The development of in situ fracture toughness evaluation techniques in hydrogen environment

DOE PAGES

Wang, John Jy-An; Ren, Fei; Tan, Tin; ...

2014-12-19

Reliability of hydrogen pipelines and storage tanks is significantly influenced by the mechanical performance of the structural materials exposed in the hydrogen environment. Fracture behavior and fracture toughness are of specific interest since they are relevant to many catastrophic failures. However, many conventional fracture testing techniques are difficult to be realized under the presence of hydrogen. Thus it is desired to develop novel in situ techniques to study the fracture behavior of structural materials in hydrogen environments. In this study, special testing apparatus were designed to facilitate in situ fracture testing in H 2. A torsional fixture was developed tomore » utilize an emerging fracture testing technique, Spiral Notch Torsion Test (SNTT). The design concepts will be discussed. Preliminary in situ testing results indicated that the exposure to H 2 significantly reduces the fracture toughness of 4340 high strength steels by up to 50 percent. Furthermore, SNTT tests conducted in air demonstrated a significant fracture toughness reduction in samples subject to simulated welding heat treatment using Gleeble, which illustrated the effect of welding on the fracture toughness of this material.« less

In-situ determination of austenite and martensite formation in 13Cr6Ni2Mo supermartensitic stainless steel

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

Bojack, A., E-mail: a.bojack@tudelft.nl; Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD Delft; Zhao, L.

2012-09-15

In-situ analysis of the phase transformations in a 13Cr6Ni2Mo supermartensitic stainless steel (X2CrNiMoV13-5-2) was carried out using a thermo-magnetic technique, dilatometry and high temperature X-ray diffractometry (HT-XRD). A combination of the results obtained by the three applied techniques gives a valuable insight in the phase transformations during the austenitization treatment, including subsequent cooling, of the 13Cr6Ni2Mo supermartensitic stainless steel, where the magnetic technique offers a high accuracy in monitoring the austenite fraction. It was found by dilatometry that the austenite formation during heating takes place in two stages, most likely caused by partitioning of Ni into austenite. The in-situ evolutionmore » of the austenite fraction is monitored by high-temperature XRD and dilatometry. The progress of martensite formation during cooling was described with a Koistinen-Marburger relation for the results obtained from the magnetic and dilatometer experiments. Enhanced martensite formation at the sample surface was detected by X-ray diffraction, which is assumed to be due to relaxation of transformation stresses at the sample surface. Due to the high alloy content and high thermodynamic stability of austenite at room temperature, 4 vol.% of austenite was found to be stable at room temperature after the austenitization treatment. - Highlights: Black-Right-Pointing-Pointer We in-situ analyzed phase transformations and fractions of a 13Cr6Ni2Mo SMSS. Black-Right-Pointing-Pointer Higher accuracy of the austenite fraction was obtained from magnetic technique. Black-Right-Pointing-Pointer Austenite formation during heating takes place in two stages. Black-Right-Pointing-Pointer Enhanced martensite formation at the sample surface detected by X-ray diffraction.« less

The ID-KArD technique: In-situ dating on Mars

NASA Astrophysics Data System (ADS)

Cartwright, J. A.; Farley, K. A.; Hurowitz, J.; Asimow, P. D.; Jacobson, N. S.

2013-12-01

The ability to measure absolute ages on the Martian surface is crucial for understanding the planet's evolution. A detailed geological history of the Moon has been determined through analysis of returned samples from specific units, and relative ages calculated by crater counting techniques. However, without returned samples or in-situ dating analyses, we lack absolute age markers for Mars and thus cannot accurately or precisely date its well-documented surface. Instead, we have relied on an estimated Mars/Moon cratering ratio and relative crater counting techniques in an attempt to calculate surface ages and classify geological units. The use of such relative parameters diminishes the precision and accuracy for surface age calculations, and thus highlights the need for independent age determinations from returned samples or in-situ dating. In this research, we describe our technique - ID-KArD (Isotope Dilution K-Ar Dating) - intended for in-situ age dating of geological units on the Martian surface. ID-KArD resolves two challenges that have previously obstructed in-situ age dating on Mars: 1) High fusion temperatures are avoided with the use of a lithium-borate flux; 2) Sample mass measurement is not required, due to the addition of an isotope dilution doubly-spiked glass. The glass has a known 39Ar/41K ratio, which removes the need for concentration measurements. Thus, only isotope ratios are required for a K-Ar age determination. ID-KArD has the potential to address Mars chronology inaccuracies, and would be a suitable technique for consideration on future missions. In the first phase of ID-KArD proof of concept, we selected a Viluy trap basalt (K2O ~ 0.7 wt%), with concordant K-Ar and Ar-Ar ages of 354.3 × 3.5 and 357.7 × 1.4 Ma respectively (Courtillot et al., 2010). An aliquot was combined into a crucible with the flux and the spike glass for separate Ar (MAP 215:50, Caltech), followed by K (KEMS, GRC) isotopic analysis. Combining our results, we obtained an age of 351 × 19 Ma (Farley et al., 2013), in good agreement with the previously published ages. For the second phase, we have designed and built a single instrument, capable of analysing both Ar and K from a single sample. The instrument includes two ionisation sources for separate K (thermal) and Ar (electron impact) ionsiation, and a quadrupole mass spectrometer. In addition, we have designed a sample heating mechanism that allows degassing of flux prior to sample addition, and achieves temperatures in the range of the SAM oven on Curiosity. Thus far, the instrument has successfully measured both isotopic systems, and following further testing in the coming weeks, we will date Martian surface analogues, age standards, and finally meteoritic material.

Determination of lysine content based on an in situ pretreatment and headspace gas chromatographic measurement technique.

PubMed

Wan, Xiao-Fang; Liu, Bao-Lian; Yu, Teng; Yan, Ning; Chai, Xin-Sheng; Li, You-Ming; Chen, Guang-Xue

2018-05-01

This work reports on a simple method for the determination of lysine content by an in situ sample pretreatment and headspace gas chromatographic measurement (HS-GC) technique, based on carbon dioxide (CO 2 ) formation from the pretreatment reaction (between lysine and ninhydrin solution) in a closed vial. It was observed that complete lysine conversion to CO 2 could be achieved within 60 min at 60 °C in a phosphate buffer medium (pH = 4.0), with a minimum molar ratio of ninhydrin/lysine of 16. The results showed that the method had a good precision (RSD < 5.23%) and accuracy (within 6.80%), compared to the results measured by a reference method (ninhydrin spectroscopic method). Due to the feature of in situ sample pretreatment and headspace measurement, the present method becomes very simple and particularly suitable to be used for batch sample analysis in lysine-related research and applications. Graphical abstract The flow path of the reaction and HS-GC measurement for the lysine analysis.

Avoiding treatment bias of REDD+ monitoring by sampling with partial replacement

Treesearch

Michael Kohl; Charles T Scott; Andrew J Lister; Inez Demon; Daniel Plugge

2015-01-01

Implementing REDD+ renders the development of a measurement, reporting and verification (MRV) system necessary to monitor carbon stock changes. MRV systems generally apply a combination of remote sensing techniques and in-situ field assessments. In-situ assessments can be based on 1) permanent plots, which are assessed on all successive occasions, 2) temporary plots,...

In-situ X-ray diffraction system using sources and detectors at fixed angular positions

DOEpatents

Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

2007-06-26

An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

Continued Development of in Situ Geochronology for Planetary Using KArLE (Potassium-Argon Laser Experiment)

NASA Technical Reports Server (NTRS)

Devismes, D.; Cohen, B. A.

2016-01-01

Geochronology is a fundamental measurement for planetary samples, providing the ability to establish an absolute chronology for geological events, including crystallization history, magmatic evolution, and alteration events, and providing global and solar system context for such events. The capability for in situ geochronology will open up the ability for geochronology to be accomplished as part of lander or rover complement, on multiple samples rather than just those returned. An in situ geochronology package can also complement sample return missions by identifying the most interesting rocks to cache or return to Earth. The K-Ar radiometric dating approach to in situ dating has been validated by the Curiosity rover on Mars as well as several laboratories on Earth. Several independent projects developing in situ rock dating for planetary samples, based on the K-Ar method, are giving promising results. Among them, the Potassium (K)-Argon Laser Experiment (KArLE) at MSFC is based on techniques already in use for in planetary exploration, specifically, Laser-induced Breakdown Spectroscopy (LIBS, used on the Curiosity Chemcam), mass spectroscopy (used on multiple planetary missions, including Curiosity, ExoMars, and Rosetta), and optical imaging (used on most missions).

Development and Validation of a SPME-GC-MS Method for In situ Passive Sampling of Root Volatiles from Glasshouse-Grown Broccoli Plants Undergoing Below-Ground Herbivory by Larvae of Cabbage Root Fly, Delia radicum L.

PubMed

Deasy, William; Shepherd, Tom; Alexander, Colin J; Birch, A Nicholas E; Evans, K Andrew

2016-11-01

Research on plant root chemical ecology has benefited greatly from recent developments in analytical chemistry. Numerous reports document techniques for sampling root volatiles, although only a limited number describe in situ collection. To demonstrate a new method for non-invasive in situ passive sampling using solid phase micro extraction (SPME), from the immediate vicinity of growing roots. SPME fibres inserted into polyfluorotetrafluoroethylene (PTFE) sampling tubes located in situ which were either perforated, covered with stainless steel mesh or with microporous PTFE tubing, were used for non-invasive sub-surface sampling of root volatiles from glasshouse-grown broccoli. Sampling methods were compared with above surface headspace collection using Tenax TA. The roots were either mechanically damaged or infested with Delia radicum larvae. Principal component analysis (PCA) was used to investigate the effect of damage on the composition of volatiles released by broccoli roots. Analyses by gas chromatography-mass spectrometry (GC-MS) with SPME and automated thermal desorption (ATD) confirmed that sulphur compounds, showing characteristic temporal emission patterns, were the principal volatiles released by roots following insect larval damage. Use of SPME with in situ perforated PTFE sampling tubes was the most robust method for out-of-lab sampling. This study describes a new method for non-invasive passive sampling of volatiles in situ from intact and insect damaged roots using SPME. The method is highly suitable for remote sampling and has potential for wide application in chemical ecology/root/soil research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

In Situ Noble-Gas Based Chronology on Mars

NASA Technical Reports Server (NTRS)

Swindle, T. D.

2000-01-01

Determining radiometric ages in situ on another planet's surface has never been done, and there are good reasons to think that it will be extremely difficult. It is certainly hard to imagine that such ages could be measured as precisely as they could be measured on returned samples in state-of-the-art terrestrial laboratories. However, it may be possible, by using simple noble-gas-based chronology techniques, to determine ages on Mars to a precision that is scientifically useful. This abstract will: (1) describe the techniques we envision; (2) give some examples of how such information might be scientifically useful; and (3) describe the system we are developing, including the requirements in terms of mass, power, volume, and sample selection and preparation.

Toward in situ x-ray diffraction imaging at the nanometer scale

NASA Astrophysics Data System (ADS)

Zatsepin, Nadia A.; Dilanian, Ruben A.; Nikulin, Andrei Y.; Gable, Brian M.; Muddle, Barry C.; Sakata, Osami

2008-08-01

We present the results of preliminary investigations determining the sensitivity and applicability of a novel x-ray diffraction based nanoscale imaging technique, including simulations and experiments. The ultimate aim of this nascent technique is non-destructive, bulk-material characterization on the nanometer scale, involving three dimensional image reconstructions of embedded nanoparticles and in situ sample characterization. The approach is insensitive to x-ray coherence, making it applicable to synchrotron and laboratory hard x-ray sources, opening the possibility of unprecedented nanometer resolution with the latter. The technique is being developed with a focus on analyzing a technologically important light metal alloy, Al-xCu (where x is 2.0-5.0 %wt). The mono- and polycrystalline samples contain crystallographically oriented, weakly diffracting Al2Cu nanoprecipitates in a sparse, spatially random dispersion within the Al matrix. By employing a triple-axis diffractometer in the non-dispersive setup we collected two-dimensional reciprocal space maps of synchrotron x-rays diffracted from the Al2Cu nanoparticles. The intensity profiles of the diffraction peaks confirmed the sensitivity of the technique to the presence and orientation of the nanoparticles. This is a fundamental step towards in situ observation of such extremely sparse, weakly diffracting nanoprecipitates embedded in light metal alloys at early stages of their growth.

Transfer-arm evaporator cell for rapid loading and deposition of organic thin films.

PubMed

Greiner, M T; Helander, M G; Wang, Z B; Lu, Z H

2009-12-01

Described herein is a transfer-arm evaporator cell (TAE-cell), which allows for rapid loading of materials into vacuum for low-temperature sublimation deposition of thin films. This design can be incorporated with an existing analysis system for convenient in situ thin film characterization. This evaporator is especially well suited for photoemission characterization of organic semiconductor interfaces. Photoemission is one of the most important techniques for characterizing such, however, it generally requires in situ sample preparation. The ease with which materials can be loaded and evaporated with this design increases the throughput of in situ photoemission characterization, and broadens the research scope of the technique. Here, we describe the design, operation, and performance of the TAE-cell.

Using Laser Ultrasound to Detect Subsurface Defects in Metal Laser Powder Bed Fusion Components

NASA Astrophysics Data System (ADS)

Everton, Sarah; Dickens, Phill; Tuck, Chris; Dutton, Ben

2018-03-01

Laser powder bed fusion offers many advantages over conventional manufacturing methods, such as the integration of multiple parts that can result in significant weight-savings. The increased design freedom that layer-wise manufacture allows has also been seen to enhance component performance at little or no added cost. For such benefits to be realized, however, the material quality must first be assured. Laser ultrasonic testing is a noncontact inspection technique that has been proposed as suitable for in situ monitoring of metal additive manufacturing processes. This article explores the current capability of this technique to detect manufactured, subsurface defects in Ti-6Al-4V samples, ex situ. The results are compared with x-ray computed tomography reconstructions and focus variation microscopy. Although laser ultrasound has been used to identify material discontinuities, further work is required before this technique could be implemented in situ.

Scanning force microscope for in situ nanofocused X-ray diffraction studies

PubMed Central

Ren, Zhe; Mastropietro, Francesca; Davydok, Anton; Langlais, Simon; Richard, Marie-Ingrid; Furter, Jean-Jacques; Thomas, Olivier; Dupraz, Maxime; Verdier, Marc; Beutier, Guillaume; Boesecke, Peter; Cornelius, Thomas W.

2014-01-01

A compact scanning force microscope has been developed for in situ combination with nanofocused X-ray diffraction techniques at third-generation synchrotron beamlines. Its capabilities are demonstrated on Au nano-islands grown on a sapphire substrate. The new in situ device allows for in situ imaging the sample topography and the crystallinity by recording simultaneously an atomic force microscope (AFM) image and a scanning X-ray diffraction map of the same area. Moreover, a selected Au island can be mechanically deformed using the AFM tip while monitoring the deformation of the atomic lattice by nanofocused X-ray diffraction. This in situ approach gives access to the mechanical behavior of nanomaterials. PMID:25178002

Identifying and managing radiation damage during in situ transmission x-ray microscopy of Li-ion batteries

NASA Astrophysics Data System (ADS)

Nelson, Johanna; Yang, Yuan; Misra, Sumohan; Andrews, Joy C.; Cui, Yi; Toney, Michael F.

2013-09-01

Radiation damage is a topic typically sidestepped in formal discussions of characterization techniques utilizing ionizing radiation. Nevertheless, such damage is critical to consider when planning and performing experiments requiring large radiation doses or radiation sensitive samples. High resolution, in situ transmission X-ray microscopy of Li-ion batteries involves both large X-ray doses and radiation sensitive samples. To successfully identify changes over time solely due to an applied current, the effects of radiation damage must be identified and avoided. Although radiation damage is often significantly sample and instrument dependent, the general procedure to identify and minimize damage is transferable. Here we outline our method of determining and managing the radiation damage observed in lithium sulfur batteries during in situ X-ray imaging on the transmission X-ray microscope at Stanford Synchrotron Radiation Lightsource.

In situ synthesis, characterization, and catalytic performance of tungstophosphoric acid encapsulated into the framework of mesoporous silica pillared clay.

PubMed

Li, Baoshan; Liu, Zhenxing; Han, Chunying; Ma, Wei; Zhao, Songjie

2012-07-01

Mesoporous silica pillared clay (SPC) incorporated with tungstophosphoric acid (HPW) has been synthesized via in situ introducing P and W source in the acidic suspension of the clay interlayer template during the formation of the silica pillared clay. The samples were characterized by XRD, XRF, FT-IR, TG-DTA, N(2) adsorption-desorption, and SEM techniques. The results showed that the HPW formed by in situ method has been effectively introduced into the framework of mesoporous silica pillared clay and its Keggin structure remained perfectly after formation of the materials. In addition, samples with similar HPW loadings were also prepared by impregnation method using SPC as the support. HPW in the incorporated samples was better dispersed into the silica pillared clay than in the impregnated samples. The results of catalytic tests indicated that the encapsulated materials demonstrated better catalytic performance than the impregnated samples in oxidative desulfurization (ODS) of dibenzothiophene (DBT). Copyright © 2012 Elsevier Inc. All rights reserved.

Ambient ionisation mass spectrometry for in situ analysis of intact proteins

PubMed Central

Kocurek, Klaudia I.; Griffiths, Rian L.

2018-01-01

Abstract Ambient surface mass spectrometry is an emerging field which shows great promise for the analysis of biomolecules directly from their biological substrate. In this article, we describe ambient ionisation mass spectrometry techniques for the in situ analysis of intact proteins. As a broad approach, the analysis of intact proteins offers unique advantages for the determination of primary sequence variations and posttranslational modifications, as well as interrogation of tertiary and quaternary structure and protein‐protein/ligand interactions. In situ analysis of intact proteins offers the potential to couple these advantages with information relating to their biological environment, for example, their spatial distributions within healthy and diseased tissues. Here, we describe the techniques most commonly applied to in situ protein analysis (liquid extraction surface analysis, continuous flow liquid microjunction surface sampling, nano desorption electrospray ionisation, and desorption electrospray ionisation), their advantages, and limitations and describe their applications to date. We also discuss the incorporation of ion mobility spectrometry techniques (high field asymmetric waveform ion mobility spectrometry and travelling wave ion mobility spectrometry) into ambient workflows. Finally, future directions for the field are discussed. PMID:29607564

“Metallic burn paper” used for in situ characterization of laser beam properties

DOE PAGES

Bass, Isaac L.; Negres, Raluca A.; Stanion, Ken; ...

2016-04-12

In situ ablation of thin metal films on fused silica substrates by picosecond class lasers was investigated in this paper as a method of characterizing the beam at the sample plane. The technique involved plotting the areas enclosed by constant fluence contours identified in optical microscope images of the ablation sites versus the logs of the pulse energies. Inconel films on commercially available neutral density filters as well as magnetron sputtered gold films were used. It was also shown that this technique could be used to calibrate real-time beam profile diagnostics against the beam at the sample plane. Finally, themore » contours were shown to correspond to the boundary where part or all of the film was ablated.« less

Variation of surface water spectral response as a function of in situ sampling technique

NASA Technical Reports Server (NTRS)

Davis, Bruce A.; Hodgson, Michael E.

1988-01-01

Tests were carried out to determine the spectral variation contributed by a particular sampling technique. A portable radiometer was used to measure the surface water spectral response. Variation due to the reflectance of objects near the radiometer (i.e., the boat side) during data acquisition was studied. Consideration was also given to the variation due to the temporal nature of the phenomena (i.e., wave activity).

Analytical Protocols for Analysis of Organic Molecules in Mars Analog Materials

NASA Technical Reports Server (NTRS)

Mahaffy, Paul R.; Brinkerhoff, W.; Buch, A.; Demick, J.; Glavin, D. P.

2004-01-01

A range of analytical techniques and protocols that might be applied b in situ investigations of martian fines, ices, and rock samples are evaluated by analysis of organic molecules m Mars analogues. These simulants 6om terrestrial (i.e. tephra from Hawaii) or extraterrestrial (meteoritic) samples are examined by pyrolysis gas chromatograph mass spectrometry (GCMS), organic extraction followed by chemical derivatization GCMS, and laser desorption mass spectrometry (LDMS). The combination of techniques imparts analysis breadth since each technique provides a unique analysis capability for Certain classes of organic molecules.

Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials.

PubMed

Jiang, Chenchen; Lu, Haojian; Zhang, Hongti; Shen, Yajing; Lu, Yang

2017-01-01

In the past decades, in situ scanning electron microscopy (SEM) has become a powerful technique for the experimental study of low-dimensional (1D/2D) nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications.

Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials

PubMed Central

Jiang, Chenchen; Lu, Haojian; Zhang, Hongti

2017-01-01

In the past decades, in situ scanning electron microscopy (SEM) has become a powerful technique for the experimental study of low-dimensional (1D/2D) nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications. PMID:29209445

Variable Temperature Nuclear Magnetic Resonance and Magnetic Resonance Imaging System as a Novel Technique for In Situ Monitoring of Food Phase Transition.

PubMed

Song, Yukun; Cheng, Shasha; Wang, Huihui; Zhu, Bei-Wei; Zhou, Dayong; Yang, Peiqiang; Tan, Mingqian

2018-01-24

A nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) system with a 45 mm variable temperature (VT) sample probe (VT-NMR-MRI) was developed as an innovative technique for in situ monitoring of food phase transition. The system was designed to allow for dual deployment in either a freezing (-37 °C) or high temperature (150 °C) environment. The major breakthrough of the developed VT-NMR-MRI system is that it is able to measure the water states simultaneously in situ during food processing. The performance of the VT-NMR-MRI system was evaluated by measuring the phase transition for salmon flesh and hen egg samples. The NMR relaxometry results demonstrated that the freezing point of salmon flesh was -8.08 °C, and the salmon flesh denaturation temperature was 42.16 °C. The protein denaturation of egg was 70.61 °C, and the protein denaturation occurred at 24.12 min. Meanwhile, the use of MRI in phase transition of food was also investigated to gain internal structural information. All these results showed that the VT-NMR-MRI system provided an effective means for in situ monitoring of phase transition in food processing.

In-Situ Real-Time Focus Detection during Laser Processing Using Double-Hole Masks and Advanced Image Sensor Software

PubMed Central

Hoang, Phuong Le; Ahn, Sanghoon; Kim, Jeng-o; Kang, Heeshin; Noh, Jiwhan

2017-01-01

In modern high-intensity ultrafast laser processing, detecting the focal position of the working laser beam, at which the intensity is the highest and the beam diameter is the lowest, and immediately locating the target sample at that point are challenging tasks. A system that allows in-situ real-time focus determination and fabrication using a high-power laser has been in high demand among both engineers and scientists. Conventional techniques require the complicated mathematical theory of wave optics, employing interference as well as diffraction phenomena to detect the focal position; however, these methods are ineffective and expensive for industrial application. Moreover, these techniques could not perform detection and fabrication simultaneously. In this paper, we propose an optical design capable of detecting the focal point and fabricating complex patterns on a planar sample surface simultaneously. In-situ real-time focus detection is performed using a bandpass filter, which only allows for the detection of laser transmission. The technique enables rapid, non-destructive, and precise detection of the focal point. Furthermore, it is sufficiently simple for application in both science and industry for mass production, and it is expected to contribute to the next generation of laser equipment, which can be used to fabricate micro-patterns with high complexity. PMID:28671566

Dereplicating and Spatial Mapping of Secondary Metabolites from Fungal Cultures in Situ.

PubMed

Sica, Vincent P; Raja, Huzefa A; El-Elimat, Tamam; Kertesz, Vilmos; Van Berkel, Gary J; Pearce, Cedric J; Oberlies, Nicholas H

2015-08-28

Ambient ionization mass spectrometry techniques have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. These techniques retain invaluable spatial and temporal details that are lost through traditional extraction processes. However, most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/vis spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet-liquid microjunction-surface sampling probe (droplet-LMJ-SSP) was coupled with UPLC-PDA-HRMS-MS/MS, thus providing separation, retention times, MS data, and UV/vis data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites can be confidently and rapidly assigned in situ. Using the droplet-LMJ-SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. Furthermore, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture.

Learning About Dirt

ERIC Educational Resources Information Center

Atyeo, Marilyn J.

1972-01-01

Describes techniques for introducing studies of the soil in the early primary grades or in preschool classes. Includes suggestions for observation of soil samples, field trips to examine various soils in situ, and establishing a small garden. (AL)

Neutron Bragg-edge-imaging for strain mapping under in situ tensile loading

NASA Astrophysics Data System (ADS)

Woracek, R.; Penumadu, D.; Kardjilov, N.; Hilger, A.; Strobl, M.; Wimpory, R. C.; Manke, I.; Banhart, J.

2011-05-01

Wavelength selective neutron radiography at a cold neutron reactor source was used to measure strain and determine (residual) stresses in a steel sample under plane stress conditions. We present a new technique that uses an energy-resolved neutron imaging system based on a double crystal monochromator and is equipped with a specially developed (in situ) biaxial load frame to perform Bragg edge based transmission imaging. The neutron imaging technique provides a viewing area of 7 cm by 7 cm with a spatial resolution on the order of ˜ 100 μm. The stress-induced shifts of the Bragg edge corresponding to the (110) lattice plane were resolved spatially for a ferritic steel alloy A36 (ASTM international) sample. Furthermore it is demonstrated that results agree with comparative data obtained using neutron diffraction and resistance based strain-gauge rosettes.

In situ measurement of the rheological properties and agglomeration on cementitious pastes

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

Kim, Jae Hong; Yim, Hong Jae, E-mail: yimhj@knu.ac.kr; Ferron, Raissa Douglas

2016-07-15

Various factors influence the rheology of cementitious pastes, with the most important being the mixing protocol, mixture proportions, and mixture composition. This study investigated the influence of ground-granulated blast-furnace slag, on the rheological behavior of cementitious pastes. In tandem with the rheological measurements, fresh state microstructural measurements were conducted using three different techniques: A coupled stroboscope-rheometer, a coupled laser backscattering-rheometer, and a conventional laser diffraction technique. Laser diffraction and the coupled stroboscope-rheometer were not good measures of the in situ state of flocculation of a sample. Rather, only the laser backscattering technique allowed for in situ measurement on a highlymore » concentrated suspension (cementitious paste). Using the coupled laser backscattering-rheometer technique, a link between the particle system and rheological behavior was determined through a modeling approach that takes into account agglomeration properties. A higher degree of agglomeration was seen in the ordinary Portland cement paste than pastes containing the slag and this was related to the degree of capillary pressure in the paste systems.« less

In situ detrital zircon (U-Th)/He thermochronology

NASA Astrophysics Data System (ADS)

Tripathy, A.; Monteleone, B. D.; van Soest, M. C.; Hodges, K.; Hourigan, J. K.

2010-12-01

Detrital studies of both sand and rock are relevant to many problems, ranging from the climate and tectonics feedback debate to the long-term record of orogenic evolution. When applying the conventional (U-Th)/He technique to such studies, two important issues arise. Often, only euhedral grains are permissible for analysis in order to make simple geometric corrections for α-recoil. In detrital samples, this is problematic because euhedral grains can be scarce due to mechanical abrasion during transport, and potentially introduce bias in favour of more proximally sourced grains. Second, inherent to detrital studies is the need to date many grains (>100) per sample to ensure a representative sampling of the sediment source region, thus making robust conventional detrital studies both expensive and time-consuming. UV laser microprobes can improve this by permitting careful targeting of the grain interior away from the α-ejection zone, rendering the α-recoil correction unnecessary, thus eliminating bias toward euhedral grains. In the Noble Gas, Geochemistry, and Geochronology Laboratory at ASU, apatite and zircon have been successfully dated using in situ methods. For this study, the conventional and in situ techniques are compared by dating zircons from a modern river sand that drains a small catchment in the Mesozoic-Cenozoic Ladakh Batholith in NW India. This sample has a simple provenance, which allows us to demonstrate the robustness of the in situ method. Moreover, different microbeam techniques will be explored to establish the most efficient approach to obtain accurate and precise U-Th concentrations using synrock, which is our powdered, homogenized, and reconstituted zircon-rock standard. Without this, such in situ U-Th data would be difficult to obtain. 117 zircons were dated using the conventional (U-Th)/He method, revealing dates ranging from 9.70±0.35 to 106.6±3.5 Ma (2σ) with the major mode at 26 Ma. For comparison, 44 grains were dated using the in situ method, utilizing SIMS to determine the U-Th concentrations. The major mode is the same as the conventional dataset, with only single outliers missing from the in situ dataset. The in situ method is described as follows: Zircons are polished and imaged using cathodoluminesence to guide laser spot placement. Then, each grain is ablated with a 193nm ArF Excimer laser using 20-35µm beam sizes and depths of 10-17µm. After purification, 4He is analyzed on a ThermoScientific Helix Split Flight Tube mass spectrometer. U-Th concentrations are measured on the polished mount using a Cameca IMS 6f by placing a 60µm diameter beam directly over the He laser pit to cover the surface area contributing to the measured He. In theory, using LA-ICP-MS to obtain U-Th concentrations could be a faster, cheaper, but possibly less precise, technique. However, using laser ablation would allow pit sizes that average the U-Th concentration over the volume of material available that contributes to the measured He, thus accounting for intracrystalline α-recoil effects. Preliminary data on slabs of Sri Lankan zircon suggest this could be a viable method, but will require further exploration and refinement.

In situ hybridization of hepatitis C virus RNA in liver cells of an experimentally infected rhesus macaque.

PubMed

Majerowicz, Selma; Grief, Christopher; Ferguson, Debora; Airano, Renata C; Baptista, Marcia L; Pinto, Marcelo A; Barth, Ortrud Monika

2004-10-01

The liver tissue of a rhesus macaque inoculated with hepatitis C virus (HCV) has been analyzed for the presence of HCV RNA using the technique of in situ hybridization, both at light and electron microscopy levels. The animal was inoculated by the intrasplenic route using a HCV infected autogenic hepatocyte transplant. The serum sample used to infect the hepatocyte cells was characterized by polymerase chain reaction technique and shown to be positive for HCV RNA, genotype 3 with 10(7) RNA copies/ml. In situ hybridization was performed using a complementary negative strand probe made with the specific primer. We were able to detect and localize viral RNA in altered membranes of the rough endoplasmic reticulum of infected liver cells, showing evidence of virus replication in vivo.

Compact low temperature scanning tunneling microscope with in-situ sample preparation capability

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

Kim, Jungdae; Department of Physics and EHSRC, University of Ulsan, Ulsan 680-749; Nam, Hyoungdo

2015-09-15

We report on the design of a compact low temperature scanning tunneling microscope (STM) having in-situ sample preparation capability. The in-situ sample preparation chamber was designed to be compact allowing quick transfer of samples to the STM stage, which is ideal for preparing temperature sensitive samples such as ultra-thin metal films on semiconductor substrates. Conventional spring suspensions on the STM head often cause mechanical issues. To address this problem, we developed a simple vibration damper consisting of welded metal bellows and rubber pads. In addition, we developed a novel technique to ensure an ultra-high-vacuum (UHV) seal between the copper andmore » stainless steel, which provides excellent reliability for cryostats operating in UHV. The performance of the STM was tested from 2 K to 77 K by using epitaxial thin Pb films on Si. Very high mechanical stability was achieved with clear atomic resolution even when using cryostats operating at 77 K. At 2 K, a clean superconducting gap was observed, and the spectrum was easily fit using the BCS density of states with negligible broadening.« less

Compact low temperature scanning tunneling microscope with in-situ sample preparation capability.

PubMed

Kim, Jungdae; Nam, Hyoungdo; Qin, Shengyong; Kim, Sang-ui; Schroeder, Allan; Eom, Daejin; Shih, Chih-Kang

2015-09-01

We report on the design of a compact low temperature scanning tunneling microscope (STM) having in-situ sample preparation capability. The in-situ sample preparation chamber was designed to be compact allowing quick transfer of samples to the STM stage, which is ideal for preparing temperature sensitive samples such as ultra-thin metal films on semiconductor substrates. Conventional spring suspensions on the STM head often cause mechanical issues. To address this problem, we developed a simple vibration damper consisting of welded metal bellows and rubber pads. In addition, we developed a novel technique to ensure an ultra-high-vacuum (UHV) seal between the copper and stainless steel, which provides excellent reliability for cryostats operating in UHV. The performance of the STM was tested from 2 K to 77 K by using epitaxial thin Pb films on Si. Very high mechanical stability was achieved with clear atomic resolution even when using cryostats operating at 77 K. At 2 K, a clean superconducting gap was observed, and the spectrum was easily fit using the BCS density of states with negligible broadening.

Intestinal absorption of dideoxynucleosides: characterization using a multiloop in situ technique.

PubMed

Mirchandani, H L; Chien, Y W

1995-01-01

The intestinal absorption of dideoxynucleosides was studied in rabbits, using a closed-loop mesenteric-sampling in situ technique developed in this laboratory, and the kinetic profiles were characterized. Each of the dideoxynucleosides exhibited different dependence on the intestinal regions studied: 3'-azido-2',3'-dideoxythymidine was best absorbed from the ileum, while 2',3'-dideoxyinosine and 2',3'-dideoxycytidine were preferentially absorbed from the jejunum. The results were validated by the mass-balance approach; the percent of drug retained in the intestinal lumen and that degraded at the intestinal pH, by colonic flora, in the intestinal tissue, and in plasma were assessed.

In situ calibration of the foil detector for an infrared imaging video bolometer using a carbon evaporation technique

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

Mukai, K., E-mail: mukai.kiyofumi@LHD.nifs.ac.jp; Peterson, B. J.; SOKENDAI

The InfraRed imaging Video Bolometer (IRVB) is a useful diagnostic for the multi-dimensional measurement of plasma radiation profiles. For the application of IRVB measurement to the neutron environment in fusion plasma devices such as the Large Helical Device (LHD), in situ calibration of the thermal characteristics of the foil detector is required. Laser irradiation tests of sample foils show that the reproducibility and uniformity of the carbon coating for the foil were improved using a vacuum evaporation method. Also, the principle of the in situ calibration system was justified.

Simultaneous in situ Optical Monitoring Techniques during Crystal Growth of ZnSe by Physical Vapor Transport

NASA Technical Reports Server (NTRS)

Su, C.- H.; Feth, S.; Lehoczky, S. L.

1998-01-01

ZnSe crystals grown in sealed ampoules by the physical vapor transport method were monitored in situ using three techniques, simultaneously. A Michelson interferometer was set-up to observe the growth rate and surface morphological evolution. An interference pattern (interferogram) is formed by the interaction between the reflection of a HeNe laser (632.8 nm wavelength) off the crystal-vapor interface and a reference beam from the same laser. Preliminary results indicate that the rate of growth/thermal-etching can be calculated using analog data acquisition and simple fringe counting techniques. Gross surface features may also be observed using a digital frame grabber and fringe analysis software. The second in situ technique uses optical absorption to determine the partial pressures of the vapor species. The Se2 and Zn vapor species present in the sealed ampoule absorb light at characteristic wavelengths. The optical absorption is determined by monitoring the light intensity difference between the sample and reference beams. The Se2 Partial pressure profile along the length of the ampoule was estimated from the vibronic absorption peaks at 340.5, 350.8, 361.3 and 379.2 nm using the Beer's law constants established in the calibration runs of pure Se. Finally, because the high temperature crystal growth furnace contains windows, in situ visual observation of the growing crystal is also possible. The use of these techniques not only permits in situ investigation of high temperature vapor growth of semiconductors, but also offers the potential for real time feed back on the growing crystal and allows the possibility of actively controlling the growth process.

Detection of distribution of avian influenza H5N1 virus by immunohistochemistry, chromogenic in situ hybridization and real-time PCR techniques in experimentally infected chickens.

PubMed

Chamnanpood, Chanpen; Sanguansermsri, Donruedee; Pongcharoen, Sutatip; Sanguansermsri, Phanchana

2011-03-01

Ten specific pathogen free (SPF) chickens were inoculated intranasally with avian influenza virus subtype H5N1. Evaluation revealed distribution of the virus in twelve organs: liver, intestine, bursa, lung, trachea, thymus, heart, pancreas, brain, spleen, kidney, and esophagus. Immunohistochemistry (IHC), chromogenic in situ hybridization (CISH), and real-time polymerase chain reaction (PCR) were developed and compared for detection of the virus from the organs. The distribution of avian influenza H5N1 in chickens varied by animal and detecting technique. The heart, kidneys, intestines, lungs, and pancreas were positive with all three techniques, while the others varied by techique. The three techniques can be used to detect avian influenza effectively, but the pros and cons of each technique need to be determined. The decision of which technique to use depends on the objective of the examination, budget, type and quality of samples, laboratory facilities and technician skills.

Micro-balance sensor integrated with atomic layer deposition chamber

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

Martinson, Alex B. F.; Libera, Joseph A.; Elam, Jeffrey W.

The invention is directed to QCM measurements in monitoring ALD processes. Previously, significant barriers remain in the ALD processes and accurate execution. To turn this exclusively dedicated in situ technique into a routine characterization method, an integral QCM fixture was developed. This new design is easily implemented on a variety of ALD tools, allows rapid sample exchange, prevents backside deposition, and minimizes both the footprint and flow disturbance. Unlike previous QCM designs, the fast thermal equilibration enables tasks such as temperature-dependent studies and ex situ sample exchange, further highlighting the feasibility of this QCM design for day-to-day use. Finally, themore » in situ mapping of thin film growth rates across the ALD reactor was demonstrated in a popular commercial tool operating in both continuous and quasi-static ALD modes.« less

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

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

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site`s microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog {reg_sign} evaluation of enzyme activity in collected water samples.more » Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog{reg_sign} activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.« less

In situ calibration of a high-resolution gamma-ray borehole sonde for assaying uranium-bearing sandstone deposits

USGS Publications Warehouse

Day, J.H.

1985-01-01

A method is presented for assaying radioactive sandstone deposits in situ by using a high-resolution borehole gamma-ray spectrometer. Gamma-ray photopeaks from the same spectrum acquired to analyze a sample are used to characterize gamma-ray attenuation properties, from which a calibration function is determined. Assay results are independent of differences between properties of field samples and those of laboratory or test-hole standards generally used to calibrate a borehole sonde. This assaying technique is also independent of the state of radioactive disequilibrium that usually exists in nature among members of the natural-decay chains. ?? 1985.

In situ synchrotron investigation of grain growth behavior of nano-grained UO 2

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

Miao, Yinbin; Yao, Tiankai; Lian, Jie

Here, we report on the study of grain growth kinetics in nano-grained UO 2 samples. Dense nano-grained UO 2 samples with well-controlled stoichiometry and grain size were fabricated using the spark plasma sintering technique. To determine the grain growth kinetics at elevated temperatures, a synchrotron wide-angle X-ray scattering (WAXS) study was performed in situ to measure the real-time grain size evolution based on the modified Williamson-Hall analysis. The unique grain growth kinetics of nanocrystalline UO 2 at 730 °C and 820 °C were observed and explained by the difference in mobility of various grain boundaries.

In situ synchrotron investigation of grain growth behavior of nano-grained UO 2

DOE PAGES

Miao, Yinbin; Yao, Tiankai; Lian, Jie; ...

2017-01-09

Here, we report on the study of grain growth kinetics in nano-grained UO 2 samples. Dense nano-grained UO 2 samples with well-controlled stoichiometry and grain size were fabricated using the spark plasma sintering technique. To determine the grain growth kinetics at elevated temperatures, a synchrotron wide-angle X-ray scattering (WAXS) study was performed in situ to measure the real-time grain size evolution based on the modified Williamson-Hall analysis. The unique grain growth kinetics of nanocrystalline UO 2 at 730 °C and 820 °C were observed and explained by the difference in mobility of various grain boundaries.

Methods for collection and analysis of water samples

USGS Publications Warehouse

Rainwater, Frank Hays; Thatcher, Leland Lincoln

1960-01-01

This manual contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water samples. Throughout, the emphasis is on obtaining analytical results that accurately describe the chemical composition of the water in situ. Among the topics discussed are selection of sampling sites, frequency of sampling, field equipment, preservatives and fixatives, analytical techniques of water analysis, and instruments. Seventy-seven laboratory and field procedures are given for determining fifty-three water properties.

The Characterization of Biosignatures in Caves Using an Instrument Suite

NASA Astrophysics Data System (ADS)

Uckert, Kyle; Chanover, Nancy J.; Getty, Stephanie; Voelz, David G.; Brinckerhoff, William B.; McMillan, Nancy; Xiao, Xifeng; Boston, Penelope J.; Li, Xiang; McAdam, Amy; Glenar, David A.; Chavez, Arriana

2017-12-01

The search for life and habitable environments on other Solar System bodies is a major motivator for planetary exploration. Due to the difficulty and significance of detecting extant or extinct extraterrestrial life in situ, several independent measurements from multiple instrument techniques will bolster the community's confidence in making any such claim. We demonstrate the detection of subsurface biosignatures using a suite of instrument techniques including IR reflectance spectroscopy, laser-induced breakdown spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy. We focus our measurements on subterranean calcium carbonate field samples, whose biosignatures are analogous to those that might be expected on some high-interest astrobiology targets. In this work, we discuss the feasibility and advantages of using each of the aforementioned instrument techniques for the in situ search for biosignatures and present results on the autonomous characterization of biosignatures using multivariate statistical analysis techniques.

The Characterization of Biosignatures in Caves Using an Instrument Suite.

PubMed

Uckert, Kyle; Chanover, Nancy J; Getty, Stephanie; Voelz, David G; Brinckerhoff, William B; McMillan, Nancy; Xiao, Xifeng; Boston, Penelope J; Li, Xiang; McAdam, Amy; Glenar, David A; Chavez, Arriana

2017-12-01

The search for life and habitable environments on other Solar System bodies is a major motivator for planetary exploration. Due to the difficulty and significance of detecting extant or extinct extraterrestrial life in situ, several independent measurements from multiple instrument techniques will bolster the community's confidence in making any such claim. We demonstrate the detection of subsurface biosignatures using a suite of instrument techniques including IR reflectance spectroscopy, laser-induced breakdown spectroscopy, and scanning electron microscopy/energy dispersive X-ray spectroscopy. We focus our measurements on subterranean calcium carbonate field samples, whose biosignatures are analogous to those that might be expected on some high-interest astrobiology targets. In this work, we discuss the feasibility and advantages of using each of the aforementioned instrument techniques for the in situ search for biosignatures and present results on the autonomous characterization of biosignatures using multivariate statistical analysis techniques. Key Words: Biosignature suites-Caves-Mars-Life detection. Astrobiology 17, 1203-1218.

Feasibility of in situ controlled heat treatment (ISHT) of Inconel 718 during electron beam melting additive manufacturing

DOE PAGES

Sames, William J.; Unocic, Kinga A.; Helmreich, Grant W.; ...

2016-10-07

A novel technique was developed to control the microstructure evolution in Alloy 718 processed using Electron Beam Melting (EBM). In situ solution treatment and aging of Alloy 718 was performed by heating the top surface of the build after build completion scanning an electron beam to act as a planar heat source during the cool down process. Results demonstrate that the measured hardness (478 ± 7 HV) of the material processed using in situ heat treatment similar to that of peak-aged Inconel 718. Large solidification grains and cracks formed, which are identified as the likely mechanism leading to failure ofmore » tensile tests of the in situ heat treatment material under loading. Despite poor tensile performance, the technique proposed was shown to successively age Alloy 718 (increase precipitate size and hardness) without removing the sample from the process chamber, which can reduce the number of process steps in producing a part. Lastly, tighter controls on processing temperature during layer melting to lower process temperature and selective heating during in situ heat treatment to reduce over-sintering are proposed as methods for improving the process.« less

In Situ Miniaturised Solid Phase Extraction (m-SPE) for Organic Pollutants in Seawater Samples

PubMed Central

Abaroa-Pérez, B.; Sánchez-Almeida, G.; Hernández-Brito, J. J.

2018-01-01

Solid phase extraction (SPE) is a consolidated technique for determining pollutants in seawater samples. The current tendency is to miniaturise systems that extract and determine pollutants in the environment, reducing the use of organic solvents, while maintaining the quality in the extraction and preconcentration. On the other hand, there is a need to develop new extraction systems that can be fitted to in situ continual monitoring buoys, especially for the marine environment. This work has developed a first model of a low-pressure micro-SPE (m-SPE) for persistent organic pollutants (POPs) that can be simply applied to in situ monitoring in the marine environment. This system reduces the volumes of sample and solvents required in the laboratory in comparison with conventional SPE. In the future, it could be used in automated or robotic systems in marine technologies such as marine gliders and oceanographic buoys. This system has been optimised and validated to determine polycyclic aromatic hydrocarbons (PAH) in seawater samples, but it could also be applied to other kinds of persistent organic pollutants (POPs) and emerging pollutants. PMID:29805837

Continued Development of In Situ Geochronology for Planetary Missions Using KArLE (Potassium-Argon-Laser Experiment)

NASA Technical Reports Server (NTRS)

Devismes, Damien; Cohen, Barbara

2016-01-01

Since these techniques are very new and as they have never been used or this purpose. they will need to be replicated by several independent studies. These techniques may be very important if the optical imaging encounters difficulties, for example, if a sample is made of very dark or monochromatic material and in the case of very deep pits (>500 microns) Based on the preliminary results, the LIBS continuum technique is more appropriate to the large pits produced by long ablations The relationship may work best homogeneous samples, but the continuum is collected with every LIBS analysis so does not require any addition to the experimental suite of techniques. The integration of a QCMB in the ablation chamber may be a very interesting solution to determine the ablated mass. Even if it only measures a fraction of the total mass, its sensitivity should be able to weigh hundreds of nanograms accumulated on the crystal during ablation and relate it to the actual ablated mass. In the future. these options may help in situ K-Ar dating to give the age of the rock with the best accuracy and precision.

In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

DOE PAGES

Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; ...

2015-04-16

Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronalmore » annealing between 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO 2 and ThO 2, respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO 2 and ThO 2.« less

Size really does matter: effects of filter fractionation on microbial community structure in a model oxygen minimum zone.

NASA Astrophysics Data System (ADS)

Torres Beltran, M.

2016-02-01

The Scientific Committee on Oceanographic Research (SCOR) Working Group 144 "Microbial Community Responses to Ocean Deoxygenation" workshop held in Vancouver, British Columbia in July 2014 had the primary objective of kick-starting the establishment of a minimal core of technologies, techniques and standard operating procedures (SOPs) to enable compatible process rate and multi-molecular data (DNA, RNA and protein) collection in marine oxygen minimum zones (OMZs) and other oxygen starved waters. Experimental activities conducted in Saanich Inlet, a seasonally anoxic fjord on Vancouver Island British Columbia, were designed to compare and cross-calibrate in situ sampling devices (McLane PPS system) with conventional bottle sampling and incubation methods. Bottle effects on microbial community composition, and activity were tested using different filter combinations and sample volumes to compare PPS/IPS (0.4 µm) versus Sterivex (0.22 µm) filtration methods with and without prefilters (2.7 µm). Resulting biomass was processed for small subunit ribosomal RNA gene sequencing across all three domains of life on the 454 platform followed by downstream community structure analyses. Significant community shifts occurred within and between filter fractions for in situ versus on-ship processed samples. For instance, the relative abundance of several bacterial phyla including Bacteroidetes, Delta and Gammaproteobacteria decreased five-fold on-ship when compared to in situ filtration. Similarly, experimental mesocosms showed similar community structure and activity to in situ filtered samples indicating the need to cross-calibrate incubations to constrain bottle effects. In addition, alpha and beta diversity significantly changed as function of filter size and volume, as well as the operational taxonomic units identified using indicator species analysis for each filter size. Our results provide statistical support that microbial community structure is systematically biased by filter fraction methods and highlight the need for establishing compatible techniques among researchers that facilitate comparative and reproducible science for the whole community.

Measurement of in situ sulfur isotopes by laser ablation multi-collector ICPMS: opening Pandora’s Box

USGS Publications Warehouse

Ridley, William I.; Pribil, Michael; Koenig, Alan E.; Slack, John F.

2015-01-01

Laser ablation multi-collector ICPMS is a modern tool for in situ measurement of S isotopes. Advantages of the technique are speed of analysis and relatively minor matrix effects combined with spatial resolution sufficient for many applications. The main disadvantage is a more destructive sampling mechanism relative to the ion microprobe technique. Recent advances in instrumentation allow precise measurement with spatial resolutions down to 25 microns. We describe specific examples from economic geology where increased spatial resolution has greatly expanded insights into the sources and evolution of fluids that cause mineralization and illuminated genetic relations between individual deposits in single mineral districts.

Analysis of peptides using an integrated microchip HPLC-MS/MS system.

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

Kirby, Brian J.; Chirica, Gabriela S.; Reichmuth, David S.

Hyphendated LC-MS techniques are quickly becoming the standard tool for protemic analyses. For large homogeneous samples, bulk processing methods and capillary injection and separation techniques are suitable. However, for analysis of small or heterogeneous samples, techniques that can manipulate picoliter samples without dilution are required or samples will be lost or corrupted; further, static nanospray-type flowrates are required to maximize SNR. Microchip-level integration of sample injection with separation and mass spectrometry allow small-volume analytes to be processed on chip and immediately injected without dilution for analysis. An on-chip HPLC was fabricated using in situ polymerization of both fixed and mobilemore » polymer monoliths. Integration of the chip with a nanospray MS emitter enables identification of peptides by the use of tandem MS. The chip is capable of analyzing of very small sample volumes (< 200 pl) in short times (< 3 min).« less

A comparison of in situ methods for measuring net nitrogen mineralization rates of organic soil amendments.

PubMed

Hanselman, Travis A; Graetz, Donald A; Obreza, Thomas A

2004-01-01

In situ incubation methods may help provide site-specific estimates of N mineralization from land-applied wastes. However, there are concerns about the reliability of the data generated by the various methods due to containment artifacts. We amended a sandy soil with either poultry manure, biosolids, or yard-waste compost and incubated the mixtures using four in situ methods (buried bags, covered cylinders, standard resin traps, and "new" soil-resin traps) and a conventional laboratory technique in plastic bags. Each incubation device was destructively sampled at 45-d intervals for 180 d and net N mineralization was determined by measuring the amount of inorganic N that accumulated in the soil or soil plus resin traps. Containment effects were evaluated by comparing water content of the containerized soil to a field-reference soil column. In situ incubation methods provided reasonable estimates of short-term (< 45 d) N mineralization, but long-term (> 45 d) mineralization data were not accurate due to a variety of problems specific to each technique. Buried bags and covered cylinders did not retain mineralized N due to water movement into and out of the containers. Neither resin method captured all of the mineralized N that leached through the soil columns, but the new soil-resin trap method tracked field soil water content better than all other in situ methods evaluated. With further refinement and validation, the new soil-resin trap method may be a useful in situ incubation technique for measuring net N mineralization rates of organic soil amendments.

In-Situ XRF Measurements in Lunar Surface Exploration Using Apollo Samples as a Standard

NASA Technical Reports Server (NTRS)

Young, Kelsey E.; Evans, C.; Allen, C.; Mosie, A.; Hodges, K. V.

2011-01-01

Samples collected during the Apollo lunar surface missions were sampled and returned to Earth by astronauts with varying degrees of geological experience. The technology used in these EVAs, or extravehicular activities, included nothing more advanced than traditional terrestrial field instruments: rock hammer, scoop, claw tool, and sample bags. 40 years after Apollo, technology is being developed that will allow for a high-resolution geochemical map to be created in the field real-time. Handheld x-ray fluorescence (XRF) technology is one such technology. We use handheld XRF to enable a broad in-situ characterization of a geologic site of interest based on fairly rapid techniques that can be implemented by either an astronaut or a robotic explorer. The handheld XRF instrument we used for this study was the Innov-X Systems Delta XRF spectrometer.

A literature review of in situ transmission electron microscopy technique in corrosion studies.

PubMed

Song, Zhengwei; Xie, Zhi-Hui

2018-06-18

One of the biggest challenges in corrosion investigation is foreseeing precisely how and where materials will degenerate in a designated condition owing to scarceness of accurate corrosion mechanisms. Recent fast development of in situ transmission electron microscopy (TEM) technique makes it achievable to better understand the corrosion mechanism and physicochemical processes at the interfaces between samples and gases or electrolytes by dynamical capture the microstructural and chemical changes with high resolution within a realistic or near-realistic environment. However, a detailed and in-depth account summing up the development and latest achievements of in situ TEM techniques, especially the application of emerging liquid and electrochemical cells in the community of corrosion study in the last several years is lacking and is urgently needed for its heathy development. To fill this gap, this critical review summarizes firstly the key scientific issues in corrosion research, followed by introducing the configurations of several typical closed-type cells. Then, the achievements of in situ TEM using open-type or closed-type cells in corrosion study are presented in detail. The study directions in the future are commented finally in terms of spatial and temporal resolution, electron radiation, and linkage between microstructure and electrochemical performance in corrosion community. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

DTIC Science & Technology

2002-09-30

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

Validation of a Crystal Plasticity Model Using High Energy Diffraction Microscopy

NASA Technical Reports Server (NTRS)

Beaudoin, A. J.; Obstalecki, M.; Storer, R.; Tayon, W.; Mach, J.; Kenesei, P.; Lienert, U.

2012-01-01

High energy diffraction microscopy is used to measure the crystallographic orientation and evolution of lattice strain in an Al Li alloy. The relative spatial arrangement of the several pancake-shaped grains in a tensile sample is determined through in situ and ex situ techniques. A model for crystal plasticity with continuity of lattice spin is posed, where grains are represented by layers in a finite element mesh following the arrangement indicated by experiment. Comparison is drawn between experiment and simulation.

Improved Flotation Technique for Microscopy of In Situ Soil and Sediment Microorganisms

PubMed Central

Bone, T. L.; Balkwill, D. L.

1986-01-01

An improved flotation method for microscopy of in situ soil and sediment microorganisms was developed. Microbial cells were released into gellike flotation films that were stripped from soil and sediment aggregates as these aggregates were submerged in 0.5% solutions of polyvinylpyrrolidone. The use of polyvinylpyrrolidone solutions instead of water facilitated the release of films from saturated samples such as aquifer sediments as well as from typical surface soils. In situ microbial morphological characteristics could then be surveyed rapidly by light microscopy of films stained with acridine orange. This method effectively determined the ranges of morphological diversity in a variety of sample types. It also detected microcolonies and other spatial relationships among microbial cells. Only a small fraction (3.4 to 10.1%) of the microflora was released into the flotation films, but plating and direct evaluations by microscopy showed that this fraction was representative of the total population. Images PMID:16347005

Neutron, fluorescence, and optical imaging: An in situ combination of complementary techniques

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

Wagner, D.; Egelhaaf, S. U.; Hermes, H. E.

2015-09-15

An apparatus which enables the simultaneous combination of three complementary imaging techniques, optical imaging, fluorescence imaging, and neutron radiography, is presented. While each individual technique can provide information on certain aspects of the sample and their time evolution, a combination of the three techniques in one setup provides a more complete and consistent data set. The setup can be used in transmission and reflection modes and thus with optically transparent as well as opaque samples. Its capabilities are illustrated with two examples. A polymer hydrogel represents a transparent sample and the diffusion of fluorescent particles into and through this polymermore » matrix is followed. In reflection mode, the absorption of solvent by a nile red-functionalized mesoporous silica powder and the corresponding change in fluorescent signal are studied.« less

(Project 13-5292) Correlating thermal and mechanical coupling based multiphysics behavior of nuclear materials through in-situ measurements

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

Tomar, Vikas

Irradiations and post characterization experiments were performed first on Zr samples. This step will help understand the effect of the 2.5% alloying elements on the behavior of Zircaloy-4 (PWR cladding material) when compared to pure Zr. Irradiation flux measurements and sample temperature calibrations were performed at different energies prior to the irradiation experiments. Irradiations were performed with two different energy regimes1: non-displacment energies and displacement energies. Time was also dedicated to optimize transmission electron microscopy (TEM) sample preparation conditions via electropolishing technique. This step is crucial to prepare TEM samples for the in-situ TEM/irradiation experiments (Year 2). In addition, Zircaloy-4more » samples are being prepared for irradiation, and a setup is built by one of our collaborators (Dr. Mert Efe) to prepare ultrafine (UF) and nanocrystalline (NC) Zircaloy-4 samples for comparison with the commercial Zircaloy-4 samples.« less

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

NASA Astrophysics Data System (ADS)

Walte, N.; Keppler, H.

2005-12-01

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

Use of non-standardised micro-destructive techniques in the characterization of traditional construction materials

NASA Astrophysics Data System (ADS)

Ioannou, Ioannis; Theodoridou, Magdalini; Modestou, Sevasti; Fournari, Revecca; Dagrain, Fabrice

2013-04-01

The characterization of material properties and the diagnosis of their state of weathering and conservation are three of the most important steps in the field of cultural heritage preservation. Several standardised experimental methods exist, especially for determining the material properties and their durability. However, they are limited in their application by the required size of test specimens and the controlled laboratory conditions needed to undertake the tests; this is especially true when the materials under study constitute immovable parts of heritage structures. The current use of other advanced methods of analysis, such as imaging techniques, in the aforementioned field of research offers invaluable results. However, these techniques may not always be accessible to the wider research community due to their complex nature and relatively high cost of application. This study presents innovative applications of two recently developed cutting techniques; the portable Drilling Resistance Measuring System (DRMS) and the scratch tool. Both methods are defined as micro-destructive, since they only destroy a very small portion of sample material. The general concept of both methods lies within the forces needed to cut a material by linear (scratch tool) or rotational (DRMS) cutting action; these forces are related to the mechanical properties of the material and the technological parameters applied on the tool. Therefore, for a given testing configuration, the only parameter influencing the forces applied is the strength of the material. These two techniques have been used alongside a series of standardised laboratory tests aiming at the correlation of various stone properties (density, porosity, dynamic elastic modulus and uniaxial compressive strength). The results prove the potential of both techniques in assessing the uniaxial compressive strength of stones. The scratch tool has also been used effectively to estimate the compressive strength of mud bricks. It therefore follows that both micro-destructive techniques may prove useful in the physico-mechanical characterization of materials which demand in-situ measurements or allow very limited sampling. Moreover, both techniques have been used, for the first time, to map the distribution of salts in building stone in the laboratory; micro-drilling was also applied in the same context in-situ. The results of the laboratory tests performed on limestone impregnated with sodium and magnesium sulfate confirm that both the scratch tool and the DRMS may successfully detect the location of the salt front, as they respond to pore clogging by salt crystals by providing increased scratching/drilling resistance values. Drilling and scratching of duplicate samples treated with a hydrophobic product show the sensitivity of both techniques as they clearly detect changes to the salt front location (i.e. cryptoflorescence) caused by surface treatments. Both techniques were also successful in highlighting the difference in the crystallisation location and pattern of magnesium sulphate and sodium chloride. In-situ application of the micro-drilling test demonstrated its potential for use in the assessment of masonry salt weathering; the results suggest that this technique may, in fact, be useful as a preventive measure against salt damage. Last but not least, both aforementioned novel micro-destructive techniques have been used to assess the effectiveness of commercially available consolidants. The results of the scratch tool have also been utilised to develop a tomography image of the samples under test. Scratching tomography may potentially be combined with in-situ micro-drilling tests to evaluate the effectiveness of consolidation treatments applied on monuments and historic buildings.

A Coordinated Focused Ion Beam/Ultramicrotomy Technique for Serial Sectioning of Hayabusa Particles and Other Returned Samples

NASA Technical Reports Server (NTRS)

Berger, E. L.; Keller, L. P.

2014-01-01

Recent sample return missions, such as NASA's Stardust mission to comet 81P/Wild 2 and JAXA's Hayabusa mission to asteroid 25143 Itokawa, have returned particulate samples (typically 5-50 µm) that pose tremendous challenges to coordinated analysis using a variety of nano- and micro-beam techniques. The ability to glean maximal information from individual particles has become increasingly important and depends critically on how the samples are prepared for analysis. This also holds true for other extraterrestrial materials, including interplanetary dust particles, micrometeorites and lunar regolith grains. Traditionally, particulate samples have been prepared using microtomy techniques (e.g., [1]). However, for hard mineral particles ?20 µm, microtome thin sections are compromised by severe chatter and sample loss. For these difficult samples, we have developed a hybrid technique that combines traditional ultramicrotomy with focused ion beam (FIB) techniques, allowing for the in situ investigation of grain surfaces and interiors. Using this method, we have increased the number of FIB-SEM prepared sections that can be recovered from a particle with dimensions on the order of tens of µms. These sections can be subsequently analyzed using a variety of electron beam techniques. Here, we demonstrate this sample preparation technique on individual lunar regolith grains in order to study their space-weathered surfaces. We plan to extend these efforts to analyses of individual Hayabusa samples.

An integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection

NASA Astrophysics Data System (ADS)

Liu, Hai-Tao; Wen, Zhi-Yu; Xu, Yi; Shang, Zheng-Guo; Peng, Jin-Lan; Tian, Peng

2017-09-01

In this paper, an integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection was purposed based on microfluidic chips dielectrophoresis technique and electrochemical impedance detection principle. The microsystems include microfluidic chip, main control module, and drive and control module, and signal detection and processing modulet and result display unit. The main control module produce the work sequence of impedance detection system parts and achieve data communication functions, the drive and control circuit generate AC signal which amplitude and frequency adjustable, and it was applied on the foodborne pathogens impedance analysis microsystems to realize the capture enrichment and impedance detection. The signal detection and processing circuit translate the current signal into impendence of bacteria, and transfer to computer, the last detection result is displayed on the computer. The experiment sample was prepared by adding Escherichia coli standard sample into chicken sample solution, and the samples were tested on the dielectrophoresis chip capture enrichment and in-situ impedance detection microsystems with micro-array electrode microfluidic chips. The experiments show that the Escherichia coli detection limit of microsystems is 5 × 104 CFU/mL and the detection time is within 6 min in the optimization of voltage detection 10 V and detection frequency 500 KHz operating conditions. The integrated microfluidic analysis microsystems laid the solid foundation for rapid real-time in-situ detection of bacteria.

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario

NASA Astrophysics Data System (ADS)

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga; Parro, Víctor

2017-10-01

The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing.

Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

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

Makowska, Małgorzata G.; Theil Kuhn, Luise; Cleemann, Lars N.

In high material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. Our paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 degrees C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition,more » examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. Our work covers a broad field of research from fundamental to technological investigations of various types of materials and components.« less

Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

DOE PAGES

Makowska, Małgorzata G.; Theil Kuhn, Luise; Cleemann, Lars N.; ...

2015-12-17

In high material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. Our paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 degrees C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition,more » examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. Our work covers a broad field of research from fundamental to technological investigations of various types of materials and components.« less

In-situ fluorimetry: A powerful non-invasive diagnostic technique for natural dyes used in artefacts. Part II. Identification of orcein and indigo in Renaissance tapestries

NASA Astrophysics Data System (ADS)

Clementi, C.; Miliani, C.; Romani, A.; Santamaria, U.; Morresi, F.; Mlynarska, K.; Favaro, G.

2009-01-01

In this paper, three Renaissance tapestries depicting scenes painted by Raffaello Sanzio, conserved at the Vatican Museum, were investigated using in-situ UV-Visible fluorimetric measurements. The results show that this technique is suitable for the detection of natural organic colorants used for dyeing the threads woven in these tapestries. The emission signals detected on red-purple colours were assigned to the colorant orcein and those on different nuances of blue and green colours to indigo by comparison with data from reference laboratory samples. The assignments were supported by chromatographic experiments carried out on threads taken from the back side of the tapestry in the same points analysed by spectrofluorimentry.

In-situ fluorimetry: a powerful non-invasive diagnostic technique for natural dyes used in artefacts. Part II. Identification of orcein and indigo in Renaissance tapestries.

PubMed

Clementi, C; Miliani, C; Romani, A; Santamaria, U; Morresi, F; Mlynarska, K; Favaro, G

2009-01-01

In this paper, three Renaissance tapestries depicting scenes painted by Raffaello Sanzio, conserved at the Vatican Museum, were investigated using in-situ UV-Visible fluorimetric measurements. The results show that this technique is suitable for the detection of natural organic colorants used for dyeing the threads woven in these tapestries. The emission signals detected on red-purple colours were assigned to the colorant orcein and those on different nuances of blue and green colours to indigo by comparison with data from reference laboratory samples. The assignments were supported by chromatographic experiments carried out on threads taken from the back side of the tapestry in the same points analysed by spectrofluorimentry.

In Situ Raman Detection of Gas Hydrates Exposed on the Seafloor of the South China Sea

NASA Astrophysics Data System (ADS)

Zhang, Xin; Du, Zengfeng; Luan, Zhendong; Wang, Xiujuan; Xi, Shichuan; Wang, Bing; Li, Lianfu; Lian, Chao; Yan, Jun

2017-10-01

Gas hydrates are usually buried in sediments. Here we report the first discovery of gas hydrates exposed on the seafloor of the South China Sea. The in situ chemical compositions and cage structures of these hydrates were measured at the depth of 1,130 m below sea level using a Raman insertion probe (RiP-Gh) that was carried and controlled by a remotely operated vehicle (ROV) Faxian. This in situ analytical technique can avoid the physical and chemical changes associated with the transport of samples from the deep sea to the surface. Natural gas hydrate samples were analyzed at two sites. The in situ spectra suggest that the newly formed hydrate was Structure I but contains a small amount of C3H8 and H2S. Pure gas spectra of CH4, C3H8, and H2S were also observed at the SCS-SGH02 site. These data represent the first in situ proof that free gas can be trapped within the hydrate fabric during rapid hydrate formation. We provide the first in situ confirmation of the hydrate growth model for the early stages of formation of crystalline hydrates in a methane-rich seafloor environment. Our work demonstrates that natural hydrate deposits, particularly those in the early stages of formation, are not monolithic single structures but instead exhibit significant small-scale heterogeneities due to inclusions of free gas and the surrounding seawater, there inclusions also serve as indicators of the likely hydrate formation mechanism. These data also reinforce the importance of correlating visual and in situ measurements when characterizing a sampling site.

Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients.

PubMed

Siddiqui, Sanna F; Knipe, Kevin; Manero, Albert; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M; Bartsch, Marion; Raghavan, Seetha

2013-08-01

Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.

Synchrotron X-ray measurement techniques for thermal barrier coated cylindrical samples under thermal gradients

NASA Astrophysics Data System (ADS)

Siddiqui, Sanna F.; Knipe, Kevin; Manero, Albert; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Bartsch, Marion; Raghavan, Seetha

2013-08-01

Measurement techniques to obtain accurate in situ synchrotron strain measurements of thermal barrier coating systems (TBCs) applied to hollow cylindrical specimens are presented in this work. The Electron Beam Physical Vapor Deposition coated specimens with internal cooling were designed to achieve realistic temperature gradients over the TBC coated material such as that occurring in the turbine blades of aeroengines. Effects of the circular cross section on the x-ray diffraction (XRD) measurements in the various layers, including the thermally grown oxide, are investigated using high-energy synchrotron x-rays. Multiple approaches for beam penetration including collection, tangential, and normal to the layers, along with variations in collection parameters are compared for their ability to attain high-resolution XRD data from the internal layers. This study displays the ability to monitor in situ, the response of the internal layers within the TBC, while implementing a thermal gradient across the thickness of the coated sample. The thermal setup maintained coating surface temperatures in the range of operating conditions, while monitoring the substrate cooling, for a controlled thermal gradient. Through variation in measurement location and beam parameters, sufficient intensities are obtained from the internal layers which can be used for depth resolved strain measurements. Results are used to establish the various techniques for obtaining XRD measurements through multi-layered coating systems and their outcomes will pave the way towards goals in achieving realistic in situ testing of these coatings.

In situ 2D diffraction as a tool to characterize ferroelectric and piezoelectric thin films

NASA Astrophysics Data System (ADS)

Khamidy, N. I.; Kovacova, V.; Bernasconi, A.; Le Rhun, G.; Vaxelaire, N.

