Topochemical Analysis of Cell Wall Components by TOF-SIMS.

PubMed

Aoki, Dan; Fukushima, Kazuhiko

2017-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a recently developing analytical tool and a type of imaging mass spectrometry. TOF-SIMS provides mass spectral information with a lateral resolution on the order of submicrons, with widespread applicability. Sometimes, it is described as a surface analysis method without the requirement for sample pretreatment; however, several points need to be taken into account for the complete utilization of the capabilities of TOF-SIMS. In this chapter, we introduce methods for TOF-SIMS sample treatments, as well as basic knowledge of wood samples TOF-SIMS spectral and image data analysis.

Automated Interpretation and Extraction of Topographic Information from Time of Flight Secondary Ion Mass Spectrometry Data

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

Ievlev, Anton V.; Belianinov, Alexei; Jesse, Stephen

Time of flight secondary ion mass spectrometry (ToF SIMS) is one of the most powerful characterization tools allowing imaging of the chemical properties of various systems and materials. It allows precise studies of the chemical composition with sub-100-nm lateral and nanometer depth spatial resolution. However, comprehensive interpretation of ToF SIMS results is challengeable, because of the data volume and its multidimensionality. Furthermore, investigation of the samples with pronounced topographical features are complicated by the spectral shift. In this work we developed approach for the comprehensive ToF SIMS data interpretation based on the data analytics and automated extraction of the samplemore » topography based on time of flight shift. We further applied this approach to investigate correlation between biological function and chemical composition in Arabidopsis roots.« less

Automated Interpretation and Extraction of Topographic Information from Time of Flight Secondary Ion Mass Spectrometry Data

DOE PAGES

Ievlev, Anton V.; Belianinov, Alexei; Jesse, Stephen; ...

2017-12-06

Time of flight secondary ion mass spectrometry (ToF SIMS) is one of the most powerful characterization tools allowing imaging of the chemical properties of various systems and materials. It allows precise studies of the chemical composition with sub-100-nm lateral and nanometer depth spatial resolution. However, comprehensive interpretation of ToF SIMS results is challengeable, because of the data volume and its multidimensionality. Furthermore, investigation of the samples with pronounced topographical features are complicated by the spectral shift. In this work we developed approach for the comprehensive ToF SIMS data interpretation based on the data analytics and automated extraction of the samplemore » topography based on time of flight shift. We further applied this approach to investigate correlation between biological function and chemical composition in Arabidopsis roots.« less

Results from SIM's Thermo-Opto-Mechanical (TOM3) Testbed

NASA Technical Reports Server (NTRS)

Goullioud, Renaud; Lindensmith, C. A.; Hahn, I.

2006-01-01

Future space-based optical interferometers, such as the Space Interferometer Mission Planet Quest (SIM), require thermal stability of the optical wavefront to the level of picometers in order to produce astrometric data at the micro-arc-second level. In SIM, the internal path of the interferometer will be measured with a small metrology beam whereas the starlight fringe position is estimated from a large concentric annular beam. To achieve the micro-arc-second observation goal for SIM, it is necessary to maintain the optical path difference between the central and the outer annulus portions of the wavefront of the front-end telescope optics to a few tens of picometers. The Thermo-Opto-Mecha nical testbed (TOM3) was developed at the Jet Propulsion Laboratory to measure thermally induced optical deformations of a full-size flight-like beam compressor and siderostat, the two largest optics on SIM, in flight-like thermal environments. A Common Path Heterodyne Interferometer (COPHI) developed at JPL was used for the fine optical path difference measurement as the metrology sensor. The system was integrated inside a large vacuum chamber in order to mitigate the atmospheric and thermal disturbances. The siderostat was installed in a temperature-controlled thermal shroud inside the vacuum chamber, creating a flight-like thermal environment. Detailed thermal and structural models of the test articles (siderostat and compressor) were also developed for model prediction and correlation of the thermal deformations. Experimental data shows SIM required thermal stability of the test articles and good agreement with the model predictions.

simSchool: The Game of Teaching

ERIC Educational Resources Information Center

Zibit, Melanie; Gibson, David

2005-01-01

"simSchool" is a classroom simulation program funded by the Preparing Tomorrow's Teachers to Teach with Technology (PT3) program of the U.S. Department of Education. Just as a flight-simulator immerses a player in the complexities of flying a plane, "simSchool" immerses novice teachers in some of the complexities of teaching 7th-12th grade…

A comparative ToF-SIMS and GC—MS analysis of phototrophic communities collected from an alkaline silica-depositing hot spring

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

Siljestrom, S.; Parenteau, M. N.; Jahnke, L. L.

One of few techniques that is able to spatially resolve chemical data, including organic molecules, to morphological features in modern and ancient geological samples, is time-of-flight secondary ion mass spectrometry (ToF-SIMS). The ability to connect chemical data to morphology is key for interpreting the biogenicity of preserved remains in ancient samples. However, due to the lack of reference data for geologically relevant samples and the ease with which samples can be contaminated, ToF-SIMS data may be difficult to interpret. In this project, we aimed to build a ToF-SIMS spectral database by performing parallel ToF-SIMS and gas chromatography–mass spectrometry (GC–MS) analysesmore » of extant photosynthetic microbial communities collected from an alkaline silica-depositing hot spring in Yellowstone National Park, USA. We built the library by analyzing samples of increasing complexity: pure lipid standards commonly found in thermophilic phototrophs, solvent extracts of specific lipid fractions, total lipid extracts, pure cultures of dominant phototrophic community members, and unsilicified phototrophic streamer communities. The results showed that important lipids and pigments originating from phototrophs were detected by ToF-SIMS (e.g., wax esters, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sufloquinovosyldiaglycerol, alkanes, etc.) in the streamer lipid extracts. Many of the lipids were also detected in situ in the unsilicified streamer, and could even be spatially resolved to individual cells within the streamer community. Together with the ToF-SIMS database, this mapping ability will be used to further explore other microbial mats and their fossilized counterparts in the geological record. This is likely to expand the geochemical understanding of these types of samples.« less

A comparative ToF-SIMS and GC—MS analysis of phototrophic communities collected from an alkaline silica-depositing hot spring

DOE PAGES

Siljestrom, S.; Parenteau, M. N.; Jahnke, L. L.; ...

2017-04-03

One of few techniques that is able to spatially resolve chemical data, including organic molecules, to morphological features in modern and ancient geological samples, is time-of-flight secondary ion mass spectrometry (ToF-SIMS). The ability to connect chemical data to morphology is key for interpreting the biogenicity of preserved remains in ancient samples. However, due to the lack of reference data for geologically relevant samples and the ease with which samples can be contaminated, ToF-SIMS data may be difficult to interpret. In this project, we aimed to build a ToF-SIMS spectral database by performing parallel ToF-SIMS and gas chromatography–mass spectrometry (GC–MS) analysesmore » of extant photosynthetic microbial communities collected from an alkaline silica-depositing hot spring in Yellowstone National Park, USA. We built the library by analyzing samples of increasing complexity: pure lipid standards commonly found in thermophilic phototrophs, solvent extracts of specific lipid fractions, total lipid extracts, pure cultures of dominant phototrophic community members, and unsilicified phototrophic streamer communities. The results showed that important lipids and pigments originating from phototrophs were detected by ToF-SIMS (e.g., wax esters, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sufloquinovosyldiaglycerol, alkanes, etc.) in the streamer lipid extracts. Many of the lipids were also detected in situ in the unsilicified streamer, and could even be spatially resolved to individual cells within the streamer community. Together with the ToF-SIMS database, this mapping ability will be used to further explore other microbial mats and their fossilized counterparts in the geological record. This is likely to expand the geochemical understanding of these types of samples.« less

A comparative ToF-SIMS and GC–MS analysis of phototrophic communities collected from an alkaline silica-depositing hot spring

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

Siljeström, S.; Parenteau, M. N.; Jahnke, L. L.

One of few techniques that is able to spatially resolve chemical data, including organic molecules, to morphological features in modern and ancient geological samples, is time-of-flight secondary ion mass spectrometry (ToF-SIMS). The ability to connect chemical data to morphology is key for interpreting the biogenicity of preserved remains in ancient samples. However, due to the lack of reference data for geologically relevant samples and the ease with which samples can be contaminated, ToF-SIMS data may be difficult to interpret. In this project, we aimed to build a ToF-SIMS spectral database by performing parallel ToF-SIMS and gas chromatography–mass spectrometry (GC–MS) analysesmore » of extant photosynthetic microbial communities collected from an alkaline silica-depositing hot spring in Yellowstone National Park, USA. We built the library by analyzing samples of increasing complexity: pure lipid standards commonly found in thermophilic phototrophs, solvent extracts of specific lipid fractions, total lipid extracts, pure cultures of dominant phototrophic community members, and unsilicified phototrophic streamer communities. The results showed that important lipids and pigments originating from phototrophs were detected by ToF-SIMS (e.g., wax esters, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sufloquinovosyldiaglycerol, alkanes, etc.) in the streamer lipid extracts. Many of the lipids were also detected in situ in the unsilicified streamer, and could even be spatially resolved to individual cells within the streamer community. Together with the ToF-SIMS database, this mapping ability will be used to further explore other microbial mats and their fossilized counterparts in the geological record. This is likely to expand the geochemical understanding of these types of samples.« less

Improvement of the Correlative AFM and ToF-SIMS Approach Using an Empirical Sputter Model for 3D Chemical Characterization.

PubMed

Terlier, T; Lee, J; Lee, K; Lee, Y

2018-02-06

Technological progress has spurred the development of increasingly sophisticated analytical devices. The full characterization of structures in terms of sample volume and composition is now highly complex. Here, a highly improved solution for 3D characterization of samples, based on an advanced method for 3D data correction, is proposed. Traditionally, secondary ion mass spectrometry (SIMS) provides the chemical distribution of sample surfaces. Combining successive sputtering with 2D surface projections enables a 3D volume rendering to be generated. However, surface topography can distort the volume rendering by necessitating the projection of a nonflat surface onto a planar image. Moreover, the sputtering is highly dependent on the probed material. Local variation of composition affects the sputter yield and the beam-induced roughness, which in turn alters the 3D render. To circumvent these drawbacks, the correlation of atomic force microscopy (AFM) with SIMS has been proposed in previous studies as a solution for the 3D chemical characterization. To extend the applicability of this approach, we have developed a methodology using AFM-time-of-flight (ToF)-SIMS combined with an empirical sputter model, "dynamic-model-based volume correction", to universally correct 3D structures. First, the simulation of 3D structures highlighted the great advantages of this new approach compared with classical methods. Then, we explored the applicability of this new correction to two types of samples, a patterned metallic multilayer and a diblock copolymer film presenting surface asperities. In both cases, the dynamic-model-based volume correction produced an accurate 3D reconstruction of the sample volume and composition. The combination of AFM-SIMS with the dynamic-model-based volume correction improves the understanding of the surface characteristics. Beyond the useful 3D chemical information provided by dynamic-model-based volume correction, the approach permits us to enhance the correlation of chemical information from spectroscopic techniques with the physical properties obtained by AFM.

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

NASA Astrophysics Data System (ADS)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-08-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

Interfacial and Surface Science | Materials Science | NREL

Science.gov Websites

-flight SIMS (TOF-SIMS) provides surface spectroscopy of both inorganic and organic materials, and is Chamber This tool enables deposition of inorganic chalcogenides and for basic material and device studies lead halide perovskites and semiconductor quantum dots. Contact: Craig Perkins | Email | 303-384-6659

Sims for Science: Powerful Tools to Support Inquiry-Based Teaching

ERIC Educational Resources Information Center

Perkins, Katherine K.; Loeblein, Patricia J.; Dessau, Kathryn L.

2010-01-01

Since 2002, the PhET Interactive Simulations project at the University of Colorado has been working to provide learning tools for students and teachers. The project has developed over 85 interactive simulations--or sims--for teaching and learning science. Although these sims can be used in a variety of ways, they are specifically designed to make…

Multi-dimensional TOF-SIMS analysis for effective profiling of disease-related ions from the tissue surface.

PubMed

Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol

2015-06-05

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states.

Multi-dimensional TOF-SIMS analysis for effective profiling of disease-related ions from the tissue surface

PubMed Central

Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol

2015-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states. PMID:26046669

Submicron mass spectrometry imaging of single cells by combined use of mega electron volt time-of-flight secondary ion mass spectrometry and scanning transmission ion microscopy

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

Siketić, Zdravko; Bogdanović Radović, Ivančica; Jakšić, Milko

In order to better understand biochemical processes inside an individual cell, it is important to measure the molecular composition at the submicron level. One of the promising mass spectrometry imaging techniques that may be used to accomplish this is Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), using MeV energy heavy ions for excitation. MeV ions have the ability to desorb large intact molecules with a yield that is several orders of magnitude higher than conventional SIMS using keV ions. In order to increase the spatial resolution of the MeV TOF-SIMS system, we propose an independent TOF trigger using a STIM (scanningmore » transmission ion microscopy) detector that is placed just behind the thin transmission target. This arrangement is suitable for biological samples in which the STIM detector simultaneously measures the mass distribution in scanned samples. The capability of the MeV TOF-SIMS setup was demonstrated by imaging the chemical composition of CaCo-2 cells.« less

Visualization of metallodrugs in single cells by secondary ion mass spectrometry imaging.

PubMed

Wu, Kui; Jia, Feifei; Zheng, Wei; Luo, Qun; Zhao, Yao; Wang, Fuyi

2017-07-01

Secondary ion mass spectrometry, including nanoscale secondary ion mass spectrometry (NanoSIMS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), has emerged as a powerful tool for biological imaging, especially for single cell imaging. SIMS imaging can provide information on subcellular distribution of endogenous and exogenous chemicals, including metallodrugs, from membrane through to cytoplasm and nucleus without labeling, and with high spatial resolution and chemical specificity. In this mini-review, we summarize recent progress in the field of SIMS imaging, particularly in the characterization of the subcellular distribution of metallodrugs. We anticipate that the SIMS imaging method will be widely applied to visualize subcellular distributions of drugs and drug candidates in single cells, exerting significant influence on early drug evaluation and metabolism in medicinal and pharmaceutical chemistry. Recent progress of SIMS applications in characterizing the subcellular distributions of metallodrugs was summarized.

A novel ToF-SIMS operation mode for sub 100 nm lateral resolution: Application and performance.

PubMed

Kubicek, Markus; Holzlechner, Gerald; Opitz, Alexander K; Larisegger, Silvia; Hutter, Herbert; Fleig, Jürgen

2014-01-15

A novel operation mode for time of flight-secondary ion mass spectrometry (ToF-SIMS) is described for a TOF.SIMS 5 instrument with a Bi-ion gun. It features sub 100 nm lateral resolution, adjustable primary ion currents and the possibility to measure with high lateral resolution as well as high mass resolution. The adjustment and performance of the novel operation mode are described and compared to established ToF-SIMS operation modes. Several examples of application featuring novel scientific results show the capabilities of the operation mode in terms of lateral resolution, accuracy of isotope analysis of oxygen, and combination of high lateral and mass resolution. The relationship between high lateral resolution and operation of SIMS in static mode is discussed.

Chemical imaging of molecular changes in a hydrated single cell by dynamic secondary ion mass spectrometry and super-resolution microscopy

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

Hua, Xin; Szymanski, Craig; Wang, Zhaoying

2016-01-01

Chemical imaging of single cells is important in capturing biological dynamics. Single cell correlative imaging is realized between structured illumination microscopy (SIM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) using System for Analysis at the Liquid Vacuum Interface (SALVI), a multimodal microreactor. SIM characterized cells and guided subsequent ToF-SIMS analysis. Dynamic ToF-SIMS provided time- and space-resolved cell molecular mapping. Lipid fragments were identified in the hydrated cell membrane. Principal component analysis was used to elucidate chemical component differences among mouse lung cells that uptake zinc oxide nanoparticles. Our results provided submicron chemical spatial mapping for investigations of cell dynamics atmore » the molecular level.« less

Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study.

PubMed

Shard, Alexander G; Havelund, Rasmus; Spencer, Steve J; Gilmore, Ian S; Alexander, Morgan R; Angerer, Tina B; Aoyagi, Satoka; Barnes, Jean-Paul; Benayad, Anass; Bernasik, Andrzej; Ceccone, Giacomo; Counsell, Jonathan D P; Deeks, Christopher; Fletcher, John S; Graham, Daniel J; Heuser, Christian; Lee, Tae Geol; Marie, Camille; Marzec, Mateusz M; Mishra, Gautam; Rading, Derk; Renault, Olivier; Scurr, David J; Shon, Hyun Kyong; Spampinato, Valentina; Tian, Hua; Wang, Fuyi; Winograd, Nicholas; Wu, Kui; Wucher, Andreas; Zhou, Yufan; Zhu, Zihua; Cristaudo, Vanina; Poleunis, Claude

2015-08-20

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-l-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray photoelectron spectroscopy (XPS) or time-of-flight secondary ion mass spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided with the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants' data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally, we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.

Measuring Compositions in Organic Depth Profiling: Results from a VAMAS Interlaboratory Study

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

Shard, A. G.; Havelund, Rasmus; Spencer, Steve J.

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-L-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray Photoelectron Spectroscopy (XPS) or Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided withmore » the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants’ data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.« less

Protein quantification on dendrimer-activated surfaces by using time-of-flight secondary ion mass spectrometry and principal component regression

NASA Astrophysics Data System (ADS)

Kim, Young-Pil; Hong, Mi-Young; Shon, Hyun Kyong; Chegal, Won; Cho, Hyun Mo; Moon, Dae Won; Kim, Hak-Sung; Lee, Tae Geol

2008-12-01

Interaction between streptavidin and biotin on poly(amidoamine) (PAMAM) dendrimer-activated surfaces and on self-assembled monolayers (SAMs) was quantitatively studied by using time-of-flight secondary ion mass spectrometry (ToF-SIMS). The surface protein density was systematically varied as a function of protein concentration and independently quantified using the ellipsometry technique. Principal component analysis (PCA) and principal component regression (PCR) were used to identify a correlation between the intensities of the secondary ion peaks and the surface protein densities. From the ToF-SIMS and ellipsometry results, a good linear correlation of protein density was found. Our study shows that surface protein densities are higher on dendrimer-activated surfaces than on SAMs surfaces due to the spherical property of the dendrimer, and that these surface protein densities can be easily quantified with high sensitivity in a label-free manner by ToF-SIMS.

Campaign 1.7 Pu Aging. Development of Time of Flight Secondary Ion Mass Spectroscopy

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

Venhaus, Thomas J.

2015-09-09

The first application of Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) to an aged plutonium surface has resulted in a rich set of surface chemistry data, as well as some unexpected results. FY15 was highlighted by not only the first mapping of hydrogen-containing features within the metal, but also a prove-in series of experiments using the system’s Sieverts Reaction Cell. These experiments involved successfully heating the sample to ~450 oC for nearly 24 hours while the sample was dosed several times with hydrogen, followed by an in situ ToF-SIMS analysis. During this year, the data allowed for better and more consistentmore » identification of the myriad peaks that result from the SIMS sputter process. In collaboration with the AWE (U.K), the system was also fully aligned for sputter depth profiling for future experiments.« less

Taking the Measure of the Universe : Precision Astrometry with SIM PlanetQuest

NASA Technical Reports Server (NTRS)

Unwin, Stephen C.; Shao, Michael; Tanner, Angelle M.; Allen, Ronald J.; Beichman, Charles A.; Boboltz, David; Catanzarite, Joseph H.; Chaboyer, Brian C.; Ciardi, David R.; Edberg, Stephen J.;

Simulation-Based e-Learning Tools for Science,Engineering, and Technology Education(SimBeLT)

NASA Astrophysics Data System (ADS)

Davis, Doyle V.; Cherner, Y.

2006-12-01

The focus of Project SimBeLT is the research, development, testing, and dissemination of a new type of simulation-based integrated e-learning set of modules for two-year college technical and engineering curricula in the areas of thermodynamics, fluid physics, and fiber optics that can also be used in secondary schools and four-year colleges. A collection of sophisticated virtual labs is the core component of the SimBeLT modules. These labs will be designed to enhance the understanding of technical concepts and underlying fundamental principles of these topics, as well as to master certain performance based skills online. SimBeLT software will help educators to meet the National Science Education Standard that "learning science and technology is something that students do, not something that is done to them". A major component of Project SimBeLT is the development of multi-layered technology-oriented virtual labs that realistically mimic workplace-like environments. Dynamic data exchange between simulations will be implemented and links with instant instructional messages and data handling tools will be realized. A second important goal of Project SimBeLT labs is to bridge technical skills and scientific knowledge by enhancing the teaching and learning of specific scientific or engineering subjects. SimBeLT builds upon research and outcomes of interactive teaching strategies and tools developed through prior NSF funding (http://webphysics.nhctc.edu/compact/index.html) (Project SimBeLT is partially supported by a grant from the National Science Foundation DUE-0603277)

OpenSim Model Improvements to Support High Joint Angle Resistive Exercising

NASA Technical Reports Server (NTRS)

Gallo, Christopher; Thompson, William; Lewandowski, Beth; Humphreys, Brad

2016-01-01

Long duration space travel to Mars or to an asteroid will expose astronauts to extended periods of reduced gravity. Since gravity is not present to aid loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft is limited. Therefore, compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Rigorous testing of these proposed devices in space flight is difficult so computational modeling provides an estimation of the muscle forces and joint loads during exercise to gain insight on the efficacy to protect the musculoskeletal health of astronauts. The NASA Digital Astronaut Project (DAP) is supporting the Advanced Exercise Concepts (AEC) Project, Exercise Physiology and Countermeasures (ExPC) project and the National Space Biomedical Research Institute (NSBRI) funded researchers by developing computational models of exercising with these new advanced exercise device concepts

Detection and distribution of lithium in Mg-Li-Al based alloy by ToF-SIMS

NASA Astrophysics Data System (ADS)

Kumar, Vinod

2016-12-01

Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) is used to investigate the surface as well as bulk microstructural features of novel Mg-Li-Al based alloy namely Mg-9Li-7Al-3Sn-1Zn (LATZ9531). ToF-SIMS study indicates that there are six multi-oxide layers present within the surface film of LATZ9531. Furthermore, The presence of Li containing phase has been qualitatively confirmed based on the high number of Li-ion counts in SIMS, and the same is verified quantitatively by using electron probe microanalysis (EPMA). The novel approach may be useful to determine the chemical composition of the phases in various alloys which has lighter alloying elements such as lithium.

Sim1 is required for the migration and axonal projections of V3 interneurons in the developing mouse spinal cord.

PubMed

Blacklaws, Jake; Deska-Gauthier, Dylan; Jones, Christopher T; Petracca, Yanina L; Liu, Mingwei; Zhang, Han; Fawcett, James P; Glover, Joel C; Lanuza, Guillermo M; Zhang, Ying

2015-09-01

V3 spinal interneurons (INs) are a group of excitatory INs that play a crucial role in producing balanced and stable gaits in vertebrate animals. In the developing mouse spinal cord, V3 INs arise from the most ventral progenitor domain and form anatomically distinctive subpopulations in adult spinal cords. They are marked by the expression of transcription factor Sim1 postmitotically, but the function of Sim1 in V3 development remains unknown. Here, we used Sim1(Cre) ;tdTomato mice to trace the fate of V3 INs in a Sim1 mutant versus control genetic background during development. In Sim1 mutants, V3 INs are produced normally and maintain a similar position and organization as in wild types before E12.5. Further temporal analysis revealed that the V3 INs in the mutants failed to migrate properly to form V3 subgroups along the dorsoventral axis of the spinal cord. At birth, in the Sim1 mutant the number of V3 INs in the ventral subgroup was normal, but they were significantly reduced in the dorsal subgroup with a concomitant increase in the intermediate subgroup. Retrograde labeling at lumbar level revealed that loss of Sim1 led to a reduction in extension of contralateral axon projections both at E14.5 and P0 without affecting ipsilateral axon projections. These results demonstrate that Sim1 is essential for proper migration and the guidance of commissural axons of the spinal V3 INs. © 2015 Wiley Periodicals, Inc.

ToF-SIMS Investigation of the Effectiveness of Acid-Cleaning procedures for Genesis Solar Wind Collectors

NASA Technical Reports Server (NTRS)

Goreva, Y. S.; Humanyun, M.; Burnett, D. S.; Jurewicz, A. J.; Gonzalez, C. P.

2014-01-01

ToF-SIMS images of Genesis sample surfaces contain an incredible amount of important information, but they also show that the crash-derived surface contamination has many components, presenting a challenge to cleaning. Within the variability, we have shown that there are some samples which appear to be clean to begin with, e.g. 60471, and some are more contaminated. Samples 60493 and 60500 are a part of a focused study of the effectiveness of aqua regia and/or sulfuric acid cleaning of small flight Si implanted with Li-6 using ToF-SIMS.

Sub-100 nm resolution microscopy based on proximity projection grating scheme

PubMed Central

Hu, Feng; Somekh, Michael G.; Albutt, Darren J.; Webb, Kevin; Moradi, Emilia; See, Chung W.

2015-01-01

Structured illumination microscopy (SIM) has been widely used in life science imaging applications. The maximum resolution improvement of SIM, compared to conventional bright field system is a factor of 2. Here we present an approach to structured illumination microscopy using the proximity projection grating scheme (PPGS), which has the ability to further enhance the SIM resolution without invoking any nonlinearity response from the sample. With the PPGS-based SIM, sub-100 nm resolution has been obtained experimentally, and results corresponding to 2.4 times resolution improvement are presented. Furthermore, it will be shown that an improvement of greater than 3 times can be achieved. PMID:25715953

Surface studies of heterogeneous catalysts by time-of-flight secondary ion mass spectrometry.

PubMed

Grams, Jacek

2010-01-01

The aim of this paper was to present potentialities of time-of-flight secondary ion mass spectrometry (ToF- SIMS) in the studies of heterogeneous catalysts. The results of ToF-SIMS investigations of Co/Al2O3, Mo/Al2O3, Co-Mo/Al2O3, Au/Al2O3, Pt/TiO2 and Pd/TiO2 systems were described. It was demonstrated that, in this case, an application of ToF-SIMS makes possible the determination of surface composition of investigated catalysts (including an identification of surface contaminants), characterization of interactions between an active phase and support, estimation of active phase dispersion on the analyzed surface, comparison of the degree of metal oxidation after treatment of the catalyst in different conditions, investigation of catalyst deactivation processes (formation of new chemical compounds, adsorption of various impurities and poisons on the catalyst surface) and determination of organic precursors of catalysts.

Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

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

Hua, Xin; Marshall, Matthew J.; Xiong, Yijia

2015-05-01

A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface) was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. 2D images were reconstructed to report the first 3D images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis (PCA) was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS.

The impact of detergents on the tissue decellularization process: A ToF-SIMS study.

PubMed

White, Lisa J; Taylor, Adam J; Faulk, Denver M; Keane, Timothy J; Saldin, Lindsey T; Reing, Janet E; Swinehart, Ilea T; Turner, Neill J; Ratner, Buddy D; Badylak, Stephen F

2017-03-01

Biologic scaffolds are derived from mammalian tissues, which must be decellularized to remove cellular antigens that would otherwise incite an adverse immune response. Although widely used clinically, the optimum balance between cell removal and the disruption of matrix architecture and surface ligand landscape remains a considerable challenge. Here we describe the use of time of flight secondary ion mass spectroscopy (ToF-SIMS) to provide sensitive, molecular specific, localized analysis of detergent decellularized biologic scaffolds. We detected residual detergent fragments, specifically from Triton X-100, sodium deoxycholate and sodium dodecyl sulphate (SDS) in decellularized scaffolds; increased SDS concentrations from 0.1% to 1.0% increased both the intensity of SDS fragments and adverse cell outcomes. We also identified cellular remnants, by detecting phosphate and phosphocholine ions in PAA and CHAPS decellularized scaffolds. The present study demonstrates ToF-SIMS is not only a powerful tool for characterization of biologic scaffold surface molecular functionality, but also enables sensitive assessment of decellularization efficacy. We report here on the use of a highly sensitive analytical technique, time of flight secondary ion mass spectroscopy (ToF-SIMS) to characterize detergent decellularized scaffolds. ToF-SIMS detected cellular remnants and residual detergent fragments; increased intensity of the detergent fragments correlated with adverse cell matrix interactions. This study demonstrates the importance of maintaining a balance between cell removal and detergent disruption of matrix architecture and matrix surface ligand landscape. This study also demonstrates the power of ToF-SIMS for the characterization of decellularized scaffolds and capability for assessment of decellularization efficacy. Future use of biologic scaffolds in clinical tissue reconstruction will benefit from the fundamental results described in this work. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Imaging of Crystalline and Amorphous Surface Regions Using Time-of-Flight Secondary-Ion Mass Spectrometry (ToF-SIMS): Application to Pharmaceutical Materials.

PubMed

Iuraş, Andreea; Scurr, David J; Boissier, Catherine; Nicholas, Mark L; Roberts, Clive J; Alexander, Morgan R

2016-04-05

The structure of a material, in particular the extremes of crystalline and amorphous forms, significantly impacts material performance in numerous sectors such as semiconductors, energy storage, and pharmaceutical products, which are investigated in this paper. To characterize the spatial distribution for crystalline-amorphous forms at the uppermost molecular surface layer, we performed time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) measurements for quench-cooled amorphous and recrystallized samples of the drugs indomethacin, felodipine, and acetaminophen. Polarized light microscopy was used to localize crystallinity induced in the samples under controlled conditions. Principal component analysis was used to identify the subtle changes in the ToF-SIMS spectra indicative of the amorphous and crystalline forms for each drug. The indicators of amorphous and crystalline surfaces were common in type across the three drugs, and could be explained in general terms of crystal packing and intermolecular bonding, leading to intramolecular bond scission in the formation of secondary ions. Less intramolecular scission occurred in the amorphous form, resulting in a greater intensity of molecular and dimer secondary ions. To test the generality of amorphous-crystalline differentiation using ToF-SIMS, a different recrystallization method was investigated where acetaminophen single crystals were recrystallized from supersaturated solutions. The findings indicated that the ability to assign the crystalline/amorphous state of the sample using ToF-SIMS was insensitive to the recrystallization method. This demonstrates that ToF-SIMS is capable of detecting and mapping ordered crystalline and disordered amorphous molecular materials forms at micron spatial resolution in the uppermost surface of a material.

The simulation of automatic ladar sensor control during flight operations using USU LadarSIM software

NASA Astrophysics Data System (ADS)

Pack, Robert T.; Saunders, David; Fullmer, Rees; Budge, Scott

2006-05-01

USU LadarSIM Release 2.0 is a ladar simulator that has the ability to feed high-level mission scripts into a processor that automatically generates scan commands during flight simulations. The scan generation depends on specified flight trajectories and scenes consisting of terrain and targets. The scenes and trajectories can either consist of simulated or actual data. The first modeling step produces an outline of scan footprints in xyz space. Once mission goals have been analyzed and it is determined that the scan footprints are appropriately distributed or placed, specific scans can then be chosen for the generation of complete radiometry-based range images and point clouds. The simulation is capable of quickly modeling ray-trace geometry associated with (1) various focal plane arrays and scanner configurations and (2) various scene and trajectories associated with particular maneuvers or missions.

Towards practical time-of-flight secondary ion mass spectrometry lignocellulolytic enzyme assays

PubMed Central

2013-01-01

Background Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a surface sensitive mass spectrometry technique with potential strengths as a method for detecting enzymatic activity on solid materials. In particular, ToF-SIMS has been applied to detect the enzymatic degradation of woody lignocellulose. Proof-of-principle experiments previously demonstrated the detection of both lignin-degrading and cellulose-degrading enzymes on solvent-extracted hardwood and softwood. However, these preliminary experiments suffered from low sample throughput and were restricted to samples which had been solvent-extracted in order to minimize the potential for mass interferences between low molecular weight extractive compounds and polymeric lignocellulose components. Results The present work introduces a new, higher-throughput method for processing powdered wood samples for ToF-SIMS, meanwhile exploring likely sources of sample contamination. Multivariate analysis (MVA) including Principal Component Analysis (PCA) and Multivariate Curve Resolution (MCR) was regularly used to check for sample contamination as well as to detect extractives and enzyme activity. New data also demonstrates successful ToF-SIMS analysis of unextracted samples, placing an emphasis on identifying the low-mass secondary ion peaks related to extractives, revealing how extractives change previously established peak ratios used to describe enzyme activity, and elucidating peak intensity patterns for better detection of cellulase activity in the presence of extractives. The sensitivity of ToF-SIMS to a range of cellulase doses is also shown, along with preliminary experiments augmenting the cellulase cocktail with other proteins. Conclusions These new procedures increase the throughput of sample preparation for ToF-SIMS analysis of lignocellulose and expand the applications of the method to include unextracted lignocellulose. These are important steps towards the practical use of ToF-SIMS as a tool to screen for changes in plant composition, whether the transformation of the lignocellulose is achieved through enzyme application, plant mutagenesis, or other treatments. PMID:24034438

Parachute Drag Model

NASA Technical Reports Server (NTRS)

Cuthbert, Peter

2010-01-01

DTV-SIM is a computer program that implements a mathematical model of the flight dynamics of a missile-shaped drop test vehicle (DTV) equipped with a multistage parachute system that includes two simultaneously deployed drogue parachutes and three main parachutes deployed subsequently and simultaneously by use of pilot parachutes. DTV-SIM was written to support air-drop tests of the DTV/parachute system, which serves a simplified prototype of a proposed crew capsule/parachute landing system.

TOF-SIMS imaging technique with information entropy

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Kawashima, Y.; Kudo, Masahiro

2005-05-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is capable of chemical imaging of proteins on insulated samples in principal. However, selection of specific peaks related to a particular protein, which are necessary for chemical imaging, out of numerous candidates had been difficult without an appropriate spectrum analysis technique. Therefore multivariate analysis techniques, such as principal component analysis (PCA), and analysis with mutual information defined by information theory, have been applied to interpret SIMS spectra of protein samples. In this study mutual information was applied to select specific peaks related to proteins in order to obtain chemical images. Proteins on insulated materials were measured with TOF-SIMS and then SIMS spectra were analyzed by means of the analysis method based on the comparison using mutual information. Chemical mapping of each protein was obtained using specific peaks related to each protein selected based on values of mutual information. The results of TOF-SIMS images of proteins on the materials provide some useful information on properties of protein adsorption, optimality of immobilization processes and reaction between proteins. Thus chemical images of proteins by TOF-SIMS contribute to understand interactions between material surfaces and proteins and to develop sophisticated biomaterials.

TOF-SIMS Analysis of Red Color Inks of Writing and Printing Tools on Questioned Documents.

PubMed

Lee, Jihye; Nam, Yun Sik; Min, Jisook; Lee, Kang-Bong; Lee, Yeonhee

2016-05-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a well-established surface technique that provides both elemental and molecular information from several monolayers of a sample surface while also allowing depth profiling or image mapping to be performed. Static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric, biological, archaeological, and forensic materials. In forensic investigation, the use of a minimal sample for the analysis is preferable. Although the TOF-SIMS technique is destructive, the probing beams have microsized diameters so that only small portion of the questioned sample is necessary for the analysis, leaving the rest available for other analyses. In this study, TOF-SIMS and attenuated total reflectance Fourier transform infrared (ATR-FTIR) were applied to the analysis of several different pen inks, red sealing inks, and printed patterns on paper. The overlapping areas of ballpoint pen writing, red seal stamping, and laser printing in a document were investigated to identify the sequence of recording. The sequence relations for various cases were determined from the TOF-SIMS mapping image and the depth profile. TOF-SIMS images were also used to investigate numbers or characters altered with two different red pens. TOF-SIMS was successfully used to determine the sequence of intersecting lines and the forged numbers on the paper. © 2016 American Academy of Forensic Sciences.

Biochemical imaging of tissues by SIMS for biomedical applications

NASA Astrophysics Data System (ADS)

Lee, Tae Geol; Park, Ji-Won; Shon, Hyun Kyong; Moon, Dae Won; Choi, Won Woo; Li, Kapsok; Chung, Jin Ho

2008-12-01

With the development of optimal surface cleaning techniques by cluster ion beam sputtering, certain applications of SIMS for analyzing cells and tissues have been actively investigated. For this report, we collaborated with bio-medical scientists to study bio-SIMS analyses of skin and cancer tissues for biomedical diagnostics. We pay close attention to the setting up of a routine procedure for preparing tissue specimens and treating the surface before obtaining the bio-SIMS data. Bio-SIMS was used to study two biosystems, skin tissues for understanding the effects of photoaging and colon cancer tissues for insight into the development of new cancer diagnostics for cancer. Time-of-flight SIMS imaging measurements were taken after surface cleaning with cluster ion bombardment by Bi n or C 60 under varying conditions. The imaging capability of bio-SIMS with a spatial resolution of a few microns combined with principal component analysis reveal biologically meaningful information, but the lack of high molecular weight peaks even with cluster ion bombardment was a problem. This, among other problems, shows that discourse with biologists and medical doctors are critical to glean any meaningful information from SIMS mass spectrometric and imaging data. For SIMS to be accepted as a routine, daily analysis tool in biomedical laboratories, various practical sample handling methodology such as surface matrix treatment, including nano-metal particles and metal coating, in addition to cluster sputtering, should be studied.

SIM PlanetQuest: Science with the Space Interferometry Mission

NASA Technical Reports Server (NTRS)

Unwin, Stephen (Editor); Turyshev, Slava (Editor)

2004-01-01

SIM - the Space Interferometry Mission - will perform precision optical astrometry on objects as faint as R magnitude 20. It will be the first space-based astrometric interferometer, operating in the optical band with a 10-m baseline. The Project is managed by the Jet Propulsion Laboratory, California Institute of Technology, in close collaboration with two industry partners, Lockheed Martin Missiles and Space, and TRW Inc., Space and Electronics Group. Launch of SIM is currently planned for 2009. In its wide-angle astrometric mode, SIM will yield 4 microarcsecond absolute position and parallax measurements. Astrometric planet searches will be done in a narrow-angle mode, with an accuracy of 4 microarcseconds or better in a single measurement. As a pointed rather than a survey instrument, SIM will maintain.its astrometric accuracy down to the faintest, magnitudes, opening up the opportunity for astrometry of active galactic nuclei to better than 10 pas. SIM will define a new astrometric reference frame, using a grid of approximately 1500 stars with positions accurate to 4 microarcseconds. The SIM Science Team comprises the Principal Investigators of ten Key Projects, and five Mission Scientists contributing their expertise to specific areas of the mission. Their science programs cover a wide range of topics in Galactic and extragalactic astronomy. They include: searches for low-mass planets - including analogs to our own solar system - tlie formation and dynamics of our Galaxy, calibration of the cosmic distance scale, and fundamental stellar astrophysics. All of the science observing on SIM is competitively awarded; the Science Team programs total about 40% of the total available, and the remainder will be assigned via future NASA competitions. This report is a compilation of science summaries by members of the Science Team, and it illustrates the wealth of scientific problems that microarcsecond-precision astrometry can contribute to. More information on SIM, including copies of this report, may be obtained from the project web site, at http://sim. jpl.nasa.gov.

Decomposition of ultrathin LiF cathode underlayer in organic-based devices evidenced by ToF-SIMS depth profiling

NASA Astrophysics Data System (ADS)

Pakhomov, Georgy L.; Drozdov, Mikhail N.; Travkin, Vlad V.; Bochkarev, Mikhail N.

2017-11-01

In this work we investigate the chemical composition of an archetypal thin-film organic device with the Ag/LiF cathode using the time-of-flight secondary ion mass spectrometry (ToF-SIMS) with depth profiling. The LiF cathode underlayer is partly decomposed because a significant amount of lithium is released into the bulk of the multilayer device. The released lithium diffuses all the way to the substrate, accumulating, as revealed by ToF-SIMS depth profiles, at the interfaces rather than uniformly doping the underlying layers. Particularly, the bottom anode becomes chemically modified.

Surface Characterization of Polymer Blends by XPS and ToF-SIMS

PubMed Central

Chan, Chi Ming; Weng, Lu-Tao

2016-01-01

The surface properties of polymer blends are important for many industrial applications. The physical and chemical properties at the surface of polymer blends can be drastically different from those in the bulk due to the surface segregation of the low surface energy component. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary mass spectrometry (ToF-SIMS) have been widely used to characterize surface and bulk properties. This review provides a brief introduction to the principles of XPS and ToF-SIMS and their application to the study of the surface physical and chemical properties of polymer blends. PMID:28773777

A Virtual Research Environment for a Secondary Ion Mass Spectrometer (SIMS)

NASA Astrophysics Data System (ADS)

Wiedenbeck, M.; Schäfer, L.; Klump, J.; Galkin, A.

2013-12-01

Overview: This poster describes the development of a Virtual Research Environment for the Secondary Ion Mass Spectrometer (SIMS) at GFZ Potsdam. Background: Secondary Ion Mass Spectrometers (SIMS) are extremely sensitive instruments for analyzing the surfaces of solid and thin film samples. These instruments are rare, expensive and experienced operators are very highly sought after. As such, measurement time is a precious commodity, until now only accessible to small numbers of researchers. The challenge: The Virtual SIMS Project aims to set up a Virtual Research Environment for the operation of the CAMECA IMS 1280-HR instrument at the GFZ Potsdam. The objective of the VRE is to provide SIMS access not only to researchers locally present in Potsdam but also to scientists working with SIMS cooperation partners in e.g., South Africa, Brazil or India. The requirements: The system should address the complete spectrum of laboratory procedures - from online application for measurement time, to remote access for data acquisition to data archiving for the subsequent publication and for future reuse. The approach: The targeted Virtual SIMS Environment will consist of a: 1. Web Server running the Virtual SIMS website providing general information about the project, lab access proposal forms and calendar for the timing of project related tasks. 2. LIMS Server, responsible for scheduling procedures, data management and, if applicable, accounting and billing. 3. Remote SIMS Tool, devoted to the operation of the experiment within a remote control environment. 4. Publishing System, which supports the publication of results in cooperation with the GFZ Library services. 5. Training Simulator, which offers the opportunity to rehearse experiments and to prepare for possible events such as a power outages or interruptions to broadband services. First results: The SIMS Virtual Research Environment will be mainly based on open source software, the only exception being the CAMECA IMS 1280-HR SIMS operating under LabView. The Publishing System will be based on eSciDoc, which is already successfully used by the GFZ scientific library. For the LIMS Server we are currently testing various options. The challenge, however, is the successful integration of all the various components and, where necessary, the definition of useful interfaces between the modules.

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

PubMed Central

Yu, Jiachao; Zhu, Zihua; Yu, Xiao-Ying

2016-01-01

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum Interface (SALVI) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The fibronectin protein film was immobilized on the silicon nitride (SiN) membrane that forms the SALVI detection area. During ToF-SIMS analysis, three modes of analysis were conducted including high spatial resolution mass spectrometry, two-dimensional (2D) imaging, and depth profiling. Mass spectra were acquired in both positive and negative modes. Deionized water was also analyzed as a reference sample. Our results show that the fibronectin film in water has more distinct and stronger water cluster peaks compared to water alone. Characteristic peaks of amino acid fragments are also observable in the hydrated protein ToF-SIMS spectra. These results illustrate that protein molecule adsorption on a surface can be studied dynamically using SALVI and ToF-SIMS in the liquid environment for the first time. PMID:26966995

Chemical Visualization of Sweat Pores in Fingerprints Using GO-Enhanced TOF-SIMS.

PubMed

Cai, Lesi; Xia, Meng-Chan; Wang, Zhaoying; Zhao, Ya-Bin; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong

2017-08-15

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used in imaging of small molecules (<500 Da) in fingerprints, such as gunshot residues and illicit drugs. However, identifying and mapping relatively high mass molecules are quite difficult owing to insufficient ion yield of their molecular ions. In this report, graphene oxide (GO)-enhanced TOF-SIMS was used to detect and image relatively high mass molecules such as poison, alkaloids (>600 Da) and controlled drugs, and antibiotics (>700 Da) in fingerprints. Detail features of fingerprints such as the number and distribution of sweat pores in a ridge and even the delicate morphology of one pore were clearly revealed in SIMS images of relatively high mass molecules. The detail features combining with identified chemical composition were sufficient to establish a human identity and link the suspect to a crime scene. The wide detectable mass range and high spatial resolution make GO-enhanced TOF-SIMS a promising tool in accurate and fast analysis of fingerprints, especially in fragmental fingerprint analysis.

ToF-SIMS PCA analysis of Myrtus communis L.

NASA Astrophysics Data System (ADS)

Piras, F. M.; Dettori, M. F.; Magnani, A.

2009-06-01

Nowadays there is a growing interest of researchers for the application of sophisticated analytical techniques in conjunction with statistical data analysis methods to the characterization of natural products to assure their authenticity and quality, and for the possibility of direct analysis of food to obtain maximum information. In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) in conjunction with principal components analysis (PCA) are applied to study the chemical composition and variability of Sardinian myrtle ( Myrtus communis L.) through the analysis of both berries alcoholic extracts and berries epicarp. ToF-SIMS spectra of berries epicarp show that the epicuticular waxes consist mainly of carboxylic acids with chain length ranging from C20 to C30, or identical species formed from fragmentation of long-chain esters. PCA of ToF-SIMS data from myrtle berries epicarp distinguishes two groups characterized by a different surface concentration of triacontanoic acid. Variability in antocyanins, flavonols, α-tocopherol, and myrtucommulone contents is showed by ToF-SIMS PCA analysis of myrtle berries alcoholic extracts.

Imaging of single liver tumor cells intoxicated by heavy metals using ToF-SIMS

NASA Astrophysics Data System (ADS)

Mai, Fu-Der; Chen, Bo-Jung; Wu, Li-Chen; Li, Feng-Yin; Chen, Wen-Kang

2006-07-01

Human liver tumor cells intoxicated with five different Cd, Cu, Cr, Hg and Zn metals were analyzed using imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) to visualize the metal distributions in a single cell basis. A protocol was developed by combining rapid freezing, freeze-fracture and imprinting for transferring the intoxicated cells to a silicon wafer. As shown in the ToF-SIMS images, the cellular morphology was preserved indicating that this protocol can be used to prepare a representative cell for ToF-SIMS imaging analysis. Among the five metal ions investigated in this study, only Cr and Cu ions show preferential diffusion into the cell after simulated intoxication while the signals of the other three ions are either too low to be detected or unable to be distinguished from background intensity.

Enhancing the ATIC Charge Resolution

NASA Technical Reports Server (NTRS)

Guzik, T. G.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Batkov, K. E.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunashingha, R. M.

2006-01-01

The Advanced Thin Ionization Calorimeter (ATIC) experiment measures the energy spectra of elements, from H to Fe, in the energy region from about 100 GeV to tens of TeV. The ATIC instrument was flown twice in long-duration balloon flights around the South Pole; the ATIC-1 test flight during Dec. 2000 - Jan. 2001 and the ATIC-2 science flight during Dec. 2002 - Jan. 2003. Analyses of both datasets have, to date, relied upon the highly segmented Silicon Matrix (SiM) detector to separate the incident cosmic ray from the calorimeter backscatter and to identify the charge. This method has worked well, enabling ATIC to separate protons from helium and to resolve all the major species up through iron. This charge resolution can be significantly improved by restricting the analysis to particle trajectories that pass through two SiM pixels at the cost of using only a fraction of the potential instrument geometry. However, immediately below the SiM is the two layer SI hodoscope (x, y) consisting of Bicron BC-408 plastic scintillator 2 cm wide, 1 cm thick, 88.2 cm long strips viewed by Hamamatsu R5611 photomultiplier tubes on each end of each strip. The primary purpose of the ATIC hodoscopes is to provide a fast trigger, and each hodoscope includes two crossed layers of strips (42 per layer in the case of Sl) providing supplemental particle trajectory information. The hodoscope readout electronics were designed to provide reasonable charge resolution over the dynamic range from protons through iron. This presentation discusses the S 1 hodoscope energy deposit calibrations, examines the charge resolution possible with this detector and investigates combining the S1 and SiM charge measurements to improve the overall ATIC charge resolution while minimizing degradation of the instrument geometry.

Depth-Resolved Cathodoluminescence of Thorium Dioxide

DTIC Science & Technology

2013-03-01

exhibited more of an energy dependency than the cut and polished sample. However, in a companion study, ime of flight secondary ion mass spectrometry...Ion Mass Spectrometry (TOF SIMS) ......................17 2.7 Atomic Force Microscope (AFM...1 TOF SIMS……….Time of Flight Secondary Ion Mass Spectroscopy……………….62 1 DEPTH

Cross-Compiler for Modeling Space-Flight Systems

NASA Technical Reports Server (NTRS)

James, Mark

2007-01-01

Ripples is a computer program that makes it possible to specify arbitrarily complex space-flight systems in an easy-to-learn, high-level programming language and to have the specification automatically translated into LibSim, which is a text-based computing language in which such simulations are implemented. LibSim is a very powerful simulation language, but learning it takes considerable time, and it requires that models of systems and their components be described at a very low level of abstraction. To construct a model in LibSim, it is necessary to go through a time-consuming process that includes modeling each subsystem, including defining its fault-injection states, input and output conditions, and the topology of its connections to other subsystems. Ripples makes it possible to describe the same models at a much higher level of abstraction, thereby enabling the user to build models faster and with fewer errors. Ripples can be executed in a variety of computers and operating systems, and can be supplied in either source code or binary form. It must be run in conjunction with a Lisp compiler.

Semiquantitative analysis of atherosclerotic plaque using optical coherence tomography and time-of-flight secondary ion mass spectrometry

NASA Astrophysics Data System (ADS)

Korol, Renee M.; Togonu-Bickersteth, Babajide; Yang, Victor X.; Dimov, Stamen; Vatsya, Pracha; Gordon, Maggie; Vitkin, Alex; Liu, Liying; Canham, Peter; Clarke, Sharon; Lucas, Alexandra

2003-10-01

Atherosclerosis is the underlying vascular pathology that initiates arterial thromboembolic occlusions (myocardial infarctions, strokes and peripheral vessel blockage). Two imaging modalities, Optical Coherence Tomography (OCT) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), were investigated for detection and compositional analysis of unstable plaque associated with plaque erosion and sudden occlusion. OCT produces high resolution images whereas mass spectrometry images provide information on the spatial distribution of chemical elements. Diseased carotid arteries taken from patients with high-risk lesions were imaged with OCT and ToF-SIMS to give molecular and metabolic information, and matched with histopathology. OCT results show clear indications of vascular remodeling by the presence of fatty acid deposits, fibrous tissue and calcifications. ToF-SIMS further characterized changes based on secondary ion topography analysis where a high 23Na/39K ratio was indicative of arterial tissue degradation and the amount of 40Ca corresponded with late stage atherosclerosis. This pilot experiment has demonstrated that in vitro OCT imaging and ToF-SIMS of diseased carotid arteries have scientific merit for targeting clinically relevant morphology and metabolic changes to compare stable and unstable plaque. These optical techniques provide complimentary metabolic and molecular information on unstable plaque, specifically cell break-down with altered ion ratios of 23Na, 39K and 40Ca.

TOF-SIMS investigation of metallic material surface after culturing cells

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Hiromoto, Sachiko; Hanawa, Takao; Kudo, Masahiro

2004-06-01

Biomolecules such as extracellular matrix and adhesive proteins generated by adhered cells on metallic specimens were characterized by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS) in order to clarify the interaction between cells and metal surfaces. Since composition and structure of the extracellular matrix depends on conditions of cells, characterization of the interaction between cells and metallic specimens is important in order to evaluate the biocompatibility and the degradation behavior of metallic biomaterials and artificial organs. Moreover, the obtained data can contribute to the development of new metallic biomaterials. TOF-SIMS spectra were analyzed by means of mutual information described by information theory and principal components analysis (PCA). The results show that cells have great influence on adsorption of biomolecules on metallic materials because they change surface conditions of the materials. Thus TOF-SIMS is a useful technique to investigate the interaction between metallic biomaterials and cells.

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

Bernard, Laetitia, E-mail: laetitia.bernard@empa.ch; Leemann, Andreas

In this study, the potential of time-of-flight secondary ion mass spectrometry (ToF-SIMS) for the application in cement-based materials is assessed in combination and comparison with scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Mortar, concrete and samples from model systems providing products formed by the alkali–silica reaction (ASR) were studied. ToF-SIMS provides qualitative data on alkalis in cases where EDX reaches its limits in regard to detectable concentration, lateral resolution and atomic number of the elements. Due to its high in-depth resolution of a few atomic monolayers, thin layers of reaction products can be detected on the surfaces andmore » chemically analyzed with ToF-SIMS. Additionally, it delivers information on the molecular conformation within the ASR product, its hydrogen content and its isotope ratios, information not provided by EDX. Provided the samples are carefully prepared, ToF-SIMS opens up new possibilities in the analysis of cement-based materials.« less

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

Yu, Jiachao; Zhou, Yufan; Hua, Xin

We demonstrate in situ chemical imaging of protein biomolecules in the aqueous solution using System for Analysis at the Liquid Vacuum Interface (SALVI) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The fibronectin protein film was immobilized on the silicon nitride (SiN) membrane forming the SALVI detection area. During ToF-SIMS analysis, three modes of analysis were conducted including high spatial resolution mass spectra, two-dimensional (2D) imaging, and depth profiling. Mass spectra were acquired in both positive and negative modes. Deionized water was also analyzed as a reference sample. Our results show that fibronectin film in water has more distinct and strongermore » water cluster peaks compared to water alone. Characteristic peaks of amino acid fragments are also observable in the hydrated protein ToF-SIMS spectra. These results illustrate that protein molecule adsorption on a surface can be studied dynamically using SALVI and ToF-SIMS in the liquid environment.« less

Investigation of the Ionization Mechanism of NAD+/NADH-Modified Gold Electrodes in ToF-SIMS Analysis.

PubMed

Hua, Xin; Zhao, Li-Jun; Long, Yi-Tao

2018-06-04

Analysis of nicotinamide adenine dinucleotide (NAD + /NADH)-modified electrodes is important for in vitro monitoring of key biological processes. In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to analyze NAD + /NADH-modified gold electrodes. Interestingly, no obvious characteristic peaks of nicotinamide fragment could be observed in the mass spectra of NAD + /NADH in their neutral sodium pyrophosphate form. However, after acidification, the characteristic peaks for both NAD + and NADH were detected. This was due to the suppression effect of inner pyrophosphoric salts in both neutral molecules. Besides, it was proved that the suppression by inner salt was intramolecular. No obvious suppression was found between neighboring molecules. These results demonstrated the suppression effect of inner salts in ToF-SIMS analysis, providing useful evidence for the study of ToF-SIMS ionization mechanism of organic molecule-modified electrodes. Graphical Abstract ᅟ.

Auto-Coding UML Statecharts for Flight Software

NASA Technical Reports Server (NTRS)

Benowitz, Edward G; Clark, Ken; Watney, Garth J.

2006-01-01

Statecharts have been used as a means to communicate behaviors in a precise manner between system engineers and software engineers. Hand-translating a statechart to code, as done on some previous space missions, introduces the possibility of errors in the transformation from chart to code. To improve auto-coding, we have developed a process that generates flight code from UML statecharts. Our process is being used for the flight software on the Space Interferometer Mission (SIM).

Nuclear Forensics: Measurements of Uranium Oxides Using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

DTIC Science & Technology

2010-03-01

Isotope Ratio Analysis of Actinides , Fission Products, and Geolocators by High- efficiency Multi-collector Thermal Ionization Mass Spectrometry...Information, 1999. Hou, Xiaolin, and Per Roos. “ Critical Comparison of radiometric and Mass Spectrometric Methods for the Determination of...NUCLEAR FORENSICS: MEASUREMENTS OF URANIUM OXIDES USING TIME-OF-FLIGHT SECONDARY ION MASS

Using time-of-flight secondary ion mass spectrometry and multivariate statistical analysis to detect and image octabenzyl-polyhedral oligomeric silsesquioxane in polycarbonate

NASA Astrophysics Data System (ADS)

Smentkowski, V. S.; Duong, H. M.; Tamaki, R.; Keenan, M. R.; Ohlhausen, J. A. Tony; Kotula, P. G.

2006-11-01

Silsesquioxane, with an empirical formula of RSiO3/2, has the potential to combine the mechanical properties of plastics with the oxidative stability of ceramics in one material [D.W. Scott, J. Am. Chem. Soc. 68 (1946) 356; K.J. Shea, D.A. Loy, Acc. Chem. Res. 34 (2001) 707; K.-M. Kim, D.-K. Keum, Y. Chujo, Macromolecules 36 (2003) 867; M.J. Abad, L. Barral, D.P. Fasce, R.J.J. William, Macromolecules 36 (2003) 3128]. The high sensitivity, surface specificity, and ability to detect and image high mass additives make time-of-flight secondary ion mass spectrometry (ToF-SIMS) a powerful surface analytical instrument for the characterization of polymer composite surfaces in an analytical laboratory [J.C. Vickerman, D. Briggs (Eds.), ToF-SIMS Surface Analysis by Mass Spectrometry, Surface Spectra/IMPublications, UK, 2001; X. Vanden Eynde, P. Bertand, Surf. Interface Anal. 27 (1999) 157; P.M. Thompson, Anal. Chem. 63 (1991) 2447; S.J. Simko, S.R. Bryan, D.P. Griffis, R.W. Murray, R.W. Linton, Anal. Chem. 57 (1985) 1198; S. Affrossman, S.A. O'Neill, M. Stamm, Macromolecules 31 (1998) 6280]. In this paper, we compare ToF-SIMS spectra of control samples with spectra generated from polymer nano-composites based on octabenzyl-polyhedral oligomeric silsesquioxane (BnPOSS) as well as spectra (and images) generated from multivariate statistical analysis (MVSA) of the entire spectral image. We will demonstrate that ToF-SIMS is able to detect and image low concentrations of BnPOSS in polycarbonate. We emphasize the use of MVSA tools for converting the massive amount of data contained in a ToF-SIMS spectral image into a smaller number of useful chemical components (spectra and images) that fully describe the ToF-SIMS measurement.

Analysis of the Boeing 747-100 using CEASIOM

NASA Astrophysics Data System (ADS)

Richardson, Thomas S.; Beaverstock, Chris; Isikveren, Askin; Meheri, Alireza; Badcock, Ken; Da Ronch, Andrea

2011-11-01

One of the requirements for the SimSAC project was to use existing aircraft to act as benchmarks for comparison with CEASIOM generated models. Within this paper, results are given for one of these examples, the Boeing 747-100. This aircraft was selected because a complete dataset exists in the open domain, which can be used to validate SimSAC generated data. The purpose of this paper is to both give confidence in, and to demonstrate the capabilities of, the CEASIOM environment when used for preliminary aircraft and control system design. CEASIOM is the result of the integration of a set of sophisticated tools by the European Union funded, Framework 6 SimSAC program. The first part of this paper presents a comparison of the aerodynamic results for each of the solvers available within CEASIOM together with data from the 747-100 model published by NASA. The resulting nonlinear model is then trimmed and analysed using the Flight Control System Designer Toolkit (FCSDT) module. In the final section of the paper a state-feedback controller is designed within CEASIOM in order to modify the longitudinal dynamics of the aircraft. The open and closed loop models are subsequently evaluated with selected failed aerodynamic surfaces and for the case of a single failed engine. Through these results, the CEASIOM software suite is shown to be able to generate excellent quality adaptive-fidelity aerodynamic data. This data is contained within a full nonlinear aircraft model to which linear analysis and control system design can be easily applied.

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

Wang, Zhaoying; Liu, Jia; Zhou, Yufan

It has been very difficult to use popular elemental imaging techniques to image Li and B distribution in glass samples with nanoscale resolution. In this study, atom probe tomography (APT), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and nanoscale secondary ion mass spectrometry (NanoSIMS) were used to image the distribution of Li and B in two representative glass samples. APT can provide three-dimensional Li and B imaging with very high spatial resolution (≤ 2 nm). In addition, absolute quantification of Li and B is possible, though room remains to improve accuracy. However, the major drawbacks of APT include limited field ofmore » view (normally ≤ 100 × 100 × 500 nm 3) and poor sample compatibility. As a comparison, ToF-SIMS and NanoSIMS are sample-friendly with flexible field of view (up to 500 × 500 μm 2 and image stitching is feasible); however, lateral resolution is limited to only about 100 nm. Therefore, SIMS and APT can be regarded as complementary techniques for nanoscale imaging Li and B in glass and other novel materials.« less

Evaluation of oriented lysozyme immobilized with monoclonal antibody

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Okada, Keigo; Shigyo, Ayako; Man, Naoki; Karen, Akiya

2008-12-01

The orientation of a lysozyme immobilized with a monoclonal antibody was evaluated based on determination of the uppermost surface structure using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Specific peaks of the oriented lysozyme immobilized with monoclonal anti-lysozyme antibody were obtained in comparison with reference samples, non-oriented immobilized lysozyme and immobilized anti-lysozyme antibody. All samples were freeze-dried before TOF-SIMS measurement, and then each sample was measured using TOF-SIMS with a bismuth cluster ion source. TOF-SIMS spectra were analyzed to select peaks specific to the oriented immobilized lysozyme as well as to identify their chemical formula and ensemble of amino acids. The possible chemical formulae of the lysozyme fragments were then investigated with an element matching program and a residue matching program. The results from TOF-SIMS spectra analysis were compared to the amino acid sequence of the lysozyme and its three-dimensional structure registered in the protein data bank. Finally, the fragment-ion-generating regions of the oriented immobilized lysozyme were determined based on the suggested residues and the three-dimensional structure.

Advantages of TOF-SIMS analysis of hydroxyapatite and fluorapatite in comparison with XRD, HR-TEM and FT-IR.

PubMed

Okazaki, Masayuki; Hirata, Isao; Matsumoto, Takuya; Takahashi, Junzo

2005-12-01

The chemical analysis of hydroxyapatite and fluorapatite was carried out using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Hydroxyapatite and fluorapatite were synthesized at 80 +/- 1 degrees C and pH 7.4 +/- 0.2. Fluorapatite was better crystallized, with its (300) reflection shifted to a slightly higher angle. High-resolution transmission electron microscopy clearly revealed a typical, regular hexagonal cross section perpendicular to the c-axis for fluorapatite and a flattened hexagonal cross section for hydroxyapatite. FT-IR spectra of fluorapatite confirmed the absence of OH absorption peak--which was seen in hydroxyapatite at about 3570 cm(-1). TOF-SIMS mass spectra showed a peak at 40 amu due to calcium. In addition, a peak at 19 amu due to fluorine could be clearly seen, although the intensities of PO, PO2, and PO3 were very low. It was confirmed that TOF-SIMS clearly showed the differences between positive and negative mass spectra of hydroxyapatite and fluorapatite, especially for F-. We concluded that TOF-SIMS exhibited distinct advantages compared with other methods of analysis.

Distribution and visualisation of chlorhexidine within the skin using ToF-SIMS: a potential platform for the design of more efficacious skin antiseptic formulations.

PubMed

Judd, Amy M; Scurr, David J; Heylings, Jon R; Wan, Ka-Wai; Moss, Gary P

2013-07-01

In order to increase the efficacy of a topically applied antimicrobial compound the permeation profile, localisation and mechanism of action within the skin must first be investigated. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to visualise the distribution of a conventional antimicrobial compound, chlorhexidine digluconate, within porcine skin without the need for laborious preparation, radio-labels or fluorescent tags. High mass resolution and high spatial resolution mass spectra and chemical images were achieved when analysing chlorhexidine digluconate treated cryo-sectioned porcine skin sections by ToF-SIMS. The distribution of chlorhexidine digluconate was mapped throughout the skin sections and our studies indicate that the compound appears to be localised within the stratum corneum. In parallel, tape strips taken from chlorhexidine digluconate treated porcine skin were analysed by ToF-SIMS to support the distribution profile obtained from the skin sections. ToF-SIMS can act as a powerful complementary technique to map the distribution of topically applied compounds within the skin.

Using flight simulators aboard ships: human side effects of an optimal scenario with smooth seas.

PubMed

Muth, Eric R; Lawson, Ben

2003-05-01

The U.S. Navy is considering placing flight simulators aboard ships. It is known that certain types of flight simulators can elicit motion adaptation syndrome (MAS), and also that certain types of ship motion can cause MAS. The goal of this study was to determine if using a flight simulator during ship motion would cause MAS, even when the simulator stimulus and the ship motion were both very mild. All participants in this study completed three conditions. Condition 1 (Sim) entailed "flying" a personal computer-based flight simulator situated on land. Condition 2 (Ship) involved riding aboard a U.S. Navy Yard Patrol boat. Condition 3 (ShipSim) entailed "flying" a personal computer-based flight simulator while riding aboard a Yard Patrol boat. Before and after each condition, participants' balance and dynamic visual acuity were assessed. After each condition, participants filled out the Nausea Profile and the Simulator Sickness Questionnaire. Following exposure to a flight simulator aboard a ship, participants reported negligible symptoms of nausea and simulator sickness. However, participants exhibited a decrease in dynamic visual acuity after exposure to the flight simulator aboard ship (T[25] = 3.61, p < 0.05). Balance results were confounded by significant learning and, therefore, not interpretable. This study suggests that flight simulators can be used aboard ship. As a minimal safety precaution, these simulators should be used according to current safety practices for land-based simulators. Optimally, these simulators should be designed to minimize MAS, located near the ship's center of rotation and used when ship motion is not provocative.

Methodological development of topographic correction in 2D/3D ToF-SIMS images using AFM images

NASA Astrophysics Data System (ADS)

Jung, Seokwon; Lee, Nodo; Choi, Myungshin; Lee, Jungmin; Cho, Eunkyunng; Joo, Minho

2018-02-01

Time-of-flight secondary-ion mass spectrometry (ToF-SIMS) is an emerging technique that provides chemical information directly from the surface of electronic materials, e.g. OLED and solar cell. It is very versatile and highly sensitive mass spectrometric technique that provides surface molecular information with their lateral distribution as a two-dimensional (2D) molecular image. Extending the usefulness of ToF-SIMS, a 3D molecular image can be generated by acquiring multiple 2D images in a stack. These imaging techniques by ToF-SIMS provide an insight into understanding the complex structures of unknown composition in electronic material. However, one drawback in ToF-SIMS is not able to represent topographical information in 2D and 3D mapping images. To overcome this technical limitation, topographic information by ex-situ technique such as atomic force microscopy (AFM) has been combined with chemical information from SIMS that provides both chemical and physical information in one image. The key to combine two different images obtained from ToF-SIMS and AFM techniques is to develop the image processing algorithm, which performs resize and alignment by comparing the specific pixel information of each image. In this work, we present methodological development of the semiautomatic alignment and the 3D structure interpolation system for the combination of 2D/3D images obtained by ToF-SIMS and AFM measurements, which allows providing useful analytical information in a single representation.

Observation of endoplasmic reticulum tubules via TOF-SIMS tandem mass spectrometry imaging of transfected cells.

PubMed

Chini, Corryn E; Fisher, Gregory L; Johnson, Ben; Tamkun, Michael M; Kraft, Mary L

2018-02-26

Advances in three-dimensional secondary ion mass spectrometry (SIMS) imaging have enabled visualizing the subcellular distributions of various lipid species within individual cells. However, the difficulty of locating organelles using SIMS limits efforts to study their lipid compositions. Here, the authors have assessed whether endoplasmic reticulum (ER)-Tracker Blue White DPX ® , which is a commercially available stain for visualizing the endoplasmic reticulum using fluorescence microscopy, produces distinctive ions that can be used to locate the endoplasmic reticulum using SIMS. Time-of-flight-SIMS tandem mass spectrometry (MS 2 ) imaging was used to identify positively and negatively charged ions produced by the ER-Tracker stain. Then, these ions were used to localize the stain and thus the endoplasmic reticulum, within individual human embryonic kidney cells that contained higher numbers of endoplasmic reticulum-plasma membrane junctions on their surfaces. By performing MS 2 imaging of selected ions in parallel with the precursor ion (MS 1 ) imaging, the authors detected a chemical interference native to the cell at the same nominal mass as the pentafluorophenyl fragment from the ER-Tracker stain. Nonetheless, the fluorine secondary ions produced by the ER-Tracker stain provided a distinctive signal that enabled locating the endoplasmic reticulum using SIMS. This simple strategy for visualizing the endoplasmic reticulum in individual cells using SIMS could be combined with existing SIMS methodologies for imaging intracellular lipid distribution and to study the lipid composition within the endoplasmic reticulum.

First Integrated Flight Simulation For STS 114

NASA Image and Video Library

2004-10-13

JSC2004-E-45138 (13 October 2004) --- Astronaut Stephen N. Frick monitors communications at the spacecraft communicator (CAPCOM) console in the Shuttle Flight Control Room (WFCR) in Johnson Space Center’s (JSC) Mission Control Center (MCC) with the STS-114 crewmembers during a fully-integrated simulation on October 13. The seven member crew was in a JSC-based simulator during the sims. The dress rehearsal of Discovery's rendezvous and docking with the International Space Station (ISS) was the first flight-specific training for the Space Shuttle's return to flight.

Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar clusters.

PubMed

Nakano, Shusuke; Yokoyama, Yuta; Aoyagi, Satoka; Himi, Naoyuki; Fletcher, John S; Lockyer, Nicholas P; Henderson, Alex; Vickerman, John C

2016-06-08

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides detailed chemical structure information and high spatial resolution images. Therefore, ToF-SIMS is useful for studying biological phenomena such as ischemia. In this study, in order to evaluate cerebral microinfarction, the distribution of biomolecules generated by ischemia was measured with ToF-SIMS. ToF-SIMS data sets were analyzed by means of multivariate analysis for interpreting complex samples containing unknown information and to obtain biomolecular mapping indicated by fragment ions from the target biomolecules. Using conventional ToF-SIMS (primary ion source: Bi cluster ion), it is difficult to detect secondary ions beyond approximately 1000 u. Moreover, the intensity of secondary ions related to biomolecules is not always high enough for imaging because of low concentration even if the masses are lower than 1000 u. However, for the observation of biomolecular distributions in tissues, it is important to detect low amounts of biological molecules from a particular area of tissue. Rat brain tissue samples were measured with ToF-SIMS (J105, Ionoptika, Ltd., Chandlers Ford, UK), using a continuous beam of Ar clusters as a primary ion source. ToF-SIMS with Ar clusters efficiently detects secondary ions related to biomolecules and larger molecules. Molecules detected by ToF-SIMS were examined by analyzing ToF-SIMS data using multivariate analysis. Microspheres (45 μm diameter) were injected into the rat unilateral internal carotid artery (MS rat) to cause cerebral microinfarction. The rat brain was sliced and then measured with ToF-SIMS. The brain samples of a normal rat and the MS rat were examined to find specific secondary ions related to important biomolecules, and then the difference between them was investigated. Finally, specific secondary ions were found around vessels incorporating microspheres in the MS rat. The results suggest that important biomolecules related to cerebral microinfarction can be detected by ToF-SIMS.

