samples such as ionic liquids.« less

Constraining Aggregate-Scale Solar Energy Partitioning in Arctic Sea Ice Through Synthesis of Remote Sensing and Autonomous In-Situ Observations.

NASA Astrophysics Data System (ADS)

Wright, N.; Polashenski, C. M.; Deeb, E. J.; Morriss, B. F.; Song, A.; Chen, J.

2015-12-01

One of the key processes controlling sea ice mass balance in the Arctic is the partitioning of solar energy between reflection back to the atmosphere and absorption into the ice and upper ocean. We investigate the solar energy balance in the ice-ocean system using in-situ data collected from Arctic Observing Network (AON) sea ice sites and imagery from high resolution optical satellites. AON assets, including ice mass balance buoys and ice tethered profilers, monitor the storage and fluxes of heat in the ice-ocean system. High resolution satellite imagery, processed using object-based image classification techniques, allows us to quantify the evolution of surrounding ice conditions, including melt pond coverage and floe size distribution, at aggregate scale. We present results from regionally representative sites that constrain the partitioning of absorbed solar energy between ice melt and ocean storage, and quantify the strength of the ice-albedo feedback. We further demonstrate how the results can be used to validate model representations of the physical processes controlling ice-albedo feedbacks. The techniques can be extended to understand solar partitioning across the Arctic basin using additional sites and model based data integration.

Ultraviolet-Visible (UV-Vis) Microspectroscopic System Designed for the In Situ Characterization of the Dehydrogenation Reaction Over Platinum Supported Catalytic Microchannel Reactor.

PubMed

Suarnaba, Emee Grace Tabares; Lee, Yi Fuan; Yamada, Hiroshi; Tagawa, Tomohiko

2016-11-01

An ultraviolet visible (UV-Vis) microspectroscopic system was designed for the in situ characterization of the activity of the silica supported platinum (Pt) catalyst toward the dehydrogenation of 1-methyl-1,4-cyclohexadiene carried out in a custom-designed catalytic microreactor cell. The in situ catalytic microreactor cell (ICMC) with inlet/outlet ports was prepared using quartz cover as the optical window to facilitate UV-Vis observation. A fabricated thermometric stage was adapted to the UV-Vis microspectrophotometer to control the reaction temperature inside the ICMC. The spectra were collected by focusing the UV-Vis beam on a 30 × 30 µm area at the center of ICMC. At 393 K, the sequential measurement of the spectra recorded during the reaction exhibited a broad absorption peak with maximum absorbance at 260 nm that is characteristic for gaseous toluene. This result indicates that the silica supported Pt catalyst is active towards the dehydrogenation of 1-methyl-1,4-cyclohexadiene at the given experimental conditions. The onset of coke formation was also detected based on the appearance of absorption bands at 300 nm. The UV-Vis microspectroscopic system developed can be used further in studying the mechanism of the dehydrogenation reaction. © The Author(s) 2016.

Magnesium degradation observed in situ under flow by synchrotron radiation based microtomography

NASA Astrophysics Data System (ADS)

Feyerabend, Frank; Dose, Thomas; Xu, Yuling; Beckmann, Felix; Stekker, Michael; Willumeit-Römer, Regine; Schreyer, Andreas; Wilde, Fabian; Hammel, Jörg U.

2016-10-01

The use of degradable magnesium based implants is becoming clinically relevant, e.g. for the use as bone screws. Still there is a lack of analyzing techniques to characterize the in vitro degradation behavior of implant prototypes. The aim of this study was to design an in situ environment to continuously monitor the degradation processes under physiological conditions by time-lapse SRμCT. The use of physiological conditions was chosen to get a better approach to the in vivo situation, as it could be shown by many studies, that these conditions change on the one hand the degradation rate and on the other hand also the formed degradation products. The resulting in situ environment contains a closed bioreactor system to control and monitor the relevant parameters (37°C, 5 % O2, 20 % CO2) and to grant sterility of the setup. A flow cell was designed and manufactured from polyether etherketone (PEEK), which was chosen because of the good mechanical properties, high thermal and chemical resistance and radiographic translucency. Sterilization of the system including the sample was reached by a transient flush with 70 % ethanol and subsequent replacement by physiological medium (Modified Eagle Medium alpha). As proof of principle it could be shown that the system remained sterile during a beamtime of several days and that the continuous SRμCT imaging was feasible.

Temperature-responsive and biodegradable PVA:PVP k30:poloxamer 407 hydrogel for controlled delivery of human growth hormone (hGH).

PubMed

Taheri, Azade; Atyabi, Fatemeh; Dinarvnd, Rassoul

2011-01-01

Recombinant human growth hormone (rhGH) is used for replacement therapy of pediatric hypopituitary dwarfism. Growth rate in children was observed to be better on the daily injection schedule compared with the currently used therapeutic regimen of thrice a week injection. Thus, a controlled release formulation would overcome the drawback of traditional rhGH therapy such as the need for multiple injections. Poloxamers are a family of triblock copolymers consisting of two hydrophilic blocks of polyoxyethylene separated by a hydrophobic block of polyoxypropylene, which form micelles at low concentrations and form clear thermally reversible gels at high concentrations. We used poloxamer gels to develop a controlled release formulation of hGH. The objective of this study was to develop an in situ gel forming drug delivery system for hGH using the minimum possible ratio of poloxamer 407 (P407). Decreasing the concentration of poloxamer could reduce the risk of hypertriglyceridemia induction. Different additives were added to the poloxamer formulations. It was observed that among different additives polyvinylpyrrolidone k30 (PVP k30) and polyvinyl alcohol (PVA) decrease poloxamer concentration required to form in situ gelation from 18% to 10%. The dynamic viscoelastic properties of the samples were determined. Both the storage modulus and the loss modulus of the samples increased abruptly as the temperature passed a certain point. It can be concluded that combining P407 and PVP and PVA could be a promising strategy for preparation of thermally reversible in situ gel forming delivery systems of hGH with low poloxamer concentration.

CYGNSS Surface Wind Validation and Characteristics in the Maritime Continent

NASA Astrophysics Data System (ADS)

Asharaf, S.; Waliser, D. E.; Zhang, C.; Wandala, A.

2017-12-01

Surface wind over tropical oceans plays a crucial role in many local/regional weather and climate processes and helps to shape the global climate system. However, there is a lack of consistent high quality observations for surface winds. The newly launched NASA Cyclone Global Navigation Satellite System (CYGNSS) mission provides near surface wind speed over the tropical ocean with sampling that accounts for the diurnal cycle. In the early phase of the mission, validation is a critical task, and over-ocean validation is typically challenging due to a lack of robust validation resources that a cover a variety of environmental conditions. In addition, it can also be challenging to obtain in-situ observation resources and also to extract co-located CYGNSS records for some of the more scientifically interesting regions, such as the Maritime Continent (MC). The MC is regarded as a key tropical driver for the mean global circulation as well as important large-scale circulation variability such as the Madian-Julian Oscillation (MJO). The focus of this project and analysis is to take advantage of local in-situ resources from the MC regions (e.g. volunteer shipping, marine buoys, and the Year of Maritime Continent (YMC) campaign) to quantitatively characterize and validate the CYGNSS derived winds in the MC region and in turn work to unravel the complex multi-scale interactions between the MJO and MC. This presentation will show preliminary results of a comparison between the CYGNSS and the in-situ surface wind measurements focusing on the MC region. Details about the validation methods, uncertainties, and planned work will be discussed in this presentation.

In situ stress observation in oxide films and how tensile stress influences oxygen ion conduction

PubMed Central

Fluri, Aline; Pergolesi, Daniele; Roddatis, Vladimir; Wokaun, Alexander; Lippert, Thomas

2016-01-01

Many properties of materials can be changed by varying the interatomic distances in the crystal lattice by applying stress. Ideal model systems for investigations are heteroepitaxial thin films where lattice distortions can be induced by the crystallographic mismatch with the substrate. Here we describe an in situ simultaneous diagnostic of growth mode and stress during pulsed laser deposition of oxide thin films. The stress state and evolution up to the relaxation onset are monitored during the growth of oxygen ion conducting Ce0.85Sm0.15O2-δ thin films via optical wafer curvature measurements. Increasing tensile stress lowers the activation energy for charge transport and a thorough characterization of stress and morphology allows quantifying this effect using samples with the conductive properties of single crystals. The combined in situ application of optical deflectometry and electron diffraction provides an invaluable tool for strain engineering in Materials Science to fabricate novel devices with intriguing functionalities. PMID:26912416

Highly water-absorbing silk yarn with interpenetrating network via in situ polymerization.

PubMed

Lee, Ka I; Wang, Xiaowen; Guo, Xia; Yung, Ka-Fu; Fei, Bin

2017-02-01

Silk was modified via in situ polymerization of two monomers acrylamide and sodium acrylate by swelling in an effective LiBr dissolution system. Swelling of natural silks in LiBr solutions of low concentration was clearly observed under optical microscope, and their conformational changes were revealed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Dissolution tests and FTIR spectra of these modified silks suggested the presence of interpenetrating network of polyacrylamide and poly(sodium acrylate) in the silk yarns. These modified silks exhibited superior water absorption to that of raw silk and greatly improved mechanical properties in both dry and wet states. These novel modified silks also showed low cytotoxicity towards skin keratinocytes, having potential applications in biomedical textiles. This modification method by in situ polymerization after swelling in LiBr provides a new route to highly enhance the properties and performance of silk for various applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Superconducting-Magnet-Based Faraday Rotation Spectrometer for Real Time in Situ Measurement of OH Radicals at 106 Molecule/cm3 Level in an Atmospheric Simulation Chamber.

PubMed

Zhao, Weixiong; Fang, Bo; Lin, Xiaoxiao; Gai, Yanbo; Zhang, Weijun; Chen, Wenge; Chen, Zhiyou; Zhang, Haifeng; Chen, Weidong

2018-03-20

Atmospheric simulation chambers play vital roles in the validation of chemical mechanisms and act as a bridge between field measurements and modeling. Chambers operating at atmospheric levels of OH radicals (10 6 -10 7 molecule/cm 3 ) can significantly enhance the possibility for investigating the discrepancies between the observation and model predications. However, few chambers can directly detect chamber OH radicals at ambient levels. In this paper, we report on the first combination of a superconducting magnet with midinfrared Faraday rotation spectroscopy (FRS) for real time in situ measurement of the OH concentration in an atmospheric simulation chamber. With the use of a multipass enhanced FRS, a detection limit of 3.2 × 10 6 OH/cm 3 (2σ, 4 s) was achieved with an absorption path length of 108 m. The developed FRS system provided a unique, self-calibrated analytical instrument for in situ direct measurement of chamber OH concentration.

Instrumentation for optimizing an underground coal-gasification process

NASA Astrophysics Data System (ADS)

Seabaugh, W.; Zielinski, R. E.

1982-06-01

While the United States has a coal resource base of 6.4 trillion tons, only seven percent is presently recoverable by mining. The process of in-situ gasification can recover another twenty-eight percent of the vast resource, however, viable technology must be developed for effective in-situ recovery. The key to this technology is system that can optimize and control the process in real-time. An instrumentation system is described that optimizes the composition of the injection gas, controls the in-situ process and conditions the product gas for maximum utilization. The key elements of this system are Monsanto PRISM Systems, a real-time analytical system, and a real-time data acquisition and control system. This system provides from complete automation of the process but can easily be overridden by manual control. The use of this cost effective system can provide process optimization and is an effective element in developing a viable in-situ technology.

Critiquing ';pore connectivity' as basis for in situ flow in geothermal systems

NASA Astrophysics Data System (ADS)

Kenedi, C. L.; Leary, P.; Malin, P.

2013-12-01

Geothermal system in situ flow systematics derived from detailed examination of grain-scale structures, fabrics, mineral alteration, and pore connectivity may be extremely misleading if/when extrapolated to reservoir-scale flow structure. In oil/gas field clastic reservoir operations, it is standard to assume that small scale studies of flow fabric - notably the Kozeny-Carman and Archie's Law treatments at the grain-scale and well-log/well-bore sampling of formations/reservoirs at the cm-m scale - are adequate to define the reservoir-scale flow properties. In the case of clastic reservoirs, however, a wide range of reservoir-scale data wholly discredits this extrapolation: Well-log data show that grain-scale fracture density fluctuation power scales inversely with spatial frequency k, S(k) ~ 1/k^β, 1.0 < β < 1.2, 1cycle/km < k < 1cycle/cm; the scaling is a ';universal' feature of well-logs (neutron porosity, sonic velocity, chemical abundance, mass density, resistivity, in many forms of clastic rock and instances of shale bodies, for both horizontal and vertical wells). Grain-scale fracture density correlates with in situ porosity; spatial fluctuations of porosity φ in well-core correlate with spatial fluctuations in the logarithm of well-core permeability, δφ ~ δlog(κ) with typical correlation coefficient ~ 85%; a similar relation is observed in consolidating sediments/clays, indicating a generic coupling between fluid pressure and solid deformation at pore sites. In situ macroscopic flow systems are lognormally distributed according to κ ~ κ0 exp(α(φ-φ0)), α >>1 an empirical parameter for degree of in situ fracture connectivity; the lognormal distribution applies to well-productivities in US oil fields and NZ geothermal fields, ';frack productivity' in oil/gas shale body reservoirs, ore grade distributions, and trace element abundances. Although presently available evidence for these properties in geothermal reservoirs is limited, there are indications that geothermal system flow essentially obeys the same ';universal' in situ flow rules as does clastic rock: Well-log data from Los Azufres, MX, show power-law scaling S(k) ~ 1/k^β, 1.2 < β < 1.4, for spatial frequency range 2cycles/km to 0.5cycle/m; higher β-values are likely due to the relatively fresh nature of geothermal systems; Well-core at Bulalo (PH) and Ohaaki (NZ) show statistically significant spatial correlation, δφ ~ δlog(κ) Well productivity at Ohaaki/Ngawha (NZ) and in geothermal systems elsewhere are lognormally distributed; K/Th/U abundances lognormally distributed in Los Azufres well-logs We therefore caution that small-scale evidence for in situ flow fabric in geothermal systems that is interpreted in terms of ';pore connectivity' may in fact not reflect how small-scale chemical processes are integrated into a large-scale geothermal flow structure. Rather such small scale studies should (perhaps) be considered in term of the above flow rules. These flow rules are easily incorporated into standard flow simulation codes, in particular the OPM = Open Porous Media open-source industry-standard flow code. Geochemical transport data relevant to geothermal systems can thus be expected to be well modeled by OPM or equivalent (e.g., INL/LANL) codes.

In situ TEM of radiation effects in complex ceramics.

PubMed

Lian, Jie; Wang, L M; Sun, Kai; Ewing, Rodney C

2009-03-01

In situ transmission electron microscopy (TEM) has been extensively applied to study radiation effects in a wide variety of materials, such as metals, ceramics and semiconductors and is an indispensable tool in obtaining a fundamental understanding of energetic beam-matter interactions, damage events, and materials' behavior under intense radiation environments. In this article, in situ TEM observations of radiation effects in complex ceramics (e.g., oxides, silicates, and phosphates) subjected to energetic ion and electron irradiations have been summarized with a focus on irradiation-induced microstructural evolution, changes in microchemistry, and the formation of nanostructures. New results for in situ TEM observation of radiation effects in pyrochlore, A(2)B(2)O(7), and zircon, ZrSiO(4), subjected to multiple beam irradiations are presented, and the effects of simultaneous irradiations of alpha-decay and beta-decay on the microstructural evolution of potential nuclear waste forms are discussed. Furthermore, in situ TEM results of radiation effects in a sodium borosilicate glass subjected to electron-beam exposure are introduced to highlight the important applications of advanced analytical TEM techniques, including Z-contrast imaging, energy filtered TEM (EFTEM), and electron energy loss spectroscopy (EELS), in studying radiation effects in materials microstructural evolution and microchemical changes. By combining ex situ TEM and advanced analytical TEM techniques with in situ TEM observations under energetic beam irradiations, one can obtain invaluable information on the phase stability and response behaviors of materials under a wide range of irradiation conditions. (c) 2009 Wiley-Liss, Inc.

Estimating the global terrestrial hydrologic cycle through modeling, remote sensing, and data assimilation

NASA Astrophysics Data System (ADS)

Pan, Ming; Troy, Tara; Sahoo, Alok; Sheffield, Justin; Wood, Eric

2010-05-01

Documentation of the water cycle and its evolution over time is a primary scientific goal of the Global Energy and Water Cycle Experiment (GEWEX) and fundamental to assessing global change impacts. In developed countries, observation systems that include in-situ, remote sensing and modeled data can provide long-term, consistent and generally high quality datasets of water cycle variables. The export of these technologies to less developed regions has been rare, but it is these regions where information on water availability and change is probably most needed in the face of regional environmental change due to climate, land use and water management. In these data sparse regions, in situ data alone are insufficient to develop a comprehensive picture of how the water cycle is changing, and strategies that merge in-situ, model and satellite observations within a framework that results in consistent water cycle records is essential. Such an approach is envisaged by the Global Earth Observing System of Systems (GOESS), but has yet to be applied. The goal of this study is to quantify the variation and changes in the global water cycle over the past 50 years. We evaluate the global water cycle using a variety of independent large-scale datasets of hydrologic variables that are used to bridge the gap between sparse in-situ observations, including remote-sensing based retrievals, observation-forced hydrologic modeling, and weather model reanalyses. A data assimilation framework that blends these disparate sources of information together in a consistent fashion with attention to budget closure is applied to make best estimates of the global water cycle and its variation. The framework consists of a constrained Kalman filter applied to the water budget equation. With imperfect estimates of the water budget components, the equation additionally has an error residual term that is redistributed across the budget components using error statistics, which are estimated from the uncertainties among data products. The constrained Kalman filter treats the budget closure constraint as a perfect observation within the assimilation framework. Precipitation is estimated using gauge observations, reanalysis products, and remote sensing products for below 50°N. Evapotranspiration is estimated in a number of ways: from the VIC land surface hydrologic model forced with a hybrid reanalysis-observation global forcing dataset, from remote sensing retrievals based on a suite of energy balance and process based models, and from an atmospheric water budget approach using reanalysis products for the atmospheric convergence and storage terms and our best estimate for precipitation. Terrestrial water storage changes, including surface and subsurface changes, are estimated using estimates from both VIC and the GRACE remote sensing retrievals. From these components, discharge can then be calculated as a residual of the water budget and compared with gauge observations to evaluate the closure of the water budget. Through the use of these largely independent data products, we estimate both the mean seasonal cycle of the water budget components and their uncertainties for a set of 20 large river basins across the globe. We particularly focus on three regions of interest in global changes studies: the Northern Eurasian region which is experiencing rapid change in terrestrial processes; the Amazon which is a central part of the global water, energy and carbon budgets; and Africa, which is predicted to face some of the most critical challenges for water and food security in the coming decades.

Evolution of the Tropical Cyclone Integrated Data Exchange And Analysis System (TC-IDEAS)

NASA Technical Reports Server (NTRS)

Turk, J.; Chao, Y.; Haddad, Z.; Hristova-Veleva, S.; Knosp, B.; Lambrigtsen, B.; Li, P.; Licata, S.; Poulsen, W.; Su, H.;

Testing space weather connections in the solar system

NASA Astrophysics Data System (ADS)

Grison, B.; Souček, J.; Krupař, V.; Píša, D.; Santolík, O.; Taubenschuss, U.; Němec, F.

2017-09-01

This study aims at testing and validating tools for prediction of the impact of solar events in the vicinity of inner and outer solar system planets using in-situ spacecraft data (primarily MESSENGER, STEREO and ACE, but also VEX and Cassini), remote Jovian observations (Hubble telescope, Nançay decametric array), existing catalogues (HELCATS and Tao et al. (2005)) and the tested propagating models (the ICME radial propagation tool of the CDPP and the 1-D MHD code propagation model presented in Tao et al. (2005)).

Preliminary results of in situ laser-induced breakdown spectroscopy for the first wall diagnostics on EAST

NASA Astrophysics Data System (ADS)

Hu, Zhenhua; Li, Cong; Xiao, Qingmei; Liu, Ping; Fang, Ding; Mao, Hongmin; Wu, Jing; Zhao, Dongye; Ding, Hongbin; Luo, Guang-Nan; EAST Team

2017-02-01

Post-mortem methods cannot fulfill the requirement of monitoring the lifetime of the plasma facing components (PFC) and measuring the tritium inventory for the safety evaluation. Laser-induced breakdown spectroscopy (LIBS) is proposed as a promising method for the in situ study of fuel retention and impurity deposition in a tokamak. In this study, an in situ LIBS system was successfully established on EAST to investigate fuel retention and impurity deposition on the first wall without the need of removal tiles between plasma discharges. Spectral lines of D, H and impurities (Mo, Li, Si, … ) in laser-induced plasma were observed and identified within the wavelength range of 500-700 nm. Qualitative measurements such as thickness of the deposition layers, element depth profile and fuel retention on the wall are obtained by means of in situ LIBS. The results demonstrated the potential applications of LIBS for in situ characterization of fuel retention and co-deposition on the first wall of EAST. Supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB105002, 2015GB109001, and 2013GB109005), National Natural Science Foundation of China (Nos. 11575243, 11605238, 11605023), Chinesisch-Deutsches Forschungs Project (GZ765), and Korea Research Council of Fundamental Science and Technology (KRCF) under the international collaboration & research in Asian countries (PG1314).

Effect of in situ annealing on the structural and electrical properties and infrared photodetection of III-Sb on GaAs using interfacial misfit array

NASA Astrophysics Data System (ADS)

Jia, Bo Wen; Tan, Kian Hua; Loke, Wan Khai; Wicaksono, Satrio; Yoon, Soon Fatt

2018-01-01

This work presents the effects of in situ thermal annealing under antimony overpressure on the structural, electrical, and optical properties of III-Sb (GaSb and InSb) grown on (100) GaAs using an interfacial misfit array to accommodate the lattice mismatch. Both the sample growth and the in situ thermal annealing were carried out in the in the molecular beam epitaxy system, and the temperature of the as-grown sample was increased to exceed its growth temperature during the annealing. X-ray diffraction demonstrates nearly fully relaxed as-grown and annealed III-Sb layers. The optimal annealing temperatures and durations are for 590 °C, 5 min for GaSb and 420 °C, 15 min for InSb, respectively. In situ annealing decreased the surface roughness of the III-Sb layers. X-ray reciprocal space mapping and transmission electron microscopy observation showed stable interfacial misfit arrays, and no interfacial diffusion occurred in the annealed III-Sb layers. A Hall measurement of unintentionally doped III-Sb layers showed greater carrier mobility and a lower carrier concentration in the annealed samples at both 77 and 300 K. In situ annealing improved the photoresponsivity of GaSb and InSb photoconductors grown on GaAs in the near- and mid-infrared ranges, respectively.

The HUMSAT System: a CubeSat-based Constellation for In-situ and Inexpensive Environmental Measurements

NASA Astrophysics Data System (ADS)

Tubío-Pardavila, R.; Vigil, S. A.; Puig-Suari, J.; Aguado Agelet, F.

2014-12-01

There is a requirement for low cost in-situ measurements of environmental parameters such as air quality, meteorological data, and water quality in remote areas. Currently available solutions for such measurements include remote sensing from satellite and aircraft platforms, and in-situ measurements from mobile and aircraft platforms. Fixed systems such as eddy covariance networks, tall towers, and the Total Carbon Column Observing Network (TCCON) are providing precision greenhouse gas measurements. Within this context, the HUMSAT system designed by the University of Vigo (Spain) will complement existing high-precision measurement systems with low cost in-situ ground based sensors in remote locations using a constellation of CubeSats as a communications relay. The HUMSAT system standardizes radio communications in between deployed sensors and the CubeSats of the constellation, which act as store and forward satellites to ground stations for uploading to the internet. Current ground stations have been established at the University of Vigo (Spain) and California Polytechnic State University (Cal Poly). Users of the system may deploy their own environmental sensors to meet local requirements. The sensors will be linked to a low-cost satellite data transceiver using a standard HUMSAT protocol. The transceiver is capable of receiving data from the HUMSAT constellation to remotely reconfigure sensors without the need of physically going to the sensor location. This transceiver uses a UHF channel around 437 MHz to exchange short data messages with the sensors. These data messages can contain up to 32 bytes of useful information and are transmitted at a speed around 300 bps. The protocol designed for this system handles the access to the channel by all these elements and guarantees a correct transmission of the information in such an scenario. The University of Vigo has launched the first satellite of the constellation, the HUMSAT-D CubeSat in November 2013 and has deployed sensors in Spain and Brazil. Sensors will be also deployed by Cal Poly in the near future. In the following months, the SERPENS CubeSAT Mission, a joint project of the University of Brasilia and the University of Vigo will launch the second CubeSat of the constellation.

In situ observation of melting and crystallization of Si on porous Si3N4 substrate that repels Si melt

NASA Astrophysics Data System (ADS)

Itoh, Hironori; Okamura, Hideyuki; Asanoma, Susumu; Ikemura, Kouhei; Nakayama, Masaharu; Komatsu, Ryuichi

2014-09-01

High temperature in situ observation of melting and crystallization of spherical Si droplets on a substrate with a porous surface was carried out for the first time using an original in situ observation apparatus. The contact angle between the Si melt and the substrate was measured to be 160°, with the Si melt forming spherical droplets on the substrate. During crystallization, a ring-like pattern was observed on the surface of the spherical Si melt droplets due to crystal growth at low levels of supercooling. The solidified spherical Si crystals consisted of single or twin grains. This demonstrates that high-quality spherical Si crystals can be prepared easily and stably by using a Si melt-repelling substrate.

Application of Hoffman modulation contrast microscopy coupled with three-wavelength two-beam interferometry to the in situ direct observation of the growth process of a crystal in microgravity

NASA Technical Reports Server (NTRS)

Tsukamoto, Katsuo

1988-01-01

Direct visualization of three dimensional transfer process of both heat and mass around a growing crystal and mono-molecular growth layers on the surface is possible in situ by means of high resolution Hoffman modulation contrast microscopy coupled with three wavelength two beam Mach-Zehnder interferometry. This in situ observation is very suitable for the verification of the growth mechanism of a crystal in a solution or a melt in microgravity.

A GEOS-Based OSSE for the "MISTiC Winds" Concept

NASA Technical Reports Server (NTRS)

McCarty, W.; Blaisdell, J.; Fuentes, M.; Carvalho, D.; Errico, R.; Gelaro, R.; Kouvaris, L.; Moradi, I.; Pawson, S.; Prive, N.;

Experimental system for in-situ measurement of temperature rise in animal tissue under exposure to acoustic radiation force impulse.

PubMed

Nitta, Naotaka; Ishiguro, Yasunao; Sasanuma, Hideki; Taniguchi, Nobuyuki; Akiyama, Iwaki

2015-01-01

Acoustic radiation force impulse (ARFI) has recently been used for tissue elasticity measurement and imaging. On the other hand, it is predicted that a rise in temperature occurs. In-situ measurement of temperature rise in animal experiments is important, yet measurement using thermocouples has some problems such as position mismatch of the temperature measuring junction of the thermocouple and the focal point of ultrasound. Therefore, an in-situ measurement system for solving the above problems was developed in this study. The developed system is composed mainly of an ultrasound irradiation unit including a custom-made focused transducer with a through hole for inserting a thin-wire thermocouple, and a temperature measurement unit including the thermocouple. The feasibility of the developed system was evaluated by means of experiments using a tissue-mimicking material (TMM), a TMM containing a bone model or a chicken bone, and an extracted porcine liver. The similarity between the experimental results and the results of simulation using a finite element method (FEM) implied the reasonableness of in-situ temperature rise measured by the developed system. The developed system will become a useful tool for measuring in-situ temperature rise in animal experiments and obtaining findings with respect to the relationship between ultrasound irradiation conditions and in-situ temperature rise.

Weather Observation Systems and Efficiency of Fighting Forest Fires

NASA Astrophysics Data System (ADS)

Khabarov, N.; Moltchanova, E.; Obersteiner, M.

2007-12-01

Weather observation is an essential component of modern forest fire management systems. Satellite and in-situ based weather observation systems might help to reduce forest loss, human casualties and destruction of economic capital. In this paper, we develop and apply a methodology to assess the benefits of various weather observation systems on reductions of burned area due to early fire detection. In particular, we consider a model where the air patrolling schedule is determined by a fire hazard index. The index is computed from gridded daily weather data for the area covering parts Spain and Portugal. We conduct a number of simulation experiments. First, the resolution of the original data set is artificially reduced. The reduction of the total forest burned area associated with air patrolling based on a finer weather grid indicates the benefit of using higher spatially resolved weather observations. Second, we consider a stochastic model to simulate forest fires and explore the sensitivity of the model with respect to the quality of input data. The analysis of combination of satellite and ground monitoring reveals potential cost saving due to a "system of systems effect" and substantial reduction in burned area. Finally, we estimate the marginal improvement schedule for loss of life and economic capital as a function of the improved fire observing system.

Tropical Cyclone Information System

NASA Technical Reports Server (NTRS)

Li, P. Peggy; Knosp, Brian W.; Vu, Quoc A.; Yi, Chao; Hristova-Veleva, Svetla M.

2009-01-01

The JPL Tropical Cyclone Infor ma tion System (TCIS) is a Web portal (http://tropicalcyclone.jpl.nasa.gov) that provides researchers with an extensive set of observed hurricane parameters together with large-scale and convection resolving model outputs. It provides a comprehensive set of high-resolution satellite (see figure), airborne, and in-situ observations in both image and data formats. Large-scale datasets depict the surrounding environmental parameters such as SST (Sea Surface Temperature) and aerosol loading. Model outputs and analysis tools are provided to evaluate model performance and compare observations from different platforms. The system pertains to the thermodynamic and microphysical structure of the storm, the air-sea interaction processes, and the larger-scale environment as depicted by ocean heat content and the aerosol loading of the environment. Currently, the TCIS is populated with satellite observations of all tropical cyclones observed globally during 2005. There is a plan to extend the database both forward in time till present as well as backward to 1998. The portal is powered by a MySQL database and an Apache/Tomcat Web server on a Linux system. The interactive graphic user interface is provided by Google Map.

