Immunoaffinity chromatography: an introduction to applications and recent developments

PubMed Central

Moser, Annette C

2010-01-01

Immunoaffinity chromatography (IAC) combines the use of LC with the specific binding of antibodies or related agents. The resulting method can be used in assays for a particular target or for purification and concentration of analytes prior to further examination by another technique. This review discusses the history and principles of IAC and the various formats that can be used with this method. An overview is given of the general properties of antibodies and of antibody-production methods. The supports and immobilization methods used with antibodies in IAC and the selection of application and elution conditions for IAC are also discussed. Several applications of IAC are considered, including its use in purification, immunodepletion, direct sample analysis, chromatographic immunoassays and combined analysis methods. Recent developments include the use of IAC with CE or MS, ultrafast immunoextraction methods and the use of immunoaffinity columns in microanalytical systems. PMID:20640220

Microfabricated diffusion source

DOEpatents

Oborny, Michael C [Albuquerque, NM; Frye-Mason, Gregory C [Cedar Crest, NM; Manginell, Ronald P [Albuquerque, NM

2008-07-15

A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

Fluidic optics

NASA Astrophysics Data System (ADS)

Whitesides, George M.; Tang, Sindy K. Y.

2006-09-01

Fluidic optics is a new class of optical system with real-time tunability and reconfigurability enabled by the introduction of fluidic components into the optical path. We describe the design, fabrication, operation of a number of fluidic optical systems, and focus on three devices, liquid-core/liquid-cladding (L2) waveguides, microfluidic dye lasers, and diffraction gratings based on flowing, crystalline lattices of bubbles, to demonstrate the integration of microfluidics and optics. We fabricate these devices in poly(dimethylsiloxane) (PDMS) with soft-lithographic techniques. They are simple to construct, and readily integrable with microanalytical or lab-on-a-chip systems.

Cometary and interstellar dust grains - Analysis by ion microprobe mass spectrometry and other techniques

NASA Technical Reports Server (NTRS)

Zinner, Ernst

1991-01-01

A survey of microanalytical measurements on interplanetary dust particles (IDPs) and interstellar dust grains from primitive meteorites is presented. Ion-microprobe mass spectrometry with its capability to determine isotopic compositions of many elements on a micron spatial scale has played a special role. Examples are measurements of H, N, and O isotopes and refractory trace elements in IDPs; C, N, Mg, and Si isotopes in interstellar SiC grains; and C and N isotopes and H, N, Al, and Si concentrations in interstellar graphite grains.

Considering "Nonlinearity" Across the Continuum in Medical Education Assessment: Supporting Theory, Practice, and Future Research Directions.

PubMed

Durning, Steven J; Lubarsky, Stuart; Torre, Dario; Dory, Valérie; Holmboe, Eric

2015-01-01

The purpose of this article is to propose new approaches to assessment that are grounded in educational theory and the concept of "nonlinearity." The new approaches take into account related phenomena such as "uncertainty," "ambiguity," and "chaos." To illustrate these approaches, we will use the example of assessment of clinical reasoning, although the principles we outline may apply equally well to assessment of other constructs in medical education. Theoretical perspectives include a discussion of script theory, assimilation theory, self-regulated learning theory, and situated cognition. Assessment examples to include script concordance testing, concept maps, self-regulated learning microanalytic technique, and work-based assessment, which parallel the above-stated theories, respectively, are also highlighted. We conclude with some practical suggestions for approaching nonlinearity. © 2015 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on Continuing Medical Education, Association for Hospital Medical Education.

Chemical preconcentrator with integral thermal flow sensor

DOEpatents

Manginell, Ronald P.; Frye-Mason, Gregory C.

2003-01-01

A chemical preconcentrator with integral thermal flow sensor can be used to accurately measure fluid flow rate in a microanalytical system. The thermal flow sensor can be operated in either constant temperature or constant power mode and variants thereof. The chemical preconcentrator with integral thermal flow sensor can be fabricated with the same MEMS technology as the rest of the microanlaytical system. Because of its low heat capacity, low-loss, and small size, the chemical preconcentrator with integral thermal flow sensor is fast and efficient enough to be used in battery-powered, portable microanalytical systems.

Characterisation of a natural quartz crystal as a reference material for microanalytical determination of Ti, Al, Li, Fe, Mn, Ga and Ge

USGS Publications Warehouse

Audetat, Andreas; Garbe-Schonberg, Dieter; Kronz, Andreas; Pettke, Thomas; Rusk, Brian G.; Donovan, John J.; Lowers, Heather

2015-01-01

A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium-in-quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g-1), Al (154 ± 15 μg g-1), Li (30 ± 2 μg g-1), Fe (2.2 ± 0.3 μg g-1), Mn (0.34 ± 0.04 μg g-1), Ge (1.7 ± 0.2 μg g-1) and Ga (0.020 ± 0.002 μg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.

Correlated Raman micro-spectroscopy and scanning electron microscopy analyses of flame retardants in environmental samples: a micro-analytical tool for probing chemical composition, origin and spatial distribution.

PubMed

Ghosal, Sutapa; Wagner, Jeff

2013-07-07

We present correlated application of two micro-analytical techniques: scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and Raman micro-spectroscopy (RMS) for the non-invasive characterization and molecular identification of flame retardants (FRs) in environmental dusts and consumer products. The SEM/EDS-RMS technique offers correlated, morphological, molecular, spatial distribution and semi-quantitative elemental concentration information at the individual particle level with micrometer spatial resolution and minimal sample preparation. The presented methodology uses SEM/EDS analyses for rapid detection of particles containing FR specific elements as potential indicators of FR presence in a sample followed by correlated RMS analyses of the same particles for characterization of the FR sub-regions and surrounding matrices. The spatially resolved characterization enabled by this approach provides insights into the distributional heterogeneity as well as potential transfer and exposure mechanisms for FRs in the environment that is typically not available through traditional FR analysis. We have used this methodology to reveal a heterogeneous distribution of highly concentrated deca-BDE particles in environmental dust, sometimes in association with identifiable consumer materials. The observed coexistence of deca-BDE with consumer material in dust is strongly indicative of its release into the environment via weathering/abrasion of consumer products. Ingestion of such enriched FR particles in dust represents a potential for instantaneous exposure to high FR concentrations. Therefore, correlated SEM/RMS analysis offers a novel investigative tool for addressing an area of important environmental concern.

Analysis of defect structure in silicon. Characterization of SEMIX material. Silicon sheet growth development for the large area silicon sheet task of the low-cost solar array project

NASA Technical Reports Server (NTRS)

Natesh, R.; Stringfellow, G. B.; Virkar, A. V.; Dunn, J.; Guyer, T.

1983-01-01

Statistically significant quantitative structural imperfection measurements were made on samples from ubiquitous crystalline process (UCP) Ingot 5848 - 13C. Important correlation was obtained between defect densities, cell efficiency, and diffusion length. Grain boundary substructure displayed a strong influence on the conversion efficiency of solar cells from Semix material. Quantitative microscopy measurements gave statistically significant information compared to other microanalytical techniques. A surface preparation technique to obtain proper contrast of structural defects suitable for quantimet quantitative image analyzer (QTM) analysis was perfected and is used routinely. The relationships between hole mobility and grain boundary density was determined. Mobility was measured using the van der Pauw technique, and grain boundary density was measured using quantitative microscopy technique. Mobility was found to decrease with increasing grain boundary density.

Characterization and differentiation of rock varnish types from different environments by microanalytical techniques

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

Macholdt, D. S.; Jochum, K. P.; Pöhlker, C.

We investigated rock varnishes collected from several locations and environments worldwide by a wide range of microanalytical techniques. These techniques were selected to address the challenges posed by the chemical and structural complexity within the micrometer- to nanometer-sized structures in these geological materials. Femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs LA-ICP-MS), scanning transmission X-ray microscopy-near edge X-ray adsorption fine structure spectroscopy (STXM-NEXAFS) in combination with scanning electron microscopy (SEM) of focused ion beam (FIB) ultra-thin (100–200 nm) sections, conventional and polarization microscopy, as well as electron paramagnetic resonance (EPR) measurements were used to obtain information about these rock varnishes. Rockmore » varnishes from different environments, which cannot readily be distinguished based on their macroscopic appearance, differ significantly in their constituent elemental mass fractions, e.g., of Mn, Fe, Ni, Co, Ba, and Pb, and their rare earth element (REE) patterns. Structural characteristics such as the particle sizes of embedded dust grains, internal structures such as layers of Mn-, Fe-, and Ca -rich material, and structures such as cavities varied between varnishes from different environments and regions in the world. The EPR spectra were consistent with aged biogenic Mn oxides in all samples, but showed subtle differences between samples of different origin. Our observations allow us to separate rock varnishes into different types, with differences that might be indicators of distinct geneses. Five different types of rock varnish could be distinguished, Type I–V, of which only Type I might be used as potential paleoclimate archive. Each varnish type has specific characteristics in terms of their elemental composition, element distribution, and structures. The combination of element ratios (Mn/Ba, Al/Ni, Mn/REY, Mn/Ce, Mn/Pb, La N /Yb N , and Ce/Ce*), total REE contents, and structures can be used to separate the different types of rock varnish from each other.« less

Method for making electro-fluidic connections in microfluidic devices

DOEpatents

Frye-Mason, Gregory C.; Martinez, David; Manginell, Ronald P.; Heller, Edwin J.; Chanchani, Rajen

2004-08-10

A method for forming electro-fluidic interconnections in microfluidic devices comprises forming an electrical connection between matching bond pads on a die containing an active electrical element and a microfluidic substrate and forming a fluidic seal ring that circumscribes the active electrical element and a fluidic feedthrough. Preferably, the electrical connection and the seal ring are formed in a single bonding step. The simple method is particularly useful for chemical microanalytical systems wherein a plurality of microanalytical components, such as a chemical preconcentrator, a gas chromatography column, and a surface acoustic wave detector, are fluidically interconnected on a hybrid microfluidic substrate having electrical connection to external support electronics.

The Space Shuttle Columbia Accident Investigation and Reconstruction: Two Years Later

NASA Technical Reports Server (NTRS)

McDanels, Steven J.

2005-01-01

The Space Shuttle Columbia was lost during re-entry over two years ago. Since the release of the official materials-related findings in August of 2003, additional testing and analysis of select pieces of debris has continued. Microanalytical techniques, including EMPA, ESCA, and x-ray elemental dot mapping, were employed during the initial investigation; the results related the microstructural characteristics of deposit layers to the breach location in the leading edge of the left wing. Such characteristics included deposition order, composition, and distribution. Subsequent to the original efforts, new analytical data and information, not available at the time of the primary investigation, has been generated. This data was obtained via a low-vacuum SEM, fitted not only with a light-element EDS detector, but an XRF tube as well. Essentially, for elements up to sodium, classic EDS was utilized; above sodium, XRF was used. Predominantly, the elements of interest were aluminum, titanium, chromium, iron, nickel, and copper. The findings of both old and new data are compared, and their application to the overall accident investigation detailed.

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

Rodríguez-Pulido, A.; Martínez-Gutiérrez, H.; Calderon-Polania, G. A.

Nitrogen-doped multiwalled carbon nanotubes (CNx-MWNTs) have been decorated with γ-Al 2O 3 nanoparticles by a novel method. This process involved a wet chemical approach in conjunction with thermal treatment. During the particle anchoring process, individual CNx-MWNT nanotubes agglomerated into bundles, resulting in arrays of aligned CNx-MWNT coated with γ-Al 2O 3. Extensive characterization of the resulting γ-Al 2O 3/CNx-MWNT bundles was performed using a range of electron microscopy imaging and microanalytical techniques. In conclusion, a possible mechanism explaining the nanobundle alignment is described, and possible applications of these materials for the fabrication of ceramic composites using CNx-MWNTs are briefly discussed.

Integrated Experimental and Modelling Research for Non-Ferrous Smelting and Recycling Systems

NASA Astrophysics Data System (ADS)

Jak, Evgueni; Hidayat, Taufiq; Shishin, Denis; Mehrjardi, Ata Fallah; Chen, Jiang; Decterov, Sergei; Hayes, Peter

The chemistries of industrial pyrometallurgical non-ferrous smelting and recycling processes are becoming increasingly complex. Optimisation of process conditions, charge composition, temperature, oxygen partial pressure, and partitioning of minor elements between phases and different process streams require accurate description of phase equilibria and thermodynamics which are the focus of the present research. The experiments involve high temperature equilibration in controlled gas atmospheres, rapid quenching and direct measurement of equilibrium phase compositions with quantitative microanalytical techniques including electron probe X-ray microanalysis and Laser Ablation ICP-MS. The thermodynamic modelling is undertaken using computer package FactSage with the quasi-chemical model for the liquid slag phase and other advanced models. Experimental and modelling studies are combined into an integrated research program focused on the major elements Cu-Pb-Fe-O-Si-S system, slagging Al, Ca, Mg and other minor elements. The ongoing development of the research methodologies has resulted in significant advances in research capabilities. Examples of applications are given.

Anchorage of γ-Al 2O 3 nanoparticles on nitrogen-doped multiwalled carbon nanotubes

DOE PAGES

Rodríguez-Pulido, A.; Martínez-Gutiérrez, H.; Calderon-Polania, G. A.; ...

2016-06-07

Nitrogen-doped multiwalled carbon nanotubes (CNx-MWNTs) have been decorated with γ-Al 2O 3 nanoparticles by a novel method. This process involved a wet chemical approach in conjunction with thermal treatment. During the particle anchoring process, individual CNx-MWNT nanotubes agglomerated into bundles, resulting in arrays of aligned CNx-MWNT coated with γ-Al 2O 3. Extensive characterization of the resulting γ-Al 2O 3/CNx-MWNT bundles was performed using a range of electron microscopy imaging and microanalytical techniques. In conclusion, a possible mechanism explaining the nanobundle alignment is described, and possible applications of these materials for the fabrication of ceramic composites using CNx-MWNTs are briefly discussed.

White spots on Smoke rings by Bruce Nauman: a case study on contemporary art conservation using microanalytical techniques.

PubMed

Mafalda, Ana Cardeira; da Câmara, Rodrigo Bettencourt; Strzelec, Patrick; Schiavon, Nick; Mirão, José; Candeias, António; Carvalho, Maria Luísa; Manso, Marta

2015-02-01

The artwork "Smoke Rings: Two Concentric Tunnels, Non-Communicating" by Bruce Nauman represents a case study of corrosion of a black patina-coated Al-alloy contemporary artwork. The main concern over this artwork was the widespread presence of white spots on its surface. Alloy substrate, patina, and white spots were characterized by means of energy-dispersive X-ray fluorescence and scanning electron microscopy with energy-dispersive spectroscopy. Alloy substrate was identified as an aluminum alloy 6,000 series Al-Si-Mg. Patina's identified composition confirmed the documentation provided by the atelier. Concerning the white spots, zircon particles were found on patina surface as external elements.

Capacitive chemical sensor

DOEpatents

Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

2014-05-27

A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

Microanalysis characterization of bioactive protein-bound polysaccharides produced by Amanita ponderosa cultures.

PubMed

Salvador, Cátia; Martins, M Rosário; Caldeira, A Teresa

2015-02-01

Different compounds of edible mushrooms are responsible for their bioactivity. The ability to synthesize polysaccharides, namely protein-polysaccharide (PPS) complexes, is related to the antioxidant capacity of these compounds and present great interest in preventing a number of diseases, including cancer, cardiovascular and auto-immune diseases, and accelerated aging. Amanita ponderosa are wild edible mushrooms that grow in Mediterranean "montado" areas [Portuguese name given to cork oak (Quercus suber) and holm oak (Quercus ilex) forests]. The aim of this study was to evaluate the production of PPS complexes obtained from A. ponderosa cultures using a new microanalytical approach to quickly and easily monitor the production process. Microanalysis using Fourier-transform infrared using attenuated total reflection and Raman spectroscopy of PPS samples showed spectra compatible with identification of this type of compound in culture extracts. PPS separated by size-exclusion chromatography showed seven main complexes. Molecular weights of the main PPS complexes isolated from cultures ranged between 1.5 and 20 kDa and did not present toxicity against Artemia salina, demonstrating the potential of A. ponderosa as a source of biologically active compounds with nutraceutical value. Application of this microanalytical approach to monitoring the production of PPS compounds can be successfully applied in biotechnological processes.

The effects of strontium on bone mineral: A review on current knowledge and microanalytical approaches.

PubMed

Querido, William; Rossi, Andre L; Farina, Marcos

2016-01-01

The interest in effects of strontium (Sr) on bone has greatly increased in the last decade due to the development of the promising drug strontium ranelate. This drug is used for treating osteoporosis, a major bone disease affecting hundreds of millions of people worldwide, especially postmenopausal women. The novelty of strontium ranelate compared to other treatments for osteoporosis is its unique effect on bone: it simultaneously promotes bone formation by osteoblasts and inhibits bone resorption by osteoclasts. Besides affecting bone cells, treatment with strontium ranelate also has a direct effect on the mineralized bone matrix. Due to the chemical similarities between Sr and Ca, a topic that has long been of particular interest is the incorporation of Sr into bones replacing Ca from the mineral phase, which is composed by carbonated hydroxyapatite nanocrystals. Several groups have analyzed the mineral produced during treatment; however, most analysis were done with relatively large samples containing numerous nanocrystals, resulting thus on data that represents an average of many crystalline domains. The nanoscale analysis of the bone apatite crystals containing Sr has only been described in a few studies. In this study, we review the current knowledge on the effects of Sr on bone mineral and discuss the methodological approaches that have been used in the field. In particular, we focus on the great potential that advanced microscopy and microanalytical techniques may have on the detailed analysis of the nanostructure and composition of bone apatite nanocrystals produced during treatment with strontium ranelate. Copyright © 2015. Published by Elsevier Ltd.

Structure, chemistry, and stress corrosion cracking of grain boundaries in alloys 600 and 690

NASA Astrophysics Data System (ADS)

Stiller, Krystyna; Nilsson, Jan-Olof; Norring, Kjell

1996-02-01

The microstructure in six commercial batches of alloys 600 and 690 has been investigated using scanning electron microscopy (SEM), analytical transmission electron microscopy (ATEM), atom probe field ion microscopy (APFIM), and secondary ion mass spectroscopy (SIMS). The materials were also tested with respect to their resistance to intergranular stress corrosion cracking (IGSCC) in high-purity water at 365 °. Applied microanalytical techniques allowed direct measurement of carbon concentration in the matrix together with determination of grain boundary micro structure and microchemistry in all material conditions. The distribution of oxygen near a crack in material tested with respect to IGSCC was also investigated. The role of carbon and chromium and intergranular precipitates on IGSCC is discussed.

Geochemical and mineralogical controls on metal(loid) mobility in the oxide zone of the Prairie Creek Deposit, NWT

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

Stavinga, Drew; Jamieson, Heather; Layton-Matthews, Daniel

2017-02-01

Prairie Creek is an unmined high grade Zn-Pb-Ag deposit in the southern Mackenzie Mountains of the Northwest Territories, located in a 320 km2 enclave surrounded by the Nahanni National Park reserve. The upper portion of the quartz-carbonate-sulphide vein mineralization has undergone extensive oxidation, forming high grade zones, rich in smithsonite (ZnCO3) and cerussite (PbCO3). This weathered zone represents a significant resource and a potential component of mine waste material. This study is focused on characterizing the geochemical and mineralogical controls on metal(loid) mobility under mine waste conditions, with particular attention to the metal carbonates as a potential source of tracemore » elements to the environment. Analyses were conducted using a combination of microanalytical techniques (electron microprobe, scanning electron microscopy with automated mineralogy, laser-ablation inductively-coupled mass spectrometry, and synchrotron-based element mapping, micro-X-ray diffraction and micro-X-ray absorbance). The elements of interest included Zn, Pb, Ag, As, Cd, Cu, Hg, Sb and Se.« less

Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques.

PubMed

Terzano, Roberto; Santoro, Anna; Spagnuolo, Matteo; Vekemans, Bart; Medici, Luca; Janssens, Koen; Göttlicher, Jörg; Denecke, Melissa A; Mangold, Stefan; Ruggiero, Pacifico

2010-08-01

Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg(-1). Hg chemical forms were identified and quantified by sequential extractions and bulk- and micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as mu-XRF, mu-XRD and mu-XANES were necessary to solve bulk Hg speciation, in both soil fractions <2 mm and <2 microm. The main Hg-species found in the soil samples were metacinnabar (beta-HgS), cinnabar (alpha-HgS), corderoite (Hg(3)S(2)Cl(2)), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction <2 microm. No interaction among Hg-species and soil components was observed. All the observed Hg-species originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution. Copyright 2010 Elsevier Ltd. All rights reserved.

Mechanical stability of heat-treated nanoporous anodic alumina subjected to repetitive mechanical deformation

NASA Astrophysics Data System (ADS)

Bankova, A.; Videkov, V.; Tzaneva, B.; Mitov, M.

2018-03-01

We report studies on the mechanical response and deformation behavior of heat-treated nanoporous anodic alumina using a micro-balance test and experimental test equipment especially designed for this purpose. AAO samples were characterized mechanically by a three-point bending test using a micro-analytical balance. The deformation behavior was studied by repetitive mechanical bending of the AAO membranes using an electronically controlled system. The nanoporous AAO structures were prepared electrochemically from Al sheet substrates using a two-step anodizing technique in oxalic acid followed by heat treatment at 700 °C in air. The morphological study of the aluminum oxide layer after the mechanical tests and mechanical deformation was conducted using scanning electron and optical microscopy, respectively. The experimental results showed that the techniques proposed are simple and accurate; they could, therefore, be combined to constitute a method for mechanical stability assessment of nanostructured AAO films, which are important structural components in the design of MEMS devices and sensors.

How Does Microanalysis of Mother-Infant Communication Inform Maternal Sensitivity and Infant Attachment?

PubMed Central

Beebe, Beatrice; Steele, Miriam

2013-01-01

Microanalysis research on 4-month mother-infant face-to-face communication operates like a “social microscope” and identifies aspects of maternal sensitivity and the origins of attachment with a more detailed lens. We hope to enhance a dialogue between these two paradigms, microanalysis of mother-infant communication and maternal sensitivity and emerging working models of attachment. The prediction of infant attachment from microanalytic approaches and their contribution to concepts of maternal sensitivity are described. We summarize aspects of one microanalytic study by Beebe and colleagues (2010) that documents new communication patterns between mothers and infants at 4 months that predict future disorganized (vs. secure) attachment. The microanalysis approach opens up a new window on the details of the micro-processes of face-to-face communication. It provides a new, rich set of behaviors with which to extend our understanding of the origins of infant attachment and of maternal sensitivity. PMID:24299136

How does microanalysis of mother-infant communication inform maternal sensitivity and infant attachment?

PubMed

Beebe, Beatrice; Steele, Miriam

2013-01-01

Microanalysis research on 4-month infant-mother face-to-face communication operates like a "social microscope" and identifies aspects of maternal sensitivity and the origins of attachment with a more detailed lens. We hope to enhance a dialogue between these two paradigms, microanalysis of mother-infant communication and maternal sensitivity and emerging working models of attachment. The prediction of infant attachment from microanalytic approaches and their contribution to concepts of maternal sensitivity are described. We summarize aspects of one microanalytic study by Beebe and colleagues published in 2010 that documents new communication patterns between mothers and infants at 4 months that predict future disorganized (vs. secure) attachment. The microanalysis approach opens up a new window on the details of the micro-processes of face-to-face communication. It provides a new, rich set of behaviors with which to extend our understanding of the origins of infant attachment and of maternal sensitivity.

Microanalytic Assessment of Self-Regulated Learning During Clinical Reasoning Tasks: Recent Developments and Next Steps.

PubMed

Cleary, Timothy J; Durning, Steven J; Artino, Anthony R

2016-11-01

Helping medical educators obtain and use assessment data to assist medical students, residents, and physicians in reducing diagnostic errors and other forms of ineffective clinical practice is of critical importance. Self-Regulated Learning-Microanalytic Assessment and Training is an assessment-to-intervention framework designed to address this need by generating data about trainees' strategic processes (e.g., focusing on clinical task procedures), regulatory processes (e.g., planning how to do a task), and motivational processes (e.g., increasing confidence for performing a task) as they perform clinical activities. In this article, the authors review several studies that have used an innovative assessment approach, called self-regulated learning (SRL) microanalysis, to generate data about how trainees regulate their thinking and actions during clinical reasoning tasks. Across the studies, initial findings revealed that medical students often do not exhibit strategic thinking and action during clinical reasoning practice tasks even though some regulatory processes (e.g., planning) are predictive of important medical education outcomes. Further, trainees' motivation beliefs, strategic thinking, and self-evaluative judgments tend to shift rapidly during clinical skills practice and may also vary across different parts of a patient encounter. Collectively, these findings underscore the value of dynamically assessing trainees' SRL as they complete clinical tasks. The findings also set the stage for exploring how medical educators can best use SRL microanalytic assessment data to guide remedial practices and the provision of feedback to trainees. Implications and future research directions for connecting assessments to intervention in medical education are discussed.

The evolution of Yellowstone's magmatic system over the past 630 kyr: Insights from the crystal record

NASA Astrophysics Data System (ADS)

Stelten, M. E.

2017-12-01

The Yellowstone Plateau volcanic field in northwestern Wyoming is one of the world's largest, active silicic volcanic centers, and has produced three caldera-forming "super eruptions" over the past 2.1 Myr. As a result, the petrologic evolution of Yellowstone's magmatic system has been the focus of numerous studies over the past 60 years. Early studies at Yellowstone focused on characterizing whole-rock chemical and isotopic variations observed in magmas erupted over Yellowstone's lifetime. While these have provided important insights into the source of Yellowstone magmas and the processes controlling their compositional evolution though time, whole-rock studies are limited in their ability to identify the mechanisms and timescales of rhyolite generation. In contrast, much of the recent work at Yellowstone has focused on applying micro-analytical techniques to characterize the age and composition of phenocrysts hosted in Yellowstone rhyolites. These studies have greatly advanced our understanding of the magmatic system at Yellowstone and have provided crucial new insights into the mechanisms and timescales of rhyolite generation. In particular, recent work has focused on applying micro-analytical techniques to study the age and origin of the [1] three caldera-forming eruptions that produced the Huckleberry Ridge, Mesa Falls, Lava Creek tuffs and [2] post-Lava Creek tuff intracaldera rhyolites that compose the Plateau Rhyolite. As a result, a wealth of crystal-chemical data now exists for rhyolites erupted throughout Yellowstone's 2.1 Myr history. These data provide a unique opportunity to create a detailed reconstruction of Yellowstone's magmatic system through time. In this contribution, I integrate available age, chemical, and isotopic data for phenocrysts hosted in Yellowstone rhyolites to construct a model for the evolution of Yellowstone's magmatic system from the caldera-forming eruption of the Lava Creek tuff at ca. 0.63 Ma to the present day. In particular, I highlight new insights into [1] the physical nature of Yellowstone's magmatic system, [2] the ways in which the mechanisms and timescales of rhyolite generation have changed though time, and [3] implications for the current state of the Yellowstone's magmatic system.

Microanalytical Efforts in Support of NASA's Materials Science Programs

NASA Technical Reports Server (NTRS)

Gillies, Donald C.

2004-01-01

Following a brief overview of NASA s Microgravity Materials Science programs, specific examples will be given showing electron beam and optical microscopic applications to two-phase glass structures, dendrite tip radii, solid solution semiconductors, undercooled two-phase stainless steels and meteorites.

Morphological classification and microanalysis of tire tread particles worn by abrasion or corrosion

NASA Astrophysics Data System (ADS)

Crosta, Giovanni F.

2011-06-01

Two types of tread wear particles are investigated: tread wear particles from a steel brush abrader (TrBP) and particles produced during a steering pad run (TrSP). A leaching experiment in water at pH = 7.5 for 24 and 48h was carried out on TrBP to simulate environmental degradation. Images of all materials were collected by a scanning electron microscope (SEM) together with element microanalytical (EDX) data. Surface morphology is described by a function of wave number (the "enhanced spectrum") obtained from SEM image analysis and non-linear filtering. A surface roughness index, ρ, is derived from the enhanced spectrum. The innovative contribution of this work is the representation of morphology by means of ρ, which, together with EDX data, allows the quantitative characterization of the materials. In particular, the surface roughness of leached TrBP is shown to decay in time and is related to the corresponding microanalytical data for the first time. The morphology of steering pad TrSP, affected by included mineral particles, is shown to be more heterogeneous. Differences in morphology (enhanced spectra and ρ), elemental composition and surface chemistry of TrBP and TrSP are discussed. All methods described and implemented herewith can be immediately applied to other types of tread wear material. The arguments put forward herewith should help in the proper design of those experiments aimed at assessing the impact of tread wear materials on the environment and on human health.

Microstructural and Microanalytical Study on Concrete Exposed to the Sulfate Environment

NASA Astrophysics Data System (ADS)

Qing, Fang; Beixing, Li; Jiangang, Yin; Xiaolu, Yuan

2017-11-01

Microstructural properties have been examined to investigate the effect of mineral admixtures on the sulfate resistance of concrete. Concrete and cement paste specimens made with ordinary Portland cement (OPC) or ordinary Portland cement incorporating 20% fly ash (FA) or 30% ground blast furnace slag (GBFS), were made and exposed to 250 cycles of the cyclic sulfate environment. Microstructural and Microanalytical study was conducted by means of x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and mercury intrusion porosimetry (MIP). Results indicate that the pore structure of concrete after sulfate exposure possesses the fractal feature. The OPC concrete presents more complex pore internal surface, higher porosity and less micro-pores than the concrete incorporating fly ash and GBFS. Portlandite in OPC concrete and OPC-FA concrete is mainly converted to gypsum; while for OPC-GBFS concrete, both gypsum and ettringite are formed. In the cyclic sulfate environment, repeated hydration and dehydration of sulfates produce the expansive stress in pores, aggravating the demolishment of concrete structure.

Advances toward submicron resolution optics for x-ray instrumentation and applications

NASA Astrophysics Data System (ADS)

Cordier, Mark; Stripe, Benjamin; Yun, Wenbing; Lau, S. H.; Lyon, Alan; Reynolds, David; Lewis, Sylvia J. Y.; Chen, Sharon; Semenov, Vladimir A.; Spink, Richard I.; Seshadri, Srivatsan

2017-08-01

Sigray's axially symmetric x-ray optics enable advanced microanalytical capabilities for focusing x-rays to microns-scale to submicron spot sizes, which can potentially unlock many avenues for laboratory micro-analysis. The design of these optics allows submicron spot sizes even at low x-ray energies, enabling research into low atomic number elements and allows increased sensitivity of grazing incidence measurements and surface analysis. We will discuss advances made in the fabrication of these double paraboloidal mirror lenses designed for use in laboratory x-ray applications. We will additionally present results from as-built paraboloids, including surface figure error and focal spot size achieved to-date.

Fully integrated three-dimensional electrodes for electrochemical detection in microchips: fabrication, characterization, and applications.

PubMed

Pai, Rekha S; Walsh, Kevin M; Crain, Mark M; Roussel, Thomas J; Jackson, Douglas J; Baldwin, Richard P; Keynton, Robert S; Naber, John F

2009-06-15

A scalable and rather inexpensive solution to producing microanalytical systems with "on-chip" three-dimensional (3D) microelectrodes is presented in this study, along with applicability to practical electrochemical (EC) detection scenarios such as preconcentration and interferant removal. This technique to create high-aspect-ratio (as much as 4:1) gold microstructures in constrained areas involved the modification of stud bump geometry with microfabricated silicon molds via an optimized combination of temperature, pressure, and time. The microelectrodes that resulted consisted of an array of square pillars approximately 18 microm tall and 20 microm wide on each side, placed at the end of a microfabricated electrophoresis channel. This technique increased the active surface area of the microelectrodes by as much as a factor of 50, while mass transfer and, consequently, preconcentration collection efficiencies were increased to approximately 100%, compared to approximately 30% efficiency for planar nonmodified microelectrodes (samples that were used included the neurotransmitters dopamine and catechol). The 3D microelectrodes were used both in a stand-alone configuration, for direct EC detection of model catecholamine analytes, and, more interestingly, in dual electrode configurations for EC sample processing prior to detection downstream at a second planar electrode. In particular, the 3D electrodes were shown to be capable of performing coulometry or complete (100%) redox conversion of analyte species over a wide range of concentrations, from 4.3 microM to 4.4 mM, in either plug-flow or continuous-flow formats.

Trace-Based Microanalytic Measurement of Self-Regulated Learning Processes

ERIC Educational Resources Information Center

Siadaty, Melody; Gaševic, Dragan; Hatala, Marek

2016-01-01

To keep pace with today's rapidly growing knowledge-driven society, productive self-regulation of one's learning processes are essential. We introduce and discuss a trace-based measurement protocol to measure the effects of scaffolding interventions on self-regulated learning (SRL) processes. It guides tracing of learners' actions in a learning…

Soil fertility affects elemental distribution in needles of the conifer Araucaria angustifolia: A microanalytical study

USDA-ARS?s Scientific Manuscript database

Araucaria angustifolia is a conifer species found in South American subtropical forests that comprises less than 3% of the native vegetation. Thus, little is known concerning the accumulation of nutritional elements in its needles. In this study, scanning electron microscopy (SEM) coupled with energ...

Entrepreneur Grows Microswitch Company

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

Czaja, Danny; Christenson, Todd

2014-10-24

Todd Christenson took advantage of Sandia National Laboratories’ Entrepreneurial Separation to Transfer Technology (ESTT) program to start HT MicroAnalytical (HT Micro) in 2003 in order to apply his specialized expertise in high aspect ratio microfabrication (HARM) technology gained while at Sandia to the creation of the world’s smallest electromechanical switches.

Practices of Grading: An Ethnographic Study of Educational Assessment

ERIC Educational Resources Information Center

Kalthoff, Herbert

2013-01-01

The school as an institution assumes that students' grades are constituted by their assessments. This paper examines the background of this presupposition and provides a micro-analytical perspective of the grading practice of teachers in German High Schools ("Gymnasium"). This paper conceptualises the theoretical framework of the…

Critical Narrative Analysis: The Interplay of Critical Discourse and Narrative Analyses

ERIC Educational Resources Information Center

Souto-Manning, Mariana

2014-01-01

In this article, I question the micro-macro separation in discourse analysis, the separation of personal and institutional discourses. I apply a mostly macroanalytic perspective (critical discourse analysis [CDA]) to inform a predominantly microanalytic perspective (analysis of conversational narratives) and vice versa. In the combination of these…

Microdisc gel electrophoresis in sodium dodecyl sulfate of organic material from rat otoconial complexes

NASA Technical Reports Server (NTRS)

Ross, M. D.; Pote, K. G.; Rarey, K. E.; Verma, L. M.

1981-01-01

The gravity receptors of all vertebrates utilize a 'test mass' consisting of a complex arrangement of mineral and organic substance that lies over the sensory receptor areas. In most vertebrates, the mineral is a polymorph of calcium carbonate in the form of minute, single crystals called otoconia. An investigation is conducted to determine the number of proteins in otoconial complexes and their molecular weights. The investigation makes use of a microdisk gel electrophoresis method reported by Gainer (1971). The most important finding of the reported research is that analysis of the proteins of the organic material of the otoconial complexes is possible when sensitive microanalytical methods are employed. Further modification of the basic technique employed and the inclusion of other sensitive staining methods should mean that, in the future, protein separation by molecular weight will be possible in sample pools containing only two otoconial masses.

Polymer-encapsulated metal nanoparticles: optical, structural, micro-analytical and hydrogenation studies of a composite material.

PubMed

Scalzullo, Stefania; Mondal, Kartick; Witcomb, Mike; Deshmukh, Amit; Scurrell, Mike; Mallick, Kaushik

2008-02-20

A single-step synthesis route is described for the preparation of a metal-polymer composite in which palladium acetate and meta-amino benzoic acid were used as the precursors for palladium nanoparticles and poly(meta-amino benzoic acid) (PABA). The palladium nanoparticles were found to be uniformly dispersed and highly stabilized throughout the macromolecule matrix. The resultant composite material was characterized by means of different techniques, such as IR and Raman spectroscopy, which provided information regarding the chemical structure of the polymer, whereas electron microscopy images yielded information regarding the morphology of the composite material and the distribution of the metal particles in the composite material. The composite material was used as a catalyst for the ethylene hydrogenation reaction and showed catalytic activity at higher temperatures. TEM studies confirmed the changed environment of the nanoparticles at these temperatures.

Catastrophic optical bulk degradation in high-power single- and multi-mode InGaAs-AlGaAs strained QW lasers: part II

NASA Astrophysics Data System (ADS)

Sin, Yongkun; Ayvazian, Talin; Brodie, Miles; Lingley, Zachary

2018-03-01

High-power single-mode (SM) and multi-mode (MM) InGaAs-AlGaAs strained quantum well (QW) lasers are critical components for both terrestrial and space satellite communications systems. Since these lasers predominantly fail by catastrophic and sudden degradation due to catastrophic optical damage (COD), it is especially crucial for space satellite applications to investigate reliability, failure modes, precursor signatures of failure, and degradation mechanisms of these lasers. Our group reported a new failure mode in MM and SM InGaAs-AlGaAs strained QW lasers in 2009 and 2016, respectively. Our group also reported in 2017 that bulk failure due to catastrophic optical bulk damage (COBD) is the dominant failure mode of both SM and MM lasers that were subject to long-term life-tests. For the present study, we continued our physics of failure investigation by performing long-term life-tests followed by failure mode analysis (FMA) using nondestructive and destructive micro-analytical techniques. We performed long-term accelerated life-tests on state-of-the-art SM and MM InGaAs- AlGaAs strained QW lasers under ACC mode. Our life-tests have accumulated over 25,000 test hours for SM lasers and over 35,000 test hours for MM lasers. We first employed electron beam induced current (EBIC) technique to identify failure modes of degraded SM lasers by observing dark line defects. All the SM failures that we studied showed catastrophic and sudden degradation and all of these failures were bulk failures. Since degradation mechanisms responsible for COBD are still not well understood, we also employed other techniques including focused ion beam (FIB) and high-resolution TEM to further study dark line defects and dislocations in post-aged lasers. Keywor

[Polyethylene abrasion: cause or consequence of an endoprosthesis loosening? Investigations of firm and loosened hip implants].

PubMed

Busse, B; Niecke, M; Püschel, K; Delling, G; Katzer, A; Hahn, M

2007-01-01

Periprosthetic tissue was analysed by the combination of different investigation techniques without destruction. The localisation and geometry of polyethylene abrasion particles were determined quantitatively to differentiate between abrasion due to function and abrasion due to implant loosening. Non-polyethylene particles from implant components which contaminate the tissue were micro-analytically measured. The results will help us to understand loosening mechanisms and thus lead to implant optimisations. A non-destructive particle analysis using highly sensitive proton-induced X-ray emission (PIXE) was developed to achieve a better histological allocation. Five autopsy cases with firmly fitting hip endoprosthesis (2 x Endo-Modell Mark III, 1 x St. Georg Mark II, LINK, Germany; 2 x Spongiosa Metal II, ESKA, Germany) were prepared as ground tissue specimens. Wear investigations were accomplished with a combined application of different microscopic techniques and microanalysis. The abrasion due to implant loosening was histologically evaluated on 293 loosened cup implants (St. Georg Mark II, LINK, Germany). Wear particles are heterogeneously distributed in the soft tissue. In cases of cemented prostheses, cement particles are dominating whereas metal particles could rarely be detected. The concentration of the alloy constituent cobalt (Co) is increased in the mineralised bone tissue. The measured co-depositions depend on the localisation and/or lifetime of an implant. Functional polyethylene (PE) abrasion needs to be differentiated from PE abrasion of another genesis (loosening, impingement) morphologically and by different tissue reactions. In the past a reduction of abrasion was targeted primarily by the optimisation of the bearing surfaces and tribology. The interpretation of our findings indicates that different mechanisms of origin in terms of tissue contamination with wear debris and the alloy should be included in the improvement of implants or implantation techniques.

A Development Strategy for Creating a Suite of Reference Materials for the in-situ Microanalysis of Non-conventional Raw Materials

NASA Astrophysics Data System (ADS)

Renno, A. D.; Merchel, S.; Michalak, P. P.; Munnik, F.; Wiedenbeck, M.

2010-12-01

Recent economic trends regarding the supply of rare metals readily justify scientific research into non-conventional raw materials, where a particular need is a better understanding of the relationship between mineralogy, microstructure and the distribution of key metals within ore deposits (geometallurgy). Achieving these goals will require an extensive usage of in-situ microanalytical techniques capable of spatially resolving material heterogeneities which can be key for understanding better resource utilization. The availability of certified reference materials (CRMs) is an essential prerequisite for (1) validating new analytical methods, (2) demonstrating data quality to the contracting authorities, (3) supporting method development and instrument calibration, and (4) establishing traceability between new analytical approaches and existing data sets. This need has led to the granting of funding by the European Union and the German Free State of Saxony for a program to develop such reference materials . This effort will apply the following strategies during the selection of the phases: (1) will use exclusively synthetic minerals, thereby providing large volumes of homogeneous starting material. (2) will focus on matrices which are capable of incorporating many ‘important’ elements while avoid exotic compositions which would not be optimal matrix matches. (3) will emphasise those phases which remain stable during the various microanalytical procedure. This initiative will assess the homogeneity of the reference materials at sampling sizes ranging between 50 and 1 µm; it is also intended to document crystal structural homogeneity too, as this too may potentially impact specific analytical methods. As far as possible both definitive methods as well as methods involving matrix corrections will be used for determining the compositions of the of the individual materials. A critical challenge will be the validation of the determination of analytes concentrations as sub-µg sampling masses. It is planned to cooperate with those who are interested in the development of such reference materials and we invite them to take part in round-robin exercises.

Constraints on the timing of multiple thermal events and re-equilibration recorded by high-U zircon and xenotime: Case study of pegmatite from Piława Górna (Góry Sowie Block, SW Poland)

NASA Astrophysics Data System (ADS)

Budzyń, Bartosz; Sláma, Jiří; Kozub-Budzyń, Gabriela A.; Konečný, Patrik; Holický, Ivan; Rzepa, Grzegorz; Jastrzębski, Mirosław

2018-06-01

The application of zircon and xenotime geochronometers requires knowledge of their potential and limitations related to possible disturbance of the age record. The alteration of the intergrown zircon and xenotime in pegmatite from the Góry Sowie Block (SW Poland) was studied using the electron microprobe analysis, X-ray WDS compositional mapping, micro-Raman analysis, and LA-ICP-MS U-Pb dating of zircon and xenotime, as well as the U-Th-total Pb dating of uraninite. These microanalytical techniques were applied to understand the formation mechanisms of the secondary textures related to post-magmatic processes in the zircon and xenotime intergrowth, and to constrain their timing. Textural and compositional features combined with U-Pb data indicate that the pegmatite-related crystallization of the zircon and xenotime intergrowth occurred ca. 2.09 Ga (2086 ± 35 Ma for zircon and 2093 ± 52 Ma for xenotime), followed by the re-equilibration of zircon and xenotime ca. 370 Ma (373 ± 18 Ma and 368 ± 6 Ma, respectively) during the formation of the younger pegmatite. The zircon and xenotime were most likely derived from Precambrian basement rocks and emplaced in the pegmatite as a restite. The zircon preserved textures related to diffusion-reaction processes that affected its high-U core (up to ca. 9.6 wt% UO2), which underwent further metamictization and amorphization due to self-radiation damage. The zircon rim and xenotime were affected by coupled dissolution-reprecipitation processes that resulted in patchy zoning, age disturbance and sponge-like textures. Xenotime was also partially replaced by fluorapatite or hingganite-(Y) and Y-enriched allanite-(Ce). The termination of the low-temperature alteration was constrained by the U-Th-total Pb age of the uraninite inclusions that crystallized in zircon at 281 ± 2 Ma, which is consistent with the age of 278 ± 15 Ma obtained from the youngest cluster of U-Pb ages in the re-equilibrated high-U zircon domains. This study demonstrates the importance of the careful examination of compositional, microtextural and geochronological data obtained using microanalytical techniques to reconstruct the complex thermal histories recorded by accessory minerals.

The Interactional Management of Claims of Insufficient Knowledge in English Language Classrooms

ERIC Educational Resources Information Center

Sert, Olcay; Walsh, Steve

2013-01-01

This paper primarily investigates the interactional unfolding and management of "claims of insufficient knowledge" (Beach and Metzger 1997) in two English language classrooms from a multi-modal, conversation-analytic perspective. The analyses draw on a close, micro-analytic account of sequential organisation of talk as well as on various…

Using Microanalytical Simulation Methods in Educational Evaluation: An Exploratory Study

ERIC Educational Resources Information Center

Sondergeld, Toni A.; Beltyukova, Svetlana A.; Fox, Christine M.; Stone, Gregory E.

2012-01-01

Scientifically based research used to inform evidence based school reform efforts has been required by the federal government in order to receive grant funding since the reenactment of No Child Left Behind (2002). Educational evaluators are thus faced with the challenge to use rigorous research designs to establish causal relationships. However,…

Shifting Attention

ERIC Educational Resources Information Center

Ingram, Jenni

2014-01-01

This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

Entrepreneur Grows Microswitch Company

ScienceCinema

Czaja, Danny; Christenson, Todd

2018-05-30

Todd Christenson took advantage of Sandia National Laboratories’ Entrepreneurial Separation to Transfer Technology (ESTT) program to start HT MicroAnalytical (HT Micro) in 2003 in order to apply his specialized expertise in high aspect ratio microfabrication (HARM) technology gained while at Sandia to the creation of the world’s smallest electromechanical switches.

Examining Shifts in Medical Students' Microanalytic Motivation Beliefs and Regulatory Processes during a Diagnostic Reasoning Task

ERIC Educational Resources Information Center

Cleary, Timothy J.; Dong, Ting; Artino, Anthony R., Jr.

2015-01-01

This study examined within-group shifts in the motivation beliefs and regulatory processes of second-year medical students as they engaged in a diagnostic reasoning activity. Using a contextualized assessment methodology called self-regulated learning microanalysis, the authors found that the 71 medical student participants showed statistically…

Bullying in Context: Stories of Bullying on an Internet Discussion Board

ERIC Educational Resources Information Center

Osvaldsson, Karin

2011-01-01

The paper examines how young people describe experiences of bullying when participating in an Internet community dedicated to young people experiencing mental health problems. The micro-analytic focus demonstrates how young people construct their identities in relation to their telling about their experiences of being victims of bullying,…

Tensions in the Biology Laboratory: What Are They?

ERIC Educational Resources Information Center

Tan, Aik-Ling

2008-01-01

The purpose of this paper is to identify tensions in teacher-student interaction in a high school biology laboratory. Using micro-analytic analysis of classroom talk, the interaction between the students and a teacher working in the biology laboratory session on "Reproduction in Plants" is studied. The two tensions highlighted here are…

Affordances for Participation: Children's Appropriation of Rules in a Reggio Emilia School

ERIC Educational Resources Information Center

Martin, Cathrin; Evaldsson, Ann-Carita

2012-01-01

This study explores how young children appropriate school rules and what opportunities for active participation are afforded in a Reggio Emilia elementary classroom with particular interest in the interactional and communicative competences children display in situated practice. An ethnographic and microanalytic approach is used to study how the…

Late-Preterm Birth, Maternal Symptomatology, and Infant Negativity

PubMed Central

Voegtline, Kristin M.; Stifter, Cynthia A.

2010-01-01

The present study examined infant negativity and maternal symptomatology by term status in a predominately low-income, rural sample of 132 infants (66 late-preterm) and their mothers. Late-preterm and term infants were group-matched by race, income, and maternal age. Maternal depression and anxiety symptoms were measured with the Brief Symptom Inventory 18 (BSI-18) when infants were 2 and 6 months of age. Also at 6 months, infant negativity was assessed by global observer ratings, maternal ratings, and microanalytic behavioral coding of fear and frustration. Results indicate that after controlling for infant age, late-preterm status predicted higher ratings of infant negativity by mothers, but not by global observers or microanalytic coding, despite a positive association in negativity across the three measures. Further, mothers of late-preterm infants reported more elevated and chronic co-morbid symptoms of depression and anxiety, which in turn, was related to concurrent maternal ratings of their infant’s negativity. Mothers response to late-preterm birth and partiality in the assessment of their infant’s temperament is discussed. PMID:20732715

New techniques for imaging and analyzing lung tissue.

PubMed Central

Roggli, V L; Ingram, P; Linton, R W; Gutknecht, W F; Mastin, P; Shelburne, J D

1984-01-01

The recent technological revolution in the field of imaging techniques has provided pathologists and toxicologists with an expanding repertoire of analytical techniques for studying the interaction between the lung and the various exogenous materials to which it is exposed. Analytical problems requiring elemental sensitivity or specificity beyond the range of that offered by conventional scanning electron microscopy and energy dispersive X-ray analysis are particularly appropriate for the application of these newer techniques. Electron energy loss spectrometry, Auger electron spectroscopy, secondary ion mass spectrometry, and laser microprobe mass analysis each offer unique advantages in this regard, but also possess their own limitations and disadvantages. Diffraction techniques provide crystalline structural information available through no other means. Bulk chemical techniques provide useful cross-checks on the data obtained by microanalytical approaches. It is the purpose of this review to summarize the methodology of these techniques, acknowledge situations in which they have been used in addressing problems in pulmonary toxicology, and comment on the relative advantages and disadvantages of each approach. It is necessary for an investigator to weigh each of these factors when deciding which technique is best suited for any given analytical problem; often it is useful to employ a combination of two or more of the techniques discussed. It is anticipated that there will be increasing utilization of these technologies for problems in pulmonary toxicology in the decades to come. Images FIGURE 3. A FIGURE 3. B FIGURE 3. C FIGURE 3. D FIGURE 4. FIGURE 5. FIGURE 7. A FIGURE 7. B FIGURE 8. A FIGURE 8. B FIGURE 8. C FIGURE 9. A FIGURE 9. B FIGURE 10. PMID:6090115

Development in Dialogic Teaching Skills: A Micro-Analytic Case Study of a Pre-Service ITA

ERIC Educational Resources Information Center

Rine, Emily F.

2009-01-01

As universities have come to depend increasingly on international, non-native English-speaking graduate students to teach many of the undergraduate courses, they have created International Teaching Assistant (ITA) programs in order to provide ITAs with the cultural, pedagogical, and linguistic skills needed to instruct in an American university…

Microanalytic Case studies of Individual Participation Patterns in an Asynchronous Online Discussion in an Undergraduate Blended Course

ERIC Educational Resources Information Center

Wise, Alyssa Friend; Perera, Nishan; Hsiao, Ying-Ting; Speer, Jennifer; Marbouti, Farshid

2012-01-01

This study presents three case studies of students' participation patterns in an online discussion to address the gap in our current understanding of how "individuals" experience asynchronous learning environments. Cases were constructed via microanalysis of log-file data, post contents, and the evolving discussion structure. The first student was…

[Microanalytical determinations of gold alloys for fixed dentures].

PubMed

Lotito, M; Negri, P; Fraschini, M

1993-01-01

In this work the authors analyse gold alloys for fixed prosthesis by X-ray spectrometry in energy dispersion (EDS). The results of this analysis, given in graphic and table form, show remarkable differences in alloy composition. For this reason recommended dentists are to be attentive and severe in the control of gold alloys for fixed prosthesis.

A microanalytical method for the determination of dihydroquercetin in wood

Treesearch

Richard W. Hemingway; W.E. Hillis

1969-01-01

Dihydroquercetin (3,5,7,3',4'-pentahydroxyflavanone) is a major constituent of the alcohol soluble materials in the wood of Larch species and the wood and bark of Douglas-fir. A sensitive analytical method is needed to enable rapid assessment of amounts of dihydroquercetin (DHQ) when processing commercial materials and for studies of biochemical aspects of...

Working Memory Capacity and the Antisaccade Task: A Microanalytic-Macroanalytic Investigation of Individual Differences in Goal Activation and Maintenance

ERIC Educational Resources Information Center

Meier, Matt E.; Smeekens, Bridget A.; Silvia, Paul J.; Kwapil, Thomas R.; Kane, Michael J.

2018-01-01

The association between working memory capacity (WMC) and the antisaccade task, which requires subjects to move their eyes and attention away from a strong visual cue, supports the claim that WMC is partially an attentional construct (Kane, Bleckley, Conway, & Engle, 2001; Unsworth, Schrock, & Engle, 2004). Specifically, the…

Analysis of metal-binding proteins separated by non-denaturating gel electrophoresis using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

PubMed

Becker, J Susanne; Mounicou, Sandra; Zoriy, Miroslav V; Becker, J Sabine; Lobinski, Ryszard

2008-09-15

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have become established as very efficient and sensitive biopolymer and elemental mass spectrometric techniques for studying metal-binding proteins (metalloproteins) in life sciences. Protein complexes present in rat tissues (liver and kidney) were separated in their native state in the first dimension by blue native gel electrophoresis (BN-PAGE). Essential and toxic metals, such as zinc, copper, iron, nickel, chromium, cadmium and lead, were detected by scanning the gel bands using quadrupole LA-ICP-MS with and without collision cell as a microanalytical technique. Several proteins were identified by using MALDI-TOF-MS together with a database search. For example, on one protein band cut from the BN-PAGE gel and digested with the enzyme trypsin, two different proteins - protein FAM44B and cathepsin B precursor - were identified. By combining biomolecular and elemental mass spectrometry, it was possible to characterize and identify selected metal-binding rat liver and kidney tissue proteins.

Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

PubMed

Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie

2009-11-15

Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

From Dates to Rates: The Emergence of Integrated Geochronometry (Invited)

NASA Astrophysics Data System (ADS)

Hodges, K. V.; Adams, B. A.; Bohon, W.; Cooper, F. J.; Tripathy-Lang, A.; Van Soest, M. C.; Watson, E. B.; Young, K. E.

2013-12-01

Many applications of isotope geochemistry to telling time have involved geochronology - the measurement of the crystallization age of a mineral - or thermochronology, the measurement of the time at which a mineral cooled through an estimated closure temperature. The resulting data typically provide one or two points along an evolving temperature-time (Tt) path. Unfortunately, many problems require a richer knowledge of longer portions of the Tt path and thus the integrated application of multiple chronometers to individual minerals or suites of minerals from a particular sample or outcrop. In this presentation, we review some of the most recent advances in geochronometry, the direct dating of rates of a wide range of geologic processes on timescales ranging from seconds (in the case of bolide impact on Earth and elsewhere in the Solar System) to hundreds of millions of years (in the case of very slowly cooled Precambrian terrains). For all chronometers except those based on the production of fission tracks, our capacity to extract precise and accurate Tt paths depends on a good understanding of the kinetics of diffusive loss of radiogenic daughter isotopes. Laboratory experiments have substantially improved our understanding of nominal kinetic parameters in recent years, but our increased use of new methods for their determination (e.g., Rutherford backscattering spectroscopy, nuclear reaction analysis, and laser depth profiling) have demonstrated complexities related to compositional variations and asymmetric diffusion. At the same time, a growing number of geologic applications of these chronometers illustrate the importance of deformation history and radiation damage in modifying effective diffusion parameters. Such factors have two important implications for geochronometry. First, they suggest that studies of multiple minerals employing multiple isotopic methods - integrated geochronometry - are likely to produce more robust constraints on Tt paths than those involving the application of a single geochronometer. Second, they suggest that characterization of the chemistry and structure of minerals prior to dating may become standard procedure in most laboratories. Some of the most valuable constraints on the cooling histories of individual crystals come from microanalytical techniques that illuminate natural diffusive loss profiles, either directly (e.g., laser and ion microprobe mapping) or indirectly (e.g., 40Ar/39Ar and 4He/3He incremental heating experimentation). For most materials and most cooling histories, direct microanalytical approaches yield less spatial resolution and thus a poorer resolution of the cooling history. On the other hand, the extraction of cooling histories based on data obtained through indirect techniques requires significant simplifying assumptions regarding the three-dimensional distribution of parent isotopes that are not always warranted. Studies that integrate such techniques, rare in the literature thus far, are ushering in a new era of quantitative geochronometry.

Fluorescence-based Sensing of 2,4,6-Trinitrotoluene (TNT) Using a Multi-channeled Poly(methyl methacrylate) (PMMA) Microimmunosensor

DTIC Science & Technology

2010-01-22

Davidson, Y.Y.; McWhorter, C.S.; Soper , S.A.; McCarley, R.L. Surface modification of poly(methyl methacrylate) used in the fabrication of microanalytical...J.; Hupert, M.L.; Patterson, D.; Gottert, J.; McCarley, R.L.; Nikitopoulos, D.; Murphy, M.C.; Soper , S.A. Highly efficient circulating tumor cell

Microanalytical study of a ferrous agricultural tool recovered from a historical site in Rio de Janeiro

NASA Astrophysics Data System (ADS)

Campos, G. N.; Solórzano, I. G.

The present work has as its objective a microanalytical study of a metallic archeological artifact using methods of optical microscopy (MO), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The object of the study corresponds to an agricultural tool (a hoe) from the Brazilian colonial period, dating from the late XVIII century, removed from an archeological site (Sítio Rochedo) in excavations conducted by researchers of the Brazilian Archeological Institute. Sample preparation required a meticulous procedure in view of the fragility of the object. The hoe has been suffering the action of oxidation-corrosion over the years, thereby making the impregnation of mineral sediments possible. A detailed metallographic analysis, coupled with spectroscopic SEM and TEM measurements, allows one to conclude that the hoe was made of puddle iron, retaining significant amount of slag. The hoe was probably made by African slaves who had metallurgical knowledge acquired from their ancestors under Portuguese colonization. The equi-axial microstructure of ferrite grains, together with the alignment of slag inclusions, strongly suggest a metal forming procedure conducted on low-carbon puddled iron, followed by heat treatment and then cooling at a slow rate.

Ion beam analyses of radionuclide migration in heterogeneous rocks

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

Alonso, Ursula; Missana, Tiziana; Garcia-Gutierrez, Miguel

2013-07-18

The migration of radionuclides (RN) in the environment is a topic of general interest, for its implications on public health, and it is an issue for the long-term safety studies of deep geological repositories (DGR) for high-level radioactive waste. The role played by colloids on RN migration is also of great concern. Diffusion and sorption are fundamental mechanisms controlling RN migration in rocks and many experimental approaches are applied to determine transport parameters for low sorbing RN in homogeneous rocks. However, it is difficult to obtain relevant data for high sorbing RN or colloids, for which diffusion lengths are extremelymore » short, or within heterogeneous rocks, where transport might be different in different minerals. The ion beam techniques Rutherford Backscattering Spectrometry (RBS) and micro-Particle Induced X-Ray Emission ({mu}PIXE), rarely applied in the field, were selected for their micro-analytical potential to study RN diffusion and surface retention within heterogeneous rocks. Main achievements obtained during last 12 years are highlighted.« less

Cytology of pollutant metals in marine invertebrates: A review of microanalytical applications

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

Nott, J.A.

1991-03-01

x-ray microanalysis (XRMA) is customized for investigations of the metabolic and detoxification strategies of heavy metals taken by marine organisms from polluted environments. Sites of uptake, intracellular accumulation, transport and excretion are visualized, analysed and quantified. Cryopreparation techniques are required to prevent the translocation or loss from specimens of soluble metal species. In marine invertebrates, metals are detoxified by systems of chemical binding and intracellular compartmentalization. XRMA investigations have concentrated on marine molluscs and crustaceans and even within these restricted groups there are marked inter-species differences in the biochemical and cytological processes which reduce metal bioavailability. Some detoxification systems alsomore » protect the carnivores which ingest the metal-laden tissues of the prey. This results in the bioreduction of metals along a food chain. These processes are investigated by XRMA which can be tuned to observe the complex interactions which operate at all levels within and between the biota and polluted environments. 90 refs.« less

High-Performance and Traditional Multicrystalline Silicon: Comparing Gettering Responses and Lifetime-Limiting Defects

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

Castellanos, Sergio; Ekstrom, Kai E.; Autruffe, Antoine

2016-05-01

In recent years, high-performance multicrystalline silicon (HPMC-Si) has emerged as an attractive alternative to traditional ingot-based multicrystalline silicon (mc-Si), with a similar cost structure but improved cell performance. Herein, we evaluate the gettering response of traditional mc-Si and HPMC-Si. Microanalytical techniques demonstrate that HPMC-Si and mc-Si share similar lifetime-limiting defect types but have different relative concentrations and distributions. HPMC-Si shows a substantial lifetime improvement after P-gettering compared with mc-Si, chiefly because of lower area fraction of dislocation-rich clusters. In both materials, the dislocation clusters and grain boundaries were associated with relatively higher interstitial iron point-defect concentrations after diffusion, which ismore » suggestive of dissolving metal-impurity precipitates. The relatively fewer dislocation clusters in HPMC-Si are shown to exhibit similar characteristics to those found in mc-Si. Given similar governing principles, a proxy to determine relative recombination activity of dislocation clusters developed for mc-Si is successfully transferred to HPMC-Si.« less

Aging effect on Zn retention on a calcareous soil: column experiments and synchrotron X-ray micro-spectroscopic investigation.

PubMed

Sayen, Stéphanie; Guillon, Emmanuel

2014-07-15

In this study, a combination of column experiments and micro-analytical techniques exploiting synchrotron generated X-rays was used to assess the effect of aging time on Zn retention and mobility in the specific case of calcareous soils (high pH value, ≈ 8). The samples were subjected to aging for 2, 6, 17, and 63 days. Freshly added Zn mainly existed as an exchangeable form, and this metal fraction decreased over time due to Zn redistribution to stronger binding sites. Thus, after aging for 63 days, 45% of Zn is remobilized from exchangeable sites to stronger binding sites. μ-XRF maps were used to find correlations among elements in the sample, and μ-XANES spectra were recorded to precise Zn speciation. These analyses evidenced an increasing partitioning of Zn from organic matter to iron oxy(hydr)oxides over time. The occurrence of hydrozincite is evidenced in all samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterization and source term assessments of radioactive particles from Marshall Islands using non-destructive analytical techniques

NASA Astrophysics Data System (ADS)

Jernström, J.; Eriksson, M.; Simon, R.; Tamborini, G.; Bildstein, O.; Marquez, R. Carlos; Kehl, S. R.; Hamilton, T. F.; Ranebo, Y.; Betti, M.