2017-08-01

In this paper the application of 2D x-ray diffraction (XRD2) as a technique to characterize in situ during electrical cycling the properties of a ferroelectric and piezoelectric thin film is discussed. XRD2 is one type of XRD on which a 2D detector is used instead of a point detector. This technique enables simultaneous recording of many sample information in a much shorter time compared to conventional XRD. The discussion is focused especially on the data processing technique of the huge data acquired. The methodology to calculate an effective piezoelectric coefficient, analyze the phase and texture, and estimate the domain size and shape is described in this paper. This methodology is then applied to a lead zirconate titanate (PZT) thin film at the morphotropic phase boundary (MPB) composition (i.e. Pb[Zr0.52Ti0.48]O3) with a preferred orientation of (1 0 0). The in situ XRD2 characterization was conducted in the European synchrotron radiation facility (ESRF) in Grenoble, France. Since a high-energy beam with vertical resolution as small as 100 nm was used, a cross-sectional scan of the sample was performed over the entire thickness of the film. From these experimental results, a better understanding on the piezoelectricity phenomena in PZT thin film at MPB composition were achieved, providing original feedback between the elaboration processes and functional properties of the film.

Mars chronology: Assessing techniques for quantifying surficial processes

USGS Publications Warehouse

Doran, P.T.; Clifford, S.M.; Forman, S.L.; Nyquist, Larry; Papanastassiou, D.A.; Stewart, B.W.; Sturchio, N.C.; Swindle, T.D.; Cerling, T.; Kargel, J.; McDonald, G.; Nishiizumi, K.; Poreda, R.; Rice, J.W.; Tanaka, K.

2004-01-01

Currently, the absolute chronology of Martian rocks, deposits and events is based mainly on crater counting and remains highly imprecise with epoch boundary uncertainties in excess of 2 billion years. Answers to key questions concerning the comparative origin and evolution of Mars and Earth will not be forthcoming without a rigid Martian chronology, enabling the construction of a time scale comparable to Earth's. Priorities for exploration include calibration of the cratering rate, dating major volcanic and fluvial events and establishing chronology of the polar layered deposits. If extinct and/or extant life is discovered, the chronology of the biosphere will be of paramount importance. Many radiometric and cosmogenic techniques applicable on Earth and the Moon will apply to Mars after certain baselines (e.g. composition of the atmosphere, trace species, chemical and physical characteristics of Martian dust) are established. The high radiation regime may pose a problem for dosimetry-based techniques (e.g. luminescence). The unique isotopic composition of nitrogen in the Martian atmosphere may permit a Mars-specific chronometer for tracing the time-evolution of the atmosphere and of lithic phases with trapped atmospheric gases. Other Mars-specific chronometers include measurement of gas fluxes and accumulation of platinum group elements (PGE) in the regolith. Putting collected samples into geologic context is deemed essential, as is using multiple techniques on multiple samples. If in situ measurements are restricted to a single technique it must be shown to give consistent results on multiple samples, but in all cases, using two or more techniques (e.g. on the same lander) will reduce error. While there is no question that returned samples will yield the best ages, in situ techniques have the potential to be flown on multiple missions providing a larger data set and broader context in which to place the more accurate dates. ?? 2004 Elsevier B.V. All rights reserved.

Astrobiology Objectives for Mars Sample Return

NASA Astrophysics Data System (ADS)

Meyer, M. A.

2002-05-01

Astrobiology is the study of life in the Universe, and a major objective is to understand the past, present, and future biologic potential of Mars. The current Mars Exploration Program encompasses a series of missions for reconnaissance and in-situ analyses to define in time and space the degree of habitability on Mars. Determining whether life ever existed on Mars is a more demanding question as evidenced by controversies concerning the biogenicity of features in the Mars meteorite ALH84001 and in the earliest rocks on Earth. In-situ studies may find samples of extreme interest but resolution of the life question most probably would require a sample returned to Earth. A selected sample from Mars has the many advantages: State-of-the-art instruments, precision sample handling and processing, scrutiny by different investigators employing different techniques, and adaptation of approach to any surprises It is with a returned sample from Mars that Astrobiology has the most to gain in determining whether life did, does, or could exist on Mars.

In situ analysis of soybeans and nuts by probe electrospray ionization mass spectrometry.

PubMed

Petroselli, Gabriela; Mandal, Mridul K; Chen, Lee C; Hiraoka, Kenzo; Nonami, Hiroshi; Erra-Balsells, Rosa

2015-04-01

The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In the present work, we describe the PESI mass spectra obtained by in situ measurement of soybeans and several nuts (peanuts, walnuts, cashew nuts, macadamia nuts and almonds) using different solid needles as sampling probes. It was found that PESI-MS is a valuable approach for in situ lipid analysis of these seeds. The phospholipid and triacylglycerol PESI spectra of different nuts and soybean were compared by principal component analysis (PCA). PCA shows significant differences among the data of each family of seeds. Methanolic extracts of nuts and soybean were exposed to air and sunlight for several days. PESI mass spectra were recorded before and after the treatment. Along the aging of the oil (rancidification), the formation of oxidated species with variable number of hydroperoxide groups could be observed in the PESI spectra. The relative intensity of oxidated triacylglycerols signals increased with days of exposition. Monitoring sensitivity of PESI-MS was high. This method provides a fast, simple and sensitive technique for the analysis (detection and characterization) of lipids in seed tissue and degree of oxidation of the oil samples. Copyright © 2015 John Wiley & Sons, Ltd.

In situ atomic scale mechanical microscopy discovering the atomistic mechanisms of plasticity in nano-single crystals and grain rotation in polycrystalline metals.

PubMed

Han, Xiaodong; Wang, Lihua; Yue, Yonghai; Zhang, Ze

2015-04-01

In this review, we briefly introduce our in situ atomic-scale mechanical experimental technique (ASMET) for transmission electron microscopy (TEM), which can observe the atomic-scale deformation dynamics of materials. This in situ mechanical testing technique allows the deformation of TEM samples through a simultaneous double-tilt function, making atomic-scale mechanical microscopy feasible. This methodology is generally applicable to thin films, nanowires (NWs), tubes and regular TEM samples to allow investigation of the dynamics of mechanically stressed samples at the atomic scale. We show several examples of this technique applied to Pt and Cu single/polycrystalline specimens. The in situ atomic-scale observation revealed that when the feature size of these materials approaches the nano-scale, they often exhibit "unusual" deformation behaviours compared to their bulk counterparts. For example, in Cu single-crystalline NWs, the elastic-plastic transition is size-dependent. An ultra-large elastic strain of 7.2%, which approaches the theoretical elasticity limit, can be achieved as the diameter of the NWs decreases to ∼6 nm. The crossover plasticity transition from full dislocations to partial dislocations and twins was also discovered as the diameter of the single-crystalline Cu NWs decreased. For Pt nanocrystals (NC), the long-standing uncertainties of atomic-scale plastic deformation mechanisms in NC materials (grain size G less than 15 nm) were clarified. For larger grains with G<∼10 nm, we frequently observed movements and interactions of cross-grain full dislocations. For G between 6 and 10 nm, stacking faults resulting from partial dislocations become more frequent. For G<∼6 nm, the plasticity mechanism transforms from a mode of cross-grain dislocation to a collective grain rotation mechanism. This grain rotation process is mediated by grain boundary (GB) dislocations with the assistance of GB diffusion and shuffling. These in situ atomic-scale images provide a direct demonstration that grain rotation, through the evolution of the misorientation angle between neighbouring grains, can be quantitatively assessed by the dislocation content within the grain boundaries. In combination with the revolutionary Cs-corrected sub-angstrom imaging technologies developed by Urban et al., the opportunities for experimental mechanics at the atomic scale are emerging. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies

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

Kroner, Anna B., E-mail: anna.kroner@diamond.ac.uk; Gilbert, Martin; Duller, Graham

2016-07-27

A capillary-based sample environment with hot air blower and integrated gas system was developed at Diamond to conduct X-ray absorption spectroscopy (XAS) studies of materials under time-resolved, in situ conditions. The use of a hot air blower, operating in the temperature range of 298-1173 K, allows introduction of other techniques e.g. X-ray diffraction (XRD), Raman spectroscopy for combined techniques studies. The flexibility to use either quartz or Kapton capillaries allows users to perform XAS measurement at energies as low as 5600 eV. To demonstrate performance, time-resolved, in situ XAS results of Rh catalysts during the process of activation (Rh K-edge,more » Ce L{sub 3}-edge and Cr K-edge) and the study of mixed oxide membrane (La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3−δ}) under various partial oxygen pressure conditions are described.« less

High temperature in-situ observations of multi-segmented metal nanowires encapsulated within carbon nanotubes by in-situ filling technique.

PubMed

Hayashi, Yasuhiko; Tokunaga, Tomoharu; Iijima, Toru; Iwata, Takuya; Kalita, Golap; Tanemura, Masaki; Sasaki, Katsuhiro; Kuroda, Kotaro

2012-08-08

Multi-segmented one-dimensional metal nanowires were encapsulated within carbon nanotubes (CNTs) through in-situ filling technique during plasma-enhanced chemical vapor deposition process. Transmission electron microscopy (TEM) and environmental TEM were employed to characterize the as-prepared sample at room temperature and high temperature. The selected area electron diffractions revealed that the Pd4Si nanowire and face-centered-cubic Co nanowire on top of the Pd nanowire were encapsulated within the bottom and tip parts of the multiwall CNT, respectively. Although the strain-induced deformation of graphite walls was observed, the solid-state phases of Pd4Si and Co-Pd remain even at above their expected melting temperatures and up to 1,550 ± 50°C. Finally, the encapsulated metals were melted and flowed out from the tip of the CNT after 2 h at the same temperature due to the increase of internal pressure of the CNT.

In situ Stripline Electrochemical NMR for Batteries

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

Sorte, Eric Glenn; Banek, Nathan A.; Wagner, Michael J.

Here, there exist some long outstanding technical challenges that continue to be of hindrance to fully harnessing the unique investigative advantages of nuclear magnetic resonance (NMR) spectroscopy in the in situ investigation of rechargeable battery chemistry. For instance, the conducting materials and circuitry necessary for an operational battery always deteriorate the coil–based NMR sensitivity when placed inside the coil, and the shape mismatch between them leads to low sample filling factors and even higher detection limits. We report herein a novel and successful adaptation of stripline NMR detection that integrates seamlessly the NMR detection with construction of an electro–chemical devicemore » in general (or a battery in particular) which leads to a technique with much higher detection sensitivity, higher sample filling factors, and which is particularly suitable for mass–limited samples.« less

In situ Stripline Electrochemical NMR for Batteries

DOE PAGES

Sorte, Eric Glenn; Banek, Nathan A.; Wagner, Michael J.; ...

2018-06-11

Here, there exist some long outstanding technical challenges that continue to be of hindrance to fully harnessing the unique investigative advantages of nuclear magnetic resonance (NMR) spectroscopy in the in situ investigation of rechargeable battery chemistry. For instance, the conducting materials and circuitry necessary for an operational battery always deteriorate the coil–based NMR sensitivity when placed inside the coil, and the shape mismatch between them leads to low sample filling factors and even higher detection limits. We report herein a novel and successful adaptation of stripline NMR detection that integrates seamlessly the NMR detection with construction of an electro–chemical devicemore » in general (or a battery in particular) which leads to a technique with much higher detection sensitivity, higher sample filling factors, and which is particularly suitable for mass–limited samples.« less

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

Makowska, Małgorzata G., E-mail: malg@dtu.dk; European Spallation Source ESS AB, P.O. Box 176, SE-221 00 Lund; Theil Kuhn, Luise

High material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. This paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 °C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition, examples of experimentsmore » successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. This covers a broad field of research from fundamental to technological investigations of various types of materials and components.« less

A Compact, Solid-State UV (266 nm) Laser System Capable of Burst-Mode Operation for Laser Ablation Desorption Processing

NASA Technical Reports Server (NTRS)

Arevalo, Ricardo, Jr.; Coyle, Barry; Paulios, Demetrios; Stysley, Paul; Feng, Steve; Getty, Stephanie; Binkerhoff, William

2015-01-01

Compared to wet chemistry and pyrolysis techniques, in situ laser-based methods of chemical analysis provide an ideal way to characterize precious planetary materials without requiring extensive sample processing. In particular, laser desorption and ablation techniques allow for rapid, reproducible and robust data acquisition over a wide mass range, plus: Quantitative, spatially-resolved measurements of elemental and molecular (organic and inorganic) abundances; Low analytical blanks and limits-of-detection ( ng g-1); and, the destruction of minimal quantities of sample ( g) compared to traditional solution and/or pyrolysis analyses (mg).

Impact of grass cover on the magnetic susceptibility measurements for assessing metal contamination in urban topsoil.

PubMed

Golden, Nessa; Zhang, Chaosheng; Potito, Aaron P; Gibson, Paul J; Bargary, Norma; Morrison, Liam

2017-05-01

In recent decades, magnetic susceptibility monitoring has developed as a useful technique in environmental pollution studies, particularly metal contamination of soil. This study provides the first ever examination of the effects of grass cover on magnetic susceptibility (MS) measurements of underlying urban soils. Magnetic measurements were taken in situ to determine the effects on κ (volume magnetic susceptibility) when the grass layer was present (κ grass ) and after the grass layer was trimmed down to the root (κ no grass ). Height of grass was recorded in situ at each grid point. Soil samples (n=185) were collected and measurements of mass specific magnetic susceptibility (χ) were performed in the laboratory and frequency dependence (χ fd %) calculated. Metal concentrations (Pb, Cu, Zn and Fe) in the soil samples were determined and a gradiometry survey carried out in situ on a section of the study area. Significant correlations were found between each of the MS measurements and the metal content of the soil at the p<0.01 level. Spatial distribution maps were created using Inverse Distance Weighting (IDW) and Local Indicators of Spatial Association (LISA) to identify common patterns. κ grass (ranged from 1.67 to 301.00×10 -5 SI) and κ no grass (ranged from 2.08 to 530.67×10 -5 SI) measured in situ are highly correlated [r=0.966, n=194, p<0.01]. The volume susceptibility datasets in the presence and absence of grass coverage share a similar spatial distribution pattern. This study re-evaluates in situ κ monitoring techniques and the results suggest that the removal of grass coverage prior to obtaining in situ κ measurements of urban soil is unnecessary. This layer does not impede the MS sensor from accurately measuring elevated κ in soils, and therefore κ measurements recorded with grass coverage present can be reliably used to identify areas of urban soil metal contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

Seven-hour fluorescence in situ hybridization technique for enumeration of Enterobacteriaceae in food and environmental water sample.

PubMed

Ootsubo, M; Shimizu, T; Tanaka, R; Sawabe, T; Tajima, K; Ezura, Y

2003-01-01

A fluorescent in situ hybridization (FISH) technique using an Enterobacteriaceae-specific probe (probe D) to target 16S rRNA was improved in order to enumerate, within a single working day, Enterobacteriaceae present in food and environmental water samples. In order to minimize the time required for the FISH procedure, each step of FISH with probe D was re-evaluated using cultured Escherichia coli. Five minutes of ethanol treatment for cell fixation and hybridization were sufficient to visualize cultured E. coli, and FISH could be performed within 1 h. Because of the difficulties in detecting low levels of bacterial cells by FISH without cultivation, a FISH technique for detecting microcolonies on membrane filters was investigated to improve the bacterial detection limit. FISH with probe D following 6 h of cultivation to grow microcolonies on a 13 mm diameter membrane filter was performed, and whole Enterobacteriaceae microcolonies on the filter were then detected and enumerated by manual epifluorescence microscopic scanning at magnification of x100 in ca 5 min. The total time for FISH with probe D following cultivation (FISHFC) was reduced to within 7 h. FISHFC can be applied to enumerate cultivable Enterobacteriaceae in food (above 100 cells g-1) and environmental water samples (above 1 cell ml-1). Cultivable Enterobacteriaceae in food and water samples were enumerated accurately within 7 h using the FISHFC method. A FISHFC method capable of evaluating Enterobacteriaceae contamination in food and environmental water within a single working day was developed.

Applications of derivatization reactions to trace organic compounds during sample preparation based on pressurized liquid extraction.

PubMed

Carro, Antonia M; González, Paula; Lorenzo, Rosa A

2013-06-28

Pressurized liquid extraction (PLE) is an exhaustive technique used for the extraction of analytes from solid samples. Temperature, pressure, solvent type and volume, and the addition of other reagents notably influence the efficiency of the extraction. The analytical applications of this technique can be improved by coupling with appropriate derivatization reactions. The aim of this review is to discuss the recent applications of the sequential combination of PLE with derivatization and the approaches that involve simultaneous extraction and in situ derivatization. The potential of the latest developments to the trace analysis of environmental, food and biological samples is also analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification of morphological biosignatures in Martian analogue field specimens using in situ planetary instrumentation.

PubMed

Pullan, Derek; Westall, Frances; Hofmann, Beda A; Parnell, John; Cockell, Charles S; Edwards, Howell G M; Villar, Susana E Jorge; Schröder, Christian; Cressey, Gordon; Marinangeli, Lucia; Richter, Lutz; Klingelhöfer, Göstar

2008-02-01

We have investigated how morphological biosignatures (i.e., features related to life) might be identified with an array of viable instruments within the framework of robotic planetary surface operations at Mars. This is the first time such an integrated lab-based study has been conducted that incorporates space-qualified instrumentation designed for combined in situ imaging, analysis, and geotechnics (sampling). Specimens were selected on the basis of feature morphology, scale, and analogy to Mars rocks. Two types of morphological criteria were considered: potential signatures of extinct life (fossilized microbial filaments) and of extant life (crypto-chasmoendolithic microorganisms). The materials originated from a variety of topical martian analogue localities on Earth, including impact craters, high-latitude deserts, and hydrothermal deposits. Our in situ payload included a stereo camera, microscope, Mössbauer spectrometer, and sampling device (all space-qualified units from Beagle 2), and an array of commercial instruments, including a multi-spectral imager, an X-ray spectrometer (calibrated to the Beagle 2 instrument), a micro-Raman spectrometer, and a bespoke (custom-designed) X-ray diffractometer. All experiments were conducted within the engineering constraints of in situ operations to generate realistic data and address the practical challenges of measurement. Our results demonstrate the importance of an integrated approach for this type of work. Each technique made a proportionate contribution to the overall effectiveness of our "pseudopayload" for biogenic assessment of samples yet highlighted a number of limitations of current space instrument technology for in situ astrobiology.

In situ ionic liquid dispersive liquid-liquid microextraction coupled to gas chromatography-mass spectrometry for the determination of organophosphorus pesticides.

PubMed

Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

2018-07-20

Nine organophosphorus pesticides (OPPs) were determined in environmental waters from different origins using in situ ionic liquid dispersive liquid microextraction (IL-DLLME). This preconcentration technique was coupled to gas chromatography-mass spectrometry (GC-MS) using microvial insert thermal desorption, an approach that uses a thermal desorption injector as sample introduction system. The parameters affecting both the microextraction and sample injection steps were optimized. The proposed method showed good precision, with RSD values ranging from 4.1 to 9.7%, accuracy with recoveries in the 85-118% range, and sensitivity with DLs ranging from 5 to 16 ng L -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

Application of drilling, coring, and sampling techniques to test holes and wells

USGS Publications Warehouse

Shuter, Eugene; Teasdale, Warren E.

1989-01-01

The purpose of this manual is to provide ground-water hydrologists with a working knowledge of the techniques of test drilling, auger drilling, coring and sampling, and the related drilling and sampling equipment. For the most part, the techniques discussed deal with drilling, sampling, and completion of test holes in unconsolidated sediments because a hydrologist is interested primarily in shallow-aquifer data in this type of lithology. Successful drilling and coring of these materials usually is difficult, and published research information on the subject is not readily available. The authors emphasize in-situ sampling of unconsolidated sediments to obtain virtually undisturbed samples. Particular attention is given to auger drilling and hydraulic-rotary methods of drilling because these are the principal means of test drilling performed by the U.S. Geological Survey during hydrologic studies. Techniques for sampling areas contaminated by solid or liquid waste are discussed. Basic concepts of well development and a detailed discussion of drilling muds, as related to hole conditioning, also are included in the report. The information contained in this manual is intended to help ground-water hydrologists obtain useful subsurface data and samples from their drilling programs.

Nanorobotic System iTRo for Controllable 1D Micro/nano Material Twisting Test.

PubMed

Lu, Haojian; Shang, Wanfeng; Wei, Xueyong; Yang, Zhan; Fukuda, Toshio; Shen, Yajing

2017-06-08

In-situ micro/nano characterization is an indispensable methodology for material research. However, the precise in-situ SEM twisting of 1D material with large range is still challenge for current techniques, mainly due to the testing device's large size and the misalignment between specimen and the rotation axis. Herein, we propose an in-situ twist test robot (iTRo) to address the above challenges and realize the precise in-situ SEM twisting test for the first time. Firstly, we developed the iTRo and designed a series of control strategies, including assembly error initialization, triple-image alignment (TIA) method for rotation axis alignment, deformation-based contact detection (DCD) method for sample assembly, and switch control for robots cooperation. After that, we chose three typical 1D material, i.e., magnetic microwire Fe 74 B 13 Si 11 C 2 , glass fiber, and human hair, for twisting test and characterized their properties. The results showed that our approach is able to align the sample to the twisting axis accurately, and it can provide large twisting range, heavy load and high controllability. This work fills the blank of current in-situ mechanical characterization methodologies, which is expected to give significant impact in the fundamental nanomaterial research and practical micro/nano characterization.

Using Electrical Resistivity Imaging to Evaluate Permanganate Performance During an In Situ Treatment of a RDX-Contaminated Aquifer

DTIC Science & Technology

2009-08-01

assess the performance of remedial efforts. These techniques are expensive and, by themselves, are effectively random samples guided by the training...technology should be further explored and developed for use in pre-amendment tracer tests and quantitative remedial assessments . 15. SUBJECT TERMS...and flow of injectate. Site assessment following groundwater remediation efforts typically involves discrete point sampling using wells or

Determination of free Zn2+ concentration in synthetic and natural samples with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique).

PubMed

Chito, Diana; Weng, Liping; Galceran, Josep; Companys, Encarnació; Puy, Jaume; van Riemsdijk, Willem H; van Leeuwen, Herman P

2012-04-01

The determination of free Zn(2+) ion concentration is a key in the study of environmental systems like river water and soils, due to its impact on bioavailability and toxicity. AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique) are emerging techniques suited for the determination of free heavy metal concentrations, especially in the case of Zn(2+), given that there is no commercial Ion Selective Electrode. In this work, both techniques have been applied to synthetic samples (containing Zn and NTA) and natural samples (Rhine river water and soils), showing good agreement. pH fluctuations in DMT and N(2)/CO(2) purging system used in AGNES did not affect considerably the measurements done in Rhine river water and soil samples. Results of DMT in situ of Rhine river water are comparable to those of AGNES in the lab. The comparison of this work provides a cross-validation for both techniques. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of portable defocusing micro-scale spatially offset Raman spectroscopy.

PubMed

Realini, Marco; Botteon, Alessandra; Conti, Claudia; Colombo, Chiara; Matousek, Pavel

2016-05-10

We present, for the first time, portable defocusing micro-Spatially Offset Raman Spectroscopy (micro-SORS). Micro-SORS is a concept permitting the analysis of thin, highly turbid stratified layers beyond the reach of conventional Raman microscopy. The technique is applicable to the analysis of painted layers in cultural heritage (panels, canvases and mural paintings, painted statues and decorated objects in general) as well as in many other areas including polymer, biological and biomedical applications, catalytic and forensics sciences where highly turbid stratified layers are present and where invasive analysis is undesirable or impossible. So far the technique has been demonstrated only on benchtop Raman microscopes precluding the non-invasive analysis of larger samples and samples in situ. The new set-up is characterised conceptually on a range of artificially assembled two-layer systems demonstrating its benefits and performance across several application areas. These included stratified polymer sample, pharmaceutical tablet and layered paint samples. The same samples were also analysed by a high performance (non-portable) benchtop Raman microscope to provide benchmarking against our earlier research. The realisation of the vision of delivering portability to micro-SORS has a transformative potential spanning across multiple disciplines as it fully unlocks, for the first time, the non-invasive and non-destructive aspects of micro-SORS enabling it to be applied also to large and non-portable samples in situ without recourse to removing samples, or their fragments, for laboratory analysis on benchtop Raman microscopes.

Incorporation of Multiwalled Carbon Nanotubes into High Temperature Resin Using Dry Mixing Techniques

NASA Technical Reports Server (NTRS)

Ghose, Sayata; Watson, Kent A.; Delozier, Donavon M.; Working, Dennis C.; Siochi, Emilie J.; Connell, John W.

2006-01-01

As part of an ongoing effort to develop multifunctional advanced composites, blends of PETI330 and multiwalled carbon nanotubes (MWNTs) were prepared and characterized. Dry mixing techniques were employed and the maximum loading level of the MWNT chosen was based primarily on its effect on melt viscosity. The PETI330/ MWNT mixtures were prepared at concentrations ranging from 3 to 25 wt %. The resulting powders were characterized for homogeneity, thermal and rheological properties and extrudability as continuous fibers. Based on the characterization results, samples containing 10, 15 and 20 wt % MWNTs were chosen for more comprehensive evaluation. Samples were also prepared using in situ polymerization and solution mixing techniques and their properties were compared with the ball-mill prepared samples. The preparation and characterization of PETI330/ MWNT nanocomposites are discussed herein.

i RadMat: A thermo-mechanical testing system for in situ high-energy X-ray characterization of radioactive specimens

DOE PAGES

Zhang, Xuan; Xu, Chi; Wang, Leyun; ...

2017-01-27

Here, we present an in situ Radiated Materials (iRadMat) experimental module designed to interface with a servo-hydraulic load frame for X-ray measurements at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermo-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. The iRadMat is a radiation-shielded vacuum heating system with the sample rotation-under-load capability. We describe the design features and performances of the iRadMat and present a dataset from a 300 °C uniaxial tensile test of a neutron-irradiated pure Fe specimen to demonstrate its capabilities.

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario

PubMed Central

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga

2017-01-01

Abstract The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing. Key Words: Planetary exploration—Life detection—Microbial mat—Life detector chip—Thermogravimetry—Raman spectroscopy—NIR—DRIFTS. Astrobiology 17, 984–996. PMID:29016195

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario.

PubMed

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga; Parro, Víctor

2017-10-01

The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing. Key Words: Planetary exploration-Life detection-Microbial mat-Life detector chip-Thermogravimetry-Raman spectroscopy-NIR-DRIFTS. Astrobiology 17, 984-996.

An in situ approach to study trace element partitioning in the laser heated diamond anvil cell

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

Petitgirard, S.; Mezouar, M.; Borchert, M.

2012-01-15

Data on partitioning behavior of elements between different phases at in situ conditions are crucial for the understanding of element mobility especially for geochemical studies. Here, we present results of in situ partitioning of trace elements (Zr, Pd, and Ru) between silicate and iron melts, up to 50 GPa and 4200 K, using a modified laser heated diamond anvil cell (DAC). This new experimental set up allows simultaneous collection of x-ray fluorescence (XRF) and x-ray diffraction (XRD) data as a function of time using the high pressure beamline ID27 (ESRF, France). The technique enables the simultaneous detection of sample meltingmore » based to the appearance of diffuse scattering in the XRD pattern, characteristic of the structure factor of liquids, and measurements of elemental partitioning of the sample using XRF, before, during and after laser heating in the DAC. We were able to detect elements concentrations as low as a few ppm level (2-5 ppm) on standard solutions. In situ measurements are complimented by mapping of the chemical partitions of the trace elements after laser heating on the quenched samples to constrain the partitioning data. Our first results indicate a strong partitioning of Pd and Ru into the metallic phase, while Zr remains clearly incompatible with iron. This novel approach extends the pressure and temperature range of partitioning experiments derived from quenched samples from the large volume presses and could bring new insight to the early history of Earth.« less

The nanoaquarium: A nanofluidic platform for in situ transmission electron microscopy in liquid media

NASA Astrophysics Data System (ADS)

Grogan, Joseph M.

There are many scientifically interesting and technologically relevant nanoscale phenomena that take place in liquid media. Examples include aggregation and assembly of nanoparticles; colloidal crystal formation; liquid phase growth of structures such as nanowires; electrochemical deposition and etching for fabrication processes and battery applications; interfacial phenomena; boiling and cavitation; and biological interactions. Understanding of these fields would benefit greatly from real-time, in situ transmission electron microscope (TEM) imaging with nanoscale resolution. Most liquids cannot be imaged by traditional TEM due to evaporation in the high vacuum environment and the requirement that samples be very thin. Liquid-cell in situ TEM has emerged as an exciting new experimental technique that hermetically seals a thin slice of liquid between two electron transparent membranes to enable TEM imaging of liquid-based processes. This work presents details of the fabrication of a custom-made liquid-cell in situ TEM device, dubbed the nanoaquarium. The nanoaquarium's highlights include an exceptionally thin sample cross section (10s to 100s of nm); wafer scale processing that enables high-yield mass production; robust hermetic sealing that provides leak-free operation without use of glue, epoxy, or any polymers; compatibility with lab-on-chip technology; and on-chip integrated electrodes for sensing and actuation. The fabrication process is described, with an emphasis on direct wafer bonding. Experimental results involving direct observation of colloid aggregation using an aqueous solution of gold nanoparticles are presented. Quantitative analysis of the growth process agrees with prior results and theory, indicating that the experimental technique does not radically alter the observed phenomenon. For the first time, in situ observations of nanoparticles at a contact line and in an evaporating thin film of liquid are reported, with applications for techniques such as dip-coating and drop-casting, commonly used for depositing nanoparticles on a surface via convective-capillary assembly. Theoretical analysis suggests that the observed particle motion and aggregation are caused by gradients in surface tension and disjoining pressure in the thin liquid film.

In situ AFM investigation of slow crack propagation mechanisms in a glassy polymer

NASA Astrophysics Data System (ADS)

George, M.; Nziakou, Y.; Goerke, S.; Genix, A.-C.; Bresson, B.; Roux, S.; Delacroix, H.; Halary, J.-L.; Ciccotti, M.

2018-03-01

A novel experimental technique based on in situ AFM monitoring of the mechanisms of damage and the strain fields associated to the slow steady-state propagation of a fracture in glassy polymers is presented. This micron-scale investigation is complemented by optical measurements of the sample deformation up to the millimetric macroscopic scale of the sample in order to assess the proper crack driving conditions. These multi-scale observations provide important insights towards the modeling of the fracture toughness of glassy polymers and its relationship with the macromolecular structure and non-linear rheological properties. This novel technique is first tested on a standard PMMA thermoplastic in order to both evaluate its performance and the richness of this new kind of observations. Although the fracture propagation in PMMA is well known to proceed through crazing in the bulk of the samples, our observations provide a clear description and quantitative evaluation of a change of fracture mechanism towards shear yielding fracture accompanied by local necking close to the free surface of the sample, which can be explained by the local change of stress triaxiality. Moreover, this primary surface necking mechanism is shown to be accompanied by a network of secondary grooves that can be related to surface crazes propagating towards the interior of the sample. This overall scenario is validated by post-mortem fractographic investigations by scanning electron microscopy.

Recent developments of the in situ wet cell technology for transmission electron microscopies.

PubMed

Chen, Xin; Li, Chang; Cao, Hongling

2015-03-21

In situ wet cells for transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) allow studying structures and processes in a liquid environment with high temporal and spatial resolutions, and have been attracting increasing research interests in many fields. In this review, we highlight the structural and functional developments of the wet cells for TEM and STEM. One of the key features of the wet cells is the sealing technique used to isolate the liquid sample from the TEM/STEM vacuum environments, thus the existing in situ wet cells are grouped by different sealing methods. In this study, the advantages and shortcomings of each type of in situ wet cells are discussed, the functional developments of different wet cells are presented, and the future trends of the wet cell technology are addressed. It is suggested that in the future the in situ wet cell TEM/STEM technology will have an increasing impact on frontier nanoscale research.

On a Fast and Accurate In Situ Measuring Strategy for Recrystallization Kinetics and Its Application to an Al-Fe-Si Alloy

NASA Astrophysics Data System (ADS)

Kühbach, Markus; Brüggemann, Thiemo; Molodov, Konstantin D.; Gottstein, Günter

2015-03-01

In the current study, we detail a novel in situ X-ray diffraction-based bulk measurement technique, which allows for the continuous tracking of primary recrystallization kinetics. The approach is based on measuring the diffracted intensity that is correlated with the evolution of the volume fraction of particular texture components during annealing of a sample within a texture goniometer. The method is applied in an experimental study on a cold-rolled industrial Al-Fe-Si alloy. For comparison purposes, the macrotexture and the hardness evolution were monitored ex situ along isothermal and nonisothermal annealing. These measurements were then contrasted to the in situ obtained growth kinetics of recrystallizing grains in beta-fiber deformation and cube orientation. The results showed clearly that this method can be reliably utilized for the characterization of recrystallization kinetics in an industrial context.

Non-contact measurement of diamagnetic susceptibility change by a magnetic levitation technique

NASA Astrophysics Data System (ADS)

Takahashi, K.; Mogi, I.; Awaji, S.; Watanabe, K.

2011-03-01

A new method for measuring the temperature dependence of the diamagnetic susceptibility is described. It is based on the Faraday method and employs a magnetic levitation technique. The susceptibility of a magnetically levitating diamagnetic sample is determined from the product of the magnetic flux density and the field gradient at the levitating position observed using a micro CCD camera. The susceptibility of a sample during containerless melting and solidification can be measured to a precision of better than ±0.05%. The temperature dependence of the susceptibility of paraffin wax was measured by the magnetic levitation technique with an accuracy of ±0.25%. This method enables sensitive and contactless measurements of the diamagnetic susceptibility across the melting point with in situ observations.

In situ attosecond pulse characterization techniques to measure the electromagnetic phase

NASA Astrophysics Data System (ADS)

Spanner, M.; Bertrand, J. B.; Villeneuve, D. M.

2016-08-01

A number of techniques have been developed to characterize the attosecond emission from high-order-harmonic sources. These techniques are broadly classified as ex situ, where the attosecond pulse train photoionizes a target gas in the presence of an infrared field, and in situ, where the measurement takes place in the medium in which the attosecond pulses are generated. It is accepted that ex situ techniques measure the characteristics of the electromagnetic field, including the phase of the recombination transition moment of the emitting atom or molecule, when the phase of the second medium is known. However, there is debate about whether in situ techniques measure the electromagnetic field, or only the characteristics of the recolliding electron before recombination occurs. We show numerically that in situ measurements are not sensitive to the recombination phase, when implemented in the perturbative regime as originally envisioned, and that they do not measure the electromagnetic phase of the emission.

A Multi-Pumping Flow System for In Situ Measurements of Dissolved Manganese in Aquatic Systems

PubMed Central

Meyer, David; Prien, Ralf D.; Dellwig, Olaf; Waniek, Joanna J.; Schuffenhauer, Ingo; Donath, Jan; Krüger, Siegfried; Pallentin, Malte; Schulz-Bull, Detlef E.

2016-01-01

A METals In Situ analyzer (METIS) has been used to determine dissolved manganese (II) concentrations in the subhalocline waters of the Gotland Deep (central Baltic Sea). High-resolution in situ measurements of total dissolved Mn were obtained in near real-time by spectrophotometry using 1-(2-pyridylazo)-2-naphthol (PAN). PAN is a complexing agent of dissolved Mn and forms a wine-red complex with a maximum absorbance at a wavelength of 562 nm. Results are presented together with ancillary temperature, salinity, and dissolved O2 data. Lab calibration of the analyzer was performed in a pressure testing tank. A detection limit of 77 nM was obtained. For validation purposes, discrete water samples were taken by using a pump-CTD system. Dissolved Mn in these samples was determined by an independent laboratory based method (inductively coupled plasma–optical emission spectrometry, ICP-OES). Mn measurements from both METIS and ICP-OES analysis were in good agreement. The results showed that the in situ analysis of dissolved Mn is a powerful technique reducing dependencies on heavy and expensive equipment (pump-CTD system, ICP-OES) and is also cost and time effective. PMID:27916898

Catalytic graphitization behavior of phenolic resins by addition of in situ formed nano-Fe particles

NASA Astrophysics Data System (ADS)

Rastegar, H.; Bavand-vandchali, M.; Nemati, A.; Golestani-Fard, F.

2018-07-01

This work presents the catalytic graphitization process of phenolic resins (PR's) by addition of in situ nano-Fe particles as catalyst. Pyrolysis treatments of prepared compositions including various contents of nano-Fe particles were carried out at 600-1200 °C for 3 h under reducing atmosphere and graphitization process were evaluated by different techniques such as X-Ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), Simultaneous Thermal Analysis (STA) and Raman spectroscopy that mainly performed to identify the phase and microstructural analysis, oxidation resistance and extend of graphitized carbon formation. Results indicate that, in situ graphitic carbon development were already observed after firing the samples at 800 °C for 3 h under reducing atmosphere, increasing temperature and amount of nano-Fe led to a more effective graphitization level. In addition, the different nano crystalline carbon shapes such as onion and bamboo like and carbon nanotubes (CNTs) were in situ identified during graphitization process of nano-Fe containing samples. It was suggested that formation of these different nano carbon structures related to nano-Fe catalyst behavior and the carbon shell growth.

Specific detection of viable Listeria monocytogenes in Spanish wastewater treatment plants by Fluorescent In Situ Hybridization and PCR.

PubMed

Moreno, Yolanda; Ballesteros, Lorena; García-Hernández, Jorge; Santiago, Paula; González, Ana; Ferrús, M Antonia

2011-10-01

Listeria monocytogenes detection in wastewater can be difficult because of the large amount of background microbiota and the presence of viable but non-culturable forms in this environment. The aim of this study was to evaluate a Fluorescent In Situ Hybridization (FISH) assay combined with Direct Viable Count (DVC) method for detecting viable L. monocytogenes in wastewater samples, as an alternative to conventional culture methods. 16S rRNA sequence data were used to design a specific oligonucleotide probe. In order to assess the suitability of the method, the assays were performed on naturally (n=87) and artificially (n=14) contaminated samples and results were compared to those obtained with the isolation of cells on selective media and with a PCR method. The detection limit of FISH and PCR assays was 10(4) cells/mL without enrichment and 10 cells/mL after enrichment. A total of 47 samples, including 3 samples from effluent sites, yielded FISH positive results for L. monocytogenes. Using DVC-FISH technique, the presence of viable L. monocytogenes cells was detected in 23 out of these 47 FISH positive wastewater samples. PCR and culture methods yielded 27 and 23 positive results, respectively. According to these results, FISH technique has the potential to be used as a sensitive method for the detection and enumeration of L. monocytogenes in environmental wastewater samples. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dereplicating and spatial mapping of secondary metabolites from fungal cultures in situ

DOE PAGES

Kertesz, Vilmos; Van Berkel, Gary J.; Sica, Vincent P.; ...

2015-07-30

Ambient ionization techniques coupled to mass spectrometry have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. Identifying, mapping, and monitoring secondary metabolites directly on an organism provides invaluable spatial and temporal details that are lost through traditional extraction processes. Most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/VIS spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet liquid microjunction surface sampling probe (droplet LMJ SSP) was coupled with UPLC PDA HRMS MS/MS,more » thus providing separation, retention times, and UV/VIS data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites could be confidently and rapidly assigned in situ. Using the droplet LMJ SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures directly without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. As a result, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture.« less

Optical coherence refractometry.

PubMed

Tomlins, Peter H; Woolliams, Peter; Hart, Christian; Beaumont, Andrew; Tedaldi, Matthew

2008-10-01

We introduce a novel approach to refractometry using a low coherence interferometer at multiple angles of incidence. We show that for plane parallel samples it is possible to measure their phase refractive index rather than the group index that is usually measured by interferometric methods. This is a significant development because it enables bulk refractive index measurement of scattering and soft samples, not relying on surface measurements that can be prone to error. Our technique is also noncontact and compatible with in situ refractive index measurements. Here, we demonstrate this new technique on a pure silica test piece and a highly scattering resin slab, comparing the results with standard critical angle refractometry.

A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

NASA Astrophysics Data System (ADS)

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-09-01

It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.

In situ search for organics by gas chromatography analysis: new derivatization / thermochemolysis approach

NASA Astrophysics Data System (ADS)

Geffroy, Claude; Buch, Arnaud; David, Marc; Aissat, Lyes; El Mufleh, Amel; Papot, S.; Sternberg, Robert

Many organic molecules are present in interstellar clouds and might be carried to the early Earth by comets and meteorites during the heavy bombardment phase in the first few hundred million years of the solar system. It has been suggested that extraterrestrial organic material may well represent an important part of the organic material available for the origin of life. Until samples, brought by future space missions, are available on Earth, in situ measurements are one of the way to get unaltered and non-contaminated samples for analysis. The analytical technique has to be robust, sensitive and non-specific due to the large scope of targets molecules. The only currently flight qualified technique of analysis of organic molecules in space is gas chromatography (Viking, Cassini-Huygens, SAM-MSL, COSAC-Rosetta). The main objective of this work is to present a new approach with multi step analysis using derivatisation and thermochemolysis reagents for a one pot in situ analysis of volatile and refractory organics in surface or sub-surface samples (Mars, comets).Indeed, no single technology enables to identify all organic compounds because naturally occurring molecules have different polarities, molecular weights, being extractible or recalcitrant, bonded trapped or adsorbed on minerals. Thus, we propose to wider the scope of chemical reagent already validated for in situ wet chemistry such as MTBSTFA (Rodier et al. 2001, 2002), DMF-DMA (Rodier et al. 2002), or TMAH (Rodier et al, 2005, Geffroy-Rodier et al; 2009) to analyze enantiomers of amino acids, carbohydrates and lipids in a one pot several steps sub system using a multi reagent and multi step approach. Thus using a new derivatizing agent, we successfully identified twenty one amino acids including twelve of the twenty proteinic amino acids without inhibiting following multi step thermochemolysis. *Geffroy-Rodier C, Grasset L, Sternberg R. Buch A. Amblès A. (2009) Thermochemolysis in search for organics in extraterrestrial environments, Journal of Applied Pyrolysis 85: 454-459. *Rodier C, Sternberg R, Raulin F, Vidal-Madjar C (2001). In situ detection of organic molecules in extraterrestrial environment by gas chromatography / mass spectrometry. Journal of Chromatography A 915: 199-207. *Rodier C, Laurent C, Szopa C. Sternberg R, Raulin F (2002) Chirality and the origin of life: in situ enantiomeric separation for future space missions, Chirality 14: 527-532. *Rodier C. Sternberg R, Szopa C, Buch A, Cabane M and Raulin F (2005) Search for organics in extraterrestrial environments by in situ gas chromatography analysis. Advances in Space Research 36: 195-200. This work has been funded by CNES

Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

NASA Astrophysics Data System (ADS)

Hak, C.; Pundt, I.; Trick, S.; Kern, C.; Platt, U.; Dommen, J.; Ordóñez, C.; Prévôt, A. S. H.; Junkermann, W.; Astorga-Lloréns, C.; Larsen, B. R.; Mellqvist, J.; Strandberg, A.; Yu, Y.; Galle, B.; Kleffmann, J.; Lörzer, J. C.; Braathen, G. O.; Volkamer, R.

2005-11-01

Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine). White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within ±11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

NASA Astrophysics Data System (ADS)

Hak, C.; Pundt, I.; Kern, C.; Platt, U.; Dommen, J.; Ordóñez, C.; Prévôt, A. S. H.; Junkermann, W.; Astorga-Lloréns, C.; Larsen, B. R.; Mellqvist, J.; Strandberg, A.; Yu, Y.; Galle, B.; Kleffmann, J.; Lörzer, J. C.; Braathen, G. O.; Volkamer, R.

2005-05-01

Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine). White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within ±11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

Coupling between non-thermal plasmas and magnetic fields in space: in situ and remote observations with Parker Solar Probe and SunRISE

NASA Astrophysics Data System (ADS)

Kasper, J. C.

2017-12-01

This talk will review examples of open questions in the coupling between non-thermal plasmas and magnetic fields in space, including pressure anisotropies, in heating, and particle acceleration, in the context of space missions either preparing for launch or under study and using in situ observations or remote sensing techniques. The Parker Solar Probe, with launch in the summer of next year, will collect the first in situ samples of plasma in the outer corona, allowing us to directly observe the physical processes responsible for the heating and acceleration of the solar corona and solar wind. The Sun Radio Interferometer Space Experiment (SunRISE) mission is a low frequency radio array under study by NASA which would image for the first time locations of particle acceleration relative to coronal mass ejections and trace magnetic field lines that connect active regions to the heliosphere. Major open questions under investigation by these techniques will be explored, with an eye to connections to laboratory experiments.

A review of techniques for visualising soft tissue microstructure deformation and quantifying strain Ex Vivo.

PubMed

Disney, C M; Lee, P D; Hoyland, J A; Sherratt, M J; Bay, B K

2018-04-14

Many biological tissues have a complex hierarchical structure allowing them to function under demanding physiological loading conditions. Structural changes caused by ageing or disease can lead to loss of mechanical function. Therefore, it is necessary to characterise tissue structure to understand normal tissue function and the progression of disease. Ideally intact native tissues should be imaged in 3D and under physiological loading conditions. The current published in situ imaging methodologies demonstrate a compromise between imaging limitations and maintaining the samples native mechanical function. This review gives an overview of in situ imaging techniques used to visualise microstructural deformation of soft tissue, including three case studies of different tissues (tendon, intervertebral disc and artery). Some of the imaging techniques restricted analysis to observational mechanics or discrete strain measurement from invasive markers. Full-field local surface strain measurement has been achieved using digital image correlation. Volumetric strain fields have successfully been quantified from in situ X-ray microtomography (micro-CT) studies of bone using digital volume correlation but not in soft tissue due to low X-ray transmission contrast. With the latest developments in micro-CT showing in-line phase contrast capability to resolve native soft tissue microstructure, there is potential for future soft tissue mechanics research where 3D local strain can be quantified. These methods will provide information on the local 3D micromechanical environment experienced by cells in healthy, aged and diseased tissues. It is hoped that future applications of in situ imaging techniques will impact positively on the design and testing of potential tissue replacements or regenerative therapies. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

Water Quality Variable Estimation using Partial Least Squares Regression and Multi-Scale Remote Sensing.

NASA Astrophysics Data System (ADS)

Peterson, K. T.; Wulamu, A.

2017-12-01

Water, essential to all living organisms, is one of the Earth's most precious resources. Remote sensing offers an ideal approach to monitor water quality over traditional in-situ techniques that are highly time and resource consuming. Utilizing a multi-scale approach, incorporating data from handheld spectroscopy, UAS based hyperspectal, and satellite multispectral images were collected in coordination with in-situ water quality samples for the two midwestern watersheds. The remote sensing data was modeled and correlated to the in-situ water quality variables including chlorophyll content (Chl), turbidity, and total dissolved solids (TDS) using Normalized Difference Spectral Indices (NDSI) and Partial Least Squares Regression (PLSR). The results of the study supported the original hypothesis that correlating water quality variables with remotely sensed data benefits greatly from the use of more complex modeling and regression techniques such as PLSR. The final results generated from the PLSR analysis resulted in much higher R2 values for all variables when compared to NDSI. The combination of NDSI and PLSR analysis also identified key wavelengths for identification that aligned with previous study's findings. This research displays the advantages and future for complex modeling and machine learning techniques to improve water quality variable estimation from spectral data.

LIBS Analysis for Coal

NASA Astrophysics Data System (ADS)

E. Romero, Carlos; De Saro, Robert

Coal is a non-uniform material with large inherent variability in composition, and other important properties, such as calorific value and ash fusion temperature. This quality variability is very important when coal is used as fuel in steam generators, since it affects boiler operation and control, maintenance and availability, and the extent and treatment of environmental pollution associated with coal combustion. On-line/in situ monitoring of coal before is fed into a boiler is a necessity. A very few analytical techniques like X-ray fluorescence and prompt gamma neutron activation analysis are available commercially with enough speed and sophistication of data collection for continuous coal monitoring. However, there is still a need for a better on-line/in situ technique that has higher selectivity, sensitivity, accuracy and precision, and that is safer and has a lower installation and operating costs than the other options. Laser induced breakdown spectroscopy (LIBS) is ideal for coal monitoring in boiler applications as it need no sample preparation, it is accurate and precise it is fast, and it can detect all of the elements of concern to the coal-fired boiler industry. LIBS data can also be adapted with advanced data processing techniques to provide real-time information required by boiler operators nowadays. This chapter summarizes development of LIBS for on-line/in situ coal applications in utility boilers.

Design of a facility for the in situ measurement of catalytic reaction by neutron scattering spectroscopy

NASA Astrophysics Data System (ADS)

Tan, Shuai; Cheng, Yongqiang; Daemen, Luke L.; Lutterman, Daniel A.

2018-01-01

Catalysis is a critical enabling science for future energy needs. The next frontier of catalysis is to evolve from catalyst discovery to catalyst design, and for this next step to be realized, we must develop new techniques to better understand reaction mechanisms. To do this, we must connect catalytic reaction rates and selectivities to the kinetics, energetics, and dynamics of individual elementary steps and relate these to the structure and dynamics of the catalytic sites involved. Neutron scattering spectroscopies offer unique capabilities that are difficult or impossible to match by other techniques. The current study presents the development of a compact and portable instrumental design that enables the in situ investigation of catalytic samples by neutron scattering techniques. The developed apparatus was tested at the Spallation Neutron Source (SNS) in Oak Ridge National Laboratory and includes a gas handling panel that allows for computer hookups to control the panel externally and online measurement equipment such as coupled GC-FID/TCD (Gas Chromatography-Flame Ionization Detector/Thermal Conductivity Detector) and MS (Mass Spectrometry) to characterize offgassing while the sample is in the neutron scattering spectrometer. This system is flexible, modular, compact, and portable enabling its use for many types of gas-solid and liquid-solid reactions at the various beamlines housed at the SNS.

Experimental design and quality assurance: in situ fluorescence instrumentation

USGS Publications Warehouse

Conmy, Robyn N.; Del Castillo, Carlos E.; Downing, Bryan D.; Chen, Robert F.

2014-01-01

Both instrument design and capabilities of fluorescence spectroscopy have greatly advanced over the last several decades. Advancements include solid-state excitation sources, integration of fiber optic technology, highly sensitive multichannel detectors, rapid-scan monochromators, sensitive spectral correction techniques, and improve data manipulation software (Christian et al., 1981, Lochmuller and Saavedra, 1986; Cabniss and Shuman, 1987; Lakowicz, 2006; Hudson et al., 2007). The cumulative effect of these improvements have pushed the limits and expanded the application of fluorescence techniques to numerous scientific research fields. One of the more powerful advancements is the ability to obtain in situ fluorescence measurements of natural waters (Moore, 1994). The development of submersible fluorescence instruments has been made possible by component miniaturization and power reduction including advances in light sources technologies (light-emitting diodes, xenon lamps, ultraviolet [UV] lasers) and the compatible integration of new optical instruments with various sampling platforms (Twardowski et at., 2005 and references therein). The development of robust field sensors skirt the need for cumbersome and or time-consuming filtration techniques, the potential artifacts associated with sample storage, and coarse sampling designs by increasing spatiotemporal resolution (Chen, 1999; Robinson and Glenn, 1999). The ability to obtain rapid, high-quality, highly sensitive measurements over steep gradients has revolutionized investigations of dissolved organic matter (DOM) optical properties, thereby enabling researchers to address novel biogeochemical questions regarding colored or chromophoric DOM (CDOM). This chapter is dedicated to the origin, design, calibration, and use of in situ field fluorometers. It will serve as a review of considerations to be accounted for during the operation of fluorescence field sensors and call attention to areas of concern when making this type of measurement. Attention is also given to ways in which in-water fluorescence measurements have revolutionized biogeochemical studies of CDOM and how those measurements can be used in conjunction with remotely sense satellite data to understand better the biogeochemistry of DOM in aquatic environments.

The use of FT-IR reflection-absorbance spectroscopy to study photochemical degradation of polymeric coatings on mirrors

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

Webb, J.D.; Chughtai, A.R.; Czanderna, A.W.

1981-10-01

A technique is presented for in situ study of degradative changes in polymeric coatings on metallic substrates. The technique uses a controlled environment chamber in conjunction with a Fourier-transform infrared (FT-IR) spectrophotometer. The chamber design permits collection of IR reflection-absorbance spectra from a sample undergoing exposure to controlled ultraviolet (UV) radiation, gas mixtures, and temperatures. Initial data presented confirm the ability of the technique to provide information regarding the bulk photochemistry of bisphenol-A polycarbonate coatings on gold and aluminum substrates. Refinements of this technique should allow a detailed kinetic study of degradative reactions at the polymer/metal interface.

Use of FT-IR reflection-absorbance spectroscopy to study photochemical degradation of polymeric coatings on mirrors

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

Webb, J D; Schissel, P; Czanderna, A W

1981-01-01

A technique is presented for in situ study of degradative changes in polymeric coatings on metallic substrates. The technique uses a controlled environment chamber in conjunction with a Fourier-transform infrared (FT-IR) spectrophotometer. The chamber design permits collection of IR reflection-absorbance spectra from a sample undergoing exposure to controlled ultraviolet (uv) radiation, gas mixtures, and temperatures. Initial data presented confirm the ability of the technique to provide information regarding the bulk photochemistry of bisphenol-A polycarbonate coatings on gold and aluminum substrates. Refinements of this technique should allow a detailed kinetic study of degradative reactions at the polymer/metal interface.

Two-Step Resonance-Enhanced Desorption Laser Mass Spectrometry for In Situ Analysis of Organic-Rich Environments

NASA Technical Reports Server (NTRS)

Getty, S. A.; Grubisic, A.; Uckert, K.; Li, X.; Cornish, T.; Cook, J. E.; Brinckerhoff, W. B.

2016-01-01

A wide diversity of planetary surfaces in the solar system represent high priority targets for in situ compositional and contextual analysis as part of future missions. The planned mission portfolio will inform our knowledge of the chemistry at play on Mars, icy moons, comets, and primitive asteroids, which can lead to advances in our understanding of the interplay between inorganic and organic building blocks that led to the evolution of habitable environments on Earth and beyond. In many of these environments, the presence of water or aqueously altered mineralogy is an important indicator of habitable environments that are present or may have been present in the past. As a result, the search for complex organic chemistry that may imply the presence of a feedstock, if not an inventory of biosignatures, is naturally aligned with targeted analyses of water-rich surface materials. Here we describe the two-step laser mass spectrometry (L2MS) analytical technique that has seen broad application in the study of organics in meteoritic samples, now demonstrated to be compatible with an in situ investigation with technique improvements to target high priority planetary environments as part of a future scientific payload. An ultraviolet (UV) pulsed laser is used in previous and current embodiments of laser desorption/ionization mass spectrometry (LDMS) to produce ionized species traceable to the mineral and organic composition of a planetary surface sample. L2MS, an advanced technique in laser mass spectrometry, is selective to the aromatic organic fraction of a complex sample, which can provide additional sensitivity and confidence in the detection of specific compound structures. Use of a compact two-step laser mass spectrometer prototype has been previously reported to provide specificity to key aromatic species, such as PAHs, nucleobases, and certain amino acids. Recent improvements in this technique have focused on the interaction between the mineral matrix and the organic analyte. The majority of planetary targets of astrobiological interest are characterized by the presence of water or hydrated mineral phases. Water signatures can indicate a history of available liquid water that may have played an important role in the chemical environment of these planetary surfaces and subsurfaces. The studies we report here investigate the influence of water content on the detectability of organics by L2MS in planetary analog samples.

Can we trust intraoperative culture results in nonunions?

PubMed

Palmer, Michael P; Altman, Daniel T; Altman, Gregory T; Sewecke, Jeffrey J; Ehrlich, Garth D; Hu, Fen Z; Nistico, Laura; Melton-Kreft, Rachel; Gause, Trent M; Costerton, John W

2014-07-01

To identify the presence of bacterial biofilms in nonunions comparing molecular techniques (multiplex polymerase chain reaction and mass spectrometry, fluorescent in situ hybridization) with routine intraoperative cultures. Thirty-four patients with nonunions were scheduled for surgery and enrolled in this ongoing prospective study. Intraoperative specimens were collected from removed implants, surrounding tissue membrane, and local soft tissue followed by standard culture analysis, Ibis's second generation molecular diagnostics (Ibis Biosystems), and bacterial 16S rRNA-based fluorescence in situ hybridization (FISH). Confocal microscopy was used to visualize the tissue specimens reacted with the FISH probes, which were chosen based on the Ibis analysis. Thirty-four patient encounters were analyzed. Eight were diagnosed as infected nonunions by positive intraoperative culture results. Ibis confirmed the presence of bacteria in all 8 samples. Ibis identified bacteria in a total of 30 of 34 encounters, and these data were confirmed by FISH. Twenty-two of 30 Ibis-positive samples were culture-negative. Four samples were negative by all methods of analysis. No samples were positive by culture, but negative by molecular techniques. Our preliminary data indicate that molecular diagnostics are more sensitive for identifying bacteria than cultures in cases of bony nonunion. This is likely because of the inability of cultures to detect biofilms and bacteria previously exposed to antibiotic therapy. Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Monitoring cure of composite resins using frequency dependent electromagnetic sensing techniques

NASA Technical Reports Server (NTRS)

Kranbuehl, D. E.; Hoff, M. S.; Loos, A. C.; Freeman, W. T., Jr.; Eichinger, D. A.

1988-01-01

A nondestructive in situ measurement technique has been developed for monitoring and measuring the cure processing properties of composite resins. Frequency dependent electromagnetic sensors (FDEMS) were used to directly measure resin viscosity during cure. The effects of the cure cycle and resin aging on the viscosity during cure were investigated using the sensor. Viscosity measurements obtained using the sensor are compared with the viscosities calculated by the Loos-Springer cure process model. Good overall agreement was obtained except for the aged resin samples.

Flask sample measurements for CO2, CH4 and CO using cavity ring-down spectrometry

NASA Astrophysics Data System (ADS)

Wang, J.-L.; Jacobson, G.; Rella, C. W.; Chang, C.-Y.; Liu, I.; Liu, W.-T.; Chew, C.; Ou-Yang, C.-F.; Liao, W.-C.; Chang, C.-C.

2013-08-01

In recent years, cavity ring-down spectrometry (CRDS) has been demonstrated to be a highly sensitive, stable and fast analytical technique for real-time in situ measurements of greenhouse gases. In this study, we propose the technique (which we call flask-CRDS) of analyzing whole air flask samples for CO2, CH4 and CO using a custom gas manifold designed to connect to a CRDS analyzer. Extremely stable measurements of these gases can be achieved over a large pressure range in the flask, from 175 to 760 Torr. The wide pressure range is conducive to flask sample measurement in three ways: (1) flask samples can be collected in low-pressure environments (e.g. high-altitude locations); (2) flask samples can be first analyzed for other trace gases with the remaining low-pressure sample for CRDS analysis of CO2, CH4 and CO; and (3) flask samples can be archived and re-analyzed for validation. The repeatability of this method (1σ of 0.07 ppm for CO2, 0.4 ppb for CH4, and 0.5 ppb for CO) was assessed by analyzing five canisters filled with the same air sample to a pressure of 200 Torr. An inter-comparison of the flask-CRDS data with in-situ CRDS measurements at a high-altitude mountain baseline station revealed excellent agreement, with differences of 0.10 ± 0.09 ppm (1σ) for CO2 and 0.9 ± 1.0 ppb for CH4. This study demonstrated that the flask-CRDS method was not only simple to build and operate but could also perform highly accurate and precise measurements of atmospheric CO2, CH4 and CO in flask samples.

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry.

PubMed

Zhu, Hongying; Zou, Guichang; Wang, Ning; Zhuang, Meihui; Xiong, Wei; Huang, Guangming

2017-03-07

The use of single-cell assays has emerged as a cutting-edge technique during the past decade. Although single-cell mass spectrometry (MS) has recently achieved remarkable results, deep biological insights have not yet been obtained, probably because of various technical issues, including the unavoidable use of matrices, the inability to maintain cell viability, low throughput because of sample pretreatment, and the lack of recordings of cell physiological activities from the same cell. In this study, we describe a patch clamp/MS-based platform that enables the sensitive, rapid, and in situ chemical profiling of single living neurons. This approach integrates modified patch clamp technique and modified MS measurements to directly collect and detect nanoliter-scale samples from the cytoplasm of single neurons in mice brain slices. Abundant possible cytoplasmic constituents were detected in a single neuron at a relatively fast rate, and over 50 metabolites were identified in this study. The advantages of direct, rapid, and in situ sampling and analysis enabled us to measure the biological activities of the cytoplasmic constituents in a single neuron, including comparing neuron types by cytoplasmic chemical constituents; observing changes in constituent concentrations as the physiological conditions, such as age, vary; and identifying the metabolic pathways of small molecules.

Single-neuron identification of chemical constituents, physiological changes, and metabolism using mass spectrometry

PubMed Central

Zhu, Hongying; Zou, Guichang; Wang, Ning; Zhuang, Meihui; Xiong, Wei; Huang, Guangming

2017-01-01

The use of single-cell assays has emerged as a cutting-edge technique during the past decade. Although single-cell mass spectrometry (MS) has recently achieved remarkable results, deep biological insights have not yet been obtained, probably because of various technical issues, including the unavoidable use of matrices, the inability to maintain cell viability, low throughput because of sample pretreatment, and the lack of recordings of cell physiological activities from the same cell. In this study, we describe a patch clamp/MS-based platform that enables the sensitive, rapid, and in situ chemical profiling of single living neurons. This approach integrates modified patch clamp technique and modified MS measurements to directly collect and detect nanoliter-scale samples from the cytoplasm of single neurons in mice brain slices. Abundant possible cytoplasmic constituents were detected in a single neuron at a relatively fast rate, and over 50 metabolites were identified in this study. The advantages of direct, rapid, and in situ sampling and analysis enabled us to measure the biological activities of the cytoplasmic constituents in a single neuron, including comparing neuron types by cytoplasmic chemical constituents; observing changes in constituent concentrations as the physiological conditions, such as age, vary; and identifying the metabolic pathways of small molecules. PMID:28223513

In Situ Live-Cell Nucleus Fluorescence Labeling with Bioinspired Fluorescent Probes.

PubMed

Ding, Pan; Wang, Houyu; Song, Bin; Ji, Xiaoyuan; Su, Yuanyuan; He, Yao

2017-08-01

Fluorescent imaging techniques for visualization of nuclear structure and function in live cells are fundamentally important for exploring major cellular events. The ideal cellular labeling method is capable of realizing label-free, in situ, real-time, and long-term nucleus labeling in live cells, which can fully obtain the nucleus-relative information and effectively alleviate negative effects of alien probes on cellular metabolism. However, current established fluorescent probes-based strategies (e.g., fluorescent proteins-, organic dyes-, fluorescent organic/inorganic nanoparticles-based imaging techniques) are unable to simultaneously realize label-free, in situ, long-term, and real-time nucleus labeling, resulting in inevitable difficulties in fully visualizing nuclear structure and function in live cells. To this end, we present a type of bioinspired fluorescent probes, which are highly efficacious for in situ and label-free tracking of nucleus in long-term and real-time manners. Typically, the bioinspired polydopamine (PDA) nanoparticles, served as fluorescent probes, can be readily synthesized in situ within live cell nucleus without any further modifications under physiological conditions (37 °C, pH ∼7.4). Compared with other conventional nuclear dyes (e.g., propidium iodide (PI), Hoechst), superior spectroscopic properties (e.g., quantum yield of ∼35.8% and high photostability) and low cytotoxicity of PDA-based probes enable long-term (e.g., 3 h) fluorescence tracking of nucleus. We also demonstrate the generality of this type of bioinspired fluorescent probes in different cell lines and complex biological samples.

Determination of the acoustoelastic coefficient for surface acoustic waves using dynamic acoustoelastography: an alternative to static strain.

PubMed

Ellwood, R; Stratoudaki, T; Sharples, S D; Clark, M; Somekh, M G

2014-03-01

The third-order elastic constants of a material are believed to be sensitive to residual stress, fatigue, and creep damage. The acoustoelastic coefficient is directly related to these third-order elastic constants. Several techniques have been developed to monitor the acoustoelastic coefficient using ultrasound. In this article, two techniques to impose stress on a sample are compared, one using the classical method of applying a static strain using a bending jig and the other applying a dynamic stress due to the presence of an acoustic wave. Results on aluminum samples are compared. Both techniques are found to produce similar values for the acoustoelastic coefficient. The dynamic strain technique however has the advantages that it can be applied to large, real world components, in situ, while ensuring the measurement takes place in the nondestructive, elastic regime.

A technique for recording polycrystalline structure and orientation during in situ deformation cycles of rock analogues using an automated fabric analyser.

PubMed

Peternell, M; Russell-Head, D S; Wilson, C J L

2011-05-01

Two in situ plane-strain deformation experiments on norcamphor and natural ice using synchronous recording of crystal c-axis orientations have been performed with an automated fabric analyser and a newly developed sample press and deformation stage. Without interrupting the deformation experiment, c-axis orientations are determined for each pixel in a 5 × 5 mm sample area at a spatial resolution of 5 μm/pixel. In the case of norcamphor, changes in microstructures and associated crystallographic information, at a strain rate of ∼2 × 10(-5) s(-1), were recorded for the first time during a complete in situ deformation-cycle experiment that consisted of an annealing, deformation and post-deformation annealing path. In the case of natural ice, slower external strain rates (∼1 × 10(-6) s(-1)) enabled the investigation of small changes in the polycrystal aggregate's crystallography and microstructure for small amounts of strain. The technical setup and first results from the experiments are presented. © 2010 The Authors Journal of Microscopy © 2010 Royal Microscopical Society.

Characterizing spatial and temporal variability of dissolved gases in aquatic environments with in situ mass spectrometry.

PubMed

Camilli, Richard; Duryea, Anthony N

2009-07-01

The TETHYS mass spectrometer is intended for long-term in situ observation of dissolved gases and volatile organic compounds in aquatic environments. Its design maintains excellent low mass range sensitivity and stability during long-term operations, enabling characterization of low-frequency variability in many trace dissolved gases. Results are presented from laboratory trials and a 300-h in situ trial in a shallow marine embayment in Massachusetts, U.S.A. This time series consists of over 15000 sample measurements and represents the longest continuous record made by an in situ mass spectrometer in an aquatic environment. These measurements possess sufficient sampling density and duration to apply frequency analysis techniques for study of temporal variability in dissolved gases. Results reveal correlations with specific environmental periodicities. Numerical methods are presented for converting mass spectrometer ion peak ratios to absolute-scale dissolved gas concentrations across wide temperature regimes irrespective of ambient pressure, during vertical water column profiles in a hypoxic deep marine basin off the coast of California, U.S.A. Dissolved oxygen concentration values obtained with the TETHYS instrument indicate close correlation with polarographic oxygen sensor data across the entire depth range. These methods and technology enable observation of aquatic environmental chemical distributions and dynamics at appropriate scales of resolution.

Planetary surface exploration using Raman spectroscopy for minerals and organics

NASA Astrophysics Data System (ADS)

Blacksberg, J.; Alerstam, E.; Maruyama, Y.; Charbon, E.; Rossman, G. R.; Shkolyar, S.; Farmer, J. D.

2013-12-01

Raman spectroscopy has been identified as one of the primary techniques for planetary surface mineralogy. It is widely used as a laboratory technique since it can identify nearly all crystalline mineral phases. Using a small spot size on the surface (on the order of a micron), mineral phases can be mapped onto microscopic images preserving information about surface morphology. As a result, this technique has been steadily gaining support for in situ exploration of a variety of target bodies, for example Mars, the Moon, Venus, asteroids, and comets. In addition to in situ exploration, Raman spectroscopy has been identified as a feasible means for pre-selection of samples on Mars for subsequent return to Earth. This is in part due to the fact that Raman can detect many organics in addition to minerals. As a result, the most relevant rock samples containing organics (potentially fossil biosignatures) may potentially be selected for return to Earth. We present a next-generation instrument that builds on the widely used 532 nm Raman technique to provide a means for performing Raman spectroscopy without the background noise that is often generated by fluorescence of minerals and organics. We use time-resolved laser spectroscopy to eliminate this fluorescence interference that can often make it difficult or impossible to obtain Raman spectra. We will discuss significant advances leading to the feasibility of a compact time-resolved spectrometer, including the development of a new solid-state detector capable of sub-ns temporal resolution. We will address the challenges of analyzing surface materials, often organics, that exhibit short-lifetime fluorescence. We will present result on planetary analog samples to demonstrate the instrument performance including fluorescence rejection.