ToF-SIMS observation for evaluating the interaction between amyloid β and lipid membranes.

PubMed

Aoyagi, Satoka; Shimanouchi, Toshinori; Kawashima, Tomoko; Iwai, Hideo

2015-04-01

The adsorption behaviour of amyloid beta (Aβ), thought to be a key peptide for understanding Alzheimer's disease, was investigated by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS). Aβ aggregates depending on the lipid membrane condition though it has not been fully understood yet. In this study, Aβ samples on different lipid membranes, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), were observed with ToF-SIMS and the complex ToF-SIMS data of the Aβ samples was interpreted using data analysis techniques such as principal component analysis (PCA), gentle-SIMS (G-SIMS) and g-ogram. DOPC and DMPC are liquid crystal at room temperature, while DPPC is gel at room temperature. As primary ion beams, Bi3(+) and Ar cluster ion beams were used and the effect of an Ar cluster ion for evaluating biomolecules was also studied. The secondary ion images of the peptide fragment ions indicated by G-SIMS and g-ogram were consistent with the PCA results. It is suggested that Aβ is adsorbed homogeneously on the liquid-crystalline-phase lipid membranes, while it aggregates along the lipid on the gel-phase lipid membrane. Moreover, in the results using the Ar cluster, the influence of contamination was reduced.

ToF-SIMS measurements with topographic information in combined images.

PubMed

Koch, Sabrina; Ziegler, Georg; Hutter, Herbert

2013-09-01

In 2D and 3D time-of-flight secondary ion mass spectrometric (ToF-SIMS) analysis, accentuated structures on the sample surface induce distorted element distributions in the measurement. The origin of this effect is the 45° incidence angle of the analysis beam, recording planar images with distortion of the sample surface. For the generation of correct element distributions, these artifacts associated with the sample surface need to be eliminated by measuring the sample surface topography and applying suitable algorithms. For this purpose, the next generation of ToF-SIMS instruments will feature a scanning probe microscope directly implemented in the sample chamber which allows the performance of topography measurements in situ. This work presents the combination of 2D and 3D ToF-SIMS analysis with topographic measurements by ex situ techniques such as atomic force microscopy (AFM), confocal microscopy (CM), and digital holographic microscopy (DHM). The concept of the combination of topographic and ToF-SIMS measurements in a single representation was applied to organic and inorganic samples featuring surface structures in the nanometer and micrometer ranges. The correct representation of planar and distorted ToF-SIMS images was achieved by the combination of topographic data with images of 2D as well as 3D ToF-SIMS measurements, using either AFM, CM, or DHM for the recording of topographic data.

Quantification issues of trace metal contaminants on silicon wafers by means of TOF-SIMS, ICP-MS, and TXRF

NASA Astrophysics Data System (ADS)

Rostam-Khani, P.; Hopstaken, M. J. P.; Vullings, P.; Noij, G.; O'Halloran, O.; Claassen, W.

2004-06-01

Measurement of surface metal contamination on silicon wafers is essential for yield enhancement in IC manufacturing. Vapor phase decomposition coupled with either inductively coupled plasma mass spectrometry (VPD-ICP-MS), or total reflection X-ray fluorescence (VPD-TXRF), TXRF and more recently time of flight secondary ion mass spectrometry (TOF-SIMS) are used to monitor surface metal contamination. These techniques complement each other in their respective strengths and weaknesses. For reliable and accurate quantification, so-called relative sensitivity factors (RSF) are required for TOF-SIMS analysis. For quantification purposes in VPD, the collection efficiency (CE) is important to ensure complete collection of contamination. A standard procedure has been developed that combines the determination of these RSFs as well as the collection efficiency using all the analytical techniques mentioned above. Therefore, sample wafers were intentionally contaminated and analyzed (by TOF-SIMS) directly after preparation. After VPD-ICP-MS, several scanned surfaces were analyzed again by TOF-SIMS. Comparing the intensities of the specific metals before and after the VPD-DC procedure on the scanned surface allows the determination of so-called removing efficiency (RE). In general, very good agreement was obtained comparing the four analytical techniques after updating the RSFs for TOF-SIMS. Progress has been achieved concerning the CE evaluation as well as determining the RSFs more precisely for TOF-SIMS.

Evaluation of blood adsorption onto dialysis membranes by time-of-flight secondary ion mass spectrometry and near-field infrared microscopy.

PubMed

Aoyagi, Satoka; Abe, Kiyoshi; Yamagishi, Takayuki; Iwai, Hideo; Yamaguchi, Satoru; Sunohara, Takashi

2017-11-01

Blood adsorption onto the inside surface of hollow fiber dialysis membranes was investigated by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and near-field infrared microscopy (NFIR) in order to evaluate the biocompatibility and permeability of dialysis membranes. TOF-SIMS is useful for the imaging of particular molecules with a high spatial resolution of approximately 100 nm. In contrast, infrared spectra provide quantitative information and NFIR enables analysis with a high spatial resolution of less than 1 μm, which is close to the resolution of TOF-SIMS. A comparison was made of one of the most widely used dialysis membranes made of polysulfone (PSf), that has an asymmetric and inhomogeneous pore structure, and a newly developed asymmetric cellulose triacetate (ATA) membrane that also has an asymmetric pore structure, even though the conventional cellulose triacetate membrane has a symmetric and homogeneous pore structure. As a result, it was demonstrated that blood adsorption on the inside surface of the ATA membrane is more reduced than that on the PSf membrane. Graphical abstract Analysis of blood adsorption on inside surface of hollow fiber membrane.

Thermal annealing behavior of hydrogen and surface topography of H 2 + ion implanted tungsten

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

Zhang, Jiandong; Jiang, Weilin; Zhu, Zihua

2018-01-25

Tungsten (W) has been proposed as a plasma-facing material (PFM) in fusion reactors due to its outstanding properties. Degradation of the material properties is expected to occur as a result of hydrogen (H) isotope permeation and trapping in W. In this study, two polycrystalline W plates were implanted with 80 keV H 2 + ions to a fluence of 2E21 H+/m2 at room temperature (RT). Time-of-flight secondary ion mass spectrometry (ToF-SIMS), focused ion beam (FIB) and scanning electron microscopy (SEM) were used for sample characterization. The SIMS data shows that H atoms are distributed well beyond the ion projected range.more » Isochronal annealing appears to suggest two H release stages that might be associated with the reported activation energies. H release at RT was observed between days 10 and 70 following ion implantation, and the level was maintained over the next 60 days. In addition, FIB/SEM results exhibit H2 blister formation near the surface of the as-implanted W. The blister distribution remains unchanged after thermal annealing up to 600 °C.« less

Overview of Experimental Capabilities - Supersonics

NASA Technical Reports Server (NTRS)

Banks, Daniel W.

2007-01-01

This viewgraph presentation gives an overview of experimental capabilities applicable to the area of supersonic research. The contents include: 1) EC Objectives; 2) SUP.11: Elements; 3) NRA; 4) Advanced Flight Simulator Flexible Aircraft Simulation Studies; 5) Advanced Flight Simulator Flying Qualities Guideline Development for Flexible Supersonic Transport Aircraft; 6) Advanced Flight Simulator Rigid/Flex Flight Control; 7) Advanced Flight Simulator Rapid Sim Model Exchange; 8) Flight Test Capabilities Advanced In-Flight Infrared (IR) Thermography; 9) Flight Test Capabilities In-Flight Schlieren; 10) Flight Test Capabilities CLIP Flow Calibration; 11) Flight Test Capabilities PFTF Flowfield Survey; 12) Ground Test Capabilities Laser-Induced Thermal Acoustics (LITA); 13) Ground Test Capabilities Doppler Global Velocimetry (DGV); 14) Ground Test Capabilities Doppler Global Velocimetry (DGV); and 15) Ground Test Capabilities EDL Optical Measurement Capability (PIV) for Rigid/Flexible Decelerator Models.

Balancing Training Techniques for Flight Controller Certification

NASA Technical Reports Server (NTRS)

Gosling, Christina

2011-01-01

Training of ground control teams has been a difficult task in space operations. There are several intangible skills that must be learned to become the steely eyed men and women of mission control who respond to spacecraft failures that can lead to loss of vehicle or crew if handled improperly. And as difficult as training is, it can also be costly. Every day, month or year an operator is in training, is a day that not only they are being trained without direct benefit to the organization, but potentially an instructor or mentor is also being paid for hours spent assisting them. Therefore, optimization of the training flow is highly desired. Recently the Expedition Division (DI) at Johnson Space Flight Center has recreated their training flows for the purpose of both moving to an operator/specialist/instructor hierarchy and to address past inefficiencies in the training flow. This paper will discuss the types of training DI is utilizing in their new flows, and the balance that has been struck between the ideal learning environments and realistic constraints. Specifically, the past training flow for the ISS Attitude Determination and Control Officer will be presented, including drawbacks that were encountered. Then the new training flow will be discussed and how a new approach utilizes more training methods and teaching techniques. We will look at how DI has integrated classes, workshops, checkouts, module reviews, scenarios, OJT, paper sims, Mini Sims, and finally Integrated Sims to balance the cost and timing of training a new flight controller.

Sims to Teen Second Life: Transition of the SimSavvy Girls to Tech Savvy Isle

ERIC Educational Resources Information Center

Johnson, Barbara Z.; King, Elizabeth; Hayes, Elisabeth

2008-01-01

In its second year, the Tech Savvy Girls Project adopted "Teen Second Life" as a platform for interest-driven learning and designed projects and objects around themes important to them and their futures as technology-using, creative people. By using the building tools in an open-ended virtual world, they were able to pursue interests common to…

Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques.

PubMed

Lee, Jihye; Kang, Min Hwa; Lee, Kang-Bong; Lee, Yeonhee

2013-05-15

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric.

TOF-SIMS imaging of chlorhexidine-digluconate transport in frozen hydrated biofilms of the fungus Candida albicans

NASA Astrophysics Data System (ADS)

Tyler, Bonnie J.; Rangaranjan, Srinath; Möller, Jörg; Beumer, Andre'; Arlinghaus, Heinrich F.

2006-07-01

The diffusion of the anti-microbial chlorhexidine digluconate (CHG) has been studied in C. albicans biofilms by time-of-flight secondary-ion mass spectrometry (TOF-SIMS). C. albicans has been shown to become resistant to common anti-microbial agents, including CHG, when growing as a biofilm. Mass transport resistance within biofilms has commonly been suggested as a resistance mechanism, but measurement of transport for most anti-microbial agents in biofilms has proven extremely difficult because of the heterogeneity of the biofilms and the difficulty in detecting these agents within an intact biofilm. In this study, TOF-SIMS has been used to study the transport of CHG and glucose in a frozen hydrated biofilm. The TOF-SIMS images reveal a progression of CHG from the top of the biofilm to its base with time. Images suggest that there are channels within the biofilm and show preferential binding of CHG to cellular components of the biofilm. Additionally, both living and dead cells can be identified in the TOF-SIMS images by the sequestration of K + and the presence of cell markers. This study demonstrates that TOF-SIMS has the unique potential to simultaneously observe the presence of an antimicrobial agent, concentration of nutrients, and the viability of the cell population.

WEC-SIM Validation Testing Plan FY14 Q4.

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

Ruehl, Kelley Michelle

2016-02-01

The WEC-Sim project is currently on track, having met both the SNL and NREL FY14 Milestones, as shown in Table 1 and Table 2. This is also reflected in the Gantt chart uploaded to the WEC-Sim SharePoint site in the FY14 Q4 Deliverables folder. The work completed in FY14 includes code verification through code-to-code comparison (FY14 Q1 and Q2), preliminary code validation through comparison to experimental data (FY14 Q2 and Q3), presentation and publication of the WEC-Sim project at OMAE 2014 [1], [2], [3] and GMREC/METS 2014 [4] (FY14 Q3), WEC-Sim code development and public open-source release (FY14 Q3), andmore » development of a preliminary WEC-Sim validation test plan (FY14 Q4). This report presents the preliminary Validation Testing Plan developed in FY14 Q4. The validation test effort started in FY14 Q4 and will go on through FY15. Thus far the team has developed a device selection method, selected a device, and placed a contract with the testing facility, established several collaborations including industry contacts, and have working ideas on the testing details such as scaling, device design, and test conditions.« less

TOF-SIMS imaging of protein adsorption on dialysis membrane

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Hayama, Msayo; Hasegawa, Urara; Sakai, Kiyotaka; Hoshi, Takahiro; Kudo, Masahiro

2004-06-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is capable of chemical imaging of proteins on insulated samples such as hollow-fiber dialysis membranes. Albumin loss and a lowering of diffusive permeability caused by protein adsorption on dialysis membranes should be reduced in order to enhance dialysis adequacy of the patients. Bovine serum albumin (BSA)-adsorbed hollow-fiber dialysis membranes were tested in the present study. TOF-SIMS images and spectra of both native membranes and BSA-adsorbed membranes were compared in order to identify secondary ions related to BSA and membranes. Peaks of secondary ions related to BSA and each membrane were selected by means of information theory, and they are characterized by principal component analysis (PCA). Chemical images of BSA adsorption on both native and treated membranes were obtained to find that BSA permeability and interaction between the membranes and BSA definitely depend on the properties of a membrane. TOF-SIMS imaging obtained with information theory is a powerful tool to estimate protein adsorption on the dialysis membranes.

Detection and quantification of benzodiazepines in hair by ToF-SIMS: preliminary results

NASA Astrophysics Data System (ADS)

Audinot, J.-N.; Yegles, M.; Labarthe, A.; Ruch, D.; Wennig, R.; Migeon, H.-N.

2003-01-01

Successful results have been obtained in detection and quantification of buprenorphine in urine and hemolysed blood by time of flight-secondary ion mass spectrometry (ToF-SIMS). The present work is focused on four molecules of the benzodiazepine's family: nordiazepam, aminoflunitrozepam, diazepam and oxazepam. These drugs remain difficult to analyse in routine clinical and forensic toxicology because of their thermal instability and low therapeutic range (0.5-5 ng/ml). Internal standards are prepared by means of deuterated molecules. The benzadiazepine and their deuterated form (nordiazepam-D5, amino-flunitrazepam-D3, diazepam-D5 and oxazepam-D5) were added, in known concentration, in urine. These molecules were then extracted with several methods (pH, solvent, etc.) and, after adsorption on a noble metal, analysed by ToF-SIMS. The paper will focus for the different molecules on the comparison of the different preparation procedures, the optimisation of the SIMS conditions, the limits of detection and the limits of quantification.

Understanding Earthquake Fault Systems Using QuakeSim Analysis and Data Assimilation Tools

NASA Technical Reports Server (NTRS)

Donnellan, Andrea; Parker, Jay; Glasscoe, Margaret; Granat, Robert; Rundle, John; McLeod, Dennis; Al-Ghanmi, Rami; Grant, Lisa

2008-01-01

We are using the QuakeSim environment to model interacting fault systems. One goal of QuakeSim is to prepare for the large volumes of data that spaceborne missions such as DESDynI will produce. QuakeSim has the ability to ingest distributed heterogenous data in the form of InSAR, GPS, seismicity, and fault data into various earthquake modeling applications, automating the analysis when possible. Virtual California simulates interacting faults in California. We can compare output from long time history Virtual California runs with the current state of strain and the strain history in California. In addition to spaceborne data we will begin assimilating data from UAVSAR airborne flights over the San Francisco Bay Area, the Transverse Ranges, and the Salton Trough. Results of the models are important for understanding future earthquake risk and for providing decision support following earthquakes. Improved models require this sensor web of different data sources, and a modeling environment for understanding the combined data.

Simulation of multi-photon emission isotopes using time-resolved SimSET multiple photon history generator

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

Chiang, Chih-Chieh; Lin, Hsin-Hon; Lin, Chang-Shiun

Abstract-Multiple-photon emitters, such as In-111 or Se-75, have enormous potential in the field of nuclear medicine imaging. For example, Se-75 can be used to investigate the bile acid malabsorption and measure the bile acid pool loss. The simulation system for emission tomography (SimSET) is a well-known Monte Carlo simulation (MCS) code in nuclear medicine for its high computational efficiency. However, current SimSET cannot simulate these isotopes due to the lack of modeling of complex decay scheme and the time-dependent decay process. To extend the versatility of SimSET for simulation of those multi-photon emission isotopes, a time-resolved multiple photon history generatormore » based on SimSET codes is developed in present study. For developing the time-resolved SimSET (trSimSET) with radionuclide decay process, the new MCS model introduce new features, including decay time information and photon time-of-flight information, into this new code. The half-life of energy states were tabulated from the Evaluated Nuclear Structure Data File (ENSDF) database. The MCS results indicate that the overall percent difference is less than 8.5% for all simulation trials as compared to GATE. To sum up, we demonstrated that time-resolved SimSET multiple photon history generator can have comparable accuracy with GATE and keeping better computational efficiency. The new MCS code is very useful to study the multi-photon imaging of novel isotopes that needs the simulation of lifetime and the time-of-fight measurements. (authors)« less

Economic analysis of standard interface modules for use with the multi-mission spacecraft, volume 1

NASA Technical Reports Server (NTRS)

1976-01-01

A preliminary technical and economic feasibility study was made of the use of Standardized Interstate Modules (SIM) to perform electual interfacing functions that were historically incorporated into sensors. Sensor interface functions that are capable of standardization from the set of missions planned for the NASA Multi-Mission Spacecraft (MMS) in the 1981 to 1985 time period were identified. The cost savings that could be achieved through the replacement of nonstandard sensor interface flight hardware that might be used in these missions with SIM were examined.

Automated Re-Entry System using FNPEG

NASA Technical Reports Server (NTRS)

Johnson, Wyatt R.; Lu, Ping; Stachowiak, Susan J.

2017-01-01

This paper discusses the implementation and simulated performance of the FNPEG (Fully Numerical Predictor-corrector Entry Guidance) algorithm into GNC FSW (Guidance, Navigation, and Control Flight Software) for use in an autonomous re-entry vehicle. A few modifications to FNPEG are discussed that result in computational savings -- a change to the state propagator, and a modification to cross-range lateral logic. Finally, some Monte Carlo results are presented using a representative vehicle in both a high-fidelity 6-DOF (degree-of-freedom) sim as well as in a 3-DOF sim for independent validation.

Principal component analysis of TOF-SIMS spectra, images and depth profiles: an industrial perspective

NASA Astrophysics Data System (ADS)

Pacholski, Michaeleen L.

2004-06-01

Principal component analysis (PCA) has been successfully applied to time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra, images and depth profiles. Although SIMS spectral data sets can be small (in comparison to datasets typically discussed in literature from other analytical techniques such as gas or liquid chromatography), each spectrum has thousands of ions resulting in what can be a difficult comparison of samples. Analysis of industrially-derived samples means the identity of most surface species are unknown a priori and samples must be analyzed rapidly to satisfy customer demands. PCA enables rapid assessment of spectral differences (or lack there of) between samples and identification of chemically different areas on sample surfaces for images. Depth profile analysis helps define interfaces and identify low-level components in the system.

Optimized conditions for selective gold flotation by ToF-SIMS and ToF-LIMS

NASA Astrophysics Data System (ADS)

Chryssoulis, S. L.; Dimov, S. S.

2004-06-01

This work describes a comprehensive characterization of the factors controlling the floatability of free gold from flotation test using reagents (collectors) at plant concentration levels. A relationship between the collectors loadings on gold particles and their surface composition has been established. The findings of this study show that silver activates gold flotation and there is a strong correlation between the surface concentration of silver and the loading of certain collectors. The organic surface analysis was done by ToF-SIMS while the inorganic surface analysis was carried out by time-of-flight laser ionization mass spectrometry (ToF-LIMS). The developed testing protocol based on ToF-LIMS and ToF-SIMS complementary surface analysis allows for optimization of the flotation scheme and hence improved gold recovery.

International Space Station Mechanisms and Maintenance Flight Control Documentation and Training Development

NASA Technical Reports Server (NTRS)

Daugherty, Colin C.

2010-01-01

International Space Station (ISS) crew and flight controller training documentation is used to aid in training operations. The Generic Simulations References SharePoint (Gen Sim) site is a database used as an aid during flight simulations. The Gen Sim site is used to make individual mission segment timelines, data, and flight information easily accessible to instructors. The Waste and Hygiene Compartment (WHC) training schematic includes simple and complex fluid schematics, as well as overall hardware locations. It is used as a teaching aid during WHC lessons for both ISS crew and flight controllers. ISS flight control documentation is used to support all aspects of ISS mission operations. The Quick Look Database and Consolidated Tool Page are imagery-based references used in real-time to help the Operations Support Officer (OSO) find data faster and improve discussions with the Flight Director and Capsule Communicator (CAPCOM). A Quick Look page was created for the Permanent Multipurpose Module (PMM) by locating photos of the module interior, labeling specific hardware, and organizing them in schematic form to match the layout of the PMM interior. A Tool Page was created for the Maintenance Work Area (MWA) by gathering images, detailed drawings, safety information, procedures, certifications, demonstration videos, and general facts of each MWA component and displaying them in an easily accessible and consistent format. Participation in ISS mechanisms and maintenance lessons, mission simulation On-the-Job Training (OJT), and real-time flight OJT was used as an opportunity to train for day-to-day operations as an OSO, as well as learn how to effectively respond to failures and emergencies during mission simulations and real-time flight operations.

EngineSim: Turbojet Engine Simulator Adapted for High School Classroom Use

NASA Technical Reports Server (NTRS)

Petersen, Ruth A.

2001-01-01

EngineSim is an interactive educational computer program that allows users to explore the effect of engine operation on total aircraft performance. The software is supported by a basic propulsion web site called the Beginner's Guide to Propulsion, which includes educator-created, web-based activities for the classroom use of EngineSim. In addition, educators can schedule videoconferencing workshops in which EngineSim's creator demonstrates the software and discusses its use in the educational setting. This software is a product of NASA Glenn Research Center's Learning Technologies Project, an educational outreach initiative within the High Performance Computing and Communications Program.

Time-of-flight SIMS/MSRI reflectron mass analyzer and method

DOEpatents

Smentkowski, Vincent S.; Gruen, Dieter M.; Krauss, Alan R.; Schultz, J. Albert; Holecek, John C.

1999-12-28

A method and apparatus for analyzing the surface characteristics of a sample by Secondary Ion Mass Spectroscopy (SIMS) and Mass Spectroscopy of Recoiled Ions (MSRI) is provided. The method includes detecting back scattered primary ions, low energy ejected species, and high energy ejected species by ion beam surface analysis techniques comprising positioning a ToF SIMS/MSRI mass analyzer at a predetermined angle .theta., where .theta. is the angle between the horizontal axis of the mass analyzer and the undeflected primary ion beam line, and applying a specific voltage to the back ring of the analyzer. Preferably, .theta. is less than or equal to about 120.degree. and, more preferably, equal to 74.degree.. For positive ion analysis, the extractor, lens, and front ring of the reflectron are set at negative high voltages (-HV). The back ring of the reflectron is set at greater than about +700V for MSRI measurements and between the range of about +15 V and about +50V for SIMS measurements. The method further comprises inverting the polarity of the potentials applied to the extractor, lens, front ring, and back ring to obtain negative ion SIMS and/or MSRI data.

TOFSIMS-P: a web-based platform for analysis of large-scale TOF-SIMS data.

PubMed

Yun, So Jeong; Park, Ji-Won; Choi, Il Ju; Kang, Byeongsoo; Kim, Hark Kyun; Moon, Dae Won; Lee, Tae Geol; Hwang, Daehee

2011-12-15

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been a useful tool to profile secondary ions from the near surface region of specimens with its high molecular specificity and submicrometer spatial resolution. However, the TOF-SIMS analysis of even a moderately large size of samples has been hampered due to the lack of tools for automatically analyzing the huge amount of TOF-SIMS data. Here, we present a computational platform to automatically identify and align peaks, find discriminatory ions, build a classifier, and construct networks describing differential metabolic pathways. To demonstrate the utility of the platform, we analyzed 43 data sets generated from seven gastric cancer and eight normal tissues using TOF-SIMS. A total of 87 138 ions were detected from the 43 data sets by TOF-SIMS. We selected and then aligned 1286 ions. Among them, we found the 66 ions discriminating gastric cancer tissues from normal ones. Using these 66 ions, we then built a partial least square-discriminant analysis (PLS-DA) model resulting in a misclassification error rate of 0.024. Finally, network analysis of the 66 ions showed disregulation of amino acid metabolism in the gastric cancer tissues. The results show that the proposed framework was effective in analyzing TOF-SIMS data from a moderately large size of samples, resulting in discrimination of gastric cancer tissues from normal tissues and identification of biomarker candidates associated with the amino acid metabolism.

A high ozone episode in winter 2013 in the Uinta Basin oil and gas region characterized by aircraft measurements

NASA Astrophysics Data System (ADS)

Oltmans, S. J.; Karion, A.; Schnell, R. C.; Pétron, G.; Sweeney, C.; Wolter, S.; Neff, D.; Montzka, S. A.; Miller, B. R.; Helmig, D.; Johnson, B. J.; Hueber, J.

2014-08-01

During the winter of 2012-2013 atmospheric surface ozone mole fractions exceeded the US 8 h standard of 75 ppb on 39 days in the Uinta Basin of Utah. As part of the Uinta Basin Winter Ozone Study (UBWOS) aircraft flights were conducted throughout the basin with continuous measurements of ozone (O3), methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), and discrete whole air flask samples for determination of ∼50 trace gases including a number of non-methane hydrocarbons (NMHCs). During the course of seven flights conducted between 31 January and 7 February 2013, coinciding with strong, multi-day temperature inversions, O3 levels gradually built up in the shallow boundary layer from ∼45 ppb to ∼140 ppb. Near-surface CH4 mole fractions increased during the episode from near background levels of ∼2 ppm to over 10 ppm. Based on elevated levels of CH4 across the basin and high correlations of CH4 with NMHCs from the discrete air samples, O3 precursor NMHCs were also inferred to be elevated throughout the basin. Discrete plumes of high NO2 were observed in the gas production region of the basin suggesting that gas processing plants and compressor facilities were important point sources of reactive nitrogen oxides (NOx). Vertical profiles obtained during the flights showed that the high O3 mole fractions (as well as other elevated constituents) were confined to a shallow layer from near the ground to 300-400 m above ground level (m a.g.l.) capped by a strong temperature inversion. The highest mole fractions of the measured constituents during the study period were in an isothermal cold layer that varied from ∼300 m depth on 4 February to ∼150 m on 5 February. A gradient layer with declining mole fractions with altitude extended above the isothermal layer to ∼1900 m a.s.l. (300-400 m a.g.l.) indicative of some mixing of air out of the boundary layer. O3 mole fractions continued to increase within the basin as the high O3 episode developed over the course of a week. CH4 mole fractions, on the other hand, leveled off after several days. On several flights, the aircraft sampled the plume of a coal-fired power plant (located east of the main gas field) flowing above the inversion layer. These measurements ruled out the effluents of the power plant as a significant source of NOx for O3 production beneath the temperature inversion in the basin. The presence of elevated O3 precursors within the basin and the rapid daytime production of O3 in the atmosphere beneath the temperature inversion both indicated that O3 was being produced from precursors emitted within the basin beneath the temperature inversion. Although observations show that horizontal winds in the surface layer were relatively light during the high ozone event, they were sufficient to disperse precursors up to 80 km from primary sources in the main gas field in the southeast quadrant to the balance of the Uinta Basin.

Applications of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) to study interactions of genetically engineered proteins with noble metal films

NASA Astrophysics Data System (ADS)

Suzuki, Noriaki

Genetically engineered proteins for inorganics (GEPIs) belong to a new class of polypeptides that are designed to have specific affinities to inorganic materials. A "gold binding protein (GBP)" was chosen as a model protein for GEPIs to study the molecular origins of binding specificity to gold using Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS). TOF-SIMS, a surface-sensitive analytical instrument with extremely high mass resolutions, provides information on specific amino acid-surface interactions. We used "principal component analysis (PCA)" to analyze the data. We also introduced a new multivariate technique, "hierarchical cluster analysis (HCA)" to organize the data into meaningful structures by measuring a degree of "similarity" and "dissimilarity" of the data. This report discusses a combined use of PCA and HCA to elucidate the binding specificity of GBP to Au. Based on the knowledge gained from TOF-SIMS measurements, we further investigated the nature of the interaction between selected amino acids and noble metal surfaces by using X-ray photoelectron spectroscopy (XPS). We developed a unique capability to introduce water vapor during the adsorption of a single amino acid and applied this method to study the intrinsic nature of sidechain/Au interactions. To further apply this unique research protocol, we characterized another type of GEPI, "quartz binding protein (QBP)," to identify the possible binding sites. This thesis research aims to provide experimental protocols for analyzing short peptide-substrate interface from complex spectroscopic data by using multivariate analysis techniques.

ToF-SIMS and Laser-SNMS Imaging of Heterogeneous Topographically Complex Polymer Systems.

PubMed

Pelster, Andreas; Körsgen, Martin; Kurosawa, Takako; Morita, Hiromi; Arlinghaus, Heinrich F

2016-10-04

Heterogeneous polymer coatings, such as those used in organic electronics and medical devices, are of increasing industrial importance. In order to advance the development of these types of systems, analytical techniques are required which are able to determine the elemental and molecular spatial distributions, on a nanometer scale, with very high detection efficiency and sensitivity. The goal of this study was to investigate the suitability of laser postionization secondary neutral mass spectrometry (Laser-SNMS) with a 157 nm postionization laser beam to image structured polymer mixtures and compare the results with time-of-flight secondary ion mass spectrometry (ToF-SIMS) measurements using Bi 3 + primary ions. The results showed that Laser-SNMS is better suited than ToF-SIMS for unambiguous detection and submicrometer imaging of the wide range of polymers investigated. The data also showed that Laser-SNMS has the advantage of being much more sensitive (in general higher by more than an order of magnitude and peaking at up to 3 orders of magnitude) than ToF-SIMS while also showing superior performance on topographically complex structured insulating surfaces, due to significantly reduced field effects and a higher dynamic range as compared to ToF-SIMS. It is concluded that Laser-SNMS is a powerful complementary technique to ToF-SIMS for the analysis of heterogeneous polymers and other complex structured organic mixtures, providing submicrometer resolution and high sensitivity.

Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

PubMed Central

Lee, Jihye; Kang, Min Hwa; Lee, Kang-Bong; Lee, Yeonhee

2013-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric. PMID:28809257

Advances in understanding the surface chemistry of lignocellulosic biomass via time-of-flight secondary ion mass spectrometry

DOE PAGES

Tolbert, Allison K.; Ragauskas, Arthur J.

2016-12-12

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in order to efficiently convert biomass into biofuels or biomaterials and many times this requires some type of chemical pretreatment and/or biological treatment. While bulk chemical analysis is the traditional method of determining the impact a treatment has on biomass, the chemistry on the surface of the sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms bind to the surface of the biomass and their efficiency could be greatly impacted by the chemistry of the surface. Therefore, it is important to study and understand the chemistry of the biomassmore » at the surface. Time-of- flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool that can spectrally and spatially analyze the surface chemistry of a sample. This review discusses the advances in understanding lignocellulosic biomass surface chemistry using the ToF-SIMS by addressing the instrument parameters, biomass sample preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. Furthermore, the use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.« less

Advances in understanding the surface chemistry of lignocellulosic biomass via time-of-flight secondary ion mass spectrometry

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

Tolbert, Allison K.; Ragauskas, Arthur J.

Overcoming the natural recalcitrance of lignocellulosic biomass is necessary in order to efficiently convert biomass into biofuels or biomaterials and many times this requires some type of chemical pretreatment and/or biological treatment. While bulk chemical analysis is the traditional method of determining the impact a treatment has on biomass, the chemistry on the surface of the sample can differ from the bulk chemistry. Specifically, enzymes and microorganisms bind to the surface of the biomass and their efficiency could be greatly impacted by the chemistry of the surface. Therefore, it is important to study and understand the chemistry of the biomassmore » at the surface. Time-of- flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool that can spectrally and spatially analyze the surface chemistry of a sample. This review discusses the advances in understanding lignocellulosic biomass surface chemistry using the ToF-SIMS by addressing the instrument parameters, biomass sample preparation, and characteristic lignocellulosic ion fragmentation peaks along with their typical location in the plant cell wall. Furthermore, the use of the ToF-SIMS in detecting chemical changes due to chemical pretreatments, microbial treatments, and physical or genetic modifications is discussed along with possible future applications of the instrument in lignocellulosic biomass studies.« less

Application of ToF-SIMS to the study of surfactant removal from AuNbMCM-41 and AuMCM-41 materials

NASA Astrophysics Data System (ADS)

Grams, Jacek; Sobczak, Izabela

2010-01-01

This work is focused on the application of time-of-flight secondary ion mass spectrometry (ToF-SIMS) in investigation of the surfactant removal process from AuNbMCM-41 and AuMCM-41 catalysts (MCM-41 "Mobil Composition of Matter", ordered mesoporous materials discovered by Mobil R&D Corporation). The samples investigated were prepared by co-precipitation in the presence of a cationic surfactant (cetyltrimethylammonium chloride--CH3(CH2)15N(Cl)(CH3)3) and the incipient wetness impregnation methods. The results obtained showed that the time-of-flight secondary ion mass spectrometry appears to be a very useful tool for the investigation of the residual organic template on the surface of ordered mesoporous materials of MCM-41 type. It was demonstrated that the calcination of AuNbMCM-41 and AuMCM-41 catalysts at 550 °C caused a complete removal of the surfactant from the surface of the material investigated. Moreover, it was shown that the use of bismuth liquid metal ion gun in ToF-SIMS experiments permitted obtaining higher emission intensity (more than one order of magnitude when compared to the Ga+ primary ion source) of secondary ions originating from the surfactant molecules and may facilitate an interpretation of the results obtained.

Time of flight secondary ion mass spectrometry of bone—Impact of sample preparation and measurement conditions

PubMed Central

Henss, Anja; Hild, Anne; Rohnke, Marcus; Wenisch, Sabine; Janek, Juergen

2015-01-01

Time of flight secondary ion mass spectrometry (ToF-SIMS) enables the simultaneous detection of organic and inorganic ions and fragments with high mass and spatial resolution. Due to recent technical developments, ToF-SIMS has been increasingly applied in the life sciences where sample preparation plays an eminent role for the quality of the analytical results. This paper focusses on sample preparation of bone tissue and its impact on ToF-SIMS analysis. The analysis of bone is important for the understanding of bone diseases and the development of replacement materials and new drugs for the cure of diseased bone. The main purpose of this paper is to find out which preparation process is best suited for ToF-SIMS analysis of bone tissue in order to obtain reliable and reproducible analytical results. The influence of the embedding process on the different components of bone is evaluated using principal component analysis. It is shown that epoxy resin as well as methacrylate based plastics (Epon and Technovit) as embedding materials do not infiltrate the mineralized tissue and that cut sections are better suited for the ToF-SIMS analysis than ground sections. In case of ground samples, a resin layer is smeared over the sample surface due to the polishing step and overlap of peaks is found. Beside some signals of fatty acids in the negative ion mode, the analysis of native, not embedded samples does not provide any advantage. The influence of bismuth bombardment and O2 flooding on the signal intensity of organic and inorganic fragments due to the variation of the ionization probability is additionally discussed. As C60 sputtering has to be applied to remove the smeared resin layer, its effect especially on the organic fragments of the bone is analyzed and described herein. PMID:26253108

Time of flight secondary ion mass spectrometry of bone-Impact of sample preparation and measurement conditions.

PubMed

Henss, Anja; Hild, Anne; Rohnke, Marcus; Wenisch, Sabine; Janek, Juergen

2015-06-07

Time of flight secondary ion mass spectrometry (ToF-SIMS) enables the simultaneous detection of organic and inorganic ions and fragments with high mass and spatial resolution. Due to recent technical developments, ToF-SIMS has been increasingly applied in the life sciences where sample preparation plays an eminent role for the quality of the analytical results. This paper focusses on sample preparation of bone tissue and its impact on ToF-SIMS analysis. The analysis of bone is important for the understanding of bone diseases and the development of replacement materials and new drugs for the cure of diseased bone. The main purpose of this paper is to find out which preparation process is best suited for ToF-SIMS analysis of bone tissue in order to obtain reliable and reproducible analytical results. The influence of the embedding process on the different components of bone is evaluated using principal component analysis. It is shown that epoxy resin as well as methacrylate based plastics (Epon and Technovit) as embedding materials do not infiltrate the mineralized tissue and that cut sections are better suited for the ToF-SIMS analysis than ground sections. In case of ground samples, a resin layer is smeared over the sample surface due to the polishing step and overlap of peaks is found. Beside some signals of fatty acids in the negative ion mode, the analysis of native, not embedded samples does not provide any advantage. The influence of bismuth bombardment and O2 flooding on the signal intensity of organic and inorganic fragments due to the variation of the ionization probability is additionally discussed. As C60 sputtering has to be applied to remove the smeared resin layer, its effect especially on the organic fragments of the bone is analyzed and described herein.

Mask Design for the Space Interferometry Mission Internal Metrology

NASA Technical Reports Server (NTRS)

Marx, David; Zhao, Feng; Korechoff, Robert

2005-01-01

This slide presentation reviews the mask design used for the internal metrology of the Space Interferometry Mission (SIM). Included is information about the project, the method of measurements with SIM, the internal metrology, numerical model of internal metrology, wavefront examples, performance metrics, and mask design

Study of the Au-Cr bilayer system using X-ray reflectivity, GDOES, and ToF-SIMS

DOE PAGES

Jonnard, Philippe; Modi, Mohammed H.; Le Guen, Karine; ...

2018-04-17

Here, we study a Au (25 nm)/Cr (10 nm) bilayer system as a model of mirror for the soft X–ray energy range. The Au and Cr thin films are a few nanometer thick and are deposited on a float glass substrate. The sample is characterized by using 3 complementary techniques: soft X–ray reflectivity, glow discharge optical emission spectrometry (GDOES), and time–of–flight secondary ion mass spectroscopy (ToF–SIMS). Soft X–ray reflectivity provides information about the thickness and roughness of the different layers, while GDOES is used to obtain the elemental depth profile of the stack and ToF–SIMS to obtain the elemental andmore » chemical depth profiles. GDOES and ToF–SIMS have both a nanometer depth resolution. A coherent description of the bilayer stack is obtained through the combination of these techniques. It consists in 5 layers namely a surface contamination layer, a principal gold layer, a Au–Cr mixed layer, a Cr layer, and another contamination layer at the top of the substrate.« less

Recent advances in secondary ion mass spectrometry of solid acid catalysts: large zeolite crystals under bombardment.

PubMed

Hofmann, Jan P; Rohnke, Marcus; Weckhuysen, Bert M

2014-03-28

This Perspective aims to inform the heterogeneous catalysis and materials science community about the recent advances in Time-of-Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) to characterize catalytic solids by taking large model H-ZSM-5 zeolite crystals as a showcase system. SIMS-based techniques have been explored in the 1980-1990's to study porous catalyst materials but, due to their limited spectral and spatiotemporal resolution, there was no real major breakthrough at that time. The technical advancements in SIMS instruments, namely improved ion gun design and new mass analyser concepts, nowadays allow for a much more detailed analysis of surface species relevant to catalytic action. Imaging with high mass and lateral resolution, determination of fragment ion patterns, novel sputter ion concepts as well as new mass analysers (e.g. ToF, FTICR) are just a few novelties, which will lead to new fundamental insight from SIMS analysis of heterogeneous catalysts. The Perspective article ends with an outlook on instrumental innovations and their potential use for catalytic systems other than zeolite crystals.

Molecular imaging of cannabis leaf tissue with MeV-SIMS method

NASA Astrophysics Data System (ADS)

Jenčič, Boštjan; Jeromel, Luka; Ogrinc Potočnik, Nina; Vogel-Mikuš, Katarina; Kovačec, Eva; Regvar, Marjana; Siketić, Zdravko; Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen; Kelemen, Mitja; Kovač, Janez; Pelicon, Primož

2016-03-01

To broaden our analytical capabilities with molecular imaging in addition to the existing elemental imaging with micro-PIXE, a linear Time-Of-Flight mass spectrometer for MeV Secondary Ion Mass Spectrometry (MeV-SIMS) was constructed and added to the existing nuclear microprobe at the Jožef Stefan Institute. We measured absolute molecular yields and damage cross-section of reference materials, without significant alteration of the fragile biological samples during the duration of measurements in the mapping mode. We explored the analytical capability of the MeV-SIMS technique for chemical mapping of the plant tissue of medicinal cannabis leaves. A series of hand-cut plant tissue slices were prepared by standard shock-freezing and freeze-drying protocol and deposited on the Si wafer. We show the measured MeV-SIMS spectra showing a series of peaks in the mass area of cannabinoids, as well as their corresponding maps. The indicated molecular distributions at masses of 345.5 u and 359.4 u may be attributed to the protonated THCA and THCA-C4 acids, and show enhancement in the areas with opened trichome morphology.

Visualization of water transport into soybean nodules by Tof-SIMS cryo system.

PubMed

Iijima, Morio; Watanabe, Toshimasa; Yoshida, Tomoharu; Kawasaki, Michio; Kato, Toshiyuki; Yamane, Koji

2015-04-15

This paper examined the route of water supply into soybean nodules through the new visualization technique of time of flight secondary ion mass spectrometry (Tof-SIMS) cryo system, and obtained circumstantial evidence for the water inflow route. The maximum resolution of the Tof-SIMS imaging used by this study was 1.8 μm (defined as the three pixel step length), which allowed us to detect water movement at the cellular level. Deuterium-labeled water was supplied to soybean plants for 4h and the presence of deuterium in soybean nodules was analyzed by the Tof-SIMS cryo system. Deuterium ions were found only in the endodermis tissue surrounding the central cylinder in soybean nodules. Neither xylem vessels nor phloem complex itself did not indicate any deuterium accumulation. Deuterium-ion counts in the endodermis tissue were not changed by girdling treatment, which restricted water movement through the phloem complex. The results strongly indicated that nodule tissues did not receive water directly from the phloem complex, but received water through root cortex apoplastic pathway from the root axis. Copyright © 2015 Elsevier GmbH. All rights reserved.

Study of the Au-Cr bilayer system using X-ray reflectivity, GDOES, and ToF-SIMS

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

Jonnard, Philippe; Modi, Mohammed H.; Le Guen, Karine

Here, we study a Au (25 nm)/Cr (10 nm) bilayer system as a model of mirror for the soft X–ray energy range. The Au and Cr thin films are a few nanometer thick and are deposited on a float glass substrate. The sample is characterized by using 3 complementary techniques: soft X–ray reflectivity, glow discharge optical emission spectrometry (GDOES), and time–of–flight secondary ion mass spectroscopy (ToF–SIMS). Soft X–ray reflectivity provides information about the thickness and roughness of the different layers, while GDOES is used to obtain the elemental depth profile of the stack and ToF–SIMS to obtain the elemental andmore » chemical depth profiles. GDOES and ToF–SIMS have both a nanometer depth resolution. A coherent description of the bilayer stack is obtained through the combination of these techniques. It consists in 5 layers namely a surface contamination layer, a principal gold layer, a Au–Cr mixed layer, a Cr layer, and another contamination layer at the top of the substrate.« less

Democratizing Access to Core Mathematics across Grades 9-12

ERIC Educational Resources Information Center

Hegedus, Stephen; Dalton, Sara; Brookstein, Arden; Tapper, John; Heller, Eric

2011-01-01

The authors' proposed work builds upon 12+ years of research collectively known as the "SimCalc Projects." SimCalc Connected MathWorlds (SCM) combines two innovative technological ingredients to address core mathematical ideas in deep and sustainable ways for mathematics learners. Software that addresses content issues through dynamic…

Development and Validation of High Precision Thermal, Mechanical, and Optical Models for the Space Interferometry Mission

NASA Technical Reports Server (NTRS)

Lindensmith, Chris A.; Briggs, H. Clark; Beregovski, Yuri; Feria, V. Alfonso; Goullioud, Renaud; Gursel, Yekta; Hahn, Inseob; Kinsella, Gary; Orzewalla, Matthew; Phillips, Charles

2006-01-01

SIM Planetquest (SIM) is a large optical interferometer for making microarcsecond measurements of the positions of stars, and to detect Earth-sized planets around nearby stars. To achieve this precision, SIM requires stability of optical components to tens of picometers per hour. The combination of SIM s large size (9 meter baseline) and the high stability requirement makes it difficult and costly to measure all aspects of system performance on the ground. To reduce risks, costs and to allow for a design with fewer intermediate testing stages, the SIM project is developing an integrated thermal, mechanical and optical modeling process that will allow predictions of the system performance to be made at the required high precision. This modeling process uses commercial, off-the-shelf tools and has been validated against experimental results at the precision of the SIM performance requirements. This paper presents the description of the model development, some of the models, and their validation in the Thermo-Opto-Mechanical (TOM3) testbed which includes full scale brassboard optical components and the metrology to test them at the SIM performance requirement levels.

Astrophysics of Reference Frame Tie Objects

NASA Technical Reports Server (NTRS)

Johnston, Kenneth J.; Boboltz, David; Fey, Alan Lee; Gaume, Ralph A.; Zacharias, Norbert

2004-01-01

The Astrophysics of Reference Frame Tie Objects Key Science program will investigate the underlying physics of SIM grid objects. Extragalactic objects in the SIM grid will be used to tie the SIM reference frame to the quasi-inertial reference frame defined by extragalactic objects and to remove any residual frame rotation with respect to the extragalactic frame. The current realization of the extragalactic frame is the International Celestial Reference Frame (ICRF). The ICRF is defined by the radio positions of 212 extragalactic objects and is the IAU sanctioned fundamental astronomical reference frame. This key project will advance our knowledge of the physics of the objects which will make up the SIM grid, such as quasars and chromospherically active stars, and relates directly to the stability of the SIM reference frame. The following questions concerning the physics of reference frame tie objects will be investigated.

Time‐of‐flight secondary ion mass spectrometry imaging of biological samples with delayed extraction for high mass and high spatial resolutions

PubMed Central

Vanbellingen, Quentin P.; Elie, Nicolas; Eller, Michael J.; Della‐Negra, Serge; Touboul, David

2015-01-01

Rationale In Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS), pulsed and focused primary ion beams enable mass spectrometry imaging, a method which is particularly useful to map various small molecules such as lipids at the surface of biological samples. When using TOF‐SIMS instruments, the focusing modes of the primary ion beam delivered by liquid metal ion guns can provide either a mass resolution of several thousand or a sub‐µm lateral resolution, but the combination of both is generally not possible. Methods With a TOF‐SIMS setup, a delayed extraction applied to secondary ions has been studied extensively on rat cerebellum sections in order to compensate for the effect of long primary ion bunches. Results The use of a delayed extraction has been proven to be an efficient solution leading to unique features, i.e. a mass resolution up to 10000 at m/z 385.4 combined with a lateral resolution of about 400 nm. Simulations of ion trajectories confirm the experimental determination of optimal delayed extraction and allow understanding of the behavior of ions as a function of their mass‐to‐charge ratio. Conclusions Although the use of a delayed extraction has been well known for many years and is very popular in MALDI, it is much less used in TOF‐SIMS. Its full characterization now enables secondary ion images to be recorded in a single run with a submicron spatial resolution and with a mass resolution of several thousand. This improvement is very useful when analyzing lipids on tissue sections, or rare, precious, or very small size samples. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26395603

Correlating microscopy techniques and ToF-SIMS analysis of fully grown mammalian oocytes.

PubMed

Gulin, Alexander; Nadtochenko, Victor; Astafiev, Artyom; Pogorelova, Valentina; Rtimi, Sami; Pogorelov, Alexander

2016-06-20

The 2D-molecular thin film analysis protocol for fully grown mice oocytes is described using an innovative approach. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical microscopy imaging were applied to the same mice oocyte section on the same sample holder. A freeze-dried mice oocyte was infiltrated into embedding media, e.g. Epon, and then was cut with a microtome and 2 μm thick sections were transferred onto an ITO coated conductive glass. Mammalian oocytes can contain "nucleolus-like body" (NLB) units and ToF-SIMS analysis was used to investigate the NLB composition. The ion-spatial distribution in the cell components was identified and compared with the images acquired by SEM, AFM and optical microscopy. This study presents a significant advancement in cell embryology, cell physiology and cancer-cell biochemistry.

XPS and ToF-SIMS analysis of natural rubies and sapphires heat-treated in a reducing (5 mol% H 2/Ar) atmosphere

NASA Astrophysics Data System (ADS)

Achiwawanich, S.; James, B. D.; Liesegang, J.

2008-12-01

Surface effects on Mong Hsu rubies and Kanchanaburi sapphires after heat treatment in a controlled reducing atmosphere (5 mol% H 2/Ar) have been investigated using advanced surface science techniques including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Visual appearance of the gemstones is clearly affected by the heat treatment in a reducing atmosphere. Kanchanaburi sapphires, in particular, exhibit Fe-containing precipitates after the heat treatment which have not been observed in previous studies under an inert atmosphere. Significant correlation between changes in visual appearance of the gemstones and variations in surface concentration of trace elements, especially Ti and Fe are observed. The XPS and ToF-SIMS results suggest that; (1) a reducing atmosphere affects the oxidation state of Fe; (2) dissociation of Fe-Ti interaction may occur during heat treatment.

A novel PFIB sample preparation protocol for correlative 3D X-ray CNT and FIB-TOF-SIMS tomography.

PubMed

Priebe, Agnieszka; Audoit, Guillaume; Barnes, Jean-Paul

2017-02-01

We present a novel sample preparation method that allows correlative 3D X-ray Computed Nano-Tomography (CNT) and Focused Ion Beam Time-Of-Flight Secondary Ion Mass Spectrometry (FIB-TOF-SIMS) tomography to be performed on the same sample. In addition, our invention ensures that samples stay unmodified structurally and chemically between the subsequent experiments. The main principle is based on modifying the topography of the X-ray CNT experimental setup before FIB-TOF-SIMS measurements by incorporating a square washer around the sample. This affects the distribution of extraction field lines and therefore influences the trajectories of secondary ions that are now guided more efficiently towards the detector. As the result, secondary ion detection is significantly improved and higher, i.e. statistically better, signals are obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Smentkowski, Vincent S., E-mail: smentkow@ge.com

Changes in the oxidation state of an element can result in significant changes in the ionization efficiency and hence signal intensity during secondary ion mass spectrometry (SIMS) analysis; this is referred to as the SIMS matrix effect [Secondary Ion Mass Spectrometry: A Practical Handbook for Depth Profiling and Bulk Impurity Analysis, edited by R. G. Wilson, F. A. Stevie, and C. W. Magee (Wiley, New York, 1990)]. The SIMS matrix effect complicates quantitative analysis. Quantification of SIMS data requires the determination of relative sensitivity factors (RSFs), which can be used to convert the as measured intensity into concentration units [Secondarymore » Ion Mass Spectrometry: A Practical Handbook for Depth Profiling and Bulk Impurity Analysis, edited by R. G. Wilson, F. A. Stevie, and C. W. Magee (Wiley, New York, 1990)]. In this manuscript, the authors report both: RSFs which were determined for quantification of B in Si and SiO{sub 2} matrices using a dual beam time of flight secondary ion mass spectrometry (ToF-SIMS) instrument and the protocol they are using to provide quantitative ToF-SIMS images and line scan traces. The authors also compare RSF values that were determined using oxygen and Ar ion beams for erosion, discuss the problems that can be encountered when bulk calibration samples are used to determine RSFs, and remind the reader that errors in molecular details of the matrix (density, volume, etc.) that are used to convert from atoms/cm{sup 3} to other concentration units will propagate into errors in the determined concentrations.« less

Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

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

Subhash Chandra

2008-05-30

The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysismore » of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.« less

Improved mass resolution and mass accuracy in TOF-SIMS spectra and images using argon gas cluster ion beams.

PubMed

Shon, Hyun Kyong; Yoon, Sohee; Moon, Jeong Hee; Lee, Tae Geol

2016-06-09

The popularity of argon gas cluster ion beams (Ar-GCIB) as primary ion beams in time-of-flight secondary ion mass spectrometry (TOF-SIMS) has increased because the molecular ions of large organic- and biomolecules can be detected with less damage to the sample surfaces. However, Ar-GCIB is limited by poor mass resolution as well as poor mass accuracy. The inferior quality of the mass resolution in a TOF-SIMS spectrum obtained by using Ar-GCIB compared to the one obtained by a bismuth liquid metal cluster ion beam and others makes it difficult to identify unknown peaks because of the mass interference from the neighboring peaks. However, in this study, the authors demonstrate improved mass resolution in TOF-SIMS using Ar-GCIB through the delayed extraction of secondary ions, a method typically used in TOF mass spectrometry to increase mass resolution. As for poor mass accuracy, although mass calibration using internal peaks with low mass such as hydrogen and carbon is a common approach in TOF-SIMS, it is unsuited to the present study because of the disappearance of the low-mass peaks in the delayed extraction mode. To resolve this issue, external mass calibration, another regularly used method in TOF-MS, was adapted to enhance mass accuracy in the spectrum and image generated by TOF-SIMS using Ar-GCIB in the delayed extraction mode. By producing spectra analyses of a peptide mixture and bovine serum albumin protein digested with trypsin, along with image analyses of rat brain samples, the authors demonstrate for the first time the enhancement of mass resolution and mass accuracy for the purpose of analyzing large biomolecules in TOF-SIMS using Ar-GCIB through the use of delayed extraction and external mass calibration.

Detection of SiO2 nanoparticles in lung tissue by ToF-SIMS imaging and fluorescence microscopy.

PubMed

Veith, Lothar; Vennemann, Antje; Breitenstein, Daniel; Engelhard, Carsten; Wiemann, Martin; Hagenhoff, Birgit

2017-07-10

The direct detection of nanoparticles in tissues at high spatial resolution is a current goal in nanotoxicology. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is widely used for the direct detection of inorganic and organic substances with high spatial resolution but its capability to detect nanoparticles in tissue sections is still insufficiently explored. To estimate the applicability of this technique for nanotoxicological questions, comparative studies with established techniques on the detection of nanoparticles can offer additional insights. Here, we compare ToF-SIMS imaging data with sub-micrometer spatial resolution to fluorescence microscopy imaging data to explore the usefulness of ToF-SIMS for the detection of nanoparticles in tissues. SiO 2 nanoparticles with a mean diameter of 25 nm, core-labelled with fluorescein isothiocyanate, were intratracheally instilled into rat lungs. Subsequently, imaging of lung cryosections was performed with ToF-SIMS and fluorescence microscopy. Nanoparticles were successfully detected with ToF-SIMS in 3D microanalysis mode based on the lateral distribution of SiO 3 - (m/z 75.96), which was co-localized with the distribution pattern that was obtained from nanoparticle fluorescence. In addition, the lateral distribution of protein (CN - , m/z 26.00) and phosphate based signals (PO 3 - , m/z 78.96) originating from the tissue material could be related to the SiO 3 - lateral distribution. In conclusion, ToF-SIMS is suitable to directly detect and laterally resolve SiO 2 nanomaterials in biological tissue at sufficient intensity levels. At the same time, information about the chemical environment of the nanoparticles in the lung tissue sections is obtained.

ToF-SIMS analysis of a polymer microarray composed of poly(meth)acrylates with C6 derivative pendant groups.

PubMed

Hook, Andrew L; Scurr, David J

2016-04-01

Surface analysis plays a key role in understanding the function of materials, particularly in biological environments. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides highly surface sensitive chemical information that can readily be acquired over large areas and has, thus, become an important surface analysis tool. However, the information-rich nature of ToF-SIMS complicates the interpretation and comparison of spectra, particularly in cases where multicomponent samples are being assessed. In this study, a method is presented to assess the chemical variance across 16 poly(meth)acrylates. Materials are selected to contain C 6 pendant groups, and ten replicates of each are printed as a polymer microarray. SIMS spectra are acquired for each material with the most intense and unique ions assessed for each material to identify the predominant and distinctive fragmentation pathways within the materials studied. Differentiating acrylate/methacrylate pairs is readily achieved using secondary ions derived from both the polymer backbone and pendant groups. Principal component analysis (PCA) is performed on the SIMS spectra of the 16 polymers, whereby the resulting principal components are able to distinguish phenyl from benzyl groups, mono-functional from multi-functional monomers and acrylates from methacrylates. The principal components are applied to copolymer series to assess the predictive capabilities of the PCA. Beyond being able to predict the copolymer ratio, in some cases, the SIMS analysis is able to provide insight into the molecular sequence of a copolymer. The insight gained in this study will be beneficial for developing structure-function relationships based upon ToF-SIMS data of polymer libraries. © 2016 The Authors Surface and Interface Analysis Published by John Wiley & Sons Ltd.

Simulation Training Versus Real Time Console Training for New Flight Controllers

NASA Technical Reports Server (NTRS)

Heaton, Amanda

2010-01-01

For new flight controllers, the two main learning tools are simulations and real time console performance training. These benefit the new flight controllers in different ways and could possibly be improved. Simulations: a) Allow for mistakes without serious consequences. b) Lets new flight controllers learn the working style of other new flight controllers. c) Lets new flight controllers eventually begin to feel like they have mastered the sim world, so therefore they must be competent in the real time world too. Real time: a) Shows new flight controllers some of the unique problems that develop and have to be accounted for when dealing with certain payloads or systems. b) Lets new flight controllers experience handovers - gathering information from the previous shift on what the room needs to be aware of and what still needs to be done. c) Gives new flight controllers confidence that they can succeed in the position they are training for when they can solve real anomalies. How Sims could be improved and more like real-time ops for the ISS Operations Controller position: a) Operations Change Requests to review. b) Fewer anomalies (but still more than real time for practice). c) Payload Planning Manager Handover sheet for the E-1 and E-3 reviews. d) Flight note in system with at least one comment to verify for the E-1 and E-3 reviews How the real time console performance training could be improved for the ISS Operations Controller position: a) Schedule the new flight controller to be on console for four days but with a different certified person each day. This will force them to be the source of knowledge about every OCR in progress, everything that has happened in those few days, and every activity on the timeline. Constellation program flight controllers will have to learn entirely from simulations, thereby losing some of the elements that they will need to have experience with for real time ops. It may help them to practice real time console performance training in the International Space Station or Space Shuttle to gather some general anomaly resolution and day-to-day task management skills.

Search for Terrestrial Planets with SIM Planet Quest

NASA Technical Reports Server (NTRS)

Shao, Michael; Tanner, Angelle M.; Catanzarite, Joseph H.

2006-01-01

SIM is an astrometric mission that will be capable of 1 microarcsec relative astrometric accuracy in a single measurement of approx.1000 sec. The search for terrestrial planets in the habitable zone around nearby stars is one of the main science goals of the project. In 2001, NASA through the peer review process selected 10 key projects, two of which had as its goal, the search for terrestrial planets around nearby stars. The two teams, one led by G. Marcy (UC Berkeley) and one lead by M. Shao (JPL), have an extensive preparatory science program underway. This paper describes the status of this activity as well as the technology status of SIM's narrow angle astrometry capability, to reach 1 uas in a single epoch measure and its ability to average multiple epoch measurements to well below 1 uas.

Simulating New Drop Test Vehicles and Test Techniques for the Orion CEV Parachute Assembly System

NASA Technical Reports Server (NTRS)

Morris, Aaron L.; Fraire, Usbaldo, Jr.; Bledsoe, Kristin J.; Ray, Eric; Moore, Jim W.; Olson, Leah M.

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) project is engaged in a multi-year design and test campaign to qualify a parachute recovery system for human use on the Orion Spacecraft. Test and simulation techniques have evolved concurrently to keep up with the demands of a challenging and complex system. The primary simulations used for preflight predictions and post-test data reconstructions are Decelerator System Simulation (DSS), Decelerator System Simulation Application (DSSA), and Drop Test Vehicle Simulation (DTV-SIM). The goal of this paper is to provide a roadmap to future programs on the test technique challenges and obstacles involved in executing a large-scale, multi-year parachute test program. A focus on flight simulation modeling and correlation to test techniques executed to obtain parachute performance parameters are presented.

NanoSIMS Imaging Alternation Layers of a Leached SON68 Glass Via A FIB-made Wedged Crater

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

Wang, Yi-Chung; Schreiber, Daniel K.; Neeway, James J.

2014-11-01

Currently, nuclear wastes are commonly immobilized into glasses because of their long-term durability. Exposure to water for long periods of time, however, will eventually corrode the waste form and is the leading potential avenue for radionuclide release into the environment. Because such slow processes cannot be experimentally tested, the prediction of release requires a thorough understanding the mechanisms governing glass corrosion. In addition, due to the exceptional durability of glass, much of the testing must be performed on high-surface-area powders. A technique that can provide accurate compositional profiles with very precise depth resolution for non-flat samples would be a majormore » benefit to the field. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling is an excellent tool that has long been used to examine corrosion layers of glass. The roughness of the buried corrosion layers, however, causes the corresponding SIMS depth profiles to exhibit erroneously wide interfaces. In this study, NanoSIMS was used to image the cross-section of the corrosion layers of a leached SON68 glass sample. A wedged crater was prepared by a focused ion beam (FIB) instrument to obtain a 5× improvement in depth resolution for NanoSIMS measurements. This increase in resolution allowed us to confirm that the breakdown of the silica glass network is further from the pristine glass than a second dissolution front for boron, another glass former. The existence of these two distinct interfaces, separated by only ~20 nm distance in depth, was not apparent by traditional ToF-SIMS depth profiling but has been confirmed also by atom probe tomography. This novel sample geometry will be a major benefit to efficient NanoSIMS sampling of irregular interfaces at the nanometer scale that would otherwise be obscured within ToF-SIMS depth profiles.« less

Investigating the capability of ToF-SIMS to determine the oxidation state of Ce

NASA Astrophysics Data System (ADS)

Seed Ahmed, H. A. A.; Swart, H. C.; Kroon, R. E.

2018-04-01

The capability of time of flight secondary ion mass spectrometry (ToF-SIMS) to determine the oxidation state of Ce ions doped in a phosphor was investigated. Two samples of SiO2:Ce (4 mol%) with known Ce3+/Ce4+ relative concentrations were subjected to ToF-SIMS measurements. The spectra were very similar and no significant differences in the relative peak intensities were observed that would readily allow one to distinguish Ce3+ from Ce4+. Although ToF-SIMS was therefore not useful to distinguish the charge state of Ce ions doped in this phosphor material, the idea in principle was also tested on two other samples, namely CeF3 and CeF4 These contain Ce as part of the host (i.e. much higher concentration) and are fluorides, which is significant because ToF-SIMS has previously been reported to be able to distinguish Eu2+ from Eu3+ in Eu doped Sr5(PO4)3F phosphor. The spectrum of CeF4 contained a small peak related to Ce4+ which was not observed in the CeF3 spectrum, yet the peak related to the Ce3+ ions was found to be much more intense in the spectrum of CeF4 than CeF3, showing that the ToF-SIMS signals cannot be directly interpreted as retaining the charge state of the ions in the original material. Nevertheless, the significant differences in the Ce-related peaks in the ToF-SIMS spectra from CeF3 and CeF4 show that the charge state of Ce may be distinguished. This study shows that while in principle ToF-SIMS may be used to distinguish the charge state of Ce ions, this depends on the sample and it would not be easy to interpret the spectra without a standard or reference.

Molecule-Specific Imaging Analysis of Carcinogens in Breast Cancer Cells Using Time-of-Flight Secondary Ion Mass Spectrometry

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

Quong, J N; Knize, M G; Kulp, K S

2003-08-19

Imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to study the localization of heterocyclic amines in MCF7 line of human breast cancer cells. The detection sensitivities of a model rodent mutagen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were determined. Following an established criteria for the determination of status of freeze-fracture cells, the distribution of PhIP in the MCF7 cells are reported.

User's Guide for Flight Simulation Data Visualization Workstation

NASA Technical Reports Server (NTRS)

Kaplan, Joseph A.; Chen, Ronnie; Kenney, Patrick S.; Koval, Christopher M.; Hutchinson, Brian K.

1996-01-01

Today's modern flight simulation research produces vast amounts of time sensitive data. The meaning of this data can be difficult to assess while in its raw format. Therefore, a method of breaking the data down and presenting it to the user in a graphical format is necessary. Simulation Graphics (SimGraph) is intended as a data visualization software package that will incorporate simulation data into a variety of animated graphical displays for easy interpretation by the simulation researcher. This document is intended as an end user's guide.

MPCV Exercise Operational Volume Analysis

NASA Technical Reports Server (NTRS)

Godfrey, A.; Humphreys, B.; Funk, J.; Perusek, G.; Lewandowski, B. E.

2017-01-01

In order to minimize the loss of bone and muscle mass during spaceflight, the Multi-purpose Crew Vehicle (MPCV) will include an exercise device and enough free space within the cabin for astronauts to use the device effectively. The NASA Digital Astronaut Project (DAP) has been tasked with using computational modeling to aid in determining whether or not the available operational volume is sufficient for in-flight exercise.Motion capture data was acquired using a 12-camera Smart DX system (BTS Bioengineering, Brooklyn, NY), while exercisers performed 9 resistive exercises without volume restrictions in a 1g environment. Data were collected from two male subjects, one being in the 99th percentile of height and the other in the 50th percentile of height, using between 25 and 60 motion capture markers. Motion capture data was also recorded as a third subject, also near the 50th percentile in height, performed aerobic rowing during a parabolic flight. A motion capture system and algorithms developed previously and presented at last years HRP-IWS were utilized to collect and process the data from the parabolic flight [1]. These motions were applied to a scaled version of a biomechanical model within the biomechanical modeling software OpenSim [2], and the volume sweeps of the motions were visually assessed against an imported CAD model of the operational volume. Further numerical analysis was performed using Matlab (Mathworks, Natick, MA) and the OpenSim API. This analysis determined the location of every marker in space over the duration of the exercise motion, and the distance of each marker to the nearest surface of the volume. Containment of the exercise motions within the operational volume was determined on a per-exercise and per-subject basis. The orientation of the exerciser and the angle of the footplate were two important factors upon which containment was dependent. Regions where the exercise motion exceeds the bounds of the operational volume have been identified by determining which markers from the motion capture exceed the operational volume and by how much. A credibility assessment of this analysis was performed in accordance with NASA-STD-7009 prior to delivery to the MPCV program.

Identification and High-Resolution Imaging of α-Tocopherol from Human Cells to Whole Animals by TOF-SIMS Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Bruinen, Anne L.; Fisher, Gregory L.; Balez, Rachelle; van der Sar, Astrid M.; Ooi, Lezanne; Heeren, Ron M. A.

2018-06-01

A unique method for identification of biomolecular components in different biological specimens, while preserving the capability for high speed 2D and 3D molecular imaging, is employed to investigate cellular response to oxidative stress. The employed method enables observing the distribution of the antioxidant α-tocopherol and other molecules in cellular structures via time-of-flight secondary ion mass spectrometry (TOF-SIMS (MS1)) imaging in parallel with tandem mass spectrometry (MS2) imaging, collected simultaneously. The described method is employed to examine a network formed by neuronal cells differentiated from human induced pluripotent stem cells (iPSCs), a model for investigating human neurons in vitro. The antioxidant α-tocopherol is identified in situ within different cellular layers utilizing a 3D TOF-SIMS tandem MS imaging analysis. As oxidative stress also plays an important role in mediating inflammation, the study was expanded to whole body tissue sections of M. marinum-infected zebrafish, a model organism for tuberculosis. The TOF-SIMS tandem MS imaging results reveal an increased presence of α-tocopherol in response to the pathogen. [Figure not available: see fulltext.

ToF-SIMS Parallel Imaging MS/MS of Lipid Species in Thin Tissue Sections.

PubMed

Bruinen, Anne Lisa; Fisher, Gregory L; Heeren, Ron M A

2017-01-01

Unambiguous identification of detected species is essential in complex biomedical samples. To date, there are not many mass spectrometry imaging techniques that can provide both high spatial resolution and identification capabilities. A new and patented imaging tandem mass spectrometer, exploiting the unique characteristics of the nanoTOF II (Physical Electronics, USA) TOF-SIMS TRIFT instrument, was developed to address this.Tandem mass spectrometry is based on the selection of precursor ions from the full secondary ion spectrum (MS 1 ), followed by energetic activation and fragmentation, and collection of the fragment ions to obtain a tandem MS spectrum (MS 2 ). The PHI NanoTOF II mass spectrometer is equipped with a high-energy collision induced dissociation (CID) fragmentation cell as well as a second time-of-flight analyzer developed for simultaneous ToF-SIMS and tandem MS imaging experiments.We describe here the results of a ToF-SIMS imaging experiment on a thin tissue section of an infected zebrafish as a model organism for tuberculosis. The focus is on the obtained ion distribution plot of a fatty acid as well as its identification by tandem mass spectrometry.

Nanoscale imaging of alteration layers of corroded international simple glass particles using ToF-SIMS

DOE PAGES

Zhang, Jiandong; Neeway, James J.; Zhang, Yanyan; ...