In situ electron microscope study of the phase transformation, structure and growth of thin Te1-xSex films

NASA Astrophysics Data System (ADS)

Vermaak, J. S.; Raubenheimer, D.

1988-01-01

An in-situ electron microscope technique was utilized to observe directly the amorphous-to-crystalline phase transformation, the isothermal growth rates, as well as the orientation and structure of the recrystallized films for the Te1-xSex alloy system for x=0.2, 0.3 and 0.4. Activation energies of E=0.91, 0.93 and 0.96 eV and crystallization temperatures of Tc=-14, 81.5 and 85°C for the three alloys, respectively, were found. In all three cases the crystallization process originated from single crystalline nuclei with a hexagonal structure and with the c-axis in general parallel to the substrate surface.

In situ Raman spectroscopic investigation of the structure of subduction-zone fluids

USGS Publications Warehouse

Mibe, Kenji; Chou, I.-Ming; Bassett, William A.

2008-01-01

In situ Raman spectra of synthetic subduction-zone fluids (KAlSi3O8-H2O system) were measured to 900?? and 2.3 GPa using a hydrothermal diamond-anvil cell. The structures of aqueous fluid and hydrous melt become closer when conditions approach the second critical endpoint. Almost no three-dimensional network was observed in the supercritical fluid above 2 GPa although a large amount of silicate component is dissolved, suggesting that the physical and chemical properties of these phases change drastically at around the second critical endpoint. Our experimental results indicate that the fluids released from a subducting slab change from aqueous fluid to supercritical fluid with increasing depth under the volcanic arcs. Copyright 2008 by the American Geophysical Union.

Analysis of EDZ Development of Columnar Jointed Rock Mass in the Baihetan Diversion Tunnel

NASA Astrophysics Data System (ADS)

Hao, Xian-Jie; Feng, Xia-Ting; Yang, Cheng-Xiang; Jiang, Quan; Li, Shao-Jun

2016-04-01

Due to the time dependency of the crack propagation, columnar jointed rock masses exhibit marked time-dependent behaviour. In this study, in situ measurements, scanning electron microscope (SEM), back-analysis method and numerical simulations are presented to study the time-dependent development of the excavation damaged zone (EDZ) around underground diversion tunnels in a columnar jointed rock mass. Through in situ measurements of crack propagation and EDZ development, their extent is seen to have increased over time, despite the fact that the advancing face has passed. Similar to creep behaviour, the time-dependent EDZ development curve also consists of three stages: a deceleration stage, a stabilization stage, and an acceleration stage. A corresponding constitutive model of columnar jointed rock mass considering time-dependent behaviour is proposed. The time-dependent degradation coefficient of the roughness coefficient and residual friction angle in the Barton-Bandis strength criterion are taken into account. An intelligent back-analysis method is adopted to obtain the unknown time-dependent degradation coefficients for the proposed constitutive model. The numerical modelling results are in good agreement with the measured EDZ. Not only that, the failure pattern simulated by this time-dependent constitutive model is consistent with that observed in the scanning electron microscope (SEM) and in situ observation, indicating that this model could accurately simulate the failure pattern and time-dependent EDZ development of columnar joints. Moreover, the effects of the support system provided and the in situ stress on the time-dependent coefficients are studied. Finally, the long-term stability analysis of diversion tunnels excavated in columnar jointed rock masses is performed.

New single-aircraft integrated atmospheric observation capabilities

NASA Astrophysics Data System (ADS)

Wang, Z.

2011-12-01

Improving current weather and climate model capabilities requires better understandings of many atmospheric processes. Thus, advancing atmospheric observation capabilities has been regarded as the highest imperatives to advance the atmospheric science in the 21st century. Under the NSF CAREER support, we focus on developing new airborne observation capabilities through the developments of new instrumentations and the single-aircraft integration of multiple remote sensors with in situ probes. Two compact Wyoming cloud lidars were built to work together with a 183 GHz microwave radiometer, a multi-beam Wyoming cloud radar and in situ probes for cloud studies. The synergy of these remote sensor measurements allows us to better resolve the vertical structure of cloud microphysical properties and cloud scale dynamics. Together with detailed in situ data for aerosol, cloud, water vapor and dynamics, we developed the most advanced observational capability to study cloud-scale properties and processes from a single aircraft (Fig. 1). A compact Raman lidar was also built to work together with in situ sampling to characterize boundary layer aerosol and water vapor distributions for many important atmospheric processes studies, such as, air-sea interaction and convective initialization. Case studies will be presented to illustrate these new observation capabilities.

Ground truth management system to support multispectral scanner /MSS/ digital analysis

NASA Technical Reports Server (NTRS)

Coiner, J. C.; Ungar, S. G.

1977-01-01

A computerized geographic information system for management of ground truth has been designed and implemented to relate MSS classification results to in situ observations. The ground truth system transforms, generalizes and rectifies ground observations to conform to the pixel size and shape of high resolution MSS aircraft data. These observations can then be aggregated for comparison to lower resolution sensor data. Construction of a digital ground truth array allows direct pixel by pixel comparison between classification results of MSS data and ground truth. By making comparisons, analysts can identify spatial distribution of error within the MSS data as well as usual figures of merit for the classifications. Use of the ground truth system permits investigators to compare a variety of environmental or anthropogenic data, such as soil color or tillage patterns, with classification results and allows direct inclusion of such data into classification operations. To illustrate the system, examples from classification of simulated Thematic Mapper data for agricultural test sites in North Dakota and Kansas are provided.

The 3D Mesonet Concept: Extending Networked Surface Meteorological Tower Observations Through Unmanned Aircraft Systems

NASA Astrophysics Data System (ADS)

Chilson, P. B.; Fiebrich, C. A.; Huck, R.; Grimsley, J.; Salazar-Cerreno, J.; Carson, K.; Jacob, J.

2017-12-01

Fixed monitoring sites, such as those in the US National Weather Service Automated Surface Observing System (ASOS) and the Oklahoma Mesonet provide valuable, high temporal resolution information about the atmosphere to forecasters and the general public. The Oklahoma Mesonet is comprised of a network of 120 surface sites providing a wide array of atmospheric measurements up to a height of 10 m with an update time of five minutes. The deployment of small unmanned aircraft to collect in-situ vertical measurements of the atmospheric state in conjunction with surface conditions has potential to significantly expand weather observation capabilities. This concept can enhance the safety of individuals and support commerce through improved observations and short-term forecasts of the weather and other environmental variables in the lower atmosphere. We report on a concept of adding the capability of collecting vertical atmospheric measurements (profiles) through the use of unmanned aerial systems (UAS) at remote Oklahoma sites deemed suitable for this application. While there are a number of other technologies currently available that can provide measurements of one or a few variables, the proposed UAS concept will be expandable and modular to accommodate several different sensor packages and provide accurate in-situ measurements in virtually all weather conditions. Such a system would facilitate off-site maintenance and calibration and would provide the ability to add new sensors as they are developed or as new requirements are identified. The small UAS must be capable of accommodating the weight of all sensor packages and have lighting, communication, and aircraft avoidance systems necessary to meet existing or future FAA regulations. The system must be able to operate unattended, which necessitates the inclusion of risk mitigation measures such as a detect and avoid radar and the ability to transmit and receive transponder signals. Moreover, the system should be able to assess local weather conditions (visibility, surface winds, and cloud height) and the integrity of the vehicle (system diagnostics, fuel level) before takeoff. We provide a notional concept of operations for a 3D Mesonet being considered, describe the technical configuration for one station in the network, and discuss plans for future development.

Quantifying spatial and temporal variability in atmospheric ammonia with in situ and space-based observations--article

EPA Science Inventory

Ammonia plays an important role in many biogeochemical processes, yet atmospheric mixing ratios are not well known. Recently, methods have been developed for retrieving NH3 from space-based observations, but they have not been compared to in situ measurements. We have conducted a...

The ACRIDICON-CHUVA observational study of tropical convective clouds and precipitation using the new German research aircraft HALO

NASA Astrophysics Data System (ADS)

Wendisch, Manfred; Pöschl, Ulrich; Andreae, Meinrat O.; Machado, Luiz A. T.; Albrecht, Rachel; Schlager, Hans; Rosenfeld, Daniel; Krämer, Martina

2015-04-01

An extensive airborne/ground-based measurement campaign to study tropical convective clouds is introduced. It was performed in Brazil with focus on the Amazon rainforest from 1 September to 4 October 2014. The project combined the joint German-Brazilian ACRIDICON (Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems) and CHUVA (Machado et al.2014) projects. ACRIDICON aimed at the quantification of aerosol-cloud-precipitation interactions and their thermodynamic, dynamic and radiative effects in convective cloud systems by in-situ aircraft observations and indirect measurements (aircraft, satellite, and ground-based). The ACRIDICON-CHUVA campaign was conducted in cooperation with the second Intensive Operational Phase (IOP) of the GOAmazon (Green Ocean Amazon) program. The focus in this presentation is on the airborne observations within ACRIDICON-CHUVA. The German HALO (High Altitude and Long-Range Research Aircraft) was based in Manaus (Amazonas State); it carried out 14 research flights (96 flight hours in total). HALO was equipped with remote sensing and in-situ instrumentation for meteorological, trace gas, aerosol, cloud, and precipitation measurements. Five mission objectives were pursued: (1) cloud vertical evolution (cloud profiling), (2) aerosol processing (inflow and outflow), (3) satellite validation, (4) vertical transport and mixing (tracer experiment), and (5) clouds over forested and deforested areas. The five cloud missions collected data in clean atmospheric conditions and in contrasting polluted (urban and biomass burning) environments.

The Feasibility and Benefits of In Situ Exploration of `Oumuamua-like objects

NASA Astrophysics Data System (ADS)

Seligman, Darryl; Laughlin, Gregory

2018-04-01

A rapid accumulation of observations and interpretation have followed in the wake of 1I `Oumuamua's passage through the inner Solar System. We outline the consequences that this first detection of an interstellar asteroid implies for the planet-forming process, and we assess the near-term prospects for detecting and observing (both remotely and \\textit{in situ}) future Solar System visitors of this type. Drawing on detailed heat-transfer calculations that take both `Oumuamua's unusual shape and its chaotic tumbling into account, we affirm that the lack of a detectable coma in deep images of the object very likely arises from the presence of a radiation-modified coating of high molecular weight material (rather than a refractory bulk composition). Assuming that `Oumuamua is a typical representative of a larger population with a kinematic distribution similar to Population I stars in the local galactic neighborhood, we calculate expected arrival rates, impact parameters and velocities of similar objects and assess their prospects for detection using operational and forthcoming facilities. Using `Oumuamua as a proof-of-concept, we assess the prospects for missions that intercept ISOs using conventional chemical propulsion. Using a ``launch on detection'' paradigm, we estimate wait times of order a year between favorable mission opportunities with the detection capabilities of the Large-Scale Synoptic Survey Telescope (LSST), a figure that will be refined as the population of interstellar asteroids becomes observationally better constrained.

Particulate Matter Resuspension in Mississippi Bight Evaluated with CONCORDE's Synthesis Model

NASA Astrophysics Data System (ADS)

O'Brien, S. J.; Quas, L. M.; Miles, T. N.; Pan, C.; Cambazoglu, M. K.; Soto Ramos, I. M.; Greer, A. T.; Church, I.; Wiggert, J. D.

2017-12-01

The CONsortium for oil spill exposure pathways in COastal River-Dominated Ecosystems (CONCORDE) was established to investigate the complex fine-scale biological, chemical and physical interactions in a marine system controlled by pulsed-river plume dynamics. During CONCORDE's spring 2016 field campaign, the In Situ Ichthyoplankton Imaging System (ISIIS) on the R/V Point Sur and the Scanfish on the R/V Pelican comprehensively characterized the physical and biological structure in the region. Increased suspended particulate matter was observed by the ISIIS, with concentrations at depth sufficient to completely occlude the in situ images of planktonic organisms. Data was also collected on the continental shelf during the spring cruise by the RU31 glider in the proximity of the Mississippi River Delta, east of the ISIIS / Scanfish transects. Backscatter and salinity observed by the Scanfish and glider showed elevated suspended particulate matter and increased salinity, suggesting a linkage to shoreward advection from the continental shelf of oceanic waters that are sufficiently energetic to drive sediment resuspension. As part of the CONCORDE research effort, a four-dimensional biogeochemical/lower trophic level synthesis model for Mississippi Sound and Bight has been developed, based on the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System. This study utilizes CONCORDE's synthesis model to investigate the physical forcing mechanisms affecting the increased suspended particulate matter concentration observed in the Mississippi Bight during spring 2016, and advection pathways between estuarine and shelf waters in the northern Gulf of Mexico. The results show that episodic, advection-driven resuspension is a critical aspect controlling suspended sediment distributions in Mississippi Bight, which has implications for observed spatio-temporal patterns of planktonic species.

The USGODAE Monterey Data Server

NASA Astrophysics Data System (ADS)

Sharfstein, P. J.; Dimitriou, D.; Hankin, S. C.

2004-12-01

With oversight from the U.S. Global Ocean Data Assimilation Experiment (GODAE) Steering Committee and funding from the Office of Naval Research, the USGODAE Monterey Data Server has been established at the Fleet Numerical Meteorology and Oceanography Center (FNMOC) as an explicit U.S. contribution to GODAE. Support of the Monterey Data Server is accomplished by a cooperative effort between FNMOC and NOAA's Pacific Marine Environmental Laboratory (PMEL) in the on-going development of the server and the support of a collaborative network of GODAE assimilation groups. This server hosts near real-time in-situ oceanographic data, atmospheric forcing fields suitable for driving ocean models, and unique GODAE data sets, including demonstration ocean model products. GODAE is envisioned as a global system of observations, communications, modeling and assimilation, which will deliver regular, comprehensive information on the state of the oceans in a way that will promote and engender wide utility and availability of this resource for maximum benefit to society. It aims to make ocean monitoring and prediction a routine activity in a manner similar to weather forecasting. GODAE will contribute to an information system for the global ocean that will serve interests from climate and climate change to ship routing and fisheries. The USGODAE Server is developed and operated as a prototypical node for this global information system. Because of the broad range and diverse formats of data used by the GODAE community, presenting data with a consistent interface and ensuring its availability in standard formats is a primary challenge faced by the USGODAE Server project. To this end, all USGODAE data sets are available via HTTP and FTP. In addition, USGODAE data are served using Local Data Manager (LDM), THREDDS cataloging, OPeNDAP, and Live Access Server (LAS) from PMEL. Every effort is made to serve USGODAE data through the standards specified by the National Virtual Ocean Data System (NVODS) and the Integrated Ocean Observing System Data Management and Communications (IOOS/DMAC). To provide surface forcing, fluxes, and boundary conditions for ocean model research, USGODAE serves global data from the Navy Operational Global Atmospheric Prediction System (NOGAPS) and regional data from the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). Global meteorological data and observational data from the FNMOC Ocean QC process are posted in near real-time to USGODAE. These include T/S profiles, in-situ and satellite sea surface temperature (SST), satellite altimetry, and SSM/I sea ice. They contain all of the unclassified in-situ and satellite observations used to initialize the FNMOC NOGAPS model. Also, the Naval Oceanographic Office provides daily satellite SST and SSH retrievals to USGODAE. The USGODAE Server functions as one of two Argo Global Data Assembly Centers (GDACs), hosting the complete collection of quality-controlled Argo T/S profiling float data. USGODAE Argo data are served through OPeNDAP and LAS, providing complete integration into NVODS and the IOOS/DMAC. Due to its high reliability, ease of data access, and increasing breadth of data, the USGODAE Server is becoming an invaluable resource for both the GODAE community and the general oceanographic community. Continued integration of model, forcing, and in-situ data sets from providers throughout the world is making the USGODAE Monterey Data Server a key part of the international GODAE project.

Spacecraft Exploration of Titan and Enceladus

NASA Astrophysics Data System (ADS)

Matson, D.; Coustenis, A.; Lunine, J. I.; Lebreton, J.; Reh, K.; Beauchamp, P.; Erd, C.

2009-12-01

The future exploration of Titan and Enceladus is very important for planetary science. The study titled Titan Saturn System Mission (TSSM) led to an announcement in which ESA and NASA prioritized future OPF missions, stating that TSSM is planned after EJSM (for details see http://www.lpi.usra.edu/opag/). The TSSM concept consists of an Orbiter that would carry two in situ elements: the Titan Montgolfiere hot air balloon and the Titan Lake Lander. This mission could launch in the 2023-2025 timeframe on a trajectory to arrive ~9 years later and begin a 4-year mission in the Saturnian system. At an appropriate time after arrival at Saturn, the montgolfiere would be delivered to Titan to begin its mission of airborne, scientific observations of Titan from an altitude of about 10 km above the surface. The montgolfiere would have a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) power system whose waste heat would warm the gas in the balloon, providing buoyancy. It would be designed to survive at least 6-12 months in Titan’s atmosphere. With the predicted winds and weather, it should be possible to circumnavigate the globe! Later, on a subsequent fly-by, the TSSM orbiter would send the Lake Lander to Titan. It would descend through the atmosphere making scientific measurements, much like Huygens did, and then land and float on one of Titan’s seas. This would be its oceanographic phase of making a physical and chemical assessment of the sea. The Lake Lander would operate for 8-10 hours until its batteries become depleted. Following the delivery of the in situ elements, the TSSM orbiter would then explore the Saturn system for two years on a tour that includes in situ sampling of Enceladus’ plumes as well as flybys of Titan. After the Saturn tour, the TSSM orbiter would go into orbit around Titan and carry out a global survey phase. Synergistic observations would be carried out by the TSSM orbiter and the in situ elements. The scientific requirements for TSSM were developed by a Joint Science Definition Team (JSDT). In the TSSM study the orbiter was assumed to be NASA’s responsibility while the in situ elements were assumed to be provided by ESA. The engineering and flight operations aspects were developed in a collaborative study by NASA and ESA engineering teams. This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The European part was conducted in ESA within the Cosmic Vision 1 plan. Copyright 2008 California Institute of Technology. Government sponsorship acknowledged.

40 CFR 65.113 - Standards: Sampling connection systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt... implementation date specified in § 65.1(f). (b) Equipment requirement. Each sampling connection system shall be equipped with a closed-purge, closed-loop, or closed vent system except as provided in paragraph (d) of...

40 CFR 65.113 - Standards: Sampling connection systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt... implementation date specified in § 65.1(f). (b) Equipment requirement. Each sampling connection system shall be equipped with a closed-purge, closed-loop, or closed vent system except as provided in paragraph (d) of...

Maintaining High Quality Data and Consistency Across a Diverse Flux Network: The Ameriflux QA/QC Technical Team

NASA Astrophysics Data System (ADS)

Chan, S.; Billesbach, D. P.; Hanson, C. V.; Biraud, S.

2014-12-01

The AmeriFlux quality assurance and quality control (QA/QC) technical team conducts short term (<2 weeks) intercomparisons using a portable eddy covariance system (PECS) to maintain high quality data observations and data consistency across the AmeriFlux network (http://ameriflux.lbl.gov/). Site intercomparisons identify discrepancies between the in situ and portable measurements and calculated fluxes. Findings are jointly discussed by the site staff and the QA/QC team to improve in the situ observations. Despite the relatively short duration of an individual site intercomparison, the accumulated record of all site visits (numbering over 100 since 2002) is a unique dataset. The ability to deploy redundant sensors provides a rare opportunity to identify, quantify, and understand uncertainties in eddy covariance and ancillary measurements. We present a few specific case studies from QA/QC site visits to highlight and share new and relevant findings related to eddy covariance instrumentation and operation.

Design and Application of New Low-Cost Instruments for Marine Environmental Research

PubMed Central

Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto

2014-01-01

The development of low-cost instrumentation plays a key role in marine environmental studies and represents one of the most innovative aspects of current oceanographic research. These kinds of devices can be used for several applications, ranging from vertical profilers to stand-alone systems, and can be installed on different platforms (buoys, Voluntary Observing Ships, underwater vehicles, etc.). The availability of low-cost technologies enables the realization of extended observatory networks for the study of marine physical and biological processes through an integrated approach merging in situ observations, forecasting models and remotely sensed data. We present new low-cost sensors and probes developed to measure marine temperature, conductivity, chlorophyll a and Chromophoric Dissolved Organic Matter fluorescence, focusing on sensing strategies, general architecture, laboratory trials, in situ tests and comparison with standard instruments. Furthermore, we report the expendable (New T-FLaP), vertical profiler (T-FLaPpro) and stand-alone (Spectra) applications of these technological developments that were tested during several oceanographic surveys in the Mediterranean Sea. PMID:25490594

The Influence of Aerosols on the Shortwave Cloud Radiative Forcing from North Pacific Oceanic Clouds: Results from the Cloud Indirect Forcing Experiment (CIFEX)

NASA Technical Reports Server (NTRS)

Wilcox, Eric M.; Roberts, Greg; Ramanathan, V.

2006-01-01

Aerosols over the Northeastern Pacific Ocean enhance the cloud drop number concentration and reduce the drop size for marine stratocumulus and cumulus clouds. These microphysical effects result in brighter clouds, as evidenced by a combination of aircraft and satellite observations. In-situ measurements from the Cloud Indirect Forcing Experiment (CIFEX) indicate that the mean cloud drop number concentration in low clouds over the polluted marine boundary layer is greater by 53/cu cm compared to clean clouds, and the mean cloud drop effective radius is smaller by 4 microns. We link these in-situ measurements of cloud modification by aerosols, for the first time, with collocated satellite broadband radiative flux observations from the Clouds and the Earth's Radiant Energy System (CERES) to show that these microphysical effects of aerosols enhance the top-of-atmosphere cooling by -9.9+/-4.3 W/sq m for overcast conditions.

An investigation of methods for updating ionospheric scintillation models using topside in-situ plasma density measurements

NASA Astrophysics Data System (ADS)

Secan, James A.

1991-05-01

Modern military communication, navigation, and surveillance systems depend on reliable, noise-free transionospheric radio-frequency channels. They can be severely impacted by small-scale electron-density irregularities in the ionosphere, which cause both phase and amplitude scintillation. Basic tools used in planning and mitigation schemes are climatological in nature and thus may greatly over- and under-estimate the effects of scintillation in a given scenario. This report summarizes the results of the first year of a three-year investigation into the methods for updating ionospheric scintillation models using observations of ionospheric plasma-density irregularities measured by DMSP Scintillation Meter (SM) sensor. Results are reported from the analysis of data from a campaign conducted in January 1990 near Tromso, Norway, in which near coincident in-situ plasma-density and transionospheric scintillation measurements were made. Estimates for the level of intensity and phase scintillation on a transionospheric UHF radio link in the early-evening auroral zone were calculated from DMSP SM data and compared to the levels actually observed.

Design and Control of a Micro/Nano Load Stage for In-Situ AFM Observation and Nanoscale Structural and Mechanical Characterization of MWCNT-Epoxy Composites

NASA Astrophysics Data System (ADS)

Leininger, Wyatt Christopher

Nanomaterial composites hold improvement potential for many materials. Improvements arise through known material behaviors and unique nanoscale effects to improve performance in areas including elastic modulus and damping as well as various processes, and products. Review of research spurred development of a load-stage. The load stage could be used independently, or in conjunction with an AFM to investigate bulk and nanoscale material mechanics. The effect of MWCNT content on structural damping, elastic modulus, toughness, loss modulus, and glass transition temperature was investigated using the load stage, AMF, and DMA. Initial investigation showed elastic modulus increased 23% with 1wt.% MWCNT versus pure epoxy and in-situ imaging observed micro/nanoscale deformation. Dynamic capabilities of the load stage were investigated as a method to achieve higher stress than available through DMA. The system showed energy dissipation across all reinforce levels, with 480% peak for the 1wt.% MWCNT material vs. the neat epoxy at 1Hz.

Design and application of new low-cost instruments for marine environmental research.

PubMed

Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto

2014-12-05

The development of low-cost instrumentation plays a key role in marine environmental studies and represents one of the most innovative aspects of current oceanographic research. These kinds of devices can be used for several applications, ranging from vertical profilers to stand-alone systems, and can be installed on different platforms (buoys, Voluntary Observing Ships, underwater vehicles, etc.). The availability of low-cost technologies enables the realization of extended observatory networks for the study of marine physical and biological processes through an integrated approach merging in situ observations, forecasting models and remotely sensed data. We present new low-cost sensors and probes developed to measure marine temperature, conductivity, chlorophyll a and Chromophoric Dissolved Organic Matter fluorescence, focusing on sensing strategies, general architecture, laboratory trials, in situ tests and comparison with standard instruments. Furthermore, we report the expendable (New T-FLaP), vertical profiler (T-FLaPpro) and stand-alone (Spectra) applications of these technological developments that were tested during several oceanographic surveys in the Mediterranean Sea.

Raman shifts in electron-irradiated monolayer MoS 2

DOE PAGES

Parkin, William M.; Balan, Adrian; Liang, Liangbo; ...

2016-03-21

Here, we report how the presence of electron-beam-induced sulfur vacancies affects first-order Raman modes and correlate the effects with the evolution of the in situ transmission-electron microscopy (TEM) two-terminal conductivity of monolayer MoS 2 under electron irradiation. We observe a redshift in the E Raman peak and a less pronounced blueshift in the A' 1 peak with increasing electron dose. Using energy-dispersive X-ray spectroscopy (EDS), we show that irradiation causes partial removal of sulfur and correlate the dependence of the Raman peak shifts with S vacancy density (a few %), which is confirmed by first-principles density functional theory calculations. Inmore » situ device current measurements show exponential decrease in channel current upon irradiation. Our analysis demonstrates that the observed frequency shifts are intrinsic properties of the defective systems and that Raman spectroscopy can be used as a quantitative diagnostic tool to characterize MoS 2-based transport channels.« less

Forest-Observation-System.net - towards a global in-situ data repository for biomass datasets validation

NASA Astrophysics Data System (ADS)

Shchepashchenko, D.; Chave, J.; Phillips, O. L.; Davies, S. J.; Lewis, S. L.; Perger, C.; Dresel, C.; Fritz, S.; Scipal, K.

2017-12-01

Forest monitoring is high on the scientific and political agenda. Global measurements of forest height, biomass and how they change with time are urgently needed as essential climate and ecosystem variables. The Forest Observation System - FOS (http://forest-observation-system.net/) is an international cooperation to establish a global in-situ forest biomass database to support earth observation and to encourage investment in relevant field-based observations and science. FOS aims to link the Remote Sensing (RS) community with ecologists who measure forest biomass and estimating biodiversity in the field for a common benefit. The benefit of FOS for the RS community is the partnering of the most established teams and networks that manage permanent forest plots globally; to overcome data sharing issues and introduce a standard biomass data flow from tree level measurement to the plot level aggregation served in the most suitable form for the RS community. Ecologists benefit from the FOS with improved access to global biomass information, data standards, gap identification and potential improved funding opportunities to address the known gaps and deficiencies in the data. FOS closely collaborate with the Center for Tropical Forest Science -CTFS-ForestGEO, the ForestPlots.net (incl. RAINFOR, AfriTRON and T-FORCES), AusCover, Tropical managed Forests Observatory and the IIASA network. FOS is an open initiative with other networks and teams most welcome to join. The online database provides open access for both metadata (e.g. who conducted the measurements, where and which parameters) and actual data for a subset of plots where the authors have granted access. A minimum set of database values include: principal investigator and institution, plot coordinates, number of trees, forest type and tree species composition, wood density, canopy height and above ground biomass of trees. Plot size is 0.25 ha or large. The database will be essential for validating and calibrating satellite observations and various models.

Comparison of different methods to retrieve optical-equivalent snow grain size in central Antarctica

NASA Astrophysics Data System (ADS)

Carlsen, Tim; Birnbaum, Gerit; Ehrlich, André; Freitag, Johannes; Heygster, Georg; Istomina, Larysa; Kipfstuhl, Sepp; Orsi, Anaïs; Schäfer, Michael; Wendisch, Manfred

2017-11-01

The optical-equivalent snow grain size affects the reflectivity of snow surfaces and, thus, the local surface energy budget in particular in polar regions. Therefore, the specific surface area (SSA), from which the optical snow grain size is derived, was observed for a 2-month period in central Antarctica (Kohnen research station) during austral summer 2013/14. The data were retrieved on the basis of ground-based spectral surface albedo measurements collected by the COmpact RAdiation measurement System (CORAS) and airborne observations with the Spectral Modular Airborne Radiation measurement sysTem (SMART). The snow grain size and pollution amount (SGSP) algorithm, originally developed to analyze spaceborne reflectance measurements by the MODerate Resolution Imaging Spectroradiometer (MODIS), was modified in order to reduce the impact of the solar zenith angle on the retrieval results and to cover measurements in overcast conditions. Spectral ratios of surface albedo at 1280 and 1100 nm wavelength were used to reduce the retrieval uncertainty. The retrieval was applied to the ground-based and airborne observations and validated against optical in situ observations of SSA utilizing an IceCube device. The SSA retrieved from CORAS observations varied between 27 and 89 m2 kg-1. Snowfall events caused distinct relative maxima of the SSA which were followed by a gradual decrease in SSA due to snow metamorphism and wind-induced transport of freshly fallen ice crystals. The ability of the modified algorithm to include measurements in overcast conditions improved the data coverage, in particular at times when precipitation events occurred and the SSA changed quickly. SSA retrieved from measurements with CORAS and MODIS agree with the in situ observations within the ranges given by the measurement uncertainties. However, SSA retrieved from the airborne SMART data slightly underestimated the ground-based results.