Quantitative label-free multimodality nonlinear optical imaging for in situ differentiation of cancerous lesions

NASA Astrophysics Data System (ADS)

Xu, Xiaoyun; Li, Xiaoyan; Cheng, Jie; Liu, Zhengfan; Thrall, Michael J.; Wang, Xi; Wang, Zhiyong; Wong, Stephen T. C.

2013-03-01

The development of real-time, label-free imaging techniques has recently attracted research interest for in situ differentiation of cancerous lesions from normal tissues. Molecule-specific intrinsic contrast can arise from label-free imaging techniques such as Coherent Anti-Stokes Raman Scattering (CARS), Two-Photon Excited AutoFluorescence (TPEAF), and Second Harmonic Generation (SHG), which, in combination, would hold the promise of a powerful label-free tool for cancer diagnosis. Among cancer-related deaths, lung carcinoma is the leading cause for both sexes. Although early treatment can increase the survival rate dramatically, lesion detection and precise diagnosis at an early stage is unusual due to its asymptomatic nature and limitations of current diagnostic techniques that make screening difficult. We investigated the potential of using multimodality nonlinear optical microscopy that incorporates CARS, TPEAF, and SHG techniques for differentiation of lung cancer from normal tissue. Cancerous and non-cancerous lung tissue samples from patients were imaged using CARS, TPEAF, and SHG techniques for comparison. These images showed good pathology correlation with hematoxylin and eosin (H and E) stained sections from the same tissue samples. Ongoing work includes imaging at various penetration depths to show three-dimensional morphologies of tumor cell nuclei using CARS, elastin using TPEAF, and collagen using SHG and developing classification algorithms for quantitative feature extraction to enable lung cancer diagnosis. Our results indicate that via real-time morphology analyses, a multimodality nonlinear optical imaging platform potentially offers a powerful minimally-invasive way to differentiate cancer lesions from surrounding non-tumor tissues in vivo for clinical applications.

Processing of pulse oximeter signals using adaptive filtering and autocorrelation to isolate perfusion and oxygenation components

NASA Astrophysics Data System (ADS)

Ibey, Bennett; Subramanian, Hariharan; Ericson, Nance; Xu, Weijian; Wilson, Mark; Cote, Gerard L.

2005-03-01

A blood perfusion and oxygenation sensor has been developed for in situ monitoring of transplanted organs. In processing in situ data, motion artifacts due to increased perfusion can create invalid oxygenation saturation values. In order to remove the unwanted artifacts from the pulsatile signal, adaptive filtering was employed using a third wavelength source centered at 810nm as a reference signal. The 810 nm source resides approximately at the isosbestic point in the hemoglobin absorption curve where the absorbance of light is nearly equal for oxygenated and deoxygenated hemoglobin. Using an autocorrelation based algorithm oxygenation saturation values can be obtained without the need for large sampling data sets allowing for near real-time processing. This technique has been shown to be more reliable than traditional techniques and proven to adequately improve the measurement of oxygenation values in varying perfusion states.

[Detection of Toxoplasma gondii DNA in human lymph node tissue by in situ hybridization].

PubMed

Liu, C; Ke, O; Tan, D; Zhang, Z

1998-01-01

To detect the presence of Toxoplasma gondii in lymph node tissue in patients with Toxoplasma infection. T. gondii (RH strain) specific DNA fragment clones were obtained by using PCR and gene recombination technique. The DNA fragments used as hybridization probes were labelled with digoxigenin by random primer method. The technique of in situ hybridization (ISH) was used to detect T. g DNA in the lymph node sections. Four out of 120 samples T. g DNA were found positive, one with Hodgkin's disease (HD) (1/32), one with non-Hodgkin's lymphoma (NHL) (1/41) and 2 with chronic lymphadenitis (CL) (2/47). The total positive rate was 3.3%. It was demonstrated that this highly specific probe could detect 10 pg of the total RH strain T. g DNA. ISH was applicable in detecting pathogens in the lymph node tissues of individuals with Toxoplasma infection.

In situ spectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

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

Gerbig, Yvonne B.; Michaels, C. A.; Bradby, Jodie E.

Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique (IIT). The occurrence and evolving spatial distribution of changes in the a-Si structure caused by processes, such as polyamorphization and crystallization, induced by indentation loading were observed. Furthermore, the obtained experimental results are linked with previously published work on the plastic deformation of a-Si under hydrostatic compression and shear deformation to establish a model for the deformation behavior of a-Si under indentation loading.

In situ spectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

DOE PAGES

Gerbig, Yvonne B.; Michaels, C. A.; Bradby, Jodie E.; ...

2015-12-17

Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique (IIT). The occurrence and evolving spatial distribution of changes in the a-Si structure caused by processes, such as polyamorphization and crystallization, induced by indentation loading were observed. Furthermore, the obtained experimental results are linked with previously published work on the plastic deformation of a-Si under hydrostatic compression and shear deformation to establish a model for the deformation behavior of a-Si under indentation loading.

Mechanical properties enhancement and microstructure study of Al-Si-TiB2 in situ composites

NASA Astrophysics Data System (ADS)

Sahoo, S. K.; Majhi, J.; Pattnaik, A. B.; Sahoo, J. K.; Das, Swagat

2018-03-01

Al–Si alloy-based composite is one of the most promising MMC materials owing to its outstanding mechanical properties, wear and corrosion resistance, low cost and ability to be synthesized via conventional casting routes. Challenges in achieving clean interface between reinforced particles and matrix alloy have been overcome by means of in-situ techniques of fabrication. Present investigation is concerned with synthesizing Al-Si-TiB2 in-situ composites through stir casting route using K2TiF6 and KBF4 halide salts for exothermic salt metal reaction. X-Ray diffraction analysis revealed the existence of TiB2 in the prepared samples. Effect of TiB2in-situ particles in the Al-Si base alloy has been investigated from the results obtained from optical microscopy as well as SEM study and wear analysis with a pin on disc wear testing apparatus. Improved hardness and wear properties were observed with addition of TiB2.

Development of laser-based techniques for in situ characterization of the first wall in ITER and future fusion devices

NASA Astrophysics Data System (ADS)

Philipps, V.; Malaquias, A.; Hakola, A.; Karhunen, J.; Maddaluno, G.; Almaviva, S.; Caneve, L.; Colao, F.; Fortuna, E.; Gasior, P.; Kubkowska, M.; Czarnecka, A.; Laan, M.; Lissovski, A.; Paris, P.; van der Meiden, H. J.; Petersson, P.; Rubel, M.; Huber, A.; Zlobinski, M.; Schweer, B.; Gierse, N.; Xiao, Q.; Sergienko, G.

2013-09-01

Analysis and understanding of wall erosion, material transport and fuel retention are among the most important tasks for ITER and future devices, since these questions determine largely the lifetime and availability of the fusion reactor. These data are also of extreme value to improve the understanding and validate the models of the in vessel build-up of the T inventory in ITER and future D-T devices. So far, research in these areas is largely supported by post-mortem analysis of wall tiles. However, access to samples will be very much restricted in the next-generation devices (such as ITER, JT-60SA, W7-X, etc) with actively cooled plasma-facing components (PFC) and increasing duty cycle. This has motivated the development of methods to measure the deposition of material and retention of plasma fuel on the walls of fusion devices in situ, without removal of PFC samples. For this purpose, laser-based methods are the most promising candidates. Their feasibility has been assessed in a cooperative undertaking in various European associations under EFDA coordination. Different laser techniques have been explored both under laboratory and tokamak conditions with the emphasis to develop a conceptual design for a laser-based wall diagnostic which is integrated into an ITER port plug, aiming to characterize in situ relevant parts of the inner wall, the upper region of the inner divertor, part of the dome and the upper X-point region.

Avoiding treatment bias of REDD+ monitoring by sampling with partial replacement.

PubMed

Köhl, Michael; Scott, Charles T; Lister, Andrew J; Demon, Inez; Plugge, Daniel

2015-12-01

Implementing REDD+ renders the development of a measurement, reporting and verification (MRV) system necessary to monitor carbon stock changes. MRV systems generally apply a combination of remote sensing techniques and in-situ field assessments. In-situ assessments can be based on 1) permanent plots, which are assessed on all successive occasions, 2) temporary plots, which are assessed only once, and 3) a combination of both. The current study focuses on in-situ assessments and addresses the effect of treatment bias, which is introduced by managing permanent sampling plots differently than the surrounding forests. Temporary plots are not subject to treatment bias, but are associated with large sampling errors and low cost-efficiency. Sampling with partial replacement (SPR) utilizes both permanent and temporary plots. We apply a scenario analysis with different intensities of deforestation and forest degradation to show that SPR combines cost-efficiency with the handling of treatment bias. Without treatment bias permanent plots generally provide lower sampling errors for change estimates than SPR and temporary plots, but do not provide reliable estimates, if treatment bias occurs, SPR allows for change estimates that are comparable to those provided by permanent plots, offers the flexibility to adjust sample sizes in the course of time, and allows to compare data on permanent versus temporary plots for detecting treatment bias. Equivalence of biomass or carbon stock estimates between permanent and temporary plots serves as an indication for the absence of treatment bias while differences suggest that there is evidence for treatment bias. SPR is a flexible tool for estimating emission factors from successive measurements. It does not entirely depend on sample plots that are installed at the first occasion but allows for the adjustment of sample sizes and placement of new plots at any occasion. This ensures that in-situ samples provide representative estimates over time. SPR offers the possibility to increase sampling intensity in areas with high degradation intensities or to establish new plots in areas where permanent plots are lost due to deforestation. SPR is also an ideal approach to mitigate concerns about treatment bias.

In situ formation of the active sites in Pd-Au bimetallic nanocatalysts for CO oxidation: NAP (near ambient pressure) XPS and MS study.

PubMed

Bukhtiyarov, A V; Prosvirin, I P; Saraev, A A; Klyushin, A Yu; Knop-Gericke, A; Bukhtiyarov, V I

2018-06-07

Model bimetallic Pd-Au/HOPG catalysts have been investigated in the CO oxidation reaction using a combination of NAP XPS and MS techniques. The samples have shown catalytic activity at temperatures above 150 °C. The redistribution of Au and Pd on the surface depending on the reaction conditions has been demonstrated using NAP XPS. The Pd enrichment of the bimetallic particles' surface under reaction gas mixture has been shown. Apparently, CO adsorption induces Pd segregation on the surface. Heating the sample under reaction conditions above 150 °C decomposes the Pd-CO state due to CO desorption and reaction and simultaneous Pd-Au alloy formation on the surface takes place. Cooling back down to RT results in reversible Pd segregation due to Pd-CO formation and the sample becomes inactive. It has been shown that in situ studies are necessary for investigation of the active sites in Pd-Au bimetallic systems.

A Miniature Laser Desorption/Ionization Time-of-Flight Mass Spectrometer for in Situ Analysis of Mars Surface Composition and Identification of Hazard in Advance of Future Manned Exploration

NASA Technical Reports Server (NTRS)

Getty, S. A.; Brinckerhoff, W. B.; Arevalo, R. D.; Floyd, M. M.; Li, X.; Cornish, T.; Ecelberger, S. A.

2012-01-01

Future landed missions to Mars will be guided by two strategic directions: (1) sample return to Earth, for comprehensive compositional analyses, as recommended by the 2011 NRC Planetary Decadal Survey; and (2) preparation for human exploration in the 2030s and beyond, as laid out by US space policy. The resultant mission architecture will likely require high-fidelity in situ chemical/organic sample analyses within an extremely constrained resource envelope. Both science goals (e.g., MEPAG Goal 1, return sample selection, etc.) as well as identification of any potential toxic and biological hazards to humans, must be addressed. Over the past several years of instrument development, we have found that the adaptable, compact, and highly capable technique of laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) has significant potential to contribute substantially to these dual objectives. This concept thus addresses Challenge Area 1: instrumentation and Investigation Approaches.

[Effect of near infrared spectrum on the precision of PLS model for oil yield from oil shale].

PubMed

Wang, Zhi-Hong; Liu, Jie; Chen, Xiao-Chao; Sun, Yu-Yang; Yu, Yang; Lin, Jun

2012-10-01

It is impossible to use present measurement methods for the oil yield of oil shale to realize in-situ detection and these methods unable to meet the requirements of the oil shale resources exploration and exploitation. But in-situ oil yield analysis of oil shale can be achieved by the portable near infrared spectroscopy technique. There are different correlativities of NIR spectrum data formats and contents of sample components, and the different absorption specialities of sample components shows in different NIR spectral regions. So with the proportioning samples, the PLS modeling experiments were done by 3 formats (reflectance, absorbance and K-M function) and 4 regions of modeling spectrum, and the effect of NIR spectral format and region to the precision of PLS model for oil yield from oil shale was studied. The results show that the best data format is reflectance and the best modeling region is combination spectral range by PLS model method and proportioning samples. Therefore, the appropriate data format and the proper characteristic spectral region can increase the precision of PLS model for oil yield form oil shale.

Sustainable Diagnostic Tools for Site Characterization and Remediation

NASA Astrophysics Data System (ADS)

Driver, E. M.; Roll, I. B.; Supowit, S. D.; Halden, R. U.

2016-12-01

Three submersible diagnostic tools were developed to enable more precise and cost-effective means of sampling environmental waters and assessing remedial strategies. The In Situ Sampler (IS2) and In Situ Sampler for Biphasic Water Monitoring (IS2B), designed for sampling groundwater or simultaneous pore- and surface water, use affordable off-the-shelf solid phase extraction technology, applicable to a broad range of organic and inorganic contaminants. Flow-through design reduces hazardous waste generation, transportation costs, and carbon footprint by 90-98% compared to traditional methods. The IS2 is ideal for dynamic groundwater systems where discrete sampling may fail to capture temporal variations, leading to inaccurate assessment of exposure and risk. A 28-day sampling event in a Cr(VI)-impacted aquifer captured previously undetected tidally-induced fluctuations, while improving the reporting limit 8-fold. The IS2B elucidates contaminant partitioning and bioavailability, and was validated in a wetland-shallow aquifer system with the pesticide fipronil. Concentrations of total fipronil-related compounds were statistically indistinguishable from those determined by conventional techniques (p > 0.2), ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L in surface water and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L in porewater. For groundwater remedial testing, the In Situ Microcosm Array (ISMA) was developed to integrate laboratory column treatability studies with pilot-scale field-testing, thus minimizing costs associated with sequential lab and field analyses. In situ operation maintains (geo)chemical and microbial groundwater parameters often destroyed by extraction and laboratory storage. Onboard effluent capture permits the deployment well to return to monitoring status immediately after instrument removal. All tools employ reusable internal components and may be operated by solar power. Case study results highlight the capabilities and application range of the each technology.

Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

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

Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.

A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction (XRD) studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoringmore » the oxidation of metallic zirconium during exposure to steam at 350°C. Finally, the in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during early stages of corrosion, which can provide a better understanding the oxidation process.« less

Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

DOE PAGES

Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.; ...

2016-10-25

A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction (XRD) studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoringmore » the oxidation of metallic zirconium during exposure to steam at 350°C. Finally, the in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during early stages of corrosion, which can provide a better understanding the oxidation process.« less

In-situ investigation of protein and DNA structure using UVRRS

NASA Astrophysics Data System (ADS)

Greek, L. Shane; Schulze, H. Georg; Blades, Michael W.; Haynes, Charles A.; Turner, Robin F. B.

1997-05-01

Ultraviolet resonance Raman spectroscopy (UVRRS) has the potential to become a sensitive, specific, versatile bioanalytical and biophysical technique for routine investigations of proteins, DNA, and their monomeric components, as well as a variety smaller, physiologically important aromatic molecules. The transition of UVRRS from a complex, specialized spectroscopic method to a common laboratory assay depends upon several developments, including a robust sample introduction method permitting routine, in situ analysis in standard laboratory environments. To this end, we recently reported the first fiber-optic probes suitable for deep-UV pulsed laser UVRRS. In this paper, we extend this work by demonstrating the applicability of such probes to studies of biochemical relevance, including investigations of the resonance enhancement of phosphotyrosine, thermal denaturation of RNase T1, and specific and non-specific protein binding. The advantages and disadvantages of the probes are discussed with reference to sample conditions and probe design considerations.

Organic ferroelectric evaporator with substrate cooling and in situ transport capabilities.

PubMed

Foreman, K; Labedz, C; Shearer, M; Adenwalla, S

2014-04-01

We report on the design, operation, and performance of a thermal evaporation chamber capable of evaporating organic thin films. Organic thin films are employed in a diverse range of devices and can provide insight into fundamental physical phenomena. However, growing organic thin films is often challenging and requires very specific deposition parameters. The chamber presented here is capable of cooling sample substrates to temperatures below 130 K and allows for the detachment of the sample from the cooling stage and in situ transport. This permits the use of multiple deposition techniques in separate, but connected, deposition chambers without breaking vacuum and therefore provides clean, well characterized interfaces between the organic thin film and any adjoining layers. We also demonstrate a successful thin film deposition of an organic material with a demanding set of deposition parameters, showcasing the success of this design.

Techniques for avoiding discrimination errors in the dynamic sampling of condensable vapors

NASA Technical Reports Server (NTRS)

Lincoln, K. A.

1983-01-01

In the mass spectrometric sampling of dynamic systems, measurements of the relative concentrations of condensable and noncondensable vapors can be significantly distorted if some subtle, but important, instrumental factors are overlooked. Even with in situ measurements, the condensables are readily lost to the container walls, and the noncondensables can persist within the vacuum chamber and yield a disproportionately high output signal. Where single pulses of vapor are sampled this source of error is avoided by gating either the mass spectrometer ""on'' or the data acquisition instrumentation ""on'' only during the very brief time-window when the initial vapor cloud emanating directly from the vapor source passes through the ionizer. Instrumentation for these techniques is detailed and its effectiveness is demonstrated by comparing gated and nongated spectra obtained from the pulsed-laser vaporization of several materials.

U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf systematics of returned Mars samples

NASA Technical Reports Server (NTRS)

Tatsumoto, M.; Premo, W. R.

1988-01-01

The advantage of studying returned planetary samples cannot be overstated. A wider range of analytical techniques with higher sensitivities and accuracies can be applied to returned samples. Measurement of U-Th-Pb, Sm-Nd, Rb-Sr, and Lu-Hf isotopic systematics for chronology and isotopic tracer studies of planetary specimens cannot be done in situ with desirable precision. Returned Mars samples will be examined using all the physical, chemical, and geologic methods necessary to gain information on the origin and evolution of Mars. A returned Martian sample would provide ample information regarding the accretionary and evolutionary history of the Martian planetary body and possibly other planets of our solar system.

A compact, fast ozone UV photometer and sampling inlet for research aircraft

NASA Astrophysics Data System (ADS)

Gao, R. S.; Ballard, J.; Watts, L. A.; Thornberry, T. D.; Ciciora, S. J.; McLaughlin, R. J.; Fahey, D. W.

2012-05-01

In situ measurements of atmospheric ozone (O3) are performed routinely from many research aircraft platforms. The most common technique depends on the strong absorption of ultraviolet (UV) light by ozone. As atmospheric science advances to the widespread use of unmanned aircraft systems (UASs), there is an increasing requirement for minimizing instrument space, weight, and power while maintaining instrument accuracy, precision and time response. The design and use of a new, dual-beam, polarized, UV photometer instrument for in situ O3 measurements is described. The instrument has a fast sampling rate (2 Hz), high accuracy (3%), and precision (1.1 × 1010 O3 molecules cm-3). The size (36 l), weight (18 kg), and power (50-200 W) make the instrument suitable for many UAS and other airborne platforms. Inlet and exhaust configurations are also described for ambient sampling in the troposphere and lower stratosphere (1000-50 mb) that optimize the sample flow rate to increase time response while minimizing loss of precision due to induced turbulence in the sample cell. In-flight and laboratory intercomparisons with existing O3 instruments show that measurement accuracy is maintained in flight.

Genotyping the factor VIII intron 22 inversion locus using fluorescent in situ hybridization.

PubMed

Sheen, Campbell R; McDonald, Margaret A; George, Peter M; Smith, Mark P; Morris, Christine M

2011-02-15

The factor VIII intron 22 inversion is the most common cause of hemophilia A, accounting for approximately 40% of all severe cases of the disease. Southern hybridization and multiplex long distance PCR are the most commonly used techniques to detect the inversion in a diagnostic setting, although both have significant limitations. Here we describe our experience establishing a multicolor fluorescent in situ hybridization (FISH) based assay as an alternative to existing methods for genetic diagnosis of the inversion. Our assay was designed to apply three differentially labelled BAC DNA probes that when hybridized to interphase nuclei would exhibit signal patterns that are consistent with the normal or the inversion locus. When the FISH assay was applied to five normal and five inversion male samples, the correct genotype was assignable with p<0.001 for all samples. When applied to carrier female samples the assay could not assign a genotype to all female samples, probably due to a lower proportion of informative nuclei in female samples caused by the added complexity of a second X chromosome. Despite this complication, these pilot findings show that the assay performs favourably compared to the commonly used methods. Copyright © 2010 Elsevier Inc. All rights reserved.

Project Hyreus: Mars Sample Return Mission Utilizing in Situ Propellant Production

NASA Technical Reports Server (NTRS)

Bruckner, A. P.; Thill, Brian; Abrego, Anita; Koch, Amber; Kruse, Ross; Nicholson, Heather; Nill, Laurie; Schubert, Heidi; Schug, Eric; Smith, Brian

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Project Hyreus: Mars sample return mission utilizing in situ propellant production

NASA Technical Reports Server (NTRS)

Abrego, Anita; Bair, Chris; Hink, Anthony; Kim, Jae; Koch, Amber; Kruse, Ross; Ngo, Dung; Nicholson, Heather; Nill, Laurie; Perras, Craig

1993-01-01

Project Hyreus is an unmanned Mars sample return mission that utilizes propellants manufactured in situ from the Martian atmosphere for the return voyage. A key goal of the mission is to demonstrate the considerable benefits of using indigenous resources and to test the viability of this approach as a precursor to manned Mars missions. The techniques, materials, and equipment used in Project Hyreus represent those that are currently available or that could be developed and readied in time for the proposed launch date in 2003. Project Hyreus includes such features as a Mars-orbiting satellite equipped with ground-penetrating radar, a large rover capable of sample gathering and detailed surface investigations, and a planetary science array to perform on-site research before samples are returned to Earth. Project Hyreus calls for the Mars Landing Vehicle to land in the Mangala Valles region of Mars, where it will remain for approximately 1.5 years. Methane and oxygen propellant for the Earth return voyage will be produced using carbon dioxide from the Martian atmosphere and a small supply of hydrogen brought from Earth. This process is key to returning a large Martian sample to Earth with a single Earth launch.

Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors.

PubMed

Lombi, E; de Jonge, M D; Donner, E; Ryan, C G; Paterson, D

2011-06-01

Environmental samples are extremely diverse but share a tendency for heterogeneity and complexity. This heterogeneity poses methodological challenges when investigating biogeochemical processes. In recent years, the development of analytical tools capable of probing element distribution and speciation at the microscale have allowed this challenge to be addressed. Of these available tools, laterally resolved synchrotron techniques such as X-ray fluorescence mapping are key methods for the in situ investigation of micronutrients and inorganic contaminants in environmental samples. This article demonstrates how recent advances in X-ray fluorescence detector technology are bringing new possibilities to environmental research. Fast detectors are helping to circumvent major issues such as X-ray beam damage of hydrated samples, as dwell times during scanning are reduced. They are also helping to reduce temporal beamtime requirements, making particularly time-consuming techniques such as micro X-ray fluorescence (μXRF) tomography increasingly feasible. This article focuses on μXRF mapping of nutrients and metalloids in environmental samples, and suggests that the current divide between mapping and speciation techniques will be increasingly blurred by the development of combined approaches.

Sediment Source Analysis at Malakoff Diggins State Historic Park, California

NASA Astrophysics Data System (ADS)

Ward, A. J., IV; Monohan, C.; Matiasek, S. J.; Alpers, C. N.; Curtis, J.; Campbell, K. M.; Roth, D. A.; Howle, J.

2016-12-01

This study aims to identify the sources of suspended sediment and trace metals which are discharged during storm events into Humbug Creek from Malakoff Diggins State Historic Park (MDSHP) in Nevada County, California. MDSHP includes a pit where approximately 32,000,000 cubic meters of auriferous Eocene gravel was mined by hydraulic and dredging methods during 1866-1884 and 1893-1910. High erosion rates within the pit contribute to water-quality impairment downstream; Humbug Creek is listed as an impaired water body under section 303(d) of the Clean Water Act because of suspended sediment, copper, mercury, and zinc. Sediment fingerprinting techniques (mineralogy and geochemistry) are being used to identify stratigraphic units in the pit responsible for delivering the greatest volume of sediment to the pit drain at Hiller Tunnel, which flows to Humbug Creek. In-situ sediment samples were collected in 2015 along four vertical transects located in the mine pit. Additionally, surface water samples were collected during 2015 and 2016 within the pit and Hiller Tunnel, targeting drainage networks below the in-situ sampling sites. In-situ and suspended sediment samples were analyzed for grain-size distribution, X-ray diffraction (XRD) to obtain quantitative mineralogy, inductively coupled plasma - mass spectrometry (ICP-MS) for trace elements, and inductively coupled plasma - optical emission spectroscopy (ICP-OES) for major elements. Preliminary XRD data indicate that the fine suspended sediment in Hiller Tunnel is composed predominantly of kaolinite and halloysite, with minor smectite, illite, and muscovite. Kaolinite is abundant in many of the samples from the in-situ vertical transects, but relatively few stratigraphic units have abundant halloysite. Quantitative erosion rates from a time series of terrestrial LiDAR measurements (2014-16) and from historical aerial photos will help to refine possible scenarios regarding sediment sources within the pit. Chemical and physical characterization of the in-situ sediments may reveal key indicators, or fingerprints, which will allow for a more efficient application of mitigation efforts in MDSHP by identifying which stratigraphic units are delivering high amounts of sediment to Humbug Creek.

[Effect of mechanical grinding of Sphagnum on the structure and physiological state of bacterial communities].

PubMed

Dobrovol'skaya, T G; Golovchenko, A V; Yakushev, A V; Manucharova, N A; Yurchenko, E N

2014-01-01

The microcosm method was used to demonstrate an increase in bacterial numbers and drastic changes in the taxonomic structure of saprotrophic bacteria as a result of mechanical grinding of Sphagnum moss. Ekkrisotrophic agrobacteria predominant in untreated moss were replaced by hydrolytic bacteria. Molecular biological approaches revealed such specific hydrolytic bacteria as Janthinobacterium agaricum and Streptomyces purpurascens among the dominant taxa. The application of kinetic technique for determination of the physiological state of bacteria in situ revealed higher functional diversity of hydrolytic bacteria in ground moss than in untreated samples. A considerable decrease of the C/N ratio in ground samples of living Sphagnum incubated using the microcosm technique indicated decomposition of this substrate.

Estimation of pressure-particle velocity impedance measurement uncertainty using the Monte Carlo method.

PubMed

Brandão, Eric; Flesch, Rodolfo C C; Lenzi, Arcanjo; Flesch, Carlos A

2011-07-01

The pressure-particle velocity (PU) impedance measurement technique is an experimental method used to measure the surface impedance and the absorption coefficient of acoustic samples in situ or under free-field conditions. In this paper, the measurement uncertainty of the the absorption coefficient determined using the PU technique is explored applying the Monte Carlo method. It is shown that because of the uncertainty, it is particularly difficult to measure samples with low absorption and that difficulties associated with the localization of the acoustic centers of the sound source and the PU sensor affect the quality of the measurement roughly to the same extent as the errors in the transfer function between pressure and particle velocity do. © 2011 Acoustical Society of America

Endobronchial ultrasonography using a guide sheath technique for diagnosis of peripheral pulmonary lesions

PubMed Central

Zhang, Lei; Wu, Hongxu; Wang, Guiqi

2017-01-01

Endobronchial ultrasonography using a guide sheath (EBUS-GS) is a novel method used for collecting peripheral pulmonary lesion (PPL) samples. EBUS-GS is performed by introducing a guide sheath-covered miniprobe into the target bronchus and then withdrawing the miniprobe after lesion detection, leaving the guide sheath in situ as a working channel for obtaining lesion samples. EBUS-GS can improve PPL diagnosis rates and be used for obtaining specimens for molecular analysis. In this review, we discuss the clinical applications of EBUS-GS, the factors that affect its diagnostic sensitivity, and potential complications. We also compare EBUS-GS with other available diagnostic techniques and discuss the strengths and limitations of this method. PMID:29063872

A miniature 48-channel pressure sensor module capable of in situ calibration

NASA Technical Reports Server (NTRS)

Gross, C.; Juanarena, D. B.

1977-01-01

A new high data rate pressure sensor module with in situ calibration capability has been developed by the Langley Research Center to help reduce energy consumption in wind-tunnel facilities without loss of measurement accuracy. The sensor module allows for nearly a two order of magnitude increase in data rates over conventional electromechanically scanned pressure sampling techniques. This module consists of 16 solid state pressure sensor chips and signal multiplexing electronics integrally mounted to a four position pressure selector switch. One of the four positions of the pressure selector switch allows the in situ calibration of the 16 pressure sensors; the three other positions allow 48 channels (three sets of 16) pressure inputs to be measured by sensors. The small size of the sensor module will allow mounting within many wind-tunnel models, thus eliminating long tube lengths and their corresponding slow pressure response.

In-situ investigation of humidity-induced changes on human hair and antennae of the honey bee, Apis mellifera L., by scanning force microscopy

NASA Astrophysics Data System (ADS)

Resch, R.; Ehn, R.; Tichy, H.; Friedbacher, G.

Atomic force microscopy has already proven its large potential for in-situ investigation of a wide variety of materials under ambient conditions. In the present work our methodological developments have been utilized for in-situ studies of morphological changes on biological material under atmospheres of defined humidity. The observed changes have been evaluated on a quantitative basis through calculation of the correlation between images taken under different conditions. By using female hair as a well-known model sample it could be shown that expansions in the order of 1% or less are accessible. The analytical figures of merit will be discussed. The described technique has also been applied to study hygroreceptors of the honey bee. The promising potential of the method for studying the mechanism of humidity transduction of such organs will be addressed, too.

Quantitative methods for compensation of matrix effects and self-absorption in Laser Induced Breakdown Spectroscopy signals of solids

NASA Astrophysics Data System (ADS)

Takahashi, Tomoko; Thornton, Blair

2017-12-01

This paper reviews methods to compensate for matrix effects and self-absorption during quantitative analysis of compositions of solids measured using Laser Induced Breakdown Spectroscopy (LIBS) and their applications to in-situ analysis. Methods to reduce matrix and self-absorption effects on calibration curves are first introduced. The conditions where calibration curves are applicable to quantification of compositions of solid samples and their limitations are discussed. While calibration-free LIBS (CF-LIBS), which corrects matrix effects theoretically based on the Boltzmann distribution law and Saha equation, has been applied in a number of studies, requirements need to be satisfied for the calculation of chemical compositions to be valid. Also, peaks of all elements contained in the target need to be detected, which is a bottleneck for in-situ analysis of unknown materials. Multivariate analysis techniques are gaining momentum in LIBS analysis. Among the available techniques, principal component regression (PCR) analysis and partial least squares (PLS) regression analysis, which can extract related information to compositions from all spectral data, are widely established methods and have been applied to various fields including in-situ applications in air and for planetary explorations. Artificial neural networks (ANNs), where non-linear effects can be modelled, have also been investigated as a quantitative method and their applications are introduced. The ability to make quantitative estimates based on LIBS signals is seen as a key element for the technique to gain wider acceptance as an analytical method, especially in in-situ applications. In order to accelerate this process, it is recommended that the accuracy should be described using common figures of merit which express the overall normalised accuracy, such as the normalised root mean square errors (NRMSEs), when comparing the accuracy obtained from different setups and analytical methods.

Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques

DOE PAGES

Durham, Jessica L.; Brady, Alexander B.; Cama, Christina A.; ...

2017-08-02

Here, the structure of pristine AgFeO 2 and phase makeup of Ag 0.2FeO1.6 (a one-pot composite comprised of nanocrystalline stoichiometric AgFeO 2 and amorphous γ-Fe 2O 3 phases) was investigated using synchrotron x-ray diffraction. A new stacking-fault model was proposed for AgFeO2 powder synthesized using the co-precipitation method. The lithiation/de-lithiation mechanisms of silver ferrite, AgFeO 2 and Ag 0.2FeO 1.6 were investigated using ex-situ, in-situ, and operando characterization techniques. An amorphous γ-Fe 2O 3 component in the Ag 0.2FeO 1.6 sample is quantified. Operando XRD of electrochemically reduced AgFeO 2 and Ag 0.2FeO 1.6 composites demonstrated differences in the structuralmore » evolution of the nanocrystalline AgFeO 2 component. As complimentary techniques to XRD, ex-situ x-ray Absorption Spectroscopy (XAS) provided insight into the short-range structure of the (de)lithiated nanocrystalline electrodes, and a novel in-situ high energy x-ray fluorescence nanoprobe (HXN) mapping measurement was applied to spatially resolve the progression of discharge. Based on the results, a redox mechanism is proposed where the full reduction of Ag + to Ag0 and partial reduction of Fe 3+ to Fe 2+ occur on reduction to 1.0 V, resulting in a Li 1+yFe IIIFe IIyO 2 phase. The Li 1+yFe IIIFe IIyO 2 phase can then reversibly cycle between Fe 3+ and Fe 2+ oxidation states, permitting good capacity retention over 50 cycles. In the Ag 0.2FeO 1.6 composite, a substantial amorphous γ-Fe 2O 3 component is observed which discharges to rock salt LiFe 2O 3 and Fe 0 metal phase in the 3.5 – 1.0 V voltage range (in parallel with the AgFeO 2 mechanism), and reversibly reoxidizes to a nanocrystalline iron oxide phase.« less

Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques

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

Durham, Jessica L.; Brady, Alexander B.; Cama, Christina A.

Here, the structure of pristine AgFeO 2 and phase makeup of Ag 0.2FeO1.6 (a one-pot composite comprised of nanocrystalline stoichiometric AgFeO 2 and amorphous γ-Fe 2O 3 phases) was investigated using synchrotron x-ray diffraction. A new stacking-fault model was proposed for AgFeO2 powder synthesized using the co-precipitation method. The lithiation/de-lithiation mechanisms of silver ferrite, AgFeO 2 and Ag 0.2FeO 1.6 were investigated using ex-situ, in-situ, and operando characterization techniques. An amorphous γ-Fe 2O 3 component in the Ag 0.2FeO 1.6 sample is quantified. Operando XRD of electrochemically reduced AgFeO 2 and Ag 0.2FeO 1.6 composites demonstrated differences in the structuralmore » evolution of the nanocrystalline AgFeO 2 component. As complimentary techniques to XRD, ex-situ x-ray Absorption Spectroscopy (XAS) provided insight into the short-range structure of the (de)lithiated nanocrystalline electrodes, and a novel in-situ high energy x-ray fluorescence nanoprobe (HXN) mapping measurement was applied to spatially resolve the progression of discharge. Based on the results, a redox mechanism is proposed where the full reduction of Ag + to Ag0 and partial reduction of Fe 3+ to Fe 2+ occur on reduction to 1.0 V, resulting in a Li 1+yFe IIIFe IIyO 2 phase. The Li 1+yFe IIIFe IIyO 2 phase can then reversibly cycle between Fe 3+ and Fe 2+ oxidation states, permitting good capacity retention over 50 cycles. In the Ag 0.2FeO 1.6 composite, a substantial amorphous γ-Fe 2O 3 component is observed which discharges to rock salt LiFe 2O 3 and Fe 0 metal phase in the 3.5 – 1.0 V voltage range (in parallel with the AgFeO 2 mechanism), and reversibly reoxidizes to a nanocrystalline iron oxide phase.« less

Electrochemical (de)lithiation of silver ferrite and composites: mechanistic insights from ex situ, in situ, and operando X-ray techniques.

PubMed

Durham, Jessica L; Brady, Alexander B; Cama, Christina A; Bock, David C; Pelliccione, Christopher J; Zhang, Qing; Ge, Mingyuan; Li, Yue Ru; Zhang, Yiman; Yan, Hanfei; Huang, Xiaojing; Chu, Yong; Takeuchi, Esther S; Takeuchi, Kenneth J; Marschilok, Amy C

2017-08-23

The structure of pristine AgFeO 2 and phase makeup of Ag 0.2 FeO 1.6 (a one-pot composite comprised of nanocrystalline stoichiometric AgFeO 2 and amorphous γ-Fe 2 O 3 phases) was investigated using synchrotron X-ray diffraction. A new stacking-fault model was proposed for AgFeO 2 powder synthesized using the co-precipitation method. The lithiation/de-lithiation mechanisms of silver ferrite, AgFeO 2 and Ag 0.2 FeO 1.6 were investigated using ex situ, in situ, and operando characterization techniques. An amorphous γ-Fe 2 O 3 component in the Ag 0.2 FeO 1.6 sample is quantified. Operando XRD of electrochemically reduced AgFeO 2 and Ag 0.2 FeO 1.6 composites demonstrated differences in the structural evolution of the nanocrystalline AgFeO 2 component. As complimentary techniques to XRD, ex situ X-ray Absorption Spectroscopy (XAS) provided insight into the short-range structure of the (de)lithiated nanocrystalline electrodes, and a novel in situ high energy X-ray fluorescence nanoprobe (HXN) mapping measurement was applied to spatially resolve the progression of discharge. Based on the results, a redox mechanism is proposed where the full reduction of Ag + to Ag 0 and partial reduction of Fe 3+ to Fe 2+ occur on reduction to 1.0 V, resulting in a Li 1+y Fe III Fe II y O 2 phase. The Li 1+y Fe III Fe II y O 2 phase can then reversibly cycle between Fe 3+ and Fe 2+ oxidation states, permitting good capacity retention over 50 cycles. In the Ag 0.2 FeO 1.6 composite, a substantial amorphous γ-Fe 2 O 3 component is observed which discharges to rock salt LiFe 2 O 3 and Fe 0 metal phase in the 3.5-1.0 V voltage range (in parallel with the AgFeO 2 mechanism), and reversibly reoxidizes to a nanocrystalline iron oxide phase.

Simultaneous measurement at multiple depths of in situ rates of denitrification in the bed of a groundwater-fed river

NASA Astrophysics Data System (ADS)

Lansdown, Katrina; Trimmer, Mark; Heppell, Kate

2010-05-01

Typically characterised by steep chemical gradients and variable redox conditions, the hyporheic zone is considered a 'hotpot' or site of enhanced biogeochemical activity in the aquatic environment. As such the importance of the hyporheic zone for the attenuation of nutrients such as nitrate in a fluvial network has long been recognised. Controls on nitrogen transformations, however, especially at depths greater than 10cm below the sediment-water interface, remain comparatively less understood. Most work aimed at quantifying denitrification in the hyporheic zone has involved laboratory incubation of recovered sediments which is likely to affect the estimate of the true in situ rate. Results of such studies are usually cited as 'potential' rates of denitrification and have undoubtedly improved the understanding of nitrogen cycling in the aquatic environment. There is, however, a need for in situ measurement to improve our knowledge of nitrogen cycling in the river bed. Here, rates of denitrification in the hyporheic zone have been measured at multiple depths, simultaneously using 'push-pull' methodology (e.g. Snodgrass and Kitanidis 1998). The 'push-pull' technique involves injection of a solution containing reactant(s) (e.g. nitrate) and a conservative tracer (e.g. chloride) into the sediment and extraction of pore water samples over time. Recovered samples are screened for the removal of reactant(s) and/or the accumulation of products(s). Temporal changes in the conservative tracer are used to correct the concentration of the reactant(s) and product(s) for dispersion and advection. The disadvantage of the 'traditional' 'push-pull' methodology is that rates of nitrate removal are measured rather than rates of denitrification. In this research, comparison of measured and 'corrected' nitrate concentrations allowed the rate of nitrate removal (or production) to be quantified. In order to determine in situ rates of denitrification we used 15N-enriched nitrate as the reactant in the 'push-pull' experiments and measured the accumulation of 29N2 and 30N2 over time. Rates of denitrification were then calculated using the isotope pairing technique (as per Nielsen 1992; Sanders and Trimmer 2006). Measurements have been made at up to 40cm depth in the river bed using a miniprobe system developed from the design of Sanders and Trimmer (2006) in order to validate the experimental approach. Previous work conducted at the study site (R. Leith, Cumbria, UK) suggested than ambient conditions would not be ideal for in situ measurement of denitrification rates using 'push-pull' methodology. Slow rates of denitrification were measured during laboratory incubations of the sandy sediment (M. Trimmer, unpublished data), and the velocity of flow in the hyporheic zone would limit the duration of the in situ measurement (Käser et al. 2009). Despite difficulties posed by the site, we have measured in situ rates of denitrification at multiple depths in the hyporheic zone simultaneously. We also report measurement of in situ rates of denitrification below the zone of surface water - ground water mixing. In future we will use the experimental technique described in this paper to quantify (i) variation in N transformation rates with depth; and (ii) spatial variation in rates of nitrate consumption/production within the river bed. Käser, DH, Binley, A, Heathwaite, AL and Krause, S (2009) Spatio-temporal variations of hyporheic flow in a riffle-pool sequence. Hydrological Processes 23: 2138 - 2149. Nielsen, LP (1992) Denitrification in sediment determined from nitrogen isotope pairing. FEMS Microbiology Ecology 86: 357 - 362. Sanders, IA and Trimmer, M (2006) In situ application of the 15NO3- isotope pairing technique to measure denitrification in sediments at the surface water-groundwater interface. Limnology and oceanography: Methods 4: 142 - 152. Snodgrass, MF and Kitanidis, PK (1998) A method to infer in situ reaction rates from push-pull experiments. Ground Water 36(4): 645 - 650.

An in-situ K-Ar isochron dating method for planetary landers using a spot-by-spot laser-ablation technique

NASA Astrophysics Data System (ADS)

Cho, Yuichiro; Sugita, Seiji; Miura, Yayoi N.; Okazaki, Ryuji; Iwata, Naoyoshi; Morota, Tomokatsu; Kameda, Shingo

2016-09-01

Age is essential information for interpreting the geologic record on planetary surfaces. Although crater counting has been widely used to estimate the planetary surface ages, crater chronology in the inner solar system is largely built on radiometric age data from limited sites on the Moon. This has resulted in major uncertainty in planetary chronology. Because opportunities for sample-return missions are limited, in-situ geochronology measurements from one-way lander/rover missions are extremely valuable. Here we developed an in-situ isochron-based dating method using the K-Ar system, with K and Ar in a single rock sample extracted locally by laser ablation and measured using laser-induced breakdown spectroscopy (LIBS) and a quadrupole mass spectrometer (QMS), respectively. We built an experimental system combining flight-equivalent instruments and measured K-Ar ages for mineral samples with known ages (~1.8 Ga) and K contents (1-8 wt%); we achieved precision of 20% except for a mineral with low mechanical strength. Furthermore, validation measurements with two natural rocks (gneiss slabs) obtained K-Ar isochron ages and initial 40Ar consistent with known values for both cases. This result supports that our LIBS-MS approach can derive both isochron ages and contributions of non-in situ radiogenic 40Ar from natural rocks. Error assessments suggest that the absolute ages of key geologic events including the Noachian/Hesperian- and the Hesperian/Amazonian-transition can be dated with 10-20% errors for a rock containing ~1 wt% K2O, greatly reducing the uncertainty of current crater chronology models on Mars.

Sampling of atmospheric carbonyl compounds for determination by liquid chromatography after 2,4-dinitrophenylhydrazine labelling

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

Vairavamurthy, A.; Roberts, J.M.; Newman, L.

1991-06-01

Carbonyl compounds are both primary (directly emitted) and secondary (formed in situ) atmospheric species, which play a major role in tropospheric photochemistry. Because of trace concentrations (parts-per-billion and lower), ambient air measurements of carbonyls pose serious analytical problems. Generally, chromatographic approaches combined with chemical derivatization have been used to enhance sensitivity and selectivity in analysis. Currently, the liquid chromatographic method coupled to 2,4-dinitrophenylhydrazine derivatization (DNPH-LC) is in widespread use. Interferences arising from similar compounds are greatly minimized by chromatographic separation; however, those in the air sampling step, especially with ozone, continue to be problematic and remain to be resolved. Wemore » discuss here the different sampling techniques used for time-integrated collection of carbonyls in the DNPH-LC methods. Emphasis is placed on addressing: (1) the principles, advantages, and limitations of sampling techniques; (2) problems associated with reagent blank and sampling instrument; and (3) effects of atmospheric co-pollutants, especially ozone. 58 refs., 8 figs., 3 tabs.« less

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

PubMed Central

2018-01-01

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical guidance for standardized passive sampling, and advance the use of passive sampling in regulatory decision making by increasing confidence in the use of the technique. The study was performed by a consortium of 11 laboratories and included experiments with 14 passive sampling formats on 3 sediments for 25 target chemicals (PAHs and PCBs). The resulting overall interlaboratory variability was large (a factor of ∼10), but standardization of methods halved this variability. The remaining variability was primarily due to factors not related to passive sampling itself, i.e., sediment heterogeneity and analytical chemistry. Excluding the latter source of variability, by performing all analyses in one laboratory, showed that passive sampling results can have a high precision and a very low intermethod variability (

One Isotope, Two Tales: using plant and cosmogenic 14C to constrain Holocene glacier activity on Baffin Island.

NASA Astrophysics Data System (ADS)

Pendleton, S.; Miller, G. H.; Lifton, N. A.; Young, N. E.

2017-12-01

As the cryosphere continues to undergo rapid and accelerating change, it is more important than ever to understand past glacier activity to predict the future of the cryosphere. However, continuous Holocene glacier records are notoriously difficult to reconstruct because an advancing glacier will re-incorporate previous deposits so that moraines typically only record the farthest downvalley glacier expansion. Here we combine dates of ice margin advance from in situ dead vegetation with in situ cosmogenic 14C (in situ 14C) from preserved bedrock surfaces at the same locations to further constrain the timing of ice-free episodes during the Holocene following deglaciation on southern Baffin Island. Radiocarbon ages from recently exposed in situ plants suggest that ice last advanced over sample locations at 9.4, 9.2, 9.0, and 3.7 ka and that they remained ice covered until modern times. Associated in situ 14C inventories are variable, but well above background levels, suggesting some amount of Holocene in situ 14C production. Using plant 14C ages representing the beginning of ice coverage and in situ 14C inventories representative of exposure prior to ice coverage, a simple model of cosmogenic in situ 14C production (accounting for muon production through ice) provides constraints timing and duration of ice-free times at sample locations prior to their most recent burial. Using conservative Holocene ice thicknesses, the locations buried at 9.4, 9.2, and 9.0 ka require, at minimum, 1000 years of pre-burial exposure to match the observed in situ 14C inventory. This suggests these locations were ice free by at least 10 ka and likely earlier. The in situ 14C inventory at the location buried at 3.7 ka limits prior exposure to 2000 years, suggesting that this location experienced more complex Holocene ice cover/burial history. These pilot data show that valuable information regarding periods of exposure is contained within in situ 14C inventories. Additional paired plant and in situ 14C analyses currently underway will provide further constraints on the timing and duration of Holocene exposure. The combination of these two dating techniques supplies some of the first constraints on both ice cover and exposure and provides much needed information about the evolution of glaciers on southern Baffin Island following deglaciation.

Quantitative optical coherence microscopy for the in situ investigation of the biofilm

NASA Astrophysics Data System (ADS)

Meleppat, Ratheesh Kumar; Shearwood, Christopher; Keey, Seah Leong; Matham, Murukeshan Vadakke

2016-12-01

This paper explores the potential of optical coherence microscopy (OCM) for the in situ monitoring of biofilm growth. The quantitative imaging of the early developmental biology of a representative biofilm, Klebsiella pneumonia (KP-1), was performed using a swept source-based Fourier domain OCM system. The growth dynamics of the KP-1 biofilms and their transient response under perturbation was investigated using the enface visualization of microcolonies and their spatial localization. Furthermore, the optical density (OD) and planar density of the biofilms are calculated using an OCM technique and compared with OD and colony forming units measured using standard procedures via the sampling of the flow-cell effluent.

Magneto-ellipsometry as a powerful technique for investigating magneto-optical structures properties

NASA Astrophysics Data System (ADS)

Maximova, Olga; Kosyrev, Nikolay; Yakovlev, Ivan; Shevtsov, Dmitriy; Lyaschenko, Sergey; Varnakov, Sergey; Ovchinnikov, Sergey

2017-10-01

In this work we report on new magneto-ellipsometry set-up that allows to grow thin films and nanostructures by ultrahigh vacuum thermal evaporation as well as to conduct in situ measurements during the growth in order to analyze and control nanostructures properties. Ellipsometry and transverse magneto-optical Kerr effect measurements can be performed in situ inside this set-up. A uniform magnetic field of high intensity (more than 1 kOe) can be applied to samples inside the vacuum chamber. Also, we report on the developed method of data interpretation that is the base of the set-up software. Thus, we present a powerful tool for nanostructures synthesis and characterization.

In situ visualization of newly synthesized proteins in environmental microbes using amino acid tagging and click chemistry

PubMed Central

Hatzenpichler, Roland; Scheller, Silvan; Tavormina, Patricia L; Babin, Brett M; Tirrell, David A; Orphan, Victoria J

2014-01-01

Here we describe the application of a new click chemistry method for fluorescent tracking of protein synthesis in individual microorganisms within environmental samples. This technique, termed bioorthogonal non-canonical amino acid tagging (BONCAT), is based on the in vivo incorporation of the non-canonical amino acid L-azidohomoalanine (AHA), a surrogate for l-methionine, followed by fluorescent labelling of AHA-containing cellular proteins by azide-alkyne click chemistry. BONCAT was evaluated with a range of phylogenetically and physiologically diverse archaeal and bacterial pure cultures and enrichments, and used to visualize translationally active cells within complex environmental samples including an oral biofilm, freshwater and anoxic sediment. We also developed combined assays that couple BONCAT with ribosomal RNA (rRNA)-targeted fluorescence in situ hybridization (FISH), enabling a direct link between taxonomic identity and translational activity. Using a methanotrophic enrichment culture incubated under different conditions, we demonstrate the potential of BONCAT-FISH to study microbial physiology in situ. A direct comparison of anabolic activity using BONCAT and stable isotope labelling by nano-scale secondary ion mass spectrometry (15NH3 assimilation) for individual cells within a sediment-sourced enrichment culture showed concordance between AHA-positive cells and 15N enrichment. BONCAT-FISH offers a fast, inexpensive and straightforward fluorescence microscopy method for studying the in situ activity of environmental microbes on a single-cell level. PMID:24571640

Chemometric studies for the characterization and differentiation of microorganisms using in situ derivatization and thermal desorption ion mobility spectrometry.

PubMed

Ochoa, Mariela L; Harrington, Peter B

2005-02-01

Whole-cell bacteria were characterized and differentiated by thermal desorption ion mobility spectrometry and chemometric modeling. Principal component analysis was used to evaluate the differences in the ion mobility spectra of whole-cell bacteria and the fatty acid methyl esters (FAMEs) generated in situ after derivatization of the bacterial lipids. Alternating least squares served to extract bacterial peaks from the complex ion mobility spectra of intact microorganisms and, therefore, facilitated the characterization of bacterial strains, species, and Gram type. In situ thermal hydrolysis/methylation with tetramethylammonium hydroxide was necessary for the differentiation of Escherichia coli strains, which otherwise could not be distinguished by spectra acquired with the ITEMISER ion mobility spectrometer. The addition of the methylating agent had no effect on Gram-positive bacteria, and therefore, they could not be differentiated by genera. The classification of E. coli strains was possible by analysis of the IMS spectra from the FAMEs generated in situ. By using the fuzzy multivariate rule-building expert system and cross-validation, a correct classification rate of 96% (22 out of 23 spectra) was obtained. Chemometric modeling on bacterial ion mobility spectra coupled to thermal hydrolysis/methylation proved a simple, rapid (2 min/sample), inexpensive, and sensitive technique to characterize and differentiate intact microorganisms. The ITEMISER ion mobility spectrometer could detect as few as 4 x 10(6) cells/sample.

In situ passive sampling of sediments in the Lower Duwamish Waterway Superfund site: Replicability, comparison with ex situ measurements, and use of data.

PubMed

Apell, Jennifer N; Gschwend, Philip M

2016-11-01

Superfund sites with sediments contaminated by hydrophobic organic compounds (HOCs) can be difficult to characterize because of the complex nature of sorption to sediments. Porewater concentrations, which are often used to model transport of HOCs from the sediment bed into overlying water, benthic organisms, and the larger food web, are traditionally estimated using sediment concentrations and sorption coefficients estimated using equilibrium partitioning (EqP) theory. However, researchers have begun using polymeric samplers to determine porewater concentrations since this method does not require knowledge of the sediment's sorption properties. In this work, polyethylene passive samplers were deployed into sediments in the field (in situ passive sampling) and mixed with sediments in the laboratory (ex situ active sampling) that were contaminated with polychlorinated biphenyls (PCBs). The results show that porewater concentrations based on in situ and ex situ sampling generally agreed within a factor of two, but in situ concentrations were consistently lower than ex situ porewater concentrations. Imprecision arising from in situ passive sampling procedures does not explain this bias suggesting that field processes like bioirrigation may cause the differences observed between in situ and ex situ polymeric samplers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Applied in situ product recovery in ABE fermentation

PubMed Central

Lalander, Carl‐Axel; Lee, Jonathan G. M.; Davies, E. Timothy; Harvey, Adam P.

2017-01-01

The production of biobutanol is hindered by the product's toxicity to the bacteria, which limits the productivity of the process. In situ product recovery of butanol can improve the productivity by removing the source of inhibition. This paper reviews in situ product recovery techniques applied to the acetone butanol ethanol fermentation in a stirred tank reactor. Methods of in situ recovery include gas stripping, vacuum fermentation, pervaporation, liquid–liquid extraction, perstraction, and adsorption, all of which have been investigated for the acetone, butanol, and ethanol fermentation. All techniques have shown an improvement in substrate utilization, yield, productivity or both. Different fermentation modes favored different techniques. For batch processing gas stripping and pervaporation were most favorable, but in fed‐batch fermentations gas stripping and adsorption were most promising. During continuous processing perstraction appeared to offer the best improvement. The use of hybrid techniques can increase the final product concentration beyond that of single‐stage techniques. Therefore, the selection of an in situ product recovery technique would require comparable information on the energy demand and economics of the process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:563–579, 2017 PMID:28188696

Evaluation and study of advanced optical contamination, deposition, measurement, and removal techniques. [including computer programs and ultraviolet reflection analysis

NASA Technical Reports Server (NTRS)

Linford, R. M. F.; Allen, T. H.; Dillow, C. F.

1975-01-01

A program is described to design, fabricate and install an experimental work chamber assembly (WCA) to provide a wide range of experimental capability. The WCA incorporates several techniques for studying the kinetics of contaminant films and their effect on optical surfaces. It incorporates the capability for depositing both optical and contaminant films on temperature-controlled samples, and for in-situ measurements of the vacuum ultraviolet reflectance. Ellipsometer optics are mounted on the chamber for film thickness determinations, and other features include access ports for radiation sources and instrumentation. Several supporting studies were conducted to define specific chamber requirements, to determine the sensitivity of the measurement techniques to be incorporated in the chamber, and to establish procedures for handling samples prior to their installation in the chamber. A bibliography and literature survey of contamination-related articles is included.

Spatially resolved in vivo plant metabolomics by laser ablation-based mass spectrometry imaging (MSI) techniques: LDI-MSI and LAESI

PubMed Central

Bartels, Benjamin; Svatoš, Aleš

2015-01-01

This short review aims to summarize the current developments and applications of mass spectrometry-based methods for in situ profiling and imaging of plants with minimal or no sample pre-treatment or manipulation. Infrared-laser ablation electrospray ionization and UV-laser desorption/ionization methods are reviewed. The underlying mechanisms of the ionization techniques–namely, laser ablation of biological samples and electrospray ionization–as well as variations of the LAESI ion source for specific targets of interest are described. PMID:26217345

Multispectral Microimager for Astrobiology

NASA Technical Reports Server (NTRS)

Sellar, R. Glenn; Farmer, Jack D.; Kieta, Andrew; Huang, Julie

2006-01-01

A primary goal of the astrobiology program is the search for fossil records. The astrobiology exploration strategy calls for the location and return of samples indicative of environments conducive to life, and that best capture and preserve biomarkers. Successfully returning samples from environments conducive to life requires two primary capabilities: (1) in situ mapping of the mineralogy in order to determine whether the desired minerals are present; and (2) nondestructive screening of samples for additional in-situ testing and/or selection for return to laboratories for more in-depth examination. Two of the most powerful identification techniques are micro-imaging and visible/infrared spectroscopy. The design and test results are presented from a compact rugged instrument that combines micro-imaging and spectroscopic capability to provide in-situ analysis, mapping, and sample screening capabilities. Accurate reflectance spectra should be a measure of reflectance as a function of wavelength only. Other compact multispectral microimagers use separate LEDs (light-emitting diodes) for each wavelength and therefore vary the angles of illumination when changing wavelengths. When observing a specularly-reflecting sample, this produces grossly inaccurate spectra due to the variation in the angle of illumination. An advanced design and test results are presented for a multispectral microimager which demonstrates two key advances relative to previous LED-based microimagers: (i) acquisition of actual reflectance spectra in which the flux is a function of wavelength only, rather than a function of both wavelength and illumination geometry; and (ii) increase in the number of spectral bands to eight bands covering a spectral range of 468 to 975 nm.

Locating Stardust-like Particles in Aerogel Using X-Ray Techniques

NASA Technical Reports Server (NTRS)

Jurewicz, A. J. G.; Jones, S. M.; Tsapin, A.; Mih, D. T.; Connolly, H. C., Jr.; Graham, G. A.

2003-01-01

Silica aerogel is the material that the spacecraft STARDUST is using to collect interstellar and cometary silicates. Anticipating the return of the samples to earth in January of 2006, MANY individual investigators and, especially, the investigators in NASA's SRLIDAP program are studying means of both in situ analysis of particles, as well as particle extraction. To help individual PI's with extraction of particles from aerogel in their own laboratories, we are exploring the use of standard laboratory x-ray equipment and commercial techniques for precisely locating specific particles in aerogel. We approached the evaluation of commercial x-ray techniques as follows. First, we determined the most appropriate detector for use with aerogel and particulates. Then, we compared and contrasted techniques useful for university laboratories.

Performance of Statistical Temporal Downscaling Techniques of Wind Speed Data Over Aegean Sea

NASA Astrophysics Data System (ADS)

Gokhan Guler, Hasan; Baykal, Cuneyt; Ozyurt, Gulizar; Kisacik, Dogan

2016-04-01

Wind speed data is a key input for many meteorological and engineering applications. Many institutions provide wind speed data with temporal resolutions ranging from one hour to twenty four hours. Higher temporal resolution is generally required for some applications such as reliable wave hindcasting studies. One solution to generate wind data at high sampling frequencies is to use statistical downscaling techniques to interpolate values of the finer sampling intervals from the available data. In this study, the major aim is to assess temporal downscaling performance of nine statistical interpolation techniques by quantifying the inherent uncertainty due to selection of different techniques. For this purpose, hourly 10-m wind speed data taken from 227 data points over Aegean Sea between 1979 and 2010 having a spatial resolution of approximately 0.3 degrees are analyzed from the National Centers for Environmental Prediction (NCEP) The Climate Forecast System Reanalysis database. Additionally, hourly 10-m wind speed data of two in-situ measurement stations between June, 2014 and June, 2015 are considered to understand effect of dataset properties on the uncertainty generated by interpolation technique. In this study, nine statistical interpolation techniques are selected as w0 (left constant) interpolation, w6 (right constant) interpolation, averaging step function interpolation, linear interpolation, 1D Fast Fourier Transform interpolation, 2nd and 3rd degree Lagrange polynomial interpolation, cubic spline interpolation, piecewise cubic Hermite interpolating polynomials. Original data is down sampled to 6 hours (i.e. wind speeds at 0th, 6th, 12th and 18th hours of each day are selected), then 6 hourly data is temporally downscaled to hourly data (i.e. the wind speeds at each hour between the intervals are computed) using nine interpolation technique, and finally original data is compared with the temporally downscaled data. A penalty point system based on coefficient of variation root mean square error, normalized mean absolute error, and prediction skill is selected to rank nine interpolation techniques according to their performance. Thus, error originated from the temporal downscaling technique is quantified which is an important output to determine wind and wave modelling uncertainties, and the performance of these techniques are demonstrated over Aegean Sea indicating spatial trends and discussing relevance to data type (i.e. reanalysis data or in-situ measurements). Furthermore, bias introduced by the best temporal downscaling technique is discussed. Preliminary results show that overall piecewise cubic Hermite interpolating polynomials have the highest performance to temporally downscale wind speed data for both reanalysis data and in-situ measurements over Aegean Sea. However, it is observed that cubic spline interpolation performs much better along Aegean coastline where the data points are close to the land. Acknowledgement: This research was partly supported by TUBITAK Grant number 213M534 according to Turkish Russian Joint research grant with RFBR and the CoCoNET (Towards Coast to Coast Network of Marine Protected Areas Coupled by Wİnd Energy Potential) project funded by European Union FP7/2007-2013 program.

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

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

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

Sample and data processing considerations for the NIST quantitative infrared database

NASA Astrophysics Data System (ADS)

Chu, Pamela M.; Guenther, Franklin R.; Rhoderick, George C.; Lafferty, Walter J.; Phillips, William

1999-02-01

Fourier-transform infrared (FT-IR) spectrometry has become a useful real-time in situ analytical technique for quantitative gas phase measurements. In fact, the U.S. Environmental Protection Agency (EPA) has recently approved open-path FT-IR monitoring for the determination of hazardous air pollutants (HAP) identified in EPA's Clean Air Act of 1990. To support infrared based sensing technologies, the National Institute of Standards and Technology (NIST) is currently developing a standard quantitative spectral database of the HAPs based on gravimetrically prepared standard samples. The procedures developed to ensure the quantitative accuracy of the reference data are discussed, including sample preparation, residual sample contaminants, data processing considerations, and estimates of error.

An in situ FTIR step-scan photoacoustic investigation of kerogen and minerals in oil shale.

PubMed

Alstadt, Kristin N; Katti, Dinesh R; Katti, Kalpana S

2012-04-01

Step-scan photoacoustic infrared spectroscopy experiments were performed on Green River oil shale samples obtained from the Piceance Basin located in Colorado, USA. We have investigated the molecular nature of light and dark colored areas of the oil shale core using FTIR photoacoustic step-scan spectroscopy. This technique provided us with the means to analyze the oil shale in its original in situ form with the kerogen-mineral interactions intact. All vibrational bands characteristic of kerogen were found in the dark and light colored oil shale samples confirming that kerogen is present throughout the depth of the core. Depth profiling experiments indicated that there are changes between layers in the oil shale molecular structure at a length scale of micron. Comparisons of spectra from the light and dark colored oil shale core samples suggest that the light colored regions have high kerogen content, with spectra similar to that from isolated kerogen, whereas, the dark colored areas contain more mineral components which include clay minerals, dolomite, calcite, and pyrite. The mineral components of the oil shale are important in understanding how the kerogen is "trapped" in the oil shale. Comparing in situ kerogen spectra with spectra from isolated kerogen indicate significant band shifts suggesting important nonbonded molecular interactions between the kerogen and minerals. Copyright © 2011 Elsevier B.V. All rights reserved.

A new ultrasonic transducer sample cell for in situ small-angle scattering experiments

NASA Astrophysics Data System (ADS)

Gupta, Sudipta; Bleuel, Markus; Schneider, Gerald J.

2018-01-01

Ultrasound irradiation is a commonly used technique for nondestructive diagnostics or targeted destruction. We report on a new versatile sonication device that fits in a variety of standard sample environments for neutron and X-ray scattering instruments. A piezoelectric transducer permits measuring of the time-dependent response of the sample in situ during or after sonication. We use small-angle neutron scattering (SANS) to demonstrate the effect of a time-dependent perturbation on the structure factor of micelles formed from sodium dodecyl sulfate surfactant molecules. We observe a substantial change in the micellar structure during and after exposure to ultrasonic irradiation. We also observe a time-dependent relaxation to the equilibrium values of the unperturbed system. The strength of the perturbation of the structure factor depends systematically on the duration of sonication. The relaxation behavior can be well reproduced after multiple times of sonication. Accumulation of the recorded intensities of the different sonication cycles improves the signal-to-noise ratio and permits reaching very short relaxation times. In addition, we present SANS data for the micellar form factor on alkyl-poly (ethylene oxide) surfactant molecules irradiated by ultrasound. Due to the flexibility of our new in situ sonication device, different experiments can be performed, e.g., to explore molecular potentials in more detail by introducing a systematic time-dependent perturbation.

Mobile system for in-situ imaging of cultural objects

NASA Astrophysics Data System (ADS)

Zemlicka, J.; Jakubek, J.; Krejci, F.; Hradil, D.; Hradilova, J.; Mislerova, H.

2012-01-01

Non-invasive analytical techniques recently developed with the Timepix pixel detector have shown great potential for the inspection of objects of cultural heritage. We have developed new instrumentation and methodology for in-situ X-ray transmission radiography and X-ray fluorescence imaging and successfully tested and evaluated a mobile system for remote terrain tasks. The prototype portable imaging device comprises the radiation source tube and the spectral sensitive X-ray camera. Both components can be moreover mounted on independent motorized positioning systems allowing adaptation of irradiation geometry to the object shape. Both parts are placed onto a pair of universal portable holders (tripods). The detector is placed in a shielded box with exchangeable entrance window (beam filters and pinhole collimator). This adjustable setup allows performing in-situ measurements for both transmission and emission (XRF) radiography. The assembled system has been successfully tested in our laboratory with phantoms and real samples. The obtained and evaluated results are presented in this paper. Future work will include successive adaptation of the current system for real in-situ utilization and preparation of software allowing semi-automatic remote control of measurements.

High Resolution Tissue Imaging Using the Single-probe Mass Spectrometry under Ambient Conditions

NASA Astrophysics Data System (ADS)

Rao, Wei; Pan, Ning; Yang, Zhibo

2015-06-01

Ambient mass spectrometry imaging (MSI) is an emerging field with great potential for the detailed spatial analysis of biological samples with minimal pretreatment. We have developed a miniaturized sampling and ionization device, the Single-probe, which uses in-situ surface micro-extraction to achieve high detection sensitivity and spatial resolution during MSI experiments. The Single-probe was coupled to a Thermo LTQ Orbitrap XL mass spectrometer and was able to create high spatial and high mass resolution MS images at 8 ± 2 and 8.5 μm on flat polycarbonate microscope slides and mouse kidney sections, respectively, which are among the highest resolutions available for ambient MSI techniques. Our proof-of-principle experiments indicate that the Single-probe MSI technique has the potential to obtain ambient MS images with very high spatial resolutions with minimal sample preparation, which opens the possibility for subcellular ambient tissue MSI to be performed in the future.

Elemental, Isotopic, and Organic Analysis on Mars with Laser TOF-MS

NASA Technical Reports Server (NTRS)

Brinckerhoff, W. B.; Cornish, T. J.

2000-01-01

The in-depth landed exploration of Mars will require increasingly sophisticated robotic analytical tools for both in situ composition science [1] and reconnaissance for sample return [2]. Beyond dust, rock surfaces, and topsoil, samples must be accessed within rocks and ice, well below surface soil, and possibly in elevated deposit layers. A range of spatial scales will be studied, and for the most information-rich microscopic analyses, samples must be acquired, prepared, and positioned with high precision. In some cases samples must also be brought into a vacuum chamber. After expending such resources, it will be important to apply techniques that provide a wide range of information about the samples. Microscopy, mineralogy, and molecular/organic, elemental, and isotopic analyses are all needed, at a minimum, to begin to address the in situ goals at Mars. These techniques must work as an efficient suite to provide layers of data, each layer helping to determine if further analysis on a given sample is desired. In the spirit of broad-band and efficient data collection, we are developing miniature laser time-of-flight mass spectrometers (TOF-MS) for elemental, isotopic, and molecular/organic microanalysis of unprepared solid samples. Laser TOF-MS uses a pulsed laser to volatilize and ionize material from a small region on the sample. The laser energy and focus can be adjusted for atomic and molecular content, sampling area, and depth. Ions travel through the instrument and are detected at a sequence of times proportional to the square root of their mass-to- charge ratios. Thus, each laser pulse produces a complete mass spectrum (in less than 50 microseconds). These instruments can now be significantly miniaturized (potentially to the size of a soda can) without a loss in performance. This effort is reviewed here with an emphasis on applications to Mars exploration.