2017-02-24

Glass particles with dimensions typically ranging from tens to hundreds of microns are often used in glass corrosion research in order to accelerate testing. Two-dimensional and three-dimensional nanoscale imaging techniques are badly needed to characterize the alteration layers at the surfaces of these corroded glass particles. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) can provide a lateral resolution as low as ~100 nm, and, compared to other imaging techniques, is sensitive to elements lighter than carbon. Here, we used ToF-SIMS to characterize the alteration layers of corroded international simple glass (ISG) particles. At most particle surfaces, we observed inhomogeneous or nomore » alteration layers, indicating that the thickness of the alterations layers may be too thin to be observable by ToF-SIMS imaging. Relatively thick (e.g., 1–10 µm) alteration layers were inhomogeneously distributed at a small portion of surfaces.Interestingly, some large-size (tens of microns) glass particles were fully altered. Above observations suggest that weak attachment and the defects on ISG particle surfaces play an important role in ISG glass corrosion.« less

Nanoscale imaging of alteration layers of corroded international simple glass particles using ToF-SIMS

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

Zhang, Jiandong; Neeway, James J.; Zhang, Yanyan

Glass particles with dimensions typically ranging from tens to hundreds of microns are often used in glass corrosion research in order to accelerate testing. Two-dimensional and three-dimensional nanoscale imaging techniques are badly needed to characterize the alteration layers at the surfaces of these corroded glass particles. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) can provide a lateral resolution as low as ~100 nm, and, compared to other imaging techniques, is sensitive to elements lighter than carbon. In this work, we used ToF-SIMS to characterize the alteration layers of corroded international simple glass (ISG) particles. At most particle surfaces, inhomogeneous or nomore » alteration layers were observed, indicating that the thickness of the alterations layers may be too thin to be observable by ToF-SIMS imaging. Relatively thick (e.g., 1-10 microns) alteration layers were inhomogeneously distributed at a small portion of surfaces. More interestingly, some large-size (tens of microns) glass particles were fully altered. Above observations suggest that weak attachment and the defects on ISG particle surfaces play an important role in ISG glass corrosion.« less

The role of public policies in reducing smoking prevalence: results from the Michigan SimSmoke tobacco policy simulation model.

PubMed

Levy, David T; Huang, An-Tsun; Havumaki, Joshua S; Meza, Rafael

2016-05-01

Michigan has implemented several of the tobacco control policies recommended by the World Health Organization MPOWER goals. We consider the effect of those policies and additional policies consistent with MPOWER goals on smoking prevalence and smoking-attributable deaths (SADs). The SimSmoke tobacco control policy simulation model is used to examine the effect of past policies and a set of additional policies to meet the MPOWER goals. The model is adapted to Michigan using state population, smoking, and policy data starting in 1993. SADs are estimated using standard attribution methods. Upon validating the model, SimSmoke is used to distinguish the effect of policies implemented since 1993 against a counterfactual with policies kept at their 1993 levels. The model is then used to project the effect of implementing stronger policies beginning in 2014. SimSmoke predicts smoking prevalence accurately between 1993 and 2010. Since 1993, a relative reduction in smoking rates of 22 % by 2013 and of 30 % by 2054 can be attributed to tobacco control policies. Of the 22 % reduction, 44 % is due to taxes, 28 % to smoke-free air laws, 26 % to cessation treatment policies, and 2 % to youth access. Moreover, 234,000 SADs are projected to be averted by 2054. With additional policies consistent with MPOWER goals, the model projects that, by 2054, smoking prevalence can be further reduced by 17 % with 80,000 deaths averted relative to the absence of those policies. Michigan SimSmoke shows that tobacco control policies, including cigarette taxes, smoke-free air laws, and cessation treatment policies, have substantially reduced smoking and SADs. Higher taxes, strong mass media campaigns, and cessation treatment policies would further reduce smoking prevalence and SADs.

The Role of Public Policies in Reducing Smoking Prevalence: Results from the Michigan SimSmoke Tobacco Policy Simulation Model

PubMed Central

Levy, David T.; Huang, An-Tsun; Havumaki, Joshua S.; Meza, Rafael

2016-01-01

Introduction Michigan has implemented several of the tobacco control policies recommended by the World Health Organization MPOWER goals. We consider the effect of those policies and additional policies consistent with MPOWER goals on smoking prevalence and smoking-attributable deaths (SADs). Methods The SimSmoke tobacco control policy simulation model is used to examine the effect of past policies and a set of additional policies to meet the MPOWER goals. The model is adapted to Michigan using state population, smoking and policy data starting in 1993. SADs are estimated using standard attribution methods. Upon validating the model, SimSmoke is used to distinguish the effect of policies implemented since 1993 against a counterfactual with policies kept at their 1993 levels. The model is then used to project the effect of implementing stronger policies beginning in 2014. Results SimSmoke predicts smoking prevalence accurately between 1993 and 2010. Since 1993, a relative reduction in smoking rates of 22% by 2013 and of 30% by 2054 can be attributed to tobacco control policies. Of the 22% reduction, 44% is due to taxes, 28% to smoke-free air laws, 26% to cessation treatment policies, and 2% to youth access. Moreover, 234,000 smoking-attributable deaths are projected to be averted by 2054. With additional policies consistent with MPOWER goals, the model projects that, by 2054, smoking prevalence can be further reduced by 17% with 80,000 deaths averted relative to the absence of those policies. Conclusions Michigan SimSmoke shows that tobacco control policies, including cigarette taxes, smoke-free air laws and cessation treatment policies, have substantially reduced smoking and smoking-attributable deaths. Higher taxes, strong mass media campaigns and cessation treatment policies would further reduce smoking prevalence and smoking-attributable deaths. PMID:26983616

Linear time algorithms to construct populations fitting multiple constraint distributions at genomic scales.

PubMed

Siragusa, Enrico; Haiminen, Niina; Utro, Filippo; Parida, Laxmi

2017-10-09

Computer simulations can be used to study population genetic methods, models and parameters, as well as to predict potential outcomes. For example, in plant populations, predicting the outcome of breeding operations can be studied using simulations. In-silico construction of populations with pre-specified characteristics is an important task in breeding optimization and other population genetic studies. We present two linear time Simulation using Best-fit Algorithms (SimBA) for two classes of problems where each co-fits two distributions: SimBA-LD fits linkage disequilibrium and minimum allele frequency distributions, while SimBA-hap fits founder-haplotype and polyploid allele dosage distributions. An incremental gap-filling version of previously introduced SimBA-LD is here demonstrated to accurately fit the target distributions, allowing efficient large scale simulations. SimBA-hap accuracy and efficiency is demonstrated by simulating tetraploid populations with varying numbers of founder haplotypes, we evaluate both a linear time greedy algoritm and an optimal solution based on mixed-integer programming. SimBA is available on http://researcher.watson.ibm.com/project/5669.

Storage Information Management System (SIMS) Spaceflight Hardware Warehousing at Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Kubicko, Richard M.; Bingham, Lindy

1995-01-01

Goddard Space Flight Center (GSFC) on site and leased warehouses contain thousands of items of ground support equipment (GSE) and flight hardware including spacecraft, scaffolding, computer racks, stands, holding fixtures, test equipment, spares, etc. The control of these warehouses, and the management, accountability, and control of the items within them, is accomplished by the Logistics Management Division. To facilitate this management and tracking effort, the Logistics and Transportation Management Branch, is developing a system to provide warehouse personnel, property owners, and managers with storage and inventory information. This paper will describe that PC-based system and address how it will improve GSFC warehouse and storage management.

HepSim: A repository with predictions for high-energy physics experiments

DOE PAGES

Chekanov, S. V.

2015-02-03

A file repository for calculations of cross sections and kinematic distributions using Monte Carlo generators for high-energy collisions is discussed. The repository is used to facilitate effective preservation and archiving of data from theoretical calculations and for comparisons with experimental data. The HepSim data library is publicly accessible and includes a number of Monte Carlo event samples with Standard Model predictions for current and future experiments. The HepSim project includes a software package to automate the process of downloading and viewing online Monte Carlo event samples. Data streaming over a network for end-user analysis is discussed.

WWC Quick Review of the Report: "Scaling Up SimCalc Project: Can a Technology Enhanced Curriculum Improve Student Learning of Important Mathematics?"

ERIC Educational Resources Information Center

What Works Clearinghouse, 2008

2008-01-01

This study examines whether "SimCalc Mathworlds"[TM] improves students' knowledge of the algebra concepts of rate and proportionality. Strengths: The study is a well implemented randomized controlled trial (RCT) with acceptable sample attrition rates and no indications of other problems. Cautions: The study authors describe a rigorous…

Small molecule analysis and imaging of fatty acids in the zebra finch song system using time-of-flight-secondary ion mass spectrometry.

PubMed

Amaya, Kensey R; Sweedler, Jonathan V; Clayton, David F

2011-08-01

Fatty acids are central to brain metabolism and signaling, but their distributions within complex brain circuits have been difficult to study. Here we applied an emerging technique, time-of-flight secondary ion mass spectrometry (ToF-SIMS), to image specific fatty acids in a favorable model system for chemical analyses of brain circuits, the zebra finch (Taeniopygia guttata). The zebra finch, a songbird, produces complex learned vocalizations under the control of an interconnected set of discrete, dedicated brain nuclei 'song nuclei'. Using ToF-SIMS, the major song nuclei were visualized by virtue of differences in their content of essential and non-essential fatty acids. Essential fatty acids (arachidonic acid and docosahexaenoic acid) showed distinctive distributions across the song nuclei, and the 18-carbon fatty acids stearate and oleate discriminated the different core and shell subregions of the lateral magnocellular nucleus of the anterior nidopallium. Principal component analysis of the spectral data set provided further evidence of chemical distinctions between the song nuclei. By analyzing the robust nucleus of the arcopallium at three different ages during juvenile song learning, we obtain the first direct evidence of changes in lipid content that correlate with progression of song learning. The results demonstrate the value of ToF-SIMS to study lipids in a favorable model system for probing the function of lipids in brain organization, development and function. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

The impact of detergents on the tissue decellularization process: a ToF-SIMS study

PubMed Central

White, Lisa J; Taylor, Adam J; Faulk, Denver M; Keane, Tim J; Saldin, Lindsey T; Reing, Janet E; Swinehart, Ilea T; Turner, Neill J; Ratner, Buddy D

2017-01-01

Biologic scaffolds are derived from mammalian tissues, which must be decellularized to remove cellular antigens that would otherwise incite an adverse immune response. Although widely used clinically, the optimum balance between cell removal and the disruption of matrix architecture and surface ligand landscape remains a considerable challenge. Here we describe the use of time of flight secondary ion mass spectroscopy (ToF-SIMS) to provide sensitive, molecular specific, localized analysis of detergent decellularized biologic scaffolds. We detected residual detergent fragments, specifically from Triton X-100, sodium deoxycholate and sodium dodecyl sulphate (SDS) in decellularized scaffolds; increased SDS concentrations from 0.1% to 1.0% increased both the intensity of SDS fragments and adverse cell outcomes. We also identified cellular remnants, by detecting phosphate and phosphocholine ions in PAA and CHAPS decellularized scaffolds. The present study demonstrates ToF-SIMS is not only a powerful tool for characterization of biologic scaffold surface molecular functionality, but also enables sensitive assessment of decellularization efficacy. PMID:27993639

Image recombination transform algorithm for superresolution structured illumination microscopy

PubMed Central

Zhou, Xing; Lei, Ming; Dan, Dan; Yao, Baoli; Yang, Yanlong; Qian, Jia; Chen, Guangde; Bianco, Piero R.

2016-01-01

Abstract. Structured illumination microscopy (SIM) is an attractive choice for fast superresolution imaging. The generation of structured illumination patterns made by interference of laser beams is broadly employed to obtain high modulation depth of patterns, while the polarizations of the laser beams must be elaborately controlled to guarantee the high contrast of interference intensity, which brings a more complex configuration for the polarization control. The emerging pattern projection strategy is much more compact, but the modulation depth of patterns is deteriorated by the optical transfer function of the optical system, especially in high spatial frequency near the diffraction limit. Therefore, the traditional superresolution reconstruction algorithm for interference-based SIM will suffer from many artifacts in the case of projection-based SIM that possesses a low modulation depth. Here, we propose an alternative reconstruction algorithm based on image recombination transform, which provides an alternative solution to address this problem even in a weak modulation depth. We demonstrated the effectiveness of this algorithm in the multicolor superresolution imaging of bovine pulmonary arterial endothelial cells in our developed projection-based SIM system, which applies a computer controlled digital micromirror device for fast fringe generation and multicolor light-emitting diodes for illumination. The merit of the system incorporated with the proposed algorithm allows for a low excitation intensity fluorescence imaging even less than 1  W/cm2, which is beneficial for the long-term, in vivo superresolved imaging of live cells and tissues. PMID:27653935

STS_135_Sim

NASA Image and Video Library

2011-04-04

JSC2011-E-040335 (4 April 2011) --- NASA astronauts Rex Walheim, right, Sandy Magnus, foreground, both mission specialists, and Doug Hurley, pilot, work on the flight deck as the crew of STS-135 trains in the Fixed Base Simulator at NASA?s Johnson Space Center in Houston April 4, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Detection of Nisin and Fibrinogen Adsorption on Poly(ethylene Oxide) Coated Polyurethane Surfaces by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

PubMed Central

Schilke, Karl F.; McGuire, Joseph

2011-01-01

Stable, pendant polyethylene oxide (PEO) layers were formed on medical-grade Pellethane® and Tygon® polyurethane surfaces, by adsorption and gamma-irradiation of PEO-polybutadiene-PEO triblock surfactants. Coated and uncoated polyurethanes were challenged individually or sequentially with nisin (a small polypeptide with antimicrobial activity) and/or fibrinogen, and then analyzed with time-of-flight secondary ion mass spectrometry (TOF-SIMS). Data reduction by robust principal components analysis (PCA) allowed detection of outliers, and distinguished adsorbed nisin and fibrinogen. Fibrinogen-contacted surfaces, with or without nisin, were very similar on uncoated polymer surfaces, consistent with nearly complete displacement or coverage of previously-adsorbed nisin by fibrinogen. In contrast, nisin-loaded PEO layers remained essentially unchanged upon challenge with fibrinogen, suggesting that the adsorbed nisin is stabilized within the pendant PEO layer, while the peptide-loaded PEO layer retains its ability to repel large proteins. Coatings of PEO loaded with therapeutic polypeptides on medical polymers have the potential to be used to produce anti-fouling and biofunctional surfaces for implantable or blood-contacting devices. PMID:21440897

Project Status Update and SIM Science Breadth Discussion for the Origins Subcommittee (OS)

NASA Technical Reports Server (NTRS)

Marr, James C., IV; Shao, Mike

2003-01-01

This viewgraph presentation is composed of two sections The first reviews the features and the science goals of the Space Interferometry Mission (SIM). The goals are: (1) Perform a search for other planetary systems by surveying 2000 nearby stars for astrometric signatures of planetary companion, (2) Survey a sample of 200 nearby stars for orbiting planets down to terrestrial-type masses (3) Improve best current catalog of star positions by >lOOx and extend to fainter stars to allow extension of stellar knowledge to include our entire galaxy (4) Study dynamics and evolution of stars and star clusters in our galaxy to understand how our galaxy was formed and how it will evolve. (5) Calibrate luminosities of important stars and cosmological distance indicators to improve our understanding of stellar processes and to measure precise distance in the distant universe. The presentation also reviews the accomplishments since 2002, the plans for the subsequent 6 months. The second entitled "The Breadth of SIM Science," reviews SIM science goals in a larger context. SIM will serve to complement and pave the way for the Terrestrial Planet Finder (TPF). SIM observations of the motions of stars will tell us about the distribution of all gravitating mass (light plus dark matter) in the Galaxy. SIM observations of the motions of dwarf galaxies around our own will determine the mass distribution (light plus dark matter in the Halo. SIM will greatly extend these observations to test the theories of accretion disks around super massive black holes. SIM has advantages for studying AGN and other very compact objects.

Detection of surface mobility of poly (2, 3, 4, 5, 6-pentafluorostyrene) films by in situ variable-temperature ToF-SIMS and contact angle measurements.

PubMed

Fu, Yi; Lau, Yiu-Ting R; Weng, Lu-Tao; Ng, Kai-Mo; Chan, Chi-Ming

2014-10-01

Poly (2, 3, 4, 5, 6-pentafluorostyrene) (5FPS) was prepared by bulk radical polymerization. The spin-cast films of this polymer were analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS) at various temperatures ranging from room temperature to 120°C. Principal component analysis (PCA) of the ToF-SIMS data revealed a transition temperature (T(T)) at which the surface structure of 5FPS was rearranged. A comparison between the results of the PCA of ToF-SIMS spectra obtained on 5FPS and polystyrene (PS) indicate that the pendant groups of 5FPS and PS moved in exactly opposite directions as the temperature increased. More pendant groups of 5FPS and PS migrated from the bulk to the surface and verse versa, respectively, as the temperature increased. These results clearly support the view that the abrupt changes in the normalized principal component 1 value was caused by the surface reorientation of the polymers and not by a change in the ion fragmentation mechanism at temperatures above the T(T). Contact angle measurement, which is another extremely surface sensitive technique, was used to monitor the change in the surface tension as a function of temperature. A clear T(T) was determined by the contact angle measurements. The T(T) values determined by contact angle measurements and ToF-SIMS were very similar. Copyright © 2014 Elsevier Inc. All rights reserved.

Design and Build of Reactor Simulator for Fission Surface Power Technology Demonstrator Unit

NASA Technical Reports Server (NTRS)

Godfroy, Thomas; Dickens, Ricky; Houts, Michael; Pearson, Boise; Webster, Kenny; Gibson, Marc; Qualls, Lou; Poston, Dave; Werner, Jim; Radel, Ross

2011-01-01

The Nuclear Systems Team at NASA Marshall Space Flight Center (MSFC) focuses on technology development for state of the art capability in non-nuclear testing of nuclear system and Space Nuclear Power for fission reactor systems for lunar and Mars surface power generation as well as radioisotope power systems for both spacecraft and surface applications. Currently being designed and developed is a reactor simulator (RxSim) for incorporation into the Technology Demonstrator Unit (TDU) for the Fission Surface Power System (FSPS) Program, which is supported by multiple national laboratories and NASA centers. The ultimate purpose of the RxSim is to provide heated NaK to a pair of Stirling engines in the TDU. The RxSim includes many different systems, components, and instrumentation that have been developed at MSFC while working with pumped NaK systems and in partnership with the national laboratories and NASA centers. The main components of the RxSim are a core, a pump, a heat exchanger (to mimic the thermal load of the Stirling engines), and a flow meter for tests at MSFC. When tested at NASA Glenn Research Center (GRC) the heat exchanger will be replaced with a Stirling power conversion engine. Additional components include storage reservoirs, expansion volumes, overflow catch tanks, safety and support hardware, instrumentation (temperature, pressure, flow) for data collection, and power supplies. This paper will discuss the design and current build status of the RxSim for delivery to GRC in early 2012.

Design and Build of Reactor Simulator for Fission Surface Power Technology Demonstrator Unit

NASA Astrophysics Data System (ADS)

Godfroy, T.; Dickens, R.; Houts, M.; Pearson, B.; Webster, K.; Gibson, M.; Qualls, L.; Poston, D.; Werner, J.; Radel, R.

The Nuclear Systems Team at Marshall Space Flight Center (MSFC) focuses on technology development for state of the art capability in non-nuclear testing of nuclear system and Space Nuclear Power for fission reactor systems for lunar and mars surface power generation as well as radioisotope power systems for both spacecraft and surface applications. Currently being designed and developed is a reactor simulator (RxSim) for incorporation into the Technology Demonstrator Unit (TDU) for the Fission Surface Power System (FSPS) Program which is supported by multiple national laboratories and NASA centers. The ultimate purpose of the RxSim is to provide heated NaK to a pair of Stirling engines in the TDU. The RxSim includes many different systems, components, and instrumentation that have been developed at MSFC while working with pumped NaK systems and in partnership with the national laboratories and NASA centers. The main components of the RxSim are a core, a pump, a heat exchanger (to mimic the thermal load of the Stirling engines), and a flow meter when being tested at MSFC. When tested at GRC the heat exchanger will be replaced with a Stirling power conversion engine. Additional components include storage reservoirs, expansion volumes, overflow catch tanks, safety and support hardware, instrumenta- tion (temperature, pressure, flow) data collection, and power supplies. This paper will discuss the design and current build status of the RxSim for delivery to GRC in early 2012.

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

Yang, Li; Zhu, Zihua; Yu, Xiao-Ying

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a unique surface analysis technique because it can provide molecular recognition for organic and biological molecules. However, analyzing aqueous solution surfaces by ToF-SIMS is difficult, because ToF-SIMS is a high-vacuum technique, while the vapor pressure of water is about 2.3 kPa at room temperature (20 C). We designed and fabricated a self-contained microfluidic device, enabling in situ analysis of aqueous surfaces by scanning electron microscope (SEM) and ToF-SIMS, which has been briefly reported.1,2 In this study, we report more performance data, focusing on the performance of this device for in situ analysis ofmore » organic molecules at aqueous surfaces using ToF-SIMS. Three representative organic compounds (formic acid, glycerol, and glutamic acid) were tested, and their molecular signals were successfully observed. The device can be self-running in vacuum for 8 hours, and SIMS measurements are feasible at any time in this time range. The stability of this device under primary ion beam bombardment is also impressive. High fluence (6 × 1012 ions cm-2 s-1) measurements can be operated continuously for up to 30 minutes without any significant damage to the aperture. However, extra-high fluence measurements (>1 × 1014 ions cm-2 s-1) may lead to liquid bumping in the aperture, and the aqueous solutions may spread out quickly. Signal reproducibility is reasonably good, and relative standard deviation (RSD) for molecular ion signals can be controlled to be smaller than ±15% for consecutive measurements. Measurements at long time intervals (e.g., 60 min) show RSDs of ±40-50%. In addition, the detection limits of formic acid, glycerol, and glutamic acid are estimated to be 0.04%, 0.008%, and 0.002% (weight ratio), respectively.« less

QuakeSim Project Networking

NASA Astrophysics Data System (ADS)

Kong, D.; Donnellan, A.; Pierce, M. E.

2012-12-01

QuakeSim is an online computational framework focused on using remotely sensed geodetic imaging data to model and understand earthquakes. With the rise in online social networking over the last decade, many tools and concepts have been developed that are useful to research groups. In particular, QuakeSim is interested in the ability for researchers to post, share, and annotate files generated by modeling tools in order to facilitate collaboration. To accomplish this, features were added to the preexisting QuakeSim site that include single sign-on, automated saving of output from modeling tools, and a personal user space to manage sharing permissions on these saved files. These features implement OpenID and Lightweight Data Access Protocol (LDAP) technologies to manage files across several different servers, including a web server running Drupal and other servers hosting the computational tools themselves.

Image restoration approach to address reduced modulation contrast in structured illumination microscopy

PubMed Central

Patwary, Nurmohammed; Doblas, Ana; Preza, Chrysanthe

2018-01-01

The performance of structured illumination microscopy (SIM) is hampered in many biological applications due to the inability to modulate the light when imaging deep into the sample. This is in part because sample-induced aberration reduces the modulation contrast of the structured pattern. In this paper, we present an image restoration approach suitable for processing raw incoherent-grid-projection SIM data with a low fringe contrast. Restoration results from simulated and experimental ApoTome SIM data show results with improved signal-to-noise ratio (SNR) and optical sectioning compared to the results obtained from existing methods, such as 2D demodulation and 3D SIM deconvolution. Our proposed method provides satisfactory results (quantified by the achieved SNR and normalized mean square error) even when the modulation contrast of the illumination pattern is as low as 7%. PMID:29675307

RxnSim: a tool to compare biochemical reactions.

PubMed

Giri, Varun; Sivakumar, Tadi Venkata; Cho, Kwang Myung; Kim, Tae Yong; Bhaduri, Anirban

2015-11-15

: Quantitative assessment of chemical reaction similarity aids database searches, classification of reactions and identification of candidate enzymes. Most methods evaluate reaction similarity based on chemical transformation patterns. We describe a tool, RxnSim, which computes reaction similarity based on the molecular signatures of participating molecules. The tool is able to compare reactions based on similarities of substrates and products in addition to their transformation. It allows masking of user-defined chemical moieties for weighted similarity computations. RxnSim is implemented in R and is freely available from the Comprehensive R Archive Network, CRAN (http://cran.r-project.org/web/packages/RxnSim/). anirban.b@samsung.com or ty76.kim@samsung.com Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Stability analysis using SDSA tool

NASA Astrophysics Data System (ADS)

Goetzendorf-Grabowski, Tomasz; Mieszalski, Dawid; Marcinkiewicz, Ewa

2011-11-01

The SDSA (Simulation and Dynamic Stability Analysis) application is presented as a tool for analysing the dynamic characteristics of the aircraft just in the conceptual design stage. SDSA is part of the CEASIOM (Computerized Environment for Aircraft Synthesis and Integrated Optimization Methods) software environment which was developed within the SimSAC (Simulating Aircraft Stability And Control Characteristics for Use in Conceptual Design) project, funded by the European Commission 6th Framework Program. SDSA can also be used as stand alone software, and integrated with other design and optimisation systems using software wrappers. This paper focuses on the main functionalities of SDSA and presents both computational and free flight experimental results to compare and validate the presented software. Two aircraft are considered, the EADS Ranger 2000 and the Warsaw University designed PW-6 glider. For the two cases considered here the SDSA software is shown to be an excellent tool for predicting dynamic characteristics of an aircraft.

PhET: Interactive Simulations for Teaching and Learning Physics

NASA Astrophysics Data System (ADS)

Perkins, Katherine; Adams, Wendy; Dubson, Michael; Finkelstein, Noah; Reid, Sam; Wieman, Carl; LeMaster, Ron

2006-01-01

The Physics Education Technology (PhET) project creates useful simulations for teaching and learning physics and makes them freely available from the PhET website (http://phet.colorado.edu). The simulations (sims) are animated, interactive, and game-like environments in which students learn through exploration. In these sims, we emphasize the connections between real-life phenomena and the underlying science, and seek to make the visual and conceptual models of expert physicists accessible to students. We use a research-based approach in our design—incorporating findings from prior research and our own testing to create sims that support student engagement with and understanding of physics concepts.

FoilSim: Basic Aerodynamics Software Created

NASA Technical Reports Server (NTRS)

Peterson, Ruth A.

1999-01-01

FoilSim is interactive software that simulates the airflow around various shapes of airfoils. The graphical user interface, which looks more like a video game than a learning tool, captures and holds the students interest. The software is a product of NASA Lewis Research Center s Learning Technologies Project, an educational outreach initiative within the High Performance Computing and Communications Program (HPCCP).This airfoil view panel is a simulated view of a wing being tested in a wind tunnel. As students create new wing shapes by moving slider controls that change parameters, the software calculates their lift. FoilSim also displays plots of pressure or airspeed above and below the airfoil surface.

ToF-SIMS analysis of poly(L-lysine)-graft-poly(2-methyl-2-oxazoline) ultrathin adlayers.

PubMed

Pidhatika, Bidhari; Chen, Yin; Coullerez, Geraldine; Al-Bataineh, Sameer; Textor, Marcus

2014-02-01

Understanding of the interfacial chemistry of ultrathin polymeric adlayers is fundamentally important in the context of establishing quantitative design rules for the fabrication of nonfouling surfaces in various applications such as biomaterials and medical devices. In this study, seven poly(L-lysine)-graft-poly(2-methyl-2-oxazoline) (PLL-PMOXA) copolymers with grafting density (number of PMOXA chains per lysine residue) 0.09, 0.14, 0.19, 0.33, 0.43, 0.56, and 0.77, respectively, were synthesized and characterized by means of nuclear magnetic resonance spectroscopy (NMR). The copolymers were then adsorbed on Nb2O5 surfaces. Optical waveguide lightmode spectroscopy method was used to monitor the surface adsorption in situ of these copolymers and provide information on adlayer masses that were then converted into PLL and PMOXA surface densities. To investigate the relationship between copolymer bulk architecture (as shown by NMR data) and surface coverage as well as surface architecture, time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis was performed. Furthermore, ToF-SIMS method combined with principal component analysis (PCA) was used to verify the protein resistant properties of PLL-PMOXA adlayers, by thorough characterization before and after adlayer exposure to human serum. ToF-SIMS analysis revealed that the chemical composition as well as the architecture of the different PLL-PMOXA adlayers indeed reflects the copolymer bulk composition. ToF-SIMS results also indicated a heterogeneous surface coverage of PLL-PMOXA adlayers with high grafting densities higher than 0.33. In the case of protein resistant surface, PCA results showed clear differences between protein resistant and nonprotein-resistant surfaces. Therefore, ToF-SIMS results combined with PCA confirmed that the PLL-PMOXA adlayer with brush architecture resists protein adsorption. However, low increases of some amino acid signals in ToF-SIMS spectra were detected after the adlayer has been exposed to human serum.

ToF-SIMS imaging of molecular-level alteration mechanisms in Le Bonheur de vivre by Henri Matisse.

PubMed

Voras, Zachary E; deGhetaldi, Kristin; Wiggins, Marcie B; Buckley, Barbara; Baade, Brian; Mass, Jennifer L; Beebe, Thomas P

2015-11-01

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF-SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment-binder interactions. In this study, ToF-SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting Le Bonheur de vivre (1905-1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout Le Bonheur de vivre and co-localized in cross-sectional samples using high spatial resolution ToF-SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting's complex restoration history. ToF-SIMS's ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from Le Bonheur de vivre to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using μXANES, SR-μXRF, SEM-EDX, and SR-FTIR. The relatively high sensitivity offered by ToF-SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers.

An unsupervised MVA method to compare specific regions in human breast tumor tissue samples using ToF-SIMS.

PubMed

Bluestein, Blake M; Morrish, Fionnuala; Graham, Daniel J; Guenthoer, Jamie; Hockenbery, David; Porter, Peggy L; Gamble, Lara J

2016-03-21

Imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal component analysis (PCA) were used to investigate two sets of pre- and post-chemotherapy human breast tumor tissue sections to characterize lipids associated with tumor metabolic flexibility and response to treatment. The micron spatial resolution imaging capability of ToF-SIMS provides a powerful approach to attain spatially-resolved molecular and cellular data from cancerous tissues not available with conventional imaging techniques. Three ca. 1 mm(2) areas per tissue section were analyzed by stitching together 200 μm × 200 μm raster area scans. A method to isolate and analyze specific tissue regions of interest by utilizing PCA of ToF-SIMS images is presented, which allowed separation of cellularized areas from stromal areas. These PCA-generated regions of interest were then used as masks to reconstruct representative spectra from specifically stromal or cellular regions. The advantage of this unsupervised selection method is a reduction in scatter in the spectral PCA results when compared to analyzing all tissue areas or analyzing areas highlighted by a pathologist. Utilizing this method, stromal and cellular regions of breast tissue biopsies taken pre- versus post-chemotherapy demonstrate chemical separation using negatively-charged ion species. In this sample set, the cellular regions were predominantly all cancer cells. Fatty acids (i.e. palmitic, oleic, and stearic), monoacylglycerols, diacylglycerols and vitamin E profiles were distinctively different between the pre- and post-therapy tissues. These results validate a new unsupervised method to isolate and interpret biochemically distinct regions in cancer tissues using imaging ToF-SIMS data. In addition, the method developed here can provide a framework to compare a variety of tissue samples using imaging ToF-SIMS, especially where there is section-to-section variability that makes it difficult to use a serial hematoxylin and eosin (H&E) stained section to direct the SIMS analysis.

ToF-SIMS imaging of molecular-level alteration mechanisms in Le Bonheur de vivre by Henri Matisse

NASA Astrophysics Data System (ADS)

Voras, Zachary E.; deGhetaldi, Kristin; Wiggins, Marcie B.; Buckley, Barbara; Baade, Brian; Mass, Jennifer L.; Beebe, Thomas P.

2015-11-01

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF-SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment-binder interactions. In this study, ToF-SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting Le Bonheur de vivre (1905-1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout Le Bonheur de vivre and co-localized in cross-sectional samples using high spatial resolution ToF-SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting's complex restoration history. ToF-SIMS's ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from Le Bonheur de vivre to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using μXANES, SR-μXRF, SEM-EDX, and SR-FTIR. The relatively high sensitivity offered by ToF-SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers.

QCM-D and ToF-SIMS Investigation to Deconvolute the Relationship between Lipid Adsorption and Orientation on Lipase Activity.

PubMed

Joyce, Paul; Kempson, Ivan; Prestidge, Clive A

2015-09-22

Quartz crystal microbalance with dissipation (QCM-D) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to provide insights into the relationship between lipid adsorption kinetics and molecular behavior in porous silica particles of varying hydrophobicities on lipase activity. Lipase (an interfacial enzyme that cleaves ester bonds to break down lipids to fatty acids and monoglycerides) activity was controlled by loading triglycerides at different surface coverages in hydrophilic and hydrophobic porous silica particles. The rate of lipid adsorption increased 2-fold for the hydrophobic surface compared to the hydrophilic surface. However, for submonolayer lipid coverage, the hydrophilic surface enhanced lipase activity 4-fold, whereas the hydrophobic surface inhibited lipase activity 16-fold, compared to lipid droplets in water. A difference in lipid orientation for low surface coverage, evidenced by ToF-SIMS, indicated that lipid adsorbs to hydrophilic silica in a conformation promoting hydrolysis. Multilayer coverage on hydrophobic and hydrophilic surfaces was indistinguishable with ToF-SIMS analysis. Increased lipid adsorption for both substrates facilitated digestion kinetics comparable to a conventional emulsion. Improved understanding of the interfacial adsorption and orientation of lipid and its digestibility in porous silica has implications in improving the uptake of pharmaceuticals and nutrients from lipid-based delivery systems.

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

Hua, Xin; Yu, Xiao-Ying; Wang, Zhaoying

The first results of using a novel single channel microfluidic reactor to enable Shewanella biofilm growth and in situ characterization using time-of-flight secondary ion mass spectrometry (ToF-SIMS) in the hydrated environment are presented. The new microfluidic interface allows direct probing of the liquid surface using ToF-SIMS, a vacuum surface technique. The detection window is an aperture of 2 m in diameter on a thin silicon nitride (SiN) membrane and it allows direct detection of the liquid surface. Surface tension of the liquid flowing inside the microchannel holds the liquid within the aperture. ToF-SIMS depth profiling was used to drill throughmore » the SiN membrane and the biofilm grown on the substrate. In situ 2D imaging of the biofilm in hydrated state was acquired, providing spatial distribution of the chemical compounds in the biofilm system. This data was compared with a medium filled microfluidic reactor devoid of biofilm and dried biofilm samples deposited on clean silicon wafers. Principle Component Analysis (PCA) was used to investigate these observations. Our results show that imaging biofilms in the hydrated environment using ToF-SIMS is possible using the unique microfluidic reactor. Moreover, characteristic biofilm fatty acids fragments were observed in the hydrated biofilm grown in the microfluidic channel, illustrating the advantage of imaging biofilm in its native environment.« less

Testing of a Methane Cryogenic Heat Pipe with a Liquid Trap Turn-Off Feature for use on Space Interferometer Mission (SIM)

NASA Technical Reports Server (NTRS)

Cepeda-Rizo, Juan; Krylo, Robert; Fisher, Melanie; Bugby, David C.

2011-01-01

Camera cooling for SIM presents three thermal control challenges; stable operation at 163K (110 C), decontamination heating to +20 C, and a long span from the cameras to the radiator. A novel cryogenic cooling system based on a methane heat pipe meets these challenges. The SIM thermal team, with the help of heat pipe vendor ATK, designed and tested a complete, low temperature, cooling system. The system accommodates the two SIM cameras with a double-ended conduction bar, a single methane heat pipe, independent turn-off devices, and a flight-like radiator. The turn ]off devices consist of a liquid trap, for removing the methane from the pipe, and an electrical heater to raise the methane temperature above the critical point thus preventing two-phase operation. This is the first time a cryogenic heat pipe has been tested at JPL and is also the first heat pipe to incorporate the turn-off features. Operation at 163K with a methane heat pipe is an important new thermal control capability for the lab. In addition, the two turn-off technologies enhance the "bag of tricks" available to the JPL thermal community. The successful test program brings this heat pipe to a high level of technology readiness.

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

PubMed Central

Johnson, Grant E.; Gunaratne, K. Don Dasitha; Laskin, Julia

2014-01-01

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using conventional synthesis techniques. Coupling soft landing with in situ characterization using secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS) enables analysis of well-defined surfaces under clean vacuum conditions. The capabilities of three soft-landing instruments constructed in our laboratory are illustrated for the representative system of surface-bound organometallics prepared by soft landing of mass-selected ruthenium tris(bipyridine) dications, [Ru(bpy)3]2+ (bpy = bipyridine), onto carboxylic acid terminated self-assembled monolayer surfaces on gold (COOH-SAMs). In situ time-of-flight (TOF)-SIMS provides insight into the reactivity of the soft-landed ions. In addition, the kinetics of charge reduction, neutralization and desorption occurring on the COOH-SAM both during and after ion soft landing are studied using in situ Fourier transform ion cyclotron resonance (FT-ICR)-SIMS measurements. In situ IRRAS experiments provide insight into how the structure of organic ligands surrounding metal centers is perturbed through immobilization of organometallic ions on COOH-SAM surfaces by soft landing. Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure of well-defined species supported on surfaces. PMID:24961913

In Situ SIMS and IR Spectroscopy of Well-Defined Surfaces Prepared by Soft Landing of Mass-Selected Ions

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

Johnson, Grant E.; Gunaratne, Kalupathirannehelage Don D.; Laskin, Julia

2014-06-16

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using conventional synthesis techniques. Coupling soft landing with in situ characterization using secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS) enables analysis of well-defined surfaces under clean vacuum conditions. The capabilities of three soft-landing instruments constructed in our laboratory are illustrated for the representative system of surface-bound organometallics prepared by soft landing of mass-selected ruthenium tris(bipyridine) dications, [Ru(bpy)3]2+, onto carboxylic acid terminated self-assembled monolayer surfaces on gold (COOH-SAMs). In situ time-of-flight (TOF)-SIMS provides insight into the reactivitymore » of the soft-landed ions. In addition, the kinetics of charge reduction, neutralization and desorption occurring on the COOH-SAM both during and after ion soft landing are studied using in situ Fourier transform ion cyclotron resonance (FT-ICR)-SIMS measurements. In situ IRRAS experiments provide insight into how the structure of organic ligands surrounding metal centers is perturbed through immobilization of organometallic ions on COOH-SAM surfaces by soft landing. Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure of well-defined species supported on surfaces.« less

Multielement analysis of interplanetary dust particles using TOF-SIMS

NASA Technical Reports Server (NTRS)

Stephan, T.; Kloeck, W.; Jessberger, E. K.; Rulle, H.; Zehnpfenning, J.

1993-01-01

Sections of three stratospheric particles (U2015G1, W7029*A27, and L2005P9) were analyzed with TOF-SIMS (Time Of Flight-Secondary Ion Mass Spectrometry) continuing our efforts to investigate the element distribution in interplanetary dust particles (IDP's) with high lateral resolution (approximately 0.2 micron), to examine possible atmospheric contamination effects, and to further explore the abilities of this technique for element analysis of small samples. The samples, previously investigated with SXRF (synchrotron X-ray fluorescence analysis), are highly enriched in Br (Br/Fe: 59 x CI, 9.2 x CI, and 116 x CI, respectively). U2015G1 is the IDP with the by far highest Zn/Fe-ratio (81 x CI) ever reported in chondritic particles.

Design, Results, Evolution and Status of the ATLAS Simulation at Point1 Project

NASA Astrophysics Data System (ADS)

Ballestrero, S.; Batraneanu, S. M.; Brasolin, F.; Contescu, C.; Fazio, D.; Di Girolamo, A.; Lee, C. J.; Pozo Astigarraga, M. E.; Scannicchio, D. A.; Sedov, A.; Twomey, M. S.; Wang, F.; Zaytsev, A.

2015-12-01

During the LHC Long Shutdown 1 (LSI) period, that started in 2013, the Simulation at Point1 (Sim@P1) project takes advantage, in an opportunistic way, of the TDAQ (Trigger and Data Acquisition) HLT (High-Level Trigger) farm of the ATLAS experiment. This farm provides more than 1300 compute nodes, which are particularly suited for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2700 Virtual Machines (VMs) each with 8 CPU cores, for a total of up to 22000 parallel jobs. This contribution gives a review of the design, the results, and the evolution of the Sim@P1 project, operating a large scale OpenStack based virtualized platform deployed on top of the ATLAS TDAQ HLT farm computing resources. During LS1, Sim@P1 was one of the most productive ATLAS sites: it delivered more than 33 million CPU-hours and it generated more than 1.1 billion Monte Carlo events. The design aspects are presented: the virtualization platform exploited by Sim@P1 avoids interferences with TDAQ operations and it guarantees the security and the usability of the ATLAS private network. The cloud mechanism allows the separation of the needed support on both infrastructural (hardware, virtualization layer) and logical (Grid site support) levels. This paper focuses on the operational aspects of such a large system during the upcoming LHC Run 2 period: simple, reliable, and efficient tools are needed to quickly switch from Sim@P1 to TDAQ mode and back, to exploit the resources when they are not used for the data acquisition, even for short periods. The evolution of the central OpenStack infrastructure is described, as it was upgraded from Folsom to the Icehouse release, including the scalability issues addressed.

High Powered Rocketry: Design, Construction, and Launching Experience and Analysis

ERIC Educational Resources Information Center

Paulson, Pryce; Curtis, Jarret; Bartel, Evan; Cyr, Waycen Owens; Lamsal, Chiranjivi

2018-01-01

In this study, the nuts and bolts of designing and building a high powered rocket have been presented. A computer simulation program called RockSim was used to design the rocket. Simulation results are consistent with time variations of altitude, velocity, and acceleration obtained in the actual flight. The actual drag coefficient was determined…

ChromBiSim: Interactive chromatin biclustering using a simple approach.

PubMed

Noureen, Nighat; Zohaib, Hafiz Muhammad; Qadir, Muhammad Abdul; Fazal, Sahar

2017-10-01

Combinatorial patterns of histone modifications sketch the epigenomic locale. Specific positions of these modifications in the genome are marked by the presence of such signals. Various methods highlight such patterns on global scale hence missing the local patterns which are the actual hidden combinatorics. We present ChromBiSim, an interactive tool for mining subsets of modifications from epigenomic profiles. ChromBiSim efficiently extracts biclusters with their genomic locations. It is the very first user interface based and multiple cell type handling tool for decoding the interplay of subsets of histone modifications combinations along their genomic locations. It displays the results in the forms of charts and heat maps in accordance with saving them in files which could be used for post analysis. ChromBiSim tested on multiple cell types produced in total 803 combinatorial patterns. It could be used to highlight variations among diseased versus normal cell types of any species. ChromBiSim is available at (http://sourceforge.net/projects/chrombisim) in C-sharp and python languages. Copyright © 2017 Elsevier Inc. All rights reserved.

The Sim-SEQ Project: Comparison of Selected Flow Models for the S-3 Site

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

Mukhopadhyay, Sumit; Doughty, Christine A.; Bacon, Diana H.

Sim-SEQ is an international initiative on model comparison for geologic carbon sequestration, with an objective to understand and, if possible, quantify model uncertainties. Model comparison efforts in Sim-SEQ are at present focusing on one specific field test site, hereafter referred to as the Sim-SEQ Study site (or S-3 site). Within Sim-SEQ, different modeling teams are developing conceptual models of CO2 injection at the S-3 site. In this paper, we select five flow models of the S-3 site and provide a qualitative comparison of their attributes and predictions. These models are based on five different simulators or modeling approaches: TOUGH2/EOS7C, STOMP-CO2e,more » MoReS, TOUGH2-MP/ECO2N, and VESA. In addition to model-to-model comparison, we perform a limited model-to-data comparison, and illustrate how model choices impact model predictions. We conclude the paper by making recommendations for model refinement that are likely to result in less uncertainty in model predictions.« less

Characterization of the surface organization of nanostructured hybrid organic-inorganic materials by time-of-flight secondary ion mass spectrometry

PubMed

Cerveau; Corriu; Dabosi; Fischmeister-Lepeytre; Combarieu

1999-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used to analyse the surface composition of organic-inorganic hybrid solids obtained by a sol-gel process. Gels of type O(1.5)Si-R-SiO(1. 5), obtained from bis-silylated precursors (R'O)(3)-R-Si(OR')(3) (R' = Me, Et and R = (-CH(2))(n)-, n = 1, 2, 6, 10, 12;--CH=CH-; (-CH(2))(3)NH(CH(2))(3)-; 1, 1'-ferrocenyl; (CH(2))(n)-Ph-(CH(2))(n)- with Ph = 1,4-phenylene and n = 0, 1, 2; Ph = 1,3,5-phenyl and n = 0) were analysed. The results were highly dependent on the nature of the organic group. When the organic group was small or 'rigid', the main peaks detected corresponded to SiOH and SiOR' residual groups. Fragment ions from the organic group were poorly detected in this case. When the organic group was larger and more 'flexible', characteristic mass fragment ions were detected at higher relative intensities, indicative of a different organization of the organic units in the solid. TOF-SIMS clearly showed the differences between the xerogels derived from mono- and bis-silylated organic precursors : the organic group is present at the surface of mono-silylated xerogels, whereas for bis-silylated ones, the organization is dependent on the length and the flexibility of the organic units. These TOF-SIMS results are in agreement with other features already reported. Copyright 1999 John Wiley & Sons, Ltd.

Fusing literature and full network data improves disease similarity computation.

PubMed

Li, Ping; Nie, Yaling; Yu, Jingkai

2016-08-30

Identifying relatedness among diseases could help deepen understanding for the underlying pathogenic mechanisms of diseases, and facilitate drug repositioning projects. A number of methods for computing disease similarity had been developed; however, none of them were designed to utilize information of the entire protein interaction network, using instead only those interactions involving disease causing genes. Most of previously published methods required gene-disease association data, unfortunately, many diseases still have very few or no associated genes, which impeded broad adoption of those methods. In this study, we propose a new method (MedNetSim) for computing disease similarity by integrating medical literature and protein interaction network. MedNetSim consists of a network-based method (NetSim), which employs the entire protein interaction network, and a MEDLINE-based method (MedSim), which computes disease similarity by mining the biomedical literature. Among function-based methods, NetSim achieved the best performance. Its average AUC (area under the receiver operating characteristic curve) reached 95.2 %. MedSim, whose performance was even comparable to some function-based methods, acquired the highest average AUC in all semantic-based methods. Integration of MedSim and NetSim (MedNetSim) further improved the average AUC to 96.4 %. We further studied the effectiveness of different data sources. It was found that quality of protein interaction data was more important than its volume. On the contrary, higher volume of gene-disease association data was more beneficial, even with a lower reliability. Utilizing higher volume of disease-related gene data further improved the average AUC of MedNetSim and NetSim to 97.5 % and 96.7 %, respectively. Integrating biomedical literature and protein interaction network can be an effective way to compute disease similarity. Lacking sufficient disease-related gene data, literature-based methods such as MedSim can be a great addition to function-based algorithms. It may be beneficial to steer more resources torward studying gene-disease associations and improving the quality of protein interaction data. Disease similarities can be computed using the proposed methods at http:// www.digintelli.com:8000/ .

An orientation analysis method for protein immobilized on quantum dot particles

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Inoue, Masae

2009-11-01

The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga +) and a cluster ion source (Au 3+) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga + and Au 3+, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

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

Zhang, Jiandong; Neeway, James J.; Zhang, Yanyan

Glass particles with dimensions typically ranging from tens to hundreds of microns are often used in glass corrosion research in order to accelerate testing. Two-dimensional and three-dimensional nanoscale imaging techniques are badly needed to characterize the alteration layers at the surfaces of these corroded glass particles. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) can provide a lateral resolution as low as ~100 nm, and, compared to other imaging techniques, is sensitive to elements lighter than carbon. Here, we used ToF-SIMS to characterize the alteration layers of corroded international simple glass (ISG) particles. At most particle surfaces, we observed inhomogeneous or nomore » alteration layers, indicating that the thickness of the alterations layers may be too thin to be observable by ToF-SIMS imaging. Relatively thick (e.g., 1–10 µm) alteration layers were inhomogeneously distributed at a small portion of surfaces.Interestingly, some large-size (tens of microns) glass particles were fully altered. Above observations suggest that weak attachment and the defects on ISG particle surfaces play an important role in ISG glass corrosion.« less

Multi-spectroscopic analysis of cholesterol gallstone using TOF-SIMS, FTIR and UV-Vis spectroscopy

NASA Astrophysics Data System (ADS)

Jaswal, Brij Bir S.; Kumar, Vinay; Swart, H. C.; Sharma, Jitendra; Rai, Pradeep K.; Singh, Vivek K.

2015-10-01

For the first time, spatial distribution of major and trace elements has been studied in cholesterol gallstones using time-of-flight secondary mass ion mass spectrometry (TOF-SIMS). The TOF-SIMS has been used to study the elemental constituents of the center and surface parts of the gallstone sample. We have classified the gallstone sample using Fourier transform spectroscopy. The detected elements in cholesterol gallstone sample were carbon (C), hydrogen (H), calcium (Ca), sodium (Na), potassium (K), strontium (Sr), copper (Cu), iron (Fe), chromium (Cr), mercury (Hg) and lead (Pb). The detected molecules in the cholesterol gallstone were CH3 +, CO3 +, CaCO3 + and C3H+. Our results revealed that the contents of these elements in cholesterol gallstone were higher in the center part than that in the surface part. In the present paper, we have also presented the UV-Vis spectroscopic studies of the center and surface parts of the gallstone sample which indicated the presence of a higher content of cholesterol in the surface part and bilirubin in the center part.

3D ToF-SIMS Analysis of Peptide Incorporation into MALDI Matrix Crystals with Sub-micrometer Resolution.

PubMed

Körsgen, Martin; Pelster, Andreas; Dreisewerd, Klaus; Arlinghaus, Heinrich F

2016-02-01

The analytical sensitivity in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is largely affected by the specific analyte-matrix interaction, in particular by the possible incorporation of the analytes into crystalline MALDI matrices. Here we used time-of-flight secondary ion mass spectrometry (ToF-SIMS) to visualize the incorporation of three peptides with different hydrophobicities, bradykinin, Substance P, and vasopressin, into two classic MALDI matrices, 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (HCCA). For depth profiling, an Ar cluster ion beam was used to gradually sputter through the matrix crystals without causing significant degradation of matrix or biomolecules. A pulsed Bi3 ion cluster beam was used to image the lateral analyte distribution in the center of the sputter crater. Using this dual beam technique, the 3D distribution of the analytes and spatial segregation effects within the matrix crystals were imaged with sub-μm resolution. The technique could in the future enable matrix-enhanced (ME)-ToF-SIMS imaging of peptides in tissue slices at ultra-high resolution. Graphical Abstract ᅟ.

Investigation of anodic TiO2 nanotube composition with high spatial resolution AES and ToF SIMS

NASA Astrophysics Data System (ADS)

Dronov, Alexey; Gavrilin, Ilya; Kirilenko, Elena; Dronova, Daria; Gavrilov, Sergey

2018-03-01

High resolution Scanning Auger Electron Spectroscopy (AES) and Time-of-Flight Secondary Ion Mass-Spectrometry (ToF SIMS) were used to investigate structure and elemental composition variation of both across an array of TiO2 nanotubes (NTs) and single tube of an array. The TiO2 NT array was grown by anodic oxidation of Ti foil in fluorine-containing ethylene glycol electrolyte. It was found that the studied anodic TiO2 nanotubes have a layered structure with rather sharp interfaces. The differences in AES depth profiling results of a single tube with the focused primary electron beam (point analysis) and over an area of 75 μm in diameter of a nanotube array with the defocused primary electron beam are discussed. Depth profiling by ToF SIMS was carried out over approximately the same size of a nanotube array to determine possible ionic fragments in the structure. The analysis results show that the combination of both mentioned methods is useful for a detailed analysis of nanostructures with complex morphology and multi-layered nature.

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

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

Komorek, Rachel; Wei, Wenchao; Yu, Xiaofei

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) and their roles in environmental microbiology. This study outlines a method to cultivate biofilm attachment to the System for Analysis at the Liquid Vacuum Interface (SALVI) and achieve in situ chemical mapping of a living biofilm by time-of-flight secondary ion mass spectrometry (ToF-SIMS). This is done through the culturing of bacteria both outside and within the SALVI channel with our specialized setup, as well as through optical imaging techniques to detect the biofilm presence and thickness before ToF-SIMS analysis. Our results show themore » characteristic peaks of the Shewanella biofilm in its natural hydrated state, highlighting upon its localized water cluster environment, as well as EPS fragments, which are drastically different from the same biofilm’s dehydrated state. These results demonstrate the breakthrough capability of SALVI that allows for in situ biofilm imaging with a vacuum-based chemical imaging instrument.« less

Rapid discrimination of the causal agents of urinary tract infection using ToF-SIMS with chemometric cluster analysis

NASA Astrophysics Data System (ADS)

Fletcher, John S.; Henderson, Alexander; Jarvis, Roger M.; Lockyer, Nicholas P.; Vickerman, John C.; Goodacre, Royston

2006-07-01

Advances in time of flight secondary ion mass spectrometry (ToF-SIMS) have enabled this technique to become a powerful tool for the analysis of biological samples. Such samples are often very complex and as a result full interpretation of the acquired data can be extremely difficult. To simplify the interpretation of these information rich data, the use of chemometric techniques is becoming widespread in the ToF-SIMS community. Here we discuss the application of principal components-discriminant function analysis (PC-DFA) to the separation and classification of a number of bacterial samples that are known to be major causal agents of urinary tract infection. A large data set has been generated using three biological replicates of each isolate and three machine replicates were acquired from each biological replicate. Ordination plots generated using the PC-DFA are presented demonstrating strain level discrimination of the bacteria. The results are discussed in terms of biological differences between certain species and with reference to FT-IR, Raman spectroscopy and pyrolysis mass spectrometric studies of similar samples.

3D ToF-SIMS Analysis of Peptide Incorporation into MALDI Matrix Crystals with Sub-micrometer Resolution

NASA Astrophysics Data System (ADS)

Körsgen, Martin; Pelster, Andreas; Dreisewerd, Klaus; Arlinghaus, Heinrich F.

2016-02-01

The analytical sensitivity in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is largely affected by the specific analyte-matrix interaction, in particular by the possible incorporation of the analytes into crystalline MALDI matrices. Here we used time-of-flight secondary ion mass spectrometry (ToF-SIMS) to visualize the incorporation of three peptides with different hydrophobicities, bradykinin, Substance P, and vasopressin, into two classic MALDI matrices, 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (HCCA). For depth profiling, an Ar cluster ion beam was used to gradually sputter through the matrix crystals without causing significant degradation of matrix or biomolecules. A pulsed Bi3 ion cluster beam was used to image the lateral analyte distribution in the center of the sputter crater. Using this dual beam technique, the 3D distribution of the analytes and spatial segregation effects within the matrix crystals were imaged with sub-μm resolution. The technique could in the future enable matrix-enhanced (ME)-ToF-SIMS imaging of peptides in tissue slices at ultra-high resolution.

Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

NASA Astrophysics Data System (ADS)

Kuo, Yi-Jie; Huang, Yung-Kai; Chou, Hsiu-Chu; Pai, Man-Hui; Lee, Ai-Wei; Mai, Fu-Der; Chang, Hung-Ming

2015-08-01

Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions.

Ga + TOF-SIMS lineshape analysis for resolution enhancement of MALDI MS spectra of a peptide mixture

NASA Astrophysics Data System (ADS)

Malyarenko, D. I.; Chen, H.; Wilkerson, A. L.; Tracy, E. R.; Cooke, W. E.; Manos, D. M.; Sasinowski, M.; Semmes, O. J.

2004-06-01

The use of mass spectrometry to obtain molecular profiles indicative of alteration of concentrations of peptides in body fluids is currently the subject of intense investigation. For surface-based time-of-flight mass spectrometry the reliability and specificity of such profiling methods depend both on the resolution of the measuring instrument and on the preparation of samples. The present work is a part of a program to use Ga + beam TOF-SIMS alone, and as an adjunct to MALDI, in the development of reliable protein and peptide markers for diseases. Here, we describe techniques to prepare samples of relatively high-mass peptides, which serve as calibration standards and proxies for biomarkers. These are: Arg8-vasopressin, human angiotensin II, and somatostatin. Their TOF-SIMS spectra show repeatable characteristic features, with mass resolution exceeding 2000, including parent peaks and chemical adducts. The lineshape analysis for high-resolution parent peaks is shown to be useful for filter construction and deconvolution of inferior resolution SELDI-TOF spectra of calibration peptide mixture.

J. Marion Sims and the Vesicovaginal Fistula: Historical Understanding, Medical Ethics, and Modern Political Sensibilities.

PubMed

Wall, L Lewis

To review the historical background surrounding the early work of Dr. J. Marion Sims, who developed the first consistently successful surgical technique for the repair of obstetric vesicovaginal fistulas by operating on a group of young, enslaved, African American women who had this condition between 1846 and 1849. Review of primary source documents on Sims and his operations, early 19th century clinical literature on the treatment of vesicovaginal fistula, the introduction of ether and chloroform anesthesia into surgical practice, and the literature on the early 19th century medical ethics pertaining to surgical innovation. The goals are to understand Sims's operations within the clinical context of the 1840s and to avoid the problems of "presentism," in which beliefs, attitudes, and practices of the 21st century are anachronistically projected backward into the early 19th century. The object is to judge Sims within the context of his time, not to hold him accountable to standards of practice which were not developed until a century after his death. A narrative of what Sims did is presented within the context of the therapeutic options available to those with fistula in the early 19th century. Review of the available material demonstrates that Sims' first fistula operations were legal, that they were carried out with express therapeutic intent for the purpose of repairing these women's injuries, that they conformed to the ethical requirements of his time, and that they were performed with the patients' knowledge, cooperation, assent, and assistance.

A Re-Engineered Software Interface and Workflow for the Open-Source SimVascular Cardiovascular Modeling Package.

PubMed

Lan, Hongzhi; Updegrove, Adam; Wilson, Nathan M; Maher, Gabriel D; Shadden, Shawn C; Marsden, Alison L

2018-02-01

Patient-specific simulation plays an important role in cardiovascular disease research, diagnosis, surgical planning and medical device design, as well as education in cardiovascular biomechanics. simvascular is an open-source software package encompassing an entire cardiovascular modeling and simulation pipeline from image segmentation, three-dimensional (3D) solid modeling, and mesh generation, to patient-specific simulation and analysis. SimVascular is widely used for cardiovascular basic science and clinical research as well as education, following increased adoption by users and development of a GATEWAY web portal to facilitate educational access. Initial efforts of the project focused on replacing commercial packages with open-source alternatives and adding increased functionality for multiscale modeling, fluid-structure interaction (FSI), and solid modeling operations. In this paper, we introduce a major SimVascular (SV) release that includes a new graphical user interface (GUI) designed to improve user experience. Additional improvements include enhanced data/project management, interactive tools to facilitate user interaction, new boundary condition (BC) functionality, plug-in mechanism to increase modularity, a new 3D segmentation tool, and new computer-aided design (CAD)-based solid modeling capabilities. Here, we focus on major changes to the software platform and outline features added in this new release. We also briefly describe our recent experiences using SimVascular in the classroom for bioengineering education.

Development and Validation of a Monte Carlo Simulation Tool for Multi-Pinhole SPECT

PubMed Central

Mok, Greta S. P.; Du, Yong; Wang, Yuchuan; Frey, Eric C.; Tsui, Benjamin M. W.

2011-01-01

Purpose In this work, we developed and validated a Monte Carlo simulation (MCS) tool for investigation and evaluation of multi-pinhole (MPH) SPECT imaging. Procedures This tool was based on a combination of the SimSET and MCNP codes. Photon attenuation and scatter in the object, as well as penetration and scatter through the collimator detector, are modeled in this tool. It allows accurate and efficient simulation of MPH SPECT with focused pinhole apertures and user-specified photon energy, aperture material, and imaging geometry. The MCS method was validated by comparing the point response function (PRF), detection efficiency (DE), and image profiles obtained from point sources and phantom experiments. A prototype single-pinhole collimator and focused four- and five-pinhole collimators fitted on a small animal imager were used for the experimental validations. We have also compared computational speed among various simulation tools for MPH SPECT, including SimSET-MCNP, MCNP, SimSET-GATE, and GATE for simulating projections of a hot sphere phantom. Results We found good agreement between the MCS and experimental results for PRF, DE, and image profiles, indicating the validity of the simulation method. The relative computational speeds for SimSET-MCNP, MCNP, SimSET-GATE, and GATE are 1: 2.73: 3.54: 7.34, respectively, for 120-view simulations. We also demonstrated the application of this MCS tool in small animal imaging by generating a set of low-noise MPH projection data of a 3D digital mouse whole body phantom. Conclusions The new method is useful for studying MPH collimator designs, data acquisition protocols, image reconstructions, and compensation techniques. It also has great potential to be applied for modeling the collimator-detector response with penetration and scatter effects for MPH in the quantitative reconstruction method. PMID:19779896

Control of food intake and energy expenditure by Nos1 neurons of the paraventricular hypothalamus.

PubMed

Sutton, Amy K; Pei, Hongjuan; Burnett, Korri H; Myers, Martin G; Rhodes, Christopher J; Olson, David P

2014-11-12

The paraventricular nucleus of the hypothalamus (PVH) contains a heterogeneous cluster of Sim1-expressing cell types that comprise a major autonomic output nucleus and play critical roles in the control of food intake and energy homeostasis. The roles of specific PVH neuronal subtypes in energy balance have yet to be defined, however. The PVH contains nitric oxide synthase-1 (Nos1)-expressing (Nos1(PVH)) neurons of unknown function; these represent a subset of the larger population of Sim1-expressing PVH (Sim1(PVH)) neurons. To determine the role of Nos1(PVH) neurons in energy balance, we used Cre-dependent viral vectors to both map their efferent projections and test their functional output in mice. Here we show that Nos1(PVH) neurons project to hindbrain and spinal cord regions important for food intake and energy expenditure control. Moreover, pharmacogenetic activation of Nos1(PVH) neurons suppresses feeding to a similar extent as Sim1(PVH) neurons, and increases energy expenditure and activity. Furthermore, we found that oxytocin-expressing PVH neurons (OXT(PVH)) are a subset of Nos1(PVH) neurons. OXT(PVH) cells project to preganglionic, sympathetic neurons in the thoracic spinal cord and increase energy expenditure upon activation, though not to the same extent as Nos1(PVH) neurons; their activation fails to alter feeding, however. Thus, Nos1(PVH) neurons promote negative energy balance through changes in feeding and energy expenditure, whereas OXT(PVH) neurons regulate energy expenditure alone, suggesting a crucial role for non-OXT Nos1(PVH) neurons in feeding regulation. Copyright © 2014 the authors 0270-6474/14/3415306-13$15.00/0.

Co-clustering directed graphs to discover asymmetries and directional communities

PubMed Central

Rohe, Karl; Qin, Tai; Yu, Bin

2016-01-01

In directed graphs, relationships are asymmetric and these asymmetries contain essential structural information about the graph. Directed relationships lead to a new type of clustering that is not feasible in undirected graphs. We propose a spectral co-clustering algorithm called di-sim for asymmetry discovery and directional clustering. A Stochastic co-Blockmodel is introduced to show favorable properties of di-sim. To account for the sparse and highly heterogeneous nature of directed networks, di-sim uses the regularized graph Laplacian and projects the rows of the eigenvector matrix onto the sphere. A nodewise asymmetry score and di-sim are used to analyze the clustering asymmetries in the networks of Enron emails, political blogs, and the Caenorhabditis elegans chemical connectome. In each example, a subset of nodes have clustering asymmetries; these nodes send edges to one cluster, but receive edges from another cluster. Such nodes yield insightful information (e.g., communication bottlenecks) about directed networks, but are missed if the analysis ignores edge direction. PMID:27791058

Co-clustering directed graphs to discover asymmetries and directional communities.

PubMed

Rohe, Karl; Qin, Tai; Yu, Bin

2016-10-21

In directed graphs, relationships are asymmetric and these asymmetries contain essential structural information about the graph. Directed relationships lead to a new type of clustering that is not feasible in undirected graphs. We propose a spectral co-clustering algorithm called di-sim for asymmetry discovery and directional clustering. A Stochastic co-Blockmodel is introduced to show favorable properties of di-sim To account for the sparse and highly heterogeneous nature of directed networks, di-sim uses the regularized graph Laplacian and projects the rows of the eigenvector matrix onto the sphere. A nodewise asymmetry score and di-sim are used to analyze the clustering asymmetries in the networks of Enron emails, political blogs, and the Caenorhabditis elegans chemical connectome. In each example, a subset of nodes have clustering asymmetries; these nodes send edges to one cluster, but receive edges from another cluster. Such nodes yield insightful information (e.g., communication bottlenecks) about directed networks, but are missed if the analysis ignores edge direction.

Bayesian Integration and Classification of Composition C-4 Plastic Explosives Based on Time-of-Flight-Secondary Ion Mass Spectrometry and Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

PubMed

Mahoney, Christine M; Kelly, Ryan T; Alexander, Liz; Newburn, Matt; Bader, Sydney; Ewing, Robert G; Fahey, Albert J; Atkinson, David A; Beagley, Nathaniel

2016-04-05

Time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) were used for characterization and identification of unique signatures from a series of 18 Composition C-4 plastic explosives. The samples were obtained from various commercial and military sources around the country. Positive and negative ion TOF-SIMS data were acquired directly from the C-4 residue on Si surfaces, where the positive ion mass spectra obtained were consistent with the major composition of organic additives, and the negative ion mass spectra were more consistent with explosive content in the C-4 samples. Each series of mass spectra was subjected to partial least squares-discriminant analysis (PLS-DA), a multivariate statistical analysis approach which serves to first find the areas of maximum variance within different classes of C-4 and subsequently to classify unknown samples based on correlations between the unknown data set and the original data set (often referred to as a training data set). This method was able to successfully classify test samples of C-4, though with a limited degree of certainty. The classification accuracy of the method was further improved by integrating the positive and negative ion data using a Bayesian approach. The TOF-SIMS data was combined with a second analytical method, LA-ICPMS, which was used to analyze elemental signatures in the C-4. The integrated data were able to classify test samples with a high degree of certainty. Results indicate that this Bayesian integrated approach constitutes a robust classification method that should be employable even in dirty samples collected in the field.

SimBA: simulation algorithm to fit extant-population distributions.

PubMed

Parida, Laxmi; Haiminen, Niina

2015-03-14

Simulation of populations with specified characteristics such as allele frequencies, linkage disequilibrium etc., is an integral component of many studies, including in-silico breeding optimization. Since the accuracy and sensitivity of population simulation is critical to the quality of the output of the applications that use them, accurate algorithms are required to provide a strong foundation to the methods in these studies. In this paper we present SimBA (Simulation using Best-fit Algorithm) a non-generative approach, based on a combination of stochastic techniques and discrete methods. We optimize a hill climbing algorithm and extend the framework to include multiple subpopulation structures. Additionally, we show that SimBA is very sensitive to the input specifications, i.e., very similar but distinct input characteristics result in distinct outputs with high fidelity to the specified distributions. This property of the simulation is not explicitly modeled or studied by previous methods. We show that SimBA outperforms the existing population simulation methods, both in terms of accuracy as well as time-efficiency. Not only does it construct populations that meet the input specifications more stringently than other published methods, SimBA is also easy to use. It does not require explicit parameter adaptations or calibrations. Also, it can work with input specified as distributions, without an exemplar matrix or population as required by some methods. SimBA is available at http://researcher.ibm.com/project/5669 .

Contaminant Interferences with SIMS Analyses of Microparticle Impactor Residues on LDEF Surfaces

NASA Technical Reports Server (NTRS)

Simon, C. G.; Batchelor, D.; Griffis, D. P.; Hunter, J. L.; Misra, V.; Ricks, D. A.; Wortman, J. J.

1992-01-01

Elemental analyses of impactor residues on high purity surface exposed to the low earth orbit (LEO) environment for 5.8 years on Long Duration Exposure Facility (LDEF) has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post-, and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets.

Analysis of antioxidants in insulation cladding of copper wire: a comparison of different mass spectrometric techniques (ESI-IT, MALDI-RTOF and RTOF-SIMS).

PubMed

Schnöller, Johannes; Pittenauer, Ernst; Hutter, Herbert; Allmaier, Günter

2009-12-01

Commercial copper wire and its polymer insulation cladding was investigated for the presence of three synthetic antioxidants (ADK STAB AO412S, Irganox 1010 and Irganox MD 1024) by three different mass spectrometric techniques including electrospray ionization-ion trap-mass spectrometry (ESI-IT-MS), matrix-assisted laser desorption/ionization reflectron time-of-flight (TOF) mass spectrometry (MALDI-RTOF-MS) and reflectron TOF secondary ion mass spectrometry (RTOF-SIMS). The samples were analyzed either directly without any treatment (RTOF-SIMS) or after a simple liquid/liquid extraction step (ESI-IT-MS, MALDI-RTOF-MS and RTOF-SIMS). Direct analysis of the copper wire itself or of the insulation cladding by RTOF-SIMS allowed the detection of at least two of the three antioxidants but at rather low sensitivity as molecular radical cations and with fairly strong fragmentation (due to the highly energetic ion beam of the primary ion gun). ESI-IT- and MALDI-RTOF-MS-generated abundant protonated and/or cationized molecules (ammoniated or sodiated) from the liquid/liquid extract. Only ESI-IT-MS allowed simultaneous detection of all three analytes in the extract of insulation claddings. The latter two so-called 'soft' desorption/ionization techniques exhibited intense fragmentation only by applying low-energy collision-induced dissociation (CID) tandem MS on a multistage ion trap-instrument and high-energy CID on a tandem TOF-instrument (TOF/RTOF), respectively. Strong differences in the fragmentation behavior of the three analytes could be observed between the different CID spectra obtained from either the IT-instrument (collision energy in the very low eV range) or the TOF/RTOF-instrument (collision energy 20 keV), but both delivered important structural information. Copyright 2009 John Wiley & Sons, Ltd.

Qualitative analysis of precipitate formation on the surface and in the tubules of dentin irrigated with sodium hypochlorite and a final rinse of chlorhexidine or QMiX.