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

The Integrated Sounding System: Description and Preliminary Observations from TOGA COARE.

NASA Astrophysics Data System (ADS)

Parsons, David; Dabberdt, Walter; Cole, Harold; Hock, Terrence; Martin, Charles; Barrett, Anne-Leslie; Miller, Erik; Spowart, Michael; Howard, Michael; Ecklund, Warner; Carter, David; Gage, Kenneth; Wilson, John

1994-04-01

An Integrated Sounding System (ISS) that combines state-of- the-art remote and in situ sensors into a single transportable facility has been developed jointly by the National Center for Atmospheric Research (NCAR) and the Aeronomy laboratory of the National Oceanic and Atmospheric Administration (NOAA/AL). The instrumentation for each ISS includes a 915-MHz wind profiler, a Radio Acoustic Sounding System (RASS), an Omega-based NAVAID sounding system, and an enhanced surface meteorological station. The general philosophy behind the ISS is that the integration of various measurement systems overcomes each system's respective limitations while taking advantage of its positive attributes. The individual observing systems within the ISS provide high-level data products to a central workstation that manages and integrates these measurements. The ISS software package performs a wide range of functions: real-time data acquisition, database support, and graphical displays; data archival and communications; and operational and post time analysis. The first deployment of the ISS consists of six sites in the western tropical Pacific-four land-based deployments and two ship-based deployments. The sites serve the Coupled Ocean-Atmosphere Response Experiment (COARE) of the Tropical Ocean and Global Atmosphere (TOGA) program and TOGA's enhanced atmospheric monitoring effort. Examples of ISS data taken during this deployment are shown in order to demonstrate the capabilities of this new sounding system and to demonstrate the performance of these in situ and remote sensing instruments in a moist tropical environment. In particular, a strong convective outflow with a pronounced impact of the atmospheric boundary layer and heat fluxes from the ocean surface was examined with a shipboard ISS. If these strong outflows commonly occur, they may prove to be an important component of the surface energy budget of the western tropical Pacific.

Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy

NASA Astrophysics Data System (ADS)

Tay, S. E. R.; Goode, A. E.; Nelson Weker, J.; Cruickshank, A. A.; Heutz, S.; Porter, A. E.; Ryan, M. P.; Toney, M. F.

2016-01-01

The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation.The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation. Electronic supplementary information (ESI) available: Methods and videos of nanoparticle growth. See DOI: 10.1039/c5nr07019h

Google Earth Engine derived areal extents to infer elevation variation of lakes and reservoirs

NASA Astrophysics Data System (ADS)

Nguy-Robertson, Anthony; May, Jack; Dartevelle, Sebastien; Griffin, Sean; Miller, Justin; Tetrault, Robert; Birkett, Charon; Lucero, Eileen; Russo, Tess; Zentner, Matthew

2017-04-01

Monitoring water supplies is important for identifying potential national security issues before they begin. As a means to estimate lake and reservoir storage for sites without reliable water stage data, this study defines correlations between water body levels from hypsometry curves based on in situ gauge station and altimeter data (i.e. TOPEX/Poseidon, Jason series) and sensor areal extents observed in historic multispectral (i.e. MODIS and Landsat TM/ETM+/OLI) imagery. Water levels measured using in situ observations and altimeters, when in situ data were unavailable, were used to estimate the relationship between water elevation and surface area for 18 sites globally. Altimeters were generally more accurate (RMSE: 0.40 - 0.49 m) for estimating in situ lake elevations from Iraq and Afghanistan than the modeled elevation data using multispectral sensor areal extents: Landsat (RMSE: 0.25 - 1.5 m) and MODIS (RMSE 0.53 - 3.0 m). Correlations between altimeter data and Landsat imagery processed with Google Earth Engine confirmed similar relationships exists for a broader range of lakes without reported in situ data across the globe (RMSE: 0.24 - 1.6 m). Thus, while altimetry is still preferred to an areal extent model, lake surface area derived with Google Earth Engine can be used as a reasonable proxy for lake storage, expanding the number of observable lakes beyond the current constellation of altimeters and in situ gauges.

Effect of temperature on the nano/microstructure and mechanical behavior of nanotwinned Ag films

DOE PAGES

Zhang, Huan; Geng, Jie; Ott, Ryan T.; ...

2015-06-24

In situ and ex situ annealed nanotwinned (NT) Ag thin films have been investigated by TEM and tensile testing to reveal the thermal stability of the twin boundaries, grain boundaries, dislocation densities, and their respective influence of the macroscopic yield stress. The NT Ag films synthesized by magnetron sputtering form both coherent (CTB, Σ3{111}) and incoherent (ITB, Σ3{112}) twin boundaries that are thermally stable up to 473 K (200 Celsius), i.e., no obvious changes in grain size, twin spacing, and yield stress. In situ TEM observations show the dislocations become mobile at 453 K (180 Celsius) resulting in dislocation annihilationmore » primarily at twin and grain boundaries. Rotation of grains with low-angle grain boundaries was observed during in situ heating, resulting in the growth of columnar grains above 453 K (180 Celsius). However, no noticeable changes in the spacings of CTBs were observed during the entire in situ and ex situ annealing [up to 873 K (600 Celsius)]. The increase in grain size and concomitant decrease in yield stress following annealing at various temperatures can be described by the Hall-Petch relationship, demonstrating that grain size rather than twin spacing is most sensitive to thermal annealing and plays a dominant role in the deformation of NT Ag films.« less

Astronomy and Space Science from the Moon: Proceedings of Symposium E4 of the COSPAR 29th Plenary Meeting held in Washington, DC, 28 Aug.-5 Sep., 1992

NASA Technical Reports Server (NTRS)

Foing, B. H. (Editor)

1994-01-01

The goal of the conference was to assess the moon as a base for conducting astronomy, solar system observations, and space sciences. The lunar vacuum allows a complete opening of the electromagnetic window and distortion-free measurements at the highest angular resolution, precision, and temporal stability. The moon is perfect for continuous monitoring of the Sun, Solar System targets, and for deep observations of galactic and extragalactic objects. It is an in-situ laboratory for selenophysics, chemistry, and exobiology. The moon contains useful resources and is accessible from Earth for installation, operations maintenance, robotics, and human activities.

Biotransformation of caffeine, cotinine, and nicotine in stream sediments: Implications for use as wastewater indicators

USGS Publications Warehouse

Bradley, P.M.; Barber, L.B.; Kolpin, D.W.; McMahon, P.B.; Chapelle, F.H.

2007-01-01

Microbially catalyzed cleavage of the imadazole ring of caffeine was observed in stream sediments collected upstream and downstream of municipal wastewater treatment plants (WWTP) in three geographically separate stream systems. Microbial demethylation of the N-methyl component of cotinine and its metabolic precursor, nicotine, also was observed in these sediments. These findings indicate that stream sediment microorganisms are able to substantially alter the chemical structure and thus the analytical signatures of these candidate waste indicator compounds. The potential for in situ biotransformation must be considered if these compounds are employed as markers to identify the sources and track the fate of wastewater compounds in surface-water systems.

Remote measurements of the structure of midwest thunderstorm tops and anvils from high altitude aircraft

NASA Technical Reports Server (NTRS)

Heymsfield, Gerald M.; Fulton, Richard

1990-01-01

Results are presented from observations by a visible and IR scanning radiometer, a scanning passive microwave radiometer, and a nadir-viewing cloud lidar system (CLS), carried out from ER-2 overflights for two midwest severe weather events both of which presented following phenomena: (1) a group of severe thunderstorms which later transformed into a linear mesoscale convective system, and (2) a severe thunderstorm which produced large hail. Most of the aircraft in situ and remote measurements pointed to a deep subsidence region and gravity waves downstream of the overshooting cloud tops. The observations do not support a radiative explanation for the warm areas in the anvil.

Reviews and syntheses: guiding the evolution of the observing system for the carbon cycle through quantitative network design

NASA Astrophysics Data System (ADS)

Kaminski, Thomas; Rayner, Peter Julian

2017-10-01

Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. These observations have the potential to reduce uncertainties in past, current, and predicted natural and anthropogenic surface fluxes. In particular such observations provide independent information for verification of actions as requested by the Paris Agreement. It is, however, difficult to decide which variables to sample, and how, where, and when to sample them, in order to achieve an optimal use of the observational capabilities. Quantitative network design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit to be expected from planned space missions. This paper describes recent progress and highlights aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy.

Serotonin 1A receptor (5-HT1A) of the sea lamprey: cDNA cloning and expression in the central nervous system.

PubMed

Cornide-Petronio, María Eugenia; Anadón, Ramón; Barreiro-Iglesias, Antón; Rodicio, María Celina

2013-09-01

Serotonergic cells are among the earliest neurons to be born in the developing central nervous system and serotonin is known to regulate the development of the nervous system. One of the major targets of the activity of serotonergic cells is the serotonin 1A receptor (5-HT1A), an ancestral archetypical serotonin receptor. In this study, we cloned and characterized the 3D structure of the sea lamprey 5-HT1A, and studied the expression of its transcript in the central nervous system by means of in situ hybridization. In phylogenetic analyses, the sea lamprey 5-HT1A sequence clustered together with 5-HT1A sequences of vertebrates and emerged as an outgroup to all gnathostome sequences. In situ hybridization analysis during prolarval, larval and adult stages showed a widespread expression of the lamprey 5-ht1a transcript. In P1 prolarvae 5-ht1a mRNA expression was observed in diencephalic nuclei, the rhombencephalon and rostral spinal cord. At P2 prolarval stage the 5-ht1a expression extended to other brain areas including telencephalic regions. 5-ht1a expression in larvae was observed throughout almost all the main brain regions with the strongest expression in the olfactory bulbs, lateral pallium, striatum, preoptic region, habenula, prethalamus, thalamus, pretectum, hypothalamus, rhombencephalic reticular area, dorsal column nucleus and rostral spinal cord. In adults, the 5-ht1a transcript was also observed in cells of the subcommissural organ. Comparison of the expression of 5-ht1a between the sea lamprey and other vertebrates reveals a conserved pattern in most of the brain regions, likely reflecting the ancestral vertebrate condition.

NiAl Oxidation Reaction Processes Studied In Situ Using MEMS-Based Closed-Cell Gas Reaction Transmission Electron Microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unocic, Kinga A.; Shin, Dongwon; Unocic, Raymond R.

The nanoscale oxidation mechanisms and kinetics of a model β-NiAl system were investigated using in situ closed-cell gas reaction scanning transmission electron microscopy (STEM). Here, we directly visualize the dynamic structural and chemical changes that occur during high-temperature oxidation at a high spatial resolution of 50.3Ni–49.7Al (at.%) nanoparticles under static air conditions at 730 Torr with heating up to 750 °C at 5 °C/s. A MEMS-based gas cell system, with microfabricated heater devices and a gas delivery system, was used to reveal site-specific oxidation initiation sites. Through time-resolved annular dark-field STEM imaging, we tracked the nanoscale oxidation kinetics of Almore » 2O 3. After oxidation at 750 °C, nucleation of voids at the Ni/Al 2O 3 interface was observed along a NiAl grain boundary, followed by the formation of faceted NiO crystals. Small faceted cubic crystals of NiO were formed at the initial stage of oxidation at high PO 2 due to the outward self-diffusion of Ni 2+ ions, followed by the formation of a mixture of metastable and stable α-Al 2O 3 at the oxide/metal interface that is attributed to a PO 2 decrease with oxidation time, which agreed with thermodynamic modeling calculations. Furthermore, the results from these in situ oxidation experiments in the β-NiAl system are in agreement with the established oxidation mechanisms; however, with in situ closed-cell gas microscopy it is now feasible to investigate nanoscale oxidation mechanisms and kinetics in real time and at high spatial resolution and can be broadly applied to understand the basic high-temperature oxidation mechanisms for a wide range of alloy compositions.« less

NiAl Oxidation Reaction Processes Studied In Situ Using MEMS-Based Closed-Cell Gas Reaction Transmission Electron Microscopy

DOE PAGES

Unocic, Kinga A.; Shin, Dongwon; Unocic, Raymond R.; ...

2017-02-07

The nanoscale oxidation mechanisms and kinetics of a model β-NiAl system were investigated using in situ closed-cell gas reaction scanning transmission electron microscopy (STEM). Here, we directly visualize the dynamic structural and chemical changes that occur during high-temperature oxidation at a high spatial resolution of 50.3Ni–49.7Al (at.%) nanoparticles under static air conditions at 730 Torr with heating up to 750 °C at 5 °C/s. A MEMS-based gas cell system, with microfabricated heater devices and a gas delivery system, was used to reveal site-specific oxidation initiation sites. Through time-resolved annular dark-field STEM imaging, we tracked the nanoscale oxidation kinetics of Almore » 2O 3. After oxidation at 750 °C, nucleation of voids at the Ni/Al 2O 3 interface was observed along a NiAl grain boundary, followed by the formation of faceted NiO crystals. Small faceted cubic crystals of NiO were formed at the initial stage of oxidation at high PO 2 due to the outward self-diffusion of Ni 2+ ions, followed by the formation of a mixture of metastable and stable α-Al 2O 3 at the oxide/metal interface that is attributed to a PO 2 decrease with oxidation time, which agreed with thermodynamic modeling calculations. Furthermore, the results from these in situ oxidation experiments in the β-NiAl system are in agreement with the established oxidation mechanisms; however, with in situ closed-cell gas microscopy it is now feasible to investigate nanoscale oxidation mechanisms and kinetics in real time and at high spatial resolution and can be broadly applied to understand the basic high-temperature oxidation mechanisms for a wide range of alloy compositions.« less

Atomistic observation and simulation analysis of spatio-temporal fluctuations during radiation-induced amorphization.

PubMed

Watanabe, Seiichi; Hoshino, Misaki; Koike, Takuto; Suda, Takanori; Ohnuki, Soumei; Takahashi, Heishichirou; Lam, Nighi Q

2003-01-01

We performed a dynamical-atomistic study of radiation-induced amorphization in the NiTi intermetallic compound using in situ high-resolution high-voltage electron microscopy and molecular dynamics simulations in connection with image simulation. Spatio-temporal fluctuations as non-equilibrium fluctuations in an energy-dissipative system, due to transient atom-cluster formation during amorphization, were revealed by the present spatial autocorrelation analysis.

The CSSL (combined sporadic structures and layers) payload: In situ observations of mesospheric sodium and related parameters

NASA Technical Reports Server (NTRS)

Machuga, David W.; Kane, Timothy J.; Wheeler, Timothy F.; Croskey, Charles L.; Mathews, John D.; Mitchell, John D.

1997-01-01

The objectives, design and results of the sensor systems for the combined sporadic structures and layers (CSSL) payload are analyzed. The CSSL main objectives were to: validate current models of mesospheric sodium chemistry; explore the relationship between turbulence and Na fluctuations; and to explore the relationship between high latitude electric fields and the formation of Na anomalies.

Study on Preparing Al2O3 Particles Reinforced ZL109 Composite by in Situ Reaction of Fe2O3/Al System

NASA Astrophysics Data System (ADS)

Zhang, Jing; Yu, Huashun; Zhao, Qi; Wang, Haitao; Min, Guanghui

Al2O3 particles reinforced ZL109 composite was prepared by in situ reaction between Fe2O3 and Al. The phases were identified by XRD and the microstructures were observed by SEM and TEM. The Al2O3 particles in sub-micron size distribute uniformly in the matrix and Fe displaced from the in situ reaction forms net-like alloy phases with Cu, Ni, Al, Mn ect. The hardness and the tensile strength at room temperature of the composites have a small increase compared with the matrix. However, the tensile strength at 350°C can reach 92.18 MPa, which is 18.87 MPa higher than that of the matrix. The mechanism of the reaction in the Fe2O3/Al system was studied by DSC. The reaction between Fe2O3 and Al involves two steps. The first step in which Fe2O3 reacts with Al to form FeO and Al2O3 takes place at the matrix alloy melting temperature. The second step in which FeO reacts with Al to form Fe and Al2O3 takes place at a higher temperature.

In situ microbial filter used for bioremediation

DOEpatents

Carman, M. Leslie; Taylor, Robert T.

2000-01-01

An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

[In-situ measurement of background atmospheric HCFC-142b using GC-MS and GC-ECD method].

PubMed

Guo, Li-feng; Yao, Bo; Zhou, Ling-xi; Li, Pei-chang; Xu, Lin

2013-05-01

Custom-made GC-MS and GC-ECD in-situ measurement systems were established at the Shangdianzi GAW Regional station. From May 2010 to May 2011, the precisions for GC-MS and GC-ECD systems were 0.23% and 0.88%, respectively, and the HCFC-142b mole fraction during the observation period ranged from 21 x 10(-12) to 355 x 10(-12). The result of the independent-sample T test was P > 0.05, and there was no significant difference in HCFC-142b mole fraction measured by the two systems. The small difference of HCFC-142b mole fraction measured by GC-MS and GC-ECD might be associated with the different sampling time and precision of the two systems. A statistical filter of "robust local regression" was applied to separate HCFC-142b background and pollution data. The mean difference, median difference, 25 and 75 percent difference of background data measured by GC-MS and GC-ECD were all within the precisions. The pollution events captured by the two systems showed similar characters. Results from both systems showed a higher HCFC-142b level in summer and autumn than in winter. The pollution mole fraction of the two systems showed similar seasonal changes.

In-situ high resolution transmission electron microscopy observation of silicon nanocrystal nucleation in a SiO{sub 2} bilayered matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, T. C.-J., E-mail: terry.yang@unsw.edu.au; Wu, L.; Lin, Z.

2014-08-04

Solid-state nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix was observed at temperatures as low as 450 °C. This was achieved by aberration corrected high-resolution transmission electron microscopy (HRTEM) with real-time in-situ heating up to 600 °C. This technique is a valuable characterization tool especially with the recent interest in Si nanostructures for light emitting devices, non-volatile memories, and third-generation photovoltaics which all typically require a heating step in their fabrication. The control of size, shape, and distribution of the Si nanocrystals are critical for these applications. This experimental study involves in-situ observation of the nucleation of Si nanocrystals inmore » a SiO{sub 2} bilayered matrix fabricated through radio frequency co-sputtering. The results show that the shapes of Si nanocrystals in amorphous SiO{sub 2} bilayered matrices are irregular and not spherical, in contrast to many claims in the literature. Furthermore, the Si nanocrystals are well confined within their layers by the amorphous SiO{sub 2}. This study demonstrates the potential of in-situ HRTEM as a tool to observe the real time nucleation of Si nanocrystals in a SiO{sub 2} bilayered matrix. Furthermore, ideas for improvements on this in-situ heating HRTEM technique are discussed.« less

The Chamber for Studying Rice Response to Elevated Nighttime Temperature in Field

PubMed Central

Chen, Song; Zheng, Xi; Wang, Dangying; Xu, Chunmei; Laza, Ma. Rebecca C.; Zhang, Xiufu

2013-01-01

An in situ temperature-controlled field chamber was developed for studying a large population of rice plant under different nighttime temperature treatments while maintaining conditions similar to those in the field during daytime. The system consists of a pipe hoop shed-type chamber with manually removable covers manipulated to provide a natural environment at daytime and a relatively stable and accurate temperature at night. Average air temperatures of 22.4 ± 0.3°C at setting of 22°C, 27.6 ± 0.4°C at 27°C, and 23.8 ± 0.7°C ambient conditions were maintained with the system. No significant horizontal and vertical differences in temperature were found and only slight changes in water temperatures were observed between the chambers and ambient conditions at 36 days after transplanting. A slight variation in CO2 concentration was observed at the end of the treatment during the day, but the 10-μmol CO2 mol−1 difference was too small to alter plant response. The present utilitarian system, which only utilizes an air conditioner/heater, is suitable for studying the effect of nighttime temperature on plant physiological responses with minimal perturbation of other environmental factors. At the same time, it will enable in situ screening of many rice genotypes. PMID:24089603

Global regime shift dynamics of catastrophic sea urchin overgrazing

PubMed Central

Ling, S. D.; Scheibling, R. E.; Rassweiler, A.; Johnson, C. R.; Shears, N.; Connell, S. D.; Salomon, A. K.; Norderhaug, K. M.; Pérez-Matus, A.; Hernández, J. C.; Clemente, S.; Blamey, L. K.; Hereu, B.; Ballesteros, E.; Sala, E.; Garrabou, J.; Cebrian, E.; Zabala, M.; Fujita, D.; Johnson, L. E.

2015-01-01

A pronounced, widespread and persistent regime shift among marine ecosystems is observable on temperate rocky reefs as a result of sea urchin overgrazing. Here, we empirically define regime-shift dynamics for this grazing system which transitions between productive macroalgal beds and impoverished urchin barrens. Catastrophic in nature, urchin overgrazing in a well-studied Australian system demonstrates a discontinuous regime shift, which is of particular management concern as recovery of desirable macroalgal beds requires reducing grazers to well below the initial threshold of overgrazing. Generality of this regime-shift dynamic is explored across 13 rocky reef systems (spanning 11 different regions from both hemispheres) by compiling available survey data (totalling 10 901 quadrats surveyed in situ) plus experimental regime-shift responses (observed during a total of 57 in situ manipulations). The emergent and globally coherent pattern shows urchin grazing to cause a discontinuous ‘catastrophic’ regime shift, with hysteresis effect of approximately one order of magnitude in urchin biomass between critical thresholds of overgrazing and recovery. Different life-history traits appear to create asymmetry in the pace of overgrazing versus recovery. Once shifted, strong feedback mechanisms provide resilience for each alternative state thus defining the catastrophic nature of this regime shift. Importantly, human-derived stressors can act to erode resilience of desirable macroalgal beds while strengthening resilience of urchin barrens, thus exacerbating the risk, spatial extent and irreversibility of an unwanted regime shift for marine ecosystems.

40 CFR 63.1032 - Sampling connection systems standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of a closed purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the... no later than the compliance dates specified in the referencing subpart. (b) Equipment requirement...

40 CFR 63.1032 - Sampling connection systems standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of a closed purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the... no later than the compliance dates specified in the referencing subpart. (b) Equipment requirement...

A Portable Ground-Based Atmospheric Monitoring System (PGAMS) for the Calibration and Validation of Atmospheric Correction Algorithms Applied to Aircraft and Satellite Images

NASA Technical Reports Server (NTRS)

Schiller, Stephen; Luvall, Jeffrey C.; Rickman, Doug L.; Arnold, James E. (Technical Monitor)

2000-01-01

Detecting changes in the Earth's environment using satellite images of ocean and land surfaces must take into account atmospheric effects. As a result, major programs are underway to develop algorithms for image retrieval of atmospheric aerosol properties and atmospheric correction. However, because of the temporal and spatial variability of atmospheric transmittance it is very difficult to model atmospheric effects and implement models in an operational mode. For this reason, simultaneous in situ ground measurements of atmospheric optical properties are vital to the development of accurate atmospheric correction techniques. Presented in this paper is a spectroradiometer system that provides an optimized set of surface measurements for the calibration and validation of atmospheric correction algorithms. The Portable Ground-based Atmospheric Monitoring System (PGAMS) obtains a comprehensive series of in situ irradiance, radiance, and reflectance measurements for the calibration of atmospheric correction algorithms applied to multispectral. and hyperspectral images. The observations include: total downwelling irradiance, diffuse sky irradiance, direct solar irradiance, path radiance in the direction of the north celestial pole, path radiance in the direction of the overflying satellite, almucantar scans of path radiance, full sky radiance maps, and surface reflectance. Each of these parameters are recorded over a wavelength range from 350 to 1050 nm in 512 channels. The system is fast, with the potential to acquire the complete set of observations in only 8 to 10 minutes depending on the selected spatial resolution of the sky path radiance measurements

A Novel Scoring Metrics for Quality Assurance of Ocean Color Observations

NASA Astrophysics Data System (ADS)

Wei, J.; Lee, Z.

2016-02-01

Interpretation of the ocean bio-optical properties from ocean color observations depends on the quality of the ocean color data, specifically the spectrum of remote sensing reflectance (Rrs). The in situ and remotely measured Rrs spectra are inevitably subject to errors induced by instrument calibration, sea-surface correction and atmospheric correction, and other environmental factors. Great efforts have been devoted to the ocean color calibration and validation. Yet, there exist no objective and consensus criteria for assessment of the ocean color data quality. In this study, the gap is filled by developing a novel metrics for such data quality assurance and quality control (QA/QC). This new QA metrics is not intended to discard "suspicious" Rrs spectra from available datasets. Rather, it takes into account the Rrs spectral shapes and amplitudes as a whole and grades each Rrs spectrum. This scoring system is developed based on a large ensemble of in situ hyperspectral remote sensing reflectance data measured from various aquatic environments and processed with robust procedures. This system is further tested with the NASA bio-Optical Marine Algorithm Data set (NOMAD), with results indicating significant improvements in the estimation of bio-optical properties when Rrs spectra marked with higher quality assurance are used. This scoring system is further verified with simulated data and satellite ocean color data in various regions, and we envision higher quality ocean color products with the implementation of such a quality screening system.

The design of a microscopic system for typical fluorescent in-situ hybridization applications

NASA Astrophysics Data System (ADS)

Yi, Dingrong; Xie, Shaochuan

2013-12-01

Fluorescence in situ hybridization (FISH) is a modern molecular biology technique used for the detection of genetic abnormalities in terms of the number and structure of chromosomes and genes. The FISH technique is typically employed for prenatal diagnosis of congenital dementia in the Obstetrics and Genecology department. It is also routinely used to pick up qualifying breast cancer patients that are known to be highly curable by the prescription of Her2 targeted therapy. During the microscopic observation phase, the technician needs to count typically green probe dots and red probe dots contained in a single nucleus and calculate their ratio. This procedure need to be done to over hundreds of nuclei. Successful implementation of FISH tests critically depends on a suitable fluorescent microscope which is primarily imported from overseas due to the complexity of such a system beyond the maturity of the domestic optoelectrical industry. In this paper, the typical requirements of a fluorescent microscope that is suitable for FISH applications are first reviewed. The focus of this paper is on the system design and computational methods of an automatic florescent microscopy with high magnification APO objectives, a fast spinning automatic filter wheel, an automatic shutter, a cooled CCD camera used as a photo-detector, and a software platform for image acquisition, registration, pseudo-color generation, multi-channel fusing and multi-focus fusion. Preliminary results from FISH experiments indicate that this system satisfies routine FISH microscopic observation tasks.

Reduction reactions and densification during in situ TEM heating of iron oxide nanochains

NASA Astrophysics Data System (ADS)

Bonifacio, Cecile S.; Das, Gautom; Kennedy, Ian M.; van Benthem, Klaus

2017-12-01

The reduction reactions and densification of nanochains assembled from γ-Fe2O3 nanoparticles were investigated using in situ transmission electron microscopy (TEM). Morphological changes and reduction of the metal oxide nanochains were observed during in situ TEM annealing through simultaneous imaging and quantitative analysis of the near-edge fine structures of Fe L2,3 absorption edges acquired by spatially resolved electron energy loss spectroscopy. A change in the oxidation states during annealing of the iron oxide nanochains was observed with phase transformations due to continuous reduction from Fe2O3 over Fe3O4, FeO to metallic Fe. Phase transitions during the in situ heating experiments were accompanied with morphological changes in the nanochains, specifically rough-to-smooth surface transitions below 500 °C, neck formation between adjacent particles around 500 °C, and subsequent neck growth. At higher temperatures, coalescence of FeO particles was observed, representing densification.

Interactions of infectious F-specific RNA bacteriophages with suspended matter and sediment: Towards an understanding of FRNAPH distribution in a river water system.

PubMed

Fauvel, Blandine; Ogorzaly, Leslie; Cauchie, Henry-Michel; Gantzer, Christophe

2017-01-01

The association of viruses with settling particles is certainly a major process controlling the spread of viral pollution in surface water and sediment. To better understand the viral distribution in a river system, the behavior of F-specific RNA bacteriophages (FRNAPHs) was investigated in relationship with the suspended solids and sediment. The partitioning of phage particles (free or associated with solids) in surface water and the attachment capabilities of eight distinct strains of phages to sediment were studied in lab experiments. In situ observations were also performed with the genotyping of 166 individual plaques of FRNAPHs isolated from surface water and sediment. The results reported here demonstrate a variation of the status of infectious phages as a function of the hydro-climatological conditions. Phage-solid association seems to mainly occur during the peak of rainfall-runoff events but also to a certain extent during the recession phase compared to low flow conditions. The transfer of phages from the water column to sediment may occur at this time. Furthermore, the ability of FRNAPHs to interact with sediment was established for six strains out of eight, belonging to genogroups II, III and IV. A similar dynamic was observed for strains within a same genogroup despite different intensity of attachment and inactivation rates for strains of genogroups III and IV. The latter results match the in situ observations in the water and sediment compartments of the studied area. Infectious FRNAPH genogroup II was more abundant in sediment than in surface water. Its capability to sorb to sediment and its higher persistence in the environment compared to genogroups III and IV were the two main explanations. Together, lab and in situ experiments produce an overall vision of the mechanisms governing FRNAPH distribution among the water column and riverbed sediment. Copyright © 2016 Office national des forêts. Published by Elsevier B.V. All rights reserved.