The utility of polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) in surface and in situ studies: new data processing and presentation approach.

PubMed

Monyoncho, Evans A; Zamlynny, Vlad; Woo, Tom K; Baranova, Elena A

2018-05-29

Infrared spectroscopy is a powerful non-destructive technique for the identification and quantification of organic molecules widely used in scientific studies. For many years, efforts have been made to adopt this technique for the in situ monitoring of reactions. From these efforts, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was developed three decades ago. Unfortunately, because of the complexity of data processing and interpretation, PM-IRRAS had been avoided in lieu of the single potential alteration infrared spectroscopy (SPAIRS) and subtractively normalized interfacial Fourier transform infrared (SNIFTIR). In this work, we present a new approach for PM-IRRAS data processing and presentation, which provides more insight into in situ and surface studies besides dramatically improving the S/N. In this new approach, we recommend three complementary methods of data treatment (eqn (7), (9) and (10)) as the new protocols for presenting PM-IRRAS data. These equations are robust in visualising the surface processes at the solid-liquid and solid-gas interphases. Eqn (7) contrasts the surface adsorbed species with respect to the isotropic background with or without the influence of the applied potential. Eqn (9) highlights the surface potential-driven changes between the sample and the reference spectra. Eqn (10) focuses on the bulk-phase (solution/gas and surface species) potential-driven changes between the sample and the reference spectra, and hence it can be used to track the production of species, which desorb from the surface upon their formation. Examples of ethanol electro-oxidation reaction are provided as a test system for in situ studies and PVP deposited on glassy carbon for thin-film studies to illustrate the utility of the new PM-IRRAS data handling protocol, which is poised to improve the understanding of the chemistry and physics of surface processes.

A sub-sampled approach to extremely low-dose STEM

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

Stevens, A.; Luzi, L.; Yang, H.

The inpainting of randomly sub-sampled images acquired by scanning transmission electron microscopy (STEM) is an attractive method for imaging under low-dose conditions (≤ 1 e -Å 2) without changing either the operation of the microscope or the physics of the imaging process. We show that 1) adaptive sub-sampling increases acquisition speed, resolution, and sensitivity; and 2) random (non-adaptive) sub-sampling is equivalent, but faster than, traditional low-dose techniques. Adaptive sub-sampling opens numerous possibilities for the analysis of beam sensitive materials and in-situ dynamic processes at the resolution limit of the aberration corrected microscope and is demonstrated here for the analysis ofmore » the node distribution in metal-organic frameworks (MOFs).« less

In situ demonstration of tissue proliferative activity using anti-bromo-deoxyuridine monoclonal antibody.

PubMed Central

Veronese, S; Gambacorta, M; Falini, B

1989-01-01

Immunohistochemical staining with anti-bromo-deoxyuridine (BrdU) monoclonal antibody was performed on a variety of human tissues following in vitro incubation with BrdU. The effect of different fixatives and DNA denaturation techniques on the reactivity with anti-BrdU was investigated. Optimal preservation of the antigenicity of BrdU incorporated into the DNA of proliferating cells was seen in tissues fixed in Bouin's fluid, while samples which had been fixed with cross-linking reagents, such as formalin, were usually unreactive. Positivity for BrdU was restored in formalin fixed tissues after digestion with pepsin, but this was usually associated with loss of morphological details. Acid and thermal DNA denaturation techniques gave similar results. It is concluded that Bouin fixation followed by acid or thermal denaturation of DNA is the method of choice for the in situ detection of cells in S-phase using anti-BrdU monoclonal antibody. Images Fig 1 Fig 1 PMID:2475528

A neutron-X-ray, NMR and calorimetric study of glassy Probucol synthesized using containerless techniques

NASA Astrophysics Data System (ADS)

Weber, J. K. R.; Benmore, C. J.; Tailor, A. N.; Tumber, S. K.; Neuefeind, J.; Cherry, B.; Yarger, J. L.; Mou, Q.; Weber, W.; Byrn, S. R.

2013-10-01

Acoustic levitation was used to trap 1-3 mm diameter drops of Probucol and other pharmaceutical materials in containerless conditions. Samples were studied in situ using X-ray diffraction and ex situ using neutron diffraction, NMR and DSC techniques. The materials were brought into non-equilibrium states by supersaturating solutions or by supercooling melts. The glass transition and crystallization temperatures of glassy Probucol were 29 ± 1 and 71 ± 1 °C respectively. The glassy form was stable with a shelf life of at least 8 months. A neutron/X-ray difference function of the glass showed that while molecular sub-groups remain rigid, many of the hydrogen correlations observed in the crystal become smeared out in the disordered material. The glass is principally comprised of slightly distorted Form I Probucol molecules with disordered packing rather than large changes in the individual molecular structure. Avoiding surface contact-induced nucleation provided access to highly non-equilibrium phases and enabled synthesis of phase-pure glasses.

Visualization and Enumeration of Bacteria Carrying a Specific Gene Sequence by In Situ Rolling Circle Amplification

PubMed Central

Maruyama, Fumito; Kenzaka, Takehiko; Yamaguchi, Nobuyasu; Tani, Katsuji; Nasu, Masao

2005-01-01

Rolling circle amplification (RCA) generates large single-stranded and tandem repeats of target DNA as amplicons. This technique was applied to in situ nucleic acid amplification (in situ RCA) to visualize and count single Escherichia coli cells carrying a specific gene sequence. The method features (i) one short target sequence (35 to 39 bp) that allows specific detection; (ii) maintaining constant fluorescent intensity of positive cells permeabilized extensively after amplicon detection by fluorescence in situ hybridization, which facilitates the detection of target bacteria in various physiological states; and (iii) reliable enumeration of target bacteria by concentration on a gelatin-coated membrane filter. To test our approach, the presence of the following genes were visualized by in situ RCA: green fluorescent protein gene, the ampicillin resistance gene and the replication origin region on multicopy pUC19 plasmid, as well as the single-copy Shiga-like toxin gene on chromosomes inside E. coli cells. Fluorescent antibody staining after in situ RCA also simultaneously identified cells harboring target genes and determined the specificity of in situ RCA. E. coli cells in a nonculturable state from a prolonged incubation were periodically sampled and used for plasmid uptake study. The numbers of cells taking up plasmids determined by in situ RCA was up to 106-fold higher than that measured by selective plating. In addition, in situ RCA allowed the detection of cells taking up plasmids even when colony-forming cells were not detected during the incubation period. By optimizing the cell permeabilization condition for in situ RCA, this method can become a valuable tool for studying free DNA uptake, especially in nonculturable bacteria. PMID:16332770

X-Ray photoelectron Spectroscopy Applications

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

Engelhard, Mark H.; Droubay, Timothy C.; Du, Yingge

2017-01-03

With capability for obtaining quantitative elemental composition, chemical and electronic state, and overlayer thickness information from the top ~10 nm of a sample surface, X-ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA) is a versatile and widely used technique for analyzing surfaces. The technique is applied to a host of materials, from insulators to conductors in virtually every scientific field and sub-discipline. More recently, XPS has been extended under in-situ and operando conditions. Following a brief introduction to XPS principles and instrument components, this article exemplifies widely ranging XPS applications in material and life sciences.

Technique for examining biological materials using diffuse reflectance spectroscopy and the kubelka-munk function

DOEpatents

Alfano, Robert R.; Yang, Yuanlong

2003-09-02

Method and apparatus for examining biological materials using diffuse reflectance spectroscopy and the Kubelka-Munk function. In one aspect, the method is used to determine whether a tissue sample is cancerous or not and comprises the steps of (a) measuring the diffuse reflectance from the tissue sample at a first wavelength and at a second wavelength, wherein the first wavelength is a wavelength selected from the group consisting of 255-265 nm and wherein the second wavelength is a wavelength selected from the group consisting of 275-285 nm; (b) using the Kubelka-Munk function to transform the diffuse reflectance measurement obtained at the first and second wavelengths; and (c) comparing a ratio or a difference of the transformed Kubelka-Munk measurements at the first and second wavelengths to appropriate standards determine whether or not the tissue sample is cancerous. One can use the spectral profile of KMF between 250 nm to 300 nm to determine whether or not the tissue sample is cancerous or precancerous. According to the value at the first and second wavelengths determine whether or not the malignant tissue is invasive or mixed invasive and in situ or carcinoma in situ.

In Situ 3D Coherent X-ray Diffraction Imaging of Shock Experiments: Possible?

NASA Astrophysics Data System (ADS)

Barber, John

2011-03-01

In traditional coherent X-ray diffraction imaging (CXDI), a 2D or quasi-2D object is illuminated by a beam of coherent X-rays to produce a diffraction pattern, which is then manipulated via a process known as iterative phase retrieval to reconstruct an image of the original 2D sample. Recently, there have been dramatic advances in methods for performing fully 3D CXDI of a sample from a single diffraction pattern [Raines et al, Nature 463 214-7 (2010)], and these methods have been used to image samples tens of microns in size using soft X-rays. In this work, I explore the theoretical possibility of applying 3D CXDI techniques to the in situ imaging of the interaction between a shock front and a polycrystal, a far more stringent problem. A delicate trade-off is required between photon energy, spot size, imaging resolution, and the dimensions of the experimental setup. In this talk, I will outline the experimental and computational requirements for performing such an experiment, and I will present images and movies from simulations of one such hypothetical experiment, including both the time-resolved X-ray diffraction patterns and the time-resolved sample imagery.

In-vial pyrolysis (PyroVial) with pre- and post-sample treatment combined with different chromatographic techniques.

PubMed

Tienpont, Bart; David, Frank; Pereira, Alberto; Sandra, Pat

2011-11-18

A new generic pyrolysis unit (PyroVial) is presented. Pyrolysis is carried out in a 2 mL autosampler vial placed in a XYZ robot for automated pyrolysis as well as for pre- and post-pyrolysis treatment of the sample. Analysis of the volatiles is performed by headspace analysis while the semi- and non-volatiles are extracted from the pyrolysate with an organic solvent. The features of the PyroVial are such that all chromatographic techniques can be applied. The pyrolysis unit is discussed in terms of its technical features and its performance is illustrated with applications including conventional pyrolysis, in situ and post-pyrolysis derivatization, reaction pyrolysis and catalytic cracking. Copyright © 2011 Elsevier B.V. All rights reserved.

Measurement Protocols for In situ Analysis of Organic Compounds at Mars and Comets

NASA Technical Reports Server (NTRS)

Mahaffy, P. R.; Brinckerhuff, W. B.; Buch, A.; Cabane, M.; Coll, P.; Demick, J.; Glavin, D. P.; Navarro-Gonzalez, R.

2005-01-01

The determination of the abundance and chemical and isotopic composition of organic molecules in comets and those that might be found in protected environments at Mars is a first step toward understanding prebiotic chemistries on these solar system bodies. While future sample return missions from Mars and comets will enable detailed chemical and isotopic analysis with a wide range of analytical techniques, precursor insitu investigations can complement these missions and facilitate the identification of optimal sites for sample return. Robust automated experiments that make efficient use of limited spacecraft power, mass, and data volume resources are required for use by insitu missions. Within these constraints we continue to explore a range of instrument techniques and measurement protocols that can maximize the return from such insitu investigations.

Measurement Protocols for In Situ Analysis of Organic Compounds at Mars and Comets

NASA Technical Reports Server (NTRS)

Mahaffy, P. R.; Brinckerhoff, W. B.; Buch, A.; Cabane, M.; Coll, P.; Demick, J.; Glavin, D. P.; Navarro-Gonzalez, R.

2005-01-01

The determination of the abundance and chemical and isotopic composition of organic molecules in comets and those that might be found in protected environments at Mars is a first step toward understanding prebiotic chemistries on these solar system bodies. While future sample return missions from Mars and comets will enable detailed chemical and isotopic analysis with a wide range of analytical techniques, precursor insitu investigations can complement these missions and facilitate the identification of optimal sites for sample return. Robust automated experiments that make efficient use of limited spacecraft power, mass, and data volume resources are required for use by insitu missions. Within these constraints we continue to explore a range of instrument techniques and measurement protocols that can maximize the return from such insitu investigations.

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.

Nanoscale characterization of local structures and defects in photonic crystals using synchrotron-based transmission soft X-ray microscopy

PubMed Central

Nho, Hyun Woo; Kalegowda, Yogesh; Shin, Hyun-Joon; Yoon, Tae Hyun

2016-01-01

For the structural characterization of the polystyrene (PS)-based photonic crystals (PCs), fast and direct imaging capabilities of full field transmission X-ray microscopy (TXM) were demonstrated at soft X-ray energy. PS-based PCs were prepared on an O2-plasma treated Si3N4 window and their local structures and defects were investigated using this label-free TXM technique with an image acquisition speed of ~10 sec/frame and marginal radiation damage. Micro-domains of face-centered cubic (FCC (111)) and hexagonal close-packed (HCP (0001)) structures were dominantly found in PS-based PCs, while point and line defects, FCC (100), and 12-fold symmetry structures were also identified as minor components. Additionally, in situ observation capability for hydrated samples and 3D tomographic reconstruction of TXM images were also demonstrated. This soft X-ray full field TXM technique with faster image acquisition speed, in situ observation, and 3D tomography capability can be complementally used with the other X-ray microscopic techniques (i.e., scanning transmission X-ray microscopy, STXM) as well as conventional characterization methods (e.g., electron microscopic and optical/fluorescence microscopic techniques) for clearer structure identification of self-assembled PCs and better understanding of the relationship between their structures and resultant optical properties. PMID:27087141

Work plan for the identification of techniques for in-situ sensing of layering/interfaces of Hanford high level waste tank

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

Vargo, G.F. Jr.

1995-06-16

The purpose of this work scope is to identify a specific potential technology/device/instrument/ideas that would provide the tank waste data. A method is needed for identifying layering and physical state within the large waste tanks at the Hanford site in Washington State. These interfaces and state changes can adversely impact sampling and characterization activities.

Applied in situ product recovery in ABE fermentation.

PubMed

Outram, Victoria; Lalander, Carl-Axel; Lee, Jonathan G M; Davies, E Timothy; Harvey, Adam P

2017-05-01

The production of biobutanol is hindered by the product's toxicity to the bacteria, which limits the productivity of the process. In situ product recovery of butanol can improve the productivity by removing the source of inhibition. This paper reviews in situ product recovery techniques applied to the acetone butanol ethanol fermentation in a stirred tank reactor. Methods of in situ recovery include gas stripping, vacuum fermentation, pervaporation, liquid-liquid extraction, perstraction, and adsorption, all of which have been investigated for the acetone, butanol, and ethanol fermentation. All techniques have shown an improvement in substrate utilization, yield, productivity or both. Different fermentation modes favored different techniques. For batch processing gas stripping and pervaporation were most favorable, but in fed-batch fermentations gas stripping and adsorption were most promising. During continuous processing perstraction appeared to offer the best improvement. The use of hybrid techniques can increase the final product concentration beyond that of single-stage techniques. Therefore, the selection of an in situ product recovery technique would require comparable information on the energy demand and economics of the process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:563-579, 2017. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

Salivary density of Streptococcus mutans and Streptococcus sobrinus and dental caries in children and adolescents with Down syndrome.

PubMed

Scalioni, Flávia; Carrada, Camila; Machado, Fernanda; Devito, Karina; Ribeiro, Luiz Cláudio; Cesar, Dionéia; Ribeiro, Rosangela

2017-01-01

To assess and compare dental caries experience and salivary S. mutans, S. sobrinus, and streptococci counts between groups of Down syndrome and non-Down syndrome children and adolescents. This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Dental caries experience was estimated by the number of decayed, missing, and filled teeth in the primary dentition and the permanent dentition. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization technique was used to identify the presence and counts of the bacteria. The statistical analysis included chi-square, Student's t-test and Spearman's correlation. The G-DS exhibited a significantly higher caries-free rate (p<0.001) and a lower S. mutans salivary density (p<0.001). No significant differences were found in the salivary densities of S. sobrinus or streptococci between the groups (p=0.09 and p=0.21, respectively). The salivary S. mutans or S. sobrinus densities were not associated with dental caries experience in neither group. The reduced dental caries experience observed in this group of Down syndrome children and adolescents cannot be attributed to lower salivary S. mutans densities, as determined with the fluorescence in situ hybridization technique.

Visual and efficient immunosensor technique for advancing biomedical applications of quantum dots on Salmonella detection and isolation

NASA Astrophysics Data System (ADS)

Tang, Feng; Pang, Dai-Wen; Chen, Zhi; Shao, Jian-Bo; Xiong, Ling-Hong; Xiang, Yan-Ping; Xiong, Yan; Wu, Kai; Ai, Hong-Wu; Zhang, Hui; Zheng, Xiao-Li; Lv, Jing-Rui; Liu, Wei-Yong; Hu, Hong-Bing; Mei, Hong; Zhang, Zhen; Sun, Hong; Xiang, Yun; Sun, Zi-Yong

2016-02-01

It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab (a solid-phase enrichment system). The selective and chromogenic medium used on this swab can achieve the ultrasensitive amplification of target bacteria and form chromogenic colonies in situ based on a simple biochemical reaction. More importantly, because this swab can serve as an attachment site for the targeted pathogens to immobilize and immunologically capture nanobioprobes, our mAb-conjugated QD bioprobes were successfully applied on the solid-phase enrichment system to capture the fluorescence of targeted colonies under a designed excitation light instrument based on blue light-emitting diodes combined with stereomicroscopy or laser scanning confocal microscopy. Compared with the traditional methods using 4-7 days to isolate Salmonella from the bacterial mixture, this method took only 2 days to do this, and the process of initial screening and preliminary diagnosis can be completed in only one and a half days. Furthermore, the limit of detection can reach as low as 101 cells per mL Salmonella on the background of 105 cells per mL non-Salmonella (Escherichia coli, Proteus mirabilis or Citrobacter freundii, respectively) in experimental samples, and even in human anal ones. The visual and efficient immunosensor technique may be proved to be a favorable alternative for screening and isolating Salmonella in a large number of samples related to public health surveillance.It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab (a solid-phase enrichment system). The selective and chromogenic medium used on this swab can achieve the ultrasensitive amplification of target bacteria and form chromogenic colonies in situ based on a simple biochemical reaction. More importantly, because this swab can serve as an attachment site for the targeted pathogens to immobilize and immunologically capture nanobioprobes, our mAb-conjugated QD bioprobes were successfully applied on the solid-phase enrichment system to capture the fluorescence of targeted colonies under a designed excitation light instrument based on blue light-emitting diodes combined with stereomicroscopy or laser scanning confocal microscopy. Compared with the traditional methods using 4-7 days to isolate Salmonella from the bacterial mixture, this method took only 2 days to do this, and the process of initial screening and preliminary diagnosis can be completed in only one and a half days. Furthermore, the limit of detection can reach as low as 101 cells per mL Salmonella on the background of 105 cells per mL non-Salmonella (Escherichia coli, Proteus mirabilis or Citrobacter freundii, respectively) in experimental samples, and even in human anal ones. The visual and efficient immunosensor technique may be proved to be a favorable alternative for screening and isolating Salmonella in a large number of samples related to public health surveillance. Electronic supplementary information (ESI) available: One additional figure (Fig. S1), two additional tables (Tables S1 and S2) and additional information. See DOI: 10.1039/c5nr07424j

In-situ monitoring of ? phase transformation in Ti-6Al-6V-2Sn using laser ultrasonics

NASA Astrophysics Data System (ADS)

Hinterlechner, Irina; Barriobero-Vila, Pere; Reitinger, Bernhard; Fromherz, Thomas; Requena, Guillermo; Burgholzer, Peter

2018-04-01

Titanium is of great interest for metal processing industries due to its superior material properties, but it is also quite expensive. Therefore, a detailed knowledge of ? phase transformation and consequential the distribution of ? and ? phase in titanium alloys is crucial for their material properties and as a consequence for further processing steps. Measuring the ultrasonic velocity and attenuation by laser ultrasonics technology (LUS) as a non-destructive and non-contact technique, it is possible to qualitatively monitor in-situ the phase transformation during heating the sample from room temperature up to ?. We validate LUS methodology against high energy X-ray diffraction as well as against conventional metallurgic measurements and get excellent agreement between the results of these methods.

Application of ex situ dynamic nuclear polarization in studying small molecules.

PubMed

Ludwig, Christian; Marin-Montesinos, Ildefonso; Saunders, Martin G; Emwas, Abdul-Hamid; Pikramenou, Zoe; Hammond, Stephen P; Günther, Ulrich L

2010-06-14

Dynamic nuclear polarization (DNP) has become an attractive technique to boost the sensitivity of NMR experiments. In the case of ex situ polarizations two-dimensional (2D) spectra are limited by the short lifetime of the polarization after dissolution and sample transfer to a high field NMR magnet. This limitation can be overcome by various approaches. Here we show how the use of (13)C-labelled acetyl tags can help to obtain 2D-HMQC spectra for many small molecules, owing to a nuclear Overhauser enhancement between (13)C spins originating from the long-lived carbonyl carbon, which extends the lifetimes of other (13)C spins with shorter longitudinal relaxation times. We also show an alternative approach of using an optimized polarization matrix.

Deep UV Native Fluorescence Imaging of Antarctic Cryptoendolithic Communities

NASA Technical Reports Server (NTRS)

Storrie-Lombardi, M. C.; Douglas, S.; Sun, H.; McDonald, G. D.; Bhartia, R.; Nealson, K. H.; Hug, W. F.

2001-01-01

An interdisciplinary team at the Jet Propulsion Laboratory Center for Life Detection has embarked on a project to provide in situ chemical and morphological characterization of Antarctic cryptoendolithic microbial communities. We present here in situ deep ultraviolet (UV) native fluorescence and environmental scanning electron microscopy images transiting 8.5 mm into a sandstone sample from the Antarctic Dry Valleys. The deep ultraviolet imaging system employs 224.3, 248.6, and 325 nm lasers to elicit differential fluorescence and resonance Raman responses from biomolecules and minerals. The 224.3 and 248.6 nm lasers elicit a fluorescence response from the aromatic amino and nucleic acids. Excitation at 325 nm may elicit activity from a variety of biomolecules, but is more likely to elicit mineral fluorescence. The resultant fluorescence images provide in situ chemical and morphological maps of microorganisms and the associated organic matrix. Visible broadband reflectance images provide orientation against the mineral background. Environmental scanning electron micrographs provided detailed morphological information. The technique has made possible the construction of detailed fluorescent maps extending from the surface of an Antarctic sandstone sample to a depth of 8.5 mm. The images detect no evidence of microbial life in the superficial 0.2 mm crustal layer. The black lichen component between 0.3 and 0.5 mm deep absorbs all wavelengths of both laser and broadband illumination. Filamentous deep ultraviolet native fluorescent activity dominates in the white layer between 0.6 mm and 5.0 mm from the surface. These filamentous forms are fungi that continue into the red (iron-rich) region of the sample extending from 5.0 to 8.5 mm. Using differential image subtraction techniques it is possible to identify fungal nuclei. The ultraviolet response is markedly attenuated in this region, apparently from the absorption of ultraviolet light by iron-rich particles coating the filaments. Below 8.5 mm the filamentous morphology of the upper layers gives way to punctate 1-2 micron particles evidencing fluorescent activity following excitation at both deep ultraviolet wavelengths.

Characterizing precipitate evolution of an Al–Zn–Mg–Cu-based commercial alloy during artificial aging and non-isothermal heat treatments by in situ electrical resistivity monitoring

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

Jiang, Fulin; Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7; Zurob, Hatem S., E-mail: zurobh@mcmaster.ca

In situ electrical resistivity monitoring technique was employed to continuously evaluate the precipitate evolution of an Al–Zn–Mg–Cu-based commercial alloy during typical artificial aging treatments. The effects of artificial aging on the precipitates stability during non-isothermal heat treatments were also explored. Conventional hardness test, transmission electron microscopy and differential scanning calorimetry were also adopted to verify the electrical resistivity results. The results indicated that both the precipitation process and its timely rate could be followed by the monitored electrical resistivity during artificial aging treatments. The electrical resistivity results gave overall information on continuous precipitation and dissolution processes, especially under high heatingmore » rates. Samples artificial aging heat treated at 120 °C for 24 h followed by aging at 150 °C for 24 h presented more stable state and coarser precipitates than the samples only artificial aging heat treated at 120 °C for 24 h or triple artificial aging heat treated at 120 °C/24 h + 195 °C/15 min + 120 °/24 h. While the incoherent η precipitates in the samples artificial aging heat treated at 120 °C for 24 h followed by aging at 150 °C for 24 h were more easiness to coarsening and dissolve during non-isothermal heat treatments as well. - Highlights: • In situ electrical resistivity monitoring technique was employed on an Al-Zn-Mg-Cu alloy. • The precipitate evolution during typical artificial aging treatments was studied. • The precipitate stability during non-isothermal heat treatments was explored. • The electrical resistivity wonderfully monitored continuous precipitation and dissolution. • The alloy submitted to a T7 treatment presents a more stable state during heating due to incoherent η precipitates.« less

Exploring laser-induced breakdown spectroscopy for nuclear materials analysis and in-situ applications

NASA Astrophysics Data System (ADS)

Martin, Madhavi Z.; Allman, Steve; Brice, Deanne J.; Martin, Rodger C.; Andre, Nicolas O.

2012-08-01

Laser-induced breakdown spectroscopy (LIBS) has been used to determine the limits of detection of strontium (Sr) and cesium (Cs), common nuclear fission products. Additionally, detection limits were determined for cerium (Ce), often used as a surrogate for radioactive plutonium in laboratory studies. Results were obtained using a laboratory instrument with a Nd:YAG laser at fundamental wavelength of 1064 nm, frequency doubled to 532 nm with energy of 50 mJ/pulse. The data was compared for different concentrations of Sr and Ce dispersed in a CaCO3 (white) and carbon (black) matrix. We have addressed the sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis in pellets that were doped with the different elements at various concentrations. These results demonstrate that LIBS technique is inherently well suited for in situ analysis of nuclear materials in hot cells. Three key advantages are evident: (1) small samples (mg) can be evaluated; (2) nuclear materials can be analyzed with minimal sample preparation; and (3) samples can be remotely analyzed very rapidly (ms-seconds). Our studies also show that the methods can be made quantitative. Very robust multivariate models have been used to provide quantitative measurement and statistical evaluation of complex materials derived from our previous research on wood and soil samples.

Combining in situ characterization methods in one set-up: looking with more eyes into the intricate chemistry of the synthesis and working of heterogeneous catalysts.

PubMed

Bentrup, Ursula

2010-12-01

Several in situ techniques are known which allow investigations of catalysts and catalytic reactions under real reaction conditions using different spectroscopic and X-ray methods. In recent years, specific set-ups have been established which combine two or more in situ methods in order to get a more detailed understanding of catalytic systems. This tutorial review will give a summary of currently available set-ups equipped with multiple techniques for in situ catalyst characterization, catalyst preparation, and reaction monitoring. Besides experimental and technical aspects of method coupling including X-ray techniques, spectroscopic methods (Raman, UV-vis, FTIR), and magnetic resonance spectroscopies (NMR, EPR), essential results will be presented to demonstrate the added value of multitechnique in situ approaches. A special section is focussed on selected examples of use which show new developments and application fields.

Calculation of Ceramic Phase Diagrams

DTIC Science & Technology

1979-11-30

Recent examples of the use of data bases and computer techniques in solw~ng problems associated with: in-situ formation of columbium, nickel and...examples of the use of data bases and computer techniques in solving problems associated with: in-situ formation of columbium, nickel and cobalt based...covers processing of in-situ eutectic composite formation in columbium, nickel and cobalt base superalloys, sigma phase formation in high temperature

In situ sensors for measurements in the global trosposphere

NASA Technical Reports Server (NTRS)

Saeger, M. L.; Eaton, W. C.; Wright, R. S.; White, J. H.; Tommerdahl, J. B.

1981-01-01

Current techniques available for the in situ measurement of ambient trace gas species, particulate composition, and particulate size distribution are reviewed. The operational specifications of the various techniques are described. Most of the techniques described are those that have been used in airborne applications or show promise of being adaptable to airborne applications. Some of the instruments described are specialty items that are not commercially-available. In situ measurement techniques for several meteorological parameters important in the study of the distribution and transport of ambient air pollutants are discussed. Some remote measurement techniques for meteorological parameters are also discussed. State-of-the-art measurement capabilities are compared with a list of capabilities and specifications desired by NASA for ambient measurements in the global troposphere.

Ambient in-situ immersion freezing measurements - findings from the ZAMBIS 2014 field campaign for three ice nucleation techniques

NASA Astrophysics Data System (ADS)

Kohn, Monika; Atkinson, James D.; Lohmann, Ulrike; Kanji, Zamin A.

2015-04-01

To estimate the influence of clouds on the Earth's radiation budget, it is crucial to understand cloud formation processes in the atmosphere. A key process, which significantly affects cloud microphysical properties and the initiation of precipitation thus contributing to the hydrological cycle, is the prevailing type of ice nucleation mechanism. In mixed-phase clouds immersion freezing is the dominant ice crystal forming mechanism, whereby ice nucleating particles (INP) first act as cloud condensation nuclei (CCN) and are activated to cloud droplets followed by freezing upon supercooling. There are a number of experimental methods and techniques to investigate the ice nucleating ability in the immersion mode, however most techniques are offline for field sampling or only suitable for laboratory measurements. In-situ atmospheric studies are needed to understand the ice formation processes of 'real world' particles. Laboratory experiments simulate conditions of atmospheric processes like ageing or coating but are still idealized. Our method is able to measure ambient in-situ immersion freezing on single immersed aerosol particles. The instrumental setup consists of the recently developed portable immersion mode cooling chamber (PIMCA) as a vertical extension to the portable ice nucleation chamber (PINC, [1]), where the frozen fraction of activated aerosol particles are detected by the ice optical depolarization detector (IODE, [2]). Two additional immersion freezing techniques based on a droplet freezing array [3,4] are used to sample ambient aerosol particles either in a suspension (fraction larger ~0.6 μm) or on PM10-filters to compare different ice nucleation techniques. Here, we present ambient in-situ measurements at an urban forest site in Zurich, Switzerland held during the Zurich ambient immersion freezing study (ZAMBIS) in spring 2014. We investigated the ice nucleating ability of natural atmospheric aerosol with the PIMCA/PINC immersion freezing setup as well as a droplet freezing method on aerosol particles either collected in a suspension or on PM10-filters to obtain atmospheric IN concentrations based on the measured ambient aerosol. Investigation of physical properties (number and size distribution) and chemical composition as well as the meteorological conditions provide supplementary information that help to understand the nature of particles and air masses that contribute to immersion freezing. Acknowledgements We thank Hannes Wydler and Hansjörg Frei from ETH Zurich for their technical support. Furthermore, the authors want thank Franz Conen from the University of Basel for sharing equipment and training in the drop freezing experiment. References [1] Chou et al. (2011), Atmos. Chem. Phys., 11, 4725-4738. [2] Nicolet et al. (2010), Atmos. Chem. Phys., 10, 313-325. [3] Conen et al. (2012), Atmos. Meas. Tech., 5, 321-327. [4] Stopelli et al. (2014), Atmos. Meas. Tech., 7, 129-134.

Sensing Free Sulfur Dioxide in Wine

PubMed Central

Monro, Tanya M.; Moore, Rachel L.; Nguyen, Mai-Chi; Ebendorff-Heidepriem, Heike; Skouroumounis, George K.; Elsey, Gordon M.; Taylor, Dennis K.

2012-01-01

Sulfur dioxide (SO2) is important in the winemaking process as it aids in preventing microbial growth and the oxidation of wine. These processes and others consume the SO2 over time, resulting in wines with little SO2 protection. Furthermore, SO2 and sulfiting agents are known to be allergens to many individuals and for that reason their levels need to be monitored and regulated in final wine products. Many of the current techniques for monitoring SO2 in wine require the SO2 to be separated from the wine prior to analysis. This investigation demonstrates a technique capable of measuring free sulfite concentrations in low volume liquid samples in white wine. This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte. We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring. PMID:23112627

Applications of in situ optical measurements in ecological and biogeochemical studies - a framework for a user-driven national network

NASA Astrophysics Data System (ADS)

Bergamaschi, B. A.; Pellerin, B. A.; Downing, B. D.; Saraceno, J.; Aiken, G.; Stumpner, P.

2010-12-01

A critical challenge for understanding the dynamics between water quality, and ecological processes is obtaining data at time scales in which changes occur. Traditional, discrete sampling, approaches for data collection are often limited by analytical and field costs, site access, and logistical challenges, for long-term sampling at a large number of sites. The timescales of change, however, are often minutes, hours, or years. In situ optical (absorbance and fluorescence) instruments offer opportunities to help overcome these difficulties by directly or indirectly measuring constituents of interest. In situ optical instrumentation have been in use in oceanographic studies for well over 50 years, and as advances in the science, engineering and technology of these sensors have improved, optical sensors have become more commercially viable and available for research. We present several examples that highlight applications of in situ optical measurements for understanding dynamics in stream, river, and estuary systems. Examples illustrate the utility of in situ optical sensors for studies over short-duration events of days to weeks (diurnal cycles, tidal cycles, storm events and snowmelt periods) as well as longer-term continuous monitoring for months to years. We also highlight applied in situ optical measurements as proxies for constituents that are difficult and expensive to measure at high spatiotemporal resolution, for example, dissolved organic carbon, dissolved organic nitrogen, mercury and methylmercury, trihalomethane precursors, harmful algal blooms, and others. We propose that relatively simple absorbance and fluorescence measurements made in situ could be incorporated into short and long-term ecological research and monitoring programs, resulting in advanced understanding of sources that contribute to water quality improvements or degradation, contaminant and carbon cycling, and the occurrence and persistence of harmful algal blooms. Linking these efforts through common calibration and validation techniques, as well as hosted data sharing and online user forums - as has been proposed by CUAHSI and USGS - will permit more rapid advances in applications of in situ optical sensors as well as in our understanding of aquatic processes.

Extraction of in situ cosmogenic 14C from olivine

USGS Publications Warehouse

Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

2010-01-01

Chemical pretreatment and extraction techniques have been developed previously to extract in situ cosmogenic radiocarbon (in situ 14C) from quartz and carbonate. These minerals can be found in most environments on Earth, but are usually absent from mafic terrains. To fill this gap, we conducted numerous experiments aimed at extracting in situ 14C from olivine ((Fe,Mg)2SiO4). We were able to extract a stable and reproducible in situ 14C component from olivine using stepped heating and a lithium metaborate (LiBO2) flux, following treatment with dilute HNO3 over a variety of experimental conditions. However, measured concentrations for samples from the Tabernacle Hill basalt flow (17.3 ?? 0.3 ka4) in central Utah and the McCarty's basalt flow (3.0 ?? 0.2 ka) in western New Mexico were significantly lower than expected based on exposure of olivine in our samples to cosmic rays at each site. The source of the discrepancy is not clear. We speculate that in situ 14C atoms may not have been released from Mg-rich crystal lattices (the olivine composition at both sites was ~Fo65Fa35). Alternatively, a portion of the 14C atoms released from the olivine grains may have become trapped in synthetic spinel-like minerals that were created in the olivine-flux mixture during the extraction process, or were simply retained in the mixture itself. Regardless, the magnitude of the discrepancy appears to be inversely proportional to the Fe/(Fe+Mg) ratio of the olivine separates. If we apply a simple correction factor based on the chemical composition of the separates, then corrected in situ 14C concentrations are similar to theoretical values at both sites. At this time, we do not know if this agreement is fortuitous or real. Future research should include measurement of in situ 14C concentrations in olivine from known-age basalt flows with different chemical compositions (i.e. more Fe-rich) to determine if this correction is robust for all olivine-bearing rocks. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

Rapid Sequential in Situ Multiplexing with DNA Exchange Imaging in Neuronal Cells and Tissues.

PubMed

Wang, Yu; Woehrstein, Johannes B; Donoghue, Noah; Dai, Mingjie; Avendaño, Maier S; Schackmann, Ron C J; Zoeller, Jason J; Wang, Shan Shan H; Tillberg, Paul W; Park, Demian; Lapan, Sylvain W; Boyden, Edward S; Brugge, Joan S; Kaeser, Pascal S; Church, George M; Agasti, Sarit S; Jungmann, Ralf; Yin, Peng

2017-10-11

To decipher the molecular mechanisms of biological function, it is critical to map the molecular composition of individual cells or even more importantly tissue samples in the context of their biological environment in situ. Immunofluorescence (IF) provides specific labeling for molecular profiling. However, conventional IF methods have finite multiplexing capabilities due to spectral overlap of the fluorophores. Various sequential imaging methods have been developed to circumvent this spectral limit but are not widely adopted due to the common limitation of requiring multirounds of slow (typically over 2 h at room temperature to overnight at 4 °C in practice) immunostaining. We present here a practical and robust method, which we call DNA Exchange Imaging (DEI), for rapid in situ spectrally unlimited multiplexing. This technique overcomes speed restrictions by allowing for single-round immunostaining with DNA-barcoded antibodies, followed by rapid (less than 10 min) buffer exchange of fluorophore-bearing DNA imager strands. The programmability of DEI allows us to apply it to diverse microscopy platforms (with Exchange Confocal, Exchange-SIM, Exchange-STED, and Exchange-PAINT demonstrated here) at multiple desired resolution scales (from ∼300 nm down to sub-20 nm). We optimized and validated the use of DEI in complex biological samples, including primary neuron cultures and tissue sections. These results collectively suggest DNA exchange as a versatile, practical platform for rapid, highly multiplexed in situ imaging, potentially enabling new applications ranging from basic science, to drug discovery, and to clinical pathology.

Continual in situ monitoring of pore water stable isotopes in the subsurface

NASA Astrophysics Data System (ADS)

Volkmann, T. H. M.; Weiler, M.

2014-05-01

Stable isotope signatures provide an integral fingerprint of origin, flow paths, transport processes, and residence times of water in the environment. However, the full potential of stable isotopes to quantitatively characterize subsurface water dynamics is yet unfolded due to the difficulty in obtaining extensive, detailed, and repeated measurements of pore water in the unsaturated and saturated zone. This paper presents a functional and cost-efficient system for non-destructive continual in situ monitoring of pore water stable isotope signatures with high resolution. Automatic controllable valve arrays are used to continuously extract diluted water vapor in soil air via a branching network of small microporous probes into a commercial laser-based isotope analyzer. Normalized liquid-phase isotope signatures are then obtained based on a specific on-site calibration approach along with basic corrections for instrument bias and temperature dependent isotopic fractionation. The system was applied to sample depth profiles on three experimental plots with varied vegetation cover in southwest Germany. Two methods (i.e., based on advective versus diffusive vapor extraction) and two modes of sampling (i.e., using multiple permanently installed probes versus a single repeatedly inserted probe) were tested and compared. The results show that the isotope distribution along natural profiles could be resolved with sufficiently high accuracy and precision at sampling intervals of less than four minutes. The presented in situ approaches may thereby be used interchangeably with each other and with concurrent laboratory-based direct equilibration measurements of destructively collected samples. It is thus found that the introduced sampling techniques provide powerful tools towards a detailed quantitative understanding of dynamic and heterogeneous shallow subsurface and vadose zone processes.

Quantitative measurement of the chemical composition of geological standards with a miniature laser ablation/ionization mass spectrometer designed for in situ application in space research

NASA Astrophysics Data System (ADS)

Neuland, M. B.; Grimaudo, V.; Mezger, K.; Moreno-García, P.; Riedo, A.; Tulej, M.; Wurz, P.

2016-03-01

A key interest of planetary space missions is the quantitative determination of the chemical composition of the planetary surface material. The chemical composition of surface material (minerals, rocks, soils) yields fundamental information that can be used to answer key scientific questions about the formation and evolution of the planetary body in particular and the Solar System in general. We present a miniature time-of-flight type laser ablation/ionization mass spectrometer (LMS) and demonstrate its capability in measuring the elemental and mineralogical composition of planetary surface samples quantitatively by using a femtosecond laser for ablation/ionization. The small size and weight of the LMS make it a remarkable tool for in situ chemical composition measurements in space research, convenient for operation on a lander or rover exploring a planetary surface. In the laboratory, we measured the chemical composition of four geological standard reference samples USGS AGV-2 Andesite, USGS SCo-l Cody Shale, NIST 97b Flint Clay and USGS QLO-1 Quartz Latite with LMS. These standard samples are used to determine the sensitivity factors of the instrument. One important result is that all sensitivity factors are close to 1. Additionally, it is observed that the sensitivity factor of an element depends on its electron configuration, hence on the electron work function and the elemental group in agreement with existing theory. Furthermore, the conformity of the sensitivity factors is supported by mineralogical analyses of the USGS SCo-l and the NIST 97b samples. With the four different reference samples, the consistency of the calibration factors can be demonstrated, which constitutes the fundamental basis for a standard-less measurement-technique for in situ quantitative chemical composition measurements on planetary surface.

In situ micro-Raman analysis and X-ray diffraction of nickel silicide thin films on silicon.

PubMed

Bhaskaran, M; Sriram, S; Perova, T S; Ermakov, V; Thorogood, G J; Short, K T; Holland, A S

2009-01-01

This article reports on the in situ analysis of nickel silicide (NiSi) thin films formed by thermal processing of nickel thin films deposited on silicon substrates. The in situ techniques employed for this study include micro-Raman spectroscopy (microRS) and X-ray diffraction (XRD); in both cases the variations for temperatures up to 350 degrees C has been studied. Nickel silicide thin films formed by vacuum annealing of nickel on silicon were used as a reference for these measurements. In situ analysis was carried out on nickel thin films on silicon, while the samples were heated from room temperature to 350 degrees C. Data was gathered at regular temperature intervals and other specific points of interest (such as 250 degrees C, where the reaction between nickel and silicon to form Ni(2)Si is expected). The transformations from the metallic state, through the intermediate reaction states, until the desired metal-silicon reaction product is attained, are discussed. The evolution of nickel silicide from the nickel film can be observed from both the microRS and XRD in situ studies. Variations in the evolution of silicide from metal for different silicon substrates are discussed, and these include (100) n-type, (100) p-type, and (110) p-type silicon substrates.

Rapid-prenatal diagnosis through fluorescence in situ hybridization for preventing aneuploidy related birth defects

PubMed Central

Fauzdar, Ashish; Chowdhry, Mohit; Makroo, R. N.; Mishra, Manoj; Srivastava, Priyanka; Tyagi, Richa; Bhadauria, Preeti; Kaul, Anita

2013-01-01

BACKGROUND AND OBJECTIVE: Women with high-risk pregnancies are offered prenatal diagnosis through amniocentesis for cytogenetic analysis of fetal cells. The aim of this study was to evaluate the effectiveness of the rapid fluorescence in situ hybridization (FISH) technique for detecting numerical aberrations of chromosomes 13, 21, 18, X and Y in high-risk pregnancies in an Indian scenario. MATERIALS AND METHODS: A total of 163 samples were received for a FISH and/or a full karyotype for prenatal diagnosis from high-risk pregnancies. In 116 samples both conventional culture techniques for getting karyotype through G-banding techniques were applied in conjunction to FISH test using the AneuVysion kit (Abbott Molecular, Inc.), following standard recommended protocol to compare the both the techniques in our setup. RESULTS: Out of 116 patients, we got 96 normal for the five major chromosome abnormality and seven patients were found to be abnormal (04 trisomy 21, 02 monosomy X, and 01 trisomy 13) and all the FISH results correlated with conventional cytogenetics. To summarize the results of total 163 patients for the major chromosomal abnormalities analyzed by both/or cytogenetics and FISH there were 140 (86%) normal, 9 (6%) cases were abnormal and another 4 (2.5%) cases were suspicious mosaic and 10 (6%) cases of culture failure. The diagnostic detection rate with FISH in 116 patients was 97.5%. There were no false-positive and false-negative autosomal or sex chromosomal results, within our established criteria for reporting FISH signals. CONCLUSION: Rapid FISH is a reliable and prompt method for detecting numerical chromosomal aberrations and has now been implemented as a routine diagnostic procedure for detection of fetal aneuploidy in India. PMID:23901191

Rapid-prenatal diagnosis through fluorescence in situ hybridization for preventing aneuploidy related birth defects.

PubMed

Fauzdar, Ashish; Chowdhry, Mohit; Makroo, R N; Mishra, Manoj; Srivastava, Priyanka; Tyagi, Richa; Bhadauria, Preeti; Kaul, Anita

2013-01-01

Women with high-risk pregnancies are offered prenatal diagnosis through amniocentesis for cytogenetic analysis of fetal cells. The aim of this study was to evaluate the effectiveness of the rapid fluorescence in situ hybridization (FISH) technique for detecting numerical aberrations of chromosomes 13, 21, 18, X and Y in high-risk pregnancies in an Indian scenario. A total of 163 samples were received for a FISH and/or a full karyotype for prenatal diagnosis from high-risk pregnancies. In 116 samples both conventional culture techniques for getting karyotype through G-banding techniques were applied in conjunction to FISH test using the AneuVysion kit (Abbott Molecular, Inc.), following standard recommended protocol to compare the both the techniques in our setup. Out of 116 patients, we got 96 normal for the five major chromosome abnormality and seven patients were found to be abnormal (04 trisomy 21, 02 monosomy X, and 01 trisomy 13) and all the FISH results correlated with conventional cytogenetics. To summarize the results of total 163 patients for the major chromosomal abnormalities analyzed by both/or cytogenetics and FISH there were 140 (86%) normal, 9 (6%) cases were abnormal and another 4 (2.5%) cases were suspicious mosaic and 10 (6%) cases of culture failure. The diagnostic detection rate with FISH in 116 patients was 97.5%. There were no false-positive and false-negative autosomal or sex chromosomal results, within our established criteria for reporting FISH signals. Rapid FISH is a reliable and prompt method for detecting numerical chromosomal aberrations and has now been implemented as a routine diagnostic procedure for detection of fetal aneuploidy in India.

Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis.

PubMed

Huber, R; Burggraf, S; Mayer, T; Barns, S M; Rossnagel, P; Stetter, K O

1995-07-06

A variety of hyperthermophilic bacteria and archaea have been isolated from high-temperature environments by plating and serial dilutions. However, these techniques allow only the small percentage of organisms able to form colonies, or those that are predominant within environmental samples, to be obtained in pure culture. Recently, in situ 16S ribosomal RNA analyses of samples from the Obsidian hot pool at Yellowstone National Park, Wyoming, revealed a variety of archaeal sequences, which were all different from those of previously isolated species. This suggests substantial diversity of archaea with so far unknown morphological, physiological and biochemical features, which may play an important part within high-temperature ecosystems. Here we describe a procedure to obtain pure cultures of unknown organisms harbouring specific 16S rRNA sequences identified previously within the environment. It combines visual recognition of single cells by phylogenetic staining and cloning by 'optical tweezers'. Our result validates polymerase chain reaction data on the existence of large archael communities.

Room-temperature in situ nuclear spin hyperpolarization from optically pumped nitrogen vacancy centres in diamond

DOE PAGES

King, Jonathan P.; Jeong, Keunhong; Vassiliou, Christophoros C.; ...

2015-12-07

Low detection sensitivity stemming from the weak polarization of nuclear spins is a primary limitation of magnetic resonance spectroscopy and imaging. Methods have been developed to enhance nuclear spin polarization but they typically require high magnetic fields, cryogenic temperatures or sample transfer between magnets. Here we report bulk, room-temperature hyperpolarization of 13C nuclear spins observed via high-field magnetic resonance. The technique harnesses the high optically induced spin polarization of diamond nitrogen vacancy centres at room temperature in combination with dynamic nuclear polarization. We observe bulk nuclear spin polarization of 6%, an enhancement of ~170,000 over thermal equilibrium. The signal ofmore » the hyperpolarized spins was detected in situ with a standard nuclear magnetic resonance probe without the need for sample shuttling or precise crystal orientation. In conclusion, hyperpolarization via optical pumping/dynamic nuclear polarization should function at arbitrary magnetic fields enabling orders of magnitude sensitivity enhancement for nuclear magnetic resonance of solids and liquids under ambient conditions.« less

Reducing risk and increasing confidence of decision making at a lower cost: In-situ pXRF assessment of metal-contaminated sites.

PubMed

Rouillon, Marek; Taylor, Mark P; Dong, Chenyin

2017-10-01

This study evaluates the in-situ use of field portable X-ray Fluorescence (pXRF) for metal-contaminated site assessments, and assesses the advantages of increased sampling to reduce risk, and increase confidence of decision making at a lower cost. Five metal-contaminated sites were assessed using both in-situ pXRF and ex-situ inductively coupled plasma mass spectrometry (ICP-MS) analyses at various sampling resolutions. Twenty second in-situ pXRF measurements of Mn, Zn and Pb were corrected using a subset of parallel ICP-MS measurements taken at each site. Field and analytical duplicates revealed sampling as the major contributor (>95% variation) to measurement uncertainties. This study shows that increased sampling led to several benefits including more representative site characterisation, higher soil-metal mapping resolution, reduced uncertainty around the site mean, and reduced sampling uncertainty. Real time pXRF data enabled efficient, on-site decision making for further judgemental sampling, without the need to return to the site. Additionally, in-situ pXRF was more cost effective than the current approach of ex-situ sampling and ICP-MS analysis, even with higher sampling at each site. Lastly, a probabilistic site assessment approach was applied to demonstrate the advantages of integrating estimated measurement uncertainties into site reporting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

DOEpatents

Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

2015-11-24

A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

Nanomechanical Characterization of lD Nanomaterials for Structure and Energy Applications

NASA Astrophysics Data System (ADS)

Loya, Phillip Edward

Classical fracture mechanics and conventional dislocation based understanding of metal yield and failure was well researched and understood until the recent advancement of electron microscopy techniques and the ability to produce small-scale metal samples. Once a critical dimension with respect to grain or geometrical size for a metal was reached, the deformation and fracture behaviors began to deviate from traditional theories and predictions. Recent research has focused on one-dimensional (1D) nanomaterials produced from their bulk counterparts to probe corresponding mechanical behaviors. However, this could alter the intrinsic material properties due to modifications caused by the milling/machining process. In this thesis, metal nanowires/fibers produced by an alternative process, and samples with controlled defect density, were used to gain a fundamental understanding of the critical dimension effects and small-scale mechanical behavior of metals. Another important aspect of this thesis is the development of a state-of-the-art nanomechanical characterization technique in the transmission electron microscope, where a detailed structure-property relationship could be reliably established with unprecedented resolutions. In the first part, single crystalline silver fibers were grown with dimensions varying from 2mum down to 400 nm and investigated using an advanced in-situ method. A critical dimension was observed near 1mum, below which the yield stress began to increase and the number of deformation slip bands began to decrease. Secondly, single crystal Mo-alloy fibers produced by a similar technique were pre-strained to introduce pre-existing dislocations and simulate bulk characteristics. In-situ tensile test showed the pre-straining effect on the yield stress, and the existence of a negative strain rate sensitivity. Next, pristine Mo-alloy fibers were irradiated with He and Ar ions to test the effects of irradiation induced defects on their mechanical behaviors at this length scale. A clear size effect was observed depending on the damage produced by the irradiation. Finally, a detailed description of an in-situ quantitative TEM stage based on a MEMS device and its successful applications are presented. This set-up was designed and built to compliment the in-situ SEM test by offering high resolution observations of the microstructural evolution under testing conditions and providing additional insights to the important structure-property relationship.

New Techniques for Hydrothermal Exploration: In Situ Chemical Sensors on AUVs - Preliminary Results From the Lau Basin

NASA Astrophysics Data System (ADS)

German, C. R.; Connelly, D. P.; Prien, R. D.; Yoerger, D.; Jakuba, M.; Bradley, A.; Shank, T. J.; Edmonds, H. N.; Langmuir, C. H.

2004-12-01

Less than one quarter of the global ridge-crest has yet received even cursory investigation for the presence or absence of hydrothermal activity. To improve exploration efficiency, particularly at high latitudes, new methodologies independent of tethered vehicles are required. To that end, we have begun the use of in situ chemical sensors allied to the increasing capabilities of autonomous underwater vehicles. Here, we present first results from our most recent efforts aboard the second R2K cruise to the Lau Basin (C.Langmuir, PI; Autumn 2004) to (a) map non-buoyant hydrothermal plumes, (b) intercept buoyant hydrothermal plumes and (c) locate and image novel hydrothermal fields on the seafloor. The AUV used for this work is ABE and the sensors deployed are direct extensions of the in situ Fe/Mn sensor deployed previously on SOC's AUTOSUB to investigate seasonally-reducing waters in Loch Etive, NW Scotland. Each in situ instrument comprises an electronics package that contains a tattletale control system with a flash memory card for on-board logging and a chemical manifold, consisting of a series of valves, pumps and a colorimetric cell. Analysis of iron is enabled by the determination of the coloured complex formed between iron II and ferrozine, manganese uses the colour change of PAN in the presence of reduced manganese. The system includes capacity for switching between sample, blank and two on-board samples for "in flight" calibrations with blanks and standards held in medical bags, outside of the pressure-balanced manifold, to attain in situ water-column temperatures. An in-line filter prevents large particle clogging and detection limits for both iron II and manganese II are ca.2nM.

Rapid In Situ Profiling of Lipid C═C Location Isomers in Tissue Using Ambient Mass Spectrometry with Photochemical Reactions.

PubMed

Tang, Fei; Guo, Chengan; Ma, Xiaoxiao; Zhang, Jian; Su, Yuan; Tian, Ran; Shi, Riyi; Xia, Yu; Wang, Xiaohao; Ouyang, Zheng

2018-05-01

Rapid and in situ profiling of lipids using ambient mass spectrometry (AMS) techniques has great potential for clinical diagnosis, biological studies, and biomarker discovery. In this study, the online photochemical reaction involving carbon-carbon double bonds was coupled with a surface sampling technique to develop a direct tissue-analysis method with specificity to lipid C═C isomers. This method enabled the in situ analysis of lipids from the surface of various tissues or tissue sections, which allowed the structural characterization of lipid isomers within 2 min. Under optimized reaction conditions, we have established a method for the relative quantitation of lipid C═C location isomers by comparing the abundances of the diagnostic ions arising from each isomer, which has been proven effective through the established linear relationship ( R 2 = 0.999) between molar ratio and diagnostic ion ratio of the FA 18:1 C═C location isomers. This method was then used for the rapid profiling of unsaturated lipid C═C isomers in the sections of rat brain, lung, liver, spleen, and kidney, as well as in normal and diseased rat tissues. Quantitative information on FA 18:1 and PC 16:0-18:1 C═C isomers was obtained, and significant differences were observed between different samples. To the best of our knowledge, this is the first study to report the direct analysis of lipid C═C isomers in tissues using AMS. Our results demonstrated that this method can serve as a rapid analytical approach for the profiling of unsaturated lipid C═C isomers in biological tissues and should contribute to functional lipidomics and clinical diagnosis.

Self-potential and Complex Conductivity Monitoring of In Situ Hydrocarbon Remediation in Microbial Fuel Cell

NASA Astrophysics Data System (ADS)

Zhang, C.; Revil, A.; Ren, Z.; Karaoulis, M.; Mendonca, C. A.

2013-12-01

Petroleum hydrocarbon contamination of soil and groundwater in both non-aqueous phase liquid and dissolved forms generated from spills and leaks is a wide spread environmental issue. Traditional cleanup of hydrocarbon contamination in soils and ground water using physical, chemical, and biological remedial techniques is often expensive and ineffective. Recent studies show that the microbial fuel cell (MFC) can simultaneously enhance biodegradation of hydrocarbons in soil and groundwater and yield electricity. Non-invasive geophysical techniques such as self-potential (SP) and complex conductivity (induced polarization) have shown the potential to detect and characterize the nature of electron transport mechanism of in situ bioremediation of organic contamination plumes. In this study, we deployed both SP and complex conductivity in lab scale MFCs to monitor time-laps geophysical response of degradation of hydrocarbons by MFC. Two different sizes of MFC reactors were used in this study (DI=15 cm cylinder reactor and 94.5cm x 43.5 cm rectangle reactor), and the initial hydrocarbon concentration is 15 g diesel/kg soil. SP and complex conductivity measurements were measured using non-polarizing Ag/AgCl electrodes. Sensitivity study was also performed using COMSOL Multiphysics to test different electrode configurations. The SP measurements showed stronger anomalies adjacent to the MFC than locations afar, and both real and imaginary parts of complex conductivity are greater in areas close to MFC than areas further away and control samples without MFC. The joint use of SP and complex conductivity could in situ evaluate the dynamic changes of electrochemical parameters during this bioremediation process at spatiotemporal scales unachievable with traditional sampling methods. The joint inversion of these two methods to evaluate the efficiency of MFC enhanced hydrocarbon remediation in the subsurface.

Bismuth-based oxide semiconductors: Mild synthesis and practical applications

NASA Astrophysics Data System (ADS)

Timmaji, Hari Krishna

In this dissertation study, bismuth based oxide semiconductors were prepared using 'mild' synthesis techniques---electrodeposition and solution combustion synthesis. Potential environmental remediation and solar energy applications of the prepared oxides were evaluated. Bismuth vanadate (BiVO4) was prepared by electrodeposition and solution combustion synthesis. A two step electrosynthesis strategy was developed and demonstrated for the first time. In the first step, a Bi film was first electrodeposited on a Pt substrate from an acidic BiCl3 medium. Then, this film was anodically stripped in a medium containing hydrolyzed vanadium precursor, to generate Bi3+, and subsequent BiVO4 formation by in situ precipitation. The photoelectrochemical data were consistent with the in situ formation of n-type semiconductor films. In the solution combustion synthesis procedure, BiVO4 powders were prepared using bismuth nitrate pentahydrate as the bismuth precursor and either vanadium chloride or vanadium oxysulfate as the vanadium precursor. Urea, glycine, or citric acid was used as the fuel. The effect of the vanadium precursor on the photocatalytic activity of combustion synthesized BiVO 4 was evaluated in this study. Methyl orange was used as a probe to test the photocatalytic attributes of the combustion synthesized (CS) samples, and benchmarked against a commercial bismuth vanadate sample. The CS samples showed superior activity to the commercial benchmark sample, and samples derived from vanadium chloride were superior to vanadium oxysulfate counterparts. The photoelectrochemical properties of the various CS samples were also studied and these samples were shown to be useful both for environmental photocatalytic remediation and water photooxidation applications. Silver bismuth tungstate (AgBiW2O8) nanoparticles were prepared for the first time by solution combustion synthesis by using silver nitrate, bismuth nitrate, sodium tungstate as precursors for Ag, Bi, and W respectively and urea as the fuel. The photocatalytic activity of these nanoparticles was superior to a sample prepared by solid-state synthesis. The combustion-synthesized particles were subsequently modified with Pt catalyst islands using a photodeposition technique and then used for the photo-generation of syngas (CO + H2). Formic acid was used in these experiments for in situ generation of CO2 and its subsequent reduction to CO. In the absence of Pt modification, H2 was not obtained. These results were compared with those obtained with acetic acid in place of formic acid, and finally the mechanistic pathways for syngas and methane photogeneration are presented.

Electrokinetic Stringency Control in Self-Assembled Monolayer-based Biosensors for Multiplex Urinary Tract Infection Diagnosis

PubMed Central

Liu, Tingting; Sin, Mandy L. Y.; Pyne, Jeff D.; Gau, Vincent; Liao, Joseph C.; Wong, Pak Kin

2013-01-01

Rapid detection of bacterial pathogens is critical toward judicious management of infectious diseases. Herein, we demonstrate an in situ electrokinetic stringency control approach for a self-assembled monolayer-based electrochemical biosensor toward urinary tract infection diagnosis. The in situ electrokinetic stringency control technique generates Joule heating induced temperature rise and electrothermal fluid motion directly on the sensor to improve its performance for detecting bacterial 16S rRNA, a phylogenetic biomarker. The dependence of the hybridization efficiency reveals that in situ electrokinetic stringency control is capable of discriminating single-base mismatches. With electrokinetic stringency control, the background noise due to the matrix effects of clinical urine samples can be reduced by 60%. The applicability of the system is demonstrated by multiplex detection of three uropathogenic clinical isolates with similar 16S rRNA sequences. The results demonstrate that electrokinetic stringency control can significantly improve the signal-to-noise ratio of the biosensor for multiplex urinary tract infection diagnosis. PMID:23891989

A DTA/GC for the in Situ Identification of the Martian Surface Material

NASA Technical Reports Server (NTRS)

Mancinelli, R. L.; White, M. R.; Orenberg, J. B.

1993-01-01

The composition and mineralogy of the Martian surface material remain largely unknown. To determine its composition and mineralogy, several techniques are being considered for in situ analyses of the Martian surface material during missions to Mars. We have successfully developed, constructed, and tested a laboratory DTA/GC. The DTA is a Dupont model 1600 high temperature DTA coupled with a GC equipped with a MID detector. The system is operated by a Sun Sparc 11 workstation. When gas evolves during a thermal chemical event, it is shunted into the GC and the temperature is recorded in association with the specific thermal event. We have used this laboratory instrument to define experimental criteria necessary for determining the composition and mineralogy of the Martian surface in situ (e.g., heating of sample to 1100 C to distinguish clays). Our studies indicate that DTA/GC will provide a broad spectrum of mineralogical and evolved gas data pertinent to exobiology, geochemistry, and geology.

Stencil lithography of superconducting contacts on MBE-grown topological insulator thin films

NASA Astrophysics Data System (ADS)

Schüffelgen, Peter; Rosenbach, Daniel; Neumann, Elmar; Stehno, Martin P.; Lanius, Martin; Zhao, Jialin; Wang, Meng; Sheehan, Brendan; Schmidt, Michael; Gao, Bo; Brinkman, Alexander; Mussler, Gregor; Schäpers, Thomas; Grützmacher, Detlev

2017-11-01

Topological insulator (Bi0.06Sb0.94)2Te3 thin films grown by molecular beam epitaxy have been capped in-situ with a 2 nm Al film to conserve the pristine topological surface states. Subsequently, a shadow mask - structured by means of focus ion beam - was in-situ placed underneath the sample to deposit a thick layer of Al on well-defined microscopically small areas. The 2 nm thin Al layer fully oxidizes after exposure to air and in this way protects the TI surface from degradation. The thick Al layer remains metallic underneath a 3-4 nm thick native oxide layer and therefore serves as (super-) conducting contacts. Superconductor-Topological Insulator-Superconductor junctions with lateral dimensions in the nm range have then been fabricated via an alternative stencil lithography technique. Despite the in-situ deposition, transport measurements and transmission electron microscope analysis indicate a low transparency, due to an intermixed region at the interface between topological insulator thin film and metallic Al.

Knudsen Cell Studies of Ti-Al Thermodynamics

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Copland, Evan H.; Mehrotra, Gopal M.; Auping, Judith; Gray, Hugh R. (Technical Monitor)

2002-01-01

In this paper we describe the Knudsen cell technique for measurement of thermodynamic activities in alloys. Numerous experimental details must be adhered to in order to obtain useful experimental data. These include introduction of an in-situ standard, precise temperature measurement, elimination of thermal gradients, and precise cell positioning. Our first design is discussed and some sample data on Ti-Al alloys is presented. The second modification and associated improvements are also discussed.

Improved Ambient Pressure Pyroelectric Ion Source

NASA Technical Reports Server (NTRS)

Beegle, Luther W.; Kim, Hugh I.; Kanik, Isik; Ryu, Ernest K.; Beckett, Brett

2011-01-01

The detection of volatile vapors of unknown species in a complex field environment is required in many different applications. Mass spectroscopic techniques require subsystems including an ionization unit and sample transport mechanism. All of these subsystems must have low mass, small volume, low power, and be rugged. A volatile molecular detector, an ambient pressure pyroelectric ion source (APPIS) that met these requirements, was recently reported by Caltech researchers to be used in in situ environments.

Method and apparatus for analyzing particle-containing gaseous suspensions

DOEpatents

Solomon, Peter R.; Carangelo, Robert M.; Best, Philip E.

1987-01-01

The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided.

Method and apparatus for analyzing particle-containing gaseous suspensions

DOEpatents

Solomon, P.R.; Carangelo, R.M.; Best, P.E.

1987-03-24

The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided. 51 figs.

Sample selection and preservation techniques for the Mars sample return mission

NASA Technical Reports Server (NTRS)

Tsay, Fun-Dow

1988-01-01

It is proposed that a miniaturized electron spin resonance (ESR) spectrometer be developed as an effective, nondestructivew sample selection and characterization instrument for the Mars Rover Sample Return mission. The ESR instrument can meet rover science payload requirements and yet has the capability and versatility to perform the following in situ Martian sample analyses: (1) detection of active oxygen species, and characterization of Martian surface chemistry and photocatalytic oxidation processes; (2) determination of paramagnetic Fe(3+) in clay silicate minerals, Mn(2+) in carbonates, and ferromagnetic centers of magnetite, maghemite and hematite; (3) search for organic compounds in the form of free radicals in subsoil, and detection of Martian fossil organic matter likely to be associated with carbonate and other sedimentary deposits. The proposed instrument is further detailed.

Development of an in situ calibration technique for combustible gas detectors

NASA Technical Reports Server (NTRS)

Shumar, J. W.; Wynveen, R. A.; Lance, N., Jr.; Lantz, J. B.

1977-01-01

This paper describes the development of an in situ calibration procedure for combustible gas detectors (CGD). The CGD will be a necessary device for future space vehicles as many subsystems in the Environmental Control/Life Support System utilize or produce hydrogen (H2) gas. Existing calibration techniques are time-consuming and require support equipment such as an environmental chamber and calibration gas supply. The in situ calibration procedure involves utilization of a water vapor electrolysis cell for the automatic in situ generation of a H2/air calibration mixture within the flame arrestor of the CGD. The development effort concluded with the successful demonstration of in situ span calibrations of a CGD.

In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish

PubMed Central

Akins, John L; Morris, James A; Green, Stephanie J

2014-01-01

Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible. PMID:25614791

In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish.

PubMed

Akins, John L; Morris, James A; Green, Stephanie J

2014-10-01

Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible.

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.

MEASUREMENT OF NATURAL RADIONUCLIDES AND EXTERNAL RADIATION EXPOSURE DUE TO FLY ASH FROM A COAL-FIRED POWER PLANT (SPAIN) DEPOSITED ON SOILS. COMPARISON USING TWO DIFFERENT MEASUREMENT TECHNIQUES.

PubMed

Corbacho, J A; Baeza, A

2018-05-17

The evaluation of the radiological impact in soils due to the fly-ash ponds using both in situ techniques and laboratory based measurements is presented. In order to check the in situ techniques capabilities for monitoring this type of industries, a comparison between both techniques was performed. A characterization of external radiation exposure in the fly-ash pond and in its surrounding soils was made. The associated external radiological hazard due to the fly-ash pond has been evaluated. In situ techniques could be used to determine the radiological impact on soils due to fly-ash deposition, but its use could be limited due to the associated uncertainties.

In situ chemical functionalization of gallium nitride with phosphonic acid derivatives during etching.

PubMed

Wilkins, Stewart J; Greenough, Michelle; Arellano, Consuelo; Paskova, Tania; Ivanisevic, Albena

2014-03-04

In situ functionalization of polar (c plane) and nonpolar (a plane) gallium nitride (GaN) was performed by adding (3-bromopropyl) phosphonic acid or propyl phosphonic acid to a phosphoric acid etch. The target was to modulate the emission properties and oxide formation of GaN, which was explored through surface characterization with atomic force microscopy, X-ray photoelectron spectroscopy, photoluminescence (PL), inductively coupled plasma-mass spectrometry, and water contact angle. The use of (3-bromopropyl) phosphonic acid and propyl phosphonic acid in phosphoric acid demonstrated lower amounts of gallium oxide formation and greater hydrophobicity for both sample sets, while also improving PL emission of polar GaN samples. In addition to crystal orientation, growth-related factors such as defect density in bulk GaN versus thin GaN films residing on sapphire substrates were investigated as well as their responses to in situ functionalization. Thin nonpolar GaN layers were the most sensitive to etching treatments due in part to higher defect densities (stacking faults and threading dislocations), which accounts for large surface depressions. High-quality GaN (both free-standing bulk polar and bulk nonpolar) demonstrated increased sensitivity to oxide formation. Room-temperature PL stands out as an excellent technique to identify nonradiative recombination as observed in the spectra of heteroepitaxially grown GaN samples. The chemical methods applied to tune optical and physical properties of GaN provide a quantitative framework for future novel chemical and biochemical sensor development.