2006-08-01

Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized by non-destructive analytical and microanalytical methods. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector and with wavelength dispersive system as well as a secondary ion mass spectrometer were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups: particles with pure Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogenously distributed. All of the particles were identified as nuclear fuel fragments of exploded weapon components. As containing plutonium with low 240Pu/ 239Pu atomic ratio, less than 0.065, which corresponds to weapons-grade plutonium or a detonation with low fission yield, the particles were identified to originate from the safety test and low-yield tests conducted in the history of Runit Island. The Si/O-rich particles contained traces of 137Cs ( 239 + 240 Pu/ 137Cs activity ratio higher than 2500), which indicated that a minor fission process occurred during the explosion. The average 241Am/ 239Pu atomic ratio in the six particles was 3.7 × 10 - 3 ± 0.2 × 10 - 3 (February 2006), which indicated that plutonium in the different particles had similar age.

A microanalytic study of self-regulated learning processes of expert, non-expert, and at-risk science students

NASA Astrophysics Data System (ADS)

Dibenedetto, Maria K.

2009-12-01

The present investigation sought to examine differences in the self-regulated learning processes and beliefs of students who vary in their level of expertise in science and to investigate if there are gender differences. Participants were 51 ethnically diverse 11th grade students from three parochial high schools consisting of 34 females and 17 males. Students were grouped as either expert, non-expert, or at-risk based on the school's classification. Students were provided with a short passage on tornados to read and study. The two achievement measures obtained were the Tornado Knowledge Test : ten short-answer questions and the Conceptual Model Test : a question which required the students to draw and describe the three sequential images of tornado development from the textual description of the three phases. A microanalytic methodology was used which consists of asking a series of questions aimed at assessing students' psychological behaviors, feelings, and thoughts in each of Zimmerman's three phases of self-regulation: forethought, performance, and reflection. These questions were asked of the students while they were engaged in learning. Two additional measures were obtained: the Rating Student Self-Regulated Learning Outcomes: A Teacher Scale (RSSRL) and the Self-Efficacy for Self-Regulated Learning (SELF). Analysis of variance, chi square analysis, and post hoc test results showed significant expertise differences, large effect sizes, and positive linear trends on most measures. Regarding gender, there were significant differences on only two measures. Correlational analyses also revealed significant relations among the self-regulatory subprocesses across the three phases. The microanalytic measures were combined across the three phases and entered into a regression formula to predict the students' scores on the Tornado Knowledge Test. These self-regulatory processes explained 77% of the variance in the Tornado Knowledge Test, which was a significant and substantial effect. Prior to this investigation, there have been no studies which have tested Zimmerman's three phase model on an academic task, such as science, within an expertise framework. Implications from the present study suggest that students varying in expertise level in science achievement also vary in self-regulatory behavior, and that gender is not a significant factor.

Evaluation of new geological reference materials for uranium-series measurements: Chinese Geological Standard Glasses (CGSG) and macusanite obsidian.

PubMed

Denton, J S; Murrell, M T; Goldstein, S J; Nunn, A J; Amato, R S; Hinrichs, K A

2013-10-15

Recent advances in high-resolution, rapid, in situ microanalytical techniques present numerous opportunities for the analytical community, provided accurately characterized reference materials are available. Here, we present multicollector thermal ionization mass spectrometry (MC-TIMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) uranium and thorium concentration and isotopic data obtained by isotope dilution for a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of compositions including basalt, syenite, andesite, and a soil. Uranium concentrations for these glasses range from ∼2 to 14 μg g(-1), Th/U weight ratios range from ∼4 to 6, (234)U/(238)U activity ratios range from 0.93 to 1.02, and (230)Th/(238)U activity ratios range from 0.98 to 1.12. Uranium and thorium concentration and isotopic data are also presented for a rhyolitic obsidian from Macusani, SE Peru (macusanite). This glass can also be used as a rhyolitic reference material, has a very low Th/U weight ratio (around 0.077), and is approximately in (238)U-(234)U-(230)Th secular equilibrium. The U-Th concentration data agree with but are significantly more precise than those previously measured. U-Th concentration and isotopic data agree within estimated errors for the two measurement techniques, providing validation of the two methods. The large (238)U-(234)U-(230)Th disequilibria for some of the glasses, along with the wide range in their chemical compositions and Th/U ratios should provide useful reference points for the U-series analytical community.

The Analytical Limits of Modeling Short Diffusion Timescales

NASA Astrophysics Data System (ADS)

Bradshaw, R. W.; Kent, A. J.

2016-12-01

Chemical and isotopic zoning in minerals is widely used to constrain the timescales of magmatic processes such as magma mixing and crystal residence, etc. via diffusion modeling. Forward modeling of diffusion relies on fitting diffusion profiles to measured compositional gradients. However, an individual measurement is essentially an average composition for a segment of the gradient defined by the spatial resolution of the analysis. Thus there is the potential for the analytical spatial resolution to limit the timescales that can be determined for an element of given diffusivity, particularly where the scale of the gradient approaches that of the measurement. Here we use a probabilistic modeling approach to investigate the effect of analytical spatial resolution on estimated timescales from diffusion modeling. Our method investigates how accurately the age of a synthetic diffusion profile can be obtained by modeling an "unknown" profile derived from discrete sampling of the synthetic compositional gradient at a given spatial resolution. We also include the effects of analytical uncertainty and the position of measurements relative to the diffusion gradient. We apply this method to the spatial resolutions of common microanalytical techniques (LA-ICP-MS, SIMS, EMP, NanoSIMS). Our results confirm that for a given diffusivity, higher spatial resolution gives access to shorter timescales, and that each analytical spacing has a minimum timescale, below which it overestimates the timescale. For example, for Ba diffusion in plagioclase at 750 °C timescales are accurate (within 20%) above 10, 100, 2,600, and 71,000 years at 0.3, 1, 5, and 25 mm spatial resolution, respectively. For Sr diffusion in plagioclase at 750 °C, timescales are accurate above 0.02, 0.2, 4, and 120 years at the same spatial resolutions. Our results highlight the importance of selecting appropriate analytical techniques to estimate accurate diffusion-based timescales.

Cesium distribution and phases in proxy experiments on the incineration of radioactively contaminated waste from the Fukushima area.

PubMed

Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Kakuta, Yoshitada; Kawano, Takashi

2014-10-01

After the March 11, 2011 Tohoku earthquake and Fukushima I Nuclear Power Plant accident, incineration was initially adopted as an effective technique for the treatment of post-disaster wastes. Accordingly, considerable amounts of radioactively contaminated residues were immediately generated through incineration. The level of radioactivity associated with radiocesium in the incineration ash residues (bottom ash and fly ash) became significantly high (several thousand to 100,000 Bq/kg) as a result of this treatment. In order to understand the modes of occurrence of radiocesium, bottom ash products were synthesized through combusting of refuse-derived fuel (RDF) with stable Cs salts in a pilot incinerator. Microscopic and microanalytical (SEM-EDX) techniques were applied and the following Cs categories were identified: low and high concentrations in the matrix glass, low-level partitioning into some newly-formed silicate minerals, partitioning into metal-sulfide compounds, and occurring in newly-formed Cs-rich minerals. These categories that are essentially silicate-bound are the most dominant forms in large and medium size bottom ash particles. It is expected that these achievements provide solutions to the immobilization of radiocesium in the incineration ash products contaminated by Fukushima nuclear accident. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nanostructure characterisation of flow-formed Cr-Mo-V steel using transmission Kikuchi diffraction technique.

PubMed

Birosca, S; Ding, R; Ooi, S; Buckingham, R; Coleman, C; Dicks, K

2015-06-01

Nowadays flow-forming has become a desired near net shape manufacturing method as it provides excellent mechanical properties with improved surface finish and significant manufacturing cost reduction. However, the material is subjected to excessive plastic deformation during flow-forming process, generating a very fine and complex microstructure. In addition, the intense dislocation density and residual stress that is generated in the component during processing makes the microstructure characterisation using conventional micro-analytical tools challenging. Thus, the microstructure/property relationship study in such a material is rather difficult. In the present study a flow-formed Cr-Mo-V steel nanostructure and crystallographic texture were characterised by means of Transmission Kikuchi Diffraction (TKD). Here, TKD is shown to be a powerful technique in revealing very fine martensite laths within an austenite matrix. Moreover, fine precipitates in the order of 20-70 nm on the martensite lath boundaries were clearly imaged and characterised. This greatly assisted in understanding the preferable site formation of the carbides in such a complex microstructure. The results showed that the actual TKD spatial resolution was in the range of 5-10 nm using 25 kV for flow-formed Cr-Mo-V steel. Copyright © 2015 Elsevier B.V. All rights reserved.

Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques.

PubMed

Zhu, Yumin; Zhang, Hua; Shao, Liming; He, Pinjing

2015-01-01

Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW). In this study, we investigated fine particles of <2mm, which are small fractions in MSW but constitute a significant component of the total heavy metal content, using bulk detection techniques. A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction. We also discussed the association, speciation and source apportionment of heavy metals. Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of <10 μm within the fine particles. Zn-Cu, Pb-Fe and Fe-Mn-Cr had significant correlations in terms of spatial distribution. The overlapped enrichment, spatial association, and the mineral phases of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles. The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products. Copyright © 2014. Published by Elsevier B.V.

Prospects for Practical Laser Ablation U/Pb and (U-Th)/He Double-Dating (LADD) of Detrital Apatite

NASA Astrophysics Data System (ADS)

Horne, A.; Hodges, K. V.; Van Soest, M. C.

2017-12-01

A laser ablation micro-analytical technique for (U-Th)/He dating has been shown to be an effective approach to the thermochronologic study of detrital zircons (Tripathy-Lang et al., J. Geophys. Res., 2013), while Evans et al. (J. Anal. At. Spectrom., 2015) and Horne et al. (Geochim. Cosmochim. Acta, 2016) demonstrated how the technique could be modified to enable laser ablation U/Pb and (U-Th)/He double-dating (LADD) of detrital zircon and titanite. These successes beg the question of whether or not LADD is viable for another commonly encountered detrital mineral: apatite. Exploratory LADD studies in Arizona State University's Group 18 Laboratories - using Durango fluorapatite, apatite from the Fish Canyon tuff, and detrital apatite from modern fluvial sediments in the eastern Sierra Nevada of California - illustrate that the method is indeed viable for detrital apatite. However, the method may not be appropriate for all detrital samples. For example, many apatite grains encountered in detrital samples from young orogenic settings have low concentrations of U and Th and small crystal sizes. This can lead to imprecise laser ablation (U-Th)/He dates, especially for very young grains potentially obscuring or inhibiting relevant interpretations of the data set.

Temperature programmable microfabricated gas chromatography column

DOEpatents

Manginell, Ronald P.; Frye-Mason, Gregory C.

2003-12-23

A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

Spectroscopic Studies of Nuclear Submarine Atmospheres. I. Desorption and Analysis of Contaminants from Hopcalite

DTIC Science & Technology

A semi-microanalytical method is described for desorbing contaminants from Hopcalite , an oxide catalyst used in the purification of submarine...contaminants are desorbed from the Hopcalite by passing pressurized steam through a column of the catalyst. The various compounds are eluted from the column...appropriate solvent. Infrared spectral analyses of contaminants desorbed from Hopcalite following its use as a catalyst for the oxidation of pure

Exploring Clinical Reasoning in Novices: A Self-Regulated Learning Microanalytic Approach

DTIC Science & Technology

2013-07-05

important medical school performance outcomes. Self-Regulated Learning Microanalysis Social-cognitive researchers have defined SRL as “the...It is important to note at the outset, however, that our plan was not to use SRL microanalysis to comprehensively assess students’ reasoning skills...2.97 1.31 .29* 1.39 .51 .32 † 22 Discussion This study was important because it represents an initial attempt to examine SRL

Mechanisms of contextual risk for adolescent self-injury: invalidation and conflict escalation in mother-child interactions.

PubMed

Crowell, Sheila E; Baucom, Brian R; McCauley, Elizabeth; Potapova, Natalia V; Fitelson, Martha; Barth, Heather; Smith, Cindy J; Beauchaine, Theodore P

2013-01-01

According to developmental theories of self-injury, both child characteristics and environmental contexts shape and maintain problematic behaviors. Although progress has been made toward identifying biological vulnerabilities to self-injury, mechanisms underlying psychosocial risk have received less attention. In the present study, we compared self-injuring adolescents (n = 17) with typical controls (n = 20) during a mother-child conflict discussion. Dyadic interactions were coded using both global and microanalytic systems, allowing for a highly detailed characterization of mother-child interactions. We also assessed resting state psychophysiological regulation, as indexed by respiratory sinus arrhythmia (RSA). Global coding revealed that maternal invalidation was associated with adolescent anger. Furthermore, maternal invalidation and coerciveness were both related to adolescent opposition/defiance. Results from the microanalytic system indicated that self-injuring dyads were more likely to escalate conflict, suggesting a potential mechanism through which emotion dysregulation is shaped and maintained over time. Finally, mother and teen aversiveness interacted to predict adolescent resting RSA. Low-aversive teens with highly aversive mothers had the highest RSA, whereas teens in high-high dyads showed the lowest RSA. These findings are consistent with theories that emotion invalidation and conflict escalation are possible contextual risk factors for self-injury.

Mechanisms of Contextual Risk for Adolescent Self-Injury: Invalidation and Conflict Escalation in Mother-Child Interactions

PubMed Central

Crowell, Sheila E.; Baucom, Brian R.; McCauley, Elizabeth; Potapova, Natalia V.; Fitelson, Martha; Barth, Heather; Smith, Cindy J.; Beauchaine, Theodore P.

2013-01-01

OBJECTIVE According to developmental theories of self-injury, both child characteristics and environmental contexts shape and maintain problematic behaviors. Although progress has been made toward identifying biological vulnerabilities to self-injury, mechanisms underlying psychosocial risk have received less attention. METHOD In the present study, we compared self-injuring adolescents (n=17) with typical controls (n=20) during a mother-child conflict discussion. Dyadic interactions were coded using both global and microanalytic systems, allowing for a highly detailed characterization of mother-child interactions. We also assessed resting state psychophysiological regulation, as indexed by respiratory sinus arrhythmia (RSA). RESULTS Global coding revealed that maternal invalidation was associated with adolescent anger. Furthermore, maternal invalidation and coerciveness were both related to adolescent opposition/defiance. Results from the microanalytic system indicated that self-injuring dyads were more likely to escalate conflict, suggesting a potential mechanism through which emotion dysregulation is shaped and maintained over time. Finally, mother and teen aversiveness interacted to predict adolescent resting RSA. Low-aversive teens with highly aversive mothers had the highest RSA, whereas teens in high-high dyads showed the lowest RSA. CONCLUSIONS These findings are consistent with theories that emotion invalidation and conflict escalation are possible contextual risk factors for self-injury. PMID:23581508

Root causes investigation of catastrophic optical bulk damage in high-power InGaAs-AlGaAs strained QW lasers

NASA Astrophysics Data System (ADS)

Sin, Yongkun; Lingley, Zachary; Ayvazian, Talin; Brodie, Miles; Ives, Neil

2018-02-01

High-power single-mode (SM) and multi-mode (MM) InGaAs-AlGaAs strained quantum well (QW) lasers are critical components for both terrestrial and space satellite communications systems. Since these lasers predominantly fail by catastrophic and sudden degradation due to COD, it is especially crucial for space satellite applications to investigate reliability, failure modes, and degradation mechanisms of these lasers. Our group reported a new failure mode in MM and SM InGaAs-AlGaAs strained QW lasers in 2009 and 2016, respectively. Our group also reported in 2017 that bulk failure due to catastrophic optical bulk damage (COBD) is the dominant failure mode of both SM and MM lasers that were subject to long-term life-tests. For the present study, we report root causes investigation of COBD by performing long-term lifetests followed by failure mode analysis (FMA) using various micro-analytical techniques including electron beam induced current (EBIC), time-resolved electroluminescence (EL), focused ion beam (FIB), high-resolution transmission electron microscopy (TEM), and deep level transient spectroscopy (DLTS). Our life-tests with accumulated test hours of over 25,000 hours for SM lasers and over 35,000 hours for MM lasers generated a number of COBD failures with various failure times. EBIC techniques were employed to study dark line defects (DLDs) generated in SM COBD failures stressed under different test conditions. FIB and high-resolution TEM were employed to prepare cross sectional and plan view TEM specimens to study DLD areas (dislocations) in post-aged SM lasers. Time-resolved EL techniques were employed to study initiation and progressions of dark spots and dark lines in real time as MM lasers were aged. Lastly, to investigate precursor signatures of failure and degradation mechanisms responsible for COBD in both SM and MM lasers, we employed DLTS techniques to study a role that electron traps (non-radiative recombination centers) play in degradation of these lasers. Our in-depth root causes investigation results are reported.

Tracking Radionuclide Fractionation in the First Atomic Explosion Using Stable Elements

DOE PAGES

Bonamici, Chloë E.; Hervig, Richard L.; Kinman, William S.

2017-08-25

Compositional analysis of postdetonation fallout is a tool for forensic identification of nuclear devices. However, the relationship between device composition and fallout composition is difficult to interpret because of the complex combination of physical mixing, nuclear reactions, and chemical fractionations that occur in the chaotic nuclear fireball. By using a combination of in situ microanalytical techniques (electron microprobe analysis and secondary ion mass spectrometry), we show that some heavy stable elements (Rb, Sr, Zr, Ba, Cs, Ba, La, Ce, Nd, Sm, Dy, Lu, U, Th) in glassy fallout from the first nuclear test, Trinity, are reliable chemical proxies for radionuclidesmore » generated during the explosion. Stable-element proxies show that radionuclides from the Trinity device were chemically, but not isotopically, fractionated by condensation. Moreover, stable-element proxies delineate chemical fractionation trends that can be used to connect present-day fallout composition to past fireball composition. Stable-element proxies therefore offer a novel approach for elucidating the phenomenology of the nuclear fireball as it relates to the formation of debris and the fixation of device materials within debris.« less

Tracking Radionuclide Fractionation in the First Atomic Explosion Using Stable Elements

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

Bonamici, Chloë E.; Hervig, Richard L.; Kinman, William S.

Compositional analysis of postdetonation fallout is a tool for forensic identification of nuclear devices. However, the relationship between device composition and fallout composition is difficult to interpret because of the complex combination of physical mixing, nuclear reactions, and chemical fractionations that occur in the chaotic nuclear fireball. By using a combination of in situ microanalytical techniques (electron microprobe analysis and secondary ion mass spectrometry), we show that some heavy stable elements (Rb, Sr, Zr, Ba, Cs, Ba, La, Ce, Nd, Sm, Dy, Lu, U, Th) in glassy fallout from the first nuclear test, Trinity, are reliable chemical proxies for radionuclidesmore » generated during the explosion. Stable-element proxies show that radionuclides from the Trinity device were chemically, but not isotopically, fractionated by condensation. Moreover, stable-element proxies delineate chemical fractionation trends that can be used to connect present-day fallout composition to past fireball composition. Stable-element proxies therefore offer a novel approach for elucidating the phenomenology of the nuclear fireball as it relates to the formation of debris and the fixation of device materials within debris.« less

Tracking Radionuclide Fractionation in the First Atomic Explosion Using Stable Elements.

PubMed

Bonamici, Chloë E; Hervig, Richard L; Kinman, William S

2017-09-19

Compositional analysis of postdetonation fallout is a tool for forensic identification of nuclear devices. However, the relationship between device composition and fallout composition is difficult to interpret because of the complex combination of physical mixing, nuclear reactions, and chemical fractionations that occur in the chaotic nuclear fireball. Using a combination of in situ microanalytical techniques (electron microprobe analysis and secondary ion mass spectrometry), we show that some heavy stable elements (Rb, Sr, Zr, Ba, Cs, Ba, La, Ce, Nd, Sm, Dy, Lu, U, Th) in glassy fallout from the first nuclear test, Trinity, are reliable chemical proxies for radionuclides generated during the explosion. Stable-element proxies show that radionuclides from the Trinity device were chemically, but not isotopically, fractionated by condensation. Furthermore, stable-element proxies delineate chemical fractionation trends that can be used to connect present-day fallout composition to past fireball composition. Stable-element proxies therefore offer a novel approach for elucidating the phenomenology of the nuclear fireball as it relates to the formation of debris and the fixation of device materials within debris.

Synthesis, spectral characterization and antimicrobial studies of nano-sized oxovanadium(IV) complexes with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazole and indoline-2,3-dione.

PubMed

Sahani, M K; Yadava, U; Pandey, O P; Sengupta, S K

2014-05-05

A new class of oxovanadium(IV) complexes with Schiff bases derived by the condensation of 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazoles and indoline-2,3-dione have been prepared in ethanol in the presence of sodium acetate. Micro-analytical data, magnetic susceptibility, UV-Vis, IR, EPR and XRD spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-pyramidal geometry. The oxovanadium(IV) complexes have monoclinic crystal system and particle sizes were found to be in the range 18.0 nm to 24.0 nm (nano-size). In vitro antifungal activity of synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The oxovanadium(IV) complexes have higher antimicrobial effect than free ligands. Copyright © 2014 Elsevier B.V. All rights reserved.

Computational Methodology for Absolute Calibration Curves for Microfluidic Optical Analyses

PubMed Central

Chang, Chia-Pin; Nagel, David J.; Zaghloul, Mona E.

2010-01-01

Optical fluorescence and absorption are two of the primary techniques used for analytical microfluidics. We provide a thorough yet tractable method for computing the performance of diverse optical micro-analytical systems. Sample sizes range from nano- to many micro-liters and concentrations from nano- to milli-molar. Equations are provided to trace quantitatively the flow of the fundamental entities, namely photons and electrons, and the conversion of energy from the source, through optical components, samples and spectral-selective components, to the detectors and beyond. The equations permit facile computations of calibration curves that relate the concentrations or numbers of molecules measured to the absolute signals from the system. This methodology provides the basis for both detailed understanding and improved design of microfluidic optical analytical systems. It saves prototype turn-around time, and is much simpler and faster to use than ray tracing programs. Over two thousand spreadsheet computations were performed during this study. We found that some design variations produce higher signal levels and, for constant noise levels, lower minimum detection limits. Improvements of more than a factor of 1,000 were realized. PMID:22163573

Microanalytical identification of barium sulphate crystals in statoliths of Chara Rhizoids

NASA Technical Reports Server (NTRS)

Schroeter, K.; Lauchli, A.; Sievers, A. J.

1979-01-01

In contrast to higher plants, Chara rhizoids contain statolith vacuoles filled with biocrystallites of BaS04 in the form of rods composed of globular subunits ca. 7 nm in diameter. The revelation of the crystallites under electron microscopy is dependent on the fixative; best structural preservation was observed after fixation in a buffered glutaraldehyde + acrolein solution; 0s04 and KMnO4 partially dissolved both the biocrystallites and synthetic BaS04.

Microfabricated thermionic detector

DOEpatents

Lewis, Patrick R; Manginell, Ronald P; Wheeler, David R; Trudell, Daniel E

2012-10-30

A microfabricated TID comprises a microhotplate and a thermionic source disposed on the microhotplate. The microfabricated TID can provide high sensitivity and selectivity to nitrogen- and phosphorous-containing compounds and other compounds containing electronegative function groups. The microfabricated TID can be microfabricated with semiconductor-based materials. The microfabricated TID can be combined with a microfabricated separation column and used in microanalytical system for the rapid on-site detection of pesticides, chemical warfare agents, explosives, pharmaceuticals, and other organic compounds that contain nitrogen or phosphorus.

Space Science

NASA Image and Video Library

2003-06-07

The heart of a colorimetric solid phase extractor (CSPE) test kit quickly measures the concentration of the biocides silver or iodine in astronauts’ drinking water to determine whether concentrations are safe. When 10 milliliters (ml) of water is drawn through the disk, the disk will turn color (yellow in this picture for iodine) indicating the presence of the biocides. The device could someday be used to test water safety at reservoirs and water treatment plants on Earth. (photo credit: Microanalytical Instrumentation Center, Iowa State University).

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

Vilches, J.; Lopez, A.; Martinez, M.C.

This paper discusses the value of scanning electron microscopy (SEM) and x-ray microanalysis in the classification of craniopharyngiomas. This neoplasm shows epithelial nest, cords of cuboid cells, foci of squamous metaplasia, and microcystic degeneration. SEM reveals that the epithelial cysts are lined with elongated cells that possess numerous microvilli and blebs and that some cysts are lined with polyhedral cells. The microvilli are interpreted as characteristic of the fast growing craniopharyngiomas. A microanalytical study of the calcified areas reveals the presence of magnesium, phosphorus, and calcium.

Analytical electron microscopy in mineralogy; exsolved phases in pyroxenes

USGS Publications Warehouse

Nord, G.L.

1982-01-01

Analytical scanning transmission electron microscopy has been successfully used to characterize the structure and composition of lamellar exsolution products in pyroxenes. At operating voltages of 100 and 200 keV, microanalytical techniques of x-ray energy analysis, convergent-beam electron diffraction, and lattice imaging have been used to chemically and structurally characterize exsolution lamellae only a few unit cells wide. Quantitative X-ray energy analysis using ratios of peak intensities has been adopted for the U.S. Geological Survey AEM in order to study the compositions of exsolved phases and changes in compositional profiles as a function of time and temperature. The quantitative analysis procedure involves 1) removal of instrument-induced background, 2) reduction of contamination, and 3) measurement of correction factors obtained from a wide range of standard compositions. The peak-ratio technique requires that the specimen thickness at the point of analysis be thin enough to make absorption corrections unnecessary (i.e., to satisfy the "thin-foil criteria"). In pyroxenes, the calculated "maximum thicknesses" range from 130 to 1400 nm for the ratios Mg/Si, Fe/Si, and Ca/Si; these "maximum thicknesses" have been contoured in pyroxene composition space as a guide during analysis. Analytical spatial resolutions of 50-100 nm have been achieved in AEM at 200 keV from the composition-profile studies, and analytical reproducibility in AEM from homogeneous pyroxene standards is ?? 1.5 mol% endmember. ?? 1982.

Microchannel gel electrophoretic separation systems and methods for preparing and using

DOEpatents

Herr, Amy E; Singh, Anup K; Throckmorton, Daniel J

2015-02-24

A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays that are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.

Microchannel gel electrophoretic separation systems and methods for preparing and using

DOEpatents

Herr, Amy; Singh, Anup K; Throckmorton, Daniel J

2013-09-03

A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic separation and quantifying analyte concentration based upon conventional polyacrylamide gel electrophoresis (PAGE). To retain biological activity of proteins and maintain intact immune complexes, native PAGE conditions were employed. Both direct (non-competitive) and competitive immunoassay formats are demonstrated in microchips for detecting toxins and biomarkers (cytokines, c-reactive protein) in bodily fluids (serum, saliva, oral fluids). Further, a description of gradient gels fabrication is included, in an effort to describe methods we have developed for further optimization of on-chip PAGE immunoassays. The described chip-based PAGE immunoassay method enables immunoassays that are fast (minutes) and require very small amounts of sample (less than a few microliters). Use of microfabricated chips as a platform enables integration, parallel assays, automation and development of portable devices.

Miniature Bioreactor System for Long-Term Cell Culture

NASA Technical Reports Server (NTRS)

Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

2010-01-01

A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

Microscopy and Microanalysis of Blood in a Snake Head Fish, Channa gachua Exposed to Environmental Pollution.

PubMed

Pala, Eva M; Dey, Sudip

2016-02-01

Conventional and highly sophisticated analytical methods (Cyria et al., 1989; Massar et al., 2012a) were used to analyze micro-structural and micro-analytical aspects of the blood of snake head fish, Channa gachua, exposed to municipal wastes and city garbage. Red (RBC) and white blood cell (WBC) counts and hemhemoglobin content were found to be higher in pollution affected fish as compared with control. Scanning electron microscopy revealed the occurrence of abnormal erythrocytes such as crenated cells, echinocytes, lobopodial projections, membrane internalization, spherocytes, ruptured cells, contracted cells, depression, and uneven elongation of erythrocyte membranes in fish inhabiting the polluted sites. Energy-dispersive X-ray spectroscopy (EDS) revealed the presence of silicon and lead in the RBCs of pollution affected fish. Significance of the study includes the highly sophisticated analytical approach, which revealed the aforementioned micro-structural abnormalities.

Study of Chemical Changes in Uranium Oxyfluoride Particles Progress Report March - October 2009

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

Kips, R; Kristo, M; Hutcheon, I

2009-11-22

Nuclear forensics relies on the analysis of certain sample characteristics to determine the origin and history of a nuclear material. In the specific case of uranium enrichment facilities, it is the release of trace amounts of uranium hexafluoride (UF{sub 6}) gas - used for the enrichment of uranium - that leaves a process-characteristic fingerprint. When UF{sub 6} gas interacts with atmospheric moisture, uranium oxyfluoride particles or particle agglomerates are formed with sizes ranging from several microns down to a few tens of nanometers. These particles are routinely collected by safeguards organizations, such as the International Atomic Energy Agency (IAEA), allowingmore » them to verify whether a facility is compliant with its declarations. Spectrometric analysis of uranium particles from UF{sub 6} hydrolysis has revealed the presence of both particles that contain fluorine, and particles that do not. It is therefore assumed that uranium oxyfluoride is unstable, and decomposes to form uranium oxide. Understanding the rate of fluorine loss in uranium oxyfluoride particles, and the parameters that control it, may therefore contribute to placing boundaries on the particle's exposure time in the environment. Expressly for the purpose of this study, we prepared a set of uranium oxyfluoride particles at the Institute for Reference Materials and Measurements (EU-JRC-IRMM) from a static release of UF{sub 6} in a humid atmosphere. The majority of the samples was stored in controlled temperature, humidity and lighting conditions. Single particles were characterized by a suite of micro-analytical techniques, including NanoSIMS, micro-Raman spectrometry (MRS), scanning (SEM) and transmission (TEM) electron microscopy, energy-dispersive X-ray spectrometry (EDX) and focused ion beam (FIB). The small particle size was found to be the main analytical challenge. The relative amount of fluorine, as well as the particle chemical composition and morphology were determined at different stages in the ageing process, and immediately after preparation. This report summarizes our most recent findings for each of the analytical techniques listed above, and provides an outlook on what remains to be resolved. Additional spectroscopic and mass spectrometric measurements were carried out at Pacific Northwest National Laboratory, but are not included in this summary.« less

Isotopic and elemental chemistry of sedimentary pyrite: A combined analytical and statistical approach to a novel planetary biosignature

NASA Astrophysics Data System (ADS)

Figueroa, M. C.; Gregory, D. D.; Lyons, T. W.; Williford, K. H.

2017-12-01

Life processes affect trace element abundances in pyrite such that sedimentary and hydrothermal pyrite have significantly different trace element signatures. Thus, we propose that these biogeochemical data could be used to identify pyrite that formed biogenetically either early in our planet's history or on other planets, particularly Mars. The potential for this approach is elevated because pyrite is common in diverse sedimentary settings, and its trace element content can be preserved despite secondary overprints up to greenschist facies, thus minimizing the concerns about remobilization that can plague traditional whole rock studies. We are also including in-situ sulfur isotope analysis to further refine our understanding of the complex signatures of ancient pyrite. Sulfur isotope data can point straightforwardly to the involvement of life, because pyrite in sediments is inextricably linked to bacterial sulfate reduction and its diagnostic isotopic expressions. In addition to analyzing pyrite of known biological origin formed in the modern and ancient oceans under a range of conditions, we are building a data set for pyrite formed by hydrothermal and metamorphic processes to minimize the risk of false positives in life detection. We have used Random Forests (RF), a machine learning statistical technique with proven efficiency for classifying large geological datasets, to classify pyrite into biotic and abiotic end members. Coupling the trace element and sulfur isotope data from our analyses with a large existing dataset from diverse settings has yielded 4500 analyses with 18 different variables. Our initial results reveal the promise of the RF approach, correctly identifying biogenic pyrite 97 percent of the time. We will continue to couple new in-situ S-isotope and trace element analyses of biogenic pyrite grains from modern and ancient environments, using cutting-edge microanalytical techniques, with new data from high temperature settings. Our ultimately goal is a refined search tool with straightforward application in the search for early life on Earth and distant life recorded in meteorites, returned samples, and in situ measurements.

Next-generation confirmatory disease diagnostics

NASA Astrophysics Data System (ADS)

Lin, Robert; Gerver, Rachel; Karns, Kelly; Apori, Akwasi A.; Denisin, Aleksandra K.; Herr, Amy E.

2014-06-01

Microfluidic tools are advancing capabilities in screening diagnostics for use in near-patient settings. Here, we review three case studies to illustrate the flexibility and analytical power offered by microanalytical tools. We first overview a near-patient tool for detection of protein markers found in cerebrospinal fluid (CSF), as a means to identify the presence of cerebrospinal fluid in nasal mucous - an indication that CSF is leaking into the nasal cavity. Microfluidic design allowed integration of several up-stream preparatory steps and rapid, specific completion of the human CSF protein assay. Second, we overview a tear fluid based assay for lactoferrin, a protein produced in the lacrimal gland, then secreted into tear fluid. Tear Lf is a putative biomarker for primary SS. A critical contribution of this and related work being measurement of Lf, even in light of well-known and significant matrix interactions and losses during the tear fluid collection and preparation. Lastly, we review a microfluidic barcode platform that enables rapid measurement of multiple infectious disease biomarkers in human sera. The assay presents a new approach to multiplexed biomarker detection, yet in a simple straight microchannel - thus providing a streamlined, simplified microanalytical platform, as is relevant to robust operation in diagnostic settings. We view microfluidic design and analytical chemistry as the basis for emerging, sophisticated assays that will advance not just screening diagnostic technology, but confirmatory assays, sample preparation and handling, and thus introduction and utilization of new biomarkers and assay formats.

Manual for Transference Work Scale; a micro-analytical tool for therapy process analyses.

PubMed

Ulberg, Randi; Amlo, Svein; Høglend, Per

2014-11-18

The present paper is a manual for the Transference Work Scale (TWS). The inter-rater agreement on the 26 TWS items was good to excellent and previously published. TWS is a therapy process rating scale focusing on Transference Work (TW) (i.e. analysis of the patient-therapist relationship). TW is considered a core active ingredient in dynamic psychotherapy. Adequate process scales are needed to identify and analyze in-session effects of therapist techniques in psychodynamic psychotherapy and empirically establish their links to outcome. TWS was constructed to identify and categorize relational (transference) interventions, and explore the in-session impact of analysis of the patient-therapist relationship (transference work). TWS has sub scales that rate timing, content, and valence of the transference interventions, as well as response from the patient. Descriptions and elaborations of the items in TWS are provided. Clinical examples of transference work from the First Experimental Study of Transference Interpretations (FEST) are included and followed by examples of how to rate transcripts from therapy sessions with TWS. The present manual describes in detail the rating procedure when using Transference Work Scale. Ratings are illustrated with clinical examples from FEST. TWS might be a potentially useful tool to explore the interaction of timing, category, and valence of transference work in predicting in-session patient response as well as treatment outcome. TWS might prove especially suitable for intensive case studies combining quantitative and narrative data. First Experimental Study of Transference-interpretations (FEST307/95). ClinicalTrials.gov Identifier: NCT00423462. URL: http://clinicaltrials.gov/ct2/show/NCT00423462?term=FEST&rank=2.

Laser micromachined isoelectric focusing devices on polymer substrate for electrospray mass spectrometry

NASA Astrophysics Data System (ADS)

Lin, Yuehe; Wen, Jenny; Fan, Xiang; Matson, Dean W.; Smith, Richard D.

1999-08-01

A microfabricated device for isoelectric focusing (IEF) incorporating an optimized electrospray ionization (ESI) tip was constructed on polycarbonate plates using a laser micromachining technique. The separation channels on an IEF chip were 16 cm long, 50 micrometers wide and 30 micrometers deep. Electrical potentials used for IEF focusing and electrospray were applied through platinum electrodes placed in the buffer reservoirs, and which were isolated from the separation channel by molecular porous membranes. On-line ESI produced directly from a sharp `tip' on the microchip was evaluated. The results indicate that this design can produce a stable electrospray that is further improved and made more flexible with the assistance of sheath gas and sheath liquid. Error analysis of the spectral data shows that the standard deviation in signal intensity for an analyte peak was less than approximately 5% over 3 hours. The production of stable electrosprays directly from microchip IEF devices represents a step towards easily- fabricated microanalytical devices. IEF separations of protein mixtures were demonstrated for uncoated polycarbonate microchips. On-line IEF/ESI-MS was demonstrated using the microfabricated chip with an ion-trap ESI mass spectrometer for characterization of protein mixtures.

Spectral, biological screening of metal chelates of chalcone based Schiff bases of N-(3-aminopropyl) imidazole.

PubMed

Kalanithi, M; Rajarajan, M; Tharmaraj, P; Sheela, C D

2012-02-15

Tridentate chelate complexes of Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized from the chalcone based ligands 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol(HL(1)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-p-tolylallyl]phenol(HL(2)), 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol(HL(3)). Microanalytical data, UV-vis spectrophotometric method, magnetic susceptibility measurements, IR, 1H NMR, Mass, and EPR techniques were used to characterize the structure of chelates. The electronic absorption spectra and magnetic susceptibility measurements suggest a distorted square planar geometry for the copper(II) ion. The other metal complexes show distorted tetrahedral geometry. The coordination of the ligands with metal(II) ions was further confirmed by solution fluorescence spectrum. The antimicrobial activity of the ligands and metal(II) complexes against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger has been carried out and compared. The electrochemical behavior of copper(II) complex is studied by cyclic voltammetry. Copyright © 2011 Elsevier B.V. All rights reserved.

Propellant's differentiation using FTIR-photoacoustic detection for forensic studies of improvised explosive devices.

PubMed

Álvarez, Ángela; Yáñez, Jorge; Contreras, David; Saavedra, Renato; Sáez, Pedro; Amarasiriwardena, Dulasiri

2017-11-01

The use of propellant for making improvised explosive devices (IED) is an incipient criminal practice. Propellant can be used as initiator in explosive mixtures along with other components such as coal, ammonium nitrate, sulfur, etc. The identification of the propellant's brand used in homemade explosives can provide additional forensic information of this evidence. In this work, four of the most common propellant brands were characterized by Fourier-transform infrared photoacoustic spectroscopy (FTIR-PAS) which is a non-destructive micro-analytical technique. Spectra shows characteristic signals of typical compounds in the propellants, such as nitrocellulose, nitroglycerin, guanidine, diphenylamine, etc. The differentiation of propellant components was achieved by using FTIR-PAS combined with chemometric methods of classification. Principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) were used to achieve an effective differentiation and classification (100%) of propellant brands. Furthermore, propellant brand differentiation was also assessed using partial least squares discriminant analyses (PLS-DA) by leave one out cross (∼97%) and external (∼100%) validation method. Our results show the ability of FTIR-PAS combined with chemometric analysis to identify and differentiate propellant brands in different explosive formulations of IED. Copyright © 2017 Elsevier B.V. All rights reserved.

A review of electrochemiluminescence (ECL) in and for microfluidic analytical devices.

PubMed

Kirschbaum, Stefanie E K; Baeumner, Antje J

2015-05-01

The concept and realization of microfluidic total analysis systems (microTAS) have revolutionized the analytical process by integrating the whole breadth of analytical techniques into miniaturized systems. Paramount for efficient and competitive microTAS are integrated detection strategies, which lead to low limits of detection while reducing the sample volume. The concept of electrochemiluminescence (ECL) has been intriguing ever since its introduction based on Ru(bpy)3 (2+) by Tokel and Bard [1] (J Am Chem Soc 1853:2862-2863, 1972), especially because of its immense sensitivity, nonexistent auto-luminescent background signal, and simplicity in experimental design. Therefore, integrating ECL detection into microTAS is a logical consequence to achieve simple, yet highly sensitive, sensors. However, published microanalytical devices employing ECL detection focus in general on traditional ECL chemistry and have yet to take advantage of advances made in standard bench-top ECL strategies. This review will therefore focus on the most recent advancements in microfluidic ECL approaches, but also evaluate the potential impact of bench-top ECL research progress that would further improve performance and lower limits of detection of micro analytical ECL systems, ensuring their desirability as detection principle for microTAS applications.

Stable isotopes in mid-ocean ridge hydrothermal systems: Interactions between fluids, minerals, and organisms

USGS Publications Warehouse

Shanks, Wayne C.; Böhlke, John Karl; Seal, Robert R.; Humphries, S.D.; Zierenberg, Robert A.; Mullineaux, Lauren S.; Thomson, Richard E.

1995-01-01

Studies of abundance variations of light stable isotopes in nature have had a tremendous impact on all aspects of geochemistry since the development, in 1947, of a gas source isotope ratio mass spectrometer capable of measuring small variations in stable isotope ratios (Nice, 1947]. Stable isotope geochemistry is now a mature field, as witnessed by the proliferation of commercially available mass spectrometers installed at virtually every major academic, government, and private-sector research geochemistry laboratory. A recent search of a literature database revealed over 3,000 articles that utilized stable isotope geochemistry over the last 20 years. Nonetheless, many exciting new technical developments are leading to exciting new discoveries and applications. In particular, micro-analytical techniques involving new generations of laser- and ion-microprobes are revolutionizing the types of analyses that can be done on spot sizes as small as a few tens of micrometers [Shanks and Criss, 1989]. New generations of conventional gas source and thermal ionization mass spectrometers, with high levels of automation and increased sensitivity and precision, are allowing analyses of large numbers of samples, like those needed for stable isotope stratigraphy in marine sediments, and are enabling the development and application of new isotopic systems.

Electroosmotic pumps for microflow analysis

PubMed Central

Wang, Xiayan; Wang, Shili; Gendhar, Brina; Cheng, Chang; Byun, Chang Kyu; Li, Guanbin; Zhao, Meiping; Liu, Shaorong

2009-01-01

With rapid development in microflow analysis, electroosmotic pumps are receiving increasing attention. Compared to other micropumps, electroosmotic pumps have several unique features. For example, they are bi-directional, can generate constant and pulse-free flows with flow rates well suited to microanalytical systems, and can be readily integrated with lab-on-chip devices. The magnitude and the direction of flow of an electroosmotic pump can be changed instantly. In addition, electroosmotic pumps have no moving parts. In this article, we discuss common features, introduce fabrication technologies and highlight applications of electroosmotic pumps. PMID:20047021

Non-planar chemical preconcentrator

DOEpatents

Manginell, Ronald P [Albuquerque, NM; Adkins, Douglas R [Albuquerque, NM; Sokolowski, Sara S [Albuquerque, NM; Lewis, Patrick R [Albuquerque, NM

2006-10-10

A non-planar chemical preconcentrator comprises a high-surface area, low mass, three-dimensional, flow-through sorption support structure that can be coated or packed with a sorptive material. The sorptive material can collect and concentrate a chemical analyte from a fluid stream and rapidly release it as a very narrow temporal plug for improved separations in a microanalytical system. The non-planar chemical preconcentrator retains most of the thermal and fabrication benefits of a planar preconcentrator, but has improved ruggedness and uptake, while reducing sorptive coating concerns and extending the range of collectible analytes.

Sub-to super-ambient temperature programmable microfabricated gas chromatography column

DOEpatents

Robinson, Alex L.; Anderson, Lawrence F.

2004-03-16

A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

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

Vilches, J.; Lopez, A.; De Palacio, L.

Calculi removed from human prostates affected with nodular hyperplasia were analyzed with scanning electron microscopy and EDAX system. The general spectrum was made up of Na, Al, Mg, S, P, Ca and Zn. Two types of stone were identified morphostructurally and microanalytically: calculi type I of nodular surface with high peaks of S, and calculi type II polyfaceted with high peaks of P and Ca. Their formation from corpora amylacea and/or exogenous constituents is discussed. The superficial deposit of Zn suggests its incorporation from the prostatic liquid and does not seem to play an important role in the genesis.

Reference Materials for Trace Element Microanalysis of Carbonates by SIMS and other Mass Spectrometric Techniques

NASA Astrophysics Data System (ADS)

Layne, G. D.

2009-12-01

Today, many areas of geochemical research utilize microanalytical determinations of trace elements in carbonate minerals. In particular, there has been an explosion in the application of Secondary Ion Mass Spectrometry (SIMS) to studies of marine biomineralization. SIMS provides highly precise determinations of Mg and Sr at the concentration levels normally encountered in corals, mollusks or fish otoliths. It is also a highly effective means for determining a wide range of other trace elements at ppm levels (e.g., Na, Fe, Mn, Ba, REE, Pb, Th, and U) in a variety of naturally occurring calcite and aragonite matrices - and so is potentially valuable in studies of diagenesis, hydrothermal fluids and carbonatitic magmas. For SIMS, modest time per spot (often <5 min), lateral spatial resolution (<10 μm), sample volume consumption (<10 ng) and overall reproducibility compare extremely favorably with other microanalytical techniques for these applications. However, accuracy and reproducibility are currently wholly limited by the homogeneity of available solid reference material - which is far inferior to the tenths of a percent levels of precision achieved by SIMS. Due to variation in the sputtered ion yields of most elements with the major element composition of the sample matrix, accuracy of SIMS depends intimately on matrix-matched solid reference materials. Despite its rapidly increasing use for trace element analyses of carbonates, there remains a dearth of certified reference materials suitable for calibrating SIMS. The pressed powders used by some analysts to calibrate LA-ICP-MS do not perform well for SIMS - they are not perfectly dense or homogeneous to the desired level at the micron scale of sampling. Further, they often prove incompatible with the sample high vacuum compatibility requirement for stable SIMS analysis (10-8 to 10-9 torr). Some naturally occurring calcite has apparent utility as a reference material. For example, equigranular calcite from some zones of carbonatite intrusions (sovites) and recrystallized calcites from highly metamorphosed metallic ore deposits. Most calcite marbles, though possibly appropriate as Sr standards, show substantial inhomogeneity in Mg, Mn and Ba. Some hydrothermal “Iceland Spar” calcite may prove useful as a reference for extremely low concentrations of Mg, Sr and Ba. The best carbonatitic calcites currently in use appear homogeneous to better than 2-3% for Sr (and somewhat less homogeneous for Mg). But these standards still require numerous replicate analyses during analytical sessions to reduce the overall uncertainty to <<1.0%.The availability of appropriate certified solid reference materials with a high degree of homogeneity would greatly benefit the utilization and inter-comparison of SIMS determinations in carbonates, while substantially reducing the time consumed in calibration. Some studies would also benefit from the extension of this effort to the characterization of appropriate standards of other rhombohedral carbonates (especially dolomite and Fe-rich calcite).

Characterization and speciation of mercury-bearing mine wastes using X-ray absorption spectroscopy

USGS Publications Warehouse

Kim, C.S.; Brown, Gordon E.; Rytuba, J.J.

2000-01-01

Mining of mercury deposits located in the California Coast Range has resulted in the release of mercury to the local environment and water supplies. The solubility, transport, and potential bioavailability of mercury are controlled by its chemical speciation, which can be directly determined for samples with total mercury concentrations greater than 100 mg kg-1 (ppm) using X-ray absorption spectroscopy (XAS). This technique has the additional benefits of being non-destructive to the sample, element-specific, relatively sensitive at low concentrations, and requiring minimal sample preparation. In this study, Hg L(III)-edge extended X-ray absorption fine structure (EXAFS) spectra were collected for several mercury mine tailings (calcines) in the California Coast Range. Total mercury concentrations of samples analyzed ranged from 230 to 1060 ppm. Speciation data (mercury phases present and relative abundances) were obtained by comparing the spectra from heterogeneous, roasted (calcined) mine tailings samples with a spectral database of mercury minerals and sorbed mercury complexes. Speciation analyses were also conducted on known mixtures of pure mercury minerals in order to assess the quantitative accuracy of the technique. While some calcine samples were found to consist exclusively of mercuric sulfide, others contain additional, more soluble mercury phases, indicating a greater potential for the release of mercury into solution. Also, a correlation was observed between samples from hot-spring mercury deposits, in which chloride levels are elevated, and the presence of mercury-chloride species as detected by the speciation analysis. The speciation results demonstrate the ability of XAS to identify multiple mercury phases in a heterogeneous sample, with a quantitative accuracy of ??25% for the mercury-containing phases considered. Use of this technique, in conjunction with standard microanalytical techniques such as X-ray diffraction and electron probe microanalysis, is beneficial in the prioritization and remediation of mercury-contaminated mine sites. (C) 2000 Elsevier Science B.V.

Trace and minor elements in sphalerite from metamorphosed sulphide deposits

NASA Astrophysics Data System (ADS)

Lockington, Julian A.; Cook, Nigel J.; Ciobanu, Cristiana L.

2014-12-01

Sphalerite is a common sulphide and is the dominant ore mineral in Zn-Pb sulphide deposits. Precise determination of minor and trace element concentrations in sulphides, including sphalerite, by Laser-Ablation Inductively-Coupled-Plasma Mass-Spectrometry (LA-ICP-MS) is a potentially valuable petrogenetic tool. In this study, LA-ICP-MS is used to analyse 19 sphalerite samples from metamorphosed, sphalerite-bearing volcanic-associated and sedimentary exhalative massive sulphide deposits in Norway and Australia. The distributions of Mn, Fe, Co, Cu, Ga, Se, Ag, Cd, In, Sn, Sb, Hg, Tl, Pb and Bi are addressed with emphasis on how concentrations of these elements vary with metamorphic grade of the deposit and the extent of sulphide recrystallization. Results show that the concentrations of a group of trace elements which are believed to be present in sphalerite as micro- to nano-scale inclusions (Pb, Bi, and to some degree Cu and Ag) diminish with increasing metamorphic grade. This is interpreted as due to release of these elements during sphalerite recrystallization and subsequent remobilization to form discrete minerals elsewhere. The concentrations of lattice-bound elements (Mn, Fe, Cd, In and Hg) show no correlation with metamorphic grade. Primary metal sources, physico-chemical conditions during initial deposition, and element partitioning between sphalerite and co-existing sulphides are dominant in defining the concentrations of these elements and they appear to be readily re-incorporated into recrystallized sphalerite, offering potential insights into ore genesis. Given that sphalerite accommodates a variety of trace elements that can be precisely determined by contemporary microanalytical techniques, the mineral has considerable potential as a geothermometer, providing that element partitioning between sphalerite and coexisting minerals (galena, chalcopyrite etc.) can be quantified in samples for which the crystallization temperature can be independently constrained.

[Early interaction is a prerequisite for favorable psychic development].

PubMed

Pesonen, Anu-Katriina

2010-01-01

Empirical studies on the parent-baby interaction have greatly influenced our insight into the child's psychological development. Initial stages of the research attempted to reveal features in the mother's action that would predict the child's favorable development. Since then, also fathers and the child's development in a more broad sense have been studied. The most prominent progress has taken place in microanalytical methods for these interactions. The research has increased our knowledge of the baby's interactive capabilities and the significance of successful interactive events for the child's development, laying the basis for various interventions related to parenthood.

Microanalytical study of some cosmic dust discovered in sea-floor sediments in China

NASA Technical Reports Server (NTRS)

Shijie, Z.; Hanchang, P.; Zhong, Y.

1984-01-01

The study of cosmic dust can provide useful data in the investigation of the origin of the Earth and the evolution of celestial bodies. Three types of cosmic dust (ferriginous, siliceous, and glassy) were discovered in the seafloor sediments near China. Their chemical composition and microstructure were examined by X-ray diffraction, fractography, and electron microscopy. The major mineral in an iron-containing cosmic dust is magnetite. The silicate spheres contain sundry metals and metal oxides. Glassy microtektites are similar in composition to tektites, and are found in all the major meteorite areas worldwide.

Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell

NASA Astrophysics Data System (ADS)

Hazen, R. M.

2002-05-01

Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive large-volume presses side-by-side with a wide variety of diamond-anvil cells.

Biomineralization of endolithic microbes in rocks from the McMurdo Dry Valleys of Antarctica: implications for microbial fossil formation and their detection.

PubMed

Wierzchos, Jacek; Sancho, Leopoldo García; Ascaso, Carmen

2005-04-01

In some zones of Antarctica's cold and dry desert, the extinction of cryptoendolithic microorganisms leaves behind inorganic traces of microbial life. In this paper, we examine the transition from live microorganisms, through their decay, to microbial fossils using in situ microscopy (transmission electron microscopy, scanning electron microscopy in back-scattered electron mode) and microanalytical (energy dispersive X-ray spectroscopy) techniques. Our results demonstrate that, after their death, endolithic microorganisms inhabiting Commonwealth Glacier sandstone from the Antarctica McMurdo Dry Valleys become mineralized. In some cases, epicellular deposition of minerals and/or simply filling up of empty moulds by minerals leads to the formation of cell-shaped structures that may be considered biomarkers. The continuous deposition of allochthonous clay minerals and sulfate-rich salts fills the sandstone pores. This process can give rise to microbial fossils with distinguishable cell wall structures. Often, fossilized cell interiors were of a different chemical composition to the mineralized cell walls. We propose that the microbial fossil formation observed was induced by mineral precipitation resulting from inorganic processes occurring after the death of cryptoendolithic microorganisms. Nevertheless, it must have been the organic template that provoked the diffusion of mineral elements and gave rise to their characteristic distribution pattern inside the fossilized cells.

The influence of maternal language responsiveness on the expressive speech production of children with autism spectrum disorders: a microanalysis of mother-child play interactions.

PubMed

Walton, Katherine M; Ingersoll, Brooke R

2015-05-01

Adult responsiveness is related to language development both in young typically developing children and in children with autism spectrum disorders, such that parents who use more responsive language with their children have children who develop better language skills over time. This study used a micro-analytic technique to examine how two facets of maternal utterances, relationship to child focus of attention and degree of demandingness, influenced the immediate use of appropriate expressive language of preschool-aged children with autism spectrum disorders (n = 28) and toddlers with typical development (n = 16) within a naturalistic mother-child play session. Mothers' use of follow-in demanding language was most likely to elicit appropriate expressive speech in both children with autism spectrum disorders and children with typical development. For children with autism spectrum disorders, but not children with typical development, mothers' use of orienting cues conferred an additional benefit for expressive speech production. These findings are consistent with the naturalistic behavioral intervention philosophy and suggest that following a child's lead while prompting for language is likely to elicit speech production in children with autism spectrum disorders and children with typical development. Furthermore, using orienting cues may help children with autism spectrum disorders to verbally respond. © The Author(s) 2014.

Photoresponse and DFT studies of new synthesized 2-benzylidene-3-hydroxy -1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine and optical sensor application

NASA Astrophysics Data System (ADS)

Taha, A.; Farag, A. A. M.; Adly, O. M. I.; Roushdy, N.; Shebl, Magdy; Ahmed, H. M.

2017-08-01

A newly Schiff base,2-benzylidene-3-hydroxy-1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine] (HBDHT) was synthesized and characterized on the basis of micro-analytical and spectroscopic studies. Basic parameters of the combined compound HBDHT were ascertained on the premise of DFT level actualized on Gaussian 09. Thin films of HBDHT were successfully prepared by spin coating technique and confirmed by atomic force microscopy (AFM). The optical attributes of the studied films were considered utilizing spectrophotometric estimations in a wide spectral range of 200-2500 nm. Some important optical parameters such as extinction index, refractive index, dispersion energy, oscillator energy and high-frequency dielectric constant were extracted. Analysis of the absorption coefficient near the fundamental absorption edge confirms an indirectly allowed transition with an energy gap of 1.7eV. The refractive index dispersion was estimated on basis of single oscillator model expressed by Wemple-Didomenico. Current-voltage (I-V) characteristics were studied in dark and under illumination of 100 mW/cm2 to clarify the sensitivity to light. Moreover, the photo-transient properties were also investigated to confirm that the prepared heterojunction based HBDHT can be operated as a photodiode.

Chromium oxidation state mapping in human cells

NASA Astrophysics Data System (ADS)

Ortega, R.; Fayard, B.; Salomé, M.; Devès, G.; Susini, J.

2003-03-01

The widespread use of chromium in industrial applications such as chemical production of pigments, refractory brick production, tanning, metallurgy, electroplating, and combustion of fuels has lead to human occupational exposure and to its increased introduction into the environment. Hexavalent chromium compounds are established carcinogens but their mechanism of cell transformation is not known. Up to now, no microanalytical technique was sensitive enough to allow the observation of chromium distribution, and oxidation state identification, within isolated cells at carcinogenic concentrations. In this experiment, we used successfully the ID-21 X-ray microscope to map Cr(VI) and total Cr distributions in cells exposed in vitro to soluble, and insoluble, Cr(VI) compounds. Exposure to soluble compounds, weak carcinogens, resulted in a homogeneous intracellular distribution of Cr, confirming by in situ measurement that Cr is present in the cell nucleus. Cr(VI) was never detected in cells which suggests a mechanism of rapid intracellular reducticn. On the other hand, exposure to insoluble compounds, strong carcinogens, also resulted in a homogeneous distribution of reduced forms of Cr in cells, and their nucleus. However, in this case, Cr(VI)-rich structures were observed into the cells suggesting that carcinogenicity is enhanced when oxidation reactions due to Cr(VI) chronic exposure are associated to Cr-DNA alterations.

Airborne Particulate Threat Assessment

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

Patrick Treado; Oksana Klueva; Jeffrey Beckstead

Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. governmentmore » agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our findings and APICD Gen II subsystems for automated collection, deposition and detection of ambient particulate matter. Key findings from the APTA Program include: Ambient biological PM taxonomy; Demonstration of key subsystems needed for autonomous bioaerosol detection; System design; Efficient electrostatic collection; Automated bioagent recognition; Raman analysis performance validating Td<9 sec; Efficient collection surface regeneration; and Development of a quantitative bioaerosol defection model. The objective of the APTA program was to advance the state of our knowledge of ambient background PM composition. Operation of an automated aerosol detection system was enhanced by a more accurate assessment of background variability, especially for sensitive and specific sensing strategies like Raman detection that are background-limited in performance. Based on this improved knowledge of background, the overall threat detection performance of Raman sensors was improved.« less

Formation of hydrogen peroxide in the silver reductor: A micro-analytical method for iron

USGS Publications Warehouse

Fryling, C.F.; Tooley, F.V.

1936-01-01

1. An attempt to determine small quantities of iron by reduction with silver followed by titration with eerie sulfate revealed an error attributable to the formation of hydrogen peroxide in the reductor. 2. By conducting the reduction in an atmosphere of hydrogen, thereby decreasing the reductor correction, and applying a correction for the indicator, it was possible to determine quantities of iron of the order of 1.5 mg. with a high degree of accuracy. 3. The method was found to be relatively rapid and not to require the use of large platinum dishes, thus possessing advantages of practical value.

Preliminary Characterization of a Microbial Community of Rock Varnish from Death Valley, California

NASA Technical Reports Server (NTRS)

Kuhlman, K. R.; LaDuc, M. T.; Kuhlman, G. M.; Anderson, R. C.; Newcombe, D. A.; Fusco, W.; Steucker, T.; Allenbach, L.; Ball, C.; Crawford, R. L.

2003-01-01

Rock varnish (also referred to as desert varnish in the literature because it is particularly noticeable in desert environments) is a dark, thin (typically 50-500 m thick), layered veneer composed of clay minerals cemented together by oxides and hydroxides of manganese and iron. Some scientists suggest that varnish may provide a historical record of environmental processes such as global warming and long-term climate change. However, despite more than 30 years of study using modern microanalytical and microbial culturing techniques, the nucleation and growth mechanisms of rock varnish remain a mystery. Rock varnish is of interest to the Mars science community because a varnish-like sheen has been reported on the rocks at the Viking Lander sites. It therefore important for us to understand the formation mechanisms of terrestrial varnish abiotic, biotic, or a combination of the two -- as this understanding may give us clues concerning the chemical and physical processes occurring on the surface of Mars. It is strongly believed by some in the biogeochemistry community that microbes have a role in forming rock varnish, and iron- and manganese-oxidation by microbes isolated from varnish has been extensively investigated. Only two of these studies have investigated the microbial genetics of varnish. These studies examined the morphological, physiological and molecular characteristics of microbes that had previously been cultured from various rock varnishes and identified the cultivars using 16S rDNA sequencing techniques. However, it is well known that most of organisms existing in nature are refractory to cultivation, so many important organisms would have been missed. The currently described work investigates the genetics of rock varnish microbial community from a site in the Whipple Mtns., south of Death Valley, CA, near Parker, Arizona. We employed both cultural and molecular techniques to characterize the microorganisms found within the varnish and surrounding soil with the objectives of (a) identifying microorganisms potentially involved in varnish formation, and (b) discovering microorganisms that simply use the varnish as an extreme habitat.

Chemical compositions of primitive solar system particles

NASA Technical Reports Server (NTRS)

Sutton, Steve R.; Bajt, S.

1994-01-01

Chemical studies of micrometeorites are of fundamental importance primarily because atmospheric entry selection effects (such as destruction of friable objects) are less significant than those for conventional meteorites. As a result, particles that have experienced very little postaccretional processing have a significant chance of surviving the Earth encounter and subsequent collection. Thus, chemical analyses of these relatively unaltered micrometeorites may lead to a better understanding of the compositions of the most primitive materials in the solar system and thereby constrain the conditions (physical and chemical) that existed in the early solar nebula. Micrometeorites have been collected from the stratosphere, polar ices, and ocean sediments, but the stratospheric collection is the best source for the most unaltered material because they are small and are not heated to their melting points. Despite the fact that the stratospheric micrometeorites have masses in the nanogram range, a variety of microanalytical techniques have been applied to bulk chemical analyses with part-per-million sensitivity. In some cases, multi-disciplinary studies (e.g., chemistry and mineralogy) have been performed on individual particles. The first-order conclusion is that the chondrite-like particles are chemically similar to carbonaceous chondrites but in detail are distinct from members of the conventional meteorite collection. The purpose of this paper is to provide an overview of the results to date and identify important areas for further study.

Microanalytical investigation of degradation issues in Byzantine wall paintings

NASA Astrophysics Data System (ADS)

Sotiropoulou, S.; Daniilia, Sister; Miliani, C.; Rosi, F.; Cartechini, L.; Papanikola-Bakirtzis, D.

2008-07-01

The St. Euthymius wall paintings, in the Cathedral of Thessaloniki, dated 1303 AD., are stylistically attributed to the School of Panselinos, one of the most important painters of Palaeologean Art. An in situ non-invasive study has been carried out as part of a MOLAB project (a mobile laboratory accessible through the Eu-ARTECH project, funded by the EC 6th FP) combining different analytical techniques such as XRF, mid-FTIR and UV-vis diffuse reflectance spectroscopy. It was during this comprehensive in situ study that certain scientific queries were raised about sensitive areas, where indications of the phenomena of decay requested further attention. A subsequent laboratory study of selected cross-sections using microscopic analysis with μFTIR, SEM-EDS and μRaman, further confirmed the identification of only the atypical in situ observations. The comparative interpretation of all respective results on the specific regions of interest permitted the identification of several degradation phenomena which justify certain aesthetic or stylistic incoherences in the representations. Namely, (i) thermal dehydration of the yellow ochre explaining the reddish appearance of the flesh tones and halos as an accidental effect of the fire; (ii) thermal degradation of azurite converted to tenorite explaining the atypical instance of dark lightings on the purple garments; (iii) degradation of red lead employed in the lightings of the red garments; (iv) widespread presence of oxalates in the paint surface.