New methods for state estimation and adaptive observation of environmental flow systems leveraging coordinated swarms of sensor vehicles

NASA Astrophysics Data System (ADS)

Bewley, Thomas

2015-11-01

Accurate long-term forecasts of the path and intensity of hurricanes are imperative to protect property and save lives. Accurate estimations and forecasts of the spread of large-scale contaminant plumes, such as those from Deepwater Horizon, Fukushima, and recent volcanic eruptions in Iceland, are essential for assessing environment impact, coordinating remediation efforts, and in certain cases moving folks out of harm's way. The challenges in estimating and forecasting such systems include: (a) environmental flow modeling, (b) high-performance real-time computing, (c) assimilating measured data into numerical simulations, and (d) acquiring in-situ data, beyond what can be measured from satellites, that is maximally relevant for reducing forecast uncertainty. This talk will focus on new techniques for addressing (c) and (d), namely, data assimilation and adaptive observation, in both hurricanes and large-scale environmental plumes. In particular, we will present a new technique for the energy-efficient coordination of swarms of sensor-laden balloons for persistent, in-situ, distributed, real-time measurement of developing hurricanes, leveraging buoyancy control only (coupled with the predictable and strongly stratified flowfield within the hurricane). Animations of these results are available at http://flowcontrol.ucsd.edu/3dhurricane.mp4 and http://flowcontrol.ucsd.edu/katrina.mp4. We also will survey our unique hybridization of the venerable Ensemble Kalman and Variational approaches to large-scale data assimilation in environmental flow systems, and how essentially the dual of this hybrid approach may be used to solve the adaptive observation problem in a uniquely effective and rigorous fashion.

Cooperative Autonomous Observation of Coherent Atmospheric Structures using Small Unmanned Aircraft Systems

NASA Astrophysics Data System (ADS)

Ravela, S.

2014-12-01

Mapping the structure of localized atmospheric phenomena, from sea breeze and shallow cumuli to thunderstorms and hurricanes, is of scientific interest. Low-cost small unmanned aircraft systems (sUAS) open the possibility for autonomous "instruments" to map important small-scale phenomena (kilometers, hours) and serve as a testbed for for much larger scales. Localized phenomena viewed as coherent structures interacting with their large-scale environment are difficult to map. As simple simulations show, naive Eulerian or Lagrangian strategies can fail in mapping localized phenomena. Model-based techniques are needed. Meteorological targeting, where supplementary UAS measurements additionally constrain numerical models is promising, but may require many primary measurements to be successful. We propose a new, data-driven, field-operable, cooperative autonomous observing system (CAOS) framework. A remote observer (on a UAS) tracks tracers to identify an apparent motion model over short timescales. Motion-based predictions seed MCMC flight plans for other UAS to gather in-situ data, which is fused with the remote measurements to produce maps. The tracking and mapping cycles repeat, and maps can be assimilated into numerical models for longer term forecasting. CAOS has been applied to study small scale emissions. At Popocatepetl, in collaboration with CENAPRED and IPN, it is being applied map the plume using remote IR/UV UAS and in-situ SO2 sensing, with additional plans for water vapor, the electric field and ash. The combination of sUAS with autonomy appears to be highly promising methodology for environmental mapping. For more information, please visit http://caos.mit.edu

Comparative modeling of an in situ diffusion experiment in granite at the Grimsel Test Site.

PubMed

Soler, Josep M; Landa, Jiri; Havlova, Vaclava; Tachi, Yukio; Ebina, Takanori; Sardini, Paul; Siitari-Kauppi, Marja; Eikenberg, Jost; Martin, Andrew J

2015-08-01

An in situ diffusion experiment was performed at the Grimsel Test Site (Switzerland). Several tracers ((3)H as HTO, (22)Na(+), (134)Cs(+), (131)I(-) with stable I(-) as carrier) were continuously circulated through a packed-off borehole and the decrease in tracer concentrations in the liquid phase was monitored for a period of about 2years. Subsequently, the borehole section was overcored and the tracer profiles in the rock analyzed ((3)H, (22)Na(+), (134)Cs(+)). (3)H and (22)Na(+) showed a similar decrease in activity in the circulation system (slightly larger drop for (3)H). The drop in activity for (134)Cs(+) was much more pronounced. Transport distances in the rock were about 20cm for (3)H, 10cm for (22)Na(+), and 1cm for (134)Cs(+). The dataset (except for (131)I(-) because of complete decay at the end of the experiment) was analyzed with different diffusion-sorption models by different teams (IDAEA-CSIC, UJV-Rez, JAEA) using different codes, with the goal of obtaining effective diffusion coefficients (De) and porosity (ϕ) or rock capacity (α) values. From the activity measurements in the rock, it was observed that it was not possible to recover the full tracer activity in the rock (no activity balance when adding the activities in the rock and in the fluid circulation system). A Borehole Disturbed Zone (BDZ) had to be taken into account to fit the experimental observations. The extension of the BDZ (1-2mm) is about the same magnitude than the mean grain size of the quartz and feldspar grains. IDAEA-CSIC and UJV-Rez tried directly to match the results of the in situ experiment, without forcing any laboratory-based parameter values into the models. JAEA conducted a predictive modeling based on laboratory diffusion data and their scaling to in situ conditions. The results from the different codes have been compared, also with results from small-scale laboratory experiments. Outstanding issues to be resolved are the need for a very large capacity factor in the BDZ for (3)H and the difference between apparent diffusion coefficients (Da) from the in situ experiment and out-leaching laboratory tests. Copyright © 2015 Elsevier B.V. All rights reserved.

A Climate Data Record (CDR) for the global terrestrial water budget: 1984–2010

DOE PAGES

Zhang, Yu; Pan, Ming; Sheffield, Justin; ...

2018-01-12

Closing the terrestrial water budget is necessary to provide consistent estimates of budget components for understanding water resources and changes over time. Given the lack of in situ observations of budget components at anything but local scale, merging information from multiple data sources (e.g., in situ observation, satellite remote sensing, land surface model, and reanalysis) through data assimilation techniques that optimize the estimation of fluxes is a promising approach. Conditioned on the current limited data availability, a systematic method is developed to optimally combine multiple available data sources for precipitation ( P), evapotranspiration (ET), runoff ( R), and the totalmore » water storage change (TWSC) at 0.5° spatial resolution globally and to obtain water budget closure (i.e., to enforce P-ET- R-TWSC = 0) through a constrained Kalman filter (CKF) data assimilation technique under the assumption that the deviation from the ensemble mean of all data sources for the same budget variable is used as a proxy of the uncertainty in individual water budget variables. The resulting long-term (1984–2010), monthly 0.5° resolution global terrestrial water cycle Climate Data Record (CDR) data set is developed under the auspices of the National Aeronautics and Space Administration (NASA) Earth System Data Records (ESDRs) program. This data set serves to bridge the gap between sparsely gauged regions and the regions with sufficient in situ observations in investigating the temporal and spatial variability in the terrestrial hydrology at multiple scales. The CDR created in this study is validated against in situ measurements like river discharge from the Global Runoff Data Centre (GRDC) and the United States Geological Survey (USGS), and ET from FLUXNET. The data set is shown to be reliable and can serve the scientific community in understanding historical climate variability in water cycle fluxes and stores, benchmarking the current climate, and validating models.« less

A Climate Data Record (CDR) for the global terrestrial water budget: 1984–2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yu; Pan, Ming; Sheffield, Justin

Closing the terrestrial water budget is necessary to provide consistent estimates of budget components for understanding water resources and changes over time. Given the lack of in situ observations of budget components at anything but local scale, merging information from multiple data sources (e.g., in situ observation, satellite remote sensing, land surface model, and reanalysis) through data assimilation techniques that optimize the estimation of fluxes is a promising approach. Conditioned on the current limited data availability, a systematic method is developed to optimally combine multiple available data sources for precipitation ( P), evapotranspiration (ET), runoff ( R), and the totalmore » water storage change (TWSC) at 0.5° spatial resolution globally and to obtain water budget closure (i.e., to enforce P-ET- R-TWSC = 0) through a constrained Kalman filter (CKF) data assimilation technique under the assumption that the deviation from the ensemble mean of all data sources for the same budget variable is used as a proxy of the uncertainty in individual water budget variables. The resulting long-term (1984–2010), monthly 0.5° resolution global terrestrial water cycle Climate Data Record (CDR) data set is developed under the auspices of the National Aeronautics and Space Administration (NASA) Earth System Data Records (ESDRs) program. This data set serves to bridge the gap between sparsely gauged regions and the regions with sufficient in situ observations in investigating the temporal and spatial variability in the terrestrial hydrology at multiple scales. The CDR created in this study is validated against in situ measurements like river discharge from the Global Runoff Data Centre (GRDC) and the United States Geological Survey (USGS), and ET from FLUXNET. The data set is shown to be reliable and can serve the scientific community in understanding historical climate variability in water cycle fluxes and stores, benchmarking the current climate, and validating models.« less

A Climate Data Record (CDR) for the global terrestrial water budget: 1984-2010

NASA Astrophysics Data System (ADS)

Zhang, Yu; Pan, Ming; Sheffield, Justin; Siemann, Amanda L.; Fisher, Colby K.; Liang, Miaoling; Beck, Hylke E.; Wanders, Niko; MacCracken, Rosalyn F.; Houser, Paul R.; Zhou, Tian; Lettenmaier, Dennis P.; Pinker, Rachel T.; Bytheway, Janice; Kummerow, Christian D.; Wood, Eric F.

2018-01-01

Closing the terrestrial water budget is necessary to provide consistent estimates of budget components for understanding water resources and changes over time. Given the lack of in situ observations of budget components at anything but local scale, merging information from multiple data sources (e.g., in situ observation, satellite remote sensing, land surface model, and reanalysis) through data assimilation techniques that optimize the estimation of fluxes is a promising approach. Conditioned on the current limited data availability, a systematic method is developed to optimally combine multiple available data sources for precipitation (P), evapotranspiration (ET), runoff (R), and the total water storage change (TWSC) at 0.5° spatial resolution globally and to obtain water budget closure (i.e., to enforce P - ET - R - TWSC = 0) through a constrained Kalman filter (CKF) data assimilation technique under the assumption that the deviation from the ensemble mean of all data sources for the same budget variable is used as a proxy of the uncertainty in individual water budget variables. The resulting long-term (1984-2010), monthly 0.5° resolution global terrestrial water cycle Climate Data Record (CDR) data set is developed under the auspices of the National Aeronautics and Space Administration (NASA) Earth System Data Records (ESDRs) program. This data set serves to bridge the gap between sparsely gauged regions and the regions with sufficient in situ observations in investigating the temporal and spatial variability in the terrestrial hydrology at multiple scales. The CDR created in this study is validated against in situ measurements like river discharge from the Global Runoff Data Centre (GRDC) and the United States Geological Survey (USGS), and ET from FLUXNET. The data set is shown to be reliable and can serve the scientific community in understanding historical climate variability in water cycle fluxes and stores, benchmarking the current climate, and validating models.

Sensor Web Dynamic Measurement Techniques and Adaptive Observing Strategies

NASA Technical Reports Server (NTRS)

Talabac, Stephen J.

2004-01-01

Sensor Web observing systems may have the potential to significantly improve our ability to monitor, understand, and predict the evolution of rapidly evolving, transient, or variable environmental features and events. This improvement will come about by integrating novel data collection techniques, new or improved instruments, emerging communications technologies and protocols, sensor mark-up languages, and interoperable planning and scheduling systems. In contrast to today's observing systems, "event-driven" sensor webs will synthesize real- or near-real time measurements and information from other platforms and then react by reconfiguring the platforms and instruments to invoke new measurement modes and adaptive observation strategies. Similarly, "model-driven" sensor webs will utilize environmental prediction models to initiate targeted sensor measurements or to use a new observing strategy. The sensor web concept contrasts with today's data collection techniques and observing system operations concepts where independent measurements are made by remote sensing and in situ platforms that do not share, and therefore cannot act upon, potentially useful complementary sensor measurement data and platform state information. This presentation describes NASA's view of event-driven and model-driven Sensor Webs and highlights several research and development activities at the Goddard Space Flight Center.

Conditioning of the vacuum system of the TPS storage ring without baking in situ

NASA Astrophysics Data System (ADS)

Chan, C. K.; Chang, C. C.; Shueh, C.; Yang, I. C.; Wu, L. H.; Chen, B. Y.; Cheng, C. M.; Huang, Y. T.; Chuang, J. Y.; Cheng, Y. T.; Hsiao, Y. M.; Sheng, Albert

2017-04-01

To shorten the machine downtime, a maintenance procedure without baking in situ has been developed and applied to maintain and to upgrade the vacuum system of the TPS storage ring. The data of photon-stimulated desorption (PSD) reveal no obvious discrepancy between baking and not baking the vacuum system in situ. A beam-conditioning dose of extent only 11.8 A h is required to recover quickly the dynamic pressure of an unbaked vacuum system to its pre-intervention value according to the TPS maintenance experience.

Topology of the European Network of Earth Observation Networks and the need for an European Network of Networks

NASA Astrophysics Data System (ADS)

Masó, Joan; Serral, Ivette; McCallum, Ian; Blonda, Palma; Plag, Hans-Peter

2016-04-01

ConnectinGEO (Coordinating an Observation Network of Networks EnCompassing saTellite and IN-situ to fill the Gaps in European Observations" is an H2020 Coordination and Support Action with the primary goal of linking existing Earth Observation networks with science and technology (S&T) communities, the industry sector, the Group on Earth Observations (GEO), and Copernicus. The project will end in February 2017. ConnectinGEO will initiate a European Network of Earth Observation Networks (ENEON) that will encompass space-based, airborne and in-situ observations networks. ENEON will be composed of project partners representing thematic observation networks along with the GEOSS Science and Technology Stakeholder Network, GEO Communities of Practices, Copernicus services, Sentinel missions and in-situ support data representatives, representatives of the European space-based, airborne and in-situ observations networks. This communication presents the complex panorama of Earth Observations Networks in Europe. The list of networks is classified by discipline, variables, geospatial scope, etc. We also capture the membership and relations with other networks and umbrella organizations like GEO. The result is a complex interrelation between networks that can not be clearly expressed in a flat list. Technically the networks can be represented as nodes with relations between them as lines connecting the nodes in a graph. We have chosen RDF as a language and an AllegroGraph 3.3 triple store that is visualized in several ways using for example Gruff 5.7. Our final aim is to identify gaps in the EO Networks and justify the need for a more structured coordination between them.

In Situ Characterization of the Initial Effect of Water on Molecular Interactions at the Interface of Organic/Inorganic Hybrid Systems

PubMed Central

Pletincx, Sven; Trotochaud, Lena; Fockaert, Laura-Lynn; Mol, Johannes M. C.; Head, Ashley R.; Karslıoğlu, Osman; Bluhm, Hendrik; Terryn, Herman; Hauffman, Tom

2017-01-01

Probing initial interactions at the interface of hybrid systems under humid conditions has the potential to reveal the local chemical environment at solid/solid interfaces under real-world, technologically relevant conditions. Here, we show that ambient pressure X-ray photoelectron spectroscopy (APXPS) with a conventional X-ray source can be used to study the effects of water exposure on the interaction of a nanometer-thin polyacrylic acid (PAA) layer with a native aluminum oxide surface. The formation of a carboxylate ionic bond at the interface is characterized both with APXPS and in situ attenuated total reflectance Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann). When water is dosed in the APXPS chamber up to 5 Torr (~28% relative humidity), an increase in the amount of ionic bonds at the interface is observed. To confirm our APXPS interpretation, complementary ATR-FTIR Kretschmann experiments on a similar model system, which is exposed to an aqueous electrolyte, are conducted. These spectra demonstrate that water leads to an increased wet adhesion through increased ionic bond formation. PMID:28327587

ARPS Enabled Titan Rover Concept with Inflatable Wheels

NASA Technical Reports Server (NTRS)

Balint, Tibor S.; Schriener, Timothy M.; Shirley, James H.

2006-01-01

The Decadal Survey identified Titan as one of the top priority science destinations in the large moons category, while NASA's proposed Design Reference Mission Set ranked a Titan in-situ explorer second, after a recommended Europa Geophysical Observer mission. This paper discusses a Titan rover concept, enabled by a single advanced Radioisotope Power System that could provide about 110We (BOL). The concept targets the smaller Flagship or potentially the New Frontiers mission class. This MSL class rover would traverse on four 1.5 m diameter inflatable wheels during its 3 years mission duration and would use as much design and flight heritage as possible to reduce mission cost. Direct to Earth communication would remove the need for a relay orbiter. Details on the strawman instrument payload, and rover subsystems are given for this science driven mission concept. In addition, power system trades between Advanced RTG, TPV, and Advanced Stirling and Brayton Radioisotope Power Systems (RPS) are outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kupar, J.; Hasek, M.

The Sanitary Landfill Corrective Action Plan proposes a two pronged approach to remediation. The first part of the total remediation strategy is the placement of a RCRA style closure cap to provide source control of contaminants into the groundwater. The second part of the proposed remediation package is a phased approach primarily using an in situ bioremediation system for groundwater clean up of the Constituents of Concern (COCs) that exceed their proposed Alternate Concentration Limits (ACL). The phased in approach of groundwater clean up will involve operation of the in situ bioremediation system, followed by evaluation of the Phase 1more » system and, if necessary, additional phased remediation strategies. This document presents pertinent information on operations, well locations, anticipated capture zones, monitoring strategies, observation wells and other information which will allow a decision on the acceptability of the remedial strategy as an interim corrective action prior to permit application approval. The proposed interim phase of the remediation program will position two horizontal bioremediation wells such that the respective zones of influence will intersect the migration path for the highest concentrations of each plume.« less

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated fluorescence in situ hybridization (FISH... Laboratory Equipment and Reagents § 866.4700 Automated fluorescence in situ hybridization (FISH) enumeration... document entitled “Class II Special Controls Guidance Document: Automated Fluorescence in situ...

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated fluorescence in situ hybridization (FISH... Laboratory Equipment and Reagents § 866.4700 Automated fluorescence in situ hybridization (FISH) enumeration... document entitled “Class II Special Controls Guidance Document: Automated Fluorescence in situ...

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated fluorescence in situ hybridization (FISH... Laboratory Equipment and Reagents § 866.4700 Automated fluorescence in situ hybridization (FISH) enumeration... document entitled “Class II Special Controls Guidance Document: Automated Fluorescence in situ...

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated fluorescence in situ hybridization (FISH... Laboratory Equipment and Reagents § 866.4700 Automated fluorescence in situ hybridization (FISH) enumeration... document entitled “Class II Special Controls Guidance Document: Automated Fluorescence in situ...

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated fluorescence in situ hybridization (FISH... Laboratory Equipment and Reagents § 866.4700 Automated fluorescence in situ hybridization (FISH) enumeration... document entitled “Class II Special Controls Guidance Document: Automated Fluorescence in situ...

Detection of soil microorganism in situ by combined gas chromatography mass spectrometry

NASA Technical Reports Server (NTRS)

Alexander, M.; Duxbury, J. M.; Francis, A. J.; Adamson, J.

1972-01-01

Experimental tests were made to determine whether analysis of volatile metabolic products, formed in situ, is a viable procedure for an extraterrestrial life detection system. Laboratory experiments, carried out under anaerobic conditions with addition of carbon source, extended to include a variety of soils and additional substrates. In situ experiments were conducted without amendment using a vacuum sampling system.

In Situ Forming Polymeric Drug Delivery Systems

PubMed Central

Madan, M.; Bajaj, A.; Lewis, S.; Udupa, N.; Baig, J. A.

2009-01-01

In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

In Situ and ex Situ Catalytic Pyrolysis of Pine in a Bench-Scale Fluidized Bed Reactor System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iisa, Kristiina; French, Richard J.; Orton, Kellene A.

In situ and ex situ catalytic pyrolysis were compared in a system with two 2-in. bubbling fluidized bed reactors. Pine was pyrolyzed in the system with a catalyst, HZSM-5 with a silica-to-alumina ratio of 30, placed either in the first (pyrolysis) reactor or the second (upgrading) reactor. Both the pyrolysis and upgrading temperatures were 500 degrees C, and the weight hourly space velocity was 1.1 h -1. Five catalytic cycles were completed in each experiment. The catalytic cycles were continued until oxygenates in the vapors became dominant. The catalyst was then oxidized, after which a new catalytic cycle was begun.more » The in situ configuration gave slightly higher oil yield but also higher oxygen content than the ex situ configuration, which indicates that the catalyst deactivated faster in the in situ configuration than the ex situ configuration. Analysis of the spent catalysts confirmed higher accumulation of metals in the in situ experiment. In all experiments, the organic oil mass yields varied between 14 and 17% and the carbon efficiencies between 20 and 25%. The organic oxygen concentrations in the oils were 16-18%, which represented a 45% reduction compared to corresponding noncatalytic pyrolysis oils prepared in the same fluidized bed reactor system. GC/MS analysis showed the oils to contain one- to four-ring aromatic hydrocarbons and a variety of oxygenates (phenols, furans, benzofurans, methoxyphenols, naphthalenols, indenols). Lastly, high fractions of oxygen were rejected as water, CO, and CO 2, which indicates the importance of dehydration, decarbonylation, and decarboxylation reactions. Light gases were the major sources of carbon losses, followed by char and coke.« less

In Situ and ex Situ Catalytic Pyrolysis of Pine in a Bench-Scale Fluidized Bed Reactor System

DOE PAGES

Iisa, Kristiina; French, Richard J.; Orton, Kellene A.; ...

2016-02-03

In situ and ex situ catalytic pyrolysis were compared in a system with two 2-in. bubbling fluidized bed reactors. Pine was pyrolyzed in the system with a catalyst, HZSM-5 with a silica-to-alumina ratio of 30, placed either in the first (pyrolysis) reactor or the second (upgrading) reactor. Both the pyrolysis and upgrading temperatures were 500 degrees C, and the weight hourly space velocity was 1.1 h -1. Five catalytic cycles were completed in each experiment. The catalytic cycles were continued until oxygenates in the vapors became dominant. The catalyst was then oxidized, after which a new catalytic cycle was begun.more » The in situ configuration gave slightly higher oil yield but also higher oxygen content than the ex situ configuration, which indicates that the catalyst deactivated faster in the in situ configuration than the ex situ configuration. Analysis of the spent catalysts confirmed higher accumulation of metals in the in situ experiment. In all experiments, the organic oil mass yields varied between 14 and 17% and the carbon efficiencies between 20 and 25%. The organic oxygen concentrations in the oils were 16-18%, which represented a 45% reduction compared to corresponding noncatalytic pyrolysis oils prepared in the same fluidized bed reactor system. GC/MS analysis showed the oils to contain one- to four-ring aromatic hydrocarbons and a variety of oxygenates (phenols, furans, benzofurans, methoxyphenols, naphthalenols, indenols). Lastly, high fractions of oxygen were rejected as water, CO, and CO 2, which indicates the importance of dehydration, decarbonylation, and decarboxylation reactions. Light gases were the major sources of carbon losses, followed by char and coke.« less

Method for enhanced longevity of in situ microbial filter used for bioremediation

DOEpatents

Carman, M. Leslie; Taylor, Robert T.

1999-01-01

An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

Planar Laser Imaging of Scattering and Fluorescence of Zooplankton Feeding in Layers of Phytoplankton in situ

DTIC Science & Technology

2007-09-30

Planar Laser Imaging of Scattering and Fluorescence of Zooplankton Feeding in Layers of Phytoplankton in situ Peter J.S. Franks Scripps...herbivorous copepod feeding in the laboratory, and 2) to apply these methods in the field to observe the dynamics of copepod feeding in situ. In...particular we intend to test the “ feeding sorties” hypothesis vs. the “in situ feeding ” hypothesis regarding the location and timing of copepod feeding

A domain analysis approach to clear-air turbulence forecasting using high-density in-situ measurements

NASA Astrophysics Data System (ADS)

Abernethy, Jennifer A.

Pilots' ability to avoid clear-air turbulence (CAT) during flight affects the safety of the millions of people who fly commercial airlines and other aircraft, and turbulence costs millions in injuries and aircraft maintenance every year. Forecasting CAT is not straightforward, however; microscale features like the turbulence eddies that affect aircraft (100m) are below the current resolution of operational numerical weather prediction (NWP) models, and the only evidence of CAT episodes, until recently, has been sparse, subjective reports from pilots known as PIREPs. To forecast CAT, researchers use a simple weighted sum of top-performing turbulence indicators derived from NWP model outputs---termed diagnostics---based on their agreement with current PIREPs. However, a new, quantitative source of observation data---high-density measurements made by sensor equipment and software on aircraft, called in-situ measurements---is now available. The main goal of this thesis is to develop new data analysis and processing techniques to apply to the model and new observation data, in order to improve CAT forecasting accuracy. This thesis shows that using in-situ data improves forecasting accuracy and that automated machine learning algorithms such as support vector machines (SVM), logistic regression, and random forests, can match current performance while eliminating almost all hand-tuning. Feature subset selection is paired with the new algorithms to choose diagnostics that predict well as a group rather than individually. Specializing forecasts and choice of diagnostics by geographic region further improves accuracy because of the geographic variation in turbulence sources. This work uses random forests to find climatologically-relevant regions based on these variations and implements a forecasting system testbed which brings these techniques together to rapidly prototype new, regionalized versions of operational CAT forecasting systems.

The impact of calcium carbonate as pore forming agent and drug entrapment method towards drug dissolution mechanism of amoxicillin trihydrate encapsulated by chitosan-methyl cellulose semi-IPN hydrogel for floating drug delivery system

NASA Astrophysics Data System (ADS)

Dewantara, Fauzi; Budianto, Emil

2018-04-01

Chitosan-methyl cellulose semi-IPN hydrogel is used as floating drug delivery system, and calcium carbonate also added as pore forming agent. The hydrogel network arranged by not only using biopolymer chitosan and methyl cellulose, but also the crosslink agent that is glutaraldehyde. Amoxicillin trihydrate entrapped into the polymer network with two different method, in situ loading and post loading. Furthermore both method has been tested for drug entrapment efficiency along with drug dissolution test, and the result for drug entrapment efficiency is in situ loading method has highest value of 100%, compared to post loading method which has value only 71%. Moreover, at the final time of drug dissolution test shows in situ loading method has value of 96% for total accumulative of drug dissolution, meanwhile post loading method has 72%. The value of drug dissolution test from both method is used for analyzing drug dissolution mechanism of amoxicillin trihydrate from hydrogel network with four mathematical drug mechanism models as parameter. The polymer network encounter destructive degradation causes by acid solution which used as dissolution medium, and the level of degradation is observed with optical microscope. However the result shows that degradation of the polymer network doesn't affect drug dissolution mechanism directly. Although the pore forming agent causes the pore inside the hydrogel network create interconnection and it was quite influential to drug dissolution mechanism. Interconnected pore is observed with Scanning Electron Microscope (SEM) and shows that the amount and area of interconnected pore inside the hydrogel network is increasing as drug dissolution goes on.

Level 2 processing for the imaging Fourier transform spectrometer GLORIA: derivation and validation of temperature and trace gas volume mixing ratios from calibrated dynamics mode spectra

NASA Astrophysics Data System (ADS)

Ungermann, J.; Blank, J.; Dick, M.; Ebersoldt, A.; Friedl-Vallon, F.; Giez, A.; Guggenmoser, T.; Höpfner, M.; Jurkat, T.; Kaufmann, M.; Kaufmann, S.; Kleinert, A.; Krämer, M.; Latzko, T.; Oelhaf, H.; Olchewski, F.; Preusse, P.; Rolf, C.; Schillings, J.; Suminska-Ebersoldt, O.; Tan, V.; Thomas, N.; Voigt, C.; Zahn, A.; Zöger, M.; Riese, M.

2015-06-01

The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an airborne infrared limb imager combining a two-dimensional infrared detector with a Fourier transform spectrometer. It was operated aboard the new German Gulfstream G550 High Altitude LOng Range (HALO) research aircraft during the Transport And Composition in the upper Troposphere/lowermost Stratosphere (TACTS) and Earth System Model Validation (ESMVAL) campaigns in summer 2012. This paper describes the retrieval of temperature and trace gas (H2O, O3, HNO3) volume mixing ratios from GLORIA dynamics mode spectra that are spectrally sampled every 0.625 cm-1. A total of 26 integrated spectral windows are employed in a joint fit to retrieve seven targets using consecutively a fast and an accurate tabulated radiative transfer model. Typical diagnostic quantities are provided including effects of uncertainties in the calibration and horizontal resolution along the line of sight. Simultaneous in situ observations by the Basic Halo Measurement and Sensor System (BAHAMAS), the Fast In-situ Stratospheric Hygrometer (FISH), an ozone detector named Fairo, and the Atmospheric chemical Ionization Mass Spectrometer (AIMS) allow a validation of retrieved values for three flights in the upper troposphere/lowermost stratosphere region spanning polar and sub-tropical latitudes. A high correlation is achieved between the remote sensing and the in situ trace gas data, and discrepancies can to a large extent be attributed to differences in the probed air masses caused by different sampling characteristics of the instruments. This 1-D processing of GLORIA dynamics mode spectra provides the basis for future tomographic inversions from circular and linear flight paths to better understand selected dynamical processes of the upper troposphere and lowermost stratosphere.

Level 2 processing for the imaging Fourier transform spectrometer GLORIA: derivation and validation of temperature and trace gas volume mixing ratios from calibrated dynamics mode spectra

NASA Astrophysics Data System (ADS)

Ungermann, J.; Blank, J.; Dick, M.; Ebersoldt, A.; Friedl-Vallon, F.; Giez, A.; Guggenmoser, T.; Höpfner, M.; Jurkat, T.; Kaufmann, M.; Kaufmann, S.; Kleinert, A.; Krämer, M.; Latzko, T.; Oelhaf, H.; Olchewski, F.; Preusse, P.; Rolf, C.; Schillings, J.; Suminska-Ebersoldt, O.; Tan, V.; Thomas, N.; Voigt, C.; Zahn, A.; Zöger, M.; Riese, M.