Multi-scale monitoring of a marine geologic methane source in the Santa Barbara Channel using imaging spectrometry, ARCTAS-CARB in situ sampling and coastal hourly total hydrocarbon measurements

NASA Astrophysics Data System (ADS)

Bradley, E. S.; Leifer, I.; Roberts, D.; Dennison, P. E.; Margolis, J.; Moritsch, M.; Diskin, G. S.; Sachse, G. W.

2009-12-01

The Coal Oil Point (COP) hydrocarbon seep field off the coast of Santa Barbara, CA is one of the most active and best-studied marine geologic methane sources in the world and contributes to elevated terrestrial methane concentrations downwind. In this study, we investigate the spatiotemporal variability of this local source and the influence of meteorological conditions on transport and concentration. A methane plume emanating from Trilogy Seep was mapped with the Airborne Visible Infrared Imaging Spectrometer at a 7.5 m resolution with a short-wave infrared band ratio technique. This structure agrees with the local wind speed and direction and is orthogonal to the surface currents. ARCTAS-CARB aircraft in situ sampling of lower-troposphere methane is compared to sub-hour total hydrocarbon concentration (THC) measurements from the Santa Barbara Air Pollution Control District (SBAPCD) station located near COP. Hourly SBAPCD THC values from 1980-2008 demonstrate a decrease in seep source strength until the late 1990s, followed by a consistent increase. The occurrence of elevated SBAPCD THC values for onshore wind conditions as well as numerous positive outliers as high as 17 ppm suggests that seep field emissions are both quasi-steady state and transient, direct (bubble) and diffuse (outgassing). As demonstrated for the COP seeps, the combination of imaging spectrometry, aircraft in situ sampling, and ground-based monitoring provides a powerful approach for understanding local methane sources and transport processes.

In-situ vacuum deposition technique of lithium on neutron production target for BNCT

NASA Astrophysics Data System (ADS)

Ishiyama, S.; Baba, Y.; Fujii, R.; Nakamura, M.; Imahori, Y.

2012-10-01

For the purpose of avoiding the radiation blistering of the lithium target for neutron production in BNCT (Boron Neutron Capture Therapy) device, trilaminar Li target, of which palladium thin layer was inserted between cupper substrate and Li layer, was newly designed. In-situ vacuum deposition and electrolytic coating techniques were applied to validate the method of fabrication of the Li/Pd/Cu target, and the layered structures of the synthesized target were characterized. In-situ vacuum re-deposition technique was also established for repairing and maintenance for lithium target damaged. Following conclusions were derived; (1) Uniform lithium layers with the thickness from 1.6 nm to a few hundreds nanometer were formed on Pd/Cu multilayer surface by in situ vacuum deposition technique using metallic lithium as a source material. (2) Re-deposition of lithium layer on Li surface can be achieved by in situ vacuum deposition technique. (3) Small amount of water and carbonate was observed on the top surface of Li. But the thickness of the adsorbed layer was less than monolayer, which will not affect the quality of the Li target. (4) The formation of Pd-Li alloy layer was observed at the Pd and Li interface. The alloy layer would contribute to the stability of the Li layer.

Bioremediation techniques-classification based on site of application: principles, advantages, limitations and prospects.

PubMed

Azubuike, Christopher Chibueze; Chikere, Chioma Blaise; Okpokwasili, Gideon Chijioke

2016-11-01

Environmental pollution has been on the rise in the past few decades owing to increased human activities on energy reservoirs, unsafe agricultural practices and rapid industrialization. Amongst the pollutants that are of environmental and public health concerns due to their toxicities are: heavy metals, nuclear wastes, pesticides, green house gases, and hydrocarbons. Remediation of polluted sites using microbial process (bioremediation) has proven effective and reliable due to its eco-friendly features. Bioremediation can either be carried out ex situ or in situ, depending on several factors, which include but not limited to cost, site characteristics, type and concentration of pollutants. Generally, ex situ techniques apparently are more expensive compared to in situ techniques as a result of additional cost attributable to excavation. However, cost of on-site installation of equipment, and inability to effectively visualize and control the subsurface of polluted sites are of major concerns when carrying out in situ bioremediation. Therefore, choosing appropriate bioremediation technique, which will effectively reduce pollutant concentrations to an innocuous state, is crucial for a successful bioremediation project. Furthermore, the two major approaches to enhance bioremediation are biostimulation and bioaugmentation provided that environmental factors, which determine the success of bioremediation, are maintained at optimal range. This review provides more insight into the two major bioremediation techniques, their principles, advantages, limitations and prospects.

Remote sensing for oceanography: Past, present, future

NASA Technical Reports Server (NTRS)

Mcgoldrick, L. F.

1984-01-01

Oceanic dynamics was traditionally investigated by sampling from instruments in situ, yielding quantitative measurements that are intermittent in both space and time; the ocean is undersampled. The need to obtain proper sampling of the averaged quantities treated in analytical and numerical models is at present the most significant limitation on advances in physical oceanography. Within the past decade, many electromagnetic techniques for the study of the Earth and planets were applied to the study of the ocean. Now satellites promise nearly total coverage of the world's oceans using only a few days to a few weeks of observations. Both a review of the early and present techniques applied to satellite oceanography and a description of some future systems to be launched into orbit during the remainder of this century are presented. Both scientific and technologic capabilities are discussed.

Analytical techniques for the evaluation of past conservation treatments on stone material from archaeological sites of Roman Augusta Emerita (Merida, Spain).

NASA Astrophysics Data System (ADS)

Perez, Natalia; Alvarez, Monica

2013-04-01

The effects that conservation treatments may have on stone material from archaeological sites are still unknown in many cases, taking into account the particular features of this material and the conditionality of each context. Unlike the standardized protocols used in other disciplines, in situ conservation of archaeological sites suffers from certain anarchy, both in the execution phase, as in that of subsequent monitoring process, usually nonexistent. That is why there are some inefficient treatments that are still in application in this field, and its effects, in terms of efficacy and durability, still unidentified. Moreover, the use of a very limited number of products has been commonly used in archaeology, not evolving as for instance architectural heritage. The project that is been carried out in some archaeological sites of the Roman city of Emerita Augusta (Mérida, Spain) focuses on this subject. The first phase involved the documentation and location of all interventions executed in selected sites, since the beginning of excavations in 1911, until today. Selected areas for analysis both on site and in laboratory will help to determine mentioned effects after some years of application. To assess the presence of any treatment, repair or product that has been either documented in the consulted reports and/or papers, or that can be observed just by looking, the following techniques are planned to be used: 1) In situ: portable and non destructive techniques such as Raman, XRF, spectrophotometer, roughness meter, ultrasound velocity, hardness tester, magnetometer, infrared camera, water absorption (Karsten tube) and humidity recordings of the surface. 2) Sampling: the minimum number and the smallest samples will be taken of different building materials, treated and untreated, unaltered and decayed, to be analyzed in the laboratory. 3) Samples will be analyzed by XRD, FTIR, optical and scanning electron microscope (SEM+EDS) and some properties determined as the water-repellence of the treatment by means of the contact angle analyzer. All these analyses will prove the conservation state of both the product/treatment and the substrate. 4) Some treatments will be tested in situ and its efficacy and durability measured and monitored by some non-destructive techniques and some other laboratory tests. This work is part of a PhD project which is been carried out within two research groups: - Analysis and Intervention in Architectural Heritage (AIPA, Universidad Politecnica de Madrid) - Applied Petrology for Heritage Conservation Research Group, Geosciences Institute (CSIC,UCM)

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

PubMed Central

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel

2017-01-01

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2. PMID:28961199

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

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

Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due tomore » irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.« less

Radionuclide observables during the Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty

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

Burnett, Jonathan L.; Miley, Harry S.; Milbrath, Brian D.

In 2014 the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) undertook the Integrated Field Exercise (IFE) in Jordan. The exercise consisted of a simulated 0.5 – 2 kT underground explosion triggering an On-site Inspection (OSI) to search for evidence of a Treaty violation. This research evaluates two of the OSI techniques, including laboratory-based gamma-spectrometry of soil samples and in situ gamma-spectrometry for 17 particulate radionuclides indicative of nuclear weapon tests. The detection sensitivity is evaluated using real IFE and model data. It indicates that higher sensitivity laboratory measurements are the optimum technique during the IFE and OSI timeframes.

Scanning AC Nanocalorimetry and Its Applications

NASA Astrophysics Data System (ADS)

Xiao, Kechao

This thesis presents an AC nanocalorimetry technique that enables calorimetry measurements on very small quantities of materials over a wide range of scanning rates (from isothermal to 3x10. 3 K/s), temperatures(up to 1200 K), and environments. Such working range bridges the gap between traditional scanning calorimetry of bulk materials and nanocalorimetry. The method relies on a micromachined nanocalorimeter with negligible thermal lags between heater, thermometer, and sample. The ability to perform calorimetry measurements over such a broad range of scanning rates makes it an ideal tool to characterize the kinetics of phase transformations, reactions at elevated temperatures or to explore the behavior of materials far from equilibrium. We demonstrate the technique by performing measurements on thin-film samples of Sn, In, and Bi with thicknesses ranging from 100 to 300 nm. The experimental heat capacities and melting temperatures agree well with literature values. The measured heat capacities are insensitive to the applied AC frequency, scan rate, and heat loss to the environment over a broad range of experimental conditions. The dynamic range of scanning AC nanocalorimetry enables the combination of nanocalorimetry with in-situ x-ray diffraction (XRD) to facilitate interpretation of the calorimetry measurements. Time-resolved XRD during in-situ operation of nanocalorimetry sensors using intense, high-energy synchrotron radiation allows unprecedented characterization of thermal and structural material properties. We demonstrate this experiment with detailed characterization of the melting and solidification of elemental Bi, In and Sn thin-film samples, using heating and cooling rates up to 300 K/s. By combining scanning DC and AC nano-calorimetry techniques, we study the nucleation behavior of undercooled liquid Bi at cooling rates ranging from 10. 1 to 10. 4 K/s. Upon initial melting, the Bi thin-film sample breaksup into isolated islands. The number of islands in a typical sample is sufficiently large that highly repeatable nucleation behavior is observed, despite the stochastic nature of the nucleation process. We establish a data reduction technique to evaluate the nucleation rate from DC and AC calorimetry results. The results show that the driving force for the nucleation of melted Bi is well described by classical nucleation theory over a wide range of cooling rates. The proposed technique provides a unique and efficient way to examine nucleation kinetics with cooling rates over several orders of magnitude. The technique is quite general and can be used to evaluate reaction kinetics in other materials. Lastly, we apply the scanning AC nanocalorimetry technique to study solid-gas phase reactions by measuring the change in heat capacity of a sample during reaction. We apply this approach to evaluate the oxidation kinetics of thin-film samples of zirconium in air. The results confirm parabolic oxidation kinetics with an activation energy of 0.59+/-0.03 eV. The nano-calorimetry measurements were performed using a device that contains an array of micromachined nano-calorimeter sensors in an architecture designed for combinatorial studies. We demonstrate that the oxidation kinetics can be quantified using a single sample, thus enabling high-throughput mapping of the composition-dependence of the reaction rate.

Environmental Electrokinetics for a sustainable subsurface.

PubMed

Lima, A T; Hofmann, A; Reynolds, D; Ptacek, C J; Van Cappellen, P; Ottosen, L M; Pamukcu, S; Alshawabekh, A; O'Carroll, D M; Riis, C; Cox, E; Gent, D B; Landis, R; Wang, J; Chowdhury, A I A; Secord, E L; Sanchez-Hachair, A

2017-08-01

Soil and groundwater are key components in the sustainable management of the subsurface environment. Source contamination is one of its main threats and is commonly addressed using established remediation techniques such as in-situ chemical oxidation (ISCO), in-situ chemical reduction (ISCR; most notably using zero-valent iron [ZVI]), enhanced in-situ bioremediation (EISB), phytoremediation, soil-washing, pump-and-treat, soil vapour extraction (SVE), thermal treatment, and excavation and disposal. Decades of field applications have shown that these techniques can successfully treat or control contaminants in higher permeability subsurface materials such as sands, but achieve only limited success at sites where low permeability soils, such as silts and clays, prevail. Electrokinetics (EK), a soil remediation technique mostly recognized in in-situ treatment of low permeability soils, has, for the last decade, been combined with more conventional techniques and can significantly enhance the performance of several of these remediation technologies, including ISCO, ISCR, EISB and phytoremediation. Herein, we discuss the use of emerging EK techniques in tandem with conventional remediation techniques, to achieve improved remediation performance. Furthermore, we highlight new EK applications that may come to play a role in the sustainable treatment of the contaminated subsurface. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mobile Soil Moisture Sensing in High Elevations: Applications of the Cosmic Ray Neutron Sensor Technique in Heterogeneous Terrain

NASA Astrophysics Data System (ADS)

Franz, T. E.; Avery, W. A.; Wahbi, A.; Dercon, G.; Heng, L.; Strauss, P.

2017-12-01

The use of the Cosmic Ray Neutron Sensor (CRNS) for the detection of field-scale soil moisture ( 20 ha) has been the subject of a multitude research applications over the past decade. One exciting area within agriculture aims to provide soil moisture and soil property information for irrigation scheduling. The CRNS technology exists in both a stationary and mobile form. The use of a mobile CRNS opens possibilities for application in many diverse environments. This work details the use of a mobile "backpack" CRNS device in high elevation heterogeneous terrain in the alpine mountains of western Austria. This research demonstrates the utilization of established calibration and validation techniques associated with the use of the CRNS within difficult to reach landscapes that are either inaccessible or impractical to both the stationary CRNS and other more traditional soil moisture sensing technology. Field work was conducted during the summer of 2016 in the Rauris valley of the Austrian Alps at three field sites located at different representative elevations within the same Rauris watershed. Calibrations of the "backpack" CRNS were performed at each site along with data validation via in-situ Time Domain Reflectometry (TDR) and gravimetric soil sampling. Validation data show that the relationship between in-situ soil moisture data determined via TDR and soil sampling and soil moisture data determined via the mobile CRNS is strong (RMSE <2.5 % volumetric). The efficacy of this technique in remote alpine landscapes shows great potential for use in early warning systems for landslides and flooding, watershed hydrology, and high elevation agricultural water management.

POWTEX Neutron Diffractometer at FRM II - New Perspectives for In-Situ Rock Deformation Analysis

NASA Astrophysics Data System (ADS)

Walter, J. M.; Stipp, M.; Ullemeyer, K.; Klein, H.; Leiss, B.; Hansen, B. T.; Kuhs, W. F.

2012-04-01

In Geoscience quantitative texture analysis here defined as the quantitative analysis of the crystallographic preferred orientation (CPO), is a common tool for the investigation of fabric development in mono- and polyphase rocks, their deformation histories and kinematics. Bulk texture measurements also allow the quantitative characterisation of the anisotropic physical properties of rock materials. A routine tool to measure bulk sample volumes is neutron texture diffraction, as neutrons have large penetration capabilities of several cm in geological sample materials. The new POWTEX (POWder and TEXture) Diffractometer at the neutron research reactor FRM II in Garching, Germany is designed as a high-intensity diffractometer by groups from the RWTH Aachen, Forschungszentrum Jülich and the University of Göttingen. Complementary to existing neutron diffractometers (SKAT at Dubna, Russia; GEM at ISIS, UK; HIPPO at Los Alamos, USA; D20 at ILL, France; and the local STRESS-SPEC and SPODI at FRM II) the layout of POWTEX is focused on fast time-resolved experiments and the measurement of larger sample series as necessary for the study of large scale geological structures. POWTEX is a dedicated beam line for geoscientific research. Effective texture measurements without sample tilting and rotation are possible firstly by utilizing a range of neutron wavelengths simultaneously (Time-of-Flight technique) and secondly by the high detector coverage (9.8 sr) and a high flux (~1 - 107 n/cm2s) at the sample. Furthermore the instrument and the angular detector resolution is designed also for strong recrystallisation textures as well as for weak textures of polyphase rocks. These instrument characteristics allow in-situ time-resolved texture measurements during deformation experiments on rocksalt, ice and other materials as large sample environments will be implemented at POWTEX. The in-situ deformation apparatus is operated by a uniaxial spindle drive with a maximum axial load of 250 kN, which will be redesigned to minimize shadowing effects inside the cylindrical detector. The HT deformatione experiments will be carried out in uniaxial compression or extension and an upgrade to triaxial deformation conditions is envisaged. The load frame can alternatively be used for ice deformation by inserting a cryostat cell for temperatures down to 77 K with a triaxial apparatus allowing also simple shear experiments on ice. Strain rates range between 10-8 and 10-3 s-1 reaching to at least 50 % axial strain. The deformation apparatus is designed for continuous long-term deformation experiments and can be exchanged between in-situ and ex-situ placements during continuous operation inside and outside the neutron detector.

Electronically scanned pressure sensor module with in SITU calibration capability

NASA Technical Reports Server (NTRS)

Gross, C. (Inventor)

1978-01-01

This high data rate pressure sensor module helps reduce energy consumption in wind tunnel facilities without loss of measurement accuracy. The sensor module allows for nearly a two order of magnitude increase in data rates over conventional electromechanically scanned pressure sampling techniques. The module consists of 16 solid state pressure sensor chips and signal multiplexing electronics integrally mounted to a four position pressure selector switch. One of the four positions of the pressure selector switch allows the in situ calibration of the 16 pressure sensors; the three other positions allow 48 channels (three sets of 16) pressure inputs to be measured by the sensors. The small size of the sensor module will allow mounting within many wind tunnel models, thus eliminating long tube lengths and their corresponding slow pressure response.

Facility for low-temperature spin-polarized-scanning tunneling microscopy studies of magnetic/spintronic materials prepared in situ by nitride molecular beam epitaxy.

PubMed

Lin, Wenzhi; Foley, Andrew; Alam, Khan; Wang, Kangkang; Liu, Yinghao; Chen, Tianjiao; Pak, Jeongihm; Smith, Arthur R

2014-04-01

Based on the interest in, as well as exciting outlook for, nitride semiconductor based structures with regard to electronic, optoelectronic, and spintronic applications, it is compelling to investigate these systems using the powerful technique of spin-polarized scanning tunneling microscopy (STM), a technique capable of achieving magnetic resolution down to the atomic scale. However, the delicate surfaces of these materials are easily corrupted by in-air transfers, making it unfeasible to study them in stand-alone ultra-high vacuum STM facilities. Therefore, we have carried out the development of a hybrid system including a nitrogen plasma assisted molecular beam epitaxy/pulsed laser epitaxy facility for sample growth combined with a low-temperature, spin-polarized scanning tunneling microscope system. The custom-designed molecular beam epitaxy growth system supports up to eight sources, including up to seven effusion cells plus a radio frequency nitrogen plasma source, for epitaxially growing a variety of materials, such as nitride semiconductors, magnetic materials, and their hetero-structures, and also incorporating in situ reflection high energy electron diffraction. The growth system also enables integration of pulsed laser epitaxy. The STM unit has a modular design, consisting of an upper body and a lower body. The upper body contains the coarse approach mechanism and the scanner unit, while the lower body accepts molecular beam epitaxy grown samples using compression springs and sample skis. The design of the system employs two stages of vibration isolation as well as a layer of acoustic noise isolation in order to reduce noise during STM measurements. This isolation allows the system to effectively acquire STM data in a typical lab space, which during its construction had no special and highly costly elements included, (such as isolated slabs) which would lower the environmental noise. The design further enables tip exchange and tip coating without breaking vacuum, and convenient visual access to the sample and tip inside a superconducting magnet cryostat. A sample/tip handling system is optimized for both the molecular beam epitaxy growth system and the scanning tunneling microscope system. The sample/tip handing system enables in situ STM studies on epitaxially grown samples, and tip exchange in the superconducting magnet cryostat. The hybrid molecular beam epitaxy and low temperature scanning tunneling microscopy system is capable of growing semiconductor-based hetero-structures with controlled accuracy down to a single atomic-layer and imaging them down to atomic resolution.

Evaluation of fluorescence in situ hybridisation (FISH) for the detection of fungi directly from blood cultures and cerebrospinal fluid from patients with suspected invasive mycoses.

PubMed

Da Silva, Roberto Moreira; Da Silva Neto, João Ricardo; Santos, Carla Silvana; Frickmann, Hagen; Poppert, Sven; Cruz, Kátia Santana; Koshikene, Daniela; De Souza, João Vicente Braga

2015-01-31

The aim of this study was to evaluate the diagnostic performance of in-house FISH (fluorescence in situ hybridisation) procedures for the direct identification of invasive fungal infections in blood cultures and cerebrospinal fluid (CSF) samples and to compare these FISH results with those obtained using traditional microbiological techniques and PCR targeting of the ITS1 region of the rRNA gene. In total, 112 CSF samples and 30 positive blood cultures were investigated by microscopic examination, culture, PCR-RFLP and FISH. The sensitivity of FISH for fungal infections in CSF proved to be slightly better than that of conventional microscopy (India ink) under the experimental conditions, detecting 48 (instead of 46) infections in 112 samples. The discriminatory powers of traditional microbiology, PCR-RFLP and FISH for fungal bloodstream infections were equivalent, with the detection of 14 fungal infections in 30 samples. However, the mean times to diagnosis after the detection of microbial growth by automated blood culture systems were 5 hours, 20 hours and 6 days for FISH, PCR-RFLP and traditional microbiology, respectively. The results demonstrate that FISH is a valuable tool for the identification of invasive mycoses that can be implemented in the diagnostic routine of hospital laboratories.

Time-lapsed investigation of three-dimensional failure and damage accumulation in trabecular bone using synchrotron light.

PubMed

Thurner, P J; Wyss, P; Voide, R; Stauber, M; Stampanoni, M; Sennhauser, U; Müller, R

2006-08-01

Synchrotron radiation micro-computed tomography (SRmicroCT) is a very useful technique when it comes to three-dimensional (3D) imaging of complex internal and external geometries. Being a fully non-destructive technique, SRmicroCT can be combined with other experiments in situ for functional imaging. We are especially interested in the combination of SRmicroCT with mechanical testing in order to gain new insights in the failure mechanism of trabecular bone. This interest is motivated by the immense costs in health care due to patients suffering from osteoporosis, a systemic skeletal disease resulting in decreased bone stability and increased fracture risk. To better investigate the different failure mechanisms on the microlevel, we have developed a novel in situ mechanical compression device, capable of exerting both static and dynamic displacements on experimental samples. The device was calibrated for mechanical testing using solid aluminum and bovine trabecular bone samples. To study different failure mechanisms in trabecular bone, we compared a fatigued and a non-fatigued bovine bone sample with respect to failure initiation and propagation. The fatigued sample failed in a burst-like fashion in contrast to the non-fatigued sample, which exhibited a distinct localized failure band. Moreover, microscopic cracks - microcracks and microfractures - were uncovered in a 3D fashion illustrating the failure process in great detail. The majority of these cracks were connected to a bone surface. The data also showed that the classification of microcracks and -fractures from 2D section can sometimes be ambiguous, which is also true for the distinction of diffuse and distinct microdamage. Detailed investigation of the failure mechanism in these samples illustrated that trabecular bone often fails in delamination, providing a mechanism for energy dissipation while conserving trabecular bone architecture. In the future, this will allow an even better understanding of bone mechanics related to its hierarchical structural organization.

In situ electrostatic characterisation of ion beams in the region of ion acceleration

NASA Astrophysics Data System (ADS)

Bennet, Alexander; Charles, Christine; Boswell, Rod

2018-02-01

In situ and ex situ techniques have been used to measure directional ion beams created by a sharp axial potential drop in low pressure expanding plasmas. Although Retarding Field Energy Analysers (RFEAs) are the most convenient technique to measure the ion velocities and plasma potentials along with the plasma density, they are bulky and are contained in a grounded shield that may perturb the electric potential profile of the expanding plasma. In principle, ex situ techniques produce a more reliable measurement and Laser Induced Fluorescence spectroscopy (LIF) has previously been used to characterise the spatial velocity profile of ion beams in the same region of acceleration for a range of pressures. Here, satisfactory agreement between the ion velocity profiles measured by LIF and RFEA techniques has allowed the RFEA method to be confidently used to probe the ion beam characteristics in the regions of high gradients in plasma density and DC electric fields which have previously proven difficult.

In situ neutron scattering study of nanoscale phase evolution in PbTe-PbS thermoelectric material

DOE PAGES

Ren, Fei; Schmidt, Robert; Keum, Jong K.; ...

2016-08-24

Introducing nanostructural second phases has been proved to be an effective approach to reduce the lattice thermal conductivity and thus enhance the figure of merit for many thermoelectric materials. Furthermore studies of the formation and evolution of these second phases are central to understanding temperature dependent material behavior, improving thermal stabilities, as well as designing new materials. We examined powder samples of PbTe-PbS thermoelectric material using in situ neutron diffraction and small angle neutron scattering (SANS) techniques from room temperature to elevated temperature up to 663 K, to explore quantitative information on the structure, weight fraction, and size of themore » second phase. Neutron diffraction data showed the as-milled powder was primarily solid solution before heat treatment. During heating, PbS second phase precipitated out of the PbTe matrix around 480 K, while re-dissolution started around 570 K. The second phase remained separated from the matrix upon cooling. Furthermore, SANS data indicated there are two populations of nanostructures. The size of the smaller nanostructure increased from initially 5 nm to approximately 25 nm after annealing at 650 K, while the size of the larger nanostructure remained unchanged. Our study demonstrated that in situ neutron techniques are effective means to obtain quantitative information to study temperature dependent nanostructural behavior of thermoelectrics and likely other high-temperature materials.« less

Deformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. II. In situ transmission electron microscopy study of deformation mechanism change of a Zr-2.5Nb alloy upon heavy ion irradiation

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

Long, Fei; Daymond, Mark R., E-mail: mark.daymond@queensu.ca; Yao, Zhongwen

2015-03-14

The effect of heavy-ion irradiation on deformation mechanisms of a Zr-2.5Nb alloy was investigated by using the in situ transmission electron microscopy deformation technique. The gliding behavior of prismatic 〈a〉 dislocations has been dynamically observed before and after irradiation at room temperature and 300 °C. Irradiation induced loops were shown to strongly pin the gliding dislocations. Unpinning occurred while loops were incorporated into or eliminated by 〈a〉 dislocations. In the irradiated sample, loop depleted areas with a boundary parallel to the basal plane trace were found by post-mortem observation after room temperature deformation, supporting the possibility of basal channel formation inmore » bulk neutron irradiated samples. Strong activity of pyramidal slip was also observed at both temperatures, which might be another important mechanism to induce plastic instability in irradiated zirconium alloys. Finally, (011{sup ¯}1)〈01{sup ¯}12〉 twinning was identified in the irradiated sample deformed at 300 °C.« less

Deformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. II. In situ transmission electron microscopy study of deformation mechanism change of a Zr-2.5Nb alloy upon heavy ion irradiation.

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

Long, Fei; Daymond, Mark R.; Yao, Zhongwen

2015-03-14

The effect of heavy-ion irradiation on deformation mechanisms of a Zr-2.5Nb alloy was investigated by using the in situ transmission electron microscopy deformation technique. The gliding behavior of prismatic < a > dislocations has been dynamically observed before and after irradiation at room temperature and 300 degrees C. Irradiation induced loops were shown to strongly pin the gliding dislocations. Unpinning occurred while loops were incorporated into or eliminated by < a > dislocations. In the irradiated sample, loop depleted areas with a boundary parallel to the basal plane trace were found by post-mortem observation after room temperature deformation, supporting themore » possibility of basal channel formation in bulk neutron irradiated samples. Strong activity of pyramidal slip was also observed at both temperatures, which might be another important mechanism to induce plastic instability in irradiated zirconium alloys. Finally, {01 (1) over bar1}< 0 (1) over bar 12 > twinning was identified in the irradiated sample deformed at 300 degrees C.« less

[Molecular diagnostics of ALK-positive lung cancer].

PubMed

Tímár, József; Lotz, Gábor; Rásó, Erzsébet; Moldvay, Judit

2017-09-20

ALK translocation is the 3rd most frequent genetic aberration in lung adenocarcinoma, and several inhibitors are now clinically available in first and second line settings. Accordingly, molecular diagnostics of ALK-positive lung cancer is very important and can be done with the rational combination of several methods. All international recommendations suggest that, except for cytological samples, screening technology for ALK-positive tumors is immunohistochemistry using a validated test. It is highly recommended that in case of ALK protein positive samples gene translocation must be confirmed by fluorescent in situ hybridization (FISH). In case of cytological samples FISH technique must be used as ALK diagnostics. In equivocal cases the genetic alteration of ALK can be confirmed by alternative molecular techniques such as next generation sequencing or RNAbased PCR methods. Upon administration of ALK inhibitors, acquired resistance is frequent which is mostly due to ALK amplification and/or mutation. It is evident that the diagnostics of these secondary ALK gene alterations must be done from recurrent tumors or circulating nucleic acids.

On-target digestion of collected bacteria for MALDI mass spectrometry.

PubMed

Dugas, Alton J; Murray, Kermit K

2008-10-03

An on-target protein digestion system was developed for the identification of microorganisms in collected bioaerosols using off-line matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Bacteria analysis techniques based on MALDI-MS were adapted for use with an orthogonal MALDI quadrupole-time-of-flight mass spectrometer. Bioaerosols were generated using a pneumatic nebulizer and infused into a chamber for sampling. An Andersen N6 single-stage impactor was used to collect the bioaerosols on a MALDI target. On-target digestion was carried out inside temporary mini-wells placed over the impacted samples. The wells served as miniature reactors for proteolysis. Collected test aerosol particles containing the protein cytochrome c and E. coli bacteria were proteolyzed in situ using trypsin or cyanogen bromide. A total of 19 unique proteins were identified for E. coli. Using the TOF-MS spectra of the digested samples, peptide mass mapping was performed using the MASCOT search engine and an iterative search technique.

Application of X-ray phase contrast micro-tomography to the identification of traditional Chinese medicines

NASA Astrophysics Data System (ADS)

Ye, L. L.; Xue, Y. L.; Ni, L. H.; Tan, H.; Wang, Y. D.; Xiao, T. Q.

2013-07-01

Nondestructive and in situ investigation to the characteristic microstructures are important to the identification of traditional Chinese medicines (TCMs), especially for precious specimens and samples with oil contains. X-ray phase contrast micro-tomography (XPCMT) could be a practical solution for this kind of investigation. Fructus Foeniculi, a fruit kind of TCMs, is selected as the test sample. Experimental results show that the characteristic microstructures of Fructus Foeniculi, including vittae, vascular bundles, embryo, endosperm and the mesocarp reticulate cells around the vittae can be clearly distinguished and the integrated dissepiments microstructure in the vittae was observed successfully. Especially, for the first time, with virtual slice technique, it can investigate the liquid contains inside the TCMs. The results show that the vittae filled with volatile oil in the oil chamber were observed with this nondestructive and in situ 3-dimensional imaging technique. Furthermore, taking the advantage of micro-computed tomography, we can obtain the characteristic microstructures' quantitative information of the volume in liquid state. The volume of the oil chambers and the volatile oil, which are contained inside the vittae, was quantitatively analyzed. Accordingly, it can calculate the volume ratio of the volatile oil easily and accurately. As a result, we could conclude that XPCMT could be a useful tool for the nondestructive identification and quantitative analysis to TCMs.

In-situ laser ultrasonic measurement of the hcp to bcc transformation in commercially pure titanium

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

Shinbine, A., E-mail: alyssa.shinbine@gmail.com; Garcin, T.; Sinclair, C.

2016-07-15

Using a novel in-situ laser ultrasonic technique, the evolution of longitudinal velocity was used to measure the α − β transformation during cyclic heating and cooling in commercially pure titanium. In order to quantify the transformation kinetics, it is shown that changes in texture can not be ignored. This is particularly important in the case of titanium where significant grain growth occurs in the β-phase leading to the ultrasonic wave sampling a decreasing number of grains on each thermal treatment cycle. Electron backscatter diffraction measurements made postmortem in the region where the ultrasonic pulse traveled were used to obtain anmore » estimate of such local texture and grain size changes. An analysis technique for including the anisotropy of wave velocity depending on local texture is presented and shown to give self consistent results for the transformation kinetics. - Highlights: • Laser ultrasound and EBSD interpret the hcp/bcc phase transformation in cp-Ti. • Grain growth and texture produced variation in velocity during similar treatments. • Texture was deconvoluted from phase addition to obtain transformation kinetics.« less

An animal model for instructing and the study of in situ arterial bypass.

PubMed

Saifi, J; Chang, B B; Paty, P S; Kaufman, J; Leather, R P; Shah, D M

1990-11-01

A canine model that used the cephalic vein to bypass from the brachial to the ulnar artery was designed for use in instructing and evaluating surgical technique needed for constructing an in situ arterial bypass. This model was used for instructing vascular residents in the in situ vein bypass technique. The use of this model enabled the resident to become more adept with the instruments for valve incision and construction of small vessel anastomosis. The improvement in the resident's operative technique was reflected by a decrease in the number of technical complications (missed valves, missed arteriovenous fistulas, poorly constructed anastomoses) and improved patency rate.

Application of in-situ hybridization for the detection and identification of avian malaria parasites in paraffin wax-embedded tissues from captive penguins

PubMed Central

Dinhopl, Nora; Mostegl, Meike M.; Richter, Barbara; Nedorost, Nora; Maderner, Anton; Fragner, Karin; Weissenböck, Herbert

2011-01-01

In captive penguins, avian malaria due to Plasmodium parasites is a well-recognized disease problem as these protozoa may cause severe losses among valuable collections of zoo birds. In blood films from naturally infected birds, identification and differentiation of malaria parasites based on morphological criteria are difficult because parasitaemia is frequently light and blood stages, which are necessary for identification of parasites, are often absent. Post-mortem diagnosis by histological examination of tissue samples is sometimes inconclusive due to the difficulties in differentiating protozoal tissue stages from fragmented nuclei in necrotic tissue. The diagnosis of avian malaria would be facilitated by a technique with the ability to specifically identify developmental stages of Plasmodium in tissue samples. Thus, a chromogenic in-situ hybridization (ISH) procedure with a digoxigenin-labelled probe, targeting a fragment of the 18S rRNA, was developed for the detection of Plasmodium parasites in paraffin wax-embedded tissues. This method was validated in comparison with traditional techniques (histology, polymerase chain reaction), on various tissues from 48 captive penguins that died at the zoological garden Schönbrunn, Vienna, Austria. Meronts of Plasmodium gave clear signals and were easily identified using ISH. Potential cross-reactivity of the probe was ruled out by the negative outcome of the ISH against a number of protozoa and fungi. Thus, ISH proved to be a powerful, specific and sensitive tool for unambiguous detection of Plasmodium parasites in paraffin wax-embedded tissue samples. PMID:21711191

Dissolution enhancement of gliclazide using pH change approach in presence of twelve stabilizers with various physico-chemical properties.

PubMed

Talari, Roya; Varshosaz, Jaleh; Mostafavi, Seyed Abolfazl; Nokhodchi, Ali

2009-01-01

The micronization using milling process to enhance dissolution rate is extremely inefficient due to a high energy input, and disruptions in the crystal lattice which can cause physical or chemical instability. Therefore, the aim of the present study is to use in situ micronization process through pH change method to produce micron-size gliclazide particles for fast dissolution hence better bioavailability. Gliclazide was recrystallized in presence of 12 different stabilizers and the effects of each stabilizer on micromeritic behaviors, morphology of microcrystals, dissolution rate and solid state of recrystallized drug particles were investigated. The results showed that recrystallized samples showed faster dissolution rate than untreated gliclazide particles and the fastest dissolution rate was observed for the samples recrystallized in presence of PEG 1500. Some of the recrystallized drug samples in presence of stabilizers dissolved 100% within the first 5 min showing at least 10 times greater dissolution rate than the dissolution rate of untreated gliclazide powders. Micromeritic studies showed that in situ micronization technique via pH change method is able to produce smaller particle size with a high surface area. The results also showed that the type of stabilizer had significant impact on morphology of recrystallized drug particles. The untreated gliclazide is rod or rectangular shape, whereas the crystals produced in presence of stabilizers, depending on the type of stabilizer, were very fine particles with irregular, cubic, rectangular, granular and spherical/modular shape. The results showed that crystallization of gliclazide in presence of stabilizers reduced the crystallinity of the samples as confirmed by XRPD and DSC results. In situ micronization of gliclazide through pH change method can successfully be used to produce micron-sized drug particles to enhance dissolution rate.

In situ monitoring using Lab on Chip devices, with particular reference to dissolved silica.

NASA Astrophysics Data System (ADS)

Turner, G. S. C.; Loucaides, S.; Slavik, G. J.; Owsianka, D. R.; Beaton, A.; Nightingale, A.; Mowlem, M. C.

2016-02-01

In situ sensors are attractive alternatives to discrete sampling of natural waters, offering the potential for sustained long term monitoring and eliminating the need for sample handling. This can reduce sample contamination and degradation. In addition, sensors can be clustered into multi-parameter observatories and networked to provide both spatial and time series coverage. High resolution, low cost, and long term monitoring are the biggest advantages of these technologies to oceanographers. Microfluidic technology miniaturises bench-top assay systems into portable devices, known as a `lab on a chip' (LOC). The principle advantages of this technology are low power consumption, simplicity, speed, and stability without compromising on quality (accuracy, precision, selectivity, sensitivity). We have successfully demonstrated in situ sensors based on this technology for the measurement of pH, nitrate and nitrite. Dissolved silica (dSi) is an important macro-nutrient supporting a major fraction of oceanic primary production carried out by diatoms. The biogeochemical Si cycle is undergoing significant modifications due to human activities, which affects availability of dSi, and consequently primary production. Monitoring dSi concentrations is therefore critical in increasing our understanding of the biogeochemical Si cycle to predict and manage anthropogenic perturbations. The standard bench top air segmented flow technique utilising the reduction of silicomolybdic acid with spectrophotometric detection has been miniaturised into a LOC system; the target limit of detection is 1 nM, with ± 5% accuracy and 3% precision. Results from the assay optimisation are presented along with reagent shelf life to demonstrate the robustness of the chemistry. Laboratory trials of the sensor using ideal solutions and environmental samples in environmentally relevant conditions (temperature, pressure) are discussed, along with an overview of our current LOC analytical capabilities.

Quantitative comparison of the in situ microbial communities in different biomes

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

White, D.C.; Ringelberg, D.B.; Palmer, R.J.

1995-12-31

A system to define microbial communities in different biomes requires the application of non-traditional methodology. Classical microbiological methods have severe limitations for the analysis of environmental samples. Pure-culture isolation, biochemical testing, and/or enumeration by direct microscopic counting are not well suited for the estimation of total biomass or the assessment of community composition within environmental samples. Such methods provide little insight into the in situ phenotypic activity of the extant microbiota since these techniques are dependent on microbial growth and thus select against many environmental microorganisms which are non- culturable under a wide range of conditions. It has been repeatedlymore » documented in the literature that viable counts or direct counts of bacteria attached to sediment grains are difficult to quantitative and may grossly underestimate the extent of the existing community. The traditional tests provide little indication of the in situ nutritional status or for evidence of toxicity within the microbial community. A more recent development (MIDI Microbial Identification System), measure free and ester-linked fatty acids from isolated microorganisms. Bacterial isolates are identified by comparing their fatty acid profiles to the MIKI database which contains over 8000 entries. The application of the MIKI system to the analysis of environmental samples however, has significant drawbacks. The MIDI system was developed to identify clinical microorganisms and requires their isolation and culture on trypticase soy agar at 27{degrees}C. Since many isolates are unable to grow at these restrictive growth conditions, the system does not lend itself to identification of some environmental organisms. A more applicable methodology for environmental microbial analysis is based on the liquid extrication and separation of microbial lipids from environmental samples, followed by quantitative analysis using gas chromatography/« less

In situ speciation of uranium in treated acid mine drainage using the diffusion gradients in thin films technique (DGT).

PubMed

Pedrobom, Jorge Henrique; Eismann, Carlos Eduardo; Menegário, Amauri A; Galhardi, Juliana Aparecida; Luko, Karen Silva; Dourado, Thiago de Araujo; Kiang, Chang Hung

2017-02-01

The exchange membranes P81 and DE81 and Chelex-100 resin were used to perform in situ speciation of uranium in treated acid mine drainage at the Osamu Utsumi mining site, Poços de Caldas city, Southeast Brazil. To investigate possible chemical modifications in the samples during analysis, the three ligands were deployed in situ and in a laboratory (in lab). The results obtained in situ were also compared to a speciation performed using Visual MINTEQ software. Chelex-100 retained total labile U for a period of up to 48 h. The labile U fraction determined by Chelex 100 ranged from 107 ± 6% to 147 ± 44% in situ and from 115 ± 22% to 191 ± 5% in lab. DE81 retained anionic U species up to 8 h, with labile fractions ranging from 37 ± 2% to 76 ± 3% in situ and 34 ± 12% to 180 ± 17% in lab. P81 exhibited a lower efficiency in retaining U species, with concentrations ranging from 6± 2% to 19± 2% in situ and 3± 2% to 18± 2% in lab. The speciation obtained from MINTEQ suggests that the major U species were UO 2 OH + , UO 2 (OH) 3- , UO 2 (OH) 2(aq) , Ca 2 UO 2 (CO 3 ) 3(aq) , CaUO 2 (CO 3 ) 3 2- , UO 2 (CO 3 ) 2 2- , and UO 2 (CO 3 ) 3 4- . This result is in accordance with the results obtained in situ. Differences concerning speciation and the total and soluble U concentrations were observed between the deployments performed in situ and in the laboratory, indicating that U speciation must be performed in situ. Copyright © 2016 Elsevier Ltd. All rights reserved.

Amino acid distribution in meteorites: diagenesis, extraction methods, and standard metrics in the search for extraterrestrial biosignatures.

PubMed

McDonald, Gene D; Storrie-Lombardi, Michael C

2006-02-01

The relative abundance of the protein amino acids has been previously investigated as a potential marker for biogenicity in meteoritic samples. However, these investigations were executed without a quantitative metric to evaluate distribution variations, and they did not account for the possibility of interdisciplinary systematic error arising from inter-laboratory differences in extraction and detection techniques. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and stochastic probabilistic artificial neural networks (ANNs) were used to compare the distributions for nine protein amino acids previously reported for the Murchison carbonaceous chondrite, Mars meteorites (ALH84001, Nakhla, and EETA79001), prebiotic synthesis experiments, and terrestrial biota and sediments. These techniques allowed us (1) to identify a shift in terrestrial amino acid distributions secondary to diagenesis; (2) to detect differences in terrestrial distributions that may be systematic differences between extraction and analysis techniques in biological and geological laboratories; and (3) to determine that distributions in meteoritic samples appear more similar to prebiotic chemistry samples than they do to the terrestrial unaltered or diagenetic samples. Both diagenesis and putative interdisciplinary differences in analysis complicate interpretation of meteoritic amino acid distributions. We propose that the analysis of future samples from such diverse sources as meteoritic influx, sample return missions, and in situ exploration of Mars would be less ambiguous with adoption of standardized assay techniques, systematic inclusion of assay standards, and the use of a quantitative, probabilistic metric. We present here one such metric determined by sequential feature extraction and normalization (PCA), information-driven automated exploration of classification possibilities (HCA), and prediction of classification accuracy (ANNs).

Identification and determination of the viability of Giardia lamblia cysts and Cryptosporidium parvum and Cryptosporidium hominis oocysts in human fecal and water supply samples by fluorescent in situ hybridization (FISH) and monoclonal antibodies.

PubMed

Lemos, Vanessa; Graczyk, Thaddeus K; Alves, Margarida; Lobo, Maria Luísa; Sousa, Maria C; Antunes, Francisco; Matos, Olga

2005-12-01

In the present study, fluorescent in situ hybridization (FISH) and monoclonal antibodies (MAbs) were evaluated for species-specific detection and viability determination of Giardia lamblia, Cryptosporidium parvum, and Cryptosporidium hominis in human fecal and water supply samples. A total of 50 fecal human samples positive for G. lamblia cysts, 38 positive for C. parvum, and 23 positive for C. hominis were studied. Also, 18 water supply samples positive for Giardia spp. and Cryptosporidium spp. by the United States Environmental Protection Agency (USEPA) Method 1623 were studied by FISH and fluorescein isothiocyanate (FITC)-conjugated MAbs. Eighteen percent of the fecal samples parasitologically positive for G. lamblia presented viable and nonviable cysts, and 5% of those positive for Cryptosporidium spp. presented viable and nonviable oocysts. Of the 18 water supply samples analyzed, 6 (33%) presented Giardia spp. viable and nonviable cysts and 2 (11%) presented viable and nonviable Cryptosporidium spp. oocysts. G. lamblia identification was confirmed by polymerase chain reaction (PCR) and sequencing of the beta-giardin gene in the fecal and water samples found positive by FISH and FITC-conjugated MAbs. C. parvum and Cryptosporidium muris were identified, by PCR and sequencing of the small subunit of ribosomal RNA gene, in seven and one water samples, respectively. Our results confirm that this technique enables simultaneous visualization, species-specific identification, and viability determination of the organisms present in human fecal and water supply samples.

Super resolution imaging of HER2 gene amplification

NASA Astrophysics Data System (ADS)

Okada, Masaya; Kubo, Takuya; Masumoto, Kanako; Iwanaga, Shigeki

2016-02-01

HER2 positive breast cancer is currently examined by counting HER2 genes using fluorescence in situ hybridization (FISH)-stained breast carcinoma samples. In this research, two-dimensional super resolution fluorescence microscopy based on stochastic optical reconstruction microscopy (STORM), with a spatial resolution of approximately 20 nm in the lateral direction, was used to more precisely distinguish and count HER2 genes in a FISH-stained tissue section. Furthermore, by introducing double-helix point spread function (DH-PSF), an optical phase modulation technique, to super resolution microscopy, three-dimensional images were obtained of HER2 in a breast carcinoma sample approximately 4 μm thick.

Note: A novel method for in situ loading of gases via x-ray induced chemistry

NASA Astrophysics Data System (ADS)

Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan

2011-10-01

We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO3) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

Note: A novel method for in situ loading of gases via x-ray induced chemistry.

PubMed

Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan

2011-10-01

We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO(3)) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

Structured illumination diffuse optical tomography for noninvasive functional neuroimaging in mice.

PubMed

Reisman, Matthew D; Markow, Zachary E; Bauer, Adam Q; Culver, Joseph P

2017-04-01

Optical intrinsic signal (OIS) imaging has been a powerful tool for capturing functional brain hemodynamics in rodents. Recent wide field-of-view implementations of OIS have provided efficient maps of functional connectivity from spontaneous brain activity in mice. However, OIS requires scalp retraction and is limited to superficial cortical tissues. Diffuse optical tomography (DOT) techniques provide noninvasive imaging, but previous DOT systems for rodent neuroimaging have been limited either by sparse spatial sampling or by slow speed. Here, we develop a DOT system with asymmetric source-detector sampling that combines the high-density spatial sampling (0.4 mm) detection of a scientific complementary metal-oxide-semiconductor camera with the rapid (2 Hz) imaging of a few ([Formula: see text]) structured illumination (SI) patterns. Analysis techniques are developed to take advantage of the system's flexibility and optimize trade-offs among spatial sampling, imaging speed, and signal-to-noise ratio. An effective source-detector separation for the SI patterns was developed and compared with light intensity for a quantitative assessment of data quality. The light fall-off versus effective distance was also used for in situ empirical optimization of our light model. We demonstrated the feasibility of this technique by noninvasively mapping the functional response in the somatosensory cortex of the mouse following electrical stimulation of the forepaw.

Correlation between HER2 gene amplification and protein overexpression through fluorescence in situ hybridization and immunohistochemistry in breast carcinoma patients.

PubMed

Makroo, R N; Chowdhry, Mohit; Kumar, Manoj; Srivastava, Priyanka; Tyagi, Richa; Bhadauria, Preeti; Kaul, Sumaid; Sarin, Ramesh; Das, P K; Dua, Harsh

2012-01-01

In India, the incidence of breast cancer has increased in the urban population, with 1 in every 22 women diagnosed with breast cancer. It is important to know the HER2/neu gene status for a better prognostication of these patients. The aim of this study was to compare the efficacy of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for determining HER2/neu alteration in breast carcinoma. A total of 188 histologically proven breast carcinoma cases between the years 2007 and 2011 were retrospectively analyzed on the paraffin tissue sections by both IHC and FISH techniques. FISH for HER2/neu gene amplification was performed on cases where the IHC status was already known and the results were compared. A total of 64 (30%) patients were found to be amplified and the remaining 124 (65.9%) cases were found to be unamplified through FISH. Patients observed with 3+ reading on IHC were later confirmed as unamplified in 29.5% cases through FISH. It has been confirmed with the present study that IHC is a prudent first-step technique to screen tissue samples for HER2/neu gene status, but should be supplemented with the FISH technique especially in equivocal cases.

Biogenicity and Syngeneity of Organic Matter in Ancient Sedimentary Rocks: Recent Advances in the Search for Evidence of Past Life

NASA Astrophysics Data System (ADS)

Oehler, Dorothy Z.; Cady, Sherry L.

2014-08-01

The past decade has seen an explosion of new technologies for assessment of biogenicity and syngeneity of carbonaceous material within sedimentary rocks. Advances have been made in techniques for analysis of in situ organic matter as well as for extracted bulk samples of soluble and insoluble (kerogen) organic fractions. The in situ techniques allow analysis of micrometer-to-sub-micrometer-scale organic residues within their host rocks and include Raman and fluorescence spectroscopy/imagery, confocal laser scanning microscopy, and forms of secondary ion/laser-based mass spectrometry, analytical transmission electron microscopy, and X-ray absorption microscopy/spectroscopy. Analyses can be made for chemical, molecular, and isotopic composition coupled with assessment of spatial relationships to surrounding minerals, veins, and fractures. The bulk analyses include improved methods for minimizing contamination and recognizing syngenetic constituents of soluble organic fractions as well as enhanced spectroscopic and pyrolytic techniques for unlocking syngenetic molecular signatures in kerogen. Together, these technologies provide vital tools for the study of some of the oldest and problematic carbonaceous residues and for advancing our understanding of the earliest stages of biological evolution on Earth and the search for evidence of life beyond Earth. We discuss each of these new technologies, emphasizing their advantages and disadvantages, applications, and likely future directions.

Application of in situ ductal perfusion to facilitate isolation of high-quality RNA from mouse pancreas.

PubMed

Mullin, Anne E; Soukatcheva, Galina; Verchere, C Bruce; Chantler, Janet K

2006-05-01

A technique to isolate high-quality intact RNA from murine pancreas is described. This technique involves in situ ductal perfusion of the pancreas with an RNase inhibitor prior to removal of the organ for RNA extraction. In this way, the pancreatic RNases are inhibited in situ allowing good yields of intact RNA, suitable for studies on pancreatic gene transcription by real-time PCR or microarray analysis, to be obtained in a reliable way.

Manipulation of Samples at Extreme Temperatures for Fast in-situ Synchrotron Measurements

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

Weber, Richard

An aerodynamic sample levitation system with laser beam heating was integrated with the APS beamlines 6 ID-D, 11 ID-C and 20 BM-B. The new capability enables in-situ measurements of structure and XANES at extreme temperatures (300-3500 °C) and in conditions that completely avoid contact with container surfaces. In addition to maintaining a high degree of sample purity, the use of aerodynamic levitation enables deep supercooling and greatly enhanced glass formation from a wide variety of melts and liquids. Development and integration of controlled extreme sample environments and new measurement techniques is an important aspect of beamline operations and user support.more » Processing and solidifying liquids is a critical value-adding step in manufacturing semiconductors, optical materials, metals and in the operation of many energy conversion devices. Understanding structural evolution is of fundamental importance in condensed materials, geology, and biology. The new capability provides unique possibilities for materials research and helps to develop and maintain a competitive materials manufacturing and energy utilization industry. Test samples were used to demonstrate key features of the capability including experiments on hot crystalline materials, liquids at temperatures from about 500 to 3500 °C. The use of controlled atmospheres using redox gas mixtures enabled in-situ changes in the oxidation states of cations in melts. Significant innovations in this work were: (i) Use of redox gas mixtures to adjust the oxidation state of cations in-situ (ii) Operation with a fully enclosed system suitable for work with nuclear fuel materials (iii) Making high quality high energy in-situ x-ray diffraction measurements (iv) Making high quality in-situ XANES measurements (v) Publishing high impact results (vi) Developing independent funding for the research on nuclear materials This SBIR project work led to a commercial instrument product for the niche market of processing and studying materials in extreme conditions. MDI registered the trademark “Instruments for Innovation®” and sells products under this trademark. SBIR is the ideal vehicle for funding developments such as this since the total market size is relatively small meaning that venture investments to develop products cannot typically be obtained. The sale of niche market instruments for work in extreme conditions has been several million dollars over the last decade. The work to develop and build and sell this instrument has created stable high paying jobs in the technology manufacturing sector. Outreach enabled by this research helped with PhD thesis research, supported three undergraduate interns and one local high school student. In addition, several scientific articles were published, papers were presented at international conferences, and a workshop was held.« less

A new technique for in situ measurement of the composition of neutral gas in interplanetary space

NASA Technical Reports Server (NTRS)

Gruntman, Michael A.

1993-01-01

Neutral atoms in interplanetary space play an important role in many processes relevant to the formation and evolution of the Solar System. An experimental approach is proposed for in situ atom detection based on the conversion of neutral atoms to negative ions at a specially prepared sensitive surface. Negative ions are subsequently analyzed and detected in an essentially noise-free mode. The use of the technique for in situ study of the composition of neutral interstellar atoms is considered. It is shown that interstellar H, D, and O atoms and possibly H2 molecules can be measured by the proposed technique. The experiment can be performed from a high-apogee Earth-orbiting satellite or from a deep space probe. Possible applications of the technique are discussed.

Recent advances in Lorentz microscopy

DOE PAGES

Phatak, C.; Petford-Long, A. K.; De Graef, M.

2016-01-05

Lorentz transmission electron microscopy (LTEM) has evolved from a qualitative magnetic domain observation technique to a quantitative technique for the determination of the magnetization state of a sample. Here, we describe recent developments in techniques and imaging modes, including the use of spherical aberration correction to improve the spatial resolution of LTEM into the single nanometer range, and novel in situ observation modes. We also review recent advances in the modeling of the wave optical magnetic phase shift as well as in the area of phase reconstruction by means of the Transport of Intensity Equation (TIE) approach, and discuss vectormore » field electron tomography, which has emerged as a powerful tool for the 3D reconstruction of magnetization configurations. Finally, we conclude this review with a brief overview of recent LTEM applications.« less

Semiconductor/dielectric interface engineering and characterization

NASA Astrophysics Data System (ADS)

Lucero, Antonio T.

The focus of this dissertation is the application and characterization of several, novel interface passivation techniques for III-V semiconductors, and the development of an in-situ electrical characterization. Two different interface passivation techniques were evaluated. The first is interface nitridation using a nitrogen radical plasma source. The nitrogen radical plasma generator is a unique system which is capable of producing a large flux of N-radicals free of energetic ions. This was applied to Si and the surface was studied using x-ray photoelectron spectroscopy (XPS). Ultra-thin nitride layers could be formed from 200-400° C. Metal-oxide-semiconductor capacitors (MOSCAPs) were fabricated using this passivation technique. Interface nitridation was able to reduce leakage current and improve the equivalent oxide thickness of the devices. The second passivation technique studied is the atomic layer deposition (ALD) diethylzinc (DEZ)/water treatment of sulfur treated InGaAs and GaSb. On InGaAs this passivation technique is able to chemically reduce higher oxidation states on the surface, and the process results in the deposition of a ZnS/ZnO interface passivation layer, as determined by XPS. Capacitance-voltage (C-V) measurements of MOSCAPs made on p-InGaAs reveal a large reduction in accumulation dispersion and a reduction in the density of interfacial traps. The same technique was applied to GaSb and the process was studied in an in-situ half-cycle XPS experiment. DEZ/H2O is able to remove all Sb-S from the surface, forming a stable ZnS passivation layer. This passivation layer is resistant to further reoxidation during dielectric deposition. The final part of this dissertation is the design and construction of an ultra-high vacuum cluster tool for in-situ electrical characterization. The system consists of three deposition chambers coupled to an electrical probe station. With this setup, devices can be processed and subsequently electrically characterized without exposing the sample to air. This is the first time that such a system has been reported. A special air-gap C-V probe will allow top gated measurements to be made, allowing semiconductor-dielectric interfaces to be studied during device processing.

Combined micro-droplet and thin-film-assisted pre-concentration of lead traces for on-line monitoring using anodic stripping voltammetry.

PubMed

Belostotsky, Inessa; Gridin, Vladimir V; Schechter, Israel; Yarnitzky, Chaim N

2003-02-01

An improved analytical method for airborne lead traces is reported. It is based on using a Venturi scrubber sampling device for simultaneous thin-film stripping and droplet entrapment of aerosol influxes. At least threefold enhancement of the lead-trace pre-concentration is achieved. The sampled traces are analyzed by square-wave anodic stripping voltammetry. The method was tested by a series of pilot experiments. These were performed using contaminant-controlled air intakes. Reproducible calibration plots were obtained. The data were validated by traditional analysis using filter sampling. LODs are comparable with the conventional techniques. The method was successfully applied to on-line and in situ environmental monitoring of lead.

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

NASA Technical Reports Server (NTRS)

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

1981-01-01

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

Comparison of soil pollution concentrations determined using AAS and portable XRF techniques.

PubMed

Radu, Tanja; Diamond, Dermot

2009-11-15

Past mining activities in the area of Silvermines, Ireland, have resulted in heavily polluted soils. The possibility of spreading pollution to the surrounding areas through dust blow-offs poses a potential threat for the local communities. Conventional environmental soil and dust analysis techniques are very slow and laborious and consequently there is a need for fast and accurate analytical methods, which can provide real-time in situ pollution mapping. Laboratory-based aqua regia acid digestion of the soil samples collected in the area followed by the atomic absorption spectrophotometry (AAS) analysis confirmed very high pollution, especially by Pb, As, Cu, and Zn. In parallel, samples were analyzed using portable X-ray fluorescence radioisotope and miniature tube powered (XRF) NITON instruments and their performance was compared. Overall, the portable XRF instrument gave excellent correlation with the laboratory-based reference AAS method.

Tissue diagnosis by means of endogenous fluorophores

NASA Astrophysics Data System (ADS)

Lohmann, Wolfgang; Dreyer, Thomas; Nilles, M.; Bohle, Rainer M.; Schill, Wolf-Bernhard; Glanz, Hiltrud; Fryen, Andreas; Horn, Gisela; Pollich, Beate

1995-01-01

In vitro or in situ single spot or area excitation of human tissue with either 337 nm or 365 nm results in a fluorescence spectrum at about 470 nm. Since in most tissue samples the spectra obtained look alike and differ in intensity only, the 2D tomographical distribution of the fluorescence intensity was also investigated. It could be shown that the fluorescence images of unfixed and unstained cryosections match the histological images (HE stained cryosections). They exhibit a fluorescence pattern unique for the different types of diseases investigated (basalioma, melanoma, nevi, psoriasis, seborrheic keratosis). Additional information can be obtained by elastica van Gieson stained images and by illuminating the HE stained cryosections with 365 nm. Since the cryosections can be prepared and evaluated in less than 5 minutes, this technique might be used as a fast cut technique for determining e.g. the diagnosis of a biopsy sample, also during surgery.

Implications of sampling design and sample size for national carbon accounting systems.

PubMed

Köhl, Michael; Lister, Andrew; Scott, Charles T; Baldauf, Thomas; Plugge, Daniel

2011-11-08

Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of earth-observation data and in-situ field assessments as data sources. We compared the cost-efficiency of four different sampling design alternatives (simple random sampling, regression estimators, stratified sampling, 2-phase sampling with regression estimators) that have been proposed in the scope of REDD. Three of the design alternatives provide for a combination of in-situ and earth-observation data. Under different settings of remote sensing coverage, cost per field plot, cost of remote sensing imagery, correlation between attributes quantified in remote sensing and field data, as well as population variability and the percent standard error over total survey cost was calculated. The cost-efficiency of forest carbon stock assessments is driven by the sampling design chosen. Our results indicate that the cost of remote sensing imagery is decisive for the cost-efficiency of a sampling design. The variability of the sample population impairs cost-efficiency, but does not reverse the pattern of cost-efficiency of the individual design alternatives. Our results clearly indicate that it is important to consider cost-efficiency in the development of forest carbon stock assessments and the selection of remote sensing techniques. The development of MRV-systems for REDD need to be based on a sound optimization process that compares different data sources and sampling designs with respect to their cost-efficiency. This helps to reduce the uncertainties related with the quantification of carbon stocks and to increase the financial benefits from adopting a REDD regime.

40 CFR 65.113 - Standards: Sampling connection systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt... implementation date specified in § 65.1(f). (b) Equipment requirement. Each sampling connection system shall be equipped with a closed-purge, closed-loop, or closed vent system except as provided in paragraph (d) of...

40 CFR 65.113 - Standards: Sampling connection systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt... implementation date specified in § 65.1(f). (b) Equipment requirement. Each sampling connection system shall be equipped with a closed-purge, closed-loop, or closed vent system except as provided in paragraph (d) of...

A New Technique for In Situ X-ray Microtomography Under High Pressure

NASA Astrophysics Data System (ADS)

Uchida, T.; Wang, Y.; Westferro, F.; Gebhardt, J.; Rivers, M. L.; Sutton, S. R.

2004-12-01

We have developed a new technique for in situ synchrotron microtomography to study texture evolution in multi-phase specimens under high pressure and temperature. Two critical issues in performing tomography experiments under pressure are (1) the limited X-ray access to the sample because of the highly absorbing materials, such as tungsten carbide and tool steel, typically used in the pressure vessel and (2) a high pressure compatible rotation mechanism to collect projections of the sample continuously from 0 to 180° . We addressed these issues by (1) employing an opposed-anvil high pressure cell, known as the Drickamer cell, with an X-ray transparent containment ring, to allow panoramic X-ray access, and (2) rotating the Dricakmer cell by Harmonic DriveTM gear reducers, with thrust bearings supporting the hydraulic load. The design of the rotation mechanism benefited from the rotational deformation apparatus developed by Yamazaki and Karato (Rev. Sci. Instrum., 72, 4207, 2001). We report results obtained from a test run performed under pressure with monochromatic synchrotron radiation. A sapphire sphere (1.0 mm dia.) was embedded in a powdered mixture of Fe and 9 wt.% S alloy. The diameter of the sample chamber was 2 mm. Under pressure, the entire Drickamer cell was rotated to collect radiographs of the sample at various angles from 0 to 179.5° in 0.5° step size. Computational reconstruction of these projections provided three dimensional (3D) distribution of linear attenuation coefficient of the sample with a spatial resolution of 6 microns. The shape change in the sapphire sphere during compression was clearly observed. Using the program Blob3d, reconstructed 3D images of the sphere were separated from the surrounding Fe-S alloy. Volumes of the sphere were then accurately determined from the extracted images, by carefully defining the image intensity threshold. The errors in the volume measurement are about 0.3 to 0.7%, mostly due to shadowing by anvil deformation. The results, although performed using a solid sample, demonstrate the potential of measuring melt volume. Previous density measurements using X-ray radiography with only one dimensional data assumed that the shape of the sample remained unchanged throughout the experiment. In our new technique, this assumption is no longer required and density of melts can be inferred directly from the sample volume even when the molten sample is distorted. Other applications of this apparatus will be also discussed.

Versatile in situ gas analysis apparatus for nanomaterials reactors.

PubMed

Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

2014-09-02

We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

Qualitative evaluation of maternal milk and commercial infant formulas via LIBS.

PubMed

Abdel-Salam, Z; Al Sharnoubi, J; Harith, M A

2013-10-15

This study focuses on the use of laser-induced breakdown spectroscopy (LIBS) for the evaluation of the nutrients in maternal milk and some commercially available infant formulas. The results of such evaluation are vital for adequate and healthy feeding for babies during lactation period. Laser-induced breakdown spectroscopy offers special advantages in comparison to the other conventional analytical techniques. Specifically, LIBS is a straightforward technique that can be used in situ to provide qualitative analytical information in few minutes for the samples under investigation without preparation processes. The samples studied in the current work were maternal milk samples collected during the first 3 months of lactation (not colostrum milk) and samples from six different types of commercially available infant formulas. The samples' elemental composition has been compared with respect to the relative abundance of the elements of nutrition importance, namely Mg, Ca, Na, and Fe using their spectral emission lines in the relevant LIBS spectra. In addition, CN and C2 molecular emission bands in the same spectra have been studied as indicators of proteins content in the samples. The obtained analytical results demonstrate the higher elemental contents of the maternal milk compared with the commercial formulas samples. Similar results have been obtained as for the proteins content. It has been also shown that calcium and proteins have similar relative concentration trends in the studied samples. This work demonstrates the feasibility of adopting LIBS as a fast, safe, less costly technique evaluating qualitatively the nutrients content of both maternal and commercial milk samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and Testing of Dispersion-Strengthened Tungsten Alloys via Spark Plasma Sinterin

NASA Astrophysics Data System (ADS)

Lang, Eric; Madden, Nathan; Smith, Charles; Krogstad, Jessica; Allain, Jean Paul

2017-10-01

Tungsten (W) is a common plasma-facing component (PFC) material in the divertor region of tokamak fusion devices due to its high melting point and high sputter threshold. However, W is intrinsically brittle and is further embrittled under neutron irradiation, and the low recrystallization temperature pose complications in fusion environments. More ductile W alloys, such as dispersion-strengthened tungsten are being developed. In this work, W samples are processed via spark plasma sintering (SPS) with TiC, ZrC, and TaC dispersoids alloyed from 0.5 to 10 weight %. SPS is a powder compaction technique that provides high pressure and heating rates via electrical current, allowing for a lower final temperature and hold time for compaction. Initial testing of material properties, smicrostructure, and composition of specimens will be presented. Deuterium and helium irradiations have been performed in IGNIS, a multi-functional, in-situ irradiation and characterization facility at the University of Illinois. High-flux, low-energy exposures at the Magnum-PSI facility at DIFFER exposed samples to a D fluence of 1×1026 cm-2 and He fluence of 1x1025-1x1026 cm-2 at temperatures of 300-1000 C. In-situ chemistry changes via XPS and ex-situ morphology changes via SEM will be studied. Work supported by US DOE Contract DE-SC0014267.

Beam-folding ultraviolet-visible Fourier transform spectrometry and underwater cytometry for in situ measurement of marine phytoplankton

NASA Astrophysics Data System (ADS)

Wang, Xuzhu

The system complexity and hence high cost needed for generating the high-resolution and precise position-sampling triggers over very long distances is one of main hindrances to the popularization of the UV-visible Fourier transform spectrometer (FTS). In part one of this thesis, the specially designed beam-folding and improved beam-folding methods to optically subdivide the laser fringes are presented. The Near-UV to Near-infrared FTSs based on 4-fold beam-folding systems were developed. The experimental results have demonstrated that these techniques are promising methods to produce the high-resolution and high-precision sampling triggers of scanning mechanism of UV-visible FTSs without the need for complicated optics, sophisticated detector electronics and high-stability motion control systems. The FTS based on the beam-folding technique can reach a spectral resolution of ˜4 cm-1 (0.1nm) in the visible wavelengths; The FTS based on the improved beam-folding technique can achieve a spectral resolution of ˜0.28 cm-1 (0.01nm) in the visible wavelengths. In the improved beam-folding FTS, The adoption of retroreflectors and the symmetrical arrangement of two back-to back interferometers produced much higher performance than that of the beam-folding FTS employing prism mirrors. The replacement of prism mirrors by retroreflectors and the symmetrical optical arrangement maintain the FTS in perfect optical alignment during scanning process by keeping all beams parallel with the incident beams. The vertex of the movable retroreflector in the measurement interferometer is arranged very close to the midpoint of the vertices of the movable retroreflectors in the tracking interferometer so that the optical symmetrical axes for both interferometers always keep in line with each other. That is, the change of the OPD of the tracking interferometer always remains synchronous to that of the OPD of the measurement interferometer even for any moving misalignments, making the FTS itself insensitive to these fluctuations. In addition, an attempt on fast-scanning visible IFTS based on the improved beam-folding technique was done. Preliminary experimental results demonstrated the feasibility of the fast-scanning visible IFTS based on the improved beam-folding technique. In part two, an underwater cytometer for in situ measurement of marine phytoplankton using a combining technique of laser-induced fluorescence (LIF) and laser differential Doppler velocimetry (LDDV) was developed. The advancement compared to the previous work done in the laboratory is to realize an in situ underwater measurement system by means of improving the optical design. The experimental results in June and August 2004 in the coastal area of Hong Kong demonstrated that the new cytometer can be used for in situ measurement of marine phytoplankton. The mean concentration detected by this instrument agreed closely with the experimental data measured by the traditional cell counting under a microscope. With an underwater optical sensing unit that does not rely on an electrical power source, the sensing unit can stay submerged underwater for long periods, making a long-term real-time monitoring system possible.