ATR-FTIR microscopy in mapping mode for the study of verdigris and its secondary products

NASA Astrophysics Data System (ADS)

Prati, S.; Bonacini, I.; Sciutto, G.; Genty-Vincent, A.; Cotte, M.; Eveno, M.; Menu, M.; Mazzeo, R.

2016-01-01

To study degradation processes occurring on painting materials, the use of high-resolution micro-analytical techniques is highly requested since it provides a detailed identification and localisation of both the original and deteriorated ingredients. Among the various pigments recently studied, the characterisation of verdigris has received a major interest. This pigment has not a unique chemical formula, but its composition depends on the recipe employed for its manufacturing. Moreover, verdigris paints are not stable and are subject to a colour change from blue-green to green, which occurs in the first few months after the application. In this paper, we focused our attention on the use of ATR-FTIR mapping as a useful method to identify verdigris secondary products and pathways. Several mock-ups and real samples have been analysed, and the correlation among the detected compounds and their spatial location, obtained by the application of ATR-FTIR microscopy in mapping mode, allowed formulating some hypotheses on the degradation pattern of verdigris, which may feed the discussion on the transformation and stability of this pigment. From an analytical point of view, we showed how FTIR mapping approaches may be extremely useful both for the identification of compounds in complex matrix in which single spectra may limit the exhaustive characterisations due to bands overlapping and for the study of degradation pathways by taking into consideration the relative distribution of degradation products.

Detecting Cancer Quickly and Accurately

NASA Astrophysics Data System (ADS)

Gourley, Paul; McDonald, Anthony; Hendricks, Judy; Copeland, Guild; Hunter, John; Akhil, Ohmar; Capps, Heather; Curry, Marc; Skirboll, Steve

2000-03-01

We present a new technique for high throughput screening of tumor cells in a sensitive nanodevice that has the potential to quickly identify a cell population that has begun the rapid protein synthesis and mitosis characteristic of cancer cell proliferation. Currently, pathologists rely on microscopic examination of cell morphology using century-old staining methods that are labor-intensive, time-consuming and frequently in error. New micro-analytical methods for automated, real time screening without chemical modification are critically needed to advance pathology and improve diagnoses. We have teamed scientists with physicians to create a microlaser biochip (based upon our R&D award winning bio-laser concept)1 which evaluates tumor cells by quantifying their growth kinetics. The key new discovery was demonstrating that the lasing spectra are sensitive to the biomolecular mass in the cell, which changes the speed of light in the laser microcavity. Initial results with normal and cancerous human brain cells show that only a few hundred cells -- the equivalent of a billionth of a liter -- are required to detect abnormal growth. The ability to detect cancer in such a minute tissue sample is crucial for resecting a tumor margin or grading highly localized tumor malignancy. 1. P. L. Gourley, NanoLasers, Scientific American, March 1998, pp. 56-61. This work supported under DOE contract DE-AC04-94AL85000 and the Office of Basic Energy Sciences.

Radioactive particles released to the environment from the Fukushima reactors-Confirmation is still needed.

PubMed

Salbu, Brit; Lind, Ole Christian

2016-10-01

After severe nuclear events, a major fraction of refractory radionuclides such as U and Pu are released to the environment in the form of radioactive particles. After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Pu isotope ratio signals different from that of global fallout have been reported, indicating that spent fuel particles have been released from the reactors or reactor vessels. Radioactive particles containing (37) Cs and other volatile radionuclides, as well as a series of stable refractory metals (Cs, Fe, Zn, U, etc.), have been identified by several authors claiming that these particles originated from the FDNPP fuel. If so, long-lived radioactive isotopes of the refractory metals should have been identified in these particles. It is therefore most probable that volatile radionuclides released as gases during the accidents have deposited on available surfaces such as fly ash, forming condensation particles during release or transport. If spent fuel particles have been deposited in the FDNPP surroundings, information on particle characteristics influencing ecosystem transport, uptake, and effects is essential for assessing environmental impact and risk. More emphasis should therefore be put on the identification of hot spots in the FDNPP environment followed by the characterization of radioactive particles using nanoanalytical-microanalytical techniques to support environmental monitoring, as recommended in the present study. Integr Environ Assess Manag 2016;12:687-689. © 2016 SETAC. © 2016 SETAC.

The epididymal microenvironment: a site of attack for a male contraceptive?

PubMed

Hinton, B T

1980-07-01

During their development, spermatozoa are continually bathed in fluid provided by epithelial secretions of the seminiferous tubule and the epididymal duct. This fluid or microenvironment is probably very important for spermatozoal maturation and survival. Micropuncture and microanalytic studies have revealed the occurrence of several biochemical changes of this specialized microenvironment along the epididymal duct; these changes seem to be linked to sperm maturation. The interactions between maturing spermatozoa and their microenvironment must be understood before interference in sperm maturation through intervention of the formation of the microenvironment is possible. Several compounds have been shown to interfere in spermatozoal maturation in the epididymis although their use as male contraceptives requires further investigation.

Vital effects in coral skeletal composition display strict three-dimensional control

USGS Publications Warehouse

Meibom, A.; Yurimoto, H.; Cuif, J.-P.; Domart-Coulon, I.; Houlbreque, F.; Constantz, B.; Dauphin, Y.; Tambutte, E.; Tambutte, S.; Allemand, D.; Wooden, J.; Dunbar, R.

2006-01-01

Biological control over coral skeletal composition is poorly understood but critically important to paleoenvironmental reconstructions. We present microanalytical measurements of trace-element abundances as well as oxygen and carbon isotopic compositions of individual skeletal components in the zooxanthellate coral Colpophyllia sp. Our data show that centers of calcification (COC) have higher trace element concentrations and distinctly lighter isotopic compositions than the fibrous components of the skeleton. These observations necessitate that COC and the fibrous skeleton are precipitated by different mechanisms, which are controlled by specialized domains of the calicoblastic cell-layer. Biological processes control the composition of the skeleton even at the ultra-structure level. Copyright 2006 by the American Geophysical Union.

Volatile concentrations in variably vesicular pyroclasts from the Rotongaio ash (181 AD Taupo eruption): did shallow magma degassing trigger exceptionally violent phreatomagmatic activity?

NASA Astrophysics Data System (ADS)

Tuffen, Hugh; Houghton, Bruce F.; Dingwellp, Donald B.; Pinkerton, Harry

2010-05-01

Measurement of dissolved volatile concentrations in pyroclasts has formed the basis of our understanding of the links between magma degassing and the explosivity of silicic eruptions[1]. To date these studies have focussed exclusively on the densest pyroclastic obsidians, which comprise on a tiny proportion of the erupted products, in order to bypass the difficulty of analysing vesicular material. As a consequence, crucial information is missing about how degassing in the densest clasts relates to the behaviour of the bulk of the magma volume. To overcome this shortcoming, the volatile content of variably vesicular pyroclasts from the Rotongaio ash has been analysed using both micro-analytical (SIMS, synchrotron FTIR) and bulk techniques (TGA-MS). The Rotongaio ash was an exceptionally violent phase of phreatomagmatic activity during the 181 AD rhyolitic eruption of Taupo (New Zealand), the most powerful worldwide in the last 5000 years. The Rotongaio phase involved opening of new vents beneath Lake Taupo and the ash is characterised by a wide range of clast vesicularities (<10 to ~80 % by volume). Volatile measurement was challenging due to the high bubble number densities and small clast sizes. The mismatch between the water content of matrix glasses measured using bulk and micro-analytical techniques reflects pervasive post-eruption hydration of vesicle walls, which is most problematic at high vesicularities. Micron-scale maps of water concentration variations around vesicles in 30-50 vol % vesicular samples were acquired using SIMS. They indicate strong hydration within ~5 microns of vesicle walls, with pockets of unhydrated glass remaining in the thickest septa. Analysis of these unhydrated domains allowed robust measurement of water contents in pyroclasts ranging from ~1 to >50 vol % vesicles. Matrix glasses had largely degassed (0.19-0.49 wt % H2O, compared with an initial concentration in melt inclusions of ~3.6 wt %). The water contents measured using SIMS decreased systematically with increasing magma vesicularity. These results are fit well by a simple magma degassing model, in which a batch of magma first undergoes partial open-system degassing to a uniform water concentration of ~0.4 wt % H2O. Vesiculation then occurs with closed-system degassing, creating a negative relationship between vesicle content and the water content remaining in the melt. This model is consistent with the intrusion of a shallow cryptodome beneath Lake Taupo (depth ~100-200 metres) and prolonged stalling of magma at this shallow level. This was then followed by abrupt magma ascent and vesiculation, accompanied by interaction with the overlying lake water. Recent experiments have shown that the most violent interactions between rhyolitic magma and water may occur when the magma is highly viscous and prone to shear failure, as this creates the initial surface area for magma-water contact that results in explosive fuel-coolant interaction. The accumulation of a large volume (~1 km3) of degassed, highly-viscous rhyolitic magma directly beneath Lake Taupo may have therefore caused the exceptionally violent magma-water interaction that occurred during the Rotongaio phase. This reveals new links between magma degassing and the explosivity of eruptions when external water is involved, and illustrates the value of analysing pyroclastic material spanning a wide range of vesicularity in order to better reconstruct degassing systematics. References [1] Newman S. et al. (1988) J. Volcanol. Geotherm. Res. 35, 75-96. [2] Smith RT & Houghton BF (1995) Bull. Volcanol. 57, 432-439. [3] A. Austin-Erickson et al. (2008) J. Geophys. Res., 113, B11201.

Exploring clinical reasoning in novices: a self-regulated learning microanalytic assessment approach

PubMed Central

Artino, Anthony R; Cleary, Timothy J; Dong, Ting; Hemmer, Paul A; Durning, Steven J

2014-01-01

Objectives The primary objectives of this study were to examine the regulatory processes of medical students as they completed a diagnostic reasoning task and to examine whether the strategic quality of these regulatory processes were related to short-term and longer-term medical education outcomes. Methods A self-regulated learning (SRL) microanalytic assessment was administered to 71 second-year medical students while they read a clinical case and worked to formulate the most probable diagnosis. Verbal responses to open-ended questions targeting forethought and performance phase processes of a cyclical model of SRL were recorded verbatim and subsequently coded using a framework from prior research. Descriptive statistics and hierarchical linear regression models were used to examine the relationships between the SRL processes and several outcomes. Results Most participants (90%) reported focusing on specific diagnostic reasoning strategies during the task (metacognitive monitoring), but only about one-third of students referenced these strategies (e.g. identifying symptoms, integration) in relation to their task goals and plans for completing the task. After accounting for prior undergraduate achievement and verbal reasoning ability, strategic planning explained significant additional variance in course grade (ΔR2 = 0.15, p < 0.01), second-year grade point average (ΔR2 = 0.14, p < 0.01), United States Medical Licensing Examination Step 1 score (ΔR2 = 0.08, p < 0.05) and National Board of Medical Examiner subject examination score in internal medicine (ΔR2 = 0.10, p < 0.05). Conclusions These findings suggest that most students in the formative stages of learning diagnostic reasoning skills are aware of and think about at least one key diagnostic reasoning process or strategy while solving a clinical case, but a substantially smaller percentage set goals or develop plans that incorporate such strategies. Given that students who developed more strategic plans achieved better outcomes, the potential importance of forethought regulatory processes is underscored. PMID:24528463

Examining Middle School Science Student Self-Regulated Learning in a Hypermedia Learning Environment through Microanalysis

NASA Astrophysics Data System (ADS)

Mandell, Brian E.

The purpose of the present embedded mixed method study was to examine the self-regulatory processes used by high, average, and low achieving seventh grade students as they learned about a complex science topic from a hypermedia learning environment. Thirty participants were sampled. Participants were administered a number of measures to assess their achievement and self-efficacy. In addition, a microanalytic methodology, grounded in Zimmerman's cyclical model of self-regulated learning, was used to assess student self-regulated learning. It was hypothesized that there would be modest positive correlations between Zimmerman's three phases of self-regulated learning, that high achieving science students would deploy more self-regulatory subprocesses than average and low achieving science students, that high achieving science students would have higher self-efficacy beliefs to engage in self-regulated learning than average and low achieving science students, and that low achieving science students would over-estimate their self-efficacy for performance beliefs, average achieving science students would slightly overestimate their self-efficacy for performance beliefs, and high achieving science students would under-estimate their self-efficacy for performance beliefs. All hypotheses were supported except for the high achieving science students who under-estimated their self-efficacy for performance beliefs on the Declarative Knowledge Measure and slightly overestimated their self-efficacy for performance beliefs on the Conceptual Knowledge Measure. Finally, all measures of self-regulated learning were combined and entered into a regression formula to predict the students' scores on the two science tests, and it was revealed that the combined measure predicted 91% of the variance on the Declarative Knowledge Measure and 92% of the variance on the Conceptual Knowledge Measure. This study adds hypermedia learning environments to the contexts that the microanalytic methodology has been successfully administered. Educational implications and limitations to the study are also discussed.

Syntrophic interactions and mechanisms underpinning anaerobic methane oxidation: targeted metaproteogenomics, single-cell protein detection and quantitative isotope imaging of microbial consortia

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

Orphan, Victoria Jeanne

2014-11-26

Syntrophy and mutualism play a central role in carbon and nutrient cycling by microorganisms. Yet, our ability to effectively study symbionts in culture has been hindered by the inherent interdependence of syntrophic associations, their dynamic behavior, and their frequent existence at thermodynamic limits. Now solutions to these challenges are emerging in the form of new methodologies. Developing strategies that establish links between the identity of microorganisms and their metabolic potential, as well as techniques that can probe metabolic networks on a scale that captures individual molecule exchange and processing, is at the forefront of microbial ecology. Understanding the interactions betweenmore » microorganisms on this level, at a resolution previously intractable, will lead to our greater understanding of carbon turnover and microbial community resilience to environmental perturbations. In this project, we studied an enigmatic syntrophic association between uncultured methane-oxidizing archaea and sulfate-reducing bacteria. This environmental archaeal-bacterial partnership represents a globally important sink for methane in anoxic environments. The specific goals of this project were organized into 3 major tasks designed to address questions relating to the ecophysiology of these syntrophic organisms under changing environmental conditions (e.g. different electron acceptors and nutrients), primarily through the development of microanalytical imaging methods which enable the visualization of the spatial distribution of the partners within aggregates, consumption and exchange of isotopically labeled substrates, and expression of targeted proteins identified via metaproteomics. The advanced tool set developed here to collect, correlate, and analyze these high resolution image and isotope-based datasets from methane-oxidizing consortia has the potential to be widely applicable for studying and modeling patterns of activity and interactions across a broad range of spatially structured microbial partnerships, including other syntrophic associations, microbial mats, biofilms, and plant-microbe or animal-microbe symbioses in nature.« less

New geochemical insights into volcanic degassing.

PubMed

Edmonds, Marie

2008-12-28

Magma degassing plays a fundamental role in controlling the style of volcanic eruptions. Whether a volcanic eruption is explosive, or effusive, is of crucial importance to approximately 500 million people living in the shadow of hazardous volcanoes worldwide. Studies of how gases exsolve and separate from magma prior to and during eruptions have been given new impetus by the emergence of more accurate and automated methods to measure volatile species both as volcanic gases and dissolved in the glasses of erupted products. The composition of volcanic gases is dependent on a number of factors, the most important being magma composition and the depth of gas-melt segregation prior to eruption; this latter parameter has proved difficult to constrain in the past, yet is arguably the most critical for controlling eruptive style. Spectroscopic techniques operating in the infrared have proved to be of great value in measuring the composition of gases at high temporal resolution. Such methods, when used in tandem with microanalytical geochemical investigations of erupted products, are leading to better constraints on the depth at which gases are generated and separated from magma. A number of recent studies have focused on transitions between explosive and effusive activity and have led to a better understanding of gas-melt segregation at basaltic volcanoes. Other studies have focused on degassing during intermediate and silicic eruptions. Important new results include the recognition of fluxing by deep-derived gases, which buffer the amount of dissolved volatiles in the melt at shallow depths, and the observation of gas flow up permeable conduit wall shear zones, which may be the primary mechanism for gas loss at the cusp of the most explosive and unpredictable volcanic eruptions. In this paper, I review current and future directions in the field of geochemical studies of volcanic degassing processes and illustrate how the new insights are beginning to change the way in which we understand and classify volcanic eruptions.

The Byzantine Church of ``40 Holy Martyrs'' in Veliko Turnovo, Bulgaria: Pigments and Technique

NASA Astrophysics Data System (ADS)

Sakellariou, E.; Zorba, T.; Pavlidou, E.; Angelova, S.; Paraskevopoulos, K. M.

2010-01-01

The "St. 40 Martyrs" church is the most famous medieval building in Veliko Turnovo, Bulgaria. It is located in Assenova mahala, just next to Tsarevets. It was built and its walls were painted during the reign of Bulgarian king Ivan Assen II after the victory against Epyrus despot Theodoros Comninos (1230 AD). It consists of two buildings - a six-column basilica and another, smaller building on its western wall, which was built later. During the presence of the Ottoman Turks, maybe until the first half of the 18th century, the church remained christian. When it was converted to a mosque, all the christian symbols in it were destroyed. The archeological researches on site were initiated in 1969. As it is clear, the 40 Martyrs church is a historical monument of culture with great significance. The church had murals, from the earlier period, but in the following years and especially during the Ottoman period, the church has suffered many and different destructions. Nevertheless, the very few pieces of murals that are rescued till nowadays provide important information for the technique and the pigments that were used on its wall paintings. In the present work, twelve series of samples from the wall paintings were studied in order to characterize the materials and the technique used for church iconography. The study was based on the micro-analytical techniques of the Fourier Transform Infrared micro-spectroscopy (μs-FTIR), the Optical Microscopy and the Scanning Electron Microscopy (SEM) coupled to an Energy Dispersive X-ray Spectrometer (EDS). In the FTIR spectra of all pigments the characteristic peaks of calcite were detected, confirming the use of fresco technique for the creation of murals. The combination of FTIR spectroscopy and SEM-EDS analysis, reveal the existence of lapis-lazuli for the blue color, green earth for the green color, cinnabar for the red color, calcite for the white color and carbon black for the black color. Moreover, in other chromatic layers, the presence of iron oxides (hematite and limonite) indicating the use of ochre for the yellow and red pigments, is identified. Finally, the surface of some samples was covered by a transparent and tensile material. This material was characterized by μs-FTIR spectroscopy as an organic substance, probably a natural resin that was used to protect the murals in the early ages.

X-ray microanalytical surveys of minor element concentrations in unsectioned biological samples

NASA Astrophysics Data System (ADS)

Schofield, R. M. S.; Lefevre, H. W.; Overley, J. C.; Macdonald, J. D.

1988-03-01

Approximate concentration maps of small unsectioned biological samples are made using the pixel by pixel ratio of PIXE images to areal density images. Areal density images are derived from scanning transmission ion microscopy (STIM) proton energy-loss images. Corrections for X-ray production cross section variations, X-ray attenuation, and depth averaging are approximated or ignored. Estimates of the magnitude of the resulting error are made. Approximate calcium concentrations within the head of a fruit fly are reported. Concentrations in the retinula cell region of the eye average about 1 mg/g dry weight. Concentrations of zinc in the mandible of several ant species average about 40 mg/g. Zinc concentrations in the stomachs of these ants are at least 1 mg/g.

Sample injector for high pressure liquid chromatography

DOEpatents

Paul, Phillip H.; Arnold, Don W.; Neyer, David W.

2001-01-01

Apparatus and method for driving a sample, having a well-defined volume, under pressure into a chromatography column. A conventional high pressure sampling valve is replaced by a sample injector composed of a pair of injector components connected in series to a common junction. The injector components are containers of porous dielectric material constructed so as to provide for electroosmotic flow of a sample into the junction. At an appropriate time, a pressure pulse from a high pressure source, that can be an electrokinetic pump, connected to the common junction, drives a portion of the sample, whose size is determined by the dead volume of the common junction, into the chromatographic column for subsequent separation and analysis. The apparatus can be fabricated on a substrate for microanalytical applications.

The Amsterdam quintuplet nuclear microprobe

NASA Astrophysics Data System (ADS)

van den Putte, M. J. J.; van den Brand, J. F. J.; Jamieson, D. N.; Rout, B.; Szymanski, R.

2003-09-01

A new nuclear microprobe comprising of a quintuplet lens system is being constructed at the Ion Beam Facility of the "Vrije Universiteit" Amsterdam in collaboration with the Microanalytical Research Centre of the University of Melbourne. An overview of the Amsterdam set-up will be presented. Detailed characterisation of the individual lenses was performed with the grid shadow method using a 2000 mesh Cu grid mounted at a relative angle of 0.5° to the vertical lens line focus. The lenses were found to have very low parasitic aberrations equal or below the minimum detectable limit for the method, which was approximately 0.1% for the sextupole component and 0.2% for the octupole component. We present experimental and theoretical grid shadow patterns, showing results for all five lenses.

Integrative molecular and microanalytical studies of syntrophic partnerships linking C, S, and N cycles in anoxic environments

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

Orphan, Victoria

2016-07-15

Syntrophy and other forms of symbiotic associations between microorganisms are central to carbon and nutrient cycling in the environment. However, the inherent interdependence of these interactions, dynamic behavior, and frequent existence at thermodynamic limits has hindered our ability to both recognize syntrophic partnerships in nature and effectively study their behavior in the laboratory. To characterize and understand the underlying factors influencing syntrophic associations within complex communities requires a suite of tools that extend beyond basic molecular identification and cultivation. This specifically includes methods that preserve the natural spatial relationships between metabolically interdependent microorganisms while allowing downstream geochemical and/or molecular analysis.more » With support from this award, we have developed and applied new combinations of molecular, microscopy, and stable isotope-based methodologies that enable the characterization of fundamental links between phylogenetically-identified microorganisms and their specific metabolic activities and interactions in the environment. Through the coupling of fluorescence in situ hybridization (FISH) with cell capture and targeted metagenomics (Magneto-FISH), and FISH + secondary ion mass spectrometry (i.e. FISH-SIMS or FISH-nanoSIMS), we have defined new microbial interactions and the ecophysiology of anaerobic microorganisms involved in environmental methane cycling.« less

X-Ray Microanalytic Concentration Measurements in Unsectioned Specimens: a Technique and its Application to Zinc, Manganese, and Iron Enriched Mechanical Structures of Organisms from Three Phyla

NASA Astrophysics Data System (ADS)

Schofield, Robert M. S.

A method for measuring concentrations of minor elements in microscopic volumes of heterogeneous, unsectioned biological specimens using an ion microprobe is developed. The element quantity is obtained from PIXE (Proton Induced X-ray Emission) and the total quantity of material is derived from STIM (Scanning Transmission Ion Microscopy) energy loss measurements. Sources of error, including changes in x-ray production cross section with proton energy and absorption of induced x-rays, are discussed and a method of calculating the total measurement uncertainty, typically about 25% here, is developed. The measurement accuracy is shown to be improved for symmetric specimens, and a method of using the bremsstrahlung background to correct for x-ray attenuation within irregular specimens is developed. Methods for measuring local concentrations in internal features are also discussed. With this technique, scorpions were found to contain cuticular accumulations of one or more heavy metals (manganese up to 5% of dry weight, iron up to 8%, zinc up to 24%) in the chelicera, pedipalp denticles, tarsal claws, and stingers; different region soften contained different metals. The stingers are argued to be of particular interest because they are not homologous to legs. Similar accumulations were found in spiders, some other chelicerates and crustaceans. Previous reports of manganese and zinc accumulations in insect and worm mouth parts were augmented with local concentration measurements and with the detection of other enrichment features (such as 6% iron in the paragnaths of the worm Nereis vexillosa). Zinc accumulations (up to only 0.1%) were also found in the tips of the teeth of a hagfish, Myxine + glutinosa. X-ray images of several of these features are presented. It is argued that the extreme magnitude of some concentration values suggests that some metals are incorporated in unusual biominerals rather than organically bound. Results of x-ray diffractometry and Vickers microhardness measurements are reported although the results are inconclusive. The atomic ratio of zinc to chlorine in these accumulations is shown not to be constant. It is suggested from their typical locations that at least two of the observed accumulation patterns impart different mechanical properties to the cuticle.

Direct tandem mass spectrometry for the simultaneous assay of opioids, cocaine and metabolites in dried urine spots.

PubMed

Otero-Fernández, Mara; Cocho, José Ángel; Tabernero, María Jesús; Bermejo, Ana María; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

2013-06-19

A micro-analytical method based on spotting urine samples (20μL) onto blood/urine spot collection cards followed by air-drying and extraction (dried urine spot, DUS) was developed and validated for the screening/confirmation assay of morphine, 6-methylacetylmorphine (6-MAM), codeine, cocaine and benzoylecgonine (BZE). Acetonitrile (3 mL) was found to be a useful solvent for target extraction from DUSs under an orbital-horizontal stirring at 180 rpm for 10 min. Determinations were performed by direct electrospray ionization tandem mass spectrometry (ESI-MS/MS) under positive electrospray ionization conditions, and by using multiple reaction monitoring (MRM) with one precursor ion/product ion transition for the identification and quantification (deuterated analogs of each target as internal standards) of each analyte. The limits of detection of the method were 0.26, 0.94, 1.5, 1.1, and 2.0 ng mL(-1), for cocaine, BZE, codeine, morphine and 6-MAM, respectively; whereas, relative standard deviations of intra- and inter-day precision were lower than 8 and 11%, respectively, and intra- and inter-day analytical recoveries ranged from 94±4 to 105±3%. The small volume of urine required (20 μL), combined with the simplicity of the analytical technique makes it a useful procedure for screening/quantifying drugs of abuse. The method was successfully applied to the analysis of urine from polydrug abusers. Copyright © 2013 Elsevier B.V. All rights reserved.

Pedothem carbonates reveal anomalous North American atmospheric circulation 70,000–55,000 years ago

PubMed Central

Sharp, Warren D.; Oster, Jessica L.; Ebeling, Angela; Valley, John W.; Kozdon, Reinhard; Orland, Ian J.; Woodhead, Jon D.; Hergt, Janet M.; Chadwick, Oliver A.; Amundson, Ronald

2016-01-01

Our understanding of climatic conditions, and therefore forcing factors, in North America during the past two glacial cycles is limited in part by the scarcity of long, well-dated, continuous paleoclimate records. Here, we present the first, to our knowledge, continuous, millennial-resolution paleoclimate proxy record derived from millimeter-thick pedogenic carbonate clast coatings (pedothems), which are widely distributed in semiarid to arid regions worldwide. Our new multiisotope pedothem record from the Wind River Basin in Wyoming confirms a previously hypothesized period of increased transport of Gulf of Mexico moisture northward into the continental interior from 70,000 to 55,000 years ago based on oxygen and carbon isotopes determined by ion microprobe and uranium isotopes and U-Th dating by laser ablation inductively coupled plasma mass spectrometry. This pronounced meridional moisture transport, which contrasts with the dominant zonal transport of Pacific moisture into the North American interior by westerly winds before and after 70,000–55,000 years ago, may have resulted from a persistent anticyclone developed above the North American ice sheet during Marine Isotope Stage 4. We conclude that pedothems, when analyzed using microanalytical techniques, can provide high-resolution paleoclimate records that may open new avenues into understanding past terrestrial climates in regions where paleoclimate records are not otherwise available. When pedothem paleoclimate records are combined with existing records they will add complimentary soil-based perspectives on paleoclimate conditions. PMID:26755592

Searching for Life in Death Valley (and Other Deserts) - Microchemical Investigations on Desert Varnish

NASA Astrophysics Data System (ADS)

Andreae, M. O.; Al-Amri, A. M.; Jochum, K. P.; Kappl, M.; Kilcoyne, A. D.; Macholdt, D.; Müller, M.; Pöhlker, C.; Weber, B.; Weigand, M.

2014-12-01

Desert varnishes are thin, shiny, blackish to brown coatings frequently found on the surfaces of exposed rocks in deserts around the globe. They have been proposed as terrestrial analogues of superficial hematite enrichments observed on Mars. While the first scientific studies of such varnishes go back to Darwin and von Humboldt, and intensive studies by a variety of techniques have been conducted over the last few decades, their origin is still a matter of debate. Microscopic and molecular studies have shown the presence of fungi and bacteria, but it is still unclear whether they are involved in the formation of the varnish material or just opportunistic colonizers on available surfaces. We have analysed samples of desert varnish from sites in Death Valley, the Mojave Desert, the Negev of Israel, Central Saudi Arabia, and the Succulent Karoo by a variety of microanalytical techniques. Measurements by UV-femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry show enrichments of manganese, iron, barium and other elements. Isotopic and trace chemical signatures show that these enriched elements cannot originate from the rocks that form the substrate on which the crusts have been deposited, but most likely are the result of (bio?)chemical transformation of windblown material. For a more detailed investigation of the internal structure of the crusts, we prepared ultra-thin sections (~100 nm) using focused ion beam slicing and analysed them by Scanning Transmission X-ray Microscopy with Near-Edge X-ray Absorption Fine Structure spectroscopy (STXM-NEXAFS). This technique revealed layered or chaotic structures consisting of alternating Mn and Fe-rich zones. Some of these layers are enriched in organic carbon with spectral features dominated by aromatic and carboxylate functionalities, indicating a biological origin of some of the crust material. Some crusts also show cavities that are lined with similar organic material. Since the age of these crusts is of the order of 100-10,000 of years, this organic matter must represent fossil evidence that has survived intensive solar radiation, extreme temperatures, and chemical weathering over long periods of time within microns from the varnish surface.

Postvaccinal sarcomas in the cat: epidemiology and electron probe microanalytical identification of aluminum

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

Hendrick, M.J.; Goldschmidt, M.H.; Shofer, F.S.

1992-10-01

An increase in fibrosarcomas in a biopsy population of cats in the Pennsylvania area appears to be related to the increased vaccination of cats following enactment of a mandatory rabies vaccination law. The majority of fibrosarcomas arose in sites routinely used by veterinarians for vaccination, and 42 of 198 tumors were surrounded by lymphocytes and macrophages containing foreign material identical to that previously described in postvaccinal inflammatory injection site reactions. Some of the vaccines used have aluminum-based adjuvants, and macrophages surrounding three tumors contained aluminum oxide identified by electron probe microanalysis and imaged by energy-filtered electron microscopy. Persistence of inflammatorymore » and immunological reactions associated with aluminum may predispose the cat to a derangement of its fibrous connective tissue repair response, leading to neoplasia.« less

Synthesis, characterization and biological properties of thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes.

PubMed

Chohan, Zahid H; Sumrra, Sajjad H

2012-04-01

A new series of biologically active thienyl derived triazole Schiff bases and their oxovanadium(IV) complexes have been synthesized and characterized on the basis of physical (m.p., magnetic susceptibility and conductivity), spectral (IR, ¹H and ¹³C NMR, electronic and mass spectrometry) and microanalytical data. All the Schiff base ligands and their oxovanadium(IV) complexes have been subjected to in vitro antibacterial activity against four Gram-negative (Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella enterica serover typhi) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains and, for in vitro antifungal activity against Trichophyton longifucus, Candida albican, Aspergillus flavus, Microscopum canis, Fusarium solani and Candida glabrata. Brine shrimp bioassay was also carried out to check the cytotoxic nature of these compounds.

Aberration-Corrected STEM Imaging Through Off-Site Remote Operation

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

Jarvis, Karalee; Allard Jr, Lawrence Frederick; Jerome, Timothy Y

2010-01-01

Recent advances in aberration-corrected electron microscopy have allowed researchers to image materials at sub- ngstr m resolution. Many of these modern instruments are designed to be operated from separate 'control' rooms, removing the effect of the operator on the instrument s physical environment. This capability also allows operation from suitable workstations, over internet connections, from literally anywhere in the world [1]. Researchers at the University of Texas at Austin (UTA) have collaborated with Oak Ridge National Laboratory (ORNL) and JEOL Ltd. to routinely conduct research sessions in which high-resolution images and X-ray microanalytical data are acquired during after-hours research sessions,more » utilizing the JEOL 2200FS aberration-corrected STEM/TEM at ORNL from their lab in Austin. Details of the remote operation are presented here.« less

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

Sakellariou, E.; Zorba, T.; Pavlidou, E.

The 'St. 40 Martyrs' church is the most famous medieval building in Veliko Turnovo, Bulgaria. It is located in Assenova mahala, just next to Tsarevets. It was built and its walls were painted during the reign of Bulgarian king Ivan Assen II after the victory against Epyrus despot Theodoros Comninos (1230 AD). It consists of two buildings - a six-column basilica and another, smaller building on its western wall, which was built later. During the presence of the Ottoman Turks, maybe until the first half of the 18th century, the church remained christian. When it was converted to a mosque,more » all the christian symbols in it were destroyed. The archeological researches on site were initiated in 1969. As it is clear, the 40 Martyrs church is a historical monument of culture with great significance. The church had murals, from the earlier period, but in the following years and especially during the Ottoman period, the church has suffered many and different destructions. Nevertheless, the very few pieces of murals that are rescued till nowadays provide important information for the technique and the pigments that were used on its wall paintings. In the present work, twelve series of samples from the wall paintings were studied in order to characterize the materials and the technique used for church iconography. The study was based on the micro-analytical techniques of the Fourier Transform Infrared micro-spectroscopy (mus-FTIR), the Optical Microscopy and the Scanning Electron Microscopy (SEM) coupled to an Energy Dispersive X-ray Spectrometer (EDS). In the FTIR spectra of all pigments the characteristic peaks of calcite were detected, confirming the use of fresco technique for the creation of murals. The combination of FTIR spectroscopy and SEM-EDS analysis, reveal the existence of lapis-lazuli for the blue color, green earth for the green color, cinnabar for the red color, calcite for the white color and carbon black for the black color. Moreover, in other chromatic layers, the presence of iron oxides (hematite and limonite) indicating the use of ochre for the yellow and red pigments, is identified. Finally, the surface of some samples was covered by a transparent and tensile material. This material was characterized by mus-FTIR spectroscopy as an organic substance, probably a natural resin that was used to protect the murals in the early ages.« less

The behaviour of monazite at high temperature and high stress in the lower crust

NASA Astrophysics Data System (ADS)

Clark, Chris; Taylor, Richard; Erickson, Timmons; Reddy, Steven; Fougerouse, Denis; Fitzsimons, Ian; Hand, Martin

2017-04-01

Monazite is fast becoming the go to geochronometer for establishing the timing of metamorphic, deformational and hydrothermal events in crustal rocks. This is principally due to monazite forming in rocks that are petrologically useful (e.g. metapelites), it's susceptibility to recrystallization (both fluid and deformation driven) and the suite of trace elements it incorporates during growth. In dry conditions (i.e. the melt-depleted lower crust) monazite has a high closure temperature. It therefore has the ability to record the timing of prograde to peak metamorphic conditions. The reactivity of monazite in the presence of fluid allows the timing of post-peak fluid and melt crystallisation events to be constrained. Under high-stress monazite will recrystallise, forming new crystals that can be used to constrain the age of deformational events - this feature is particularly useful as high-grade reworking of lower crustal rocks often leave no geochronological record within other accessory minerals (e.g. zircon). However, it has long been recognised that monazite can record a cryptic range and/or distribution of ages that are difficult reconcile with how we traditionally believe the lower crust responds to deformational events - e.g. the anhydrous nature of lower crustal rocks and the preservation of granulite facies mineral assemblages. Here we present datasets collected by a suite of microanalytical techniques on monazite grains from lower-crustal rocks that have experienced deformation, fluid-rock interaction and ultrahigh temperature metamorphism. To better understand how monazite behaves in these environments we integrate electron probe, electron backscatter diffraction, laser ablation split stream petrochronology, transmission electron microscopy and Atom Probe Tomography datasets to image and quantify behaviour of key elements from the micro- to the nanoscale. When used sequentially, these techniques provide a detailed view of the processes that re-distribute U-Th-REE-Y-Pb at the nanoscale. Understanding how monazite behaves under different stress and thermal conditions is the key to using this geochronometer to develop and refine event chronologies in the lower crust.

Exploring clinical reasoning in novices: a self-regulated learning microanalytic assessment approach.

PubMed

Artino, Anthony R; Cleary, Timothy J; Dong, Ting; Hemmer, Paul A; Durning, Steven J

2014-03-01

The primary objectives of this study were to examine the regulatory processes of medical students as they completed a diagnostic reasoning task and to examine whether the strategic quality of these regulatory processes were related to short-term and longer-term medical education outcomes. A self-regulated learning (SRL) microanalytic assessment was administered to 71 second-year medical students while they read a clinical case and worked to formulate the most probable diagnosis. Verbal responses to open-ended questions targeting forethought and performance phase processes of a cyclical model of SRL were recorded verbatim and subsequently coded using a framework from prior research. Descriptive statistics and hierarchical linear regression models were used to examine the relationships between the SRL processes and several outcomes. Most participants (90%) reported focusing on specific diagnostic reasoning strategies during the task (metacognitive monitoring), but only about one-third of students referenced these strategies (e.g. identifying symptoms, integration) in relation to their task goals and plans for completing the task. After accounting for prior undergraduate achievement and verbal reasoning ability, strategic planning explained significant additional variance in course grade (ΔR(2 ) = 0.15, p < 0.01), second-year grade point average (ΔR(2) = 0.14, p < 0.01), United States Medical Licensing Examination Step 1 score (ΔR(2) = 0.08, p < 0.05) and National Board of Medical Examiner subject examination score in internal medicine (ΔR(2) = 0.10, p < 0.05). These findings suggest that most students in the formative stages of learning diagnostic reasoning skills are aware of and think about at least one key diagnostic reasoning process or strategy while solving a clinical case, but a substantially smaller percentage set goals or develop plans that incorporate such strategies. Given that students who developed more strategic plans achieved better outcomes, the potential importance of forethought regulatory processes is underscored. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Medical Education published by John Wiley & Sons Ltd.

Glimpses into the blind spot: Social interaction and autism.

PubMed

Bottema-Beutel, Kristen

2017-07-01

A primary feature of autism spectrum disorder (ASD) is marked difficulty in social interactions. Despite the centrality of social interaction differences to the clinical presentation of ASD, only a small portion of research in this field characterizes interaction in everyday social contexts. This theoretical paper reviews the growing corpus of interactional research on ASD, including discourse analysis (DA) and conversation analysis (CA) approaches. DA and CA are micro-analytic methods aimed at understanding the organizational structure of, and actions pursued within, social encounters. These methods are aligned with enactive theories of social interaction. The bulk of current ASD research construes social interaction as involving isolated individuals who represent and/or theorize about the minds of an interlocutor. Enactive approaches posit that achieving intersubjectivity does not require theories of other minds, but instead a propensity for coordinating social actions with others. Through the complementary lenses of enactivism and interactional research, I offer an account of autistic social interaction as involving differences in interactional coordination, interactional priorities, and the enactment of meaning across conversational turns. This characterization challenges the explanatory role of cognitive processes such as Theory of Mind, and points to new avenues for conceptualizing, measuring, and supporting social interaction. Copyright © 2017 Elsevier Inc. All rights reserved.

Al Eskan disease: Persian Gulf syndrome.

PubMed

Korényi-Both, A L; Korényi-Both, A L; Juncer, D J

1997-01-01

This article examines the potential relationship between Al Eskan disease and the Persian Gulf syndrome. Al Eskan disease, reported in Military Medicine in 1992, is a novel and previously unreported condition triggered by the exceptionally fine sand dust of the Central and Eastern Saudi Arabian peninsula. We repeat our study of the pathogenesis of Al Eskan disease to include the ultrastructural and microanalytical study of the sand, aerobiological studies of the Kingdom of Saudi Arabia, and the etiology, symptoms, and prevalence of the disease. We conclude that immunodepression resulting from the continued presence of sand particles less than 1 micron in diameter in the lungs and bodies of Persian Gulf veterans explains not only the symptoms of the hyperegic lung condition of phase I and the symptoms of phase II of Al Eskan disease, but also provides an important clue to a common factor in most cases of Persian Gulf illnesses. We include a discussion of most of the commonly suspected agents in the Persian Gulf syndrome. In this case, we conclude that each of these factors, such as oil well fires, old-world diseases, or depleted uranium, are probably adjuvant or contributing causes. The only common exposure that would lead to recognition of the Persian Gulf syndrome as a single medical condition, rather than a catch-all phrase for unrelated conditions, appears to be exposure to the ubiquitous, fine sand of the area, and a resulting immunosuppression that is aggravated by opportunistic infections and other nonmicrobial ailments.

Electrochemical Sensors for the Detection of Lead and Other Toxic Heavy Metals: The Next Generation of Personal Exposure Biomonitors

PubMed Central

Yantasee, Wassana; Lin, Yuehe; Hongsirikarn, Kitiya; Fryxell, Glen E.; Addleman, Raymond; Timchalk, Charles

2007-01-01

To support the development and implementation of biological monitoring programs, we need quantitative technologies for measuring xenobiotic exposure. Microanalytical based sensors that work with complex biomatrices such as blood, urine, or saliva are being developed and validated and will improve our ability to make definitive associations between chemical exposures and disease. Among toxic metals, lead continues to be one of the most problematic. Despite considerable efforts to identify and eliminate Pb exposure sources, this metal remains a significant health concern, particularly for young children. Ongoing research focuses on the development of portable metal analyzers that have many advantages over current available technologies, thus potentially representing the next generation of toxic metal analyzers. In this article, we highlight the development and validation of two classes of metal analyzers for the voltammetric detection of Pb, including: a) an analyzer based on flow injection analysis and anodic stripping voltammetry at a mercury-film electrode, and b) Hg-free metal analyzers employing adsorptive stripping voltammetry and novel nanostructure materials that include the self-assembled monolayers on mesoporous supports and carbon nanotubes. These sensors have been optimized to detect Pb in urine, blood, and saliva as accurately as the state-of-the-art inductively coupled plasma-mass spectrometry with high reproducibility, and sensitivity allows. These improved and portable analytical sensor platforms will facilitate our ability to conduct biological monitoring programs to understand the relationship between chemical exposure assessment and disease outcomes. PMID:18087583

NENIMF: Northeast National Ion Microprobe Facility - A Multi-User Facility for SIMS Microanalysis

NASA Astrophysics Data System (ADS)

Layne, G. D.; Shimizu, N.

2002-12-01

The MIT-Brown-Harvard Regional Ion Microprobe Facility was one of the earliest multi-user facilities enabled by Dan Weill's Instrumentation and Facilities Program - and began with the delivery of a Cameca IMS 3f ion microprobe to MIT in 1978. The Northeast National Ion Microprobe Facility (NENIMF) is the direct descendant of this original facility. Now housed at WHOI, the facility incorporates both the original IMS 3f, and a new generation, high transmission-high resolution instrument - the Cameca IMS 1270. Purchased with support from NSF, and from a consortium of academic institutions in the Northeast (The American Museum of Natural History, Brown University, The Lamont-Doherty Earth Observatory, MIT, Rensselaer Polytechnic Institute, WHOI) - this latest instrument was delivered and installed during 1996. NENIMF continues to be supported by NSF EAR I&F as a multi-user facility for geochemical research. Work at NENIMF has extended the original design strength of the IMS 1270 for microanalytical U-Pb zircon geochronology to a wide variety of novel and improved techniques for geochemical research. Isotope microanalysis for studies in volcanology and petrology is currently the largest single component of facility activity. This includes the direct measurement of Pb isotopes in melt inclusions, an application developed at NENIMF, which is making an increasingly significant contribution to our understanding of basalt petrogenesis. This same technique has also been extended to the determination of Pb isotopes in detrital feldspar grains, for the study of sedimentary provenance and tectonics of the Himalayas and other terrains. The determination of δ11B in volcanic melt inclusions has also proven to be a powerful tool in the modeling of subduction-related magmatism. The recent development of δ34S and δ37Cl determination in glasses is being applied to studies of the behavior of these volatile elements in both natural and experimental systems. Other recent undertakings have included development of high precision 232Th/230Th for U-series disequilibrium studies of young volcanic rocks, and the implementation and refinement of U-Th-Pb dating of individual monazite crystals. The facility is also developing an expanding number of applications in the general field of biogeochemistry. Examples include; δ18O in biogenic carbonates for climate and paleotemperature studies, determination of δ13C in graphite microfossils for early life studies, and determination of δ13C and trace metal concentrations in bacterial cultures in support of studies of natural microbial ecosystems. The IMS 3f instrument - now in its 25th year of operation - continues to be a productive resource for trace element and rare earth element determinations in natural and experimental materials. It has also become an important component of ongoing research in the derivation of paleotemperatures from marine biomineralization using trace element ratios of biogenic aragonite.

QACD: A method for the quantitative assessment of compositional distribution in geologic materials

NASA Astrophysics Data System (ADS)

Loocke, M. P.; Lissenberg, J. C. J.; MacLeod, C. J.

2017-12-01

In order to fully understand the petrogenetic history of a rock, it is critical to obtain a thorough characterization of the chemical and textural relationships of its mineral constituents. Element mapping combines the microanalytical techniques that allow for the analysis of major- and minor elements at high spatial resolutions (e.g., electron microbeam analysis) with 2D mapping of samples in order to provide unprecedented detail regarding the growth histories and compositional distributions of minerals within a sample. We present a method for the acquisition and processing of large area X-ray element maps obtained by energy-dispersive X-ray spectrometer (EDS) to produce a quantitative assessment of compositional distribution (QACD) of mineral populations within geologic materials. By optimizing the conditions at which the EDS X-ray element maps are acquired, we are able to obtain full thin section quantitative element maps for most major elements in relatively short amounts of time. Such maps can be used to not only accurately identify all phases and calculate mineral modes for a sample (e.g., a petrographic thin section), but, critically, enable a complete quantitative assessment of their compositions. The QACD method has been incorporated into a python-based, easy-to-use graphical user interface (GUI) called Quack. The Quack software facilitates the generation of mineral modes, element and molar ratio maps and the quantification of full-sample compositional distributions. The open-source nature of the Quack software provides a versatile platform which can be easily adapted and modified to suit the needs of the user.

Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

NASA Astrophysics Data System (ADS)

Sahlstedt, Elina; Arppe, Laura

2017-04-01

Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

Revealing the sub-nanometere three-dimensional microscture of a metallic meteorite

NASA Astrophysics Data System (ADS)

Einsle, J. F.; Harrison, R.; Blukis, R.; Eggeman, A.; Saghi, Z.; Martineau, B.; Bagot, P.; Collins, S. M.; Midgley, P. A.

2017-12-01

Coming from from the core of differentiated planetesimals, iron-nickel meteorites provide some of the only direct material artefacts from planetary cores. Iron - nickel meteorites contain a record of their thermal and magnetic history, written in the intergrowth of iron-rich and nickel-rich phases that formed during slow cooling over millions of years. Of intense interest for understanding the thermal and magnetic history is the `'cloudy zone''. This nanoscale intergrowth that has recently been used to provide a record of magnetic activity on the parent body of stony-iron meteorites. The cloudy zone consists of islands of tetrataenite surrounded by a matrix phase, Here we use a multi-scale and multidimensional comparative study using high-resolution electron diffraction, scanning transmission electron tomography with chemical mapping, atom probe tomography and micromagnetic simulations to reveal the three-dimensional architecture of the cloudy zone with sub-nanometre spatial resolution. Machine learning data deconvolution strategies enable the three microanalytical techniques to converge on a consistent microstructural description for the cloudy zone. Isolated islands of tetrataenite are found, embedded in a continuous matrix of an FCC-supercell of Fe27Ni5 structure, never before identified in nature. The tetrataenite islands are arranged in clusters of three crystallographic variants, which control how magnetic information is encoded into the nanostructure during slow cooling. The new compositional, crystallographic and micromagnetic data have profound implications for how the cloudy zone acquires magnetic remanence, and requires a revision of the low-temperature metastable phase diagram of the Fe-Ni system. This can lead to a refinement of core dynamics in small planetoids.

Ultrastructural and x-ray microanalytical observations of minocycline-related hyperpigmentation of the skin

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

Sato, S.; Murphy, G.F.; Bernhard, J.D.

1981-09-01

In order to elucidate the nature and distribution of the pigment responsible for the circumscribed blue-black cutaneous hyperpigmentation occurring after administration of minocycline hydrochloride, transmission electron microscopy and energy-dispersive electron x-ray microanalysis were performed on lesional skin. Ultrastructural observations demonstrated electron-dense iron-containing particles either incorporated into a variety of siderosomes, within dermal histiocytes, free within the cytoplasm, or, rarely, scattered among dermal collagen fibers. Electron x-ray microanalysis confirmed iron content present within these particles. Although siderosomal inclusions contained occasional melanosome complexes, the degree of deposition of electron-dense iron-containing particles in dermal histiocytes seemed to be primarily responsible for the blue-blackmore » discoloration of the skin. The present study is an investigation of the structure and composition of the pigment responsible for minocycline-related cutaneous hyperpigmentation.« less

The effects of trace element content on pyrite oxidation rates

NASA Astrophysics Data System (ADS)

Gregory, D. D.; Lyons, T.; Cliff, J. B.; Perea, D. E.; Johnson, A.; Romaniello, S. J.; Large, R. R.

2017-12-01

Pyrite acts as both an important source and sink for many different metals and metalloids in the environment, including many that are toxic. Oxidation of pyrite can release these elements while at the same time producing significant amounts of sulfuric acid. Such issues are common in the vicinity of abandoned mines and smelters, but, as pyrite is a common accessory mineral in many different lithologies, significant pyrite oxidation can occur whenever pyritic rocks are exposed to oxygenated water or the atmosphere. Accelerated exposure to oxygen can occur during deforestation, fracking for petroleum, and construction projects. Geochemical models for pyrite oxidation can help us develop strategies to mitigate these deleterious effects. An important component of these models is an accurate pyrite oxidation rate; however, current pyrite oxidation rates have been determined using relatively pure pyrite. Natural pyrite is rarely pure and has a wide range of trace element concentrations that may affect the oxidation rate. Furthermore, the position of trace elements within the mineral lattice can also affect the oxidation rate. For example, elements such as Ni and Co, which substitute into the pyrite lattice, are thought to stabilize the lattice and thus prevent pyrite oxidation. Alternatively, trace elements that are held within inclusions of other minerals could form a galvanic cell with the surrounding pyrite, thus enhancing pyrite oxidation rates. In this study, we present preliminary analyses from three different pyrite oxidation experiments each using natural pyrite with different trace element compositions. These results show that the pyrite with the highest trace element concentration has approximately an order of magnitude higher oxidation rate compared to the lowest trace element sample. To further elucidate the mechanisms, we employed microanalytical techniques to investigate how the trace elements are held within the pyrite. LA-ICPMS was used to determine the variability of trace element content from the pyrite samples. These data were then used to select areas of interest for NanoSIMS analyses, which in turn was used to select areas for TEM and APT. These analyses show that the trace element content of pyrite can be highly variable, which may significantly affect the rate of pyrite oxidation.

Tortuous path chemical preconcentrator

DOEpatents

Manginell, Ronald P.; Lewis, Patrick R.; Adkins, Douglas R.; Wheeler, David R.; Simonson, Robert J.

2010-09-21

A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

Cosmic Dust Collection Facility: Scientific objectives and programmatic relations

NASA Technical Reports Server (NTRS)

Hoerz, Fred (Editor); Brownlee, D. E.; Bunch, T. E.; Grounds, D.; Grun, E.; Rummel, Y.; Quaide, W. L.; Walker, R. M.

1990-01-01

The science objectives are summarized for the Cosmic Dust Collection Facility (CDCF) on Space Station Freedom and these objectives are related to ongoing science programs and mission planning within NASA. The purpose is to illustrate the potential of the CDCF project within the broad context of early solar system sciences that emphasize the study of primitive objects in state-of-the-art analytical and experimental laboratories on Earth. Current knowledge about the sources of cosmic dust and their associated orbital dynamics is examined, and the results are reviewed of modern microanalytical investigations of extraterrestrial dust particles collected on Earth. Major areas of scientific inquiry and uncertainty are identified and it is shown how CDCF will contribute to their solution. General facility and instrument concepts that need to be pursued are introduced, and the major development tasks that are needed to attain the scientific objectives of the CDCF project are identified.

Preparation of metallic Pd nanoparticles using supercritical CO2 deposition: An efficient catalyst for Suzuki cross-coupling reaction

NASA Astrophysics Data System (ADS)

Tezcan, Burcu; Ulusal, Fatma; Egitmen, Asım; Guzel, Bilgehan

2018-05-01

Ligand-free palladium nanoparticles supported on multi-walled carbon nanotubes (Pd/MWCNT) were prepared by the supercritical carbon dioxide (scCO2) deposition method using a novel scCO2-soluble Pd organometallic complex as a precursor. The precursor with the perfluoroalkyl chain group was synthesized and identified by microanalytic methods. The deposition was carried out at the temperature of 363.15 K and pressure of 27.6 MPa CO2. The prepared metallic nanoparticles were obtained with an average size of 2 nm. Pd/MWCNT was utilized as a heterogeneous catalyst in Suzuki cross-coupling reaction. The nanocatalyst was found very effective in Suzuki reaction and it could also be recovered easily from the reaction media and reused over several cycles without significant loss of catalytic activity under mild conditions. [Figure not available: see fulltext.

Synthesis, in Vivo Anti-inflammatory, and in Vitro Antimicrobial Activity of New 5-Benzofuranyl Fused Pyrimidines.

PubMed

Nassar, Ekhlass; El-Badry, Yaser Abdel-Moemen; El Kazaz, Hagar

2016-01-01

Chalcone (3) has been synthesized as a new chalcone derivative bearing benzofuran moiety at 1 position. Such chalcone was used as a model dielectrophile applied to react with some nucleophiles such as 5-amino pyrazoles, 5-amino-1,2,4-triazole, 2-aminobenzimidazole, and 6-uraciles under Michael reaction conditions and resulted in a new series of fused pyrimidines such as pyrazolo[1,5-a]pyrimidines 7a-e, [1,2,4]-triazolo[1,5-a]pyrimidine 9, pyrimido[1,2-a]benzimidazole 11, and synthesis of pyrido[2,3-d]pyrimidinones 13a and b. The structures of the synthesized target heterocyclic compounds were confirmed by microanalytical and spectral data such as Fourier transform (FT)-IR, (1)H-NMR, and MS spectra. The newly synthesized compounds were evaluated for their anti-inflammatory and antimicrobial activities; most showed significant activities.

Effects of lead pollution on Ammonia parkinsoniana (foraminifera): ultrastructural and microanalytical approaches.

PubMed

Frontalini, F; Curzi, D; Giordano, F M; Bernhard, J M; Falcieri, E; Coccioni, R

2015-01-30

The responses of Ammonia parkinsoniana (Foraminifera) exposed to different concentrations of lead (Pb) were evaluated at the cytological level. Foraminifera-bearing sediments were placed in mesocosms that were housed in aquaria each with seawater of a different lead concentration. On the basis of transmission electron microscopy and environmental scanning electron microscopy coupled with energy dispersive spectrometer analyses, it was possible to recognize numerous morphological differences between untreated (i.e., control) and treated (i.e., lead enrichment) specimens. In particular, higher concentrations of this pollutant led to numerical increase of lipid droplets characterized by a more electron-dense core, proliferation of residual bodies, a thickening of the organic lining, mitochondrial degeneration, autophagosome proliferation and the development of inorganic aggregates.  All these cytological modifications might be related to the pollutant-induced stress and some of them such as the thickening of organic lining might suggest a potential mechanism of protection adopted by foraminifera.

Fundamentals and practice for ultrasensitive laser-induced fluorescence detection in microanalytical systems.

PubMed

Johnson, Mitchell E; Landers, James P

2004-11-01

Laser-induced fluorescence is an extremely sensitive method for detection in chemical separations. In addition, it is well-suited to detection in small volumes, and as such is widely used for capillary electrophoresis and microchip-based separations. This review explores the detailed instrumental conditions required for sub-zeptomole, sub-picomolar detection limits. The key to achieving the best sensitivity is to use an excitation and emission volume that is matched to the separation system and that, simultaneously, will keep scattering and luminescence background to a minimum. We discuss how this is accomplished with confocal detection, 90 degrees on-capillary detection, and sheath-flow detection. It is shown that each of these methods have their advantages and disadvantages, but that all can be used to produce extremely sensitive detectors for capillary- or microchip-based separations. Analysis of these capabilities allows prediction of the optimal means of achieving ultrasensitive detection on microchips.

Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

NASA Astrophysics Data System (ADS)

Refat, Moamen S.

2013-03-01

Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

Characterization of blue decorated Renaissance pottery fragments from Caltagirone (Sicily, Italy)

NASA Astrophysics Data System (ADS)

Barilaro, D.; Crupi, V.; Interdonato, S.; Majolino, D.; Venuti, V.; Barone, G.; La Russa, M. F.; Bardelli, F.

2008-07-01

Renaissance blue decorated pottery fragments from the archaeological site of Caltagirone (Sicily, Italy) were analysed by scanning electron microscopy - energy dispersive X-ray spectrometry (SEM/EDS). The samples were dated back to 16th century AD on the basis of archaeological observations. The micro-chemical analyses were performed on the ceramic body and the surface decorated layer of the samples. Particularly, the investigation was addressed the characterization of the coating blue decorations. The obtained results allowed us to clearly identify smalt as pigment. Also the presence of arsenic (As) was revealed and the Co/As ratio values were calculated and related to the different process used for the pigment preparation. Further spectroscopic analyses, performed through X-ray absorbance spectroscopy (XAS), carried out at the Co K-edge, confirmed the micro-analytical results and permitted us to identify the oxidation form and the local environment of cobalt atoms.

Progress Towards an Open Data Ecosystem for Australian Geochemistry and Geochronology Data

NASA Astrophysics Data System (ADS)

McInnes, B.; Rawling, T.; Brown, W.; Liffers, M.; Wyborn, L. A.; Brown, A.; Cox, S. J. D.

2016-12-01

Technological improvements in laboratory automation and microanalytical methods are producing an unprecedented volume of high-value geochemical data for use by geoscientists in understanding geological and planetary processes. In contrast, the research infrastructure necessary to systematically manage, deliver and archive analytical data has not progressed much beyond the minimum effort necessary to produce a peer-reviewed publication. Anecdotal evidence indicates that the majority of publically funded data is underreported, and what is published is relatively undiscoverable to experienced researchers let alone the general public. Government-funded "open data" initiatives have a role to play in the development of networks of data management and delivery ecosystems and practices allowing access to publically funded data. This paper reports on progress in Australia towards creation of an open data ecosystem involving multiple academic and government research institutions cooperating to create an open data architecture linking researchers, physical samples, sample metadata, laboratory metadata, analytical data and consumers.

X-ray microanalytical studies of mineral elements in the tripartite symbiosis between lima bean, N2-fixing bacteria and mycorrhizal fungi.

PubMed

Rodak, Bruna Wurr; Freitas, Douglas Siqueira; Bamberg, Soraya Marx; Carneiro, Marco Aurélio Carbone; Guilherme, Luiz Roberto Guimarães

2017-01-01

The symbiosis between legumes, arbuscular mycorrhizal (AM) fungi, and N 2 -fixing bacteria (NFB) provides mutual nutritional gains. However, assessing the nutritional status of the microorganisms is a difficult task. A methodology that could assess this status, in situ, could assist managing these organisms in agriculture. This study used X-ray microanalyses to quantify and locate mineral elements in structures formed in a tripartite symbiosis. Lima bean (Phaseolus lunatus L. Walp) was cultivated in pots under greenhouse conditions, to which we have added AM fungal isolates (Glomus macrocarpum and Acaulospora colombiana) and NFB (Bradyrhizobium japonicum) inocula. Uninoculated control plants were also included. Symbionts were evaluated at the onset of flowering. Quantification of the mineral elements in the symbiotic components was performed using energy dispersive X-ray spectroscopy (EDX) and a scanning electron microscopy (SEM) was used to identify structures. EDX analysis detected 13 elements with the most abundant being N, Ca, and Se, occurring in all tissues, Fe in roots, Ni and Al in epidermis and P and Mo in nodules. Elemental quantification in fungal structures was not possible. The distribution of elements was related to their symbiotic function. X-ray microanalysis can be efficiently applied for nutritional diagnosis in tripartite symbiosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Lead arthritis and lead poisoning following bullet wounds: a clinicopathologic, ultrastructural, and microanalytic study of two cases.

PubMed

Slavin, R E; Swedo, J; Cartwright, J; Viegas, S; Custer, E M

1988-02-01

Bullet wounds causing lead synovitis in the wrist and knee are reported in two patients, one of whom also developed clinical plumbism. Very high lead levels in the synovial fluid are believed to be responsible for toxicity changes that occurred in the synovium and bone. Ultrastructurally, these alterations included the formation of nuclear lead inclusions, dilation, and degranulation of the rough endoplasmic reticulum and deposition of crystalline precipitates in the matrix of the mitochondria in macrophages, osteoclasts, and synoviocytes, as well as the development of cytoplasmic lead inclusions in osteoclasts. Energy-dispersive x-ray elemental analysis (EDXEA) indicated that the nuclear inclusions contained only lead, whereas precipitates within the mitochondria and elsewhere in the cytoplasm were composed of complexes containing lead, calcium, and phosphorus. Similarly constituted extracellular complexes were incorporated into newly formed trabecular bone laid down as a physiologic response to the bullet lodged within the wrist bones. This bone subsequently exhibited defects in bone resorption, which were characterized by depressed osteoclastic function and a unique lesion termed incomplete osteocytic osteolysis. The genesis of this latter lesion is uncertain. The sequestration of the partially degraded bone fragments containing lead complexes into the marrow and eventually into the joint spaces and synovium permitted the recycling of bone lead, and this may have played an important role in inducing clinical plumbism in one of the patients in this study.

Research Spotlight: The next big thing is actually small.