2014-12-01

The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an airborne infrared limb-imager combining a two-dimensional infrared detector with a Fourier transform spectrometer. It was operated aboard the new German Gulfstream G550 research aircraft HALO during the Transport And Composition in the upper Troposphere/lowermost Stratosphere (TACTS) and Earth System Model Validation (ESMVAL) campaigns in summer 2012. This paper describes the retrieval of temperature and trace gas (H2O, O3, HNO3) volume mixing ratios from GLORIA dynamics mode spectra. 26 integrated spectral windows are employed in a joint fit to retrieve seven targets using consecutively a fast and an accurate tabulated radiative transfer model. Typical diagnostic quantities are provided including effects of uncertainties in the calibration and horizontal resolution along the line-of-sight. Simultaneous in-situ observations by the BAsic HALO Measurement And Sensor System (BAHAMAS), the Fast In-Situ Stratospheric Hygrometer (FISH), FAIRO, and the Atmospheric chemical Ionization Mass Spectrometer (AIMS) allow a validation of retrieved values for three flights in the upper troposphere/lowermost stratosphere region spanning polar and sub-tropical latitudes. A high correlation is achieved between the remote sensing and the in-situ trace gas data, and discrepancies can to a large fraction be attributed to differences in the probed air masses caused by different sampling characteristics of the instruments. This 1-D processing of GLORIA dynamics mode spectra provides the basis for future tomographic inversions from circular and linear flight paths to better understand selected dynamical processes of the upper troposphere and lowermost stratosphere.

Specific findings on ice crystal microphysical properties from in-situ observation

NASA Astrophysics Data System (ADS)

Coutris, Pierre; Leroy, Delphine; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter

2017-04-01

This study focuses on microphysical properties of ice particles populating high ice water content areas in Mesoscale Convective Systems (MCS). These clouds have been extensively sampled during the High Altitude Ice Crystal - High Ice Water Content international projects (HAIC-HIWC, Dezitter et al. 2013, Strapp et al. 2015) with the objective of characterizing ice particle properties such as size distribution, radar reflectivity and ice water content. The in-situ data collected during these campaigns at different temperature levels and in different type of MCS (oceanic, continental) make the HAIC-HIWC data set a unique opportunity to study ice particle microphysical properties. Recently, a new approach to retrieve ice particle mass from in-situ measurements has been developed: a forward model that relates ice particles' mass to Particle Size Distribution (PSD) and Ice Water Content (IWC) is formulated as a linear system of equations and the retrieval process consists in solving the inverse problem with numerical optimization tools (Coutris et al. 2016). In this study, this new method is applied to HAIC-HIWC data set and main outcomes are discussed. First, the method is compared to a classical power-law based method using data from one single flight performed in Darwin area on February, 7th 2014. The observed differences in retrieved quantities such as ice particle mass, ice water content or median mass diameter, highlight the potential benefit of abandoning the power law simplistic assumption. The method is then applied to data measured at different cloud temperatures ranging from -40°C to -10°C during several flights of both Darwin 2014 and Cayenne 2015 campaigns. Specific findings about ice microphysical properties such as variations of effective density with particle size and the influence of cloud temperature on particle effective density are presented.

A review of sensors, samplers and methods for marine biological observations.

NASA Astrophysics Data System (ADS)

Simmons, S. E.; Chavez, F.; Pearlman, J.; Working Group, T B S

2016-02-01

Physical scientists now have Argo floats, gliders and AUVs to supplement satellites to provide a 3-D view of the time-varying global ocean temperature and salinity structure. Biogeochemists are catching up with evolving sensors for nitrate, optical properties, oxygen and pH that can now be added to these autonomous systems. Biologists are still lagging, although some promising sensor systems based on but not limited to acoustic, chemical, genomic or imaging techniques, that can sense from microbes to whales, are on the horizon. These techniques can not only be applied in situ but also on samples returned to the laboratory using the autonomous systems. The number of samples is limiting, requiring adaptive and smart systems. Given the importance of biology to ocean health and the future earth, and the present reliance on humans and ships for observing species and abundance it is paramount that new biological sensor systems be developed. This abstract will review recent efforts to identify core biological variables for the US Integrated Ocean Observing System and address new sensors and innovations for observing these variables, particularly focused on availability and maturity of sensors. The relevance of this work in a global context will also be touched on.

Improving attachments of remotely-deployed dorsal fin-mounted tags: tissue structure, hydrodynamics, in situ performance, and tagged-animal follow-up

DTIC Science & Technology

2011-09-01

Examine the in situ performance of our current attachment devices and then design and test improved retention systems Report Documentation Page Form...behavior (e.g., beaked whale versus melon-headed whale). 3. In situ behavior of retention system elements (Key individuals: Andrews, Schorr...Although we have a good idea of how the LIMPET retention system operates when first implanted, we do not fully understand the mechanics in a living fin

Fracture Mechanics Modelling of an In Situ Concrete Spalling Experiment

NASA Astrophysics Data System (ADS)

Siren, Topias; Uotinen, Lauri; Rinne, Mikael; Shen, Baotang

2015-07-01

During the operation of nuclear waste disposal facilities, some sprayed concrete reinforced underground spaces will be in use for approximately 100 years. During this time of use, the local stress regime will be altered by the radioactive decay heat. The change in the stress state will impose high demands on sprayed concrete, as it may suffer stress damage or lose its adhesion to the rock surface. It is also unclear what kind of support pressure the sprayed concrete layer will apply to the rock. To investigate this, an in situ experiment is planned in the ONKALO underground rock characterization facility at Olkiluoto, Finland. A vertical experimental hole will be concreted, and the surrounding rock mass will be instrumented with heat sources, in order to simulate an increase in the surrounding stress field. The experiment is instrumented with an acoustic emission system for the observation of rock failure and temperature, as well as strain gauges to observe the thermo-mechanical interactive behaviour of the concrete and rock at several levels, in both rock and concrete. A thermo-mechanical fracture mechanics study is necessary for the prediction of the damage before the experiment, in order to plan the experiment and instrumentation, and for generating a proper prediction/outcome study due to the special nature of the in situ experiment. The prediction of acoustic emission patterns is made by Fracod 2D and the model later compared to the actual observed acoustic emissions. The fracture mechanics model will be compared to a COMSOL Multiphysics 3D model to study the geometrical effects along the hole axis.

Spatiotemporal interpolation of discharge across a river network by using synthetic SWOT satellite data

NASA Astrophysics Data System (ADS)

Paiva, Rodrigo C. D.; Durand, Michael T.; Hossain, Faisal

2015-01-01

Recent efforts have sought to estimate river discharge and other surface water-related quantities using spaceborne sensors, with better spatial coverage but worse temporal sampling as compared with in situ measurements. The Surface Water and Ocean Topography (SWOT) mission will provide river discharge estimates globally from space. However, questions on how to optimally use the spatially distributed but asynchronous satellite observations to generate continuous fields still exist. This paper presents a statistical model (River Kriging-RK), for estimating discharge time series in a river network in the context of the SWOT mission. RK uses discharge estimates at different locations and times to produce a continuous field using spatiotemporal kriging. A key component of RK is the space-time river discharge covariance, which was derived analytically from the diffusive wave approximation of Saint Venant's equations. The RK covariance also accounts for the loss of correlation at confluences. The model performed well in a case study on Ganges-Brahmaputra-Meghna (GBM) River system in Bangladesh using synthetic SWOT observations. The correlation model reproduced empirically derived values. RK (R2=0.83) outperformed other kriging-based methods (R2=0.80), as well as a simple time series linear interpolation (R2=0.72). RK was used to combine discharge from SWOT and in situ observations, improving estimates when the latter is included (R2=0.91). The proposed statistical concepts may eventually provide a feasible framework to estimate continuous discharge time series across a river network based on SWOT data, other altimetry missions, and/or in situ data.

System to measure accurate temperature dependence of electric conductivity down to 20 K in ultrahigh vacuum.

PubMed

Sakai, C; Takeda, S N; Daimon, H

2013-07-01

We have developed the new in situ electrical-conductivity measurement system which can be operated in ultrahigh vacuum (UHV) with accurate temperature measurement down to 20 K. This system is mainly composed of a new sample-holder fixing mechanism, a new movable conductivity-measurement mechanism, a cryostat, and two receptors for sample- and four-probe holders. Sample-holder is pushed strongly against the receptor, which is connected to a cryostat, by using this new sample-holder fixing mechanism to obtain high thermal conductivity. Test pieces on the sample-holders have been cooled down to about 20 K using this fixing mechanism, although they were cooled down to only about 60 K without this mechanism. Four probes are able to be touched to a sample surface using this new movable conductivity-measurement mechanism for measuring electrical conductivity after making film on substrates or obtaining clean surfaces by cleavage, flashing, and so on. Accurate temperature measurement is possible since the sample can be transferred with a thermocouple and∕or diode being attached directly to the sample. A single crystal of Bi-based copper oxide high-Tc superconductor (HTSC) was cleaved in UHV to obtain clean surface, and its superconducting critical temperature has been successfully measured in situ. The importance of in situ measurement of resistance in UHV was demonstrated for this HTSC before and after cesium (Cs) adsorption on its surface. The Tc onset increase and the Tc offset decrease by Cs adsorption were observed.

High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope.

PubMed

Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

2016-03-01

In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10(-7) Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies.

Multi-parameter brain tissue microsensor and interface systems: calibration, reliability and user experiences of pressure and temperature sensors in the setting of neurointensive care.

PubMed

Childs, Charmaine; Wang, Li; Neoh, Boon Kwee; Goh, Hok Liok; Zu, Mya Myint; Aung, Phyo Wai; Yeo, Tseng Tsai

2014-10-01

The objective was to investigate sensor measurement uncertainty for intracerebral probes inserted during neurosurgery and remaining in situ during neurocritical care. This describes a prospective observational study of two sensor types and including performance of the complete sensor-bedside monitoring and readout system. Sensors from 16 patients with severe traumatic brain injury (TBI) were obtained at the time of removal from the brain. When tested, 40% of sensors achieved the manufacturer temperature specification of 0.1 °C. Pressure sensors calibration differed from the manufacturers at all test pressures in 8/20 sensors. The largest pressure measurement error was in the intraparenchymal triple sensor. Measurement uncertainty is not influenced by duration in situ. User experiences reveal problems with sensor 'handling', alarms and firmware. Rigorous investigation of the performance of intracerebral sensors in the laboratory and at the bedside has established measurement uncertainty in the 'real world' setting of neurocritical care.

In situ electron microscopy of Braille microsystems: photo-actuation of ethylene vinyl acetate/carbon nanotube composites

NASA Astrophysics Data System (ADS)

Czaniková, Klaudia; Krupa, Igor; Račko, Dušan; Šmatko, Vasilij; Campo, Eva M.; Pavlova, Ewa; Omastová, Mária

2015-02-01

The development of new types of tactile displays based on the actuation of composite materials can aid the visually impaired. Micro/nano systems based on ethylene vinyl acetate (EVA) polymeric matrices enriched with multiwalled carbon nanotubes (MWCNT) can produce ensembles capable of light-induced actuation. In this report, we investigate two types of commercial EVA copolymers matrices containing 28 and 50 wt% vinyl-acetate (VA). Non-covalent modification of carbon nanotubes was achieved through a compatibilization technique that appends the pyrenenyl and cholesteryl groups on the carbon nanotubes (CNTs) surface. EVA/MWCNT nanocomposites were prepared by casting from a solution. These composites were shaped into Braille elements using molds. The deformation of the Braille element (BE) under light-emitting diode (LED) illumination was observed for the first time by in situ scanning electron microscopy (SEM). The superior actuation performance promoted by the EVA/MWCNT nanocomposites indicates that these materials will be useful in the future as light-driven micro/nano system actuators.

Using Multiple Big Datasets and Machine Learning to Produce a New Global Particulate Dataset: A Technology Challenge Case Study

NASA Astrophysics Data System (ADS)

Lary, D. J.

2013-12-01

A BigData case study is described where multiple datasets from several satellites, high-resolution global meteorological data, social media and in-situ observations are combined using machine learning on a distributed cluster using an automated workflow. The global particulate dataset is relevant to global public health studies and would not be possible to produce without the use of the multiple big datasets, in-situ data and machine learning.To greatly reduce the development time and enhance the functionality a high level language capable of parallel processing has been used (Matlab). A key consideration for the system is high speed access due to the large data volume, persistence of the large data volumes and a precise process time scheduling capability.

A new ultrasonic transducer sample cell for in situ small-angle scattering experiments

NASA Astrophysics Data System (ADS)

Gupta, Sudipta; Bleuel, Markus; Schneider, Gerald J.

2018-01-01

Ultrasound irradiation is a commonly used technique for nondestructive diagnostics or targeted destruction. We report on a new versatile sonication device that fits in a variety of standard sample environments for neutron and X-ray scattering instruments. A piezoelectric transducer permits measuring of the time-dependent response of the sample in situ during or after sonication. We use small-angle neutron scattering (SANS) to demonstrate the effect of a time-dependent perturbation on the structure factor of micelles formed from sodium dodecyl sulfate surfactant molecules. We observe a substantial change in the micellar structure during and after exposure to ultrasonic irradiation. We also observe a time-dependent relaxation to the equilibrium values of the unperturbed system. The strength of the perturbation of the structure factor depends systematically on the duration of sonication. The relaxation behavior can be well reproduced after multiple times of sonication. Accumulation of the recorded intensities of the different sonication cycles improves the signal-to-noise ratio and permits reaching very short relaxation times. In addition, we present SANS data for the micellar form factor on alkyl-poly (ethylene oxide) surfactant molecules irradiated by ultrasound. Due to the flexibility of our new in situ sonication device, different experiments can be performed, e.g., to explore molecular potentials in more detail by introducing a systematic time-dependent perturbation.

In situ characterization of charge rate dependent stress and structure changes in V2O5 cathode prepared by atomic layer deposition

NASA Astrophysics Data System (ADS)

Jung, Hyun; Gerasopoulos, Konstantinos; Talin, A. Alec; Ghodssi, Reza

2017-02-01

The insertion/extraction of lithium into/from various host materials is the basic process by which lithium-ion batteries reversible store charge. This process is generally accompanied by strain in the host material, inducing stress which can lead to capacity loss. Therefore, understanding of both the structural changes and the associated stress - investigated almost exclusively separate to date - is a critical factor for developing high-performance batteries. Here, we report an in situ method, which utilizes Raman spectroscopy in parallel with optical interferometry to study effects of varying charging rates (C-rates) on the structure and stress in a V2O5 thin film cathode. Abrupt stress changes at specific crystal phase transitions in the Lisbnd Vsbnd O system are observed and the magnitude of the stress changes with the amount of lithium inserted into the electrode are correlated. A linear increase in the stress as a function of x in LixV2O5 is observed, indicating that C-rate does not directly contribute to larger intercalation stress. However, a more rapid increase in disorder within the LixV2O5 layers is correlated with higher C-rate. Ultimately, these experiments demonstrate how the simultaneous stress/Raman in situ approach can be utilized as a characterization platform for investigating various critical factors affecting lithium-ion battery performance.

Oxidation Induced Doping of Nanoparticles Revealed by in Situ X-ray Absorption Studies.

PubMed

Kwon, Soon Gu; Chattopadhyay, Soma; Koo, Bonil; Dos Santos Claro, Paula Cecilia; Shibata, Tomohiro; Requejo, Félix G; Giovanetti, Lisandro J; Liu, Yuzi; Johnson, Christopher; Prakapenka, Vitali; Lee, Byeongdu; Shevchenko, Elena V

2016-06-08

Doping is a well-known approach to modulate the electronic and optical properties of nanoparticles (NPs). However, doping at nanoscale is still very challenging, and the reasons for that are not well understood. We studied the formation and doping process of iron and iron oxide NPs in real time by in situ synchrotron X-ray absorption spectroscopy. Our study revealed that the mass flow of the iron triggered by oxidation is responsible for the internalization of the dopant (molybdenum) adsorbed at the surface of the host iron NPs. The oxidation induced doping allows controlling the doping levels by varying the amount of dopant precursor. Our in situ studies also revealed that the dopant precursor substantially changes the reaction kinetics of formation of iron and iron oxide NPs. Thus, in the presence of dopant precursor we observed significantly faster decomposition rate of iron precursors and substantially higher stability of iron NPs against oxidation. The same doping mechanism and higher stability of host metal NPs against oxidation was observed for cobalt-based systems. Since the internalization of the adsorbed dopant at the surface of the host NPs is driven by the mass transport of the host, this mechanism can be potentially applied to introduce dopants into different oxidized forms of metal and metal alloy NPs providing the extra degree of compositional control in material design.

Intrinsic stress in ZrN thin films: Evaluation of grain boundary contribution from in situ wafer curvature and ex situ x-ray diffraction techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koutsokeras, L. E.; Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110; Abadias, G.

2012-05-01

Low-mobility materials, like transition metal nitrides, usually undergo large residual stress when sputter-deposited as thin films. While the origin of stress development has been an active area of research for high-mobility materials, atomistic processes are less understood for low-mobility systems. In the present work, the contribution of grain boundary to intrinsic stress in reactively magnetron-sputtered ZrN films is evaluated by combining in situ wafer curvature measurements, providing information on the overall biaxial stress, and ex situ x-ray diffraction, giving information on elastic strain (and related stress) inside crystallites. The thermal stress contribution was also determined from the in situ stressmore » evolution during cooling down, after deposition was stopped. The stress data are correlated with variations in film microstructure and growth energetics, in the 0.13-0.42 Pa working pressure range investigated, and discussed based on existing stress models. At low pressure (high energetic bombardment conditions), a large compressive stress is observed due to atomic peening, which induces defects inside crystallites but also promotes incorporation of excess atoms in the grain boundary. Above 0.3-0.4 Pa, the adatom surface mobility is reduced, leading to the build-up of tensile stress resulting from attractive forces between under-dense neighbouring column boundary and possible void formation, while crystallites can still remain under compressive stress.« less

Geomechanical Study of Bakken Formation for Improved Oil Recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ling, Kegang; Zeng, Zhengwen; He, Jun

2013-12-31

On October 1, 2008 US DOE-sponsored research project entitled “Geomechanical Study of Bakken Formation for Improved Oil Recovery” under agreement DE-FC26-08NT0005643 officially started at The University of North Dakota (UND). This is the final report of the project; it covers the work performed during the project period of October 1, 2008 to December 31, 2013. The objectives of this project are to outline the methodology proposed to determine the in-situ stress field and geomechanical properties of the Bakken Formation in Williston Basin, North Dakota, USA to increase the success rate of horizontal drilling and hydraulic fracturing so as to improvemore » the recovery factor of this unconventional crude oil resource from the current 3% to a higher level. The success of horizontal drilling and hydraulic fracturing depends on knowing local in-situ stress and geomechanical properties of the rocks. We propose a proactive approach to determine the in-situ stress and related geomechanical properties of the Bakken Formation in representative areas through integrated analysis of field and well data, core sample and lab experiments. Geomechanical properties are measured by AutoLab 1500 geomechanics testing system. By integrating lab testing, core observation, numerical simulation, well log and seismic image, drilling, completion, stimulation, and production data, in-situ stresses of Bakken formation are generated. These in-situ stress maps can be used as a guideline for future horizontal drilling and multi-stage fracturing design to improve the recovery of Bakken unconventional oil.« less

In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

NASA Astrophysics Data System (ADS)

Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

2015-07-01

Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

In Situ Observations of Electric-Field Induced Nanoparticle Aggregation

NASA Astrophysics Data System (ADS)

Woehl, T. J.; Browning, N. D.; Ristenpart, W. D.

2010-11-01

Nanoparticles have been widely observed to aggregate laterally on electrodes in response to applied electric fields. The mechanism driving this behavior, however, is unclear. Several groups have interpreted the aggregation in terms of electrohydrodynamic or electroosmotic fluid motion, but little corroborating evidence has been presented. Notably, work to date has relied on post situ observations using electron microscopy. Here we present a fluorescence microscopy technique to track the dynamics of nanoparticle aggregation in situ. Fluorescent 20-nm polystyrene nanoparticles are observed to form optically visible aggregates in response to an applied AC field. Although single particle resolution is lost, the existence of aggregates on the electrode surface is marked by growing clusters of increasingly bright intensity. We present a systematic investigation of the effects of applied potential and frequency on the aggregation rate, and we interpret the behavior in terms of a mechanism based on electrically induced convective flow.

A measurement routine to determine 137Cs activities at steep mountain slopes

NASA Astrophysics Data System (ADS)

Schaub, Monika; Konz, Nadine; Meusburger, Katrin; Alewell, Chrstine

2010-05-01

Caesium-137 (137Cs) is a common tracer for soil erosion. So far, in-situ measurements in steep alpine environments have not often been done. Most studies have been carried out in arable lands and with Ge detectors. However, the NaI detector system is a good priced, easy to handle field instrument. A comparison of laboratory measurements with GeLi detector and in-situ measurements with NaI detector of 137Cs gamma soil radiation has been done in an alpine catchment (Urseren Valley, Swizerland). The aim of this study was to calibrate the in-situ NaI detector system for application at steep alpine slopes. Replicate samples from an altitudinal transect through the Urseren Valley were measured ex situ in the laboratory with a GeLi detector, and compared to in situ NaI detector measurements. Ex situ soil samples showed a big variability in 137Cs activities at a meter-scale. This large, small scale heterogeneity determined with the GeLi detector is smoothed out by uncollimated in-situ measurements with the NaI detector, which provide integrated estimates of 137Cs within the field of view of each measurement (3.1 m2). There was no dependency of 137Cs on pH, clay content and carbon content. However, a close relationship was determined between 137Cs and soil moisture. Thus, in-situ data must be corrected for soil moisture. Close correlation (R2 = 0.86) was found for 137Cs activities (in Bq kg-1) estimated with both, in-situ (NaI detector) and laboratory (GeLi detector) methods which proves the validity of the in-situ measurements with the NaI detector system. This paper describes the calibration of the NaI detector system for field application under elevated 137Cs activities originating from Chernobyl fallout.

How to spy on your neighbor's water consumption from space

NASA Astrophysics Data System (ADS)

Neely, W.; Borsa, A. A.; Burney, J. A.

2017-12-01

Dependence on groundwater has increased in the agricultural production regions of California's Central Valley due to recent and persistent droughts. To protect the long-term reliability of groundwater resources in California, the state passed the Sustainable Groundwater Management Act (SGMA) in September 2014. In situ observation of subsurface reservoir levels is ideal for monitoring aquifer health at a water district scale, but is limited by the low density of monitoring wells and temporal gaps between measurements. An alternative to well measurements relies on the fact that groundwater extraction may lead to surface subsidence due to the compaction of the aquifer at depth. Such surface displacements can be resolved using geodetic techniques. We present an integrative approach using Interferometric Synthetic Aperture Radar (InSAR) and continuous Global Positioning System (cGPS) station observations to characterize surface deformation related to extensive pumping at a farm-level resolution every 12-24 days. We demonstrate our technique in the southern Central Valley where we observe subsidence upwards of 25 cm/yr from late 2014 to early 2017. Our methods offer an inexpensive supplement to in situ measurements that allows for the detection and deterrence of water mismanagement.

Aerokats and Rover

NASA Astrophysics Data System (ADS)

Bland, G.; Miles, T.; Nagchaudhuri, A.; Henry, A.; Coronado, P.; Smith, S.; Bydlowski, D.; Gaines, J.; Hartman, C.

2015-12-01

Two novel tools are being developed for team-based environmental and science observations suitable for use in Middle School through Undergraduate settings. Partnerships with NASA's Goddard Space Flight Center are critical for this work, and the concepts and practices are aimed at providing affordable and easy-to-field hardware to the classroom. The Advanced Earth Research Observation Kites and Atmospheric and Terrestrial Sensors (AEROKATS) system brings affordable and easy-to-field remote sensing and in-situ measurements within reach for local-scale Earth observations and data gathering. Using commercial kites, a wide variety of sensors, and a new NASA technology, AEROKATS offers a quick-to-learn method to gather airborne remote sensing and in-situ data for classroom analysis. The Remotely Operated Vehicle for Education and Research (ROVER) project introduces team building for mission operations and research, using modern technologies for exploring aquatic environments. ROVER projects use hobby-type radio control hardware and common in-water instrumentation, to highlight the numerous roles and responsibilities needed in real-world research missions, such as technology, operations, and science disciplines. NASA GSFC's partnerships have enabled the fielding of several AEROKATS and ROVER prototypes, and results suggest application of these methods is feasible and engaging.

Metastable solidification of hypereutectic Co 2Si-CoSi composition: Microstructural studies and in-situ observations

DOE PAGES

Wang, Yeqing; Gao, Jianrong; Kolbe, Matthias; ...

2017-09-18

Metastable solidification of undercooled Co 60Si 40 melts was investigated by microstructural studies and in-situ high-energy X-ray diffraction. Five solidification paths were identified. Three of them were observed at low undercoolings, which show uncoupled and coupled growth of stable β-Co 2Si and CoSi compounds. The other paths were observed at high undercoolings, which show peritectic and primary crystallization of a metastable Co 5Si 3 compound. The β-Co 2Si and Co 5Si 3 compounds crystallize into a hexagonal crystal structure and experience solid-state decomposition. Microstructure formation depends on solidification path. The coupled and uncoupled growth of the stable compounds produces amore » regular lamellar eutectic structure and an anomalous eutectic structure, respectively. The crystallization and solid-state decomposition of the metastable Co 5Si 3 compound brings about a fine-grained two-phase mixture, which represents another type of anomalous eutectic structure. Here, the results provide proof of two rare mechanisms of anomalous eutectic formation and shed light onto metastable phase relations in the undercooled region of the Co-Si system.« less

Metastable solidification of hypereutectic Co 2Si-CoSi composition: Microstructural studies and in-situ observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yeqing; Gao, Jianrong; Kolbe, Matthias

Metastable solidification of undercooled Co 60Si 40 melts was investigated by microstructural studies and in-situ high-energy X-ray diffraction. Five solidification paths were identified. Three of them were observed at low undercoolings, which show uncoupled and coupled growth of stable β-Co 2Si and CoSi compounds. The other paths were observed at high undercoolings, which show peritectic and primary crystallization of a metastable Co 5Si 3 compound. The β-Co 2Si and Co 5Si 3 compounds crystallize into a hexagonal crystal structure and experience solid-state decomposition. Microstructure formation depends on solidification path. The coupled and uncoupled growth of the stable compounds produces amore » regular lamellar eutectic structure and an anomalous eutectic structure, respectively. The crystallization and solid-state decomposition of the metastable Co 5Si 3 compound brings about a fine-grained two-phase mixture, which represents another type of anomalous eutectic structure. Here, the results provide proof of two rare mechanisms of anomalous eutectic formation and shed light onto metastable phase relations in the undercooled region of the Co-Si system.« less

Autonomous aerial observations to extend and complement the Earth Observing System: a science-driven systems-oriented approach

NASA Astrophysics Data System (ADS)

Sandford, Stephen P.; Harrison, F. W.; Langford, John; Johnson, James W.; Qualls, Garry; Emmitt, David; Jones, W. Linwood; Shugart, Herman H., Jr.

2004-12-01

The current Earth observing capability depends primarily on spacecraft missions and ground-based networks to provide the critical on-going observations necessary for improved understanding of the Earth system. Aircraft missions play an important role in process studies but are limited to relatively short-duration flights. Suborbital observations have contributed to global environmental knowledge by providing in-depth, high-resolution observations that space-based and in-situ systems are challenged to provide; however, the limitations of aerial platforms - e.g., limited observing envelope, restrictions associated with crew safety and high cost of operations have restricted the suborbital program to a supporting role. For over a decade, it has been recognized that autonomous aerial observations could potentially be important. Advances in several technologies now enable autonomous aerial observation systems (AAOS) that can provide fundamentally new observational capability for Earth science and applications and thus lead scientists and engineers to rethink how suborbital assets can best contribute to Earth system science. Properly developed and integrated, these technologies will enable new Earth science and operational mission scenarios with long term persistence, higher-spatial and higher-temporal resolution at lower cost than space or ground based approaches. This paper presents the results of a science driven, systems oriented study of broad Earth science measurement needs. These needs identify aerial mission scenarios that complement and extend the current Earth Observing System. These aerial missions are analogous to space missions in their complexity and potential for providing significant data sets for Earth scientists. Mission classes are identified and presented based on science driven measurement needs in atmospheric, ocean and land studies. Also presented is a nominal concept of operations for an AAOS: an innovative set of suborbital assets that complements and augments current and planned space-based observing systems.

Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

PubMed

Cai, Zheng; Song, Xiangrong; Sun, Feng; Yang, Zhaoxiang; Hou, Shixiang; Liu, Zhongqiu

2011-12-01

Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

Estimation of the Ocean Skin Temperature using the NASA GEOS Atmospheric Data Assimilation System

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Akella, Santha; Todling, Ricardo; Suarez, Max

2016-01-01

This report documents the status of the development of a sea surface temperature (SST) analysis for the Goddard Earth Observing System (GEOS) Version-5 atmospheric data assimilation system (ADAS). Its implementation is part of the steps being taken toward the development of an integrated earth system analysis. Currently, GEOS-ADAS SST is a bulk ocean temperature (from ocean boundary conditions), and is almost identical to the skin sea surface temperature. Here we describe changes to the atmosphere-ocean interface layer of the GEOS-atmospheric general circulation model (AGCM) to include near surface diurnal warming and cool-skin effects. We also added SST relevant Advanced Very High Resolution Radiometer (AVHRR) observations to the GEOS-ADAS observing system. We provide a detailed description of our analysis of these observations, along with the modifications to the interface between the GEOS atmospheric general circulation model, gridpoint statistical interpolation-based atmospheric analysis and the community radiative transfer model. Our experiments (with and without these changes) show improved assimilation of satellite radiance observations. We obtained a closer fit to withheld, in-situ buoys measuring near-surface SST. Evaluation of forecast skill scores corroborate improvements seen in the observation fits. Along with a discussion of our results, we also include directions for future work.

In Situ Detection of Macronutrients and Chloride in Seawater by Submersible Electrochemical Sensors.