PubMed

Kolosowski, Kamil P; Sodhi, Rana N S; Kishen, Anil; Basrani, Bettina R

2014-12-01

Interaction of sodium hypochlorite (NaOCl) mixed with chlorhexidine (CHX) produces a brown precipitate containing para-chloroaniline (PCA). When QMiX is mixed with NaOCl, no precipitate forms, but color change occurs. The aim of this study was to qualitatively assess the formation of precipitate and PCA on the surface and in the tubules of dentin irrigated with NaOCl, followed either by EDTA, NaOCl, and CHX or by saline and QMiX by using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Dentin blocks were obtained from human maxillary molars, embedded in resin, and cross-sectioned to expose dentin. Specimens in group 1 were immersed in 2.5% NaOCl, followed by 17% EDTA, 2.5% NaOCl, and 2% CHX. Specimens in group 2 were immersed in 2.5% NaOCl, followed by saline and QMiX. The dentin surfaces were subjected to TOF-SIMS spectra analysis. Longitudinal sections of dentin blocks were then exposed and subjected to TOF-SIMS analysis. All samples and analysis were performed in triplicate for confirmation. TOF-SIMS analysis of group 1 revealed an irregular precipitate, containing PCA and CHX breakdown products, on the dentin surfaces, occluding and extending into the tubules. In TOF-SIMS analysis of group 2, no precipitates, including PCA, were detected on the dentin surface or in the tubules. Within the limitations of this study, precipitate containing PCA was formed in the tubules of dentin irrigated with NaOCl followed by CHX. No precipitates or PCA were detected in the tubules of dentin irrigated with NaOCl followed by saline and QMiX. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Molecular imaging of alkaloids in khat (Catha edulis) leaves with MeV-SIMS

NASA Astrophysics Data System (ADS)

Jenčič, Boštjan; Jeromel, Luka; Ogrinc Potočnik, Nina; Vogel-Mikuš, Katarina; Vavpetič, Primož; Rupnik, Zdravko; Bučar, Klemen; Vencelj, Matjaž; Kelemen, Mitja; Matsuo, Jiro; Kusakari, Masakazu; Siketić, Zdravko; Al-Jalali, Muhammad A.; Shaltout, Abdallah; Pelicon, Primož

2017-08-01

Imaging Mass Spectroscopy (IMS) is a unique research tool providing localization and identification of a wide range of biomolecules as essential data to understand biochemical processes in living organisms. Secondary Ion Mass Spectrometry with high-energy heavy ions (MeV-SIMS) is emerging as a promising IMS technique for chemical imaging of biological tissue. We measured the molecular mass spatial distributions in leaves of khat (Catha edulis). Khat is a natural drug plant, native to eastern Africa and the Arabian Peninsula. In these countries, fresh leaves are being chewed by significant part of population. It was reported that 80% of the adult population in Yemen chew the khat leaves. The main stimulating effects of khat are induced by a monoamine alkaloid called cathinone. During leaf ageing, cathinone is further metabolised to cathine and norephedrine. Earlier studies identified the alkaloids in khat, however little is known on their spatial distribution, reflecting the biosynthesis and accumulation in the tissue. Chemical mapping of alkaloids on cross-sections of khat leaves by MeV-SIMS was done at JSI by a pulsed 5.8 MeV 35Cl6+ beam, focused to a diameter of 15 μm, using a linear time-of-flight (TOF) spectrometer with a mass resolution of 500. In addition, measurements of MeV-SIMS mass spectra were performed at Kyoto University by a continuous broad beam of 6 MeV 63Cu4+ ions at an orthogonal TOF spectrometer with a high mass resolution of 11,000. Sections of leaves were analysed and mass spectra obtained at both MeV-SIMS setups were compared. Tissue-level distributions of detected alkaloids are presented and discussed.

Lakeside: Merging Urban Design with Scientific Analysis

ScienceCinema

Guzowski, Leah; Catlett, Charlie; Woodbury, Ed

2018-01-16

Researchers at the U.S. Department of Energy's Argonne National Laboratory and the University of Chicago are developing tools that merge urban design with scientific analysis to improve the decision-making process associated with large-scale urban developments. One such tool, called LakeSim, has been prototyped with an initial focus on consumer-driven energy and transportation demand, through a partnership with the Chicago-based architectural and engineering design firm Skidmore, Owings & Merrill, Clean Energy Trust and developer McCaffery Interests. LakeSim began with the need to answer practical questions about urban design and planning, requiring a better understanding about the long-term impact of design decisions on energy and transportation demand for a 600-acre development project on Chicago's South Side - the Chicago Lakeside Development project.

Sims Prototype System 2 test results: Engineering analysis

NASA Technical Reports Server (NTRS)

1978-01-01

The testing, problems encountered, and the results and conclusions obtained from tests performed on the IBM Prototype System, 2, solar hot water system, at the Marshall Space Flight Center Solar Test Facility was described. System 2 is a liquid, non draining solar energy system for supplying domestic hot water to single residences. The system consists of collectors, storage tank, heat exchanger, pumps and associated plumbing and controls.

Advanced Crash Avoidance Technologies (ACAT) Program - Final Report of the Volvo-Ford-UMTRI Project: Safety Impact Methodology for Lane Departure Warning - Method Development and Estimation of Benefits

DOT National Transportation Integrated Search

2010-10-01

The Volvo-Ford-UMTRI project: Safety Impact Methodology (SIM) for Lane Departure Warning is part of the U.S. Department of Transportation's Advanced Crash Avoidance Technologies (ACAT) program. The project developed a basic analytical framework for e...

Brassboard Astrometric Beam Combiner (ABC) Development for the Space Interferometry Mission (SIM)

NASA Technical Reports Server (NTRS)

Jeganathan, Muthu; Kuan, Gary; Rud, Mike; Lin, Sean; Sutherland, Kristen; Moore, James; An, Xin

2008-01-01

The Astrometric Beam Combiner (ABC) is a critical element of the Space Interferometry Mission (SIM) that performs three key functions: coherently combine starlight from two siderostats; individually detect starlight for angle tracking; and disperse and detect the interferometric fringes. In addition, the ABC contains: a stimulus, cornercubes and shutters for in-orbit calibration; several tip/tilt mirror mechanisms for in-orbit alignment; and internal metrology beam launcher for pathlength monitoring. The detailed design of the brassboard ABC (which has the form, fit and function of the flight unit) is complete, procurement of long-lead items is underway, and assembly and testing is expected to be completed in Spring 2009. In this paper, we present the key requirements for the ABC, details of the completed optical and mechanical design as well as plans for assembly and alignment.

Distribution of coniferin in freeze-fixed stem of Ginkgo biloba L. by cryo-TOF-SIMS/SEM

NASA Astrophysics Data System (ADS)

Aoki, Dan; Hanaya, Yuto; Akita, Takuya; Matsushita, Yasuyuki; Yoshida, Masato; Kuroda, Katsushi; Yagami, Sachie; Takama, Ruka; Fukushima, Kazuhiko

2016-08-01

To clarify the role of coniferin in planta, semi-quantitative cellular distribution of coniferin in quick-frozen Ginkgo biloba L. (ginkgo) was visualized by cryo time-of-flight secondary ion mass spectrometry and scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. The amount and rough distribution of coniferin were confirmed through quantitative chromatography measurement using serial tangential sections of the freeze-fixed ginkgo stem. The lignification stage of the sample was estimated using microscopic observations. Coniferin distribution visualized at the transverse and radial surfaces of freeze-fixed ginkgo stem suggested that coniferin is stored in the vacuoles, and showed good agreement with the assimilation timing of coniferin to lignin in differentiating xylem. Consequently, it is suggested that coniferin is stored in the tracheid cells of differentiating xylem and is a lignin precursor.

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

Metal-assisted SIMS and cluster ion bombardment for ion yield enhancement

NASA Astrophysics Data System (ADS)

Heile, A.; Lipinsky, D.; Wehbe, N.; Delcorte, A.; Bertrand, P.; Felten, A.; Houssiau, L.; Pireaux, J.-J.; De Mondt, R.; Van Vaeck, L.; Arlinghaus, H. F.

2008-12-01

In addition to structural information, a detailed knowledge of the local chemical environment proves to be of ever greater importance, for example for the development of new types of materials as well as for specific modifications of surfaces and interfaces in multiple fields of materials science or various biomedical and chemical applications. But the ongoing miniaturization and therefore reduction of the amount of material available for analysis constitute a challenge to the detection limits of analytical methods. In the case of time-of-flight secondary ion mass spectrometry (TOF-SIMS), several methods of secondary ion yield enhancement have been proposed. This paper focuses on the investigation of the effects of two of these methods, metal-assisted SIMS and polyatomic primary ion bombardment. For this purpose, thicker layers of polystyrene (PS), both pristine and metallized with different amounts of gold, were analyzed using monoatomic (Ar +, Ga +, Xe +, Bi +) and polyatomic (SF 5+, Bi 3+, C 60+) primary ions. It was found that polyatomic ions generally induce a significant increase of the secondary ion yield. On the other hand, with gold deposition, a yield enhancement can only be detected for monoatomic ion bombardment.

ToF-SIMS cluster ion imaging of hippocampal CA1 pyramidal rat neurons

NASA Astrophysics Data System (ADS)

Francis, J. T.; Nie, H.-Y.; Taylor, A. R.; Walzak, M. J.; Chang, W. H.; MacFabe, D. F.; Lau, W. M.

2008-12-01

Recent studies have demonstrated the power of time-of-flight secondary ion mass spectrometry (ToF-SIMS) cluster ion imaging to characterize biological structures, such as that of the rat central nervous system. A large number of the studies to date have been carried out on the "structural scale" imaging several mm 2 using mounted thin sections. In this work, we present our ToF-SIMS cluster ion imaging results on hippocampal rat brain neurons, at the cellular and sub-cellular levels. As a part of an ongoing investigation to examine gut linked metabolic factors in autism spectrum disorders using a novel rat model, we have observed a possible variation in hippocampal Cornu ammonis 1 (CA1) pyramidal neuron geometry in thin, paraformaldehyde fixed brain sections. However, the fixation process alters the tissue matrix such that much biochemical information appears to be lost. In an effort to preserve as much as possible this original information, we have established a protocol using unfixed thin brain sections, along with low dose, 500 eV Cs + pre-sputtering that allows imaging down to the sub-cellular scale with minimal sample preparation.

SIM PlanetQuest Key Project Precursor Observations to Detect Gas Giant Planets Around Young Stars

NASA Technical Reports Server (NTRS)

Tanner, Angelle; Beichman, Charles; Akeson, Rachel; Ghez, Andrea; Grankin, Konstantin N.; Herbst, William; Hillenbrand, Lynne; Huerta, Marcos; Konopacky, Quinn; Metchev, Stanimir;

Dyeing regions of oxidative hair dyes in human hair investigated by nanoscale secondary ion mass spectrometry.

PubMed

Kojima, Toru; Yamada, Hiromi; Yamamoto, Toshihiko; Matsushita, Yasuyuki; Fukushima, Kazuhiko

2013-06-01

To develop more effective oxidative hair coloring products, it is important to understand the localization of colored chromophores, which are formed from oxidative dyes, in the fine structure of hair. However, the dyeing regions of oxidative hair dyes in the fine structure of hair have not been extensively examined. In this study, we investigated the distribution and localization of colored chromophores formed by an oxidative hair coloring product in the fine structure of human hair by using a stable isotope-labeled oxidative dye with nanoscale secondary ion mass spectrometry (NanoSIMS). First, formation of the colored chromophore from a deuterium-labeled oxidative dye was examined by visible spectra similarly to a study of its formation using nonlabeled oxidative dye. Furthermore, the formation of binuclear indo dye containing deuterium in its chemical structure was confirmed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis. As a result of the NanoSIMS image on a cross-sectional dyed hair, although deuterium ions were detected in whole hair cross-section, quite a few of them were detected at particulate regions. These particulate regions of the dyed black hair in which deuterium ions were intensely detected were identified as melanin granules, by comparing the dyeing behaviors of black and white hair. NanoSIMS analysis revealed that melanin granules of black human hair are important dyeing regions in oxidative hair coloring. Copyright © 2013 Elsevier B.V. All rights reserved.

ON-SITE SOLID PHRASE EXTRACTION AND LABORATORY ...

EPA Pesticide Factsheets

Fragrance materials, such as synthetic musks in aqueous samples, are normally analyzed by GC/MS in the selected ion monitoring (SIM) mode to provide maximum sensitivity after liquid-liquid extraction of I -L samples. A I -L sample, however, usually provides too little analyte for full-scan data acquisition. An on-site extraction method for extracting synthetic musks from 60 L of wastewater effluent has been developed. Such a large sample volume permits high-quality, full-scan mass spectra to be obtained for various synthetic musk compounds. Quantification of these compounds was conveniently achieved from the full-scan data directly, without preparing SIM descriptors for each compound to acquire SIM data. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-sol

IN SITU SOLID-PHASE EXTRACTION AND ANALYSIS OF ...

EPA Pesticide Factsheets

Fragrance materials, such as synthetic musks in aqueous samples, are normally analyzed by GC/MS in the selected ion monitoring (SIM) mode to provide maximum sensitivity after liquid-liquid extraction of 1-L samples. A 1-L sample, however, usually provides too little analyte for full-scan data acquisition.We have developed an on-site extraction method for extracting synthetic musks from 60 L of wastewater effluent. Such a large sample volume permits high-quality, full-scan mass spectra to be obtained for various synthetic musk compounds. Quantification of these compounds was conveniently achieved from the full-scan data directly, without preparing SIM descriptors for each compound to acquire SIM data. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-s

Automatization Project for the Carl-Zeiss-Jena Coudè Telescope of the Simón Bolívar Planetarium I. The Electro-Mechanic System

NASA Astrophysics Data System (ADS)

Núñez, A.; Maharaj, A.; Muñoz, A. G.

2009-05-01

The ``Complejo Científico, Cultural y Turístico Simón Bolívar'' (CCCTSB), located in Maracaibo, Venezuela, lodges the Simón Bolívar Planetarium and an 150 mm aperture, 2250 mm focal length Carl-Zeiss-Jena Coudè refractor telescope. In this work we discuss the schematics for the automatization project of this Telescope, the planned improvements, methodology, engines, micro-controllers, interfaces and the uptodate status of the project. This project is working on the first two levels of the automation pyramid, the sensor -- actuator level and the control or Plant floor level. The Process control level correspond to the software related section. This mean that this project work immediately with the electrical, electronic and mechanical stuffs, and with the assembler micro controller language. All the pc related stuff, like GUI (Graphic user interfaces), remote control, Grid database, and others, correspond to the next two automation pyramid levels. The idea is that little human intervention will be required to manipulate the telescope, only giving a pair of coordinates to ubicate and follow an object on the sky. A set of three servomotors, coupling it with the telescope with a gear box, are going to manipulate right ascension, declination and focus movement. For the dome rotation, a three phase induction motor will be used. For dome aperture/closure it is suggested a DC motor powered with solar panels. All those actuators are controlled by a 8 bits micro-controller, which receive the coordinate imput, the signal from the position sensors and have the PID control algorithm. This algorithm is tuned based on the mathematical model of the telescope electro-mechanical instrumentation.

Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

DTIC Science & Technology

2013-08-01

ENGINEERING AND TECHNOLOGY SYMPOSIUM (GVSETS), SET FOR AUG. 21-22, 2013 14. ABSTRACT briefing charts 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17...EDL & Aero-Flight DSENDS Airships Planetary & Terrain models SimScape Simulation framework Dshell Flex & Multibody dynamics DARTS 3D...7 DARTS Rigid/Flexible Real-Time Multibody Dynamics Engine Recipient of the NASA Software of the Year Award. Abhinandan Jain, "Robot and

CoMA: A high resolution Time-Of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) for in situ analysis of cometary matter

NASA Technical Reports Server (NTRS)

Zscheeg, Harry; Kissel, J.; Natour, G.

1992-01-01

A lot of clues concerning the origin of the solar system can be found by sending an exploring spacecraft to a rendezvous with a comet. The space experiment CoMA, which will measure the elemental, isotopic, and molecular composition of cometary dust grains is described. It will be flown on NASA's Comet Rendezvous Asteroid Flyby (CRAF) mission.

Analysis of hopanes and steranes in single oil-bearing fluid inclusions using time-of-flight secondary ion mass spectrometry (ToF-SIMS).

PubMed

Siljeström, S; Lausmaa, J; Sjövall, P; Broman, C; Thiel, V; Hode, T

2010-01-01

Steranes and hopanes are organic biomarkers used as indicators for the first appearance of eukaryotes and cyanobacteria on Earth. Oil-bearing fluid inclusions may provide a contamination-free source of Precambrian biomarkers, as the oil has been secluded from the environment since the formation of the inclusion. However, analysis of biomarkers in single oil-bearing fluid inclusions, which is often necessary due to the presence of different generations of inclusions, has not been possible due to the small size of most inclusions. Here, we have used time-of-flight secondary ion mass spectrometry (ToF-SIMS) to monitor in real time the opening of individual inclusions trapped in hydrothermal veins of fluorite and calcite and containing oil from Ordovician source rocks. Opening of the inclusions was performed by using a focused C(60)(+) ion beam and the in situ content was precisely analysed for C(27)-C(29) steranes and C(29)-C(32) hopanes using Bi(3)(+) as primary ions. The capacity to unambiguously detect these biomarkers in the picoliter amount of crude oil from a single, normal-sized (15-30 mum in diameter) inclusion makes the approach promising in the search of organic biomarkers for life's early evolution on Earth.

Classification of time-of-flight secondary ion mass spectrometry spectra from complex Cu-Fe sulphides by principal component analysis and artificial neural networks.

PubMed

Kalegowda, Yogesh; Harmer, Sarah L

2013-01-08

Artificial neural network (ANN) and a hybrid principal component analysis-artificial neural network (PCA-ANN) classifiers have been successfully implemented for classification of static time-of-flight secondary ion mass spectrometry (ToF-SIMS) mass spectra collected from complex Cu-Fe sulphides (chalcopyrite, bornite, chalcocite and pyrite) at different flotation conditions. ANNs are very good pattern classifiers because of: their ability to learn and generalise patterns that are not linearly separable; their fault and noise tolerance capability; and high parallelism. In the first approach, fragments from the whole ToF-SIMS spectrum were used as input to the ANN, the model yielded high overall correct classification rates of 100% for feed samples, 88% for conditioned feed samples and 91% for Eh modified samples. In the second approach, the hybrid pattern classifier PCA-ANN was integrated. PCA is a very effective multivariate data analysis tool applied to enhance species features and reduce data dimensionality. Principal component (PC) scores which accounted for 95% of the raw spectral data variance, were used as input to the ANN, the model yielded high overall correct classification rates of 88% for conditioned feed samples and 95% for Eh modified samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterization of extreme ultraviolet laser ablation mass spectrometry for actinide trace analysis and nanoscale isotopic imaging

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

Green, Tyler; Kuznetsov, Ilya; Willingham, David

The purpose of this research was to characterize Extreme Ultraviolet Time-of-Flight (EUV TOF) Laser Ablation Mass Spectrometry for high spatial resolution elemental and isotopic analysis. We compare EUV TOF results with Secondary Ionization Mass Spectrometry (SIMS) to orient the EUV TOF method within the overall field of analytical mass spectrometry. Using the well-characterized NIST 61x glasses, we show that the EUV ionization approach produces relatively few molecular ion interferences in comparison to TOF SIMS. We demonstrate that the ratio of element ion to element oxide ion is adjustable with EUV laser pulse energy and that the EUV TOF instrument hasmore » a sample utilization efficiency of 0.014%. The EUV TOF system also achieves a lateral resolution of 80 nm and we demonstrate this lateral resolution with isotopic imaging of closely spaced particles or uranium isotopic standard materials.« less

Suppression of self-organized surface nanopatterning on GaSb/InAs multilayers induced by low energy oxygen ion bombardment by using simultaneously sample rotation and oxygen flooding

NASA Astrophysics Data System (ADS)

Beainy, Georges; Cerba, Tiphaine; Bassani, Franck; Martin, Mickaël; Baron, Thierry; Barnes, Jean-Paul

2018-05-01

Time of flight secondary ion mass spectrometry (ToF-SIMS) is a well-adapted analytical method for the chemical characterization of concentration profiles in layered or multilayered materials. However, under ion beam bombardment, initially smooth material surface becomes morphologically unstable. This leads to abnormal secondary ion yields and depth profile distortions. In this contribution, we explore the surface topography and roughening evolution induced by O2+ ion bombardment on GaSb/InAs multilayers. We demonstrate the formation of nanodots and ripples patterning according to the ion beam energy. Since the latter are undesirable for ToF-SIMS analysis, we managed to totally stop their growth by using simultaneously sample rotation and oxygen flooding. This unprecedented coupling between these two latter mechanisms leads to a significant enhancement in depth profiles resolution.

Using ToF-SIMS and EIS to evaluate green pretreatment reagent: Corrosion protection of aluminum alloy by silica/zirconium/cerium hybrid coating

NASA Astrophysics Data System (ADS)

Chang, Chun-Chao; Wang, Chiung-Chi; Wu, Chia-Wei; Liu, Shou-Ching; Mai, Fu-Der

2008-12-01

Increasing environmental concern has led to the restrictive use of chromate conversion coatings to protect Al-alloys from corrosion. Our research is under way to find environmentally compliant substitute coating such as Si/Zr/Ce hybrid coating. The corrosion protection effect of green pretreatment reagent consisted of Si-containing base solution, Ce- and Zr-containing sealing solutions on the corrosion protection of Al-alloys was studied with a 3.5% NaCl aqueous testing solution. The correlation between the corrosion resistance measured by electrochemical impedance spectroscopy (EIS) and surface chemical composition of the hybrid coating measured by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) was studied. The proposed green pretreatment reagent was found improve the corrosion protection of Al-alloys, presumably due to the formation of protective oxide film acting as an oxygen barrier.

High powered rocketry: design, construction, and launching experience and analysis

NASA Astrophysics Data System (ADS)

Paulson, Pryce; Curtis, Jarret; Bartel, Evan; Owens Cyr, Waycen; Lamsal, Chiranjivi

2018-01-01

In this study, the nuts and bolts of designing and building a high powered rocket have been presented. A computer simulation program called RockSim was used to design the rocket. Simulation results are consistent with time variations of altitude, velocity, and acceleration obtained in the actual flight. The actual drag coefficient was determined by using altitude back-tracking method and found to be 0.825. Speed of the exhaust determined to be 2.5 km s-1 by analyzing the thrust curve of the rocket. Acceleration in the coasting phase of the flight, represented by the second-degree polynomial of a small leading coefficient, have been found to approach ‘-g’ asymptotically.

Polymer surface functionalities that control human embryoid body cell adhesion revealed by high throughput surface characterization of combinatorial material microarrays

PubMed Central

Yang, Jing; Mei, Ying; Hook, Andrew L.; Taylor, Michael; Urquhart, Andrew J.; Bogatyrev, Said R.; Langer, Robert; Anderson, Daniel G.; Davies, Martyn C.; Alexander, Morgan R.

2010-01-01

High throughput materials discovery using combinatorial polymer microarrays to screen for new biomaterials with new and improved function is established as a powerful strategy. Here we combine this screening approach with high throughput surface characterisation (HT-SC) to identify surface structure-function relationships. We explore how this combination can help to identify surface chemical moieties that control protein adsorption and subsequent cellular response. The adhesion of human embryoid body (hEB) cells to a large number (496) of different acrylate polymers synthesized in a microarray format is screened using a high throughput procedure. To determine the role of the polymer surface properties on hEB cell adhesion, detailed HT-SC of these acrylate polymers is carried out using time of flight secondary ion mass spectrometry (ToF SIMS), x-ray photoelectron spectroscopy (XPS), pico litre drop sessile water contact angle (WCA) measurement and atomic force microscopy (AFM). A structure-function relationship is identified between the ToF SIMS analysis of the surface chemistry after a fibronectin (Fn) pre-conditioning step and the cell adhesion to each spot using the multivariate analysis technique partial least squares (PLS) regression. Secondary ions indicative of the adsorbed Fn correlate with increased cell adhesion whereas glycol and other functionalities from the polymers are identified that reduce cell adhesion. Furthermore, a strong relationship between the ToF SIMS spectra of bare polymers and the cell adhesion to each spot is identified using PLS regression. This identifies a role for both the surface chemistry of the bare polymer and the pre-adsorbed Fn, as-represented in the ToF SIMS spectra, in controlling cellular adhesion. In contrast, no relationship is found between cell adhesion and wettability, surface roughness, elemental or functional surface composition. The correlation between ToF SIMS data of the surfaces and the cell adhesion demonstrates the ability of identifying surface moieties that control protein adsorption and subsequent cell adhesion using ToF SIMS and multivariate analysis. PMID:20832108

Cost-Savings to Medicare From Pre-Medicare Colorectal Cancer Screening.

PubMed

Goede, Simon L; Kuntz, Karen M; van Ballegooijen, Marjolein; Knudsen, Amy B; Lansdorp-Vogelaar, Iris; Tangka, Florence K; Howard, David H; Chin, Joseph; Zauber, Ann G; Seeff, Laura C

2015-07-01

Many individuals have not received recommended colorectal cancer (CRC) screening before they become Medicare eligible at the age of 65. We aimed to estimate the long-term implications of increased CRC screening in the pre-Medicare population (50-64 y) on costs in the pre-Medicare and Medicare populations (65+ y). We used 2 independently developed microsimulation models [Microsimulation Screening Analysis Colon (MISCAN) and Simulation Model of CRC (SimCRC)] to project CRC screening and treatment costs under 2 scenarios, starting in 2010: "current trends" (60% of the population up-to-date with screening recommendations) and "enhanced participation" (70% up-to-date). The population was scaled to the projected US population for each year between 2010 and 2060. Costs per year were derived by age group (50-64 and 65+ y). By 2060, the discounted cumulative total costs in the pre-Medicare population were $35.7 and $28.1 billion higher with enhanced screening participation, than in the current trends scenario ($252.1 billion with MISCAN and $239.5 billion with SimCRC, respectively). Because of CRC treatment savings with enhanced participation, cumulative costs in the Medicare population were $18.3 and $32.7 billion lower (current trends: $423.5 billion with MISCAN and $372.8 billion with SimCRC). Over the 50-year time horizon an estimated 60% (MISCAN) and 89% (SimCRC) of the increased screening costs could be offset by savings in Medicare CRC treatment costs. Increased CRC screening participation in the pre-Medicare population could reduce CRC incidence and mortality, whereas the additional screening costs can be largely offset by long-term Medicare treatment savings.

Surface characterization of dialyzer polymer membranes by imaging ToF-SIMS and quantitative XPS line scans.

PubMed

Holzweber, Markus; Lippitz, Andreas; Krueger, Katharina; Jankowski, Joachim; Unger, Wolfgang E S

2015-03-24

The surfaces of polymeric dialyzer membranes consisting of polysulfone and polyvinylpyrrolidone were investigated regarding the lateral distribution and quantitative surface composition using time-of-flight secondary-ion-mass-spectrometry and x-ray photoelectron spectroscopy. Knowledge of the distribution and composition on the outer surface region is of utmost importance for understanding the biocompatibility of such dialyzer membranes. Both flat membranes and hollow fiber membranes were studied.

Fabrication of Nanoscaled Systems

DTIC Science & Technology

2007-05-01

corresponds to an effective dose as low as a few ýC/cm2 for sputtering of a 50 rum resist film. Comparison to observed sputtering rates in other polymeric ...materials (e.g. polystyrene and AZ and SU8 resists), coupled with time of flight SIMS measurements indicate that the relevant mechanism is indeed ion...approximately unity between GMR substrate and resist (for both electron and ion exposed HSQ), which we would not expect to be attainable using polymeric

Proceedings of the first U.S. Geological Survey scientific information management workshop, March 21-23, 2006

USGS Publications Warehouse

Henkel, Heather S.

2007-01-01

In March 2006, the U.S. Geological Survey (USGS) held the first Scientific Information Management (SIM) Workshop in Reston, Virginia. The workshop brought together more than 150 SIM professionals from across the organization to discuss the range and importance of SIM problems, identify common challenges and solutions, and investigate the use and value of “communities of practice” (CoP) as mechanisms to address these issues. The 3-day workshop began with presentations of SIM challenges faced by the Long Term Ecological Research (LTER) network and two USGS programs from geology and hydrology. These presentations were followed by a keynote address and discussion of CoP by Dr. Etienne Wenger, a pioneer and leading expert in CoP, who defined them as "groups of people who share a passion for something that they know how to do and who interact regularly to learn how to do it better." Wenger addressed the roles and characteristics of CoP, how they complement formal organizational structures, and how they can be fostered. Following this motivating overview, five panelists (including Dr. Wenger) with CoP experience in different institutional settings provided their perspectives and lessons learned. The first day closed with an open discussion on the potential intersection of SIM at the USGS with SIM challenges and the potential for CoP. The second session began the process of developing a common vocabulary for both scientific data management and CoP, and a list of eight guiding principles for information management were proposed for discussion and constructive criticism. Following this discussion, 20 live demonstrations and posters of SIM tools developed by various USGS programs and projects were presented. Two community-building sessions were held to explore the next steps in 12 specific areas: Archiving of Scientific Data and Information; Database Networks; Digital Libraries; Emerging Workforce; Field Data for Small Research Projects; Knowledge Capture; Knowledge Organization Systems and Controlled Vocabularies; Large Time Series Data Sets; Metadata; Portals and Frameworks; Preservation of Physical Collections; and Scientific Data from Monitoring Programs. In about two-thirds of these areas, initial steps to forming CoP are now underway. The final afternoon included a panel in which information professionals, managers, program coordinators, and associate directors shared their perspectives on the workshop, on ways in which the USGS could better manage its scientific information, and on the use of CoP as informal mechanisms to complement formal organizational structures. The final session focused on developing the next steps, an action plan, and a communication strategy to ensure continued development.

Space Interferometry Mission: Dynamical Observations of Galaxies (SIMDOG)

NASA Technical Reports Server (NTRS)

Shaya, Edward J.; Borne, Kirk D.; Nusser, Adi; Peebles, P. J. E.; Tonry, John; Tully, Brent R.; Vogel, Stuart; Zaritsky, Dennis

2004-01-01

Space Interferometry Mission (SIM) will be used to obtain proper motions for a sample of 27 galaxies; the first proper motion measurements of galaxies beyond the satellite system of the Milky Way. SIM measurements lead to knowledge of the full 6-dimensional position and velocity vector of each galaxy. In conjunction with new gravitational flow models, the result will be the first total mass measurements of individual galaxies. The project, includes developnient of powerful theoretical methods for orbital calculations. This SIM study will lead to vastly improved determinations of individual galaxy masses, halo sizes, and the fractional contribution of dark matter. Astronomers have struggled to calculate the orbits of galaxies with only position and redshift information. Traditional N-body techniques are unsuitable for an analysis backward in time from a present distribution if any components of velocity or position are not very precisely known.

CBP PHASE I CODE INTEGRATION

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

Smith, F.; Brown, K.; Flach, G.

The goal of the Cementitious Barriers Partnership (CBP) is to develop a reasonable and credible set of software tools to predict the structural, hydraulic, and chemical performance of cement barriers used in nuclear applications over extended time frames (greater than 100 years for operating facilities and greater than 1000 years for waste management). The simulation tools will be used to evaluate and predict the behavior of cementitious barriers used in near surface engineered waste disposal systems including waste forms, containment structures, entombments, and environmental remediation. These cementitious materials are exposed to dynamic environmental conditions that cause changes in material propertiesmore » via (i) aging, (ii) chloride attack, (iii) sulfate attack, (iv) carbonation, (v) oxidation, and (vi) primary constituent leaching. A set of state-of-the-art software tools has been selected as a starting point to capture these important aging and degradation phenomena. Integration of existing software developed by the CBP partner organizations was determined to be the quickest method of meeting the CBP goal of providing a computational tool that improves the prediction of the long-term behavior of cementitious materials. These partner codes were selected based on their maturity and ability to address the problems outlined above. The GoldSim Monte Carlo simulation program (GTG 2010a, GTG 2010b) was chosen as the code integration platform (Brown & Flach 2009b). GoldSim (current Version 10.5) is a Windows based graphical object-oriented computer program that provides a flexible environment for model development (Brown & Flach 2009b). The linking of GoldSim to external codes has previously been successfully demonstrated (Eary 2007, Mattie et al. 2007). GoldSim is capable of performing deterministic and probabilistic simulations and of modeling radioactive decay and constituent transport. As part of the CBP project, a general Dynamic Link Library (DLL) interface was developed to link GoldSim with external codes (Smith III et al. 2010). The DLL uses a list of code inputs provided by GoldSim to create an input file for the external application, runs the external code, and returns a list of outputs (read from files created by the external application) back to GoldSim. In this way GoldSim provides: (1) a unified user interface to the applications, (2) the capability of coupling selected codes in a synergistic manner, and (3) the capability of performing probabilistic uncertainty analysis with the codes. GoldSim is made available by the GoldSim Technology Group as a free 'Player' version that allows running but not editing GoldSim models. The player version makes the software readily available to a wider community of users that would wish to use the CBP application but do not have a license for GoldSim.« less

Segment fusion of ToF-SIMS images.

PubMed

Milillo, Tammy M; Miller, Mary E; Fischione, Remo; Montes, Angelina; Gardella, Joseph A

2016-06-08

The imaging capabilities of time-of-flight secondary ion mass spectrometry (ToF-SIMS) have not been used to their full potential in the analysis of polymer and biological samples. Imaging has been limited by the size of the dataset and the chemical complexity of the sample being imaged. Pixel and segment based image fusion algorithms commonly used in remote sensing, ecology, geography, and geology provide a way to improve spatial resolution and classification of biological images. In this study, a sample of Arabidopsis thaliana was treated with silver nanoparticles and imaged with ToF-SIMS. These images provide insight into the uptake mechanism for the silver nanoparticles into the plant tissue, giving new understanding to the mechanism of uptake of heavy metals in the environment. The Munechika algorithm was programmed in-house and applied to achieve pixel based fusion, which improved the spatial resolution of the image obtained. Multispectral and quadtree segment or region based fusion algorithms were performed using ecognition software, a commercially available remote sensing software suite, and used to classify the images. The Munechika fusion improved the spatial resolution for the images containing silver nanoparticles, while the segment fusion allowed classification and fusion based on the tissue types in the sample, suggesting potential pathways for the uptake of the silver nanoparticles.

Molecular imaging of enhanced Na + expression in the liver of total sleep deprived rats by TOF-SIMS

NASA Astrophysics Data System (ADS)

Chang, Hung-Ming; Chen, Bo-Jung; Wu, Un-In; Huang, Yi-Lun; Mai, Fu-Der

2008-12-01

Sleep disorder is associated with metabolic disturbances, which was related to oxidative stress and subsequently sodium overload. Since liver plays important roles in metabolic regulation, present study is aimed to determine whether hepatic sodium, together with oxidative stress, would significantly alter after total sleep deprivation (TSD). Sodium ion was investigated by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Parameter for oxidative stress was examined by heat shock protein-25 (HSP-25) immunohistochemistry. TOF-SIMS spectrum indicated that hepatic Na +/K + ratio counting as 82.41 ± 9.5 was obtained in normal rats. Sodium ions were distributed in hepatocytes with several aggregations. However, following TSD, the intensity for Na +/K + ratio was relatively increased (101.94 ± 6.9) and signals for sodium image were strongly expressed throughout hepatocytes without spatial localization. Quantitative analysis revealed that HSP-25 staining intensity is 1.78 ± 0.27 in TSD rats, which was significantly higher than that of normal ones (0.68 ± 0.15). HSP-25 augmentation suggests that hepatocytes suffer from oxidative stress following TSD. Concerning oxidative stress induced sodium overload would impair metabolic function; enhanced hepatic sodium expression after TSD may be a major cause of TSD relevant metabolic diseases.

Spatial Elucidation of Spinal Cord Lipid- and Metabolite- Regulations in Amyotrophic Lateral Sclerosis

NASA Astrophysics Data System (ADS)

Hanrieder, Jörg; Ewing, Andrew G.

2014-06-01

Amyotrophic lateral sclerosis (ALS) is a devastating, rapidly progressing disease of the central nervous system that is characterized by motor neuron degeneration in the brain stem and the spinal cord. We employed time of flight secondary ion mass spectrometry (ToF-SIMS) to profile spatial lipid- and metabolite- regulations in post mortem human spinal cord tissue from ALS patients to investigate chemical markers of ALS pathogenesis. ToF-SIMS scans and multivariate analysis of image and spectral data were performed on thoracic human spinal cord sections. Multivariate statistics of the image data allowed delineation of anatomical regions of interest based on their chemical identity. Spectral data extracted from these regions were compared using two different approaches for multivariate statistics, for investigating ALS related lipid and metabolite changes. The results show a significant decrease for cholesterol, triglycerides, and vitamin E in the ventral horn of ALS samples, which is presumably a consequence of motor neuron degeneration. Conversely, the biogenic mediator lipid lysophosphatidylcholine and its fragments were increased in ALS ventral spinal cord, pointing towards neuroinflammatory mechanisms associated with neuronal cell death. ToF-SIMS imaging is a promising approach for chemical histology and pathology for investigating the subcellular mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis.

Comparative study on the copper activation and xanthate adsorption on sphalerite and marmatite surfaces

NASA Astrophysics Data System (ADS)

Liu, Jian; Wang, Yu; Luo, Deqiang; Chen, Luzheng; Deng, Jiushuai

2018-05-01

The copper activation and potassium butyl xanthate (PBX) adsorption on sphalerite and marmatite surfaces were comparatively investigated using in situ local electrochemical impedance spectroscopy (LEIS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and surface adsorption tests. Comparing the LEIS and surface adsorption results, it was found that the activation time is a key factor influencing the copper activation and PBX adsorption on marmatite surface, but it has a negligible influence on sphalerite. For a short activation time within 10 min, the Fe impurity in marmatite shows an adverse influence on the speed of Cu adsorption and ion exchange as well as on the subsequent PBX adsorption. For a long activation time of 30 min, the LEIS, ToF-SIMS and surface adsorption results suggested that the Fe impurity in marmatite enhances the copper adsorption, whereas such enhanced copper adsorption of marmatite cannot result in corresponding enhancing of PBX adsorption. DFT result showed that the Fe impurity in marmatite has harmful influence on the PBX interaction with the Cu-activated surface by increasing the interaction energy. ToF-SIMS result further indicated that the Cu distribution in the outermost surface of marmatite is less than that of the sphalerite, which also results in the less PBX adsorption for the marmatite.

Visualizing Intrapopulation Hematopoietic Cell Heterogeneity with Self-Organizing Maps of SIMS Data.

PubMed

Mirshafiee, Vahid; Harley, Brendan A C; Kraft, Mary L

2018-05-07

Characterization of the heterogeneity within stem cell populations, which affects their differentiation potential, is necessary for the design of artificial cultures for stem cell expansion. In this study, we assessed whether self-organizing maps (SOMs) of single-cell time-of-flight secondary ion mass spectrometry (TOF-SIMS) data provide insight into the spectral, and thus the related functional heterogeneity between and within three hematopoietic cell populations. SOMs were created of TOF-SIMS data from individual hematopoietic stem and progenitor cells (HSPCs), lineage-committed common lymphoid progenitors (CLPs), and fully differentiated B cells that had been isolated from murine bone marrow via conventional flow cytometry. The positions of these cells on the SOMs and the spectral variation between adjacent map units, shown on the corresponding unified distance matrix (U-matrix), indicated the CLPs exhibited the highest intrapopulation spectral variation, regardless of the age of the donor mice. SOMs of HSPCs, CLPs, and B cells isolated from young and old mice using the same surface antigen profiles revealed the HSPCs exhibited the most age-related spectral variation, whereas B cells exhibited the least. These results demonstrate that SOMs of single-cell spectra enable characterizing the heterogeneity between and within cell populations that lie along distinct differentiation pathways.

Antimony leaching and chemical species analyses in an industrial solid waste: Surface and bulk speciation using ToF-SIMS and XANES.

PubMed

Kappen, P; Ferrando-Miguel, G; Reichman, S M; Innes, L; Welter, E; Pigram, P J

2017-05-05

The surface chemistry and bulk chemical speciation of solid industrial wastes containing 8wt-% antimony (Sb) were investigated using synchrotron X-ray Absorption Near Edge Structure (XANES) and Time-of-Flight Ion Secondary Mass Spectrometry (ToF-SIMS). Leaching experiments were conducted in order to better understand the behavior of Sb in waste streams and to inform regulatory management of antimony-containing wastes. The experiments also demonstrate how a combination of XANES and ToF-SIMS adds value to the field of waste investigations. Leaching treatments (acid and base) were performed at a synchrotron over 24h time periods. Surface analyses of the wastes before leaching showed the presence of Sb associated with S and O. Bulk analyses revealed Sb to be present, primarily, as trivalent sulfide species. Both acid and base leaching did not change the antimony speciation on the solid. Leaching transferred about 1% of the total Sb into solution where Sb was found to be present as Sb(V). XANES data showed similarities between leachate and FeSbO 4 . During base leaching, the Sb content in solution gradually increased over time, and potential desorption mechanisms are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace elements in lenses of normal Wistar Kyoto rats

NASA Astrophysics Data System (ADS)

Kinoshita, Akio; Gong, Huaqing; Amemiya, Tsugio; Takaya, Kenichi; Tozu, Miyako; Ohashi, Yoshiharu

2003-01-01

Chemical analysis of the element and organic substance at the site of pathological changes due to aging is one of the approaches of cataract research. Time of flight secondary ion mass spectrometry (TOF-SIMS) microscopy is expected to analyze elements and organic substances in the lens. The purpose of the present study is to compare elements and organic substances in the lenses of normal 4-month-old rats with those of normal 15-month-old rats by means of a TOF-SIMS microscope. The present study showed that the concentration of Ca and Fe was significantly higher, and that of Na and Mg was significantly lower in 15-month-old rats than that in 4-month-old rats. No changes were found in the concentration of K. The present study also showed that the equator contained more Ca, Na and Mg than the nucleus; in contrast, the Cu concentration was higher in the nucleus than in the equator. In 15-month-old rats, Mg and Vit. A in the equator and Zn in the nucleus were significantly lower than those in 4-month-old rats. TOF-SIMS microscopy could detect elemental changes in the rat lens with age, and is expected to be useful approach of cataract studies.

Development and validation of TOF-SIMS and CLSM imaging method for cytotoxicity study of ZnO nanoparticles in HaCaT cells.

PubMed

Lee, Pei-Ling; Chen, Bo-Chia; Gollavelli, Ganesh; Shen, Sin-Yu; Yin, Yu-Sheng; Lei, Shiu-Ling; Jhang, Cian-Ling; Lee, Woan-Ruoh; Ling, Yong-Chien

2014-07-30

Zinc oxide nanoparticles (ZnO NPs) exhibit novel physiochemical properties and have found increasing use in sunscreen products and cosmetics. The potential toxicity is of increasing concern due to their close association with human skin. A time-of-flight secondary ion mass spectrometry (TOF-SIMS) and confocal laser scanning microscopy (CLSM) imaging method was developed and validated for rapid and sensitive cytotoxicity study of ZnO NPs using human skin equivalent HaCaT cells as a model system. Assorted material, chemical, and toxicological analysis methods were used to confirm their shape, size, crystalline structure, and aggregation properties as well as dissolution behavior and effect on HaCaT cell viability in the presence of various concentrations of ZnO NPs in aqueous media. Comparative and correlative analyses of aforementioned results with TOF-SIMS and CLSM imaging results exhibit reasonable and acceptable outcome. A marked drop in survival rate was observed with 50μg/ml ZnO NPs. The CLSM images reveal the absorption and localization of ZnO NPs in cytoplasm and nuclei. The TOF-SIMS images demonstrate elevated levels of intracellular ZnO concentration and associated Zn concentration-dependent (40)Ca/(39)K ratio, presumably caused by the dissolution behavior of ZnO NPs. Additional validation by using stable isotope-labeled (68)ZnO NPs as tracers under the same experimental conditions yields similar cytotoxicity effect. The imaging results demonstrate spatially-resolved cytotoxicity relationship between intracellular ZnO NPs, (40)Ca/(39)K ratio, phosphocholine fragments, and glutathione fragments. The trend of change in TOF-SIMS spectra and images of ZnO NPs treated HaCaT cells demonstrate the possible mode of actions by ZnO NP involves cell membrane disruption, cytotoxic response, and ROS mediated apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Cosensitized Porphyrin System for High-Performance Solar Cells with TOF-SIMS Analysis.

PubMed

Wu, Wenjun; Xiang, Huaide; Fan, Wei; Wang, Jinglin; Wang, Haifeng; Hua, Xin; Wang, Zhaohui; Long, Yitao; Tian, He; Zhu, Wei-Hong

2017-05-17

To date, development of organic sensitizers has been predominately focused on light harvesting, highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels, and the electron transferring process. In contrast, their adsorption mode as well as the dynamic loading behavior onto nanoporous TiO 2 is rarely considered. Herein, we have employed the time-of-flight secondary ion mass spectrometry (TOF-SIMS) to gain insight into the competitive dye adsorption mode and kinetics in the cosensitized porphyrin system. Using novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well-compared with two different anchoring groups, such as benzoic acid and cyanoacrylic acid. With the bombardment mode in TOF-SIMS spectra, we have speculated that the cyano group grafts onto nanoporous TiO 2 as tridentate binding for the common anchoring unit of cyanoacrylic acid and confirmed it through extensive first-principles density functional theory calculation by anchoring either the carboxyl or cyano group, which shows that the cyano group can efficiently participate in the adsorption of the WS-5 molecule onto the TiO 2 nanocrystal. The grafting reinforcement interaction between the cyano group and TiO 2 in WS-5 can well-explain the rapid adsorption characteristics. A strong coordinate bond between the lone pair of electrons on the nitrogen or oxygen atom and the Lewis acid sites of TiO 2 can increase electron injection efficiencies with respect to those from the bond between the benzoic acid group and the Brønsted acid sites of the TiO 2 surface. Upon optimization of the coadsorption process with dye WS-5, the photoelectric conversion efficiency based on porphyrin dye FW-1 is increased from 6.14 to 9.72%. The study on the adsorption dynamics of organic sensitizers with TOF-SIMS analysis might provide a new venue for improvement of cosensitized solar cells.

A perspective on two chemometrics tools: PCA and MCR, and introduction of a new one: Pattern recognition entropy (PRE), as applied to XPS and ToF-SIMS depth profiles of organic and inorganic materials

NASA Astrophysics Data System (ADS)

Chatterjee, Shiladitya; Singh, Bhupinder; Diwan, Anubhav; Lee, Zheng Rong; Engelhard, Mark H.; Terry, Jeff; Tolley, H. Dennis; Gallagher, Neal B.; Linford, Matthew R.

2018-03-01

X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are much used analytical techniques that provide information about the outermost atomic and molecular layers of materials. In this work, we discuss the application of multivariate spectral techniques, including principal component analysis (PCA) and multivariate curve resolution (MCR), to the analysis of XPS and ToF-SIMS depth profiles. Multivariate analyses often provide insight into data sets that is not easily obtained in a univariate fashion. Pattern recognition entropy (PRE), which has its roots in Shannon's information theory, is also introduced. This approach is not the same as the mutual information/entropy approaches sometimes used in data processing. A discussion of the theory of each technique is presented. PCA, MCR, and PRE are applied to four different data sets obtained from: a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized C3F6 on Si, a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized PNIPAM (poly (N-isopropylacrylamide)) on Si, an XPS depth profile through a film of SiO2 on Si, and an XPS depth profile through a film of Ta2O5 on Ta. PCA, MCR, and PRE reveal the presence of interfaces in the films, and often indicate that the first few scans in the depth profiles are different from those that follow. PRE and backward difference PRE provide this information in a straightforward fashion. Rises in the PRE signals at interfaces suggest greater complexity to the corresponding spectra. Results from PCA, especially for the higher principal components, were sometimes difficult to understand. MCR analyses were generally more interpretable.

SIM Planetquest Science and Technology: A Status Report

NASA Technical Reports Server (NTRS)

Edberg, Stephen J.; Laskin, Robert A.; Marr, James C., IV; Unwin, Stephen C.; Shao, Michael

2007-01-01

Optical interferometry will open new vistas for astronomy over the next decade. The Space Interferometry Mission (SIM-PlanetQuest), operating unfettered by the Earth's atmosphere, will offer unprecedented astrometric precision that promises the discovery of Earth-analog extra-solar planets as well as a wealth of important astrophysics. Results from SIM will permit the determination of stellar masses to accuracies of 2% or better for objects ranging from brown dwarfs through main sequence stars to evolved white dwarfs, neutron stars, and black holes. Studies of star clusters will yield age determinations and internal dynamics. Microlensing measurements will present the mass spectrum of the Milky Way internal to the Sun while proper motion surveys will show the Sun's orbital radius and speed. Studies of the Galaxy's halo component and companion dwarf galaxies permit the determination of the Milky Way's mass distribution, including its Dark Matter component and the mass distribution and Dark Matter component of the Local Group. Cosmology benefits from precision (1-2%) determination of distances to Cepheid and RR Lyrae standard candles. The emission mechanism of supermassive black holes will be investigated. Finally, radio and optical celestial reference frames will be tied together by an improvement of two orders of magnitude. Optical interferometers present severe technological challenges. The Jet Propulsion Laboratory, with the support of Lockheed Martin Advanced Technology Center (LM ATC) and Northrop Grumman Space Technology (NGST), has addressed these challenges with a technology development program that is now complete. The requirements for SIM have been satisfied, based on outside peer review, using a series of laboratory tests and appropriate computer simulations: laser metrology systems perform with 10 picometer precision; mechanical vibrations have been controlled to nanometers, demonstrating orders of magnitude disturbance rejection; and knowledge of component positions throughout the whole test assembly has been demonstrated to the required picometer level. Technology transfer to the SIM flight team is now well along.

SIM PlanetQuest science and technology: a status report

NASA Astrophysics Data System (ADS)

Edberg, Stephen J.; Laskin, Robert A.; Marr, James C., IV; Unwin, Stephen C.; Shao, Michael

2007-09-01

Optical interferometry will open new vistas for astronomy over the next decade. The Space Interferometry Mission (SIM-PlanetQuest), operating unfettered by the Earth's atmosphere, will offer unprecedented astrometric precision that promises the discovery of Earth-analog extra-solar planets as well as a wealth of important astrophysics. Results from SIM will permit the determination of stellar masses to accuracies of 2% or better for objects ranging from brown dwarfs through main sequence stars to evolved white dwarfs, neutron stars, and black holes. Studies of star clusters will yield age determinations and internal dynamics. Microlensing measurements will present the mass spectrum of the Milky Way internal to the Sun while proper motion surveys will show the Sun's orbital radius and speed. Studies of the Galaxy's halo component and companion dwarf galaxies permit the determination of the Milky Way's mass distribution, including its Dark Matter component and the mass distribution and Dark Matter component of the Local Group. Cosmology benefits from precision (1-2%) determination of distances to Cepheid and RR Lyrae standard candles. The emission mechanism of supermassive black holes will be investigated. Finally, radio and optical celestial reference frames will be tied together by an improvement of two orders of magnitude. Optical interferometers present severe technological challenges. The Jet Propulsion Laboratory, with the support of Lockheed Martin Advanced Technology Center (LM ATC) and Northrop Grumman Space Technology (NGST), has addressed these challenges with a technology development program that is now complete. The requirements for SIM have been satisfied, based on outside peer review, using a series of laboratory tests and appropriate computer simulations: laser metrology systems perform with 10 picometer precision; mechanical vibrations have been controlled to nanometers, demonstrating orders of magnitude disturbance rejection; and knowledge of component positions throughout the whole test assembly has been demonstrated to the required picometer level. Technology transfer to the SIM flight team is now well along.

ToF-SIMS study of differentiation of human bone-derived stromal cells: new insights into osteoporosis.

PubMed

Schaepe, Kaija; Werner, Janina; Glenske, Kristina; Bartges, Tessa; Henss, Anja; Rohnke, Marcus; Wenisch, Sabine; Janek, Jürgen

2017-07-01

Lipids have numerous important functions in the human body, as they form the cells' plasma membranes and play a key role in many disease states, presumably also in osteoporosis. Here, the fatty acid composition of the outer plasma membranes of cells differentiated into the osteogenic and adipogenic direction is studied with surface-sensitive time-of-flight secondary ion mass spectrometry (ToF-SIMS). For data evaluation, principal component analysis (PCA) is applied. Human (bone-derived) mesenchymal stromal cells (hMSCs) from an osteoporotic donor and a control donor are compared to reveal differences in the fatty acid composition of the membranes. The chemical information is correlated to staining and real-time quantitative polymerase chain reaction (rt-qPCR) results to provide insight into the gene expression of several differentiation markers on the RNA level. Adipogenic differentiation of hMSCs from a non-osteoporotic donor correlates with increased relative intensities of all fatty acids under investigation. After osteogenic differentiation of non-osteoporotic cells, the relative mass signal intensities of unsaturated fatty acids such as oleic and linoleic acids are increased. However, the osteoporotic cells show increased levels of palmitic acid in the plasma membrane after exposure to osteogenic differentiation conditions, which correlates to an immature differentiation state relative to non-osteoporotic osteogenic cells. This immature differentiation state is confirmed by increased early osteogenic differentiation factor Runx2 on RNA level and by less calcium mineralization spots seen in von Kossa staining and ToF-SIMS images. Graphical abstract Time-of-flight secondary ion mass spectrometry is applied to analyze the fatty acid composition of the outer plasma membranes of cells differentiated into the adipogenic and osteogenic direction. Cells from an osteoporotic and a control donor are compared to reveal differences due to differentiation and disease stage of the cells.

Tobacco Policies in Louisiana: Recommendations for Future Tobacco Control Investment from SimSmoke, a Policy Simulation Model.

PubMed

Levy, David; Fergus, Cristin; Rudov, Lindsey; McCormick-Ricket, Iben; Carton, Thomas

2016-02-01

Despite the presence of tobacco control policies, Louisiana continues to experience a high smoking burden and elevated smoking-attributable deaths. The SimSmoke model provides projections of these health outcomes in the face of existing and expanded (simulated) tobacco control polices. The SimSmoke model utilizes population data, smoking rates, and various tobacco control policy measures from Louisiana to predict smoking prevalence and smoking-attributable deaths. The model begins in 1993 and estimates are projected through 2054. The model is validated against existing Louisiana smoking prevalence data. The most powerful individual policy measure for reducing smoking prevalence is cigarette excise tax. However, a comprehensive cessation treatment policy is predicted to save the most lives. A combination of tobacco control policies provides the greatest reduction in smoking prevalence and smoking-attributable deaths. The existing Louisiana excise tax ranks as one of the lowest in the country and the legislature is against further increases. Alternative policy measures aimed at lowering prevalence and attributable deaths are: cessation treatments, comprehensive smoke-free policies, and limiting youth access. These three policies have a substantial effect on smoking prevalence and attributable deaths and are likely to encounter more favor in the Louisiana legislature than increasing the state excise tax.

Lunar Exploration Island, NASA’s Return to the Moon in Second Life

NASA Astrophysics Data System (ADS)

Ireton, F. M.; Bleacher, L.; Day, B.; Hsu, B. C.; Mitchell, B. K.

2009-12-01

Second Life is a metaverse—a massively multi-user virtual world (MMVR) community. With over 9 million users worldwide, there are 40,000-50,000 users on line at any one time. Second Life hosts over 200 educational and institutional simulation locations termed “islands” or sims that are developed by users providing support for education and business endeavors. On-line tools are provided to construct structures and landforms simulating a real world in a virtual three-dimensional environment. Users develop a persona and are seen on screen as a human figure or avatar. Avatars move in Second Life by walking, flying, or teleporting and interact with other users via text or voice chat. This poster details the design and creation of the Second Life exhibit hall for NASA’s Lunar Precursor Robotics Program and the LRO/LCROSS missions. The hall has been placed on the Lunar Exploration Island (LEI) in Second Life. Avatars enter via teleportation to an orientation room with information about the project, a simulator map, and other information. A central hall of flight houses exhibits pertaining to the LRO/ LCROSS missions and includes full size models of the two spacecraft and launch vehicle. Storyboards with information about the missions interpret the exhibits while links to external websites provide further information on the missions, both spacecraft instrument suites, and EPO directed to support the missions. The sim includes several sites for meetings, a conference amphitheater with a stage and screen for video links such as live broadcasts of conferences and speakers. A link is provided to NASATV for live viewing LRO/LCROSS launch and impact activities and other NASA events. Recently visitors have viewed the Hubble servicing mission and several shuttle launches as well as the LRO/LCROSS launch. Lunar Exploration Island in Second Life

Ocean power technology design optimization

DOE PAGES

van Rij, Jennifer; Yu, Yi -Hsiang; Edwards, Kathleen; ...

2017-07-18

For this study, the National Renewable Energy Laboratory and Ocean Power Technologies (OPT) conducted a collaborative code validation and design optimization study for OPT's PowerBuoy wave energy converter (WEC). NREL utilized WEC-Sim, an open-source WEC simulator, to compare four design variations of OPT's PowerBuoy. As an input to the WEC-Sim models, viscous drag coefficients for the PowerBuoy floats were first evaluated using computational fluid dynamics. The resulting WEC-Sim PowerBuoy models were then validated with experimental power output and fatigue load data provided by OPT. The validated WEC-Sim models were then used to simulate the power performance and loads for operationalmore » conditions, extreme conditions, and directional waves, for each of the four PowerBuoy design variations, assuming the wave environment of Humboldt Bay, California. And finally, ratios of power-to-weight, power-to-fatigue-load, power-to-maximum-extreme-load, power-to-water-plane-area, and power-to-wetted-surface-area were used to make a final comparison of the potential PowerBuoy WEC designs. Lastly, the design comparison methodologies developed and presented in this study are applicable to other WEC devices and may be useful as a framework for future WEC design development projects.« less

The Global Streamflow Indices and Metadata archive (G-SIM): A compilation of global streamflow time series indices and meta-data

NASA Astrophysics Data System (ADS)

Do, Hong; Gudmundsson, Lukas; Leonard, Michael; Westra, Seth; Senerivatne, Sonia

2017-04-01

In-situ observations of daily streamflow with global coverage are a crucial asset for understanding large-scale freshwater resources which are an essential component of the Earth system and a prerequisite for societal development. Here we present the Global Streamflow Indices and Metadata archive (G-SIM), a collection indices derived from more than 20,000 daily streamflow time series across the globe. These indices are designed to support global assessments of change in wet and dry extremes, and have been compiled from 12 free-to-access online databases (seven national databases and five international collections). The G-SIM archive also includes significant metadata to help support detailed understanding of streamflow dynamics, with the inclusion of drainage area shapefile and many essential catchment properties such as land cover type, soil and topographic characteristics. The automated procedure in data handling and quality control of the project makes G-SIM a reproducible, extendible archive and can be utilised for many purposes in large-scale hydrology. Some potential applications include the identification of observational trends in hydrological extremes, the assessment of climate change impacts on streamflow regimes, and the validation of global hydrological models.

Ocean power technology design optimization

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

van Rij, Jennifer; Yu, Yi -Hsiang; Edwards, Kathleen

For this study, the National Renewable Energy Laboratory and Ocean Power Technologies (OPT) conducted a collaborative code validation and design optimization study for OPT's PowerBuoy wave energy converter (WEC). NREL utilized WEC-Sim, an open-source WEC simulator, to compare four design variations of OPT's PowerBuoy. As an input to the WEC-Sim models, viscous drag coefficients for the PowerBuoy floats were first evaluated using computational fluid dynamics. The resulting WEC-Sim PowerBuoy models were then validated with experimental power output and fatigue load data provided by OPT. The validated WEC-Sim models were then used to simulate the power performance and loads for operationalmore » conditions, extreme conditions, and directional waves, for each of the four PowerBuoy design variations, assuming the wave environment of Humboldt Bay, California. And finally, ratios of power-to-weight, power-to-fatigue-load, power-to-maximum-extreme-load, power-to-water-plane-area, and power-to-wetted-surface-area were used to make a final comparison of the potential PowerBuoy WEC designs. Lastly, the design comparison methodologies developed and presented in this study are applicable to other WEC devices and may be useful as a framework for future WEC design development projects.« less

Sweden SimSmoke: the effect of tobacco control policies on smoking and snus prevalence and attributable deaths

PubMed Central

Near, Aimee M.; Blackman, Kenneth; Currie, Laura M.

2014-01-01

Background: This study examines the effect of past tobacco control policies and projects the effect of future policies on smoking and snus use prevalence and associated premature mortality in Sweden. Methods: The established SimSmoke model was adapted with population, smoking rates and tobacco control policy data from Sweden. SimSmoke evaluates the effect of taxes, smoke-free air, mass media, marketing bans, warning labels, cessation treatment and youth access policies on smoking and snus prevalence and the number of deaths attributable to smoking and snus use by gender from 2010 to 2040. Results: Sweden SimSmoke estimates that significant inroads to reducing smoking and snus prevalence and premature mortality can be achieved through tax increases, especially when combined with other policies. Smoking prevalence can be decreased by as much as 26% in the first few years, reaching a 37% reduction within 30 years. Without effective tobacco control policies, almost 54 500 lives will be lost in Sweden due to tobacco use by the year 2040. Conclusion: Besides presenting the benefits of a comprehensive tobacco control strategy, the model identifies gaps in surveillance and evaluation that can help better focus tobacco control policy in Sweden. PMID:24287030

Surface characterization of dialyzer polymer membranes by imaging ToF-SIMS and quantitative XPS line scans

PubMed Central

Holzweber, Markus; Lippitz, Andreas; Krueger, Katharina; Jankowski, Joachim; Unger, Wolfgang E. S.

2015-01-01

The surfaces of polymeric dialyzer membranes consisting of polysulfone and poly-vinylpyrrolidone were investigated regarding the lateral distribution and quantitative surface composition using time-of-flight secondary-ion-mass-spectrometry and x-ray photoelectron spectroscopy. Knowledge of the distribution and composition on the outer surface region is of utmost importance for understanding the biocompatibility of such dialyzer membranes. Both flat membranes and hollow fiber membranes were studied. PMID:25711334

Chemometric and multivariate statistical analysis of time-of-flight secondary ion mass spectrometry spectra from complex Cu-Fe sulfides.

PubMed

Kalegowda, Yogesh; Harmer, Sarah L

2012-03-20

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra of mineral samples are complex, comprised of large mass ranges and many peaks. Consequently, characterization and classification analysis of these systems is challenging. In this study, different chemometric and statistical data evaluation methods, based on monolayer sensitive TOF-SIMS data, have been tested for the characterization and classification of copper-iron sulfide minerals (chalcopyrite, chalcocite, bornite, and pyrite) at different flotation pulp conditions (feed, conditioned feed, and Eh modified). The complex mass spectral data sets were analyzed using the following chemometric and statistical techniques: principal component analysis (PCA); principal component-discriminant functional analysis (PC-DFA); soft independent modeling of class analogy (SIMCA); and k-Nearest Neighbor (k-NN) classification. PCA was found to be an important first step in multivariate analysis, providing insight into both the relative grouping of samples and the elemental/molecular basis for those groupings. For samples exposed to oxidative conditions (at Eh ~430 mV), each technique (PCA, PC-DFA, SIMCA, and k-NN) was found to produce excellent classification. For samples at reductive conditions (at Eh ~ -200 mV SHE), k-NN and SIMCA produced the most accurate classification. Phase identification of particles that contain the same elements but a different crystal structure in a mixed multimetal mineral system has been achieved.

Time-of-flight secondary ion mass spectrometry study on the distribution of alendronate sodium in drug-loaded ultra-high molecular weight polyethylene.

PubMed

Liu, Xiaomin; Qu, Shuxin; Lu, Xiong; Ge, Xiang; Leng, Yang

2009-12-01

The aim of this study was to investigate the drug distribution in ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN), which was developed to treat particle-induced osteolysis after artificial joint replacements, since the drug distribution in UHMWPE could play a key role in controlling drug release. A mixture of UHMWPE powder and ALN was dried and hot pressed to prepare UHMWPE loaded with ALN (UHMWPE-ALN). Fourier transform infrared spectroscopy analysis demonstrated that the hot press had no effect on the functional groups of ALN in UHMWPE-ALN. X-ray diffraction indicated that there was no phase change of the UHMWPE after hot pressing. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra revealed the existence of characteristic elements and functional groups from ALN in UHMWPE-ALN, such as Na+, C3H8N+, PO3(-) and PO3H(-). In addition, SIMS images suggested that ALN did not agglomerate in UHMWPE-ALN. A small punch test and hardness test were carried out and the results indicated that ALN did not affect the mechanical properties at the present content level. The present study demonstrated that it was feasible to fabricate the un-agglomerated distributed drug in UHMWPE with good mechanical properties. This ALN loaded UHMWPE would have potential application in clinics.

AMOR - the time-of-flight neutron reflectometer at SINQ/PSI

NASA Astrophysics Data System (ADS)

Gupta, Mukul; Gutberlet, T.; Stahn, J.; Keller, P.; Clemens, D.

2004-07-01

The apparatus for multioptional reflectometry (AMOR) at SINQ/PSI is a versatile reflectometer operational in the time-of-flight (TOF) mode (in a wavelength range of 0.15 nm <λ < 1.3 nm) as well as in the monochromatic (theta-2theta) mode with both polarized and unpolarized neutrons. AMOR is designed to perform reflectometry measurements in horizontal sample-plane geometry which allows studying both solid-liquid and liquid-liquid interfaces. A pulsed cold neutron beam from the end position of the neutron guide is produced by a dual-chopper system (side-by-side) having two windows at 180^{circ} and rotatable with a maximum frequency of 200 Hz. In the TOF mode, the chopper frequency, width of the gating window and the chopper-detector distance can be selected independently providing a wide range of q-resolution (Delta q/q=1-10&%slash;). Remanent FeCoV/Ti : N supermirrors are used as polarizer/analyzer with a polarization efficiency of sim97&%slash;. For the monochromatic wavelength mode, a Ni/Ti multilayer is used as a monochromator, giving sim50&%slash; reflectivity at a wavelength of 0.47 nm. In the present work, a detailed description of the instrument and setting-up of the polarization option is described. Results from some of the recent studies with polarized neutrons and measurements on liquid surfaces are presented.

Structural analysis of aerosol particles by microscopic observation using a time-of-flight secondary ion mass spectrometer

NASA Astrophysics Data System (ADS)

Takami, Akinori; Mayama, Norihito; Sakamoto, Tetsuo; Ohishi, Kenji; Irei, Satoshi; Yoshino, Ayako; Hatakeyama, Shiro; Murano, Kentaro; Sadanaga, Yasuhiro; Bandow, Hiroshi; Misawa, Kentaro; Fujii, Masaaki

2013-06-01

The chemical composition and structure of fine aerosol particles with diameters of less than 1 µm were analyzed in the spring of 2011 at Fukue Island, Japan, using an aerosol quadrupole mass spectrometer (Q-AMS, Aerodyne Research, Inc.) and a time-of-flight secondary ion mass spectrometer (TOF-SIMS). The Q-AMS results were similar to those of previous studies conducted at the same location, suggesting that the composition we observed is typical of this site. Based on the TOF-SIMS results, we classified the fine aerosol particles into three types: Type A, in which sulfate was covered with organic matter (OM); Type B, in which soil-containing particles with a diameter of 0.5 µm were associated with sulfate and OM; and Type C, in which black carbon (BC) and sulfate aggregates were associated with OM. During the observation period, the relative abundances of Type A, B, and C particles were 55%, 20%, and 25%, respectively. The structure, chemical composition, and the proportion of each type of particles provide information for a more representative particle model in radiative models. The relative abundance of Type C, i.e., BC-containing particles, is quite different to that in Tokyo, suggesting that Type C could be an indicator of transboundary air pollution, in this case from mainland China.

CystiSim – An Agent-Based Model for Taenia solium Transmission and Control

PubMed Central

Gabriël, Sarah; Dorny, Pierre; Speybroeck, Niko; Magnussen, Pascal; Torgerson, Paul; Johansen, Maria Vang

2016-01-01

Taenia solium taeniosis/cysticercosis was declared eradicable by the International Task Force for Disease Eradication in 1993, but remains a neglected zoonosis. To assist in the attempt to regionally eliminate this parasite, we developed cystiSim, an agent-based model for T. solium transmission and control. The model was developed in R and available as an R package (http://cran.r-project.org/package=cystiSim). cystiSim was adapted to an observed setting using field data from Tanzania, but adaptable to other settings if necessary. The model description adheres to the Overview, Design concepts, and Details (ODD) protocol and consists of two entities—pigs and humans. Pigs acquire cysticercosis through the environment or by direct contact with a tapeworm carrier's faeces. Humans acquire taeniosis from slaughtered pigs proportional to their infection intensity. The model allows for evaluation of three interventions measures or combinations hereof: treatment of humans, treatment of pigs, and pig vaccination, and allows for customary coverage and efficacy settings. cystiSim is the first agent-based transmission model for T. solium and suggests that control using a strategy consisting of an intervention only targeting the porcine host is possible, but that coverage and efficacy must be high if elimination is the ultimate goal. Good coverage of the intervention is important, but can be compensated for by including an additional intervention targeting the human host. cystiSim shows that the scenarios combining interventions in both hosts, mass drug administration to humans, and vaccination and treatment of pigs, have a high probability of success if coverage of 75% can be maintained over at least a four year period. In comparison with an existing mathematical model for T. solium transmission, cystiSim also includes parasite maturation, host immunity, and environmental contamination. Adding these biological parameters to the model resulted in new insights in the potential effect of intervention measures. PMID:27984581

CystiSim - An Agent-Based Model for Taenia solium Transmission and Control.

PubMed

Braae, Uffe Christian; Devleesschauwer, Brecht; Gabriël, Sarah; Dorny, Pierre; Speybroeck, Niko; Magnussen, Pascal; Torgerson, Paul; Johansen, Maria Vang

2016-12-01

Taenia solium taeniosis/cysticercosis was declared eradicable by the International Task Force for Disease Eradication in 1993, but remains a neglected zoonosis. To assist in the attempt to regionally eliminate this parasite, we developed cystiSim, an agent-based model for T. solium transmission and control. The model was developed in R and available as an R package (http://cran.r-project.org/package=cystiSim). cystiSim was adapted to an observed setting using field data from Tanzania, but adaptable to other settings if necessary. The model description adheres to the Overview, Design concepts, and Details (ODD) protocol and consists of two entities-pigs and humans. Pigs acquire cysticercosis through the environment or by direct contact with a tapeworm carrier's faeces. Humans acquire taeniosis from slaughtered pigs proportional to their infection intensity. The model allows for evaluation of three interventions measures or combinations hereof: treatment of humans, treatment of pigs, and pig vaccination, and allows for customary coverage and efficacy settings. cystiSim is the first agent-based transmission model for T. solium and suggests that control using a strategy consisting of an intervention only targeting the porcine host is possible, but that coverage and efficacy must be high if elimination is the ultimate goal. Good coverage of the intervention is important, but can be compensated for by including an additional intervention targeting the human host. cystiSim shows that the scenarios combining interventions in both hosts, mass drug administration to humans, and vaccination and treatment of pigs, have a high probability of success if coverage of 75% can be maintained over at least a four year period. In comparison with an existing mathematical model for T. solium transmission, cystiSim also includes parasite maturation, host immunity, and environmental contamination. Adding these biological parameters to the model resulted in new insights in the potential effect of intervention measures.