PubMed

Garcia, Carlos D

2012-07-01

Recent developments in materials, surface modifications, separation schemes, detection systems and associated instrumentation have allowed significant advances in the performance of lab-on-a-chip devices. These devices, also referred to as micro total analysis systems (µTAS), offer great versatility, high throughput, short analysis time, low cost and, more importantly, performance that is comparable to standard bench-top instrumentation. To date, µTAS have demonstrated advantages in a significant number of fields including biochemical, pharmaceutical, military and environmental. Perhaps most importantly, µTAS represent excellent platforms to introduce students to microfabrication and nanotechnology, bridging chemistry with other fields, such as engineering and biology, enabling the integration of various skills and curricular concepts. Considering the advantages of the technology and the potential impact to society, our research program aims to address the need for simpler, more affordable, faster and portable devices to measure biologically active compounds. Specifically, the program is focused on the development and characterization of a series of novel strategies towards the realization of integrated microanalytical devices. One key aspect of our research projects is that the developed analytical strategies must be compatible with each other; therefore, enabling their use in integrated devices. The program combines spectroscopy, surface chemistry, capillary electrophoresis, electrochemical detection and nanomaterials. This article discusses some of the most recent results obtained in two main areas of emphasis: capillary electrophoresis, microchip-capillary electrophoresis, electrochemical detection and interaction of proteins with nanomaterials.

Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

USGS Publications Warehouse

Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

2016-01-01

The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05–0.45 MPa s−1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

Function and Dynamics of Auxin and Carbohydrates during Earlywood/Latewood Transition in Scots Pine1

PubMed Central

Uggla, Claes; Magel, Elisabeth; Moritz, Thomas; Sundberg, Björn

2001-01-01

In temperate regions the annual pattern of wood development is characterized by the formation of radially narrow and thick walled latewood cells. This takes place at the later part of the growing season when cambial cell division declines. To gain new insight into the regulation of this process, micro-analytical techniques were used to visualize the distribution of indole-3-acetic acid (IAA), soluble carbohydrates, and activities of sucrose (Suc)-metabolizing enzymes across the cambial region tissues in Scots pine (Pinus sylvestris). The total amount of IAA in the cambial region did not change with latewood initiation. But its radial distribution pattern was altered, resulting in an increased concentration in the cambial meristem and its recent derivatives. Thus, initiation of latewood formation and cessation of cambial cell division is not a consequence of decreased IAA concentrations in dividing and expanding cells. Rather, IAA most likely has a role in defining the altered developmental pattern associated with latewood formation. Carbohydrates and enzyme activities showed distinctive radial distribution patterns. Suc peaked in the phloem and decreased sharply to low levels across the cambial zone, whereas fructose and glucose reached their highest levels in the maturing tracheids. Suc synthase was the dominating Suc cleaving enzyme with a peak in the secondary wall-forming tracheids and in the phloem. Soluble acid invertase peaked in dividing and expanding cells. Suc-phosphate synthase had its highest activities in the phloem. Activities of cell wall bound invertase were low. The absence of major seasonal variations indicates that carbohydrate availability is not a trigger for latewood initiation. However, steep concentration gradients of the sugars suggest a role for sugar signaling in vascular development. PMID:11299382

Function and dynamics of auxin and carbohydrates during earlywood/latewood transition in scots pine.

PubMed

Uggla, C; Magel, E; Moritz, T; Sundberg, B

2001-04-01

In temperate regions the annual pattern of wood development is characterized by the formation of radially narrow and thick walled latewood cells. This takes place at the later part of the growing season when cambial cell division declines. To gain new insight into the regulation of this process, micro-analytical techniques were used to visualize the distribution of indole-3-acetic acid (IAA), soluble carbohydrates, and activities of sucrose (Suc)-metabolizing enzymes across the cambial region tissues in Scots pine (Pinus sylvestris). The total amount of IAA in the cambial region did not change with latewood initiation. But its radial distribution pattern was altered, resulting in an increased concentration in the cambial meristem and its recent derivatives. Thus, initiation of latewood formation and cessation of cambial cell division is not a consequence of decreased IAA concentrations in dividing and expanding cells. Rather, IAA most likely has a role in defining the altered developmental pattern associated with latewood formation. Carbohydrates and enzyme activities showed distinctive radial distribution patterns. Suc peaked in the phloem and decreased sharply to low levels across the cambial zone, whereas fructose and glucose reached their highest levels in the maturing tracheids. Suc synthase was the dominating Suc cleaving enzyme with a peak in the secondary wall-forming tracheids and in the phloem. Soluble acid invertase peaked in dividing and expanding cells. Suc-phosphate synthase had its highest activities in the phloem. Activities of cell wall bound invertase were low. The absence of major seasonal variations indicates that carbohydrate availability is not a trigger for latewood initiation. However, steep concentration gradients of the sugars suggest a role for sugar signaling in vascular development.

Blending Curriculum with Research in an Undergraduate Petrology Course: A Recipe for Success?

NASA Astrophysics Data System (ADS)

Gonzales, D. A.; Semken, S. C.

2009-12-01

In this presentation we discuss the design, key curricular elements, and strengths and weaknesses of an undergraduate course in the Department of Geosciences at Fort Lewis College that was recast to focus on petrologic studies in the Southern Rocky Mountains and Colorado Plateau. Redesign of the course retained an additional petrology option in the curriculum and offered undergraduates a richer opportunity to learn and practice science-research skills. This course emphasizes direct engagement and student responsibility for learning: traits valuable in transforming undergraduates into experienced and competent professionals. Previous offerings of this course have been field based, each having a unique context for research. The primary pedagogical strategy was to blend field studies with inquiry to promote authentic, student-driven research. Students applied and tested their prior knowledge, and used observational and interpretative skills, to investigate major regional rock bodies and geologic histories, as opposed to completing a set of activities with predefined outcomes. In 2010, students will work on an NSF-funded project to test hypotheses on the origin and evolution of mafic magmas of the Navajo volcanic field. This research will most involve petrographic and microanalytical techniques on rock specimens with a subordinate amount of field work. Formative and summative assessment data for previous offerings of this course reveal that these classes have an impact on the academic interests and future successes of students. Assessment data collected from students, and other faculty that interacted with them, indicate that students in this research-oriented petrology course have gained a greater understanding of the elements and complications of research. They have also developed geologic skills and a passion for geologic research that have influenced subsequent academic (and later career) paths of the students.

Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

NASA Astrophysics Data System (ADS)

Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

2016-10-01

The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05-0.45 MPa s-1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

Retrieval analysis of different orthodontic brackets: the applicability of electron microprobe techniques for determining material heterogeneities and corrosive potential

PubMed Central

HOLST, Alexandra Ioana; HOLST, Stefan; HIRSCHFELDER, Ursula; von SECKENDORFF, Volker

2012-01-01

Objective The objective of this study was to investigate the applicability of micro-analytical methods with high spatial resolution to the characterization of the composition and corrosion behavior of two bracket systems. Material and methods The surfaces of six nickel-free brackets and six nickel-containing brackets were examined for signs of corrosion and qualitative surface analysis using an electron probe microanalyzer (EPMA), prior to bonding to patient's tooth surfaces and four months after clinical use. The surfaces were characterized qualitatively by secondary electron (SE) images and back scattered electron (BSE) images in both compositional and topographical mode. Qualitative and quantitative wavelength-dispersive analyses were performed for different elements, and by utilizing qualitative analysis the relative concentration of selected elements was mapped two-dimensionally. The absolute concentration of the elements was determined in specially prepared brackets by quantitative analysis using pure element standards for calibration and calculating correction-factors (ZAF). Results Clear differences were observed between the different bracket types. The nickel-containing stainless steel brackets consist of two separate pieces joined by a brazing alloy. Compositional analysis revealed two different alloy compositions, and reaction zones on both sides of the brazing alloy. The nickel-free bracket was a single piece with only slight variation in element concentration, but had a significantly rougher surface. After clinical use, no corrosive phenomena were detectable with the methods applied. Traces of intraoral wear at the contact areas between the bracket slot and the arch wire were verified. Conclusion Electron probe microanalysis is a valuable tool for the characterization of element distribution and quantitative analysis for corrosion studies. PMID:23032212

High temperature gas-solid reactions in calc-silicate Cu-Au skarn formation; Ertsberg, Papua Province, Indonesia

NASA Astrophysics Data System (ADS)

Henley, Richard W.; Brink, Frank J.; King, Penelope L.; Leys, Clyde; Ganguly, Jibamitra; Mernagh, Terrance; Middleton, Jill; Renggli, Christian J.; Sieber, Melanie; Troitzsch, Ulrike; Turner, Michael

2017-12-01

The 2.7-3 Ma Ertsberg East Skarn System (Indonesia), adjacent to the giant Grasberg Porphyry Copper deposit, is part of the world's largest system of Cu -Au skarn deposits. Published fluid inclusion and stable isotope data show that it formed through the flux of magma-derived fluid through contact metamorphosed carbonate rock sequences at temperatures well above 600° C and pressures of less than 50 MPa. Under these conditions, the fluid has very low density and the properties of a gas. Combining a range of micro-analytical techniques, high-resolution QEMSCAN mineral mapping and computer-assisted X-ray micro-tomography, an array of coupled gas-solid reactions may be identified that controlled reactive mass transfer through the 1 km3 hydrothermal skarn system. Vacancy-driven mineral chemisorption reactions are identified as a new type of reactive transport process for high-temperature skarn alteration. These gas-solid reactions are maintained by the interaction of unsatisfied bonds on mineral surfaces and dipolar gas-phase reactants such as SO2 and HCl that are continuously supplied through open fractures and intergranular diffusion. Principal reactions are (a) incongruent dissolution of almandine-grossular to andradite and anorthite (an alteration mineral not previously recognized at Ertsberg), and (b) sulfation of anorthite to anhydrite. These sulfation reactions also generate reduced sulfur with consequent co-deposition of metal sulfides. Diopside undergoes similar reactions with deposition of Fe-enriched pyroxene in crypto-veins and vein selvedges. The loss of calcium from contact metamorphic garnet to form vein anhydrite necessarily results in Fe-enrichment of wallrock, and does not require Fe-addition from a vein fluid as is commonly assumed.

Evaluation of laboratory powder X-ray micro-diffraction for applications in the fields of cultural heritage and forensic science.

PubMed

Svarcová, Silvie; Kocí, Eva; Bezdicka, Petr; Hradil, David; Hradilová, Janka

2010-09-01

The uniqueness and limited amounts of forensic samples and samples from objects of cultural heritage together with the complexity of their composition requires the application of a wide range of micro-analytical methods, which are non-destructive to the samples, because these must be preserved for potential late revision. Laboratory powder X-ray micro-diffraction (micro-XRD) is a very effective non-destructive technique for direct phase analysis of samples smaller than 1 mm containing crystal constituents. It compliments optical and electron microscopy with elemental micro-analysis, especially in cases of complicated mixtures containing phases with similar chemical composition. However, modification of X-ray diffraction to the micro-scale together with its application for very heterogeneous real samples leads to deviations from the standard procedure. Knowledge of both the limits and the phenomena which can arise during the analysis is crucial for the meaningful and proper application of the method. We evaluated basic limits of micro-XRD equipped with a mono-capillary with an exit diameter of 0.1 mm, for example the size of irradiated area, appropriate grain size, and detection limits allowing identification of given phases. We tested the reliability and accuracy of quantitative phase analysis based on micro-XRD data in comparison with conventional XRD (reflection and transmission), carrying out experiments with two-phase model mixtures simulating historic colour layers. Furthermore, we demonstrate the wide use of micro-XRD for investigation of various types of micro-samples (contact traces, powder traps, colour layers) and we show how to enhance data quality by proper choice of experiment geometry and conditions.

Compartmentation of metals in foliage of Populus tremula grown on soils with mixed contamination. II. Zinc binding inside leaf cell organelles.

PubMed

Vollenweider, Pierre; Bernasconi, Petra; Gautschi, Hans-Peter; Menard, Terry; Frey, Beat; Günthardt-Goerg, Madeleine S

2011-01-01

The phytoextraction potential of plants for removing heavy metals from polluted soils is determined by their capacity to store contaminants in aboveground organs and complex them safely. In this study, the metal compartmentation, elemental composition of zinc deposits and zinc complexation within leaves from poplars grown on soil with mixed metal contamination was analysed combining several histochemical and microanalytical approaches. Zinc was the only heavy metal detected and was stored in several organelles in the form of globoid deposits showing β-metachromasy. It was associated to oxygen anions and different cations, noteworthy phosphorous. The deposit structure, elemental composition and element ratios indicated that zinc was chelated by phytic acid ligands. Maturation processes in vacuolar vs. cytoplasmic deposits were suggested by differences in size and amounts of complexed zinc. Hence, zinc complexation by phytate contributed to metal detoxification and accumulation in foliage but could not prevent toxicity reactions therein. Copyright © 2010 Elsevier Ltd. All rights reserved.

Compound Nucleus Reactions in LENR, Analogy to Uranium Fission

NASA Astrophysics Data System (ADS)

Hora, Heinrich; Miley, George; Philberth, Karl

2008-03-01

The discovery of nuclear fission by Hahn and Strassmann was based on a very rare microanalytical result that could not initially indicate the very complicated details of this most important process. A similarity is discussed for the low energy nuclear reactions (LENRs) with analogies to the yield structure found in measurements of uranium fission. The LENR product distribution measured earlier in a reproducible way in experiments with thin film electrodes and a high density deuteron concentration in palladium has several striking similarities with the uranium fission fragment yield curve.ootnotetextG.H. Miley and J.A. Patterson, J. New Energy 1, 11 (1996); G.H. Miley et al, Proc ICCF6, p. 629 (1997).This comparison is specifically focussed to the Maruhn-Greiner local maximum of the distribution within the large-scale minimum when the fission nuclei are excited. Implications for uranium fission are discussed in comparison with LENR relative to the identification of fission a hypothetical compound nuclear reaction via a element ^306X126 with double magic numbers.

Development and characterization of a voltammetric carbon-fiber microelectrode pH sensor.

PubMed

Makos, Monique A; Omiatek, Donna M; Ewing, Andrew G; Heien, Michael L

2010-06-15

This work describes the development and characterization of a modified carbon-fiber microelectrode sensor capable of measuring real-time physiological pH changes in biological microenvironments. The reagentless sensor was fabricated under ambient conditions from voltammetric reduction of the diazonium salt Fast Blue RR onto a carbon-fiber surface in aprotic media. Fast-scan cyclic voltammetry was used to probe redox activity of the p-quinone moiety of the surface-bound molecule as a function of pH. In vitro calibration of the sensor in solutions ranging from pH 6.5 to 8.0 resulted in a pH-dependent anodic peak potential response. Flow-injection analysis was used to characterize the modified microelectrode, revealing sensitivity to acidic and basic changes discernible to 0.005 pH units. Furthermore, the modified electrode was used to measure dynamic in vivo pH changes evoked during neurotransmitter release in the central nervous system of the microanalytical model organism Drosophila melanogaster.

Characterization of uranium tetrafluoride (UF 4) with Raman spectroscopy

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

Villa-Aleman, Eliel; Wellons, Matthew S.

The Raman spectrum of uranium tetrafluoride (UF 4) is unambiguously characterized with multiple Raman excitation laser sources for the first time. Across different laser excitation wavelengths, UF 4 demonstrates 16 distinct Raman bands within the 50-400 cm -1 region. The observed Raman bands are representative of various F-F vibrational modes. UF 4 also shows intense fluorescent bands in the 325 – 750 nm spectral region. Comparison of the UF 4 spectrum with the ZrF 4 spectrum, its crystalline analog, demonstrates a similar Raman band structure consistent with group theory predictions for expected Raman bands. Additionally, a demonstration of combined scanningmore » electron microscopy (SEM) and in situ Raman spectroscopy microanalytical measurements of UF 4 particulates shows that despite the inherent weak intensity of Raman bands, identification and characterization are possible for micron-sized particulates with modern instrumentation. The published well characterized UF 4 spectrum is extremely relevant to nuclear materials and nuclear safeguard applications.« less

Characterization of uranium tetrafluoride (UF 4) with Raman spectroscopy

DOE PAGES

Villa-Aleman, Eliel; Wellons, Matthew S.

2016-03-22

The Raman spectrum of uranium tetrafluoride (UF 4) is unambiguously characterized with multiple Raman excitation laser sources for the first time. Across different laser excitation wavelengths, UF 4 demonstrates 16 distinct Raman bands within the 50-400 cm -1 region. The observed Raman bands are representative of various F-F vibrational modes. UF 4 also shows intense fluorescent bands in the 325 – 750 nm spectral region. Comparison of the UF 4 spectrum with the ZrF 4 spectrum, its crystalline analog, demonstrates a similar Raman band structure consistent with group theory predictions for expected Raman bands. Additionally, a demonstration of combined scanningmore » electron microscopy (SEM) and in situ Raman spectroscopy microanalytical measurements of UF 4 particulates shows that despite the inherent weak intensity of Raman bands, identification and characterization are possible for micron-sized particulates with modern instrumentation. The published well characterized UF 4 spectrum is extremely relevant to nuclear materials and nuclear safeguard applications.« less

Sample displacement chromatography as a method for purification of proteins and peptides from complex mixtures

PubMed Central

Gajdosik, Martina Srajer; Clifton, James; Josic, Djuro

2012-01-01

Sample displacement chromatography (SDC) in reversed-phase and ion-exchange modes was introduced approximately twenty years ago. This method takes advantage of relative binding affinities of components in a sample mixture. During loading, there is a competition among different sample components for the sorption on the surface of the stationary phase. SDC was first used for the preparative purification of proteins. Later, it was demonstrated that this kind of chromatography can also be performed in ion-exchange, affinity and hydrophobic-interaction mode. It has also been shown that SDC can be performed on monoliths and membrane-based supports in both analytical and preparative scale. Recently, SDC in ion-exchange and hydrophobic interaction mode was also employed successfully for the removal of trace proteins from monoclonal antibody preparations and for the enrichment of low abundance proteins from human plasma. In this review, the principals of SDC are introduced, and the potential for separation of proteins and peptides in micro-analytical, analytical and preparative scale is discussed. PMID:22520159

Wear of liquid nitrogen-cooled 440C bearing steels in an oxygen environment

NASA Technical Reports Server (NTRS)

Chaudhuri, Dilip K.; Verma, Ravi

1988-01-01

This paper presents up-to-date findings of the research being conducted to understand the mechanism of sliding wear in unlubricated 440C bearing steels under oxidative conditions. A sliding wear test rig has been designed and built with a cylinder-on-flat geometry. The equipment is capable of testing specimens under high axial loads and sliding speeds in a simulated LOX environment. Samples of 440C steel, quenched and tempered to a hardness of Rc 56, were tested under a load of 890 N and a sliding speed of 2.05 m/sec for total sliding distances of up to 5.54 km. Flash temperatures during these tests were measured with an IR camera and a fast digital recorder. Microstructural and microanalytical data from the worn surfaces and the debris particles are analyzed extensively, along with wear rates, flash temperatures, surface profiles, hardnesses, and residual stresses, in the context of oxidation and wear theories.

The development of maternal touch across the first year of life.

PubMed

Ferber, Sari Goldstein; Feldman, Ruth; Makhoul, Imad R

2008-06-01

The developmental trajectories of specific forms of maternal touch during natural caregiving were examined across the first year in relation to the development of mother-infant reciprocal communication. One hundred and thirty-one mothers and infants in four groups aged 3, 6, 9, and 12 months were observed in a cross-sectional design at home during natural caregiving and mother-child play sessions. Microanalytic coding of the caregiving sessions considered nine forms of maternal touch, which were aggregated into three global touch categories: affectionate, stimulating, and instrumental. Play sessions were coded for maternal sensitivity and dyadic reciprocity. Maternal affectionate and stimulating touch decreased significantly during the second 6 months of life. In parallel, dyadic reciprocity increased in the second half year. Dyadic reciprocity was predicted by the frequency of affectionate touch but not by any other form of touch. Results contribute to specifying the role of touch as it evolves across the first year of life within the global mother-infant communication system.

[Microanalytical identification of barium sulphate crystals in statoliths of Chara rhizoids (Ch. fragilis, desv.)].

PubMed

Schröter, K; Läuchli, A; Sievers, A

1975-01-01

In contrast to the statocytes of higher plants, in which amyloplasts function as statoliths, Chara-rhizoids contain statolith vacuoles filled with biocrystallites of BaSO4. This was revealed by qualitative and quantitative electron microprobe analysis, atomic absorption spectrophotometry and selected area electron diffraction. The barium sulphate crystallites are rods which are linearly composed of globular subunits approximately 7 nm in diameter.The electron optical evidence of the crystallites depends on the nature of the fixatives. Best structural preservation was observed after fixation in a buffered solution of glutaraldehyde plus acrolein without addition of heavy metals. OsO4 and particularly KMnO4 partially dissolve the biocrystallites as well as synthetic BaSO4. The crystal solubility must be taken into consideration when micrographs of such small crystallites are interpreted.The fact that BaSO4 is chemically very inert seems to exclude biochemical interactions of the statoliths with other cell components during graviperception. It favours the theory that only the mass of the statoliths is effective.

Maternal Responsiveness and Sensitivity Re-Considered: Some Is More

PubMed Central

Bornstein, Marc H.; Manian, Nanmathi

2013-01-01

Is it always or necessarily the case that common and important parenting practices are better insofar as they occur more often, or worse because they occur less often? Perhaps, less is more, or some is more. To address this question, we studied mothers’ microcoded contingent responsiveness to their infants (M = 5.4 months, SD = 0.2) in relation to independent global judgments of the same mothers’ parenting sensitivity. In a community sample of 335 European American dyads, videorecorded infant and maternal behaviors were timed microanalytically throughout an extended home observation; separately and independently, global maternal sensitivity was rated macroanalytically. Sequential analysis and spline regression showed that, as maternal contingent responsiveness increased, judged maternal sensitivity increased to significance on the contingency continuum, after which mothers who were even more contingent were judged less sensitive. Just significant levels of maternal responsiveness are deemed optimally sensitive. Implications of these findings for typical and atypical parenting, child development, and intervention science are discussed. PMID:24229542

Combined oxygen-isotope and U-Pb zoning studies of titanite: New criteria for age preservation

DOE PAGES

Bonamici, Chloe E.; Fanning, C. Mark; Kozdon, Reinhard; ...

2015-02-11

Here, titanite is an important U-Pb chronometer for dating geologic events, but its high-temperature applicability depends upon its retention of radiogenic lead (Pb). Experimental data predict similar rates of diffusion for lead (Pb) and oxygen (O) in titanite at granulite-facies metamorphic conditions (T = 650-800°C). This study therefore investigates the utility of O-isotope zoning as an indicator for U-Pb zoning in natural titanite samples from the Carthage-Colton Mylonite Zone of the Adirondack Mountains, New York. Based on previous field, textural, and microanalytical work, there are four generations (types) of titanite in the study area, at least two of which preservemore » diffusion-related δ 18O zoning. U-Th-Pb was analyzed by SIMS along traverses across three grains of type-2 titanite, which show well-developed diffusional δ 18O zoning, and one representative grain from each of the other titanite generations.« less

Spectroscopic, structural characterizations and antioxidant capacity of the chromium (III) niacinamide compound as a diabetes mellitus drug model

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; El-Megharbel, Samy M.; Hussien, M. A.; Hamza, Reham Z.; Al-Omar, Mohamed A.; Naglah, Ahmed M.; Afifi, Walid M.; Kobeasy, Mohamed I.

2017-02-01

New binuclear chromium (III) niacinamide compound with chemical formula [Cr2(Nic)(Cl)6(H2O)4]·H2O was obtained upon the reaction of chromium (III) chloride with niacinamide (Nic) in methanol solvent at 60 °C. The proposed structure was discussed with the help of microanalytical analyses, conductivity, spectroscopic (FT-IR and UV-vis.), magnetic calculations, thermogravimetric analyses (TG/TGA), and morphological studies (X-ray of solid powder and scan electron microscopy. The infrared spectrum of free niacinamide in comparison with its chromium (III) compound indicated that the chelation mode occurs via both nitrogen atoms of pyridine ring and primary -NH2 group. The efficiency of chromium (III) niacinamide compound in decreasing of glucose level of blood and HbA1c in case of diabetic rats was checked. The ameliorating gluconeogenic enzymes, lipid profile and antioxidant defense capacities are considered as an indicator of the efficiency of new chromium (III) compound as antidiabetic drug model.

Development and Characterization of a Voltammetric Carbon-fiber Microelectrode pH Sensor

PubMed Central

Makos, Monique A.; Omiatek, Donna M.; Ewing, Andrew G.; Heien, Michael L.

2010-01-01

This work describes the development and characterization of a modified carbon-fiber microelectrode sensor capable of measuring real-time physiological pH changes in biological microenvironments. The reagentless sensor was fabricated under ambient conditions from voltammetric reduction of the diazonium salt Fast Blue RR onto a carbon-fiber surface in aprotic media. Fast-scan cyclic voltammetry was used to probe redox activity of the p-quinone moiety of the surface-bound molecule as a function of pH. In vitro calibration of the sensor in solutions ranging from pH 6.5 to 8.0 resulted in a pH-dependent anodic peak potential response. Flow-injection analysis was used to characterize the modified microelectrode, revealing sensitivity to acidic and basic changes discernable to 0.005 pH units. Furthermore, the modified electrode was used to measure dynamic in vivo pH changes evoked during neurotransmitter release in the central nervous system of the microanalytical model organism Drosophila melanogaster. PMID:20380393

The Next Big Thing is Actually Small

PubMed Central

Garcia, Carlos D.

2013-01-01

Summary Recent developments in materials, surface modifications, separation schemes, detection systems, and associated instrumentation have allowed significant advances in the performance of lab-on-a-chip devices. These devices, also referred to as micro total analysis systems (µTAS), offer great versatility, high throughput, short analysis time, low cost, and more importantly, performance that is comparable to standard bench-top instrumentation. To date, µTAS have demonstrated advantages in a significant number of fields including biochemical, pharmaceutical, military, and environmental. Perhaps most importantly, µTAS represent excellent platforms to introduce students to microfabrication and nanotechnology, bridging chemistry with other fields such as engineering and biology, enabling the integration of various skills and curricular concepts. Considering the advantages of the technology and the potential impact to society, our research program aims to address the need for simpler, more affordable, faster, and portable devices to measure biologically-active compounds. Specifically, the program is focused on the development and characterization of a series of novel strategies towards the realization of integrated microanalytical devices. One key aspect of our research projects is that the developed analytical strategies must be compatible with each other, therefore enabling their use in integrated devices. The program combines spectroscopy, surface chemistry, capillary electrophoresis, electrochemical detection, and nanomaterials. This article discusses some of the most recent results obtained in two main areas of emphasis: ▪Capillary Electrophoresis, Microchip-CE, Electrochemical Detection, and▪Interaction of Proteins with Nanomaterials PMID:22877217

Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air.

PubMed

Coelho, Lúcia H G; Melchert, Wanessa R; Rocha, Flavio R; Rocha, Fábio R P; Gutz, Ivano G R

2010-11-15

The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the μg m(-3) range) and their variations with sampling site and time. In this work, a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE), a quick separation technique that requires nothing more than some nanoliters of sample and, when combined with capacitively coupled contactless conductometric detection (C(4)D), is particularly favorable for ionic species that do not absorb in the UV-vis region, like the target analytes formaldehyde, formic acid, acetic acid and ammonium. The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry's constant such as formaldehyde and carboxylic acids, or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8.3 nL s(-1)), while the sample was aspirated through the annular gap of the concentric tubes at 2.5 mL s(-1). A second unit, in all similar to the CMDS, was operated as a capillary membrane diffusion emitter (CMDE), generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS. The fluids of the system were driven with inexpensive aquarium air pumps, and the collected samples were stored in vials cooled by a Peltier element. Complete protocols were developed for the analysis, in air, of NH(3), CH(3)COOH, HCOOH and, with a derivatization setup, CH(2)O, by associating the CMDS collection with the determination by CE-C(4)D. The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot's reaction. Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction, solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW). All techniques and methods of this work are in line with the green analytical chemistry trends. Copyright © 2010 Elsevier B.V. All rights reserved.

Removal of lead from aqueous solution using superparamagnetic palygorskite nanocomposite: Material characterization and regeneration studies.

PubMed

Rusmin, Ruhaida; Sarkar, Binoy; Tsuzuki, Takuya; Kawashima, Nobuyuki; Naidu, Ravi

2017-11-01

A palygorskite-iron oxide nanocomposite (Pal-IO) was synthesized in situ by embedding magnetite into the palygorskite structure through co-precipitation method. The physico-chemical characteristics of Pal-IO and their pristine components were examined through various spectroscopic and micro-analytical techniques. Batch adsorption experiments were conducted to evaluate the performance of Pal-IO in removing Pb(II) from aqueous solution. The surface morphology, magnetic recyclability and adsorption efficiency of regenerated Pal-IO using desorbing agents HCl (Pal-IO-HCl) and ethylenediaminetetraacetic acid disodium salt (EDTA-Na 2 ) (Pal-IO-EDTA) were compared. The nanocomposite showed a superparamagnetic property (magnetic susceptibility: 20.2 emu g -1 ) with higher specific surface area (99.8 m 2  g -1 ) than the pristine palygorskite (49.4 m 2  g -1 ) and iron oxide (72.6 m 2  g -1 ). Pal-IO showed a maximum Pb(II) adsorption capacity of 26.6 mg g -1 (experimental condition: 5 g L -1 adsorbent loading, 150 agitations min -1 , initial Pb(II) concentration from 20 to 500 mg L -1 , at 25 °C) with easy separation of the spent adsorbent. The adsorption data best fitted to the Langmuir isotherm model (R 2  = 0.9995) and pseudo-second order kinetic model (R 2  = 0.9945). Pb(II) desorption using EDTA as the complexing agent produced no disaggregation of Pal-IO crystal bundles, and was able to preserve the composite's magnetic recyclability. Pal-IO-EDTA exhibited almost 64% removal capacity after three cycles of regeneration and preserved the nanocomposite's structural integrity and magnetic properties (15.6 emu g -1 ). The nanocomposite holds advantages as a sustainable material (easily separable and recyclable) for potential application in purifying heavy metal contaminated wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-resolution (SIMS) versus bulk sulfur isotope patterns of pyrite in Proterozoic microbialites with diverse mat textures

NASA Astrophysics Data System (ADS)

Gomes, M. L.; Fike, D. A.; Bergmann, K.; Knoll, A. H.

2015-12-01

Sulfur (S) isotope signatures of sedimentary pyrite preserved in marine rocks provide a rich suite of information about changes in biogeochemical cycling associated with the evolution of microbial metabolisms and oxygenation of Earth surface environments. Conventionally, these S isotope records are based on bulk rock measurements. Yet, in modern microbial mat environments, S isotope compositions of sulfide can vary by up to 40‰ over a spatial range of ~ 1 mm. Similar ranges of S isotope variability have been found in Archean pyrite grains using both Secondary Ion Mass Spectrometry and other micro-analytical techniques. These micron-scale patterns have been linked to changes in rates of microbial sulfate reduction and/or sulfide oxidation, isotopic distillation of the sulfate reservoir due to microbial sulfate reduction, and post-depositional alteration. Fine-scale mapping of S isotope compositions of pyrite can thus be used to differentiate primary environmental signals from post-depositional overprinting - improving our understanding of both. Here, we examine micron-scale S isotope patterns of pyrite in microbialites from the Mesoproterozoic-Neoproterozoic Sukhaya Tunguska Formation and Neoproterozoic Draken Formation in order to explore S isotope variability associated with different mat textures and pyrite grain morphologies. A primary goal is to link modern observations of how sulfide spatial isotope distributions reflect active microbial communities present at given depths in the mats to ancient processes driving fine-sale pyrite variability in microbialites. We find large (up to 60‰) S isotope variability within a spatial range of less than 2.5cm. The micron-scale S isotope measurements converge around the S isotope composition of pyrite extracted from bulk samples of the same microbialites. These micron-scale pyrite S isotope patterns have the potential to reveal important information about ancient biogeochemical cycling in Proterozoic mat environments with implications for interpreting S isotope signatures from the geological record.

Tapered-Tip Capillary Electrophoresis Nano-Electrospray Ionization Mass Spectrometry for Ultrasensitive Proteomics: the Mouse Cortex

NASA Astrophysics Data System (ADS)

Choi, Sam B.; Zamarbide, Marta; Manzini, M. Chiara; Nemes, Peter

2017-04-01

Ultrasensitive characterization of the proteome raises the potential to understand how differential gene expression orchestrates cell heterogeneity in the brain. Here, we report a microanalytical capillary electrophoresis nano-flow electrospray ionization (CE-nanoESI) interface for mass spectrometry to enable the measurement of limited amounts of proteins in the mouse cortex. Our design integrates a custom-built CE system to a tapered-tip metal emitter in a co-axial sheath-flow configuration. This interface can be constructed in <15 min using readily available components, facilitating broad adaptation. Tapered-tip CE-nanoESI generates stable electrospray by reproducibly anchoring the Taylor cone, minimizes sample dilution in the ion source, and ensures efficient ion generation by sustaining the cone-jet spraying regime. Parallel reaction monitoring provided a 260-zmol lower limit of detection for angiotensin II (156,000 copies). CE was able to resolve a complex mixture of peptides in 330,000 theoretical plates and identify 15 amol ( 1 pg) of BSA or cytochrome c. Over 30 min of separation, 1 ng protein digest from the mouse cortex yielded 217 nonredundant proteins encompassing a 3-log-order concentration range using a quadrupole time-of-flight mass spectrometer. Identified proteins included many products from genes that are traditionally used to mark oligodendrocytes, astrocytes, and microglia. Finally, key proteins involved in neurodegenerative disorders were detected (e.g., parkinsonism and spastic paraplegia). CE-nanoESI-HRMS delivers sufficient sensitivity to detect proteins in limited amounts of tissues and cell populations to help understand how gene expression differences maintain cell heterogeneity in the brain.

Studies of Scale Formation and Kinetics of Crofer 22 APU and Haynes 230 in Carbon Oxide-Containing Environment for SOFC Applications

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

Ziomek-Moroz, M.; Covino, B.S., Jr.; Holcomb, G.R.

2006-01-01

Significant progress in reducing the operating temperature of SOFCs below 800oC may allow the use of chromia-forming metallic interconnects at a substantial cost savings. Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Carbon oxides present in the hydrogen fuel can cause significant performance problems due to carbon formation (coking). Also, literature data indicate that in CO/CO2 gaseous environments, metallic materials that gain their corrosion resistance due to formation of Cr2O3,more » could form stable chromium carbides. The chromium carbide formation causes depletion of chromium in these alloys. If the carbides oxidize, they form non-protective scales. Considering a potential detrimental effect of carbon oxides on iron- and nickel-base alloy stability, determining corrosion performance of metallic interconnect candidates in carbon oxide-containing environments at SOFC operating temperatures is a must. In this research, the corrosion behavior of Crofer 22 APU and Haynes 230 was studied in a CO-rich atmosphere at 750°C. Chemical composition of the gaseous environment at the outlet was determined using gas chromatography (GC). After 800 h of exposure to the gaseous environment the surfaces of the corroded samples were studied by scanning electron microscopy (SEM) equipped with microanalytical capabilities. X-ray diffraction (XRD) analysis was also used in this study.« less

Achieving an empathic stance: dialogical sequence analysis of a change episode.

PubMed

Tikkanen, Soile; Stiles, William B; Leiman, Mikael

2013-01-01

Abstract This study examined a client's therapeutic progress within one session of an 18-session child neurological assessment. The analysis focused on a parent-psychologist dialogue in one session of the assessment process. Dialogical sequence analysis (DSA; Leiman, 2004, 2012) was used as a micro-analytic method to examine the developing discourse. The analysis traced the mother's developing of a reflective stance toward herself and her problematic ways of interacting with her daughter, who was the client. During the dialogue, the mother began to recognize her own contribution in maintaining the problematic pattern. Her gradual acknowledgment of the child's perspective and her growing sense of the child's otherness were mediated by an observer position (third-person view) toward the problematic pattern, which allowed a flexible exchange between the perspectives of self and the other. The results demonstrate the parallel development of intrapersonal and interpersonal empathy shown previously to characterize the transition from stage 3 (problem statement/clarification) to stage 4 (understanding/insight) in the assimilation of problematic experiences sequence (Brinegar, Salvi, Stiles, & Greenberg, 2006).

Fundamentals of Passive Oxidation In SiC and Si3N4

NASA Technical Reports Server (NTRS)

Thomas-Ogbuji, Linus U.

1998-01-01

The very slow oxidation kinetics of silicon carbide and silicon nitride, which derive from their adherent and passivating oxide films, has been explored at length in a broad series of studies utilizing thermogravimetric analysis, electron and optical micrography, energy dispersive spectrometry, x-ray diffractometry, micro-analytical depth profiling, etc. Some interesting microstructural phenomena accompanying the process of oxidation in the two materials will be presented. In Si3N4 the oxide is stratified, with an SiO2 topscale (which is relatively impervious to O2)underlain by a coherent subscale of silicon oxynitride which is even less permeable to O2- Such "defence in depth" endows Si3N4 with what is perhaps the highest oxidation resistance of any material, and results in a unique set of oxidation processes. In SiC the oxidation reactions are much simpler, yet new issues still emerge; for instance, studies involving controlled devitrification of the amorphous silica scale confirmed that the oxidation rate of SiC drops by more than an order of magnitude when the oxide scale fully crystallizes.

Hg localisation in Tillandsia usneoides L. (Bromeliaceae), an atmospheric biomonitor

NASA Astrophysics Data System (ADS)

Amado Filho, G. M.; Andrade, L. R.; Farina, M.; Malm, O.

The Spanish moss, Tillandsia usneoides, has been applied as an atmospheric biomonitor of Hg contamination, although the mechanism of metal plant accumulation has not been understood until now. In the present work, analytical scanning electron microscopy (SEM) was used to localize Hg in T. usneoides exposed to a Hg-air-contaminated area during 15 days. After this period, Hg was determined by the flow injection mercury system, and plants were prepared for SEM observation and energy-dispersive X-ray analysis. A concentration of 2702±318 μg Hg g -1 was determined in exposed plants. The presented microanalytical results demonstrated that Hg was partly associated with atmospheric particles deposited upon the plant surface, but it was highly absorbed by the scales, stem and leaves surfaces and less absorbed by epidermal cells of T. usneoides. No Hg was detected in mesophyll parenchyma or in vascular system cells. The great surface adsorption area provided by the scales, in addition to the characteristics of T. usneoides morphology, especially of the node region, are suggested to confer the great capability of T. usneoides in Hg holding.

A microanalytical method for ammonium and short-chain primary aliphatic amines using precolumn derivatization and capillary liquid chromatography.

PubMed

Moliner-Martínez, Y; Herráez-Hernández, R; Campíns-Falcó, P

2007-09-14

A new microscale method is presented for the determination of ammonium and primary short-chain aliphatic amines (methylamine, ethylamine, propylamine, n-butylamine and n-pentylamine) in water. The assay uses precolumn derivatization with the reagent o-phthaldialdehyde (OPA) in combination with the thiol N-acetyl-L-cysteine (NAC), and capillary liquid chromatography with UV detection at 330 nm. The described method is very simple and rapid as no preconcentration of the analytes is necessary, and the volume of sample required is only 0.1 mL. Under the proposed conditions good linearity has been obtained up to a concentration of the analytes of 10.0 mgL(-1), the limits of detection being of 8-50 microgL(-1). No matrix effect was found, and recoveries between 97 and 110% were obtained. The precision of the method was good, and the achieved variation coefficients were below 12%. The reliability of the proposed approach has been tested by analyzing a microsample of fogwater collected from leaf surfaces.

Engineering of PDMS Surfaces for use in Microsystems for Capture and Isolation of Complex and Biomedically Important Proteins: Epidermal Growth Factor Receptor as a Model System

PubMed Central

Lowe, Aaron M.; Ozer, Byram H.; Wiepz, Gregory J.; Bertics, Paul J.; Abbott, Nicholas L.

2009-01-01

Elastomers based on poly(dimethylsiloxane) (PDMS) are promising materials for fabrication of a wide range of microanalytical systems due to their mechanical and optical properties and ease of processing. To date, however, quantitative studies that demonstrate reliable and reproducible methods for attachment of binding groups that capture complex receptor proteins of relevance to biomedical applications of PDMS microsystems have not been reported. Herein we describe methods that lead to the reproducible capture of a transmembrane protein, the human epidermal growth factor (EGF) receptor, onto PDMS surfaces presenting covalently immobilized antibodies for EGF receptor, and subsequent isolation of the captured receptor by mechanical transfer of the receptor onto a chemically functionalized surface of a gold film for detection. This result is particularly significant because the physical properties of transmembrane proteins make this class of proteins a difficult one to analyze. We benchmark the performance of antibodies to the human EGF receptor covalently immobilized on PDMS against the performance of the same antibodies physisorbed to conventional surfaces utilized in ELISA assays through the use of EGF receptor that was 32P-radiolabeled in its autophosphorylation domain. These results reveal that two pan-reactive antibodies for the EGF receptor (H11 and 111.6) and one phosphospecific EGF receptor antibody (pY1068) capture the receptor on both PDMS and ELISA plates. When using H11 antibody to capture EGF receptor and subsequent treatment with a stripping buffer (NaOH and sodium dodecylsulfate) to isolate the receptor, the signal-to-background obtained using the PDMS surface was 82:1, exceeding the signal-to-background measured on the ELISA plate (<48:1). We also characterized the isolation of captured EGF receptor by mechanical contact of the PDMS surface with a chemically functionalized gold film. The efficiency of mechanical transfer of the transmembrane protein from the PDMS surface was found to be 75–81%. However, the transfer of non-specifically bound protein was substantially less than 75%, thus leading to the important finding that mechanical transfer of the EGF receptor leads to an approximately four-fold increase in signal-to-background from 20:1 to 88:1. The signal-to-background obtained following mechanical transfer is also better than that obtained using ELISA plates and stripping buffer (<48:1). The EGF receptor is a clinically important protein and the target of numerous anticancer agents and thus these results, when combined, provide guidance for the design of PDMS-based microanalytical systems for the capture and isolation of complex and clinically important transmembrane proteins. PMID:18651079

Engineering of PDMS surfaces for use in microsystems for capture and isolation of complex and biomedically important proteins: epidermal growth factor receptor as a model system.

PubMed

Lowe, Aaron M; Ozer, Byram H; Wiepz, Gregory J; Bertics, Paul J; Abbott, Nicholas L

2008-08-01

Elastomers based on poly(dimethylsiloxane) (PDMS) are promising materials for fabrication of a wide range of microanalytical systems due to their mechanical and optical properties and ease of processing. To date, however, quantitative studies that demonstrate reliable and reproducible methods for attachment of binding groups that capture complex receptor proteins of relevance to biomedical applications of PDMS microsystems have not been reported. Herein we describe methods that lead to the reproducible capture of a transmembrane protein, the human epidermal growth factor (EGF) receptor, onto PDMS surfaces presenting covalently immobilized antibodies for EGF receptor, and subsequent isolation of the captured receptor by mechanical transfer of the receptor onto a chemically functionalized surface of a gold film for detection. This result is particularly significant because the physical properties of transmembrane proteins make this class of proteins a difficult one to analyze. We benchmark the performance of antibodies to the human EGF receptor covalently immobilized on PDMS against the performance of the same antibodies physisorbed to conventional surfaces utilized in ELISA assays through the use of EGF receptor that was (32)P-radiolabeled in its autophosphorylation domain. These results reveal that two pan-reactive antibodies for the EGF receptor (clones H11 and 111.6) and one phosphospecific EGF receptor antibody (clone pY1068) capture the receptor on both PDMS and ELISA plates. When using H11 antibody to capture EGF receptor and subsequent treatment with a stripping buffer (NaOH and sodium dodecylsulfate) to isolate the receptor, the signal-to-background obtained using the PDMS surface was 82 : 1, exceeding the signal-to-background measured on the ELISA plate (<48 : 1). We also characterized the isolation of captured EGF receptor by mechanical contact of the PDMS surface with a chemically functionalized gold film. The efficiency of mechanical transfer of the transmembrane protein from the PDMS surface was found to be 75-81%. However, the transfer of non-specifically bound protein was substantially less than 75%, thus leading to the important finding that mechanical transfer of the EGF receptor leads to an approximately four-fold increase in signal-to-background from 20 : 1 to 88 : 1. The signal-to-background obtained following mechanical transfer is also better than that obtained using ELISA plates and stripping buffer (<48 : 1). The EGF receptor is a clinically important protein and the target of numerous anticancer agents and thus these results, when combined, provide guidance for the design of PDMS-based microanalytical systems for the capture and isolation of complex and clinically important transmembrane proteins.

Patterning flows and polymers

NASA Astrophysics Data System (ADS)

Stroock, Abraham Duncan

This thesis presents the use of patterned surfaces for controlling fluid dynamics on a sub-millimeter scale, and for fabricating a new class of polymeric materials. In chapters 1--4, chemical and mechanical structures were used to control the form of flows of fluids in microchannels. This work was done in the context of the development of microfluidic technology for performing chemical tasks in portable, integrated devices. Chapter 1 reviews this work for an audience of chemists who are potential users of these techniques in the development of micro-analytical and micro-synthetic devices. Appendix 1 contains a more general review of microfluidics. Chapter 2 presents experimental results on the use of patterned surface charge density to create new electroosmotic (EO) flows in microchannels; the chapter includes a successful model of the observed flows. In Chapter 3, patterns of topography on the wall of a microchannel were used to generate recirculation in pressure-driven flows. The design and characterization of an efficient mixer based on these flows is presented. A theoretical treatment of these flows is given in Appendix 2. The experimental methods used for the work with both EO and pressure-driven flows are presented in Chapter 4. In Chapter 5, a pattern of asymmetrical grooves in a heated plate was used to perturb Marangoni-Benard (M-B) convection, a dynamic system that spontaneously forms patterned flows. The interaction of the imposed pattern and the inherent pattern of the M-B convection led to a net flow in the plane of convecting layer of fluid. The direction of this flow depended on the orientation of the asymmetrical grooves, the temperature difference across the layer, and the thickness of the layer. A phenomenological model is presented to explain this ratchet effect in which local recirculation was coupled into a global flow. In Chapter 6, surfaces patterned by microcontact printing were used as a workbench on which to build molecularly thin polymer films of well-defined lateral size and shape for subsequent release into solution; the released structures are referred to as two-dimensional (2D) polymers. This type of structure has been a theoretical curiosity and an experimental challenge for several decades. The key element of this method was the use of hydrophobic interactions as a "switchable" adhesive that attached the films to the surface during growth in water and then allowed the completed films to be removed in air. The structure and chemical composition of the films was characterized.

Short-term effect of zoledronic acid upon fracture resistance of the mandibular condyle and femoral head in an animal model.

PubMed

Camacho-Alonso, Fabio; López-Jornet, Pía; Vicente-Hernández, Ascensión

2013-05-01

The aim of this study was to compare the effects in terms of resistance to fracture of the mandibular condyle and femoral head following different doses of zoledronic acid in an animal model. A total of 80 adult male Sprague-Dawley rats were included in a prospective randomized study. The animals were randomly divided into four groups of 20 rats each. Group 1 (control) received sterile saline solution, while groups 2, 3 and 4 received a accumulated dose of 0.2 mg, 0.4 mg and 0.6 mg of zoledronic acid, respectively. The animals were sacrificed 28 days after the last dose, and the right hemimandible and the right femur were removed. The fracture strength was measured (in Newtons) with a universal test machine using a 1 kN load connected to a metal rod with one end angled at 30 degrees. The cross-head speed was 1 mm/min. Later, the specimens were observed under a scanning electron microscope with backscattered electron imaging (SEM-BSE). At last, chemical analysis and elemental mapping of the mineral bone composition were generated using a microanalytical system based on energy-dispersive and X-ray spectrometry (EDX). A total of 160 fracture tests were performed. The fracture resistance increased in mandible and femur with a higher accumulated dose of zoledronic acid. Statistically significant differences were recorded versus the controls with all the studies groups. The chemical analysis in mandible showed a significantly increased of calcium and phosphorous to compare the control with all of the study groups; however, in femur no statistically significant differences between the four study groups were observed. The administration of bisphosphonates increases the fracture resistance in mandible and femur.

A randomised controlled trial of a computerised intervention for children with social communication difficulties to support peer collaboration.

PubMed

Murphy, Suzanne M; Faulkner, Dorothy M; Reynolds, Laura R

2014-11-01

An intervention aiming to support children with social communication difficulties was tested using a randomised controlled design. Children aged 5-6 years old (n=32) were tested and selected for participation on the basis of their scores on the Test of Pragmatic Skills (TPS) and were then randomly assigned to the intervention arm or to the delayed intervention control group. Following previous research which suggested that computer technology may be particularly useful for this group of children, the intervention included a collaborative computer game which the children played with an adult. Subsequently, children's performance as they played the game with a classmate was observed. Micro-analytic observational methods were used to analyse the audio-recorded interaction of the children as they played. Pre- and post-intervention measures comprised the Test of Pragmatic Skills, children's performance on the computer game and verbal communication measures that the children used during the game. This evaluation of the intervention shows promise. At post-test, the children who had received the intervention, by comparison to the control group who had not, showed significant gains in their scores on the Test of Pragmatic Skills (p=.009, effect size r=-.42), a significant improvement in their performance on the computer game (p=.03, r=-.32) and significantly greater use of high-quality questioning during collaboration (p<.001, r=-.60). Furthermore, the children who received the intervention made significantly more positive statements about the game and about their partners (p=.02, r=-.34) suggesting that the intervention increased their confidence and enjoyment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of Austenitic ODS Strengthened Alloys for Very High Temperature Applications

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

Stubbins, James; Heuser, Brent; Robertson, Ian

2015-04-22

This “Blue Sky” project was directed at exploring the opportunities that would be gained by developing Oxide Dispersion Strengthened (ODS) alloys based on the Fe-Cr-Ni austenitic alloy system. A great deal of research effort has been directed toward ferritic and ferritic/martensitic ODS alloys which has resulted in reasonable advances in alloy properties. Similar gains should be possible with austenitic alloy which would also take advantage of other superior properties of that alloy system. The research effort was aimed at the developing an in-depth understanding of the microstructural-level strengthening effects of ODS particles in austentic alloys. This was accomplished on amore » variety of alloy compositions with the main focus on 304SS and 316SS compositions. A further goal was to develop an understanding other the role of ODS particles on crack propagation and creep performance. Since these later two properties require bulk alloy material which was not available, this work was carried out on promising austentic alloy systems which could later be enhanced with ODS strengthening. The research relied on a large variety of micro-analytical techniques, many of which were available through various scientific user facilities. Access to these facilities throughout the course of this work was instrumental in gathering complimentary data from various analysis techniques to form a well-rounded picture of the processes which control austenitic ODS alloy performance. Micromechanical testing of the austenitic ODS alloys confirmed their highly superior mechanical properties at elevated temperature from the enhanced strengthening effects. The study analyzed the microstructural mechanisms that provide this enhanced high temperature performance. The findings confirm that the smallest size ODS particles provide the most potent strengthening component. Larger particles and other thermally- driven precipitate structures were less effective contributors and, in some cases, limited overall properties. With this understanding, the major materials development challenge is to provide a high uniformly distributed population of very fine ODS particles to be able to realize the full promise of dispersion strengthening. This should be a major goal of future work. This program had the further goal to develop graduate student researcher with the experience and capabilities to move this field forward. The support in this program was used for graduate student support and for research expenses; none of the program funds directly supported the faculty in the program. In this sense, the program was successful in supporting several very promising graduate researchers. Four of the graduate students supported here will complete their PhDs in 2015.« less

Gender Differences in Emotion Expression in Low-Income Adolescents Under Stress

PubMed Central

Panjwani, Naaila; Chaplin, Tara M.; Sinha, Rajita; Mayes, Linda C.

2015-01-01

Gender roles in mainstream U.S. culture suggest that girls express more happiness, sadness, anxiety, and shame/embarrassment than boys, while boys express more anger and externalizing emotions, such as contempt. However, gender roles and emotion expression may be different in low-income and ethnically diverse families, as children and parents are often faced with greater environmental stressors and may have different gender expectations. This study examined gender differences in emotion expression in low-income adolescents, an understudied population. One hundred and seventy nine adolescents (aged 14-17) participated in the Trier Social Stress Test (TSST). Trained coders rated adolescents’ expressions of happiness, sadness, anxiety, shame/embarrassment, anger, and contempt during the TSST using a micro-analytic coding system. Analyses showed that, consistent with gender roles, girls expressed higher levels of happiness and shame than boys; however, contrary to traditional gender roles, girls showed higher levels of contempt than boys. Also, in contrast to cultural stereotypes, there were no differences in anger between boys and girls. Findings suggest gender-role inconsistent displays of externalizing emotions in low-income adolescents under acute stress, and may reflect different emotion socialization experiences in this group. PMID:29056804

Gender Differences in Emotion Expression in Low-Income Adolescents Under Stress.

PubMed

Panjwani, Naaila; Chaplin, Tara M; Sinha, Rajita; Mayes, Linda C

2016-06-01

Gender roles in mainstream U.S. culture suggest that girls express more happiness, sadness, anxiety, and shame/embarrassment than boys, while boys express more anger and externalizing emotions, such as contempt. However, gender roles and emotion expression may be different in low-income and ethnically diverse families, as children and parents are often faced with greater environmental stressors and may have different gender expectations. This study examined gender differences in emotion expression in low-income adolescents, an understudied population. One hundred and seventy nine adolescents (aged 14-17) participated in the Trier Social Stress Test (TSST). Trained coders rated adolescents' expressions of happiness, sadness, anxiety, shame/embarrassment, anger, and contempt during the TSST using a micro-analytic coding system. Analyses showed that, consistent with gender roles, girls expressed higher levels of happiness and shame than boys; however, contrary to traditional gender roles, girls showed higher levels of contempt than boys. Also, in contrast to cultural stereotypes, there were no differences in anger between boys and girls. Findings suggest gender-role inconsistent displays of externalizing emotions in low-income adolescents under acute stress, and may reflect different emotion socialization experiences in this group.

Subcellular distribution of a new fluorinated, biocompatible, non-ionic telomeric carrier: a study in cultured B16 melanoma and rat skin fibroblasts.

PubMed

Chehade, F; Maurizis, J C; Pucci, B; Pavia, A A; Ollier, M; Veyre, A; Escaig, F; Jeanguillaume, C; Dennebouy, R; Slodzian, G; Hindié, E

1996-05-01

Tris-hydroxymethyl-amino-methane telomers bearing a fluorinated end have recently been proposed as potential drug carriers. Using ion microscopy, we have investigated the cell uptake and subcellular distribution of a perfluorinated telomere, called F-TAC, in two cell lines, malignant murine B16 melanoma and normal rat skin fibroblasts. Single layer cell cultures on gold plates were incubated with F-TAC at different concentrations. Ion microscopy using mass spectrometry enabled the detection of Fluorine 19 atoms entering into F-TAC constitution. This microanalytical study showed an elective cytoplasmic localization of the molecule, wherein the distribution is relatively homogeneous. Within same culture and incubation conditions, intercellular variations in F-TAC content were very low. In the malignant line, the intracellular concentration remains practically identical when increasing F-TAC concentration in the culture medium above 0.2 mg/ml, indicating that the uptake phenomenon is saturable. In conclusion, the F-TAC telomer easily crosses the plasma membrane, however, it has difficulties in crossing the nuclear membrane. It is likely that intracellular penetration is essentially due to rapid endocytosis of the telomer.

Characterisation of high temperature refractory ceramics for nuclear applications

NASA Astrophysics Data System (ADS)

Bottomley, P. D. W.; Wiss, Th; Janssen, A.; Cremer, B.; Thiele, H.; Manara, D.; Scheindlin, M.; Murray-Farthing, M.; Lajarge, P.; Menna, M.; Bouexière, D.; Rondinella, V. V.

2012-03-01

The ternary oxide ceramic system UO2-ZrO2-FeO is a refractory system that is of great relevance to the nuclear industry as it represents one of the main systems resulting from the interaction of the Zircaloy cladding, the UO2 fuel and the structural elements of a nuclear reactor. It is particularly the high temperature properties that require investigation; that is, when substantial overheating of the nuclear core occurs and interactions can lead to its degradation, melting and result in a severe nuclear accident. There has been much work on the UO2-ZrO2 system and also on the ternary system with FeO but there is still a need to examine 2 further aspects; firstly the effect of sub-oxidized systems, the UO2-Zr and FeO-Zr systems, and secondly the effect of Fe/Zr or Fe/U ratios on the melting point of the U-Zr-Fe oxide system. Samples of UO2-Zr and UO2-ZrO2-FeO were fabricated at ITU and then characterized by optical microscopy (OM) and X-ray diffraction to determine the ceramic's structure and verify the composition. Thereafter the samples are to be melted by laser flash heating and their liquidus and solidus temperatures determined by pyrometry. This programme is currently ongoing. The frozen samples, after testing, were then sectioned, polished and the molten zone micro-analytically examined by OM & SEM-EDS in order to determine its structure and composition and to compare with the existing phase diagrams. Examples of results from these systems will be given. Finally, a reacted Zr-FeO thermite mixture was examined, which had been used to generate high temperatures during tests of reactor melt-concrete interactions. The aim was to assess the reaction and estimate the heat generation from this novel technique. These results allow verification or improvement of the phase diagram and are of primary importance as input to models used to predict materials interactions in a severe nuclear accident.

Petrographic and Geochemical Investigation of Andesitic Arc Volcanism: Mount Kerinci, Sunda Arc, Indonesia

NASA Astrophysics Data System (ADS)

Tully, M.; Saunders, K.; Troll, V. R.; Jolis, E.; Muir, D. D.; Deegan, F. M.; Budd, D. A.; Astbury, R.; Bromiley, G. D.

2014-12-01

Present knowledge of the chain of dominantly andesitic volcanoes, which span the Sumatran portion of the Sunda Arc is extremely limited. Previous studies have focused on Toba and Krakatau, although over 13 further volcanic edifices are known. Several recent explosive eruptions in Sumatra such as that of Mt. Sinabung, 2014, have highlighted the potential hazard that these volcanoes pose to the local and regional communities. Mount Kerinci, is one of the most active of the volcanoes in this region, yet little is known about the petrogenesis of the magma by which it is fed. Kerinci is located approximately mid-way between Toba in the North and Krakatau in the south. Along arc variations are observed in the major, minor and trace elements of whole rock analyses. However, bulk rock approaches produce an average chemical composition for a sample, potentially masking important chemical signatures. In-situ micro-analytical analysis of individual components of samples such as melt inclusions, crystals and groundmass provides chemical signatures of individual components allowing the evolution of volcanic centres to be deciphered in considerably more detail. Examination of whole rock chemistry indicates its location may be key to unravelling the petrogenesis of the arc as significant chemical changes occur between Kerinci and Kaba, 250 km to the south. Kerinci samples are dominantly porphyritic with large crystals of plagioclase, pyroxene and Fe-Ti oxides, rare olivine crystals are observed. Plagioclase and pyroxene crystals are chemically zoned and host melt inclusions. Multiple plagioclase populations are observed. A combination of in-situ micro-analysis techniques will be used to characterise the chemical composition of melt inclusions and crystals. These data can be used along with extant geothermobarometric models to help determine the magma source, storage conditions and composition of the evolving melt. Integration of the findings from this study with existing data for the volcanic chain will enable along-arc variations in magmatic processes in Sumatra to be assessed more thoroughly, providing fundamental insights into the evolution of not only Kerinci, but magma genesis in Sumatra in general. Keywords: Sunda Arc, andesite, arc volcanism, petrogenesis.

Fabrication of functional devices using soft lithography and unconventional micropatterning

NASA Astrophysics Data System (ADS)

Deng, Tao

In this thesis, I present part of our work in the fabrication of functional devices using soft lithography, and also describe unconventional micropatterning techniques involving photographic films. Soft lithography is a set of techniques that are complementary to photolithography, but not limited to planar patterning. It offers the capability of generating micro and nanostructures to a larger community than that familiar with conventional fabrication facilities. The first part of this thesis (chapter 1--4) focuses on the fabrication of microelectronic and micromagnetic devices. These successful demonstrations establish the compatibility of soft lithography with multilayer fabrication of functional devices, and open the door for the further development in these areas. Chapter 1 and 2 describe the use of microtransfer molding (muTM), micromolding in capillaries (MIMIC), and microcontact (muCP) for fabricating Schottky diodes and half-wave rectifier circuits. The fabrication processes involve multiple soft lithography steps and address the registrations between different layer of structures. Room temperature characteristics of these devices resemble those of diodes and rectifiers fabricated by photolithography. Chapter 3 and 4 demonstrate the fabrication of micromagnetic systems. In chapter 3, a one-dimensional bead motor is reported. Based on current-carrying wire systems, the bead motor can trap and transfer magnetic beads suspended in aqueous solutions. Chapter 4 shows a microfiltration system that uses arrays of nickel posts positioned in a polydimethylsiloxane (PDMS) microfluidic channel as the filtering elements. Turning on or off the magnetic field that is localized by these nickel posts can trap or release magnetic beads flowing by. The second part of this thesis (chapter 5--7) focuses on the development of unconventional microfabrication. The major objective underlying this work is to explore the simplest and most broadly available techniques that we could identify for forming patterns with features useful in functional microstructures. Chapter 5 and 6 describe the use of photographic films (microfiche and slide film) and transparencies printed using different printers as photomasks in the fabrication of PDMS stamps/molds for soft lithography. In chapter 6, we also compare different methods of generating microstructures using facilities readily and inexpensively available to chemistry and biology laboratories. Among the films and transparencies investigated, microfiche carries the highest resolution. It can generate structures as small as ˜10 mum in lateral dimensions. Chapter 7 shows a new rapid prototyping process for the fabrication of metallic microstructures using silver halide-based photographic film. The whole process, which involves photographic development and electrochemical deposition, only takes ˜2 hours, starting from a computer design file. It can generate electrically continuous structures with the smallest dimension of ˜30 mum in the plane of the film. The resulting structures---either supported on the film backing, or freed from it---are appropriate for use as passive, structural materials such as wire frames or meshes, and can also be used in microfluidic, microanalytical, and microelectromechanical systems (MEMS).