PubMed

Cuartero, Maria; Crespo, Gaston; Cherubini, Thomas; Pankratova, Nadezda; Confalonieri, Fabio; Massa, Francesco; Tercier-Waeber, Mary-Lou; Abdou, Melina; Schäfer, Jörg; Bakker, Eric

2018-04-03

A new submersible probe for the in situ detection of nitrate, nitrite, and chloride in seawater is presented. Inline coupling of a desalination unit, an acidification unit, and a sensing flow cell containing all-solid-state membrane electrodes allows for the potentiometric detection of nitrate and nitrite after removal of the key interfering ions in seawater, chloride and hydroxide. Thus, the electrodes exhibited attractive analytical performances for the potentiometric detection of nitrate and nitrite in desalinated and acidified seawater: fast response time ( t 95 < 12 s), excellent stability (long-term drifts of <0.5 mV h -1 ), good reproducibility (calibration parameter deviation of <3%), and satisfactory accuracy (uncertainties <8%Diff compared to reference technique). The desalination cell, which can be repetitively used for about 30 times, may additionally be used as an exhaustive, and therefore calibration-free, electrochemical sensor for chloride and indirect salinity detection. The detection of these two parameters together with nitrate and nitrite may be useful for the correlation of relative changes in macronutrient levels with salinity cycles, which is of special interest in recessed coastal water bodies. The system is capable of autonomous operation during deployment, with routines for repetitive measurements (every 2 h), data storage and management, and computer visualization of the data in real time. In situ temporal profiles observed in the Arcachon Bay (France) showed valuable environmental information concerning tide-dependent cycles of nitrate and chloride levels in the lagoon, which are here observed for the first time using direct in situ measurements. The submersible probe based on membrane electrodes presented herein may facilitate the study of biogeochemical processes occurring in marine ecosystems by the direct monitoring of nitrate and nitrite levels, which are key chemical targets in coastal waters.

Regional and Coastal Prediction with the Relocatable Ocean Nowcast/Forecast System

DTIC Science & Technology

2014-09-01

and those that may be resolved with a suite of satellite altimeters when several are present and operational (~ 100 km). The altimeter data provide...September 2014 47 The observational data used for assimilation include satellite sea surface temperature (SST), satellite altimeter sea surface height...anomaly (SSHA), satellite microwave-derived sea ice concentration, and in situ surface and profile data from sensors on ships; drifters; fixed buoys

Assessment of Hybrid Coordinate Model Velocity Fields During Agulhas Return Current 2012 Cruise

DTIC Science & Technology

2013-06-01

Forecasts GDEM Generalized Digital Environmental Model GPS Global Positioning System HYCOM HYbrid Coordinate Ocean Model MICOM Miami Isopycnal...speed profiles was climatology from the Generalized Digital Environmental Model ( GDEM ; Teague et al. 1990). Made operational in 1999, the Modular... GDEM was the only tool a naval oceanographer had at his or her disposal to characterize ocean conditions where in-situ observations could not be

Backside Wear Analysis of Retrieved Acetabular Liners with a Press-Fit Locking Mechanism in Comparison to Wear Simulation In Vitro.

PubMed

Puente Reyna, Ana Laura; Jäger, Marcus; Floerkemeier, Thilo; Frecher, Sven; Delank, Karl-Stefan; Schilling, Christoph; Grupp, Thomas M

2016-01-01

Backside wear due to micromotion and poor conformity between the liner and its titanium alloy shell may contribute to the high rates of retroacetabular osteolysis and consequent aseptic loosening. The purpose of our study was to understand the wear process on the backside of polyethylene liners from two acetabular cup systems, whose locking mechanism is based on a press-fit cone in combination with a rough titanium conical inner surface on the fixation area. A direct comparison between in vitro wear simulator tests (equivalent to 3 years of use) and retrieved liners (average 13.1 months in situ) was done in order to evaluate the backside wear characteristics and behavior of these systems. Similar wear scores between in vitro tested and retrieved liners were observed. The results showed that this locking mechanism did not significantly produce wear marks at the backside of the polyethylene liners due to micromotion. In all the analyzed liners, the most common wear modes observed were small scratches at the cranial fixation zone directly below the rough titanium inner surface of the shell. It was concluded that most of the wear marks were produced during the insertion and removal of the liner, rather than during its time in situ.

Progress Report on the GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height) Research Project

NASA Astrophysics Data System (ADS)

Kitazawa, Y.; Ichikawa, K.; Akiyama, H.; Ebinuma, T.; Isoguchi, O.; Kimura, N.; Konda, M.; Kouguchi, N.; Tamura, H.; Tomita, H.; Yoshikawa, Y.; Waseda, T.

2016-12-01

Global Navigation Satellite Systems (GNSS), such as GPS is a system of satellites that provide autonomous geo-spatial positioning with global coverage. It allows small electronic receivers to determine their location to high precision using radio signals transmitted from satellites, GNSS reflectometry (GNSS-R) involves making measurements from the reflections from the Earth of navigation signals from GNSS satellites. Reflected signals from sea surface are considered that those are useful to observe sea state and sea surface height. We have started a research program for GNSS-R applications on oceanographic observations under the contract with MEXT (Ministry of Education Culture, Sports, Science and Technology, JAPAN) and launched a Japanese research consortium, GROWTH (GNSS Reflectometry for Ocean Waves, Tides, and Height). It is aiming to evaluate the capabilities of GNSS-R observations for oceanographic phenomena with different time scales, such as ocean waves (1/10 to tens of seconds), tides (one or half days), and sea surface dynamic height (a few days to years). In situ observations of ocean wave spectrum, wind speed vertical profile, and sea surface height will be quantitatively compared with equivalent estimates from simultaneous GNSS-R measurements. The GROWTH project will utilize different types of observation platforms; marine observation towers (about 20 m height), multi-copters (about 100 to 150 m height), and much higher-altitude CYGNSS data. Cross-platform data, together with in situ oceanographic observations, will be compared after adequate temporal averaging that accounts differences of the footprint sizes and temporal and spatial scales of oceanographic phenomena. This paper will provide overview of the GROWTH project, preliminary test results, obtained by the multi-sensor platform at observation towers, suggest actual footprint sizes and identification of swell. Preparation status of a ground station which will be supplied to receive CYGNSS data at Japan, is also reported. Compatibility tests to CYGNSS data and refurbishment of the ground station were completed.

A simplified In Situ cosmogenic 14C extraction system

USGS Publications Warehouse

Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

2010-01-01

We describe the design, construction, and testing of a new, simplified in situ radiocarbon extraction system at the University of Arizona. Blank levels for the new system are low ((234 ?? 11) ?? 103 atoms (1 ??; n = 7)) and stable. The precision of a given measurement depends on the concentration of 14C, but is typically <5% for concentrations of 100 ?? 103 atoms g-1 or more. The new system is relatively small and easy to construct, costs significantly less than the original in situ 14C extraction system at Arizona, and lends itself to future automation. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

Experimentally Determined Phase Diagram for the Barium Sulfide-Copper(I) Sulfide System Above 873 K (600 °C)

NASA Astrophysics Data System (ADS)

Stinn, Caspar; Nose, Katsuhiro; Okabe, Toru; Allanore, Antoine

2017-12-01

The phase diagram of the barium sulfide-copper(I) sulfide system was investigated above 873 K (600 °C) using a custom-built differential thermal analysis (DTA) apparatus. The melting point of barium sulfide was determined utilizing a floating zone furnace. Four new compounds, Ba2Cu14S9, Ba2Cu2S3, Ba5Cu4S7, and Ba9Cu2S10, were identified through quench experiments analyzed with wavelength dispersive X-ray spectroscopy (WDS) and energy dispersive X-ray analysis (EDS). A miscibility gap was observed between 72 and 92 mol pct BaS using both DTA experiments and in situ melts observation in a floating zone furnace. A monotectic was observed at 94.5 mol pct BaS and 1288 K (1015 °C).

Tests of halogen photochemistry using in situ measurements of ClO and BrO in the lower polar stratosphere

NASA Astrophysics Data System (ADS)

Avallone, Linnea M.; Toohey, Darin W.

2001-05-01

In situ observations of the halogen oxides ClO and BrO made from the NASA ER-2 during the Airborne Arctic Stratospheric Expedition (AASE) I and II missions are used to test current understanding of photochemical parameters. Measurements of ClO obtained during AASE I in the dark perturbed polar vortex are analyzed with respect to temperature to derive the equilibrium expression for the ClO/Cl2O2 system. Assuming photochemical steady state and complete activation of chlorine (ClO + 2Cl2O2 = Cly), observations of ClO made during AASE II are used to derive the photolysis rate of Cl2O2. The photolysis rate derived from atmospheric observations is compared to J values calculated with a photochemical model and various values for the absorption cross section of Cl2O2. The photolysis rate calculated with the cross section of Huder and DeMore [1995] is shown to be systematically too small, while those of Burkholder et al. [1990] and Cox and Hayman [1988] are too large to be consistent with atmospheric observations. Observations of BrO made during AASE II indicate that our understanding of the inorganic bromine budget in the polar regions is incomplete. A possible role for the adduct BrOOCl is investigated.

Pneumatic Planetary Regolith Feed System for In-Situ Resource Utilization

NASA Technical Reports Server (NTRS)

Mantovani, James G.; Mueller, Robert P.; Townsend, Ivan I.; Craft, Jack; Zacny, Kris

2010-01-01

The NASA In-situ Resource Utilization (ISRU) project requires a regolith feed system that can transfer lunar regolith several meters vertically into a chemical reactor for oxygen production on the moon.

Overview of the Ozone Water-Land Environmental Transition Study: Summary of Observations and Initial Results

NASA Astrophysics Data System (ADS)

Berkoff, T.; Sullivan, J.; Pippin, M. R.; Gronoff, G.; Knepp, T. N.; Twigg, L.; Schroeder, J.; Carrion, W.; Farris, B.; Kowalewski, M. G.; Nino, L.; Gargulinski, E.; Rodio, L.; Sanchez, P.; Desorae Davis, A. A.; Janz, S. J.; Judd, L.; Pusede, S.; Wolfe, G. M.; Stauffer, R. M.; Munyan, J.; Flynn, J.; Moore, B.; Dreessen, J.; Salkovitz, D.; Stumpf, K.; King, B.; Hanisco, T. F.; Brandt, J.; Blake, D. R.; Abuhassan, N.; Cede, A.; Tzortziou, M.; Demoz, B.; Tsay, S. C.; Swap, R.; Holben, B. N.; Szykman, J.; McGee, T. J.; Neilan, J.; Allen, D.

2017-12-01

The monitoring of ozone (O3) in the troposphere is of pronounced interest due to its known toxicity and health hazard as a photo-chemically generated pollutant. One of the major difficulties for the air quality modeling, forecasting and satellite communities is the validation of O3 levels in sharp transition regions, as well as near-surface vertical gradients. Land-water gradients of O3 near coastal regions can be large due to differences in surface deposition, boundary layer height, and cloud coverage. Observations in horizontal and vertical directions over the Chesapeake Bay are needed to better understand O3 formation and redistribution within regional recirculation patterns. The O3 Water-Land Environmental Transition Study (OWLETS) was a field campaign conducted in the summer 2017 in the VA Tidewater region to better characterize O3 across the coastal boundary. To obtain over-water measurements, the NASA Langley Ozone Lidar as well as supplemental measurements from other sensors (e.g. Pandora, AERONET) were deployed on the Chesapeake Bay Bridge Tunnel (CBBT) 7-8 miles offshore. These observations were complimented by NASA Goddard's Tropospheric Ozone Lidar along with ground-based measurements over-land at the NASA Langley Research Center (LaRC) in Hampton, VA. On measurement days, time-synchronized data were collected, including launches of ozonesondes from CBBT and LaRC sites that provided additional O3, wind, and temperature vertical distribution differences between land and water. These measurements were complimented with: in-situ O3 sensors on two mobile cars, a micro-pulse lidar at Hampton University, an in-situ O3 sensor on a small UAV-drone, and Virginia DEQ air-quality sites. Two aircraft and a research vessel also contributed to OWLETS at various points during the campaign: the NASA UC-12B with the GeoTASO passive remote sensor, the NASA C-23 with an in-situ chemistry analysis suite, and a SERC research vessel with both remote and in-situ sensors. This combination of observations provided a unique 4-D (horizontal, vertical, and time) view of O3 to help provide feedback to air quality forecast models as well as future satellite remote sensing systems such as NASA's TEMPO mission. In this presentation, a summary of observations and initial results will be presented from the OWLETS campaign.

MetNet Precursor - Network Mission to Mars

NASA Astrophysics Data System (ADS)

Harri, Arri-Matti

2010-05-01

We are developing a new kind of planetary exploration mission for Mars - MetNet in situ observation network based on a new semi-hard landing vehicle called the Met-Net Lander (MNL). The first MetNet vehicle, MetNet Precursor, slated for launch in 2011. The MetNet development work started already in 2001. The actual practical Precursor Mission development work started in January 2009 with participation from various space research institutes and agencies. The scientific rationale and goals as well as key mission solutions will be discussed. The eventual scope of the MetNet Mission is to deploy some 20 MNLs on the Martian surface using inflatable descent system structures, which will be supported by observations from the orbit around Mars. Currently we are working on the MetNet Mars Precursor Mission (MMPM) to deploy one MetNet Lander to Mars in the 2011 launch window as a technology and science demonstration mission. The MNL will have a versatile science payload focused on the atmospheric science of Mars. Time-resolved in situ Martian meteorological measurements acquired by the Viking, Mars Pathfinder and Phoenix landers and remote sensing observations by the Mariner 9, Viking, Mars Global Surveyor, Mars Odyssey and the Mars Express orbiters have provided the basis for our current understanding of the behavior of weather and climate on Mars. However, the available amount of data is still scarce and a wealth of additional in situ observations are needed on varying types of Martian orography, terrain and altitude spanning all latitudes and longitudes to address microscale and mesoscale atmospheric phenomena. Detailed characterization of the Martian atmospheric circulation patterns and climatological cycles requires simultaneous in situ atmospheric observations. The scientific payload of the MetNet Mission encompasses separate instrument packages for the atmospheric entry and descent phase and for the surface operation phase. The MetNet mission concept and key probe technologies have been developed and the critical subsystems have been qualified to meet the Martian environmental and functional conditions. The flight unit of the landing vehicle has been manufactured and tested. This development effort has been fulfilled in collaboration between the Finnish Meteorological Institute (FMI), the Russian Lavoschkin Association (LA) and the Russian Space Research Institute (IKI) since August 2001. INTA (Instituto Nacional de Técnica Aeroespacial) from Spain joined the MetNet Mission team in 2008, and is participating significantly in the MetNet payload development.

Smoke over haze: Comparative analysis of satellite, surface radiometer, and airborne in situ measurements of aerosol optical properties and radiative forcing over the eastern United States

NASA Astrophysics Data System (ADS)

Vant-Hull, Brian; Li, Zhanqing; Taubman, Brett F.; Levy, Robert; Marufu, Lackson; Chang, Fu-Lung; Doddridge, Bruce G.; Dickerson, Russell R.

2005-05-01

In July 2002 Canadian forest fires produced a major smoke episode that blanketed the east coast of the United States. Properties of the smoke aerosol were measured in situ from aircraft, complementing operational Aerosol Robotic Network (AERONET), and Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed aerosol retrievals. This study compares single scattering albedo and phase function derived from the in situ measurements and AERONET retrievals in order to evaluate their consistency for application to satellite retrievals of optical depth and radiative forcing. These optical properties were combined with MODIS reflectance observations to calculate optical depth. The use of AERONET optical properties yielded optical depths 2-16% lower than those directly measured by AERONET. The use of in situ-derived optical properties resulted in optical depths 22-43% higher than AERONET measurements. These higher optical depths are attributed primarily to the higher absorption measured in situ, which is roughly twice that retrieved by AERONET. The resulting satellite retrieved optical depths were in turn used to calculate integrated radiative forcing at both the surface and top of atmosphere. Comparisons to surface (Surface Radiation Budget Network (SURFRAD) and ISIS) and to satellite (Clouds and Earth Radiant Energy System CERES) broadband radiometer measurements demonstrate that the use of optical properties derived from the aircraft measurements provided a better broadband forcing estimate (21% error) than those derived from AERONET (33% error). Thus AERONET-derived optical properties produced better fits to optical depth measurements, while in situ properties resulted in better fits to forcing measurements. These apparent inconsistencies underline the significant challenges facing the aerosol community in achieving column closure between narrow and broadband measurements and calculations.

A 20 year independent record of sea surface temperature for climate from Along-Track Scanning Radiometers

NASA Astrophysics Data System (ADS)

Merchant, Christopher J.; Embury, Owen; Rayner, Nick A.; Berry, David I.; Corlett, Gary K.; Lean, Katie; Veal, Karen L.; Kent, Elizabeth C.; Llewellyn-Jones, David T.; Remedios, John J.; Saunders, Roger

2012-12-01

A new record of sea surface temperature (SST) for climate applications is described. This record provides independent corroboration of global variations estimated from SST measurements made in situ. Infrared imagery from Along-Track Scanning Radiometers (ATSRs) is used to create a 20 year time series of SST at 0.1° latitude-longitude resolution, in the ATSR Reprocessing for Climate (ARC) project. A very high degree of independence of in situ measurements is achieved via physics-based techniques. Skin SST and SST estimated for 20 cm depth are provided, with grid cell uncertainty estimates. Comparison with in situ data sets establishes that ARC SSTs generally have bias of order 0.1 K or smaller. The precision of the ARC SSTs is 0.14 K during 2003 to 2009, from three-way error analysis. Over the period 1994 to 2010, ARC SSTs are stable, with better than 95% confidence, to within 0.005 K yr-1(demonstrated for tropical regions). The data set appears useful for cleanly quantifying interannual variability in SST and major SST anomalies. The ARC SST global anomaly time series is compared to the in situ-based Hadley Centre SST data set version 3 (HadSST3). Within known uncertainties in bias adjustments applied to in situ measurements, the independent ARC record and HadSST3 present the same variations in global marine temperature since 1996. Since the in situ observing system evolved significantly in its mix of measurement platforms and techniques over this period, ARC SSTs provide an important corroboration that HadSST3 accurately represents recent variability and change in this essential climate variable.

In situ electron microscopy four-point electromechanical characterization of freestanding metallic and semiconducting nanowires.

PubMed

Bernal, Rodrigo A; Filleter, Tobin; Connell, Justin G; Sohn, Kwonnam; Huang, Jiaxing; Lauhon, Lincoln J; Espinosa, Horacio D

2014-02-26

Electromechanical coupling is a topic of current interest in nanostructures, such as metallic and semiconducting nanowires, for a variety of electronic and energy applications. As a result, the determination of structure-property relations that dictate the electromechanical coupling requires the development of experimental tools to perform accurate metrology. Here, a novel micro-electro-mechanical system (MEMS) that allows integrated four-point, uniaxial, electromechanical measurements of freestanding nanostructures in-situ electron microscopy, is reported. Coupled mechanical and electrical measurements are carried out for penta-twinned silver nanowires, their resistance is identified as a function of strain, and it is shown that resistance variations are the result of nanowire dimensional changes. Furthermore, in situ SEM piezoresistive measurements on n-type, [111]-oriented silicon nanowires up to unprecedented levels of ∼7% strain are demonstrated. The piezoresistance coefficients are found to be similar to bulk values. For both metallic and semiconducting nanowires, variations of the contact resistance as strain is applied are observed. These variations must be considered in the interpretation of future two-point electromechanical measurements. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In situ TEM visualization of superior nanomechanical flexibility of shear-exfoliated phosphorene

DOE PAGES

Xu, Feng; Ma, Hongyu; Lei, Shuangying; ...

2016-06-20

Recently discovered atomically thin black phosphorus (called phosphorene) holds great promise for applications in flexible nanoelectronic devices. Experimentally identifying and characterizing nanomechanical properties of phosphorene are challenging, but also potentially rewarding. Our work combines for the first time in situ transmission electron microscopy (TEM) imaging and an in situ micro-manipulation system to directly visualize the nanomechanical behaviour of individual phosphorene nanoflakes. Furthermore, we demonstrate that the phosphorene nanoflakes can be easily bent, scrolled, and stretched, showing remarkable mechanical flexibility rather than fracturing. An out-of-plane plate-like bending mechanism and in-plane tensile strain of up to 34% were observed. Moreover, a facilemore » liquid-phase shear exfoliation route has been developed to produce such mono-layer and few-layer phosphorene nanoflakes in organic solvents using only a household kitchen blender. The effects of surface tensions of the applied solvents on the ratio of average length and thickness (L/T) of the nanoflakes were studied systematically. These results reported here will pave the way for potential industrial-scale applications of flexible phosphorene nanoelectronic devices.« less

Direct observation of twin deformation in YBa2Cu3O7-x thin films by in situ nanoindentation in TEM

NASA Astrophysics Data System (ADS)

Lee, Joon Hwan; Zhang, Xinghang; Wang, Haiyan

2011-04-01

The deformation behaviors of YBa2Cu3O7-x (YBCO) thin films with twinning structures were studied via in situ nanoindentation experiments in a transmission electron microscope. The YBCO films were grown on SrTiO3 (001) substrates by pulsed laser deposition. Both ex situ (conventional) and in situ nanoindentation were conducted to reveal the deformation of the YBCO films from the directions perpendicular and parallel to the twin interfaces. The hardness measured perpendicular to the twin interfaces is ˜50% and 40% higher than that measured parallel to the twin interfaces ex situ and in situ, respectively. Detailed in situ movie analysis reveals that the twin structures play an important role in deformation and strengthening mechanisms in YBCO thin films.

DESIGN, DEVELOPMENT, AND FIELD DEMONSTRATION OF A REMOTELY DEPLOYABLE WATER QUALITY MONITORING SYSTEM

EPA Science Inventory

A prototype water quality monitoring system is described which offers almost continuous in situ monitoring. The two-man portable system features: (1) a microprocessor controlled central processing unit which allows preprogrammed sampling schedules and reprogramming in situ; (2) a...

In-situ Thermal Treatment of Trichloroethene at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Cole, Jason; McElroy, William J.; Glasgow, Jason; Heron, Gorm; Galligan, Jim; Parker, Ken; Davis, E. F.

2008-01-01

This viewgraph presentation describes the in-situ thermal treatment of trichloroethene at Marshall space Flight Center. The contents include: 1) Background 1 and 2; 2) Source Area-13; 3) In-situ Thermal Treatment; 4) SA-13 Lithology; 5) SA-13 In-Situ Thermal TS; 6) SA-13 ISTD System Components; 7) ISTD Overview; 8) Heaters; 9) SA-13 ISTD Wellfield Layout; 10) SA-13 Well Field; 11) ISTD Process and Instrumentation; 12) Treatment Zone Temperature; 13) SA-13 System Removals; 14) SA-13 DNAPL (typical photos); 15) Treatment Results 1-5; and 16) SA-13 TCE Removal Summary.

The Coastal Observing System for Northern and Arctic Seas (COSYNA)

NASA Astrophysics Data System (ADS)

Baschek, Burkard; Schroeder, Friedhelm; Brix, Holger; Riethmüller, Rolf; Badewien, Thomas H.; Breitbach, Gisbert; Brügge, Bernd; Colijn, Franciscus; Doerffer, Roland; Eschenbach, Christiane; Friedrich, Jana; Fischer, Philipp; Garthe, Stefan; Horstmann, Jochen; Krasemann, Hajo; Metfies, Katja; Merckelbach, Lucas; Ohle, Nino; Petersen, Wilhelm; Pröfrock, Daniel; Röttgers, Rüdiger; Schlüter, Michael; Schulz, Jan; Schulz-Stellenfleth, Johannes; Stanev, Emil; Staneva, Joanna; Winter, Christian; Wirtz, Kai; Wollschläger, Jochen; Zielinski, Oliver; Ziemer, Friedwart

2017-05-01

The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the German Bight in the North Sea as a prime example of a heavily used coastal area, and Svalbard as an example of an Arctic coast that is under strong pressure due to global change.The COSYNA automated observing and modelling system is designed to monitor real-time conditions and provide short-term forecasts, data, and data products to help assess the impact of anthropogenically induced change. Observations are carried out by combining satellite and radar remote sensing with various in situ platforms. Novel sensors, instruments, and algorithms are developed to further improve the understanding of the interdisciplinary interactions between physics, biogeochemistry, and the ecology of coastal seas. New modelling and data assimilation techniques are used to integrate observations and models in a quasi-operational system providing descriptions and forecasts of key hydrographic variables. Data and data products are publicly available free of charge and in real time. They are used by multiple interest groups in science, agencies, politics, industry, and the public.

Assimilation of Spatially Sparse In Situ Soil Moisture Networks into a Continuous Model Domain

NASA Astrophysics Data System (ADS)

Gruber, A.; Crow, W. T.; Dorigo, W. A.

2018-02-01

Growth in the availability of near-real-time soil moisture observations from ground-based networks has spurred interest in the assimilation of these observations into land surface models via a two-dimensional data assimilation system. However, the design of such systems is currently hampered by our ignorance concerning the spatial structure of error afflicting ground and model-based soil moisture estimates. Here we apply newly developed triple collocation techniques to provide the spatial error information required to fully parameterize a two-dimensional (2-D) data assimilation system designed to assimilate spatially sparse observations acquired from existing ground-based soil moisture networks into a spatially continuous Antecedent Precipitation Index (API) model for operational agricultural drought monitoring. Over the contiguous United States (CONUS), the posterior uncertainty of surface soil moisture estimates associated with this 2-D system is compared to that obtained from the 1-D assimilation of remote sensing retrievals to assess the value of ground-based observations to constrain a surface soil moisture analysis. Results demonstrate that a fourfold increase in existing CONUS ground station density is needed for ground network observations to provide a level of skill comparable to that provided by existing satellite-based surface soil moisture retrievals.

Development of a Novel Floating In-situ Gelling System for Stomach Specific Drug Delivery of the Narrow Absorption Window Drug Baclofen.

PubMed

R Jivani, Rishad; N Patel, Chhagan; M Patel, Dashrath; P Jivani, Nurudin

2010-01-01

The present study deals with development of a floating in-situ gel of the narrow absorption window drug baclofen. Sodium alginate-based in-situ gelling systems were prepared by dissolving various concentrations of sodium alginate in deionized water, to which varying concentrations of drug and calcium bicarbonate were added. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to check the presence of any interaction between the drug and the excipients. A 3(2) full factorial design was used for optimization. The concentrations of sodium alginate (X1) and calcium bicarbonate (X2) were selected as the independent variables. The amount of the drug released after 1 h (Q1) and 10 h (Q10) and the viscosity of the solution were selected as the dependent variables. The gels were studied for their viscosity, in-vitro buoyancy and drug release. Contour plots were drawn for each dependent variable and check-point batches were prepared in order to get desirable release profiles. The drug release profiles were fitted into different kinetic models. The floating lag time and floating time found to be 2 min and 12 h respectively. A decreasing trend in drug release was observed with increasing concentrations of CaCO3. The computed values of Q1 and Q10 for the check-point batch were 25% and 86% respectively, compared to the experimental values of 27.1% and 88.34%. The similarity factor (f 2) for the check-point batch being 80.25 showed that the two dissolution profiles were similar. The drug release from the in-situ gel follows the Higuchi model, which indicates a diffusion-controlled release. A stomach specific in-situ gel of baclofen could be prepared using floating mechanism to increase the residence time of the drug in stomach and thereby increase the absorption.

On the role of ice-nucleating aerosol in the formation of ice particles in tropical mesoscale convective systems

NASA Astrophysics Data System (ADS)

Ladino, Luis A.; Korolev, Alexei; Heckman, Ivan; Wolde, Mengistu; Fridlind, Ann M.; Ackerman, Andrew S.

2017-02-01

Over the decades, the cloud physics community has debated the nature and role of aerosol particles in ice initiation. The present study shows that the measured concentration of ice crystals in tropical mesoscale convective systems exceeds the concentration of ice nucleating particles (INPs) by several orders of magnitude. The concentration of INPs was assessed from the measured aerosol particle concentration in the size range of 0.5 to 1 µm. The observations from this study suggest that primary ice crystals formed on INPs make only a minor contribution to the total concentration of ice crystals in tropical mesoscale convective systems. This is found by comparing the predicted INP number concentrations with in situ ice particle number concentrations. The obtained measurements suggest that ice multiplication is the likely explanation for the observed high concentrations of ice crystals in this type of convective system.

Conjugate Event Study of Geomagnetic ULF Pulsations with Wavelet-based Indices

NASA Astrophysics Data System (ADS)

Xu, Z.; Clauer, C. R.; Kim, H.; Weimer, D. R.; Cai, X.

2013-12-01

The interactions between the solar wind and geomagnetic field produce a variety of space weather phenomena, which can impact the advanced technology systems of modern society including, for example, power systems, communication systems, and navigation systems. One type of phenomena is the geomagnetic ULF pulsation observed by ground-based or in-situ satellite measurements. Here, we describe a wavelet-based index and apply it to study the geomagnetic ULF pulsations observed in Antarctica and Greenland magnetometer arrays. The wavelet indices computed from these data show spectrum, correlation, and magnitudes information regarding the geomagnetic pulsations. The results show that the geomagnetic field at conjugate locations responds differently according to the frequency of pulsations. The index is effective for identification of the pulsation events and measures important characteristics of the pulsations. It could be a useful tool for the purpose of monitoring geomagnetic pulsations.

On the role of ice-nucleating aerosol in the formation of ice particles in tropical mesoscale convective systems

PubMed Central

Ladino, Luis A.; Korolev, Alexei; Heckman, Ivan; Wolde, Mengistu; Fridlind, Ann M.; Ackerman, Andrew S.