Highly charged ion based time of flight emission microscope

DOEpatents

Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

2001-01-01

A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

Service-Learning in the Undergraduate Geoscience Classroom: Establishing Community Partnerships to Enhance Education in Climate Change Science in Local Schools

NASA Astrophysics Data System (ADS)

Joseph, L. H.; Faust, R.

2009-12-01

The complexity of the science surrounding global climate change makes effective communication about this issue to the public difficult, especially at a time when many would argue that public understanding of science in general has decreased. As a service-learning project, a partnership was created between an upper-level environmental studies climate change class at Ursinus College (UC) and the UC Science In Motion (SIM) program to construct an appropriate lab activity that would foster scientific knowledge and abilities in high school students particularly in relation to basic climate change science. The Pennsylvania SIM program is a state-funded initiative to make a selection of lab activities, equipment, and expertise available to teachers at secondary schools at no cost to the schools with the goal to “strengthen the quality of science education for all.” The twelve SIM sites are dispersed throughout PA and serve over 200 school districts overall. The UC SIM program has served over 30 local schools with labs and activities from which the teachers may select. Prior to the partnership discussed here, there were no labs in the UC SIM program that incorporated the concepts of climate change and though a “drop-off” climate change lab was desired, the staff would have no time to design one. The adaptation of a previously written lab set on climate change was assigned as a project for the 9 environmental studies majors at UC enrolled in a Fall 2008 course exploring the science of global climate change. While an advanced course within the environmental studies curriculum, the science backgrounds of the college students themselves were mixed, ranging from science majors to students for whom this was the first or second science course taken at college. In addition to the typical load of coursework, the students worked in small groups on this project throughout the semester, collecting the supplies, testing and adapting the labs, creating a video to guide users through the lab, visiting a local high school for a trial run, and editing and writing the worksheets and teacher guides. It was necessary for the students to clearly understand the concepts behind the labs so the activities could be adapted and presented appropriately. Effective communication of the concepts through visuals and written work was also important. Continued coordination with UC SIM staff was required and helpful and the final product was turned over to the UC SIM for further adaptation and use. The college students appreciated the positive impact the lab could have on climate change science education even after the end of the semester and found it both motivating and rewarding. Partnering with an organization already established and utilized as a source of science education activities for the local school districts ensured quick dissemination of the lab activity. Between 1/09-6/09, ~12 teachers have used this global climate change lab with ~500 students of mixed academic levels. The lab has received positive feedback from teachers and supplies have been duplicated to meet demand, likely indicative of a desire for accessible lab activities within the field of environmental science.

Model studies of diffusion-controlled (2-hydroxyethyl methacrylate) HEMA hydrogel membranes for controlled release of proteins

NASA Astrophysics Data System (ADS)

Appawu, Jennifer A. M.

This thesis project consisted of three main components that were connected by roots in chemical analysis for studies in tissue engineering. The first part focused on characterizing the structural parameters of synthetic cross-linked poly (2-hydroxyethyl methacrylate) (Poly(HEMA) hydrogel membranes to determine optimal formulations for clinical studies. Poly(HEMA) membranes were loaded with Keratincocyte Growth Factor (KGF) for controlled release studies. Protein loading and release kinetics were determined with fluorescence spectroscopy. The spatial distribution of a protein in the membrane was determined using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The last part of the project focused on determining the biological effects of the polymer membranes in-vitro with a model cell line and a pilot in-vivo animal study. Based on the components completed in this project, five chapters are included in this dissertation document and are summarized below. A new protocol was developed using fluorescence spectroscopy that measured the rate of protein diffusion into cross-linked polymer membranes by measuring the change in the fluorescence intensity of the protein solution. This technique was also able to detect a conformational change that occurs within protein when KGF was imbibed within these cross-linked polymer membranes. ToF-SIMS chemical imaging and 3D depth profiling was used to determine the spatial distribution of KGF protein in frozen-hydrated HEMA hydrogel membranes. The 3D depth profiles showed that the KGF protein was aggregated in bright spots that indicated that KGF was not spatially homogenous on the surface and through the depth profiles. 3D depth profiles of the membranes studied at various times during release studies show that areas with aggregated proteins were retained during release, and at times with maximum release. The interpretation of the bright regions is that the KGf protein interacted with the cross-linked network of the hydrogel membranes, making it not available for release. The in-vitro biological experiments with the HaCaT cell line showed that the HEMA hydrogels were capable of sustaining cell viability, proliferation, and adhesion through cell adhesion and wounding experiments. The pilot in-vivo animal study also revealed that KGF protein had retained its pharmacological activity. The study also showed that the KGF protein enhanced the rate of wound closure.

Simultaneous versus sequential bilateral cochlear implants in adults: Cost analysis in a US setting.

PubMed

Trinidade, Aaron; Page, Joshua C; Kennett, Sarah W; Cox, Matthew D; Dornhoffer, John L

2017-11-01

From a purely surgical efficiency point of view, simultaneous cochlear implantation (SimCI) is more cost-effective than sequential cochlear implantation (SeqCI) when total direct costs are considered (implant and hospital costs). However, in a setting where only SeqCI is practiced and a proportion of initially unilaterally implanted patients do not progress to a second implant, this may not be the case, especially when audiological costs are factored in. We present a cost analysis of such a scenario as would occur in our institution. Retrospective review and cost analysis. Between 2005 and 2015, 370 patients fulfilled the audiological criteria for bilateral implantation. Of those, 267 (72.1%) underwent unilateral cochlear implantation only, 101 (27.3%) progressed to SeqCI, and two underwent SimCI. The total hospital, surgical, and implant costs, and initial implant stimulation series audiological costs between August 2015 and August 2016 (29 adult patients) were used in this analysis. The total hospital, surgical, and implant costs for this period was $2,731,360.42. Based on previous local trends, if a projected eight (27.3%) of these patients decide to progress to SeqCI, this will cost an additional $750,811.04, resulting in an overall total of $3,482,171.46 for these 29 patients. Had all 29 undergone SimCI, the total projected cost would have been $3,332,991.75, representing a total potential saving of $149,179.67 (4.3%). In institutions where only SeqCI is allowed in adults, overall patient management may cost marginally more than if SimCI were practiced. This will be of interest to CI programs and health insurance companies. 4. Laryngoscope, 127:2615-2618, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Reconstructing Holocene climate using a climate model: Model strategy and preliminary results

NASA Astrophysics Data System (ADS)

Haberkorn, K.; Blender, R.; Lunkeit, F.; Fraedrich, K.

2009-04-01

An Earth system model of intermediate complexity (Planet Simulator; PlaSim) is used to reconstruct Holocene climate based on proxy data. The Planet Simulator is a user friendly general circulation model (GCM) suitable for palaeoclimate research. Its easy handling and the modular structure allow for fast and problem dependent simulations. The spectral model is based on the moist primitive equations conserving momentum, mass, energy and moisture. Besides the atmospheric part, a mixed layer-ocean with sea ice and a land surface with biosphere are included. The present-day climate of PlaSim, based on an AMIP II control-run (T21/10L resolution), shows reasonable agreement with ERA-40 reanalysis data. Combining PlaSim with a socio-technological model (GLUES; DFG priority project INTERDYNAMIK) provides improved knowledge on the shift from hunting-gathering to agropastoral subsistence societies. This is achieved by a data assimilation approach, incorporating proxy time series into PlaSim to initialize palaeoclimate simulations during the Holocene. For this, the following strategy is applied: The sensitivities of the terrestrial PlaSim climate are determined with respect to sea surface temperature (SST) anomalies. Here, the focus is the impact of regionally varying SST both in the tropics and the Northern Hemisphere mid-latitudes. The inverse of these sensitivities is used to determine the SST conditions necessary for the nudging of land and coastal proxy climates. Preliminary results indicate the potential, the uncertainty and the limitations of the method.

Effects of molecular weight and cationization agent on the sensitivity of Bi cluster secondary ion mass spectrometry.

PubMed

Fujii, Makiko; Shishido, Rie; Satoh, Takaya; Suzuki, Shigeru; Matsuo, Jiro

2016-07-30

Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively. The measurements were performed by using a commercial Bi cluster SIMS and MALDI-TOFMS systems. The mass spectrum obtained with MALDI-TOFMS was used as a reference molecular weight distribution to evaluate the effects of molecular weight and primary ion species (Bi + , Bi 3 + , Bi 3 2 + ) on the sensitivity of Bi cluster SIMS. The intensity of each secondary ion was the highest in Bi 3 2 + irradiation, and the lowest in Bi + irradiation. Regarding the cationization agents, the secondary ion yield was the highest for the sample mixed with Ag, while the degree of decay of sensitivity along with the increase in molecular weight was the smallest for the sample mixed with Na. It was suggested that the cationization mechanism consists of pre-formed ionization and gas-phase ionization processes. The sensitivity of Bi cluster SIMS decreases to approximately one-fiftieth in every 1000 u. These results might help in understanding the mechanism of cationization and further enhancement of secondary ion yields of polymers. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison between thaw-mounting and use of conductive tape for sample preparation in ToF-SIMS imaging of lipids in Drosophila microRNA-14 model.

PubMed

Le, Minh Uyen Thi; Son, Jin Gyeong; Shon, Hyun Kyoung; Park, Jeong Hyang; Lee, Sung Bae; Lee, Tae Geol

2018-03-30

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging elucidates molecular distributions in tissue sections, providing useful information about the metabolic pathways linked to diseases. However, delocalization of the analytes and inadequate tissue adherence during sample preparation are among some of the unfortunate phenomena associated with this technique due to their role in the reduction of the quality, reliability, and spatial resolution of the ToF-SIMS images. For these reasons, ToF-SIMS imaging requires a more rigorous sample preparation method in order to preserve the natural state of the tissues. The traditional thaw-mounting method is particularly vulnerable to altered distributions of the analytes due to thermal effects, as well as to tissue shrinkage. In the present study, the authors made comparisons of different tissue mounting methods, including the thaw-mounting method. The authors used conductive tape as the tissue-mounting material on the substrate because it does not require heat from the finger for the tissue section to adhere to the substrate and can reduce charge accumulation during data acquisition. With the conductive-tape sampling method, they were able to acquire reproducible tissue sections and high-quality images without redistribution of the molecules. Also, the authors were successful in preserving the natural states and chemical distributions of the different components of fat metabolites such as diacylglycerol and fatty acids by using the tape-supported sampling in microRNA-14 (miR-14) deleted Drosophila models. The method highlighted here shows an improvement in the accuracy of mass spectrometric imaging of tissue samples.

ToF-SIMS and principal component analysis of lipids and amino acids from inflamed and dysplastic human colonic mucosa.

PubMed

Urbini, Marco; Petito, Valentina; de Notaristefani, Francesco; Scaldaferri, Franco; Gasbarrini, Antonio; Tortora, Luca

2017-10-01

Here, time of flight secondary ion mass spectrometry (ToF-SIMS) and multivariate analysis were combined to study the role of ulcerative colitis (UC), a type of inflammatory bowel disease (IBD), in the colon cancer progression. ToF-SIMS was used to obtain mass spectra and chemical maps from the mucosal surface of human normal (NC), inflamed (IC), and dysplastic (DC) colon tissues. Chemical mapping with a lateral resolution of ≈ 1 μm allowed to evaluate zonation of fatty acids and amino acids as well as the morphological condition of the intestinal glands. High mass resolution ToF-SIMS spectra showed chemical differences in lipid and amino acid composition as a function of pathological state. In positive ion mode, mono- (MAG), di- (DAG), and triacylglycerol (TAG) signals were detected in NC tissues, while in IC and DC tissues, the only cholesterol was present as lipid class representative. Signals from fatty acids, collected in negative ion mode, were subjected to principal component analysis (PCA). PCA showed a strict correlation between IC and DC samples, due to an increase of stearic, arachidonic, and linoleic acid. In the same way, differences in the amino acid composition were highlighted through multivariate analysis. PCA revealed that glutamic acid, leucine/isoleucine, and valine fragments are related to IC tissues. On the other hand, tyrosine, methionine, and tryptophan peaks contributed highly to the separation of DC tissues. Finally, a classification of NC, IC, and DC patients was also achieved through hierarchical cluster analysis of amino acid fragments. In this case, human colonic inflammation showed a stronger relationship with normal than dysplastic condition. Graphical Abstract ᅟ.

Nitric oxide assisted C60 secondary ion mass spectrometry for molecular depth profiling of polyelectrolyte multilayers.

PubMed

Zappalà, G; Motta, V; Tuccitto, N; Vitale, S; Torrisi, A; Licciardello, A

2015-12-15

Secondary ion mass spectrometry (SIMS) with polyatomic primary ions provides a successful tool for molecular depth profiling of polymer systems, relevant in many technological applications. Widespread C60 sources, however, cause in some polymers extensive damage with loss of molecular information along depth. We study a method, based on the use of a radical scavenger, for inhibiting ion-beam-induced reactions causing sample damage. Layered polystyrene sulfonate and polyacrylic acid based polyelectrolyte films, behaving differently towards C60 beam-induced damage, were selected and prepared as model systems. They were depth profiled by means of time-of-flight (TOF)-SIMS in dual beam mode, using fullerene ions for sputtering. Nitric oxide was introduced into the analysis chamber as a radical scavenger. The effect of sample cooling combined with NO-dosing on the quality of depth profiles was explored. NO-dosing during C60-SIMS depth profiling of >1 micrometer-thick multilayered polyelectrolytes allows detection, along depth, of characteristic fragments from systems otherwise damaged by C60 bombardment, and increases sputtering yield by more than one order of magnitude. By contrast, NO has little influence on those layers that are well profiled with C60 alone. Such leveling effect, more pronounced at low temperature, leads to a dramatic improvement of profile quality, with a clear definition of interfaces. NO-dosing provides a tool for extending the applicability, in SIMS depth profiling, of the widely spread fullerene ion sources. In view of the acceptable erosion rates on inorganics, obtainable with C60, the method could be of relevance also in connection with the 3D-imaging of hybrid polymer/inorganic systems. Copyright © 2015 John Wiley & Sons, Ltd.

Preliminary Airspace Operations Simulations Findings Report

NASA Technical Reports Server (NTRS)

2005-01-01

Provides preliminary findings of the initial series (normal operations and contingency management) of airspace operations simulations. The key elements of this report discuss feedback from controller subjects for UAS flight above FL430. Findings provide initial evaluation of routine UAS operations above dense ARTCC airspace (ZOB), and identify areas of further research, policy direction and procedural development. This document further serves as an addendum to the detailed AOS simulation plan (Deliverable SIM001), incorporating feedback from FAA air traffic personnel and Access 5 IPTs.

Discover Supercomputer 5

NASA Image and Video Library

2017-12-08

Two rows of the “Discover” supercomputer at the NASA Center for Climate Simulation (NCCS) contain more than 4,000 computer processors. Discover has a total of nearly 15,000 processors. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Discover Supercomputer 4

NASA Image and Video Library

2017-12-08

This close-up view highlights one row—approximately 2,000 computer processors—of the “Discover” supercomputer at the NASA Center for Climate Simulation (NCCS). Discover has a total of nearly 15,000 processors. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Electrochemical behavior of Al in a non-aqueous alkyl carbonate solution containing LiBOB salt

NASA Astrophysics Data System (ADS)

Myung, Seung-Taek; Natsui, Hiroshi; Sun, Yang-Kook; Yashiro, Hitoshi

Aluminum was studied as a current collector for rechargeable lithium batteries to understand electrochemical and passivation behavior. Electrochemical polarization tests, in situ scratch polarization tests and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) analysis in lithium bis-oxalato borate (LiBOB)-containing alkyl carbonate solution were conducted. The Al foil did not follow the alloy and de-alloy process with the LiBOB salt in electrolyte at 0 V vs. Li/Li + in the cathodic sweep. During the anodic scan to the noble direction, the absence of an oxidation peak up to 3 V vs. Li/Li + indicated that the air-formed oxide layer of Al was not reduced to metal. Oxide-free Al surfaces made by the in situ scratch test during the electrochemical polarization resulted in abrupt alloy formation with Li at 0 V vs. Li/Li +, but the newly formed surface formed passive films at higher potential with oxygen, namely, Al-O compound, as confirmed by ToF-SIMS.

Understanding the Interface Dipole of Copper Phthalocyanine (CuPc)/C60: Theory and Experiment.

PubMed

Sai, Na; Gearba, Raluca; Dolocan, Andrei; Tritsch, John R; Chan, Wai-Lun; Chelikowsky, James R; Leung, Kevin; Zhu, Xiaoyang

2012-08-16

Interface dipole determines the electronic energy alignment in donor/acceptor interfaces and plays an important role in organic photovoltaics. Here we present a study combining first principles density functional theory (DFT) with ultraviolet photoemission spectroscopy (UPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to investigate the interface dipole, energy level alignment, and structural properties at the interface between CuPc and C60. DFT finds a sizable interface dipole for the face-on orientation, in quantitative agreement with the UPS measurement, and rules out charge transfer as the origin of the interface dipole. Using TOF-SIMS, we show that the interfacial morphology for the bilayer CuPc/C60 film is characterized by molecular intermixing, containing both the face-on and the edge-on orientation. The complementary experimental and theoretical results provide both insight into the origin of the interface dipole and direct evidence for the effect of interfacial morphology on the interface dipole.

Interfacial micropore defect formation in PEDOT:PSS-Si hybrid solar cells probed by TOF-SIMS 3D chemical imaging.

PubMed

Thomas, Joseph P; Zhao, Liyan; Abd-Ellah, Marwa; Heinig, Nina F; Leung, K T

2013-07-16

Conducting p-type polymer layers on n-type Si have been widely studied for the fabrication of cost-effective hybrid solar cells. In this work, time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to provide three-dimensional chemical imaging of the interface between poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) and SiOx/Si in a hybrid solar cell. To minimize structural damage to the polymer layer, an Ar cluster sputtering source is used for depth profiling. The present result shows the formation of micropore defects in the interface region of the PEDOT:PSS layer on the SiOx/Si substrate. This interfacial micropore defect formation becomes more prominent with increasing thickness of the native oxide layer, which is a key device parameter that greatly affects the hybrid solar cell performance. Three-dimensional chemical imaging coupled with Ar cluster ion sputtering has therefore been demonstrated as an emerging technique for probing the interface of this and other polymer-inorganic systems.

Direct Observation of Ion Distributions near Electrodes in Ionic Polymer Actuators Containing Ionic Liquids

PubMed Central

Liu, Yang; Lu, Caiyan; Twigg, Stephen; Ghaffari, Mehdi; Lin, Junhong; Winograd, Nicholas; Zhang, Q. M.

2013-01-01

The recent boom of energy storage and conversion devices, exploiting ionic liquids (ILs) to enhance the performance, requires an in-depth understanding of this new class of electrolytes in device operation conditions. One central question critical to device performance is how the mobile ions accumulate near charged electrodes. Here, we present the excess ion depth profiles of ILs in ionomer membrane actuators (Aquivion/1-butyl-2,3-dimethylimidazolium chloride (BMMI-Cl), 27 μm thick), characterized directly by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) at liquid nitrogen temperature. Experimental results reveal that for the IL studied, cations and anions are accumulated at both electrodes. The large difference in the total volume occupied by the excess ions between the two electrodes cause the observed large bending actuation of the actuator. Hence we demonstrate that ToF-SIMS experiment provides great insights on the physics nature of ionic devices. PMID:23512124

Protein adsorption/desorption and antibody binding stoichiometry on silicon interferometric biosensors examined with TOF-SIMS

NASA Astrophysics Data System (ADS)

Gajos, Katarzyna; Budkowski, Andrzej; Petrou, Panagiota; Pagkali, Varvara; Awsiuk, Kamil; Rysz, Jakub; Bernasik, Andrzej; Misiakos, Konstantinos; Raptis, Ioannis; Kakabakos, Sotirios

2018-06-01

Time-of-flight secondary ion mass spectrometry has been employed to examine, with biomolecular discrimination, sensing arm areas (20 μm × 600 μm) of integrated onto silicon chips Mach-Zehnder interferometers aiming to optimize their biofunctionalization with regard to indirect immunochemical (competitive) detection of ochratoxin A. Sensing areas are examined after: modification with (3-aminopropyl)triethoxysilane, spotting of OTA-ovalbumin conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin, reaction with OTA-specific mouse monoclonal antibody followed by goat anti-mouse IgG secondary antibody. Component mass loadings of all proteins involved in immunodetection are determined from TOF-SIMS micro-analysis combined with ellipsometry of planar surfaces. These data show that partial desorption of surface-bound probe and blocking protein takes place upon primary immunoreaction to a degree that depends on probe concentration in spotting solution. Taking into account this desorption, apparent binding stoichiometry of both antibodies in immune complexes formed onto chip surface is determined more accurately than the respective evaluation based on real-time sensor response. In addition, mass loadings for probe and secondary antibody is observed to saturate for optimum probe concentrations. Also, principal component analysis of TOF-SIMS data could resolve both immunoreactions and biofunctionalization and discriminate surfaces prepared with optimum probe concentrations from those prepared using suboptimum ones.

Up-regulation of Na + expression in the area postrema of total sleep deprived rats by TOF-SIMS analysis

NASA Astrophysics Data System (ADS)

Mai, Fu-Der; Chen, Bo-Jung; Ling, Yong-Chien; Wu, Un-In; Huang, Yi-Lun; Chang, Hung-Ming

2008-12-01

Area postrema (AP) is a circumventricular organ plays an important role in sodium homeostasis and cardiovascular regulation. Since sleep deficiency will cause cardiovascular dysfunction, the present study aims to determine whether sodium level would significantly alter in AP following total sleep deprivation (TSD). Sodium level was investigated in vivo by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Clinical manifestation of cardiovascular function was demonstrated by mean arterial pressure (MAP) values. Results indicated that in normal rats, TOF-SIMS spectrum revealed a major peak of sodium ion counting as 5.61 × 10 5 at m/ z 23. The sodium ions were homogeneous distributed in AP without specific localization. However, following TSD, the sodium intensity was relatively increased (6.73 × 10 5) and the signal for sodium image was strongly expressed throughout AP with definite spatial distribution. MAP of TSD rats is 138 ± 5 mmHg, which is significantly higher than that of normal ones (121 ± 3 mmHg). Regarding AP is an important area for sodium sensation and development of hypernatremic related sympatho-excitation; up-regulation of sodium expression following TSD suggests that high sodium level might over-activate AP, through complex neuronal networks involving in sympathetic regulation, which could lead to the formation of TSD relevant cardiovascular diseases.

DMD-based LED-illumination super-resolution and optical sectioning microscopy.

PubMed

Dan, Dan; Lei, Ming; Yao, Baoli; Wang, Wen; Winterhalder, Martin; Zumbusch, Andreas; Qi, Yujiao; Xia, Liang; Yan, Shaohui; Yang, Yanlong; Gao, Peng; Ye, Tong; Zhao, Wei

2013-01-01

Super-resolution three-dimensional (3D) optical microscopy has incomparable advantages over other high-resolution microscopic technologies, such as electron microscopy and atomic force microscopy, in the study of biological molecules, pathways and events in live cells and tissues. We present a novel approach of structured illumination microscopy (SIM) by using a digital micromirror device (DMD) for fringe projection and a low-coherence LED light for illumination. The lateral resolution of 90 nm and the optical sectioning depth of 120 μm were achieved. The maximum acquisition speed for 3D imaging in the optical sectioning mode was 1.6×10(7) pixels/second, which was mainly limited by the sensitivity and speed of the CCD camera. In contrast to other SIM techniques, the DMD-based LED-illumination SIM is cost-effective, ease of multi-wavelength switchable and speckle-noise-free. The 2D super-resolution and 3D optical sectioning modalities can be easily switched and applied to either fluorescent or non-fluorescent specimens.

DMD-based LED-illumination Super-resolution and optical sectioning microscopy

PubMed Central

Dan, Dan; Lei, Ming; Yao, Baoli; Wang, Wen; Winterhalder, Martin; Zumbusch, Andreas; Qi, Yujiao; Xia, Liang; Yan, Shaohui; Yang, Yanlong; Gao, Peng; Ye, Tong; Zhao, Wei

2013-01-01

Super-resolution three-dimensional (3D) optical microscopy has incomparable advantages over other high-resolution microscopic technologies, such as electron microscopy and atomic force microscopy, in the study of biological molecules, pathways and events in live cells and tissues. We present a novel approach of structured illumination microscopy (SIM) by using a digital micromirror device (DMD) for fringe projection and a low-coherence LED light for illumination. The lateral resolution of 90 nm and the optical sectioning depth of 120 μm were achieved. The maximum acquisition speed for 3D imaging in the optical sectioning mode was 1.6×107 pixels/second, which was mainly limited by the sensitivity and speed of the CCD camera. In contrast to other SIM techniques, the DMD-based LED-illumination SIM is cost-effective, ease of multi-wavelength switchable and speckle-noise-free. The 2D super-resolution and 3D optical sectioning modalities can be easily switched and applied to either fluorescent or non-fluorescent specimens. PMID:23346373

The effects of text messaging on young novice driver performance

DOT National Transportation Integrated Search

2006-02-01

This project aimed to evaluate, using the advanced driving simulator located at the Monash University Accident Research Centre, the effects of text (SMS) messaging on the driving performance of young novice drivers. Twenty participants drove on a sim...

Sweden SimSmoke: the effect of tobacco control policies on smoking and snus prevalence and attributable deaths.

PubMed

Near, Aimee M; Blackman, Kenneth; Currie, Laura M; Levy, David T

2014-06-01

This study examines the effect of past tobacco control policies and projects the effect of future policies on smoking and snus use prevalence and associated premature mortality in Sweden. The established SimSmoke model was adapted with population, smoking rates and tobacco control policy data from Sweden. SimSmoke evaluates the effect of taxes, smoke-free air, mass media, marketing bans, warning labels, cessation treatment and youth access policies on smoking and snus prevalence and the number of deaths attributable to smoking and snus use by gender from 2010 to 2040. Sweden SimSmoke estimates that significant inroads to reducing smoking and snus prevalence and premature mortality can be achieved through tax increases, especially when combined with other policies. Smoking prevalence can be decreased by as much as 26% in the first few years, reaching a 37% reduction within 30 years. Without effective tobacco control policies, almost 54 500 lives will be lost in Sweden due to tobacco use by the year 2040. Besides presenting the benefits of a comprehensive tobacco control strategy, the model identifies gaps in surveillance and evaluation that can help better focus tobacco control policy in Sweden. © The Author 2013. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

SimPhospho: a software tool enabling confident phosphosite assignment.

PubMed

Suni, Veronika; Suomi, Tomi; Tsubosaka, Tomoya; Imanishi, Susumu Y; Elo, Laura L; Corthals, Garry L

2018-03-27

Mass spectrometry combined with enrichment strategies for phosphorylated peptides has been successfully employed for two decades to identify sites of phosphorylation. However, unambiguous phosphosite assignment is considered challenging. Given that site-specific phosphorylation events function as different molecular switches, validation of phosphorylation sites is of utmost importance. In our earlier study we developed a method based on simulated phosphopeptide spectral libraries, which enables highly sensitive and accurate phosphosite assignments. To promote more widespread use of this method, we here introduce a software implementation with improved usability and performance. We present SimPhospho, a fast and user-friendly tool for accurate simulation of phosphopeptide tandem mass spectra. Simulated phosphopeptide spectral libraries are used to validate and supplement database search results, with a goal to improve reliable phosphoproteome identification and reporting. The presented program can be easily used together with the Trans-Proteomic Pipeline and integrated in a phosphoproteomics data analysis workflow. SimPhospho is available for Windows, Linux and Mac operating systems at https://sourceforge.net/projects/simphospho/. It is open source and implemented in C ++. A user's manual with detailed description of data analysis using SimPhospho as well as test data can be found as supplementary material of this article. Supplementary data are available at https://www.btk.fi/research/ computational-biomedicine/software/.

Computational Modeling Using OpenSim to Simulate a Squat Exercise Motion

NASA Technical Reports Server (NTRS)

Gallo, C. A.; Thompson, W. K.; Lewandowski, B. E.; Humphreys, B. T.; Funk, J. H.; Funk, N. H.; Weaver, A. S.; Perusek, G. P.; Sheehan, C. C.; Mulugeta, L.

2015-01-01

Long duration space travel to destinations such as Mars or an asteroid will expose astronauts to extended periods of reduced gravity. Astronauts will use an exercise regime for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Since the area available in the spacecraft for an exercise device is limited and gravity is not present to aid loading, compact resistance exercise device prototypes are being developed. Since it is difficult to rigorously test these proposed devices in space flight, computational modeling provides an estimation of the muscle forces, joint torques and joint loads during exercise to gain insight on the efficacy to protect the musculoskeletal health of astronauts.

The SCD - Stem Cell Differentiation ESA Project: Preparatory Work for the Spaceflight Mission

NASA Astrophysics Data System (ADS)

Versari, Silvia; Barenghi, Livia; van Loon, Jack; Bradamante, Silvia

2016-04-01

Due to spaceflight, astronauts experience serious, weightlessness-induced bone loss because of an unbalanced process of bone remodeling that involves bone marrow mesenchymal stem cells (BMSCs), as well as osteoblasts, osteocytes, and osteoclasts. The effects of microgravity on osteo-cells have been extensively studied, but it is only recently that consideration has been given to the role of BMSCs. Previous researches indicated that human BMSCs cultured in simulated microgravity (sim-μg) alter their proliferation and differentiation. The spaceflight opportunities for biomedical experiments are rare and suffer from a number of operative constraints that could bias the validity of the experiment itself, but remain a unique opportunity to confirm and explain the effects due to microgravity, that are only partially activated/detectable in simulated conditions. For this reason, we carefully prepared the SCD - STEM CELLS DIFFERENTIATION experiment, selected by the European Space Agency (ESA) and now on the International Space Station (ISS). Here we present the preparatory studies performed on ground to adapt the project to the spaceflight constraints in terms of culture conditions, fixation and storage of human BMSCs in space aiming at satisfying the biological requirements mandatory to retrieve suitable samples for post-flight analyses. We expect to understand better the molecular mechanisms governing human BMSC growth and differentiation hoping to outline new countermeasures against astronaut bone loss.

Secondary ion mass spectrometry imaging and multivariate data analysis reveal co-aggregation patterns of Populus trichocarpa leaf surface compounds on a micrometer scale.

PubMed

Kulkarni, Purva; Dost, Mina; Bulut, Özgül Demir; Welle, Alexander; Böcker, Sebastian; Boland, Wilhelm; Svatoš, Aleš

2018-01-01

Spatially resolved analysis of a multitude of compound classes has become feasible with the rapid advancement in mass spectrometry imaging strategies. In this study, we present a protocol that combines high lateral resolution time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging with a multivariate data analysis (MVA) approach to probe the complex leaf surface chemistry of Populus trichocarpa. Here, epicuticular waxes (EWs) found on the adaxial leaf surface of P. trichocarpa were blotted on silicon wafers and imaged using TOF-SIMS at 10 μm and 1 μm lateral resolution. Intense M +● and M -● molecular ions were clearly visible, which made it possible to resolve the individual compound classes present in EWs. Series of long-chain aliphatic saturated alcohols (C 21 -C 30 ), hydrocarbons (C 25 -C 33 ) and wax esters (WEs; C 44 -C 48 ) were clearly observed. These data correlated with the 7 Li-chelation matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, which yielded mostly molecular adduct ions of the analyzed compounds. Subsequently, MVA was used to interrogate the TOF-SIMS dataset for identifying hidden patterns on the leaf's surface based on its chemical profile. After the application of principal component analysis (PCA), a small number of principal components (PCs) were found to be sufficient to explain maximum variance in the data. To further confirm the contributions from pure components, a five-factor multivariate curve resolution (MCR) model was applied. Two distinct patterns of small islets, here termed 'crystals', were apparent from the resulting score plots. Based on PCA and MCR results, the crystals were found to be formed by C 23 or C 29 alcohols. Other less obvious patterns observed in the PCs revealed that the adaxial leaf surface is coated with a relatively homogenous layer of alcohols, hydrocarbons and WEs. The ultra-high-resolution TOF-SIMS imaging combined with the MVA approach helped to highlight the diverse patterns underlying the leaf's surface. Currently, the methods available to analyze the surface chemistry of waxes in conjunction with the spatial information related to the distribution of compounds are limited. This study uses tools that may provide important biological insights into the composition of the wax layer, how this layer is repaired after mechanical damage or insect feeding, and which transport mechanisms are involved in deploying wax constituents to specific regions on the leaf surface. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Developing a Serious Game for decision making for the water-land-food-energy-climate Nexus in Sardinia-Italy: The SIM4NEXUS approach

NASA Astrophysics Data System (ADS)

Vamvakeridou-Lyroudia, Lydia; Alexandri, Eva; Blanco, Maria; Chew, Chengzi; Conradt, Tobias; Daskalou, Olympia; Evans, Barry; Guitart, Francesc; Mereu, Simone; Sartori, Martina; Susnik, Janez; Savic, Dragan

2017-04-01

A four-year EU H2020 project "Sustainable Integrated Management FOR the NEXUS of water-land-food-energy-climate for a resource-efficient Europe (SIM4NEXUS)" started in June 2016, with an overall grant of € 7.9M (www.sim4nexus.eu). The project involves 25 partners from 15 European countries. SIM4NEXUS has four objectives: (i) to adopt existing knowledge and develop new expertise on the water-energy-food-climate-land use Nexus; (ii) to reduce uncertainties of how policies, governance and institutions affect complex environmental systems; (iii) to showcase the implementation via a network of three regional, five national, two transboundary case studies in Europe, as well as continental and global studies; (iv) to valorise the project outputs by suitable business models. SIM4NEXUS develops an innovative concept and methodologies to facilitate the design of policies and bridge knowledge and technology gaps in the field of the Nexus under global change. The project will develop a methodology of integration using a complexity science approach and a Serious Game (a decision-based platform that allows policy makers to play out scenarios to see what would bring the best outcome) as an integrating tool for testing and evaluating policy decisions. The Serious Game is based on Aqua Republica (http://www.dhigroup.com/upload/publications/scribd/172629015-Exploring-the-World-of-Aqua-Republica-DHI-Case-Story.pdf ) and will cover a vast array of scenarios for all the case studies, over short, medium and long terms. In this presentation we focus on all the stages of the development of the Serious Game for one of our Case Studies (Sardinia, Italy) which is being used as a pilot example prior to wider rollout. Specifically we detail the components and steps involved in Game development including: (i) linking thematic models (CAPRI- http://www.capri-model.org/dokuwiki/doku.php and E3ME- http://www.e3me.com/) and downscaling to regional level; (ii) climate change scenarios (using and downscaling HADGEM2 models - http://www.metoffice.gov.uk/research/modelling-systems/unified-model/climate-models/hadgem2); (iii) socio-economic inputs and projections (GTAP - http://en.openei.org/wiki/Global_Trade_and_Analysis_Project_(GTAP)_Model) with System Dynamic Modelling (SDM) using STELLA for the visual environment- http://www.iseesystems.com/store/products/stella-professional.aspx and STELLAR as an open source programming language - http://www.r-gis.net/stellar/); (iv) creating a Knowledge Elicitation Engine (KEE), providing nexus semantics to the outputs of the SDM and (v) generating knowledge from Serious Game user interaction. Local data from Sardinian experts and stakeholders are being used in the pilot, which has been developed with their participation. The presentation will show results from sample scenarios and the approach to simulating uncertainties using SDM, as well as the overall data transfer and management scheme. It should be pointed out that the process of linking thematic models to System Dynamics (Complexity Science Modelling) and creating a KEE out of this combination is, to the best of our knowledge, novel and does not exist in the literature.

Integrating meso- and micro-simulation models to evaluate traffic management strategies - year 1 : final report.

DOT National Transportation Integrated Search

2016-06-01

In this project the researchers developed a hierarchical multi-resolution traffic simulation system for metropolitan areas, referred to as MetroSim. Categorically, the focus is on integrating two types of simulation: microscopic simulation in which i...

Computer aiding for low-altitude helicopter flight

NASA Technical Reports Server (NTRS)

Swenson, Harry N.

1991-01-01

A computer-aiding concept for low-altitude helicopter flight was developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generated algorithm based on dynamic programming, and a head-up display (HUD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor symbol. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and advanced navigation information to determine a trajectory between mission waypoints that minimizes threat exposure by seeking valleys. The pilot evaluation was conducted at NASA Ames Research Center's Sim Lab facility in both the fixed-base Interchangeable Cab (ICAB) simulator and the moving-base Vertical Motion Simulator (VMS) by pilots representing NASA, the U.S. Army, and the U.S. Air Force. The pilots manually tracked the trajectory generated by the algorithm utilizing the HUD symbology. They were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world.

Loss of hypothalamic corticotropin-releasing hormone markedly reduces anxiety behaviors in mice.

PubMed

Zhang, R; Asai, M; Mahoney, C E; Joachim, M; Shen, Y; Gunner, G; Majzoub, J A

2017-05-01

A long-standing paradigm posits that hypothalamic corticotropin-releasing hormone (CRH) regulates neuroendocrine functions such as adrenal glucocorticoid release, whereas extra-hypothalamic CRH has a key role in stressor-triggered behaviors. Here we report that hypothalamus-specific Crh knockout mice (Sim1CrhKO mice, created by crossing Crhflox with Sim1Cre mice) have absent Crh mRNA and peptide mainly in the paraventricular nucleus of the hypothalamus (PVH) but preserved Crh expression in other brain regions including amygdala and cerebral cortex. As expected, Sim1CrhKO mice exhibit adrenal atrophy as well as decreased basal, diurnal and stressor-stimulated plasma corticosterone secretion and basal plasma adrenocorticotropic hormone, but surprisingly, have a profound anxiolytic phenotype when evaluated using multiple stressors including open-field, elevated plus maze, holeboard, light-dark box and novel object recognition task. Restoring plasma corticosterone did not reverse the anxiolytic phenotype of Sim1CrhKO mice. Crh-Cre driver mice revealed that PVHCrh fibers project abundantly to cingulate cortex and the nucleus accumbens shell, and moderately to medial amygdala, locus coeruleus and solitary tract, consistent with the existence of PVHCrh-dependent behavioral pathways. Although previous, nonselective attenuation of CRH production or action, genetically in mice and pharmacologically in humans, respectively, has not produced the anticipated anxiolytic effects, our data show that targeted interference specifically with hypothalamic Crh expression results in anxiolysis. Our data identify neurons that express both Sim1 and Crh as a cellular entry point into the study of CRH-mediated, anxiety-like behaviors and their therapeutic attenuation.

Loss of hypothalamic corticotropin-releasing hormone markedly reduces anxiety behaviors in mice

PubMed Central

Zhang, Rong; Asai, Masato; Mahoney, Carrie E; Joachim, Maria; Shen, Yuan; Gunner, Georgia; Majzoub, Joseph A

2016-01-01

A long-standing paradigm posits that hypothalamic corticotropin-releasing hormone (CRH) regulates neuroendocrine functions such as adrenal glucocorticoid release, while extra-hypothalamic CRH plays a key role in stressor-triggered behaviors. Here we report that hypothalamus-specific Crh knockout mice (Sim1CrhKO mice, created by crossing Crhflox with Sim1Cre mice) have absent Crh mRNA and peptide mainly in the paraventricular nucleus of the hypothalamus (PVH) but preserved Crh expression in other brain regions including amygdala and cerebral cortex. As expected, Sim1CrhKO mice exhibit adrenal atrophy as well as decreased basal, diurnal and stressor-stimulated plasma corticosterone secretion and basal plasma ACTH, but surprisingly, have a profound anxiolytic phenotype when evaluated using multiple stressors including open field, elevated plus maze, holeboard, light-dark box, and novel object recognition task. Restoring plasma corticosterone did not reverse the anxiolytic phenotype of Sim1CrhKO mice. Crh-Cre driver mice revealed that PVHCrh fibers project abundantly to cingulate cortex and the nucleus accumbens shell, and moderately to medial amygdala, locus coeruleus, and solitary tract, consistent with the existence of PVHCrh-dependent behavioral pathways. Although previous, nonselective attenuation of CRH production or action, genetically in mice and pharmacologically in humans, respectively, has not produced the anticipated anxiolytic effects, our data show that targeted interference specifically with hypothalamic Crh expression results in anxiolysis. Our data identify neurons that express both Sim1 and Crh as a cellular entry point into the study of CRH-mediated, anxiety-like behaviors and their therapeutic attenuation. PMID:27595593

Simultaneous 99mtc/111in spect reconstruction using accelerated convolution-based forced detection monte carlo

NASA Astrophysics Data System (ADS)

Karamat, Muhammad I.; Farncombe, Troy H.

2015-10-01

Simultaneous multi-isotope Single Photon Emission Computed Tomography (SPECT) imaging has a number of applications in cardiac, brain, and cancer imaging. The major concern however, is the significant crosstalk contamination due to photon scatter between the different isotopes. The current study focuses on a method of crosstalk compensation between two isotopes in simultaneous dual isotope SPECT acquisition applied to cancer imaging using 99mTc and 111In. We have developed an iterative image reconstruction technique that simulates the photon down-scatter from one isotope into the acquisition window of a second isotope. Our approach uses an accelerated Monte Carlo (MC) technique for the forward projection step in an iterative reconstruction algorithm. The MC estimated scatter contamination of a radionuclide contained in a given projection view is then used to compensate for the photon contamination in the acquisition window of other nuclide. We use a modified ordered subset-expectation maximization (OS-EM) algorithm named simultaneous ordered subset-expectation maximization (Sim-OSEM), to perform this step. We have undertaken a number of simulation tests and phantom studies to verify this approach. The proposed reconstruction technique was also evaluated by reconstruction of experimentally acquired phantom data. Reconstruction using Sim-OSEM showed very promising results in terms of contrast recovery and uniformity of object background compared to alternative reconstruction methods implementing alternative scatter correction schemes (i.e., triple energy window or separately acquired projection data). In this study the evaluation is based on the quality of reconstructed images and activity estimated using Sim-OSEM. In order to quantitate the possible improvement in spatial resolution and signal to noise ratio (SNR) observed in this study, further simulation and experimental studies are required.

X-43A Final Flight Observations

NASA Technical Reports Server (NTRS)

Grindle, Laurie

2011-01-01

The presentation will provide an overview of the final flight of the NASA X-43A project. The project consisted of three flights, two planned for Mach 7 and one for Mach 10. The first flight, conducted on June 2, 2001, was unsuccessful and resulted in a nine-month mishap investigation. A two-year return to flight effort ensued and concluded when the second Mach 7 flight was successfully conducted on March 27, 2004. The third and final flight, which occurred on November 16, 2004, was the first Mach 10 flight demonstration of an airframe-integrated, scramjet-powered, hypersonic vehicle. As such, the final flight presented first time technical challenges in addition to final flight project closeout concerns. The goals and objectives for the third flight as well as those for the project will be presented. The configuration of the Hyper-X stack including the X-43A, Hyper-X launch vehicle, and Hyper-X research vehicle adapter wil also be presented. Mission differences, vehicle modifications and lessons learned from the first and second flights as they applied to the third flight will also be discussed. Although X-43A flight 3 was always planned to be the final flight of the X-43A project, the X-43 program had two other vehicles and corresponding flight phases in X-43C and X-43B. Those other projects never manifested under the X-43 banner and X-43A flight 3 also became the final flight of X-43 program.

The LSST Metrics Analysis Framework (MAF)

NASA Astrophysics Data System (ADS)

Jones, R. Lynne; Yoachim, Peter; Chandrasekharan, Srinivasan; Connolly, Andrew J.; Cook, Kem H.; Ivezic, Zeljko; Krughoff, K. Simon; Petry, Catherine E.; Ridgway, Stephen T.

2015-01-01

Studying potential observing strategies or cadences for the Large Synoptic Survey Telescope (LSST) is a complicated but important problem. To address this, LSST has created an Operations Simulator (OpSim) to create simulated surveys, including realistic weather and sky conditions. Analyzing the results of these simulated surveys for the wide variety of science cases to be considered for LSST is, however, difficult. We have created a Metric Analysis Framework (MAF), an open-source python framework, to be a user-friendly, customizable and easily extensible tool to help analyze the outputs of the OpSim.MAF reads the pointing history of the LSST generated by the OpSim, then enables the subdivision of these pointings based on position on the sky (RA/Dec, etc.) or the characteristics of the observations (e.g. airmass or sky brightness) and a calculation of how well these observations meet a specified science objective (or metric). An example simple metric could be the mean single visit limiting magnitude for each position in the sky; a more complex metric might be the expected astrometric precision. The output of these metrics can be generated for a full survey, for specified time intervals, or for regions of the sky, and can be easily visualized using a web interface.An important goal for MAF is to facilitate analysis of the OpSim outputs for a wide variety of science cases. A user can often write a new metric to evaluate OpSim for new science goals in less than a day once they are familiar with the framework. Some of these new metrics are illustrated in the accompanying poster, "Analyzing Simulated LSST Survey Performance With MAF".While MAF has been developed primarily for application to OpSim outputs, it can be applied to any dataset. The most obvious examples are examining pointing histories of other survey projects or telescopes, such as CFHT.

Development of a bio-inspired UAV perching system

NASA Astrophysics Data System (ADS)

Xie, Pu

Although technologies of unmanned aerial vehicles (UAVs) including micro air vehicles (MAVs) have been greatly advanced in the recent years, it is still very difficult for a UAV to perform some very challenging tasks such as perching to any desired spot reliably and agilely like a bird. Unlike the UAVs, the biological control mechanism of birds has been optimized through millions of year evolution and hence, they can perform many extremely maneuverability tasks, such as perching or grasping accurately and robustly. Therefore, we have good reason to learn from the nature in order to significantly improve the capabilities of UAVs. The development of a UAV perching system is becoming feasible, especially after a lot of research contributions in ornithology which involve the analysis of the bird's functionalities. Meanwhile, as technology advances in many engineering fields, such as airframes, propulsion, sensors, batteries, micro-electromechanical-system (MEMS), and UAV technology is also advancing rapidly. All of these research efforts in ornithology and the fast growing development technologies in UAV applications are motivating further interests and development in the area of UAV perching and grasping research. During the last decade, the research contributions about UAV perching and grasping were mainly based on fixed-wing, flapping-wing, and rotorcraft UAVs. However, most of the current researches in UAV systems with perching and grasping capability are focusing on either active (powered) grasping and perching or passive (unpowered) perching. Although birds do have both active and passive perching capabilities depending on their needs, there is no UAV perching system with both capabilities. In this project, we focused on filling this gap. Inspired by the anatomy analysis of bird legs and feet, a novel perching system has been developed to implement the bionics action for both active grasping and passive perching. In addition, for developing a robust and autonomous perching system, the following objectives were included for this project. The statics model was derived through both quasi-static and analytical method. The grasping stable condition and grasping target of the mechanical gripper were studied through the static analysis. Furthermore, the contact behavior between each foot and the perched object was modeled and evaluated on SimMechanics based on the contact force model derived through virtual principle. The kinematics modeling of UAV perching system was governed with Euler angles and quaternions. Also the propulsion model of the brushless motors was introduced and calibrated. In addition, the flight dynamics model of the UAV system was developed for simulation-based analysis prior to developing a hardware prototype and flight experiment. A special inertial measurement unit (IMU) was designed which has the capability of indirectly calculating the angular acceleration from the angular velocity and the linear acceleration readings. Moreover, a commercial-of-the-shelf (COTS) autopilot-APM 2.6 was selected for the autonomous flight control of the quadrotor. The APM 2.6 is a complete open source autopilot system, which allows the user to turn any fixed, rotary wing or multi-rotor vehicle into a fully autonomous vehicle and capable of performing programmed GPS missions with pre-programed waypoints. In addition, algorithms for inverted pendulum control and autonomous perching control was introduced. The proportion-integrate-differential (PID) controller was used for the simplified UAV perching with inverted pendulum model for horizontal balance. The performance of the controller was verified through both simulation and experiment. In addition, for the purpose of achieving the autonomous perching, guidance and control algorithms were developed the UAV perching system. For guidance, the desired flight trajectory was developed based on a bio-behavioral tau theory which was established from studying the natural motion patterns of animals and human arms approaching to a fixed or moving target for grasping or capturing. The autonomous flight control was also implemented through a PID controller. Autonomous flight performance was proved through simulation in SimMechanics. Finally, the prototyping of our designs were conducted in different generations of our bio-inspired UAV perching system, which include the leg prototype, gripper prototype, and system prototype. Both the machined prototype and 3D printed prototype were tried. The performance of these prototypes was tested through experiments.

SIM Configuration Evolution

NASA Technical Reports Server (NTRS)

Aaron, Kim M.

2000-01-01

The Space Interferometry Mission (SIM) is a space-based 10 m baseline Michelson interferometer. Planned for launch in 2005 aboard a Delta III launch vehicle, or equivalent, its primary objective is to measure the positions of stars and other celestial objects with an unprecedented accuracy of 4 micro arc seconds. With such an instrument, tremendous advancement can be expected in our understanding of stellar and galactic dynamics. Using triangulation from opposite sides of the orbit around the sun (i.e. by using parallax) one can measure the distance to any observable object in our galaxy. By directly measuring the orbital wobble of nearby stars, the mass and orbit of planets can be determined over a wide range of parameters. The distribution of velocity within nearby galaxies will be measurable. Observations of these and other objects will improve the calibration of distance estimators by more than an order of magnitude. This will permit a much better determination of the Hubble Constant as well as improving our overall understanding of the evolution of the universe. SIM has undergone several transformations, especially over the past year and a half since the start of Phase A. During this phase of a project, it is desirable to perform system-level trade studies, so the substantial evolution of the design that has occurred is quite appropriate. Part of the trade-off process has addressed two major underlying architectures: SIM Classic; and Son of SIM. The difference between these two architectures is related to the overall arrangement of the optical elements and the associated metrology system. Several different configurations have been developed for each architecture. Each configuration is the result of design choices that are influenced by many competing considerations. Some of the more important aspects will be discussed. The Space Interferometry Mission has some extremely challenging goals: millikelvin thermal stability, nanometer stabilization of optics, picometer measurement of wavefront, and others. In order to meet these goals, a significant amount of technological development is required. Although there has been a program operating for about a decade developing technologies specifically to address the challenges of space-based interferometry, there still remains a tremendous effort to achieve the incredible accuracy required of SIM. The projected viability of some of these areas has influenced design choices during the evolution of the many configurations that have been developed. For instance, the perceived complexity of the IR laser metrology system used to measure and control the positions of key optical elements was the strongest discriminator between the two architectures, and led to a decision to select SOS rather than Classic in early 1998. More recently, an appreciation of the sensitivity to beam-walk within the SOS architecture is forcing a reconsideration of that decision. At the time of submission of this abstract, there is some hope that a full-aperture metrology system may alleviate this issue. In addition to describing the current configuration of SIM, the influence of a few selected areas on the evolution of the configuration will be discussed.

Discover Supercomputer 3

NASA Image and Video Library

2017-12-08

The heart of the NASA Center for Climate Simulation (NCCS) is the “Discover” supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Discover Supercomputer 2

NASA Image and Video Library

2017-12-08

The heart of the NASA Center for Climate Simulation (NCCS) is the “Discover” supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Discover Supercomputer 1

NASA Image and Video Library

2017-12-08

The heart of the NASA Center for Climate Simulation (NCCS) is the “Discover” supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Analysis of Interplanetary Dust Experiment Detectors and Other Witness Plates

NASA Technical Reports Server (NTRS)

Griffis, D. P.; Wortman, J. J.

1992-01-01

The development of analytical procedures for identifying the chemical composition of residue from impacts that occurred on the Interplanetary Dust Experiment (IDE) detectors during the flight of Long Duration Exposure Facility (LDEF) and the carrying out of actual analysis on IDE detectors and other witness plates are discussed. Two papers on the following topics are presented: (1) experimental analysis of hypervelocity microparticle impact sites on IDE sensor surfaces; and (2) contaminant interfaces with secondary Ion Mass Spectrometer (SIMS) analysis of microparticle impactor residues on LDEF surfaces.

On the merging cluster Abell 578 and its central radio galaxy 4C+67.13

DOE PAGES

Hagino, K.; Stawarz, Ł.; Siemiginowska, A.; ...

2015-05-26

Here we analyze radio, optical, and X-ray data for the peculiar cluster Abell 578. This cluster is not fully relaxed and consists of two merging sub-systems. The brightest cluster galaxy (BCG), CGPG 0719.8+6704, is a pair of interacting ellipticals with projected separation ~10 kpc, the brighter of which hosts the radio source 4C+67.13. The Fanaroff–Riley type-II radio morphology of 4C+67.13 is unusual for central radio galaxies in local Abell clusters. Our new optical spectroscopy revealed that both nuclei of the CGPG 0719.8+6704 pair are active, albeit at low accretion rates corresponding to the Eddington ratiomore » $$\\sim {{10}^{-4}}$$ (for the estimated black hole masses of $$\\sim 3\\times {{10}^{8}}\\;{{M}_{\\odot }}$$ and $$\\sim {{10}^{9}}\\;{{M}_{\\odot }}$$). The gathered X-ray (Chandra) data allowed us to confirm and to quantify robustly the previously noted elongation of the gaseous atmosphere in the dominant sub-cluster, as well as a large spatial offset (~60 kpc projected) between the position of the BCG and the cluster center inferred from the modeling of the X-ray surface brightness distribution. Detailed analysis of the brightness profiles and temperature revealed also that the cluster gas in the vicinity of 4C+67.13 is compressed (by a factor of about ~1.4) and heated (from $$\\simeq 2.0$$ keV up to 2.7 keV), consistent with the presence of a weak shock (Mach number ~1.3) driven by the expanding jet cocoon. As a result, this would then require the jet kinetic power of the order of $$\\sim {{10}^{45}}$$ erg s –1, implying either a very high efficiency of the jet production for the current accretion rate, or a highly modulated jet/accretion activity in the system.« less

From Ions to Bits - Developing the IT infrastructure around the CAMECA IMS 1280-HR SIMS lab at GFZ Potsdam

NASA Astrophysics Data System (ADS)

Galkin, A.; Klump, J.; Wiedenbeck, M.

2012-04-01

Secondary Ion Mass Spectrometers (SIMS) is an highly sensitive technique for analyzing the surfaces of solids and thin film samples, but has the major drawback that such instruments are both rare and expensive. The Virtual SIMS project aims to design, develop and operate the IT infrastructure around the CAMECA IMS 1280-HR SIMS at GFZ Potsdam. The system will cover the whole spectrum of the procedures in the lab - from the online application for measurement time, to the remote access to the instrument and finally the maintenance of the data for publishing and future re-use. A virtual lab infrastructure around the IMS 1280 will enable remote access to the instrument and make measurement time available to the broadest possible user community. Envisioned is that the IT infrastructure would consist of the following: web portal, data repository, sample repository, project management software, communication arrangements between the lab staff and distant researcher and remote access to the instruments. The web portal will handle online applications for the measurement time. The data from the experiments, the monitoring sensor logs and the lab logbook entries are to be stored and archived. Researchers will be able to access their data remotely in real time, thus imposing a user rights management strucuture. Also planned is that all samples and the standards will be assigned a unique International GeoSample Number (IGSN) and that the images of the samples will be stored and made accessible in addition to any additional documents which might be uploaded by the researcher. The project management application will schedule the application process, the measurements times, notifications and alerts. A video conference capability is forseen for communication between the Potsdam staff and the remote researcher. The remote access to the instruments requires a sophisticated client-server solution. This highly sensitive instrument has to be controlled in real-time with latencies diminished to a minimum. Also, failures and shortages of the internet connection, as well as possible outages on the client side, have to be considered and safe fallbacks for such events must be provided. The level of skills of the researcher remotely operating the instrument will define the scope of control given during an operating session. An important aspect of the project is the design of the virtual lab system in collaboration with the laboratory operators and the researchers who will use the instrument and its peripherals. Different approaches for the IT solutions will be tested and evaluated, so imporved guidelines can evolve from obsperved operating performance.

The use of a block diagram simulation language for rapid model prototyping

NASA Technical Reports Server (NTRS)

Whitlow, Jonathan E.

1995-01-01

The research performed this summer focussed on the development of a predictive model for the loading of liquid oxygen (LO2) into the external tank (ET) of the shuttle prior to launch. A predictive model can greatly aid the operational personnel since instrumentation aboard the orbiter and ET is limited due to weight constraints. The model, which focuses primarily on the orbiter section of the system was developed using a block diagram based simulation language known as VisSim. Simulations were run on LO2 loading data for shuttle flights STS50 and STS55 and the model was demonstrated to accurately predict the sensor data recorded for these flights. As a consequence of the simulation results, it can be concluded that the software tool can be very useful for rapid prototyping of complex models.

Reactor Simulator Testing

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise J.

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Reactor Simulator Integration and Testing

NASA Technical Reports Server (NTRS)

Schoenfield, M. P.; Webster, K. L.; Pearson, J. B.

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator (RxSim) test loop was designed and built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing were to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V because the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This Technical Memorandum summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained, which was lower than the predicted 750 K but 156 K higher than the cold temperature, indicating the design provided some heat regeneration. The annular linear induction pump tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

Comparative analysis of lignin peroxidase and manganese peroxidase activity on coniferous and deciduous wood using ToF-SIMS.

PubMed

MacDonald, Jacqueline; Goacher, Robyn E; Abou-Zaid, Mamdouh; Master, Emma R

2016-09-01

White-rot fungi are distinguished by their ability to efficiently degrade lignin via lignin-modifying type II peroxidases, including manganese peroxidase (MnP) and lignin peroxidase (LiP). In the present study, time-of flight secondary ion mass spectrometry (ToF-SIMS) was used to evaluate lignin modification in three coniferous and three deciduous wood preparations following treatment with commercial preparations of LiP and MnP from two different white-rot fungi. Percent modification of lignin was calculated as a loss of intact methoxylated lignin over nonfunctionalized aromatic rings, which is consistent with oxidative cleavage of methoxy moieties within the lignin structure. Exposure to MnP resulted in greater modification of lignin in coniferous compared to deciduous wood (28 vs. 18 % modification of lignin); and greater modification of G-lignin compared to S-lignin within the deciduous wood samples (21 vs. 12 %). In contrast, exposure to LiP resulted in similar percent modification of lignin in all wood samples (21 vs 22 %), and of G- and S-lignin within the deciduous wood (22 vs. 23 %). These findings suggest that the selected MnP and LiP may particularly benefit delignification of coniferous and deciduous wood, respectively. Moreover, the current analysis further demonstrates the utility of ToF-SIMS for characterizing enzymatic modification of lignin in wood fibre along with potential advantages over UV and HPCL-MS detection of solubilized delignification products.

Self-assembled organic radicals on Au(111) surfaces: a combined ToF-SIMS, STM, and ESR study.

PubMed

Mannini, Matteo; Sorace, Lorenzo; Gorini, Lapo; Piras, Federica M; Caneschi, Andrea; Magnani, Agnese; Menichetti, Stefano; Gatteschi, Dante

2007-02-27

Electron spin resonance (ESR), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and scanning tunneling microscopy (STM) have been used in parallel to characterize the deposition on gold surface of a series of nitronyl nitroxide radicals. These compounds have been specifically synthesized with methyl-thio linking groups suitable to interact with the gold surface to form self-assembled monolayers (SAMs), which can be considered relevant in the research for molecular-based spintronics devices, as suggested in recent papers. The degree of the expected ordering on the surface of these SAMs has been tuned by varying the chemical structure of synthesized radicals. ToF-SIMS has been used to support the evidence of the occurrence of the deposition process. STM has shown the different qualities of the obtained SAMs, with the degree of local order increasing as the degree of freedom of the molecules on the surface is decreased. Finally, ESR has confirmed that the deposition process does not affect the paramagnetic characteristics of radicals and that it affords a complete single-layered coverage of the surface. Further, the absence of angular dependence in the spectra indicates that the small regions of local ordering do not give rise to a long-range order and suggests a quite large mobility of the radical on the surface, probably due to the weak interaction with gold provided by the methyl-thio linking group.

Exploring the Surface Sensitivity of ToF-SIMS by Measuring the Implantation and Sampling Depths of Bin and C60 Ions in Organic Films

PubMed Central

Muramoto, Shin; Brison, Jeremy; Castner, David G.

2011-01-01

The surface sensitivity of Binq+ (n = 1, 3, 5, q = 1, 2) and C60q+ (q = 1, 2) primary ions in static time-of-flight secondary ion mass spectrometry (ToF-SIMS) experiments were investigated for molecular trehalose and polymeric tetraglyme organic films. Parameters related to surface sensitivity (impact crater depth, implantation depth, and molecular escape depths) were measured. Under static ToF-SIMS conditions (primary ion doses of 1 × 1012 ions/cm2), the 25 keV Bi1+ primary ions were the most surface sensitive with a molecular escape depth of 1.8 nm for protein films with tetraglyme overlayers, but they had the deepest implantation depth (~18 and 26 nm in trehalose and tetraglyme films, respectively). The 20 keV C60++ primary ions were the second most surface sensitive with a slightly larger molecular escape depth of 2.3 nm. The most important factor that determined the surface sensitivity of the primary ion was its impact crater depth, or the amount of surface erosion. The most surface sensitive primary ions, Bi1+ and C60++, created impact craters with depths of 0.3 and 1.0 nm, respectively, in tetraglyme films. In contrast, Bi5++ primary ions created impact craters with a depth of 1.8 nm in tetraglyme films and were the least surface sensitive with a molecular escape depth of 4.7 nm. PMID:22084828

Contaminant characterization on hair and fiber surfaces using imaging TOF-SIMS

NASA Astrophysics Data System (ADS)

Groenewold, Gary S.; Gresham, Garold L.; Gianotto, Anita K.; Avci, Recep

1999-02-01

Imaging time-of-flight secondary ion mass spectrometry (SIMS) was used to evaluate the detection of contaminant chemicals on the surfaces of single synthetic textile and canine hair fibers. The results of the study showed that a variety of chemical classes can be detected. Both cocaine and heroin could be easily observed as intact protonated molecules ([M + H]+) in the cation spectra acquired from textile fibers. Two organophosphates were evaluated: malathion, which is a common pesticide, and pinacolyl methyl phosphonic acid (PMPA), which is the principal degradation product of the nerve agent soman (a close relative of sarin). Malathion could be observed as (CH3O)2P(equalsS)S-, which is formed by thiophosphate cleavage of the intact malathion. PMPA is observed as the conjugate base ([PMPA - H]-). Surfactant chemicals found in hair care products were successfully detected on single hair fibers. Specifically, alkyl sulfates, ethoxylated alkyl sulfates, silicones, and alkylammonium compounds could be readily identified in spectra acquired from single hair fiber samples exposed to shampoo and/or conditioner. Generally, the results of the study show that imaging SIMS is applicable to single fiber analysis, for a range of adsorbed compound types. The forensic application of this instrumental approach has not been widely recognized. However, the ability of the technique to acquire specific chemical information from trace samples clearly points to applications where the need for chemical analysis is great, but the amount of sample is limited.

Search for the direct production of charginos and neutralinos in final states with tau leptons in $$\\sqrt{s}$$ =13 TeV pp collisions with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2018-02-22

Here, a search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1fb -1, recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios ofmore » $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ pair production and of $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ and $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of the $$\\sim\\atop{\\tau}_L$$ state is set to be halfway between the masses of the $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ for a massless $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Common $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ masses up to 760 GeV are excluded in the case of production of $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ and $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$-\\atop{1}$$ assuming a massless $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the Open image in new window $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$ are also studied by varying the $$\\sim\\atop{\\tau}_L$$ mass between the masses of the $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$.« less

Search for the direct production of charginos and neutralinos in final states with tau leptons in $$\\sqrt{s}$$ =13 TeV pp collisions with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

Here, a search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1fb -1, recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios ofmore » $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ pair production and of $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ and $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of the $$\\sim\\atop{\\tau}_L$$ state is set to be halfway between the masses of the $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$\\bar{1}$$ for a massless $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Common $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ masses up to 760 GeV are excluded in the case of production of $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$0\\atop{2}$$ and $$\\sim\\atop{\\chi}$$ $$+\\atop{1}$$ $$\\sim\\atop{\\chi}$$ $$-\\atop{1}$$ assuming a massless $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$. Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the Open image in new window $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$ are also studied by varying the $$\\sim\\atop{\\tau}_L$$ mass between the masses of the $$\\sim\\atop{\\chi}$$ $$±\\atop{1}$$ and the $$\\sim\\atop{\\chi}$$ $$0\\atop{1}$$.« less

Epidemilogical Simulation System, Version 2.4

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

2004-01-30

EpiSims uses a detailed simulation of disease spread to evaluate demographically and geographically targeted biological threat reduction strategies. Abstract: EpiSims simulates the spread of disease and analyzes the consequences of intervention strategies in a large urban area at the level of individuals. The simulation combines models of three dynamical systems: urban social networks, disease transmission, and within-host progression of a disease. Validated population mobility and activity generation technology provides the social network models, Disease models are based on fusion of expert opinion and available data. EpiSims provides a previously unavailable detailed representation of the course of an outbreak in urbanmore » area. A letter of August 16, 2002 from the Office of Homeland Security states: "Ability of EpiSims to provide comprehensive data on daily activity patterns of individuals makes it far superior to traditional SIR models — clearly had an impact on pre-attack smallpox vaccination policy." EpiSims leverages a unique Los Alamos National Laboratory resource — the population mobility and activity data developed by TRANSIMS (Transportation Analysis and SiMulation System) — to create epidemiological analyses at an unprecedented level of detail. We create models of microscopic (individual-level) physical and biological processes from which, through simulation, emerge the macroscopic (urban regional level) quantities that are the inputs to alternative models. For example, the contact patterns of individuals in different demographic groups determine the overall mixing rates those groups. The characteristics of a person-to-person transmission together with their contact patterns determine the reproductive numbers — how many people will be infected on average by each case. Mixing rates and reproductive numbers are the basic parameters of other epidemiological models. Because interventions — and people’s reactions to them — are ultimately applied at the individual level, EpiSims is uniquely suited to evaluate their macroscopic consequences. For example, the debate over the logistics of targeted vaccination for smallpox, and thus the magnitude of the threat it poses, can best be resolved through an individual- based approach. EpiSims is the only available analytical tool using the individual-based approach that can scale to populations of a million or more without introducing ad-hoc assumptions about the nature of the social network. Impact: The first study commissioned for the EpiSims project was to analyze the effectiveness of targeted vaccination and isolation strategies in the aftermath of a covert release of smallpox at a crowded urban location. In particular we compared casualties and resources required for targeted strategies with those in the case of large-scale quarantine and/or mass vaccination campaigns. We produced this analysis in a sixty-day effort, while prototype software was still under development and delivered it to the Office of Homeland Security in June 2002. More recently, EpiSims provided casualty estimates and cost/benefit analyses for various proposed responses to an attack with pneumonic plague during the TOPOFF-2 exercise. Capabilities: EpiSims is designed to simulate human-human transmissible disease, but it is part of a suite of tools that naturally allow it to estimate individual exposures to air-borne or water-borne spread. Combined with data on animal density and mobility, EpiSims could simulate diseases spread by non-human vectors. EpiSims incorporates reactions of individuals, and is particularly powerful if those reactions are correlated with demographics. It provides a standard for modeling scenarios that cuts across agencies.« less

Surface Contamination Monitor and Survey Information Management System

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

NONE

1998-02-01

Shonka Research Associates, Inc.`s (SRA) Surface Contamination Monitor and Survey Information management System (SCM/SIMS) is designed to perform alpha and beta radiation surveys of floors and surfaces and document the measured data. The SRA-SCM/SIMS technology can be applied to routine operational surveys, characterization surveys, and free release and site closure surveys. Any large nuclear site can make use of this technology. This report describes a demonstration of the SRA-SCM/SIMS technology. This demonstration is part of the chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), Office of Science and Technology (ST), Deactivation and Decommissioningmore » Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East`s (ANL) CP-5 Research Reactor Facility. The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies.« less

"Afterlife experiment": use of MALDI-MS and SIMS imaging for the study of the nitrogen cycle within plants.

PubMed

Seaman, Callie; Flinders, Bryn; Eijkel, Gert; Heeren, Ron M A; Bricklebank, Neil; Clench, Malcolm R

2014-10-21

As part of a project to demonstrate the science of decay, a series of mass spectrometry imaging experiments were performed. The aim was to demonstrate that decay and decomposition are only part of the story and to show pictorially that atoms and molecules from dead plants and animals are incorporated into new life. Radish plants (Raphanus sativus) were grown hydroponically using a nutrient system containing (15)N KNO3 (98% labeled) as the only source of nitrogen. Plants were cropped and left to ferment in water for 2 weeks to create a radish "tea", which was used as a source of nitrogen for radish grown in a second hydroponics experiment. After 5 weeks of growth, the radish plants were harvested and cryosectioned, and sections were imaged by positive-ion MALDI and SIMS mass spectrometry imaging. The presence of labeled species in the plants grown using (15)N KNO3 as nutrient and those grown from the radish "tea" was readily discernible. The uptake of (15)N into a number of identifiable metabolites has been studied by MALDI-MS and SIMS imaging.

Abort Flight Test Project Overview

NASA Technical Reports Server (NTRS)

Sitz, Joel

2007-01-01

A general overview of the Orion abort flight test is presented. The contents include: 1) Abort Flight Test Project Overview; 2) DFRC Exploration Mission Directorate; 3) Abort Flight Test; 4) Flight Test Configurations; 5) Flight Test Vehicle Engineering Office; 6) DFRC FTA Scope; 7) Flight Test Operations; 8) DFRC Ops Support; 9) Launch Facilities; and 10) Scope of Launch Abort Flight Test

Surface Characterization of Populus during Caldicellulosiruptor bescii Growth by TOF-SIMS Analysis

DOE PAGES

Tolbert, Allison K.; Young, Jenna M.; Jung, Seokwon; ...

2017-01-30

Caldicellulosiruptor bescii is a thermophilic, anaerobic bacterium that is capable of utilizing unpretreated biomass in addition to breaking down cellulose and hemicellulose into simple sugars. Despite the fact that C. bescii must first bind to the surface of the biomass, there has been no analysis of the morphological or chemical changes to the biomass surface as a result of incubation with the micro-organism. To understand more about C. bescii growth, juvenile poplar stems were sectioned (80 μm thick) and incubated with C. bescii beyond the typical 24 h experiment length. Monitoring the cell counts during incubation revealed a biphasic growthmore » pattern. The impact the micro-organism had on the surface was determined by scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), which showed physical crevices in the cell wall caused by the C. bescii along with a decrease of polysaccharide ions and an increase in lignin ions on the poplar surface. Employing infrared microspectroscopy, the decreasing trend was corroborated.« less

Port-O-Sim Object Simulation Application

NASA Technical Reports Server (NTRS)

Lanzi, Raymond J.