Deformation behaviour of feldspar in greenschist facies granitoide shear zones from the Austroalpine basement to the south of the western Tauern window, Eastern Alps

NASA Astrophysics Data System (ADS)

Hentschel, Felix; Trepmann, Claudia

2015-04-01

Objective of this study is to elucidate the feldspar deformation behaviour at greenschist facies conditions relevant for the long-term rheological properties of continental crust. Uncertainties in models for the rheological properties are partly due to a poor knowledge of the deformation mechanisms taking place in granitoid rocks at inaccessible depth. The deformation behaviour of feldspar, the most abundant mineral in the continental crust, is characterized by an interaction of brittle, dissolution-precipitation and crystal-plastic processes, which is difficult to evaluate in experiments given the problematic extrapolation of experimental conditions to reasonable natural conditions. However, microfabrics of metamorphic granitoid rocks record the grain-scale deformation mechanisms and involved chemical reactions proceeding during their geological history. This usually includes deformation and modification through several stages in space (depth, i.e., P, T conditions) and/or time. For deciphering the rock's record this implies both, challenge and chance to resolve these different stages. Here, we use the deformation record of mylonitic pegmatites from the Austroalpine basement south to the western Tauern window. The structural, crystallographic and chemical characteristics of the feldspar microfabrics are determined via micro-analytical techniques (polarized light microscopy, scanning electron microscopy, SEM, electron back scatter diffraction, EBSD) to identify the relevant deformation mechanisms and deformation conditions. The pegmatites represent a relatively simple Ca-poor granitoid system, mineralogically dominated by albite-rich plagioclase, K-feldspar and quartz. The matrix of the mylonitic pegmatites is composed of alternating monomineralic albite and quartz ribbons defining the foliation. Fragmented tourmaline and K-feldspar porphyroclasts occur isolated within the matrix. At sites of dilation along the stretching lineation K-feldspar porphyroclasts show serrated boundaries to matrix albite grains. In intragranular zones within K-feldspar porphyroclasts, small albite but also K-feldspar grains and "subgrains" (K-feldspar domains with a small misorientation angle to the host K-feldspar porphyroclast) occur. Strain shadows around porphyroclasts are composed of polymineralic aggregates of albite, K-feldspar and quartz. The albite grains in ribbons show a shape preferred orientation (SPO) with a long axis of about 50-100 µm in the foliation plane and EBSD data reveal an absent to very weak crystallographic orientation (CPO). These microfabrics show indication of a sequence of brittle behaviour, localized dislocation glide-controlled deformation and dissolution-precipitation creep of feldspar. Monomineralic quartz ribbons and shear bands show evidence of dislocation glide by a pronounced CPO, implying dislocation creep. The microfabric is interpreted to have evolved during different stages of episodic deformation at transient high stresses with subsequent viscous flow at decreasing stresses.

Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics.

PubMed

Ali, Nasir; Rampazzo, Rita de Cássia Pontello; Costa, Alexandre Dias Tavares; Krieger, Marco Aurelio

2017-01-01

Nucleic acid extraction (NAE) plays a vital role in molecular biology as the primary step for many downstream applications. Many modifications have been introduced to the original 1869 method. Modern processes are categorized into chemical or mechanical, each with peculiarities that influence their use, especially in point-of-care diagnostics (POC-Dx). POC-Dx is a new approach aiming to replace sophisticated analytical machinery with microanalytical systems, able to be used near the patient, at the point of care or point of need . Although notable efforts have been made, a simple and effective extraction method is still a major challenge for widespread use of POC-Dx. In this review, we dissected the working principle of each of the most common NAE methods, overviewing their advantages and disadvantages, as well their potential for integration in POC-Dx systems. At present, it seems difficult, if not impossible, to establish a procedure which can be universally applied to POC-Dx. We also discuss the effects of the NAE chemicals upon the main plastic polymers used to mass produce POC-Dx systems. We end our review discussing the limitations and challenges that should guide the quest for an efficient extraction method that can be integrated in a POC-Dx system.

Incorporation of Metals into Calcite in a Deep Anoxic Granite Aquifer.

PubMed

Drake, Henrik; Mathurin, Frédéric A; Zack, Thomas; Schäfer, Thorsten; Roberts, Nick Mw; Whitehouse, Martin; Karlsson, Andreas; Broman, Curt; Åström, Mats E

2018-01-16

Understanding metal scavenging by calcite in deep aquifers in granite is of importance for deciphering and modeling hydrochemical fluctuations and water-rock interaction in the upper crust and for retention mechanisms associated with underground repositories for toxic wastes. Metal scavenging into calcite has generally been established in the laboratory or in natural environments that cannot be unreservedly applied to conditions in deep crystalline rocks, an environment of broad interest for nuclear waste repositories. Here, we report a microanalytical study of calcite precipitated over a period of 17 years from anoxic, low-temperature (14 °C), neutral (pH: 7.4-7.7), and brackish (Cl: 1700-7100 mg/L) groundwater flowing in fractures at >400 m depth in granite rock. This enabled assessment of the trace metal uptake by calcite under these deep-seated conditions. Aquatic speciation modeling was carried out to assess influence of metal complexation on the partitioning into calcite. The resulting environment-specific partition coefficients were for several divalent ions in line with values obtained in controlled laboratory experiments, whereas for several other ions they differed substantially. High absolute uptake of rare earth elements and U(IV) suggests that coprecipitation into calcite can be an important sink for these metals and analogousactinides in the vicinity of geological repositories.

Transmission electron microscopy, fluorescence microscopy, and confocal raman microscopic analysis of ultrastructural and compositional heterogeneity of Cornus alba L. wood cell wall.

PubMed

Ma, Jianfeng; Ji, Zhe; Zhou, Xia; Zhang, Zhiheng; Xu, Feng

2013-02-01

Transmission electron microscopy (TEM), fluorescence microscopy, and confocal Raman microscopy can be used to characterize ultrastructural and compositional heterogeneity of plant cell walls. In this study, TEM observations revealed the ultrastructural characterization of Cornus alba L. fiber, vessel, axial parenchyma, ray parenchyma, and pit membrane between cells, notably with the ray parenchyma consisting of two well-defined layers. Fluorescence microscopy evidenced that cell corner middle lamella was more lignified than adjacent compound middle lamella and secondary wall with variation in lignification level from cell to cell. In situ Raman images showed that the inhomogeneity in cell wall components (cellulose and lignin) among different cells and within morphologically distinct cell wall layers. As the significant precursors of lignin biosynthesis, the pattern of coniferyl alcohol and aldehyde (joint abbreviation Lignin-CAA for both structures) distribution in fiber cell wall was also identified by Raman images, with higher concentration occurring in the fiber secondary wall where there was the highest cellulose concentration. Moreover, noteworthy was the observation that higher concentration of lignin and very minor amounts of cellulose were visualized in the pit membrane areas. These complementary microanalytical methods provide more accurate and complete information with regard to ultrastructural and compositional characterization of plant cell walls.

TCP is hardly resorbed and not osteoconductive in a non-loading calvarial model.

PubMed

Handschel, Jörg; Wiesmann, Hans Peter; Stratmann, Udo; Kleinheinz, Johannes; Meyer, Ulrich; Joos, Ulrich

2002-04-01

Tricalciumphosphate (TCP) has been used as a ceramic bone substitute material in the orthopedic field as well as in craniofacial surgery. Some controversies exist concerning the osteoconductive potential of this material in different implantation sites. This study was designed to evaluate the biological response of calvarial bone towards TCP granules under non-loading conditions to assess the potential of TCP as a biodegredable and osteoconductive bone substitue material for the cranial vault. Full-thickness non-critical size defects were made bilaterally in the calvaria of 21 adult Wistar rats. One side was filled by TCP granules, the contralateral side was left empty and used as a control. Animals were sacrified in defined time intervals up to 6 months. Bone regeneration was analyzed with special respect toward the micromorphological and microanalytical features of the material-bone interaction by electron microscopy and electron diffraction analysis. Histologic examination revealed no TCP degradation even after 6 months of implantation. In contrast, a nearly complete bone regeneration of control defects was found after 6 months. At all times TCP was surrounded by a thin fibrous layer without presence of osteoblasts and features of regular mineralization. As far as degradation and substitution are concerned, TCP is a less favourable material tinder conditions of non-loading.

Current Nucleic Acid Extraction Methods and Their Implications to Point-of-Care Diagnostics

PubMed Central

Ali, Nasir; Rampazzo, Rita de Cássia Pontello; Krieger, Marco Aurelio

2017-01-01

Nucleic acid extraction (NAE) plays a vital role in molecular biology as the primary step for many downstream applications. Many modifications have been introduced to the original 1869 method. Modern processes are categorized into chemical or mechanical, each with peculiarities that influence their use, especially in point-of-care diagnostics (POC-Dx). POC-Dx is a new approach aiming to replace sophisticated analytical machinery with microanalytical systems, able to be used near the patient, at the point of care or point of need. Although notable efforts have been made, a simple and effective extraction method is still a major challenge for widespread use of POC-Dx. In this review, we dissected the working principle of each of the most common NAE methods, overviewing their advantages and disadvantages, as well their potential for integration in POC-Dx systems. At present, it seems difficult, if not impossible, to establish a procedure which can be universally applied to POC-Dx. We also discuss the effects of the NAE chemicals upon the main plastic polymers used to mass produce POC-Dx systems. We end our review discussing the limitations and challenges that should guide the quest for an efficient extraction method that can be integrated in a POC-Dx system. PMID:28785592

Short-term effect of zoledronic acid upon fracture resistance of the mandibular condyle and femoral head in an animal model

PubMed Central

López-Jornet, Pía; Vicente-Hernández, Ascensión

2013-01-01

Objective: The aim of this study was to compare the effects in terms of resistance to fracture of the mandibular condyle and femoral head following different doses of zoledronic acid in an animal model. Study design: A total of 80 adult male Sprague-Dawley rats were included in a prospective randomized study. The animals were randomly divided into four groups of 20 rats each. Group 1 (control) received sterile saline solution, while groups 2, 3 and 4 received a accumulated dose of 0.2 mg, 0.4 mg and 0.6 mg of zoledronic acid, respectively. The animals were sacrificed 28 days after the last dose, and the right hemimandible and the right femur were removed. The fracture strength was measured (in Newtons) with a universal test machine using a 1 kN load connected to a metal rod with one end angled at 30 degrees. The cross-head speed was 1 mm/min. Later, the specimens were observed under a scanning electron microscope with backscattered electron imaging (SEM-BSE). At last, chemical analysis and elemental mapping of the mineral bone composition were generated using a microanalytical system based on energy-dispersive and X-ray spectrometry (EDX). Results: A total of 160 fracture tests were performed. The fracture resistance increased in mandible and femur with a higher accumulated dose of zoledronic acid. Statistically significant differences were recorded versus the controls with all the studies groups. The chemical analysis in mandible showed a significantly increased of calcium and phosphorous to compare the control with all of the study groups; however, in femur no statistically significant differences between the four study groups were observed. Conclusions: The administration of bisphosphonates increases the fracture resistance in mandible and femur. Key words:Zoledronic acid, bisphosphonates, animal experimentation, fracture test. PMID:23524420

Sulphate partitioning into calcite: Experimental verification of pH control and application to seasonality in speleothems

NASA Astrophysics Data System (ADS)

Wynn, Peter M.; Fairchild, Ian J.; Borsato, Andrea; Spötl, Christoph; Hartland, Adam; Baker, Andy; Frisia, Silvia; Baldini, James U. L.

2018-04-01

Carbonate-associated sulphate (CAS) is a useful carrier of palaeoenvironmental information throughout the geologic record, particularly through its stable isotope composition. However, a paucity of experimental data restricts quantitative understanding of sulphate incorporation into carbonates, and consequently CAS concentrations and their diagenetic modifications are rarely interpreted. However, in the case of calcite speleothems, the remarkably high-resolution CAS records which are obtainable via modern microanalytical techniques represent a potentially invaluable source of palaeoenvironmental information. Here, we describe the results of controlled experiments of sulphate co-precipitation with calcite in freshwater solutions where pH, saturation state, and sulphate concentration were varied independently of each other. Solution pH is confirmed as the principal control on sulphate incorporation into calcite. The relative efficiency of incorporation was calculated as a partition coefficient DSO4 = (mSO4/mCO3)solid/(mSO4/mCO3)solution. High crystal growth rates (driven by either pH or saturation state) encouraged higher values of DSO4 because of an increasing concentration of defect sites on crystal surfaces. At low growth rates, DSO4 was reduced due to an inferred competition between sulphate and bicarbonate at the calcite surface. These experimental results are applied to understand the incorporation of sulphate into speleothem calcite. The experimentally determined pH-dependence suggests that strong seasonal variations in cave air PCO2 could account for annual cycles in sulphate concentration observed in stalagmites. Our new experimentally determined values of DSO4 were compared with DSO4 values calculated from speleothem-drip water monitoring from two caves within the Austrian and Italian Alps. At Obir cave, Austria, DSO4 (×105) varies between 11.1 (winter) and 9.0 (summer) and the corresponding figures for Ernesto cave, Italy, are 15.4 (winter) and 14.9 (summer). These values approximate predicted DSO4 values based on our chamber experiments containing both low (2 ppm) and high (20 ppm) sulphate concentrations. Our experimental values of DSO4 obtained at crystal growth rates typical of stalagmites, closely match those observed in other cave sites from around the world. This validates the universality of the controls behind DSO4 and will enhance the use of speleothem CAS as a palaeoenvironmental proxy.

Rhythmic patterns in ancient shells: Can we reconstruct sub-annual cyclicity in trace element and stable isotope profiles from rudist bivalves?

NASA Astrophysics Data System (ADS)

de Winter, N.; Sinnesael, M.; Vansteenberge, S.; Goderis, S.; Snoeck, C.; Van Malderen, S. J. M.; Vanhaecke, F. F.; Claeys, P.

2017-12-01

Well-preserved shells of Torreites rudists from the Late Campanian Saiwan Formation in Oman exhibit fine internal layering. These fine (±20 µm) laminae are rhythmically bundled (±400 µm) and subdivide the shells' larger scale annual lamination (±15 mm), suggesting the presence of several interfering cycles in shell growth rate. The aim of the present study is to determine the duration and chemical signature of these rhythmic variations in shell composition. To achieve this, a range of micro-analytical techniques is applied on cross sections through the shells. Firstly, microscopy-based layer counting and colorimetric analysis are carried out on thin sections of shell calcite. Secondly, X-Ray Fluorescence (XRF) and Fourier Transform InfraRed (FTIR) mapping of cross sections of the shells reveal chemical and structural differences between laminae in 2D. Thirdly, high-resolution XRF (25 µm) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS; 10 µm) trace element profiles are used to quantify variations in chemical composition between shell laminae. Fourthly, annual chronology is established based on micro-sampled stable carbon and oxygen stable isotope measurements (250 µm) along the growth axis of the shells. Finally, spectral analysis routines are applied to extract rhythmic patterns matched to the shell laminae from the structural, chemical and colorimetric data. Combining these methods allows for a full evaluation of the structural and chemical characteristics as well as the timing of sub-annual lamination in rudist shells. The results of this study shed light on the external factors that influenced growth rates in rudist bivalves. A better understanding of the timing of deposition of these laminae allows them to be used to improve age models of geochemical records in rudist shells. Characterization of small scale variations in shell composition will characterize the uncertainties contained within lower resolution proxy records from these fossil bivalves. Finally, the study of these laminae enables the reconstruction of sub-annual cyclicity in the environment of Late Cretaceous rudist bivalves. This may in turn shed light on the mechanics of climate in this shallow marine hothouse setting, which provide an analogue of future climate in the light of anthropogenic climate change.

Microanalytical study of discontinuous precipitation and dissolution in Ni-4 at. % Sn: Local and global characterization of the reactions

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

Zieba, P.; Gust, W.

1999-07-09

The morphology and kinetics of the discontinuous precipitation (DP) and discontinuous dissolution (DD) reactions have been studied in a Ni-4 at.% Sn alloy. High spatial resolution energy-dispersive X-ray microanalysis has been used to determine the Sn concentration profiles left behind the moving reaction front for the individual cells of the Sn-depleted [alpha] lamellae and Ni[sub 3]Sn compound. These data, combined with the local values of the reaction front velocity and the thickness of the [alpha]lamellae, have been used to evaluate the local s[delta]D[sub b] values (D[sub b] is the grain-boundary chemical diffusion coefficient, [delta] is the grain-boundary thickness and smore » is the segregation factor). The obtained results have been compared with those calculated by the global approach to the DP and DD reactions, which is relevant for the whole population of the cells. It has been shown that the application of the local characterization of the DP and DD reactions removes essentially the differences between the s[delta]D[sub b] values calculated by the Petermann-Hornbogen equation and the equations of Cahn and Zieba-Pawlowski. Moreover, both sets of data do not show any substantial differences from the s[delta]D[sub b] values obtained from measurements of the tracer diffusion of tin along stationary grain boundaries in nickel.« less

Microanalysis of tool steel and glass with laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Loebe, Klaus; Uhl, Arnold; Lucht, Hartmut

2003-10-01

A laser microscope system for the microanalytical characterization of complex materials is described. The universal measuring principle of laser-induced breakdown spectroscopy (LIBS) in combination with echelle optics permits a fast simultaneous multielement analysis with a possible spatial resolution below 10 pm. The developed system features completely UV-transparent optics for the laser-microscope coupling and the emission beam path and enables parallel signal detection within the wavelength range of 200-800 nm with a spectral resolution of a few picometers. Investigations of glass defects and tool steels were performed. The characterization of a glass defect in a tumbler by a micro-LIBS line scan, with use of a 266-nm diode-pumped Nd:YAG laser for excitation, is possible by simple comparison of plasma spectra of the defect and the surrounding area. Variations in the main elemental composition as well as impurities by trace elements are detected at the same time. Through measurement of the calibration samples with the known concentration of the corresponding element, a correlation between the intensity of spectral lines and the element concentration was also achieved. The change of elemental composition at the transient stellite solder of tool steels has been determined by an area scan. The two-dimensional pictures show abrupt changes of the element distribution along the solder edge and allow fundamental researches of dynamic modifications (e.g., diffusion) in steel.

Microanalytical X-ray imaging of depleted uranium speciation in environmentally aged munitions residues.

PubMed

Crean, Daniel E; Livens, Francis R; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

2014-01-01

Use of depleted uranium (DU) munitions has resulted in contamination of the near-surface environment with penetrator residues. Uncertainty in the long-term environmental fate of particles produced by impact of DU penetrators with hard targets is a specific concern. In this study DU particles produced in this way and exposed to the surface terrestrial environment for longer than 30 years at a U.K. firing range were characterized using synchrotron X-ray chemical imaging. Two sites were sampled: a surface soil and a disposal area for DU-contaminated wood, and the U speciation was different between the two areas. Surface soil particles showed little extent of alteration, with U speciated as oxides U3O7 and U3O8. Uranium oxidation state and crystalline phase mapping revealed these oxides occur as separate particles, reflecting heterogeneous formation conditions. Particles recovered from the disposal area were substantially weathered, and U(VI) phosphate phases such as meta-ankoleite (K(UO2)(PO4) · 3H2O) were dominant. Chemical imaging revealed domains of contrasting U oxidation state linked to the presence of both U3O7 and meta-ankoleite, indicating growth of a particle alteration layer. This study demonstrates that substantial alteration of DU residues can occur, which directly influences the health and environmental hazards posed by this contamination.

Influence of dyadic matching of affect on infant self-regulation.

PubMed

Noe, Daniela; Schluckwerder, Sabine; Reck, Corinna

2015-01-01

Affective behavioural matching during face-to-face interaction fosters the transition from mutual regulation to infant self-regulation. Optimum midrange models of mother-infant interaction hold that moderate degrees of dyadic matching facilitate infant socio-emotional development. The aim of this study was to examine which degree of dyadic matching is most beneficial for infant self-regulation. To evaluate this model, 3 groups of highly, midrange and poorly matched dyads were created from a mixed sample of 68 dyads with healthy and post-partum depressed mothers and their infants (age range = 1-8 months, mean age = 3.9 months). Mother-infant interactions were videotaped in the face-to-face still-face paradigm (FFSF) and micro-analytically coded. Specifically, the relation between affective behavioural matching in FFSF play and infant positive and negative affect in FFSF still face and FFSF reunion was explored. Contrary to our expectation, we found a monotonous trend for all groups: the more matching in FFSF play, the more positive and less negative affect the infant showed in FFSF still face and FFSF reunion, respectively. The present findings further illuminate the association between different degrees of dyadic matching in early mother-infant interaction and infant self-regulation. Further research should focus on the integration and replication of findings and conceptual approaches to further evaluate and refine the concept of midrange matching and make it applicable to therapeutic work with mothers and their infants.

Relation Between Solid-Phase and Dissolved Arsenic in the Ground-Water System Underlying Northern Preble County, Ohio

USGS Publications Warehouse

Thomas, Mary Ann; Diehl, Sharon F.; Pletsch, Bruce A.; Schumann, Thomas L.; Pavey, Richard R.; Swinford, E. Mac

2008-01-01

The U.S. Geological Survey (USGS), in cooperation with the Miami Conservancy District, collected and analyzed samples of the aquifer materials and ground water from multiple depths at two sites in northern Preble County, Ohio. The aquifer materials included glacial deposits and Silurian carbonate bedrock. In the study area, elevated arsenic concentrations have been detected in ground water from both types of aquifers. The aquifer materials were described in terms of the stratigraphy and the bulk elemental composition of 70 samples. In addition, six water-producing horizons were selected for more detailed study; ground-water quality was analyzed, microanalytical techniques were used to examine thin sections of the aquifer materials, and simplified geochemical modeling was done to identify plausible reactions between the ground water and aquifer materials. At both study sites, the highest solid-phase arsenic concentrations were from a roughly similar stratigraphic position - a transition zone that extends from just above the Wisconsinan/Illinoian contact to just below the Pleistocene/Silurian contact. For carbonate bedrock, the solid-phase arsenic concentrations were generally low (<1 to 4 mg/kg (milligrams per kilogram)). The one notable exception was a thin horizon about 10 feet below the top of bedrock, which had an arsenic concentration of 42 mg/kg. This horizon showed some textural and compositional evidence of alteration by geothermal fluids. Additional study might be warranted to investigate whether arsenic concentrations in ground water from carbonate bedrock could be decreased by excluding discrete horizons from the open intervals of wells. For glacial deposits, solid-phase arsenic concentrations were slightly higher in fine-grained deposits (2 to 20 mg/kg) than in coarse-grained deposits (2 to 9 mg/kg). In ground water, arsenic concentrations ranged from <1 to 51 ug/L (micrograms per liter); samples from two horizons had concentrations greater than the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) of 10 ug/L. Dissolved arsenic concentrations appear to be more closely related to redox conditions of the ground water than to the arsenic content of the aquifer materials. Geochemical modeling and thin-section analysis were generally consistent with the idea that arsenic was released to water from iron oxides under iron-reducing conditions. In addition, there was some evidence in support of the idea that arsenic can be removed from ground water by precipitation of sulfide minerals, which occurs under sulfate-reducing conditions. At one site, the dissolved arsenic concentrations in two water-bearing horizons increased from <1 to 51 ug/L over a depth of 15 feet. The large increase might be due to a shift from sulfate-reducing to methanogenic conditions; in the absence of sulfate reduction, arsenic is not sequestered in sulfide minerals and may accumulate in the ground water.

Laser depth profiling of diffusion and alpha ejection profiles in Durango apatite: testing the fundamental parameters of apatite (U-Th)/He dating

NASA Astrophysics Data System (ADS)

van Soest, M. C.; Monteleone, B. D.; Boyce, J. W.; Hodges, K.

2009-12-01

Since its development (e.g. Zeitler et al., 1987, Lippolt et al., 1994, Farley et al., 1996, Wolf et al., 1996) as a viable low temperature thermochronological method (U-Th)/He dating of apatite has become a popular and widely applied low temperature thermochronometer. The method has been applied with success to a great variety of geological problems, and the fundamental parameters of the method: the bulk diffusion parameters of helium in apatite, and the calculated theoretical helium stopping distance in apatite used to correct the ages for the effects of alpha ejection appear sound. However, the development of the UV laser microprobe technique for the (U-Th)/He method (Boyce et al., 2006) allows for in-situ testing of the helium bulk diffusion parameters (Farley, 2000) and can provide a direct measurement of the alpha ejection distance in apatite. So, with the ultimate goal of further developing the in-situ (U-Th)/He dating method and micro-analytical depth profiling techniques to constrain cooling histories in natural grains, we conducted a helium depth profiling study of induced diffusion and natural alpha ejection profiles in Durango apatite. For the diffusion depth profiling, a Durango crystal was cut in slabs oriented parallel and perpendicular to the crystal c-axis. The slabs were polished and heated using different temperature and time schedules to induce predictable diffusion profiles based on the bulk helium diffusion parameters in apatite. Depth profiling of the 4He diffusion profiles was done using an ArF excimer laser. The measured diffusion depth profiles at 350°, 400°, and 450° C coincide well with the predicted bulk diffusion curves, independent of slab orientation, but the 300° C profiles consistently deviate significantly. The possible cause for this deviation is currently being investigated. Alpha ejection profiling was carried out on crystal margins from two different Durango apatite crystals, several faces from each crystal were analyzed to evaluate the potential effects of crystallographic orientation on alpha ejection. The results from both crystals were very reproducible irrespective of crystal surface used and confirm the findings of Monteleone et al. (2008) that the measured alpha ejection profiles deviate significantly from and are shorter than the calculated theoretical average value. Efforts are currently underway to better constrain the measured alpha ejection distance and measure alpha ejection profiles in apatite crystals other than Durango apatite. References: Boyce, J. et al. (2006) GCA 70, pp. 3031-3039. Farley, K. et al. (1996) GCA 60, pp. 4223-4229. Farley, K. (2006) JGR SE 105, p. 2903-2914. Lippolt, H. et al. (1994) Chem Geol 112, pp. 179-191. Monteleone, B. et al. (2008) Eos Trans AGU, 89 Fall Meeting V53B-2162. Wolf, R. et al. (1996) GCA 60, pp. 4231-4240. Zeitler, P. et al. (1987) GCA 51, pp. 2865-2868.

A useful and non-invasive microanalysis method for dental restoration materials

NASA Astrophysics Data System (ADS)

Hosoki, M.; Satsuma, T.; Nishigawa, K.; Takeuchi, H.; Asaoka, K.

2012-12-01

The elemental analysis of intraoral dental restorations provides considerable information for the treatment of dental metal allergy. Elemental analyses require specific instruments and complicated procedures, so this examination is not commonly carried out in private dental clinics. We describe a novel, simple and useful micro-analytical method for dental metal restorations. Micro metal dust was obtained by polishing the surface of restorative metal material with an unused silicone point (SUPER-SNAP). The metal dust on the silicone point was then rubbed onto adhesive tape, and this tape was covered with polyethylene film. The amount of metal dust material was <20 μg. An energy dispersive X-ray fluorescence spectrometer was used to carry out the elementary analysis of the metal dust on the polyethylene film. Three types of dental metal alloy materials of known components were examined. The results of elementary analyses were compared with the specifications provided by the manufacturer. The same procedure was carried out for three dental metal restorations of an adult female volunteer in vivo. The results of elemental analyses for five alloy materials exactly matched the product specification. Three metal samples obtained from intraoral restoration were also available for elemental analyses. The distinct advantage of this method is that it enables sample extraction without an invasive effect for the restoration. The metal sample is in a polyethylene film, so it is easy to mail it for inspection at specialist institutes yet it can be also be used in general dental clinics.

Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago.

PubMed

Wilde, S A; Valley, J W; Peck, W H; Graham, C M

2001-01-11

No crustal rocks are known to have survived since the time of the intense meteor bombardment that affected Earth between its formation about 4,550 Myr ago and 4,030 Myr, the age of the oldest known components in the Acasta Gneiss of northwestern Canada. But evidence of an even older crust is provided by detrital zircons in metamorphosed sediments at Mt Narryer and Jack Hills in the Narryer Gneiss Terrane, Yilgarn Craton, Western Australia, where grains as old as approximately 4,276 Myr have been found. Here we report, based on a detailed micro-analytical study of Jack Hills zircons, the discovery of a detrital zircon with an age as old as 4,404+/-8 Myr--about 130 million years older than any previously identified on Earth. We found that the zircon is zoned with respect to rare earth elements and oxygen isotope ratios (delta18O values from 7.4 to 5.0%), indicating that it formed from an evolving magmatic source. The evolved chemistry, high delta18O value and micro-inclusions of SiO2 are consistent with growth from a granitic melt with a delta18O value from 8.5 to 9.5%. Magmatic oxygen isotope ratios in this range point toward the involvement of supracrustal material that has undergone low-temperature interaction with a liquid hydrosphere. This zircon thus represents the earliest evidence for continental crust and oceans on the Earth.

Microanalytical characterization of multi-rare earth nanocrystalline magnets by TEM and APT

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

Wu, Y. Q.; Tang, W.; Miller, Michael K

2006-01-01

The partitioning behavior of various rare-earth (RE) elements during solidification and their segregation behavior at the grain boundaries were investigated in nanocrystalline (Y{sub 0.5}Dy{sub 0.5}{sub 2.2}Fe{sub 14}B and (Nd{sub 0.5}Y{sub 0.25}Dy{sub 0.25}){sub 1.8}Zr{sub 0.4}Co{sub 1.5}Fe{sub 12.5}B alloys by transmission electron microscopy and atom probe tomography. The best hard magnetic properties obtained are H{sub cj} = 22 kOe, B{sub r}=5.10 kG, and (BH){sub max} = 5.97 MG Oe for the Y-Dy-based alloy and H{sub cj}=10.6 kOe, B{sub r}=6.64 kG, and (BH){sub max}=9.56 MG Oe for the Y-Nd-Dy based alloy. The grain size of the Y-Dy based alloy was {approx} 50 nm.more » The Y-Nd-Dy based alloy had an overall finer, bimodal grain size. An intergranular (Y{sub 0.36}Dy{sub 0.64}){sub 6}Fe{sub 23} phase was detected in the Y-Dy based alloy. A uniform distribution of RE elements was found within the 2-14-1 grains in both alloys. The Y:(Dy+Nd) ratio in the Y-Nd-Dy alloy was lower than its nominal composition, indicating that the Y is segregating to grain boundaries or forming a second phase.« less

Biodegradation of aromatic compounds by white rot and ectomycorrhizal fungal species and the accumulation of chlorinated benzoic acid in ectomycorrhizal pine seedlings.

PubMed

Dittmann, Jens; Heyser, Wolfgang; Bücking, Heike

2002-10-01

The capability of different white rot (WR, Heterobasidion annosum, Phanerochaete chrysosporium, Trametes versicolor) and ectomycorrhizal (ECM, Paxillus involutus, Suillus bovinus) fungal species to degrade different aromatic compounds and the absorption of 3-chlorobenzoic acid (3-CBA) by ECM pine seedlings was examined. The effect of aromatic compounds on the fungal biomass development varied considerably and depended on (a) the compound, (b) the external concentration, and (c) the fungal species. The highest effect on the fungal biomass development was observed for 3-CBA. Generally the tolerance of WR fungi against aromatic compounds was higher than that of the biotrophic fungal species. The capability of different fungi to degrade aromatic substances varied between the species but not generally between biotrophic and saprotrophic fungi. The highest degradation capability for aromatic compounds was detected for T. versicolor and H. annosum, whereas for Phanerochaete chrysosporium and the ECM fungi lower degradation rates were found. However, Paxillus involutus and S. bovinus showed comparable degradation rates at low concentrations of benzoic acid and 4-hydroxybenzoic acid. In contrast to liquid cultures, where no biodegradation of 3-CBA by S. bovinus was observed, mycorrhizal pines inoculated with S. bovinus showed a low capability to remove 3-CBA from soil substrates. Additional X-ray microanalytical investigations showed, that 3-CBA supplied to mycorrhizal plants was accumulated in the root cell cytoplasm and is translocated across the endodermis to the shoot of mycorrhizal pine seedlings.

Coming to see objects of knowledge: Guiding student conceptualization through teacher embodied instruction in a robotics programming class

NASA Astrophysics Data System (ADS)

Kwah, Helen

This thesis explores the questions of how a teacher guides students to see concepts, and the role of gesture and gesture viewpoints in mediating the process of guidance. To examine these questions, two sociocultural theoretical frameworks--Radford's cultural-semiotic theory of knowledge objectification (e.g., 2003), and Goldman's Points of Viewing theory (e.g., 2007)--were applied to conduct a microanalytic, explanatory case study of the instructional activity of an exemplary teacher and his students in a middle school robotics programming class. According to Radford, students acquire concepts as they draw upon semiotic resources such as language and gesture to generalize and objectify initially concrete perceptions and actions. I applied Radford's framework to explain the mediations that a teacher might enact in guiding students to objectify and see concepts. Furthermore, I focused on gesture as semiotic means because of emergent research on gesture's role in communicating the visuospatial imagery that underlies math/ scientific concepts. I extended the view of gestures to the viewpoints constructed in gesture, and applied Goldman's theory to explain how perspectives might be actively constructed and shared in the process of guiding student conceptualization. Data was collected over a semester through participant observation, field notes, teacher and student interviews, and reviews of artifacts. Multimodal microanalyses were conducted on video data from eight class sessions. The findings provide confirmations and some disconfirmations about the applicability of Radford's and Goldman's theories for explaining a teacher's process of guiding student conceptualization. Notably, some of Radford's notions about de-contextualization and symbolic generalizations were not confirmed. Overall, the findings are summarized through three themes including, grounding, and perceptual organizers as two ways that gesture and other means served to both index and identify action-perception schemes for bridging to the symbolic level of programming concepts and conceptual structures. A third theme of iteration, shifting, and layering described the quality of the teacher's process, and the importance of constructing shifting and multiple viewpoints in gesture and speech, as Goldman's theory proposed. Finally, implications for designing educational applications that draw upon gesture as mediational means are discussed.

Advantages and Disadvantages of Transtibial, Anteromedial Portal, and Outside-In Femoral Tunnel Drilling in Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PubMed

Robin, Brett N; Jani, Sunil S; Marvil, Sean C; Reid, John B; Schillhammer, Carl K; Lubowitz, James H

2015-07-01

Controversy exists regarding the best method for creating the knee anterior cruciate ligament (ACL) femoral tunnel or socket. The purpose of this study was to systematically review the risks, benefits, advantages, and disadvantages of the endoscopic transtibial (TT) technique, anteromedial portal technique, outside-in technique, and outside-in retrograde drilling technique for creating the ACL femoral tunnel. A PubMed search of English-language studies published between January 1, 2000, and February 17, 2014, was performed using the following keywords: "anterior cruciate ligament" AND "femoral tunnel." Included were studies reporting risks, benefits, advantages, and/or disadvantages of any ACL femoral technique. In addition, references of included articles were reviewed to identify potential studies missed in the original search. A total of 27 articles were identified through the search. TT technique advantages include familiarity and proven long-term outcomes; disadvantages include the risk of nonanatomic placement because of constrained (TT) drilling. Anteromedial portal technique advantages include unconstrained anatomic placement; disadvantages include technical challenges, short tunnels or sockets, and posterior-wall blowout. Outside-in technique advantages include unconstrained anatomic placement; disadvantages include the need for 2 incisions. Retrograde drilling technique advantages include unconstrained anatomic placement, as well as all-epiphyseal drilling in skeletally immature patients; disadvantages include the need for fluoroscopy for all-epiphyseal drilling. There is no one, single, established "gold-standard" technique for creation of the ACL femoral socket. Four accepted techniques show diverse and subjective advantages, disadvantages, risks, and benefits. Level V, systematic review of Level II through V evidence. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

[Recent advances of anastomosis techniques of esophagojejunostomy after laparoscopic totally gastrectomy in gastric tumor].

PubMed

Li, Xi; Ke, Chongwei

2015-05-01

The esophageal jejunum anastomosis of the digestive tract reconstruction techniques in laparoscopic total gastrectomy includes two categories: circular stapler anastomosis techniques and linear stapler anastomosis techniques. Circular stapler anastomosis techniques include manual anastomosis method, purse string instrument method, Hiki improved special anvil anastomosis technique, the transorally inserted anvil(OrVil(TM)) and reverse puncture device technique. Linear stapler anastomosis techniques include side to side anastomosis technique and Overlap side to side anastomosis technique. Esophageal jejunum anastomosis technique has a wide selection of different technologies with different strengths and the corresponding limitations. This article will introduce research progress of laparoscopic total gastrectomy esophagus jejunum anastomosis from both sides of the development of anastomosis technology and the selection of anastomosis technology.

Redox interplay of oxo-thio-tungsten centers with sulfur-donor co-ligands.

PubMed

Thomas, Simon; Eagle, Aston A; Sproules, Stephen A; Hill, Jason P; White, Jonathan M; Tiekink, Edward R T; George, Graham N; Young, Charles G

2003-09-22

The oxo-thio-W(VI) complexes TpWOS(S(2)PR(2)-S) and TpWOS(pyS-S) (Tp = hydrotris(3,5-dimethylpyrazol-1-yl)borate, R = OEt, Ph; pyS = pyridine-2-thiolate) have been prepared and characterized by microanalytical, spectroscopic, and structural techniques. Crystals of the 1,2-dichloroethane hemisolvate of TpWOS(S(2)PPh(2)-S) belong to the triclinic space group Ponemacr; with a = 10.732(6) A, b = 16.91(1) A, c = 10.021(4) A, alpha = 104.40(4) degrees, beta = 107.52(3) degrees, gamma = 96.09(5) degrees, V = 1647(1) A(3) for Z = 2. The complex exhibits a distorted octahedral structure featuring a facial tridentate Tp ligand and mutually cis terminal oxo (W-O(1) = 1.712(7) A), terminal thio (W-S(1) = 2.162(3) A), and monodentate dithiophosphinate ligands. X-ray absorption and extended X-ray absorption fine structure results support a related oxo-thio formulation for TpWOS(pyS-S). The complexes are reduced to the corresponding oxo-thio-W(V) anions, [TpWOS(S(2)PR(2)-S)](-) and [TpWOS(pyS-S)](-), which exhibit highly anisotropic EPR spectra. They are oxidized to form the EPR-active (dithio)oxo-W(V) cations, [TpWO(S(3)PR(2)-S,S')](+) and [TpWO(pyS(2)-N,S)](+) (pyS(2) = pyridine-2-dithio). Green [TpWO(pyS(2)-N,S)]BF(4), formed in the reaction of TpWOS(pyS) and NOBF(4), has been isolated and spectroscopically and structurally characterized. Crystals of [TpWO(pyS(2)-N,S)]BF(4) belong to the monoclinic space group Cc with a = 16.007(5) A, b = 14.091(4) A, c = 13.608(4) A, beta = 124.525(4) degrees, V = 2528.8(13) A(3) for Z = 4. The cation exhibits a distorted octahedral structure featuring facial tridentate Tp, terminal oxo (W-O(1) = 1.632(12) A), and bidentate pyridine-2-dithio-N,S (W-S(1) = 2.317(7) A, S(1)-S(2) = 2.037(9) A) ligands. The structures and redox behavior of the complexes are compared and contrasted with those of the related molybdenum complexes, TpMo(VI)OS(S(2)PR(2)-S) and TpMo(IV)O(pyS(2)-N,S) (Hill, J. P.; Laughlin, L. J.; Gable, R. W.; Young, C. G. Inorg. Chem. 1996, 35, 3447).

Relationship between Rock Varnish and Adjacent Mineral Dust Compositions Using Microanalytical Techniques

NASA Astrophysics Data System (ADS)

Macholdt, D.; Jochum, K. P.; Otter, L.; Stoll, B.; Weis, U.; Pöhlker, C.; Müller, M.; Kappl, M.; Weber, B.; Kilcoyne, A. L. D.; Weigand, M.; Al-Amri, A. M.; Andreae, M. O.

2015-12-01

Rock varnishes are up to 250 μm thick, Mn- and Fe-rich, dark black to brownish-orange lustrous rock coatings. Water and aeolian dust (60-70%), in combination with biological oxidation or inorganic precipitation processes, or even a combination of both, induce varnish growth rates of a few μm per 1000 a, indicating that element enrichment and aging processes are of major importance for the varnish formation. A combination of 200 nm-fs laser- and 213 nm-ns laser ablation- inductively coupled plasma-mass spectrometry (LA-ICP-MS), focused ion beam (FIB) slicing, and scanning transmission X-ray microscopy-near edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS) was chosen for high-spatial-resolution analyses. The aim was to identify provenance, chemistry, and dynamics of the varnishes, and their formation over the millennia. To this end, mineral dust and adjacent varnishes were sampled in six arid to semi-arid deserts, in Israel, South Africa, California, and Saudi Arabia. Dust minerals incorporated in the varnishes were examined by STXM-NEXAFS spectroscopic and element mapping at the nm scale. Varnishes from different locations can be distinguished by element ratio plots of Pb/Ni vs. Mn/Ba. A comparison of dust element ratios of particles <50 μm to ratios of adjacent varnishes reveals much lower values for dust. However, the factors between the element ratios of dust and of varnish are similar for four of six regions (Mn/Ba: 6 ± 2; Pb/Ni: 4 ± 3). Two of the six regions diverge, which are South African (Mn/Ba: 20, Pb/Ni: 0.5) and Californian (Anza Borrego Desert: Mn/Ba: 4.5; Pb/Ni: 16.5) varnishes.The results indicate that the enrichment and degradation processes might be similar for most locations, and that Mn and Pb are preferably incorporated and immobilized in most varnishes compared to Ba and Ni. The Pb/Ni ratios of the South African varnishes are indicators for either a preferred incorporation of Ni compared to Pb from available dust, and therefore possibly a different genesis, or it shows a changed dust source over time, or even an additional element source. The latter two arguments, or even Pb pollution by automobiles, might also be true for the Anza Borrego varnish with its higher Pb/Ni ratios. Our investigations of dust and the rock coatings at the nm scale may help to unravel the genesis of rock varnish.

Lichen-rock interaction in volcanic environments: evidences of soil-precursor formation

NASA Astrophysics Data System (ADS)

Vingiani, S.; Adamo, P.; Terribile, F.

2012-04-01

The weathering action of the lichens Lecidea fuscoatra (L.) Ach. and Stereocaulon vesuvianum Pers. on basaltic rock collected on the slopes of Mt. Etna (Sicily) at 1550 m a.s.l. has been studied using optical (OM) and electron (SEM) microscopy equipped with microanalytical device (EDS). Biological factors associated with lichen growth play a major role in the weathering of minerals on bare rocks and contribute to the preliminary phases of soil formation. The present work investigates the biogeophysical and biogeochemical weathering associated to the growth of epilithic lichens on lava flows from Mt. Etna (Sicily) and Mt. Vesuvius (Campania). The chosen lichen species were the crustose Lecidea fuscoatra (L.) Ach., the foliose Xanthoparmelia conspersa and the fructicose Stereocaulon vesuvianum Pers. An integrated approach based on the study of both disturbed and undisturbed samples of lichenized rock was applied in order to appreciate the complexity of the rock-lichen interface environment in terms of micromorphological, mineralogical and chemical properties. XRD and XRF analyses coupled to microscopical (OM), submicroscopical (SEM) and microanalitical (EDS) observations were the used techniques. In both study environments, the chemical, mineralogical and micromorphological properties of the uncoherent materials found at the lichen-rock interface suggest they consist of rock fragments eroded from the surroundings and accumulated in cavities and fissures of the rough lava flows. According to the thallus morphology, the lichens colonizing the lava preserve the interface materials from further aeolic and water erosion, provide these materials of organic matter and moisture, entrap allochtonous quartz and clay minerals. The calcium oxalate production by L. fuscoatra and X. conspersa, the Al enrichment around S. vesuvianum hyphae and the occurrence of Fe-oxide phases at the rock-lichen interface are evidences of lichens interaction with the underlying sediments. Indeed, according to the young age of the basaltic lava the recent lichen colonization results in a physical reorganization and chemical modification of the interface materials, which are not necessarily produced by the lichen action on the rock substrate. In volcanic environment, the ability of lichens to retain considerable amount of unconsolidated material, which becomes mixed with organic matter, produced by decomposition of the thallus, and trap atmospheric dust may contribute to the andosolization process. Accumulation of Al and Fe, found at the rock-lichen interface likely as organo-metal complexes, can be considered initial stage of Al and Fe active phases formation, distinguishing features of Andosols development. The simple chelating oxalic acid, produced by the lichens, may be involved in the formation of organo-metal complexes.

Volcano deformation--Geodetic monitoring techniques

USGS Publications Warehouse

Dzurisin, Daniel; Lu, Zhong

2007-01-01

This book describes the techniques used by volcanologists to successfully predict several recent volcanic eruptions by combining information from various scientific disciplines, including geodetic techniques. Many recent developments in the use of state-of-the-art and emerging techniques, including Global Positioning System and Synthetic Aperture Radar Interferometry, mean that most books on volcanology are out of date, and this book includes chapters devoted entirely to these two techniques.

Distributed Transforms for Efficient Data Gathering in Sensor Networks

NASA Technical Reports Server (NTRS)

Ortega, Antonio (Inventor); Shen, Godwin (Inventor); Narang, Sunil K. (Inventor); Perez-Trufero, Javier (Inventor)

2014-01-01

Devices, systems, and techniques for data collecting network such as wireless sensors are disclosed. A described technique includes detecting one or more remote nodes included in the wireless sensor network using a local power level that controls a radio range of the local node. The technique includes transmitting a local outdegree. The local outdegree can be based on a quantity of the one or more remote nodes. The technique includes receiving one or more remote outdegrees from the one or more remote nodes. The technique includes determining a local node type of the local node based on detecting a node type of the one or more remote nodes, using the one or more remote outdegrees, and using the local outdegree. The technique includes adjusting characteristics, including an energy usage characteristic and a data compression characteristic, of the wireless sensor network by selectively modifying the local power level and selectively changing the local node type.

Infants, mothers, and dyadic contributions to stability and prediction of social stress response at 6 months.

PubMed

Provenzi, Livio; Olson, Karen L; Montirosso, Rosario; Tronick, Ed

2016-01-01

The study of infants' interactive style and social stress response to repeated stress exposures is of great interest for developmental and clinical psychologists. Stable maternal and dyadic behavior is critical to sustain infants' development of an adaptive social stress response, but the association between infants' interactive style and social stress response has received scant attention in previous literature. In the present article, overtime stability of infant, maternal, and dyadic behaviors was measured across 2 social stress (i.e., Face-to-Face Still-Face, FFSF) exposures, separated by 15 days. Moreover, infant, maternal, and dyadic behaviors were simultaneously assessed as predictors of infants' social stress to both FFSF exposures. Eighty-one mother-infant dyads underwent the FFSF twice, at 6 months (Exposure 1: the first social stress) and at 6 months and 15 days (Exposure 2: repeated social stress). Infant and mother behavior and dyadic synchrony were microanalytically coded. Overall, individual behavioral stability emerged between FFSF exposures. Infants' response to the first stress was predicted by infant behavior during Exposure 1 Play. Infants' response to the repeated social stress was predicted by infants' response to the first exposure to the Still-Face and by infants' behavior and dyadic synchrony during Exposure 2 Play. Findings reveal stability for individual, but not for dyadic, behavior between 2 social stress exposures at 6 months. Infants' response to repeated social stress was predicted by infants' earlier stress response, infants' own behavior in play, and dyadic synchrony. No predictive effects of maternal behavior were found. Insights for research and clinical work are discussed. (c) 2015 APA, all rights reserved).

A dynamic system analysis of dyadic flexibility and stability across the Face-to-Face Still-Face procedure: application of the State Space Grid.

PubMed

Provenzi, Livio; Borgatti, Renato; Menozzi, Giorgia; Montirosso, Rosario

2015-02-01

The Face-to-Face Still-Face (FFSF) paradigm allows to study the mother-infant dyad as a dynamic system coping with social stress perturbations. The State Space Grid (SSG) method is thought to depict both flexibility and stability of the dyad across perturbations, but previous SSG evidence for the FFSF is limited. The main aims were: (1) to investigate mother-infant dyadic flexibility and stability across the FFSF using the SSG; (2) to evaluate the influence of dyadic functioning during Play on infant Still-Face response and of infant stress response in affecting dyadic functioning during Reunion. Forty 4-month-old infants and their mothers were micro-analytically coded during a FFSF and eight SSG dyadic states were obtained. Dyadic flexibility and attractor states were assessed during Play and Reunion. Infants' stress response was coded as negative engagement during the Still-Face episode. Two dyadic states, "maternal hetero-regulation" and "affective mismatch", showed significant changes in the number of visits from Play to Reunion. During Play "maternal positive support to infant play" emerged as attractor state, whereas during Reunion a second attractor emerged, namely "affective mismatch". Dyadic affective mismatch during Play correlated with infants' negative engagement during Still-Face, whereas infants' response to Still-Face resulted in minor social matching during Reunion. Findings provide new insights into the flexible, yet stable, functioning of the mother-infant dyad as a dynamic system. Evidence of a reciprocal influence between dyadic functioning and infant social stress response are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

Design and fabrication of a multilayered polymer microfluidic chip with nanofluidic interconnects via adhesive contact printing.

PubMed

Flachsbart, Bruce R; Wong, Kachuen; Iannacone, Jamie M; Abante, Edward N; Vlach, Robert L; Rauchfuss, Peter A; Bohn, Paul W; Sweedler, Jonathan V; Shannon, Mark A

2006-05-01

The design and fabrication of a multilayered polymer micro-nanofluidic chip is described that consists of poly(methylmethacrylate) (PMMA) layers that contain microfluidic channels separated in the vertical direction by polycarbonate (PC) membranes that incorporate an array of nanometre diameter cylindrical pores. The materials are optically transparent to allow inspection of the fluids within the channels in the near UV and visible spectrum. The design architecture enables nanofluidic interconnections to be placed in the vertical direction between microfluidic channels. Such an architecture allows microchannel separations within the chip, as well as allowing unique operations that utilize nanocapillary interconnects: the separation of analytes based on molecular size, channel isolation, enhanced mixing, and sample concentration. Device fabrication is made possible by a transfer process of labile membranes and the development of a contact printing method for a thermally curable epoxy based adhesive. This adhesive is shown to have bond strengths that prevent leakage and delamination and channel rupture tests exceed 6 atm (0.6 MPa) under applied pressure. Channels 100 microm in width and 20 microm in depth are contact printed without the adhesive entering the microchannel. The chip is characterized in terms of resistivity measurements along the microfluidic channels, electroosmotic flow (EOF) measurements at different pH values and laser-induced-fluorescence (LIF) detection of green-fluorescent protein (GFP) plugs injected across the nanocapillary membrane and into a microfluidic channel. The results indicate that the mixed polymer micro-nanofluidic multilayer chip has electrical characteristics needed for use in microanalytical systems.

Space-Time Evolution of Magma Storage and Transfer at Mt. Etna Volcano (Italy): The 2015-2016 Reawakening of Voragine Crater

NASA Astrophysics Data System (ADS)

Cannata, Andrea; Di Grazia, Giuseppe; Giuffrida, Marisa; Gresta, Stefano; Palano, Mimmo; Sciotto, Mariangela; Viccaro, Marco; Zuccarello, Francesco

2018-02-01

The eruptions of December 2015 and May 2016 at Voragine crater were among the most explosive recorded during the last two decades at Mt. Etna volcano. Here we present data coming from geophysics (infrasound, LP, VLP, volcanic tremor, VT earthquakes, and ground deformations) and petrology (textural and microanalytical data on plagioclase and olivine crystals) to investigate the preeruptive magma storage and transfer dynamics leading to these exceptional explosive eruptions. Integration of all the available data has led us to constrain chemically, physically, and kinetically the environments where magmas were stored before the eruption, and how they have interacted during the transfer en-route to the surface. Although the evolution and behavior of volcanic phenomena at the surface was rather similar, some differences in storage and transfer dynamics were observed for 2015 and 2016 eruptions. Specifically, the 2015 eruptions have been fed by magmas stored at shallow levels that were pushed upward as a response of magma injections from deeper environments, whereas evidence of chemical interaction between shallow and deep magmatic environments becomes more prominent during the 2016 eruptions. Main findings evidence the activation of magmatic environments deeper than those generally observed for other recent Etnean eruptions, with involvement of deep basic magmas that were brought to shallow crustal levels in very short time scales (˜1 month). The fast transfer from the deepest levels of the plumbing system of basic, undegassed magmas might be viewed as the crucial triggering factor leading to development of exceptionally violent volcanic phenomena even with only basic magma involved.

The effect of mineral reactions and microstructure on long-term experimental fault zone weakening

NASA Astrophysics Data System (ADS)

Niemeijer, Andre R.

2017-04-01

The frictional properties of fault rocks and, in particular, the velocity dependence of friction and associated rate-and-state parameters, are thought to exert an important control on earthquake nucleation and propagation. Experimental results obtained from natural fault gouges typically show that the velocity dependence of friction is a function of both temperature and sliding velocity, indicating that thermally activated time-dependent processes are fundamentally responsible for causing velocity-weakening behavior in silicate-bearing gouges at earthquake "nucleation velocities" (˜ 1 μm/s) and temperatures around 150-300 ˚ C. In addition, slow experiments at velocities of 10s of nm/s using three different fault gouge types all exhibit major weakening with ongoing displacement at constant velocity. Microstructural and microanalytical analyses demonstrate that the development of a weak through-going foliation as well as the (shear-enhanced) formation of new, weak minerals such as talc or muscovite occurred, which both presumably contributed to the observed weakening. Importantly, the slow deformation rates allow for time-dependent viscous deformation (e.g. pressure solution) to occur at low shear stress within the hard, frictionally strong minerals such as quartz. The results highlight the importance of the chemical effects of fluids and microstructural development on long-term fault weakening under slow loading conditions. The resultant frictionally weak fault gouges allow strain to remain localized, yield a strong permeability anisotropy and provide a barrier for rupture propagation. Along-fault variations in the chemical conditions thus have the potential to produce strong contrasts in frictional properties, which can have a large effect on potential earthquake rupture size and style.

Immunomodulatory effect of new quinolone derivative against cisplatin/gamma radiation-induced renal and brain toxicity in mice.

PubMed

Nabeel, Asmaa I; Moawed, Fatma S M; Hassan, Heba

2018-07-01

Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Recent studies synthesize new quinolone derivatives to satisfy other purposes such as treatment of inflammatory and malignant diseases. The main purpose of the present study is to evaluate the effect of a new quinolone derivative; 2-(1-Ethyl-4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-2-oxoacetic acid (EHQA) and its possible mechanism against gamma radiation (IRR) and cisplatin (Cis) induced nephrotoxicity and neurotoxicity in mice. The structure of the newly synthesized quinolone derivative was elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. Exposure to Cis and IRR significantly induced renal damage manifested by a significant increase in levels of urea and creatinine. Moreover, the exposure to both Cis and IRR significantly decreased the levels of anti-apoptotic protein; Bcl-2 in both renal and brain tissue homogenate accompanied by activation of an inflammatory marker; IL-17. Immunophenoting results showed an activation of T- lymphocytes marker; CD3 and B-lymphocytes marker; CD19. Interperitonial administration of EHQA significantly ameliorated the above-mentioned parameters. Overall, the present results indicated that EHQA is a promising anti-inflammatory and anti-apoptotic agent. From the obtained results it can be concluded that EHQA could be a candidate as immunomodulatory agents. Further studies are required to establish its molecular mechanism. Copyright © 2018 Elsevier B.V. All rights reserved.

Motherhood in adolescent mothers: maternal attachment, mother-infant styles of interaction and emotion regulation at three months.

PubMed

Riva Crugnola, Cristina; Ierardi, Elena; Gazzotti, Simona; Albizzati, Alessandro

2014-02-01

Early motherhood is considered a risk factor for an adequate relationship between mother and infant and for the subsequent development of the infant. The principal aim of the study is to analyze micro-analytically the effect of motherhood in adolescence on the quality of mother-infant interaction and emotion regulation at three months, considering at the same time the effect of maternal attachment on these variables. Participants were 30 adolescent mother-infant dyads compared to 30 adult mother-infant dyads. At infant 3 months, mother-infant interaction was video-recorded and coded with a modified version of the Infant Caregiver Engagement Phases and the Adult Attachment Interview was administered to the mother. Analysis showed that adolescent mothers (vs. adult mothers) spent more time in negative engagement and their infants spent less time in positive engagement and more time in negative engagement. Adolescent mothers are also less involved in play with their infants than adult mothers. Adolescent mother-infant dyads (vs. adult mother-infant dyads) showed a greater duration of negative matches and spent less time in positive matches. Insecure adolescent mother-infant dyads (vs. insecure adult mother-infant dyads) demonstrated less involvement in play with objects and spent less time in positive matches. To sum up adolescent mother-infant dyads adopt styles of emotion regulation and interaction with objects which are less adequate than those of dyads with adult mothers. Insecure maternal attachment in dyads with adolescent mothers (vs. adult mother infant dyads) is more influential as risk factor. Copyright © 2014 Elsevier Inc. All rights reserved.

Synthesis, molecular and crystalline architectures, and properties of mononuclear cobalt(II)thiocyanates containing a symmetrical tailored diimine/an unsymmetrical bidentate Schiff base

NASA Astrophysics Data System (ADS)

Sarkar, Bhola Nath; Bhar, Kishalay; Kundu, Subhasis; Fun, Hoong-Kun; Ghosh, Barindra Kumar

2009-11-01

Two hexacoordinated mononuclear cobalt(II)thiocyanate complexes of general formula [Co(LL) 2(NCS) 2]. nH 2O [LL = 2,2'-dipyridylamine (dpa), n = 1, 1; LL = N-((pyridin-2-yl)benzylidene)benzylamine (pbba), n = 0, 2] have been prepared and characterized using microanalytical, spectroscopic and other physicochemical results. The compounds are non-electrolytes and behave as three-electron paramagnets. Structures of 1 and 2 are solved by X-ray diffraction measurements. Structural analyses show that each metal center in 1 and 2 adopts a distorted octahedral geometry with a CoN 6 chromophore ligated through four N atoms of two bidentate LL units; the hexacoordination is completed by two N atoms of terminal thiocyanates in mutual cis orientation. The mononuclear units in 1 are engaged in weak intermolecular N-H…S and C-H…S hydrogen bonds to give a 2D sheet structure, which is further stabilized by π…π interactions among the pyridine rings of dpa units. In the long-range form, two mononuclear units of 2 are locked by weak doubly C-H…S hydrogen bonds producing a dimeric unit, which packs through C-H…π interaction leading to a 2D continuum. In MeCN solutions, the compounds show a nearly reversible one-electron oxidative response corresponding to cobalt(III)-cobalt(II) couple. The complexes display intraligand 1(π-π∗) fluorescence at room temperature and intraligand 3(π-π∗) phosphorescence in glassy solutions (DMF at 77 K).

Bibliography on augmentation of convective heat and mass transfer-II

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

Bergles, A.E.; Nirmalan, V.; Junkhan, G.H.

1983-12-01

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. This report presents and updated bibliography of world literature on augmentation. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fifteen techniques are grouped in terms of their applications to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 3045, including 135 surveys of various techniques and 86 papers on performancemore » evaluation of passive techniques. Patents are not included, as they are the subject of a separate bibliographic report.« less

Bibliography on augmentation of convective heat and mass transfer

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

Bergles, A.E.; Webb, R.L.; Junkhan, G.H.

1979-05-01

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. A bibliography of world literature on augmentation is presented. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fourteen techniques are grouped in terms of their application to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 1,967, including 75 surveys of various techniques and 42 papers on performance evaluation ofmore » passive techniques. Patents are not included as they will be the subject of a future topical report.« less

76 FR 44604 - Draft Anacostia Park Wetland and Resident Canada Goose Management Plan/Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... the current wetland and goose management techniques which include: Invasive species management, trash... techniques. Proposed extensive wetland restoration opportunities could include: Managing invasive species.... Some of the wetland management techniques could include managing invasive species and [[Page 44605...

TECHNIQUES FOR TEACHING CONSERVATION EDUCATION.

ERIC Educational Resources Information Center

BROWN, ROBERT E.; MOUSER, G.W.

CONSERVATION PRINCIPLES, FIELD METHODS AND TECHNIQUES, AND SPECIFIC FIELD LEARNING ACTIVITIES ARE INCLUDED IN THIS REFERENCE VOLUME FOR TEACHERS. CONSERVATION PRINCIPLES INCLUDE STATEMENTS PERTAINING TO (1) SOIL, (2) WATER, (3) FOREST, AND (4) WILDLIFE. FIELD METHODS AND TECHNIQUES INCLUDE (1) PREPARING FOR A FIELD TRIP, (2) GETTING STUDENT…

Nanosized (mu12-Pt)Pd164-xPtx(CO)72(PPh3)20 (x approximately 7) containing Pt-centered four-shell 165-atom Pd-Pt core with unprecedented intershell bridging carbonyl ligands: comparative analysis of icosahedral shell-growth patterns with geometrically related Pd145(CO)x(PEt3)30 (x approximately 60) containing capped three-shell Pd145 core.

PubMed

Mednikov, Evgueni G; Jewell, Matthew C; Dahl, Lawrence F

2007-09-19

Presented herein are the preparation and crystallographic/microanalytical/magnetic/spectroscopic characterization of the Pt-centered four-shell 165-atom Pd-Pt cluster, (mu(12)-Pt)Pd(164-x)Pt(x)(CO)(72)(PPh(3))(20) (x approximately 7), 1, that replaces the geometrically related capped three-shell icosahedral Pd(145) cluster, Pd(145)(CO)(x)(PEt(3))(30) (x approximately 60), 2, as the largest crystallographically determined discrete transition metal cluster with direct metal-metal bonding. A detailed comparison of their shell-growth patterns gives rise to important stereochemical implications concerning completely unexpected structural dissimilarities as well as similarities and provides new insight concerning possible synthetic approaches for generation of multi-shell metal clusters. 1 was reproducibly prepared in small yields (<10%) from the reaction of Pd(10)(CO)(12)(PPh(3))(6) with Pt(CO)(2)(PPh(3))(2). Its 165-atom metal-core geometry and 20 PPh(3) and 72 CO ligands were established from a low-temperature (100 K) CCD X-ray diffraction study. The well-determined crystal structure is attributed largely to 1 possessing cubic T(h) (2/m3) site symmetry, which is the highest crystallographic subgroup of the noncrystallographic pseudo-icosahedral I(h) (2/m35) symmetry. The "full" four-shell Pd-Pt anatomy of 1 consists of: (a) shell 1 with the centered (mu(12)-Pt) atom encapsulated by the 12-atom icosahedral Pt(x)Pd(12-x) cage, x = 1.2(3); (b) shell 2 with the 42-atom nu(2) icosahedral Pt(x)Pd(42-x) cage, x = 3.5(5); (c) shell 3 with the anti-Mackay 60-atom semi-regular rhombicosidodecahedral Pt(x)Pd(60-x) cage, x = 2.2(6); (d) shell 4 with the 50-atom nu(2) pentagonal dodecahedral Pd(50) cage. The total number of crystallographically estimated Pt atoms, 8 +/- 3, which was obtained from least-squares (Pt(x)/Pd(1-x))-occupancy analysis of the X-ray data that conclusively revealed the central atom to be pure Pt (occupancy factor, x = 1.00(3)), is fortuitously in agreement with that of 7.6(7) found from an X-ray Pt/Pd microanalysis (WDS spectrometer) on three crystals of 1. Our utilization of this site-occupancy (Pt(x)Pd(1-x))-analysis for shells 1-3 originated from the microanalytical results; otherwise, the presumed metal-core composition would have been (mu(12)-Pt)Pd(164). [Alternatively, the (mu(12)-Pt)M(164) core-geometry of 1 may be viewed as a pseudo-Ih Pt-centered six-shell successive nu(1) polyhedral system, each with radially equivalent vertex atoms: Pt@M(12)(icosahedron)@M(30)(icosidodecahedron)@M(12)(icosahedron)@M(60)(rhombicosidodecahedron)@M(30)(icosidodecahedron)@M(20)(pentagonal dodecahedron)]. Completely surprising structural dissimilarities between 1 and 2 are: (1) to date 1 is only reproducibly isolated as a heterometallic Pd-Pt cluster with a central Pt instead of Pd atom; (2) the 50 atoms comprising the outer fourth nu(2) pentagonal dodecahedral shell in 1 are less than the 60 atoms of the inner third shell in 1, in contradistinction to shell-by-shell growth processes in all other known shell-based structures; (3) the 10 fewer PR3 ligands in 1 necessitate larger bulky PPh(3) ligands to protect the Pd-Pt core-geometry; (4) the 72 CO ligands consist of six bridging COs within each of the 12 pentagons in shell 4 that are coordinated to intershell metal atoms. SQUID magnetometry measurements showed a single-crystal sample of 1 to be diamagnetic over the entire temperature range of 10-300 K.