2018-01-01

Over decades, the cloud physics community has debated the nature and role of aerosol particles in ice initiation. The present study shows that the measured concentration of ice crystals in tropical mesoscale convective systems exceeds the concentration of ice nucleating particles (INPs) by several orders of magnitude. The concentration of INPs was assessed from the measured aerosol particles concentration in the size range of 0.5 to 1 µm. The observations from this study suggest that primary ice crystals formed on INPs make only a minor contribution to the total concentration of ice crystals in tropical mesoscale convective systems. This is found by comparing the predicted INP number concentrations with in-situ ice particle number concentrations. The obtained measurements suggest that ice multiplication is the likely explanation for the observed high concentrations of ice crystals in this type of convective system. PMID:29551842

Histopathological grading of breast ductal carcinoma in situ: validation of a web-based survey through intra-observer reproducibility analysis.

PubMed

Schuh, Fernando; Biazús, Jorge Villanova; Resetkova, Erika; Benfica, Camila Zanella; Ventura, Alessandra de Freitas; Uchoa, Diego; Graudenz, Márcia; Edelweiss, Maria Isabel Albano

2015-07-10

Histopathological grading diagnosis of ductal carcinoma in situ (DCIS) of the breast may be very difficult even for experts, and it is important for therapeutic decisions. The challenge may be due to the inaccurate and/or subjective application of the diagnosis criteria. The aim of this study was to investigate the intra-observer agreement between a traditional method and a developed web-based questionnaire for scoring breast DCIS. A cross-sectional study was carried out to evaluate the diagnostic agreement of an electronic questionnaire and its point scoring system with the subjective reading of digital images for 3 different DCIS grading systems: Holland, Van Nuys and modified Black nuclear grade system. Three pathologists analyzed the same set of digitized images from 43 DCIS cases using two different web-based programs. In the first phase, they accessed a website with a newly created questionnaire and scoring system developed to allow the determination of the histological grade of the cases. After at least 6 months, the pathologists read again the same images, but without the help of the questionnaire, indicating subjectively the diagnoses. The intra-observer agreement analysis was employed to validate this innovative web-based survey. Overall, diagnostic reproducibility was similar for all histologic grading classification systems, with kappa values of 0.57 ± 0.10, 0.67 ± 0.09 and 0.67 ± 0.09 for Holland, Van Nuys classification and modified Black nuclear grade system respectively. Only two 2-step diagnostic disagreements were found, one for Holland and another for Van Nuys. Both cases were superestimated by the web-based survey. The diagnostic agreement between the web-based questionnaire and a traditional method, both using digital images, is moderate to good for Holland, Van Nuys and modified Black nuclear grade system. The use of a scoring point system does not appear to pose a major risk of presenting large (2-step) diagnostic disagreements. These findings indicate that the use of this point scoring system in this web-based survey to grade objectively DCIS lesions is a useful diagnostic tool.

The Feasibility and Benefits of In Situ Exploration of ‘Oumuamua-like Objects

NASA Astrophysics Data System (ADS)

Seligman, Darryl; Laughlin, Gregory

2018-05-01

A rapid accumulation of observations and interpretation has followed in the wake of 1I ‘Oumuamua’s passage through the inner solar system. We briefly outline the consequences that this first detection of an interstellar asteroid implies for the planet-forming process, and we assess the near-term prospects for detecting and observing (both remotely and in situ) future solar system visitors of this type. Drawing on detailed heat-transfer calculations that take both ‘Oumuamua’s unusual shape and its chaotic tumbling into account, we affirm that the lack of a detectable coma in deep images of the object very likely arises from the presence of a radiation-modified coating of high molecular weight material (rather than a refractory bulk composition). Assuming that ‘Oumuamua is a typical representative of a larger population with a kinematic distribution similar to Population I stars in the local galactic neighborhood, we calculate expected arrival rates, impact parameters, and velocities of similar objects and assess their prospects for detection using operational and forthcoming facilities. Using ‘Oumuamua as a proof of concept, we assess the prospects for missions that intercept interstellar objects using conventional chemical propulsion. Using a “launch on detection” paradigm, we estimate wait times of order of 10 years between favorable mission opportunities with the detection capabilities of the Large-scale Synoptic Survey Telescope, a figure that will be refined as the population of interstellar asteroids becomes observationally better constrained.

Student Dust Counter I : Science Objectives

NASA Astrophysics Data System (ADS)

Mitchell, C.; Bryant, C.; Bunch, N.; Chanthawanich, T.; Colgan, M.; Fernandez, A.; Grogan, B.; Holland, G.; Krauss, C.; Krauss, E.; Krauss, O.; Neeland, M.; Horanyi, M.

2003-12-01

The New Horizons mission to Pluto and the Kuiper Belt is scheduled for launch in January 2006. As part of the Education and Public Outreach activity of the mission, undergraduate and graduate students at the Laboratory for Atmospheric and Space Physics, University of Colorado, are building a space experiment: the Student Dust Counter (SDC). This talk will summarize the scientific goals of this experiment. An accompanying poster describes the technical details of SDC. The primary goal of SDC is to map the dust distribution in the Solar System from 1 to 50 AU. It will greatly enhance our knowledge of dust production and transport in the outer Solar System by providing more sensitive observations than earlier experiments past Saturn, and the first in situ dust observations beyond 18 AU.

Examining the Suitability of a Sparse In Situ Soil Moisture Monitoring Network for Assimilation into a Spatially Distributed Hydrologic Model

NASA Astrophysics Data System (ADS)

De Vleeschouwer, N.; Verhoest, N.; Pauwels, V. R. N.

2015-12-01

The continuous monitoring of soil moisture in a permanent network can yield an interesting data product for use in hydrological data assimilation. Major advantages of in situ observations compared to remote sensing products are the potential vertical extent of the measurements, the finer temporal resolution of the observation time series, the smaller impact of land cover variability on the observation bias, etc. However, two major disadvantages are the typical small integration volume of in situ measurements and the often large spacing between monitoring locations. This causes only a small part of the modelling domain to be directly observed. Furthermore, the spatial configuration of the monitoring network is typically temporally non-dynamic. Therefore two questions can be raised. Do spatially sparse in situ soil moisture observations contain a sufficient data representativeness to successfully assimilate them into the largely unobserved spatial extent of a distributed hydrological model? And if so, how is this assimilation best performed? Consequently two important factors that can influence the success of assimilating in situ monitored soil moisture are the spatial configuration of the monitoring network and the applied assimilation algorithm. In this research the influence of those factors is examined by means of synthetic data-assimilation experiments. The study area is the ± 100 km² catchment of the Bellebeek in Flanders, Belgium. The influence of the spatial configuration is examined by varying the amount of locations and their position in the landscape. The latter is performed using several techniques including temporal stability analysis and clustering. Furthermore the observation depth is considered by comparing assimilation of surface layer (5 cm) and deeper layer (50 cm) observations. The impact of the assimilation algorithm is assessed by comparing the performance obtained with two well-known algorithms: Newtonian nudging and the Ensemble Kalman Filter.

Seeing the light: Applications of in situ optical measurements for understanding DOM dynamics in river systems (Invited)

NASA Astrophysics Data System (ADS)

Pellerin, B. A.; Bergamaschi, B. A.; Downing, B. D.; Saraceno, J.; Fleck, J.; Shanley, J. B.; Aiken, G.; Boss, E.; Fujii, R.

2009-12-01

A critical challenge for understanding the sources, character and cycling of dissolved organic matter (DOM) is making measurements at the time scales in which changes occur in aquatic systems. Traditional approaches for data collection (daily to monthly discrete sampling) are often limited by analytical and field costs, site access and logistical challenges, particularly for long-term sampling at a large number of sites. The ability to make optical measurements of DOM in situ has been known for more than 50 years, but much of the work on in situ DOM absorbance and fluorescence using commercially-available instruments has taken place in the last few years. Here we present several recent examples that highlight the application of in situ measurements for understanding DOM dynamics in riverine systems at intervals of minutes to hours. Examples illustrate the utility of in situ optical sensors for studies of DOM over short-duration events of days to weeks (diurnal cycles, tidal cycles, storm events and snowmelt periods) as well as longer-term continuous monitoring for months to years. We also highlight the application of in situ optical DOM measurements as proxies for constituents that are significantly more difficult and expensive to measure at high frequencies (e.g. methylmercury, trihalomethanes). Relatively simple DOM absorbance and fluorescence measurements made in situ could be incorporated into short and long-term ecological research and monitoring programs, resulting in advanced understanding of organic matter sources, character and cycling in riverine systems.

A new view of solar coronal mass ejections with the Heliophysics System Observatory (Arne Richter Award for Outstanding Young Scientists Lecture)

NASA Astrophysics Data System (ADS)

Moestl, Christian

2016-04-01

Solar coronal mass ejections (CMEs) play a pivotal role in solar, heliospheric and planetary physics because they lead to connections of plasma phenomena from the Sun to the planets throughout the solar system. CMEs drive the strongest geomagnetic storms, fill the heliosphere with energetic particles, illuminate planetary skies with aurorae, modulate cosmic rays on planetary surfaces, and lead to erosion of planetary atmospheres over long time scales. Thus, even for studying the detection of life on exoplanets, the role of possible stellar CMEs should not be neglected. However, besides the simple fascination of studying the biggest explosions in the solar system, they are of increasingly high practical significance concerning risk mitigation of natural desasters and the protection of our common wealth. As the impact of a "super-CME", a rare but possible event, may affect the entire planet Earth, coordinated international efforts for their fundamental understanding, as well as building dedicated space weather missions for daily forecasts is necessary. There is a chance of a CME on the order of a Carrington event, with a minimum Dst of about -1000 nT, impacting Earth once every 100 years - or a 10% chance in a given solar cycle. An impact of such a super-CME is expected to cause e.g. wide-spread electricity blackouts and satellite failures. In the last 10 years, the field has made major advantages in understanding how CMEs evolve from the Sun to the planets. Because of the extension of CMEs on the order of 60-100 degree heliospheric longitude and radial sizes around 0.1-0.2 AU, multipoint imaging and in situ observations are inevitably necessary to understand basic CME physics. To this end, I will show data, as provided by the Heliophysics System Observatory (HSO), and their interpretation with various modeling effors. The HSO can be understood as a web of sensors placed throughout the heliosphere, consisting of spacecraft such as STEREO, Wind, ACE, Venus Express and MESSENGER. They provide, mainly with their magnetometers, multipoint in situ observations of CMEs. The STEREO mission plays a key role, as it has provided for the first time data of heliospheric imagers far away from the Sun-Earth line. This data set now covers almost a full solar cycle, bridging the observational gap between the Sun and the terrestrial planets. This means that we are now entering a new era where big catalogues of solar and heliospheric events are routinely available. I further focus on unsolved problems in the field, such as finding connections between coronagraph, heliospheric imaging and in situ CME detections, and understanding the global shape of the CME shock and magnetic flux rope. The biggest problem concerns the prediction of the CME core magnetic field, and in particular its Bz profile, which is the main reason why space weather prediction is still quite inaccurate. Finally, the upcoming missions Solar Orbiter and Solar Probe Plus are bound to disruptively transform the field in the upcoming years with out-of-ecliptic heliospheric imaging and in situ observations of the Sun's corona.

In-situ observation of equilibrium transitions in Ni films; agglomeration and impurity effects.

PubMed

Thron, Andrew M; Greene, Peter; Liu, Kai; van Benthem, Klaus

2014-02-01

Dewetting of ultra-thin Ni films deposited on SiO2 layers was observed, in cross-section, by in situ scanning transmission electron microscopy. Holes were observed to nucleate by voids which formed at the Ni/SiO2 interface rather than at triple junctions at the free surface of the Ni film. Ni islands were observed to retract, in attempt to reach equilibrium on the SiO2 layer. SiO2 layers with 120 nm thickness were found to limit in situ heating experiments due to poor thermal conductivity of SiO2. The formation of graphite was observed during the agglomeration of ultra-thin Ni films. Graphite was observed to wet both the free surface and the Ni/SiO2 interface of the Ni islands. Cr forms surface oxide layers on the free surface of the SiO2 layer and the Ni islands. Cr does not prevent the dewetting of Ni, however it will likely alter the equilibrium shape of the Ni islands. © 2013 Published by Elsevier B.V.

In situ spectroscopic monitoring of CO2 reduction at copper oxide electrode.

PubMed

Wang, Liying; Gupta, Kalyani; Goodall, Josephine B M; Darr, Jawwad A; Holt, Katherine B

2017-04-28

Copper oxide modified electrodes were investigated as a function of applied electrode potential using in situ infrared spectroscopy and ex situ Raman and X-ray photoelectron spectroscopy. In deoxygenated KHCO 3 electrolyte bicarbonate and carbonate species were found to adsorb to the electrode during reduction and the CuO was reduced to Cu(i) or Cu(0) species. Carbonate was incorporated into the structure and the CuO starting material was not regenerated on cycling to positive potentials. In contrast, in CO 2 saturated KHCO 3 solution, surface adsorption of bicarbonate and carbonate was not observed and adsorption of a carbonato-species was observed with in situ infrared spectroscopy. This species is believed to be activated, bent CO 2 . On cycling to negative potentials, larger reduction currents were observed in the presence of CO 2 ; however, less of the charge could be attributed to the reduction of CuO. In the presence of CO 2 CuO underwent reduction to Cu 2 O and potentially Cu, with no incorporation of carbonate. Under these conditions the CuO starting material could be regenerated by cycling to positive potentials.

Earth Observations for Global Water Security

NASA Technical Reports Server (NTRS)

Lawford, Richard; Strauch, Adrian; Toll, David; Fekete, Balazs; Cripe, Douglas

2013-01-01

The combined effects of population growth, increasing demands for water to support agriculture, energy security, and industrial expansion, and the challenges of climate change give rise to an urgent need to carefully monitor and assess trends and variations in water resources. Doing so will ensure that sustainable access to adequate quantities of safe and useable water will serve as a foundation for water security. Both satellite and in situ observations combined with data assimilation and models are needed for effective, integrated monitoring of the water cycle's trends and variability in terms of both quantity and quality. On the basis of a review of existing observational systems, we argue that a new integrated monitoring capability for water security purposes is urgently needed. Furthermore, the components for this capability exist and could be integrated through the cooperation of national observational programmes. The Group on Earth Observations should play a central role in the design, implementation, management and analysis of this system and its products.

Designing the Climate Observing System of the Future

NASA Astrophysics Data System (ADS)

Weatherhead, Elizabeth C.; Wielicki, Bruce A.; Ramaswamy, V.; Abbott, Mark; Ackerman, Thomas P.; Atlas, Robert; Brasseur, Guy; Bruhwiler, Lori; Busalacchi, Antonio J.; Butler, James H.; Clack, Christopher T. M.; Cooke, Roger; Cucurull, Lidia; Davis, Sean M.; English, Jason M.; Fahey, David W.; Fine, Steven S.; Lazo, Jeffrey K.; Liang, Shunlin; Loeb, Norman G.; Rignot, Eric; Soden, Brian; Stanitski, Diane; Stephens, Graeme; Tapley, Byron D.; Thompson, Anne M.; Trenberth, Kevin E.; Wuebbles, Donald

2018-01-01

Climate observations are needed to address a large range of important societal issues including sea level rise, droughts, floods, extreme heat events, food security, and freshwater availability in the coming decades. Past, targeted investments in specific climate questions have resulted in tremendous improvements in issues important to human health, security, and infrastructure. However, the current climate observing system was not planned in a comprehensive, focused manner required to adequately address the full range of climate needs. A potential approach to planning the observing system of the future is presented in this article. First, this article proposes that priority be given to the most critical needs as identified within the World Climate Research Program as Grand Challenges. These currently include seven important topics: melting ice and global consequences; clouds, circulation and climate sensitivity; carbon feedbacks in the climate system; understanding and predicting weather and climate extremes; water for the food baskets of the world; regional sea-level change and coastal impacts; and near-term climate prediction. For each Grand Challenge, observations are needed for long-term monitoring, process studies and forecasting capabilities. Second, objective evaluations of proposed observing systems, including satellites, ground-based and in situ observations as well as potentially new, unidentified observational approaches, can quantify the ability to address these climate priorities. And third, investments in effective climate observations will be economically important as they will offer a magnified return on investment that justifies a far greater development of observations to serve society's needs.

A web portal for accessing, viewing and comparing in situ observations, EO products and model output data

NASA Astrophysics Data System (ADS)

Vines, Aleksander; Hamre, Torill; Lygre, Kjetil

2014-05-01

The GreenSeas project (Development of global plankton data base and model system for eco-climate early warning) aims to advance the knowledge and predictive capacities of how marine ecosystems will respond to global change. A main task has been to set up a data delivery and monitoring core service following the open and free data access policy implemented in the Global Monitoring for the Environment and Security (GMES) programme. A key feature of the system is its ability to compare data from different datasets, including an option to upload one's own netCDF files. The user can for example search in an in situ database for different variables (like temperature, salinity, different elements, light, specific plankton types or rate measurements) with different criteria (bounding box, date/time, depth, Longhurst region, cruise/transect) and compare the data with model data. The user can choose model data or Earth observation data from a list, or upload his/her own netCDF files to use in the comparison. The data can be visualized on a map, as graphs and plots (e.g. time series and property-property plots), or downloaded in various formats. The aim is to ensure open and free access to historical plankton data, new data (EO products and in situ measurements), model data (including estimates of simulation error) and biological, environmental and climatic indicators to a range of stakeholders, such as scientists, policy makers and environmental managers. We have implemented a web-based GIS(Geographical Information Systems) system and want to demonstrate the use of this. The tool is designed for a wide range of users: Novice users, who want a simple way to be able to get basic information about the current state of the marine planktonic ecosystem by utilizing predefined queries and comparisons with models. Intermediate level users who want to explore the database on their own and customize the prefedined setups. Advanced users who want to perform complex queries and inventory searching and compare the data in their own way or with their own models.

Ocean Thermal and Color Evolution During the 1997/1998 ENSO Event

NASA Technical Reports Server (NTRS)

Rienecker, Michele

1998-01-01

A reduced gravity primitive equation modeling and assimilation system is used to study the evolution of the tropical Pacific during the 1997/1998 ENSO cycle. The modeling/assimilation scheme ingests satellite altimeter data and TAO temperature profiles and uses SSM/I satellite derived winds as surface boundary forcing. The four-dimensional structure of the upper ocean circulation structure will be compared against available in situ observations across the Pacific basin. In particular, variability near the Galapagos Islands will be highlighted during the spring of 1998 when phytoplankton concentrations were observed to increase a hundred-fold over a two week period.

In-situ electrical, mechanical and electrochemical characterizations of one-dimensional nanostructures

NASA Astrophysics Data System (ADS)

Mir Shah Ghassemi, Seyyed Hessam

One-dimensional nanostructures initiated new aspects to the materials applications due to their superior properties compared to the bulk materials. Properties of nanostructures have been characterized by many techniques and used for various device applications. However, simultaneous correlation between the physical and structural properties of these nanomaterials has not been widely investigated. Therefore, it is necessary to perform in-situ study on the physical and structural properties of nanomaterials to understand their relation. In this work, we will use a unique instrument to perform real time atomic force microscopy (AFM) and scanning tunneling microscopy (STM) of nanomaterials inside a transmission electron microscopy (TEM) system. This AFM/STM-TEM system is used to investigate the mechanical, electrical, and electrochemical properties of boron nitride nanotubes (BNNTs) and Silicon nanorods (SiNRs). BNNTs are one of the subjects of this PhD research due to their comparable, and in some cases superior, properties compared to carbon nanotubes. Therefore, to further develop their applications, it is required to investigate these characteristics in atomic level. In this research, the mechanical properties of multi-walled BNNTs were first studied. Several tests were designed to study and characterize their real-time deformation behavior to the applied force. Observations revealed that BNNTs possess highly flexible structures under applied force. Detailed studies were then conducted to understand the bending mechanism of the BNNTs. Formations of reversible ripples were observed and described in terms of thermodynamic energy of the system. Fracture failure of BNNTs were initiated at the outermost walls and characterized to be brittle. Second, the electrical properties of individual BNNTs were studied. Results showed that the bandgap and electronic properties of BNNTs can be engineered by means of applied strain. It was found that the conductivity, electron concentration and carrier mobility of BNNTs can be tuned as a function of applied stress. Although, BNNTs are considered to be candidate for field emission applications, observations revealed that their properties degrade upon cycles of emissions. Results showed that due to the high emission current density, the temperature of the sample was increased and reached to the decomposition temperature at which the B-N bonds start to break. In addition to BNNTs, we have also performed in-situ study on the electrochemical properties of silicon nanorods (SiNRs). Specifically, lithiation and delithiation of SiNRs were studied by our STM-TEM system. Our observations showed the direct formation of Li22Si 5 phases as a result of lithium intercalation. Radial expansion of the anode materials were observed and characterized in terms of size-scale. Later, the formation and growth of the lithium fibers on the surface of the anode materials were observed and studied. Results revealed the formation of lithium islands inside the ionic liquid electrolyte which then grew as Li dendrite toward the cathode material.

The Midlatitude Continental Convective Clouds Experiment (MC3E)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, Mark P.; Petersen, Walt A.; Bansemer, Aaron

The Midlatitude Continental Convective Clouds Experiment (MC3E), a field program jointly led by the U.S. Department of Energy’s Atmospheric Radiation Measurement program and the NASA Global Precipitation Measurement (GPM) Mission, was conducted in south-central Oklahoma during April – May 2011. MC3E science objectives were motivated by the need to improve understanding of midlatitude continental convective cloud system lifecycles, microphysics, and GPM precipitation retrieval algorithms. To achieve these objectives a multi-scale surface- and aircraft-based in situ and remote sensing observing strategy was employed. A variety of cloud and precipitation events were sampled during the MC3E, of which results from three deepmore » convective events are highlighted. Vertical structure, air motions, precipitation drop-size distributions and ice properties were retrieved from multi-wavelength radar, profiler, and aircraft observations for an MCS on 11 May. Aircraft observations for another MCS observed on 20 May were used to test agreement between observed radar reflectivities and those calculated with forward-modeled reflectivity and microwave brightness temperatures using in situ particle size distributions and ice water content. Multi-platform observations of a supercell that occurred on 23 May allowed for an integrated analysis of kinematic and microphysical interactions. A core updraft of 25 ms-1 supported growth of hail and large rain drops. Data collected during the MC3E campaign is being used in a number of current and ongoing research projects and is available through the DOE ARM and NASA data archives.« less

In Situ Surveying of Saturn's Rings

NASA Astrophysics Data System (ADS)

Clark, P. E.; Rilee, M. L.; Curtis, S. A.; Cheung, C.

2004-03-01

Saturn Autonomous Ring Array (SARA) mission concept is an application for the Autonomous Nano-Technology Swarm (ANTS) architecture that would perform in situ observations of compositional and dynamic properties of ring particles, a challenge unachievable by previous mission designs.

Methods for Validation and Intercomparison of Remote Sensing and In situ Ice Water Measurements: Case Studies from CRYSTAL-FACE and Model Results

NASA Technical Reports Server (NTRS)

Sayres, D.S.; Pittman, J. V.; Smith, J. B.; Weinstock, E. M.; Anderson, J. G.; Heymsfield, G.; Li, L.; Fridlind, A.; Ackerman, A. S.

2004-01-01

Remote sensing observations, such as those from AURA, are necessary to understand the role of cirrus in determining the radiative and humidity budgets of the upper troposphere. Using these measurements quantitatively requires comparisons with in situ measurements that have previously been validated. However, a direct comparison of remote and in situ measurements is difficult due to the requirement that the spatial and temporal overlap be sufficient in order to guarantee that both instruments are measuring the same air parcel. A difficult as this might be for gas phase intercomparisons, cloud inhomogeneities significantly exacerbate the problem for cloud ice water content measurements. The CRYSTAL-FACE mission provided an opportunity to assess how well such intercomparisons can be performed and to establish flight plans that will be necessary for validation of future satellite instruments. During CRYSTAL-FACE, remote and in situ instruments were placed on different aircraft (NASA's ER-2 and WB-59, and the two planes flew in tandem so that the in situ payload flew in the field of view of the remote instruments. We show here that, even with this type of careful flight planning, it is not always possible to guarantee that remote and in situ instruments are viewing the same air parcel. We use ice water data derived from the in situ Harvard Total Water (HV-TW) instrument, and the remote Goddard Cloud Radar System (CRS) and show that agreement between HV-TW and CRS is a strong function of the horizontal separation and the time delay between the aircraft transects. We also use a cloud model to simulate possible trajectories through a cloud and evaluate the use of statistical analysis in determining the agreement between the two instruments. This type of analysis should guide flight planning for future intercomparison efforts, whether for aircraft or satellite-borne instrumentation.

Surface polymerization of (3,4-ethylenedioxythiophene) probed by in situ scanning tunneling microscopy on Au(111) in ionic liquids.

PubMed

Ahmad, Shahzada; Carstens, Timo; Berger, Rüdiger; Butt, Hans-Jürgen; Endres, Frank

2011-01-01

The electropolymerization of 3,4-ethylenedioxythiophene (EDOT) to poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated in the air and water-stable ionic liquids 1-hexyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate [HMIm]FAP and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide [EMIm]TFSA. In situ scanning tunnelling microscopy (STM) results show that the electropolymerization of EDOT in the ionic liquid can be probed on the nanoscale. In contrast to present understanding, it was observed that the EDOT can be oxidised in ionic liquids well below its oxidation potential and the under potential growth of polymer was visualized by in situ STM. These results serve as the first study to confirm the under potential growth of conducting polymers in ionic liquids. Furthermore, ex situ microscopy measurements were performed. Quite a high current of 670 nA was observed on the nanoscale by conductive scanning force microscopy (CSFM).

Collection of in situ forest canopy spectra using a helicopter - A discussion of methodology and preliminary results

NASA Technical Reports Server (NTRS)

Williams, D. L.; Walthall, C. L.; Goward, S. N.

1984-01-01

An important part of fundamental remote sensing research is based on the measurement and analysis of spectral reflectance from earth surface materials in situ. It has been found that for an effective analysis of the target of interest, different applications of remotely sensed data require spectral measurements from different portions of the electromagnetic spectrum. It is pointed out that the detailed spectral reflectance characteristics of forest vegetation are currently not well understood, particularly in the middle infrared wavelength region. Details regarding the need for in situ forest canopy measurements are examined, taking into account certain difficulties arising in the case of satellite observations. Because of these difficulties, the present paper provides a discussion of methodology and preliminary spectra based on an experiment to use a helicopter as an observing platform for in situ forest canopy spectra measurement.

Method for enhanced longevity of in situ microbial filter used for bioremediation

DOEpatents

Carman, M.L.; Taylor, R.T.

1999-03-30

An improved method is disclosed for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method is presented for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system is also disclosed for in situ field water remediation. 31 figs.

In situ-forming hydrogels for sustained ophthalmic drug delivery.

PubMed

Nanjawade, Basavaraj K; Manvi, F V; Manjappa, A S

2007-09-26

Ophthalmic drug delivery is one of the most interesting and challenging endeavors facing the pharmaceutical scientist. The conventional ocular drug delivery systems like solutions, suspensions, and ointments show drawbacks such as increased precorneal elimination, high variability in efficiency, and blurred vision respectively. In situ-forming hydrogels are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form visco-elastic gel and this provides a response to environmental changes. In the past few years, an impressive number of novel temperature, pH, and ion induced in situ-forming systems have been reported for sustain ophthalmic drug delivery. Each system has its own advantages and drawbacks. The choice of a particular hydrogel depends on its intrinsic properties and envisaged therapeutic use. This review includes various temperature, pH, and ion induced in situ-forming polymeric systems used to achieve prolonged contact time of drugs with the cornea and increase their bioavailability.

Interplanetary Propagation of Coronal Mass Ejections

NASA Technical Reports Server (NTRS)

Gopalswamy, Nat

2011-01-01

Although more than ten thousand coronal mass ejections (CMEs) are produced during each solar cycle at the Sun, only a small fraction hits the Earth. Only a small fraction of the Earth-directed CMEs ultimately arrive at Earth depending on their interaction with the solar wind and other large-scale structures such as coronal holes and CMEs. The interplanetary propagation is essentially controlled by the drag force because the propelling force and the solar gravity are significant only near the Sun. Combined remote-sensing and in situ observations have helped us estimate the influence of the solar wind on the propagation of CMEs. However, these measurements have severe limitations because the remote-sensed and in-situ observations correspond to different portions of the CME. Attempts to overcome this problem are made in two ways: the first is to model the CME and get the space speed of the CME, which can be compared with the in situ speed. The second method is to use stereoscopic observation so that the remote-sensed and in-situ observations make measurements on the Earth-arriving part of CMEs. The Solar Terrestrial Relations Observatory (STEREO) mission observed several such CMEs, which helped understand the interplanetary evolution of these CMEs and to test earlier model results. This paper discusses some of these issues and updates the CME/shock travel time estimates for a number of CMEs.

OMI and Ground-Based In-Situ Tropospheric Nitrogen Dioxide Observations over Several Important European Cities during 2005-2014.

PubMed

Paraschiv, Spiru; Constantin, Daniel-Eduard; Paraschiv, Simona-Lizica; Voiculescu, Mirela

2017-11-20

In this work we present the evolution of tropospheric nitrogen dioxide (NO₂) content over several important European cities during 2005-2014 using space observations and ground-based in-situ measurements. The NO₂ content was derived using the daily observations provided by the Ozone Monitoring Instrument (OMI), while the NO₂ volume mixing ratio measurements were obtained from the European Environment Agency (EEA) air quality monitoring stations database. The European cities selected are: Athens (37.98° N, 23.72° E), Berlin (52.51° N, 13.41° E), Bucharest (44.43° N, 26.10° E), Madrid (40.38° N, 3.71° W), Lisbon (38.71° N, 9.13° W), Paris (48.85° N, 2.35° E), Rome (41.9° N, 12.50° E), and Rotterdam (51.91° N, 4.46° E). We show that OMI NO₂ tropospheric column data can be used to assess the evolution of NO₂ over important European cities. According to the statistical analysis, using the seasonal variation, we found good correlations (R > 0.50) between OMI and ground-based in-situ observations for all of the cities presented in this work. Highest correlation coefficients (R > 0.80) between ground-based monitoring stations and OMI observations were calculated for the cities of Berlin, Madrid, and Rome. Both types of observations, in-situ and remote sensing, show an NO₂ negative trend for all of locations presented in this study.