2009-01-01

Port-O-Sim is a software application that supports engineering modeling and simulation of launch-range systems and subsystems, as well as the vehicles that operate on them. It is flexible, distributed, object-oriented, and realtime. A scripting language is used to configure an array of simulation objects and link them together. The script is contained in a text file, but executed and controlled using a graphical user interface. A set of modules is defined, each with input variables, output variables, and settings. These engineering models can be either linked to each other or run as standalone. The settings can be modified during execution. Since 2001, this application has been used for pre-mission failure mode training for many Range Safety Scenarios. It contains range asset link analysis, develops look-angle data, supports sky-screen site selection, drives GPS (Global Positioning System) and IMU (Inertial Measurement Unit) simulators, and can support conceptual design efforts for multiple flight programs with its capacity for rapid six-degrees-of-freedom model development. Due to the assembly of various object types into one application, the application is applicable across a wide variety of launch range problem domains.

Interaction of monovalent cations with acetonitrile

NASA Astrophysics Data System (ADS)

Černušák, Ivan; Aranyosiová, Monika; Vollárová, Ol'ga; Velič, Dušan; Kirdajová, Ol'ga; Benko, Ján

Solvation of monovalent cations (Me+) of alkali metals=Na+, K+, Rb+, and Cs+, coinage metals=Cu+, Ag+, Au+, and p-block elements Ga+, In+, and Tl+ with acetonitrile was studied by means of ab initio calculations and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The intermolecular interactions in the complexes Me+···CH3CN were investigated using the coupled clusters theory including single, double, and noniterative triple substitutions (CCSD(T)) in conjunction with the Pol and Pol-dk basis sets. The binding energies of these donor-acceptor complexes were estimated; taking into account the basis set superposition error, zero-point vibrations, correlation contribution, and scalar relativistic corrections. The theoretical ΔG0298 K values based on CCSD(T)/Pol and/or CCSD(T)/Pol-dk binding energies correlated well with experimental transfer Gibbs energies (from water to acetonitrile) for the series of cations. In the case of Au monocation, relativistic correction turned out to be extremely important. Composition of the complex of Ag+ and Na+ with acetonitrile was determined by using SIMS supporting both theoretical and experimental transfer Gibbs energies.

Comparative study of the native oxide on 316L stainless steel by XPS and ToF-SIMS

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

Tardio, Sabrina, E-mail: s.tardio@surrey.ac.uk; Abel, Marie-Laure; Castle, James E.

2015-09-15

The very thin native oxide film on stainless steel, of the order of 2 nm, is known to be readily modified by immersion in aqueous media. In this paper, X-ray photoelectron spectroscopy (XPS) and time of flight secondary ions mass spectrometry are employed to investigate the nature of the air-formed film and modification after water emersion. The film is described in terms of oxide, hydroxide, and water content. The preferential dissolution of iron is shown to occur on immersion. It is shown that a water absorbed layer and a hydroxide layer are present above the oxide-like passive film. The concentrations ofmore » water and hydroxide appear to be higher in the case of exposure to water. A secure method for the peak fitting of Fe2p and Cr2p XPS spectra of such films on their metallic substrates is described. The importance of XPS survey spectra is underlined and the feasibility of C{sub 60}{sup +} SIMS depth profiling of a thin oxide layer is shown.« less

Analysis of particulates on tape lift samples

NASA Astrophysics Data System (ADS)

Moision, Robert M.; Chaney, John A.; Panetta, Chris J.; Liu, De-Ling

2014-09-01

Particle counts on tape lift samples taken from a hardware surface exceeded threshold requirements in six successive tests despite repeated cleaning of the surface. Subsequent analysis of the particle size distributions of the failed tests revealed that the handling and processing of the tape lift samples may have played a role in the test failures. In order to explore plausible causes for the observed size distribution anomalies, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to perform chemical analysis on collected particulates. SEM/EDX identified Na and S containing particles on the hardware samples in a size range identified as being responsible for the test failures. ToF-SIMS was employed to further examine the Na and S containing particulates and identified the molecular signature of sodium alkylbenzene sulfonates, a common surfactant used in industrial detergent. The root cause investigation suggests that the tape lift test failures originated from detergent residue left behind on the glass slides used to mount and transport the tape following sampling and not from the hardware surface.

Regional climate assessment of precipitation and temperature in Southern Punjab (Pakistan) using SimCLIM climate model for different temporal scales

NASA Astrophysics Data System (ADS)

Amin, Asad; Nasim, Wajid; Mubeen, Muhammad; Sarwar, Saleem; Urich, Peter; Ahmad, Ashfaq; Wajid, Aftab; Khaliq, Tasneem; Rasul, Fahd; Hammad, Hafiz Mohkum; Rehmani, Muhammad Ishaq Asif; Mubarak, Hussani; Mirza, Nosheen; Wahid, Abdul; Ahamd, Shakeel; Fahad, Shah; Ullah, Abid; Khan, Mohammad Nauman; Ameen, Asif; Amanullah; Shahzad, Babar; Saud, Shah; Alharby, Hesham; Ata-Ul-Karim, Syed Tahir; Adnan, Muhammad; Islam, Faisal; Ali, Qazi Shoaib

2018-01-01

Unbalanced climate during the last decades has created spatially alarming and destructive situations in the world. Anomalies in temperature and precipitation enhance the risks for crop production in large agricultural region (especially the Southern Punjab) of Pakistan. Detailed analysis of historic weather data (1980-2011) record helped in creating baseline data to compare with model projection (SimCLIM) for regional level. Ensemble of 40 GCMs used for climatic projections with greenhouse gas (GHG) representative concentration pathways (RCP-4.5, 6.0, 8.5) was selected on the baseline comparison and used for 2025 and 2050 climate projection. Precipitation projected by ensemble and regional weather observatory at baseline showed highly unpredictable nature while both temperature extremes showed 95 % confidence level on a monthly projection. Percentage change in precipitation projected by model with RCP-4.5, RCP-6.0, and RCP-8.5 showed uncertainty 3.3 to 5.6 %, 2.9 to 5.2 %, and 3.6 to 7.9 % for 2025 and 2050, respectively. Percentage change of minimum temperature from base temperature showed that 5.1, 4.7, and 5.8 % for 2025 and 9.0, 8.1, and 12.0 % increase for projection year 2050 with RCP-4.5, 6.0, and 8.5 and maximum temperature 2.7, 2.5, and 3.0 % for 2025 and 4.7, 4.4, and 6.4 % for 2050 will be increased with RCP-4.5, 6.0, and 8.5, respectively. Uneven increase in precipitation and asymmetric increase in temperature extremes in future would also increase the risk associated with management of climatic uncertainties. Future climate projection will enable us for better risk management decisions.

MS/MS analysis and imaging of lipids across Drosophila brain using secondary ion mass spectrometry.

PubMed

Phan, Nhu T N; Munem, Marwa; Ewing, Andrew G; Fletcher, John S

2017-06-01

Lipids are abundant biomolecules performing central roles to maintain proper functioning of cells and biological bodies. Due to their highly complex composition, it is critical to obtain information of lipid structures in order to identify particular lipids which are relevant for a biological process or metabolic pathway under study. Among currently available molecular identification techniques, MS/MS in secondary ion mass spectrometry (SIMS) imaging has been of high interest in the bioanalytical community as it allows visualization of intact molecules in biological samples as well as elucidation of their chemical structures. However, there have been few applications using SIMS and MS/MS owing to instrumental challenges for this capability. We performed MS and MS/MS imaging to study the lipid structures of Drosophila brain using the J105 and 40-keV Ar 4000 + gas cluster ion source, with the novelty being the use of MS/MS SIMS analysis of intact lipids in the fly brain. Glycerophospholipids were identified by MS/MS profiling. MS/MS was also used to characterize diglyceride fragment ions and to identify them as triacylglyceride fragments. Moreover, MS/MS imaging offers a unique possibility for detailed elucidation of biomolecular distribution with high accuracy based on the ion images of its fragments. This is particularly useful in the presence of interferences which disturb the interpretation of biomolecular localization. Graphical abstract MS/MS was performed during time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of Drosophila melongaster (fruit fly) to elucidate the structure and origin of different chemical species in the brain including a range of different phospholipid classes (PC, PI, PE) and di- and triacylglycerides (DAG & TAG) species where reference MS/MS spectra provided a potential means of discriminating between the isobaric [M-OH] + ion of DAGs and the [M-RCO] + ion of TAGs.

X-43C Flight Demonstrator Project Overview

NASA Technical Reports Server (NTRS)

Moses, Paul L.

2003-01-01

The X-43C Flight Demonstrator Project is a joint NASA-USAF hypersonic propulsion technology flight demonstration project that will expand the hypersonic flight envelope for air-breathing engines. The Project will demonstrate sustained accelerating flight through three flights of expendable X-43C Demonstrator Vehicles (DVs). The approximately 16-foot long X-43C DV will be boosted to the starting test conditions, separate from the booster, and accelerate from Mach 5 to Mach 7 under its own power and autonomous control. The DVs will be powered by a liquid hydrocarbon-fueled, fuel-cooled, dual-mode, airframe integrated scramjet engine system developed under the USAF HyTech Program. The Project is managed by NASA Langley Research Center as part of NASA's Next Generation Launch Technology Program. Flight tests will be conducted by NASA Dryden Flight Research Center off the coast of California over water in the Pacific Test Range. The NASA/USAF/industry project is a natural extension of the Hyper-X Program (X-43A), which will demonstrate short duration (approximately 10 seconds) gaseous hydrogen-fueled scramjet powered flight at Mach 7 and Mach 10 using a heavy-weight, largely heat sink construction, experimental engine. The X-43C Project will demonstrate sustained accelerating flight from Mach 5 to Mach 7 (approximately 4 minutes) using a flight-weight, fuel-cooled, scramjet engine powered by much denser liquid hydrocarbon fuel. The X-43C DV design flows from integrating USAF HyTech developed engine technologies with a NASA Air-Breathing Launch Vehicle accelerator-class configuration and Hyper-X heritage vehicle systems designs. This paper describes the X-43C Project and provides the background for NASA's current hypersonic flight demonstration efforts.

Flight Projects Office Information Systems Testbed (FIST)

NASA Technical Reports Server (NTRS)

Liggett, Patricia

1991-01-01

Viewgraphs on the Flight Projects Office Information Systems Testbed (FIST) are presented. The goal is to perform technology evaluation and prototyping of information systems to support SFOC and JPL flight projects in order to reduce risk in the development of operational data systems for such projects.

Dendrimer pre-treatment enhances the skin permeation of chlorhexidine digluconate: Characterisation by in vitro percutaneous absorption studies and Time-of-Flight Secondary Ion Mass Spectrometry.

PubMed

Holmes, Amy M; Scurr, David J; Heylings, Jon R; Wan, Ka-Wai; Moss, Gary P

2017-06-15

Skin penetration and localisation of chlorhexidine digluconate (CHG) within the skin have been investigated in order to better understand and optimise the delivery using a nano polymeric delivery system of this topically-applied antimicrobial drug. Franz-type diffusion cell studies using in vitro porcine skin and tape stripping procedures were coupled with Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to visualise the skin during various treatments with CHG and polyamidoamine dendrimers (PAMAM). Pre-treatment of the skin with PAMAM dendrimers significantly increased the amount and depth of permeation of CHG into the skin in vitro. The effect observed was not concentration dependant in the range 0.5-10mM PAMAM. This could be important in terms of the efficiency of treatment of bacterial infection in the skin. It appears that the mechanism of enhancement is due to the PAMAM dendrimer disrupting skin barrier lipid conformation or by occluding the skin surface. Franz-type diffusion cell experiments are complimented by the detailed visualisation offered by the semi-quantitative ToF-SIMS method which provides excellent benefits in terms of sensitivity and fragment ion specificity. This allows a more accurate depth profile of chlorhexidine permeation within the skin to be obtained and potentially affords the opportunity to map the co-localisation of permeants with skin structures, thus providing a greater ability to characterise skin absorption and to understand the mechanism of permeation, providing opportunities for new and more effective therapies. Copyright © 2017. Published by Elsevier B.V.

Very short-lived bromomethanes measured by the CARIBIC observatory over the North Atlantic, Africa and Southeast Asia during 2009-2013

NASA Astrophysics Data System (ADS)

Wisher, A.; Oram, D. E.; Laube, J. C.; Mills, G. P.; van Velthoven, P.; Zahn, A.; Brenninkmeijer, C. A. M.

2014-04-01

Short-lived organic brominated compounds make up a significant part of the organic bromine budget in the atmosphere. Emissions of these compounds are highly variable and there are limited measurements, particularly in the extra-tropical upper troposphere/lower stratosphere and tropical troposphere. Measurements of five very short-lived bromomethanes (VSLB) were made in air samples collected on the CARIBIC project aircraft over three flight routes; Germany to Venezuela/Columbia during 2009-2011, Germany to South Africa during 2010 and 2011 and Germany to Thailand/Kuala Lumpur, Malaysia during 2012 and 2013. In the tropical troposphere, as the most important entrance region to the stratosphere, we observe a total mean organic bromine derived from these compounds across all flights at 10-12 km altitude of 3.4 ± 1.5 ppt. Individual mean tropical tropospheric mixing ratios across all flights were 0.43, 0.74, 0.14, 0.23 and 0.11 ppt for CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CH2BrCl respectively. The highest levels of VSLB-derived bromine (4.20 ± 0.56 ppt) were observed in flights between Bangkok and Kuala Lumpur indicating that the South China Sea is an important source region for these compounds. Across all routes, CHBr3 and CH2Br2 accounted for 34% (4.7-71) and 48% (14-73) respectively of total bromine derived from the analysed VSLB in the tropical mid-upper troposphere totalling 82% (54-89). In samples collected between Germany and Venezuela/Columbia, we find decreasing mean mixing ratios with increasing potential temperature in the extra-tropics. Tropical mean mixing ratios are higher than extra-tropical values between 340-350 K indicating that rapid uplift is important in determining mixing ratios in the lower tropical tropopause layer in the West Atlantic tropics. O3 was used as a tracer for stratospherically influenced air and we detect rapidly decreasing mixing ratios for all VSLB above ∼100 ppb O3 corresponding to the extra-tropical tropopause layer.

siMS Score: Simple Method for Quantifying Metabolic Syndrome.

PubMed

Soldatovic, Ivan; Vukovic, Rade; Culafic, Djordje; Gajic, Milan; Dimitrijevic-Sreckovic, Vesna

2016-01-01

To evaluate siMS score and siMS risk score, novel continuous metabolic syndrome scores as methods for quantification of metabolic status and risk. Developed siMS score was calculated using formula: siMS score = 2*Waist/Height + Gly/5.6 + Tg/1.7 + TAsystolic/130-HDL/1.02 or 1.28 (for male or female subjects, respectively). siMS risk score was calculated using formula: siMS risk score = siMS score * age/45 or 50 (for male or female subjects, respectively) * family history of cardio/cerebro-vascular events (event = 1.2, no event = 1). A sample of 528 obese and non-obese participants was used to validate siMS score and siMS risk score. Scores calculated as sum of z-scores (each component of metabolic syndrome regressed with age and gender) and sum of scores derived from principal component analysis (PCA) were used for evaluation of siMS score. Variants were made by replacing glucose with HOMA in calculations. Framingham score was used for evaluation of siMS risk score. Correlation between siMS score with sum of z-scores and weighted sum of factors of PCA was high (r = 0.866 and r = 0.822, respectively). Correlation between siMS risk score and log transformed Framingham score was medium to high for age groups 18+,30+ and 35+ (0.835, 0.707 and 0.667, respectively). siMS score and siMS risk score showed high correlation with more complex scores. Demonstrated accuracy together with superior simplicity and the ability to evaluate and follow-up individual patients makes siMS and siMS risk scores very convenient for use in clinical practice and research as well.

Model Comparison in Subsurface Science: The DECOVALEX and Sim-SEQ Initiatives (Invited)

NASA Astrophysics Data System (ADS)

Birkholzer, J. T.; Mukhopadhyay, S.; Rutqvist, J.; Tsang, C.

2013-12-01

Building predictive model for flow and transport processes in the subsurface is a challenging task, even more so if these processes are coupled to geomechanical and/or geochemical effects. Modelers must take into consideration a multiplicity of length scales, a wide range of time scales, the coupling between processes, different model components, and the spatial variability in the value of most model input parameters (and often limited knowledge about them). Consequently, modelers have to make choices while developing their conceptual models. Such model choices may cause a wide range in the predictions made by different models and different modeling groups, even if each of the underlying simulators has been perfectly verified against appropriate benchmarks. In other words, the modeling activity itself is prone to uncertainty and bias. This uncertainty, referred to here as model selection uncertainty, forms one of the greatest sources of uncertainty for predictive modeling. In this paper, we discuss two examples of model intercomparison exercises that are currently undertaken to better understand model selection uncertainty, elucidate system behavior, inform needs for data collection and better physics parameterizations, and enhance community understanding of capabilities. The first example is the international DECOVALEX project, which was launched in 1992 by a group of countries dealing with modeling issues related to geologic disposal of radioactive waste. DECOVALEX is an acronym for DEvelopment of COupled THM models and their VALidation against Experiments. To date, the project has progressed successfully through five stages, each of which featuring a small number of test cases for model comparison related to coupled thermo-hydro-mechanical (THM) processes in geologic systems. The test cases are proposed and developed by the organizations participating in DECOVALEX; they typically involve results from major field and laboratory experiments. Over the past decades, the DECOVALEX project has played a major role in improving our understanding of coupled THM processes in fractured rock and buffer/backfill materials, a subject of importance to performance assessment of a radioactive waste geologic repository. The second example is the Sim-SEQ project, a relatively recent model comparison initiative addressing multi-phase processes relevant in geologic carbon sequestration. Like DECOVALEX, Sim-SEQ is not about benchmarking, but rather about evaluating model building efforts in a broad and comprehensive sense. In Sim-SEQ, sixteen international modeling teams are building their own models for a specific carbon sequestration site referred to as the Sim-SEQ Study site (the S-3 site). The S-3 site is patterned after the ongoing SECARB Phase III Early Test site in southwestern Mississippi, where CO2 is injected into a fluvial sandstone unit with high vertical and lateral heterogeneity. The complex geology of the S-3 site, its location in the water leg of a CO2-EOR field with a strong water drive, and the presence of methane in the reservoir brine make this a challenging task, requiring the modelers to use their best judgment in making a large number of choices about how to model various processes and properties of the system.

Comparison of future and base precipitation anomalies by SimCLIM statistical projection through ensemble approach in Pakistan

NASA Astrophysics Data System (ADS)

Amin, Asad; Nasim, Wajid; Mubeen, Muhammad; Kazmi, Dildar Hussain; Lin, Zhaohui; Wahid, Abdul; Sultana, Syeda Refat; Gibbs, Jim; Fahad, Shah

2017-09-01

Unpredictable precipitation trends have largely influenced by climate change which prolonged droughts or floods in South Asia. Statistical analysis of monthly, seasonal, and annual precipitation trend carried out for different temporal (1996-2015 and 2041-2060) and spatial scale (39 meteorological stations) in Pakistan. Statistical downscaling model (SimCLIM) was used for future precipitation projection (2041-2060) and analyzed by statistical approach. Ensemble approach combined with representative concentration pathways (RCPs) at medium level used for future projections. The magnitude and slop of trends were derived by applying Mann-Kendal and Sen's slop statistical approaches. Geo-statistical application used to generate precipitation trend maps. Comparison of base and projected precipitation by statistical analysis represented by maps and graphical visualization which facilitate to detect trends. Results of this study projects that precipitation trend was increasing more than 70% of weather stations for February, March, April, August, and September represented as base years. Precipitation trend was decreased in February to April but increase in July to October in projected years. Highest decreasing trend was reported in January for base years which was also decreased in projected years. Greater variation in precipitation trends for projected and base years was reported in February to April. Variations in projected precipitation trend for Punjab and Baluchistan highly accredited in March and April. Seasonal analysis shows large variation in winter, which shows increasing trend for more than 30% of weather stations and this increased trend approaches 40% for projected precipitation. High risk was reported in base year pre-monsoon season where 90% of weather station shows increasing trend but in projected years this trend decreased up to 33%. Finally, the annual precipitation trend has increased for more than 90% of meteorological stations in base (1996-2015) which has decreased for projected year (2041-2060) up to 76%. These result revealed that overall precipitation trend is decreasing in future year which may prolonged the drought in 14% of weather stations under study.

The use of secondary ion mass spectrometry in forensic analyses of ultra-small samples

NASA Astrophysics Data System (ADS)

Cliff, John

2010-05-01

It is becoming increasingly important in forensic science to perform chemical and isotopic analyses on very small sample sizes. Moreover, in some instances the signature of interest may be incorporated in a vast background making analyses impossible by bulk methods. Recent advances in instrumentation make secondary ion mass spectrometry (SIMS) a powerful tool to apply to these problems. As an introduction, we present three types of forensic analyses in which SIMS may be useful. The causal organism of anthrax (Bacillus anthracis) chelates Ca and other metals during spore formation. Thus, the spores contain a trace element signature related to the growth medium that produced the organisms. Although other techniques have been shown to be useful in analyzing these signatures, the sample size requirements are generally relatively large. We have shown that time of flight SIMS (TOF-SIMS) combined with multivariate analysis, can clearly separate Bacillus sp. cultures prepared in different growth media using analytical spot sizes containing approximately one nanogram of spores. An important emerging field in forensic analysis is that of provenance of fecal pollution. The strategy of choice for these analyses-developing host-specific nucleic acid probes-has met with considerable difficulty due to lack of specificity of the probes. One potentially fruitful strategy is to combine in situ nucleic acid probing with high precision isotopic analyses. Bulk analyses of human and bovine fecal bacteria, for example, indicate a relative difference in d13C content of about 4 per mil. We have shown that sample sizes of several nanograms can be analyzed with the IMS 1280 with precisions capable of separating two per mil differences in d13C. The NanoSIMS 50 is capable of much better spatial resolution than the IMS 1280, albeit at a cost of analytical precision. Nevertheless we have documented precision capable of separating five per mil differences in d13C using analytical spots containing less than 300 picograms of bacteria. Perhaps the most successful application of SIMS for forensic purposes to date is in the field of nuclear forensics. An example that has been used by laboratories associated with the International Atomic Energy Agency is the examination of environmental samples for enriched uranium particles indicative of clandestine weapons production activities.. The analytical challenge in these types of measurements is to search complex environmental matrices for U-bearing particles which must then be analyzed for 234U, 235U, and 236U content with high precision and accuracy. Older-generation SIMS instruments were hampered by small geometries that made resolution of significant interferences problematic. In addition, automated particle search software was proprietary and difficult to obtain. With the development of new search software, the IMS 1280 is capable of searching a sample in a matter of hours, flagging U-bearing particles for later analyses, and providing a rough 235U content. Particles of interest can be revisited for high precision analyses, and all U-isotopes can be measured simultaneously in multicollector mode, dramatically improving analysis time and internal precision. Further, the large geometry of the instrument allows complete resolution of isobaric interferences that have traditionally limited SIMS analyses of difficult samples. Examples of analyses of micron-sized standard particles indicate that estimates of 235U enrichment can be obtained with an external relative precision of 0.1% and 234U and 236U contents can be obtained with a relative precision of less than 1%. Analyses of 'real' samples show a dramatic improvement in the data quality obtained compared with small-geometry SIMS instruments making SIMS the method of choice for these high-profile samples when accurate, precise, and rapid results are required.

A combined ToF-SIMS and XPS study for the elucidation of the role of water in the performances of a Post-Plasma Process using LaMnO3+δ as catalyst in the total oxidation of trichloroethylene

NASA Astrophysics Data System (ADS)

Nuns, N.; Beaurain, A.; Dinh, M. T. Nguyen; Vandenbroucke, A.; De Geyter, N.; Morent, R.; Leys, C.; Giraudon, J.-M.; Lamonier, J.-F.

2014-11-01

LaMnO3+δ which is an environment-friendly and inexpensive material has been previously used as catalyst in Post-Plasma Catalysis (PPC) in the total oxidation of trichloroethylene (TCE) which is a solvent widely used in dry cleaning and degreasing processes. It has been shown that the process efficiency increases in moist air (RH = 18%).The issue we want to address herein is the effect of water on the location of chlorine at the surface of the catalyst as chlorine is able to alter the catalyst structure, activity and stability. Therefore, a combined Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS) study has been carried out on the fresh LaMnO3+δ catalyst (LM) and used catalysts after performing PPC with TCE diluted in dry synthetic air (LM0) or with industrial air containing water (LM18; 18 stands for the Relative Humidity) and CO2 (about 560 ppmv) at a temperature of 150 °C. XPS and ToF-SIMS results both show the presence of chlorine on the tested catalysts whose amount increases by exposure of the catalyst to the reactive mixture in dry synthetic air. XPS results reveal that chlorine is present as both chloride ion and covalent chlorine on LM0 while organic chlorinated residues are absent on LM18 catalyst. ToF-SIMS study indicates that lanthanum excess as oxide(hydroxide) partially covering the perovskite mainly transforms into LaOCl and to a minor extent into LaCl3. Extent of Mn chlorination seems to be favored over LM0 having a higher MnClx±/MnOCl± ionic ratio compared to LM18. Furthermore ToF-SIMS clearly identifies C1 chlorinated organic ions, mainly CH2Cl+ and CHCl2-, on LM0 which may contribute to the XPS Cl organic component. From the combined ToF-SIMS and XPS results it is found that water delays the surface degradation extent of the perovskite into related (oxy)(hydroxy)chlorinated inorganic phases by less molecular chlorine and related chlorine species on the catalyst surface. A reaction scheme of Cl removal over LaMnO3+δ emphasing the role of water is given taking into account the detection of ToF-SIMS ions representative of the successive Mn intermediate states. As a consequence water allows tuning the degradation pathways of the main intermediate of the reaction, dichloroacetyl chloride (DCAC), which decomposes to give phosgene, HCCl3 and CCl4 by a successive Cl incorporation over (oxy)(hydroxy)chorinated perovskite or/and Mn species while COx species are likely formed over the perovskite.

NASA's F-15B testbed aircraft in flight during the first evaluation flight of the joint NASA/Gulfstream Quiet Spike project

NASA Image and Video Library

2006-08-10

NASA's F-15B testbed aircraft in flight during the first evaluation flight of the joint NASA/Gulfstream Quiet Spike project. The project seeks to verify the structural integrity of the multi-segmented, articulating spike attachment designed to reduce and control a sonic boom.

A Chief Engineer's View of the NASA X-43A Scramjet Flight Test

NASA Technical Reports Server (NTRS)

Marshall, Laurie A.; Corpening, Griffin P.; Sherrill, Robert

2005-01-01

This paper presents an overview of the preparation and execution of the first two flights of the NASA X-43A scramjet flight test project. The project consisted of three flights, two planned for Mach 7 and one for Mach 10. The first flight, conducted on June 2, 2001, was unsuccessful and resulted in a nine-month mishap investigation. A two-year return to flight effort ensued and concluded when the second Mach 7 flight was successfully conducted on March 27, 2004. The challenges faced by the project team as they prepared the first ever scramjet-powered airplane for flight are presented. Modifications made to the second flight vehicle as a result of the first flight failure and the return to flight activities are discussed. Flight results and lessons learned are also presented.

Future risk assessment by estimating historical heat wave trends with projected heat accumulation using SimCLIM climate model in Pakistan

NASA Astrophysics Data System (ADS)

Nasim, Wajid; Amin, Asad; Fahad, Shah; Awais, Muhammad; Khan, Naeem; Mubeen, Muhammad; Wahid, Abdul; Turan, Veysel; Rehman, Muhammad Habibur; Ihsan, Muhammad Zahid; Ahmad, Shakeel; Hussain, Sajjad; Mian, Ishaq Ahmad; Khan, Bushra; Jamal, Yousaf

2018-06-01

Climate change has adverse effects at global, regional and local level. Heat wave events have serious contribution for global warming and natural hazards in Pakistan. Historical (1997-2015) heat wave were analyzed over different provinces (Punjab, Sindh and Baluchistan) of Pakistan to identify the maximum temperature trend. Heat accumulation in Pakistan were simulated by the General Circulation Model (GCM) combined with 3 GHG (Green House Gases) Representative Concentration Pathways (RCPs) (RCP-4.5, 6.0, and 8.5) by using SimCLIM model (statistical downscaling model for future trend projections). Heat accumulation was projected for year 2030, 2060, and 2090 for seasonal and annual analysis in Pakistan. Heat accumulation were projected to increase by the baseline year (1995) was represented in percentage change. Projection shows that Sindh and southern Punjab was mostly affected by heat accumulation. This study identified the rising trend of heat wave over the period (1997-2015) for Punjab, Sindh and Baluchistan (provinces of Pakistan), which identified that most of the meteorological stations in Punjab and Sindh are highly prone to heat waves. According to model projection; future trend of annual heat accumulation, in 2030 was increased 17%, 26%, and 32% but for 2060 the trends were reported by 54%, 49%, and 86% for 2090 showed highest upto 62%, 75%, and 140% for RCP-4.5, RCP-6.0, and RCP-8.5, respectively. While seasonal trends of heat accumulation were projected to maximum values for monsoon and followed by pre-monsoon and post monsoon. Heat accumulation in monsoon may affect the agricultural activities in the region under study.

Using a Computerized Classroom Simulation to Prepare Pre-Service Teachers

ERIC Educational Resources Information Center

McPherson, Rebekah; Tyler-Wood, Tandra; McEnturff Ellison, Amber; Peak, Pamela

2011-01-01

This study at a large midwestern university evaluated the use of a web-based simulated classroom, simSchool, with pre-service and in-service special education students, to determine if use of the simulated classroom influences students' perceptions of inclusion and teacher preparation. The project used a nonequivalent comparison group,…

Blended Teaching and Learning in the School of Science and Technology of UniSIM

ERIC Educational Resources Information Center

Toon, Andrew John; Samir, Attallah; Kheng, Jennifer Huang Mui; Chew, Lim Kin; Vythilingam, Moorthy; Kiat, Stephen Low Wee

2009-01-01

Purpose: The purpose of this paper is to investigate the blended learning preferences under which adult students study mathematics, electronics and industry certificate examinations like project management and e-SAP (systems, applications and products). Design/methodology/approach: The study is based on four case studies in mathematics,…

Reactor Simulator Testing

NASA Technical Reports Server (NTRS)

Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise Jon

2013-01-01

As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz. Keywords: fission, space power, nuclear, liquid metal, NaK.

Mission operations and command assurance: Flight operations quality improvements

NASA Technical Reports Server (NTRS)

Welz, Linda L.; Bruno, Kristin J.; Kazz, Sheri L.; Potts, Sherrill S.; Witkowski, Mona M.

1994-01-01

Mission Operations and Command Assurance (MO&CA) is a Total Quality Management (TQM) task on JPL projects to instill quality in flight mission operations. From a system engineering view, MO&CA facilitates communication and problem-solving among flight teams and provides continuous solving among flight teams and provides continuous process improvement to reduce risk in mission operations by addressing human factors. The MO&CA task has evolved from participating as a member of the spacecraft team, to an independent team reporting directly to flight project management and providing system level assurance. JPL flight projects have benefited significantly from MO&CA's effort to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit from previous and ongoing flight experience.

Hyper-X Stage Separation: Simulation Development and Results

NASA Technical Reports Server (NTRS)

Reubush, David E.; Martin, John G.; Robinson, Jeffrey S.; Bose, David M.; Strovers, Brian K.

2001-01-01

This paper provides an overview of stage separation simulation development and results for NASA's Hyper-X program; a focused hypersonic technology effort designed to move hypersonic, airbreathing vehicle technology from the laboratory environment to the flight environment. This paper presents an account of the development of the current 14 degree of freedom stage separation simulation tool (SepSim) and results from use of the tool in a Monte Carlo analysis to evaluate the risk of failure for the separation event. Results from use of the tool show that there is only a very small risk of failure in the separation event.

Overview of the NASA Dryden Flight Research Facility aeronautical flight projects

NASA Technical Reports Server (NTRS)

Meyer, Robert R., Jr.

1992-01-01

Several principal aerodynamics flight projects of the NASA Dryden Flight Research Facility are discussed. Key vehicle technology areas from a wide range of flight vehicles are highlighted. These areas include flight research data obtained for ground facility and computation correlation, applied research in areas not well suited to ground facilities (wind tunnels), and concept demonstration.

Gold coatings for cube-corner retro-reflectors

NASA Astrophysics Data System (ADS)

Dligatch, Svetlana; Gross, Mark; Netterfield, Roger P.; Pereira, Nathan; Platt, Benjamin C.; Nemati, Bijan

2005-09-01

The Space Interferometry Mission (SIM) PlanetQuest is managed by the Jet Propulsion Laboratory for the National Aeronautics and Space Administration. SIM requires, among other things, high precision double cube-corner retroreflectors. A test device has recently been fabricated for this project with demanding specifications on the optical surfaces and gold reflective coatings. Several gold deposition techniques were examined to meet the stringent specifications on uniformity, optical properties, micro-roughness and surface quality. We report on a comparative study of optical performance of gold films deposited by resistive and e-beam pvaporation, including measurements of the scattering from the coated surfaces. The effects of oxygen bombardment and titanium under-layer on optical properties and adhesion were evaluated. The influence of surface preparation on the optical properties was examined also.

X-PEEM, XPS and ToF-SIMS characterisation of xanthate induced chalcopyrite flotation: Effect of pulp potential

NASA Astrophysics Data System (ADS)

Kalegowda, Yogesh; Chan, Yuet-Loy; Wei, Der-Hsin; Harmer, Sarah L.

2015-05-01

Synchrotron-based X-ray photoemission electron microscopy (X-PEEM), X-ray photo-electron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and ultraviolet visible spectroscopy were used to characterize the flotation behaviour of chalcopyrite with xanthate at different processing conditions. The flotation recovery of chalcopyrite decreased from 97% under oxidative conditions (Eh ~ 385 mV SHE, pH 4) to 41% at a reductive potential of - 100 mV SHE (at pH 9). X-PEEM images constructed from the metal L3 absorption edges were used to produce near-edge X-ray absorption fine structure (NEXAFS) spectra from regions of interest, allowing the variability in mineral surface chemistry of each mineral particle to be analysed, and the effect of pulp potential (Eh) on the flotation of chalcopyrite to be determined. XPS, ToF-SIMS and NEXAFS analyses of chalcopyrite particles at oxidative conditions show that the surface was mildly oxidised and covered with adsorbed molecular CuEX. The Cu 2p XPS and Cu L2,3 NEXAFS spectra were dominated by CuI species attributed to bulk chalcopyrite and adsorbed CuEX. At a reductive potential of - 100 mV SHE, an increase in concentration of CuI and FeIII oxides and hydroxides was observed. X-PEEM analysis was able to show the presence of a low percentage of CuII oxides (CuO or Cu(OH)2) with predominantly CuI oxide (Cu2O) which is not evident in Cu 2p XPS spectra.

Grafting titanium nitride surfaces with sodium styrene sulfonate thin films

PubMed Central

Zorn, Gilad; Migonney, Véronique; Castner, David G.

2014-01-01

The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm2. PMID:25280842

A ToF-SIMS and XPS study of protein adsorption and cell attachment across PEG-like plasma polymer films with lateral compositional gradients

NASA Astrophysics Data System (ADS)

Menzies, Donna J.; Jasieniak, Marek; Griesser, Hans J.; Forsythe, John S.; Johnson, Graham; McFarland, Gail A.; Muir, Benjamin W.

2012-12-01

In this work we report a detailed X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) study of poly(ethylene glycol) PEG-like chemical gradients deposited via plasma enhanced chemical vapour deposition (PECVD) at two different load powers using diethylene glycol dimethyl ether (DG) as a monomer. Principal component analysis (PCA) was applied to the ToF-SIMS data both before and after protein adsorption on the plasma polymer thin films. Results of the PCA loadings indicated a higher content of hydrocarbon fragments across the higher load power gradient, which adsorbed higher amounts of proteins. Gradients deposited at a lower load power retained a higher degree of monomer like functionality as did the central region directly underneath the knife edge electrode. Analysis of the adsorption of serum proteins (human serum albumin and fetal bovine serum) was monitored across the gradient films and increased with decreasing ether (PEG-like) film chemistries. The effect of protein incubation time on the levels adsorbed fetal bovine serum on the plasma polymer films was critical, with significantly more protein adsorbing after 24 hour incubation times on both gradient films. The attachment of HeLa cells on the gradients appeared to be dictated not only by the surface chemistry, but also by the adsorption of serum proteins. XPS analysis revealed that at surface ether concentrations of less than 70% in the gradient films, significant increases in protein and cell attachment were observed.

Mission operations and command assurance: Instilling quality into flight operations

NASA Technical Reports Server (NTRS)

Welz, Linda L.; Witkowski, Mona M.; Bruno, Kristin J.; Potts, Sherrill S.

1993-01-01

Mission Operations and Command Assurance (MO&CA) is a Total Quality Management (TQM) task on JPL projects to instill quality in flight mission operations. From a system engineering view, MO&CA facilitates communication and problem-solving among flight teams and provides continuous process improvement to reduce the probability of radiating incorrect commands to a spacecraft. The MO&CA task has evolved from participating as a member of the spacecraft team to an independent team reporting directly to flight project management and providing system level assurance. JPL flight projects have benefited significantly from MO&CA's effort to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit from previous and ongoing flight experience.

The path to an experiment in space (from concept to flight)

NASA Technical Reports Server (NTRS)

Salzman, Jack A.

1994-01-01

The following are discussed in this viewgraph presentation on developing flight experiments for NASA's Microgravity Science and Applications Program: time from flight PI selection to launch; key flight experiment phases and schedule drivers; microgravity experiment definition/development process; definition and engineering development phase; ground-based reduced gravity research facilities; project organization; responsibilities and duties of principle investigator/co-investigators, project scientist, and project manager; the science requirements document; flight development phase; experiment cost and schedule; and keys to experiment success.

Marshall Space Flight Center and the Reactor-in-Flight Stage: A Look Back at Using Nuclear Propulsion to Power Space Vehicles in the 1960's

NASA Technical Reports Server (NTRS)

Wright, Mike

2003-01-01

This paper examines the Marshall Space Flight Center s role in the Reactor-In-Flight (RIlT) project that NASA was involved with in the early 1960 s. The paper outlines the project s relation to the joint NASA-Atomic Energy Commission nuclear initiative known as Project Rover. It describes the justification for the RIFT project, its scope, and the difficulties that were encountered during the project. It also provides as assessment of NASA s overall capabilities related to nuclear propulsion in the early 1960 s.

Flight projects overview

NASA Technical Reports Server (NTRS)

Levine, Jack

1988-01-01

Information is given in viewgraph form on the activities of the Flight Projects Division of NASA's Office of Aeronautics and Space Technology. Information is given on space research and technology strategy, current space flight experiments, the Long Duration Exposure Facility, the Orbiter Experiment Program, the Lidar In-Space Technology Experiment, the Ion Auxiliary Propulsion System, the Arcjet Flight Experiment, the Telerobotic Intelligent Interface Flight Experiment, the Cryogenic Fluid Management Flight Experiment, the Industry/University In-Space Flight Experiments, and the Aeroassist Flight Experiment.

14 CFR 1216.305 - Criteria for actions requiring environmental assessments.

Code of Federal Regulations, 2012 CFR

2012-01-01

... assessment are: (1) Specific spacecraft development and flight projects in space science. (2) Specific spacecraft development and flight projects in space and terrestrial applications. (3) Specific experimental... spacecraft development and flight projects. (2) R&D activities in space and terrestrial applications (e.g...

Post flight system analysis of FRECOPA (AO 138)

NASA Technical Reports Server (NTRS)

Durin, Christian

1991-01-01

The unexpected duration for the flight of the Long Duration Exposure Facility (LDEF) conducted CNES to create a special investigation group in order to analyze all the materials and systems which compose the French Cooperative Payload (FRECOPA) except the experiments especially prepared for the flight. The FRECOPA tray was on the trailing face (V-) of the LDEF and protected from the atomic oxygen flux during all the flight. However, the solar irradiation was very important with solar flux quite perpendicular to the experiment once an orbit. There was also a good vacuum environment. The objectives are to test the effects of the combined space environment on materials and components like: structure, thermal control coatings and blankets, electronic unit, motors, and mechanical fixtures. When the LDEF returned to Kennedy Space Center, a visual inspection showed the very good behavior of the materials used and it was noted that the three mechanisms to open and close the experiment canisters worked completely. Many impacts of micrometeoroids or space debris on the structure and on the thermal protections were observed. After FRECOPA was brought back to Toulouse, many tests were performed and include: working order tests, mechanical tests (tension), optical and electronic microscopy (SEM), surface analysis (ESCA, SIMS, RBS, AUGER, etc.), thermal analysis, pressure measurements, and gas analysis (outgassing tests). The results of these experiments are discussed.

Structural analysis of poly-SUMO chain recognition by the RNF4-SIMs domain.

PubMed

Kung, Camy C-H; Naik, Mandar T; Wang, Szu-Huan; Shih, Hsiu-Ming; Chang, Che-Chang; Lin, Li-Ying; Chen, Chia-Lin; Ma, Che; Chang, Chi-Fon; Huang, Tai-Huang

2014-08-15

The E3 ubiquitin ligase RNF4 (RING finger protein 4) contains four tandem SIM [SUMO (small ubiquitin-like modifier)-interaction motif] repeats for selective interaction with poly-SUMO-modified proteins, which it targets for degradation. We employed a multi-faceted approach to characterize the structure of the RNF4-SIMs domain and the tetra-SUMO2 chain to elucidate the interaction between them. In solution, the SIM domain was intrinsically disordered and the linkers of the tetra-SUMO2 were highly flexible. Individual SIMs of the RNF4-SIMs domains bind to SUMO2 in the groove between the β2-strand and the α1-helix parallel to the β2-strand. SIM2 and SIM3 bound to SUMO with a high affinity and together constituted the recognition module necessary for SUMO binding. SIM4 alone bound to SUMO with low affinity; however, its contribution to tetra-SUMO2 binding avidity is comparable with that of SIM3 when in the RNF4-SIMs domain. The SAXS data of the tetra-SUMO2-RNF4-SIMs domain complex indicate that it exists as an ordered structure. The HADDOCK model showed that the tandem RNF4-SIMs domain bound antiparallel to the tetra-SUMO2 chain orientation and wrapped around the SUMO protamers in a superhelical turn without imposing steric hindrance on either molecule.

R&D Project on Algebra Software Seen to Show Promise

ERIC Educational Resources Information Center

Trotter, Andrew

2007-01-01

Computer software that shows students visual models of mathematical concepts--and lets them manipulate those models by doing math--has a certain intuitive appeal. Now, recent research on SimCalc Mathworlds, one of the pioneering examples of such software, is providing some of the best evidence so far that the approach can lead to gains in student…

Satellite irrigation management support with the terrestrial observation and prediction system: A framework for integration of satellite & surface observations to support improvements in agricultural water resource management

USDA-ARS?s Scientific Manuscript database

In California and other regions vulnerable to water shortages, satellite-derived estimates of key hydrologic parameters can support agricultural producers and water managers in maximizing the benefits of available water supplies. The Satellite Irrigation Management Support (SIMS) project combines N...

A Case Study in User Support for Managing OpenSim Based Multi User Learning Environments

ERIC Educational Resources Information Center

Perera, Indika; Miller, Alan; Allison, Colin

2017-01-01

Immersive 3D Multi User Learning Environments (MULE) have shown sufficient success to warrant their consideration as a mainstream educational paradigm. These are based on 3D Multi User Virtual Environment platforms (MUVE), and although they have been used for various innovative educational projects their complex permission systems and large…

Web-based multimedia courseware for emergency cardiac patient management simulations.

PubMed

Ambrosiadou, V; Compton, T; Panchal, T; Polovina, S

2000-01-01

This is a multidisciplinary inter-departmental/faculty project between the departments of computer science, electronic, communications and electrical engineering and nursing and paramedic sciences. The objective is to develop a web based multimedia front end to existing simulations of cardiac emergency scenaria. It will be used firstly in the teaching of nurses. The University of Hertfordshire is the only University in Britain using simulations of cardiac emergency scenaria for nurse and paramedic science education and therefore this project will add the multimedia dimension in distributed courses over the web and will assess the improvement in the educational process. The use of network and multimedia technologies, provide interactive learning, immediate feedback to students' responses, individually tailored instructions, objective testing and entertaining delivery. The end product of this project will serve as interactive material to enhance experiential learning for nursing students using the simulations of cardiac emergency scenaria. The emergency treatment simulations have been developed using VisSim and may be compiled as C code. The objective of the project is to provide a web based user friendly multimedia interface in order to demonstrate the way in which patients may be managed in critical situations by applying advanced technological equipment and drug administration. Then the user will be able to better appreciate the concepts involved by running the VisSim simulations. The evaluation group for the proposed software will be the Department of Nursing and Paramedic Sciences About 200 nurses use simulations every year for training purposes as part of their course requirements.

Total and Spectral Solar Irradiance Sensor (TSIS) Project Status

NASA Technical Reports Server (NTRS)

Carlisle, Candace

2018-01-01

TSIS-1 studies the Sun's energy input to Earth and how solar variability affects climate. TSIS-1 will measure both the total amount of light that falls on Earth, known as the total solar irradiance (TSI), and how that light is distributed among ultraviolet, visible and infrared wavelengths, called solar spectral irradiance (SSI). TSIS-1 will provide the most accurate measurements of sunlight and continue the long-term climate data record. TSIS-1 includes two instruments: the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM), integrated into a single payload on the International Space Station (ISS). The TSIS-1 TIM and SIM instruments are upgraded versions of the two instruments that are flying on the Solar Radiation and Climate Experiment (SORCE) mission launched in January 2003. NASA Goddard's TSIS project responsibilities include project management, system engineering, safety and mission assurance, and engineering oversight for TSIS-1. TSIS-1 was installed on the International Space Station in December 2017. At the end of the 90-day commissioning phase, responsibility for TSIS-1 operations transitions to the Earth Science Mission Operations (ESMO) project at Goddard for its 5-year operations. NASA contracts with the University of Colorado Laboratory for Atmospheric and Space Physics (LASP) for the design, development and testing of TSIS-1, support for ISS integration, science operations of the TSIS-1 instrument, data processing, data evaluation, calibration and delivery to the Goddard Earth Science Data and Information Services Center (GES DISC).

Time-of-flight secondary ion mass spectrometry (ToF-SIMS)-based analysis and imaging of polyethylene microplastics formation during sea surf simulation.

PubMed

Jungnickel, H; Pund, R; Tentschert, J; Reichardt, P; Laux, P; Harbach, H; Luch, A

2016-09-01

Plastic particles smaller than 5mm, so called microplastics have the capability to accumulate in rivers, lakes and the marine environment and therefore have begun to be considered in eco-toxicology and human health risk assessment. Environmental microplastic contaminants may originate from consumer products like body wash, tooth pastes and cosmetic products, but also from degradation of plastic waste; they represent a potential but unpredictable threat to aquatic organisms and possibly also to humans. We investigated exemplarily for polyethylene (PE), the most abundant constituent of microplastic particles in the environment, whether such fragments could be produced from larger pellets (2mm×6mm). So far only few analytical methods exist to identify microplastic particles smaller than 10μm, especially no imaging mass spectrometry technique. We used at first time-of-flight secondary ion mass spectrometry (ToF-SIMS) for analysis and imaging of small PE-microplastic particles directly in the model system Ottawa sand during exposure to sea surf simulation. As a prerequisite, a method for identification of PE was established by identification of characteristic ions for PE out of an analysis of grinded polymer samples. The method was applied onto Ottawa sand in order to investigate the influence of simulated environmental conditions on particle transformation. A severe degradation of the primary PE pellet surface, associated with the transformation of larger particles into smaller ones already after 14days of sea surf simulation, was observed. Within the subsequent period of 14days to 1month of exposure the number of detected smallest-sized particles increased significantly (50%) while the second smallest fraction increased even further to 350%. Results were verified using artificially degraded PE pellets and Ottawa sand. Copyright © 2016 Elsevier B.V. All rights reserved.

Immobilization and detection of platelet-derived extracellular vesicles on functionalized silicon substrate: cytometric and spectrometric approach.

PubMed

Gajos, Katarzyna; Kamińska, Agnieszka; Awsiuk, Kamil; Bajor, Adrianna; Gruszczyński, Krzysztof; Pawlak, Anna; Żądło, Andrzej; Kowalik, Artur; Budkowski, Andrzej; Stępień, Ewa

2017-02-01

Among the various biomarkers that are used to diagnose or monitor disease, extracellular vesicles (EVs) represent one of the most promising targets in the development of new therapeutic strategies and the application of new diagnostic methods. The detection of circulating platelet-derived microvesicles (PMVs) is a considerable challenge for laboratory diagnostics, especially in the preliminary phase of a disease. In this study, we present a multistep approach to immobilizing and detecting PMVs in biological samples (microvesicles generated from activated platelets and human platelet-poor plasma) on functionalized silicon substrate. We describe the application of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and spectroscopic ellipsometry methods to the detection of immobilized PMVs in the context of a novel imaging flow cytometry (ISX) technique and atomic force microscopy (AFM). This novel approach allowed us to confirm the presence of the abundant microvesicle phospholipids phosphatidylserine (PS) and phosphatidylethanolamine (PE) on a surface with immobilized PMVs. Phosphatidylcholine groups (C 5 H 12 N + ; C 5 H 15 PNO 4 + ) were also detected. Moreover, we were able to show that ellipsometry permitted the immobilization of PMVs on a functionalized surface to be evaluated. The sensitivity of the ISX technique depends on the size and refractive index of the analyzed microvesicles. Graphical abstract Human platelets activated with thrombin (in concentration 1IU/mL) generate population of PMVs (platelet derived microvesicles), which can be detected and enumerated with fluorescent-label method (imaging cytometry). Alternatively, PMVs can be immobilized on the modified silicon substrate which is functionalized with a specific IgM murine monoclonal antibody against human glycoprotein IIb/IIIa complex (PAC-1). Immobilized PMVs can be subjected to label-free analyses by means ellipsometry, atomic force microscopy (AFM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS).

Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples.

PubMed

Goacher, Robyn E; Braham, Erick J; Michienzi, Courtney L; Flick, Robert M; Yakunin, Alexander F; Master, Emma R

2017-12-29

The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion. © 2017 Scandinavian Plant Physiology Society.

Uptake of Ra during the recrystallization of barite: a microscopic and time of flight-secondary ion mass spectrometry study.

PubMed

Klinkenberg, Martina; Brandt, Felix; Breuer, Uwe; Bosbach, Dirk

2014-06-17

A combined macroscopic and microanalytical approach was applied on two distinct barite samples from Ra uptake batch experiments using time of flight-secondary ion mass spectrometry (ToF-SIMS) and detailed scanning electron microscopy (SEM) investigations. The experiments were set up at near to equilibrium conditions to distinguish between two possible scenarios for the uptake of Ra by already existent barite: (1) formation of a Ba1-xRaxSO4 solid solution surface layer on the barite or (2) a complete recrystallization, leading to homogeneous Ba1-xRaxSO4 crystals. It could be clearly shown that Ra uptake in all barite particles analyzed within this study is not limited to the surface but extends to the entire solid. For most grains a homogeneous distribution of Ra could be determined, indicating a complete recrystallization of barite into a Ba1-xRaxSO4 solid solution. The maxima of the Ra/Ba intensity ratio distribution histograms calculated from ToF-SIMS are identical with the expected Ra/Ba ratios calculated from mass balance assuming a complete recrystallization. In addition, the role of Ra during the recrystallization of barite was examined via detailed SEM investigations. Depending on the type of barite used, an additional coarsening effect or a strong formation of oriented aggregates was observed compared to blank samples without Ra. In conclusion, the addition of Ra to a barite at close to equilibrium conditions has a major impact on the system leading to a fast re-equilibration of the solid to a Ba1-xRaxSO4 solid solution and visible effects on the particle size distribution, even at room temperature.

Flight Research and Validation Formerly Experimental Capabilities Supersonic Project

NASA Technical Reports Server (NTRS)

Banks, Daniel

2009-01-01

This slide presentation reviews the work of the Experimental Capabilities Supersonic project, that is being reorganized into Flight Research and Validation. The work of Experimental Capabilities Project in FY '09 is reviewed, and the specific centers that is assigned to do the work is given. The portfolio of the newly formed Flight Research and Validation (FRV) group is also reviewed. The various projects for FY '10 for the FRV are detailed. These projects include: Eagle Probe, Channeled Centerbody Inlet Experiment (CCIE), Supersonic Boundary layer Transition test (SBLT), Aero-elastic Test Wing-2 (ATW-2), G-V External Vision Systems (G5 XVS), Air-to-Air Schlieren (A2A), In Flight Background Oriented Schlieren (BOS), Dynamic Inertia Measurement Technique (DIM), and Advanced In-Flight IR Thermography (AIR-T).

Overview With Results and Lessons Learned of the X-43A Mach 10 Flight

NASA Technical Reports Server (NTRS)

Marshall, Laurie A.; Bahm, Catherine; Corpening, Griffin P.; Sherrill, Robert

2005-01-01

This paper provides an overview of the final flight of the NASA X-43A project. The project consisted of three flights, two planned for Mach 7 and one for Mach 10. The third and final flight, November 16, 2004, was the first Mach 10 flight demonstration of an airframe-integrated, scramjet-powered, hypersonic vehicle. The goals and objectives for the project as well as those for the third flight are presented. The configuration of the Hyper-X stack including the X-43A, Hyper-X launch vehicle, and Hyper-X research vehicle adapter is discussed. The second flight of the X-43A was successfully conducted on March 27, 2004. Mission differences, vehicle modifications and lessons learned from the second flight as they applied to the third flight are also discussed. An overview of flight 3 results is presented.

Spatial and temporal localization during embryonic and fetal human development of the transcription factor SIM2 in brain regions altered in Down syndrome.

PubMed

Rachidi, Mohammed; Lopes, Carmela; Charron, Giselle; Delezoide, Anne-Lise; Paly, Evelyne; Bloch, Bernard; Delabar, Jean-Maurice

2005-08-01

Human SIM2 is the ortholog of Drosophila single-minded (sim), a master regulator of neurogenesis and transcriptional factor controlling midline cell fate determination. We previously localized SIM2 in a chromosome 21 critical region for Down syndrome (DS). Here, we studied SIM2 gene using a new approach to provide insights in understanding of its potential role in human development. For the first time, we showed SIM2 spatial and temporal expression pattern during human central nervous system (CNS) development, from embryonic to fetal stages. Additional investigations were performed using a new optic microscopy technology to compare signal intensity and cell density [M. Rachidi, C. Lopes, S. Gassanova, P.M. Sinet, M. Vekemans, T. Attie, A.L. Delezoide, J.M. Delabar, Regional and cellular specificity of the expression of TPRD, the tetratricopeptide Down syndrome gene, during human embryonic development, Mech. Dev. 93 (2000) 189--193]. In embryonic stages, SIM2 was identified predominantly in restricted regions of CNS, in ventral part of D1/D2 diencephalic neuroepithelium, along the neural tube and in a few cell subsets of dorsal root ganglia. In fetal stages, SIM2 showed differential expression in pyramidal and granular cell layers of hippocampal formation, in cortical cells and in cerebellar external granular and Purkinje cell layers. SIM2 expression in embryonic and fetal brain could suggest a potential role in human CNS development, in agreement with Drosophila and mouse Sim mutant phenotypes and with the conservation of the Sim function in CNS development from Drosophila to Human. SIM2 expression in human fetal brain regions, which correspond to key structures for cognitive processes, correlates well with the behavioral phenotypes of Drosophila Sim mutants and transgenic mice overexpressing Sim2. In addition, SIM2-expressing brain regions correspond to the altered structures in DS patients. All together, these findings suggest a potential role of SIM2 in CNS development and indicate that SIM2 overexpression could participate to the pathogenesis of mental retardation in Down syndrome patients.

Proceedings of the Second NASA Formal Methods Symposium

NASA Technical Reports Server (NTRS)

Munoz, Cesar (Editor)

2010-01-01

This publication contains the proceedings of the Second NASA Formal Methods Symposium sponsored by the National Aeronautics and Space Administration and held in Washington D.C. April 13-15, 2010. Topics covered include: Decision Engines for Software Analysis using Satisfiability Modulo Theories Solvers; Verification and Validation of Flight-Critical Systems; Formal Methods at Intel -- An Overview; Automatic Review of Abstract State Machines by Meta Property Verification; Hardware-independent Proofs of Numerical Programs; Slice-based Formal Specification Measures -- Mapping Coupling and Cohesion Measures to Formal Z; How Formal Methods Impels Discovery: A Short History of an Air Traffic Management Project; A Machine-Checked Proof of A State-Space Construction Algorithm; Automated Assume-Guarantee Reasoning for Omega-Regular Systems and Specifications; Modeling Regular Replacement for String Constraint Solving; Using Integer Clocks to Verify the Timing-Sync Sensor Network Protocol; Can Regulatory Bodies Expect Efficient Help from Formal Methods?; Synthesis of Greedy Algorithms Using Dominance Relations; A New Method for Incremental Testing of Finite State Machines; Verification of Faulty Message Passing Systems with Continuous State Space in PVS; Phase Two Feasibility Study for Software Safety Requirements Analysis Using Model Checking; A Prototype Embedding of Bluespec System Verilog in the PVS Theorem Prover; SimCheck: An Expressive Type System for Simulink; Coverage Metrics for Requirements-Based Testing: Evaluation of Effectiveness; Software Model Checking of ARINC-653 Flight Code with MCP; Evaluation of a Guideline by Formal Modelling of Cruise Control System in Event-B; Formal Verification of Large Software Systems; Symbolic Computation of Strongly Connected Components Using Saturation; Towards the Formal Verification of a Distributed Real-Time Automotive System; Slicing AADL Specifications for Model Checking; Model Checking with Edge-valued Decision Diagrams; and Data-flow based Model Analysis.

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

Yang, Li; Zhu, Zihua; Yu, Xiao-Ying

In this study, we report new results of in situ study of 5 nm goat anti-mouse IgG gold nanoparticles in a novel portable vacuum compatible microfluidic device using scanning electron microscope (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The unique feature of the liquid flow cell is that the detection window is open to the vacuum allowing direct probing of the liquid surface. The flow cell is composed of a silicon nitride (SiN) membrane and polydimethylsiloxane (PDMS), and it is fully compatible with vacuum operations for surface analysis. The aperture can be drilled through the 100 nm SiN membranemore » using a focused ion beam. Characteristic signals of the conjugated gold nanoparticles were successfully observed through the aperture by both energy-dispersive X-ray spectroscopy (EDX) in SEM and ToF-SIMS. Comparison was also made among wet samples, dry samples, and liquid sample in the flow cell using SEM/EDX. Stronger gold signal can be observed in our novel portable device by SEM/EDX compared with the wet or dry samples, respectively. Our results indicate that analyses of the nanoparticle components are better made in their native liquid environment. This is made possible using our unique microfluidic flow cell.« less

Removal properties of diesel exhaust particles by a dielectric barrier discharge reactor.

PubMed

Suzuki, Ken-ichiro; Takeuchi, Naomi; Madokoro, Kazuhiko; Fushimi, Chihiro; Yao, Shuiliang; Fujioka, Yuichi; Nihei, Yoshimasa

2008-02-01

The removal properties of diesel exhaust particles (DEP) were investigated using an engine exhaust particle size spectrometer (EEPS), field emission-type scanning electron microscopy (FE-SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). DEP were treated using a dielectric barrier discharge (DBD) reactor installed in the tail pipe of a diesel engine, and a model DBD reactor fed with DEP in the mixture of N(2) and O(2). When changing the experimental parameters of both the plasma conditions and the engine load conditions, we obtained characteristic information of DEP treated with plasma discharges from the particle diameter and the composition. In evaluating the model DBD reactor, it became clear that there were two types of plasma processes (reactions with active oxygen species to yield CO(2) and reactions with active nitrogen species to yield nitrogen containing compounds). Moreover, from the result of a TOF-SIMS analysis, the characteristic secondary ions, such as C(2)H(6)N(+), C(4)H(12)N(+), and C(10)H(20)N(2)(+), were strongly detected from the DEP surfaces during the plasma discharges. This indicates that the nitrogen contained hydrocarbons were generated by plasma reactions.

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

Pletincx, Sven; Marcoen, Kristof; Trotochaud, Lena

Understanding the stability of chemical interactions at the polymer/metal oxide interface under humid conditions is vital to understand the long-term durability of hybrid systems. Therefore, the interface of ultrathin PMMA films on native aluminum oxide, deposited by reactive adsorption, was studied. The characterization of the interface of the coated substrates was performed using ambient pressure X-ray photoelectron spectroscopy (APXPS), Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The formation of hydrogen bonds and carboxylate ionic bonds at the interface are observed. The formed ionic bond is stable up to 5 Torrmore » water vapour pressure as shown by APXPS. However, when the coated samples are exposed to an excess of aqueous electrolyte, an increase in the amount of carboxylate bonds at the interface, as a result of hydrolysis of the methoxy group, is observed by ATR-FTIR Kretschmann. In conclusion, these observations, supported by ToF-SIMS spectra, lead to the proposal of an adsorption mechanism of PMMA on aluminum oxide, which shows the formation of methanol at the interface and the effect of water molecules on the different interfacial interactions.« less

Microplasma array patterning of reactive oxygen and nitrogen species onto polystyrene

NASA Astrophysics Data System (ADS)

Szili, Endre J.; Dedrick, James; Oh, Jun-Seok; Bradley, James W.; Boswell, Roderick W.; Charles, Christine; Short, Robert D.; Al-Bataineh, Sameer A.

2017-02-01

We investigate an approach for the patterning of reactive oxygen and nitrogen species (RONS) onto polystyrene using atmospheric-pressure microplasma arrays. The spectrally integrated and time-resolved optical emission from the array is characterised with respect to the applied voltage, applied-voltage frequency and pressure; and the array is used to achieve spatially resolved modification of polystyrene at three pressures: 500 Torr, 760 Torr and 1000 Torr. As determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS), regions over which surface modification occurs are clearly restricted to areas that are exposed to individual microplasma cavities. Analysis of the negative-ion ToF-SIMS mass spectra from the centre of the modified microspots shows that the level of oxidation is dependent on the operating pressure, and closely correlated with the spatial distribution of the optical emission. The functional groups that are generated by the microplasma array on the polystyrene surface are shown to readily participate in an oxidative reaction in phosphate buffered saline solution (pH 7.4). Patterns of oxidised and chemically reactive functionalities could potentially be applied to the future development of biomaterial surfaces, where spatial control over biomolecule or cell function is needed.

Rosmarinic acid content in antidiabetic aqueous extract of Ocimum canum sims grown in Ghana.

PubMed

Berhow, Mark A; Affum, Andrews Obeng; Gyan, Ben A

2012-07-01

Rosmarinic acid (RA) is an important antioxidant polyphenol that is found in a variety of spices and herbs, including Ocimum canum Sims (locally called eme or akokobesa in Ghana). Aqueous extracts from the leaves of O. canum are used as an antidiabetic herbal medicine in Ghana. Analytical thin-layer chromatography was used to examine the composition of the polyphenols in leaf extracts. The polyphenol content in the aqueous and methanol extracts from the leaf, as determined by the Folin-Ciocalteu method, were 314 and 315 mg gallic acid equivalent/g leaf sample, respectively. The total flavonoid concentration as determined by the aluminum(III) chloride method was 135 mg catechin equivalent/g leaf sample. High-performance liquid chromatography coupled to an electrospray Quadrupole time-of-flight mass spectrometer was also used to determine the polyphenol fingerprint profile in the leaf extracts of O. canum. Although the average RA concentration in the O. canum leaf extracts from Ghana was 1.69 mg/g dry weight (reported values range from 0.01 to 99.62 mg/g dry weight), this polyphenol was still a prominent peak in addition to caffeic acid derivatives.

Food-induced changes of lipids in rat neuronal tissue visualized by ToF-SIMS imaging.

PubMed

Dowlatshahi Pour, Masoumeh; Jennische, Eva; Lange, Stefan; Ewing, Andrew G; Malmberg, Per

2016-09-06

Time of flight secondary ion mass spectrometry (ToF-SIMS) was used to image the lipid localization in brain tissue sections from rats fed specially processed cereals (SPC). An IonTof 5 instrument equipped with a Bi cluster ion gun was used to analyze the tissue sections. Data from 15 brain samples from control and cereal-fed rats were recorded and exported to principal components analysis (PCA). The data clearly show changes of certain lipids in the brain following cereal feeding. PCA score plots show a good separation in lipid distribution between the control and the SPC-fed group. The loadings plot reveal that the groups separated mainly due to changes in cholesterol, vitamin E and c18:2, c16:0 fatty acid distribution as well as some short chain monocarboxylic fatty acid compositions. These insights relate to the working mechanism of SPC as a dietary supplement. SPC is thought to activate antisecretory factor (AF), an endogenous protein with regulatory function for inflammation and fluid secretion. These data provide insights into lipid content in brain following SPC feeding and suggest a relation to activating AF.

Microgravity

NASA Image and Video Library

1998-09-30

The Electrostatic Levitator (ESL) Facility established at Marshall Space Flight Center (MSFC) supports NASA's Microgravity Materials Science Research Program. NASA materials science investigations include ground-based, flight definition and flight projects. Flight definition projects, with demanding science concept review schedules, receive highest priority for scheduling experiment time in the Electrostatic Levitator (ESL) Facility.

Structured illumination microscopy as a diagnostic tool for nephrotic disease

NASA Astrophysics Data System (ADS)

Nylk, Jonathan; Pullman, James M.; Campbell, Elaine C.; Gunn-Moore, Frank J.; Prystowsky, Michael B.; Dholakia, Kishan

2017-02-01

Nephrotic disease is a group of debilitating and sometimes lethal diseases affecting kidney function, specifically the loss of ability to retain vital proteins in the blood while smaller molecules are removed through filtration into the urine. Treatment routes are often dictated by microscopic analysis of kidney biopsies. Podocytes within the glomeruli of the kidney have many interdigitating projections (foot processes), which form the main filtration system. Nephrotic disease is characterised by the loss of this tightly interdigitating substructure and its observation by electron microscopy (EM) is necessitated as these structures are typically 250 500nm wide, with 40nm spacing. Diagnosis by EM is both expensive and time consuming; it can take up to one week to complete the preparation, imaging, and analysis of a single sample. We propose structured illumination microscopy (SIM) as an alternative, optical diagnostic tool. Our results show that SIM can resolve the structure of fluorescent probes tagged to podocin, a protein localised to the periphery of the podocyte foot processes. Three-dimensional podocin maps were acquired in healthy tissue and tissue from patients diagnosed with two different nephrotic disease states; minimal change disease and membranous nephropathy. These structures correlated well with EM images of the same structure. Preparation, imaging, and analysis could be achieved in several hours. Additionally, the volumetric information of the SIM images revealed morphological changes in disease states not observed by EM. This evidence supports the use of SIM as a diagnostic tool for nephrotic disease and can potentially reduce the time and cost per diagnosis.

CET exSim: mineral exploration experience via simulation

NASA Astrophysics Data System (ADS)

Wong, Jason C.; Holden, Eun-Jung; Kovesi, Peter; McCuaig, T. Campbell; Hronsky, Jon

2013-08-01

Undercover mineral exploration is a challenging task as it requires understanding of subsurface geology by relying heavily on remotely sensed (i.e. geophysical) data. Cost-effective exploration is essential in order to increase the chance of success using finite budgets. This requires effective decision-making in both the process of selecting the optimum data collection methods and in the process of achieving accuracy during subsequent interpretation. Traditionally, developing the skills, behaviour and practices of exploration decision-making requires many years of experience through working on exploration projects under various geological settings, commodities and levels of available resources. This implies long periods of sub-optimal exploration decision-making, before the necessary experience has been successfully obtained. To address this critical industry issue, our ongoing research focuses on the development of the unique and novel e-learning environment, exSim, which simulates exploration scenarios where users can test their strategies and learn the consequences of their choices. This simulator provides an engaging platform for self-learning and experimentation in exploration decision strategies, providing a means to build experience more effectively. The exSim environment also provides a unique platform on which numerous scenarios and situations (e.g. deposit styles) can be simulated, potentially allowing the user to become virtually familiarised with a broader scope of exploration practices. Harnessing the power of computer simulation, visualisation and an intuitive graphical user interface, the simulator provides a way to assess the user's exploration decisions and subsequent interpretations. In this paper, we present the prototype functionalities in exSim including: simulation of geophysical surveys, follow-up drill testing and interpretation assistive tools.

SimPackJ/S: a web-oriented toolkit for discrete event simulation

NASA Astrophysics Data System (ADS)

Park, Minho; Fishwick, Paul A.

2002-07-01

SimPackJ/S is the JavaScript and Java version of SimPack, which means SimPackJ/S is a collection of JavaScript and Java libraries and executable programs for computer simulations. The main purpose of creating SimPackJ/S is that we allow existing SimPack users to expand simulation areas and provide future users with a freeware simulation toolkit to simulate and model a system in web environments. One of the goals for this paper is to introduce SimPackJ/S. The other goal is to propose translation rules for converting C to JavaScript and Java. Most parts demonstrate the translation rules with examples. In addition, we discuss a 3D dynamic system model and overview an approach to 3D dynamic systems using SimPackJ/S. We explain an interface between SimPackJ/S and the 3D language--Virtual Reality Modeling Language (VRML). This paper documents how to translate C to JavaScript and Java and how to utilize SimPackJ/S within a 3D web environment.