An iterative analytical technique for the design of interplanetary direct transfer trajectories including perturbations

NASA Astrophysics Data System (ADS)

Parvathi, S. P.; Ramanan, R. V.

2018-06-01

An iterative analytical trajectory design technique that includes perturbations in the departure phase of the interplanetary orbiter missions is proposed. The perturbations such as non-spherical gravity of Earth and the third body perturbations due to Sun and Moon are included in the analytical design process. In the design process, first the design is obtained using the iterative patched conic technique without including the perturbations and then modified to include the perturbations. The modification is based on, (i) backward analytical propagation of the state vector obtained from the iterative patched conic technique at the sphere of influence by including the perturbations, and (ii) quantification of deviations in the orbital elements at periapsis of the departure hyperbolic orbit. The orbital elements at the sphere of influence are changed to nullify the deviations at the periapsis. The analytical backward propagation is carried out using the linear approximation technique. The new analytical design technique, named as biased iterative patched conic technique, does not depend upon numerical integration and all computations are carried out using closed form expressions. The improved design is very close to the numerical design. The design analysis using the proposed technique provides a realistic insight into the mission aspects. Also, the proposed design is an excellent initial guess for numerical refinement and helps arrive at the four distinct design options for a given opportunity.

Micron-scale Analysis of Carbonate-Associated Sulfate by Secondary Ionization Mass Spectrometry: Insights into Spatial Variability in δ34SCAS

NASA Astrophysics Data System (ADS)

Fike, D. A.; Jones, D. S.

2012-12-01

The proliferation of carbonate-associated sulfate (CAS) isotope analyses in recent years has revolutionized our understanding of marine sulfur cycling over much of Earth history. In marine carbonate rocks, δ34SCAS is thought to be a faithful recorder of the isotopic composition of marine sulfate (δ34SSO4). However, as the chemostratigraphic record becomes better resolved in time and space, reports of coeval but discordant δ34SCAS values are becoming increasingly common. These differences could arise in part from a) water column stratification or physiographic separations between separate ocean basins (i.e., paleoceanographic variability in δ34SSO4); b) syndepositional processes that decouple the relationship between δ34SSO4 and δ34SCAS during deposition or prior to lithification; or c) diagenetic alteration of the δ34SCAS signal following deposition. To help disentangle these processes, we have developed a microanalytical approach to determine the abundance and isotopic composition of CAS using secondary ionization mass spectrometry (SIMS). While our current precision (~1‰) cannot compete with that obtained from traditional bulk analysis on gas source isotope ratio mass spectrometers, we believe that the unparalleled spatial resolution can provide substantial insights into many of the fundamental questions that remain regarding the mechanisms by which CAS concentration and isotopic composition can be altered during carbonate precipitation and/or recrystallization. With a spatial resolution as low as ~ 5 μm, it is possible to analyze suites of primary and diagenetic phases, including individual carbonate allochems, muds, and cements. Preliminary results indicate that δ34SCAS can vary by as much as 10‰ between phases in a single sample. This scale of analysis allows for a rigorous evaluation of the susceptibility of δ34SCAS to syndepositional and diagenetic alteration, especially when coupled with parallel analysis of δ13Ccarb/δ18Ocarb and diagnostic trace element abundances. Such detailed measurements illuminate the complex relationships between the isotopic composition of individual constituents of carbonate rocks and the bulk δ34SCAS values on which much of our understanding of sulfur cycling in deep time is based. The resulting insights can be used to re-examine existing δ34SCAS records and our understanding of the evolution of sulfur cycling over Earth history.

Working memory capacity and the antisaccade task: A microanalytic-macroanalytic investigation of individual differences in goal activation and maintenance.

PubMed

Meier, Matt E; Smeekens, Bridget A; Silvia, Paul J; Kwapil, Thomas R; Kane, Michael J

2018-01-01

The association between working memory capacity (WMC) and the antisaccade task, which requires subjects to move their eyes and attention away from a strong visual cue, supports the claim that WMC is partially an attentional construct (Kane, Bleckley, Conway, & Engle, 2001; Unsworth, Schrock, & Engle, 2004). Specifically, the WMC-antisaccade relation suggests that WMC helps maintain and execute task goals despite interference from habitual actions. Related work has recently shown that mind wandering (McVay & Kane, 2009, 2012a, 2012b) and reaction time (RT) variability (Unsworth, 2015) are also related to WMC and they partially explain WMC's prediction of cognitive abilities. Here, we tested whether mind-wandering propensity and intraindividual RT variation account for WMC's associations with 2 antisaccade-cued choice RT tasks. In addition, we asked whether any influences of WMC, mind wandering, or intraindividual RT variation on antisaccade are moderated by (a) the temporal gap between fixation and the flashing location cue, and (b) whether targets switch sides on consecutive trials. Our quasi-experimental study reexamined a published dataset (Kane et al., 2016) comprising 472 subjects who completed 6 WMC tasks, 5 attentional tasks with mind-wandering probes, 5 tasks from which we measured intraindividual RT variation, and 2 antisaccade tasks with varying fixation-cue gap durations. The WMC-antisaccade association was not accounted for by mind wandering or intraindividual RT variation. WMC's effects on antisaccade performance were greater with longer fixation-to-cue intervals, suggesting that goal activation processes-beyond the ability to control mind wandering and RT variability-are partially responsible for the WMC-antisaccade relation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The behaviour of young children with social communication disorders during dyadic interaction with peers.

PubMed

Murphy, Suzanne M; Faulkner, Dorothy M; Farley, Laura R

2014-02-01

Children with social communication disorders are known to experience more problematic peer relations than typically-developing children. However, detailed observation of their behaviour and communication during interaction with peers has not previously been undertaken. Micro-analytic observational methods were used to analyse the audio-taped interaction of children (N = 112) selected from mainstream schools (ages 5-6 years-old) on a computerised dyadic collaborative task. Comparisons were made between children with average-to-high- and low-pragmatic language skill as measured by the Test of Pragmatic Skills. Dyads were composed of an average-to-high-skilled child plus a low-skilled child (32 dyads), or of two average-to-high-skilled children (24 dyads). Consistently with their pragmatic language scores, low-skilled children were more likely to ignore other children's questions and requests than were average-to-high-skilled children. When average-to-high-skilled children worked with low-skilled children, as opposed to with other average-to-high-skilled children, they showed some sensitivity and adaptation to these children's difficulties; they used significantly more directives, clarification and provided more information. However, there was a cost in terms of the emotional tone of these interactions; when working with low-skilled children, the average-to-high-skilled children expressed considerably more negative feelings towards their partners than with another average-to-high-skilled child. In conclusion, observation of the interaction of average-to-high- and low-skilled children suggests promise for peer-assisted interventions and specifies which communicative behaviours could be targeted. However, care should be taken to manage the affective climate of these interactions for the benefit of all children involved.

Wherever I may roam: Processes of self-esteem development from adolescence to emerging adulthood in the context of international student exchange.

PubMed

Hutteman, Roos; Nestler, Steffen; Wagner, Jenny; Egloff, Boris; Back, Mitja D

2015-05-01

Previous studies on self-esteem development show substantial changes as well as interindividual differences in change from adolescence to young adulthood. However, the processes underlying these developmental trajectories are still not well understood. The aim of the present study was to shed light on the macro- and microprocesses of self-esteem development. We investigated a sample of 876 German high school students (M = 16.0 years at Time 1) participating in an international exchange year. Exchange students provided 3 waves of trait self-esteem data (shortly before they departed, immediately after return, and 1 year later), as well as 9 monthly state measures of self-esteem and social inclusion during their stay abroad. In addition, a control group of high school students who stayed in Germany (N = 714) provided 2 waves of trait self-esteem data. From a macroperspective, results showed an effect of student exchange on trait self-esteem development: Exchange students showed a steeper mean-level increase and a lower rank-order stability compared with control students. Zooming in on the microprocesses underlying these developmental patterns, we found trait changes in exchange students to be mediated by state changes in self-esteem during their exchange. These fluctuations in state self-esteem were found to be predicted by feelings of social inclusion in the host country, and vice versa, providing support for both sociometer and self-broadcasting perspectives on self-esteem dynamics. In sum, our findings emphasize the importance of incorporating a microanalytical approach when investigating self-esteem development by showing that the environment triggers changes in this relatively stable personality trait through changes in states. (c) 2015 APA, all rights reserved).

Syntheses, structures and properties of homo- and heterobimetallic complexes of the type [Zn(tren)NCS] 2[M(NCS) 4] [tren = tris(2-aminoethyl)amine; M = Zn, Cu

NASA Astrophysics Data System (ADS)

Chattopadhyay, Soumi; Bhar, Kishalay; Das, Sumitra; Chantrapromma, Suchada; Fun, Hoong-Kun; Ghosh, Barindra Kumar

2010-04-01

A 2:2:1:6 molar ratio of Zn(ClO 4) 2·6H 2O, tris(2-aminoethyl)amine (tren), Zn(ClO 4) 2·6H 2O/Cu(ClO 4) 2·6H 2O and NH 4NCS in methanol-water solution mixtures affords homo-/heterobimetallic compounds of the type [Zn(tren)NCS] 2[M(NCS) 4] (M = Zn, 1; M = Cu, 2) which have been characterized using microanalytical, spectroscopic, magnetic and other physicochemical results. The structures of the compounds are determined by X-ray diffraction measurements. Structural analyses reveal that 1 and 2 are isomorphous and consist of two discrete [Zn(tren)NCS] + cations and a [M(NCS) 4] 2- (M = Zn/Cu) anion. Zinc(II) centers in the [Zn(tren)NCS] + units adopt distorted trigonal bipyramidal geometry with ZnN 5 chromophores coordinated through four N atoms of tren and one N atom of terminal thiocyanate. Each metal(II) center in [M(NCS) 4] 2- has a distorted tetrahedral coordination environment with an MN 4 chromophore ligated by four N atoms of the terminal thiocyanates. In solid state, doubly N-H…S hydrogen bonded 1D chains of [Zn(tren)NCS] + cations are interconnected by tetrahedral [Zn(NCS) 4] 2-/[Cu(NCS) 4] 2- anions through cooperative N-H…S and N-H…N (in 1) and N-H…S and C-H…S (in 2) hydrogen bonds resulting in 3D network structures. Establishment of such networks seems to be aiding the crystallization.

Mother-Infant Emotion Regulation at Three Months: The Role of Maternal Anxiety, Depression and Parenting Stress.

PubMed

Riva Crugnola, Cristina; Ierardi, Elena; Ferro, Valentino; Gallucci, Marcello; Parodi, Cinzia; Astengo, Marina

While the association between anxiety and postpartum depression is well known, few studies have investigated the relationship between these two states and parenting stress. Furthermore, a number of studies have found that postpartum depression affects mother-infant emotion regulation, but there has been only one study on anxiety and emotion regulation and no studies at all on parenting stress and emotion regulation. Therefore, the primary aim of our study is to identify, in a community sample of 71 mothers, the relationship between maternal depression, anxiety, and parenting stress. The second aim is to examine the relationship between anxiety, postpartum depression, and parenting stress and mother-infant emotion regulation assessed at 3 months. Mother-infant interaction was coded with a modified version of the Infant Caregiver and Engagement Phases (ICEP) using a microanalytic approach. The Edinburgh Postnatal Depression Scale (EPDS), State-Trait Anxiety Inventory (STAI), and Parenting Stress Index-Short Form (PSI-SF) were administered to the mothers to assess depression, anxiety, and parenting stress, respectively. Analysis revealed correlations between anxiety and depression, showing that parenting stress is associated with both states. In a laboratory observation, depression was correlated with both negative maternal states and negative dyadic matches as well as infant positive/mother negative mismatches; anxiety was correlated with both negative maternal states and infant negative states as well as mismatches involving one of the partners having a negative state. Multiple regression analysis showed that anxiety is a greater predictor than depression of less adequate styles of mother-infant emotion regulation. Parenting stress was not shown to predict such regulation. © 2016 S. Karger AG, Basel.

[Doctor-patient-communication in an oncological outpatient department. A linguistic study of communication problems].

PubMed

Sator, Marlene; Gstettner, Andreas; Hladschik-Kermer, Birgit

2008-01-01

Recognising and attending to patients' most relevant issues and main concerns are the basis for patient-oriented work. This qualitative study investigates the ways in which doctors communicate with their patients. The method of study is conversation and discourse analysis. The source of data are audio recordings of 20 introductory medical consultations in an oncological outpatient department in Austria. In a macro-analytical approach the duration of verbal contribution as well as the topics mentioned are analyzed. Results show that 34% of the consultation time is used for activities other than the actual doctor-patient-communication. Furthermore, the share of patients' verbal contribution was found to be half that of the doctor. Much room is given to information about chemotherapy, less is dedicated to topics like the stages of the illness and the hope for recovery. The micro-analytical approach shows that patients keep trying to allude to topics which are especially relevant to them. This happens very subtly and implicitly by means of interactional markings of relevance. These are communicative and interactive methods such as a change in volume or in speech patterns, the use of strong metaphors or hesitation phenomena. Doctors, however, often give insufficient attention to such initiatives from patients and follow their own, often institutionally-related, pre-requisites. Drawing on two examples, this article shows how insufficient attention to patient-relevant issues results in a lower quality of doctor-patient-communication, and lower satisfaction of patients and doctors. Two positive examples show that adequate attention to patient-relevant issues is possible and increases quality of doctor-patient-communication, as well as participants' satisfaction. It is argued that insufficient attention to patient-relevant issues also reduces time efficiency.

Investigating the Geological History of Asteroid 101955 Bennu Through Remote Sensing and Returned Sample Analyses

NASA Technical Reports Server (NTRS)

Messenger, S.; Connolly, H. C., Jr.; Lauretta, D. S.; Bottke, W. F.

2014-01-01

The NASA New Frontiers Mission OSRIS-REx will return surface regolith samples from near-Earth asteroid 101955 Bennu in September 2023. This target is classified as a B-type asteroid and is spectrally similar to CI and CM chondrite meteorites [1]. The returned samples are thus expected to contain primitive ancient Solar System materials that formed in planetary, nebular, interstellar, and circumstellar environments. Laboratory studies of primitive astromaterials have yielded detailed constraints on the origins, properties, and evolutionary histories of a wide range of Solar System bodies. Yet, the parent bodies of meteorites and cosmic dust are generally unknown, genetic and evolutionary relationships among asteroids and comets are unsettled, and links between laboratory and remote observations remain tenuous. The OSIRIS-REx mission will offer the opportunity to coordinate detailed laboratory analyses of asteroidal materials with known and well characterized geological context from which the samples originated. A primary goal of the OSIRIS-REx mission will be to provide detailed constraints on the origin and geological and dynamical history of Bennu through coordinated analytical studies of the returned samples. These microanalytical studies will be placed in geological context through an extensive orbital remote sensing campaign that will characterize the global geological features and chemical diversity of Bennu. The first views of the asteroid surface and of the returned samples will undoubtedly bring remarkable surprises. However, a wealth of laboratory studies of meteorites and spacecraft encounters with primitive bodies provides a useful framework to formulate priority scientific questions and effective analytical approaches well before the samples are returned. Here we summarize our approach to unraveling the geological history of Bennu through returned sample analyses.

High-Pressure Minerals in Meteorites: Constraints on Shock Conditions and Duration

NASA Technical Reports Server (NTRS)

Sharp, Thomas G.

2004-01-01

The objective of this research was to better understand the conditions and duration of shock metamorphism in meteorites through microstructural and microanalytical characterization of high-pressure minerals. A) Continue to investigate the mineralogy and microstructures of melt-veins in a suite of chondritic samples ranging from shock grades S3 through S6 to determine how the mineral assemblages that crystallize at high-pressure and are related to shock grade. B) Investigate the chemical, mineralogical, and microstructural heterogeneities that occur across melt veins to interpret crystallization histories. C) Use static high-pressure experiments to simulate crystallization of melt veins for mineralogical and textural comparisons with the melt veins of naturally shocked samples. D) Characterize the compositions and defect microstructures of polycrystalline ringwoodite, wadsleyite, majorite, (Mg,Fe)Si03-ilmenite and (Mg,Fe)SiO3-perovskite in S6 samples to understand the mechanisms of phase transformations that occur during shock. These results will combined with kinetic data to constrain the time scales of kinetic processes. E) Investigate the transformations of metastable high-pressure minerals back to low- pressure forms to constrain post-shock temperatures and estimates of the peak shock pressure. Of these objectives, we have obtained publishable data on A, B and D. I am currently doing difficult high-pressure melting and quench experiments on an L chondrite known as Mbale. These experiments will provide additional constraints on the mineral assemblages that are produced during rapid quench of an L chondrite at pressures of 16 to 25 GPa. Results from published or nearly published research is presented below. Lists of theses, dissertations and publications are given below.

A Generalized Approach to Forensic Dye Identification: Development and Utility of Reference Libraries.

PubMed

Groves, Ethan; Palenik, Skip; Palenik, Christopher S

2018-04-18

While color is arguably the most important optical property of evidential fibers, the actual dyestuffs responsible for its expression in them are, in forensic trace evidence examinations, rarely analyzed and still less often identified. This is due, primarily, to the exceedingly small quantities of dye present in a single fiber as well as to the fact that dye identification is a challenging analytical problem, even when large quantities are available for analysis. Among the practical reasons for this are the wide range of dyestuffs available (and the even larger number of trade names), the low total concentration of dyes in the finished product, the limited amount of sample typically available for analysis in forensic cases, and the complexity of the dye mixtures that may exist within a single fiber. Literature on the topic of dye analysis is often limited to a specific method, subset of dyestuffs, or an approach that is not applicable given the constraints of a forensic analysis. Here, we present a generalized approach to dye identification that ( 1 ) combines several robust analytical methods, ( 2 ) is broadly applicable to a wide range of dye chemistries, application classes, and fiber types, and ( 3 ) can be scaled down to forensic casework-sized samples. The approach is based on the development of a reference collection of 300 commercially relevant textile dyes that have been characterized by a variety of microanalytical methods (HPTLC, Raman microspectroscopy, infrared microspectroscopy, UV-Vis spectroscopy, and visible microspectrophotometry). Although there is no single approach that is applicable to all dyes on every type of fiber, a combination of these analytical methods has been applied using a reproducible approach that permits the use of reference libraries to constrain the identity of and, in many cases, identify the dye (or dyes) present in a textile fiber sample.

Doing, talking and writing science: A discourse analysis of the process of resemiotization in a middle school lab-based science class

NASA Astrophysics Data System (ADS)

Wright, Laura J.

This study examines students' sense making practices in a middle school science class from a discourse analytic perspective. Using Mediated Discourse Analysis (MDA) (Scollon 1998, 2001) and interactional sociolinguistics (Gumperz 1999, 2001, Schiffrin 1994), my research seeks to enrich findings from recent sociocultural studies of science classrooms that focus on doing, talking and writing science (Roth 2005, Kress, et al. 2002, Halliday & Martin 1993, Lemke 1990). Within a middle school science classroom, these fundamental activities form a nexus of practice (Scollon 1998, 2001) basic to science literacy (AAAS 1989) and reflective of the work of practicing scientists. Moreover, students' engagement in these practices provides insight into the cultural production and reproduction of science and scientist. I first examine how the students' curriculum text encourages these three scientific practices and then trace students' uptake; that is, how they subsequently do, talk, and write science throughout the course of the unit. I argue that learning science with this curriculum unit requires students to resemiotize (Iedema 2001, 2003) first hand experience so they can represent their knowledge cohesively and coherently in evaluable forms. Ultimately, students must transform language from the curriculum text and their teacher into action in their laboratory activities and action in their laboratory activities into language. In addition, I show how students are apprenticed to the conventionalized practices and voices (Bakhtin 1986) of science (i.e. the scientific register), and how their figures of personhood (Agha 2005) reflect the development of their scientific identities. Overall, I argue that the microanalytic methods I use illuminate how students draw upon curricular resources to become scientifically literate and develop scientific identities.

Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts.

PubMed

Kim, Jin-Hyoung; Lee, Han-Seung

2017-09-07

In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6-104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO₃ was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite.

Improvement of Early Strength of Cement Mortar Containing Granulated Blast Furnace Slag Using Industrial Byproducts

PubMed Central

Kim, Jin-Hyoung; Lee, Han-Seung

2017-01-01

In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6–104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO3 was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite. PMID:28880256

Crystal Cargo Characterization: Unravelling Granite Petrogenesis through Combined MicroXRF Imaging and In-situ Analyses.

NASA Astrophysics Data System (ADS)

McLeod, C. L.; Brown, K.; Brydon, R.; Haley, M.; Hill, T.; Shaulis, B.; Tronnes, R. G.

2017-12-01

Advances in the capabilities of microanalysis over the past several decades have promoted a redefinition of traditional petrological terminology. This has allowed a more accurate evaluation of a samples petrogenetic history. For example, the term "phenocryst", specifically describes crystals that grew from the liquid that solidified into the groundmass. Evolving from this idea is the term xenocryst, referring to crystals that did not originate in the magma but were gathered by it, and antecrysts, which crystallized from a progenitor of the magma that solidified into the groundmass. Through identification of a magmas different, and distinct, crystal populations, the petrogenetic history of a magmatic rock can therefore be unraveled. This approach has been widely applied to terrestrial volcanic systems throughout the past several decades. This study presents results from a combined microimaging and in-situ microanalytical investigation of granitic magmas crystal cargoes in order to unravel how granitic batholiths are constructed. 27 lithological units from two granite batholiths in the Oslo Rift, Norway form the basis of this investigation. Micro X-Ray Fluorescence (µXRF) mapping of major elements and selected trace elements is used in order to chemically map each granitic unit, identify any characteristic growth zoning, and compare the crystal cargoes of the different units. Major and trace elemental abundances of the major phases (feldspars, biotite, amphibole) and minor phases (apatite and titanite) are to be quantified through electron microprobe analysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) respectively. Through chemically fingerprinting the crystal cargoes of these Oslo Rift granitic magmas, the open vs. closed nature of granitic, intrusive, magmatic systems will be investigated. Within the context of the Oslo Rift, this study also offers an opportunity to evaluate the processes inherent to granitoid magmatism during continental rifting.

The enantioselective population pharmacokinetics of intravenous ketorolac in children using a stereoselective assay suitable for microanalysis.

PubMed

Mohammed, Baba S; Engelhardt, Thomas; Hawwa, Ahmed F; Cameron, Garry A; McLay, James S

2015-09-01

To describe the effect of age and body size on enantiomer selective pharmacokinetic (PK) of intravenous ketorolac in children using a microanalytical assay. Blood samples were obtained at 0, 15 and 30 min and at 1, 2, 4, 6, 8 and 12 h after a weight-dependent dose of ketorolac. Enantiomer concentration was measured using a liquid chromatography tandem mass spectrometry method. Non-linear mixed-effect modelling was used to assess PK parameters. Data from 11 children (1.7-15.6 years, weight 10.7-67.4 kg) were best described by a two-compartment model for R(+), S(-) and racemic ketorolac. Only weight (WT) significantly improved the goodness of fit. The final population models were CL = 1.5 × (WT/46)(0.75) , V1  = 8.2 × (WT/46), Q = 3.4 × (WT/46)(0.75) , V2  = 7.9 × (WT/46), CL = 2.98 × (WT/46), V1  = 13.2 × (WT/46), Q = 2.8 × (WT/46)(0.75) , V2  = 51.5 × (WT/46), and CL = 1.1 × (WT/46)(0.75) , V1  = 4.9 × (WT/46), Q = 1.7 × (WT/46)(0.75) and V2  = 6.3 × (WT/46)for R(+), S(-) and racemic ketorolac. Only body weight influenced the PK parameters for R(+) and S(-) ketorolac. Using allometric size scaling significantly affected the clearances (CL, Q) and volumes of distribution (V1 , V2 ). © 2015 Royal Pharmaceutical Society.

The oxidation state of Fe in MORB glasses and the oxygen fugacity of the upper mantle

NASA Astrophysics Data System (ADS)

Cottrell, Elizabeth; Kelley, Katherine A.

2011-05-01

Micro-analytical determination of Fe3+/∑Fe ratios in mid-ocean ridge basalt (MORB) glasses using micro X-ray absorption near edge structure (μ-XANES) spectroscopy reveals a substantially more oxidized upper mantle than determined by previous studies. Here, we show that global MORBs yield average Fe3+/∑Fe ratios of 0.16 ± 0.01 (n = 103), which trace back to primary MORB melts equilibrated at the conditions of the quartz-fayalite-magnetite (QFM) buffer. Our results necessitate an upward revision of the Fe3+/∑Fe ratios of MORBs, mantle oxygen fugacity, and the ferric iron content of the mantle relative to previous wet chemical determinations. We show that only 0.01 (absolute, or < 10%) of the difference between Fe3+/∑Fe ratios determined by micro-colorimety and XANES can be attributed to the Mössbauer-based XANES calibration. The difference must instead derive from a bias between micro-colorimetry performed on experimental vs. natural basalts. Co-variations of Fe3+/∑Fe ratios in global MORB with indices of low-pressure fractional crystallization are consistent with Fe3+ behaving incompatibly in shallow MORB magma chambers. MORB Fe3+/∑Fe ratios do not, however, vary with indices of the extent of mantle melting (e.g., Na2O(8)) or water concentration. We offer two hypotheses to explain these observations: The bulk partition coefficient of Fe3+ may be higher during peridotite melting than previously thought, and may vary with temperature, or redox exchange between sulfide and sulfate species could buffer mantle melting at ~ QFM. Both explanations, in combination with the measured MORB Fe3+/∑Fe ratios, point to a fertile MORB source with greater than 0.3 wt.% Fe2O3.

Uptake of Ra during the recrystallization of barite: a microscopic and time of flight-secondary ion mass spectrometry study.

PubMed

Klinkenberg, Martina; Brandt, Felix; Breuer, Uwe; Bosbach, Dirk

2014-06-17

A combined macroscopic and microanalytical approach was applied on two distinct barite samples from Ra uptake batch experiments using time of flight-secondary ion mass spectrometry (ToF-SIMS) and detailed scanning electron microscopy (SEM) investigations. The experiments were set up at near to equilibrium conditions to distinguish between two possible scenarios for the uptake of Ra by already existent barite: (1) formation of a Ba1-xRaxSO4 solid solution surface layer on the barite or (2) a complete recrystallization, leading to homogeneous Ba1-xRaxSO4 crystals. It could be clearly shown that Ra uptake in all barite particles analyzed within this study is not limited to the surface but extends to the entire solid. For most grains a homogeneous distribution of Ra could be determined, indicating a complete recrystallization of barite into a Ba1-xRaxSO4 solid solution. The maxima of the Ra/Ba intensity ratio distribution histograms calculated from ToF-SIMS are identical with the expected Ra/Ba ratios calculated from mass balance assuming a complete recrystallization. In addition, the role of Ra during the recrystallization of barite was examined via detailed SEM investigations. Depending on the type of barite used, an additional coarsening effect or a strong formation of oriented aggregates was observed compared to blank samples without Ra. In conclusion, the addition of Ra to a barite at close to equilibrium conditions has a major impact on the system leading to a fast re-equilibration of the solid to a Ba1-xRaxSO4 solid solution and visible effects on the particle size distribution, even at room temperature.

An introduction to Kundalini yoga meditation techniques that are specific for the treatment of psychiatric disorders.

PubMed

Shannahoff-Khalsa, David S

2004-02-01

The ancient system of Kundalini yoga includes a vast array of meditation techniques and many were discovered to be specific for treating the psychiatric disorders as we know them today. One such technique was found to be specific for treating obsessive-compulsive disorder (OCD), the fourth most common psychiatric disorder, and the tenth most disabling disorder worldwide. Two published clinical trials are described here for treating OCD using a specific Kundalini yoga protocol. This OCD protocol also includes techniques that are useful for a wide range of anxiety disorders, as well as a technique specific for learning to manage fear, one for tranquilizing an angry mind, one for meeting mental challenges, and one for turning negative thoughts into positive thoughts. Part of that protocol is included here and published in detail elsewhere. In addition, a number of other disorder-specific meditation techniques are included here to help bring these tools to the attention of the medical and scientific community. These techniques are specific for phobias, addictive and substance abuse disorders, major depressive disorders, dyslexia, grief, insomnia and other sleep disorders.

Wave Propagation Through Inhomogeneities With Applications to Novel Sensing Techniques

NASA Technical Reports Server (NTRS)

Adamovsky, G.; Tokars, R.; Varga, D.; Floyd B.

2008-01-01

The paper describes phenomena observed as a result of laser pencil beam interactions with abrupt interfaces including aerodynamic shocks. Based on these phenomena, a novel flow visualization technique based on a laser scanning pencil beam is introduced. The technique reveals properties of light interaction with interfaces including aerodynamic shocks that are not seen using conventional visualization. Various configurations of scanning beam devices including those with no moving parts, as well as results of "proof-of-concept" tests, are included.

Digital Mapping Techniques '11–12 workshop proceedings

USGS Publications Warehouse

Soller, David R.

2014-01-01

At these meetings, oral and poster presentations and special discussion sessions emphasized: (1) methods for creating and publishing map products (here, "publishing" includes Web-based release); (2) field data capture software and techniques, including the use of LiDAR; (3) digital cartographic techniques; (4) migration of digital maps into ArcGIS Geodatabase formats; (5) analytical GIS techniques; and (6) continued development of the National Geologic Map Database.

Somatic Treatments for Mood Disorders

PubMed Central

Rosa, Moacyr A; Lisanby, Sarah H

2012-01-01

Somatic treatments for mood disorders represent a class of interventions available either as a stand-alone option, or in combination with psychopharmacology and/or psychotherapy. Here, we review the currently available techniques, including those already in clinical use and those still under research. Techniques are grouped into the following categories: (1) seizure therapies, including electroconvulsive therapy and magnetic seizure therapy, (2) noninvasive techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and cranial electric stimulation, (3) surgical approaches, including vagus nerve stimulation, epidural electrical stimulation, and deep brain stimulation, and (4) technologies on the horizon. Additionally, we discuss novel approaches to the optimization of each treatment, and new techniques that are under active investigation. PMID:21976043

Holographic radar imaging privacy techniques utilizing dual-frequency implementation

NASA Astrophysics Data System (ADS)

McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.

2008-04-01

Over the last 15 years, the Pacific Northwest National Laboratory has performed significant research and development activities to enhance the state of the art of holographic radar imaging systems to be used at security checkpoints for screening people for concealed threats hidden under their garments. These enhancement activities included improvements to privacy techniques to remove human features and providing automatic detection of body-worn concealed threats. The enhanced privacy and detection methods used both physical and software imaging techniques. The physical imaging techniques included polarization-diversity illumination and reception, dual-frequency implementation, and high-frequency imaging at 60 GHz. Software imaging techniques to enhance the privacy of the person under surveillance included extracting concealed threat artifacts from the imagery to automatically detect the threat. This paper will focus on physical privacy techniques using dual-frequency implementation.

Holographic Radar Imaging Privacy Techniques Utilizing Dual-Frequency Implementation

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

McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.

2008-04-18

Over the last 15 years, the Pacific Northwest National Laboratory has performed significant research and development activities to enhance the state of the art of holographic radar imaging systems to be used at security checkpoints for screening people for concealed threats hidden under their garments. These enhancement activities included improvements to privacy techniques to remove human features and providing automatic detection of body-worn concealed threats. The enhanced privacy and detection methods used both physical and software imaging techniques. The physical imaging techniques included polarization-diversity illumination and reception, dual-frequency implementation, and high-frequency imaging at 60 GHz. Software imaging techniques to enhancemore » the privacy of the person under surveillance included extracting concealed threat artifacts from the imagery to automatically detect the threat. This paper will focus on physical privacy techniques using dual-frequency implementation.« less

Research in network management techniques for tactical data communications networks

NASA Astrophysics Data System (ADS)

Boorstyn, R.; Kershenbaum, A.; Maglaris, B.; Sarachik, P.

1982-09-01

This is the final technical report for work performed on network management techniques for tactical data networks. It includes all technical papers that have been published during the control period. Research areas include Packet Network modelling, adaptive network routing, network design algorithms, network design techniques, and local area networks.

Survey of techniques used to preserve biological materials

NASA Technical Reports Server (NTRS)

Feinler, E. J.; Hubbard, R. W.

1972-01-01

The techniques used to preserve biological materials are documented and summarized. The report is presented in a handbook format that categorizes the most important preservation techniques available, and includes a representative sampling of the thousands of applications of these techniques to biological materials and organisms. Details of the information coverage and method of approach are outlined. Data are given in tabular form, and an index and extensive bibliography are included.

Barriers impacting the utilization of supervision techniques in genetic counseling.

PubMed

Masunga, Abigail; Wusik, Katie; He, Hua; Yager, Geoffrey; Atzinger, Carrie

2014-12-01

Clinical supervision is an essential element in training genetic counselors. Although live supervision has been identified as the most common supervision technique utilized in genetic counseling, there is limited information on factors influencing its use as well as the use of other techniques. The purpose of this study was to identify barriers supervisors face when implementing supervision techniques. All participants (N = 141) reported utilizing co-counseling. This was most used with novice students (96.1%) and intermediate students (93.7%). Other commonly used techniques included live supervision where the supervisor is silent during session (98.6%) which was used most frequently with advanced students (94.0%), and student self-report (64.7%) used most often with advanced students (61.2%). Though no barrier to these commonly used techniques was identified by a majority of participants, the most frequently reported barriers included time and concern about patient's welfare. The remaining supervision techniques (live remote observation, video, and audio recording) were each used by less than 10% of participants. Barriers that significantly influenced use of these techniques included lack of facilities/equipment and concern about patient reactions to technique. Understanding barriers to implementation of supervisory techniques may allow students to be efficiently trained in the future by reducing supervisor burnout and increasing the diversity of techniques used.

47 CFR 80.213 - Modulation requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the 2900-3100 MHz band. Racons using frequency agile transmitting techniques must include circuitry... using frequency agile techniques must include circuitry designed to reduce interference caused by...

47 CFR 80.213 - Modulation requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the 2900-3100 MHz band. Racons using frequency agile transmitting techniques must include circuitry... using frequency agile techniques must include circuitry designed to reduce interference caused by...

Sterilization techniques for biodegradable scaffolds in tissue engineering applications

PubMed Central

Dai, Zheng; Ronholm, Jennifer; Tian, Yiping; Sethi, Benu; Cao, Xudong

2016-01-01

Biodegradable scaffolds have been extensively studied due to their wide applications in biomaterials and tissue engineering. However, infections associated with in vivo use of these scaffolds by different microbiological contaminants remain to be a significant challenge. This review focuses on different sterilization techniques including heat, chemical, irradiation, and other novel sterilization techniques for various biodegradable scaffolds. Comparisons of these techniques, including their sterilization mechanisms, post-sterilization effects, and sterilization efficiencies, are discussed. PMID:27247758

[Progress of study on the detection technique of microRNA].

PubMed

Zhao, Hai-Feng; Yang, Ren-Chi

2009-12-01

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their targeted mRNAs. MiRNAs are involved in critical biologic processes, including development, cell differentiation, proliferation and the pathogenesis of disease. This review focuses on recent researches on the detection techniques of miRNA including micorarray technique, Northern blot, real-time quantitative PCR, detection technique of miRNA function and so on.

A review of recent developments in flight test techniques at the Ames Research Center, Dryden Flight Research Facility

NASA Technical Reports Server (NTRS)

Layton, G. P.

1984-01-01

New flight test techniques in use at Ames Dryden are reviewed. The use of the pilot in combination with ground and airborne computational capabilities to maximize data return is discussed, including the remotely piloted research vehicle technique for high-risk testing, the remotely augmented vehicle technique for handling qualities research, and use of ground computed flight director information to fly unique profiles such as constant Reynolds number profiles through the transonic flight regime. Techniques used for checkout and design verification of systems-oriented aircraft are discussed, including descriptions of the various simulations, iron bird setups, and vehicle tests. Some newly developed techniques to support the aeronautical research disciplines are discussed, including a new approach to position-error determination, and the use of a large skin friction balance for the measurement of drag caused by various excrescencies.

Communications techniques and equipment: A compilation

NASA Technical Reports Server (NTRS)

1975-01-01

This Compilation is devoted to equipment and techniques in the field of communications. It contains three sections. One section is on telemetry, including articles on radar and antennas. The second section describes techniques and equipment for coding and handling data. The third and final section includes descriptions of amplifiers, receivers, and other communications subsystems.

A manual for inexpensive methods of analyzing and utilizing remote sensor data

NASA Technical Reports Server (NTRS)

Elifrits, C. D.; Barr, D. J.

1978-01-01

Instructions are provided for inexpensive methods of using remote sensor data to assist in the completion of the need to observe the earth's surface. When possible, relative costs were included. Equipment need for analysis of remote sensor data is described, and methods of use of these equipment items are included, as well as advantages and disadvantages of the use of individual items. Interpretation and analysis of stereo photos and the interpretation of typical patterns such as tone and texture, landcover, drainage, and erosional form are described. Similar treatment is given to monoscopic image interpretation, including LANDSAT MSS data. Enhancement techniques are detailed with respect to their application and simple techniques of creating an enhanced data item. Techniques described include additive and subtractive (Diazo processes) color techniques and enlargement of photos or images. Applications of these processes, including mappings of land resources, engineering soils, geology, water resources, environmental conditions, and crops and/or vegetation, are outlined.

Including internal mammary lymph nodes in radiation therapy for synchronous bilateral breast cancer: an international survey of treatment technique and clinical priorities.

PubMed

Roumeliotis, M; Long, K; Phan, T; Graham, D; Quirk, S

2018-06-05

The aim of this study was to understand the international standard practice for radiation therapy treatment techniques and clinical priorities for institutions including the internal mammary lymph nodes (IMLNs) in the target volume for patients with synchronous bilateral breast cancer. An international survey was developed to include questions that would provide awareness of favored treatment techniques, treatment planning and delivery resource requirements, and the clinical priorities that may lead to the utilization of preferred treatment techniques. Of the 135 respondents, 82 indicated that IMLNs are regularly included in the target volume for radiation therapy (IMLN-inclusion) when the patient is otherwise generally indicated for regional nodal irradiation. Of the 82 respondents that regularly include IMLNs, five were removed as those respondents do not treat this population synchronously. Of the 77 respondents, institutional standard of care varied significantly, though VMAT (34%) and combined static photon and electron fields (21%) were the most commonly utilized techniques. Respondents did preferentially select target volume coverage (70%) as the most important clinical priority, followed by normal tissue sparing (25%). The results of the survey indicate that the IMLN-inclusion for radiation therapy has not yet been comprehensively adopted. As well, no consensus on best practice for radiation therapy treatment techniques has been reached.

Wood lens design philosophy based on a binary additive manufacturing technique

NASA Astrophysics Data System (ADS)

Marasco, Peter L.; Bailey, Christopher

2016-04-01

Using additive manufacturing techniques in optical engineering to construct a gradient index (GRIN) optic may overcome a number of limitations of GRIN technology. Such techniques are maturing quickly, yielding additional design degrees of freedom for the engineer. How best to employ these degrees of freedom is not completely clear at this time. This paper describes a preliminary design philosophy, including assumptions, pertaining to a particular printing technique for GRIN optics. It includes an analysis based on simulation and initial component measurement.

Applications of Electromigration Techniques: Applications of Electromigration Techniques in Food Analysis

NASA Astrophysics Data System (ADS)

Wieczorek, Piotr; Ligor, Magdalena; Buszewski, Bogusław

Electromigration techniques, including capillary electrophoresis (CE), are widely used for separation and identification of compounds present in food products. These techniques may also be considered as alternate and complementary with respect to commonly used analytical techniques, such as high-performance liquid chromatography (HPLC), or gas chromatography (GC). Applications of CE concern the determination of high-molecular compounds, like polyphenols, including flavonoids, pigments, vitamins, food additives (preservatives, antioxidants, sweeteners, artificial pigments) are presented. Also, the method developed for the determination of proteins and peptides composed of amino acids, which are basic components of food products, are studied. Other substances such as carbohydrates, nucleic acids, biogenic amines, natural toxins, and other contaminations including pesticides and antibiotics are discussed. The possibility of CE application in food control laboratories, where analysis of the composition of food and food products are conducted, is of great importance. CE technique may be used during the control of technological processes in the food industry and for the identification of numerous compounds present in food. Due to the numerous advantages of the CE technique it is successfully used in routine food analysis.

[Use of stimulation techniques in pain treatment].

PubMed

Rosted, Palle; Andersen, Claus

2006-05-15

Stimulation techniques (SB) include manipulation, acupuncture, acupressure, physiotherapy, transcutaneous electrical nerve stimulation, reflexotherapy, laser treatment and epidural stimulation technique. The purpose of this paper is to investigate the scientific evidence for these techniques. The Cochrane Library and Medline were searched for all techniques from 2000 to date. Only randomised controlled studies written in English were included. Search words were used, such as; acupuncture and neck pain, shoulder pain, etc. In total 587 papers were identified for the following diseases; headache, neck pain, shoulder pain, elbow pain, low back pain and knee pain. 415 papers were excluded, and the remaining 172 papers, a total of 20,431 patients, are the basis for this study. The effect of acupuncture and epidural stimulation technique is scientifically well-supported. For the remaining techniques, the scientific evidence is dubious.

A Novel Catalyst Deposition Technique for the Growth of Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Delzeit, Lance; Cassell, A.; Stevens, R.; Nguyen, C.; Meyyappan, M.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

This viewgraph presentation provides information on the development of a technique at NASA's Ames Research Center by which carbon nanotubes (NT) can be grown. The project had several goals which included: 1) scaleability, 2) ability to control single wall nanotube (SWNT) and multiwall nanotube (MWNT) formation, 3) ability to control the density of nanotubes as they grow, 4) ability to apply standard masking techniques for NT patterning. Information regarding the growth technique includes its use of a catalyst deposition process. SWNTs of varying thicknesses can be grown by changing the catalyst composition. Demonstrations are given of various methods of masking including the use of transmission electron microscopic (TEM) grids.

Information Exchange Between Resilient and High-Threat Networks: Techniques for Threat Mitigation

DTIC Science & Technology

2004-11-01

Information Exchange between Resilient and High-Threat Networks : Techniques for Threat Mitigation Tim Dean and Graham Wyatt QinetiQ...SUMMARY High resilience military networks frequently have requirements for exchange of information with networks of low assurance, including networks of...assured, two-way, information flow between high resilience networks and other networks of unknown threat. The techniques include conventional and

Apollo Onboard Navigation Techniques

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

This viewgraph presentation reviews basic navigation concepts, describes coordinate systems and identifies attitude determination techniques including Primary Guidance, Navigation and Control System (PGNCS) IMU management and Command and Service Module Stabilization and Control System/Lunar Module (LM) Abort Guidance System (AGS) attitude management. The presentation also identifies state vector determination techniques, including PGNCS coasting flight navigation, PGNCS powered flight navigation and LM AGS navigation.

INNOVATIONS IN EQUIPMENT AND TECHNIQUES FOR THE BIOLOGY TEACHING LABORATORY.

ERIC Educational Resources Information Center

BARTHELEMY, RICHARD E.; AND OTHERS

LABORATORY TECHNIQUES AND EQUIPMENT APPROPRIATE FOR TEACHING BIOLOGICAL SCIENCE CURRICULUM STUDY BIOLOGY ARE EMPHASIZED. MAJOR CATEGORIES INCLUDE (1) LABORATORY FACILITIES, (2) EQUIPMENT AND TECHNIQUES FOR CULTURE OF MICRO-ORGANISMS, (3) LABORATORY ANIMALS AND THEIR HOUSING, (4) TECHNIQUES FOR STUDYING PLANT GROWTH, (5) TECHNIQUES FOR STUDYING…

Analytical Electrochemistry: Methodology and Applications of Dynamic Techniques.

ERIC Educational Resources Information Center

Heineman, William R.; Kissinger, Peter T.

1980-01-01

Reports developments involving the experimental aspects of finite and current analytical electrochemistry including electrode materials (97 cited references), hydrodynamic techniques (56), spectroelectrochemistry (62), stripping voltammetry (70), voltammetric techniques (27), polarographic techniques (59), and miscellany (12). (CS)

Functional Imaging and Related Techniques: An Introduction for Rehabilitation Researchers

PubMed Central

Crosson, Bruce; Ford, Anastasia; McGregor, Keith M.; Meinzer, Marcus; Cheshkov, Sergey; Li, Xiufeng; Walker-Batson, Delaina; Briggs, Richard W.

2010-01-01

Functional neuroimaging and related neuroimaging techniques are becoming important tools for rehabilitation research. Functional neuroimaging techniques can be used to determine the effects of brain injury or disease on brain systems related to cognition and behavior and to determine how rehabilitation changes brain systems. These techniques include: functional magnetic resonance imaging (fMRI), positron emission tomography (PET), electroencephalography (EEG), magnetoencephalography (MEG), near infrared spectroscopy (NIRS), and transcranial magnetic stimulation (TMS). Related diffusion weighted magnetic resonance imaging techniques (DWI), including diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), can quantify white matter integrity. With the proliferation of these imaging techniques in rehabilitation research, it is critical that rehabilitation researchers, as well as consumers of rehabilitation research, become familiar with neuroimaging techniques, what they can offer, and their strengths and weaknesses The purpose to this review is to provide such an introduction to these neuroimaging techniques. PMID:20593321

Behaviour change techniques and contraceptive use in low and middle income countries: a review.

PubMed

Phiri, Mwelwa; King, R; Newell, J N

2015-10-30

We aimed to identify effective behaviour change techniques to increase modern contraceptive use in low and middle income countries (LMICs). Literature was identified in Global Health, Web of Science, MEDLINE, PsycINFO and Popline, as well as peer reviewed journals. Articles were included if they were written in English, had an outcome evaluation of contraceptive use, modern contraceptive use, contraceptive initiation/uptake, contraceptive adherence or continuation of contraception, were a systematic review or randomised controlled trial, and were conducted in a low or middle income country. We assessed the behaviour change techniques used in each intervention and included a new category of male partner involvement. We identified six studies meeting the inclusion criteria. The most effective interventions were those that involve male partner involvement in the decision to initiate contraceptive use. The findings also suggest that providing access to contraceptives in the community promotes their use. The interventions that had positive effects on contraceptive use used a combination of behaviour change techniques. Performance techniques were not used in any of the interventions. The use of social support techniques, which are meant to improve wider social acceptability, did not appear except in two of the interventions. Our findings suggest that when information and contraceptives are provided, contraceptive use improves. Recommendations include reporting of behaviour change studies to include more details of the intervention and techniques employed. There is also a need for further research to understand which techniques are especially effective.

Computer-assisted techniques to evaluate fringe patterns

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Bhat, Gopalakrishna K.

1992-01-01

Strain measurement using interferometry requires an efficient way to extract the desired information from interferometric fringes. Availability of digital image processing systems makes it possible to use digital techniques for the analysis of fringes. In the past, there have been several developments in the area of one dimensional and two dimensional fringe analysis techniques, including the carrier fringe method (spatial heterodyning) and the phase stepping (quasi-heterodyning) technique. This paper presents some new developments in the area of two dimensional fringe analysis, including a phase stepping technique supplemented by the carrier fringe method and a two dimensional Fourier transform method to obtain the strain directly from the discontinuous phase contour map.

Pressure relief and other joint rehabilitation techniques

DOT National Transportation Integrated Search

1987-02-01

A study of four major concrete pavement joint rehabilitation techniques has been conducted, including: pressure relief joints, full-depth repairs, partial-depth repairs and joint resealing. The products of this research include the following for each...

Physical Limitations in Lithography for Microelectronics.

ERIC Educational Resources Information Center

Flavin, P. G.

1981-01-01

Describes techniques being used in the production of microelectronics kits which have replaced traditional optical lithography, including contact and optical projection printing, and X-ray and electron beam lithography. Also includes limitations of each technique described. (SK)

Simulation verification techniques study

NASA Technical Reports Server (NTRS)

Schoonmaker, P. B.; Wenglinski, T. H.

1975-01-01

Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided.

NASA reliability preferred practices for design and test

NASA Technical Reports Server (NTRS)

1991-01-01

Given here is a manual that was produced to communicate within the aerospace community design practices that have contributed to NASA mission success. The information represents the best technical advice that NASA has to offer on reliability design and test practices. Topics covered include reliability practices, including design criteria, test procedures, and analytical techniques that have been applied to previous space flight programs; and reliability guidelines, including techniques currently applied to space flight projects, where sufficient information exists to certify that the technique will contribute to mission success.

Submucosal tunneling techniques: current perspectives.

PubMed

Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

2014-01-01

Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

Analysis of Synthetic Polymers.

ERIC Educational Resources Information Center

Smith, Charles G.; And Others

1989-01-01

Reviews techniques for the characterization and analysis of synthetic polymers, copolymers, and blends. Includes techniques for structure determination, separation, and quantitation of additives and residual monomers; determination of molecular weight; and the study of thermal properties including degradation mechanisms. (MVL)

Pressure relief and other joint rehabilitation techniques : appendices

DOT National Transportation Integrated Search

1987-02-01

Appendices of a study of four major concrete pavement joint rehabilitation techniques has been conducted, including: pressure relief joints, full-depth repairs, partial-depth repairs and joint resealing. The products of this research include the foll...

A Survey of Colormaps in Visualization

PubMed Central

Zhou, Liang; Hansen, Charles D.

2016-01-01

Colormaps are a vital method for users to gain insights into data in a visualization. With a good choice of colormaps, users are able to acquire information in the data more effectively and efficiently. In this survey, we attempt to provide readers with a comprehensive review of colormap generation techniques and provide readers a taxonomy which is helpful for finding appropriate techniques to use for their data and applications. Specifically, we first briefly introduce the basics of color spaces including color appearance models. In the core of our paper, we survey colormap generation techniques, including the latest advances in the field by grouping these techniques into four classes: procedural methods, user-study based methods, rule-based methods, and data-driven methods; we also include a section on methods that are beyond pure data comprehension purposes. We then classify colormapping techniques into a taxonomy for readers to quickly identify the appropriate techniques they might use. Furthermore, a representative set of visualization techniques that explicitly discuss the use of colormaps is reviewed and classified based on the nature of the data in these applications. Our paper is also intended to be a reference of colormap choices for readers when they are faced with similar data and/or tasks. PMID:26513793

Data analysis techniques

NASA Technical Reports Server (NTRS)

Park, Steve

1990-01-01

A large and diverse number of computational techniques are routinely used to process and analyze remotely sensed data. These techniques include: univariate statistics; multivariate statistics; principal component analysis; pattern recognition and classification; other multivariate techniques; geometric correction; registration and resampling; radiometric correction; enhancement; restoration; Fourier analysis; and filtering. Each of these techniques will be considered, in order.

Photomorphic analysis techniques: An interim spatial analysis using satellite remote sensor imagery and historical data

NASA Technical Reports Server (NTRS)

Keuper, H. R.; Peplies, R. W.; Gillooly, R. P.

1977-01-01

The use of machine scanning and/or computer-based techniques to provide greater objectivity in the photomorphic approach was investigated. Photomorphic analysis and its application in regional planning are discussed. Topics included: delineation of photomorphic regions; inadequacies of existing classification systems; tonal and textural characteristics and signature analysis techniques; pattern recognition and Fourier transform analysis; and optical experiments. A bibliography is included.

Gynecomastia Management: An Evolution and Refinement in Technique at UT Southwestern Medical Center

PubMed Central

Bailey, Steven H.; Guenther, Dax; Constantine, Fadi

2016-01-01

Summary: Gynecomastia is a benign proliferation of male breast glandular tissue. Gynecomastia can affect men at any stage of life. Traditional treatment options involved excisional surgeries with periareolar or T-shaped scars, which can leave more visible scars on the chest. The technique presented represents a technique used by the senior author, which relies on ultrasonic liposuction and pull-through technique to remove breast tissue. A retrospective chart review was performed, including all patients who were treated, from 2000 to 2013 by the senior author, for gynecomastia. A deidentified database was created to record patient characteristics, including age, height, weight, ptosis, stage of gynecomastia, and gynecomastia classification. Surgical approaches, complications, and revisions were also recorded. Our experience includes 75 patients with all grades of gynecomastia from 2000 to 2013. These cases span the evolution of our technique to include direct pull-through excision with ultrasound-assisted liposuction. The distribution of the grades I, II, III, and IV ptosis was 30.6%, 36 %, 22.6%, and 10.6% respectively. There were no complications in this series. Only one patient with grade III ptosis required revision surgery. This technique provides a safe and aesthetically pleasing way to treat gynecomastia with a low need for revision. PMID:27482482

Advanced endoscopic imaging to improve adenoma detection

PubMed Central

Neumann, Helmut; Nägel, Andreas; Buda, Andrea

2015-01-01

Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of them equipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system. PMID:25789092

Mitigation and enhancement techniques for the Upper Mississippi River system and other large river systems

USGS Publications Warehouse

Schnick, Rosalie A.; Morton, John M.; Mochalski, Jeffrey C.; Beall, Jonathan T.

1982-01-01

Extensive information is provided on techniques that can reduce or eliminate the negative impact of man's activities (particularly those related to navigation) on large river systems, with special reference to the Upper Mississippi River. These techniques should help resource managers who are concerned with such river systems to establish sound environmental programs. Discussion of each technique or group of techniques include (1) situation to be mitigated or enhanced; (2) description of technique; (3) impacts on the environment; (4) costs; and (5) evaluation for use on the Upper Mississippi River Systems. The techniques are divided into four primary categories: Bank Stabilization Techniques, Dredging and Disposal of Dredged Material, Fishery Management Techniques, and Wildlife Management Techniques. Because techniques have been grouped by function, rather than by structure, some structures are discussed in several contexts. For example, gabions are discussed for use in revetments, river training structures, and breakwaters. The measures covered under Bank Stabilization Techniques include the use of riprap revetments, other revetments, bulkheads, river training structures, breakwater structures, chemical soil stabilizers, erosion-control mattings, and filter fabrics; the planting of vegetation; the creation of islands; the creation of berms or enrichment of beaches; and the control of water level and boat traffic. The discussions of Dredging and the Disposal of Dredged Material consider dredges, dredging methods, and disposal of dredged material. The following subjects are considered under Fishery Management Techniques: fish attractors; spawning structures; nursery ponds, coves, and marshes; fish screens and barriers; fish passage; water control structures; management of water levels and flows; wing dam modification; side channel modification; aeration techniques; control of nuisance aquatic plants; and manipulated of fish populations. Wildlife Management Techniques include treatments of artificial nest structures, island creation or development, marsh creation or development, greentree reservoirs and mast management, vegetation control, water level control, and revegetation.

Technique and cue selection for graphical presentation of generic hyperdimensional data

NASA Astrophysics Data System (ADS)

Howard, Lee M.; Burton, Robert P.

2013-12-01

Several presentation techniques have been created for visualization of data with more than three variables. Packages have been written, each of which implements a subset of these techniques. However, these packages generally fail to provide all the features needed by the user during the visualization process. Further, packages generally limit support for presentation techniques to a few techniques. A new package called Petrichor accommodates all necessary and useful features together in one system. Any presentation technique may be added easily through an extensible plugin system. Features are supported by a user interface that allows easy interaction with data. Annotations allow users to mark up visualizations and share information with others. By providing a hyperdimensional graphics package that easily accommodates presentation techniques and includes a complete set of features, including those that are rarely or never supported elsewhere, the user is provided with a tool that facilitates improved interaction with multivariate data to extract and disseminate information.

Surgical Techniques for the Reconstruction of Medial Collateral Ligament and Posteromedial Corner Injuries of the Knee: A Systematic Review.

PubMed

DeLong, Jeffrey M; Waterman, Brian R

2015-11-01

To systematically review reconstruction techniques of the medial collateral ligament (MCL) and associated medial structures of the knee (e.g., posterior oblique ligament). A systematic review of Medline/PubMed Database (1966 to November 2013), reference list scanning and citation searches of included articles, and manual searches of high-impact journals (2000 to July 2013) and conference proceedings (2009 to July 2013) were performed to identify publications describing MCL reconstruction techniques of the knee. Exclusion criteria included (1) MCL primary repair techniques or advancement procedures, (2) lack of clear description of MCL reconstruction technique, (3) animal models, (4) nonrelevant study design, (5) and foreign language articles without available translation. After review of 4,600 references, 25 publications with 359 of 388 patients (92.5%) were isolated for analysis, including 18 single-bundle MCL and 10 double-bundle reconstruction techniques. Only 2 techniques were classified as anatomic reconstructions, and clinical and objective outcomes (n = 28; 100% <3 mm side-to-side difference [SSD]) were superior to those with nonanatomic reconstruction (n = 182; 79.1% <3 mm SSD) and tendon transfer techniques (n = 114; 52.6% <3 mm SSD). This systematic review demonstrated that numerous medial reconstruction techniques have been used in the treatment of isolated and combined medial knee injuries in the existent literature. Many variations exist among reconstruction techniques and may differ by graft choices, method of fixation, number of bundles, tensioning protocol, and degree of anatomic restoration of medial and posteromedial corner knee restraints. Further studies are required to better ascertain the comparative clinical outcomes with anatomic, non-anatomic, and tendon transfer techniques for medial knee reconstruction. Level IV, systematic review of level IV studies and surgical techniques. Published by Elsevier Inc.

Applications of Geodesy to Geodynamics, an International Symposium

NASA Technical Reports Server (NTRS)

Mueller, I. I. (Editor)

1978-01-01

Geodetic techniques in detecting and monitoring geodynamic phenomena are reviewed. Specific areas covered include: rotation of the earth and polar motion; tectonic plate movements and crustal deformations (space techniques); horizontal crustal movements (terrestrial techniques); vertical crustal movements (terrestrial techniques); gravity field, geoid, and ocean surface by space techniques; surface gravity and new techniques for the geophysical interpretation of gravity and geoid undulation; and earth tides and geodesy.

10 CFR Appendix A to Part 725 - Categories of Restricted Data Available

Code of Federal Regulations, 2013 CFR

2013-01-01

... and radiation studies. b. Chemistry, chemical engineering and radiochemistry of all the elements and their compounds. Included are techniques and processes of chemical separations, radioactive waste..., including chemical engineering, processes and techniques. Reactor physics, engineering and criticality...

Micro- and nanofabrication methods in nanotechnological medical and pharmaceutical devices

PubMed Central

Betancourt, Tania; Brannon-Peppas, Lisa

2006-01-01

Micro- and nanofabrication techniques have revolutionized the pharmaceutical and medical fields as they offer the possibility for highly reproducible mass-fabrication of systems with complex geometries and functionalities, including novel drug delivery systems and bionsensors. The principal micro- and nanofabrication techniques are described, including photolithography, soft lithography, film deposition, etching, bonding, molecular self assembly, electrically induced nanopatterning, rapid prototyping, and electron, X-ray, colloidal monolayer, and focused ion beam lithography. Application of these techniques for the fabrication of drug delivery and biosensing systems including injectable, implantable, transdermal, and mucoadhesive devices is described. PMID:17722281

Combining Vector Quantization and Histogram Equalization.

ERIC Educational Resources Information Center

Cosman, Pamela C.; And Others

1992-01-01

Discussion of contrast enhancement techniques focuses on the use of histogram equalization with a data compression technique, i.e., tree-structured vector quantization. The enhancement technique of intensity windowing is described, and the use of enhancement techniques for medical images is explained, including adaptive histogram equalization.…

Microfabrication Techniques for Plastic Microelectromechanical Systems (MEMS)

DTIC Science & Technology

2003-07-01

micromachining techniques were investigated. Surface micromachining techniques include deposition of thin and thick polymer films using vacuum and spin ...1 2.0 Introduction ...100 4.3.1 Nozzle-diffuser pumps theory

[Development of computer aided forming techniques in manufacturing scaffolds for bone tissue engineering].

PubMed

Wei, Xuelei; Dong, Fuhui

2011-12-01

To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.

Neuroimaging techniques for memory detection: scientific, ethical, and legal issues.

PubMed

Meegan, Daniel V

2008-01-01

There is considerable interest in the use of neuroimaging techniques for forensic purposes. Memory detection techniques, including the well-publicized Brain Fingerprinting technique (Brain Fingerprinting Laboratories, Inc., Seattle WA), exploit the fact that the brain responds differently to sensory stimuli to which it has been exposed before. When a stimulus is specifically associated with a crime, the resulting brain activity should differentiate between someone who was present at the crime and someone who was not. This article reviews the scientific literature on three such techniques: priming, old/new, and P300 effects. The forensic potential of these techniques is evaluated based on four criteria: specificity, automaticity, encoding flexibility, and longevity. This article concludes that none of the techniques are devoid of forensic potential, although much research is yet to be done. Ethical issues, including rights to privacy and against self-incrimination, are discussed. A discussion of legal issues concludes that current memory detection techniques do not yet meet United States standards of legal admissibility.