Advances in Raman spectroscopy for In Situ Identification of Minerals and Organics on Diverse Planetary Surfaces: from Mars to Titan

NASA Astrophysics Data System (ADS)

Blacksberg, J.; Alerstam, E.; Maruyama, Y.; Cochrane, C.; Rossman, G. R.

2015-12-01

We present recent developments in time-resolved Raman spectroscopy for in situ planetary surface exploration, aimed at identification of both minerals and organics. Raman is a non-destructive surface technique that requires no sample preparation. Raman spectra are highly material specific and can be used for identification of a wide range of unknown samples. In combination with micro-scale imaging and point mapping, Raman spectroscopy can be used to directly interrogate rocks and regolith materials, while placing compositional analyses within a microtextural context, essential for understanding surface evolutionary pathways. Due to these unique capabilities, Raman spectroscopy is of great interest for the exploration of all rocky and icy bodies, for example Mars, Venus, the Moon, Mars' moons, asteroids, comets, Europa, and Titan. In this work, we focus on overcoming one of the most difficult challenges faced in Raman spectroscopy: interference from background fluorescence of the very minerals and organics that we wish to characterize. To tackle this problem we use time-resolved Raman spectroscopy, which separates the Raman from background processes in the time domain. This same technique also enables operation in daylight without the need for light shielding. Two key components are essential for the success of this technique: a fast solid-state detector and a short-pulse laser. Our detector is a custom developed Single Photon Avalanche Diode (SPAD) array, capable of sub-ns time-gating. Our pulsed lasers are solid-state miniature pulsed microchip lasers. We discuss optimization of laser and detector parameters for our application. We then present Raman spectra of particularly challenging planetary analog samples to demonstrate the unique capabilities of this time-resolved Raman instrument, for example, Mars-analog clays and Titan-analog organics. The research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

Comparison of Niskin vs. in situ approaches for analysis of gene expression in deep Mediterranean Sea water samples

NASA Astrophysics Data System (ADS)

Edgcomb, V. P.; Taylor, C.; Pachiadaki, M. G.; Honjo, S.; Engstrom, I.; Yakimov, M.

2016-07-01

Obtaining an accurate picture of microbial processes occurring in situ is essential for our understanding of marine biogeochemical cycles of global importance. Water samples are typically collected at depth and returned to the sea surface for processing and downstream experiments. Metatranscriptome analysis is one powerful approach for investigating metabolic activities of microorganisms in their habitat and which can be informative for determining responses of microbiota to disturbances such as the Deepwater Horizon oil spill. For studies of microbial processes occurring in the deep sea, however, sample handling, pressure, and other changes during sample recovery can subject microorganisms to physiological changes that alter the expression profile of labile messenger RNA. Here we report a comparison of gene expression profiles for whole microbial communities in a bathypelagic water column sample collected in the Eastern Mediterranean Sea using Niskin bottle sample collection and a new water column sampler for studies of marine microbial ecology, the Microbial Sampler - In Situ Incubation Device (MS-SID). For some taxa, gene expression profiles from samples collected and preserved in situ were significantly different from potentially more stressful Niskin sampling and preservation on deck. Some categories of transcribed genes also appear to be affected by sample handling more than others. This suggests that for future studies of marine microbial ecology, particularly targeting deep sea samples, an in situ sample collection and preservation approach should be considered.

Passive PE Sampling in Support of In Situ Remediation of Contaminated Sediments: Standard Operating Procedure for PE Analysis

DTIC Science & Technology

2012-12-01

4.5 Food-grade aluminum foil 4.6 Stainless steel forceps 4.7 Single-edge razor blades 4.8 Teflon (or similar non-contaminating material) cutting...handling PE to avoid cross-contaminating the PE. 6.3 Methylene chloride (pesticide grade) rinsed, stainless steel forceps and scissors are used...3.1 PE is susceptible to contamination from atmospheric and surfaces, and so it must be handled using clean techniques. 3.2 While the formation of

Apparatus and method for quantitative determination of materials contained in fluids

DOEpatents

Radziemski, Leon J.; Cremers, David A.

1985-01-01

Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is demonstrated. Significant shortening of analysis time is achieved from those of the usual chemical techniques of analysis.

Apparatus and method for quantitative determination of materials contained in fluids

DOEpatents

Radziemski, L.J.; Cremers, D.A.

1982-09-07

Apparatus and method for near real-time in-situ monitoring of particulates and vapors contained in fluids are described. Initial filtration of a known volume of the fluid sample is combined with laser-induced dielectric breakdown spectroscopy of the filter employed to obtain qualitative and quantitative information with high sensitivity. Application of the invention to monitoring of beryllium, beryllium oxide, or other beryllium-alloy dusts is shown. Significant shortening of analysis time is achieved from the usual chemical techniques of analysis.

Image analysis for TSH mRNA in situ hybridization in pituitary glands from rats with thyroid follicular cell hypertrophy after treatment with three different test compounds.

PubMed

Funk, Juergen; Ebeling, Martin; Singer, Thomas; Landes, Christian

2017-10-01

The goal of this in situ hybridization and image analysis technique is to study the effects of new pharmacological/chemical entities on the thyroid and pituitary gland in rats, reveal the pathogenesis of thyroid follicular cell hypertrophy and to retrospectively exclude the risk of thyroid tumor development in humans. In the present study, we describe the increase of thyroid-stimulating hormone- (TSH-) beta subunit mRNA in the pars distalis of the pituitary gland and the quantitative measurement of TSH mRNA positive cells from rats of three 4-week toxicity studies treated with three different test compounds inducing thyroid follicular cell and hepatocellular hypertrophy in rats. Compared to immunohistochemistry (IHC), in situ hybridization (ISH) for TSH was found to be more sensitive. With this technique we are able to exclude a direct effect of the test compound on the thyroid gland by showing the activation of thyrotrope cells from the pituitary gland and therefore this technique retrospectively enables us to exclude a possible risk for humans at an early stage of drug development. Also in case blood serum samples for evaluation of TSH are not available anymore or hepatocellular hypertrophy is not present (close metabolic relationship between thyroid gland and liver in rodents), the described method allows retrospective investigations on thyroid follicular cell hypertrophy or hyperplasia. This can be of high relevance in human safety assessment for certain drugs in order to exclude a primary effect on the thyroid gland especially when it comes to thyroid neoplasia in rodents as previously described. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ hybridisation of EBV DNA-DNA hybrids using wet heat in polypropylene containers.

PubMed Central

Labrecque, L G

1992-01-01

AIMS: To explore procedures designed to optimise DNA-DNA in situ hybridisation, using cells infected with Epstein-Barr virus (EBV) and tissues and subfragments of the EBV DNA as probes. METHODS: The denaturation step occurred in a polypropylene container, using wet heat generated by a hot water container, the pressure cooker, or the microwave oven, without coverslips, reaching a temperature of 121 degrees C or more in these two last systems. Two different visualisation systems were used. RESULTS: Fixed cells and tumours harbouring a high and medium to low copy number (a few hundreds to 33 copies per cell), were clearly labelled, using a simple reiterated subfragment (BamW) of the EBV DNA, and fresh frozen cells, harbouring a very low copy number (one to two on average) labelled using BamW as well as BamH (single non-reiterated 6 kilobase subfragment). CONCLUSION: This is a valuable alternative technique for DNA-DNA ISH that can be used in fresh frozen samples as well as fixed samples. Images PMID:1336018

In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

DOE PAGES

Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J.; ...

2015-12-04

In the epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO 3/SrTiO 3 superlattices on SrTiO 3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effectsmore » of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO 3 substrates and 20 nm SrRuO 3 thin films on SrTiO 3 substrates. Our experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.« less

A novel headspace gas chromatographic method for in situ monitoring of monomer conversion during polymerization in an emulsion environment.

PubMed

Chai, Xin-Sheng; Zhong, Jin-Feng; Hu, Hui-Chao

2012-05-18

This paper describes a novel multiple-headspace extraction/gas chromatographic (MHE-GC) technique for monitoring monomer conversion during a polymerization reaction in a water-based emulsion environment. The polymerization reaction of methyl methacrylate (MMA) in an aqueous emulsion is used as an example. The reaction was performed in a closed headspace sample vial (as a mini-reactor), with pentane as a tracer. In situ monitoring of the vapor concentration of the tracer, employing a multiple headspace extraction (sampling) scheme, coupled to a GC, makes it possible to quantitatively follow the conversion of MMA during the early stages of polymerization. Data on the integrated amount of the tracer vapor released from the monomer droplet phase during the polymerization is described by a mathematic equation from which the monomer conversion can be calculated. The present method is simple, automated and economical, and provides an efficient tool in the investigation of the reaction kinetics and effects of the reaction conditions on the early stage of polymerization. Copyright © 2012 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2011-01-01

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

Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

NASA Astrophysics Data System (ADS)

Ebrahimpour, Omid

In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the second part of the project. Alumina sol was synthesized by the hydrolysis of Aluminum isopropoxide using the Yoldas method. Alumina sol was homogenous and had a needle-like shape with a thickness of 2--3 nm. Crystalline changes during the heating process of alumina sol were studied using XRD. In addition, Fourier transform infrared (FTIR) spectroscopy was performed to identify the functional groups on the alumina sol surface as a function of temperature. In the third part of the project, the feasibility of the in-situ polymerization technique was investigated to fabricate porous SiC ceramics. In this part, the mixture of SiC and calcined alumina powders were coated by polyethylene via in-situ polymerizing referred to as the polymerization compounding process in a slurry phase. The polymerization was conducted under very moderate operational conditions using the Ziegler-Natta catalyst system. Differential scanning calorimetry (DSC) and TGA analysis and morphological studies (SEM and TEM) revealed the presence of a high density of polyethylene on the surface of SiC and alumina powders. The amount of polymer was controlled by the polymerization reaction time. Most parts of particles were coated by a thin layer of polyethylene and polymer. The porous SiC ceramics, which were fabricated by these treated particles showed higher mechanical and physical properties compared to the samples made without any treatment. The relative intensity of mullite was higher compared to the samples prepared by the traditional process. The effects of the sintering temperature, forming pressure and polymer content were also studied on the physical and mechanical properties of the final product. In the last phase of this research work, the focus of the investigation was to take advantage of both the sol-gel processing and in-situ polymerization method to develop a new process to manufacture mullite-bonded porous SiC ceramic with enhanced mechanical and physical properties. Therefore, first the SiC particles and alumina nano powders were mixed in alumina sol to adjust the alumina weight to 35 wt%. Then, the desired amount of catalyst, which depends on the total surface area of the particles, was grafted onto the surface of the powders under an inert atmosphere. Consequently, the polymerization started from the surface of the substrate. The treated powders were characterized by SEM, XPS and TGA. In addition, the amount of pore-former was determined by TGA analysis. Porous SiC ceramics, which were fabricated by the novel process, consist of mullite, SiC, cristobalite and a small amount of alumina and TiO 2 as a result of reaction of TiCl4 with air. Furthermore, the effect of the sintering temperatures (1500°C, 1550°C and 1600°C) on the crystalline structure of the porous samples was investigated. Furthermore, it was proposed that converting TiCl4 to TiO2 acted as the sintering additive to form mullite at a lower sintering temperature. (Abstract shortened by UMI.).

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

NASA Astrophysics Data System (ADS)

Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

2015-06-01

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques.

PubMed

Baier, S; Rochet, A; Hofmann, G; Kraut, M; Grunwaldt, J-D

2015-06-01

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

In Situ Detection of Anaplasma spp. by DNA Target-Primed Rolling-Circle Amplification of a Padlock Probe and Intracellular Colocalization with Immunofluorescently Labeled Host Cell von Willebrand Factor ▿

PubMed Central

Wamsley, Heather L.; Barbet, Anthony F.

2008-01-01

Endothelial cell culture and preliminary immunofluorescent staining of Anaplasma-infected tissues suggest that endothelial cells may be an in vivo nidus of mammalian infection. To investigate endothelial cells and other potentially cryptic sites of Anaplasma sp. infection in mammalian tissues, a sensitive and specific isothermal in situ technique to detect localized Anaplasma gene sequences by using rolling-circle amplification of circularizable, linear, oligonucleotide probes (padlock probes) was developed. Cytospin preparations of uninfected or Anaplasma-infected cell cultures were examined using this technique. Via fluorescence microscopy, the technique described here, and a combination of differential interference contrast microscopy and von Willebrand factor immunofluorescence, Anaplasma phagocytophilum and Anaplasma marginale were successfully localized in situ within intact cultured mammalian cells. This work represents the first application of this in situ method for the detection of a microorganism and forms the foundation for future applications of this technique to detect, localize, and analyze Anaplasma nucleotide sequences in the tissues of infected mammalian and arthropod hosts and in cell cultures. PMID:18495855

Bulk Heterojunction Solar Cell with Nitrogen-Doped Carbon Nanotubes in the Active Layer: Effect of Nanocomposite Synthesis Technique on Photovoltaic Properties

PubMed Central

Keru, Godfrey; Ndungu, Patrick G.; Mola, Genene T.; Nyamori, Vincent O.

2015-01-01

Nanocomposites of poly(3-hexylthiophene) (P3HT) and nitrogen-doped carbon nanotubes (N-CNTs) have been synthesized by two methods; specifically, direct solution mixing and in situ polymerization. The nanocomposites were characterized by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray dispersive spectroscopy, UV-Vis spectrophotometry, photoluminescence spectrophotometry (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis, and dispersive surface energy analysis. The nanocomposites were used in the active layer of a bulk heterojunction organic solar cell with the composition ITO/PEDOT:PSS/P3HT:N-CNTS:PCBM/LiF/Al. TEM and SEM analysis showed that the polymer successfully wrapped the N-CNTs. FTIR results indicated good π-π interaction within the nanocomposite synthesized by in situ polymerization as opposed to samples made by direct solution mixing. Dispersive surface energies of the N-CNTs and nanocomposites supported the fact that polymer covered the N-CNTs well. J-V analysis show that good devices were formed from the two nanocomposites, however, the in situ polymerization nanocomposite showed better photovoltaic characteristics.

On the use of SEM correlative tools for in situ mechanical tests.

PubMed

Shi, Qiwei; Roux, Stéphane; Latourte, Félix; Hild, François; Loisnard, Dominique; Brynaert, Nicolas

2018-01-01

In situ SEM mechanical tests are key to study crystal plasticity. In particular, imaging and diffraction (EBSD) allow microstructure and surface kinematics to be monitored all along the test. However, to get a full benefit from different modalities, it is necessary to register all images and crystallographic orientation maps from EBSD into the same frame. Different correlative approaches tracking either Pt surface markings, crystal orientations or grain boundaries, allow such registrations to be performed and displacement as well as rotation fields to be measured, a primary information for crystal plasticity identification. However, the different contrasts that are captured in different modalities and unavoidable stage motions also give rise to artifacts that are to be corrected to register the different information onto the same material points. The same image correlation tools reveal very powerful to correct such artifacts. Illustrated by an in situ uniaxial tensile test performed on a bainitic-ferritic steel sample, recent advances in image correlation techniques are reviewed and shown to provide a comprehensive picture of local strain and rotation maps. Copyright © 2017 Elsevier B.V. All rights reserved.

In situ ionic liquid dispersive liquid-liquid microextraction and direct microvial insert thermal desorption for gas chromatographic determination of bisphenol compounds.

PubMed

Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel

2016-01-01

A new procedure based on direct insert microvial thermal desorption injection allows the direct analysis of ionic liquid extracts by gas chromatography and mass spectrometry (GC-MS). For this purpose, an in situ ionic liquid dispersive liquid-liquid microextraction (in situ IL DLLME) has been developed for the quantification of bisphenol A (BPA), bisphenol Z (BPZ) and bisphenol F (BPF). Different parameters affecting the extraction efficiency of the microextraction technique and the thermal desorption step were studied. The optimized procedure, determining the analytes as acetyl derivatives, provided detection limits of 26, 18 and 19 ng L(-1) for BPA, BPZ and BPF, respectively. The release of the three analytes from plastic containers was monitored using this newly developed analytical method. Analysis of the migration test solutions for 15 different plastic containers in daily use identified the presence of the analytes at concentrations ranging between 0.07 and 37 μg L(-1) in six of the samples studied, BPA being the most commonly found and at higher concentrations than the other analytes.

Effect of in-situ disturbance within the soil mass on the stress-strain behaviour of silty soil

NASA Astrophysics Data System (ADS)

Noor, Sarah T.; Rabika Rahman, SS; Nahar, Sabiqun

2018-04-01

To date, different techniques have been evolved to collect soil in undisturbed condition so that the in-situ soil behaviour can be determined by carrying out laboratory tests. For the same reason, the execution of undisturbed soil sampling in practice is given a lot of efforts. However, this study brings the fact into consideration that the in-situ soil condition may not remain constant, rather it might vary time to time, because of different internal or external reasons. For example, the internal stress state of soil layers, existing below or above the swelling soil layer, become modified during shrinking and swelling resulting from drying and wetting of swelling clay, respectively. Further, foundations of building may transfer cyclic loads (generated by vibration installed in the building) to the soil below the foundation. Therefore, this study investigates the effects of stress-strain behaviour due to the disturbances on the shear strength of the soil with respect to that of undisturbed specimens. The shear strength of disturbed soil shows deviation from that of undisturbed specimen depending on the different parameters defining the severity of disturbance.

Search for Organic Matter on Mars: Complementarity of In Situ Analyses and Laboratory Analyses of Martian Samples

NASA Astrophysics Data System (ADS)

Brack, A.; Commeyras, A.; Derenne, S.; Despois, D.; Dhamelincourt, P.; Dobrijevic, M.; Engrand, C.; Geffard, M.; Grenier-Loustalot, M. F.; Largeau, C.

2000-07-01

On Earth, the molecules which participated in the emergence of life about 4 Ga ago have been erased by plate tectonics, the permanent presence of running water, unshielded solar ultraviolet radiation and by oxygen produced by life. Since the environment of the early Mars about 3.5-4 Ga ago was probably very close to that of the early Earth, life might have emerged on Mars as well and might give us some insight into the prebiotic chemistry that took place on Earth about 4 Ga ago. Furthermore, there is a possibility that life still exists on Mars, protected from the harsh environment in some specific locales. In order to search for life on Mars, one should look for potential biogenic markers such as organic matter and inorganic signatures (microfossils, biominerals, biogenic etching, isotopic fingerprints...) which have different degrees of resistance to the Martian environment. As biomarkers could be organic or inorganic in nature, complete organic and mineral analyses should therefore be conducted in parallel on the same sets of samples, going from the least destructive to the most destructive technique of micro-analysis. Furthermore, in situ analyses should be complemented by high precision and high sensitivity laboratory measurements of returned Martian samples. Due to the very oxidized Martian environment, organic molecules should be searched for in protected sites, either surface boulders or near sub-surface, in layers deep enough for avoiding the oxidizing effect of the atmosphere. Molecules that should be looked for include low and high molecular weight organics (like alkanoic acids, peroxiacids, PAHs and amino acids, respectively), and macromolecular com-pounds like kerogens or kerogen-like materials. Previous in situ analyses were performed using pyrolysis systems which allow to detect organic compounds but do not always permit the identification of individual molecules. New possible analytical solutions could include gas chromatography-based techniques coupled with a mass spectrometer using multi GC columns systems, including columns able to separate enantiomers, chemical derivatization cells (using new derivatization schemes in particular for amino acid analysis), high performance liquid chromatography and supercritical fluid chromatography.

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

40 CFR 63.1013 - Sampling connection systems standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the requirements of... than the compliance dates specified in the referencing subpart. (b) Equipment requirement. Each...

Preliminary 3D In-situ measurements of the texture evolution of strained H2O ice during annealing using neutron Laue diffractometry

NASA Astrophysics Data System (ADS)

Journaux, Baptiste; Montagnat, Maurine; Chauve, Thomas; Ouladdiaf, Bachir; Allibon, John

2015-04-01

Dynamic recrystallization (DRX) strongly affects the evolution of microstructure (grain size and shape) and texture (crystal preferred orientation) in materials during deformation at high temperature. Since texturing leads to anisotropic physical properties, predicting the effect of DRX is essential for industrial applications, for interpreting geophysical data and modeling geodynamic flows, and predicting ice sheet flow and climate evolution. A large amount of literature is available related to metallurgy, geology or glaciology, but there remains overall fundamental questions about the relationship between nucleation, grain boundary migration and texture development at the microscopic scale. Previous measurements of DRX in ice were either conducted using 2D ex-situ techniques such as AITA [1,2] or Electron Backscattering Diffraction (EBSD) [3], or using 3D statistical ex-situ [4] or in-situ [5] techniques. Nevertheless, all these techniques failed to observe at the scale of nucleation processes during DRX in full 3D. Here we present a new approach using neutron Laue diffraction, which enable to perform 3D measurements of in-situ texture evolution of strained polycrystalline H2O ice (>2% at 266 K) during annealing at the microscopic scale. Thanks the CYCLOPS instrument [6] (Institut Laue Langevin Grenoble, France) and the intrinsic low background of this setup, preliminary observations enabled us to follow, in H2O ice, the evolution of serrated grain boundaries, and kink-band during annealing. Our observations show a significant evolution of the texture and internal misorientation over the course of few hours at an annealing temperature of 268.5 K. In the contrary, ice kink-band structures seem to be very stable over time at near melting temperatures. The same samples have been analyzed ex-situ using EBSD for comparison. These results represent a first step toward in-situ microscopic measurements of dynamic recrystallization processes in ice during strain. This experiment has been conducted in the frame of the ANR-funded DREAM project that focuses on the recrystallization processes in anisotropic materials. References [1] D. S. Russell-Head and C.J.L. Wilson., 2001, Journal of Glaciology, 24, 117-130. [2] Wilson, C.J.L., Peternell, M., Piazolo, S., Luzin, V., 2014, Journal of Structural Geology, Microdynamics of Ice, 61, 50-77. [3] M. Montagnat, T. Chauve, F. Barou, A. Tommasi, B. Beausir, C. Fressengeas., in prep. [4] T. H. Jacka and J. Li., 2000, In T. Hondoh, editor, Physics of Ice Core Records, pages 83-102. Hokkaido University Press, Sapporo. [5] S. Piazolo, C. J. L. Wilson, V. Luzin, C. Brouzet, and M. Peternell., 2013, Geochemistry, Geophysics, Geosystems, 14, 4185-4194. [6] B. Ouladdiaf et al., 2011, Journal of Applied Crystallography, 44, 392-397.

Comparison of conventional culture method and fluorescent in situ hybridization technique for detection of Listeria spp. in ground beef, turkey, and chicken breast fillets in İzmir, Turkey.

PubMed

Baysal, Ayse Handan

2014-12-01

The occurrence of Listeria species in refrigerated fresh chicken breast fillet, turkey breast fillet, and ground beef was evaluated, comparing the conventional culture method and fluorescent in situ hybridization (FISH). FISH uses hybridization of a nucleic acid sequence target of a microorganism with a specific DNA probe labeled with a fluorochrome and imaging by a fluorescence microscope. First, Listeria was inoculated in chicken breast fillet, turkey breast fillet, or ground beef, and the applicability of the FISH method was evaluated. Second, Listeria was detected in fresh chicken breast fillet, turkey breast fillet, and ground beef by culture and FISH methods. Listeria was isolated from 27 (37.4%) of 216 samples by the standard culture method, whereas FISH detected 25 (24.7%) preenriched samples. Of these isolates, 17 (63%) were L. innocua, 6 (22%) L. welshimeri, and 4 (14.8%) L. seeligeri. Overall, the prevalences of Listeria spp. found with the conventional culture method in chicken breast fillet, turkey breast fillet, and ground beef were 9.7, 6.9, and 20.8%, whereas with the FISH technique these values were 11.1, 6.9, and 16.7%, respectively. The molecular FISH technique appears to be a cheap, sensitive, and time-efficient procedure that could be used for routine detection of Listeria spp. in meat. This study showed that retail raw meats are potentially contaminated with Listeria spp. and are, thus, vehicles for transmitting diseases caused by foodborne pathogens, underlining the need for increased precautions, such as implementation of hazard analysis and critical control points and consumer food safety education.

Fluorescence in situ hybridization (CARD-FISH) of microorganisms in hydrocarbon contaminated aquifer sediment samples.

PubMed

Tischer, Karolin; Zeder, Michael; Klug, Rebecca; Pernthaler, Jakob; Schattenhofer, Martha; Harms, Hauke; Wendeberg, Annelie

2012-12-01

Groundwater ecosystems are the most important sources of drinking water worldwide but they are threatened by contamination and overexploitation. Petroleum spills account for the most common source of contamination and the high carbon load results in anoxia and steep geochemical gradients. Microbes play a major role in the transformation of petroleum hydrocarbons into less toxic substances. To investigate microbial populations at the single cell level, fluorescence in situ hybridization (FISH) is now a well-established technique. Recently, however, catalyzed reporter deposition (CARD)-FISH has been introduced for the detection of microbes from oligotrophic environments. Nevertheless, petroleum contaminated aquifers present a worst case scenario for FISH techniques due to the combination of high background fluorescence of hydrocarbons and the presence of small microbial cells caused by the low turnover rates characteristic of groundwater ecosystems. It is therefore not surprising that studies of microorganisms from such sites are mostly based on cultivation techniques, fingerprinting, and amplicon sequencing. However, to reveal the population dynamics and interspecies relationships of the key participants of contaminant degradation, FISH is an indispensable tool. In this study, a protocol for FISH was developed in combination with cell quantification using an automated counting microscope. The protocol includes the separation and purification of microbial cells from sediment particles, cell permeabilization and, finally, CARD-FISH in a microwave oven. As a proof of principle, the distribution of Archaea and Bacteria was shown in 60 sediment samples taken across the contaminant plume of an aquifer (Leuna, Germany), which has been heavily contaminated with several ten-thousand tonnes of petroleum hydrocarbons since World War II. Copyright © 2012 Elsevier GmbH. All rights reserved.

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

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

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I 3TEM) offers the unique ability to observe microstructural changes duemore » to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. As a result, this work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO 2.« less

In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

DOE PAGES

Taylor, Caitlin Anne; Bufford, Daniel Charles; Muntifering, Brittany Rana; ...

2017-09-29

Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I 3TEM) offers the unique ability to observe microstructural changes duemore » to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. As a result, this work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO 2.« less

X-ray elemental mapping techniques for elucidating the ecophysiology of hyperaccumulator plants.

PubMed

van der Ent, Antony; Przybyłowicz, Wojciech J; de Jonge, Martin D; Harris, Hugh H; Ryan, Chris G; Tylko, Grzegorz; Paterson, David J; Barnabas, Alban D; Kopittke, Peter M; Mesjasz-Przybyłowicz, Jolanta

2018-04-01

Contents Summary 432 I. Introduction 433 II. Preparation of plant samples for X-ray micro-analysis 433 III. X-ray elemental mapping techniques 438 IV. X-ray data analysis 442 V. Case studies 443 VI. Conclusions 446 Acknowledgements 449 Author contributions 449 References 449 SUMMARY: Hyperaccumulators are attractive models for studying metal(loid) homeostasis, and probing the spatial distribution and coordination chemistry of metal(loid)s in their tissues is important for advancing our understanding of their ecophysiology. X-ray elemental mapping techniques are unique in providing in situ information, and with appropriate sample preparation offer results true to biological conditions of the living plant. The common platform of these techniques is a reliance on characteristic X-rays of elements present in a sample, excited either by electrons (scanning/transmission electron microscopy), protons (proton-induced X-ray emission) or X-rays (X-ray fluorescence microscopy). Elucidating the cellular and tissue-level distribution of metal(loid)s is inherently challenging and accurate X-ray analysis places strict demands on sample collection, preparation and analytical conditions, to avoid elemental redistribution, chemical modification or ultrastructural alterations. We compare the merits and limitations of the individual techniques, and focus on the optimal field of applications for inferring ecophysiological processes in hyperaccumulator plants. X-ray elemental mapping techniques can play a key role in answering questions at every level of metal(loid) homeostasis in plants, from the rhizosphere interface, to uptake pathways in the roots and shoots. Further improvements in technological capabilities offer exciting perspectives for the study of hyperaccumulator plants into the future. © 2017 University of Queensland. New Phytologist © 2017 New Phytologist Trust.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses.

PubMed

Miglierini, Marcel B; Procházka, Vít; Vrba, Vlastimil; Švec, Peter; Janičkovič, Dušan; Matúš, Peter

2018-06-07

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57 Fe isotope, namely Mössbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. Mössbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

In Situ Analysis of DNA Methylation in Plants.

PubMed

Kathiria, Palak; Kovalchuk, Igor

2017-01-01

Epigenetic regulation in the plant genome is associated with the determination of expression patterns of various genes. Methylation of DNA at cytosine residues is one of the mechanisms of epigenetic regulation and has been a subject of various studies. Various techniques have been developed to analyze DNA methylation, most of which involve isolation of chromatin from cells and further in vitro studies. Limited techniques are available for in situ study of DNA methylation in plants. Here, we present such an in situ method for DNA methylation analysis which has high sensitivity and good reproducibility.

Use of the semipermeable membrane device (SPMD) to sample polycyclic aromatic hydrocarbon pollution in a lotic system

USGS Publications Warehouse

Lebo, Jon A.; Zajicek, James L.; Orazio, Carl E.; Petty, Jimmie D.; Huckins, James; Douglas, Ernest H.

1996-01-01

Relative concentrations of aqueous polycyclic aromatic hydrocarbons (PAH) were investigated in an urban creek. Samples were obtained at five sites within a 600-m segment of the creek that is critical habitat for an endangered species of fish. the sampling technique entailed immersion of semipermeable membrane devices (SPMDs) in the water for intervals as long as 64 d. SPMDs are passive, in situ, mtegrative samplers of bioavailable (truly dissolved) PAH and other hydrophobic organic contaminants. Two point sources of PAH to the 600-m segment of the creek were differentiated. Aqueous concentrations were found to wane dramatically over the relatively short section of the creek between the point sources. All samples were almost devoid of alkyl-substituted PAH, indicating that the ultimate sources were probably of pyrogenic nature.

Electrofracturing test system and method of determining material characteristics of electrofractured material samples

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

Bauer, Stephen J.; Glover, Steven F.; Pfeifle, Tom

A device for electrofracturing a material sample and analyzing the material sample is disclosed. The device simulates an in situ electrofracturing environment so as to obtain electrofractured material characteristics representative of field applications while allowing permeability testing of the fractured sample under in situ conditions.

40 CFR 63.1032 - Sampling connection systems standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of a closed purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the... no later than the compliance dates specified in the referencing subpart. (b) Equipment requirement...

40 CFR 63.1032 - Sampling connection systems standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of a closed purge system must be covered or closed when not being filled or emptied. (d) In-situ sampling systems. In-situ sampling systems and sampling systems without purges are exempt from the... no later than the compliance dates specified in the referencing subpart. (b) Equipment requirement...

Synthesis and characterization of structural and magnetic properties of polyaniline-cobalt ferrite (PA-CoFe) nanocomposites

NASA Astrophysics Data System (ADS)

Thakur, Sonika; Kaur, Parminder; Singh, Lakhwant

2018-05-01

The growing interest in the investigation of the properties of modified conducting polymers stems from their potential applications in various fields such as in sensing and catalytic devices. The present work reports the modification of conducting polymer polyaniline with cobalt ferrite (CoFe) nanoparticles, where CoFe nanoparticles are added in different successive weight percents. The composite samples were synthesized by in-situ chemical oxidative polymerization technique. The density of the samples has been found to increase with an increase in the CoFe content. Structural analysis of the synthesized sample has been done using X-ray diffraction studies. Perusal of the hysteresis curves of the prepared samples depicts that the introduction of CoFe into the polymer matrix leads to enhancement in the ferromagnetic behavior of the synthesized samples, suggesting that these nanocomposites have excellent microwave absorbing capacity.

Characterization of Thin Film Dissolution in Water with in Situ Monitoring of Film Thickness Using Reflectometry.

PubMed

Yersak, Alexander S; Lewis, Ryan J; Tran, Jenny; Lee, Yung C

2016-07-13

Reflectometry was implemented as an in situ thickness measurement technique for rapid characterization of the dissolution dynamics of thin film protective barriers in elevated water temperatures above 100 °C. Using this technique, multiple types of coatings were simultaneously evaluated in days rather than years. This technique enabled the uninterrupted characterization of dissolution rates for different coating deposition temperatures, postdeposition annealing conditions, and locations on the coating surfaces. Atomic layer deposition (ALD) SiO2 and wet thermally grown SiO2 (wtg-SiO2) thin films were demonstrated to be dissolution-predictable barriers for the protection of metals such as copper. A ∼49% reduction in dissolution rate was achieved for ALD SiO2 films by increasing the deposition temperatures from 150 to 300 °C. ALD SiO2 deposited at 300 °C and followed by annealing in an inert N2 environment at 1065 °C resulted in a further ∼51% reduction in dissolution rate compared with the nonannealed sample. ALD SiO2 dissolution rates were thus lowered to values of wtg-SiO2 in water by the combination of increasing the deposition temperature and postdeposition annealing. Thin metal films, such as copper, without a SiO2 barrier corroded at an expected ∼1-2 nm/day rate when immersed in room temperature water. This measurement technique can be applied to any optically transparent coating.

Ground Water Sample Preservation at In-Situ Chemical Oxidation Sites – Recommended Guidelines

EPA Pesticide Factsheets

This issue paper describes the recommended processes for sampling at in Situ Chemical Oxidation sites. Care must be taken because the oxidizing chemicals used for the remediation process can create an erroneously low sampling result.

Adaptation of the rumen microbial population to native potato starch degradation determined with the gas production technique and the nylon bag technique.

PubMed

Cone, J W; van Gelder, A H

2006-12-01

Experiments were conducted to investigate the influence of the adaptation of rumen micro-organisms on the degradation of native potato starch (PS) in the rumen. Cows were fed with rations used for gas production (GP) analysis (dry cows, 1.6% starch) and for the nylon bag (NB) technique (lactating cows, 23% starch, mainly maize starch) and a ration containing 19% native PS (lactating cows). Fermentation characteristics of 13 samples were investigated with the GP technique using rumen fluid from cows fed each of the three rations. The same samples were investigated with the NB technique in the cows obtaining the NB ration and the PS ration. The results showed that the rate of GP was influenced by the source of the rumen fluid. The fermentation rate of PS was considerably enhanced by using rumen fluid adapted to the fermentation of native PS instead of using the other rumen fluids. Incubating in cows fed the PS ration, the rate of PS degradation determined with the NB technique, was higher compared with cows fed other rations. Using the PS ration the observed lag period for PS was shorter. The results show a clear influence of ration on the degradation characteristics of starch, determined with both the GP technique and the NB technique. However, these changes in behaviour did not explain observed differences in amounts of rumen escape PS measured in vivo in animal experiments and in situ, using the NB technique.

X-Ray Diffraction for In-Situ Mineralogical Analysis of Planetesimals.

NASA Astrophysics Data System (ADS)

Sarrazin, P.; Blake, D. F.; Dera, P.; Downs, R. T.; Taylor, J.

2017-12-01

X-ray diffraction (XRD) is a general purpose technique for definitive, quantitative mineralogical analysis. When combined with XRF data for sample chemistry, XRD analyses yield as complete a characterization as is possible by any spacecraft-capable techniques. The MSL CheMin instrument, the first XRD instrument flown in space, has been used to establish the quantitative mineralogy of the Mars global soil, to discover the first habitable environment on another planet, and to provide the first in-situ evidence of silicic volcanism on Mars. CheMin is now used to characterize the depositional and diagenetic environments associated with the mudstone sediments of lower strata of Mt. Sharp. Conventional powder XRD requires samples comprised of small grains presented in random orientations. In CheMin, sample cells are vibrated to cause loose powder to flow within the cell, driven by granular convection, which relaxes the requirement for fine grained samples. Nevertheless, CheMin still requires mechanisms to collect, crush, sieve and deliver samples before analysis. XTRA (Extraterrestrial Regolith Analyzer) is an evolution of CheMin intended to analyze fines in as-delivered surface regolith, without sample preparation. Fine-grained regolith coats the surfaces of most airless bodies in the solar system, and because this fraction is typically comminuted from the rocky regolith, it can often be used as a proxy for the surface as a whole. HXRD (Hybrid-XRD) is concept under development to analyze rocks or soils without sample preparation. Like in CheMin, the diffracted signal is collected with direct illumination CCD's. If the material is sufficiently fine-grained, a powder XRD pattern of the characteristic X-ray tube emission is obtained, similar to CheMin or XTRA. With coarse grained crystals, the white bremsstrahlung radiation of the tube is diffracted into Laue patterns. Unlike typical Laue applications, HXRD uses the CCD's capability to distinguish energy and analyze the "colors" of each Laue spot, which enable phase identification. The concept was demonstrated with prototypes and dedicated crystallographic software was developed for identification the minerals responsible for the Laue patterns. High TRL subsystems are under development for future deployment opportunities of these new XRD instruments.

In situ neutron scattering study of nanoscale phase evolution in PbTe-PbS thermoelectric material

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

Ren, Fei, E-mail: renfei@temple.edu, E-mail: kean@ornl.gov; Qian, Bosen; Schmidt, Robert

2016-08-22

Introducing nanostructural second phases has proved to be an effective approach to reduce the lattice thermal conductivity and thus enhances the figure of merit for many thermoelectric materials. Studies of the formation and evolution of these second phases are essential to understanding material temperature dependent behaviors, improving thermal stabilities, as well as designing new materials. In this study, powder samples of the PbTe-PbS thermoelectric material were examined using in situ neutron diffraction and small angle neutron scattering (SANS) techniques between room temperature and elevated temperature up to 663 K, to explore quantitative information on the structure, weight fraction, and size ofmore » the second phase. Neutron diffraction data showed that the as-milled powder was primarily a solid solution prior to heat treatment. During heating, a PbS second phase precipitated out of the PbTe matrix around 500 K, while re-dissolution started around 600 K. The second phase remained separated from the matrix upon cooling. Furthermore, SANS data indicated that there are two populations of nanostructures. The size of the smaller nanostructure increased from initially 5 nm to approximately 25 nm after annealing at 650 K, while the size of the larger one remained unchanged. This study demonstrated that in situ neutron techniques are effective means to obtain quantitative information on temperature-dependent nanostructural behavior of thermoelectrics and likely other high-temperature materials.« less

Detection of in situ protein-protein complexes at the Drosophila larval neuromuscular junction using proximity ligation assay.

PubMed

Wang, Simon; Yoo, SooHyun; Kim, Hae-Yoon; Wang, Mannan; Zheng, Clare; Parkhouse, Wade; Krieger, Charles; Harden, Nicholas

2015-01-20

Discs large (Dlg) is a conserved member of the membrane-associated guanylate kinase family, and serves as a major scaffolding protein at the larval neuromuscular junction (NMJ) in Drosophila. Previous studies have shown that the postsynaptic distribution of Dlg at the larval NMJ overlaps with that of Hu-li tai shao (Hts), a homologue to the mammalian adducins. In addition, Dlg and Hts are observed to form a complex with each other based on co-immunoprecipitation experiments involving whole adult fly lysates. Due to the nature of these experiments, however, it was unknown whether this complex exists specifically at the NMJ during larval development. Proximity Ligation Assay (PLA) is a recently developed technique used mostly in cell and tissue culture that can detect protein-protein interactions in situ. In this assay, samples are incubated with primary antibodies against the two proteins of interest using standard immunohistochemical procedures. The primary antibodies are then detected with a specially designed pair of oligonucleotide-conjugated secondary antibodies, termed PLA probes, which can be used to generate a signal only when the two probes have bound in close proximity to each other. Thus, proteins that are in a complex can be visualized. Here, it is demonstrated how PLA can be used to detect in situ protein-protein interactions at the Drosophila larval NMJ. The technique is performed on larval body wall muscle preparations to show that a complex between Dlg and Hts does indeed exist at the postsynaptic region of NMJs.

The external morphology of adult female Egrasilus labracis as shown using hexamethyldisilazane treated, uncoated specimens for scanning electron microscopy.

PubMed

Murray, Harry M; Hill, Stephen J; Ang, Keng P

2016-07-01

The description and application of a modified Scanning Electron Microscope preparation technique using hexamethyldisilazane for small parasitic copepods was demonstrated though a high resolution depiction of individuals of Ergasilus labracis sampled from three spined stickleback (Gasterosteus aculeatus) in Bay D'Espoir, Newfoundland during summer 2015 and from archival samples retrieved from Atlantic salmon par (Salmo salar) stored at the Atlantic reference centre, St. Andrews, New Brunswick. The specimens were very well preserved showing high quality detail of important features and verifying those previously described using light microscopy by Hogans. Additionally the technique allowed excellent in situ demonstrations of mouth parts, swimming legs, and unusual and previously undescribed features of the second antenna including prominent striations and pore-like structures found to define the claw. It is thought that this technique will become a quick and efficient tool for describing important taxonomic features of small parasitic copepods like E. labracis or other similar small aquatic organisms. Microsc. Res. Tech. 79:657-663, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Flexible cystoscopic bladder biopsies: a technique for outpatient evaluation of the lower urinary tract urothelium.

PubMed

Beaghler, M; Grasso, M

1994-11-01

Routine urothelial biopsies of the lower urinary tract are obtained using the cold cup biopsy technique. This procedure is most often performed in the surgical suite and requires rigid endoscopic access and the use of biopsy forceps and Bugbee electrodes to obtain tissue for histologic examination. A new single-step biopsy forceps has been used through the flexible cystoscope. Using a 16 F actively deflectable, flexible cystoscope and the 5.4 F Therma Jaw Hot Urologic Forceps, bladder biopsies were obtained in 27 patients for a variety of indications. This biopsy forceps allows simultaneous tissue sampling and electrocoagulation of the biopsy site, thus eliminating the need for exchange of instruments through the flexible cystoscope. Tissue samples are somewhat protected from thermal changes during coagulation through the use of a Faraday cage. Biopsies were frequently obtained in an outpatient setting, requiring only local topical anesthesia (2% lidocaine jelly). Carcinoma in situ, transitional cell carcinoma, acute and chronic inflammation, and normal bladder mucosa were differentiated histologically. Using this technique, lower urinary tract urothelial mapping can be performed safely in the office with minimal patient discomfort.

Bacterial and chemical oxidation of pyritic mine tailings at low temperatures

NASA Astrophysics Data System (ADS)

Elberling, Bo; Schippers, Axel; Sand, Wolfgang

2000-02-01

Microbial and chemical sulfide oxidation activity and oxygen consumption was investigated in the active layer of pyritic mine tailings at Nanisivik Mine, located in a permafrost area on Baffin Island in northern Canada. Samples of tailings were collected up to a depth of 60 cm in mid-August 1998 at 4 sites, for which the metabolic activity of sulfur- and iron-oxidizing leaching bacteria besides the chemical pyrite oxidation activity were measured on 39 tailings samples and 7 samples from a natural pyritic site by calorimetry. The tailings of varying age and water content were deposited under alkaline conditions. In situ oxygen uptake rates were measured at the tailings surface every third day, prior to sampling. In addition, cell counts of iron(II), sulfur, and thiosulfate oxidizing, lithotrophic bacteria and chemoorganotrophic microorganisms were determined quantitatively by the most-probable-number technique or by agar-plating. Results show consistent pyrite oxidation rates based on in situ oxygen uptake rates, and laboratory heat output measurements. Litho- and organotrophic bacteria were found in the tailings. Calorimetric measurements revealed that the present bacterial activity is responsible for approximately one third of the ongoing oxidation. Although leaching bacteria have previously been found in the Arctic, this study is the first to prove the significance of bacterial activity in the overall pollution resulting from tailings deposited in the Arctic.

Detection of Inter-chromosomal Stable Aberrations by Multiple Fluorescence In Situ Hybridization (mFISH) and Spectral Karyotyping (SKY) in Irradiated Mice

PubMed Central

Pathak, Rupak; Koturbash, Igor; Hauer-Jensen, Martin

2017-01-01

Ionizing radiation (IR) induces numerous stable and unstable chromosomal aberrations. Unstable aberrations, where chromosome morphology is substantially compromised, can easily be identified by conventional chromosome staining techniques. However, detection of stable aberrations, which involve exchange or translocation of genetic materials without considerable modification in the chromosome morphology, requires sophisticated chromosome painting techniques that rely on in situ hybridization of fluorescently labeled DNA probes, a chromosome painting technique popularly known as fluorescence in situ hybridization (FISH). FISH probes can be specific for whole chromosome/s or precise sub-region on chromosome/s. The method not only allows visualization of stable aberrations, but it can also allow detection of the chromosome/s or specific DNA sequence/s involved in a particular aberration formation. A variety of chromosome painting techniques are available in cytogenetics; here two highly sensitive methods, multiple fluorescence in situ hybridization (mFISH) and spectral karyotyping (SKY), are discussed to identify inter-chromosomal stable aberrations that form in the bone marrow cells of mice after exposure to total body irradiation. Although both techniques rely on fluorescent labeled DNA probes, the method of detection and the process of image acquisition of the fluorescent signals are different. These two techniques have been used in various research areas, such as radiation biology, cancer cytogenetics, retrospective radiation biodosimetry, clinical cytogenetics, evolutionary cytogenetics, and comparative cytogenetics. PMID:28117817

In-situ XRD vs ex-situ vacuum annealing of tantalum oxynitride thin films: Assessments on the structural evolution

NASA Astrophysics Data System (ADS)

Cunha, L.; Apreutesei, M.; Moura, C.; Alves, E.; Barradas, N. P.; Cristea, D.

2018-04-01

The purpose of this work is to discuss the main structural characteristics of a group of tantalum oxynitride (TaNxOy) thin films, with different compositions, prepared by magnetron sputtering, and to interpret and compare the structural changes, by X-ray diffraction (XRD), when the samples are vacuum annealed under two different conditions: i) annealing, followed by ex-situ XRD: one sample of each deposition run was annealed at a different temperature, until a maximum of 800 °C, and the XRD patterns were obtained, at room temperature, after each annealing process; ii) annealing with in-situ XRD: the diffraction patterns are obtained, at certain temperatures, during the annealing process, using always the same sample. In-situ XRD annealing could be an interesting process to perform annealing, and analysing the evolution of the structure with the temperature, when compared to the classical process. A higher structural stability was observed in some of the samples, particularly on those with highest oxygen content, but also on the sample with non-metal (O + N) to metal (Ta) ratio around 0.5.

Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging.

PubMed

Evans, P G; Chahine, G; Grifone, R; Jacques, V L R; Spalenka, J W; Schülli, T U

2013-11-01

X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 1-2 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.

Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging

NASA Astrophysics Data System (ADS)

Evans, P. G.; Chahine, G.; Grifone, R.; Jacques, V. L. R.; Spalenka, J. W.; Schülli, T. U.

2013-11-01

X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 1-2 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.

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

PubMed Central

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

2016-01-01

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

Comparison of in situ and in vitro techniques for measuring ruminal degradation of animal by-product proteins.

PubMed

England, M L; Broderick, G A; Shaver, R D; Combs, D K

1997-11-01

Ruminally undegraded protein (RUP) values of blood meal (n = 2), hydrolyzed feather meal (n = 2), fish meal (n = 2), meat and bone meal, and soybean meal were estimated using an in situ method, an inhibitor in vitro method, and an inhibitor in vitro technique applying Michaelis-Menten saturation kinetics. Degradation rates for in situ and inhibitor in vitro methods were calculated by regression of the natural log of the proportion of crude protein (CP) remaining undegraded versus time. Nonlinear regression analysis of the integrated Michaelis-Menten equation was used to determine maximum velocity, the Michaelis constant, and degradation rate (the ratio of maximum velocity to the Michaelis constant). A ruminal passage rate of 0.06/h was assumed in the calculation of RUP. The in situ and inhibitor in vitro techniques yielded similar estimates of ruminal degradation. Mean RUP estimated for soybean meal, blood meal, hydrolyzed feather meal, fish meal, and meat and bone meal were, respectively, 28.6, 86.0, 77.4, 52.9, and 52.6% of CP by the in situ method and 26.4, 86.1, 76.0, 59.6, and 49.5% of CP by the inhibitor in vitro technique. The Michaelis-Menten inhibitor in vitro technique yielded more rapid CP degradation rates and decreased estimates of RUP. The inhibitor in vitro method required less time and labor than did the other two techniques to estimate the RUP values of animal by-product proteins. Results from in vitro incubations with pepsin.HCl suggested that low postruminal digestibility of hydrolyzed feather meal may impair its value as a source of RUP.

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

PubMed

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

2016-01-01

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

Photocatalytic reduction of CO2 with H2O to CH4 on Cu(I) supported TiO2 nanosheets with defective {001} facets.

PubMed

Zhu, Shuying; Liang, Shijing; Tong, Yuecong; An, Xiaohan; Long, Jinlin; Fu, Xianzhi; Wang, Xuxu

2015-04-21

Highly dispersed Cu2O clusters loaded on TiO2 nanosheets with dominant exposed {001} facets are prepared by a hydrothermal treatment followed by photodeposition. The physicochemical properties of the as-prepared samples are characterized carefully. The deposition position and chemical state of the Cu2O clusters are characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, EPR spectroscopy, and in situ CO-adsorbed FTIR spectroscopy, respectively. The results show that in situ Cu deposition leads to in situ formation of abundant oxygen vacancies (Vo) on the surface of the TiO2 nanosheets. Interestingly, the co-existence of Vo and Cu2O clusters could promote the photoactivity of CO2 reduction efficiently. The surface Vo play a significant role in the reduction of CO2. Meanwhile, the deposited Cu(I) species serve also as active sites for the formation of CH4, and then protect CH4 from degradation by generated oxidation species. For the photoreduction of CO2 to CH4, it is found that the content level of Cu2O has a significant influence on the activity. Cu-TiO2-1.0 shows the highest photocatalytic activity, which is over 30 times higher than that of the parent TiO2. This great enhancement of photocatalytic activity may be contributed by high CO2 adsorption capacity, high electron mobility, and high concentration of Vo. However, the effect of the surface area of the samples on the activity is negligible. All of this evidence is obtained by CO2-sorption, electrochemistry, in situ FTIR spectroscopy, in situ ERP techniques, etc. The reaction intermediates are detected by in situ FTIR spectroscopy. Finally, a probable mechanism is proposed based on the experimental results. It is hoped that our work could render one of the most effective strategies to achieve advanced properties over photofunctional materials for solar energy conversion of CO2.

Graphene addition to MgB{sub 2} superconductor obtained by ex-situ spark plasma sintering technique

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

Aldica, G.; Burdusel, M.; Popa, S.

Highlights: • Graphene-added dense MgB{sub 2} was prepared by ex-situ spark plasma sintering. • There is a limited interaction between graphene and MgB{sub 2}. • Addition of graphene (G) shows a small enhancement of J{sub c} and μ{sub 0}H{sub irr}. • G is one of the least effective C-containing additions. - Abstract: Graphene nanopowder (G) with average thickness particle size of about 6–8 nm was added to MgB{sub 2} commercial powder. Starting composition was (MgB{sub 2}){sub (1−x)}(G){sub x}, x = 0.0125, 0.025, 0.05. Processing was performed by Spark Plasma Sintering (SPS) technique. All added samples have high density (above 95%).more » The critical temperature (T{sub c}) and the lattice parameter a (c-axis lattice parameter is constant) show a small variation suggesting that carbon substitution for boron is low. TEM observations show the presence of un-reacted graphene plates supporting the T{sub c} and structural results. It also indicates that G-addition does not modify the MgB{sub 2} microstructure. Despite this, there is an optimum doped sample (MgB{sub 2}){sub 0.9875}(G){sub 0.0125} for which the critical current density at temperatures below 25 K is slightly higher at high magnetic fields than for the pristine sample. The addition of G is found as one of the least effective C-source additions enhancing J{sub c}. We discuss results as being strongly related to variation of the residual stress.« less

Image processing for identification and quantification of filamentous bacteria in in situ acquired images.

PubMed

Dias, Philipe A; Dunkel, Thiemo; Fajado, Diego A S; Gallegos, Erika de León; Denecke, Martin; Wiedemann, Philipp; Schneider, Fabio K; Suhr, Hajo

2016-06-11

In the activated sludge process, problems of filamentous bulking and foaming can occur due to overgrowth of certain filamentous bacteria. Nowadays, these microorganisms are typically monitored by means of light microscopy, commonly combined with staining techniques. As drawbacks, these methods are susceptible to human errors, subjectivity and limited by the use of discontinuous microscopy. The in situ microscope appears as a suitable tool for continuous monitoring of filamentous bacteria, providing real-time examination, automated analysis and eliminating sampling, preparation and transport of samples. In this context, a proper image processing algorithm is proposed for automated recognition and measurement of filamentous objects. This work introduces a method for real-time evaluation of images without any staining, phase-contrast or dilution techniques, differently from studies present in the literature. Moreover, we introduce an algorithm which estimates the total extended filament length based on geodesic distance calculation. For a period of twelve months, samples from an industrial activated sludge plant were weekly collected and imaged without any prior conditioning, replicating real environment conditions. Trends of filament growth rate-the most important parameter for decision making-are correctly identified. For reference images whose filaments were marked by specialists, the algorithm correctly recognized 72 % of the filaments pixels, with a false positive rate of at most 14 %. An average execution time of 0.7 s per image was achieved. Experiments have shown that the designed algorithm provided a suitable quantification of filaments when compared with human perception and standard methods. The algorithm's average execution time proved its suitability for being optimally mapped into a computational architecture to provide real-time monitoring.

The analysis of ALK gene rearrangement by fluorescence in situ hybridization in non-small cell lung cancer patients

PubMed Central

Krawczyk, Paweł Adam; Ramlau, Rodryg Adam; Szumiło, Justyna; Kozielski, Jerzy; Kalinka-Warzocha, Ewa; Bryl, Maciej; Knopik-Dąbrowicz, Alina; Spychalski, Łukasz; Szczęsna, Aleksandra; Rydzik, Ewelina; Milanowski, Janusz

2013-01-01

Introduction ALK gene rearrangement is observed in a small subset (3–7%) of non-small cell lung cancer (NSCLC) patients. The efficacy of crizotinib was shown in lung cancer patients harbouring ALK rearrangement. Nowadays, the analysis of ALK gene rearrangement is added to molecular examination of predictive factors. Aim of the study The frequency of ALK gene rearrangement as well as the type of its irregularity was analysed by fluorescence in situ hybridisation (FISH) in tissue samples from NSCLC patients. Material and methods The ALK gene rearrangement was analysed in 71 samples including 53 histological and 18 cytological samples. The analysis could be performed in 56 cases (78.87%), significantly more frequently in histological than in cytological materials. The encountered problem with ALK rearrangement diagnosis resulted from the scarcity of tumour cells in cytological samples, high background fluorescence noises and fragmentation of cell nuclei. Results The normal ALK copy number without gene rearrangement was observed in 26 (36.62%) patients ALK gene polysomy without gene rearrangement was observed in 25 (35.21%) samples while in 3 (4.23%) samples ALK gene amplification was found. ALK gene rearrangement was observed in 2 (2.82%) samples from males, while in the first case the rearrangement coexisted with ALK amplification. In the second case, signet-ring tumour cells were found during histopathological examination and this patient was successfully treated with crizotinib with partial remission lasting 16 months. Conclusions FISH is a useful technique for ALK gene rearrangement analysis which allows us to specify the type of gene irregularities. ALK gene examination could be performed in histological as well as cytological (cellblocks) samples, but obtaining a reliable result in cytological samples depends on the cellularity of examined materials. PMID:24592134

Characterization of sputtering deposited NiTi shape memory thin films using a temperature controllable atomic force microscope

NASA Astrophysics Data System (ADS)

He, Q.; Huang, W. M.; Hong, M. H.; Wu, M. J.; Fu, Y. Q.; Chong, T. C.; Chellet, F.; Du, H. J.

2004-10-01

NiTi shape memory thin films are potentially desirable for micro-electro-mechanical system (MEMS) actuators, because they have a much higher work output per volume and also a significantly improved response speed due to a larger surface-to-volume ratio. A new technique using a temperature controllable atomic force microscope (AFM) is presented in order to find the transformation temperatures of NiTi shape memory thin films of micrometer size, since traditional techniques, such as differential scanning calorimetry (DSC) and the curvature method, have difficulty in dealing with samples of such a scale as this. This technique is based on the surface relief phenomenon in shape memory alloys upon thermal cycling. The reliability of this technique is investigated and compared with the DSC result in terms of the transformation fraction (xgr). It appears that the new technique is nondestructive, in situ and capable of characterizing sputtering deposited very small NiTi shape memory thin films.

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

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

Baier, S.; Rochet, A.; Hofmann, G.

2015-06-15

We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor formore » in situ studies.« less

Woodstove Emission Sampling Methods Comparability Analysis and In-situ Evaluation of New Technology Woodstoves.

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

Simons, Carl A.

1988-06-01

One major objective of this study was to compare several woodstove particulate emission sampling methods under laboratory and in-situ conditions. The laboratory work compared the EPA Method 5H, EPA Method 5G, and OMNI Automated Woodstove Emission Sampler (AWES)/Data LOG'r particulate emission sampling systems. A second major objective of the study was to evaluate the performance of two integral catalytic, two low emission non-catalytic, and two conventional technology woodstoves under in-situ conditions with AWES/Data LOG'r system. The AWES/Data LOG'r and EPA Method 5G sampling systems were also compared in an in-situ test on one of the integral catalytic woodstove models. 7more » figs., 12 tabs.« less

Measuring of electrical changes induced by in situ combustion through flow-through electrodes in a laboratory sample of core material

DOEpatents

Lee, D.O.; Montoya, P.C.; Wayland, J.R. Jr.

1986-12-09

Method and apparatus are provided for obtaining accurate dynamic measurements for passage of phase fronts through a core sample in a test fixture. Flow-through grid structures are provided for electrodes to permit data to be obtained before, during and after passage of a front there through. Such electrodes are incorporated in a test apparatus for obtaining electrical characteristics of the core sample. With the inventive structure a method is provided for measurement of instabilities in a phase front progressing through the medium. Availability of accurate dynamic data representing parameters descriptive of material characteristics before, during and after passage of a front provides a more efficient method for enhanced recovery of oil using a fire flood technique. 12 figs.

Measuring of electrical changes induced by in situ combustion through flow-through electrodes in a laboratory sample of core material

DOEpatents

Lee, David O.; Montoya, Paul C.; Wayland, Jr., James R.

1986-01-01

Method and apparatus are provided for obtaining accurate dynamic measurements for passage of phase fronts through a core sample in a test fixture. Flow-through grid structures are provided for electrodes to permit data to be obtained before, during and after passage of a front therethrough. Such electrodes are incorporated in a test apparatus for obtaining electrical characteristics of the core sample. With the inventive structure a method is provided for measurement of instabilities in a phase front progressing through the medium. Availability of accurate dynamic data representing parameters descriptive of material characteristics before, during and after passage of a front provides a more efficient method for enhanced recovery of oil using a fire flood technique.

In situ mechanical characterization of the cell nucleus by atomic force microscopy.

PubMed

Liu, Haijiao; Wen, Jun; Xiao, Yun; Liu, Jun; Hopyan, Sevan; Radisic, Milica; Simmons, Craig A; Sun, Yu

2014-04-22

The study of nuclear mechanical properties can provide insights into nuclear dynamics and its role in cellular mechanotransduction. While several methods have been developed to characterize nuclear mechanical properties, direct intracellular probing of the nucleus in situ is challenging. Here, a modified AFM (atomic force microscopy) needle penetration technique is demonstrated to mechanically characterize cell nuclei in situ. Cytoplasmic and nuclear stiffness were determined based on two different segments on the AFM indentation curves and were correlated with simultaneous confocal Z-stack microscopy reconstructions. On the basis of direct intracellular measurement, we show that the isolated nuclei from fibroblast-like cells exhibited significantly lower Young's moduli than intact nuclei in situ. We also show that there is in situ nucleus softening in the highly metastatic bladder cancer cell line T24 when compared to its less metastatic counterpart RT4. This technique has potential to become a reliable quantitative measurement tool for intracellular mechanics studies.

Extrapolation of dynamic load behaviour on hydroelectric turbine blades with cyclostationary modelling

NASA Astrophysics Data System (ADS)

Poirier, Marc; Gagnon, Martin; Tahan, Antoine; Coutu, André; Chamberland-lauzon, Joël

2017-01-01

In this paper, we present the application of cyclostationary modelling for the extrapolation of short stationary load strain samples measured in situ on hydraulic turbine blades. Long periods of measurements allow for a wide range of fluctuations representative of long-term reality to be considered. However, sampling over short periods limits the dynamic strain fluctuations available for analysis. The purpose of the technique presented here is therefore to generate a representative signal containing proper long term characteristics and expected spectrum starting with a much shorter signal period. The final objective is to obtain a strain history that can be used to estimate long-term fatigue behaviour of hydroelectric turbine runners.

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

DOE PAGES

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

2015-05-14

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

In situ alkali-silica reaction observed by x-ray microscopy

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

Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.

1997-04-01

In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques availablemore » for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.« less

Controlled in situ boron doping of diamond thin films using solution phase

NASA Astrophysics Data System (ADS)

Roy, M.; Dua, A. K.; Nuwad, J.; Girija, K. G.; Tyagi, A. K.; Kulshreshtha, S. K.

2006-12-01

Controlled boron doping of diamond film using nontoxic reagents is a challenge in itself. During the present study, attempts have been made to dope diamond films in situ with boron from a solution of boric acid (H3BO3) in methanol (CH3OH) using a specially designed bubbler that ensured continuous and controlled flow of vapors of boron precursors during deposition. The samples are thoroughly characterized using a host of techniques comprising of x-ray photoelectron spectroscopy, Raman, x-ray diffraction, and current-voltage measurements (I-V). Cross-sectional micro-Raman spectroscopy has been used to obtain depth profile of boron in diamond films. Boron concentration ([B]) in the films is found to vary linearly on a semilog scale with molarity (M) of H3BO3 in CH3OH. Lattice constant of our samples is smaller than the reported American society for testing and materials (ASTM) values due to oxygen incorporation and it increases with [B] in the diamond samples. Heavily boron doped samples exhibit Fano deformation of the Raman line shape and negative and/zero activation barrier in temperature dependent I-V measurements that indicate the formation of metallic phase in the samples. The present study illustrates the feasibility of safe and controlled boron doping of diamond films using a solution of H3BO3 in CH3OH over a significant range of [B] from semiconductor to metallic regime but with a little adverse effect due to unintentional but unavoidable incorporation of oxygen.

Sponge Sampling with Fluorescent In Situ Hybridization as a Screening Tool for the Early Detection of Esophageal Cancer.

PubMed

Haisley, Kelly R; Dolan, James P; Olson, Susan B; Toledo-Valdovinos, Sergio A; Hart, Kyle D; Bakis, Gene; Enestvedt, Brintha K; Hunter, John G

2017-02-01

Sponge cytology is a novel screening tool for esophageal cancer but has been unable to be validated for widespread use. Our aim was to apply fluorescent in situ hybridization to sponge cytology samples in order to evaluate the safety and efficacy of this modality in screening for esophageal cancer. At a single, multidisciplinary, NCI-designated cancer center, patients completed sponge cytology sampling prior to upper endoscopy. Samples were analyzed by p53 fluorescent in situ hybridization, and results were compared to the endoscopic diagnosis. Fifty patients were enrolled (96 % Caucasian, 68 % male, median age of 67). All patients successfully swallowed the capsule. No complications (string breakage, bleeding, mucosal injury) occurred. Endoscopy revealed that 38 % had normal esophageal mucosa and 62 % had an esophageal mucosal abnormality. In total, six samples demonstrated p53 loss (94 % specificity for any abnormality). The sensitivity of the p53 fluorescent in situ hybridization probe was13.3 % for any abnormality, 10 % for intestinal metaplasia, and 0 % for dysplasia or esophageal cancer. Esophageal sponge cytology is a promising, safe, and tolerable method for collecting esophageal cell samples. However, our data suggest that p53 fluorescent in situ hybridization does not improve the sensitivity for detecting cancer in these samples.

Application of Genomic In Situ Hybridization in Horticultural Science

PubMed Central

Ramzan, Fahad; Lim, Ki-Byung

2017-01-01

Molecular cytogenetic techniques, such as in situ hybridization methods, are admirable tools to analyze the genomic structure and function, chromosome constituents, recombination patterns, alien gene introgression, genome evolution, aneuploidy, and polyploidy and also genome constitution visualization and chromosome discrimination from different genomes in allopolyploids of various horticultural crops. Using GISH advancement as multicolor detection is a significant approach to analyze the small and numerous chromosomes in fruit species, for example, Diospyros hybrids. This analytical technique has proved to be the most exact and effective way for hybrid status confirmation and helps remarkably to distinguish donor parental genomes in hybrids such as Clivia, Rhododendron, and Lycoris ornamental hybrids. The genome characterization facilitates in hybrid selection having potential desirable characteristics during the early hybridization breeding, as this technique expedites to detect introgressed sequence chromosomes. This review study epitomizes applications and advancements of genomic in situ hybridization (GISH) techniques in horticultural plants. PMID:28459054

Remediation techniques for heavy metal-contaminated soils: Principles and applicability.

PubMed

Liu, Lianwen; Li, Wei; Song, Weiping; Guo, Mingxin

2018-08-15

Globally there are over 20millionha of land contaminated by the heavy metal(loid)s As, Cd, Cr, Hg, Pb, Co, Cu, Ni, Zn, and Se, with the present soil concentrations higher than the geo-baseline or regulatory levels. In-situ and ex-situ remediation techniques have been developed to rectify the heavy metal-contaminated sites, including surface capping, encapsulation, landfilling, soil flushing, soil washing, electrokinetic extraction, stabilization, solidification, vitrification, phytoremediation, and bioremediation. These remediation techniques employ containment, extraction/removal, and immobilization mechanisms to reduce the contamination effects through physical, chemical, biological, electrical, and thermal remedy processes. These techniques demonstrate specific advantages, disadvantages, and applicability. In general, in-situ soil remediation is more cost-effective than ex-situ treatment, and contaminant removal/extraction is more favorable than immobilization and containment. Among the available soil remediation techniques, electrokinetic extraction, chemical stabilization, and phytoremediation are at the development stage, while the others have been practiced at full, field scales. Comprehensive assessment indicates that chemical stabilization serves as a temporary soil remediation technique, phytoremediation needs improvement in efficiency, surface capping and landfilling are applicable to small, serious-contamination sites, while solidification and vitrification are the last remediation option. The cost and duration of soil remediation are technique-dependent and site-specific, up to $500ton -1 soil (or $1500m -3 soil or $100m -2 land) and 15years. Treatability studies are crucial to selecting feasible techniques for a soil remediation project, with considerations of the type and degree of contamination, remediation goals, site characteristics, cost effectiveness, implementation time, and public acceptability. Copyright © 2018 Elsevier B.V. All rights reserved.

Outside-out "sniffer-patch" clamp technique for in situ measures of neurotransmitter release.

PubMed

Muller-Chrétien, Emilie

2014-01-01

The mechanism underlying neurotransmitter release is a critical research domain for the understanding of neuronal network function; however, few techniques are available for the direct detection and measurement of neurotransmitter release. To date, the sniffer-patch clamp technique is mainly used to investigate these mechanisms from individual cultured cells. In this study, we propose to adapt the sniffer-patch clamp technique to in situ detection of neurosecretion. Using outside-out patches from donor cells as specific biosensors plunged in acute cerebral slices, this technique allows for proper detection and quantification of neurotransmitter release at the level of the neuronal network.