Open-source image reconstruction of super-resolution structured illumination microscopy data in ImageJ

PubMed Central

Müller, Marcel; Mönkemöller, Viola; Hennig, Simon; Hübner, Wolfgang; Huser, Thomas

2016-01-01

Super-resolved structured illumination microscopy (SR-SIM) is an important tool for fluorescence microscopy. SR-SIM microscopes perform multiple image acquisitions with varying illumination patterns, and reconstruct them to a super-resolved image. In its most frequent, linear implementation, SR-SIM doubles the spatial resolution. The reconstruction is performed numerically on the acquired wide-field image data, and thus relies on a software implementation of specific SR-SIM image reconstruction algorithms. We present fairSIM, an easy-to-use plugin that provides SR-SIM reconstructions for a wide range of SR-SIM platforms directly within ImageJ. For research groups developing their own implementations of super-resolution structured illumination microscopy, fairSIM takes away the hurdle of generating yet another implementation of the reconstruction algorithm. For users of commercial microscopes, it offers an additional, in-depth analysis option for their data independent of specific operating systems. As a modular, open-source solution, fairSIM can easily be adapted, automated and extended as the field of SR-SIM progresses. PMID:26996201

(abstract) Mission Operations and Control Assurance: Flight Operations Quality Improvements

NASA Technical Reports Server (NTRS)

Welz, Linda L.; Bruno, Kristin J.; Kazz, Sheri L.; Witkowski, Mona M.

1993-01-01

Mission Operations and Command Assurance (MO&CA), a recent addition to flight operations teams at JPL. provides a system level function to instill quality in mission operations. MO&CA's primary goal at JPL is to help improve the operational reliability for projects during flight. MO&CA tasks include early detection and correction of process design and procedural deficiencies within projects. Early detection and correction are essential during development of operational procedures and training of operational teams. MO&CA's effort focuses directly on reducing the probability of radiating incorrect commands to a spacecraft. Over the last seven years at JPL, MO&CA has become a valuable asset to JPL flight projects. JPL flight projects have benefited significantly from MO&CA's efforts to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit directly from previous and ongoing experience. Since MO&CA, like Total Quality Management (TQM), focuses on continuous improvement of processes and elimination of rework, we recommend that this effort be continued on NASA flight projects.

Effect of Simvastatin Prodrug on Experimental Periodontitis.

PubMed

Bradley, Aaron D; Zhang, Yijia; Jia, Zhenshan; Zhao, Gang; Wang, Xiaobei; Pranke, Laura; Schmid, Marian J; Wang, Dong; Reinhardt, Richard A

2016-05-01

Local application of statins has shown potential in preventing and regenerating bone loss associated with experimental periodontitis. This study evaluates the effect of a novel simvastatin (SIM) prodrug (capable of delivering high doses to periodontitis inflammatory lesion and cells) on experimental periodontitis bone loss and inflammation. Forty mature female Sprague Dawley rats were subjected to ligature-induced experimental periodontitis between maxillary first and second molars (M1-M2). Equal groups were treated with three weekly doses of: 1) prodrug carrier alone (mPEG); 2) 0.5 mg SIM dose equivalent in carrier (SIM/SIM-mPEG); 3) 1.0 mg SIM/SIM-mPEG; 4) 1.5 mg SIM/SIM-mPEG; or 5) ligature alone. Contralateral molars served as unmanipulated controls. Four weeks after initiation of periodontitis, animals were euthanized, the M1-M2 interproximal was evaluated with microcomputed tomography and histology, and data were analyzed with one-way analysis of variance. Ligature alone caused a mean bone loss of 1.01 ± 0.06 mm from the cemento-enamel junction, whereas all doses of SIM/SIM-mPEG reduced bone loss, especially 1.5 mg SIM/SIM-mPEG (0.68 ± 0.05 mm, P <0.001), which was not statistically different from contralateral control (0.47 ± 0.06 mm). A dose of 1.5 mg SIM/SIM-mPEG also reduced percentage of neutrophils compared with carrier alone (2.0% ± 1.0% versus 5.7% ± 1.1%; P <0.05), and increased amount of uninflamed connective tissue in the M1-M2 interproximal area (65.2% ± 3.3% versus 46.3% ± 3.3%; P <0.001). The mPEG carrier alone did not have bone-sparing or anti-inflammatory properties. Multiple local 1.5-mg doses of a macromolecular SIM prodrug decreases amount of experimental periodontitis bone loss and inflammation in rats.

Automated Discovery of Simulation Between Programs

DTIC Science & Technology

2014-10-18

relation. These relations enable the refinement-step of SimAbs. We have implemented SimAbs using UFO framework and Z3 SMT-solver and applied it to...step of SimAbs. We implemented SimAbs and AE-VAL on the top of the UFO framework [1, 15] and an SMT-solver Z3 [8], respectively. We have evaluated SimAbs...ut 6 Evaluation We have implemented SimAbs in the UFO framework, and evaluated it on the Software Verification Competition (SVCOMP’14) benchmarks and

Space Shuttle Projects Overview to Columbia Air Forces War College

NASA Technical Reports Server (NTRS)

Singer, Jody; McCool, Alex (Technical Monitor)

2000-01-01

This paper presents, in viewgraph form, a general overview of space shuttle projects. Some of the topics include: 1) Space Shuttle Projects; 2) Marshall Space Flight Center Space Shuttle Projects Office; 3) Space Shuttle Propulsion systems; 4) Space Shuttle Program Major Sites; 5) NASA Office of Space flight (OSF) Center Roles in Space Shuttle Program; 6) Space Shuttle Hardware Flow; and 7) Shuttle Flights To Date.

Secondary Ion Mass Spectrometry SIMS XI

NASA Astrophysics Data System (ADS)

Gillen, G.; Lareau, R.; Bennett, J.; Stevie, F.

2003-05-01

This volume contains 252 contributions presented as plenary, invited and contributed poster and oral presentations at the 11th International Conference on Secondary Ion Mass Spectrometry (SIMS XI) held at the Hilton Hotel, Walt Disney World Village, Orlando, Florida, 7 12 September, 1997. The book covers a diverse range of research, reflecting the rapid growth in advanced semiconductor characterization, ultra shallow depth profiling, TOF-SIMS and the new areas in which SIMS techniques are being used, for example in biological sciences and organic surface characterization. Papers are presented under the following categories: Isotopic SIMS Biological SIMS Semiconductor Characterization Techniques and Applications Ultra Shallow Depth Profiling Depth Profiling Fundamental/Modelling and Diffusion Sputter-Induced Topography Fundamentals of Molecular Desorption Organic Materials Practical TOF-SIMS Polyatomic Primary Ions Materials/Surface Analysis Postionization Instrumentation Geological SIMS Imaging Fundamentals of Sputtering Ion Formation and Cluster Formation Quantitative Analysis Environmental/Particle Characterization Related Techniques These proceedings provide an invaluable source of reference for both newcomers to the field and experienced SIMS users.

Sim1 haploinsufficiency impairs melanocortin-mediated anorexia and activation of paraventricular nucleus neurons.

PubMed

Kublaoui, Bassil M; Holder, J Lloyd; Gemelli, Terry; Zinn, Andrew R

2006-10-01

Single-minded 1 (SIM1) is one of only six genes implicated in human monogenic obesity. Haploinsufficiency of this hypothalamic transcription factor is associated with hyperphagic obesity and increased linear growth in both humans and mice. Additionally, Sim1 heterozygous mice show enhanced hyperphagia and obesity in response to a high-fat diet. Thus the phenotype of Sim1 haploinsufficiency is similar to that of agouti yellow (Ay), and melanocortin 4 receptor (Mc4r) knockout mice, both of which are defective in hypothalamic melanocortin signaling. Sim1 and Mc4r are both expressed in the paraventricular nucleus (PVN). Here we report that Sim1 heterozygous mice, which have normal energy expenditure, are hyperphagic despite having elevated hypothalamic proopiomelanocortin (Pomc) expression. In response to the melanocortin agonist melanotan-2 (MTII) they exhibit a blunted suppression of feeding yet increase their energy expenditure normally. They also fail to activate PVN neurons in response to the drug at a dose that induces robust c-Fos expression in a subset of Sim1 PVN neurons in wild-type mice. The resistance to melanocortin signaling in Sim1 heterozygotes is not due to a reduced number of Sim1 neurons in the PVN. Hypothalamic Sim1 gene expression is induced by leptin and MTII treatment. Our results demonstrate that Sim1 heterozygotes are resistant to hypothalamic melanocortin signaling and suggest that Sim1-expressing PVN neurons regulate feeding, but not energy expenditure, in response to melanocortin signaling.

Structures of the TetR-like simocyclinone efflux pump repressor, SimR, and the mechanism of ligand-mediated derepression.

PubMed

Le, Tung B K; Stevenson, Clare E M; Fiedler, Hans-Peter; Maxwell, Anthony; Lawson, David M; Buttner, Mark J

2011-04-22

Simocyclinone D8 (SD8), a potent DNA gyrase inhibitor made by Streptomyces antibioticus, is exported from the producing organism by the SimX efflux pump. The expression of simX is under the control of SimR, a member of the TetR family of transcriptional regulators. SimR represses simX transcription by binding to operators in the intergenic region between simR and simX. Previously, we have shown that the mature antibiotic SD8 or its biosynthetic intermediate, simocyclinone C4, can dissociate SimR from its operators, leading to derepression of simX and export of SD8 from the cell. This provides a mechanism that couples the biosynthesis of the antibiotic to its export. Here, we report the crystal structures of SimR alone and in complex with either SD8 or simocyclinone C4. The ligand-binding pocket is unusual compared to those of other characterized TetR-family transcriptional regulators: the structures show an extensive ligand-binding pocket spanning both monomers in the functional dimeric unit, with the aminocoumarin moiety of SD8 buried in the protein core, while the angucyclic polyketide moiety is partially exposed to bulk solvent. Through comparisons of the structures, we postulate a derepression mechanism for SimR that invokes rigid-body motions of the subunits relative to one another, coupled with a putative locking mechanism to restrict further conformational change. Copyright © 2011 Elsevier Ltd. All rights reserved.

Error Modeling of Multi-baseline Optical Truss. Part II; Application to SIM Metrology Truss Field Dependent Error

NASA Technical Reports Server (NTRS)

Zhang, Liwei Dennis; Milman, Mark; Korechoff, Robert

2004-01-01

The current design of the Space Interferometry Mission (SIM) employs a 19 laser-metrology-beam system (also called L19 external metrology truss) to monitor changes of distances between the fiducials of the flight system's multiple baselines. The function of the external metrology truss is to aid in the determination of the time-variations of the interferometer baseline. The largest contributor to truss error occurs in SIM wide-angle observations when the articulation of the siderostat mirrors (in order to gather starlight from different sky coordinates) brings to light systematic errors due to offsets at levels of instrument components (which include comer cube retro-reflectors, etc.). This error is labeled external metrology wide-angle field-dependent error. Physics-based model of field-dependent error at single metrology gauge level is developed and linearly propagated to errors in interferometer delay. In this manner delay error sensitivity to various error parameters or their combination can be studied using eigenvalue/eigenvector analysis. Also validation of physics-based field-dependent model on SIM testbed lends support to the present approach. As a first example, dihedral error model is developed for the comer cubes (CC) attached to the siderostat mirrors. Then the delay errors due to this effect can be characterized using the eigenvectors of composite CC dihedral error. The essence of the linear error model is contained in an error-mapping matrix. A corresponding Zernike component matrix approach is developed in parallel, first for convenience of describing the RMS of errors across the field-of-regard (FOR), and second for convenience of combining with additional models. Average and worst case residual errors are computed when various orders of field-dependent terms are removed from the delay error. Results of the residual errors are important in arriving at external metrology system component requirements. Double CCs with ideally co-incident vertices reside with the siderostat. The non-common vertex error (NCVE) is treated as a second example. Finally combination of models, and various other errors are discussed.

Development and characterization of a stable adhesive bond between a poly(dimethylsiloxane) catheter material and a bacterial biofilm resistant acrylate polymer coating

PubMed Central

Tyler, Bonnie J.; Hook, Andrew; Pelster, Andreas; Williams, Paul; Alexander, Morgan; Arlinghaus, Heinrich F.

2017-01-01

Catheter associated urinary tract infections are the most common health related infections worldwide, contributing significantly to patient morbidity and mortality and increased health care costs. To reduce the incidence of these infections, new materials that resist bacterial biofilm formation are needed. A composite catheter material, consisting of bulk poly(dimethylsiloxane) (PDMS) coated with a novel bacterial biofilm resistant polyacrylate [ethylene glycol dicyclopentenyl ether acrylate (EGDPEA)-co-di(ethyleneglycol) methyl ether methacrylate (DEGMA)], has been proposed. The coated material shows excellent bacterial resistance when compared to commercial catheter materials, but delamination of the EGDPEA-co-DEGMA coatings under mechanical stress presents a challenge. In this work, the use of oxygen plasma treatment to improve the wettability and reactivity of the PDMS catheter material and improve adhesion with the EGDPEA-co-DEGMA coating has been investigated. Argon cluster three dimensional-imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used to probe the buried adhesive interface between the EGDPEA-co-DEGMA coating and the treated PDMS. ToF-SIMS analysis was performed in both dry and frozen-hydrated states, and the results were compared to mechanical tests. From the ToF-SIMS data, the authors have been able to observe the presence of PDMS, silicates, salt particles, cracks, and water at the adhesive interface. In the dry catheters, low molecular weight PDMS oligomers at the interface were associated with poor adhesion. When hydrated, the hydrophilic silicates attracted water to the interface and led to easy delamination of the coating. The best adhesion results, under hydrated conditions, were obtained using a combination of 5 min O2 plasma treatment and silane primers. Cryo-ToF-SIMS analysis of the hydrated catheter material showed that the bond between the primed PDMS catheter and the EGDPEA-co-DEGMA coating was stable in the presence of water. The resulting catheter material resisted Escherichia coli and Proteus mirabilis biofilm colonization by up to 95% compared with uncoated PDMS after 10 days of continuous bacterial exposure and had the mechanical properties necessary for use as a urinary catheter. PMID:28535686

Visualizing Antimicrobials in Bacterial Biofilms: Three-Dimensional Biochemical Imaging Using TOF-SIMS.

PubMed

Davies, Sarah K; Fearn, Sarah; Allsopp, Luke P; Harrison, Freya; Ware, Ecaterina; Diggle, Stephen P; Filloux, Alain; McPhail, David S; Bundy, Jacob G

2017-01-01

Bacterial biofilms are groups of bacteria that exist within a self-produced extracellular matrix, adhering to each other and usually to a surface. They grow on medical equipment and inserts such as catheters and are responsible for many persistent infections throughout the body, as they can have high resistance to many antimicrobials. Pseudomonas aeruginosa is an opportunistic pathogen that can cause both acute and chronic infections and is used as a model for research into biofilms. Direct biochemical methods of imaging of molecules in bacterial biofilms are of high value in gaining a better understanding of the fundamental biology of biofilms and biochemical gradients within them. Time of flight-secondary-ion mass spectrometry (TOF-SIMS) is one approach, which combines relatively high spatial resolution and sensitivity and can perform depth profiling analysis. It has been used to analyze bacterial biofilms but has not yet been used to study the distribution of antimicrobials (including antibiotics and the antimicrobial metal gallium) within biofilms. Here we compared two methods of imaging of the interior structure of P. aeruginosa in biological samples using TOF-SIMS, looking at both antimicrobials and endogenous biochemicals: cryosectioning of tissue samples and depth profiling to give pseudo-three-dimensional (pseudo-3D) images. The sample types included both simple biofilms grown on glass slides and bacteria growing in tissues in an ex vivo pig lung model. The two techniques for the 3D imaging of biofilms are potentially valuable complementary tools for analyzing bacterial infection. IMPORTANCE Modern analytical techniques are becoming increasingly important in the life sciences; imaging mass spectrometry offers the opportunity to gain unprecedented amounts of information on the distribution of chemicals in samples-both xenobiotics and endogenous compounds. In particular, simultaneous imaging of antibiotics (and other antimicrobial compounds) and bacterium-derived metabolites in complex biological samples could be very important in the future for helping to understand how sample matrices impact the survival of bacteria under antibiotic challenge. We have shown that an imaging mass spectrometric technique, TOF-SIMS, will be potentially extremely valuable for this kind of research in the future.

Data Exploration Theater 3

NASA Image and Video Library

2017-12-08

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 3.5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Data Exploration Theater 4

NASA Image and Video Library

2017-12-08

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Data Exploration Theater 1

NASA Image and Video Library

2017-12-08

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 3.5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Data Exploration Theater 2

NASA Image and Video Library

2017-12-08

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Pat Izzo To learn more about NCCS go to: www.nasa.gov/topics/earth/features/climate-sim-center.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Image and compositional characteristics of the LDEF Big Guy impact crater

NASA Technical Reports Server (NTRS)

Bunch, T. E.; Paque, Julie M.; Zolensky, Michael

1995-01-01

A 5.2 mm crater in Al-metal represents the largest found on LDEF. We have examined this crater by field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and time-of-flight/secondary ion mass spectroscopy (TOF-SIMS) in order to determine if there is any evidence of impactor residue. Droplet and dome-shaped columns, along with flow features, are evidence of melting. EDS from the crater cavity and rim show Mg, C, O and variable amounts of Si, in addition to Al. No evidence for a chondritic impactor was found, and it hypothesized that the crater may be the result of impact with space debris.

Constructing Virtual Training Demonstrations

DTIC Science & Technology

2008-12-01

virtual environments have been shown to be effective for training, and distributed game -based architectures contribute an added benefit of wide...investigation of how a demonstration authoring toolset can be constructed from existing virtual training environments using 3-D multiplayer gaming ...intelligent agents project to create AI middleware for simulations and videogames . The result was SimBionic®, which enables users to graphically author

Development of Wien filter for small ion gun of surface analysis

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

Bahng, Jungbae; Busan Center, Korea Basic Science Institute, Busan 609-735; Hong, Jonggi

The gas cluster ion beam (GCIB) and liquid metal ion beam have been studied in the context of ion beam usage for analytical equipment in applications such as X-ray photoelectron spectroscopy and secondary ion mass spectroscopy (SIMS). In particular, small ion sources are used for the secondary ion generation and ion etching. To set the context to this study, the SIMS project has been launched to develop ion-gun based analytical equipment for the Korea Basic Science Institute. The objective of the first stage of the project is the generation of argon beams with a GCIB system [A. Kirkpatrick, Nucl. Instrum.more » Methods Phys. Res., Sect. B 206, 830–837 (2003)] that consists of a nozzle, skimmer, ionizer, acceleration tube, separation system, transport system, and target. The Wien filter directs the selected cluster beam to the target system by exploiting the velocity difference of the generated particles from GCIB. In this paper, we present the theoretical modeling and three-dimensional electromagnetic analysis of the Wien filter, which can separate Ar{sup +}{sub 2500} clusters from Ar{sup +}{sub 2400} to Ar{sup +}{sub 2600} clusters with a 1-mm collimator.« less

A Hybrid Parachute Simulation Environment for the Orion Parachute Development Project

NASA Technical Reports Server (NTRS)

Moore, James W.

2011-01-01

A parachute simulation environment (PSE) has been developed that aims to take advantage of legacy parachute simulation codes and modern object-oriented programming techniques. This hybrid simulation environment provides the parachute analyst with a natural and intuitive way to construct simulation tasks while preserving the pedigree and authority of established parachute simulations. NASA currently employs four simulation tools for developing and analyzing air-drop tests performed by the CEV Parachute Assembly System (CPAS) Project. These tools were developed at different times, in different languages, and with different capabilities in mind. As a result, each tool has a distinct interface and set of inputs and outputs. However, regardless of the simulation code that is most appropriate for the type of test, engineers typically perform similar tasks for each drop test such as prediction of loads, assessment of altitude, and sequencing of disreefs or cut-aways. An object-oriented approach to simulation configuration allows the analyst to choose models of real physical test articles (parachutes, vehicles, etc.) and sequence them to achieve the desired test conditions. Once configured, these objects are translated into traditional input lists and processed by the legacy simulation codes. This approach minimizes the number of sim inputs that the engineer must track while configuring an input file. An object oriented approach to simulation output allows a common set of post-processing functions to perform routine tasks such as plotting and timeline generation with minimal sensitivity to the simulation that generated the data. Flight test data may also be translated into the common output class to simplify test reconstruction and analysis.

SimSchool: An Opportunity for Using Serious Gaming for Training Teachers in Rural Areas

ERIC Educational Resources Information Center

Tyler-Wood, Tandra; Estes, Mary; Christensen, Rhonda; Knezek, Gerald; Gibson, David

2015-01-01

This article examines the use of simSchool as a training tool for educators working with students with special needs in rural districts. SimSchool is a game that emulates a classroom utilizing a virtual environment. The theory supporting simSchool is explored and current research associated with simSchool is reviewed. The issues surrounding…

Molecular imaging of lipids in cells and tissues

NASA Astrophysics Data System (ADS)

Borner, Katrin; Malmberg, Per; Mansson, Jan-Eric; Nygren, Hakan

2007-02-01

The distribution pattern of lipid species in biological tissues was analyzed with imaging mass spectrometry (TOF-SIMS; time-of-flight secondary ion mass spectrometry). The first application shows distribution of a glycosphingolipid, the galactosylceramide-sulfate (sulfatide) with different hydrocarbon chain lengths and the fatty acids palmitate and oleate in rat cerebellum. Sulfatides were seen localized in regions suggested as paranodal areas of rat cerebellar white matter as well as in the granular layer, with highest concentrations at the borders of the white matter. Different distribution patterns could be shown for the fatty acid C16:0 palmitate and C18:1 oleate in rat cerebellum, which seem to origin partly from the hydrocarbon chains of phosphatidylcholine. Results were shown for two different tissue preparation methods, which were plunge-freezing and cryostat sectioning as well as high-pressure freezing, freeze-fracturing and freeze-drying. The second application shows TOF-SIMS analysis on a biological trial of choleratoxin treatment in mouse intestine. The effect of cholera toxin on lipids in the intestinal epithelium was shown by comparing control and cholera toxin treated mouse intestine samples. A significant increase of the cholesterol concentration was seen after treatment. Cholesterol was mainly localized to the brush border of enterocytes of the intestinal villi, which could be explained by the presence of cholesterol-rich lipid rafts present on the microvilli or by relations to cholesterol uptake. After cholera toxin exposure, cholesterol was seen increased in the nuclei of enterocytes and apparently in the interstitium of the villi. We find that imaging TOF-SIMS is a powerful tool for studies of lipid distributions in cells and tissues, enabling the elucidation of their role in cell function and biology.

SIMS chemical analysis of extended impacts on the leading and trailing edges of LDEF experiment AO187-2

NASA Technical Reports Server (NTRS)

Amari, S.; Foote, J.; Swan, P.; Walker, R. M.; Zinner, E.; Lange, G.

1993-01-01

Numerous 'extended impacts' found in both leading and trailing edge capture cells were successfully analyzed for the chemical composition of projectile residues by secondary ion mass spectrometry (SIMS). Most data were obtained from the trailing edge cells where 45 of 58 impacts were classified as 'probably natural' and the remainder as 'possibly man-made debris.' This is in striking contrast to leading edge cells where 9 of 11 impacts so far measured are definitely classified as orbital debris. Although all the leading edge cells had lost their plastic entrance foils during flight, the rate of foil failure was similar to that of the trailing edge cells, 10 percent of which were recovered intact. Ultraviolet embrittlement is suspected as the major cause of failure on both leading and trailing edges. The major impediment to the accurate determination of projectile chemistry is the fractionation of volatile and refractory elements in the hypervelocity impact and redeposition processes. This effect had been noted in a simulation experiment but is more pronounced in the LDEF capture cells, probably due to the higher average velocities of the space impacts. Surface contamination of the pure Ge surfaces with a substance rich in Si, but also containing Mg and Al, provides an additional problem for the accurate determination of impactor chemistry. The effect is variable, being much larger on surfaces that were exposed to space than in those cells that remained intact. Future work will concentrate on the analyses of more leading edge impacts and the development of new SIMS techniques for the measurement of elemental abundances in extended impacts.

Development of a patient-specific dosimetry estimation system in nuclear medicine examination

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

Lin, H. H.; Dong, S. L.; Yang, H. J.

2011-07-01

The purpose of this study is to develop a patient-specific dosimetry estimation system in nuclear medicine examination using a SimSET-based Monte Carlo code. We added a dose deposition routine to store the deposited energy of the photons during their flights in SimSET and developed a user-friendly interface for reading PET and CT images. Dose calculated on ORNL phantom was used to validate the accuracy of this system. The S values for {sup 99m}Tc, {sup 18}F and {sup 131}I obtained by the system were compared to those from the MCNP4C code and OLINDA. The ratios of S values computed by thismore » system to those obtained with OLINDA for various organs were ranged from 0.93 to 1.18, which are comparable to that obtained from MCNP4C code (0.94 to 1.20). The average ratios of S value were 0.99{+-}0.04, 1.03{+-}0.05, and 1.00{+-}0.07 for isotopes {sup 131}I, {sup 18}F, and {sup 99m}Tc, respectively. The simulation time of SimSET was two times faster than MCNP4C's for various isotopes. A 3D dose calculation was also performed on a patient data set with PET/CT examination using this system. Results from the patient data showed that the estimated S values using this system differed slightly from those of OLINDA for ORNL phantom. In conclusion, this system can generate patient-specific dose distribution and display the isodose curves on top of the anatomic structure through a friendly graphic user interface. It may also provide a useful tool to establish an appropriate dose-reduction strategy to patients in nuclear medicine environments. (authors)« less

Animal urine as painting materials in African rock art revealed by cluster ToF-SIMS mass spectrometry imaging.

PubMed

Mazel, Vincent; Richardin, Pascale; Touboul, David; Brunelle, Alain; Richard, Caroline; Laval, Eric; Walter, Philippe; Laprévote, Olivier

2010-08-01

The rock art site at the village of Songo in Mali is a very important Dogon ritual place where, since the end of the nineteenth century until today, takes place the ceremony of circumcision. During these ceremonies, paintings are performed on the walls of the shelter with mainly three colors: red, black and white. Ethnological literature mentions the use of animal urine of different species such as birds, lizards or snakes as a white pigment. Urine of these animals is mainly composed of uric acid or urate salts. In this article, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is used to compare uric acid, snake urine and a sample of a white pigment of a Dogon painting coming from the rock art site of Songo. ToF-SIMS measurements in both positive and negative ion modes on reference compounds and snake urine proved useful for the study of uric acid and urate salts. This method enables to identify unambiguously these compounds owing to the detection in negative ion mode of the ion corresponding to the deprotonated molecule ([M-H](-) at m/z 167.01) and its fragment ions. Moreover, the mass spectra obtained in positive ion mode permit to differentiate uric acid and urate salts on the basis of specific ions. Applying this method to the Dogon white pigments sample, we show that the sample is entirely composed of uric acid. This proves for the first time, that animal urine was used as a pigment by the Dogon. The presence of uric acid instead of urate salts as normally expected in animal urine could be explained by the preparation of the pigment for its application on the stone. Copyright 2010 John Wiley & Sons, Ltd.

These two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project o

NASA Technical Reports Server (NTRS)

2001-01-01

Two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project over California's Mojave Desert. This second flight phase is mapping the wingtip vortex of the lead aircraft, the Systems Research Aircraft (tail number 847), on the trailing F/A-18 tail number 847. Wingtip vortex is a spiraling wind flowing from the wing during flight. The project is studying the drag and fuel reduction of precision formation flying.

Lessons Learned and Flight Results from the F15 Intelligent Flight Control System Project

NASA Technical Reports Server (NTRS)

Bosworth, John

2006-01-01

A viewgraph presentation on the lessons learned and flight results from the F15 Intelligent Flight Control System (IFCS) project is shown. The topics include: 1) F-15 IFCS Project Goals; 2) Motivation; 3) IFCS Approach; 4) NASA F-15 #837 Aircraft Description; 5) Flight Envelope; 6) Limited Authority System; 7) NN Floating Limiter; 8) Flight Experiment; 9) Adaptation Goals; 10) Handling Qualities Performance Metric; 11) Project Phases; 12) Indirect Adaptive Control Architecture; 13) Indirect Adaptive Experience and Lessons Learned; 14) Gen II Direct Adaptive Control Architecture; 15) Current Status; 16) Effect of Canard Multiplier; 17) Simulated Canard Failure Stab Open Loop; 18) Canard Multiplier Effect Closed Loop Freq. Resp.; 19) Simulated Canard Failure Stab Open Loop with Adaptation; 20) Canard Multiplier Effect Closed Loop with Adaptation; 21) Gen 2 NN Wts from Simulation; 22) Direct Adaptive Experience and Lessons Learned; and 23) Conclusions

Auditory cortex controls sound-driven innate defense behaviour through corticofugal projections to inferior colliculus.

PubMed

Xiong, Xiaorui R; Liang, Feixue; Zingg, Brian; Ji, Xu-ying; Ibrahim, Leena A; Tao, Huizhong W; Zhang, Li I

2015-06-11

Defense against environmental threats is essential for animal survival. However, the neural circuits responsible for transforming unconditioned sensory stimuli and generating defensive behaviours remain largely unclear. Here, we show that corticofugal neurons in the auditory cortex (ACx) targeting the inferior colliculus (IC) mediate an innate, sound-induced flight behaviour. Optogenetic activation of these neurons, or their projection terminals in the IC, is sufficient for initiating flight responses, while the inhibition of these projections reduces sound-induced flight responses. Corticocollicular axons monosynaptically innervate neurons in the cortex of the IC (ICx), and optogenetic activation of the projections from the ICx to the dorsal periaqueductal gray is sufficient for provoking flight behaviours. Our results suggest that ACx can both amplify innate acoustic-motor responses and directly drive flight behaviours in the absence of sound input through corticocollicular projections to ICx. Such corticofugal control may be a general feature of innate defense circuits across sensory modalities.

Ablation of Sim1 Neurons Causes Obesity through Hyperphagia and Reduced Energy Expenditure

PubMed Central

Xi, Dong; Gandhi, Nilay; Lai, Meizan; Kublaoui, Bassil M.

2012-01-01

Single-minded 1 (Sim1) is a transcription factor necessary for development of the paraventricular nucleus of the hypothalamus (PVH). This nucleus is a critical regulator of appetite, energy expenditure and body weight. Previously we showed that Sim1+/− mice and conditional postnatal Sim1−/− mice exhibit hyperphagia, obesity, increased linear growth and susceptibility to diet-induced obesity, but no decrease in energy expenditure. Bilateral ablation of the PVH causes obesity due to hyperphagia and reduced energy expenditure. It remains unknown whether Sim1 neurons regulate energy expenditure. In this study, Sim1cre mice were bred to homozygous inducible diphtheria toxin receptor (iDTR) mice to generate mice expressing the simian DTR in Sim1 cells. In these mice, Sim1 neuron ablation was performed by intracerebroventricular (ICV) injection of diphtheria toxin. Compared to controls, mice with Sim1 neuron ablation became obese (with increased fat mass) on a chow diet due to increased food intake and reduced energy expenditure. In post-injection mice, we observed a strong inverse correlation between the degree of obesity and hypothalamic Sim1 expression. The reduction in baseline energy expenditure observed in these mice was accompanied by a reduction in activity. This reduction in activity did not fully account for the reduced energy expenditure as these mice exhibited decreased resting energy expenditure, decreased body temperature, decreased brown adipose tissue temperature, and decreased UCP1 expression suggesting an impairment of thermogenesis. In injected mice, hypothalamic gene expression of Sim1, oxytocin (OXT) and thyrotropin releasing hormone (TRH) was reduced by about 50%. These results demonstrate that Sim1 neurons in adult mice regulate both food intake and energy expenditure. Based on the body of work in the field, feeding regulation by Sim1 neurons likely occurs in both the PVH and medial amygdala, in contrast to energy expenditure regulation by Sim1 neurons, which likely is localized to the PVH. PMID:22558467

Ablation of Sim1 neurons causes obesity through hyperphagia and reduced energy expenditure.

PubMed

Xi, Dong; Gandhi, Nilay; Lai, Meizan; Kublaoui, Bassil M

2012-01-01

Single-minded 1 (Sim1) is a transcription factor necessary for development of the paraventricular nucleus of the hypothalamus (PVH). This nucleus is a critical regulator of appetite, energy expenditure and body weight. Previously we showed that Sim1(+/-) mice and conditional postnatal Sim1(-/-) mice exhibit hyperphagia, obesity, increased linear growth and susceptibility to diet-induced obesity, but no decrease in energy expenditure. Bilateral ablation of the PVH causes obesity due to hyperphagia and reduced energy expenditure. It remains unknown whether Sim1 neurons regulate energy expenditure. In this study, Sim1cre mice were bred to homozygous inducible diphtheria toxin receptor (iDTR) mice to generate mice expressing the simian DTR in Sim1 cells. In these mice, Sim1 neuron ablation was performed by intracerebroventricular (ICV) injection of diphtheria toxin. Compared to controls, mice with Sim1 neuron ablation became obese (with increased fat mass) on a chow diet due to increased food intake and reduced energy expenditure. In post-injection mice, we observed a strong inverse correlation between the degree of obesity and hypothalamic Sim1 expression. The reduction in baseline energy expenditure observed in these mice was accompanied by a reduction in activity. This reduction in activity did not fully account for the reduced energy expenditure as these mice exhibited decreased resting energy expenditure, decreased body temperature, decreased brown adipose tissue temperature, and decreased UCP1 expression suggesting an impairment of thermogenesis. In injected mice, hypothalamic gene expression of Sim1, oxytocin (OXT) and thyrotropin releasing hormone (TRH) was reduced by about 50%. These results demonstrate that Sim1 neurons in adult mice regulate both food intake and energy expenditure. Based on the body of work in the field, feeding regulation by Sim1 neurons likely occurs in both the PVH and medial amygdala, in contrast to energy expenditure regulation by Sim1 neurons, which likely is localized to the PVH.

Surface immobilized antibody orientation determined using ToF-SIMS and multivariate analysis.

PubMed

Welch, Nicholas G; Madiona, Robert M T; Payten, Thomas B; Easton, Christopher D; Pontes-Braz, Luisa; Brack, Narelle; Scoble, Judith A; Muir, Benjamin W; Pigram, Paul J

2017-06-01

Antibody orientation at solid phase interfaces plays a critical role in the sensitive detection of biomolecules during immunoassays. Correctly oriented antibodies with solution-facing antigen binding regions have improved antigen capture as compared to their randomly oriented counterparts. Direct characterization of oriented proteins with surface analysis methods still remains a challenge however surface sensitive techniques such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) provide information-rich data that can be used to probe antibody orientation. Diethylene glycol dimethyl ether plasma polymers (DGpp) functionalized with chromium (DGpp+Cr) have improved immunoassay performance that is indicative of preferential antibody orientation. Herein, ToF-SIMS data from proteolytic fragments of anti-EGFR antibody bound to DGpp and DGpp+Cr are used to construct artificial neural network (ANN) and principal component analysis (PCA) models indicative of correctly oriented systems. Whole antibody samples (IgG) test against each of the models indicated preferential antibody orientation on DGpp+Cr. Cross-reference between ANN and PCA models yield 20 mass fragments associated with F(ab') 2 region representing correct orientation, and 23 mass fragments associated with the Fc region representing incorrect orientation. Mass fragments were then compared to amino acid fragments and amino acid composition in F(ab') 2 and Fc regions. A ratio of the sum of the ToF-SIMS ion intensities from the F(ab') 2 fragments to the Fc fragments demonstrated a 50% increase in intensity for IgG on DGpp+Cr as compared to DGpp. The systematic data analysis methodology employed herein offers a new approach for the investigation of antibody orientation applicable to a range of substrates. Controlled orientation of antibodies at solid phases is critical for maximizing antigen detection in biosensors and immunoassays. Surface-sensitive techniques (such as ToF-SIMS), capable of direct characterization of surface immobilized and oriented antibodies, are under-utilized in current practice. Selection of a small number of mass fragments for analysis, typically pertaining to amino acids, is commonplace in literature, leaving the majority of the information-rich spectra unanalyzed. The novelty of this work is the utilization of a comprehensive, unbiased mass fragment list and the employment of principal component analysis (PCA) and artificial neural network (ANN) models in a unique methodology to prove antibody orientation. This methodology is of significant and broad interest to the scientific community as it is applicable to a range of substrates and allows for direct, label-free characterization of surface bound proteins. Copyright © 2017 Acta Materialia Inc. All rights reserved.

NASA's F-15B testbed aircraft undergoes pre-flight checks before performing the first flight of the Quiet Spike project

NASA Image and Video Library

2006-08-10

NASA's F-15B testbed aircraft undergoes pre-flight checks before performing the first flight of the Quiet Spike project. The first flight was performed for evaluation purposes, and the spike was not extended. The Quiet Spike was developed as a means of controlling and reducing the sonic boom caused by an aircraft 'breaking' the sound barrier.

Asset Analysis and Operational Concepts for Separation Assurance Flight Testing at Dryden Flight Research Center

NASA Technical Reports Server (NTRS)

Costa, Guillermo J.; Arteaga, Ricardo A.

2011-01-01

A preliminary survey of existing separation assurance and collision avoidance advancements, technologies, and efforts has been conducted in order to develop a concept of operations for flight testing autonomous separation assurance at Dryden Flight Research Center. This effort was part of the Unmanned Aerial Systems in the National Airspace System project. The survey focused primarily on separation assurance projects validated through flight testing (including lessons learned), however current forays into the field were also examined. Comparisons between current Dryden flight and range assets were conducted using House of Quality matrices in order to allow project management to make determinations regarding asset utilization for future flight tests. This was conducted in order to establish a body of knowledge of the current collision avoidance landscape, and thus focus Dryden s efforts more effectively towards the providing of assets and test ranges for future flight testing within this research field.

Secondary Ion Mass Spectrometry Imaging of Tissues, Cells, and Microbial Systems

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

Anderton, Christopher R.; Gamble, Lara J.

2016-03-01

Mass spectrometry imaging (MSI) techniques are increasingly being utilized within many biological fields, including medicine, pathology, microbial ecology, and more. Of the MSI methods available, secondary ion mass spectrometry (SIMS) offers the highest lateral resolution of any technique. Moreover, SIMS versatility in the number of different operating modes and types of mass spectrometers available has made it an increasing popular method for bio-related measurements. Here, we discuss SIMS ability to image tissues, single cells, and microbes with a particular emphasis on the types chemical and spatial information that can be ascertained by the different types of SIMS instruments and methods.more » The recently developed Fourier transform ion cyclotron resonance (FTICR) SIMS located at PNNL is capable of generating molecular maps of tissues with an unprecedented mass resolving power and mass accuracy, with respect to SIMS measurements. ToF-SIMS can generate chemical maps, where detection of small molecules and fragments can be acquired with an order of magnitude better lateral resolution than the FTICR-SIMS. Furthermore, many of commercially available ToF-SIMS instruments are capable of depth profiling measurements, offering the ability to attain three-dimensional information of one’s sample. The NanoSIMS instrument offers the highest lateral resolution of any MSI method available. In practice, NanoSIMS regularly achieves sub-100 nm resolution of atomic and diatomic secondary ions within biological samples. The strengths of the different SIMS methods are more and more being leveraged in both multimodal-imaging endeavors that use complementary MSI techniques as well with optical, fluorescence, and force microscopy methods.« less

The deep space network, volume 10

NASA Technical Reports Server (NTRS)

1972-01-01

Progress on the Deep Space Network (DSN) supporting research and technology is reported. The objectives, functions and facilities of the DSN are described along with the mission support for the following: interplanetary flight projects, planetary flight projects, and manned space flight projects. Work in advanced engineering and communications systems is reported along with changes in hardware and software configurations in the DSN/MSFN tracking stations.

Preparing strategic information management plans for hospitals: a practical guideline SIM plans for hospitals: a guideline.

PubMed

Brigl, B; Ammenwerth, E; Dujat, C; Gräber, S; Grosse, A; Häber, A; Jostes, C; Winter, A

2005-01-01

Systematic information management in hospitals demands for a strategic information management plan (SIM plan). As preparing a SIM plan is a considerable challenge we provide a practical guideline that is directly applicable when a SIM plan is going to be prepared. The guideline recommends a detailed structure of a SIM plan and gives advice about its content and the preparation process. It may be used as template, which can be adapted to the individual demands of any hospital. The guideline was used in several hospitals preparing a SIM plan. Experiences showed that the SIM plans could be prepared very efficiently and timely using the guideline, that the proposed SIM plan structure suited well, that the guideline offers enough flexibility to meet the requirements of the individual hospitals and that the specific recommendations of the guideline were very helpful. Nevertheless, we must strive for a more comprehensive theory of strategic information management planning which -- in the sense of enterprise architecture planning -- represents the intrinsic correlations of the different parts of a SIM plan to a greater extent.

Anticipatory Water Management in Phoenix using Advanced Scenario Planning and Analyses: WaterSim 5

NASA Astrophysics Data System (ADS)

Sampson, D. A.; Quay, R.; White, D. D.; Gober, P.; Kirkwood, C.

2013-12-01

Complexity, uncertainty, and variability are inherent properties of linked social and natural processes; sustainable resource management must somehow consider all three. Typically, a decision support tool (using scenario analyses) is used to examine management alternatives under suspected trajectories in driver variables (i.e., climate forcing's, growth or economic projections, etc.). This traditional planning focuses on a small set of envisioned scenarios whose outputs are compared against one-another in order to evaluate their differing impacts on desired metrics. Human cognition typically limits this to three to five scenarios. However, complex and highly uncertain issues may require more, often much more, than five scenarios. In this case advanced scenario analysis provides quantitative or qualitative methods that can reveal patterns and associations among scenario metrics for a large ensemble of scenarios. From this analysis, then, a smaller set of heuristics that describe the complexity and uncertainty revealed provides a basis to guide planning in an anticipatory fashion. Our water policy and management model, termed WaterSim, permits advanced scenario planning and analysis for the Phoenix Metropolitan Area. In this contribution we examine the concepts of advanced scenario analysis on a large scale ensemble of scenarios using our work with WaterSim as a case study. For this case study we created a range of possible water futures by creating scenarios that encompasses differences in water supplies (our surrogates for climate change, drought, and inherent variability in riverine flows), population growth, and per capital water consumption. We used IPCC estimates of plausible, future, alterations in riverine runoff, locally produced and vetted estimates of population growth projections, and empirical trends in per capita water consumption for metropolitan cities. This ensemble consisted of ~ 30, 700 scenarios (~575 k observations). We compared and contrasted two metropolitan communities that exhibit differing growth projections and water portfolios; moderate growth with a diverse portfolio versus high growth for a more restrictive portfolio. Results illustrate that both communities exhibited an expanding envelope of possible, future water outcomes with rational water management trajectories. However, a more diverse portfolio resulted in a broad, time-insensitive decision space for management interventions. The reverse was true for the more restrictive water portfolio with high growth projections.

Space Flight: The First 30 Years

NASA Technical Reports Server (NTRS)

1991-01-01

A history of space flight from Project Mercury to the Space Shuttle is told from the perspective of NASA flight programs. Details are given on Mercury missions, Gemini missions, Apollo missions, Skylab missions, the Apollo-Soyuz Test Project, and the Space Shuttle missions.

Strategic petroleum reserve supporting research. Quarterly technical report, January 1-March 31, 1986

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

Woodward, P.W.

1986-01-01

The basic objective is to provide technical support to the Strategic Petroleum Reserve Office (SPRO), through the Bartlesville Project Office. This support includes routine analyses, experimental research, and technical consultation at the SPRO's request. Accomplishments for this past quarter include: stable D, /sup 34/S, and /sup 13/C isotope ratio analyses for 27 samples of SPR crude oil; gas chromatographic simulated distillation (Sim-dis) of 74 SPR crude samples; sim-dis of sludge samples to check for bimodal distributions; data for 8 comprehensive analyses have been entered into the Bonner and Moore ''Crude Assay II'' library; 25 samples which included both whole crudesmore » and distillate fractions were chromatographed using Siemens dual-oven GC and PIANO software; separation of 4 sludge samples into acid, base, and neutral fractions by ion exchange chromatography; and proton and sodium-23 NMR measurements of sludge samples. 1 fig., 5 tabs.« less

PhET: The Best Education Software You Can't Buy

NASA Astrophysics Data System (ADS)

Dubson, M.; Duncan, D. K.

2009-12-01

Project PhET provides free educational software in the form of stand-alone java and flash simulations and associated classroom materials. Our motto is "It's the best educational software that money can buy, except you can't buy it, because its free." You can start playing with PhET sims right now at http://phet.colorado.edu and add to our 1 million hits per month. PhET originally stood for Physics Education Technology, but we now include other science fields so PhET is now a brand name. Our site has about 80 simulations, mostly in physics and math, but also in chemistry, geology, and biology. Based on careful research and student interviews, our sims have no instructions because no one reads instructions. These simulations can be used in lecture demonstrations, classroom activities, and homework assignments. The PhET site includes a long list of user-tested classroom activities and teacher tips.

The QuakeSim Project: Web Services for Managing Geophysical Data and Applications

NASA Astrophysics Data System (ADS)

Pierce, Marlon E.; Fox, Geoffrey C.; Aktas, Mehmet S.; Aydin, Galip; Gadgil, Harshawardhan; Qi, Zhigang; Sayar, Ahmet

2008-04-01

We describe our distributed systems research efforts to build the “cyberinfrastructure” components that constitute a geophysical Grid, or more accurately, a Grid of Grids. Service-oriented computing principles are used to build a distributed infrastructure of Web accessible components for accessing data and scientific applications. Our data services fall into two major categories: Archival, database-backed services based around Geographical Information System (GIS) standards from the Open Geospatial Consortium, and streaming services that can be used to filter and route real-time data sources such as Global Positioning System data streams. Execution support services include application execution management services and services for transferring remote files. These data and execution service families are bound together through metadata information and workflow services for service orchestration. Users may access the system through the QuakeSim scientific Web portal, which is built using a portlet component approach.

Elemental and isotopic imaging of biological samples using NanoSIMS.

PubMed

Kilburn, Matt R; Clode, Peta L

2014-01-01

With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research.

High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy

NASA Astrophysics Data System (ADS)

Wirtz, T.; Philipp, P.; Audinot, J.-N.; Dowsett, D.; Eswara, S.

2015-10-01

Secondary ion mass spectrometry (SIMS) constitutes an extremely sensitive technique for imaging surfaces in 2D and 3D. Apart from its excellent sensitivity and high lateral resolution (50 nm on state-of-the-art SIMS instruments), advantages of SIMS include high dynamic range and the ability to differentiate between isotopes. This paper first reviews the underlying principles of SIMS as well as the performance and applications of 2D and 3D SIMS elemental imaging. The prospects for further improving the capabilities of SIMS imaging are discussed. The lateral resolution in SIMS imaging when using the microprobe mode is limited by (i) the ion probe size, which is dependent on the brightness of the primary ion source, the quality of the optics of the primary ion column and the electric fields in the near sample region used to extract secondary ions; (ii) the sensitivity of the analysis as a reasonable secondary ion signal, which must be detected from very tiny voxel sizes and thus from a very limited number of sputtered atoms; and (iii) the physical dimensions of the collision cascade determining the origin of the sputtered ions with respect to the impact site of the incident primary ion probe. One interesting prospect is the use of SIMS-based correlative microscopy. In this approach SIMS is combined with various high-resolution microscopy techniques, so that elemental/chemical information at the highest sensitivity can be obtained with SIMS, while excellent spatial resolution is provided by overlaying the SIMS images with high-resolution images obtained by these microscopy techniques. Examples of this approach are given by presenting in situ combinations of SIMS with transmission electron microscopy (TEM), helium ion microscopy (HIM) and scanning probe microscopy (SPM).

The Richmond Flight Project

ERIC Educational Resources Information Center

Journal of Aerospace Education, 1976

1976-01-01

Evaluation of a project that provided flight instruction to inner-city junior high school students showed that former project youths are demonstrably better off than controls in the areas of employment, avoidance of deviant behavior, and advanced education. (MLH)

The SIM Time Network

PubMed Central

Lombardi, Michael A.; Novick, Andrew N.; Lopez R, J. Mauricio; Jimenez, Francisco; de Carlos Lopez, Eduardo; Boulanger, Jean-Simon; Pelletier, Raymond; de Carvalho, Ricardo J.; Solis, Raul; Sanchez, Harold; Quevedo, Carlos Andres; Pascoe, Gregory; Perez, Daniel; Bances, Eduardo; Trigo, Leonardo; Masi, Victor; Postigo, Henry; Questelles, Anthony; Gittens, Anselm

2011-01-01

The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends throughout North, Central, and South America and the Caribbean Islands. About half of the SIM NMIs maintain national standards of time and frequency and must participate in international comparisons in order to establish metrological traceability to the International System (SI) of units. The SIM time network (SIMTN) was developed as a practical, cost effective, and technically sound way to automate these comparisons. The SIMTN continuously compares the time standards of SIM NMIs and produces measurement results in near real-time by utilizing the Internet and the Global Positioning System (GPS). Fifteen SIM NMIs have joined the network as of December 2010. This paper provides a brief overview of SIM and a technical description of the SIMTN. It presents international comparison results and examines the measurement uncertainties. It also discusses the metrological benefits that the network provides to its participants. PMID:26989584

The SIM Time Network.

PubMed

Lombardi, Michael A; Novick, Andrew N; Lopez R, J Mauricio; Jimenez, Francisco; de Carlos Lopez, Eduardo; Boulanger, Jean-Simon; Pelletier, Raymond; de Carvalho, Ricardo J; Solis, Raul; Sanchez, Harold; Quevedo, Carlos Andres; Pascoe, Gregory; Perez, Daniel; Bances, Eduardo; Trigo, Leonardo; Masi, Victor; Postigo, Henry; Questelles, Anthony; Gittens, Anselm

2011-01-01

The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends throughout North, Central, and South America and the Caribbean Islands. About half of the SIM NMIs maintain national standards of time and frequency and must participate in international comparisons in order to establish metrological traceability to the International System (SI) of units. The SIM time network (SIMTN) was developed as a practical, cost effective, and technically sound way to automate these comparisons. The SIMTN continuously compares the time standards of SIM NMIs and produces measurement results in near real-time by utilizing the Internet and the Global Positioning System (GPS). Fifteen SIM NMIs have joined the network as of December 2010. This paper provides a brief overview of SIM and a technical description of the SIMTN. It presents international comparison results and examines the measurement uncertainties. It also discusses the metrological benefits that the network provides to its participants.

UAV Swarm Operational Risk Assessment System

DTIC Science & Technology

2015-09-01

a SIPRNET connection. For practicality in development of this prototype, the interface was created using the MATLAB GUI language . By design, the use ...and Budget, Paperwork Reduction Project (0704-0188) Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE September 2015 3...discrete-event simulation of UAV swarm attacks using ExtendSim, statistical analysis of the simulation data using Minitab, and a graphical user interface

Mega drought in the Colorado River Basin, water supply, and adaptive scenario planning for the Phoenix Metropolitan Area; simulations using WaterSim 5.

NASA Astrophysics Data System (ADS)

Sampson, D. A.

2015-12-01

The Decision Center for a Desert City (DCDC), a boundary organization, bridges science and policy (to foster knowledge-based decision making); we study how decisions are made in the face of uncertainty. Our water policy and management model for the Phoenix Metropolitan Area (hereafter "Phoenix"), termed WaterSim, represents one such bridging mechanism. We evaluated the effect of varying the length of drought on water availability for Phoenix. We examined droughts (starting in 2000) lasting 15, 25, and 50 years. We picked a 60-year window of runoff estimates from the paleo reconstruction data for the Colorado River (CO) (1121 through 1180 A.D.), and the two local rivers (1391 through 1450 A.D.), and assumed that the proportional difference in median flow between these periods and the long-term record represented an estimate of potential drought reductions on river flows. This resulted in a 12%, and 19% reduction in flows for the CO River and the Salt-Verde (SV) Rivers, respectively. WaterSim uses 30-year trace periods from the historical flow records to simulate river flow for future projections. We used each 30-year trace from the historical record (1906 to present, CO River; 1945 to present SV Rivers) , and default settings, to simulate 60 year projections of Lake Mead elevation and the accompanying Colorado River water shortages to Phoenix. Overall, elevations for Lake Mead fell below the 1st shortage sharing tier (1075 ft) in 83% of the simulations; 74% of the simulations fell below the 2nd tier (1050 ft), and 64% fell below the 3rd (1025 ft). Length of drought, however, determined the shortage tiers met. Median elevations for droughts ending in 2015, 2025, and 2050 were 1036, 1019, and 967 feet msl, respectively. We present the plausible water futures with adaptive anticipatory scenario planning for the projected reductions in surface water availability to demonstrate decision points for water conservation measures to effectively manage shortage conditions.

Using a simulation cell for exercise realism.

PubMed

Lerner, Ken

2013-01-01

A simulation cell or SimCell is an effective and flexible tool for control of emergency management exercises. It allows exercise participants to interact, via simulation, with a wide variety of nonplaying organizations and officials. Adapted from military application, the Chemical Stockpile Emergency Preparedness Program (CSEPP) applied, developed, and refined the SimCell concept for emergency management exercises. It has now been incorporated into national exercise guidance through the Homeland Security Exercise and Evaluation Program, and has been used in a wide variety of national, regional, and local exercises. This article reviews development of the SimCell concept in CSEPP, briefly surveys current practice incorporating SimCells in exercise control, and offers practical lessons-learned and tips on using a SimCell to best advantage. Lessons learned include using a SimCell as an exercise-control hub; preparing inject material for exercise controllers as part of the Master Scenario Event List; laying the groundwork for success through exercise player and controller training; developing protocol for SimCell communications; and capturing feedback from SimCell controllers for inclusion in the exercise evaluation reporting process. The SimCell concept is flexible and can be applied to a variety of exercise types and through a variety of methods.

Initial clinical experience with a radiation oncology dedicated open 1.0T MR‐simulation

PubMed Central

Wen, Ning; Hearshen, David; Kim, Joshua; Pantelic, Milan; Zhao, Bo; Mancell, Tina; Levin, Kenneth; Movsas, Benjamin; Chetty, Indrin J.; Siddiqui, M. Salim

2015-01-01

The purpose of this study was to describe our experience with 1.0T MR‐SIM including characterization, quality assurance (QA) program, and features necessary for treatment planning. Staffing, safety, and patient screening procedures were developed. Utilization of an external laser positioning system (ELPS) and MR‐compatible couchtop were illustrated. Spatial and volumetric analyses were conducted between CT‐SIM and MR‐SIM using a stereotactic QA phantom with known landmarks and volumes. Magnetic field inhomogeneity was determined using phase difference analysis. System‐related, in‐plane distortion was evaluated and temporal changes were assessed. 3D distortion was characterized for regions of interest (ROIs) 5–20 cm away from isocenter. American College of Radiology (ACR) recommended tests and impact of ELPS on image quality were analyzed. Combined ultrashort echotime Dixon (UTE/Dixon) sequence was evaluated. Amplitude‐triggered 4D MRI was implemented using a motion phantom (2–10 phases, ~2 cm excursion, 3–5 s periods) and a liver cancer patient. Duty cycle, acquisition time, and excursion were evaluated between maximum intensity projection (MIP) datasets. Less than 2% difference from expected was obtained between CT‐SIM and MR‐SIM volumes, with a mean distance of <0.2 mm between landmarks. Magnetic field inhomogeneity was <2 ppm. 2D distortion was <2 mm over 28.6–33.6 mm of isocenter. Within 5 cm radius of isocenter, mean 3D geometric distortion was 0.59±0.32 mm (maximum=1.65 mm) and increased 10–15 cm from isocenter (mean=1.57±1.06 mm, maximum=6.26 mm). ELPS interference was within the operating frequency of the scanner and was characterized by line patterns and a reduction in signal‐to‐noise ratio (4.6–12.6% for TE=50−150 ms). Image quality checks were within ACR recommendations. UTE/Dixon sequences yielded detectability between bone and air. For 4D MRI, faster breathing periods had higher duty cycles than slow (50.4% (3 s) and 39.4% (5 s), p<0.001) and ~ fourfold acquisition time increase was measured for ten‐phase versus two‐phase. Superior–inferior object extent was underestimated 8% (6 mm) for two‐phase as compared to ten‐phase MIPs, although <2% difference was obtained for ≥4 phases. 4D MRI for a patient demonstrated acceptable image quality in ~7 min. MR‐SIM was integrated into our workflow and QA procedures were developed. Clinical applicability was demonstrated for 4D MRI and UTE imaging to support MR‐SIM for single modality treatment planning. PACS numbers: 87.56.Fc, 87.61.‐c, 87.57.cp PMID:26103190

CalSimHydro Tool - A Web-based interactive tool for the CalSim 3.0 Hydrology Prepropessor

NASA Astrophysics Data System (ADS)

Li, P.; Stough, T.; Vu, Q.; Granger, S. L.; Jones, D. J.; Ferreira, I.; Chen, Z.

2011-12-01

CalSimHydro, the CalSim 3.0 Hydrology Preprocessor, is an application designed to automate the various steps in the computation of hydrologic inputs for CalSim 3.0, a water resources planning model developed jointly by California State Department of Water Resources and United States Bureau of Reclamation, Mid-Pacific Region. CalSimHydro consists of a five-step FORTRAN based program that runs the individual models in succession passing information from one model to the next and aggregating data as required by each model. The final product of CalSimHydro is an updated CalSim 3.0 state variable (SV) DSS input file. CalSimHydro consists of (1) a Rainfall-Runoff Model to compute monthly infiltration, (2) a Soil moisture and demand calculator (IDC) that estimates surface runoff, deep percolation, and water demands for natural vegetation cover and various crops other than rice, (3) a Rice Water Use Model to compute the water demands, deep percolation, irrigation return flow, and runoff from precipitation for the rice fields, (4) a Refuge Water Use Model that simulates the ponding operations for managed wetlands, and (5) a Data Aggregation and Transfer Module to aggregate the outputs from the above modules and transfer them to the CalSim SV input file. In this presentation, we describe a web-based user interface for CalSimHydro using Google Earth Plug-In. The CalSimHydro tool allows users to - interact with geo-referenced layers of the Water Budget Areas (WBA) and Demand Units (DU) displayed over the Sacramento Valley, - view the input parameters of the hydrology preprocessor for a selected WBA or DU in a time series plot or a tabular form, - edit the values of the input parameters in the table or by downloading a spreadsheet of the selected parameter in a selected time range, - run the CalSimHydro modules in the backend server and notify the user when the job is done, - visualize the model output and compare it with a base run result, - download the output SV file to be used to run CalSim 3.0. The CalSimHydro tool streamlines the complicated steps to configure and run the hydrology preprocessor by providing a user-friendly visual interface and back-end services to validate user inputs and manage the model execution. It is a powerful addition to the new CalSim 3.0 system.

Simvastatin Prodrug Micelles Target Fracture and Improve Healing

PubMed Central

Dusad, Anand; Yuan, Hongjiang; Ren, Ke; Li, Fei; Fehringer, Edward V.; Purdue, P. Edward; Goldring, Steven R.; Daluiski, Aaron; Wang, Dong

2014-01-01

Simvastatin (SIM), a widely used anti-lipidaemic drug, has been identified as a bone anabolic agent. Its poor water solubility and the lack of distribution to the skeleton, however, have limited its application in the treatment of bone metabolic diseases. In this study, an amphiphilic macromolecular prodrug of SIM was designed and synthesized to overcome these limitations. The polyethylene glycol (PEG)-based prodrug can spontaneously self-assemble to form micelles. The use of SIM trimer as the prodrug’s hydrophobic segment allows easy encapsulation of additional free SIM. The in vitro studies showed that SIM/SIM-mPEG micelles were internalized by MC3T3 cells via lysosomal trafficking and consistently induced expression of both BMP2 and DKK1 mRNA, suggesting that the prodrug micelle retains the biological functions of SIM. After systemic administration, optical imaging suggests that the micelles would passively target to bone fracture sites associated with hematoma and inflammation. Furthermore, flow cytometry study revealed that SIM/SIM-mPEG micelles had preferred cellular uptake by inflammatory and resident cells within the fracture callus tissue. The treatment study using a mouse osteotomy model validated the micelles’ therapeutic efficacy in promoting bone fracture healing as demonstrated by micro-CT and histological analyses. Collectively, these data suggest that the macromolecular prodrug-based micelle formulation of SIM may have great potential for clinical management of impaired fracture healing. PMID:25542644

BLT Flight Experiment Overview and In-Situ Measurements

NASA Technical Reports Server (NTRS)

Anderson, Brian P.; Campbell, Charles H.; Saucedo, Luis A.; Kinder, Gerald R.

2010-01-01

In support of the Boundary Layer Transition Flight Experiment (BLT FE) Project, a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for the flight of STS-119. Additional instrumentation was also installed in order to obtain more spatially resolved measurements. This paper will provide an overview of the BLT FE Project, including the project history, organizations involved, and motivations for the flight experiment. Significant efforts were made to place the protuberance at an appropriate location on the Orbiter and to design the protuberance to withstand the expected environments. Efforts were also extended to understand the as-fabricated shape of the protuberance and the thermal protection system tile configuration surrounding the protuberance. A high level overview of the in-situ flight data will be presented, along with a summary of the comparisons between pre- and post-flight analysis predictions and flight data.

An overview of integrated flight-propulsion controls flight research on the NASA F-15 research airplane

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Gatlin, Donald H.; Stewart, James F.

1995-01-01

The NASA Dryden Flight Research Center has been conducting integrated flight-propulsion control flight research using the NASA F-15 airplane for the past 12 years. The research began with the digital electronic engine control (DEEC) project, followed by the F100 Engine Model Derivative (EMD). HIDEC (Highly Integrated Digital Electronic Control) became the umbrella name for a series of experiments including: the Advanced Digital Engine Controls System (ADECS), a twin jet acoustics flight experiment, self-repairing flight control system (SRFCS), performance-seeking control (PSC), and propulsion controlled aircraft (PCA). The upcoming F-15 project is ACTIVE (Advanced Control Technology for Integrated Vehicles). This paper provides a brief summary of these activities and provides background for the PCA and PSC papers, and includes a bibliography of all papers and reports from the NASA F-15 project.

Auditory cortex controls sound-driven innate defense behaviour through corticofugal projections to inferior colliculus

PubMed Central

Xiong, Xiaorui R.; Liang, Feixue; Zingg, Brian; Ji, Xu-ying; Ibrahim, Leena A.; Tao, Huizhong W.; Zhang, Li I.

2015-01-01

Defense against environmental threats is essential for animal survival. However, the neural circuits responsible for transforming unconditioned sensory stimuli and generating defensive behaviours remain largely unclear. Here, we show that corticofugal neurons in the auditory cortex (ACx) targeting the inferior colliculus (IC) mediate an innate, sound-induced flight behaviour. Optogenetic activation of these neurons, or their projection terminals in the IC, is sufficient for initiating flight responses, while the inhibition of these projections reduces sound-induced flight responses. Corticocollicular axons monosynaptically innervate neurons in the cortex of the IC (ICx), and optogenetic activation of the projections from the ICx to the dorsal periaqueductal gray is sufficient for provoking flight behaviours. Our results suggest that ACx can both amplify innate acoustic-motor responses and directly drive flight behaviours in the absence of sound input through corticocollicular projections to ICx. Such corticofugal control may be a general feature of innate defense circuits across sensory modalities. PMID:26068082

Scanning Apollo Flight Films and Reconstructing CSM Trajectories

NASA Astrophysics Data System (ADS)

Speyerer, E.; Robinson, M. S.; Grunsfeld, J. M.; Locke, S. D.; White, M.

2006-12-01

Over thirty years ago, the astronauts of the Apollo program made the journey from the Earth to the Moon and back. To record their historic voyages and collect scientific observations many thousands of photographs were acquired with handheld and automated cameras. After returning to Earth, these films were developed and stored at the film archive at Johnson Space Center (JSC), where they still reside. Due to the historical significance of the original flight films typically only duplicate (2nd or 3rd generation) film products are studied and used to make prints. To allow full access to the original flight films for both researchers and the general public, JSC and Arizona State University are scanning and creating an online digital archive. A Leica photogrammetric scanner is being used to insure geometric and radiometric fidelity. Scanning resolution will preserve the grain of the film. Color frames are being scanned and archived as 48 bit pixels to insure capture of the full dynamic range of the film (16 bit for BW). The raw scans will consist of 70 Terabytes of data (10,000 BW Hasselblad, 10,000 color Hasselblad, 10,000 Metric frames, 4500 Pan frames, 620 35mm frames counts; are estimates). All the scanned films will be made available for download through a searchable database. Special tools are being developed to locate images based on various search parameters. To geolocate metric and panoramic frames acquired during Apollos 15\\-17, prototype SPICE kernels are being generated from existing photographic support data by entering state vectors and timestamps from multiple points throughout each orbit into the NAIF toolkit to create a type 9 Spacecraft and Planet Ephemeris Kernel (SPK), a nadir pointing C\\- matrix Kernel (CK), and a Spacecraft Clock Kernel (SCLK). These SPICE kernels, in addition to the Instrument Kernel (IK) and Frames Kernel (FK) that also under development, will be archived along with the scanned images. From the generated kernels, several IDL programs have been designed to display orbital tracks, produce footprint plots, and create image projections. Using the output from these SPICE based programs enables accurate geolocating of SIM bay photography as well as providing potential data from lunar gravitational studies.

Eclipse project QF-106 and C-141A climbs out under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW LAUNCH DEMONSTRATION - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 climbs out under tow by a USAF C-141A on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse project QF-106 and C-141A takeoff on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

TOW ROPE TAKEOFF - The Kelly Space & Technology (KST)/USAF Eclipse project's modified QF-106 and a USAF C-141A takeoff for the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse project closeup of QF-106 under tow on takeoff on first flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

OFF THE GROUND - The Kelly Space & Technology (KST)/USAF/NASA Eclipse project's modified QF-106 lifts off under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, hosted the project, providing engineering and facility support as well as the project pilot. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

Eclipse project closeup of QF-106 under tow on first tethered flight December 20, 1997

NASA Technical Reports Server (NTRS)

1997-01-01

The Kelly Space and Technology (KST)/USAF/NASA Eclipse project's modified QF-106 is shown under tow on the project's first tethered flight on December 20, 1997. The successful 18-minute-long flight reached an altitude of 10,000 feet. NASA's Dryden Flight Research Center, Edwards, California, is hosting the project, providing engineering and facility support as well as the project pilot, Mark Stucky. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

History of Manned Space Flight

NASA Technical Reports Server (NTRS)

1975-01-01

U.S. manned space projects from Mercury Redstone 3 through Skylab 4 are briefly described including dates, flight duration, crew, and number of earth/moon orbits. The flight costs of each project are itemized. Highlights in the history of the manned space program from 1957 to February, 1974 are included.

Structural, chemical and electrical characterisation of conductive graphene-polymer composite films

NASA Astrophysics Data System (ADS)

Brennan, Barry; Spencer, Steve J.; Belsey, Natalie A.; Faris, Tsegie; Cronin, Harry; Silva, S. Ravi P.; Sainsbury, Toby; Gilmore, Ian S.; Stoeva, Zlatka; Pollard, Andrew J.

2017-05-01

Graphene poly-acrylic and PEDOT:PSS nanocomposite films were produced using two alternative commercial graphene powders to explore how the graphene flake dimensions and chemical composition affected the electrical performance of the film. A range of analytical techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), were employed to systematically analyse the initial graphene materials as well as the nanocomposite films. Electrical measurements indicated that the sheet resistance of the films was affected by the properties of the graphene flakes used. To further explore the composition of the films, ToF-SIMS mapping was employed and provided a direct means to elucidate the nature of the graphene dispersion in the films and to correlate this with the electrical analysis. These results reveal important implications for how the dispersion of the graphene material in films produced from printable inks can be affected by the type of graphene powder used and the corresponding effect on electrical performance of the nanocomposites. This work provides direct evidence for how accurate and comparable characterisation of the graphene material is required for real-world graphene materials to develop graphene enabled films and proposes a measurement protocol for comparing graphene materials that can be used for international standardisation.

Surface initiated atom transfer radical polymerization grafting of sodium styrene sulfonate from titanium and silicon substrates.

PubMed

Foster, Rami N; Keefe, Andrew J; Jiang, Shaoyi; Castner, David G

2013-11-01

This study investigates the grafting of poly-sodium styrene sulfonate (pNaSS) from trichlorosilane/10-undecen-1-yl 2-bromo-2-methylpropionate functionalized Si and Ti substrates by atom transfer radical polymerization (ATRP). The composition, molecular structure, thickness, and topography of the grafted pNaSS films were characterized with x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), variable angle spectroscopic ellipsometry (VASE), and atomic force microscopy (AFM), respectively. XPS and ToF-SIMS results were consistent with the successful grafting of a thick and uniform pNaSS film on both substrates. VASE and AFM scratch tests showed the films were between 25 and 49 nm thick on Si, and between 13 and 35 nm thick on Ti. AFM determined root-mean-square roughness values were ∼2 nm on both Si and Ti substrates. Therefore, ATRP grafting is capable of producing relatively smooth, thick, and chemically homogeneous pNaSS films on Si and Ti substrates. These films will be used in subsequent studies to test the hypothesis that pNaSS-grafted Ti implants preferentially adsorb certain plasma proteins in an orientation and conformation that modulates the foreign body response and promotes formation of new bone.

On the temperature dependence of Na migration in thin SiO 2 films during ToF-SIMS O 2+ depth profiling

NASA Astrophysics Data System (ADS)

Krivec, Stefan; Detzel, Thomas; Buchmayr, Michael; Hutter, Herbert

2010-10-01

The detection of Na in insulating samples by means of time of flight-secondary ion mass spectrometry (ToF-SIMS) depth profiling has always been a challenge. In particular the use of O 2+ as sputter species causes a severe artifact in the Na depth distribution due to Na migration under the influence of an internal electrical filed. In this paper we address the influence of the sample temperature on this artifact. It is shown that the transport of Na is a dynamic process in concordance with the proceeding sputter front. Low temperatures mitigated the migration process by reducing the Na mobility in the target. In the course of this work two sample types have been investigated: (i) A Na doped PMMA layer, deposited on a thin SiO 2 film. Here, the incorporation behavior of Na into SiO 2 during depth profiling is demonstrated. (ii) Na implanted into a thin SiO 2 film. By this sample type the migration behavior could be examined when defects, originating from the implantation process, are present in the SiO 2 target. In addition, we propose an approach for the evaluation of an implanted Na profile, which is unaffected by the migration process.