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection

PubMed Central

Mizutani, Hiroya; Ono, Satoshi; Ohki, Daisuke; Takeuchi, Chihiro; Yakabi, Seiichi; Kataoka, Yosuke; Saito, Itaru; Sakaguchi, Yoshiki; Minatsuki, Chihiro; Tsuji, Yosuke; Niimi, Keiko; Kodashima, Shinya; Yamamichi, Nobutake; Fujishiro, Mitsuhiro; Koike, Kazuhiko

2017-01-01

Colorectal endoscopic submucosal dissection (ESD) is now a well-established endoscopic treatment for early-stage colorectal neoplasms, especially in Asian countries, including Japan. Despite the spread of colorectal ESD, there are still situations in which achieving successful submucosal dissection is difficult. Various novel techniques and devices have been developed to overcome these difficulties, and past reports have shown that some of these strategies can be applied to colorectal ESD. We review several recent developments in the field. The techniques reviewed include the pocket creation method and traction methods and the devices reviewed include the overtube with balloon and electrosurgical knives with water-jet function. These improved techniques and devices can facilitate safer, more reliable ESDs and expand its applicability and acceptability all over the world. PMID:29207854

High resolution trace element records from the deep sea hydrocoral Stylaster venustus: Implications for stylasterids as a paleoceanographic archive

NASA Astrophysics Data System (ADS)

Aranha, R. S.; Layne, G. D.; Edinger, E.; Piercey, G.

2009-12-01

Stylasterids are one of the lesser known groups of deep sea corals, but appear to have potential to serve as viable geochemical archives for reconstructing temperature, salinity and nutrient regimes in the deep ocean. This group of hydrocorals are present in most, if not all of the world’s major oceans. Stylasterid species dominantly have aragonitic skeletons, with a small percentage of species having calcitic skeletons (1). A recent study on the biomineralization of a deep sea stylasterid (Errina dabneyi) has revealed that during the organism’s growth, a steady dissolution and reprecipitation of skeletal material occurs in the central canals of the skeleton. This skeletal modification likely alters the stable isotope and/or trace element profiles of these corals, making them potentially less reliable as geochemical archives, depending on the scale of sampling (2). Recent specimens of Stylaster venustus were collected in July, 2008 from the Olympic Coast National Marine sanctuary off the coast of Washington at depths of 200 - 350 m. We used a Cameca IMS 4f Secondary Ion Mass Spectrometer (SIMS) to perform high spatial resolution (<25 µm) spot analyses of Sr/Ca, Mg/Ca and Na/Ca in detailed traverses across the basal cross-sections from three of these specimens. We identified the remineralized material by remnant porous texture and/or a substantially different trace element composition. Spot analyses corresponding to the remineralized material were eliminated from the dataset. In all three specimens we observed a pronounced inverse correlation (r = -0.36) of Mg/Ca and Sr/Ca profiles throughout the length of the transects . A positive correlation (r =0.46) between Na/Ca and Mg/Ca profiles was also noted in two of the specimens analyzed. These correlations strongly imply that the coral skeleton is recording either cyclical or episodic variations in temperature, with possible overprinting from other environmental variation. The exact relationship between the visible banding in the skeletal cross-section and any cyclicity of trace element profiles is currently ambiguous. However, our analyses demonstrate that microanalytical techniques are a viable means of extracting trace element records from these corals. Further statistical analysis of the trace element transects, in combination with a variety of imaging analyses of the same samples, should help us elucidate what portion of the geochemical signal is temperature dependent and what magnitude of temperature change is actually being recorded. Correlating these trace element profiles with instrumental temperature records will help confirm that useful geochemical archives are preserved by stylasterid skeletons. References: (1) Cairns SD and Macintyre IG. 1992. Phylogenetic implications of calcium carbonate mineralogy in the Stylasteridae (Cnidaria:Hydrozoa).Palaios 7: 96-107. (2) Wisshak M, López Correa M, Zibrowius H, Jakobsen J & Freiwald. (in press). Skeletal reorganisation affects geochemical signals, exemplified in the stylasterid hydrocoral Errina dabneyi (Azores Archipelago). Marine Ecology Progress Series.

Micro-analyses of Interplanetary Dust Particles (IDPs) and Micrometeorites (MMs): Implications for sample return missions to undifferentiated protoplanets

NASA Astrophysics Data System (ADS)

Rietmeijer, F.

The good news is that the original, typically non-chondritic, presolar dust had an extremely simple mineralogy of predominantly Mg-rich olivines and -pyroxenes, pyrrhotite (Fe7 S8 ), Fe-o xides and Fe,Ni-metal. This unique property is preserved in the least modified protoplanets for in situ sampling (e.g. STARDUST, MUSES-C) and in their debris in the form of stratospheric IDPs and MMs. The corollary is that mineralogical complexity in all extraterrestrial materials is an evolved secondary property. The earliest stages of solar system evolution were defined by hierarchical dust accretion whereby the accreting dust was recycled prior to the formation of the final surviving protoplanets. This recycling concentrated initially minor elements so they could form new minerals , e.g. alkali-feldspars and plagioclase. The least- modified protoplanets are comet nuclei, i.e. random mixtures of rubble piles and dirty snowballs, and the icy (ultra)carbonaceous asteroids. Second best are the dormant, extinct and rare active comet nuclei among the near-Earth asteroids that are relatively easy to access by sample return missions. Third are the anhydrous CO/CV carbonaceous chondrites and the low metamorphic grade, unequilibrated ordinary chondrites from the main asteroid belt. Lithification of the original rubble piles in these asteroids erased all structural properties but not the mineralogy and chemistry of the accreted entities, i.e. matrix, chondrules and CAIs.Consequently , returned samples of small chips, fragments or powders from the surface of undifferentiated protoplanets will amply suffice for a full mineralogical and chemical characterization of these small bodies, including modifications from interactions with the space environment, e.g. space weathering, regolith formation and the black mantle on icy-protoplanets. Major improvements in the sensitivity of available micro-analytical tools means that in situ acquired samples can be analyzed at scales of individual, n m-s i z e d constituents to determine the major rock-forming and minor element abundances , isotopic compositions, the nature of and chemical bonds in organic matter. The nature of solid s , crystalline or amorphous, can be identified and the solid-state modification as a function of composition. Measurements of noble gas abundances and isotopes and the physical properties (e.g. density) require samples of only a few nano-grams. Sample site selection on rubble piles is critical. For example, boulders and pebbles in comet nuclei might be proto- CI material that is the most pristine, anhydrous lithified rock in the solar system.

Crustal forensics in arc magmas

NASA Astrophysics Data System (ADS)

Davidson, Jon P.; Hora, John M.; Garrison, Jennifer M.; Dungan, Michael A.

2005-01-01

The geochemical characteristics of continental crust are present in nearly all arc magmas. These characteristics may reflect a specific source process, such as fluid fluxing, common to both arc magmas and the continental crust, and/or may reflect the incorporation of continental crust into arc magmas either at source via subducted sediment, or via contamination during differentiation. Resolving the relative mass contributions of juvenile, mantle-derived material, versus that derived from pre-existing crust of the upper plate, and providing these estimates on an element-by-element basis, is important because: (1) we want to constrain crustal growth rates; (2) we want to quantitatively track element cycling at convergent margins; and (3) we want to determine the origin of economically important elements and compounds. Traditional geochemical approaches for determining the contributions of various components to arc magmas are particularly successful when applied on a comparative basis. Studies of suites from multiple magmatic systems along arcs, for which differentiation effects can be individually constrained, can be used to extrapolate to potential source compositions. In the Lesser Antilles Arc, for example, differentiation trends from individual volcanoes are consistent with open-system evolution. However, such trends do not project back to a common primitive magma composition, suggesting that differentiation modifies magmas that were derived from distinct mantle sources. We propose that such approaches should now be complemented by petrographically constrained mineral-scale isotope and trace element analysis to unravel the contributing components to arc magmas. This innovative approach can: (1) better constrain true end-member compositions by returning wider ranges in geochemical compositions among constituent minerals than is found in whole rocks; (2) better determine magmatic evolution processes from core-rim isotopic or trace element profiles from the phases contained in magmas; and (3) constrain rates of differentiation by applying diffusion-controlled timescales to element profiles. An example from Nguaruhoe Volcano, New Zealand, underscores the importance of such a microsampling approach, showing that mineral isotopic compositions encompass wide ranges, that whole-rock isotopic compositions are consequently simply element-weighted averages of the heterogeneous crystal cargo, and that open-system evolution is proved by core-rim variations in Sr isotope ratios. Nguaruhoe is just one of many systems examined through microanalytical approaches. The overwhelming conclusion of these studies is that crystal cargoes are not truly phenocrystic, but are inherited from various sources. The implication of this realization is that the interpretation of whole-rock isotopic data, including the currently popular U-series, needs careful evaluation in the context of petrographic observations.

Videogrammetric Model Deformation Measurement Technique

NASA Technical Reports Server (NTRS)

Burner, A. W.; Liu, Tian-Shu

2001-01-01

The theory, methods, and applications of the videogrammetric model deformation (VMD) measurement technique used at NASA for wind tunnel testing are presented. The VMD technique, based on non-topographic photogrammetry, can determine static and dynamic aeroelastic deformation and attitude of a wind-tunnel model. Hardware of the system includes a video-rate CCD camera, a computer with an image acquisition frame grabber board, illumination lights, and retroreflective or painted targets on a wind tunnel model. Custom software includes routines for image acquisition, target-tracking/identification, target centroid calculation, camera calibration, and deformation calculations. Applications of the VMD technique at five large NASA wind tunnels are discussed.

Advances in the analysis and design of constant-torque springs

NASA Technical Reports Server (NTRS)

McGuire, John R.; Yura, Joseph A.

1996-01-01

In order to improve the design procedure of constant-torque springs used in aerospace applications, several new analysis techniques have been developed. These techniques make it possible to accurately construct a torque-rotation curve for any general constant-torque spring configuration. These new techniques allow for friction in the system to be included in the analysis, an area of analysis that has heretofore been unexplored. The new analysis techniques also include solutions for the deflected shape of the spring as well as solutions for drum and roller support reaction forces. A design procedure incorporating these new capabilities is presented.

Data analysis techniques used at the Oak Ridge Y-12 plant flywheel evaluation laboratory

NASA Astrophysics Data System (ADS)

Steels, R. S., Jr.; Babelay, E. F., Jr.

1980-07-01

Some of the more advanced data analysis techniques applied to the problem of experimentally evaluating the performance of high performance composite flywheels are presented. Real time applications include polar plots of runout with interruptions relating to balance and relative motions between parts, radial growth measurements, and temperature of the spinning part. The technique used to measure torque applied to a containment housing during flywheel failure is also presented. The discussion of pre and post test analysis techniques includes resonant frequency determination with modal analysis, waterfall charts, and runout signals at failure.

Evaluation of Noncontact Power Collection Techniques

DOT National Transportation Integrated Search

1972-07-01

An evaluation is made of four basic noncontacting techniques of power collection which have possible applicability in future high speed ground transportation systems. The techniques considered include the electric arc, magnetic induction, electrostat...

Buteyko technique use to control asthma symptoms.

PubMed

Austin, Gillian

The Buteyko breathing technique is recommended in national guidance for control of asthma symptoms. This article explores the evidence base for the technique, outlines its main principles and includes two cases studies.

Material cutting, shaping, and forming: A compilation

NASA Technical Reports Server (NTRS)

1974-01-01

Information is presented concerning cutting, shaping, and forming of materials, and the equipment and techniques required for utilizing these materials. The use of molds, electrical fields, and mechanical devices are related to forming materials. Material cutting methods by devices including borers and slicers are presented along with chemical techniques. Shaping and fabrication techniques are described for tubing, honeycomb panels, and ceramic structures. The characteristics of the materials are described. Patent information is included.

Factor Analysis and Counseling Research

ERIC Educational Resources Information Center

Weiss, David J.

1970-01-01

Topics discussed include factor analysis versus cluster analysis, analysis of Q correlation matrices, ipsativity and factor analysis, and tests for the significance of a correlation matrix prior to application of factor analytic techniques. Techniques for factor extraction discussed include principal components, canonical factor analysis, alpha…

The contemporary role of 1 vs. 2-stage repair for proximal hypospadias.

PubMed

Dason, Shawn; Wong, Nathan; Braga, Luis H

2014-12-01

This review discusses the most commonly employed techniques in the repair of proximal hypospadias, highlighting the advantages and disadvantages of single versus staged surgical techniques. Hypospadias can have a spectrum of severity with a urethral meatus ranging from the perineum to the glans. Associated abnormalities are commonly found with proximal hypospadias and encompass a large spectrum, including ventral curvature (VC) up to 50 degrees or more, ventral skin deficiency, a flattened glans, penile torsion and penoscrotal transposition. Our contemporary understanding of hypospadiology is comprised of a foundation built by experts who have described a number of techniques and their outcomes, combined with survey data detailing practice patterns. The two largest components of hypospadias repair include repair of VC and urethroplasty. VC greater than 20 degrees is considered clinically relevant to warrant surgical correction. To repair VC, the penis is first degloved-a procedure that may reduce or remove curvature by itself in some cases. Residual curvature is then repaired with dorsal plication techniques, transection of the urethral plate, and/or ventral lengthening techniques. Urethroplasty takes the form of 1- or 2-stage repairs. One-stage options include the tubularized incised urethroplasty (TIP) or various graft or flap-based techniques. Two-stage options also include grafts or flaps, including oral mucosal and preputial skin grafting. One stage repairs are an attractive option in that they may reduce cost, hospital stay, anesthetic risks, and time to the final result. The downside is that these repairs require mastery of multiple techniques may be more complex, and-depending on technique-have higher complication rates. Two-stage repairs are preferred by the majority of surveyed hypospadiologists. The 2-stage repair is versatile and has satisfactory outcomes, but necessitates a second procedure. Given the lack of clear high-quality evidence supporting the superiority of one approach over the others, hypospadiologists should develop their own algorithm, which gives them the best outcomes.

Parallel image logical operations using cross correlation

NASA Technical Reports Server (NTRS)

Strong, J. P., III

1972-01-01

Methods are presented for counting areas in an image in a parallel manner using noncoherent optical techniques. The techniques presented include the Levialdi algorithm for counting, optical techniques for binary operations, and cross-correlation.

Modified Labial Button Technique for Maintaining Occlusion After Caudal Mandibular Fracture/Temporomandibular Joint Luxation in the Cat.

PubMed

Goodman, Alice E; Carmichael, Daniel T

2016-03-01

Maxillofacial trauma in cats often results in mandibular symphyseal separation in addition to injuries of the caudal mandible and/or temporomandibular joint (TMJ). Caudal mandibular and TMJ injuries are difficult to access and stabilize using direct fixation techniques, thus indirect fixation is commonly employed. The immediate goals of fixation include stabilization for return to normal occlusion and function with the long-term objective of bony union. Indirect fixation techniques commonly used for stabilization of caudal mandibular and temporomandibular joint fracture/luxation include maxillomandibular fixation (MMF) with acrylic composite, interarcade wiring, tape muzzles, and the bignathic encircling and retaining device (BEARD) technique. This article introduces a modification of the previously described "labial reverse suture through buttons" technique used by Koestlin et al and the "labial locking with buttons" technique by Rocha et al. In cases with minimally displaced subcondylar and pericondylar fractures without joint involvement, the labial button technique can provide sufficient stabilization for healing. Advantages of the modified labial button technique include ease of application, noninvasive nature, and use of readily available materials. The construct can remain in place for a variable of amount of time, depending on its intended purpose. It serves as an alternative to the tape muzzle, which is rarely tolerated by cats. This technique can be easily used in conjunction with other maxillomandibular repairs, such as cerclage wire fixation of mandibular symphyseal separation. The purpose of this article is to demonstrate a modified labial button technique for maintaining occlusion of feline caudal mandibular fractures/TMJ luxations in a step-by-step fashion.

Review of Surgical Techniques of Experimental Renal Transplantation in Rats.

PubMed

Shrestha, Badri; Haylor, John

2017-08-01

Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.

The design and implementation of hydrographical information management system (HIMS)

NASA Astrophysics Data System (ADS)

Sui, Haigang; Hua, Li; Wang, Qi; Zhang, Anming

2005-10-01

With the development of hydrographical work and information techniques, the large variety of hydrographical information including electronic charts, documents and other materials are widely used, and the traditional management mode and techniques are unsuitable for the development of the Chinese Marine Safety Administration Bureau (CMSAB). How to manage all kinds of hydrographical information has become an important and urgent problem. A lot of advanced techniques including GIS, RS, spatial database management and VR techniques are introduced for solving these problems. Some design principles and key techniques of the HIMS including the mixed mode base on B/S, C/S and stand-alone computer mode, multi-source & multi-scale data organization and management, multi-source data integration and diverse visualization of digital chart, efficient security control strategies are illustrated in detail. Based on the above ideas and strategies, an integrated system named Hydrographical Information Management System (HIMS) was developed. And the HIMS has been applied in the Shanghai Marine Safety Administration Bureau and obtained good evaluation.

Rapid Fabrication Techniques for Liquid Rocket Channel Wall Nozzles

NASA Technical Reports Server (NTRS)

Gradl, Paul R.

2016-01-01

The functions of a regeneratively-cooled nozzle are to (1) expand combustion gases to increase exhaust gas velocity while, (2) maintaining adequate wall temperatures to prevent structural failure, and (3) transfer heat from the hot gases to the coolant fluid to promote injector performance and stability. Regeneratively-cooled nozzles are grouped into two categories: tube-wall nozzles and channel wall nozzles. A channel wall nozzle is designed with an internal liner containing a series of integral coolant channels that are closed out with an external jacket. Manifolds are attached at each end of the nozzle to distribute coolant to and away from the channels. A variety of manufacturing techniques have been explored for channel wall nozzles, including state of the art laser-welded closeouts and pressure-assisted braze closeouts. This paper discusses techniques that NASA MSFC is evaluating for rapid fabrication of channel wall nozzles that address liner fabrication, slotting techniques and liner closeout techniques. Techniques being evaluated for liner fabrication include large-scale additive manufacturing of freeform-deposition structures to create the liner blanks. Abrasive water jet milling is being evaluated for cutting the complex coolant channel geometries. Techniques being considered for rapid closeout of the slotted liners include freeform deposition, explosive bonding and Cold Spray. Each of these techniques, development work and results are discussed in further detail in this paper.

Efficient implementation of real-time programs under the VAX/VMS operating system

NASA Technical Reports Server (NTRS)

Johnson, S. C.

1985-01-01

Techniques for writing efficient real-time programs under the VAX/VMS oprating system are presented. Basic operations are presented for executing at real-time priority and for avoiding needlless processing delays. A highly efficient technique for accessing physical devices by mapping to the input/output space and accessing the device registrs directly is described. To illustrate the application of the technique, examples are included of different uses of the technique on three devices in the Langley Avionics Integration Research Lab (AIRLAB): the KW11-K dual programmable real-time clock, the Parallel Communications Link (PCL11-B) communication system, and the Datacom Synchronization Network. Timing data are included to demonstrate the performance improvements realized with these applications of the technique.

The Technique of Special Effects in Television.

ERIC Educational Resources Information Center

Wilkie, Bernard

Television, with its special need for movement and continuous shooting, often demands different special effects techniques from those used in films. This book covers the techniques used to create special effects for television which meet these requirements and which also require less time and money than many film techniques. Included are…

The backcross sterility technique

Treesearch

V. C. Mastro; A. Pellegrini-Toole

1991-01-01

The sterile insect technique (SIT) and the induced inherited (F1) sterility technique have been investigated for a number of lepidopterous pests, including the gypsy moths. Another technique, backcross sterility, which could potentially prove as or more useful for control of pest species has been developed for the control of only one lepidopteran...

40 CFR 142.46 - Alternative treatment techniques.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Alternative treatment techniques. 142... Administrator Under Section 1415(a) of the Act § 142.46 Alternative treatment techniques. The Administrator may... that an alternative treatment technique not included in such requirement is at least as efficient in...

Techniques for characterizing lignin

Treesearch

Nicole M. Stark; Daniel J. Yelle; Umesh P. Agarwal

2016-01-01

Many techniques are available to characterize lignin. The techniques presented in this chapter are considered nondegradative, which are commonly applied to lignin. A brief discussion of lignin structure is included with this chapter to aid the reader in understanding why the discussed characterization techniques are appropriate for the study of lignin. Because the...

Techniques for inventorying manmade impacts in roadway environments.

Treesearch

Dale R. Potter; J. Alan. Wagar

1971-01-01

Four techniques for inventorying manmade impacts along roadway corridors were devised and compared. Ground surveillance and ground photography techniques recorded impacts within the corridor visible from the road. Techniques on large- and small-scale aerial photography recorded impacts within a more complete corridor that included areas screened from the road by...

15 CFR 923.25 - Shoreline erosion/mitigation planning.

Code of Federal Regulations, 2011 CFR

2011-01-01

... effects of, and studying and evaluating ways to control, or lessen the impact of, shoreline erosion... must include an identification and description of enforceable policies, legal authorities, funding techniques and other techniques that will be used to manage the effects of erosion, including potential...

A Survey in Indexing and Searching XML Documents.

ERIC Educational Resources Information Center

Luk, Robert W. P.; Leong, H. V.; Dillon, Tharam S.; Chan, Alvin T. S.; Croft, W. Bruce; Allan, James

2002-01-01

Discussion of XML focuses on indexing techniques for XML documents, grouping them into flat-file, semistructured, and structured indexing paradigms. Highlights include searching techniques, including full text search and multistage search; search result presentations; database and information retrieval system integration; XML query languages; and…

Building a Competitive Edge with Additive Manufacturing

DTIC Science & Technology

2013-02-14

construct ceramic molds for complex metal parts using a 3D printing technique. They estimate the new 6 technique could eliminate all of the...processes. They include 3D printing and Additive Beam Techniques.15 Most Additive Manufacturing techniques are specific to certain classes of materials...9 Example Additive Manufacturing Techniques16 3D Printing Additive Beam Stereolithography (SLA) Direct Metal Laser Sintering (DMLS

Measurement techniques investigated for detection of hydrogen chloride gas in ambient air

NASA Technical Reports Server (NTRS)

Gregory, G. L.

1976-01-01

Nine basic techniques are discussed, ranging from concentration (parts per million) to dosage only (parts per million-seconds) measurement techniques. Data for each technique include lower detection limit, response time, instrument status, and in some cases, specificity. Several techniques discussed can detect ambient hydrogen chloride concentrations below 1 part per million with a response time of seconds.

The application of artificial intelligence techniques to large distributed networks

NASA Technical Reports Server (NTRS)

Dubyah, R.; Smith, T. R.; Star, J. L.

1985-01-01

Data accessibility and transfer of information, including the land resources information system pilot, are structured as large computer information networks. These pilot efforts include the reduction of the difficulty to find and use data, reducing processing costs, and minimize incompatibility between data sources. Artificial Intelligence (AI) techniques were suggested to achieve these goals. The applicability of certain AI techniques are explored in the context of distributed problem solving systems and the pilot land data system (PLDS). The topics discussed include: PLDS and its data processing requirements, expert systems and PLDS, distributed problem solving systems, AI problem solving paradigms, query processing, and distributed data bases.

Digital Mapping Techniques '09-Workshop Proceedings, Morgantown, West Virginia, May 10-13, 2009

USGS Publications Warehouse

Soller, David R.

2011-01-01

As in the previous years' meetings, the objective was to foster informal discussion and exchange of technical information, principally in order to develop more efficient methods for digital mapping, cartography, GIS analysis, and information management. At this meeting, oral and poster presentations and special discussion sessions emphasized (1) methods for creating and publishing map products (here, "publishing" includes Web-based release); (2) field data capture software and techniques, including the use of LiDAR; (3) digital cartographic techniques; (4) migration of digital maps into ArcGIS Geodatabase format; (5) analytical GIS techniques; and (6) continued development of the National Geologic Map Database.

Otoplasty.

PubMed

Janis, Jeffrey E; Rohrich, Rod J; Gutowski, Karol A

2005-04-01

Auricular deformities, specifically, prominent ears, are relatively frequent. Although the physiologic consequences are negligible, the aesthetic and psychological effects on the patient can be substantial. Otoplasty techniques are used to correct many auricular deformities, including the prominent ear, the constricted ear, Stahl's deformity, and cryptotia. Various treatments and techniques have been developed for the correction of these deformities, including methods that excise, bend, suture, scratch, or reposition the auricular cartilage. The multitude of different approaches indicates that there is not one clearly definitive technique for correcting these problems. This article reviews the history of otoplasty, its anatomical basis and a method for evaluation, techniques for the correction of the deformity, and potential complications of the procedure.

Computational intelligence techniques for biological data mining: An overview

NASA Astrophysics Data System (ADS)

Faye, Ibrahima; Iqbal, Muhammad Javed; Said, Abas Md; Samir, Brahim Belhaouari

2014-10-01

Computational techniques have been successfully utilized for a highly accurate analysis and modeling of multifaceted and raw biological data gathered from various genome sequencing projects. These techniques are proving much more effective to overcome the limitations of the traditional in-vitro experiments on the constantly increasing sequence data. However, most critical problems that caught the attention of the researchers may include, but not limited to these: accurate structure and function prediction of unknown proteins, protein subcellular localization prediction, finding protein-protein interactions, protein fold recognition, analysis of microarray gene expression data, etc. To solve these problems, various classification and clustering techniques using machine learning have been extensively used in the published literature. These techniques include neural network algorithms, genetic algorithms, fuzzy ARTMAP, K-Means, K-NN, SVM, Rough set classifiers, decision tree and HMM based algorithms. Major difficulties in applying the above algorithms include the limitations found in the previous feature encoding and selection methods while extracting the best features, increasing classification accuracy and decreasing the running time overheads of the learning algorithms. The application of this research would be potentially useful in the drug design and in the diagnosis of some diseases. This paper presents a concise overview of the well-known protein classification techniques.

A review and content analysis of engagement, functionality, aesthetics, information quality, and change techniques in the most popular commercial apps for weight management.

PubMed

Bardus, Marco; van Beurden, Samantha B; Smith, Jane R; Abraham, Charles

2016-03-10

There are thousands of apps promoting dietary improvement, increased physical activity (PA) and weight management. Despite a growing number of reviews in this area, popular apps have not been comprehensively analysed in terms of features related to engagement, functionality, aesthetics, information quality, and content, including the types of change techniques employed. The databases containing information about all Health and Fitness apps on GP and iTunes (7,954 and 25,491 apps) were downloaded in April 2015. Database filters were applied to select the most popular apps available in both stores. Two researchers screened the descriptions selecting only weight management apps. Features, app quality and content were independently assessed using the Mobile App Rating Scale (MARS) and previously-defined categories of techniques relevant to behaviour change. Inter-coder reliabilities were calculated, and correlations between features explored. Of the 23 popular apps included in the review 16 were free (70%), 15 (65%) addressed weight control, diet and PA combined; 19 (83%) allowed behavioural tracking. On 5-point MARS scales, apps were of average quality (Md = 3.2, IQR = 1.4); "functionality" (Md = 4.0, IQR = 1.1) was the highest and "information quality" (Md = 2.0, IQR = 1.1) was the lowest domain. On average, 10 techniques were identified per app (range: 1-17) and of the 34 categories applied, goal setting and self-monitoring techniques were most frequently identified. App quality was positively correlated with number of techniques included (rho = .58, p < .01) and number of "technical" features (rho = .48, p < .05), which was also associated with the number of techniques included (rho = .61, p < .01). Apps that provided tracking used significantly more techniques than those that did not. Apps with automated tracking scored significantly higher in engagement, aesthetics, and overall MARS scores. Those that used change techniques previously associated with effectiveness (i.e., goal setting, self-monitoring and feedback) also had better "information quality". Popular apps assessed have overall moderate quality and include behavioural tracking features and a range of change techniques associated with behaviour change. These apps may influence behaviour, although more attention to information quality and evidence-based content are warranted to improve their quality.

Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

NASA Astrophysics Data System (ADS)

Yang, Le; Wang, Shuo; Feng, Jianghua

2017-11-01

Electromagnetic interference (EMI) causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive (VFD) systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifierinverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifierinverter systems are also summarized. EMI noise suppression techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.

Automated on-line renewable solid-phase extraction-liquid chromatography exploiting multisyringe flow injection-bead injection lab-on-valve analysis.

PubMed

Quintana, José Benito; Miró, Manuel; Estela, José Manuel; Cerdà, Víctor

2006-04-15

In this paper, the third generation of flow injection analysis, also named the lab-on-valve (LOV) approach, is proposed for the first time as a front end to high-performance liquid chromatography (HPLC) for on-line solid-phase extraction (SPE) sample processing by exploiting the bead injection (BI) concept. The proposed microanalytical system based on discontinuous programmable flow features automated packing (and withdrawal after single use) of a small amount of sorbent (<5 mg) into the microconduits of the flow network and quantitative elution of sorbed species into a narrow band (150 microL of 95% MeOH). The hyphenation of multisyringe flow injection analysis (MSFIA) with BI-LOV prior to HPLC analysis is utilized for on-line postextraction treatment to ensure chemical compatibility between the eluate medium and the initial HPLC gradient conditions. This circumvents the band-broadening effect commonly observed in conventional on-line SPE-based sample processors due to the low eluting strength of the mobile phase. The potential of the novel MSFI-BI-LOV hyphenation for on-line handling of complex environmental and biological samples prior to reversed-phase chromatographic separations was assessed for the expeditious determination of five acidic pharmaceutical residues (viz., ketoprofen, naproxen, bezafibrate, diclofenac, and ibuprofen) and one metabolite (viz., salicylic acid) in surface water, urban wastewater, and urine. To this end, the copolymeric divinylbenzene-co-n-vinylpyrrolidone beads (Oasis HLB) were utilized as renewable sorptive entities in the micromachined unit. The automated analytical method features relative recovery percentages of >88%, limits of detection within the range 0.02-0.67 ng mL(-1), and coefficients of variation <11% for the column renewable mode and gives rise to a drastic reduction in operation costs ( approximately 25-fold) as compared to on-line column switching systems.

Infant negative reactivity defines the effects of parent-child synchrony on physiological and behavioral regulation of social stress.

PubMed

Pratt, Maayan; Singer, Magi; Kanat-Maymon, Yaniv; Feldman, Ruth

2015-11-01

How infants shape their own development has puzzled developmentalists for decades. Recent models suggest that infant dispositions, particularly negative reactivity and regulation, affect outcome by determining the extent of parental effects. Here, we used a microanalytic experimental approach and proposed that infants with varying levels of negative reactivity will be differentially impacted by parent-infant synchrony in predicting physiological and behavioral regulation of increasing social stress during an experimental paradigm. One hundred and twenty-two mother-infant dyads (4-6 months) were observed in the face-to-face still face (SF) paradigm and randomly assigned to three experimental conditions: SF with touch, standard SF, and SF with arms' restraint. Mother-infant synchrony and infant negative reactivity were observed at baseline, and three mechanisms of behavior regulation were microcoded; distress, disengagement, and social regulation. Respiratory sinus arrhythmia baseline, reactivity, and recovery were quantified. Structural equation modeling provided support for our hypothesis. For physiological regulation, infants high in negative reactivity receiving high mother-infant synchrony showed greater vagal withdrawal, which in turn predicted comparable levels of vagal recovery to that of nonreactive infants. In behavioral regulation, only infants low in negative reactivity who received high synchrony were able to regulate stress by employing social engagement cues during the SF phase. Distress was reduced only among calm infants to highly synchronous mothers, and disengagement was lowest among highly reactive infants experiencing high mother-infant synchrony. Findings chart two pathways by which synchrony may bolster regulation in infants of high and low reactivity. Among low reactive infants, synchrony builds a social repertoire for handling interpersonal stress, whereas in highly reactive infants, it constructs a platform for repeated reparation of momentary interactive "failures" and reduces the natural tendency of stressed infants to disengage from source of distress. Implications for the construction of synchrony-focused interventions targeting infants of varying dispositions are discussed.

La microscopie ionique analytique des tissus biologiques

NASA Astrophysics Data System (ADS)

Galle, P.

Proposed in 1960 by R. Castaing and G. Slodzian, secondary ion emission microanalysis is a microanalytical method which is now largely used for the study of inert material. The instrument called the analytical ion microscope can also be used for the study of biological spécimens ; images representing the distribution of a given stable or radioactive isotope in a tissue section are obtained with a resolution of 0.5 μm. Among the characteristics of this method, two are of particular interest in biological research : its capacity for isotopic analysis and its very high sensitivity which makes possible for the first time a chemical analysis of element at a very low or even at a trace concentration in a microvolume. Proposé en 1960 par R. Castaing et G. Slodzian, la microanalyse par émission ionique secondaire est une méthode qui permet, entre autre, d'obtenir des images représentant la distribution des isotopes présents à la surface d'un échantillon solide avec une résolution de 0,5 μm. D'intérêt très général, cette méthode a été d'abord largement utilisée pour l'étude des matériaux inertes. Elle offre en outre des possibilités entièrement nouvelles dans le domaine de la recherche biomédicale. L'instrument réalisé, le microscope ionique analytique présente deux caractéristiques particulièrement intéressantes pour la biologie : la possibilité d'analyse isotopique, et l'extrême sensibilité permettant de détecter et de localiser dans une coupe histologique des éléments à des concentrations très faibles voire à l'état de trace.

Common origin of plagioclase in the last three eruptions of Unzen volcano, Japan

NASA Astrophysics Data System (ADS)

Nakai, Shun'ichi; Maeda, Yasunobu; Nakada, Setsuya

2008-07-01

Megacrysts (large crystals of 2-15 mm in length) of plagioclases extracted from the lavas of the last three eruptions of southwestern Japan's Unzen volcano (AD 1663, AD 1792 and AD 1991-1995) have limited 87Sr/ 86Sr ratios of 0.70439-0.70454. Results of micro-drilling analyses indicated that three of eight megacrysts showed a gradual decrease in 87Sr/ 86Sr ratios from the core to the rim, whereas other megacrysts showed a homogeneous 87Sr/ 86Sr ratio. This relative homogeneity contrasts sharply to the wide variation of 87Sr/ 86Sr ratios of matrixes of the lavas of the last three eruptions (0.71417, 0.70467, 0.70447-0.70450, respectively). Most megacrysts show isotopic disequilibrium between their outer rims and their matrixes, suggesting that they did not grow in the host magmas. In addition, seven of the eight megacrysts of plagioclase also have similar trace element abundance ratios (La/Nd and Sr/Ba). Their similar chemical and isotopic compositions suggest that they crystallized from the same parent magma, which suggests to us that they were formed prior to or during the eruption in 1663. The isotopic ratios of the 1663 eruption lavas of 0.71417, however, rules out the possibility that it is the parent magma for the plagioclase megacrysts. The lavas erupted 4000 and 5000 years ago have 87Sr/ 86Sr ratios of 0.70454 and 0.70442, respectively, [Chen, C.-H., DePaolo, D.J., Nakada, S., Shieh, Y.-N., 1993. Relationship between eruption volume and neodymium isotopic composition at Unzen volcano. Nature 362, 831-834]; they are inferred to be of the parent magma because of their Sr isotope ratios. Consequently, the micro-analytical results seem to suggest that plagioclases with a single origin can be supplied to volcanic products of several different eruptions surviving several eruption events.

Image fusion of Secondary Ion Mass Spectrometry and Energy-dispersive X-Ray Spectroscopy data for the characterization of uranium-molybdenum fuel foils

NASA Astrophysics Data System (ADS)

Willingham, David; Naes, Benjamin E.; Tarolli, Jay G.; Schemer-Kohrn, Alan; Rhodes, Mark; Dahl, Michael; Guzman, Anthony; Burkes, Douglas E.

2018-01-01

Uranium-molybdenum (U-Mo) monolithic fuels represent one option for converting civilian research and test reactors operating with high enriched uranium (HEU) to low enriched uranium (LEU), effectively reducing the threat of nuclear proliferation world-wide. However, processes associated with fabrication of U-Mo monolithic fuels result in regions of elemental heterogeneity, observed as bands traversing the cross-section of representative samples. Isotopic variations (e.g., 235U and 238U) could also be introduced because of associated processing steps, particularly since HEU feedstock is melted with natural or depleted uranium diluent to produce LEU. This study demonstrates the utility of correlative analysis of Energy-Dispersive X-ray Spectroscopy (EDS) and Secondary Ion Mass Spectrometry (SIMS) with their image data streams using image fusion, resulting in a comprehensive microanalytical characterization toolbox. Elemental and isotopic measurements were made on a sample from the Advanced Test Reactor (ATR) Full-sized plate In-center flux trap Position (AFIP)-7 experiment and compared to previous optical and electron microscopy results. The image fusion results are characteristic of SIMS isotopic maps, but with the spatial resolution of EDS images and, therefore, can be used to increase the effective spatial resolution of the SIMS imaging results to better understand homogeneity or heterogeneity that persists because of processing selections. Visual inspection using the image fusion methodology indicated slight variations in the 235U/238U ratio and quantitative analysis using the image intensities across several FoVs revealed an average 235U atom percent value of 17.9 ± 2.4%, which was indicative of a non-uniform U isotopic distribution in the area sampled. Further development of this capability is useful for understanding the connections between the properties of LEU fuel alternatives and the ability to predict performance under irradiation.

Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

PubMed Central

2011-01-01

Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging. PMID:21798021

Effusion plate using additive manufacturing methods

DOEpatents

Johnson, Thomas Edward; Keener, Christopher Paul; Ostebee, Heath Michael; Wegerif, Daniel Gerritt

2016-04-12

Additive manufacturing techniques may be utilized to construct effusion plates. Such additive manufacturing techniques may include defining a configuration for an effusion plate having one or more internal cooling channels. The manufacturing techniques may further include depositing a powder into a chamber, applying an energy source to the deposited powder, and consolidating the powder into a cross-sectional shape corresponding to the defined configuration. Such methods may be implemented to construct an effusion plate having one or more channels with a curved cross-sectional geometry.

Technique for identifying, tracing, or tracking objects in image data

DOEpatents

Anderson, Robert J [Albuquerque, NM; Rothganger, Fredrick [Albuquerque, NM

2012-08-28

A technique for computer vision uses a polygon contour to trace an object. The technique includes rendering a polygon contour superimposed over a first frame of image data. The polygon contour is iteratively refined to more accurately trace the object within the first frame after each iteration. The refinement includes computing image energies along lengths of contour lines of the polygon contour and adjusting positions of the contour lines based at least in part on the image energies.

Michigan Physicians' Conference on Elder Abuse. Final Report.

ERIC Educational Resources Information Center

Sengstock, Mary C.; O'Brien, James G.

The final report describes the Michigan Physicians' Conference on Elder Abuse project. The project conference had four major content areas, including: a general introduction to the problem of elder abuse; clinical symptoms of abuse; legal issues; and referral and case management techniques. Training techniques included lectures, group discussion,…

Sketchcode: A Documentation Technique for Computer Hobbyists and Programmers

ERIC Educational Resources Information Center

Voros, Todd, L.

1978-01-01

Sketchcode is a metaprograming pseudo-language documentation technique intended to simplify the process of program writing and debugging for both high and low-level users. Helpful hints and examples for the use of the technique are included. (CMV)

Review of sonic-boom simulation devices and techniques.

NASA Technical Reports Server (NTRS)

Edge, P. M., Jr.; Hubbard, H. H.

1972-01-01

Research on aircraft-generated sonic booms has led to the development of special techniques to generate controlled sonic-boom-type disturbances without the complications and expense of supersonic flight operations. This paper contains brief descriptions of several of these techniques along with the significant hardware items involved and indicates the advantages and disadvantages of each in research applications. Included are wind tunnels, ballistic ranges, spark discharges, piston phones, shock tubes, high-speed valve systems, and shaped explosive charges. Specialized applications include sonic-boom generation and propagation studies and the responses of structures, terrain, people, and animals. Situations for which simulators are applicable are shown to include both small-scale and large-scale laboratory tests and full-scale field tests. Although no one approach to simulation is ideal, the various techniques available generally complement each other to provide desired capability for a broad range of sonic-boom studies.

HDL-level automated watermarking of IP cores

NASA Astrophysics Data System (ADS)

Castillo, E.; Meyer-Baese, U.; Parrilla, L.; García, A.; Lloris, A.

2008-04-01

This paper presents significant improvements to our previous watermarking technique for Intellectual Property Protection (IPP) of IP cores. The technique relies on hosting the bits of a digital signature at the HDL design level using resources included within the original system. Thus, any attack trying to change or remove the digital signature will damage the design. The technique also includes a procedure for secure signature extraction requiring minimal modifications to the system. The new advances refer to increasing the applicability of this watermarking technique to any design, not only to those including look-ups, and the provision of an automatic tool for signature hosting purposes. Synthesis results show that the application of the proposed watermarking strategy results in negligible degradation of system performance and very low area penalties and that the use of the automated tool, in addition to easy the signature hosting, leads to reduced area penalties.

Larval RNA Interference in the Red Flour Beetle, Tribolium castaneum

PubMed Central

Tomoyasu, Yoshinori

2014-01-01

The red flour beetle, Tribolium castaneum, offers a repertoire of experimental tools for genetic and developmental studies, including a fully annotated genome sequence, transposon-based transgenesis, and effective RNA interference (RNAi). Among these advantages, RNAi-based gene knockdown techniques are at the core of Tribolium research. T. castaneum show a robust systemic RNAi response, making it possible to perform RNAi at any life stage by simply injecting double-stranded RNA (dsRNA) into the beetle’s body cavity. In this report, we provide an overview of our larval RNAi technique in T. castaneum. The protocol includes (i) isolation of the proper stage of T. castaneum larvae for injection, (ii) preparation for the injection setting, and (iii) dsRNA injection. Larval RNAi is a simple, but powerful technique that provides us with quick access to loss-of-function phenotypes, including multiple gene knockdown phenotypes as well as a series of hypomorphic phenotypes. Since virtually all T. castaneum tissues are susceptible to extracellular dsRNA, the larval RNAi technique allows researchers to study a wide variety of tissues in diverse contexts, including the genetic basis of organismal responses to the outside environment. In addition, the simplicity of this technique stimulates more student involvement in research, making T. castaneum an ideal genetic system for use in a classroom setting. PMID:25350485

Evaluation of control laws and actuator locations for control systems applicable to deformable astronomical telescope mirrors

NASA Technical Reports Server (NTRS)

Ostroff, A. J.

1973-01-01

Some of the major difficulties associated with large orbiting astronomical telescopes are the cost of manufacturing the primary mirror to precise tolerances and the maintaining of diffraction-limited tolerances while in orbit. One successfully demonstrated approach for minimizing these problem areas is the technique of actively deforming the primary mirror by applying discrete forces to the rear of the mirror. A modal control technique, as applied to active optics, has previously been developed and analyzed. The modal control technique represents the plant to be controlled in terms of its eigenvalues and eigenfunctions which are estimated via numerical approximation techniques. The report includes an extension of previous work using the modal control technique and also describes an optimal feedback controller. The equations for both control laws are developed in state-space differential form and include such considerations as stability, controllability, and observability. These equations are general and allow the incorporation of various mode-analyzer designs; two design approaches are presented. The report also includes a technique for placing actuator and sensor locations at points on the mirror based upon the flexibility matrix of the uncontrolled or unobserved modes of the structure. The locations selected by this technique are used in the computer runs which are described. The results are based upon three different initial error distributions, two mode-analyzer designs, and both the modal and optimal control laws.

Flow-based analysis using microfluidics-chemiluminescence systems.

PubMed

Al Lawati, Haider A J

2013-01-01

This review will discuss various approaches and techniques in which analysis using microfluidics-chemiluminescence systems (MF-CL) has been reported. A variety of applications is examined, including environmental, pharmaceutical, biological, food and herbal analysis. Reported uses of CL reagents, sample introduction techniques, sample pretreatment methods, CL signal enhancement and detection systems are discussed. A hydrodynamic pumping system is predominately used for these applications. However, several reports are available in which electro-osmotic (EO) pumping has been implemented. Various sample pretreatment methods have been used, including liquid-liquid extraction, solid-phase extraction and molecularly imprinted polymers. A wide range of innovative techniques has been reported for CL signal enhancement. Most of these techniques are based on enhancement of the mixing process in the microfluidics channels, which leads to enhancement of the CL signal. However, other techniques are also reported, such as mirror reaction, liquid core waveguide, on-line pre-derivatization and the use of an opaque white chip with a thin transparent seal. Photodetectors are the most commonly used detectors; however, other detection systems have also been used, including integrated electrochemiluminescence (ECL) and organic photodiodes (OPDs). Copyright © 2012 John Wiley & Sons, Ltd.

Digital Mapping Techniques '07 - Workshop Proceedings

USGS Publications Warehouse

Soller, David R.

2008-01-01

The Digital Mapping Techniques '07 (DMT'07) workshop was attended by 85 technical experts from 49 agencies, universities, and private companies, including representatives from 27 state geological surveys. This year's meeting, the tenth in the annual series, was hosted by the South Carolina Geological Survey, from May 20-23, 2007, on the University of South Carolina campus in Columbia, South Carolina. Each DMT workshop has been coordinated by the U.S. Geological Survey's National Geologic Map Database Project and the Association of American State Geologists (AASG). As in previous year's meetings, the objective was to foster informal discussion and exchange of technical information, principally in order to develop more efficient methods for digital mapping, cartography, GIS analysis, and information management. At this meeting, oral and poster presentations and special discussion sessions emphasized: 1) methods for creating and publishing map products (here, 'publishing' includes Web-based release); 2) field data capture software and techniques, including the use of LIDAR; 3) digital cartographic techniques; 4) migration of digital maps into ArcGIS Geodatabase format; 5) analytical GIS techniques; and 6) continued development of the National Geologic Map Database.

A review on various electrochemical techniques for heavy metal ions detection with different sensing platforms.

PubMed

Bansod, BabanKumar; Kumar, Tejinder; Thakur, Ritula; Rana, Shakshi; Singh, Inderbir

2017-08-15

Heavy metal ions are non-biodegradable and contaminate most of the natural resources occurring in the environment including water. Some of the heavy metals including Lead (Pb), Mercury (Hg), Arsenic (As), Chromium (Cr) and Cadmium (Cd) are considered to be highly toxic and hazardous to human health even at trace levels. This leads to the requirement of fast, accurate and reliable techniques for the detection of heavy metal ions. This review presents various electrochemical detection techniques for heavy metal ions those are user friendly, low cost, provides on-site and real time monitoring as compared to other spectroscopic and optical techniques. The categorization of different electrochemical techniques is done on the basis of different types of detection signals generated due to presence of heavy metal ions in the solution matrix like current, potential, conductivity, electrochemical impedance, and electrochemiluminescence. Also, the recent trends in electrochemical detection of heavy metal ions with various types of sensing platforms including metals, metal films, metal oxides, nanomaterials, carbon nano tubes, polymers, microspheres and biomaterials have been evoked. Copyright © 2017 Elsevier B.V. All rights reserved.

Imaging of respiratory muscles in neuromuscular disease: A review.

PubMed

Harlaar, L; Ciet, P; van der Ploeg, A T; Brusse, E; van der Beek, N A M E; Wielopolski, P A; de Bruijne, M; Tiddens, H A W M; van Doorn, P A

2018-03-01

Respiratory muscle weakness frequently occurs in patients with neuromuscular disease. Measuring respiratory function with standard pulmonary function tests provides information about the contribution of all respiratory muscles, the lungs and airways. Imaging potentially enables the study of different respiratory muscles, including the diaphragm, separately. In this review, we provide an overview of imaging techniques used to study respiratory muscles in neuromuscular disease. We identified 26 studies which included a total of 573 patients with neuromuscular disease. Imaging of respiratory muscles was divided into static and dynamic techniques. Static techniques comprise chest radiography, B-mode (brightness mode) ultrasound, CT and MRI, and are used to assess the position and thickness of the diaphragm and the other respiratory muscles. Dynamic techniques include fluoroscopy, M-mode (motion mode) ultrasound and MRI, used to assess diaphragm motion in one or more directions. We discuss how these imaging techniques relate with spirometric values and whether these can be used to study the contribution of the different respiratory muscles in patients with neuromuscular disease. Copyright © 2017. Published by Elsevier B.V.

Multimodal system planning technique : an analytical approach to peak period operation

DOT National Transportation Integrated Search

1995-11-01

The multimodal system planning technique described in this report is an improvement of the methodology used in the Dallas System Planning Study. The technique includes a spreadsheet-based process to identify the costs of congestion, construction, and...

Managing Documents in the Wider Area: Intelligent Document Management.

ERIC Educational Resources Information Center

Bittleston, Richard

1995-01-01

Discusses techniques for managing documents in wide area networks, reviews technique limitations, and offers recommendations to database designers. Presented techniques include: increasing bandwidth, reducing data traffic, synchronizing documentation, partial synchronization, audit trials, navigation, and distribution control and security. Two…

Metal Matrix Composites: Fatigue and Fracture Testing. (Latest citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1996-01-01

The bibliography contains citations concerning techniques and results of testing metal matrix composites for fatigue and fracture. Methods include non-destructive testing techniques, and static and cyclic techniques for assessing compression, tensile, bending, and impact characteristics.

Beyond the Snapshot.

ERIC Educational Resources Information Center

Smith, Lloyd

1979-01-01

Presents some inventive darkroom techniques which can lead students to new interests in designing creative images. These techniques include easel manipulation, image blending, paper negatives, vignette, vaseline smear, cut strip, flop negative, or combinations of these. Each technique is illustrated by a student photograph. (Author/SJL)

Aerospace management techniques: Commercial and governmental applications

NASA Technical Reports Server (NTRS)

Milliken, J. G.; Morrison, E. J.

1971-01-01

A guidebook for managers and administrators is presented as a source of useful information on new management methods in business, industry, and government. The major topics discussed include: actual and potential applications of aerospace management techniques to commercial and governmental organizations; aerospace management techniques and their use within the aerospace sector; and the aerospace sector's application of innovative management techniques.

Sensing Applied Load and Damage Effects in Composites with Nondestructive Techniques

DTIC Science & Technology

2017-05-01

evaluation (NDE) techniques. Evaluation using piezoelectrically induced guided waves, acoustic emission, thermography, and X-ray imaging were compared...nondestructive inspection to further understanding of the material itself and the capabilities of various nondestructive evaluation (NDE) techniques...materials because of their inherent differences. NDE techniques exist that can evaluate composite structures for damage including C-Scan

The contemporary role of 1 vs. 2-stage repair for proximal hypospadias

PubMed Central

Dason, Shawn; Wong, Nathan

2014-01-01

This review discusses the most commonly employed techniques in the repair of proximal hypospadias, highlighting the advantages and disadvantages of single versus staged surgical techniques. Hypospadias can have a spectrum of severity with a urethral meatus ranging from the perineum to the glans. Associated abnormalities are commonly found with proximal hypospadias and encompass a large spectrum, including ventral curvature (VC) up to 50 degrees or more, ventral skin deficiency, a flattened glans, penile torsion and penoscrotal transposition. Our contemporary understanding of hypospadiology is comprised of a foundation built by experts who have described a number of techniques and their outcomes, combined with survey data detailing practice patterns. The two largest components of hypospadias repair include repair of VC and urethroplasty. VC greater than 20 degrees is considered clinically relevant to warrant surgical correction. To repair VC, the penis is first degloved—a procedure that may reduce or remove curvature by itself in some cases. Residual curvature is then repaired with dorsal plication techniques, transection of the urethral plate, and/or ventral lengthening techniques. Urethroplasty takes the form of 1- or 2-stage repairs. One-stage options include the tubularized incised urethroplasty (TIP) or various graft or flap-based techniques. Two-stage options also include grafts or flaps, including oral mucosal and preputial skin grafting. One stage repairs are an attractive option in that they may reduce cost, hospital stay, anesthetic risks, and time to the final result. The downside is that these repairs require mastery of multiple techniques may be more complex, and—depending on technique—have higher complication rates. Two-stage repairs are preferred by the majority of surveyed hypospadiologists. The 2-stage repair is versatile and has satisfactory outcomes, but necessitates a second procedure. Given the lack of clear high-quality evidence supporting the superiority of one approach over the others, hypospadiologists should develop their own algorithm, which gives them the best outcomes. PMID:26813851

Valve-sparing options in tetralogy of Fallot surgery.

PubMed

Bacha, Emile

2012-01-01

Given late outcomes of patients with tetralogy of Fallot repaired in the 1970s and 1980s, as well as a better understanding of the late deleterious effects of pulmonary regurgitation, there is a tendency toward preservation of the pulmonary valve function during primary repair of tetralogy of Fallot. The bar keeps moving downward, to include smaller and more dysmorphic pulmonary valves. This article reviews some useful indications and techniques for valve-sparing options, including intraoperative balloon dilation and cusp reconstruction using a patch. Just like other valve repair techniques, no one technique can be applied uniformly, and surgeons must master a wide armamentarium of techniques. Copyright © 2012 Elsevier Inc. All rights reserved.

Dental whitening--revisiting the myths.

PubMed

Perdigão, Jorge

2010-01-01

The popularity of dental bleaching has increased with the introduction of at-home whitening. Currently available whitening methods include those prescribed by a dental professional for use at home, those applied by the professional in the dental office, a combination of the two, or systems available over the counter. This article reviews the effect, efficacy, and safety of bleaching techniques and materials. Most whitening techniques are considered effective and safe when carried out under the supervision of a dental professional. This article also compares the efficacy and safety of some of the most popular bleaching techniques, including at-home whitening with carbamide peroxide, over-the-counter (OTC) systems, and in-office whitening. Some of these whitening techniques are illustrated in this article.

Approaches to answering critical CER questions.

PubMed

Kinnier, Christine V; Chung, Jeanette W; Bilimoria, Karl Y

2015-01-01

While randomized controlled trials (RCTs) are the gold standard for research, many research questions cannot be ethically and practically answered using an RCT. Comparative effectiveness research (CER) techniques are often better suited than RCTs to address the effects of an intervention under routine care conditions, an outcome otherwise known as effectiveness. CER research techniques covered in this section include: effectiveness-oriented experimental studies such as pragmatic trials and cluster randomized trials, treatment response heterogeneity, observational and database studies including adjustment techniques such as sensitivity analysis and propensity score analysis, systematic reviews and meta-analysis, decision analysis, and cost effectiveness analysis. Each section describes the technique and covers the strengths and weaknesses of the approach.

Research in Natural Laminar Flow and Laminar-Flow Control, part 2

NASA Technical Reports Server (NTRS)

Hefner, Jerry N. (Compiler); Sabo, Frances E. (Compiler)

1987-01-01

Part 2 of the Symposium proceedings includes papers addressing various topics in basic wind tunnel research/techniques and computational transitional research. Specific topics include: advanced measurement techniques; laminar flow control; Tollmien-Schlichting wave characteristics; boundary layer transition; flow visualization; wind tunnel tests; flight tests; boundary layer equations; swept wings; and skin friction.

Sample detection and analysis techniques for electrophoretic separation

NASA Technical Reports Server (NTRS)

Falb, R. D.; Hughes, K. E.; Powell, T. R.

1975-01-01

Methods for detecting and analyzing biological agents suitable for space flight operations were studied primarily by literature searches which were conducted of cell separation techniques. Detection methods discussed include: photometrometric, electric, radiometric, micrometry, ultrasonic, microscopic, and photographic. A bibliography, and a directory of vendors are included along with an index of commercial hardware.

Logical-Semantic Visual Navigators--Aids for Teachers

ERIC Educational Resources Information Center

Khuziakhmetov, Anvar N.; Steinberg, Valery E.

2016-01-01

The relevance of the article in question is that the success of pupils' learning depends not only on the aptitude of pupils, but also on the teaching technique, including universal educational technique of various complexities. This problem is relevant on all levels of learning--from nursery schools up to higher education, including refresher…

Techniques for Submitting Successful Proposals for SHAPE America National Conventions

ERIC Educational Resources Information Center

Stevens-Smith, Deborah

2016-01-01

This article covers the basic components of the submission process before submitting a proposal for the SHAPE America national convention. The article discusses various techniques specific to the process, including the unique discipline areas. Other issues addressed include an understanding of the SHAPE America review process and how it works,…

Prospects for laser-induced breakdown spectroscopy for biomedical applications: a review.

PubMed

Singh, Vivek Kumar; Rai, Awadhesh Kumar

2011-09-01

We review the different spectroscopic techniques including the most recent laser-induced breakdown spectroscopy (LIBS) for the characterization of materials in any phase (solid, liquid or gas) including biological materials. A brief history of the laser and its application in bioscience is presented. The development of LIBS, its working principle and its instrumentation (different parts of the experimental set up) are briefly summarized. The generation of laser-induced plasma and detection of light emitted from this plasma are also discussed. The merit and demerits of LIBS are discussed in comparison with other conventional analytical techniques. The work done using the laser in the biomedical field is also summarized. The analysis of different tissues, mineral analysis in different organs of the human body, characterization of different types of stone formed in the human body, analysis of biological aerosols using the LIBS technique are also summarized. The unique abilities of LIBS including detection of molecular species and calibration-free LIBS are compared with those of other conventional techniques including atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy and mass spectroscopy, and X-ray fluorescence.

Prospective study of wound infections in Mohs micrographic surgery using clean surgical technique in the absence of prophylactic antibiotics.

PubMed

Rogers, Heather D; Desciak, Edward B; Marcus, Rebecca P; Wang, Shuang; MacKay-Wiggan, Julian; Eliezri, Yehuda D

2010-11-01

Mohs micrographic surgery (MMS) has a low rate of surgical site infection (SSI) without the use of prophylactic antibiotics. In the studies to date, there has been variation in the steps taken by each surgeon to prevent SSIs but in all cases sterile technique was used during wound reconstruction. We sought to evaluate the rate of SSIs among patients undergoing MMS with the use of clean surgical technique for all steps of MMS including wound reconstruction in the absence of prophylactic antibiotics. We prospectively evaluated 1000 patients undergoing MMS using clean surgical technique for SSIs. Clean surgical technique includes the use of clean surgical gloves and towels and a single pack of sterile instruments for all steps including wound reconstruction. There were 11 SSIs among 1000 patients with 1204 tumors, with an overall rate of infection of 0.91% (95% confidence interval 0.38%-1.45%). Three of the 11 infections were complications of hematomas. Four of the 11 infections occurred in flap closures, which had the highest rate of SSIs of 2.67% (4/150). The study was a prospective, single-institution uncontrolled study. To our knowledge, this is the first study to examine the rate of SSIs with the use of clean surgical technique, in the absence of antibiotic prophylaxis, for all steps of MMS including wound reconstruction. Our rate of SSIs of 0.91% is exceedingly low, underscoring the overall safety of MMS and its performance in the outpatient setting without the use of antibiotic prophylaxis or sterile technique. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Eyebrow and Eyelash Hair Transplantation: A Systematic Review.

PubMed

Klingbeil, Kyle D; Fertig, Raymond

2018-06-01

The objective of this systematic review was to investigate the etiologies of hair loss of the eyebrow and eyelash that required hair transplantation, the optimal surgical technique, patient outcomes, and common complications. A total of 67 articles including 354 patients from 18 countries were included in this study. Most patients were women with an average age of 29 years. The most common etiology requiring hair transplantation was burns, occurring in 57.6 percent of cases. Both eyebrow and eyelash transplantation use follicular unit transplantation techniques most commonly; however, other techniques involving composite grafts and skin flaps continue to be utilized effectively with minimal complication rates. In summary, many techniques have been developed for use in eyebrow/eyelash transplantation and the selection of technique depends upon the dermatologic surgeon's preferences and the unique presentations of their patients.

The Fabrication Technique and Property Analysis of Racetrack-Type High Temperature Superconducting Magnet for High Power Motor

NASA Astrophysics Data System (ADS)

Xie, S. F.; Wang, Y.; Wang, D. Y.; Zhang, X. J.; Zhao, B.; Zhang, Y. Y.; Li, L.; Li, Y. N.; Chen, P. M.

2013-03-01

The superconducting motor is now the focus of the research on the application of high temperature superconducting (HTS) materials. In this manuscript, we mainly introduce the recent progress on the fabrication technique and property research of the superconducting motor magnet in Luoyang Ship Material Research Institute (LSMRI) in China, including the materials, the winding and impregnation technique, and property measurement of magnet. Several techniques and devices were developed to manufacture the magnet, including the technique of insulation and thermal conduction, the device for winding the racetrack-type magnet, etc. At last, the superconducting magnet used for the MW class motor were successfully developed, which is the largest superconducting motor magnet in china at present. The critical current of the superconducting magnet exceeds the design value (90 A at 30 K).

Disadvantages and advantages of transtibial technique for creating the anterior cruciate ligament femoral socket.

PubMed

Robin, Brett N; Lubowitz, James H

2014-10-01

Anterior cruciate ligament (ACL) femoral socket techniques have distinct advantages and disadvantages when considering the following techniques: transtibial, anteromedial portal, outside-in, and outside-in retroconstruction. There is no one perfect technique and we have an incomplete understanding of anatomical, biomechanical, isometry, stability, and clinical outcomes. Our primary focus is transtibial technique for creating the ACL femoral socket. Advantages include less invasive, isometric graft placement, stable Lachman exam, and minimal graft impingement with the tunnel and notch. Disadvantages include nonanatomic vertical graft placement that can cause rotational instability and positive pivot shift, interference screw divergence, graft-tunnel length mismatch, femoral socket constraint, posterior cruciate ligament impingement, and a short, oblique tibial tunnel that may undermine the medial plateau in an attempt to achieve anatomic ACL reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Informal Evaluation.

ERIC Educational Resources Information Center

Engel, Brenda S.

Intended for non-experts in evaluative techniques, this monograph presents suggestions and examples for assessing: (1) the child; (2) the classroom; and (3) the program or the school. Illustrative techniques of recordkeeping are presented. Methods of collecting data include documentation and formal records. Techniques to be used during evaluation…

Some Techniques for Teaching about the Structure and Function of Chromosomes.

ERIC Educational Resources Information Center

Lowery, Roger; Taylor, Neil; Nathan, Subhashni

2000-01-01

Presents a teaching activity that uses photographs and diagrams to simulate two microscopic laboratory techniques used to observe the structure of chromosomes. Techniques include observation of squashed onion root tips and the salivary glands of some fruitfly larvae. (WRM)

Intraseptal anesthesia: a review of a relevant injection technique.