Enhanced Gravity Tractor Derived from the Asteroid Redirect Mission for Deflecting Hypothetical Asteroid 2017 PDC

NASA Technical Reports Server (NTRS)

Mazanek, Daniel D.; Reeves, David M.; Abell, Paul A.; Shen, Haijun; Qu, Min

2017-01-01

The Asteroid Redirect Mission (ARM) concept would robotically visit a hazardous-size near-Earth asteroid (NEA) with a rendezvous spacecraft, collect a multi-ton boulder and regolith samples from its surface, demonstrate an innovative planetary defense technique known as the Enhanced Gravity Tractor (EGT), and return the asteroidal material to a stable orbit around the Moon, allowing astronauts to explore the returned material in the mid-2020s. Launch of the robotic vehicle to rendezvous with the ARM reference target, NEA (341843) 2008 EV5, would occur in late 2021 [1,2]. The robotic segment of the ARM concept uses a 40 kW Solar Electric Propulsion (SEP) system with a specific impulse (Isp) of 2600 s, and would provide the first ever demonstration of the EGT technique on a hazardous-size asteroid and validate one method of collecting mass in-situ. The power, propellant, and thrust capability of the ARM robotic spacecraft can be scaled from a 40 kW system to 150 kW and 300 kW, which represent a likely future power level progression. The gravity tractor technique uses the gravitational attraction of a station-keeping spacecraft with the asteroid to provide a velocity change and gradually alter the trajectory of the asteroid. EGT utilizes a spacecraft with a high-efficiency propulsion system, such as Solar Electric Propulsion (SEP), along with mass collected in-situ to augment the mass of the spacecraft, thereby increasing the gravitational force between the objects [3]. As long as the spacecraft has sufficient thrust and propellant capability, the EGT force is only limited by the amount of in-situ mass collected and can be increased several orders of magnitude compared to the traditional gravity tractor technique in which only the spacecraft mass is used to generate the gravitational attraction force. This increase in available force greatly reduces the required deflection time. The collected material can be a single boulder, multiple boulders, regolith, or a combination of different material types using a variety of collection techniques. The EGT concept assumes that the ability to efficiently collect asteroid mass in-situ from a wide variety of asteroid types and environments is a future capability that will be developed and perfected in the future by the asteroid mining community. Additionally, it is anticipated that the mass collection would likely be performed by a single or multiple separable spacecraft to allow the SEP spacecraft to operate at safe distance from the asteroid.

In Situ Analysis of Bacterial Lipopeptide Antibiotics by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

PubMed

Debois, Delphine; Ongena, Marc; Cawoy, Hélène; De Pauw, Edwin

2016-01-01

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a technique developed in the late 1990s enabling the two-dimensional mapping of a broad variety of biomolecules present at the surface of a sample. In many applications including pharmaceutical studies or biomarker discovery, the distribution of proteins, lipids or drugs, and metabolites may be visualized within tissue sections. More recently, MALDI MSI has become increasingly applied in microbiology where the versatility of the technique is perfectly suited to monitor the metabolic dynamics of bacterial colonies. The work described here is focused on the application of MALDI MSI to map secondary metabolites produced by Bacilli, especially lipopeptides, produced by bacterial cells during their interaction with their environment (bacteria, fungi, plant roots, etc.). This chapter addresses the advantages and challenges that the implementation of MALDI MSI to microbiological samples entails, including detailed protocols on sample preparation (from both microbiologist and mass spectrometrist points of view), matrix deposition, and data acquisition and interpretation. Lipopeptide images recorded from confrontation plates are also presented.

Detection of trace organics in Mars analog samples containing perchlorate by laser desorption/ionization mass spectrometry.

PubMed

Li, Xiang; Danell, Ryan M; Brinckerhoff, William B; Pinnick, Veronica T; van Amerom, Friso; Arevalo, Ricardo D; Getty, Stephanie A; Mahaffy, Paul R; Steininger, Harald; Goesmann, Fred

2015-02-01

Evidence from recent Mars missions indicates the presence of perchlorate salts up to 1 wt % level in the near-surface materials. Mixed perchlorates and other oxychlorine species may complicate the detection of organic molecules in bulk martian samples when using pyrolysis techniques. To address this analytical challenge, we report here results of laboratory measurements with laser desorption mass spectrometry, including analyses performed on both commercial and Mars Organic Molecule Analyzer (MOMA) breadboard instruments. We demonstrate that the detection of nonvolatile organics in selected spiked mineral-matrix materials by laser desorption/ionization (LDI) mass spectrometry is not inhibited by the presence of up to 1 wt % perchlorate salt. The organics in the sample are not significantly degraded or combusted in the LDI process, and the parent molecular ion is retained in the mass spectrum. The LDI technique provides distinct potential benefits for the detection of organics in situ on the martian surface and has the potential to aid in the search for signs of life on Mars.

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

Ellipsometric study of YBa2Cu3O(7-x) laser ablated and co-evaporated films

NASA Technical Reports Server (NTRS)

Alterovitz, S. A.; Sieg, R. E.; Warner, J. D.; Stan, M. A.; Vitta, S.

1990-01-01

High temperature superconducting films of YBa2Cu3O(7-x) (YBCO were grown on SrTiO3, LaA1O3, and YSZ substrates using two techniques: excimer laser ablation with in situ annealing and co-evaporation of Y, Cu, and BaF2 with ex-situ annealing. Film thicknesses were typically 5000 A, with predominant c-axis alignment perpendicular to the substrate. Critical temperatures up to Tc(R=O)=90 K were achieved by both techniques. Ellipsometric measurements were taken in the range 1.6 to 4.3 eV using a variable angle spectroscopic ellipsometer. The complex dielectric function of the laser ablated films was reproducible from run to run, and was found to be within 10 percent of that previously reported for (001) oriented single crystals. A dielectric overlayer was observed in these films, with an index of refraction of approximately 1.55 and nearly zero absorption. For the laser ablated films the optical properties were essentially independent of substrate material. The magnitude of the dielectric function obtained for the co-evaported films was much lower than the value reported for single crystals, and was sample dependent.

Measurements of Gas-Wall Partitioning of Oxidized Species in Environmental Smog Chambers and Teflon Sampling Lines

NASA Astrophysics Data System (ADS)

Krechmer, J.; Pagonis, D.; Ziemann, P. J.; Jimenez, J. L.

2015-12-01

Environmental "smog" chambers have played an integral role in atmospheric aerosol research for decades. Recently, many works have demonstrated that the loss of gas-phase material to fluorinated ethylene propylene (FEP) chamber walls can have significant effects on secondary organic aerosol (SOA) yield results. The effects of gas-wall partitioning on highly oxidized species is still controversial, however. In this work we performed a series of experiments examining the losses of oxidized gas-phase compounds that were generated in-situ­ in an environmental chamber. The loss of species to the walls was measured using three chemical ionization mass spectrometry techniques: proton-transfer-reaction (PTR), nitrate (NO3-) ion, and iodide (I-). Many oxidized species have wall loss timescales ranging between 15 to 45 minutes and scale according to the molecule's estimated saturation concentration c* and functional groups. By comparing results of the different techniques, and in particular by the use of the "wall-less" NO3- source, we find that measuring species with high chamber wall-loss rates is complicated by the use of a standard ion-molecule reaction (IMR) region, as well as long Teflon sampling lines, which can be important sinks for gas-phase species. This effect is observed even for semi-volatile species and could have significant effects on ambient sampling techniques that make highly time-resolved measurements using long sampling lines, such as eddy covariance measurements.

In–situ Spatiotemporal Chemical Reactions at Water-Solid Interfacial Processes using Microelectrode Techniques: from Biofilm to Metal Corrosion

EPA Science Inventory

Recent developments in microscale sensors allows the non-destructive and in–situ measurement of both the absolute and changes in chemical concentrations in engineered and natural aquatic systems. Microelectrodes represent a unique tool for studying in–situ chemical reactions in b...

Probing dissolved organic matter in the critical zone: a comparison between in situ sampling and aqueous soil extracts

NASA Astrophysics Data System (ADS)

Perdrial, J. N.; Perdrial, N.; Harpold, A. A.; Peterson, A. M.; Vasquez, A.; Chorover, J.

2011-12-01

Analyzing dissolved organic matter (DOM) of soil solution constitutes an integral activity in critical zone science as important insights to nutrient and carbon cycling and mineral weathering processes can be gained. Soil solution can be obtained by a variety of approaches such as by in situ zero-tension and tension samplers or by performing soil extracts in the lab. It is generally preferred to obtain soil solution in situ with the least amount of disturbance. However, in water limited environments, such as in southwestern US, in situ sampling is only possible during few hydrologic events and soil extracts are often employed. In order to evaluate the performance of different sampling approaches for OM analysis, results from aqueous soil extracts were compared with in situ samples obtained from suction cups and passive capillary wick samplers (PCAP's). Soil from an OA-horizon of mixed conifer forest Jemez River Basin Critical Zone Observatory (JRB-CZO) in NM was sampled twice and in situ samples from co-located suction cups and PCAPs were collected 7 times during the 2011 snowmelt period. Dissolved organic carbon and nitrogen concentrations (DOC and DN) as well as OM quality (FTIR, fluorescence spectroscopy and PARAFAC) were analyzed. The aqueous soil extracts (solid:solution = 1:5 mass basis) showed highest DOC and lowest DN concentrations whereas samples collected in-situ had lower DOC and higher DN concentrations. PARAFAC analysis using a four component model showed a dominance of fluorescence in region I and II (protein-like fluorescence) for samples collected in situ indicating the presence of more bio-molecules (proteins). In contrast, the dominant PARAFAC component of the soil extract was found in region 3 (fulvic acid-like fluorescence). FTIR analysis showed high intensity band at 1600 cm-1 in the case of the aqueous soil extract that correspond to asymmetric stretching of carboxyl groups. These preliminary results indicate that aqueous soil extracts likely lead to the underestimation of the amount of biomolecules and the overestimation of fulvic acid contents of soil solutions.

The in situ side-to-side bypass technique: a comprehensive review of the technical characteristics, current anastomosis approaches and surgical experience.

PubMed

Wang, Long; Cai, Li; Qian, Hai; Lawton, Michael T; Shi, Xiang'en

2018-05-02

In situ side-to-side (STS) revascularization is an intracranial-intracranial (IC-IC) bypass technique that is increasingly used to treat complex aneurysms and cerebral ischemia. This sophisticated technique involves connecting two proximal parallel vessels to create an artificial conduit for blood flow. This study aims to provide a detailed description of the configuration of the STS bypass technique and extensive information regarding its technical characteristics, current anastomosis approaches and surgical significance. A literature search was performed using the PubMed, Medline, ScienceDirect, Embase, Wiley Online Library, Cambridge Journals, SAGE Journals, Oxford Journals, Research Gate, and Google Scholar databases. The terms "intracranial-intracranial bypass", "in situ bypass", "communicating bypass" and "STS anastomosis" were searched to identify pertinent articles. Articles involving in situ STS anastomosis combined with other bypass methods were excluded. Computer tablet-drawn illustrations of this technique are provided to enhance comprehension. In total, seventy articles that met our search and inclusion criteria were identified. Overall, the radiographical and clinical outcomes of one-hundred and thirty-two (125 aneurysm and 7 cerebral ischemia) patients who underwent in situ STS revascularization were analyzed. IC-IC bypass in the STS fashion can be a safe and effective strategy for the management of complex intracranial aneurysms and cerebral ischemia and is particularly attractive in rescue, anticipated and troubleshooting cases. Despite its extreme rarity, a de novo aneurysm may be observed following STS anastomosis; thus, long-term follow-up is mandatory. Vascular neurosurgeons should consider including this procedure in their treatment armamentarium. Copyright © 2018. Published by Elsevier Inc.

Light stable isotope analysis of meteorites by ion microprobe

NASA Technical Reports Server (NTRS)

Mcsween, Harry Y., Jr.

1994-01-01

The main goal was to develop the necessary secondary ion mass spectrometer (SIMS) techniques to use a Cameca ims-4f ion microprobe to measure light stable isotope ratios (H, C, O and S) in situ and in non-conducting mineral phases. The intended application of these techniques was the analysis of meteorite samples, although the techniques that have been developed are equally applicable to the investigation of terrestrial samples. The first year established techniques for the analysis of O isotope ratios (delta O-18 and delta O-17) in conducting mineral phases and the measurement of S isotope ratios (delta S-34) in a variety of sulphide phases. In addition, a technique was developed to measure delta S-34 values in sulphates, which are insulators. Other research undertaken in the first year resulted in SIMS techniques for the measurement of wide variety of trace elements in carbonate minerals, with the aim of understanding the nature of alteration fluids in carbonaceous chondrites. In the second year we developed techniques for analyzing O isotope ratios in nonconducting mineral phases. These methods are potentially applicable to the measurement of other light stable isotopes such as H, C and S in insulators. Also, we have further explored the analytical techniques used for the analysis of S isotopes in sulphides by analyzing troilite in a number of L and H ordinary chondrites. This was done to see if there was any systematic differences with petrological type.

Glandular Lesions of the Cervix in Clinical Practice: A Cytology, Histology, and Human Papillomavirus Correlation Study From 2 Institutions.

PubMed

Miller, Ross A; Mody, Dina R; Tams, Kimberlee C; Thrall, Michael J

2015-11-01

The Papanicolaou (Pap) test has indisputably decreased cervical cancer mortality, as rates have declined by up to 80% in the United States since its implementation. However, the Pap test is considered less sensitive for detecting glandular lesions than for detecting those of squamous origin. Some studies have even suggested an increasing incidence of cervical adenocarcinoma, which may be a consequence of a relatively reduced ability to detect glandular lesions with cervical cancer screening techniques. To evaluate the detection rate of glandular lesions with screening techniques currently used for cervical cancer screening and to provide insight as to which techniques are most efficacious in our study population. We retrospectively reviewed any available cytology, human papillomavirus (HPV), and histologic malignancy data in patients diagnosed with adenocarcinoma in situ and adenocarcinoma from 2 geographically and socioeconomically disparate hospital systems. Identified patients having had a negative/unsatisfactory Pap test within 5 years of adenocarcinoma in situ or adenocarcinoma tissue diagnosis were considered Pap test screening failures. Patients with negative HPV tests on cytology samples were considered HPV screening failures. One hundred thirty cases were identified (age range, 22-93 years); 39 (30%) had no Pap history in our files. Eight of 91 remaining cases (8.8%) were screening failures. The detected sensitivity for identifying adenocarcinoma in situ/adenocarcinoma in this study was 91.2% by cytology alone and 92.3% when incorporating HPV testing. The most common cytologic diagnosis was atypical glandular cells (25 cases), and those diagnosed with adenocarcinoma were 7.4 years older than those diagnosed with adenocarcinoma in situ (50.3 versus 42.9 years). Nine of 24 HPV-tested cases (37.5%) were called atypical squamous cell of undetermined significance on cytology. Our results highlight the importance of combined Pap and HPV cotesting. Although the number of cases identified is relatively small, our data suggest screening for squamous lesions facilitates the recognition of glandular lesions in the cervix. Additionally, increased use of combined Pap and HPV cotesting may decrease detection failure rates with regard to glandular lesions.

[Prokaryotic community of subglacial bottom sediments of Antarctic Lake Untersee: detection by cultural and direct microscopic techniques].

PubMed

Muliukin, A L; Demkina, E V; Manucharova, N A; Akimov, V N; Andersen, D; McKay, C; Gal'chenko, V F

2014-01-01

The heterotrophic mesophilic component was studied in microbial communities of the samples of frozen regolith collected from the glacier near Lake Untersee collected in 2011 during the joint Russian-American expedition to central Dronning Maud Land (Eastern Antarctica). Cultural techniques revealed high bacterial numbers in the samples. For enumeration of viable cells, the most probable numbers (MPN) method proved more efficient than plating on agar media. Fluorescent in situ hybridization with the relevant oligonucleotide probes revealed members of the groups Eubacteria (Actinobacteria, Firmicutes) and Archaea. Application of the methods of cell resuscitation, such as the use of diluted media and prevention of oxidative stress, did not result in a significant increase in the numbers of viable cells retrieved form subglacial sediment samples. Our previous investigations demonstrated the necessity for special procedures for efficient reactivation of the cells from microbial communities of preserved fossil soil and permafrost samples collected in the Arctic zone. The differences in response to the special resuscitation procedures may reflect the differences in the physiological and morphological state of bacterial cells in microbial communities subject to continuous or periodic low temperatures and dehydration.

Biogenicity and Syngeneity of Organic Matter in Ancient Sedimentary Rocks: Recent Advances in the Search for Evidence of Past Life

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

Oehler, Dorothy Z.; Cady, Sherry L.

2014-12-01

he past decade has seen an explosion of new technologies for assessment of biogenicity and syngeneity of carbonaceous material within sedimentary rocks. Advances have been made in techniques for analysis of in situ organic matter as well as for extracted bulk samples of soluble and insoluble (kerogen) organic fractions. The in situ techniques allow analysis of micrometer-to-sub-micrometer-scale organic residues within their host rocks and include Raman and fluorescence spectroscopy/imagery, confocal laser scanning microscopy, and forms of secondary ion/laser-based mass spectrometry, analytical transmission electron microscopy, and X-ray absorption microscopy/spectroscopy. Analyses can be made for chemical, molecular, and isotopic composition coupled withmore » assessment of spatial relationships to surrounding minerals, veins, and fractures. The bulk analyses include improved methods for minimizing contamination and recognizing syngenetic constituents of soluble organic fractions as well as enhanced spectroscopic and pyrolytic techniques for unlocking syngenetic molecular signatures in kerogen. Together, these technologies provide vital tools for the study of some of the oldest and problematic carbonaceous residues and for advancing our understanding of the earliest stages of biological evolution on Earth and the search for evidence of life beyond Earth. We discuss each of these new technologies, emphasizing their advantages and disadvantages, applications, and likely future directions.« less

Development of synchrotron X-ray micro-tomography under extreme conditions of pressure and temperature.

PubMed

Álvarez-Murga, M; Perrillat, J P; Le Godec, Y; Bergame, F; Philippe, J; King, A; Guignot, N; Mezouar, M; Hodeau, J L

2017-01-01

X-ray tomography is a non-destructive three-dimensional imaging/microanalysis technique selective to a wide range of properties such as density, chemical composition, chemical states and crystallographic structure with extremely high sensitivity and spatial resolution. Here the development of in situ high-pressure high-temperature micro-tomography using a rotating module for the Paris-Edinburgh cell combined with synchrotron radiation is described. By rotating the sample chamber by 360°, the limited angular aperture of ordinary high-pressure cells is surmounted. Such a non-destructive high-resolution probe provides three-dimensional insight on the morphological and structural evolution of crystalline as well as amorphous phases during high pressure and temperature treatment. To demonstrate the potentials of this new experimental technique the compression behavior of a basalt glass is investigated by X-ray absorption tomography, and diffraction/scattering tomography imaging of the structural changes during the polymerization of C 60 molecules under pressure is performed. Small size and weight of the loading frame and rotating module means that this apparatus is portable, and can be readily installed on most synchrotron facilities to take advantage of the diversity of three-dimensional imaging techniques available at beamlines. This experimental breakthrough should open new ways for in situ imaging of materials under extreme pressure-temperature-stress conditions, impacting diverse areas in physics, chemistry, geology or materials sciences.

In situ cell culture monitoring on a Ti-6Al-4V surface by electrochemical techniques.

PubMed

García-Alonso, M C; Saldaña, L; Alonso, C; Barranco, V; Muñoz-Morris, M A; Escudero, M L

2009-05-01

In this work, the in situ interaction between Ti-6Al-4V alloy and osteoblastic cells has been studied by electrochemical techniques as a function of time. The interaction has been monitored for cell adhesion and growth of human osteoblastic Saos-2 cells on Ti-6Al-4V samples. The study has been carried out by electrochemical techniques, e.g., studying the evolution of corrosion potential with exposure time and by electrochemical impedance spectroscopy. The impedance results have been analyzed by using different equivalent circuit models that simulate the interface state at each testing time. The adhesion of the osteoblastic cells on the Ti-6Al-4V alloy leads to surface areas with different cell coverage rates, thus showing the different responses in the impedance diagrams with time. The effect of the cells on the electrochemical response of Ti-6Al-4V alloy is clearly seen after 4 days of testing, in which two isolated and well-differentiated time constants are clearly observed. One of these is associated with the presence of the cells and the other with a passive film on the Ti-6Al-4V alloy. After 7 days of culture, the system is governed by a resistive component over a wide frequency range which is associated with an increase in the cell coverage rate on the surface due to the extracellular matrix.

Modified Terminal Restriction Fragment Analysis for Quantifying Telomere Length Using In-gel Hybridization.

PubMed

Jenkins, Frank J; Kerr, Charles M; Fouquerel, Elise; Bovbjerg, Dana H; Opresko, Patricia L

2017-07-10

There are several different techniques for measuring telomere length, each with their own advantages and disadvantages. The traditional approach, Telomere Restriction Fragment (TRF) analysis, utilizes a DNA hybridization technique whereby genomic DNA samples are digested with restriction enzymes, leaving behind telomere DNA repeats and some sub-telomeric DNA. These are separated by agarose gel electrophoresis, transferred to a filter membrane and hybridized to oligonucleotide probes tagged with either chemiluminescence or radioactivity to visualize telomere restriction fragments. This approach, while requiring a larger quantity of DNA than other techniques such as PCR, can measure the telomere length distribution of a population of cells and allows measurement expressed in absolute kilobases. This manuscript demonstrates a modified DNA hybridization procedure for determining telomere length. Genomic DNA is first digested with restriction enzymes (that do not cut telomeres) and separated by agarose gel electrophoresis. The gel is then dried and the DNA is denatured and hybridized in situ to a radiolabeled oligonucleotide probe. This in situ hybridization avoids loss of telomere DNA and improves signal intensity. Following hybridization, the gels are imaged utilizing phosphor screens and the telomere length is quantified using a graphing program. This procedure was developed by the laboratories of Drs. Woodring Wright and Jerry Shay at the University of Texas Southwestern 1 , 2 . Here, we present a detailed description of this procedure, with some modifications.

Fundamental Studies of the Role of Grain Boundaries on Uniform Corrosion of Advanced Nuclear Reactor Materials

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

Taheri, Mitra; Motta, Arthur; Marquis, Emmanuelle

The main objective of this proposal is to develop fundamental understanding of the role of grain boundaries in stable oxide growth. To understand the process of oxide layer destabilization, it is necessary to observe the early stages of corrosion. During conventional studies in which a sample is exposed and examined after removal from the autoclave, the destabilization process will normally have already taken place, and is only examined post facto. To capture the instants of oxide destabilization, it is necessary to observe it in situ; however, significant questions always arise as to the influence of the corrosion geometry and conditionsmore » on the corrosion process. Thus, a combination of post facto examinations and in situ studies is proposed, which also combines state-of-the-art characterization techniques to derive a complete understanding of the destabilization process and the role of grain boundaries.« less

RHEED-TRAXS as a tool for in-situ stoichiometry control.

NASA Astrophysics Data System (ADS)

Chandril, Sandeep; Keenan, Cameron; Myers, Thomas; Lederman, David

2008-03-01

RHEED-total reflection x-ray spectroscopy (-TRAXS) is an in-situ chemical and structural characterization technique which is highly surface sensitive. This consists of a grazing-angle electron beam from which characteristic x-rays from the sample are measured also at grazing angles. We have demonstrated that monolayer sensitivity in Y and Mn films on GaN can be achieved. We have also developed a theoretical model for the angular dependence of the x-ray Kα peaks for the thin films, based on Parratt's formalism for x-ray reflectivity and the electron trajectory simulation software CASINO, to correct for grazing angle electron beam as a source for x-rays. As the angular dependence is highly dependent upon the film thickness and the smoothness of the film, it can be used to determine the deposition rate of individual elements as well as the interface chemical roughness

Cooperative research in coal liquefaction. Technical progress report, May 1, 1993--April 30, 1994

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

Huffman, G.P.

Accomplishments for the past year are presented for the following tasks: coliquefaction of coal with waste materials; catalysts for coal liquefaction to clean transportation fuels; fundamental research in coal liquefaction; and in situ analytical techniques for coal liquefaction and coal liquefaction catalysts some of the highlights are: very promising results have been obtained from the liquefaction of plastics, rubber tires, paper and other wastes, and the coliquefaction of wastes with coal; a number of water soluble coal liquefaction catalysts, iron, cobalt, nickel and molybdenum, have been comparatively tested; mossbauer spectroscopy, XAFS spectroscopy, TEM and XPS have been used to characterizemore » a variety of catalysts and other samples from numerous consortium and DOE liquefaction projects and in situ ESR measurements of the free radical density have been conducted at temperatures from 100 to 600{degrees}C and H{sub 2} pressures up to 600 psi.« less

Comparison of in situ DGT measurement with ex situ methods for predicting cadmium bioavailability in soils with combined pollution to biotas.

PubMed

Wang, Peifang; Liu, Cui; Yao, Yu; Wang, Chao; Wang, Teng; Yuan, Ye; Hou, Jun

2017-05-01

To assess the capabilities of the different techniques in predicting Cadmium (Cd) bioavailability in Cd-contaminated soils with the addition of Zn, one in situ technique (diffusive gradients in thin films; DGT) was compared with soil solution concentration and four widely used single-step extraction methods (acetic acid, EDTA, sodium acetate and CaCl 2 ). Wheat and maize were selected as tested species. The results demonstrated that single Cd-polluted soils inhibited the growth of wheat and maize significantly compared with control plants; the shoot and root biomasses of the plants both dropped significantly (P < 0.05). The addition of Zn exhibited a strong antagonism to the physiological toxicity induced by Cd. The Pearson correlation coefficient presented positive correlations (P < 0.01, R > 0.9) between Cd concentrations in two plants and Cd bioavailability indicated by each method in soils. Consequently, the results indicated that the DGT technique could be regarded as a good predictor of Cd bioavailability to plants, comparable to soil solution concentration and the four single-step extraction methods. Because the DGT technique can offer in situ data, it is expected to be widely used in more areas.

The Proposed Mars Astrobiology Explorer - Cacher [MAX-C] Rover: First Step in a Potential Sample Return Campaign

NASA Technical Reports Server (NTRS)

Allen, Carlton C.; Beaty, David W.

2010-01-01

Sample return from Mars has been advocated by numerous scientific advisory panels for over 30 years, most prominently beginning with the National Research Council s [1] strategy for the exploration of the inner solar system, and most recently by the Mars Exploration Program Analysis Group (MEPAG s) Next Decade Science Analysis Group [2]. Analysis of samples here on Earth would have enormous advantages over in situ analyses in producing the data quality needed to address many of the complex scientific questions the community has posed about Mars. Instead of a small, predetermined set of analytical techniques, state of the art preparative and instrumental resources of the entire scientific community could be applied to the samples. The analytical emphasis could shift as the meaning of each result becomes better appreciated. These arguments apply both to igneous rocks and to layered sedimentary materials, either of which could contain water and other volatile constituents. In 2009 MEPAG formed the Mid-Range Rover Science Analysis Group (MRR-SAG) to formulate a mission concept that would address two general objectives: (1) conduct high-priority in situ science and (2) make concrete steps towards the potential return of samples to Earth. This analysis resulted in a mission concept named the Mars Astrobiology Explorer-Cacher (MAX-C), which was envisioned for launch in the 2018 opportunity. After extensive discussion, this group concluded that by far the most definitive contribution to sample return by this mission would be to collect and cache, in an accessible location, a suite of compelling samples that could potentially be recovered and returned by a subsequent mission. This would have the effect of separating two of the essential functions of MSR, the acquisition of the sample collection and its delivery to martian orbit, into two missions.

Applications of synchrotron μ-XRF to study the distribution of biologically important elements in different environmental matrices: a review.

PubMed

Majumdar, Sanghamitra; Peralta-Videa, Jose R; Castillo-Michel, Hiram; Hong, Jie; Rico, Cyren M; Gardea-Torresdey, Jorge L

2012-11-28

Environmental matrices including soils, sediments, and living organisms are reservoirs of several essential as well as non-essential elements. Accurate qualitative and quantitative information on the distribution and interaction of biologically significant elements is vital to understand the role of these elements in environmental and biological samples. Synchrotron micro-X-ray fluorescence (μ-SXRF) allows in situ mapping of biologically important elements at nanometer to sub-micrometer scale with high sensitivity, negligible sample damage and enable tuning of the incident energy as desired. Beamlines in the synchrotron facilities are rapidly increasing their analytical versatility in terms of focusing optics, detector technologies, incident energy, and sample environment. Although extremely competitive, it is now feasible to find stations offering complimentary techniques like micro-X-ray diffraction (μ-XRD) and micro-X-ray absorption spectroscopy (μ-XAS) that will allow a more complete characterization of complex matrices. This review includes the most recent literature on the emerging applications and challenges of μ-SXRF in studying the distribution of biologically important elements and manufactured nanoparticles in soils, sediments, plants, and microbes. The advantages of using μ-SXRF and complimentary techniques in contrast to conventional techniques used for the respective studies are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Design and development of a highly sensitive, field portable plasma source instrument for on-line liquid stream monitoring and real-time sample analysis

NASA Astrophysics Data System (ADS)

Duan, Yixiang; Su, Yongxuan; Jin, Zhe; Abeln, Stephen P.

2000-03-01

The development of a highly sensitive, field portable, low-powered instrument for on-site, real-time liquid waste stream monitoring is described in this article. A series of factors such as system sensitivity and portability, plasma source, sample introduction, desolvation system, power supply, and the instrument configuration, were carefully considered in the design of the portable instrument. A newly designed, miniature, modified microwave plasma source was selected as the emission source for spectroscopy measurement, and an integrated small spectrometer with a charge-coupled device detector was installed for signal processing and detection. An innovative beam collection system with optical fibers was designed and used for emission signal collection. Microwave plasma can be sustained with various gases at relatively low power, and it possesses high detection capabilities for both metal and nonmetal pollutants, making it desirable to use for on-site, real-time, liquid waste stream monitoring. An effective in situ sampling system was coupled with a high efficiency desolvation device for direct-sampling liquid samples into the plasma. A portable computer control system is used for data processing. The new, integrated instrument can be easily used for on-site, real-time monitoring in the field. The system possesses a series of advantages, including high sensitivity for metal and nonmetal elements; in situ sampling; compact structure; low cost; and ease of operation and handling. These advantages will significantly overcome the limitations of previous monitoring techniques and make great contributions to environmental restoration and monitoring.

Beamline Electrostatic Levitator (BESL) for in-situ High Energy K-Ray Diffraction Studies of Levitated Solids and Liquids at High Temperature

NASA Technical Reports Server (NTRS)

Gangopadhyay, A. K.; Lee, G. W.; Kelton, K. F.; Rogers, J. R.; Goldman, A. I.; Robinson, D. S.; Rathz, T. J.; Hyers, R. W.

2005-01-01

Determinations of the phase formation sequence, the crystal structures and the thermodynamic properties of materials at high temperatures are difficult because of contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic (EML), aerodynamic, and acoustic levitation, are most suitable these studies. An adaptation of ESL for in-situ structural studies of a wide range of materials, including metals, semiconductors, insulators using high energy (125 keV) synchrotron x-rays is described here. This beamline ESL (BESL) allows the in-situ determination of the atomic structures of equilibrium solid and liquid phases, including undercooled liquids, as well as real-time studies of solid-solid and liquid-solid phase transformations. The use of image plate (MAR345) or GE-Angio detectors enables fast (30 ms - 1s) acquisition of complete diffraction patterns over a wide q-range (4 - 140/mm). The wide temperature range (300 - 2500 K), containerless processing under high vacuum (10(exp -7) - 10(exp -8) torr), and fast data acquisition, make BESL particularly suitable for phase diagram studies of high temperature materials. An additional, critically important, feature of BESL is the ability to also make simultaneous measurement of a host of thermo-physical properties, including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension; all on the same sample and simultaneous with the structural measurements.

In Situ Deformation of Olivine in the Transmission Electron Microscope: from Dislocation Velocity Measurements to Stress-Strain Curves

NASA Astrophysics Data System (ADS)

Bollinger, C.; Idrissi, H.; Boioli, F.; Cordier, P.

2015-12-01

There is a growing consensus to recognize that rheological law established for olivine at high-temperature (ca. >1000°C) fail when extrapolated to low temperatures relevant for the lithospheric mantle. Hence it appears necessary to fit rheological laws against data at low temperatures where olivine tends to become more and more brittle. The usual approach consists in applying confining pressure to inhibit brittleness. Here we propose an innovative approach based on the use of very small samples and numerical modelling. New commercial in situ TEM nanotensile testing equipment recently developed by Hysitron.Inc is combined with weak-beam dark-field TEM diffraction contrast imaging in order to obtain information on the elementary mechanisms controlling the plasticity of olivine: namely glide of [001] screw dislocations. The olivine tensile beams dedicated for in situ TEM nanomechanical testing were produced using microfabrication techniques based on MEMS-type procedures. The testing geometry was designed as to induce maximum resolved shear stresses on the [001](110) slip system. Under tensile loads between 2 and 3 GPa, ductile behaviour was reached with the development and propagation of dislocation loops across the sample allowing to measure the velocity of screw and non-screw dislocations as a function of stress. This information is introduced into a numerical model involving Dislocation Dynamics in order to obtain the stress-strain curves describing the mechanical response of olivine single crystals deformed in tension at room temperature.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

PubMed Central

Reid, Russell C.; Piqué, Alberto; Kang, Wonmo

2017-01-01

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (<0.02 °C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper. PMID:28605394

A new set-up for in-situ probing of radiation effects in materials and electronic devices

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

Peres, M.; Felizardo, M.; Catarino, N.

2015-07-01

The micro-probe facility installed at the Van de Graff accelerator at CTN/IST permits simultaneous measurements of Rutherford Backscattering Spectrometry (RBS), Particle Induced X-ray Emission (PIXE) and Iono-Luminescence (IL). Here we present a recent up-grade of the measurement chamber allowing improved optical sensitivity in IL measurements and opening the possibility to perform simultaneously electrical measurements. Combinations of all these characterization techniques make this setup a powerful tool to characterize and modify different materials with spatial resolution. In particular, it can be used to study radiation effects in different materials and electronic devices in-situ. IL is a luminescence technique that uses themore » ion beam as the excitation source. Compared with other luminescence techniques with spatial resolution like Cathodoluminescence, this technique has the advantage to probe deeper regions of the sample, several microns below the surface. The same ion beam used to produce luminescence, can create a high density of defects, in a controllable way and the new set-up allows monitoring optical and electrical properties in realtime. In this work we combine IL with I-V curve measurements to assess the response of Ga{sub 2}O{sub 3} and GaN to proton irradiation. Ga{sub 2}O{sub 3} and GaN are emerging materials for applications in high power electronics and are considered for radiation resistant electronics. We will present a systematic study of the changes in IL and conductivity in Ga{sub 2}O{sub 3} and GaN samples with the energy of the ion beam and with the time of exposure. In particular, it was observed that during the irradiation some luminescence bands related with intrinsic point defects decrease while other new bands appear. Simulations using the SRIM code were used to determine the depth profiles of ionization and displacement events, helping to correlate the optical and electrical response of the materials with certain radiation effects. These studies show the potentialities of measuring simultaneously IL and electrical conductivity and how these two characterization techniques can work as a sensitive tool to detect and quantify radiation effects. (authors)« less

Advanced Non-Destructive Assessment Technology to Determine the Aging of Silicon Containing Materials for Generation IV Nuclear Reactors

NASA Astrophysics Data System (ADS)

Koenig, T. W.; Olson, D. L.; Mishra, B.; King, J. C.; Fletcher, J.; Gerstenberger, L.; Lawrence, S.; Martin, A.; Mejia, C.; Meyer, M. K.; Kennedy, R.; Hu, L.; Kohse, G.; Terry, J.

2011-06-01

To create an in-situ, real-time method of monitoring neutron damage within a nuclear reactor core, irradiated silicon carbide samples are examined to correlate measurable variations in the material properties with neutron fluence levels experienced by the silicon carbide (SiC) during the irradiation process. The reaction by which phosphorus doping via thermal neutrons occurs in the silicon carbide samples is known to increase electron carrier density. A number of techniques are used to probe the properties of the SiC, including ultrasonic and Hall coefficient measurements, as well as high frequency impedance analysis. Gamma spectroscopy is also used to examine residual radioactivity resulting from irradiation activation of elements in the samples. Hall coefficient measurements produce the expected trend of increasing carrier concentration with higher fluence levels, while high frequency impedance analysis shows an increase in sample impedance with increasing fluence.

Layered double hydroxide films on nanoporous anodic aluminum oxide/aluminum wire: a new fiber for rapid analysis of Origanum vulgare essential oils.

PubMed

Piryaei, Marzieh

2018-01-01

Zn/Al layered double hydroxide (LDH) films were fabricated in situ with anodic aluminium oxide aluminium as both the substrate and the sole aluminium source by means of urea hydrolysis. Headspace solid phase microextraction using LDH fibre in combination with capillary GC-MS was utilised as a monitoring technique for the collection and detection of the volatile compounds of Origanum vulgare. Experimental parameters, including the sample weight, microwave power, extraction time and humidity effect, were examined and optimised.

Decomposition of aquatic plants in lakes

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

Godshalk, G.L.

1977-01-01

This study was carried out to systematically determine the effects of temperature and oxygen concentration, two environmental parameters crucial to lake metabolism in general, on decomposition of five species of aquatic vascular plants of three growth forms in a Michigan lake. Samples of dried plant material were decomposed in flasks in the laboratory under three different oxygen regimes, aerobic-to-anaerobic, strict anaerobic, and aerated, each at 10/sup 0/C and 25/sup 0/C. In addition, in situ decomposition of the same species was monitored using the litter bag technique under four conditions.

Experimental determination of ablation vapor species from carbon phenolic heat-shield materials

NASA Technical Reports Server (NTRS)

Lincoln, K. A.

1981-01-01

The relative concentrations of vapors produced from carbon phenolic composites under thermal loadings approximating those expected at peak heating during vehicle entry into the atmospheres of the outer planets have been determined. The technique of vaporizing the surface of bulk samples by laser irradiation while measuring in situ the vapor species by mass spectrometry is described. Results show that vapor composition varies with irradiance level and with depth of heating (or extent of pyrolysis). Attempts are made to compare these experimental results with the theoretical predictions from computer codes.

The Use of Whole-Mount "in Situ" Hybridization to Illustrate Gene Expression Regulation

ERIC Educational Resources Information Center

Llamusí, Beatriz; Muñoz-Soriano, Verónica; Paricio, Nuria; Artero, Rubén

2014-01-01

"In situ" hybridization is a widely used technique for studying gene expression. Here, we describe two experiments addressed to postgraduate genetics students in which the effect of transcription factors on gene expression is analyzed in "Drosophila embryos of different genotypes by whole-mount in situ hybridization. In one of the…

Synthesis of lithium nitride for neutron production target of BNCT by in situ lithium deposition and ion implantation

NASA Astrophysics Data System (ADS)

Ishiyama, S.; Baba, Y.; Fujii, R.; Nakamura, M.; Imahori, Y.

2012-12-01

To achieve high performance of BNCT (Boron Neutron Capture Therapy) device, Li3N/Li/Pd/Cu four layered Li target was designed and the structures of the synthesized four layered target were characterized by X-ray photoelectron spectroscopy. For the purpose of avoiding the radiation blistering and lithium evaporation, in situ vacuum deposition and nitridation techniques were established for in situ production and repairing maintenance of the lithium target. Following conclusions were derived: Uniform lithium layer of a few hundreds nanometer was formed on Pd/Cu multilayer surface by in situ vacuum deposition technique using metallic lithium as a source material. Lithium nitrides were formed by in situ nitridation reaction by the implantation of low-energy nitrogen ions on the deposited lithium layer surface. The chemical states of the nitridated zone were close to the stoichiometric lithium nitride, Li3N. This nitridated zone formed on surface of four layered lithium target is stable for a long time in air condition. The in situ nitridation is effective to protect lithium target from degradation by unfavorable reactions.

In Situ TEM Nanoindentation Studies on Stress-Induced Phase Transformations in Metallic Materials

DOE PAGES

Liu, Y.; Wang, H.; Zhang, X.

2015-11-30

Though abundant phase transformations are in general thermally driven processes, there are many examples wherein stresses can induce phase transformations. We applied numerous in situ techniques, such as in situ x-ray diffraction and neutron diffraction in order to reveal phase transformations. Recently, an in situ nanoindentation technique coupled with transmission electron microscopy demonstrated the capability to directly correlating stresses with phase transformations and microstructural evolutions at a submicron length scale. We briefly review in situ studies on stress-induced diffusional and diffusionless phase transformations in amorphous CuZrAl alloy and NiFeGa shape memory alloy. Moreover, in the amorphous CuZrAl, in situ nanoindentationmore » studies show that the nucleation of nanocrystals (a diffusional process) occurs at ultra-low stresses manifested by a prominent stress drop. In the NiFeGa shape memory alloy, two distinctive types of martensitic (diffusionless) phase transformations accompanied by stress plateaus are observed, including a reversible gradual phase transformation at low stress levels, and an irreversible abrupt phase transition at higher stress levels.« less

Advances in photo-thermal infrared imaging microspectroscopy

NASA Astrophysics Data System (ADS)

Furstenberg, Robert; Kendziora, Chris; Papantonakis, Michael; Nguyen, Viet; McGill, Andrew

2013-05-01

There is a growing need for chemical imaging techniques in many fields of science and technology: forensics, materials science, pharmaceutical and chemical industries, just to name a few. While FTIR micro-spectroscopy is commonly used, its practical resolution limit of about 20 microns or more is often insufficient. Raman micro-spectroscopy provides better spatial resolution (~1 micron), but is not always practical because of samples exhibiting fluorescence or low Raman scattering efficiency. We are developing a non-contact and non-destructive technique we call photo-thermal infrared imaging spectroscopy (PT-IRIS). It involves photo-thermal heating of the sample with a tunable quantum cascade laser and measuring the resulting increase in thermal emission with an infrared detector. Photo-thermal emission spectra resemble FTIR absorbance spectra and can be acquired in both stand-off and microscopy configurations. Furthermore, PT-IRIS allows the acquisition of absorbance-like photo-thermal spectra in a reflected geometry, suitable for field applications and for in-situ study of samples on optically IR-opaque substrates (metals, fabrics, paint, glass etc.). Conventional FTIR microscopes in reflection mode measure the reflectance spectra which are different from absorbance spectra and are usually not catalogued in FTIR spectral libraries. In this paper, we continue developing this new technique. We perform a series of numerical simulations of the laser heating of samples during photo-thermal microscopy. We develop parameterized formulas to help the user pick the appropriate laser illumination power. We also examine the influence of sample geometry on spectral signatures. Finally, we measure and compare photo-thermal and reflectance spectra for two test samples.

A study of data analysis techniques for the multi-needle Langmuir probe

NASA Astrophysics Data System (ADS)

Hoang, H.; Røed, K.; Bekkeng, T. A.; Moen, J. I.; Spicher, A.; Clausen, L. B. N.; Miloch, W. J.; Trondsen, E.; Pedersen, A.

2018-06-01

In this paper we evaluate two data analysis techniques for the multi-needle Langmuir probe (m-NLP). The instrument uses several cylindrical Langmuir probes, which are positively biased with respect to the plasma potential in order to operate in the electron saturation region. Since the currents collected by these probes can be sampled at kilohertz rates, the instrument is capable of resolving the ionospheric plasma structure down to the meter scale. The two data analysis techniques, a linear fit and a non-linear least squares fit, are discussed in detail using data from the Investigation of Cusp Irregularities 2 sounding rocket. It is shown that each technique has pros and cons with respect to the m-NLP implementation. Even though the linear fitting technique seems to be better than measurements from incoherent scatter radar and in situ instruments, m-NLPs can be longer and can be cleaned during operation to improve instrument performance. The non-linear least squares fitting technique would be more reliable provided that a higher number of probes are deployed.

Simple and Fast Sample Preparation Followed by Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS) for the Analysis of 2- and 4-Methylimidazole in Cola and Dark Beer.

PubMed

Choi, Sol Ji; Jung, Mun Yhung

2017-04-01

We have developed a simple and fast sample preparation technique in combination with a gas chromatography-tandem mass spectrometry (GC-MS/MS) for the quantification of 2-methylimidazole (2-MeI) and 4-methylimidazole (4-MeI) in colas and dark beers. Conventional sample preparation technique for GC-MS requires laborious and time-consuming steps consisting of sample concentration, pH adjustment, ion pair extraction, centrifugation, back-extraction, centrifugation, derivatization, and extraction. Our sample preparation technique consists of only 2 steps (in situ derivation and extraction) which requires less than 3 min. This method provided high linearity, low limit of detection and limit of quantification, high recovery, and high intra- and interday repeatability. It was found that internal standard method with diluted stable isotope (4-MeI-d 6 ) and 2-ethylimidazole (2-EI) could not correctly compensate the matrix effects. Thus, standard addition technique was used for the quantification of 2- and 4-MeI. The established method was successfully applied to colas and dark beers for the determination of 2-MeI and 4-MeI. The 4-MeI contents in colas and dark beers ranged from 8 to 319 μg/L and from trace to 417 μg/L, respectively. Small quantity (0 to 8 μg/L) of 2-MeI was found only in dark beers. The contents of 4-MeI (22 μg/L) in colas obtained from fast food restaurants were significantly lower than those (177 μg/L) in canned or bottled colas. © 2017 Institute of Food Technologists®.

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

EPA Science Inventory

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practica...

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

EPA Science Inventory

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical...

Toward relaxed eddy accumulation measurements of sediment-water exchange in aquatic ecosystems

NASA Astrophysics Data System (ADS)

Lemaire, Bruno J.; Noss, Christian; Lorke, Andreas

2017-09-01

Solute transport across the sediment-water interface has major implications for water quality and biogeochemical cycling in aquatic ecosystems. Existing measurement techniques, however, are not capable of resolving sediment-water fluxes of most constituents under in situ flow conditions. We investigated whether relaxed eddy accumulation (REA), a micrometeorological technique with conditional sampling of turbulent updrafts and downdrafts, can be adapted to the aquatic environment. We simulated REA fluxes by reanalyzing eddy covariance measurements from a riverine lake. We found that the empirical coefficient that relates mass fluxes to the concentration difference between both REA samples is invariant with scalar and flow and responds as predicted by a joint Gaussian distribution of linearly correlated variables. Simulated REA fluxes differed on average by around 30% from eddy covariance fluxes (mean absolute error). Assessment of the lower quantification limit suggests that REA can potentially be applied for measuring benthic fluxes of a new range of constituents that cannot be assessed by standard eddy covariance methods.

Phase imaging using highly coherent X-rays: radiography, tomography, diffraction topography.

PubMed

Baruchel, J; Cloetens, P; Härtwig, J; Ludwig, W; Mancini, L; Pernot, P; Schlenker, M

2000-05-01

Several hard X-rays imaging techniques greatly benefit from the coherence of the beams delivered by the modern synchrotron radiation sources. This is illustrated with examples recorded on the 'long' (145 m) ID19 'imaging' beamline of the ESRF. Phase imaging is directly related to the small angular size of the source as seen from one point of the sample ('effective divergence' approximately microradians). When using the ;propagation' technique, phase radiography and tomography are instrumentally very simple. They are often used in the 'edge detection' regime, where the jumps of density are clearly observed. The in situ damage assessment of micro-heterogeneous materials is one example of the many applications. Recently a more quantitative approach has been developed, which provides a three-dimensional density mapping of the sample ('holotomography'). The combination of diffraction topography and phase-contrast imaging constitutes a powerful tool. The observation of holes of discrete sizes in quasicrystals, and the investigation of poled ferroelectric materials, result from this combination.

In-Situ Ion Analysis of Fresh Waters via an ISE Multiprobe and Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Mueller, A. V.; Hemond, H.

2010-12-01

The ecological and geochemical sciences stand to substantially gain from capability for comprehensive, real-time, in-situ characterization of the chemical constituents of natural waters, e.g. by facilitating rapid high-resolution adaptive sampling campaigns and avoiding the potential errors and high costs related to traditional grab sample collection, transportation and in-lab analysis. In-situ chemical instrumentation also promotes the goals of large-scale monitoring networks, such as CUASHI and WATERS, by reducing the financial and human resources overhead required for traditional sampling at this scale. Problems of environmental remediation and monitoring of industrial waste waters would additionally benefit from such instrumental capacity. We have pursued in-situ measurement of all major ions contributing to the charge makeup (>99%) of oxic natural fresh waters via an instrument combining an array of ion-selective electrode (ISE) hardware with an appropriate multivariate signal processing architecture. Commercially available electrochemical sensors promote low cost and a fast development schedule, as well as easy maintenance and reproduction. Data processing techniques are adapted from artificial intelligence and chemometrics to extract accurate information from the corresponding in-situ data matrix. This architecture takes into account temperature, conductivity, and non-linearity effects, as well as taking advantage of sensor cross-selectivities traditionally considered as interferences. Chemical and mathematical constraints, e.g. charge balance and total ionic strength, provide further system-level information. Maximizing data recovery from the sensor array allows use of the instrument without the standard additions or ionic strength adjustment traditionally-required with use of ISEs. Initial work demonstrates the effectiveness of this methodology at predicting inorganic cations (sodium, potassium, calcium, and ammonium ) and hydrogen ion in a simplified system containing only a single non-hydroxide anion (chloride), thus allowing charge neutrality to be easily and explicitly invoked. An array of 9 ISEs are calibrated relative to the seven ions of interest, and resulting curves are used to create a representative environmental data set based on historical USGS data for New England waters. Applicability of the developed signal processing methodology is demonstrated, including use of an extended feedback architecture based on conductivity measurements and charge neutrality calculations, with algorithms tuned to optimize performance when predicting actual concentrations from these simulated signals. Results are compared to use of component probes as stand-alone sensors. Future extension of this instrument for multiple anions (including carbonate/bicarbonate, nitrate, and sulfate) will ultimately provide rapid, accurate field measurements of the entire charge balance of natural waters at high resolution, improving sampling abilities while reducing costs and errors related to transport and analysis of grab samples.

Combined near- and far-field high-energy diffraction microscopy dataset for Ti-7Al tensile specimen elastically loaded in situ

DOE PAGES

Turner, Todd J.; Shade, Paul A.; Bernier, Joel V.; ...

2016-03-18

High-energy diffraction microscopy (HEDM) constitutes a suite of combined X-ray characterization methods, which hold the unique advantage of illuminating the microstructure and micromechanical state of a material during concurrent in situ mechanical deformation. The data generated from HEDM experiments provides a heretofore unrealized opportunity to validate meso-scale modeling techniques, such as crystal plasticity finite element modeling (CPFEM), by explicitly testing the accuracy of these models at the length scales where the models predict their response. Combining HEDM methods with in situ loading under known and controlled boundary conditions represents a significant challenge, inspiring the recent development of a new high-precisionmore » rotation and axial motion system for simultaneously rotating and axially loading a sample. In this paper, we describe the initial HEDM dataset collected using this hardware on an alpha-titanium alloy (Ti-7Al) under in situ tensile deformation at the Advanced Photon Source, Argonne National Laboratory. We present both near-field HEDM data that maps out the grain morphology and intragranular crystallographic orientations and far-field HEDM data that provides the grain centroid, grain average crystallographic orientation, and grain average elastic strain tensor for each grain. Finally, we provide a finite element mesh that can be utilized to simulate deformation in the volume of this Ti-7Al specimen.« less

Determination of Organic Partitioning Coefficients in Water-Supercritical CO2 Systems by Simultaneous in Situ UV and Near-Infrared Spectroscopies.

PubMed

Bryce, David A; Shao, Hongbo; Cantrell, Kirk J; Thompson, Christopher J

2016-06-07

CO2 injected into depleted oil or gas reservoirs for long-term storage has the potential to mobilize organic compounds and distribute them between sediments and reservoir brines. Understanding this process is important when considering health and environmental risks, but little quantitative data currently exists on the partitioning of organics between supercritical CO2 and water. In this work, a high-pressure, in situ measurement capability was developed to assess the distribution of organics between CO2 and water at conditions relevant to deep underground storage of CO2. The apparatus consists of a titanium reactor with quartz windows, near-infrared and UV spectroscopic detectors, and switching valves that facilitate quantitative injection of organic reagents into the pressurized reactor. To demonstrate the utility of the system, partitioning coefficients were determined for benzene in water/supercritical CO2 over the range 35-65 °C and approximately 25-150 bar. Density changes in the CO2 phase with increasing pressure were shown to have dramatic impacts on benzene's partitioning behavior. Our partitioning coefficients were approximately 5-15 times lower than values previously determined by ex situ techniques that are prone to sampling losses. The in situ methodology reported here could be applied to quantify the distribution behavior of a wide range of organic compounds that may be present in geologic CO2 storage scenarios.

A potential drop strain sensor for in-situ power station creep monitoring

NASA Astrophysics Data System (ADS)

Corcoran, Joseph; Cawley, Peter; Nagy, Peter B.

2014-02-01

Creep is a high temperature damage mechanism of interest to the power industry and at present lacks a satisfactory inspection technique. Existing material inspection techniques are extremely laborious while strain measurements rely on often infrequent off-load measurements. A quasi-DC directional potential drop technique has been suggested that is able to suppress the effects of permeability and is primarily sensitive to changes in resistivity and also the geometry that will develop through strain. The change in creep related resistivity is shown by an equivalent effective resistivity approach to be small at <2% change when compared to the >100% change in transfer resistance that occurs due to strain as observed in laboratory tests. A biaxial inversion is then presented and demonstrated on in-lab samples showing good performance. The result is a sensor that performs as a very robust high temperature strain gauge.

Monosomy 3 by FISH in uveal melanoma: variability in techniques and results.

PubMed

Aronow, Mary; Sun, Yang; Saunthararajah, Yogen; Biscotti, Charles; Tubbs, Raymond; Triozzi, Pierre; Singh, Arun D

2012-09-01

Tumor monosomy 3 confers a poor prognosis in patients with uveal melanoma. We critically review the techniques used for fluorescence in situ hybridization (FISH) detection of monosomy 3 in order to assess variability in practice patterns and to explain differences in results. Significant variability that has likely affected reported results was found in tissue sampling methods, selection of FISH probes, number of cells counted, and the cut-off point used to determine monosomy 3 status. Clinical parameters and specific techniques employed to report FISH results should be specified so as to allow meta-analysis of published studies. FISH-based detection of monosomy 3 in uveal melanoma has not been performed in a standardized manner, which limits conclusions regarding its clinical utility. FISH is a widely available, versatile technology, and when performed optimally has the potential to be a valuable tool for determining the prognosis of uveal melanoma. Copyright © 2012 Elsevier Inc. All rights reserved.

Solid Phase Micro-extraction (SPME) with In Situ Transesterification: An Easy Method for the Detection of Non-volatile Fatty Acid Derivatives on the Insect Cuticle.

PubMed

Kühbandner, Stephan; Ruther, Joachim

2015-06-01

Triacylglycerides (TAGs) and other non-volatile fatty acid derivatives (NFADs) occur in large amounts in the internal tissues of insects, but their presence on the insect cuticle is controversially discussed. Most studies investigating cuticular lipids of insects involve solvent extraction, which implies the risk of extracting lipids from internal tissues. Here, we present a new method that overcomes this problem. The method employs solid phase micro-extraction (SPME) to sample NFADs by rubbing the SPME fiber over the insect cuticle. Subsequently, the sampled NFADs are transesterified in situ with trimethyl sulfonium hydroxide (TMSH) into more volatile fatty acid methyl esters (FAMEs), which can be analyzed by standard GC/MS. We performed two types of control experiments to enable significant conclusions: (1) to rule out contamination of the GC/MS system with NFADs, and (2) to exclude the presence of free fatty acids on the insect cuticle, which would also furnish FAMEs after TMSH treatment, and thus might simulate the presence of NFADs. In combination with these two essential control experiments, the described SPME technique can be used to detect TAGs and/or other NFADs on the insect cuticle. We analyzed six insect species from four insect orders with our method and compared the results with conventional solvent extraction followed by ex situ transesterification. Several fatty acids typically found as constituents of TAGs were detected by the SPME method on the cuticle of all species analyzed. A comparison of the two methods revealed differences in the fatty acid compositions of the samples. Saturated fatty acids showed by trend higher relative abundances when sampled with the SPME method, while several minor FAMEs were detected only in the solvent extracts. Our study suggests that TAGs and maybe other NFADs are far more common on the insect cuticle than usually thought.

Extrapolation of in situ data from 1-km squares to adjacent squares using remote sensed imagery and airborne lidar data for the assessment of habitat diversity and extent.

PubMed

Lang, M; Vain, A; Bunce, R G H; Jongman, R H G; Raet, J; Sepp, K; Kuusemets, V; Kikas, T; Liba, N

2015-03-01

Habitat surveillance and subsequent monitoring at a national level is usually carried out by recording data from in situ sample sites located according to predefined strata. This paper describes the application of remote sensing to the extension of such field data recorded in 1-km squares to adjacent squares, in order to increase sample number without further field visits. Habitats were mapped in eight central squares in northeast Estonia in 2010 using a standardized recording procedure. Around one of the squares, a special study site was established which consisted of the central square and eight surrounding squares. A Landsat-7 Enhanced Thematic Mapper Plus (ETM+) image was used for correlation with in situ data. An airborne light detection and ranging (lidar) vegetation height map was also included in the classification. A series of tests were carried out by including the lidar data and contrasting analytical techniques, which are described in detail in the paper. Training accuracy in the central square varied from 75 to 100 %. In the extrapolation procedure to the surrounding squares, accuracy varied from 53.1 to 63.1 %, which improved by 10 % with the inclusion of lidar data. The reasons for this relatively low classification accuracy were mainly inherent variability in the spectral signatures of habitats but also differences between the dates of imagery acquisition and field sampling. Improvements could therefore be made by better synchronization of the field survey and image acquisition as well as by dividing general habitat categories (GHCs) into units which are more likely to have similar spectral signatures. However, the increase in the number of sample kilometre squares compensates for the loss of accuracy in the measurements of individual squares. The methodology can be applied in other studies as the procedures used are readily available.

Protocol for Biomarker Ratio Imaging Microscopy with Specific Application to Ductal Carcinoma In situ of the Breast

PubMed Central

Clark, Andrea J.; Petty, Howard R.

2016-01-01

This protocol describes the methods and steps involved in performing biomarker ratio imaging microscopy (BRIM) using formalin fixed paraffin-embedded (FFPE) samples of human breast tissue. The technique is based on the acquisition of two fluorescence images of the same microscopic field using two biomarkers and immunohistochemical tools. The biomarkers are selected such that one biomarker correlates with breast cancer aggressiveness while the second biomarker anti-correlates with aggressiveness. When the former image is divided by the latter image, a computed ratio image is formed that reflects the aggressiveness of tumor cells while increasing contrast and eliminating path-length and other artifacts from the image. For example, the aggressiveness of epithelial cells may be assessed by computing ratio images of N-cadherin and E-cadherin images or CD44 and CD24 images, which specifically reflect the mesenchymal or stem cell nature of the constituent cells, respectively. This methodology is illustrated for tissue samples of ductal carcinoma in situ (DCIS) and invasive breast cancer. This tool should be useful in tissue studies of experimental cancer as well as the management of cancer patients. PMID:27857940

Linking metabolite production to taxonomic identity in environmental samples by (MA)LDI-FISH

PubMed Central

Kaltenpoth, Martin; Strupat, Kerstin; Svatoš, Aleš

2016-01-01

One of the greatest challenges in microbial ecology remains to link the metabolic activity of individual cells to their taxonomic identity and localization within environmental samples. Here we combined mass-spectrometric imaging (MSI) through (matrix-assisted) laser desorption ionization time-of-flight MSI ([MA]LDI-TOF/MSI) with fluorescence in situ hybridization (FISH) to monitor antibiotic production in the defensive symbiosis between beewolf wasps and ‘Streptomyces philanthi' bacteria. Our results reveal similar distributions of the different symbiont-produced antibiotics across the surface of beewolf cocoons, which colocalize with the producing cell populations. Whereas FISH achieves single-cell resolution, MSI is currently limited to a step size of 20–50 μm in the combined approach because of the destructive effects of high laser intensities that are associated with tighter laser beam focus at higher lateral resolution. However, on the basis of the applicability of (MA)LDI-MSI to a broad range of small molecules, its combination with FISH provides a powerful tool for studying microbial interactions in situ, and further modifications of this technique could allow for linking metabolic profiling to gene expression. PMID:26172211

VISTA: A μ-Thermogravimeter for Investigation of Volatile Compounds in Planetary Environments.

PubMed

Palomba, Ernesto; Longobardo, Andrea; Dirri, Fabrizio; Zampetti, Emiliano; Biondi, David; Saggin, Bortolino; Bearzotti, Andrea; Macagnano, Antonella

2016-06-01

This paper presents the VISTA (Volatile In Situ Thermogravimetry Analyser) instrument, conceived to perform planetary in-situ measurements. VISTA can detect and quantify the presence of volatile compounds of astrobiological interest, such as water and organics, in planetary samples. These measurements can be particularly relevant when performed on primitive asteroids or comets, or on targets of potential astrobiological interest such as Mars or Jupiter's satellite Europa. VISTA is based on a micro-thermogravimetry technique, widely used in different environments to study absorption and sublimation processes. The instrument core is a piezoelectric crystal microbalance, whose frequency variations are affected by variations of the mass of the deposited sample, due to chemical processes such as sublimation, condensation or absorption/desorption. The low mass (i.e. 40 g), the low volume (less than 10 cm(3)) and the low power (less than 1 W) required makes this kind of instrument very suitable for space missions. This paper discusses the planetary applications of VISTA, and shows the calibration operations performed on the breadboard, as well as the performance tests which demonstrate the capability of the breadboard to characterize volatile compounds of planetary interests.

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM.

PubMed

Yao, Juan; Arey, Bruce W; Yang, Li; Zhang, Fei; Komorek, Rachel; Chun, Jaehun; Yu, Xiao-Ying

2017-09-27

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface (SALVI) and Scanning Electron Microscopy (SEM). This paper describes the method and key steps in integrating the vacuum compatible SAVLI to SEM and obtaining secondary electron (SE) images of particles in liquid in high vacuum. Energy dispersive x-ray spectroscopy (EDX) is used to obtain elemental analysis of particles in liquid and control samples including deionized (DI) water only and an empty channel as well. Synthesized boehmite (AlOOH) particles suspended in liquid are used as a model in the liquid SEM illustration. The results demonstrate that the particles can be imaged in the SE mode with good resolution (i.e., 400 nm). The AlOOH EDX spectrum shows significant signal from the aluminum (Al) when compared with the DI water and the empty channel control. In situ liquid SEM is a powerful technique to study particles in liquid with many exciting applications. This procedure aims to provide technical know-how in order to conduct liquid SEM imaging and EDX analysis using SALVI and to reduce potential pitfalls when using this approach.

Use of multiple sensor technologies for quality control of in situ biogeochemical measurements: A SeaCycler case study

NASA Astrophysics Data System (ADS)

Atamanchuk, Dariia; Koelling, Jannes; Lai, Jeremy; Send, Uwe; Wallace, Douglas

2017-04-01

Over the last two decades observing capacity for the global ocean has increased dramatically. Emerging sensor technologies for dissolved gases, nutrients and bio-optical properties in seawater are allowing extension of in situ observations beyond the traditionally measured salinity, temperature and pressure (CTD). However the effort to extend observations using autonomous instruments and platforms carries the risk of losing the level of data quality achievable through conventional water sampling techniques. We will present results from a case study with the SeaCycler profiling winch focusing on quality control of the in-situ measurements. A total of 13 sensors were deployed from May 2016 to early 2017 on SeaCycler's profiling sensor float, including CTD, dissolved oxygen (O2, 3 sensors), carbon dioxide (pCO2, 2 sensors), nutrients, velocity sensors, fluorometer, transmissometer, single channel PAR sensor, and others. We will highlight how multiple measurement technologies (e.g. for O2 and CO2) complement each other and result in a high quality data product. We will also present an initial assessment of the bio-optical data, their implications for seasonal phytoplankton dynamics and comparisons to climatologies and ocean-color data products obtained from the MODIS satellite.

In-situ measurements of rare earth elements in deep sea sediments using nuclear methods.

PubMed

Obhođaš, Jasmina; Sudac, Davorin; Meric, Ilker; Pettersen, Helge E S; Uroić, Milivoj; Nađ, Karlo; Valković, Vlado

2018-03-21

The prospecting activities for finding new rare earth elements (REE) sources have increased greatly in recent years. One of the main discoveries was announced in 2011 by Japanese researchers who found large quantities of REE on the ocean seafloor at the sea depths greater than 4,000 m. The classic approach to investigate REE in deep sea sediments is to obtain sediment samples by drilling that is followed by laborious laboratory analysis. This is very expensive, time consuming and not appropriate for exploring vast areas. In order to efficiently explore the ocean floor for REE deposits, the further development of affordable sensors is needed. Here, we propose two nuclear techniques for exploring REE in surface deep sea sediments: i) Passive measurement of lutetium-176 radioactivity, appropriate if long-term in-situ measurements are possible, and ii) The use of the neutron sensor attached to a remotely operated vehicle for rapid in-situ measurement of gadolinium by thermal neutron-capture. Since concentrations of lutetium and gadolinium show strong linear correlation to the total REE concentrations in deep sea sediments, it is possible to deduce the total REE content by measuring Lu or Gd concentrations only.

Post-activation of in situ Bsbnd F codoped g-C3N4 for enhanced photocatalytic H2 evolution

NASA Astrophysics Data System (ADS)

Cui, Yanjuan; Wang, Hao; Yang, Chuanfeng; Li, Ming; Zhao, Yimeng; Chen, Fangyan

2018-05-01

Porous graphitic carbon nitride polymer (p-CN-BF) with enhanced photoproduction of H2 from water was prepared by a two-step treatment process including in-situ Boron and fluorine codoping using [Emim]BF4 as dopants followed by post-calcination in air. Several techniques were employed to characterize the modified structure and elucidate the doping state of B and F. It was shown that in-situ doping method is necessary for efficient doping of heteroatoms into the molecular composition of CN. The difference of doping state of B and F was that B doping primary existing in the inside skeleton of CN, but F doping merely presents in the surface layer. The inside doped B made for the enhanced visible light absorption and the production of uniform porous structure during post-sintering process. By the synergistic effect of Bsbnd F codoping and post-activation, p-CN-BF showed much enhanced photoelectron generation, transmission and separation, therefore, it performs high photocatalytic activity for H2 evolution (351 μmol h-1), which was 13 and 5 times higher than samples only modified by Bsbnd F codoping (CN-BF) or post-annealing (P-CN).

MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

PubMed Central

Fujimura, Yoshinori; Miura, Daisuke

2014-01-01

Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI) enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI)-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors), and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality) research. PMID:24957029

Rapid identification of bacteria with miniaturized pyrolysis/GC analysis

NASA Astrophysics Data System (ADS)

Morgan, Catherine H.; Mowry, Curtis; Manginell, Ronald P.; Frye-Mason, Gregory C.; Kottenstette, Richard J.; Lewis, Patrick

2001-02-01

Identification of bacteria and other biological moieties finds a broad range of applications in the environmental, biomedical, agricultural, industrial, and military arenas. Linking these applications are biological markers such as fatty acids, whose mass spectral profiles can be used to characterize biological samples and to distinguish bacteria at the gram-type, genera, and even species level. Common methods of sample analysis require sample preparation that is both lengthy and labor intensive, especially for whole cell bacteria. The background technique relied on here utilizes chemical derivatization of fatty acids to the more volatile fatty acid methyl esters (FAMEs), which can be separated on a gas chromatograph column or input directly into a mass spectrometer. More recent publications demonstrate improved sample preparation time with in situ derivatization of whole bacterial samples using pyrolysis at the inlet; although much faster than traditional techniques, these systems still rely on bench-top analytical equipment and individual sample preparation. Development of a miniaturized pyrolysis/GC instrument by this group is intended to realize the benefits of FAME identification of bacteria and other biological samples while further facilitating sample handling and instrument portability. The technologies being fabricated and tested have the potential of achieving pyrolysis and FAME separation on a very small scale, with rapid detection time (1-10 min from introduction to result), and with a modular sample inlet. Performance results and sensor characterization will be presented for the first phase of instrument development, encompassing the microfabricated pyrolysis and gas chromatograph elements.