Rapid prototyping of soil moisture estimates using the NASA Land Information System

NASA Astrophysics Data System (ADS)

Anantharaj, V.; Mostovoy, G.; Li, B.; Peters-Lidard, C.; Houser, P.; Moorhead, R.; Kumar, S.

2007-12-01

The Land Information System (LIS), developed at the NASA Goddard Space Flight Center, is a functional Land Data Assimilation System (LDAS) that incorporates a suite of land models in an interoperable computational framework. LIS has been integrated into a computational Rapid Prototyping Capabilities (RPC) infrastructure. LIS consists of a core, a number of community land models, data servers, and visualization systems - integrated in a high-performance computing environment. The land surface models (LSM) in LIS incorporate surface and atmospheric parameters of temperature, snow/water, vegetation, albedo, soil conditions, topography, and radiation. Many of these parameters are available from in-situ observations, numerical model analysis, and from NASA, NOAA, and other remote sensing satellite platforms at various spatial and temporal resolutions. The computational resources, available to LIS via the RPC infrastructure, support e- Science experiments involving the global modeling of land-atmosphere studies at 1km spatial resolutions as well as regional studies at finer resolutions. The Noah Land Surface Model, available with-in the LIS is being used to rapidly prototype soil moisture estimates in order to evaluate the viability of other science applications for decision making purposes. For example, LIS has been used to further extend the utility of the USDA Soil Climate Analysis Network of in-situ soil moisture observations. In addition, LIS also supports data assimilation capabilities that are used to assimilate remotely sensed soil moisture retrievals from the AMSR-E instrument onboard the Aqua satellite. The rapid prototyping of soil moisture estimates using LIS and their applications will be illustrated during the presentation.

Using High and Low Resolution Profiles of CO2 and CH4 Measured with AirCores to Evaluate Transport Models and Atmospheric Columns Retrieved from Space

NASA Astrophysics Data System (ADS)

Membrive, O.; Crevoisier, C. D.; Sweeney, C.; Hertzog, A.; Danis, F.; Picon, L.; Engel, A.; Boenisch, H.; Durry, G.; Amarouche, N.

2015-12-01

Over the past decades many methods have been developed to monitor the evolution of greenhouse gases (GHG): ground networks (NOAA, ICOS, TCCON), aircraft campaigns (HIPPO, CARIBIC, Contrail…), satellite observations (GOSAT, IASI, AIRS…). Nevertheless, precise and regular vertical profile measurements are currently still missing from the observing system. To address this need, an original and innovative atmospheric sampling system called AirCore has been developed at NOAA (Karion et al. 2010). This new system allows balloon measurements of GHG vertical profiles from the surface up to 30 km. New versions of this instrument have been developed at LMD: a high-resolution version "AirCore-HR" that differs from other AirCores by its high vertical resolution and two "light" versions (lower resolution) aiming to be flown under meteorological balloon. LMD AirCores were flown on multi-instrument gondolas along with other independent instruments measuring CO2 and CH4 in-situ during the Strato Science balloon campaigns operated by the French space agency CNES in collaboration with the Canadian Space Agency in Timmins (Ontario, Canada) in August 2014 and 2015. First, we will present comparisons of the vertical profiles retrieved with various AirCores (LMD and Frankfurt University) to illustrate repeatability and impact of the vertical resolution as well as comparisons with independent in-situ measurements from other instruments (laser diode based Pico-SDLA). Second, we will illustrate the usefulness of AirCore measurements in the upper troposphere and stratosphere for validating and interpreting vertical profiles from atmospheric transport models as well as observations of total and partial column of methane and carbon dioxide from several current and future spaceborne missions such as: ACE-FTS, IASI and GOSAT.

A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors.

PubMed

Waugh, C J; Rosenberg, M J; Zylstra, A B; Frenje, J A; Séguin, F H; Petrasso, R D; Glebov, V Yu; Sangster, T C; Stoeckl, C

2015-05-01

Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

DOE PAGES

Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; ...

2015-05-27

Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.

Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waugh, C. J., E-mail: cjwaugh@mit.edu; Zylstra, A. B.; Frenje, J. A.

2015-05-15

Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

Laboratory method used for bioremediation

DOEpatents

Carman, M. Leslie; Taylor, Robert T.

2000-01-01

An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

Using in situ synchrotron radiation wide angle X-ray scattering (WAXS) to study CaCO3 scale formation at ambient and elevated temperature.

PubMed

Chen, Tao; Neville, Anne; Sorbie, Ken; Zhong, Zhong

2007-01-01

The formation of calcium carbonate mineral scale is a persistent and expensive problem in oil and gas production, water piping systems, power generator, and batch precipitation. The aim of this paper is to further the understanding of scale formation and inhibition by in situ probing of crystal growth by synchrotron radiation wide angle X-ray scattering (WAXS) at ambient and elevated temperature. This novel technique enables in situ study of mineral scale formation and inhibition and as such, information on the nucleation and growth processes are accessible. This technique studies bulk precipitation and surface deposition in the same system and will be of great benefit to the understanding of an industrial scaling system. It offers an exciting prospect for the study of scaling. It has been shown that the nucleation and growth of various calcareous polymorphs and their individual crystal planes can be followed in real-time and from this the following conclusions are reached. The process of scale deposition on the surface can be divided into an unstable phase and a stable phase. The initial phase of crystallization of calcium carbonate is characterized by instability with individual planes from various vaterite and aragonite polymorphs emerging and subsequently disappearing under the hydrodynamic conditions. After the initial unstable phase, various calcium carbonate crystal planes adhere on the surface and then grow on the surface. At 25 degrees C, the main plane of surface deposit is calcite and a strong (104) peak is detected. The other calcite planes (102), (006), (110) (113) and (202) are hardly detectable under this condition. At 80 degrees C, the main planes in the surface deposit are the (104), (113) and (110) planes of calcite. Stable planes of vaterite and aragonite are also observed. This paper will discuss how surface scale evolves--exploring the power of the synchrotron in situ methodology.

Unmanned Aerial Systems as Part of a Multi-Component Assessment Strategy to Address Climate Change and Atmospheric Processes

NASA Astrophysics Data System (ADS)

Lange, Manfred; Vrekoussis, Mihalis; Sciare, Jean; Argyrides, Marios; Ioannou, Stelios; Keleshis, Christos

2015-04-01

Unmanned Aerial Systems (UAS) have been established as versatile tools for different applications, providing data and observations for atmospheric and Earth-Systems research. They offer an urgently needed link between in-situ ground based measurements and satellite remote sensing observations and are distinguished by significant versatility, flexibility and moderate operational costs. UAS have the proven potential to contribute to a multi-component assessment strategy that combines remote-sensing, numerical modelling and surface measurements in order to elucidate important atmospheric processes. This includes physical and chemical transformations related to ongoing climate change as well as issues linked to aerosol-cloud interactions and air quality. The distinct advantages offered by UAS comprise, to name but a few: (i) their ability to operate from altitudes of a few meters to up to a few kilometers; (ii) their capability to perform autonomously controlled missions, which provides for repeat-measurements to be carried out at precisely defined locations; (iii) their relative ease of operation, which enables flexible employment at short-term notice and (iv) the employment of more than one platform in stacked formation, which allows for unique, quasi-3D-observations of atmospheric properties and processes. These advantages are brought to bear in combining in-situ ground based observations and numerical modeling with UAS-based remote sensing in elucidating specific research questions that require both horizontally and vertically resolved measurements at high spatial and temporal resolutions. Employing numerical atmospheric modelling, UAS can provide survey information over spatially and temporally localized, focused areas of evolving atmospheric phenomena, as they become identified by the numerical models. Conversely, UAS observations offer urgently needed data for model verification and provide boundary conditions for numerical models. In this presentation, we will briefly describe the current elements of our observational capabilities that enable the aforementioned multi-component assessment strategy by the Unmanned Systems Research Laboratory of the Cyprus Institute. This strategy is applied and utilized in the context of the EU-funded BACCHUS project, aside from other tasks. The ongoing and planned observations are particularly relevant as they are carried out in the Eastern Mediterranean and the Middle East, a region characterized by increasing anthropogenic pressures and ongoing and anticipated severe climatic changes and their impacts.

Woodstove Emission Sampling Methods Comparability Analysis and In-situ Evaluation of New Technology Woodstoves.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simons, Carl A.

1988-06-01

One major objective of this study was to compare several woodstove particulate emission sampling methods under laboratory and in-situ conditions. The laboratory work compared the EPA Method 5H, EPA Method 5G, and OMNI Automated Woodstove Emission Sampler (AWES)/Data LOG'r particulate emission sampling systems. A second major objective of the study was to evaluate the performance of two integral catalytic, two low emission non-catalytic, and two conventional technology woodstoves under in-situ conditions with AWES/Data LOG'r system. The AWES/Data LOG'r and EPA Method 5G sampling systems were also compared in an in-situ test on one of the integral catalytic woodstove models. 7more » figs., 12 tabs.« less

Formulation, functional evaluation and ex vivo performance of thermoresponsive soluble gels - A platform for therapeutic delivery to mucosal sinus tissue.

PubMed

Pandey, Preeti; Cabot, Peter J; Wallwork, Benjamin; Panizza, Benedict J; Parekh, Harendra S

2017-01-01

Mucoadhesive in situ gelling systems (soluble gels) have received considerable attention recently as effective stimuli-transforming vectors for a range of drug delivery applications. Considering this fact, the present work involves systematic formulation development, optimization, functional evaluation and ex vivo performance of thermosensitive soluble gels containing dexamethasone 21-phosphate disodium salt (DXN) as the model therapeutic. A series of in situ gel-forming systems comprising the thermoreversible polymer poloxamer-407 (P407), along with hydroxypropyl methyl cellulose (HPMC) and chitosan were first formulated. The optimized soluble gels were evaluated for their potential to promote greater retention at the mucosal surface, for improved therapeutic efficacy, compared to existing solution/suspension-based steroid formulations used clinically. Optimized soluble gels demonstrated a desirable gelation temperature with Newtonian fluid behaviour observed under storage conditions (4-8°C), and pseudoplastic fluid behaviour recorded at nasal cavity/sinus temperature (≈34°C). The in vitro characterization of formulations including rheological evaluation, textural analysis and mucoadhesion studies of the gel form were investigated. Considerable improvement in mechanical properties and mucoadhesion was observed with incorporation of HPMC and chitosan into the gelling systems. The lead poloxamer-based soluble gels, PGHC4 and PGHC7, which were carried through to ex vivo permeation studies displayed extended drug release profiles in conditions mimicking the human nasal cavity, which indicates their suitability for treating a range of conditions affecting the nasal cavity/sinuses. Copyright © 2016 Elsevier B.V. All rights reserved.

The NASA Seasonal-to-Interannual Prediction Project (NSIPP). [Annual Report for 2000

NASA Technical Reports Server (NTRS)

Rienecker, Michele; Suarez, Max; Adamec, David; Koster, Randal; Schubert, Siegfried; Hansen, James; Koblinsky, Chester (Technical Monitor)

2001-01-01

The goal of the project is to develop an assimilation and forecast system based on a coupled atmosphere-ocean-land-surface-sea-ice model capable of using a combination of satellite and in situ data sources to improve the prediction of ENSO and other major S-I signals and their global teleconnections. The objectives of this annual report are to: (1) demonstrate the utility of satellite data, especially surface height surface winds, air-sea fluxes and soil moisture, in a coupled model prediction system; and (2) aid in the design of the observing system for short-term climate prediction by conducting OSSE's and predictability studies.

Modeling Circulation along the Vietnamese Coast Influenced by Monsoon Variability in Meteorology, River Discharge and Interactions with the Vietnamese East Sea

DTIC Science & Technology

2013-09-30

productivity. Advanced variational methods for the assimilation of satellite and in situ observations to achieve improved state estimation and subsequent...time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection...South China Sea (SCS) using the Regional Ocean Modeling System (ROMS) with Incremental Strong Constraint 4-Dimensional Variational (IS4DVAR) data

Environmental Conditions in the Norwegian-Iceland Seas, May 1987.

DTIC Science & Technology

1987-06-01

Ocanography Division auI W May Joseph W. McCaffrey Ocean Science Directorate Ocean Sensing and Prediction Division June 1987 88330 8 I - I PRELIMINARY REPORT...Leonard Walstad) using an open ocean model; and (4) ship observations aboard the West German ship PLANET . This report concentrates on the first two...validation and delivery for operational use of oceanic and acoustic numerical forecast systems, and the assimilation of in-situ and remotely sensed data

The Ocean Topography Experiment (TOPEX) - Some questions answered

NASA Technical Reports Server (NTRS)

Townsend, W. F.

1985-01-01

The Ocean Topography Experiment (TOPEX) is to provide a basis for improving the understanding of the general circulation of the global oceans. In the context of this experiment, measurements of the surface topography of the oceans are to be conducted with the aid of radar altimetry. The obtained data, when combined with appropriate in situ observations, will make it possible to determine the three-dimensional structure of the ocean currents. The in situ observations needed are to be provided by the World Ocean Circulation Experiment (WOCE). Information regarding the ocean surface winds obtained with the aid of the NASA Scatterometer (NSCAT) to be flown on the Navy Remote Ocean Sensing System (N-ROSS) can supplement the TOPEX and WOCE data about the oceans. The TOPEX satellite is to be designed for a three year lifetime, but it will carry expendables for two additional years. Attention is given to TOPEX as an international program, aspects of timing regarding the conduction of the various experiments dealing with the oceans and the global climate, and the special characteristics of the TOPEX mission.

Taking Poseidon's Measure from Space: Advances in our Understanding of the Ocean

NASA Astrophysics Data System (ADS)

Avery, S. K.

2017-12-01

In many ways the ocean defines our planet and makes it livable. It provides marine resources and ecosystem services that are critical to a sustainable society. Today we understand that there is a growing need to predict, manage, and adapt to changes on our planet - changes that occur not only in the atmosphere but also in the ocean. Over the last 40 years remarkable advances in measuring key ocean quantities have been made - through the development of new satellite technologies and successful missions as well as through in-situ observing systems enabled by advances in robotics, communications, navigation, and sensors. Ocean science (and atmospheric science) is a science of numbers, imaging, and numerical models. Predictability of the ocean is tied to the scale of variability in space and time. Satellite observations have spectacularly showed us the incredible structure and variability of the ocean. It has been the combination of satellites and in-situ sensors that have allowed us to advance understanding and prediction. This presentation will highlight some of the key scientific advances that have been enabled by satellites.

Charge collection microscopy of in-situ switchable PRAM line cells in a scanning electron microscope: Technique development and unique observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oosthoek, J. L. M.; Schuitema, R. W.; Brink, G. H. ten

2015-03-15

An imaging method has been developed based on charge collection in a scanning electron microscope (SEM) that allows discrimination between the amorphous and crystalline states of Phase-change Random Access Memory (PRAM) line cells. During imaging, the cells are electrically connected and can be switched between the states and the resistance can be measured. This allows for electrical characterization of the line cells in-situ in the SEM. Details on sample and measurement system requirements are provided which turned out to be crucial for the successful development of this method. Results show that the amorphous or crystalline state of the line cellsmore » can be readily discerned, but the spatial resolution is relatively poor. Nevertheless, it is still possible to estimate the length of the amorphous mark, and also for the first time, we could directly observe the shift of the amorphous mark from one side of the line cell to the other side when the polarity of the applied (50 ns) RESET pulse was reversed.« less

In situ imaging of single carbohydrate-binding modules on cellulose microfibrils.

PubMed

Dagel, Daryl J; Liu, Yu-San; Zhong, Lanlan; Luo, Yonghua; Himmel, Michael E; Xu, Qi; Zeng, Yining; Ding, Shi-You; Smith, Steve

2011-02-03

The low efficiency of enzymes used in the bioprocessing of biomass for biofuels is one of the primary bottlenecks that must be overcome to make lignocellulosic biofuels cost-competitive. One of the rate-limiting factors is the accessibility of the cellulase enzymes to insoluble cellulolytic substrates, facilitated by surface absorption of the carbohydrate-binding modules (CBMs), a component of most cellulase systems. Despite their importance, reports of direct observation of CBM function and activity using microscopic methods are still uncommon. Here, we examine the site-specific binding of individual CBMs to crystalline cellulose in an aqueous environment, using the single molecule fluorescence method known as Defocused Orientation and Position Imaging (DOPI). Systematic orientations were observed that are consistent with the CBMs binding to the two opposite hydrophobic faces of the cellulose microfibril, with a well-defined orientation relative to the fiber axis. The approach provides in situ physical evidence indicating the CBMs bind with a well-defined orientation on those planes, thus supporting a binding mechanism driven by chemical and structural recognition of the cellulose surface.

Ocean heat content estimation from in situ observations at the National Centers for Environmental Information: Improvements and Uncertainties

NASA Astrophysics Data System (ADS)

Boyer, T.; Locarnini, R. A.; Mishonov, A. V.; Reagan, J. R.; Seidov, D.; Zweng, M.; Levitus, S.

2017-12-01

Ocean heat uptake is the major factor in sequestering the Earth's Energy Imbalance (EEI). Since 2000, the National Centers for Environmental Information (NCEI) have been estimating historical ocean heat content (OHC) changes back to the 1950s, as well as monitoring recent OHC. Over these years, through worldwide community efforts, methods of calculating OHC have substantially improved. Similarly, estimation of the uncertainty of ocean heat content calculations provide new insight into how well EEI estimates can be constrained using in situ measurements and models. The changing ocean observing system, especially with the near-global year-round coverage afforded by Argo, has also allowed more confidence in regional and global OHC estimates and provided a benchmark for better understanding of historical OHC changes. NCEI is incorporating knowledge gained through these global efforts into the basic methods, instrument bias corrections, uncertainty measurements, and temporal and spatial resolution capabilities of historic OHC change estimation and recent monitoring. The nature of these improvements and their consequences for estimation of OHC in relation to the EEI will be discussed.

Expression of androgen-binding protein (ABP) in human cardiac myocytes.

PubMed

Schock, H W; Herbert, Z; Sigusch, H; Figulla, H R; Jirikowski, G F; Lotze, U

2006-04-01

Cardiomyocytes are known to be androgen targets. Changing systemic steroid levels are thought to be linked to various cardiac ailments, including dilated cardiomyopathy (DCM). The mode of action of gonadal steroid hormones on the human heart is unknown to date. In the present study, we used high-resolution immunocytochemistry on semithin sections (1 microm thick), IN SITU hybridization, and mass spectrometry to investigate the expression of androgen-binding protein (ABP) in human myocardial biopsies taken from male patients with DCM. We observed distinct cytoplasmic ABP immunoreactivity in a fraction of the myocytes. IN SITU hybridization with synthetic oligonucleotide probes revealed specific hybridization signals in these cells. A portion of the ABP-positive cells contained immunostaining for androgen receptor. With SELDI TOF mass spectrometry of affinity purified tissue extracts of human myocardium, we confirmed the presence of a 50 kDa protein similar to ABP. Our observations provide evidence of an intrinsic expression of ABP in human heart. ABP may be secreted from myocytes in a paracrine manner perhaps to influence the bioavailabity of gonadal steroids in myocardium.

Narrow-band filters for ocean colour imager

NASA Astrophysics Data System (ADS)

Krol, Hélène; Chazallet, Frédéric; Archer, Julien; Kirchgessner, Laurent; Torricini, Didier; Grèzes-Besset, Catherine

2017-11-01

During the last few years, the evolution of deposition technologies of optical thin films coatings and associated in-situ monitoring methods enables us today to successfully answer the increasingly request of space systems for Earth observation. Geostationary satellite COMS-1 (Communication, Ocean, Meteorological Satellite-1) of Astrium has the role of ensuring meteorological observation as well as monitoring of the oceans. It is equipped with a colour imager to observe the marine ecosystem through 8 bands in the visible spectrum with a ground resolution of 500m. For that, this very high technology instrument is constituted with a filters wheel in front of the oceanic colour imager with 8 narrow band filters carried out and qualified by Cilas.

A Novel Early Warning System Based on a Sediment Microbial Fuel Cell for In Situ and Real Time Hexavalent Chromium Detection in Industrial Wastewater.

PubMed

Zhao, Shuai; Liu, Pu; Niu, Yongyan; Chen, Zhengjun; Khan, Aman; Zhang, Pengyun; Li, Xiangkai

2018-02-22

Hexavalent chromium (Cr(VI)) is a well-known toxic heavy metal in industrial wastewater, but in situ and real time monitoring cannot be achieved by current methods used during industrial wastewater treatment processes. In this study, a Sediment Microbial Fuel Cell (SMFC) was used as a biosensor for in situ real-time monitoring of Cr(VI), which was the organic substrate is oxidized in the anode and Cr(VI) is reduced at the cathode simultaneously. The pH 6.4 and temperature 25 °C were optimal conditions for the operation. Under the optimal conditions, linearity (R² = 0.9935) of the generated voltage was observed in the Cr(VI) concentration range from 0.2 to 0.7 mg/L. The system showed high specificity for Cr(VI), as other co-existing ions such as Cu 2+ , Zn 2+ , and Pb 2+ did not interfere with Cr(VI) detection. In addition, when the sediment MFC-based biosensor was applied for measuring Cr(VI) in actual wastewater samples, a low deviation (<8%) was obtained, which indicated its potential as a reliable biosensor device. MiSeq sequencing results showed that electrochemically active bacteria ( Geobacter and Pseudomonas ) were enriched at least two-fold on the biofilm of the anode in the biosensor as compared to the SMFC without Cr(VI). Cyclic voltammetry curves indicated that a pair of oxidation/reduction peaks appeared at -111 mV and 581 mV, respectively. These results demonstrated that the proposed sediment microbial fuel cell-based biosensor can be applied as an early warning device for real time in situ detection of Cr(VI) in industrial wastewaters.

Retrievals of ice cloud microphysical properties of deep convective systems using radar measurements

NASA Astrophysics Data System (ADS)

Tian, Jingjing; Dong, Xiquan; Xi, Baike; Wang, Jingyu; Homeyer, Cameron R.; McFarquhar, Greg M.; Fan, Jiwen

2016-09-01

This study presents newly developed algorithms for retrieving ice cloud microphysical properties (ice water content (IWC) and median mass diameter (Dm)) for the stratiform rain and thick anvil regions of deep convective systems (DCSs) using Next Generation Radar (NEXRAD) reflectivity and empirical relationships from aircraft in situ measurements. A typical DCS case (20 May 2011) during the Midlatitude Continental Convective Clouds Experiment (MC3E) is selected as an example to demonstrate the 4-D retrievals. The vertical distributions of retrieved IWC are compared with previous studies and cloud-resolving model simulations. The statistics from six selected cases during MC3E show that the aircraft in situ derived IWC and Dm are 0.47 ± 0.29 g m-3 and 2.02 ± 1.3 mm, while the mean values of retrievals have a positive bias of 0.19 g m-3 (40%) and negative bias of 0.41 mm (20%), respectively. To evaluate the new retrieval algorithms, IWC and Dm are retrieved for other DCSs observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) using NEXRAD reflectivity and compared with aircraft in situ measurements. During BAMEX, a total of 63, 1 min collocated aircraft and radar samples are available for comparisons, and the averages of radar retrieved and aircraft in situ measured IWC values are 1.52 g m-3 and 1.25 g m-3 with a correlation of 0.55, and their averaged Dm values are 2.08 and 1.77 mm. In general, the new retrieval algorithms are suitable for continental DCSs during BAMEX, especially within stratiform rain and thick anvil regions.

Spatial and Temporal Precipitation Analysis over Saudi Arabia: Inferences from In-situ Rain Gauges and TRMM Derived Rainfall

NASA Astrophysics Data System (ADS)

Abouelmagd, A.; McCabe, M. F.; Lopez, O.

2013-12-01

Understanding the water resources of the Middle East and North Africa (MENA) regions presents a number of challenges due in large part to the paucity of available hydrologic data. Knowledge gaps occur not only as a result of the low density of monitoring systems, but also because where such networks might exist, they are often poorly reported or maintained. While interpreting and examining such records presents many difficulties, in-situ data represent an invaluable source with which to constrain other reporting platforms and to gain insight into the hydrological systems of the region. An in-situ network of over 300 stations that has been collecting data intermittently from 1960 to present across 13 provinces in Saudi Arabia forms the focus of this investigation. While the data is affected by an uneven spatial distribution, intermittent recordings and instrumental uncertainty, it represents the best estimate of on-ground rainfall available for many parts of the Kingdom. To provide a first-order assessment on the representativeness and fidelity of this data source, a comparison against available satellite based retrievals from the Tropical Rainfall Measuring Mission (TRMM) is undertaken. Through examining the longer in-situ time series and the more recent 15 year record of TRMM based retrievals, a rainfall climatology is being developed that can provide further insight into this critical hydrological response. Here we present the first results from this effort, examining the spatial and temporal distribution of storm events, along with an assessment of patterns and characteristics of rain features across Saudi Arabia. Understanding the capacity of TRMM to reproduce observed rainfall behavior may provide a useful tool for further bridging the hydrological knowledge gaps in the arid and data poor environments of the MENA region.

A Novel Early Warning System Based on a Sediment Microbial Fuel Cell for In Situ and Real Time Hexavalent Chromium Detection in Industrial Wastewater

PubMed Central

Zhao, Shuai; Liu, Pu; Niu, Yongyan; Chen, Zhengjun; Khan, Aman; Zhang, Pengyun; Li, Xiangkai

2018-01-01

Hexavalent chromium (Cr(VI)) is a well-known toxic heavy metal in industrial wastewater, but in situ and real time monitoring cannot be achieved by current methods used during industrial wastewater treatment processes. In this study, a Sediment Microbial Fuel Cell (SMFC) was used as a biosensor for in situ real-time monitoring of Cr(VI), which was the organic substrate is oxidized in the anode and Cr(VI) is reduced at the cathode simultaneously. The pH 6.4 and temperature 25 °C were optimal conditions for the operation. Under the optimal conditions, linearity (R2 = 0.9935) of the generated voltage was observed in the Cr(VI) concentration range from 0.2 to 0.7 mg/L. The system showed high specificity for Cr(VI), as other co-existing ions such as Cu2+, Zn2+, and Pb2+ did not interfere with Cr(VI) detection. In addition, when the sediment MFC-based biosensor was applied for measuring Cr(VI) in actual wastewater samples, a low deviation (<8%) was obtained, which indicated its potential as a reliable biosensor device. MiSeq sequencing results showed that electrochemically active bacteria (Geobacter and Pseudomonas) were enriched at least two-fold on the biofilm of the anode in the biosensor as compared to the SMFC without Cr(VI). Cyclic voltammetry curves indicated that a pair of oxidation/reduction peaks appeared at −111 mV and 581 mV, respectively. These results demonstrated that the proposed sediment microbial fuel cell-based biosensor can be applied as an early warning device for real time in situ detection of Cr(VI) in industrial wastewaters. PMID:29470394

New insights into nitrate dynamics in a karst groundwater system gained from in situ high-frequency optical sensor measurements

USGS Publications Warehouse

Opsahl, Stephen P.; Musgrove, MaryLynn; Slattery, Richard N.

2017-01-01

Understanding nitrate dynamics in groundwater systems as a function of climatic conditions, especially during contrasting patterns of drought and wet cycles, is limited by a lack of temporal and spatial data. Nitrate sensors have the capability for making accurate, high-frequency measurements of nitrate in situ, but have not yet been evaluated for long-term use in groundwater wells. We measured in situ nitrate continuously in two groundwater monitoring wells —one rural and one urban—located in the recharge zone of a productive karst aquifer in central Texas in order to resolve changes that occur over both short-term (hourly to daily) and long-term (monthly to yearly) periods. Nitrate concentrations, measured as nitrate-nitrogen in milligrams per liter (mg/L), during drought conditions showed little or no temporal change as groundwater levels declined. During aquifer recharge, extremely rapid changes in concentration occurred at both wells as documented by hourly data. At both sites, nitrate concentrations were affected by recharging surface water as evidenced by nitrate concentrations in groundwater recharge (0.8–1.3 mg/L) that were similar to previously reported values for regional recharging streams. Groundwater nitrate concentrations responded differently at urban and rural sites during groundwater recharge. Concentrations at the rural well (approximately 1.0 mg/L) increased as a result of higher nitrate concentrations in groundwater recharge relative to ambient nitrate concentrations in groundwater, whereas concentrations at the urban well (approximately 2.7 mg/L) decreased as a result of the dilution of higher ambient nitrate concentrations relative to those in groundwater recharge. Notably, nitrate concentrations decreased to as low as 0.8 mg/L at the urban site during recharge but postrecharge concentrations exceeded 3.0 mg/L. A return to higher nitrate concentrations postrecharge indicates mobilization of a localized source of elevated nitrate within the urbanized area of the aquifer. Changes in specific conductance were observed at both sites during groundwater recharge, and a significant correlation between specific conductance and nitrate (correlation coefficient [R] = 0.455) was evident at the urban site where large (3-fold) changes in nitrate occurred. Nitrate concentrations and specific conductance measured during a depth profile indicated that the water column was generally homogeneous as expected for this karst environment, but changes were observed in the most productive zone of the aquifer that might indicate some heterogeneity within the complex network of flow paths. Resolving the timing and magnitude of changes and characterizing fine-scale vertical differences would not be possible using conventional sampling techniques. The patterns observed in situ provided new insight into the dynamic nature of nitrate in a karst groundwater system.