PubMed

Woodmansey, Karl

2005-01-01

Although overshadowed by intraosseous anesthesia and the periodontal ligament injection, intraseptal anesthesia remains a useful local anesthesia technique for general dentists. Intraseptal anesthesia can be employed with safety and efficacy as an alternative to conventional local infiltration or regional nerve block injections. It also can serve as an adjunctive technique when conventional techniques fail to achieve adequate local anesthesia. This article reviews the intraseptal anesthesia technique, including its indications and limitations.

Next-Generation Technologies for Multiomics Approaches Including Interactome Sequencing

PubMed Central

Ohashi, Hiroyuki; Miyamoto-Sato, Etsuko

2015-01-01

The development of high-speed analytical techniques such as next-generation sequencing and microarrays allows high-throughput analysis of biological information at a low cost. These techniques contribute to medical and bioscience advancements and provide new avenues for scientific research. Here, we outline a variety of new innovative techniques and discuss their use in omics research (e.g., genomics, transcriptomics, metabolomics, proteomics, and interactomics). We also discuss the possible applications of these methods, including an interactome sequencing technology that we developed, in future medical and life science research. PMID:25649523

LIFES: Laser Induced Fluorescence and Environmental Sensing. [remote sensing technique for marine environment

NASA Technical Reports Server (NTRS)

Houston, W. R.; Stephenson, D. G.; Measures, R. M.

1975-01-01

A laboratory investigation has been conducted to evaluate the detection and identification capabilities of laser induced fluorescence as a remote sensing technique for the marine environment. The relative merits of fluorescence parameters including emission and excitation profiles, intensity and lifetime measurements are discussed in relation to the identification of specific targets of the marine environment including crude oils, refined petroleum products, fish oils and algae. Temporal profiles displaying the variation of lifetime with emission wavelength have proven to add a new dimension of specificity and simplicity to the technique.

Module Degradation Mechanisms Studied by a Multi-Scale Approach

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

Johnston, Steve; Al-Jassim, Mowafak; Hacke, Peter

2016-11-21

A key pathway to meeting the Department of Energy SunShot 2020 goals is to reduce financing costs by improving investor confidence through improved photovoltaic (PV) module reliability. A comprehensive approach to further understand and improve PV reliability includes characterization techniques and modeling from module to atomic scale. Imaging techniques, which include photoluminescence, electroluminescence, and lock-in thermography, are used to locate localized defects responsible for module degradation. Small area samples containing such defects are prepared using coring techniques and are then suitable and available for microscopic study and specific defect modeling and analysis.

Preservation Methods Utilized for Space Food

NASA Technical Reports Server (NTRS)

Vodovotz, Yael; Bourland, Charles

2000-01-01

Food for manned space flight has been provided by NASA-Johnson Space Center since 1962. The various mission scenarios and space craft designs dictated the type of food preservation methodologies required to meet mission objectives. The preservation techniques used in space flight include freeze-dehydration, thermostabilization, irradiation, freezing and moisture adjustment. Innovative packaging material and techniques enhanced the shelf-stability of the food items. Future space voyages may include extended duration exploration missions requiring new packaging materials and advanced preservation techniques to meet mission goals of up to 5-year shelf-life foods.

A comparative study on preprocessing techniques in diabetic retinopathy retinal images: illumination correction and contrast enhancement.

PubMed

Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

2015-01-01

To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation.

Paracoccygeal corkscrew approach to ganglion impar injections for tailbone pain.

PubMed

Foye, Patrick M; Patel, Shounuck I

2009-01-01

A new technique for performing nerve blocks of the ganglion impar (ganglion Walther) is presented. These injections have been reported to relieve coccydynia (tailbone pain), as well as other malignant and nonmalignant pelvic pain syndromes. A variety of techniques have been previously described for blocking this sympathetic nerve ganglion, which is located in the retrorectal space just anterior to the upper coccygeal segments. Prior techniques have included approaches through the anococcygeal ligament, through the sacrococcygeal joint, and through intracoccygeal joint spaces. This article presents a new, paracoccygeal approach whereby the needle is inserted alongside the coccyx and the needle is guided through three discrete steps with a rotating or corkscrew trajectory. Compared with some of the previously published techniques, this paracoccygeal corkscrew approach has multiple potential benefits, including ease of fluoroscopic guidance using the lateral view, ability to easily use a stylet for the spinal needle, and use of a shorter, thinner needle. While no single technique works best for all patients and each technique has potential advantages and disadvantages, this new technique adds to the available options.

Suture Products and Techniques: What to Use, Where, and Why.

PubMed

Regula, Christie G; Yag-Howard, Cyndi

2015-10-01

There are an increasing number of wound closure materials and suturing techniques described in the dermatologic and surgery literature. A dermatologic surgeon's familiarity with these materials and techniques is important to supplement his or her already established practices and improve surgical outcomes. To perform a thorough literature review of wound closure materials (sutures, tissue adhesives, surgical tape, and staples) and suturing techniques and to outline how and when to use them. A literature review was conducted using PubMed and other online search engines. Keywords searched included suture, tissue adhesive, tissue glue, surgical tape, staples, dermatologic suturing, and suturing techniques. Numerous articles outline the utility of various sutures, surgical adhesives, surgical tape, and staples in dermatologic surgery. In addition, there are various articles describing classic and novel suturing techniques along with their specific uses in cutaneous surgery. Numerous factors must be considered when choosing a wound closure material and suturing technique. These include wound tension, desire for wound edge eversion/inversion, desired hemostasis, repair type, patient's ability to care for the wound and return for suture removal, skin integrity, and wound location. Careful consideration of these factors and proper execution of suturing techniques can lead to excellent cosmetic results.

High Frequency Direction Finding Using Structurally Integrated Antennas on a Large Airborne Platform

DTIC Science & Technology

2011-03-24

signal processing techniques, including superresolution techniques, as a possible way to extend the airborne DF capability to the HF band. Structurally...electrically or mechan- ically scanned beams has been diminished by array processing techniques [4]. The implementation of superresolution algorithms

Numerical grid generation techniques. [conference

NASA Technical Reports Server (NTRS)

1980-01-01

The state of the art in topology and flow geometry is presented. Solution techniques for partial differential equations are reviewed and included developments in coordinate transformations, conformal mapping, and invariant imbeddings. Applications of these techniques in fluid mechanics, flow geometry, boundary value problems, and fluidics are presented.

Techniques for Teachers Section

ERIC Educational Resources Information Center

Tait, A., Ed.

1973-01-01

Includes a simple technique to demonstrate Millikan's oil drop experiment, an environmental studies experiment to measure dissolved oxygen in water samples, and a technique to demonstrate action-reaction. Science materials described are the Pol-A-Star Tomiscope, Nuffield chemistry film loops, air pucks and pH meters. (JR)

Managing Credit Card Expenses: Nova Southeastern University Shares Cost-Saving Techniques.

ERIC Educational Resources Information Center

Peskin, Carol Ann

1994-01-01

Nova Southeastern University, Florida, has implemented a variety of techniques of cost containment for campus credit card transactions. These include restricted card acceptance parameters, careful merchant rate negotiation, increased automation of transaction processing, and sophisticated processing techniques. The university has demonstrated…

Helping Individuals with Sleep Disturbances: Some Behavior Therapy Techniques.

ERIC Educational Resources Information Center

Alley, Patricia M.

1983-01-01

Describes a range of behavior therapy techniques for treating sleep disturbances, including physical activity, relaxation training, biofeedback, autogenic training, and cognitive techniques. The importance of understanding the client's background is emphasized. Restoring the client's self-control and positive psychological growth are stressed.…

Prompt Gamma Activation Analysis (PGAA): Technique of choice for nondestructive bulk analysis of returned comet samples

NASA Technical Reports Server (NTRS)

Lindstrom, David J.; Lindstrom, Richard M.

1989-01-01

Prompt gamma activation analysis (PGAA) is a well-developed analytical technique. The technique involves irradiation of samples in an external neutron beam from a nuclear reactor, with simultaneous counting of gamma rays produced in the sample by neutron capture. Capture of neutrons leads to excited nuclei which decay immediately with the emission of energetic gamma rays to the ground state. PGAA has several advantages over other techniques for the analysis of cometary materials: (1) It is nondestructive; (2) It can be used to determine abundances of a wide variety of elements, including most major and minor elements (Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni), volatiles (H, C, N, F, Cl, S), and some trace elements (those with high neutron capture cross sections, including B, Cd, Nd, Sm, and Gd); and (3) It is a true bulk analysis technique. Recent developments should improve the technique's sensitivity and accuracy considerably.

A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

NASA Technical Reports Server (NTRS)

Garmestai, H.; Harris, K.; Lourenco, L.

1997-01-01

Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

Evaluation of a novel educational strategy, including inhaler-based reminder labels, to improve asthma inhaler technique.

PubMed

Basheti, Iman A; Armour, Carol L; Bosnic-Anticevich, Sinthia Z; Reddel, Helen K

2008-07-01

To evaluate the feasibility, acceptability and effectiveness of a brief intervention about inhaler technique, delivered by community pharmacists to asthma patients. Thirty-one pharmacists received brief workshop education (Active: n=16, CONTROL: n=15). Active Group pharmacists were trained to assess and teach dry powder inhaler technique, using patient-centered educational tools including novel Inhaler Technique Labels. Interventions were delivered to patients at four visits over 6 months. At baseline, patients (Active: 53, CONTROL: 44) demonstrated poor inhaler technique (mean+/-S.D. score out of 9, 5.7+/-1.6). At 6 months, improvement in inhaler technique score was significantly greater in Active cf. CONTROL patients (2.8+/-1.6 cf. 0.9+/-1.4, p<0.001), and asthma severity was significantly improved (p=0.015). Qualitative responses from patients and pharmacists indicated a high level of satisfaction with the intervention and educational tools, both for their effectiveness and for their impact on the patient-pharmacist relationship. A simple feasible intervention in community pharmacies, incorporating daily reminders via Inhaler Technique Labels on inhalers, can lead to improvement in inhaler technique and asthma outcomes. Brief training modules and simple educational tools, such as Inhaler Technique Labels, can provide a low-cost and sustainable way of changing patient behavior in asthma, using community pharmacists as educators.

Plain Language to Communicate Physical Activity Information: A Website Content Analysis.

PubMed

Paige, Samantha R; Black, David R; Mattson, Marifran; Coster, Daniel C; Stellefson, Michael

2018-04-01

Plain language techniques are health literacy universal precautions intended to enhance health care system navigation and health outcomes. Physical activity (PA) is a popular topic on the Internet, yet it is unknown if information is communicated in plain language. This study examined how plain language techniques are included in PA websites, and if the use of plain language techniques varies according to search procedures (keyword, search engine) and website host source (government, commercial, educational/organizational). Three keywords ("physical activity," "fitness," and "exercise") were independently entered into three search engines (Google, Bing, and Yahoo) to locate a nonprobability sample of websites ( N = 61). Fourteen plain language techniques were coded within each website to examine content formatting, clarity and conciseness, and multimedia use. Approximately half ( M = 6.59; SD = 1.68) of the plain language techniques were included in each website. Keyword physical activity resulted in websites with fewer clear and concise plain language techniques ( p < .05), whereas fitness resulted in websites with more clear and concise techniques ( p < .01). Plain language techniques did not vary by search engine or the website host source. Accessing PA information that is easy to understand and behaviorally oriented may remain a challenge for users. Transdisciplinary collaborations are needed to optimize plain language techniques while communicating online PA information.

Film in Education: This Worked For Me.

ERIC Educational Resources Information Center

Breen, Myles P.

Several techniques for teaching film appreciation to adults are discussed, including the use of audio cassettes, instructional films, silent films, and film dissection. Included are the techniques, philosophy, and content of a seminar on the short film, in which the short film is viewed as a variant of a short story, a pop song, a joke, and a…

Air Force and Army Corps of Engineers Improperly Managed the Award of Contracts for the Blue Devil Block 2 Persistent Surveillance System

DTIC Science & Technology

2013-09-19

environments. This can include the development of new and/or improved analytical and numerical models, rapid data-processing techniques, and new subsurface ... imaging techniques that include active and passive sensor modalities in a variety of rural and urban terrains. Of particular interest is the broadband

Physiotherapists use a small number of behaviour change techniques when promoting physical activity: A systematic review comparing experimental and observational studies.

PubMed

Kunstler, Breanne E; Cook, Jill L; Freene, Nicole; Finch, Caroline F; Kemp, Joanne L; O'Halloran, Paul D; Gaida, James E

2018-06-01

Physiotherapists promote physical activity as part of their practice. This study reviewed the behaviour change techniques physiotherapists use when promoting physical activity in experimental and observational studies. Systematic review of experimental and observational studies. Twelve databases were searched using terms related to physiotherapy and physical activity. We included experimental studies evaluating the efficacy of physiotherapist-led physical activity interventions delivered to adults in clinic-based private practice and outpatient settings to individuals with, or at risk of, non-communicable diseases. Observational studies reporting the techniques physiotherapists use when promoting physical activity were also included. The behaviour change techniques used in all studies were identified using the Behaviour Change Technique Taxonomy. The behaviour change techniques appearing in efficacious and inefficacious experimental interventions were compared using a narrative approach. Twelve studies (nine experimental and three observational) were retained from the initial search yield of 4141. Risk of bias ranged from low to high. Physiotherapists used seven behaviour change techniques in the observational studies, compared to 30 behaviour change techniques in the experimental studies. Social support (unspecified) was the most frequently identified behaviour change technique across both settings. Efficacious experimental interventions used more behaviour change techniques (n=29) and functioned in more ways (n=6) than did inefficacious experimental interventions (behaviour change techniques=10 and functions=1). Physiotherapists use a small number of behaviour change techniques. Less behaviour change techniques were identified in observational studies compared to experimental studies, suggesting physiotherapists use less BCTs clinically than experimentally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

What about the Misgav-Ladach surgical technique in patients with previous cesarean sections?

PubMed

Bolze, Pierre-Adrien; Massoud, Mona; Gaucherand, Pascal; Doret, Muriel

2013-03-01

The Misgav-Ladach technique is recommended worldwide to perform cesarean sections but there is no consensus about the appropriate technique to use in patients with previous cesarean sections. This study evaluated the feasibility of the Misgav-Ladach technique in patients with previous cesarean sections. This prospective cohort study included all women undergoing cesarean section after 36 weeks of gestation over a 5-month period, with the Misgav-Ladach technique as first choice, whatever the previous number of cesarean sections. Among the 204 patients included, the Misgav-Ladach technique was successful in 100%, 80%, and 65.6% of patients with no, one, and multiple previous cesarean sections, respectively. When successful, the Misgav-Ladach technique was associated with a shorter incision to birth interval in patients with no previous cesarean section compared with patients with one or multiple previous cesarean sections. Anterior rectus aponeurosis fibrosis and severe peritoneal adherences were the two main reasons explaining the Misgav-Ladach technique failure. The Misgav-Ladach technique is possible in over three-fourths of patients with previous cesarean sections with a slight increase in incision to birth interval compared with patients without previous cesarean section. Further studies comparing the Misgav-Ladach and the Pfannenstiel techniques in women with previous cesarean should be done. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Electronic Components Subsystems and Equipment: a Compilation

NASA Technical Reports Server (NTRS)

1975-01-01

Developments in electronic components, subsystems, and equipment are summarized. Topics discussed include integrated circuit components and techniques, circuit components and techniques, and cables and connectors.

Radionuclides in Diagnosis.

ERIC Educational Resources Information Center

Williams, E. D.

1989-01-01

Discussed is a radionuclide imaging technique, including the gamma camera, image analysis computer, radiopharmaceuticals, and positron emission tomography. Several pictures showing the use of this technique are presented. (YP)

Glucagon Is a Safe and Inexpensive Initial Strategy in Esophageal Food Bolus Impaction.

PubMed

Haas, Jason; Leo, Julia; Vakil, Nimish

2016-03-01

Controversy exists about the utility of pharmacologic agents and endoscopic technique used for esophageal food bolus impaction. To evaluate the utility of glucagon and the technique used for endoscopic removal, including the rate of success and the adverse events of the techniques. The database of the largest healthcare provider in southeastern Wisconsin was retrospectively reviewed for patients presenting with esophageal food bolus impaction. Data extracted included glucagon administration and its success rate, outcome of radiographic studies, and the endoscopic method of removal and adverse events associated with it, including 30-day mortality. A total of 750 patients were identified with food bolus impaction from 2007 to 2012. Glucagon was administered in 440 patients and was successful in 174 (39.5%). Endoscopic removal was performed in 470 patients and was successful in 469 (99.8%). The push technique was utilized in 209 patients, reduction in the bolus size by piecemeal removal followed by the push technique was utilized in 97 patients, and the pull technique was utilized in 107 patients. There were no perforations with endoscopic removal. Only 4.5% of the X-rays performed reported a possible foreign body within the esophagus. Glucagon was a significantly less-expensive strategy than endoscopic therapy (p < 0.0001). Glucagon is low cost, is moderately effective, and may be considered as an initial strategy. Endoscopic removal regardless of technique is safe and effective. The yield of radiography is poor in the setting of food bolus impaction.

Residual anastomoses in twin-twin transfusion syndrome after laser: the Solomon randomized trial.

PubMed

Slaghekke, Femke; Lewi, Liesbeth; Middeldorp, Johanna M; Weingertner, Anne Sophie; Klumper, Frans J; Dekoninck, Philip; Devlieger, Roland; Lanna, Mariano M; Deprest, Jan; Favre, Romain; Oepkes, Dick; Lopriore, Enrico

2014-09-01

Residual anastomoses after fetoscopic laser surgery for twin-to-twin transfusion syndrome (TTTS) may lead to severe postoperative complications, including recurrent TTTS and twin anemia-polycythemia sequence (TAPS). A novel technique (Solomon technique) using laser coagulation of the entire vascular equator was recently investigated in a randomized controlled trial (Solomon trial) and compared with the Standard selective laser technique. The aim of this secondary analysis was to evaluate the occurrence and characteristics of residual anastomoses in placentas included in the Solomon trial. International multicenter randomized controlled trial in TTTS, randomized 1:1 ratio to either the Solomon laser technique or Standard laser technique. At time of laser, surgeons recorded whether they considered the procedure to be complete. Placental dye injection was performed after birth in the participating centers to evaluate the presence of residual anastomoses. A total of 151 placentas were included in the study. The percentage of placentas with residual anastomoses in the Solomon group and Standard group was 19% (14/74) and 34% (26/77), respectively (P = .04). The percentage of placentas with residual anastomoses in the subgroup of cases where the procedure was recorded as complete was 8/65 (12%) and 22/69 (32%) in the Solomon group and Standard group, respectively (P < .01). The Solomon laser technique reduces the risk of residual anastomoses. However, careful follow-up remains essential also after the Solomon technique, as complete dichorionization is not always achieved. Copyright © 2014 Mosby, Inc. All rights reserved.

Evaluation of Carbon Anodes for Rechargeable Lithium Cells

NASA Technical Reports Server (NTRS)

Huang, C-K.; Surampudi, S.; Attia, A.; Halpert, G.

1993-01-01

Both liquid phase intercalation technique and electrochemical intercalation technique were examined for the Li-carbon material preparation. The electrochemical techniques include a intermittent discharge method and a two step method. These two electrochemical techniques can ensure to achieve the maximum reversible Li capacity for common commercially available carbon materials. The carbon materials evaluated by the intercalacation method includes: pitch coke, petroleum cole, PAN fiber and graphite materials. Their reversible Li capacity were determined and compared. In this paper, we also demonstrate the importance of EPDM binder composition in the carbon electrode. Our results indicated that it can impact the Li intercalation and de-intercalation capacity in carbon materials. Finally, two possibilities that may help explain the capacity degradation during practical cell cycling were proposed.

An experimental facility for the visual study of turbulent flows.

NASA Technical Reports Server (NTRS)

Brodkey, R. S.; Hershey, H. C.; Corino, E. R.

1971-01-01

An experimental technique which allows visual observations of the wall area in turbulent pipe flow is described in detail. It requires neither the introduction of any injection or measuring device into the flow nor the presence of a two-phase flow or of a non-Newtonian fluid. The technique involves suspending solid MgO particles of colloidal size in trichloroethylene and photographing their motions near the wall with a high speed movie camera moving with the flow. Trichloroethylene was chosen in order to eliminate the index of refraction problem in a curved wall. Evaluation of the technique including a discussion of limitations is included. Also the technique is compared with previous methods of visual observations of turbulent flow.

Apparatus, systems, and methods for ultrasound synthetic aperature focusing

DOEpatents

Schuster, George J.; Crawford, Susan L.; Doctor, Steven R.; Harris, Robert V.

2005-04-12

One form of the present invention is a technique for interrogating a sample with ultrasound which includes: generating ultrasonic energy data corresponding to a volume of a sample and performing a synthetic aperture focusing technique on the ultrasonic energy data. The synthetic aperture focusing technique includes: defining a number of hyperbolic surfaces which extend through the volume at different depths and a corresponding number of multiple element accumulation vectors, performing a focused element calculation procedure for a group of vectors which are representative of the interior of a designated aperture, performing another focused element calculation procedure for vectors corresponding to the boundary of the aperture, and providing an image corresponding to features of the sample in accordance with the synthetic aperture focusing technique.

Videogrammetric Model Deformation Measurement Technique for Wind Tunnel Applications

NASA Technical Reports Server (NTRS)

Barrows, Danny A.

2006-01-01

Videogrammetric measurement technique developments at NASA Langley were driven largely by the need to quantify model deformation at the National Transonic Facility (NTF). This paper summarizes recent wind tunnel applications and issues at the NTF and other NASA Langley facilities including the Transonic Dynamics Tunnel, 31-Inch Mach 10 Tunnel, 8-Ft high Temperature Tunnel, and the 20-Ft Vertical Spin Tunnel. In addition, several adaptations of wind tunnel techniques to non-wind tunnel applications are summarized. These applications include wing deformation measurements on vehicles in flight, determining aerodynamic loads based on optical elastic deformation measurements, measurements on ultra-lightweight and inflatable space structures, and the use of an object-to-image plane scaling technique to support NASA s Space Exploration program.

Reliability techniques for computer executive programs

NASA Technical Reports Server (NTRS)

1972-01-01

Computer techniques for increasing the stability and reliability of executive and supervisory systems were studied. Program segmentation characteristics are discussed along with a validation system which is designed to retain the natural top down outlook in coding. An analysis of redundancy techniques and roll back procedures is included.

Film-Making and the Curriculum.

ERIC Educational Resources Information Center

Schwartz, Elizabeth

A guide to filmmaking techniques and the use of class-made films in the curriculum covers techniques of both animated and live-action films. The purposes of single concept, documentary, interpretive, and time-lapse films are discussed briefly. Production techniques covered include organization of personnel, scripting, filming, directing, editing,…

Reduced-Smoke Solid Propellant Combustion Products Analysis. Development of a Micromotor Combustor Technique.

DTIC Science & Technology

1976-10-01

A low-cost micromotor combustor technique has been devised to support the development of reduced-smoke solid propellant formulations. The technique...includes a simple, reusable micromotor capable of high chamber pressures, a combustion products collection system, and procedures for analysis of

Improving Classroom Behavior: The Carrot and the Stick.

ERIC Educational Resources Information Center

Talent, Barbara K.; Busch, Suzanne G.

A set of practical behavior change techniques for improving young children's classroom behavior are briefly discussed. Techniques are classified and discussed under two general categories: those that reduce frequency of behaviors ("sticks") and those that increase their frequency ("carrots"). Included under "sticks" are techniques such as ignoring…

A review of DTCA techniques: Appraising their success and potential impact on medication users.

PubMed

Babar, Zaheer-Ud-Din; Siraj, Ashna Medina; Curley, Louise

2018-03-01

Direct-to-consumer advertising (DTCA) has been present in some countries for nearly two decades. Its success and ramifications have been examined but not yet cataloged recently in a comprehensive manner. To review existing literature studies on the topic of DTCA techniques to provide an analysis of the current methods considered by drug marketers to enhance the effect of pharmaceutical product promotion and its success, as well as examine ramifications on the drug use process. A search of 7 electronic databases including MEDLINE and SCOPUS was conducted in December 2015, and updated until February 2016. A scientific review of literature (2008-2015) was performed to identify and collate information from relevant, peer reviewed original study articles investigating various DTCA techniques commonly employed in pharmaceutical promotion. A thematic analysis was undertaken to categorize categories of drug promotion, or techniques, and the saliency and impact of these. Nineteen original study articles were included in this review. All articles were based in the U.S. and New Zealand, where DTCA is legal. After reviewing all the articles, 4 themes with 11 subcategories were generated. These themes included disease mongering and medicalization, drug references, advertisement strategies and eDTCA. The themes describe different categories of techniques used to augment DTC advertisements to increase their impact and overall success in promoting a pharmaceutical product. Many DTCA techniques utilized by pharmaceutical marketers are beneficial to the success of DTC promotion of a drug. These techniques include the use of drug efficacy information, comparative claims, non-branded help seeking advertisements, formatted risks information, celebrity or expert endorsers and website trust factors. Through their use, public perception of the drug is made more favorable, increased attention is drawn to the advertisement, and the pharmaceutical product gains greater credibility and subsequent success in sales. However some techniques, although beneficial to pharmaceutical promotion, need to be monitored by policymakers and regulatory advisors, as they have the potential to negatively impact consumer health knowledge. Overall, through this review it is evident that there are a number if techniques that employed by pharmaceutical marketers to augment the success of pharmaceutical promotion. While these techniques may be beneficial to pharmaceutical companies and might increase awareness amongst consumers, it is important to be critical of them, as they have the potential to be exploited by pharmaceutical marketers. This review indicated that although some techniques are successful and appear to be satisfactory in providing information to consumers, other techniques need to be appraised more closely. Copyright © 2017 Elsevier Inc. All rights reserved.

Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction.

PubMed

Fink, Christian; Steensen, Robert; Gföller, Peter; Lawton, Robert

2018-06-01

Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction. Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

Approximate techniques of structural reanalysis

NASA Technical Reports Server (NTRS)

Noor, A. K.; Lowder, H. E.

1974-01-01

A study is made of two approximate techniques for structural reanalysis. These include Taylor series expansions for response variables in terms of design variables and the reduced-basis method. In addition, modifications to these techniques are proposed to overcome some of their major drawbacks. The modifications include a rational approach to the selection of the reduced-basis vectors and the use of Taylor series approximation in an iterative process. For the reduced basis a normalized set of vectors is chosen which consists of the original analyzed design and the first-order sensitivity analysis vectors. The use of the Taylor series approximation as a first (initial) estimate in an iterative process, can lead to significant improvements in accuracy, even with one iteration cycle. Therefore, the range of applicability of the reanalysis technique can be extended. Numerical examples are presented which demonstrate the gain in accuracy obtained by using the proposed modification techniques, for a wide range of variations in the design variables.

Position and speed control of brushless DC motors using sensorless techniques and application trends.

PubMed

Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime

2010-01-01

This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks.

Transient excitation and data processing techniques employing the fast fourier transform for aeroelastic testing

NASA Technical Reports Server (NTRS)

Jennings, W. P.; Olsen, N. L.; Walter, M. J.

1976-01-01

The development of testing techniques useful in airplane ground resonance testing, wind tunnel aeroelastic model testing, and airplane flight flutter testing is presented. Included is the consideration of impulsive excitation, steady-state sinusoidal excitation, and random and pseudorandom excitation. Reasons for the selection of fast sine sweeps for transient excitation are given. The use of the fast fourier transform dynamic analyzer (HP-5451B) is presented, together with a curve fitting data process in the Laplace domain to experimentally evaluate values of generalized mass, model frequencies, dampings, and mode shapes. The effects of poor signal to noise ratios due to turbulence creating data variance are discussed. Data manipulation techniques used to overcome variance problems are also included. The experience is described that was gained by using these techniques since the early stages of the SST program. Data measured during 747 flight flutter tests, and SST, YC-14, and 727 empennage flutter model tests are included.

Numerical solution methods for viscoelastic orthotropic materials

NASA Technical Reports Server (NTRS)

Gramoll, K. C.; Dillard, D. A.; Brinson, H. F.

1988-01-01

Numerical solution methods for viscoelastic orthotropic materials, specifically fiber reinforced composite materials, are examined. The methods include classical lamination theory using time increments, direction solution of the Volterra Integral, Zienkiewicz's linear Prony series method, and a new method called Nonlinear Differential Equation Method (NDEM) which uses a nonlinear Prony series. The criteria used for comparison of the various methods include the stability of the solution technique, time step size stability, computer solution time length, and computer memory storage. The Volterra Integral allowed the implementation of higher order solution techniques but had difficulties solving singular and weakly singular compliance function. The Zienkiewicz solution technique, which requires the viscoelastic response to be modeled by a Prony series, works well for linear viscoelastic isotropic materials and small time steps. The new method, NDEM, uses a modified Prony series which allows nonlinear stress effects to be included and can be used with orthotropic nonlinear viscoelastic materials. The NDEM technique is shown to be accurate and stable for both linear and nonlinear conditions with minimal computer time.

Advanced particle-in-cell simulation techniques for modeling the Lockheed Martin Compact Fusion Reactor

NASA Astrophysics Data System (ADS)

Welch, Dale; Font, Gabriel; Mitchell, Robert; Rose, David

2017-10-01

We report on particle-in-cell developments of the study of the Compact Fusion Reactor. Millisecond, two and three-dimensional simulations (cubic meter volume) of confinement and neutral beam heating of the magnetic confinement device requires accurate representation of the complex orbits, near perfect energy conservation, and significant computational power. In order to determine initial plasma fill and neutral beam heating, these simulations include ionization, elastic and charge exchange hydrogen reactions. To this end, we are pursuing fast electromagnetic kinetic modeling algorithms including a two implicit techniques and a hybrid quasi-neutral algorithm with kinetic ions. The kinetic modeling includes use of the Poisson-corrected direct implicit, magnetic implicit, as well as second-order cloud-in-cell techniques. The hybrid algorithm, ignoring electron inertial effects, is two orders of magnitude faster than kinetic but not as accurate with respect to confinement. The advantages and disadvantages of these techniques will be presented. Funded by Lockheed Martin.

Digital Mapping Techniques '10-Workshop Proceedings, Sacramento, California, May 16-19, 2010

USGS Publications Warehouse

Soller, David R.; Soller, David R.

2012-01-01

The Digital Mapping Techniques '10 (DMT'10) workshop was attended by 110 technical experts from 40 agencies, universities, and private companies, including representatives from 19 State geological surveys (see Appendix A). This workshop, hosted by the California Geological Survey, May 16-19, 2010, in Sacramento, California, was similar in nature to the previous 13 meetings (see Appendix B). The meeting was coordinated by the U.S. Geological Survey's (USGS) National Geologic Map Database project. As in the previous meetings, the objective was to foster informal discussion and exchange of technical information. It is with great pleasure that I note that the objective was again successfully met, as attendees continued to share and exchange knowledge and information, and renew friendships and collegial work begun at past DMT workshops. At this meeting, oral and poster presentations and special discussion sessions emphasized (1) methods for creating and publishing map products ("publishing" includes Web-based release); (2) field data capture software and techniques, including the use of LiDAR; (3) digital cartographic techniques; (4) migration of digital maps into ArcGIS Geodatabase format; (5) analytical GIS techniques; and (6) continued development of the National Geologic Map Database.

Digital Mapping Techniques '08—Workshop Proceedings, Moscow, Idaho, May 18–21, 2008

USGS Publications Warehouse

Soller, David R.

2009-01-01

The Digital Mapping Techniques '08 (DMT'08) workshop was attended by more than 100 technical experts from 40 agencies, universities, and private companies, including representatives from 24 State geological surveys. This year's meeting, the twelfth in the annual series, was hosted by the Idaho Geological Survey, from May 18-21, 2008, on the University of Idaho campus in Moscow, Idaho. Each DMT workshop has been coordinated by the U.S. Geological Survey's National Geologic Map Database Project and the Association of American State Geologists (AASG). As in previous years' meetings, the objective was to foster informal discussion and exchange of technical information, principally in order to develop more efficient methods for digital mapping, cartography, GIS analysis, and information management. At this meeting, oral and poster presentations and special discussion sessions emphasized (1) methods for creating and publishing map products (here, "publishing" includes Web-based release); (2) field data capture software and techniques, including the use of LiDAR; (3) digital cartographic techniques; (4) migration of digital maps into ArcGIS Geodatabase format; (5) analytical GIS techniques; and (6) continued development of the National Geologic Map Database.

Electron molecular ion recombination: product excitation and fragmentation.

PubMed

Adams, Nigel G; Poterya, Viktoriya; Babcock, Lucia M

2006-01-01

Electron-ion dissociative recombination is an important ionization loss process in any ionized gas containing molecular ions. This includes the interstellar medium, circumstellar shells, cometary comae, planetary ionospheres, fusion plasma boundaries, combustion flames, laser plasmas and chemical deposition and etching plasmas. In addition to controlling the ionization density, the process generates many radical species, which can contribute to a parallel neutral chemistry. Techniques used to obtain rate data and product information (flowing afterglows and storage rings) are discussed and recent data are reviewed including diatomic to polyatomic ions and cluster ions. The data are divided into rate coefficients and cross sections, including their temperature/energy dependencies, and quantitative identification of neutral reaction products. The latter involve both ground and electronically excited states and including vibrational excitation. The data from the different techniques are compared and trends in the data are examined. The reactions are considered in terms of the basic mechanisms (direct and indirect processes including tunneling) and recent theoretical developments are discussed. Finally, new techniques are mentioned (for product identification; electrostatic storage rings, including single and double rings; Coulomb explosion) and new ways forward are suggested.

The Use of Psychodrama Action Techniques in a Race Relations Class

ERIC Educational Resources Information Center

Kranz, Peter L.; Ramirez, Sylvia Z.; Lund, Nick L.

2007-01-01

This article describes psychodrama action techniques that were effectively implemented in a university-level race relations course. Essential elements of these techniques included acting out and critical self-examination of the individual's personal beliefs. In a semi-structured class format in which uncensored spontaneity was stressed, students…

Exploring Childhood Memories with Adult Survivors of Sexual Abuse: Concrete Reconstruction and Visualization Techniques.

ERIC Educational Resources Information Center

Roland, Catherine B.

1993-01-01

Describes two memory-enhancing techniques, visualization and concrete reconstruction, that have been successful in counseling adult survivors of sexual abuse. Includes suggested implementations, case examples, and implications for incorporating memory techniques into counseling process. Describes various risk factors involved in using these…

Monitoring Knowledge Base (MKB)

EPA Pesticide Factsheets

The Monitoring Knowledge Base (MKB) is a compilation of emissions measurement and monitoring techniques associated with air pollution control devices, industrial process descriptions, and permitting techniques, including flexible permit development. Using MKB, one can gain a comprehensive understanding of emissions sources, control devices, and monitoring techniques, enabling one to determine appropriate permit terms and conditions.

Stainless Steel Crown Placement Utilizing the Hall Technique

DTIC Science & Technology

2017-03-23

Technique presented at/published to HINMAN Dental Society, 33 Lenox Pointe NE, Atlanta, GA, 23-25 March 2017 in accordance with MDWI 41-108, has...DISAPPROVED D N/A Academic presentation on dental techniques using publicly avai lable in format ion. A ppropriate disclaim ers included. Approved 28

Resiliency Techniques in School Practice

ERIC Educational Resources Information Center

Molony, Terry; Henwood, Maureen; Gilroy, Shawn

2010-01-01

School psychologists can help build resilience in youth in many ways. This article offers a list of some easy techniques to use when working with individuals or groups, most based on basic cognitive-behavior therapy (CBT) techniques. They include: (1) Emotional awareness; (2) Emotional Regulation; (3) Cognitive Flexibility; (4) Self-efficacy; and…

From Ringmaster to Conductor: 10 Simple Techniques Can Turn an Unruly Class into a Productive One

ERIC Educational Resources Information Center

Kraft, Matthew A.

2010-01-01

Challenging classrooms can overwhelm a teacher. However, by using effective classroom management and behavior modification techniques, teachers can change challenging classrooms into productive ones. Classroom management techniques include using a relevant curriculum, establishing nonnegotiable rules, ensuring that students know what behavior is…

A methodology for producing reliable software, volume 1

NASA Technical Reports Server (NTRS)

Stucki, L. G.; Moranda, P. B.; Foshee, G.; Kirchoff, M.; Omre, R.

1976-01-01

An investigation into the areas having an impact on producing reliable software including automated verification tools, software modeling, testing techniques, structured programming, and management techniques is presented. This final report contains the results of this investigation, analysis of each technique, and the definition of a methodology for producing reliable software.

Extended Techniques in Trumpet Performance and Pedagogy

ERIC Educational Resources Information Center

Cherry, Amy K.

2009-01-01

The impetus for this study was the question of whether extended techniques are actually being taught in college trumpet studio settings as standard skills necessary on the instrument. The specific purposes of this document included: (1) catalogue the extended techniques available to today's trumpet performer, (2) reflect on their current use and…

Advanced techniques to prepare seed to sow

Treesearch

Robert P. Karrfalt

2013-01-01

This paper reviews research on improving the basic technique of cold stratification for tree and shrub seeds. Advanced stratification techniques include long stratification, stratification re-dry, or multiple cycles of warm-cold stratification. Research demonstrates that careful regulation of moisture levels and lengthening the stratification period have produced a...

31 CFR 205.10 - How do you document funding techniques?

Code of Federal Regulations, 2010 CFR

2010-07-01

... techniques? 205.10 Section 205.10 Money and Finance: Treasury Regulations Relating to Money and Finance... EFFICIENT FEDERAL-STATE FUNDS TRANSFERS Rules Applicable to Federal Assistance Programs Included in a Treasury-State Agreement § 205.10 How do you document funding techniques? The Treasury-State agreement must...

31 CFR 205.11 - What requirements apply to funding techniques?

Code of Federal Regulations, 2010 CFR

2010-07-01

... techniques? 205.11 Section 205.11 Money and Finance: Treasury Regulations Relating to Money and Finance... EFFICIENT FEDERAL-STATE FUNDS TRANSFERS Rules Applicable to Federal Assistance Programs Included in a Treasury-State Agreement § 205.11 What requirements apply to funding techniques? (a) A State and a Federal...

Welding and joining: A compilation

NASA Technical Reports Server (NTRS)

1975-01-01

A compilation is presented of NASA-developed technology in welding and joining. Topics discussed include welding equipment, techniques in welding, general bonding, joining techniques, and clamps and holding fixtures.

Geophysical methods in Geology. Second edition

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

Sharma, P.V.

This book presents an introduction to the methods of geophysics and their application to geological problems. The text emphasizes the broader aspects of geophysics, including the way in which geophysical methods help solve structural, correlational, and geochromological problems. Stress is laid on the principles and applications of methods rather than on instrumental techniques. This edition includes coverage of recent developments in geophysics and geology. New topics are introduced, including paleomagnetic methods, electromagnetic methods, microplate tectronics, and the use of multiple geophysical techniques.

A Comparative Study on Preprocessing Techniques in Diabetic Retinopathy Retinal Images: Illumination Correction and Contrast Enhancement

PubMed Central

Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

2015-01-01

To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation. PMID:25709940

The Third International Symposium on Space Terahertz Technology: Symposium proceedings

NASA Technical Reports Server (NTRS)

1992-01-01

Papers from the symposium are presented that are relevant to the generation, detection, and use of the terahertz spectral region for space astronomy and remote sensing of the Earth's upper atmosphere. The program included thirteen sessions covering a wide variety of topics including solid-state oscillators, power-combining techniques, mixers, harmonic multipliers, antennas and antenna arrays, submillimeter receivers, and measurement techniques.

Math in Motion: Origami in the Classroom. A Hands-On Creative Approach to Teaching Mathematics. K-8.

ERIC Educational Resources Information Center

Pearl, Barbara

This perfect bound teacher's guide presents techniques and activities to teach mathematics using origami paper folding. Part 1 includes a history of origami, mathematics and origami, and careers using mathematics. Parts 2 and 3 introduce paper-folding concepts and teaching techniques and include suggestions for low-budget paper resources. Part 4…

Micromechanical Characterization and Texture Analysis of Direct Cast Titanium Alloys Strips

NASA Technical Reports Server (NTRS)

2000-01-01

This research was conducted to determine a post-processing technique to optimize mechanical and material properties of a number of Titanium based alloys and aluminides processed via Melt Overflow Solidification Technique (MORST). This technique was developed by NASA for the development of thin sheet titanium and titanium aluminides used in high temperature applications. The materials investigated in this study included conventional titanium alloy strips and foils, Ti-1100, Ti-24Al-11Nb (Alpha-2), and Ti-48Al-2Ta (Gamma). The methodology used included micro-characterization, heat-treatment, mechanical processing and mechanical testing. Characterization techniques included optical, electron microscopy, and x-ray texture analysis. The processing included heat-treatment and mechanical deformation through cold rolling. The initial as-cast materials were evaluated for their microstructure and mechanical properties. Different heat-treatment and rolling steps were chosen to process these materials. The properties were evaluated further and a processing relationship was established in order to obtain an optimum processing condition. The results showed that the as-cast material exhibited a Widmanstatten (fine grain) microstructure that developed into a microstructure with larger grains through processing steps. The texture intensity showed little change for all processing performed in this investigation.

Perspectives on communicating risks of chemicals.

PubMed

Armbrust, Kevin; Burns, Mitchell; Crossan, Angus N; Fischhoff, David A; Hammond, Larry E; Johnston, John J; Kennedy, Ivan; Rose, Michael T; Seiber, James N; Solomon, Keith

2013-05-22

The Agrochemicals Division symposium "Perfecting Communication of Chemical Risk", held at the 244th National Meeting and Exposition of the American Chemical Society in Philadelphia, PA, August 19-23, 2012, is summarized. The symposium, organized by James Seiber, Kevin Armbrust, John Johnston, Ivan Kennedy, Thomas Potter, and Keith Solomon, included discussion of better techniques for communicating risks, lessons from past experiences, and case studies, together with proposals to improve these techniques and their communication to the public as effective information. The case studies included risks of agricultural biotechnology, an organoarsenical (Roxarsone) in animal feed, petroleum spill-derived contamination of seafood, role of biomonitoring and other exposure assessment techniques, soil fumigants, implications of listing endosulfan as a persistant organic pollutant (POP), and diuron herbicide in runoff, including use of catchment basins to limit runoff to coastal ecozones and the Great Barrier Reef. The symposium attracted chemical risk managers including ecotoxicologists, environmental chemists, agrochemists, ecosystem managers, and regulators needing better techniques that could feed into better communication of chemical risks. Policy issues related to regulation of chemical safety as well as the role of international conventions were also presented. The symposium was broadcast via webinar to an audience outside the ACS Meeting venue.

Technologies for Clinical Diagnosis Using Expired Human Breath Analysis

PubMed Central

Mathew, Thalakkotur Lazar; Pownraj, Prabhahari; Abdulla, Sukhananazerin; Pullithadathil, Biji

2015-01-01

This review elucidates the technologies in the field of exhaled breath analysis. Exhaled breath gas analysis offers an inexpensive, noninvasive and rapid method for detecting a large number of compounds under various conditions for health and disease states. There are various techniques to analyze some exhaled breath gases, including spectrometry, gas chromatography and spectroscopy. This review places emphasis on some of the critical biomarkers present in exhaled human breath, and its related effects. Additionally, various medical monitoring techniques used for breath analysis have been discussed. It also includes the current scenario of breath analysis with nanotechnology-oriented techniques. PMID:26854142

Recommended Practice for Use of Emissive Probes in Electric Propulsion Testing

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

Sheehan, J. P.; Raitses, Yevgeny; Hershkowitz, Noah

Here, this article provides recommended methods for building, operating, and taking plasma potential measurements from electron-emitting probes in electric propulsion devices, including Hall thrusters, gridded ion engines, and others. The two major techniques, the floating point technique and the inflection point technique, are described in detail as well as calibration and error-reduction methods. The major heating methods are described as well as the various considerations for emissive probe construction. Lastly, special considerations for electric propulsion plasmas are addressed, including high-energy densities, ion flows, magnetic fields, and potential fluctuations. Recommendations for probe design and operation are provided.

Application of Information-Theoretic Data Mining Techniques in a National Ambulatory Practice Outcomes Research Network

PubMed Central

Wright, Adam; Ricciardi, Thomas N.; Zwick, Martin

2005-01-01

The Medical Quality Improvement Consortium data warehouse contains de-identified data on more than 3.6 million patients including their problem lists, test results, procedures and medication lists. This study uses reconstructability analysis, an information-theoretic data mining technique, on the MQIC data warehouse to empirically identify risk factors for various complications of diabetes including myocardial infarction and microalbuminuria. The risk factors identified match those risk factors identified in the literature, demonstrating the utility of the MQIC data warehouse for outcomes research, and RA as a technique for mining clinical data warehouses. PMID:16779156

Mass spectrometry. [review of techniques

NASA Technical Reports Server (NTRS)

Burlingame, A. L.; Kimble, B. J.; Derrick, P. J.

1976-01-01

Advances in mass spectrometry (MS) and its applications over the past decade are reviewed in depth, with annotated literature references. New instrumentation and techniques surveyed include: modulated-beam MS, chromatographic MS on-line computer techniques, digital computer-compatible quadrupole MS, selected ion monitoring (mass fragmentography), and computer-aided management of MS data and interpretation. Areas of application surveyed include: organic MS and electron impact MS, field ionization kinetics, appearance potentials, translational energy release, studies of metastable species, photoionization, calculations of molecular orbitals, chemical kinetics, field desorption MS, high pressure MS, ion cyclotron resonance, biochemistry, medical/clinical chemistry, pharmacology, and environmental chemistry and pollution studies.

Paraesophageal Hernia Repair: Techniques for Success.

PubMed

Cohn, Tyler D; Soper, Nathaniel J

2017-01-01

With the introduction of laparoscopy, the outcomes of patients undergoing paraesophageal hernia repair have improved dramatically. When the fundamentals of a proper repair are followed, patients can expect to have improvement in gastroesophageal reflux symptoms, including heartburn, regurgitation, chest pain, dysphagia, and dyspnea. Adhering to these principles will alleviate patients' symptoms and avoid reoperation. This article describes the approach to paraesophageal hernia repair, including patient evaluation, operative technique, and postoperative management. Esophageal lengthening and crural reinforcement with mesh are addressed as well. Adhering to the basic techniques outlined in this article should lead to successful and durable patient outcomes following a paraesophageal hernia repair.

Detection of genetically modified organisms in foods by DNA amplification techniques.

PubMed

García-Cañas, Virginia; Cifuentes, Alejandro; González, Ramón

2004-01-01

In this article, the different DNA amplification techniques that are being used for detecting genetically modified organisms (GMOs) in foods are examined. This study intends to provide an updated overview (including works published till June 2002) on the principal applications of such techniques together with their main advantages and drawbacks in GMO detection in foods. Some relevant facts on sampling, DNA isolation, and DNA amplification methods are discussed. Moreover; these analytical protocols are discuissed from a quantitative point of view, including the newest investigations on multiplex detection of GMOs in foods and validation of methods.

Recommended Practice for Use of Emissive Probes in Electric Propulsion Testing

DOE PAGES

Sheehan, J. P.; Raitses, Yevgeny; Hershkowitz, Noah; ...

2016-11-03

Here, this article provides recommended methods for building, operating, and taking plasma potential measurements from electron-emitting probes in electric propulsion devices, including Hall thrusters, gridded ion engines, and others. The two major techniques, the floating point technique and the inflection point technique, are described in detail as well as calibration and error-reduction methods. The major heating methods are described as well as the various considerations for emissive probe construction. Lastly, special considerations for electric propulsion plasmas are addressed, including high-energy densities, ion flows, magnetic fields, and potential fluctuations. Recommendations for probe design and operation are provided.

37 CFR 351.10 - Evidence.

Code of Federal Regulations, 2013 CFR

2013-07-01

...” include still photographs, video tapes, and motion pictures. (2) Separation of irrelevant portions... considered in the analysis, the techniques of data collection, the techniques of estimation and testing, and...

37 CFR 351.10 - Evidence.

Code of Federal Regulations, 2012 CFR

2012-07-01

...” include still photographs, video tapes, and motion pictures. (2) Separation of irrelevant portions... considered in the analysis, the techniques of data collection, the techniques of estimation and testing, and...

37 CFR 351.10 - Evidence.

Code of Federal Regulations, 2011 CFR

2011-07-01

...” include still photographs, video tapes, and motion pictures. (2) Separation of irrelevant portions... considered in the analysis, the techniques of data collection, the techniques of estimation and testing, and...

37 CFR 351.10 - Evidence.

Code of Federal Regulations, 2014 CFR

2014-07-01

...” include still photographs, video tapes, and motion pictures. (2) Separation of irrelevant portions... considered in the analysis, the techniques of data collection, the techniques of estimation and testing, and...

Techniques of laparoscopic cholecystectomy: Nomenclature and selection.

PubMed

Haribhakti, Sanjiv P; Mistry, Jitendra H

2015-01-01

There are more than 50 different techniques of laparoscopic cholecystectomy (LC) available in literature mainly due to modifications by surgeons in aim to improve postoperative outcome and cosmesis. These modifications include reduction in port size and/or number than what is used in standard LC. There is no uniform nomenclature to describe these different techniques so that it is not possible to compare the outcomes of different techniques. We brief the advantages and disadvantages of each of these techniques and suggest the situation where particular technique would be useful. We also propose a nomenclature which is easy to remember and apply, so that any future comparison will be possible between the techniques.

Review of progress in quantitative NDE. [Nondestructive Evaluation (NDE)

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

Not Available

1991-01-01

This booklet is composed of abstracts from papers submitted at a meeting on quantitative NDE. A multitude of topics are discussed including analysis of composite materials, NMR uses, x-ray instruments and techniques, manufacturing uses, neural networks, eddy currents, stress measurements, magnetic materials, adhesive bonds, signal processing, NDE of mechanical structures, tomography,defect sizing, NDE of plastics and ceramics, new techniques, optical and electromagnetic techniques, and nonlinear techniques. (GHH)

Application of a sensitivity analysis technique to high-order digital flight control systems

NASA Technical Reports Server (NTRS)

Paduano, James D.; Downing, David R.

1987-01-01

A sensitivity analysis technique for multiloop flight control systems is studied. This technique uses the scaled singular values of the return difference matrix as a measure of the relative stability of a control system. It then uses the gradients of these singular values with respect to system and controller parameters to judge sensitivity. The sensitivity analysis technique is first reviewed; then it is extended to include digital systems, through the derivation of singular-value gradient equations. Gradients with respect to parameters which do not appear explicitly as control-system matrix elements are also derived, so that high-order systems can be studied. A complete review of the integrated technique is given by way of a simple example: the inverted pendulum problem. The technique is then demonstrated on the X-29 control laws. Results show linear models of real systems can be analyzed by this sensitivity technique, if it is applied with care. A computer program called SVA was written to accomplish the singular-value sensitivity analysis techniques. Thus computational methods and considerations form an integral part of many of the discussions. A user's guide to the program is included. The SVA is a fully public domain program, running on the NASA/Dryden Elxsi computer.

Anatomic partial nephrectomy: technique evolution.

PubMed

Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

2015-03-01

Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

Piezoelectric Versus Conventional Rotary Techniques for Impacted Third Molar Extraction

PubMed Central

Jiang, Qian; Qiu, Yating; Yang, Chi; Yang, Jingyun; Chen, Minjie; Zhang, Zhiyuan

2015-01-01

Abstract Impacted third molars are frequently encountered in clinical work. Surgical removal of impacted third molars is often required to prevent clinical symptoms. Traditional rotary cutting instruments are potentially injurious, and piezosurgery, as a new osteotomy technique, has been introduced in oral and maxillofacial surgery. No consistent conclusion has been reached regarding whether this new technique is associated with fewer or less severe postoperative sequelae after third molar extraction. The aim of this study was to compare piezosurgery with rotary osteotomy techniques, with regard to surgery time and the severity of postoperative sequelae, including pain, swelling, and trismus. We conducted a systematic literature search in the Cochrane Library, PubMed, Embase, and Google Scholar. The eligibility criteria of this study included the following: the patients were clearly diagnosed as having impacted mandibular third molars; the patients underwent piezosurgery osteotomy, and in the control group rotary osteotomy techniques, for removing impacted third molars; the outcomes of interest include surgery time, trismus, swelling or pain; the studies are randomized controlled trials. We used random-effects models to calculate the difference in the outcomes, and the corresponding 95% confidence interval. We calculated the weighted mean difference if the trials used the same measurement, and a standardized mean difference if otherwise. A total of seven studies met the eligibility criteria and were included in our analysis. Compared with rotary osteotomy, patients undergoing piezosurgery experienced longer surgery time (mean difference 4.13 minutes, 95% confidence interval 2.75–5.52, P < 0.0001). Patients receiving the piezoelectric technique had less swelling at postoperative days 1, 3, 5, and 7 (all Ps ≤0.023). Additionally, there was a trend of less postoperative pain and trismus in the piezosurgery groups. The number of included randomized controlled trials and the sample size of each trial were relatively small, double blinding was not possible, and cost analysis was unavailable due to a lack of data. Our meta-analysis indicates that although patients undergoing piezosurgery experienced longer surgery time, they had less postoperative swelling, indicating that piezosurgery is a promising alternative technique for extraction of impacted third molars. PMID:26469902

Piezoelectric Versus Conventional Rotary Techniques for Impacted Third Molar Extraction: A Meta-analysis of Randomized Controlled Trials.

PubMed

Jiang, Qian; Qiu, Yating; Yang, Chi; Yang, Jingyun; Chen, Minjie; Zhang, Zhiyuan

2015-10-01

Impacted third molars are frequently encountered in clinical work. Surgical removal of impacted third molars is often required to prevent clinical symptoms. Traditional rotary cutting instruments are potentially injurious, and piezosurgery, as a new osteotomy technique, has been introduced in oral and maxillofacial surgery. No consistent conclusion has been reached regarding whether this new technique is associated with fewer or less severe postoperative sequelae after third molar extraction.The aim of this study was to compare piezosurgery with rotary osteotomy techniques, with regard to surgery time and the severity of postoperative sequelae, including pain, swelling, and trismus.We conducted a systematic literature search in the Cochrane Library, PubMed, Embase, and Google Scholar.The eligibility criteria of this study included the following: the patients were clearly diagnosed as having impacted mandibular third molars; the patients underwent piezosurgery osteotomy, and in the control group rotary osteotomy techniques, for removing impacted third molars; the outcomes of interest include surgery time, trismus, swelling or pain; the studies are randomized controlled trials.We used random-effects models to calculate the difference in the outcomes, and the corresponding 95% confidence interval. We calculated the weighted mean difference if the trials used the same measurement, and a standardized mean difference if otherwise.A total of seven studies met the eligibility criteria and were included in our analysis. Compared with rotary osteotomy, patients undergoing piezosurgery experienced longer surgery time (mean difference 4.13 minutes, 95% confidence interval 2.75-5.52, P < 0.0001). Patients receiving the piezoelectric technique had less swelling at postoperative days 1, 3, 5, and 7 (all Ps ≤0.023). Additionally, there was a trend of less postoperative pain and trismus in the piezosurgery groups.The number of included randomized controlled trials and the sample size of each trial were relatively small, double blinding was not possible, and cost analysis was unavailable due to a lack of data.Our meta-analysis indicates that although patients undergoing piezosurgery experienced longer surgery time, they had less postoperative swelling, indicating that piezosurgery is a promising alternative technique for extraction of impacted third molars.

Therapist and client predictors of use of therapy techniques within the context of implementation efforts in a large public mental health system

PubMed Central

Wolk, Courtney Benjamin; Marcus, Steven C.; Weersing, V. Robin; Hawley, Kristin M.; Evans, Arthur; Hurford, Matthew; Beidas, Rinad

2016-01-01

Objective Many youth receiving community mental health treatment do not receive evidence-based interventions. Research suggests that community mental health therapists use a broad range of therapeutic techniques at low intensities. The present study examined the relationship between therapist- and client-level predictors on community-based therapists’ report of cognitive, behavioral, psychodynamic, and family techniques within the context of implementation efforts. Methods One hundred thirty therapists from 23 organizations in an urban publicly funded behavioral health system implementing evidence-based practices participated. Therapist-level predictors included age, gender, clinical experience, licensure status, and participation in evidence-based practice initiatives. Child-level predictors included therapist-reported child primary disorder (i.e., externalizing, internalizing, or other) and child age. Therapists completed the Therapist Procedures Checklist- Family Revised, a self-report measure of therapeutic techniques used. Results Unlicensed therapists were more likely to report use of both psychodynamic and behavioral techniques. Therapists who did not participate in an evidence-based practice initiative were less likely to report use of cognitive techniques. Those with externalizing clients were more likely to report use of behavioral and family techniques. Therapists with the youngest clients (aged 3-7) were most likely to report use of behavioral techniques and less likely to report use of cognitive and psychodynamic techniques. Conclusions Results suggest that both therapist and client factors predict self-reported use of therapy techniques. Participating in an evidence-based practice initiative increased report of cognitive techniques. Therapists reported using more behavioral and family techniques for youth with externalizing disorders and fewer cognitive and psychodynamic techniques with young clients. PMID:26876658

TOPICAL REVIEW: Spatial localization in nuclear magnetic resonance spectroscopy

NASA Astrophysics Data System (ADS)

Keevil, Stephen F.

2006-08-01

The ability to select a discrete region within the body for signal acquisition is a fundamental requirement of in vivo NMR spectroscopy. Ideally, it should be possible to tailor the selected volume to coincide exactly with the lesion or tissue of interest, without loss of signal from within this volume or contamination with extraneous signals. Many techniques have been developed over the past 25 years employing a combination of RF coil properties, static magnetic field gradients and pulse sequence design in an attempt to meet these goals. This review presents a comprehensive survey of these techniques, their various advantages and disadvantages, and implications for clinical applications. Particular emphasis is placed on the reliability of the techniques in terms of signal loss, contamination and the effect of nuclear relaxation and J-coupling. The survey includes techniques based on RF coil and pulse design alone, those using static magnetic field gradients, and magnetic resonance spectroscopic imaging. Although there is an emphasis on techniques currently in widespread use (PRESS, STEAM, ISIS and MRSI), the review also includes earlier techniques, in order to provide historical context, and techniques that are promising for future use in clinical and biomedical applications.

A Comparison of Three Different Thick Epinucleus Removal Techniques in Cataract Surgery.

PubMed

Hwang, Ho Sik; Lim, Byung-Su; Kim, Man Soo; Kim, Eun Chul

2017-01-01

To compare the outcomes of cataract surgery performed with three different types of the epinucleus removal techniques (safe boat, infusion/aspiration (I/A) cannulas, and phacoemulsification tip). Ninety eyes with thick adhesive epinuclei were randomly subdivided into three groups according to epinucleus removal technique: epinucleus floating (safe boat) technique, 30 patients; I/A tip, 30 patients; and phaco tip, 30 patients. Intraoperative measurements included ultrasound time (UST), mean cumulative dissipated ultrasound energy (CDE), and balanced salt solution (BSS) use. Clinical measurements were made preoperatively, and at one day, one month and two months postoperatively, including the best corrected visual acuity (BCVA), the central corneal thickness (CCT), and the endothelial cell count (ECC). Intraoperative measurements showed significantly less UST, CDE, and BSS use in the safe boat group than in the phaco tip groups (p < 0.05). The percentage of endothelial cell loss in the safe boat group was significantly lower than that in the phaco tip groups at two months post-cataract surgery (p < 0.05). The safe boat technique is a safer and more effective epinucleus removal technique than phaco tip techniques in cases with thick epinucleus.

Advantages and Disadvantages of Aquatic Plant Management Techniques

DTIC Science & Technology

2000-09-01

This report provides an overview of the environmental and practical advantages and disadvantages of the major aquatic plant management methods, including biological, chemical, mechanical, and physical control techniques.

Techniques for debris control

NASA Technical Reports Server (NTRS)

Petro, Andrew J.

1990-01-01

This paper will summarize a range of techniques which have been proposed for controlling the growth of man-made debris in earth orbit. Several techniques developed in studies at the Johnson Space Center will be described in detail. These techniques include the retrieval of inoperative satellites with an orbital maneuvering vehicle and self-disposal devices for satellites and upper stages. Self-disposal devices include propulsive deorbit motors and passive drag-augmentation devices. Concepts for sweeping small debris from the orbital environment will also be described. An evaluation of the technical feasibility and economic practicality of the various control methods will be summarized. In general, methods which prevent the accumulation of large debris objects were found to provide greater promise for control of the debris problem than methods of removing small debris particles.

Advanced analysis technique for the evaluation of linear alternators and linear motors

NASA Technical Reports Server (NTRS)

Holliday, Jeffrey C.

1995-01-01

A method for the mathematical analysis of linear alternator and linear motor devices and designs is described, and an example of its use is included. The technique seeks to surpass other methods of analysis by including more rigorous treatment of phenomena normally omitted or coarsely approximated such as eddy braking, non-linear material properties, and power losses generated within structures surrounding the device. The technique is broadly applicable to linear alternators and linear motors involving iron yoke structures and moving permanent magnets. The technique involves the application of Amperian current equivalents to the modeling of the moving permanent magnet components within a finite element formulation. The resulting steady state and transient mode field solutions can simultaneously account for the moving and static field sources within and around the device.

Development of analysis techniques for remote sensing of vegetation resources

NASA Technical Reports Server (NTRS)

Draeger, W. C.

1972-01-01

Various data handling and analysis techniques are summarized for evaluation of ERTS-A and supporting high flight imagery. These evaluations are concerned with remote sensors applied to wildland and agricultural vegetation resource inventory problems. Monitoring California's annual grassland, automatic texture analysis, agricultural ground data collection techniques, and spectral measurements are included.

Ambient air contamination: Characterization and detection techniques

NASA Technical Reports Server (NTRS)

Nulton, C. P.; Silvus, H. S.

1985-01-01

Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

Advanced silver zinc battery development for the SRB and ET range safety subsystems

NASA Technical Reports Server (NTRS)

Adamedes, Zoe

1994-01-01

This document presents in viewgraph format the design and development of silver zinc (AgZn) batteries for the solid rocket booster (SRB) and external tank (ET) range safety subsystems. Various engineering techniques, including composite separator systems, new electrode processing techniques, and new restraint techniques, were used to meet difficult requirements.

Hot-wire anemometry in hypersonic helium flow

NASA Technical Reports Server (NTRS)

Wagner, R. D.; Weinstein, L. M.

1974-01-01

Hot-wire anemometry techniques are described that have been developed and used for hypersonic-helium-flow studies. The short run time available dictated certain innovations in applying conventional hot-wire techniques. Some examples are given to show the application of the techniques used. Modifications to conventional equipment are described, including probe modifications and probe heating controls.