Influence of surface pretreatments on the quality of trivalent chromium process coatings on aluminum alloy

NASA Astrophysics Data System (ADS)

Viroulaud, Rémi; Światowska, Jolanta; Seyeux, Antoine; Zanna, Sandrine; Tardelli, Joffrey; Marcus, Philippe

2017-11-01

The effects of surface pretreatments (degreasing and pickling) on the characteristics of the Trivalent Chromium Process (TCP) coating on pure aluminum and on AA2024-T351 aluminum alloy were investigated here by means of surface sensitive techniques: X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The XPS and ToF-SIMS results evidence that the TCP coating homogeneity is strongly dependent on the pretreatment process used. The TCP coverage factor, calculated from XPS results, is significantly lower, on both pure aluminum and AA2024-T351 alloy surface, when a pickling step is applied. One of the main effects of pickling pretreatment is strong metallic copper enrichment at the surface of the 2024 alloy, associated with chemical dissolution of Al-Cu intermetallic particles. However, it is evidenced here, that the copper enrichment is not detrimental for the quality of the TCP coating. The coating failure, observed when the pickling step is applied, can be assigned to a faster kinetics of the coating growth leading to formation of thicker conversion coating more susceptible to cracking or to the localized presence of aluminum fluoride species leading to the appearance of coating defects or detachment.

Unravelling the Chemical Influence of Water on the PMMA/Aluminum Oxide Hybrid Interface In Situ

DOE PAGES

Pletincx, Sven; Marcoen, Kristof; Trotochaud, Lena; ...

2017-10-17

Understanding the stability of chemical interactions at the polymer/metal oxide interface under humid conditions is vital to understand the long-term durability of hybrid systems. Therefore, the interface of ultrathin PMMA films on native aluminum oxide, deposited by reactive adsorption, was studied. The characterization of the interface of the coated substrates was performed using ambient pressure X-ray photoelectron spectroscopy (APXPS), Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The formation of hydrogen bonds and carboxylate ionic bonds at the interface are observed. The formed ionic bond is stable up to 5 Torrmore » water vapour pressure as shown by APXPS. However, when the coated samples are exposed to an excess of aqueous electrolyte, an increase in the amount of carboxylate bonds at the interface, as a result of hydrolysis of the methoxy group, is observed by ATR-FTIR Kretschmann. In conclusion, these observations, supported by ToF-SIMS spectra, lead to the proposal of an adsorption mechanism of PMMA on aluminum oxide, which shows the formation of methanol at the interface and the effect of water molecules on the different interfacial interactions.« less

Surface initiated atom transfer radical polymerization grafting of sodium styrene sulfonate from titanium and silicon substrates

PubMed Central

Foster, Rami N.; Keefe, Andrew J.; Jiang, Shaoyi; Castner, David G.

2013-01-01

This study investigates the grafting of poly-sodium styrene sulfonate (pNaSS) from trichlorosilane/10-undecen-1-yl 2-bromo-2-methylpropionate functionalized Si and Ti substrates by atom transfer radical polymerization (ATRP). The composition, molecular structure, thickness, and topography of the grafted pNaSS films were characterized with x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), variable angle spectroscopic ellipsometry (VASE), and atomic force microscopy (AFM), respectively. XPS and ToF-SIMS results were consistent with the successful grafting of a thick and uniform pNaSS film on both substrates. VASE and AFM scratch tests showed the films were between 25 and 49 nm thick on Si, and between 13 and 35 nm thick on Ti. AFM determined root-mean-square roughness values were ∼2 nm on both Si and Ti substrates. Therefore, ATRP grafting is capable of producing relatively smooth, thick, and chemically homogeneous pNaSS films on Si and Ti substrates. These films will be used in subsequent studies to test the hypothesis that pNaSS-grafted Ti implants preferentially adsorb certain plasma proteins in an orientation and conformation that modulates the foreign body response and promotes formation of new bone. PMID:24482558

Elucidating the resistance to failure under tribological tests of various boron-based films by XPS and ToF-SIMS

NASA Astrophysics Data System (ADS)

Spadaro, F.; Rossi, A.; Lainé, E.; Woodward, P.; Spencer, N. D.

2017-12-01

Tribotests performed on boron-based thermal films have revealed higher mechanical durability and lower wear coefficients compared to results from tests performed on boron-free thermal films. In the current study, in order to follow and identify the tribochemical reactions taking place in the contact regions, post-characterization has been carried out on the steel ball and on the steel disc. The techniques adopted to achieve this goal were small-area X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary-ion mass spectroscopy (ToF-SIMS). The contact areas have been investigated before and after failure of the thermal films, revealing thermal-film removal inside the wear track on the disc and the presence of a transfer film in the contact area on the steel ball following tribotesting. Furthermore, borate contributions in the deeper layers within the tribo-stressed area on the disc were revealed at the end of the tribotest. These procedures shed light on the tribomechanical and tribochemical reactions taking place in the contact region, on the ability of boron species to sustain tribological stress and provide mechanical stability, and on the mechanical-mixing processes occurring within the sliding contacts. The mass spectra collected before tribotesting on all thermal films suggest the presence of phosphate- and borate-containing structures.

Improving Nutrient Release of Wall-disruption Bee Pollen with a Combination of Ultrasonication and High Shear Technique.

PubMed

Wu, Wei; Wang, Kai; Qiao, Jiangtao; Dong, Jie; Li, Zhanping; Zhang, Hongcheng

2018-06-22

Bee pollen, collected by honey bees, contains a substantial amount of nutrients and has a high nutritive value. However, a high level of nutrients can be difficult to be digested and absorbed due to the complex wall of bee pollen. We observed that amino acids were mostly distributed inside cell wall of lotus bee pollen, rape bee pollen, apricot bee pollen, wuweizi bee pollen and camellia bee pollen, using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Thus, five species of bee pollen were wall-disrupted with a combination of ultrasonication and high shear technique (US-HS). After the treatment, bee pollen walls were entirely broken into fragments, and a high number of nutrients were released. The contents of amino acids, fatty acids, protein, crude fat, reducing sugar, β-carotene, calcium, iron, zinc, selenium obviously increased after wall-disruption. Overall, our study demonstrates that US-HS can disrupt bee pollen wall to release nutrients. Therefore, further studies are being conducted to compare the digestibility and absorptivity of pollen nutrients before and after wall-disruption. Additionally, TOF-SIMS seems to be a reliable mapping technique for determining the distribution of food ingredients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

DETERMINATION OF A BOUND MUSK XYLENE ...

EPA Pesticide Factsheets

Musk xylene (MX) is widely used as a fragrance ingredient in commercial toiletries. Identification and quantification of a bound 4-amino-MX (AMX) metabolite was carried out by gas chromatography-mass spectrometry (GC/MS), with selected ion monitoring (SIM). Detection of AMX occurred after the cysteine adducts in carp hemoglobin, derived from the nitroso metabolite, were released by alkaline hydrolysis. The released AMX metabolite was extracted into n-hexane. The extract was preconcentrated by evaporation, and analyzed by GC-SIM-MS. The concentration of AMX metabolite was found to range from 6.0 to 30.6 ng/g in the carp Hb, collected from the Las Vegas Wash and Lake Mead, Nevada areas. The presence of an AMX metabolite in the carp Hb was confirmed when similar mass spectral features and the same retention time of the AMX metabolite were obtained for both standard AMX and carp Hb extract solutions. In the non-hydrolyzed and reagent blank extracts, the AMX metabolite was not detected. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers,

Configuration management issues and objectives for a real-time research flight test support facility

NASA Technical Reports Server (NTRS)

Yergensen, Stephen; Rhea, Donald C.

1988-01-01

Presented are some of the critical issues and objectives pertaining to configuration management for the NASA Western Aeronautical Test Range (WATR) of Ames Research Center. The primary mission of the WATR is to provide a capability for the conduct of aeronautical research flight test through real-time processing and display, tracking, and communications systems. In providing this capability, the WATR must maintain and enforce a configuration management plan which is independent of, but complimentary to, various research flight test project configuration management systems. A primary WATR objective is the continued development of generic research flight test project support capability, wherein the reliability of WATR support provided to all project users is a constant priority. Therefore, the processing of configuration change requests for specific research flight test project requirements must be evaluated within a perspective that maintains this primary objective.

Boundary Layer Transition Flight Experiment Overview and In-Situ Measurements

NASA Technical Reports Server (NTRS)

Anderson, Brian P.; Campbell, Charles H.; Saucedo, Luis A.; Kinder, Gerald R.; Berger, Karen T.

2010-01-01

In support of the Boundary Layer Transition Flight Experiment (BLTFE) Project, a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for the flights of STS-119 and STS-128. Additional instrumentation was also installed in order to obtain more spatially resolved measurements downstream of the protuberance. This paper provides an overview of the BLTFE Project, including the project history, organizations involved, and motivations for the flight experiment. Significant efforts were made to place the protuberance at an appropriate location on the Orbiter and to design the protuberance to withstand the expected environments. Efforts were also extended to understand the as-fabricated shape of the protuberance and the thermal protection system tile configuration surrounding the protuberance. A high-level overview of the in-situ flight data is presented, along with a summary of the comparisons between pre- and post-flight analysis predictions and flight data. Comparisons show that predictions for boundary layer transition onset time closely match the flight data, while predicted temperatures were significantly higher than observed flight temperatures.

Integration of optical measurement methods with flight parameter measurement systems

NASA Astrophysics Data System (ADS)

Kopecki, Grzegorz; Rzucidlo, Pawel

2016-05-01

During the AIM (advanced in-flight measurement techniques) and AIM2 projects, innovative modern techniques were developed. The purpose of the AIM project was to develop optical measurement techniques dedicated for flight tests. Such methods give information about aircraft elements deformation, thermal loads or pressure distribution, etc. In AIM2 the development of optical methods for flight testing was continued. In particular, this project aimed at the development of methods that could be easily applied in flight tests in an industrial setting. Another equally important task was to guarantee the synchronization of the classical measuring system with cameras. The PW-6U glider used in flight tests was provided by the Rzeszów University of Technology. The glider had all the equipment necessary for testing the IPCT (image pattern correlation technique) and IRT (infrared thermometry) methods. Additionally, equipment adequate for the measurement of typical flight parameters, registration and analysis has been developed. This article describes the designed system, as well as presenting the system’s application during flight tests. Additionally, the results obtained in flight tests show certain limitations of the IRT method as applied.

Managing External Relations: The Lifeblood of Mission Success

NASA Technical Reports Server (NTRS)

Dumbacher, Daniel L.

2007-01-01

The slide presentation examines the role of customer and stakeholder relations in the success of space missions. Topics include agency transformation; an overview of project and program experience with a discussion of positions, technical accomplishments, and management lessons learned; and approaches to project success with emphasis on communication. Projects and programs discussed include the Space Shuttle Main Engine System, DC-XA Flight Demonstrator, X-33 Flight Demonstrator, Space Launch Initiative/2nd Generation Reusable Launch Vehicle, X-37 Flight Demonstrator, Constellation (pre Dr. Griffin), Safety and Mission Assurance, and Exploration Launch Projects.

Poly-Small Ubiquitin-like Modifier (PolySUMO)-binding Proteins Identified through a String Search*

PubMed Central

Sun, Huaiyu; Hunter, Tony

2012-01-01

Polysumoylation is a crucial cellular response to stresses against genomic integrity or proteostasis. Like the small ubiquitin-like modifier (SUMO)-targeted ubiquitin ligase RNF4, proteins with clustered SUMO-interacting motifs (SIMs) can be important signal transducers downstream of polysumoylation. To identify novel polySUMO-binding proteins, we conducted a computational string search with a custom Python script. We found clustered SIMs in another RING domain protein Arkadia/RNF111. Detailed biochemical analysis of the Arkadia SIMs revealed that dominant SIMs in a SIM cluster often contain a pentameric VIDLT ((V/I/L/F/Y)(V/I)DLT) core sequence that is also found in the SIMs in PIAS family E3s and is likely the best-fitted structure for SUMO recognition. This idea led to the identification of additional novel SIM clusters in FLASH/CASP8AP2, C5orf25, and SOBP/JXC1. We suggest that the clustered SIMs in these proteins form distinct SUMO binding domains to recognize diverse forms of protein sumoylation. PMID:23086935

TankSIM: A Cryogenic Tank Performance Prediction Program

NASA Technical Reports Server (NTRS)

Bolshinskiy, L. G.; Hedayat, A.; Hastings, L. J.; Moder, J. P.; Schnell, A. R.; Sutherlin, S. G.

2015-01-01

Developed for predicting the behavior of cryogenic liquids inside propellant tanks under various environmental and operating conditions. Provides a multi-node analysis of pressurization, ullage venting and thermodynamic venting systems (TVS) pressure control using axial jet or spray bar TVS. Allows user to combine several different phases for predicting the liquid behavior for the entire flight mission timeline or part of it. Is a NASA in-house code, based on FORTRAN 90-95 and Intel Visual FORTRAN compiler, but can be used on any other platform (Unix-Linux, Compaq Visual FORTRAN, etc.). The last Version 7, released on December 2014, included detailed User's Manual. Includes the use of several RefPROP subroutines for calculating fluid properties.

Sample Preparation of Corn Seed Tissue to Prevent Analyte Relocations for Mass Spectrometry Imaging

NASA Astrophysics Data System (ADS)

Kim, Shin Hye; Kim, Jeongkwon; Lee, Young Jin; Lee, Tae Geol; Yoon, Sohee

2017-08-01

Corn seed tissue sections were prepared by the tape support method using an adhesive tape, and mass spectrometry imaging (MSI) was performed. The effect of heat generated during sample preparation was investigated by time-of-flight secondary mass spectrometry (TOF-SIMS) imaging of corn seed tissue prepared by the tape support and the thaw-mounted methods. Unlike thaw-mounted sample preparation, the tape support method does not cause imaging distortion because of the absence of heat, which can cause migration of the analytes on the sample. By applying the tape-support method, the corn seed tissue was prepared without structural damage and MSI with accurate spatial information of analytes was successfully performed.

Secondary ion mass spectra of gold super clusters up to 140000 Dalton

NASA Astrophysics Data System (ADS)

Feld, H.; Leute, A.; Rading, D.; Benninghoven, A.; Schmid, G.

1990-03-01

The bombardment of a two-shell gold complex (Au55(PPh3)12Cl6) with 10 keV Xe+-ions results in the formation of secondary ion masses up to 140000 u. These are by far the largest secondary ions observed under primary particle bombardment. The detection and identification of these ions with a Time-Of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) gives important information about the behavior of naked full-shell clusters. Au13 particles, generated from the Au55 cluster, serve as building blocks for a series of super-clusters up to (Au13)55. The results for keV-ion bombardment are compared to those for MeV-ion bombardment.

UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.; Santiago, Confesor

2016-01-01

The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

Time-of-flight secondary ion mass spectrometry studies of cluster ion analysis for semiconductors and diffusion of manganese in gallium arsenide at low temperatures

NASA Astrophysics Data System (ADS)

Goacher, Robyn Elizabeth

Secondary Ion Mass Spectrometry (SIMS) is an established method for the quantitative analysis of dopants in semiconductors. The quasi-parallel mass acquisition of Time-of-Flight SIMS, along with the development of polyatomic primary ions, have rapidly increased the use of SIMS for analysis of organic and biological specimens. However, the advantages and disadvantages of using cluster primary ions for quantitative analysis of inorganic materials are not clear. The research described in this dissertation investigates the consequences of using polyatomic primary ions for the analysis of inorganic compounds in ToF-SIMS. Furthermore, the diffusion of Mn in GaAs, which is important in Spintronic material applications such as spin injection, is also studied by quantitative ToF-SIMS depth profiling. In the first portion of this work, it was discovered that primary ion bombardment of pre-sputtered compound semiconductors GaAs and InP for the purpose of spectral analysis resulted in the formation of cluster secondary ions, as well as atomic secondary ions (Chapter 2). In particular, bombardment using a cluster primary ion such as Bi3q + or C60q+ resulted in higher yields of high-mass cluster secondary ions. These cluster secondary ions did not have bulk stoichiometry, "non-stoichiometric", in contrast to the paradigm of stoichiometric cluster ions generated from salts. This is attributed to the covalent bonding of the compound semiconductors, as well as to preferential sputtering. The utility of high-mass cluster secondary ions in depth profiling is also discussed. Relative sensitivity factors (RSFs) calculated for ion-implanted Fe and Mn samples in GaAs also exhibit differences based on whether monatomic or polyatomic primary ions are utilized (Chapter 3). These RSFs are important for the quantitative conversion of intensity to concentration. When Bi 32+ primary ions are used for analysis instead of Bi + primary ions, there is a significantly higher proportion of Mn and Fe ions present in the spectra, as referenced to the matrix species. The magnitude of this effect differs depending on the sputtering ion, Cs or C60. The use of C60cluster primary ions for depth profiling of GaAs is also investigated (Chapter 4). In particular, for quantitative depth profiling, parameters such as depth resolution, ion and sputter yields, and relative sensitivity factors are pertinent to profiling thin layered structures quantitatively and quickly. C60 sputtering is compared to Cs sputtering in all of these aspects. It is found that 10 keV C60+ is advantageous for the analysis of metals (such as Au contacts on Si) but that previously reported roughness problems prohibit successful analysis in Si. For Al delta layers and quantum wells in GaAs, C60 q+ sputtering induced very little roughness in the sample, and resulted in high ion yields and excellent signal-to-noise as compared to Cs+ sputtering. However, the depth resolution of C60 is at best equivalent to 1 keV Cs+ and does not extend into the sub 2-nm range. Furthermore, C60 sputtering results in significant carbon implantation. In the second portion of this work, quantitative ToF-SIMS depth profiling was used to evaluate the diffusion of Mn into GaAs. Samples were prepared by Molecular Beam Epitaxy in the department of Physics. Mn diffusion from MnAs was investigated first, and Mn diffusion from layered epitaxial structures of GaAs / Ga1-xMnxAs / GaAs was investigated second. Diffusion experiments were conducted by annealing portions of the samples in sealed glass ampoules at low temperatures (200-400°C). Different sputtering rates were measured for MnAs and GaAs and the measured depth profiles were corrected for these effects. RSFs measured for Mn ion-implanted standards were used to calibrate the intensity scale. For diffusion from MnAs, thin MnAs layers resulted in no measurable changes except in the surface transient. For thick MnAs layers, it was determined that substantial loss of As occurred at 400°C, resulting in severe sample roughening, which inhibited proper SIMS analysis. Results for the diffusion of Mn out of a thick buried layer of Ga1-xMnxAs show that annealing induces diffusion of Mn species from the Ga1-xMnxAs layer into the neighboring GaAs with an activation energy of 0.69+/-0.09 eV. This results in doping of the GaAs layer, which is detrimental to spin injection for Spintronics devices.

Health, drugs and service use among deprived single men: comparing (subgroups) of single male welfare recipients against employed single men in Amsterdam.

PubMed

Kamann, Tjerk C; de Wit, Matty A S; Cremer, Stephan; Beekman, Aartjan T F

2014-02-20

To aid public health policy in preventing severe social exclusion (like homelessness) and promoting social inclusion (like labour market participation), we aimed to quantify (unmet) health needs of an expectedly vulnerable population on which little was known about: single male welfare recipients (SIM-welfare). One of the main policy questions was: is there need to promote access to healthcare for this specific group? A cross-sectional study incorporating peer-to-peer methodology to approach and survey SIM-welfare. Sociodemographics, prevalence of ill health, harmful drug use and healthcare utilisation for subgroups of SIM-welfare assessed with a different distance to the labour market and exposed to different reintegration policy were described and compared against single employed men (SIM-work). Men between the age of 23 and 64, living in single person households in Amsterdam. A random and representative sample of 472 SIM-welfare was surveyed during 2009-2010. A reference sample of 212 SIM-work was taken from the 2008 Amsterdam Health Survey. Standardised instruments were used to assess self-reported ill somatic and mental health, harmful drug use and service use. SIM-welfare are mostly long-term jobless, low educated, older men; 70% are excluded from re-employment policy due to multiple personal barriers. Health: 50% anxiety and depression; 47% harmful drug use; 41% multiple somatic illnesses. Health differences compared with SIM-work: (1) controlled for background characteristics, SIM-welfare report more mental (OR 4.0; 95% CI 2.1 to 4.7) and somatic illnesses (OR 3.1; 95% CI 2.7 to 6.0); (2) SIM-welfare assessed with the largest distance to the labour market report most combined health problems. Controlled for ill health, SIM-welfare are more likely to have service contacts than SIM-work. SIM-welfare form a selection of men with disadvantaged human capital and health. Findings do not support a need to improve access to healthcare. The stratification of welfare clients distinguishes between health needs.

Health, drugs and service use among deprived single men: comparing (subgroups) of single male welfare recipients against employed single men in Amsterdam

PubMed Central

Kamann, Tjerk C; de Wit, Matty A S; Cremer, Stephan; Beekman, Aartjan T F

2014-01-01

Objectives To aid public health policy in preventing severe social exclusion (like homelessness) and promoting social inclusion (like labour market participation), we aimed to quantify (unmet) health needs of an expectedly vulnerable population on which little was known about: single male welfare recipients (SIM-welfare). One of the main policy questions was: is there need to promote access to healthcare for this specific group? Design A cross-sectional study incorporating peer-to-peer methodology to approach and survey SIM-welfare. Sociodemographics, prevalence of ill health, harmful drug use and healthcare utilisation for subgroups of SIM-welfare assessed with a different distance to the labour market and exposed to different reintegration policy were described and compared against single employed men (SIM-work). Setting Men between the age of 23 and 64, living in single person households in Amsterdam. Participants A random and representative sample of 472 SIM-welfare was surveyed during 2009–2010. A reference sample of 212 SIM-work was taken from the 2008 Amsterdam Health Survey. Outcome measures Standardised instruments were used to assess self-reported ill somatic and mental health, harmful drug use and service use. Results SIM-welfare are mostly long-term jobless, low educated, older men; 70% are excluded from re-employment policy due to multiple personal barriers. Health: 50% anxiety and depression; 47% harmful drug use; 41% multiple somatic illnesses. Health differences compared with SIM-work: (1) controlled for background characteristics, SIM-welfare report more mental (OR 4.0; 95% CI 2.1 to 4.7) and somatic illnesses (OR 3.1; 95% CI 2.7 to 6.0); (2) SIM-welfare assessed with the largest distance to the labour market report most combined health problems. Controlled for ill health, SIM-welfare are more likely to have service contacts than SIM-work. Conclusions SIM-welfare form a selection of men with disadvantaged human capital and health. Findings do not support a need to improve access to healthcare. The stratification of welfare clients distinguishes between health needs. PMID:24556242

The Building Blocks for JWST I and T (Integrations and Test) to Operations - From Simulator to Flight Units

NASA Technical Reports Server (NTRS)

Fatig, Curtis; Ochs, William; Johns, Alan; Seaton, Bonita; Adams, Cynthia; Wasiak, Francis; Jones, Ronald; Jackson, Wallace

2012-01-01

The James Webb Space Telescope (JWST) Project has an extended integration and test (I&T) phase due to long procurement and development times of various components as well as recent launch delays. The JWST Ground Segment and Operations group has developed a roadmap of the various ground and flight elements and their use in the various JWST I&T test programs. The JWST Project s building block approach to the eventual operational systems, while not new, is complex and challenging; a large-scale mission like JWST involves international partners, many vendors across the United States, and competing needs for the same systems. One of the challenges is resource balancing so simulators and flight products for various elements congeal into integrated systems used for I&T and flight operations activities. This building block approach to an incremental buildup provides for early problem identification with simulators and exercises the flight operations systems, products, and interfaces during the JWST I&T test programs. The JWST Project has completed some early I&T with the simulators, engineering models and some components of the operational ground system. The JWST Project is testing the various flight units as they are delivered and will continue to do so for the entire flight and operational system. The JWST Project has already and will continue to reap the value of the building block approach on the road to launch and flight operations.

Challenges of biological sample preparation for SIMS imaging of elements and molecules at subcellular resolution

NASA Astrophysics Data System (ADS)

Chandra, Subhash

2008-12-01

Secondary ion mass spectrometry (SIMS) based imaging techniques capable of subcellular resolution characterization of elements and molecules are becoming valuable tools in many areas of biology and medicine. Due to high vacuum requirements of SIMS, the live cells cannot be analyzed directly in the instrument. The sample preparation, therefore, plays a critical role in preserving the native chemical composition for SIMS analysis. This work focuses on the evaluation of frozen-hydrated and frozen freeze-dried sample preparations for SIMS studies of cultured cells with a CAMECA IMS-3f dynamic SIMS ion microscope instrument capable of producing SIMS images with a spatial resolution of 500 nm. The sandwich freeze-fracture method was used for fracturing the cells. The complimentary fracture planes in the plasma membrane were characterized by field-emission secondary electron microscopy (FESEM) in the frozen-hydrated state. The cells fractured at the dorsal surface were used for SIMS analysis. The frozen-hydrated SIMS analysis of individual cells under dynamic primary ion beam (O 2+) revealed local secondary ion signal enhancements correlated with the water image signals of 19(H 3O) +. A preferential removal of water from the frozen cell matrix in the Z-axis was also observed. These complications render the frozen-hydrated sample type less desirable for subcellular dynamic SIMS studies. The freeze-drying of frozen-hydrated cells, either inside the instrument or externally in a freeze-drier, allowed SIMS imaging of subcellular chemical composition. Morphological evaluations of fractured freeze-dried cells with SEM and confocal laser scanning microscopy (CLSM) revealed well-preserved mitochondria, Golgi apparatus, and stress fibers. SIMS analysis of fractured freeze-dried cells revealed well-preserved chemical composition of even the most highly diffusible ions like K + and Na + in physiologically relevant concentrations. The high K-low Na signature in individual cells provided a rule-of-thumb criterion for the validation of sample preparation. The fractured freeze-dried cells allowed 3-D SIMS imaging and localization of 13C 15N labeled molecules and therapeutic drugs containing an elemental tag. Examples are shown to demonstrate that both diffusible elements and molecules are prone to artifact-induced relocation at subcellular scale if the sample preparation is compromised. The sample preparation is problem dependent and may vary widely between the diverse sample types of biological systems and the type of instrument used for SIMS analysis. The sample preparation, however, must be validated so that SIMS can be applied with confidence in biology and medicine.

MSFC Technology Year in Review 2015

NASA Technical Reports Server (NTRS)

Reynolds, David; Tinker, Mike

2015-01-01

MSFC has a strong diverse portfolio of technology development projects, ranging from flight projects to very low Technology Readiness Level (TRL) laboratory projects. The 2015 Year in Review highlights the Center's technology projects and celebrates their accomplishments to raise awareness of technology development work that is integral to the success of future Agency flight programs.

Eclipse takeoff and flight

NASA Technical Reports Server (NTRS)

1998-01-01

This 25-second clip shows the QF-106 'Delta Dart' tethered to the USAF C-141A during takeoff and in flight. NASA Dryden Flight Research Center, Edwards, California, supported a Kelly Space and Technology, Inc. (KST)/U.S. Air Force project known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The purpose of the project was to demonstrate a reusable tow launch vehicle concept that had been conceived and patented by KST. Kelly Space obtained a contract with the USAF Research Laboratory for the tow launch demonstration project under the Small Business Innovation Research (SBIR) program. The USAF SBIR contract included the modifications to turn the QF-106 into the Experimental Demonstrator #1 (EXD-01), and the C141A aircraft to incorporate the tow provisions to link the two aircraft, as well as conducting flight tests. The demonstration consisted of ground and flight tests. These tests included a Combined Systems Test of both airplanes joined by a tow rope, a towed taxi test, and six towed flights. The primary goal of the project was demonstrating the tow phase of the Eclipse concept using a scaled-down tow aircraft (C-141A) and a representative aerodynamically-shaped aircraft (QF-106A) as a launch vehicle. This was successfully accomplished. On December 20, 1997, NASA research pilot Mark Stucky flew a QF-106 on the first towed flight behind an Air Force C-141 in the joint Eclipse project with KST to demonstrate the reusable tow launch vehicle concept developed by KST. Kelly hoped to use the data from the tow tests to validate a tow-to-launch procedure for reusable space launch vehicles. Stucky flew six successful tow tests between December 1997 and February 6, 1998. On February 6, 1998, the sixth and final towed flight brought the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable; actual flight measured values of tow rope tension were well within predictions made by the simulation, aerodynamic characteristics and elastic properties of the tow rope were a significant component of the towing system; and the Dryden high-fidelity simulation provided a representative model of the performance of the QF-106 and C-141A airplanes in tow configuration. Total time on tow for the entire project was 5 hours, 34 minutes, and 29 seconds. All six flights were highly productive, and all project objectives were achieved. All three of the project objectives were successfully accomplished. The objectives were: demonstration of towed takeoff, climb-out, and separation of the EXD-01 from the towing aircraft; validation of simulation models of the towed aircraft systems; and development of ground and flight procedures for towing and launching a delta-winged airplane configuration safely behind a transport-type aircraft. NASA Dryden served as the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, simulation, instrumentation, range support, research pilots, and chase aircraft for the test series. Dryden personnel also performed the modifications to convert the QF-106 into the piloted EXD-01 aircraft. During the early flight phase of the project, Tracor, Inc. provided maintenance and ground support for the two QF-106 airplanes. The Air Force Flight Test Center (AFFTC), Edwards, California, provided the C-141A transport aircraft for the project, its flight and engineering support, and the aircrew. Kelly Space and Technology provided the modification design and fabrication of the hardware that was installed on the EXD-01 aircraft. Kelly Space and Technology hopes to use the data gleaned from the tow tests to develop a series of low-cost reusable launch vehicles, in particular to gain experience towing delta-wing aircraft having high wing loading, and in general to demonstrate various operational procedures such as ground processing and abort scenarios. The first successful towed flight occurred on December 20, 1997. Prior to this first tow test flight, the C-141A and EXD-01 were used to conduct a series of tethered taxi tests that would validate the tow procedures. Before these tethered taxi tests, a successful joint flight test was conducted in late October 1996, by Dryden, AFFTC, and KST, in which one of the Dryden F-18 chase aircraft flew at various ranges and locations behind the C-141A to define the wake turbulence and wingtip vortex environment. This flight test was replicated in July 1997, with an unmodified QF-106 flight proficiency aircraft.

ImagingSIMS

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

2017-11-06

ImagingSIMS is an open source application for loading, processing, manipulating and visualizing secondary ion mass spectrometry (SIMS) data. At PNNL, a separate branch has been further developed to incorporate application specific features for dynamic SIMS data sets. These include loading CAMECA IMS-1280, NanoSIMS and modified IMS-4f raw data, creating isotopic ratio images and stitching together images from adjacent interrogation regions. In addition to other modifications of the parent open source version, this version is equipped with a point-by-point image registration tool to assist with streamlining the image fusion process.

Rapid characterisation of surface modifications and treatments using a benchtop SIMS instrument

NASA Astrophysics Data System (ADS)

McPhail, D. S.; Sokhan, M.; Rees, E. E.; Cliff, B.; Eccles, A. J.; Chater, R. J.

2004-06-01

The development of a novel benchtop SIMS instrument (Millbrook MiniSIMS) [Appl. Surf. Sci. 144 (1999) 106] has brought routine SIMS analysis to many new users, for example museum conservators. This is a result of the simple operation and the relatively low capital cost of the instrument. We report here on the continued development of the system in terms of increasing performance and functionality and its use in museum conservation based applications where a mobile instrument for high throughput, rapid SIMS analysis has proven to be of great benefit to the user. The example we describe here is the application of the MiniSIMS to the analysis of silver thread woven into a silk dress before and after laser cleaning.

Molecular Substrate Alteration by Solar Wind Radiation Documented on Flown Genesis Mission Array Materials

NASA Technical Reports Server (NTRS)

Calaway, Michael J.; Stansbery, Eileen K.

2006-01-01

The Genesis spacecraft sampling arrays were exposed to various regimes of solar wind during flight that included: 313.01 days of high-speed wind from coronal holes, 335.19 days of low-speed inter-stream wind, 191.79 days of coronal mass ejections, and 852.83 days of bulk solar wind at Lagrange 1 orbit. Ellipsometry measurements taken at NASA s Johnson Space Center show that all nine flown array materials from the four Genesis regimes have been altered by solar wind exposure during flight. These measurements show significant changes in the optical constant for all nine ultra-pure materials that flew on Genesis when compared with their non-flight material standard. This change in the optical constant (n and k) of the material suggests that the molecular structure of the all nine ultra-pure materials have been altered by solar radiation. In addition, 50 samples of float-zone and czochralski silicon bulk array ellipsometry results were modeled with an effective medium approximation layer (EMA substrate layer) revealing a solar radiation molecular damage zone depth below the SiO2 native oxide layer ranging from 392 to 613 . This bulk solar wind radiation penetration depth is comparable to the depth of solar wind implantation depth of Mg measured by SIMS and SARISA.

VERSE - Virtual Equivalent Real-time Simulation

NASA Technical Reports Server (NTRS)

Zheng, Yang; Martin, Bryan J.; Villaume, Nathaniel

2005-01-01

Distributed real-time simulations provide important timing validation and hardware in the- loop results for the spacecraft flight software development cycle. Occasionally, the need for higher fidelity modeling and more comprehensive debugging capabilities - combined with a limited amount of computational resources - calls for a non real-time simulation environment that mimics the real-time environment. By creating a non real-time environment that accommodates simulations and flight software designed for a multi-CPU real-time system, we can save development time, cut mission costs, and reduce the likelihood of errors. This paper presents such a solution: Virtual Equivalent Real-time Simulation Environment (VERSE). VERSE turns the real-time operating system RTAI (Real-time Application Interface) into an event driven simulator that runs in virtual real time. Designed to keep the original RTAI architecture as intact as possible, and therefore inheriting RTAI's many capabilities, VERSE was implemented with remarkably little change to the RTAI source code. This small footprint together with use of the same API allows users to easily run the same application in both real-time and virtual time environments. VERSE has been used to build a workstation testbed for NASA's Space Interferometry Mission (SIM PlanetQuest) instrument flight software. With its flexible simulation controls and inexpensive setup and replication costs, VERSE will become an invaluable tool in future mission development.

NASA's International Lunar Network Anchor Nodes and Robotic Lunar Lander Project Update

NASA Technical Reports Server (NTRS)

Cohen, Barbara A.; Bassler, Julie A.; Ballard, Benjamin; Chavers, Greg; Eng, Doug S.; Hammond, Monica S.; Hill, Larry A.; Harris, Danny W.; Hollaway, Todd A.; Kubota, Sanae;

Structural-Thermal-Optical-Performance (STOP) Model Development and Analysis of a Field-widened Michelson Interferometer

NASA Technical Reports Server (NTRS)

Scola, Salvatore J.; Osmundsen, James F.; Murchison, Luke S.; Davis, Warren T.; Fody, Joshua M.; Boyer, Charles M.; Cook, Anthony L.; Hostetler, Chris A.; Seaman, Shane T.; Miller, Ian J.;

The role of simulation in the development and flight test of the HiMAT vehicle

NASA Technical Reports Server (NTRS)

Evans, M. B.; Schilling, L. J.

1984-01-01

Real time simulations have been essential in the flight test program of the highly maneuverable aircraft technology (HiMAT) remotely piloted research vehicle at NASA Ames Research Center's Dryden Flight Research Facility. The HiMAT project makes extensive use of simulations in design, development, and qualification for flight, pilot training, and flight planning. Four distinct simulations, each with varying amounts of hardware in the loop, were developed for the HiMAT project. The use of simulations in detecting anomalous behavior of the flight software and hardware at the various stages of development, verification, and validation has been the key to flight qualification of the HiMAT vehicle.

"SP.ACE" 2013-2015: ASGARD Balloon and BIFROST Parabolic Flights: Latest Developments in Hands-On Space Education Projects for Secondary School Students

NASA Astrophysics Data System (ADS)

de Schrijver, E.; Chameleva, H.; Degroote, C.; D'Haese, Z.; Paice, C.; Plas, H.; Van den Bossche, A.; Vander Donckt, L.; Vander Vost, J.

2015-09-01

Flight opportunities on high-altitude ASGARD balloons offered to secondary schools worldwide since 20 1 1 have led to an ever more rapidly increasing number of project proposals. The introduction of beginners' and ‘advanced classes of experiments is hoped to draw in even larger numbers of interested school teams. Furthermore, and in cooperation with ESERO (European Space Education Resources Office), workshops and documentation are being prepared to introduce teachers and students alike to the world of microcontrollers and sensors. A student parabolic flight programme called BIFROST (Brussels' Initiative to provide Flight Research Opportunities to STudents) was initiated to meet the rising demand for hands-on space education projects and the desire to cover the widest possible range of scientific and/or technical domains, which essentially calls for a variety of flight platforms: cansats, balloons and parabolic flight.

NREL's Water Power Software Makes a Splash; NREL Highlights, Research & Development, NREL (National Renewable Energy Laboratory)

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

None

2015-06-01

WEC-Sim is a DOE-funded software tool being jointly developed by NREL and SNL. WEC-Sim computationally models wave energy converters (WEC), devices that generate electricity using movement of water systems such as oceans, rivers, etc. There is great potential for WECs to generate electricity, but as of yet, the industry has yet to establish a commercially viable concept. Modeling, design, and simulations tools are essential to the successful development of WECs. Commercial WEC modeling software tools can't be modified by the user. In contrast, WEC-Sim is a free, open-source, and flexible enough to be modified to meet the rapidly evolving needsmore » of the WEC industry. By modeling the power generation performance and dynamic loads of WEC designs, WEC-Sim can help support the development of new WEC devices by optimizing designs for cost of energy and competitiveness. By being easily accessible, WEC-Sim promises to help level the playing field in the WEC industry. Importantly, WEC-Sim is also excellent at its job! In 2014, WEC-Sim was used in conjunction with NREL’s FAST modeling software to win a hydrodynamic modeling competition. WEC-Sim and FAST performed very well at predicting the motion of a test device in comparison to other modeling tools. The most recent version of WEC-Sim (v1.1) was released in April 2015.« less

Binding properties of SUMO-interacting motifs (SIMs) in yeast.

PubMed

Jardin, Christophe; Horn, Anselm H C; Sticht, Heinrich

2015-03-01

Small ubiquitin-like modifier (SUMO) conjugation and interaction play an essential role in many cellular processes. A large number of yeast proteins is known to interact non-covalently with SUMO via short SUMO-interacting motifs (SIMs), but the structural details of this interaction are yet poorly characterized. In the present work, sequence analysis of a large dataset of 148 yeast SIMs revealed the existence of a hydrophobic core binding motif and a preference for acidic residues either within or adjacent to the core motif. Thus the sequence properties of yeast SIMs are highly similar to those described for human. Molecular dynamics simulations were performed to investigate the binding preferences for four representative SIM peptides differing in the number and distribution of acidic residues. Furthermore, the relative stability of two previously observed alternative binding orientations (parallel, antiparallel) was assessed. For all SIMs investigated, the antiparallel binding mode remained stable in the simulations and the SIMs were tightly bound via their hydrophobic core residues supplemented by polar interactions of the acidic residues. In contrary, the stability of the parallel binding mode is more dependent on the sequence features of the SIM motif like the number and position of acidic residues or the presence of additional adjacent interaction motifs. This information should be helpful to enhance the prediction of SIMs and their binding properties in different organisms to facilitate the reconstruction of the SUMO interactome.

Validation of the SimSET simulation package for modeling the Siemens Biograph mCT PET scanner

NASA Astrophysics Data System (ADS)

Poon, Jonathan K.; Dahlbom, Magnus L.; Casey, Michael E.; Qi, Jinyi; Cherry, Simon R.; Badawi, Ramsey D.

2015-02-01

Monte Carlo simulation provides a valuable tool in performance assessment and optimization of system design parameters for PET scanners. SimSET is a popular Monte Carlo simulation toolkit that features fast simulation time, as well as variance reduction tools to further enhance computational efficiency. However, SimSET has lacked the ability to simulate block detectors until its most recent release. Our goal is to validate new features of SimSET by developing a simulation model of the Siemens Biograph mCT PET scanner and comparing the results to a simulation model developed in the GATE simulation suite and to experimental results. We used the NEMA NU-2 2007 scatter fraction, count rates, and spatial resolution protocols to validate the SimSET simulation model and its new features. The SimSET model overestimated the experimental results of the count rate tests by 11-23% and the spatial resolution test by 13-28%, which is comparable to previous validation studies of other PET scanners in the literature. The difference between the SimSET and GATE simulation was approximately 4-8% for the count rate test and approximately 3-11% for the spatial resolution test. In terms of computational time, SimSET performed simulations approximately 11 times faster than GATE simulations. The new block detector model in SimSET offers a fast and reasonably accurate simulation toolkit for PET imaging applications.

SimPhy: Phylogenomic Simulation of Gene, Locus, and Species Trees

PubMed Central

Mallo, Diego; De Oliveira Martins, Leonardo; Posada, David

2016-01-01

We present a fast and flexible software package—SimPhy—for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer—all three potentially leading to species tree/gene tree discordance—and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of species, locus, and gene trees is governed by global and local parameters (e.g., genome-wide, species-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large trees, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases. PMID:26526427

Search for a scalar partner of the top quark in the jets plus missing transverse momentum final state at $$\\sqrt{s}=13 $$ TeV with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-12-15

A search for pair production of a scalar partner of the top quark in events with four or more jets plus missing transverse momentum is presented. Here, an analysis of 36.1 fb -1 ofmore » $$ \\sqrt{s}=13 $$ TeV proton-proton collisions collected using the ATLAS detector at the LHC yields no significant excess over the expected Standard Model background. To interpret the results a simplified supersymmetric model is used where the top squark is assumed to decay via $$\\sim\\atop{t}$$ 1→t(*)$$\\sim\\atop{χ}$$ $$0\\atop{1}$$ and $$\\sim\\atop{t}$$ 1→b$$\\sim\\atop{χ}$$ $$±\\atop{1}$$→bW(*)$$\\sim\\atop{χ}$$ $$0\\atop{1}$$, where χ 1 0 (χ 1 ± ) denotes the lightest neutralino (chargino). Exclusion limits are placed in terms of the top-squark and neutralino masses. Assuming a branching ratio of 100% to t$$\\sim\\atop{χ}$$ $$0\\atop{1}$$, top-squark masses in the range 450–1000 GeV are excluded for $$\\sim\\atop{χ}$$ $$0\\atop{1}$$ masses below 160 GeV. In the case where m$$\\sim\\atop{t}$$ 1-m t+m $$\\sim\\atop{χ}$$ $$0\\atop{1}$$ , top-squark masses in the range 235–590 GeV are excluded.« less

Search for a scalar partner of the top quark in the jets plus missing transverse momentum final state at $$\\sqrt{s}=13 $$ TeV with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

A search for pair production of a scalar partner of the top quark in events with four or more jets plus missing transverse momentum is presented. Here, an analysis of 36.1 fb -1 ofmore » $$ \\sqrt{s}=13 $$ TeV proton-proton collisions collected using the ATLAS detector at the LHC yields no significant excess over the expected Standard Model background. To interpret the results a simplified supersymmetric model is used where the top squark is assumed to decay via $$\\sim\\atop{t}$$ 1→t(*)$$\\sim\\atop{χ}$$ $$0\\atop{1}$$ and $$\\sim\\atop{t}$$ 1→b$$\\sim\\atop{χ}$$ $$±\\atop{1}$$→bW(*)$$\\sim\\atop{χ}$$ $$0\\atop{1}$$, where χ 1 0 (χ 1 ± ) denotes the lightest neutralino (chargino). Exclusion limits are placed in terms of the top-squark and neutralino masses. Assuming a branching ratio of 100% to t$$\\sim\\atop{χ}$$ $$0\\atop{1}$$, top-squark masses in the range 450–1000 GeV are excluded for $$\\sim\\atop{χ}$$ $$0\\atop{1}$$ masses below 160 GeV. In the case where m$$\\sim\\atop{t}$$ 1-m t+m $$\\sim\\atop{χ}$$ $$0\\atop{1}$$ , top-squark masses in the range 235–590 GeV are excluded.« less

Nonlinear Aerodynamic Modeling From Flight Data Using Advanced Piloted Maneuvers and Fuzzy Logic

NASA Technical Reports Server (NTRS)

Brandon, Jay M.; Morelli, Eugene A.

2012-01-01

Results of the Aeronautics Research Mission Directorate Seedling Project Phase I research project entitled "Nonlinear Aerodynamics Modeling using Fuzzy Logic" are presented. Efficient and rapid flight test capabilities were developed for estimating highly nonlinear models of airplane aerodynamics over a large flight envelope. Results showed that the flight maneuvers developed, used in conjunction with the fuzzy-logic system identification algorithms, produced very good model fits of the data, with no model structure inputs required, for flight conditions ranging from cruise to departure and spin conditions.

Multi-Vehicle Cooperative Control Research at the NASA Armstrong Flight Research Center, 2000-2014

NASA Technical Reports Server (NTRS)

Hanson, Curt

2014-01-01

A brief introductory overview of multi-vehicle cooperative control research conducted at the NASA Armstrong Flight Research Center from 2000 - 2014. Both flight research projects and paper studies are included. Since 2000, AFRC has been almost continuously pursuing research in the areas of formation flight for drag reduction and automated cooperative trajectories. An overview of results is given, including flight experiments done on the FA-18 and with the C-17. Other multi-vehicle cooperative research is discussed, including small UAV swarming projects and automated aerial refueling.

78 FR 8587 - American Showa, Inc.; Blanchester Plant, Including On-Site Leased Workers From Adecco and Sims...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

....; Blanchester Plant, Including On-Site Leased Workers From Adecco and Sims Bros., Inc.; Blanchester, OH; Amended... workers from Sims Bros., Inc. were working on-site at the subject firm during the relevant period and that the services supplied by Sims Bros., Inc. were related to the production of gear boxes (and parts...

Teaching the Teacher: Tutoring SimStudent Leads to More Effective Cognitive Tutor Authoring

ERIC Educational Resources Information Center

Matsuda, Noboru; Cohen, William W.; Koedinger, Kenneth R.

2015-01-01

SimStudent is a machine-learning agent initially developed to help novice authors to create cognitive tutors without heavy programming. Integrated into an existing suite of software tools called Cognitive Tutor Authoring Tools (CTAT), SimStudent helps authors to create an expert model for a cognitive tutor by tutoring SimStudent on how to solve…

NASA Aerosciences Perspective on Proposed De-Scope of Ares I-X Development Flight Instrumentation

NASA Technical Reports Server (NTRS)

Schuster, David M.

2009-01-01

This position paper is written as a result of a number of emails and a presentation that have recently been circulated concerning the potential reduction of Development Flight Instrumentation (DFI) to be included on the Ares I-X flight test vehicle. A reduction in instrumentation has been proposed presumably to reduce project costs and relieve project schedule pressures. This proposal has generated a significant amount of discussion on both sides of the issue, primarily from those within the project. The intention here is to provide a perspective on this issue from outside the mainline project.

CatSim: a new computer assisted tomography simulation environment

NASA Astrophysics Data System (ADS)

De Man, Bruno; Basu, Samit; Chandra, Naveen; Dunham, Bruce; Edic, Peter; Iatrou, Maria; McOlash, Scott; Sainath, Paavana; Shaughnessy, Charlie; Tower, Brendon; Williams, Eugene

2007-03-01

We present a new simulation environment for X-ray computed tomography, called CatSim. CatSim provides a research platform for GE researchers and collaborators to explore new reconstruction algorithms, CT architectures, and X-ray source or detector technologies. The main requirements for this simulator are accurate physics modeling, low computation times, and geometrical flexibility. CatSim allows simulating complex analytic phantoms, such as the FORBILD phantoms, including boxes, ellipsoids, elliptical cylinders, cones, and cut planes. CatSim incorporates polychromaticity, realistic quantum and electronic noise models, finite focal spot size and shape, finite detector cell size, detector cross-talk, detector lag or afterglow, bowtie filtration, finite detector efficiency, non-linear partial volume, scatter (variance-reduced Monte Carlo), and absorbed dose. We present an overview of CatSim along with a number of validation experiments.

Ares I-X Flight Data Evaluation: Executive Overview

NASA Technical Reports Server (NTRS)

Huebner, Lawrence D.; Waits, David A.; Lewis, Donny L.; Richards, James S.; Coates, R. H., Jr.; Cruit, Wendy D.; Bolte, Elizabeth J.; Bangham, Michal E.; Askins, Bruce R.; Trausch, Ann N.

2011-01-01

NASA's Constellation Program (CxP) successfully launched the Ares I-X flight test vehicle on October 28, 2009. The Ares I-X flight was a developmental flight test to demonstrate that this very large, long, and slender vehicle could be controlled successfully. The flight offered a unique opportunity for early engineering data to influence the design and development of the Ares I crew launch vehicle. As the primary customer for flight data from the Ares I-X mission, the Ares Projects Office (APO) established a set of 33 flight evaluation tasks to correlate flight results with prospective design assumptions and models. The flight evaluation tasks used Ares I-X data to partially validate tools and methodologies in technical disciplines that will ultimately influence the design and development of Ares I and future launch vehicles. Included within these tasks were direct comparisons of flight data with preflight predictions and post-flight assessments utilizing models and processes being applied to design and develop Ares I. The benefits of early development flight testing were made evident by results from these flight evaluation tasks. This overview provides summary information from assessment of the Ares I-X flight test data and represents a small subset of the detailed technical results. The Ares Projects Office published a 1,600-plus-page detailed technical report that documents the full set of results. This detailed report is subject to the International Traffic in Arms Regulations (ITAR) and is available in the Ares Projects Office archives files.

Public health benefits from pictorial health warnings on US cigarette packs: a SimSmoke simulation.

PubMed

Levy, David T; Mays, Darren; Yuan, Zhe; Hammond, David; Thrasher, James F

2017-11-01

While many countries have adopted prominent pictorial warning labels (PWLs) for cigarette packs, the USA still requires only small, text-only labels located on one side of the cigarette pack that have little effect on smoking-related outcomes. Tobacco industry litigation blocked implementation of a 2011 Food and Drug Administration's (FDA) rule requiring large PWLs. To inform FDA action on PWLs, this study provides research-based estimates of their public health impacts. Literature was reviewed to identify the impact of cigarette PWLs on smoking prevalence, cessation and initiation. Based on this analysis, the SimSmoke model was used to estimate the effect of requiring PWLs in the USA on smoking prevalence and, using standard attribution methods, on smoking-attributable deaths (SADs) and key maternal and child health outcomes. Available research consistently shows a direct association between PWLs and increased cessation and reduced smoking initiation and prevalence. The SimSmoke model projects that PWLs would reduce smoking prevalence by 5% (2.5%-9%) relative to the status quo over the short term and by 10% (4%-19%) over the long term. Over the next 50 years, PWLs are projected to avert 652 800 (327 000-1 190 500) SADs, 46 600 (17 500-92 300) low-birth-weight cases, 73 600 (27 800-145 100) preterm births and 1000 (400-2000) cases of sudden infant death syndrome. Requiring PWLs on all US cigarette packs would be appropriate for the protection of the public health, because it would substantially reduce smoking prevalence and thereby reduce SADs and the morbidity and medical costs associated with adverse smoking-attributable birth outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Effect of Actual and Simulated Microgravity on Cardiac Mass and Function in the Rat

NASA Technical Reports Server (NTRS)

Ray, Chester H.; Vasques, Marilyn; Miller, Todd H.; Wilkerson, M. Keith; Delp, Michael D.; Dalton, Bonnie (Technical Monitor)

2001-01-01

The purpose of this study was to test the hypothesis that exposure to actual or simulated microgravity induces cardiac atrophy in male Sprague-Dawley rats. For the microgravity study, rats were subdivided into four groups: Preflight (PF, n = 12); Flight (FL, n = 7); Flight Cage Simulation (SIM, n = 6), and Vivarium Control (VIV, n = 7). Animals in the FL group were exposed to 7 days of microgravity during the Spacelab 3 mission. Animals in the simulated microgravity study were subdivided into three groups: Control (CON, n = 20); 7 day hindlimb unloaded (7HU, n = 10); and 28 day unloaded (28HU, n = 19). In a subset of CON (n = 7) and 28HU (n = 6) rats, a catheter was advanced into the left ventricle to measure the rate of rise in ventricular pressure (+dP/dt) during standing as an estimate of cardiac contractility. After completion of their respective treatments, hearts were removed and weighed. Animals in the PF group were sacrificed 24 hr prior to launch while the FL group was sacrificed 11- 17 hr after landing. The SM and VIV groups were sacrificed 48 and 96 hr after the FL group, respectively. Heart mass was unchanged in adult animals exposed to 7 days of actual microgravity (PF 1.33 +/- .03 g; FL 1.32 +/- 0.02 g; SIM 1.28 +/- 0.04 g; VIV 1.35 +/- 0.04 g). Similarly, heart mass was unaltered with hinlimb unloading (CON 1.40 +/- 0.04 g; 7HU 1.35 +/- 0.06 g; 28HU 1.42 +/- 0.03 g). Hindlimb unloading also had no effect on myocardial contractility (CON 8055 +/- 385 mmHg/sec; 28HU 8545 +/- 755 mmHg/sec). These data suggest that cardiac atrophy does not occur following short-term exposure to microgravity, and that neither short- nor long-term simulated microgravity alter cardiac mass or function.

Chemical and microstructural characterizations of plasma polymer films by time-of-flight secondary ion mass spectrometry and principal component analysis

NASA Astrophysics Data System (ADS)

Cossement, Damien; Renaux, Fabian; Thiry, Damien; Ligot, Sylvie; Francq, Rémy; Snyders, Rony

2015-11-01

It is accepted that the macroscopic properties of functional plasma polymer films (PPF) are defined by their functional density and their crosslinking degree (χ) which are quantities that most of the time behave in opposite trends. If the PPF chemistry is relatively easy to evaluate, it is much more challenging for χ. This paper reviews the recent work developed in our group on the application of principal component analysis (PCA) to time-of-flight secondary ion mass spectrometric (ToF-SIMS) positive spectra data in order to extract the relative cross-linking degree (χ) of PPF. NH2-, COOR- and SH-containing PPF synthesized in our group by plasma enhanced chemical vapor deposition (PECVD) varying the applied radiofrequency power (PRF), have been used as model surfaces. For the three plasma polymer families, the scores of the first computed principal component (PC1) highlighted significant differences in the chemical composition supported by X-Ray photoelectron spectroscopy (XPS) data. The most important fragments contributing to PC1 (loadings > 90%) were used to compute an average C/H ratio index for samples synthesized at low and high PRF. This ratio being an evaluation of χ, these data, accordingly to the literature, indicates an increase of χ with PRF excepted for the SH-PPF. These results have been cross-checked by the evaluation of functional properties of the plasma polymers namely a linear correlation with the stability of NH2-PPF in ethanol and a correlation with the mechanical properties of the COOR-PPF. For the SH-PPF family, the peculiar evolution of χ is supported by the understanding of the growth mechanism of the PPF from plasma diagnostic. The whole set of data clearly demonstrates the potential of the PCA method for extracting information on the microstructure of plasma polymers from ToF-SIMS measurements.

The accumulation pattern of ferruginol in the heartwood-forming Cryptomeria japonica xylem as determined by time-of-flight secondary ion mass spectrometry and quantity analysis

PubMed Central

Kuroda, Katsushi; Fujiwara, Takeshi; Hashida, Koh; Imai, Takanori; Kushi, Masayoshi; Saito, Kaori; Fukushima, Kazuhiko

2014-01-01

Background and Aims Heartwood formation is a unique phenomenon of tree species. Although the accumulation of heartwood substances is a well-known feature of the process, the accumulation mechanism remains unclear. The aim of this study was to determine the accumulation process of ferruginol, a predominant heartwood substance of Cryptomeria japonica, in heartwood-forming xylem. Methods The radial accumulation pattern of ferruginol was examined from sapwood and through the intermediate wood to the heartwood by direct mapping using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The data were compared with quantitative results obtained from a novel method of gas chromatography analysis using laser microdissection sampling and with water distribution obtained from cryo-scanning electron microscopy. Key Results Ferruginol initially accumulated in the middle of the intermediate wood, in the earlywood near the annual ring boundary. It accumulated throughout the entire earlywood in the inner intermediate wood, and in both the earlywood and the latewood in the heartwood. The process of ferruginol accumulation continued for more than eight annual rings. Ferruginol concentration peaked at the border between the intermediate wood and heartwood, while the concentration was less in the latewood compared wiht the earlywood in each annual ring. Ferruginol tended to accumulate around the ray parenchyma cells. In addition, at the border between the intermediate wood and heartwood, the accumulation was higher in areas without water than in areas with water. Conclusions TOF-SIMS clearly revealed ferruginol distribution at the cellular level. Ferruginol accumulation begins in the middle of intermediate wood, initially in the earlywood near the annual ring boundary, then throughout the entire earlywood, and finally across to the whole annual ring in the heartwood. The heterogeneous timing of ferruginol accumulation could be related to the distribution of ray parenchyma cells and/or water in the heartwood-forming xylem. PMID:24651372

Probing the Orientation of Surface-Immobilized Protein G B1 Using ToF-SIMS Sum Frequency Generation and NEXAFS Spectroscopy

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

L Baugh; T Weidner; J Baio

2011-12-31

The ability to orient active proteins on surfaces is a critical aspect of many medical technologies. An important related challenge is characterizing protein orientation in these surface films. This study uses a combination of time-of-flight secondary ion mass spectrometry (ToF-SIMS), sum frequency generation (SFG) vibrational spectroscopy, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to characterize the orientation of surface-immobilized Protein G B1, a rigid 6 kDa domain that binds the Fc fragment of IgG. Two Protein G B1 variants with a single cysteine introduced at either end were immobilized via the cysteine thiol onto maleimide-oligo(ethylene glycol)-functionalized gold and baremore » gold substrates. X-ray photoelectron spectroscopy was used to measure the amount of immobilized protein, and ToF-SIMS was used to measure the amino acid composition of the exposed surface of the protein films and to confirm covalent attachment of protein thiol to the substrate maleimide groups. SFG and NEXAFS were used to characterize the ordering and orientation of peptide or side chain bonds. On both substrates and for both cysteine positions, ToF-SIMS data showed enrichment of mass peaks from amino acids located at the end of the protein opposite to the cysteine surface position as compared with nonspecifically immobilized protein, indicating end-on protein orientations. Orientation on the maleimide substrate was enhanced by increasing pH (7.0-9.5) and salt concentration (0-1.5 M NaCl). SFG spectral peaks characteristic of ordered {alpha}-helix and {beta}-sheet elements were observed for both variants but not for cysteine-free wild type protein on the maleimide surface. The phase of the {alpha}-helix and {beta}-sheet peaks indicated a predominantly upright orientation for both variants, consistent with an end-on protein binding configuration. Polarization dependence of the NEXAFS signal from the N 1s to {pi}* transition of {beta}-sheet peptide bonds also indicated protein ordering, with an estimated tilt angle of inner {beta}-strands of 40-50{sup o} for both variants (one variant more tilted than the other), consistent with SFG results. The combined results demonstrate the power of using complementary techniques to probe protein orientation on surfaces.« less

Space Interferometry Mission: Measuring the Universe

NASA Technical Reports Server (NTRS)

Marr, James; Dallas, Saterios; Laskin, Robert; Unwin, Stephen; Yu, Jeffrey

1991-01-01

The Space Interferometry Mission (SIM) will be the NASA Origins Program's first space based long baseline interferometric observatory. SIM will use a 10 m Michelson stellar interferometer to provide 4 microarcsecond precision absolute position measurements of stars down to 20th magnitude over its 5 yr. mission lifetime. SIM will also provide technology demonstrations of synthesis imaging and interferometric nulling. This paper describes the what, why and how of the SIM mission, including an overall mission and system description, science objectives, general description of how SIM makes its measurements, description of the design concepts now under consideration, operations concept, and supporting technology program.

Commission 8: Astrometry

NASA Astrophysics Data System (ADS)

Evans, Dafydd Wyn; Zacharias, Norbert; Kumkova, Irina; Andrei, Alexandre; Brown, Anthony; Gouda, Naoteru; Popescu, Petre; Souchay, Jean; Unwin, Stephen; Zhu, Zi

2012-04-01

Gaia is continuing well with its development and construction and is expected to achieve parallax accuracies of about 10 to 300 μas for 6 to 20 mag. It is scheduled to launch in 2013. The ICRF2 was adopted by the IAU in 2009 as the new fundamental celestial reference frame. The UCAC project concluded with the publication of its 4th data release (all-sky, over 100 million stars). The JASMINE project will launch the Nano-JASMINE satellite in 2012 and continues with the development of its other satellites which will complement the Gaia project. The PPMXL (Heidelberg) and XPM (Ukraine) catalogues provide improved astrometric accuracies from new reductions of USNO-B (USNO-A) and 2MASS data. It is disappointing that the SIM project was cancelled during this triennium. It would have further complemented the above two satellite projects and would have gone even beyond Gaia in astrometric accuracy.

Phase 1 Validation Testing and Simulation for the WEC-Sim Open Source Code

NASA Astrophysics Data System (ADS)

Ruehl, K.; Michelen, C.; Gunawan, B.; Bosma, B.; Simmons, A.; Lomonaco, P.

2015-12-01

WEC-Sim is an open source code to model wave energy converters performance in operational waves, developed by Sandia and NREL and funded by the US DOE. The code is a time-domain modeling tool developed in MATLAB/SIMULINK using the multibody dynamics solver SimMechanics, and solves the WEC's governing equations of motion using the Cummins time-domain impulse response formulation in 6 degrees of freedom. The WEC-Sim code has undergone verification through code-to-code comparisons; however validation of the code has been limited to publicly available experimental data sets. While these data sets provide preliminary code validation, the experimental tests were not explicitly designed for code validation, and as a result are limited in their ability to validate the full functionality of the WEC-Sim code. Therefore, dedicated physical model tests for WEC-Sim validation have been performed. This presentation provides an overview of the WEC-Sim validation experimental wave tank tests performed at the Oregon State University's Directional Wave Basin at Hinsdale Wave Research Laboratory. Phase 1 of experimental testing was focused on device characterization and completed in Fall 2015. Phase 2 is focused on WEC performance and scheduled for Winter 2015/2016. These experimental tests were designed explicitly to validate the performance of WEC-Sim code, and its new feature additions. Upon completion, the WEC-Sim validation data set will be made publicly available to the wave energy community. For the physical model test, a controllable model of a floating wave energy converter has been designed and constructed. The instrumentation includes state-of-the-art devices to measure pressure fields, motions in 6 DOF, multi-axial load cells, torque transducers, position transducers, and encoders. The model also incorporates a fully programmable Power-Take-Off system which can be used to generate or absorb wave energy. Numerical simulations of the experiments using WEC-Sim will be presented. These simulations highlight the code features included in the latest release of WEC-Sim (v1.2), including: wave directionality, nonlinear hydrostatics and hydrodynamics, user-defined wave elevation time-series, state space radiation, and WEC-Sim compatibility with BEMIO (open source AQWA/WAMI/NEMOH coefficient parser).

Defining and Applying Limits for Test and Flight Through the Project Lifecycle GSFC Standard. [Scope: Non-Cryogenic Systems Tested in Vacuum

NASA Technical Reports Server (NTRS)

Mosier, Carol

2015-01-01

The presentation will be given at the Annual Thermal Fluids Analysis Workshop (TFAWS 2015, NCTS 21070-15) hosted by the Goddard SpaceFlight Center (GSFC) Thermal Engineering Branch (Code 545). The powerpoint presentation details the process of defining limits throughout the lifecycle of a flight project.

The Aircraft Simulation Role in Improving Flight Safety Through Control Room Training

NASA Technical Reports Server (NTRS)

Shy, Karla S.; Hageman, Jacob J.; Le, Jeanette H.; Sitz, Joel (Technical Monitor)

2002-01-01

NASA Dryden Flight Research Center uses its six-degrees-of-freedom (6-DOF) fixed-base simulations for mission control room training to improve flight safety and operations. This concept is applied to numerous flight projects such as the F-18 High Alpha Research Vehicle (HARV), the F-15 Intelligent Flight Control System (IFCS), the X-38 Actuator Control Test (XACT), and X-43A (Hyper-X). The Dryden 6-DOF simulations are typically used through various stages of a project, from design to ground tests. The roles of these simulations have expanded to support control room training, reinforcing flight safety by building control room staff proficiency. Real-time telemetry, radar, and video data are generated from flight vehicle simulation models. These data are used to drive the control room displays. Nominal static values are used to complete information where appropriate. Audio communication is also an integral part of training sessions. This simulation capability is used to train control room personnel and flight crew for nominal missions and emergency situations. Such training sessions are also opportunities to refine flight cards and control room display pages, exercise emergency procedures, and practice control room setup for the day of flight. This paper describes this technology as it is used in the X-43A and F-15 IFCS and XACT projects.

Clinical Placement Before or After Simulated Learning Environments?: A Naturalistic Study of Clinical Skills Acquisition Among Early-Stage Paramedicine Students.

PubMed

Mills, Brennen W; Carter, Owen B J; Rudd, Cobie J; Ross, Nathan P; Claxton, Louise A

2015-10-01

There is conflicting evidence surrounding the merit of clinical placements (CPs) for early-stage health-profession students. Some contend that early-stage CPs facilitate contextualization of a subsequently learned theory. Others argue that training in simulated-learning experiences (SLEs) should occur before CP to ensure that students possess at least basic competency. We sought to investigate both claims. First-year paramedicine students (n = 85) undertook 3 days of CP and SLEs as part of course requirements. Students undertook CP either before or after participation in SLEs creating 2 groups (Clin → Sim/Sim → Clin). Clinical skills acquisition was measured via direct scenario-based clinical assessments with expert observers conducted at 4 intervals during the semester. Perceptions of difficulty of CP and SLE were measured via the National Aeronautics and Space Administration Task Load Index. Students' clinical assessment scores in both groups improved significantly from beginning to end of semester (P < 0.001). However, at semester's end, clinical assessment scores for the Sim → Clin group were statistically significantly greater than those of the Clin → Sim group (P = 0.021). Both groups found SLEs more demanding than CP (P < 0.001). However, compared with the Sim → Clin group, the Clin → Sim group rated SLE as substantially more time-demanding than CP (P = 0.003). Differences in temporal demand suggest that the Clin → Sim students had fewer opportunities to practice clinical skills during CP than the Sim → Clin students due to a more limited scope of practice. The Sim → Clin students contextualized SLE within subsequent CP resulting in greater improvement in clinical competency by semester's end in comparison with the Clin → Sim students who were forced to contextualize skills retrospectively.

Local delivery of controlled-release simvastatin to improve the biocompatibility of polyethylene terephthalate artificial ligaments for reconstruction of the anterior cruciate ligament.

PubMed

Zhang, Peng; Han, Fei; Li, Yunxia; Chen, Jiwu; Chen, Tianwu; Zhi, Yunlong; Jiang, Jia; Lin, Chao; Chen, Shiyi; Zhao, Peng

2016-01-01

The Ligament Advanced Reinforcement System has recently been widely used as the primary graft of choice in anterior cruciate ligament (ACL) reconstruction. But the biological graft-bone healing still remains a problem. Previous studies have shown that simvastatin (SIM) stimulates bone formation. The objective of this study was to investigate whether surface coating with collagen containing low-dose SIM microsphere could enhance the surface biocompatibility of polyethylene terephthalate (PET) artificial ligaments to accelerate graft-to-bone healing. The in vitro studies demonstrated that bone marrow stromal cells on the collagen-coated PET scaffolds (COL/PET) and simvastatin/collagen-coated PET scaffolds (SIM/COL/PET) proliferated vigorously. Compared with the PET group and the COL/PET group, SIM could induce bone marrow stromal cells' osteoblastic differentiation, high alkaline phosphatase activity, more mineralization deposition, and more expression of osteoblast-related genes, such as osteocalcin, runt-related transcription factor 2, bone morphogenetic protein-2, and vascular endothelial growth factor, in the SIM/COL/PET group. In vivo, rabbits received ACL reconstruction with different scaffolds. Histological analysis demonstrated that graft-bone healing was significantly greater with angiogenesis and osteogenesis in the SIM/COL/PET group than the other groups. In addition, biomechanical testing at the eighth week demonstrated a significant increase in the ultimate failure load and stiffness in the SIM/COL/PET group. The low dose of SIM-sustained release from SIM/COL/PET promoted the graft-bone healing via its effect on both angiogenesis and osteogenesis. This study suggested that collagen containing low-dose SIM microsphere coating on the surface of PET artificial ligaments could be potentially applied for ACL reconstruction.

Cross-Cultural Discussions in a 3D Virtual Environment and Their Affordances for Learners' Motivation and Foreign Language Discussion Skills

ERIC Educational Resources Information Center

Jauregi, Kristi; Kuure, Leena; Bastian, Pim; Reinhardt, Dennis; Koivisto, Tuomo

2015-01-01

Within the European TILA project a case study was carried out where pupils from schools in Finland and the Netherlands engaged in debating sessions using the 3D virtual world of OpenSim once a week for a period of 5 weeks. The case study had two main objectives: (1) to study the impact that the discussion tasks undertaken in a virtual environment…

Focused Application Software for Ferrite Patch Antennas

DTIC Science & Technology

1999-10-01

Trott Mr. Rene D. Guidry Mr. Christopher G. Repesh 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Mission Research Corporation 147 John Sims...July 99 Contract Number: F49620-97-C-0022 SBIR Topic: AF96-003 MRC Project: 97054 Prepared by: Dr. Keith D. Trott , Mr. Rene D. Guidry, and Mr...application of recent innovations in the finite element (FE) method to the problem of modeling conformal antennas embedded in or on (substrate or

Extended Duration Orbiter Medical Project

NASA Technical Reports Server (NTRS)

Sawin, Charles F. (Editor); Taylor, Gerald R. (Editor); Smith, Wanda L. (Editor); Brown, J. Travis (Technical Monitor)

1999-01-01

Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

The eponymous Dr James Marion Sims MD, LLD (1813-1883).

PubMed

West, M J; Irvine, L M

2015-02-01

Dr James Marion Sims was born in 1813 in Lancaster County, South Carolina. It was while pioneering numerous surgical procedures in Alabama that in 1849 he achieved the outstanding landmark in medical history of successfully, and consistently, repairing vesicovaginal fistulae. Sims soon developed a reputation as a fine surgeon, with new operations and techniques, using novel surgical instruments and his innovative approaches frequently published. Moving to New York City in 1853, he further established hospitals devoted entirely to women's health. Sims was controversial, with flamboyant descriptions of self-confident success, yet they were tempered with sober reflection of failure and loss. Today we remain with the Sims speculum and Sims position, eponymous tributes to his accomplishments as the 'Father of Gynaecology'. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.