Mesures spectroscopiques de constituants et de polluants atmosphériques par techniques in situ et à distance, au sol ou embarquéesSpectroscopic measurements of atmospheric constituents and pollutants by in situ and remote techniques from the ground and in flight

NASA Astrophysics Data System (ADS)

Camy-Peyret, Claude; Payan, Sébastien; Jeseck, Pascal; Té, Yao

2001-09-01

Infrared spectroscopy is a powerful tool for precise measurements of atmospheric trace species concentrations through the use of characteristic spectral signatures of the different molecular species and their associated vibration-rotation bands in the mid- or near-infrared. Different methods based on quantitative spectroscopy permit tropospheric or stratospheric measurements: in situ long path absorption, atmospheric absorption/emission by Fourier transform spectroscopy with high spectral resolution instruments on the ground, airborne, balloon-borne or satellite-borne.

Evaluating Acoustic Emission Signals as an in situ process monitoring technique for Selective Laser Melting (SLM)

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

Fisher, Karl A.; Candy, Jim V.; Guss, Gabe

2016-10-14

In situ real-time monitoring of the Selective Laser Melting (SLM) process has significant implications for the AM community. The ability to adjust the SLM process parameters during a build (in real-time) can save time, money and eliminate expensive material waste. Having a feedback loop in the process would allow the system to potentially ‘fix’ problem regions before a next powder layer is added. In this study we have investigated acoustic emission (AE) phenomena generated during the SLM process, and evaluated the results in terms of a single process parameter, of an in situ process monitoring technique.

Engineering of oriented carbon nanotubes in composite materials

PubMed Central

Beigmoradi, Razieh; Mohebbi-Kalhori, Davod

2018-01-01

The orientation and arrangement engineering of carbon nanotubes (CNTs) in composite structures is considered a challenging issue. In this regard, two groups of in situ and ex situ techniques have been developed. In the first, the arrangement is achieved during CNT growth, while in the latter, the CNTs are initially grown in random orientation and the arrangement is then achieved during the device integration process. As the ex situ techniques are free from growth restrictions and more flexible in terms of controlling the alignment and sorting of the CNTs, they are considered by some as the preferred technique for engineering of oriented CNTs. This review focuses on recent progress in the improvement of the orientation and alignment of CNTs in composite materials. Moreover, the advantages and disadvantages of the processes are discussed as well as their future outlook. PMID:29515955

High resolution spectroscopic mapping imaging applied in situ to multilayer structures for stratigraphic identification of painted art objects

NASA Astrophysics Data System (ADS)

Karagiannis, Georgios Th.

2016-04-01

The development of non-destructive techniques is a reality in the field of conservation science. These techniques are usually not so accurate, as the analytical micro-sampling techniques, however, the proper development of soft-computing techniques can improve their accuracy. In this work, we propose a real-time fast acquisition spectroscopic mapping imaging system that operates from the ultraviolet to mid infrared (UV/Vis/nIR/mIR) area of the electromagnetic spectrum and it is supported by a set of soft-computing methods to identify the materials that exist in a stratigraphic structure of paint layers. Particularly, the system acquires spectra in diffuse-reflectance mode, scanning in a Region-Of-Interest (ROI), and having wavelength range from 200 up to 5000 nm. Also, a fuzzy c-means clustering algorithm, i.e., the particular soft-computing algorithm, produces the mapping images. The evaluation of the method was tested on a byzantine painted icon.

High-resolution fiber-optic microendoscopy for in situ cellular imaging.

PubMed

Pierce, Mark; Yu, Dihua; Richards-Kortum, Rebecca

2011-01-11

Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution. Traditionally, multiple experiments are run in parallel, with individual samples removed from the study at sequential time points for evaluation by light microscopy. Several intravital techniques have been developed, with confocal, multiphoton, and second harmonic microscopy all demonstrating their ability to be used for imaging in situ. With these systems, however, the required infrastructure is complex and expensive, involving scanning laser systems and complex light sources. Here we present a protocol for the design and assembly of a high-resolution microendoscope which can be built in a day using off-the-shelf components for under US$5,000. The platform offers flexibility in terms of image resolution, field-of-view, and operating wavelength, and we describe how these parameters can be easily modified to meet the specific needs of the end user. We and others have explored the use of the high-resolution microendoscope (HRME) in in vitro cell culture, in excised and living animal tissues, and in human tissues in vivo. Users have reported the use of several different fluorescent contrast agents, including proflavine, benzoporphyrin-derivative monoacid ring A (BPD-MA), and fluoroscein, all of which have received full, or investigational approval from the FDA for use in human subjects. High-resolution microendoscopy, in the form described here, may appeal to a wide range of researchers working in the basic and clinical sciences. The technique offers an effective and economical approach which complements traditional benchtop microscopy, by enabling the user to perform high-resolution, longitudinal imaging in situ.

Development of in situ two-coil mutual inductance technique in a multifunctional scanning tunneling microscope.

PubMed

Duan, Ming-Chao; Liu, Zhi-Long; Ge, Jian-Feng; Tang, Zhi-Jun; Wang, Guan-Yong; Wang, Zi-Xin; Guan, Dandan; Li, Yao-Yi; Qian, Dong; Liu, Canhua; Jia, Jin-Feng

2017-07-01

Superconducting thin films have been a focal point for intensive research efforts since their reduced dimension allows for a wide variety of quantum phenomena. Many of these films, fabricated in UHV chambers, are highly vulnerable to air exposure, making it difficult to measure intrinsic superconducting properties such as zero resistance and perfect diamagnetism with ex situ experimental techniques. Previously, we developed a multifunctional scanning tunneling microscope (MSTM) containing in situ four-point probe (4PP) electrical transport measurement capability in addition to the usual STM capabilities [Ge et al., Rev. Sci. Instrum. 86, 053903 (2015)]. Here we improve this MSTM via development of both transmission and reflection two-coil mutual inductance techniques for in situ measurement of the diamagnetic response of a superconductor. This addition does not alter the original STM and 4PP functions of the MSTM. We demonstrate the performance of the two-coil mutual inductance setup on a 10-nm-thick NbN thin film grown on a Nb-doped SrTiO 3 (111) substrate.

A quantitative and non-contact technique to characterise microstructural variations of skin tissues during photo-damaging process based on Mueller matrix polarimetry.

PubMed

Dong, Yang; He, Honghui; Sheng, Wei; Wu, Jian; Ma, Hui

2017-10-31

Skin tissue consists of collagen and elastic fibres, which are highly susceptible to damage when exposed to ultraviolet radiation (UVR), leading to skin aging and cancer. However, a lack of non-invasive detection methods makes determining the degree of UVR damage to skin in real time difficult. As one of the fundamental features of light, polarization can be used to develop imaging techniques capable of providing structural information about tissues. In particular, Mueller matrix polarimetry is suitable for detecting changes in collagen and elastic fibres. Here, we demonstrate a novel, quantitative, non-contact and in situ technique based on Mueller matrix polarimetry for monitoring the microstructural changes of skin tissues during UVR-induced photo-damaging. We measured the Mueller matrices of nude mouse skin samples, then analysed the transformed parameters to characterise microstructural changes during the skin photo-damaging and self-repairing processes. Comparisons between samples with and without the application of a sunscreen showed that the Mueller matrix-derived parameters are potential indicators for fibrous microstructure in skin tissues. Histological examination and Monte Carlo simulations confirmed the relationship between the Mueller matrix parameters and changes to fibrous structures. This technique paves the way for non-contact evaluation of skin structure in cosmetics and dermatological health.

Method and apparatus for improved observation of in-situ combustion processes

DOEpatents

Lee, D.O.; Montoya, P.C.; Wayland, J.R. Jr.

Method and apparatus are provided for obtaining accurate dynamic measurements for passage of phase fronts through a core sample in a test fixture. Flow-through grid structures are provided for electrodes to permit data to be obtained before, during and after passage of a front there-through. Such electrodes are incorporated in a test apparatus for obtaining electrical characteristics of the core sample. With the inventive structure a method is provided for measurement of instabilities in a phase front progressing through the medium. Availability of accurate dynamic data representing parameters descriptive of material characteristics before, during and after passage of a front provides a more efficient method for enhanced recovery of oil using a fire flood technique. 6 figures, 2 tables.

OASIS: Organics Analyzer for Sampling Icy Surfaces

NASA Technical Reports Server (NTRS)

Getty, S. A.; Dworkin, J. P.; Glavin, D. P.; Martin, M.; Zheng, Y.; Balvin, M.; Southard, A. E.; Ferrance, J.; Malespin, C.

2012-01-01

Liquid chromatography mass spectrometry (LC-MS) is a well established laboratory technique for detecting and analyzing organic molecules. This approach has been especially fruitful in the analysis of nucleobases, amino acids, and establishing chirol ratios [1 -3]. We are developing OASIS, Organics Analyzer for Sampling Icy Surfaces, for future in situ landed missions to astrochemically important icy bodies, such as asteroids, comets, and icy moons. The OASIS design employs a microfabricated, on-chip analytical column to chromatographically separate liquid ana1ytes using known LC stationary phase chemistries. The elution products are then interfaced through electrospray ionization (ESI) and analyzed by a time-of-flight mass spectrometer (TOF-MS). A particular advantage of this design is its suitability for microgravity environments, such as for a primitive small body.

Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China.

PubMed

Shao, Shi-Cheng; Burgess, Kevin S; Cruse-Sanders, Jennifer M; Liu, Qiang; Fan, Xu-Li; Huang, Hui; Gao, Jiang-Yun

2017-01-01

Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum , in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum) did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44%) with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35%) at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae.

The effects of crosslinkers on physical, mechanical, and cytotoxic properties of gelatin sponge prepared via in-situ gas foaming method as a tissue engineering scaffold.

PubMed

Poursamar, S Ali; Lehner, Alexander N; Azami, Mahmoud; Ebrahimi-Barough, Somayeh; Samadikuchaksaraei, Ali; Antunes, A P M

2016-06-01

In this study porous gelatin scaffolds were prepared using in-situ gas foaming, and four crosslinking agents were used to determine a biocompatible and effective crosslinker that is suitable for such a method. Crosslinkers used in this study included: hexamethylene diisocyanate (HMDI), poly(ethylene glycol) diglycidyl ether (epoxy), glutaraldehyde (GTA), and genipin. The prepared porous structures were analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), thermal and mechanical analysis as well as water absorption analysis. The microstructures of the prepared samples were analyzed using Scanning Electron Microscopy (SEM). The effects of the crosslinking agents were studied on the cytotoxicity of the porous structure indirectly using MTT analysis. The affinity of L929 mouse fibroblast cells for attachment on the scaffold surfaces was investigated by direct cell seeding and DAPI-staining technique. It was shown that while all of the studied crosslinking agents were capable of stabilizing prepared gelatin scaffolds, there are noticeable differences among physical and mechanical properties of samples based on the crosslinker type. Epoxy-crosslinked scaffolds showed a higher capacity for water absorption and more uniform microstructures than the rest of crosslinked samples, whereas genipin and GTA-crosslinked scaffolds demonstrated higher mechanical strength. Cytotoxicity analysis showed the superior biocompatibility of the naturally occurring genipin in comparison with other synthetic crosslinking agents, in particular relative to GTA-crosslinked samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Active Sampling Device for Determining Pollutants in Surface and Pore Water - the In Situ Sampler for Biphasic Water Monitoring

NASA Astrophysics Data System (ADS)

Supowit, Samuel D.; Roll, Isaac B.; Dang, Viet D.; Kroll, Kevin J.; Denslow, Nancy D.; Halden, Rolf U.

2016-02-01

We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040-0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction.

Direct measurement of toxicants inhaled by water pipe users in the natural environment using a real-time in situ sampling technique.

PubMed

Katurji, M; Daher, N; Sheheitli, H; Saleh, R; Shihadeh, A

2010-11-01

While narghile water pipe smoking has become a global phenomenon, knowledge regarding its toxicant content and delivery, addictive properties, and health consequences is sorely lagging. One challenge in measuring toxicant content of the smoke in the laboratory is the large number of simplifying assumptions that must be made to model a "typical" smoking session using a smoking machine, resulting in uncertainty over the obtained toxicant yields. In this study, we develop an alternative approach in which smoke generated by a human water pipe user is sampled directly during the smoking session. The method, dubbed real-time in situ sampling (RINS), required developing a self-powered portable instrument capable of automatically sampling a fixed fraction of the smoke generated by the user. Instrument performance was validated in the laboratory, and the instrument was deployed in a field study involving 43 ad libitum water pipe use sessions in Beirut area cafés in which we measured inhaled nicotine, carbon monoxide (CO), and water pipe ma'ssel-derived "tar." We found that users drew a mean of 119 L of smoke containing 150 mg of CO, 4 mg of nicotine, and 602 mg of ma'ssel-derived "tar" during a single use session (mean duration = 61 min). These first direct measurements of toxicant delivery demonstrate that ordinary water pipe use involves inhaling large quantities of CO, nicotine, and dry particulate matter. Results are compared with those obtained using the Beirut method smoking machine protocol.

In situ one-pot fabrication of g-C3N4 nanosheets/NiS cocatalyst heterojunction with intimate interfaces for efficient visible light photocatalytic H2 generation

NASA Astrophysics Data System (ADS)

He, Kelin; Xie, Jun; Li, Mingli; Li, Xin

2018-02-01

Constructing high-quality earth-abundant semionconductor/cocatalyst heterojunction remains a grand challenge in the promising fields of photocatalytic solar fuel H2 production. Herein, an intimate g-C3N4 nanosheet/NiS cocatalyst heterojunction is fabricated by in situ one-step calcination of urea, thiourea and nickel acetate. Interestingly, thiourea could act as both the precursor of g-C3N4 and the sulfur source of NiS. The H2-evolution activity of as-obtained photocatalysts was tested in a triethanolamine (TEOA) scavenger solution under visible light irradiation. Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) mapping analysis clearly demonstrated that the NiS catalyst nanoparticles could be in situ fabricated and homogeneously distributed on the surface of g-C3N4 nanosheets without an obvious aggregation. The maximum H2-production rate of 29.68 μmol h-1 could be achieved, which is nearly comparable to that of 0.5 wt% Pt loaded sample. It is believed that the intimate heterojunction interfaces between NiS nanoparticles and g-C3N4 nanosheets could be in situ constructed by high temperature calcination, which achieved the improved charge separation, the enhanced oxidation ability of TEOA and the accelerated the sluggish H2-evolution kinetics, thus resulting in the remarkably enhanced hydrogen evolution. Therefore, our study provides insights into constructing high-quality robust g-C3N4-based heterojunction material for photocatalytic applications by using a simple one-step in-situ calcination technique.

M-FISH Analysis of Chromosome Aberrations in Human Fibroblast Cells After In Vitro Exposure to Low- and High-LET Radiation

NASA Technical Reports Server (NTRS)

Wu, Honglu; Furusawa, Yoshiya; George, Kerry; Kawata, Tetsuya; Cucinotta, Francis

2002-01-01

The recently commercialized multiplex fluorescence in situ hybridization (m-FISH) technique, which allows human chromosomes to be painted in 24 different colors, was used to analyze chromosome aberrations in diploid human fibroblast cells after in vitro radiation exposure. Confluent flasks of a normal primary fibroblast cell line (AG 1522) were irradiated at high dose rates with either gamma rays or 200 MeV/nucleon Fe ions (LET = 440 keV/micron), incubated at 37 C for 24 hours after exposure, and subsequently subcultured. A chemically induced premature chromosome condensation technique was used to collect chromosome samples 32 hours after subculture. Results showed that the fraction of exchanges which were identified as complex, i.e. involving misrejoining of three or more DSB, were higher in the Fe-irradiated samples compared with the gamma-irradiated samples, as has been shown previously using FISH with one or two painted chromosomes . The ratios of complex/simple type exchanges were similar for samples irradiated with 0.7 Gy and 3 Gy of Fe ions, although exchanges involving five or more breaks were found only in 3 Gy irradiated samples. The fraction of incomplete exchanges was also higher in Fe- than gamma-irradiated samples. Data on the distribution of individual chromosome involvement in interchromosomal exchanges will be presented.

Contribution a la caracterisation des betons endommages par des methodes de l'acoustique non lineaire. Application a la reaction alcalis-silice

NASA Astrophysics Data System (ADS)

Kodjo, Apedovi

The aim of this thesis is to contribute to the non-destructive characterization of concrete materials damaged by alkali-silica reaction (ASR). For this purpose, some nonlinear characterization techniques have been developed, as well as a nonlinear resonance test device. In order to optimize the sensitivity of the test device, the excitation module and signal processing have been improved. The nonlinear tests were conducted on seven samples of concrete damaged by ASR, three samples of concrete damaged by heat, three concrete samples damaged mechanically and three sound concrete samples. Since, nonlinear behaviour of the material is often attribute to its micro-defects hysteretic behaviour, it was shown at first that concrete damaged by ASR exhibits an hysteresis behaviour. To conduct this study, an acoustoelastic test was set, and then nonlinear resonance test device was used for characterizing sound concrete and concrete damaged by ASR. It was shown that the nonlinear technique can be used for characterizing the material without knowing its initial state, and also for detecting early damage in the reactive material. Studies were also carried out on the effect of moisture regarding the nonlinear parameters; they allowed understanding the low values of nonlinear parameters measured on concrete samples that were kept in high moisture conditions. In order to find a specific characteristic of damage caused by ASR, the viscosity of ASR gel was used. An approach, based on static creep analysis, performed on the material, while applying the nonlinear resonance technique. The spring-damping model of Maxwell was used for the interpretation of the results. Then, the creep time was analysed on samples damaged by ASR. It appears that the ASR gel increases the creep time. Finally, the limitations of the nonlinear resonance technique for in situ application have been explained and a new applicable nonlinear technique was initiated. This technique use an external source such as a mass for making non-linearity behaviour in the material, while an ultrasound wave is investigating the medium. Keywords. Concrete, Alkali-silica reaction, Nonlinear acoustics, Nonlinearity, Hysteresis, Damage diagnostics.

Salivary density of Streptococcus mutans and Streptococcus sobrinus and dental caries in children and adolescents with Down syndrome

PubMed Central

SCALIONI, Flávia; CARRADA, Camila; MACHADO, Fernanda; Karina, DEVITO; RIBEIRO, Luiz Cláudio; CESAR, Dionéia; RIBEIRO, Rosangela

2017-01-01

Abstract Streptococcus mutans and Streptococcus sobrinus are strongly associated with dental caries. However, the relationship between oral streptococci and dental caries in children with Down syndrome is not well characterized. Objective To assess and compare dental caries experience and salivary S. mutans, S. sobrinus, and streptococci counts between groups of Down syndrome and non-Down syndrome children and adolescents. Material and Methods This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Dental caries experience was estimated by the number of decayed, missing, and filled teeth in the primary dentition and the permanent dentition. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization technique was used to identify the presence and counts of the bacteria. The statistical analysis included chi-square, Student’s t-test and Spearman’s correlation. Results The G-DS exhibited a significantly higher caries-free rate (p<0.001) and a lower S. mutans salivary density (p<0.001). No significant differences were found in the salivary densities of S. sobrinus or streptococci between the groups (p=0.09 and p=0.21, respectively). The salivary S. mutans or S. sobrinus densities were not associated with dental caries experience in neither group. Conclusion The reduced dental caries experience observed in this group of Down syndrome children and adolescents cannot be attributed to lower salivary S. mutans densities, as determined with the fluorescence in situ hybridization technique. PMID:28678943

A laser GC-IRMS technique for in situ stable isotope analyses of carbonates and phosphates

NASA Astrophysics Data System (ADS)

Sharp, Z. D.; Cerling, T. E.

1996-08-01

A technique is described whereby in situ carbon and oxygen isotope analyses of carbonates and organic phosphates can be made with the use of a CO 2 laser. The CO 2 gas generated by thermal decarbonation from the laser is entrained in a helium carrier gas, passes through a chromatographic column (GC), and is admitted directly into the isotope ratio mass spectrometer (IRMS). No vacuum systems, pumps, or cryogenic traps are used. All carbonates and biogenic phosphates can be analyzed, no special sample preparation is required and analyses can be made every 3 minutes. The use of a helium carrier gas allows for extremely small samples to be analyzed and the GC column effectively separates CO 2 from any other potential contaminating gases (e.g., SO 2 which is a particular problem in organic apatite). The average reproducibility of calcite, dolomite, magnesite, rhodochrosite, siderite, and smithsonite (ZnCO 3) is 0.29‰ for oxygen and 0.1‰ for carbon (1σ); the most "homogeneous" samples are reproducible to better than 0.1‰ for carbon and 0.2‰ for oxygen. The difference between the laser and conventional values for carbon isotope ratios [Δ 13C (laser-conv)] is 0.05 ± 0.30‰ for all carbonates (excluding siderite). The Δ 18O(laser-conv) value varies from carbonate to carbonate and may be related to the electronegativities of the cations, grain size (or crystallinity), formation of CO and O 2, and reaction with included organic matter. For calcite and rhodochrosite, the Δ 18O(laser-conv) value is 0.3 ± 0.4‰; for siderite, magnesite, and dolomite, the Δ 18O(laser-conv) value is 1.7 ± 0.3‰. The δ 13C values of tooth enamel are the same as those obtained by conventional acid digestion. The laser δ 18O values are equal to the δ 18O values of the phosphate, and approx. 7‰ lighter than the "carbonate" oxygen. The carbonate group in the apatite (equiv. 7.6% oxygen) exchanges with the (PO 4=)-bound oxygen to produce CO 2 with a δ 18O equal to the phosphate oxygen. The laser technique provides a rapid alternative to the difficult phosphate extraction technique for oxygen isotope measurements in tooth enamel.

Cryo-isolation: a novel method for enzyme-free isolation of pancreatic islets involving in situ cryopreservation of islets and selective destruction of acinar tissue.

PubMed

Taylor, M J; Baicu, S

2011-11-01

A critical component of treating type I diabetes by transplantation is the availability of sufficient high-quality islets. Currently, islets can be obtained only by reliance on an expensive, inconsistent, and toxic enzyme digestion process. As an alternative, we hypothesize that cryobiologic techniques can be used for differential freeze destruction of the pancreas to release islets that are selectively cryopreserved in situ. Pancreases were procured from juvenile pigs with the use of approved procedures. The concept of cryo-isolation is based on differential processing of the pancreas in 5 stages: 1) infiltrating islets in situ preferentially with a cryoprotectant (CPA) cocktail via antegrade perfusion of the major arteries; 2) retrograde ductal infusion of water (or saline solution) to fully distend the gland; 3) freezing the entire pancreas to -160°C, and stored in liquid nitrogen; 4) mechanically crushing and pulverizing the frozen pancreas into small fragments; and 5) thawing, filtering and washing the frozen fragments with RPMI 1640 culture medium to remove the CPA. Finally, the filtered effluent (cryo-isolate) was stained with dithizone for identification of intact islets, and samples were taken for static glucose-stimulated insullin release assessment. As predicted the cryo-isolated contained small fragments of residual tissue comprising an amorphous mass of acinar tissue with largely intact embedded islets. The degree of cleavage of the cryoprotected islets from the freeze-destroyed exocrine cells, was variable. Islets were typically larger than their counterparts isolated from juvenile pigs with conventional enzyme-digestion techniques. Functionally, the islets from replicate cryo-isolates responded to a glucose challenge with a mean stimulation index = 3.3 ± 0.7 (n = 3). An enzyme-free method of islet isolation relying on in situ cryopreservation of islets with simultaneous freeze-destruction of acinar tissue is feasible and proposed as a novel method that avoids the problems associated with conventional collagenase digestion methods. Copyright © 2011 Elsevier Inc. All rights reserved.

Considerations for standardizing predictive molecular pathology for cancer prognosis.

PubMed

Fiorentino, Michelangelo; Scarpelli, Marina; Lopez-Beltran, Antonio; Cheng, Liang; Montironi, Rodolfo

2017-01-01

Molecular tests that were once ancillary to the core business of cyto-histopathology are becoming the most relevant workload in pathology departments after histopathology/cytopathology and before autopsies. This has resulted from innovations in molecular biology techniques, which have developed at an incredibly fast pace. Areas covered: Most of the current widely used techniques in molecular pathology such as FISH, direct sequencing, pyrosequencing, and allele-specific PCR will be replaced by massive parallel sequencing that will not be considered next generation, but rather, will be considered to be current generation sequencing. The pre-analytical steps of molecular techniques such as DNA extraction or sample preparation will be largely automated. Moreover, all the molecular pathology instruments will be part of an integrated workflow that traces the sample from extraction to the analytical steps until the results are reported; these steps will be guided by expert laboratory information systems. In situ hybridization and immunohistochemistry for quantification will be largely digitalized as much as histology will be mostly digitalized rather than viewed using microscopy. Expert commentary: This review summarizes the technical and regulatory issues concerning the standardization of molecular tests in pathology. A vision of the future perspectives of technological changes is also provided.

Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

NASA Technical Reports Server (NTRS)

Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

2016-01-01

Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

High-energy x-ray diffraction from surfaces and nanoparticles

NASA Astrophysics Data System (ADS)

Hejral, U.; Müller, P.; Shipilin, M.; Gustafson, J.; Franz, D.; Shayduk, R.; Rütt, U.; Zhang, C.; Merte, L. R.; Lundgren, E.; Vonk, V.; Stierle, A.

2017-11-01

High-energy surface-sensitive x-ray diffraction (HESXRD) is a powerful high-energy photon technique (E > 70 keV) that has in recent years proven to allow a fast data acquisition for the 3D structure determination of surfaces and nanoparticles under in situ and operando conditions. The use of a large-area detector facilitates the direct collection of nearly distortion-free diffraction patterns over a wide q range, including crystal truncation rods perpendicular to the surface and large-area reciprocal space maps from epitaxial nanoparticles, which is not possible in the conventional low-photon energy approach (E =10 -20 keV ). Here, we present a comprehensive mathematical approach, explaining the working principle of HESXRD for both single-crystal surfaces and epitaxial nanostructures on single-crystal supports. The angular calculations used in conventional crystal truncation rod measurements at low-photon energies are adopted for the high-photon-energy regime, illustrating why and to which extent large reciprocal-space areas can be probed in stationary geometry with fixed sample rotation. We discuss how imperfections such as mosaicity and finite domain size aid in sampling a substantial part of reciprocal space without the need of rotating the sample. An exact account is given of the area probed in reciprocal space using such a stationary mode, which is essential for in situ or operando time-resolved experiments on surfaces and nanostructures.

Development of a fluorescence in situ hybridization protocol for the identification of micro-organisms associated with wastewater particles and flocs.

PubMed

Ormeci, Banu; Linden, Karl G

2008-11-01

Fluorescence in situ hybridization (FISH) provides a unique tool to study micro-organisms associated with particles and flocs. FISH enables visual examination of micro-organisms while they are structurally intact and associated with particles. However, application of FISH to wastewater and sludge samples presents a specific set of problems. Wastewater samples generate high background fluorescence due to their organic and inorganic content making it difficult to differentiate a probe-conferred signal from naturally fluorescing particles with reasonable certainty. Furthermore, some of the FISH steps involve harsh treatment of samples, and are likely to disrupt the floc structure. This study developed a FISH protocol for studying micro-organisms that are associated with particles and flocs. The results indicate that choice of a proper fluorochrome and labeling technique is a key step in reducing the background fluorescence and non-specific binding, and increasing the intensity of the probe signal. Compared to other fluorochromes tested, CY3 worked very well and enabled the observation of particles and debris in red and probe signal from microbes in yellow. Fixation, hybridization, and washing steps disturbed the floc structure and particle-microbe association. Modifications to these steps were necessary, and were achieved by replacing centrifugation with filtration and employment of nylon filters. Microscope slides generated excellent quality images, but polycarbonate membrane filters performed better in preserving the floc structure.

A Field-Based Cleaning Protocol for Sampling Devices Used in Life-Detection Studies

NASA Astrophysics Data System (ADS)

Eigenbrode, Jennifer; Benning, Liane G.; Maule, Jake; Wainwright, Norm; Steele, Andrew; Amundsen, Hans E. F.

2009-06-01

Analytical approaches to extant and extinct life detection involve molecular detection often at trace levels. Thus, removal of biological materials and other organic molecules from the surfaces of devices used for sampling is essential for ascertaining meaningful results. Organic decontamination to levels consistent with null values on life-detection instruments is particularly challenging at remote field locations where Mars analog field investigations are carried out. Here, we present a seven-step, multi-reagent decontamination method that can be applied to sampling devices while in the field. In situ lipopolysaccharide detection via low-level endotoxin assays and molecular detection via gas chromatography-mass spectrometry were used to test the effectiveness of the decontamination protocol for sampling of glacial ice with a coring device and for sampling of sediments with a rover scoop during deployment at Arctic Mars-analog sites in Svalbard, Norway. Our results indicate that the protocols and detection technique sufficiently remove and detect low levels of molecular constituents necessary for life-detection tests.

A field-based cleaning protocol for sampling devices used in life-detection studies.

PubMed

Eigenbrode, Jennifer; Benning, Liane G; Maule, Jake; Wainwright, Norm; Steele, Andrew; Amundsen, Hans E F

2009-06-01

Analytical approaches to extant and extinct life detection involve molecular detection often at trace levels. Thus, removal of biological materials and other organic molecules from the surfaces of devices used for sampling is essential for ascertaining meaningful results. Organic decontamination to levels consistent with null values on life-detection instruments is particularly challenging at remote field locations where Mars analog field investigations are carried out. Here, we present a seven-step, multi-reagent decontamination method that can be applied to sampling devices while in the field. In situ lipopolysaccharide detection via low-level endotoxin assays and molecular detection via gas chromatography-mass spectrometry were used to test the effectiveness of the decontamination protocol for sampling of glacial ice with a coring device and for sampling of sediments with a rover scoop during deployment at Arctic Mars-analog sites in Svalbard, Norway. Our results indicate that the protocols and detection technique sufficiently remove and detect low levels of molecular constituents necessary for life-detection tests.

Quantum dot formation by molecular beam epitaxy of Ge on Si(100)

NASA Astrophysics Data System (ADS)

Chaparro, Sergio Arturo

1999-11-01

A new technique for producing electron systems with quantum confinement in three dimensions, quantum dots, has been studied. These quantum dots are coherent islands spontaneously formed at the early stages of Ge/Si(100) epitaxy due to the misfit of the system. Our goal is to gain understanding and control of the growth process so uniform quantum dot ensembles can be created for possible use in optoelectronic devices. A UHV Molecular Beam Epitaxy (MBE) growth system was built and calibrated to grow our samples. The samples were prepared by depositing Ge onto a Si(100) surface cleaned by flash desorption of the native oxides. Varying the growth rates from 0.6 ML/min to 4.0 ML/min, the substrate temperature from 450°C to 600°C, and the coverage from 3.5 ML to 14 ML produces different sample morphologies. After growth, the samples were analyzed both in situ and ex situ. The in situ analysis consisted of Auger electron spectroscopy for elemental analysis and reflection high energy electron diffraction, for surface structure analysis. The ex situ analysis included atomic force microscopy (AFM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM). Many digital images were obtained from the microscope analysis. A novel, computer based, analysis was developed to extract the islands parameters from the microscope images. This data, which includes island area and average height for each island on every image, was used for a statistical analysis. Also from the data, island size distributions (histograms of island size) were generated. These measurements confirm that islands form after growth of a 3 ML wetting layer and that islands evolve as they grow. As more Ge is deposited these islands grow and as they grow they evolve from huts, square based pyramids, to domes, truncated pyramids, to dislocated domes. Our results show that the substrate temperature, deposition rate, and amount of deposited material are factors that affect the growth evolution. Higher growth temperature affects the size at which islands evolve from one type of island to another, also introduces new strain release mechanisms such as alloying and trench formation that compete with dislocation formation. Finally a detailed morphological characterization of the observed islands was done.

A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces

NASA Astrophysics Data System (ADS)

Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.

2013-06-01

A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 °C. The evolved 40Ar∗/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (˜1030 °C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer. Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 ± 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of isotope ratio determinations, likely better than ±5%.

In situ studies of velocity in fractured crystalline rocks.

USGS Publications Warehouse

Moos, D.; Zoback, M.D.

1983-01-01

A study of the effects of macroscopic fractures on P and S wave velocities has been conducted in four wells drilled in granitic rock to depths between 0.6 and 1.2km. The effect of macroscopic fractures is to decrease both Vp and Vs and increase Vp/Vs. In wells with a relatively low density of macroscopic fractures, the in situ velocity is similar to that of saturated core samples under confining pressure in the laboratory, and there is a clear correlation between zones with macroscopic fractures and anomalously low velocities. In wells with numerous macroscopic fractures, the in situ velocity is lower than that of intact samples under pressure, and there is a correlation between the rate at which in situ velocity increases with depth and the rate at which the velocity of laboratory samples increases with pressure. Differences in in situ P wave velocity between wells cannot be explained solely by differences in the degree of macroscopic fracturing, thus emphasizing the importance of composition and microcracks on velocity.-from Authors

An improved FIB sample preparation technique for site-specific plan-view specimens: A new cutting geometry.

PubMed

Li, Chen; Habler, Gerlinde; Baldwin, Lisa C; Abart, Rainer

2018-01-01

Focused ion beam (FIB) sample preparation technique in plan-view geometry allows direct correlations of the atomic structure study via transmission electron microscopy with micrometer-scale property measurements. However, one main technical difficulty is that a large amount of material must be removed underneath the specimen. Furthermore, directly monitoring the milling process is difficult unless very large material volumes surrounding the TEM specimen site are removed. In this paper, a new cutting geometry is introduced for FIB lift-out sample preparation with plan-view geometry. Firstly, an "isolated" cuboid shaped specimen is cut out, leaving a "bridge" connecting it with the bulk material. Subsequently the two long sides of the "isolated" cuboid are wedged, forming a triangular prism shape. A micromanipulator needle is used for in-situ transfer of the specimen to a FIB TEM grid, which has been mounted parallel with the specimen surface using a simple custom-made sample slit. Finally, the grid is transferred to the standard FIB grid holder for final thinning with standard procedures. This new cutting geometry provides clear viewing angles for monitoring the milling process, which solves the difficulty of judging whether the specimen has been entirely detached from the bulk material, with the least possible damage to the surrounding materials. With an improved success rate and efficiency, this plan-view FIB lift-out specimen preparation technique should have a wide application for material science. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Quantitative gene expression analysis in Caenorhabditis elegans using single molecule RNA FISH.

PubMed

Bolková, Jitka; Lanctôt, Christian

2016-04-01

Advances in fluorescent probe design and synthesis have allowed the uniform in situ labeling of individual RNA molecules. In a technique referred to as single molecule RNA FISH (smRNA FISH), the labeled RNA molecules can be imaged as diffraction-limited spots and counted using image analysis algorithms. Single RNA counting has provided valuable insights into the process of gene regulation. This microscopy-based method has often revealed a high cell-to-cell variability in expression levels, which has in turn led to a growing interest in investigating the biological significance of gene expression noise. Here we describe the application of the smRNA FISH technique to samples of Caenorhabditis elegans, a well-characterized model organism. Copyright © 2015 Elsevier Inc. All rights reserved.

Resuspension of sediment, a new approach for remediation of contaminated sediment.

PubMed

Pourabadehei, Mehdi; Mulligan, Catherine N

2016-06-01

Natural events and anthropogenic activities are the reasons of undesirable resuspension of contaminated sediments in aquatic environment. Uncontrolled resuspension could remobilize weakly bound heavy metals into overlying water and pose a potential risk to aquatic ecosystem. Shallow harbours, with contaminated sediments are subjected to the risk of uncontrolled resuspension. Remediation of sediments in these areas cannot be performed by conventional in situ methods (e.g. capping with or without reactive amendment). Ex situ remediation also requires dredging of sediment, which could increase the risk of spreading contaminants. Alternatively, the resuspension technique was introduced to address these issues. The concept of the resuspension method is that finer sediments have a greater tendency to adsorb the contamination. Therefore, finer sediments, believed carry more concentration of contaminants, were targeted for removal from aquatic environment by a suspension mechanism in a confined water column. The objective of this study was to evaluate the feasibility of the resuspension technique as a new approach for remediation of contaminated sediment and a viable option to reduce the risk of remobilization of contaminants in harbours due to an undesirable resuspension event. Unlike the common in situ techniques, the resuspension method could successfully reduce the total concentration of contaminants in almost all samples below the probable effect level (PEL) with no significant change in the quality of overlying water. The results indicated that removal efficiency could be drastically enhanced for metals in sediment with a higher enrichment factor. Moreover, availability of metals (e.g. Cd and Pb) with a high concentration in labile fractions was higher in finer sediments with a high enrichment factor. Consequently, removal of contaminants from sediment through the resuspension method could reduce the risk of mobility and availability of metals under changing environmental conditions. Potential dredging in harbours could be performed safer and more cost-effective afterward. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct push driven in situ color logging tool (CLT): technique, analysis routines, and application

NASA Astrophysics Data System (ADS)

Werban, U.; Hausmann, J.; Dietrich, P.; Vienken, T.

2014-12-01

Direct push technologies have recently seen a broad development providing several tools for in situ parameterization of unconsolidated sediments. One of these techniques is the measurement of soil colors - a proxy information that reveals to soil/sediment properties. We introduce the direct push driven color logging tool (CLT) for real-time and depth-resolved investigation of soil colors within the visible spectrum. Until now, no routines exist on how to handle high-resolved (mm-scale) soil color data. To develop such a routine, we transform raw data (CIEXYZ) into soil color surrogates of selected color spaces (CIExyY, CIEL*a*b*, CIEL*c*h*, sRGB) and denoise small-scale natural variability by Haar and Daublet4 wavelet transformation, gathering interpretable color logs over depth. However, interpreting color log data as a single application remains challenging. Additional information, such as site-specific knowledge of the geological setting, is required to correlate soil color data to specific layers properties. Hence, we exemplary provide results from a joint interpretation of in situ-obtained soil color data and 'state-of-the-art' direct push based profiling tool data and discuss the benefit of additional data. The developed routine is capable of transferring the provided information obtained as colorimetric data into interpretable color surrogates. Soil color data proved to correlate with small-scale lithological/chemical changes (e.g., grain size, oxidative and reductive conditions), especially when combined with additional direct push vertical high resolution data (e.g., cone penetration testing and soil sampling). Thus, the technique allows enhanced profiling by means of providing another reproducible high-resolution parameter for analysis subsurface conditions. This opens potential new areas of application and new outputs for such data in site investigation. It is our intention to improve color measurements by means method of application and data interpretation, useful to characterize vadose layer/soil/sediment characteristics.

In situ remediation of contaminated marinesediment: an overview.

PubMed

Lofrano, G; Libralato, G; Minetto, D; De Gisi, S; Todaro, F; Conte, B; Calabrò, D; Quatraro, L; Notarnicola, M

2017-02-01

Sediment tends to accumulate inorganic and persistent hydrophobic organic contaminants representing one of the main sinks and sources of pollution. Generally, contaminated sediment poses medium- and long-term risks to humans and ecosystem health; dredging activities or natural resuspension phenomena (i.e., strongly adverse weather conditions) can remobilize pollution releasing it into the water column. Thus, ex situ traditional remediation activities (i.e., dredging) can be hazardous compared to in situ techniques that try to keep to a minimum sediment mobilization, unless dredging is compulsory to reach a desired bathymetric level. We reviewed in situ physico-chemical (i.e., active mixing and thin capping, solidification/stabilization, chemical oxidation, dechlorination, electrokinetic separation, and sediment flushing) and bio-assisted treatments, including hybrid solutions (i.e., nanocomposite reactive capping, bioreactive capping, microbial electrochemical technologies). We found that significant gaps still remain into the knowledge about the application of in situ contaminated sediment remediation techniques from the technical and the practical viewpoint. Only activated carbon-based technologies are well developed and currently applied with several available case studies. The environmental implication of in situ remediation technologies was only shortly investigated on a long-term basis after its application, so it is not clear how they can really perform.

Aerosols and Particulates Workshop Sampling Procedures and Venues Working Group Summary

NASA Technical Reports Server (NTRS)

Pachlhofer, Peter; Howard, Robert

1999-01-01

The Sampling Procedures and Venues Workgroup discussed the potential venues available and issues associated with obtaining measurements. Some of the issues included Incoming Air Quality, Sampling Locations, Probes and Sample Systems. The following is a summary of the discussion of the issues and venues. The influence of inlet air to the measurement of exhaust species, especially trace chemical species, must be considered. Analysis procedures for current engine exhaust emissions regulatory measurements require adjustments for air inlet humidity. As a matter of course in scientific investigations, it is recommended that "background" measurements for any species, particulate or chemical, be performed during inlet air flow before initiation of combustion, if possible, and during the engine test period as feasible and practical. For current regulatory measurements, this would be equivalent to setting the "zero" level for conventional gas analyzers. As a minimum, it is recommended that measurements of the humidity and particulates in the incoming air be taken at the start and end of each test run. Additional measurement points taken during the run are desirable if they can be practically obtained. It was felt that the presence of trace gases in the incoming air is not a significant problem. However, investigators should consider the ambient levels and influences of local air pollution for species of interest. Desired measurement locations depend upon the investigation requirements. A complete investigation of phenomenology of particulate formation and growth requires measurements at a number of locations both within the engine and in the exhaust field downstream of the nozzle exit plane. Desirable locations for both extractive and in situ measurements include: (1) Combustion Zone (Multiple axial locations); (2) Combustor Exit (Multiple radial locations for annular combustors); (3) Turbine Stage (Inlet and exit of the stage); (4) Exit Nozzle (Multiple axial locations downstream of the nozzle). Actual locations with potential for extractive or non-intrusive measurements depend upon the test article and test configuration. Committee members expressed the importance of making investigators aware of various ports that could allow access to various stages of the existing engines. Port locations are engine si)ecific and might allow extractive sampling or innovative hybrid optical-probe access. The turbine stage region was one the most desirable locations for obtaining samples and might be accessed through boroscope ports available in some engine designs. Discussions of probes and sampling systems quickly identified issues dependent on particular measurement quantities. With general consensus, the group recommends SAE procedures for measurements and data analyses of currently regulated exhaust species (CO2, CO, THC, NO(x),) using conventional gas sampling techniques. Special procedures following sound scientific practices must be developed as required for species and/or measurement conditions not covered by SAE standards. Several issues arose concerning short lived radicals and highly reactive species. For conventional sampling, there are concerns of perturbing the sample during extraction, line losses, line-wall reactions, and chemical reactions during the sample transport to the analyzers. Sample lines coated with quartz.or other materials should be investigated for minimization of such effects. The group advocates the development of innovative probe techniques and non-intrusive optical techniques for measurement of short lived radicals and highly reactive species that cannot be sampled accurately otherwise. Two innovative probe concepts were discussed. One concept uses specially designed probes to transfer optical beams to and from a region of flow inaccessible by traditional ports or windows. The probe can perturb the flow field but must have a negligible impact on the region to be optically sampled. Such probes are referred to as hybrid probes and are under development at AEDC for measurement in the high pressure, high temperature of a combustor under development for power generation. The other concept consists of coupling an instrument directly to the probe. The probe would isolate a representative sample stream, freeze chemical reactions and direct the sample into the analyzer portion of the probe. Thus, the measurement would be performed in situ without sample line losses due either to reactions or binding at the wall surfaces. This concept was used to develop a fast, in situ, time-of-flight mass spectrometer measurement system for temporal quantification of NO in the IMPULSE facility at AEDC. Additional work is required in this area to determine the best probe and sampling technique for each species measurement requirement identified by the Trace Chemistry Working Group. A partial list of Venues was used as a baseline for discussion. Additional venues were added to the list and the list was broken out into the following categories: (1)Engines (a) Sea Level Test Stands (b) Altitude Chambers; (2) Annular Combustor Test Stands, (3) Sector Flametube Test Stands, (4) Fundamentals Rigs/Experiments.

Nucleation and phase transformation pathways in electrolyte solutions investigated by in situ microscopy techniques

DOE PAGES

Tao, Jinhui; Nielsen, Michael H.; De Yoreo, James J.

2018-04-27

Identification of crystal nucleation and growth pathways is of fundamental importance for synthesis of functional materials, which requires control over size, orientation, polymorph, and hierarchical structure, often in the presence of additives used to tune the energy landscape defining these pathways. Furthermore we summarize the recent progress in application of in situ TEM and AFM techniques to monitor or even tune the pathway of crystal nucleation and growth.

Nucleation and phase transformation pathways in electrolyte solutions investigated by in situ microscopy techniques

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

Tao, Jinhui; Nielsen, Michael H.; De Yoreo, James J.

Identification of crystal nucleation and growth pathways is of fundamental importance for synthesis of functional materials, which requires control over size, orientation, polymorph, and hierarchical structure, often in the presence of additives used to tune the energy landscape defining these pathways. Furthermore we summarize the recent progress in application of in situ TEM and AFM techniques to monitor or even tune the pathway of crystal nucleation and growth.

Physics and Technology of III-V Pseudomorphic Structures

DTIC Science & Technology

1991-03-01

AIISIRACT Iex~am uowo,, We have developed an in situ technique for determining the group -V composition in gas-source molecular beam epitaxy (GSMBE...growth of mixed group -V compounds, such as GaAsP, InAsP, and InGaAsP. The in situ technique consists of monitoring the intensity oscillations of ’ group -V...epitaxy ........................................................................... 58 13. A study of group -V desorption from InP and InAs by reflection

Ultraviolet electroluminescence from nitrogen-doped ZnO-based heterojuntion light-emitting diodes prepared by remote plasma in situ atomic layer-doping technique.

PubMed

Chien, Jui-Fen; Liao, Hua-Yang; Yu, Sheng-Fu; Lin, Ray-Ming; Shiojiri, Makoto; Shyue, Jing-Jong; Chen, Miin-Jang

2013-01-23

Remote plasma in situ atomic layer doping technique was applied to prepare an n-type nitrogen-doped ZnO (n-ZnO:N) layer upon p-type magnesium-doped GaN (p-GaN:Mg) to fabricate the n-ZnO:N/p-GaN:Mg heterojuntion light-emitting diodes. The room-temperature electroluminescence exhibits a dominant ultraviolet peak at λ ≈ 370 nm from ZnO band-edge emission and suppressed luminescence from GaN, as a result of the decrease in electron concentration in ZnO and reduced electron injection from n-ZnO:N to p-GaN:Mg because of the nitrogen incorporation. The result indicates that the in situ atomic layer doping technique is an effective approach to tailoring the electrical properties of materials in device applications.

In-situ plasma processing to increase the accelerating gradients of SRF cavities

DOE PAGES

Doleans, Marc; Afanador, Ralph; Barnhart, Debra L.; ...

2015-12-31

A new in-situ plasma processing technique is being developed at the Spallation Neutron Source (SNS) to improve the performance of the cavities in operation. The technique utilizes a low-density reactive oxygen plasma at room temperature to remove top surface hydrocarbons. The plasma processing technique increases the work function of the cavity surface and reduces the overall amount of vacuum and electron activity during cavity operation; in particular it increases the field emission onset, which enables cavity operation at higher accelerating gradients. Experimental evidence also suggests that the SEY of the Nb surface decreases after plasma processing which helps mitigating multipactingmore » issues. This article discusses the main developments and results from the plasma processing R&D are presented and experimental results for in-situ plasma processing of dressed cavities in the SNS horizontal test apparatus.« less

Frontiers of in situ electron microscopy

DOE PAGES

Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

2015-01-01

In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore » this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

Investigation of the Surface Stress in SiC and Diamond Nanocrystals by In-situ High Pressure Powder Diffraction Technique

NASA Technical Reports Server (NTRS)

Palosz, B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Zhao, Y.; Palosz, W.

2003-01-01

The real atomic structure of nanocrystals determines key properties of the materials. For such materials the serious experimental problem lies in obtaining sufficiently accurate measurements of the structural parameters of the crystals, since very small crystals constitute rather a two-phase than a uniform crystallographic phase system. As a result, elastic properties of nanograins may be expected to reflect a dual nature of their structure, with a corresponding set of different elastic property parameters. We studied those properties by in-situ high-pressure powder diffraction technique. For nanocrystalline, even one-phase materials such measurements are particularly difficult to make since determination of the lattice parameters of very small crystals presents a challenge due to inherent limitations of standard elaboration of powder diffractograms. In this investigation we used our methodology of the structural analysis, the 'apparent lattice parameter' (alp) concept. The methodology allowed us to avoid the traps (if applied to nanocrystals) of standard powder diffraction evaluation techniques. The experiments were performed for nanocrystalline Sic and GaN powders using synchrotron sources. We applied both hydrostatic and isostatic pressures in the range of up to 40 GPa. Elastic properties of the samples were examined based on the measurements of a change of the lattice parameters with pressure. The results show a dual nature of the mechanical properties (compressibilities) of the materials, indicating a complex, core-shell structure of the grains.

Fabrication and electric measurements of nanostructures inside transmission electron microscope.

PubMed

Chen, Qing; Peng, Lian-Mao

2011-06-01

Using manipulation holders specially designed for transmission electron microscope (TEM), nanostructures can be characterized, measured, modified and even fabricated in-situ. In-situ TEM techniques not only enable real-time study of structure-property relationships of materials at atomic scale, but also provide the ability to control and manipulate materials and structures at nanoscale. This review highlights in-situ electric measurements and in-situ fabrication and structure modification using manipulation holder inside TEM. Copyright © 2011 Elsevier B.V. All rights reserved.

Carbonate and silicate rock standards for cosmogenic 36Cl

NASA Astrophysics Data System (ADS)

Mechernich, Silke; Dunai, Tibor J.; Binnie, Steven A.; Goral, Tomasz; Heinze, Stefan; Dewald, Alfred; Benedetti, Lucilla; Schimmelpfennig, Irene; Phillips, Fred; Marrero, Shasta; Akif Sarıkaya, Mehmet; Gregory, Laura C.; Phillips, Richard J.; Wilcken, Klaus; Simon, Krista; Fink, David

2017-04-01

The number of studies using cosmogenic nuclides has increased multi-fold during the last two decades and several new dedicated target preparation laboratories and Accelerator Mass Spectrometry (AMS) facilities have been established. Each facility uses sample preparation and AMS measurement techniques particular to their needs. It is thus desirable to have community-accepted and well characterized rock standards available for routine processing using identical target preparation procedures and AMS measurement methods as carried out for samples of unknown cosmogenic nuclide concentrations. The usefulness of such natural standards is that they allow more rigorous quality control, for example, the long-term reproducibility of results and hence measurement precision, or the testing of new target preparation techniques or newly established laboratories. This is particularly pertinent for in-situ 36Cl studies due to the multiplicity of 36Cl production pathways that requires a variety of elemental and isotopic determinations in addition to AMS 36Cl assay. We have prepared two natural rock samples (denoted CoCal-N and CoFsp-N) to serve as standard material for in situ-produced cosmogenic 36Cl analysis. The sample CoCal-N is a pure limestone prepared from pebbles in a Namibian lag deposit, while the alkali-feldspar CoFsp-N is derived from a single crystal in a Namibian pegmatite. The sample preparation took place at the University of Cologne, where first any impurities were removed manually from both standards. CoCal-N was leached in 10 % HNO3 to remove the outer rim, and afterwards crushed and sieved to 250-500 μm size fractions. CoFsp-N was crushed, sieved to 250-500 μm size fractions and then leached in 1% HNO3 / 1% HF until 20% of the sample were removed. Both standards were thoroughly mixed using a rotating sample splitter before being distributed to other laboratories. To date, a total of 28 CoCal-N aliquots (between 2 and 16 aliquots per facility) and 31 CoFsp-N aliquots (between 2 and 20 aliquots per facility) have been analyzed by six target preparation laboratories employing five different AMS facilities. Currently, the internal reproducibility of the measurements underlines the homogeneity of both standards. The inter-laboratory comparison suggests low over-dispersion. Further measurements are pending and should allow meaningful statistical analysis. Both standard materials are freely available and can be obtained from Tibor Dunai tdunai@uni-koeln.de).

Dating the Martian meteorite Zagami by the ⁸⁷Rb-⁸⁷Sr isochron method with a prototype in situ resonance ionization mass spectrometer.

PubMed

Anderson, F Scott; Levine, Jonathan; Whitaker, Tom J

2015-01-30

The geologic history of the Solar System builds on an extensive record of impact flux models, crater counts, and ~270 kg of lunar samples analyzed in terrestrial laboratories. However, estimates of impactor flux may be biased by the fact that most of the dated Apollo samples were only tenuously connected to an assumed geologic context. Moreover, uncertainties in the modeled cratering rates are significant enough to lead to estimated errors for dates on Mars and the Moon of ~1 Ga. Given the great cost of sample return missions, combined with the need to sample multiple terrains on multiple planets, we have developed a prototype instrument that can be used for in situ dating to better constrain the age of planetary samples. We demonstrate the first use of laser ablation resonance ionization mass spectrometry for (87)Rb-(87)Sr isochron dating of geological specimens. The demands of accuracy and precision have required us to meet challenges including regulation of the ambient temperature, measurement of appropriate backgrounds, sufficient ablation laser intensity, avoidance of the defocusing effect of the plasma created by ablation pulses, and shielding of our detector from atoms and ions of other elements. To test whether we could meaningfully date planetary materials, we have analyzed a piece of the Martian meteorite Zagami. In each of four separate measurements we obtained (87)Rb-(87)Sr isochron ages for Zagami consistent with its published age, and, in both of two measurements that reached completion, we obtained better than 200 Ma precision. Combining all our data into a single isochron with 581 spot analyses gives an (87)Rb-(87)Sr age for this specimen of 360 ±90 Ma. Our analyses of the Zagami meteorite represent the first successful application of resonance ionization mass spectrometry to isochron geochronology. Furthermore, the technique is miniaturizable for spaceflight and in situ dating on other planetary bodies. © 2014 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons, Ltd.

Dating the Martian meteorite Zagami by the 87Rb-87Sr isochron method with a prototype in situ resonance ionization mass spectrometer

PubMed Central

Scott Anderson, F; Levine, Jonathan; Whitaker, Tom J

2015-01-01

RATIONALE The geologic history of the Solar System builds on an extensive record of impact flux models, crater counts, and ∼270 kg of lunar samples analyzed in terrestrial laboratories. However, estimates of impactor flux may be biased by the fact that most of the dated Apollo samples were only tenuously connected to an assumed geologic context. Moreover, uncertainties in the modeled cratering rates are significant enough to lead to estimated errors for dates on Mars and the Moon of ∼1 Ga. Given the great cost of sample return missions, combined with the need to sample multiple terrains on multiple planets, we have developed a prototype instrument that can be used for in situ dating to better constrain the age of planetary samples. METHODS We demonstrate the first use of laser ablation resonance ionization mass spectrometry for 87Rb-87Sr isochron dating of geological specimens. The demands of accuracy and precision have required us to meet challenges including regulation of the ambient temperature, measurement of appropriate backgrounds, sufficient ablation laser intensity, avoidance of the defocusing effect of the plasma created by ablation pulses, and shielding of our detector from atoms and ions of other elements. RESULTS To test whether we could meaningfully date planetary materials, we have analyzed a piece of the Martian meteorite Zagami. In each of four separate measurements we obtained 87Rb-87Sr isochron ages for Zagami consistent with its published age, and, in both of two measurements that reached completion, we obtained better than 200 Ma precision. Combining all our data into a single isochron with 581 spot analyses gives an 87Rb-87Sr age for this specimen of 360 ±90 Ma. CONCLUSIONS Our analyses of the Zagami meteorite represent the first successful application of resonance ionization mass spectrometry to isochron geochronology. Furthermore, the technique is miniaturizable for spaceflight and in situ dating on other planetary bodies. © 2014 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons, Ltd. PMID:25641494

Use of a three-color chromosome in situ suppression technique for the detection of past radiation exposure

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

Gebhart, E.; Neubauer, S.; Schmitt, G.

1996-01-01

A three-color chromosome in situ suppression technique and classical cytogenetic analysis were compared for the detection of chromosomal aberrations in blood lymphocytes of 27 patients who had undergone radiation therapies from 1 month to 9 years ago. Depending on the respective regimens of therapy, a high variability was found in the aberration data. Aberration rates depended on the interval between exposure and scoring rather than on the locally applied radiation doses, which were rather uniform among most patients. Chromosome in situ suppression was found to be superior to classical cytogenetics with respect not only to the spectrum of detectable aberrationsmore » but also to the uncovering of long-term effects of irradiation. Of particular interest were the relative stability of the frequency of radiation-induced reciprocal translocations and the utility of chromosome in situ suppression to uncover complex rearrangements. 27 refs., 4 figs.« less

The energetics of mesopore formation in zeolites with surfactants.

PubMed

Linares, Noemi; Jardim, Erika de Oliveira; Sachse, Alexander; Serrano, Elena; Garcia-Martinez, Javier

2018-05-02

Mesoporosity can be conveniently introduced in zeolites by treating them in basic surfactant solutions. The apparent activation energy involved in the formation of mesopores in USY via surfactant-templating was obtained through the combination of in situ synchrotron XRD and ex situ gas adsorption. Additionally, techniques such as pH measurements and TG/DTA were employed to determine the OH- evolution and the CTA+ uptake during the development of mesoporosity, providing information about the different steps involved. By combining both in situ and ex situ techniques, we have been able, for the first time, to determine the apparent activation energies of the different processes involved in the mesostructuring of USY zeolites, which are in the same order of magnitude (30 - 65 kJ mol-1) of those involved in the crystallization of zeolites. Hence, important mechanistic insights on the surfactant-templating method were obtained. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Green-synthetized silver nanoparticles for Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) using a mobile instrument

NASA Astrophysics Data System (ADS)

Poggialini, F.; Campanella, B.; Giannarelli, S.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Safi, A.; Palleschi, V.

2018-03-01

When compared to other analytical techniques, LIBS shows relatively low precision and, generally, high Limits of Detection (LODs). Until recently, the attempts in improving the LIBS performances have been based on the use of more stable/powerful lasers, high sensitivity detectors or controlled environmental parameters. This can hinder the competitiveness of LIBS by increasing the instrumental setup cost and the difficulty of operation. Sample treatment has proved to be a viable and simple way to increase the LIBS signal; in particular, the Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) methodology uses a deposition of metal nanoparticles on the sample to greatly increase the emission of the LIBS plasma. In this work, we used a simple, fast, "green" and low-cost method to synthetize silver nanoparticles by using coffee extract as reducing agents for a silver nitrate solution. This allowed us to obtain nanoparticles of about 25 nm in diameter. We then explored the application of such nanoparticles to the NELIBS analysis of metallic samples with a mobile LIBS instrument. By adjusting the laser parameters and optimizing the sample preparation procedure, we obtained a NELIBS signal that is 4 times the LIBS one. This showed the potential of green-synthetized nanoparticle for NELIBS applications and suggests the possibility of an in-situ application of the technique.

Fabrication, characterization, and photocatalytic property of α-Fe2O3/graphene oxide composite

NASA Astrophysics Data System (ADS)

Li, Hong; Zhao, Qidong; Li, Xinyong; Zhu, Zhengru; Tade, Moses; Liu, Shaomin

2013-06-01

Spindle-shaped microstructure of α-Fe2O3 was successfully synthesized by a simple hydrothermal method. The α-Fe2O3/graphene oxide (GO) composites was prepared using a modified Hummers' strategy. The properties of the samples were systematically investigated by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectrophotometer, transmission electron microscope, atomic force microscope, X-ray photoelectron spectroscopy, and Raman spectroscopy (Raman) techniques. GO nanosheets act as supporting materials for anchoring the α-Fe2O3 particles. The average crystallite sizes of the α-Fe2O3 and α-Fe2O3/GO samples are ca. 27 and 24 nm, respectively. The possible growth of α-Fe2O3 onto GO layers led to a higher absorbance capacity for visible light by α-Fe2O3/GO than α-Fe2O3 composite. The photocatalytic degradation of toluene over the α-Fe2O3 and α-Fe2O3/GO samples under xenon-lamp irradiation was comparatively studied by in situ FTIR technique. The results indicate that the α-Fe2O3/GO sample synthesized exhibited a higher capacity for the degradation of toluene. The composite of α-Fe2O3/GO could be promisingly applied in photo-driven air purification.

3D Pathology Volumetric Technique: A Method for Calculating Breast Tumour Volume from Whole-Mount Serial Section Images

PubMed Central

Clarke, G. M.; Murray, M.; Holloway, C. M. B.; Liu, K.; Zubovits, J. T.; Yaffe, M. J.

2012-01-01

Tumour size, most commonly measured by maximum linear extent, remains a strong predictor of survival in breast cancer. Tumour volume, proportional to the number of tumour cells, may be a more accurate surrogate for size. We describe a novel “3D pathology volumetric technique” for lumpectomies and compare it with 2D measurements. Volume renderings and total tumour volume are computed from digitized whole-mount serial sections using custom software tools. Results are presented for two lumpectomy specimens selected for tumour features which may challenge accurate measurement of tumour burden with conventional, sampling-based pathology: (1) an infiltrative pattern admixed with normal breast elements; (2) a localized invasive mass separated from the in situ component by benign tissue. Spatial relationships between key features (tumour foci, close or involved margins) are clearly visualized in volume renderings. Invasive tumour burden can be underestimated using conventional pathology, compared to the volumetric technique (infiltrative pattern: 30% underestimation; localized mass: 3% underestimation for invasive tumour, 44% for in situ component). Tumour volume approximated from 2D measurements (i.e., maximum linear extent), assuming elliptical geometry, was seen to overestimate volume compared to the 3D volumetric calculation (by a factor of 7x for the infiltrative pattern; 1.5x for the localized invasive mass). PMID:23320179

High-resolution x-ray absorption spectroscopy studies of metal compounds in neurodegenerative brain tissue

NASA Astrophysics Data System (ADS)

Collingwood, J. F.; Mikhaylova, A.; Davidson, M. R.; Batich, C.; Streit, W. J.; Eskin, T.; Terry, J.; Barrea, R.; Underhill, R. S.; Dobson, J.

2005-01-01

Fluorescence mapping and microfocus X-ray absorption spectroscopy are used to detect, locate and identify iron biominerals and other inorganic metal accumulations in neurodegenerative brain tissue at sub-cellular resolution (<5 microns). Recent progress in developing the technique is reviewed. Synchrotron X-rays are used to map tissue sections for metals of interest, and XANES and XAFS are used to characterise anomalous concentrations of the metals in-situ so that they can be correlated with tissue structures and disease pathology. Iron anomalies associated with biogenic magnetite, ferritin and haemoglobin are located and identified in an avian tissue model with a pixel resolution ~5 microns. Subsequent studies include brain tissue sections from transgenic Huntington's mice, and the first high-resolution mapping and identification of iron biominerals in human Alzheimer's and control autopsy brain tissue. Technical developments include use of microfocus diffraction to obtain structural information about biominerals in-situ, and depositing sample location grids by lithography for the location of anomalies by conventional microscopy. The combined techniques provide a breakthrough in the study of both intra- and extra-cellular iron compounds and related metals in tissue. The information to be gained from this approach has implications for future diagnosis and treatment of neurodegeneration, and for our understanding of the mechanisms involved.

A review on the applications of portable near-infrared spectrometers in the agro-food industry.

PubMed

dos Santos, Cláudia A Teixeira; Lopo, Miguel; Páscoa, Ricardo N M J; Lopes, João A

2013-11-01

Industry has created the need for a cost-effective and nondestructive quality-control analysis system. This requirement has increased interest in near-infrared (NIR) spectroscopy, leading to the development and marketing of handheld devices that enable new applications that can be implemented in situ. Portable NIR spectrometers are powerful instruments offering several advantages for nondestructive, online, or in situ analysis: small size, low cost, robustness, simplicity of analysis, sample user interface, portability, and ergonomic design. Several studies of on-site NIR applications are presented: characterization of internal and external parameters of fruits and vegetables; conservation state and fat content of meat and fish; distinguishing among and quality evaluation of beverages and dairy products; protein content of cereals; evaluation of grape ripeness in vineyards; and soil analysis. Chemometrics is an essential part of NIR spectroscopy manipulation because wavelength-dependent scattering effects, instrumental noise, ambient effects, and other sources of variability may complicate the spectra. As a consequence, it is difficult to assign specific absorption bands to specific functional groups. To achieve useful and meaningful results, multivariate statistical techniques (essentially involving regression techniques coupled with spectral preprocessing) are therefore required to extract the information hidden in the spectra. This work reviews the evolution of the use of portable near-infrared spectrometers in the agro-food industry.

A Novel Optical Diagnostic for In Situ Measurements of Lithium Polysulfides in Battery Electrolytes.

PubMed

Saqib, Najmus; Silva, Cody J; Maupin, C Mark; Porter, Jason M

2017-07-01

An optical diagnostic technique to determine the order and concentration of lithium polysulfides in lithium-sulfur (Li-S) battery electrolytes has been developed. One of the major challenges of lithium-sulfur batteries is the problem of polysulfide shuttling between the electrodes, which leads to self-discharge and loss of active material. Here we present an optical diagnostic for quantitative in situ measurements of lithium polysulfides using attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy. Simulated infrared spectra of lithium polysulfide molecules were generated using computational quantum chemistry routines implemented in Gaussian 09. The theoretical spectra served as a starting point for experimental characterization of lithium polysulfide solutions synthesized by the direct reaction of lithium sulfide and sulfur. Attenuated total reflection FT-IR spectroscopy was used to measure absorption spectra. The lower limit of detection with this technique is 0.05 M. Measured spectra revealed trends with respect to polysulfide order and concentration, consistent with theoretical predictions, which were used to develop a set of equations relating the order and concentration of lithium polysulfides in a sample to the position and area of a characteristic infrared absorption band. The diagnostic routine can measure the order and concentration to within 5% and 0.1 M, respectively.

Versatile device for in-situ discharge cleaning and multiple coatings of long, small diameter tubes

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

Hershcovitch, A.; Blaskiewicz, M.; Brennan, J.M.

Electron clouds, which can limit machine performance, have been observed in many accelerators including RHIC at BNL. Additional concern for the RHIC machine, whose vacuum chamber is made from relatively high resistivity 316LN stainless steel, is high wall resistivity that can result in unacceptably high ohmic heating for superconducting magnets. The high resistivity can be addressed with a copper (Cu) coating; a reduction in the secondary electron yield can be achieved with a TiN or amorphous carbon (a-C) coating. Applying such coatings in an already constructed machine is rather challenging. We have been developing a robotic plasma deposition technique formore » in-situ coating of long, small diameter tubes. The technique entails fabricating a device comprising of staged magnetrons mounted on a mobile mole for deposition of about 5 ?m of Cu followed by about 0.1 ?m of a-C. As a first step, a 15-cm Cu cathode magnetron was designed, fabricated, and 30-cm long samples of the RHIC pipe have been coated with 2 ?m to 5.6 ?m of copper. Deposition rates of up to 92 A/sec with an average coating rate of 30 A/sec were measured. Effects on RF resistivity is also to be measured.« less

Efficiency of fluorescence in situ hybridization for bacterial cell identification in temporary river sediments with contrasting water content.

PubMed

Fazi, Stefano; Amalfitano, Stefano; Pizzetti, Ilaria; Pernthaler, Jakob

2007-09-01

We studied the efficiency of two hybridization techniques for the analysis of benthic bacterial community composition under varying sediment water content. Microcosms were set up with sediments from four European temporary rivers. Wet sediments were dried, and dry sediments were artificially rewetted. The percentage of bacterial cells detected by fluorescence in situ hybridization with fluorescently monolabeled probes (FISH) significantly increased from dry to wet sediments, showing a positive correlation with the community activity measured via incorporation of (3)H leucine. FISH and signal amplification by catalyzed reporter deposition (CARD-FISH) could significantly better detect cells with low activity in dried sediments. Through the application of an optimized cell permeabilization protocol, the percentage of hybridized cells by CARD-FISH showed comparable values in dry and wet conditions. This approach was unrelated to (3)H leucine incorporation rates. Moreover, the optimized protocol allowed a significantly better visualization of Gram-positive Actinobacteria in the studied samples. CARD-FISH is, therefore, proposed as an effective technique to compare bacterial communities residing in sediments with contrasting water content, irrespective of differences in the activity state of target cells. Considering the increasing frequencies of flood and drought cycles in European temporary rivers, our approach may help to better understand the dynamics of microbial communities in such systems.